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ΠΡΩΤΟΤΥΠΕΣ ΕΡΓΑΣΙΕΣ ΣΕ ΔΙΕΘΝΗ ΕΠΙΣΤΗΜΟΝΙΚΑ ΠΕΡΙΟΔΙΚΑ ΚΑΤΑ ΤΗ ΔΙΑΡΚΕΙΑ ΤΟΥ 2010

Abreu C., Sanguinetti M., Amillis S., Ramon A. (2010) UreA, the major urea/H+ symporter in Aspergillus nidulans. Fungal Genet Biol 47:1023-33.

Abstract: We report here the characterization of UreA, a high-affinity urea/H+ symporter of Aspergillus nidulans. The deletion of the encoding gene abolishes urea transport at low substrate concentrations, suggesting that in these conditions UreA is the sole transport system specific for urea in A. nidulans. The ureA gene is not inducible by urea or its precursors, but responds to nitrogen metabolite repression, necessitating for its expression the AreA GATA factor. In contrast to what was observed for other transporters in A. nidulans, repression by ammonium is also operative during the isotropic growth phase. The activity of UreA is down-regulated post-translationally by ammonium-promoted endocytosis. A number of homologues of UreA have been identified in A. nidulans and other Aspergilli, which cluster in four groups, two of which contain the urea transporters characterized so far in fungi and plants. This phylogeny may have arisen by gene duplication events, giving place to putative transport proteins that could have acquired novel, still unidentified functions.

 

Aggeli IK, Kefaloyianni E, Beis I, Gaitanaki C (2010). HOX-1 and COX-2: two differentially regulated key mediators of skeletal myoblast tolerance under oxidative stress. Free Rad Res 44 (6): 679-693. doi:10.3109/10715761003742985

Abstract: The exact physiological role of oxidative stress as a primary cause for skeletal muscle pathological conditions involving muscle degeneration remains elusive. Therefore, the present study was performed so as to decipher the signalling pathways orchestrating the potential cytoprotective role of heme oxygenase 1 (HOX-1) as well as cyclooxygenase 2 (COX-2) in skeletal myoblasts exposed to H2O2. Cell treatment with H2O2 (0.5 mM) resulted in a time- and dose-dependent response of HOX-1 and COX-2 mRNA and protein levels, with ERK1/2, p38-MAPK and MSK1 found to mediate these effects. Furthermore, Src and JNKs blockade attenuated COX-2 response. Collectively, these novel findings highlight for the first time HOX-1 and COX-2 fundamental contribution to skeletal myoblast tolerance under oxidative stress, since their inhibition significantly attenuated viability of skeletal myoblasts. The data also delineate the various effectors regulating HOX-1 and COX-2 expression, probably alleviating muscle degeneration in related disorders.

 

Anthopoulos, P.G., Hamodrakas, S.J., Bagos, P.G. (2010) Apolipoprotein E polymorphisms and type 2 diabetes: a meta-analysis of 30 studies including 5423 cases and 8197 controls. Mol Genet Metab., 100(3):283-91.

Abstract: Type 2 diabetes mellitus (T2DM) is a highly complicated metabolic disorder for which there is worldwide effort for the identification of susceptibility genes. Polymorphisms of the Apolipoprotein E (ApoE) gene are associated with plasma lipid and lipoprotein levels and influence cardiovascular risk. Since insulin resistance is known to be strongly associated with metabolic dyslipidemia, ApoE polymorphisms have been implicated in predisposition to diabetes but the results of the individual studies were inconclusive. We present here a meta-analysis of population-based case-control genetic-association studies relating ApoE polymorphisms and T2DM. We included in the analysis 30 studies, which reported data of ApoE genotypes in 5423 T2DM patients and 8197 healthy unrelated controls. Multivariate and univariate methods suggest a significant role played by the E2 allele, since carriers of the E2 allele were at elevated risk for T2DM (Odds Ratio=1.18, 95% CI: 1.02, 1.35). There was no evidence for publication bias or other small-study related bias or significant heterogeneity in the analyses. Cumulative meta-analysis revealed no trend of the effect estimates over time and influential analysis excluded the possibility of a single influential study. E2 allele of ApoE seems to be a moderate risk factor for T2DM. Meta-regression analysis provided some weak evidence that the risk conferred by E2 allele is mediated through altering serum lipid levels (Total Cholesterol, LDL and HDL). Further studies are needed in order to elucidate the metabolic mechanism of this association as well as to study its effects on larger populations.

 

Antonelou M, Kriebardis A, Stamoulis K, Ekonomou - Petersen E, Margaritis LH, Papassideri IS (2010). Red blood cell aging markers during storage in citrate-phosphate-dextrose–saline-adenine-glucose-mannitol. Transfusion 50: 376-389.

Abstract: Background: It has been suggested that red blood cell (RBC) senescence is accelerated under blood bank conditions, although neither protein profile of RBC aging nor the impact of additive solutions on it have been studied in detail. Study Design And Methods: RBCs and vesicles derived from RBCs in both citrate-phosphate-dextrose (CPD)–saline-adenine-glucose-mannitol (SAGM) and citrate-phosphate-dextrose-adenine (CPDA) were evaluated for the expression of cell senescence markers (vesiculation, protein aggregation, degradation, activation, oxidation, and topology) through immunoblotting technique and immunofluorescence or immunoelectron microscopy study. Results: A group of cellular stress proteins exhibited storage time– and storage medium–related changes in their membrane association and exocytosis. The extent, the rate, and the expression of protein oxidation, Fas oligomerization, caspase activation, and protein modifications in Band 3, hemoglobin, and immunoglobulin G were less conspicuous and/or exhibited significant time retardation under storage in CPD-SAGM, compared to the CPDA storage. There was evidence for the localization of activated caspases near to the membrane of both cells and vesicles. Conclusions: We provide circumstantial evidence for a lower protein oxidative damage in CPD-SAGM–stored RBCs compared to the CPDA-stored cells. The different expression patterns of the senescence markers in the RBCs seem to be accordingly related to the oxidative stress management of the cells. We suggest that the storage of RBCs in CPD-SAGM might be more alike the in vivo RBC aging process, compared to storage in CPDA, since it is characterized by a slower stimulation of the recognition signaling pathways that are already known to trigger the erythrophagocytosis of senescent RBCs.

 

Antonelou MH, Kriebardis AG, Papassideri Is (2010). Aging and death signaling in mature red cells: from basic science to transfusion practice. Blood Transfusion (in press).

 

Apostolakos P, Livanos P, Nikolakopoulou TL, Galatis B (2010). The role of callose in stomatal opening and closure in the fern Asplenium nidus. New Phytologist 186: 623-635.

Abstract: The involvement of callose in the mechanism of stomatal pore opening and closing in the fern Asplenium nidus was investigated by examination of the pattern of callose deposition in open and closed stomata, and by examination of the effects of callose degradation and inhibition or induction of callose synthesis in stomatal movement. Callose was identified with aniline blue staining and a callose antibody and degraded via beta-1,3-D-glucanase. Callose synthesis was inhibited with 2-deoxy-D-glucose and induced by coumarin or dichlobenil. Stomatal pore opening and closing were assessed by estimation of the stomatal pore width. The open stomata entirely lacked callose, while the closed ones displayed distinct radial fibrillar callose arrays in the external periclinal walls. The latter displayed local bending at the region of callose deposition, a deformation that was absent in the open stomata. Both callose degradation and inhibition of callose synthesis reduced the stomatal ability to open in white light and close in darkness. By contrast, callose synthesis induction considerably improved stomatal pore opening and reduced stomatal closure in same conditions. The present data revealed that: during stomatal closure the external periclinal guard cell walls experience a strong mechanical stress, probably triggering callose synthesis; and that callose participates in stomatal movement.

 

Argyropoulou C, Akoumianaki – Ioannidou A, Christodoulakis NS, Fasseas C (2010). Leaf anatomy and histochemistry in Lippia citriodora (Verbenaceae). Australian Journal of Botany, 58: 398-409.

Abstract: Lippia citriodora is an aromatic plant indigenous to South America.  It is cultivated and commercialized as ornamental and for its lemon-like scent emitted from its leaves and flowers which are utilised for the preparation of herbal tea, used for the treatment of asthma, spasms, cold, fever, flatulence, colic, diarrhoea, indigestion, insomnia and anxiety. This morphoanatomical and histochemical study revealed that leaves of L. citriodora possess one type of setae (non-glandular) and at least five types of glandular trichomes, with the latter differing anatomically and in the composition of the secondary metabolites stored in them. Scanning electron microscopy revealed that the same types of trichomes exist on the leaves and calyses. The glandular trichomes contain a combination of terpenoids, flavonoids, carbohydrates, phenolics and alkaloids and the mesophyll cells store in their vacuoles terpenoids, phenolics, flavonoids and tannins. Lamellar cytoplasmic inclusions in the mesophyll cells, possibly precursors of tannins stored in the vacuoles and this is reported for the first time.

 

Arianoutsou M, Bazos I, Delipetrou P, Kokkoris Y (2010). The alien flora of Greece: taxonomy, life traits and habitat preferences. Biological Invasions [doi: 10.1007/s10530-010-9749-0]

 

Arianoutsou M, Delipetrou P, Celesti-Grapow L, Basnou C, Bazos I, Kokkoris Y, Blasi C, Vilà M (2010). Comparing naturalized alien plants and recipient habitats across an east-west gradient in the Mediterranean Basin. Journal of Biogeography (in press).

Abstract: Aim: To investigate alien plant species invasion levels in different habitats and alien species traits by comparing the naturalized flora in different areas of the same biogeographical region. Location: Spain, Italy, Greece and Cyprus. Methods: Comparison of floristic composition, species traits and recipient habitats of naturalized alien neophytes across an east–west gradient comprising four countries in the European Mediterranean basin.Results: A total of 782 naturalized neophytes were recorded; only 30 species were present in all four countries. Although floristic similarity is low, the four alien floras share the same patterns of growth form (mostly herbs), life cycle (mostly perennials) and life form (mostly therophytes, hemicryptophytes and phanerophytes). The majority of the recipient habitats were artificial. Wetlands were the natural habitats, with the highest numbers of naturalized species. Floristic similarity analyses revealed: (1) the highest floristic similarity between Italy and Spain, both of which were more similar to Greece than to Cyprus; (2) two groups of floristic similarity between habitat categories in each country (Greece–Cyprus and Italy–Spain); (3) a higher degree of homogenization in the plant assemblages in different habitats in Greece and Cyprus and a lower degree of homogenization in those in Italy and Spain; and (4) a higher degree of homogenization in artificial and natural fresh-water habitats than in the other natural habitats. Main conclusions: The floristic similarity of naturalized neophytes between the four countries is low, although the overall analysis indicates that the western group (Italy–Spain) is separated from the eastern group (Greece–Cyprus). Similar patterns emerged regarding the life-history traits and recipient habitats. The artificial habitats and the natural wet habitats are those that are invaded most and display the greatest homogenization in all four countries. Coastal habitats display a lower degree of homogenization but a high frequency of aliens. Dry shrubs and rocky habitats display a lower degree of homogenization and a low frequency of aliens.

 

Barbati A, Arianoutsou M, Corona P, De Las Heras J, Fernandes P, Moreira F, Papageorgiou K, Vallejo R, Xanthopoulos G (2010) Post-fire forest management in southern Europe: a COST Action for gathering and disseminating scientific knowledge. iForest - Biogeosciences and Forestry, 3: 5-7, doi: 10.3832/ifor0523-003.

Abstract: Every year about 45 000 forest fires occur in Europe, burning half a million hectares of forests and rural lands; between 1995 and 2004, more than 4 million hectares burned in the Mediterranean Region alone. Post-fire management of burned areas has been given much lesser attention than combating or preventing fires. However, important questions raise public concern and call for sound scientific knowledge to undertake appropriate post-fire actions: e.g., how to evaluate fire damages in economical terms? How to manage burned areas? Is it possible to establish, in the long-term, less flammable and more fire resilient forests and landscapes? To address these questions, a network of researchers and practitioners working in the field of fire ecology and forest management from all around Europe has been established in the frame of “COST Action FP0701-Post-Fire Forest Management in Southern Europe”, supported by the European Union Research and Technology Development Framework Program. The Action aims to: i) develop and disseminate scientifically based decision criteria for planning post-fire forest management, from the stand to the landscape level; ii) translate this scientific knowledge into management practices; iii) connect scientists and stakeholders for exchanging experiences, evaluating these practices, and putting them into practice. To achieve these objectives the scientific groups involved will a) review and summarize the current scientific knowledge on post-fire management in Europe, by gathering and evaluating the results of previous and ongoing research; b) translate this knowledge into technical recommendations, by producing thematic reports, a book on the state-of-the-art of scientific knowledge on post fire assessment, and an electronic handbook on post-fire restoration; c) disseminate this knowledge to stakeholders, practitioners and decision makers. Besides publications and a project website already active (⇒ Cost Action FP0701), training schools and one major conference will be organized. Although focused on Southern Europe, the outcomes of this Action will be crucial for central and northern European countries as well, as climate change and land use changes often leading to more homogeneous and expanding forest areas are already increasing fire hazard in those regions.

 

Castritsi – Catharios J. , Soest R. W. M. van,  Kefalas E. &  Vacelet J. (2010). Redescription of Mediterranean Dictyoceratid sponge, Spongia (Spongia) zimocca (Schmidt, 1862) (Pοrifera: Demospongiae) including data on its distribution and morphology. ZOOTAXA (accepted).

 

Chavdoula ED, Panagopoulos DJ, Margaritis LH. (2010). Comparison of biological effects between continuous and intermittent exposure to GSM-900-MHz mobile phone radiation: Detection of apoptotic cell-death features. Mutat Res. 19;700(1-2):51-61.

Abstract: In the present study we used a 6-min daily exposure of dipteran flies, Drosophila melanogaster, to GSM-900MHz (Global System for Mobile Telecommunications) mobile phone electromagnetic radiation (EMR), to compare the effects between the continuous and four different intermittent exposures of 6min total duration, and also to test whether intermittent exposure provides any cumulative effects on the insect's reproductive capacity as well as on the induction of apoptotic cell death. According to our previous experiments, a 6-min continuous exposure per day for 5 days to GSM-900MHz and DCS-1800MHz (Digital Cellular System) mobile phone radiation, brought about a large decrease in the insect's reproductive capacity, as defined by the number of F(1) pupae. This decrease was found to be non-thermal and correlated with an increased percentage of induced fragmented DNA in the egg chambers' cells at early- and mid-oogenesis. In the present experiments we show that intermittent exposure also decreases the reproductive capacity and alters the actin-cytoskeleton network of the egg chambers, another known aspect of cell death that was not investigated in previous experiments, and that the effect is also due to DNA fragmentation. Intermittent exposures with 10-min intervals between exposure sessions proved to be almost equally effective as continuous exposure of the same total duration, whereas longer intervals between the exposures seemed to allow the organism the time required to recover and partly overcome the above-mentioned effects of the GSM exposure.

 

Chiari Y, Dion K, Colborn J, Parmakelis A, Powell JR (2010). On the possible role of tRNA base modifications in the evolution of codon usage: Queuosine and Drosophila. Journal of Molecular Evolution (in press).

Abstract: The best documented selection-based hypothesis to explain unequal usage of codons is based on the relative abundance of isoaccepting tRNAs. In unicellular organisms the most used codons are optimally translated by the most abundant tRNAs. The chemical bonding energies are affected by modification of the four traditional bases, in particular in the first anti-codon corresponding to the third codon position. One nearly universal modification is queuosine (Q) for guanine (G) in tRNAHis, tRNAAsp, tRNAAsn, and tRNATyr; this changes the optimal binding from codons ending in C to no preference or a slight preference for U-ending codons. Among species of Drosophila, codon usage is constant with the exception of the Drosophila willistoni lineage which has shifted primary usage from C-ending codons to U/T ending codons only for these four amino acids. In Drosophila melanogaster Q containing tRNAs only predominate in old adults. We asked the question whether in D. willistoni these Q containing tRNAs might predominate earlier in development. As a surrogate for levels of modification we studied the expression of the gene (tgt) coding for the enzyme that catalyzes the substitution of Q for G in different life stages of D. melanogaster, D. pseudoobscura, and D. willistoni. Unlike the other two species, the highest tgt expression in D. willistoni is in young females producing eggs. Because tRNAs laid down in eggs persist through the early stages of development, this implies that Q modification occurs earlier in development in D. willistoni than in other Drosophila.

 

Chondrogianni N, Kapeta S, Chinou I, Vassilatou K, Papassideri I, Gonos ES. (2010). Anti-ageing and rejuvenating effects of quercetin.Exp Gerontol. 45(10):763-71.

Abstract: Homeostasis is a key feature of the cellular lifespan. Its maintenance influences the rate of ageing and it is determined by several factors, including efficient proteolysis. The proteasome is the major cellular proteolytic machinery responsible for the degradation of both normal and damaged proteins. Alterations of proteasome function have been recorded in various biological phenomena including ageing and replicative senescence. Proteasome activities and function are decreased upon replicative senescence, whereas proteasome activation confers enhanced survival against oxidative stress, lifespan extension and maintenance of the young morphology longer in human primary fibroblasts. Several natural compounds possess anti-ageing/anti-oxidant properties. In this study, we have identified quercetin (QUER) and its derivative, namely quercetin caprylate (QU-CAP) as a proteasome activator with anti-oxidant properties that consequently influence cellular lifespan, survival and viability of HFL-1 primary human fibroblasts. Moreover, when these compounds are supplemented to already senescent fibroblasts, a rejuvenating effect is observed. Finally, we show that these compounds promote physiological alterations when applied to cells (i.e. whitening effect). In summary, these data demonstrate the existence of naturally occurring anti-ageing products that can be effectively used through topical application.

 

Chow TF, Mankaruos M, Scorilas A, Youssef Y, Girgis A, Mossad S, Metias S, Rofael Y, Honey RJ, Stewart R, Pace KT, Yousef GM (2010). The miR-17-92 Cluster is Over Expressed in and Has an Oncogenic Effect on Renal Cell Carcinoma. J Urol.183(2):743-51.

Abstract: Purpose: miRNAs are small, nonprotein coding RNAs that are differentially expressed in many malignancies. We previously identified 80 miRNAs that are dysregulated in clear cell renal cell carcinoma. In this study we validated over expression of the miR-17-92 cluster in clear cell renal cell carcinoma and tested the effect of 2 members of this cluster (miR-17-5p and miR-20a) on tumor proliferation. We also elucidated the role of miRNA in clear cell renal cell carcinoma pathogenesis with bioinformatics. Materials And Methods: miRNA expression was validated by quantitative reverse transcriptase-polymerase chain reaction. The cell proliferation effect of miR-17-5p and miR-20a was tested in a renal adenocarcinoma cell line model. Multiple in silico analyses were done of dysregulated miRNAs. Results: We validated miR-71-92 cluster over expression in clear cell renal cell carcinoma by quantitative reverse transcriptase-polymerase chain reaction. Transfection of miR-20a inhibitor significantly decreased cell proliferation in a dose dependent manner. Transfection of miR-17-5p, which is not endogenously expressed in the ACHN cell line, led to increased cell proliferation compared to control values. This effect was suppressed by miR-17-5p inhibitor. Bioinformatics analysis identified 10 clusters of miRNAs dysregulated in clear cell renal cell carcinoma that followed the same expression patterns. We also identified matching patterns between reported chromosomal aberration in clear cell renal cell carcinoma and miRNA dysregulation for 37.5% of the miRNAs. Target prediction analysis was done using multiple algorithms. Many key molecules in clear cell renal cell carcinoma pathogenesis, including HIFs, mTOR, VEGF and VHL, were potential targets for dysregulated miRNAs. Conclusions: A significant number of dysregulated proteins in clear cell renal cell carcinoma are potential miRNA targets. Also, many clear cell renal cell carcinoma dysregulated miRNAs are phylogenetically conserved.

 

Christodoulakis NS, Kogia D, Mavroeidi D, Fasseas C (2010). Anatomical and cytochemical investigation of the leaf of Teucrium polium L., a pharmaceutical shrub of the Greek phryganic formations. Journal of Biological Research, 14: 199 – 209.

Abstract: Although extensively studied for its pharmaceutical properties, Teucrium polium has yet to disclose its leaf structure and the chemical nature of the accumulated or secreted products. Therefore, light, scanning, and transmission electron microscopy along with histochemical tests were employed to investigate the leaf of this perennial dwarf Mediterranean shrub. Structural characteristics include large cells with cutinized walls, creating cavities of obscured function in contact to a vessel element of the conductive tissue and different types of glandular hairs. A variety of secreted materials was identified by certain histochemical stains within the mesophyll cells and the glandular hairs. A dense indumentum of non-glandular hairs protects the secretory apparatus and the leaf surface from the stressful conditions of the Mediterranean climate.

 

Christodoulakis NS, Kollia K, Fasseas C (2010). Leaf structure and histochemistry of the squirting cucumber [Ecballium elaterium (L.) A. Rich.]. Flora 206, In Press.

Abstract: Light, scanning and transmission electron microscopy as well as histochemical reactions were employed to study the leaf structure and secretory activity of Ecballium elaterium, a hairy pharmaceutical perennial common in the Mediterranean region. The amphistomatic leaf has a peculiar structure due to special cells supporting the conductive bundles, a remarkable shortage of mechanical tissue, and the existence of pectin strands between mesophyll cells. The secreting activity is limited mostly to secretary hairs. These attributes of the Ecballium leaf fine structures do not resemble the common structure of leaves from Mediterranean plants and point to a peculiar strategy of this species coping with stress conditions of its habitat.

 

Conde A, Diallinas G, Chaumont F, Chaves M, Gerós H (2010). Transporters, channels, or simple diffusion? Dogmas, atypical roles and complexity in transport systems. Int J Biochem Cell Biol. (in press).

Abstract: The recent breakthrough discoveries of transport systems assigned with atypical functions provide evidence for complexity in membrane transport biochemistry. Some channels are far from being simple pores creating hydrophilic passages for solutes and can, unexpectedly, act as enzymes, or mediate high-affinity uptake, and some transporters are surprisingly able to function as sensors, channels or even enzymes. Furthermore, numerous transport studies have demonstrated complex multiphasic uptake kinetics for organic and mineral nutrients. The biphasic kinetics of glucose uptake in Saccharomyces cerevisiae, a result of several genetically distinct uptake systems operating simultaneously, is a classical example that is a subject of continuous debate. In contrast, some transporters display biphasic kinetics, being bona fidae dual-affinity transporters, their kinetic properties often modulated by post-translational regulation. Also, aquaporins have recently been reported to exhibit diverse transport properties and can behave as highly adapted, multifunctional channels, transporting solutes such as CO(2), hydrogen peroxide, urea, ammonia, glycerol, polyols, carbamides, purines and pyrimidines, metalloids, glycine, and lactic acid, rather than being simple water pores. The present review provides an overview on some atypical functions displayed by transporter proteins and discusses how this novel knowledge on cellular uptake systems may be related to complex multiphasic uptake kinetics often seen in a wide variety of living organisms and the intriguing diffusive uptake of sugars and other solutes.

 

Daskalakou EN, Thanos CA (2010). Postfire seedling dynamics and performance in Pinus halepensis Mill. populations. Acta Oecologica 36 (2010) 446-453

Abstract: Postfire dynamics of Aleppo pine seedling density, survival and growth were assessed in five burned forests of Attica, Greece (Stamata, Villia, Avlona, Kapandriti and Agios Stefanos) through the establishment of permanent experimental plots. All emerging seedlings were tagged and their survival and growth monitored at regular intervals. Seedling density dynamics show an initial, steep increase (to maximumvalues 2.9e4.6 seedlings m-2) followed by a gradual decrease that levels off at the second and third postfire year (1.3e3.0 seedlings m-2); similarly, postfire seedling survival more or less stabilised at 30e50%, 2e3 years after fire. On the basis of density and mortality trends as well as relevant bibliographic data, it is predicted that very dense, mature forests (10.000 trees ha-1 or more) will be reinstated within 15e20 years. During the first 5e7 postfire years, seedling/sapling annual height followed linear trends with various yearly rates, ranging mostly between 8 and 15 cm (and 27e30 cm in two exceptional, fast growing cases). Within an individual growth season, seedling height dynamics were found to follow sigmoid curves with growth increment peaks in mid-spring. The time (on a monthly basis) of seedling emergence did not affect seedling growth or survival. On the other hand, for the first time under natural conditions, it has been shown that cotyledon number per seedling, an indirect measure of both seed size and initial photosynthetic capacity, significantly affected seedling survival but not growth. Seedlings bearing a higher number of cotyledons, presumably derived from larger seeds, showed greater survival at the end of the first postfire year than seedlings with fewer cotyledons. A postfire selective pressure, favouring large seed size, is postulated to counteract with a contrasting one, which favours small seed size, expressed during fire-free conditions.

 

Daskalakou EN, Thanos CA (2010). Seed and cone morphometric indicators: a new tool for the discrimination between the common Mediterranean pines Pinus halepensis Mill. and P. brutia Ten. Plant Biosystems Vol. 144, No. 4, December 2010, pp. 819–825.

Abstract: The two typical Mediterranean pines of Greece (Pinus halepensis Mill. and P. brutia Ten.) show a distinct, natural geographical distribution. However, in sites where they grow in sympatry (mainly due to extended reforestations), their morphological discrimination is not always easy. In the present study, three new morphometric indicators are introduced (at decreasing rank of reliability): (a) seed coat mass fraction, expressed as a percentage of the total seed mass (SM) (overall mean values 27.9±0.5 (n=160), and 58.0±0.3 (n=320) from 18 and 16 populations of Aleppo and East Mediterranean pine, respectively), (b) mean SM (16.70±0.26 mg, n=651, and 42.79±0.61 mg, n=425 from 18 and 16 populations of each of the two species, respectively) and (c) cone length/width ratio (2.20±0.01, n=651, and 1.77±0.01, n=606 from the same 18 and 16 populations, respectively). These three parameters are easily calculated, and constitute a reliable tool for the discrimination of the two pine species on the basis of their reproductive units (cones and seeds), provided that a minimal number of randomly collected samples is used for each indicator: 20 seeds for the measurement of seed coat mass fraction, about 1000 seeds for the estimation of mean SM, and 20 cones for the calculation of the cone length/width ratio. The functional implications of these adaptive traits are discussed.

 

Dimou, N.L., Nikolopoulos, G.K., Hamodrakas, S.J., Bagos, P.G.(2010) Fcgamma receptor polymorphisms and their association with periodontal disease: a meta-analysis. J Clin Periodontol.,37(3):255-65.

Abstract: Aim: A systematic review and a meta-analysis were conducted in order to investigate the potential association of Fcgamma receptor (FcgammaR) polymorphisms with susceptibility to aggressive and chronic periodontal disease. Materials & Methods: A database search yielded a total of 17 studies involving 1685 cases and 1570 controls. Three polymorphisms were included in the meta-analysis: FcgammaRIIA H131R (rs1801274), FcgammaRIIIA F158V (rs396991) and FcgammaRIIIB NA1/NA2. Random-effect models were used in the analysis. Odds ratios (ORs) along with their 95% confidence intervals (CIs) were computed to compare the distribution of alleles and genotypes between cases and controls. Results & Conclussions: The FcgammaRIIIB NA1/NA2 polymorphism was associated with both aggressive (per-allele OR 2.005, 95% CI: 1.044, 3.851) and chronic periodontitis (recessive contrast NA2NA2 versus NA1NA1+NA1NA2 OR 1.397, 95% CI: 1.039, 1.878). The analysis showed weak evidence for association between the FcgammaRIIA H131R polymorphism and aggressive periodontitis in Asians (R versus H allele OR 1.579, 95% CI: 1.025, 2.432). On the contrary, no relationship was identified between FcgammaRIIIA F158V and periodontal disease. Accumulating evidence from basic research makes the suggested association between FcgammaRIIIB NA1/NA2 polymorphism and periodontitis biologically plausible. Further research, however, is needed in order to assess possible gene-gene or gene-environment interactions (i.e. with smoking).

 

Elsen S, Efthymiou G, Peteinatos P, Diallinas G, Kyritsis P, Moulis JM (2010) A bacteria-specific 2[4Fe-4S] ferredoxin is essential in Pseudomonas aeruginosa. BMC Microbiol. 2010 Oct 28;10(1):271. [Epub ahead of print]

Abstract: BACKGROUND: Ferredoxins are small iron-sulfur proteins belonging to all domains of life. A sub-group binds two [4Fe-4S] clusters with unequal and extremely low values of the reduction potentials. These unusual properties are associated with two specific fragments of sequence. The functional importance of the very low potential ferredoxins is unknown. RESULTS: A bioinformatic screening of the sequence features defining very low potential 2[4Fe-4S] ferredoxins has revealed the almost exclusive presence of the corresponding fdx gene in the Proteobacteria phylum, without occurrence in Archaea and Eukaryota. The transcript was found to be monocistronic in Pseudomonas aeruginosa, and not part of an operon in most bacteria. Only fdx genes of bacteria which anaerobically degrade aromatic compounds belong to operons. As this pathway is not present in all bacteria having very low potential 2[4Fe-4S] ferredoxins, these proteins cannot exclusively be reductants of benzoyl CoA reductases. Expression of the ferredoxin gene did not change in response to varying growth conditions, including upon macrophage infection or aerobic growth with 4-hydroxy benzoate as carbon source. However, it increased along the growth curve in Pseudomonas aeruginosa and in Escherichia coli. The sequence immediately 5' upstream of the coding sequence contributed to the promotor activity. Deleting the fdx gene in Pseudomonas aeruginosa abolished growth, unless a plasmid copy of the gene was provided to the deleted strain. CONCLUSIONS: The gene of the very low potential 2[4Fe-4S] ferredoxin displays characteristics of a housekeeping gene, and it belongs to the minority of genes that are essential in Pseudomonas aeruginosa. These data identify a new potential antimicrobial target in this and other pathogenic Proteobacteria.

 

Emmanouilidou E, Melachroinou K, Roumeliotis T, Garbis SD, Ntzouni M, Margaritis LH, Stefanis L, Vekrellis K. (2010). Cell-produced alpha-synuclein is secreted in a calcium-dependent manner by exosomes and impacts neuronal survival. J Neurosci. 30(20):6838-51.

Abstract: alpha-Synuclein is central in Parkinson's disease pathogenesis. Although initially alpha-synuclein was considered a purely intracellular protein, recent data suggest that it can be detected in the plasma and CSF of humans and in the culture media of neuronal cells. To address a role of secreted alpha-synuclein in neuronal homeostasis, we have generated wild-type alpha-synuclein and beta-galactosidase inducible SH-SY5Y cells. Soluble oligomeric and monomeric species of alpha-synuclein are readily detected in the conditioned media (CM) of these cells at concentrations similar to those observed in human CSF. We have found that, in this model, alpha-synuclein is secreted by externalized vesicles in a calcium-dependent manner. Electron microscopy and liquid chromatography-mass spectrometry proteomic analysis demonstrate that these vesicles have the characteristic hallmarks of exosomes, secreted intraluminar vesicles of multivesicular bodies. Application of CM containing secreted alpha-synuclein causes cell death of recipient neuronal cells, which can be reversed after alpha-synuclein immunodepletion from the CM. High- and low-molecular-weight alpha-synuclein species, isolated from this CM, significantly decrease cell viability. Importantly, treatment of the CM with oligomer-interfering compounds before application rescues the recipient neuronal cells from the observed toxicity. Our results show for the first time that cell-produced alpha-synuclein is secreted via an exosomal, calcium-dependent mechanism and suggest that alpha-synuclein secretion serves to amplify and propagate Parkinson's disease-related pathology.

 

Florou D, Papadopoulos IN, Scorilas A (2010) Molecular analysis and prognostic impact of the novel apoptotic gene BCL2L12 in gastric cancer. Biochem Biophys Res Commun. 391(1):214-8.

Abstract: Stomach cancer comprises a malignancy with feeble prognosis. In gastric carcinogenesis, molecular alterations in the apoptosis-related genes have been described. In this study, the expression of BCL2-like-12 (BCL2L12) gene, discovered and cloned by members of our group, was investigated in a statistically significant sample size of cancerous and non-cancerous stomach tissues and gastric cancer cells with quantitative real-time PCR methodology. BCL2L12 transcript was indicated in cancer gastric tissues to range from 29 to 53200 mRNA copies BCL2L12/10(6) mRNA copies GAPDH. Significant associations of BCL2L12 with gastric tumors of the early stages (I/II) (p=0.044) and of intestinal histotype (p=0.034) was substantiated. Both univariate and multivariate analyses disclosed, respectively, BCL2L12 relationship with disease-free (p=0.006 and p=0.025) and overall patients' survival (p=0.007 and p=0.022). Our results open new horizons for the possible application of BCL2L12 as a novel prognostic indicator of gastric cancer.

 

Fox SC, Eliopoulos C, Moutafi I, Manolis SK (2010). A simple technique for imaging the human skeleton: An application using the auricular surface for aging. Journal of Forensic Sciences (in press).

 

Fragopoulou A, Grigoriev Y, Johansson O, Margaritis LH, Morgan L, Richter E, Sage C. (2010). Scientific panel on electromagnetic field health risks: consensus points, recommendations, and rationales. Rev Environ Health. 25(4):307-17.

Abstract: In November, 2009, a scientific panel met in Seletun, Norway, for three days of intensive discussion on existing scientific evidence and public health implications of the unprecedented global exposures to artificial electromagnetic fields (EMF). EMF exposures (static to 300 GHz) result from the use of electric power and from wireless telecommunications technologies for voice and data transmission, energy, security, military and radar use in weather and transportation. The Scientific Panel recognizes that the body of evidence on EMF requires a new approach to protection of public health; the growth and development of the fetus, and of children; and argues for strong preventative actions. New, biologically-based public exposure standards are urgently needed to protect public health worldwide.

 

Fragopoulou AF, Margaritis LH (2010). Is cognitive function affected by mobile phone radiation exposure? Review article in, "Non Thermal Effects and Mechanisms of interaction between electromagnetic fields and living matter", European Journal of Oncology-Library vol.5, pp 261-273, L. Giuliani and M. Soffritti (eds).

Abstract: Behavioral tasks, including the Morris water maze (MWM), radial arm maze and object recognition task, have been extensively used to test cognitive impairment following exposure of rodents to mobile phone (MP) radiation on various frequencies and specific absorption rate (SAR) values. Exposed animals in most of the cases revealed defects in their working memory possibly due to cholinergic pathway distraction. The only experiment on mice at very low SAR did not show statistically significant deficits by 8-arm maze, but our own data in mice exposed to GSM 900 MHz radiation, revealed memory lesions on MWM task; exposed mice had difficulties in memory consolidation and/or retrieval of the stored information. Lastly, a number of studies have been applied to volunteers showing variable results depending on the experimental setup, revealing memory improvement or deficits following MP exposure. The recorded data from the literature are generally favouring the conclusion that EMF is affecting memory function although a more rigorous and reproducible exposure system has to be adopted in relation to the recently criticized importance of SAR.

 

Fragopoulou AF, Margaritis LH, Koussoulakos SL(2010). Cranial and postcranial skeletal variations induced in mouse embryos by mobile phone radiation. Pathophysiology 17(3):169-77.

Abstract: This study focuses on foetal development following mild daily exposure of pregnant mice to near field electromagnetic radiation emitted by a mobile phone. The investigation was motivated by the fact that the potentially hazardous electromagnetic radiation emitted by mobile phones is currently of tremendous public interest. Physically comparable pregnant mice were exposed to radiofrequency radiation GSM 900MHz emitted by a mobile phone.Within 5 h after birth most cubs were fixed followed by double staining in toto, and conventional paraffin histology. Other cubs remained with their mothers until teeth eruption. Structural development was assessed by examining newborns for the presence of anomalies and/or variations in soft tissues and skeletal anatomy. Electromagnetic radiofrequency exposed newborns, externally examined, displayed a normal phenotype. Histochemical and histological studies, however, revealed variations in the exposed foetuses with respect to control ones concerning the ossification of cranial bones and thoracic cage ribs, as well as displacement of Meckelian cartilage. Littermates examined after teeth eruption displayed normal phenotypes. It is concluded that mild exposure to mobile phone radiation may affect, although transiently, mouse foetal development at the ossification level. The developmental variations observed could be explained by considering the different embryonic origin and mode of ossification of the affected skeletal elements.

 

Fragopoulou AF, Miltiadous P, Stamatakis A, Stylianopoulou F, Koussoulakos SL, Margaritis LH (2010). Whole body exposure with GSM 900MHz affects spatial memory in mice. Pathophysiology 17(3):179-187.

Abstract: Extended work has been performed worldwide on the effects of mobile phone radiation upon rats' cognitive functions, however there is great controversy to the existence or not of deficits. The present work has been designed in order to test the effects of mobile phone radiation on spatial learning and memory in mice Mus musculus Balb/c using the Morris water maze (a hippocampal-dependent spatial memory task), since there is just one other study on mice with very low SAR level (0.05W/kg) showing no effects. We have applied a 2h daily dose of pulsed GSM 900MHz radiation from commercially available mobile phone for 4 days at SAR values ranging from 0.41 to 0.98W/kg. Statistical analysis revealed that during learning, exposed animals showed a deficit in transferring the acquired spatial information across training days (increased escape latency and distance swam, compared to the sham-exposed animals, on the first trial of training days 2-4). Moreover, during the memory probe-trial sham-exposed animals showed the expected preference for the target quadrant, while the exposed animals showed no preference, indicating that the exposed mice had deficits in consolidation and/or retrieval of the learned spatial information. Our results provide a basis for more thorough investigations considering reports on non-thermal effects of electromagnetic fields (EMFs).

 

Fyllas NF, Patrizia I. Politi,  Galanidis A, Dimitrakopoulos PG, Arianoutsou M, (2010). Simulating regeneration and vegetation dynamics in Mediterranean coniferous forests, Ecological Modelling, Vol. 221, Issue 11: 1494-1504

Abstract: This study aims to provide a quantitative framework to model the dynamics of Mediterranean coniferous forests by integrating existing ecological data within a generic mathematical simulator. We developed an individual-based vegetation dynamics model, constrained on long-term field regeneration data, analyses of tree-rings and seed germination experiments. The simulator implements an asymmetric competition algorithm which is based on the location and size of each individual. Growth is parameterized through the analysis of tree-rings from more than thirty individuals of each of the three species of interest. A super-individual approach is implemented to simulate regeneration dynamics, constrained with available regeneration data across time-since-disturbance and light-availability gradients. The study concerns an insular population of an endemic to Greece Mediterranean fir (Abies cephalonica Loudon) on the island of Cephalonia (Ionian Sea) and two interacting populations of a Mediterranean pine (Pinus brutia Ten.) and a more temperate-oriented pine (Pinus nigra Arn. ssp. pallasiana) on the island of Lesbos (NE Aegean Sea), Greece. The model was validated against plot-level observations in terms of species standing biomass and regeneration vigour and adequately captured regeneration patterns and overall vegetation dynamics in both study sites. The potential effects of changing climatic patterns on the regeneration dynamics of the three species of interest were subsequently explored. With the assumption that a warmer future would probably cause changes in the duration of cold days, we tested how this change would affect the overall dynamics of the study sites, by focusing on the process of cold stratification upon seed germination. Following scenarios of a warmer future and under the current model parameterization, changes in the overall regeneration vigour controlled by a reduction in the amount of cold days, did not alter the overall dynamics in all plant populations studied. No changes were identified in the relative dominance of the interacting pine populations on Lesbos, while the observed reduction in the amount of emerging seedlings of A. cephalonica on Cephalonia did not affect biomass yield at later stages of stand development.

 

Galatis B., Apostolakos P. 2010. A new callose function: involvement in differentiation and function of fern stomatal complexes. Plant Signaling and Behavior 5:1359-1364.

Abstract: Callose in polypodiaceous ferns performs multiple roles during stomatal development and function. This highly dynamic (1→3)-β-D-glucan, in cooperation with the cytoskeleton, is involved in: (a) stomatal pore formation, (b) deposition of local GC wall thickenings and (c) the mechanism of stomatal pore opening and closure. This behavior of callose, among others, probably relies on the particular mechanical properties as well as on the ability to form and degrade rapidly, to create a scaffold or to serve as a matrix for deposition of other cell wall materials and to produce fibrillar deposits in the periclinal GC walls, radially arranged around the stomatal pore. The local callose deposition in closing stomata is an immediate response of the external periclinal GC walls experiencing strong mechanical forces induced by the neighboring cells. The radial callose fibrils transiently co-exist with radial cellulose microfibrils and, like the latter, seem to be oriented via cortical MTs.

 

Georghiou K, Delipetrou P (2010). Patterns and traits of the endemic plants of Greece. Botanical Journal of the Linnean Society, 162: 130-422.

Abstract: Greece is characterized by high plant diversity (5800 species) and endemism (15.6%). This study attempts a first overall assessment of the taxonomy, distribution, traits and conservation status of the Greek endemic plants. The endemic species belong to 56 families and 242 genera. Most of the endemic plants have a narrow geographical and altitudinal distribution range. The southern floristic regions are richer in endemic species. The species area relationships for endemics (EARs) for island and continental floristic regions explain over 50% of the variation in number of species and are characterized by steep curves. Analysis of the distributional pattern of the endemics by similarity coefficients offers useful insights into the palaeogeography and biogeography of Greece. The endemic species occur at all altitudes, but the altitudinal distribution shows a predominance of local endemics at 0–600 m in the island regions and in higher zones in the continental regions. The life form spectra show a predominance of hemicryptophytes and chamaephytes. This trait seems indicative of their habitat and adaptive strategy and may be related to speciation processes. The overview of the conservation status of the Greek endemics indicates that over 40% of the taxa are threatened or near threatened.

 

Giokas S, Thomaz D, Douris V, Lecanidou R, Rodakis GC (2010). 5000 years of molecular evolution in a population of the land snail Albinaria caerulea transported by humans. J. Mollus. Stud. 76: 49-56

Abstract: Patterns of genetic variation of Albinaria caerulea, a landsnail that was probably transported by humans to Vravrona (Attica,Greece), were analysed using the mitochondrial ATPase8 gene.The analysis of molecular variance indicated significant localdifferentiation at the subpopulation level. This considerablepopulation subdivision and genetic differentiation in a shorttime is possibly related to life history and population structureof the species. The population structure and demographic historysuggest a recent single colonization event, by a single or afew lineages, at the first site inhabited by humans in Vravrona(about 5,000 years before present). This was followed by populationexpansion and subsequent intra-colonization events (accompaniedby bottlenecks) to more recently inhabited sites. The estimatedsmall effective population size/census population size ratiofurther implies considerable population fluctuations. Bayesianinference and statistical parsimony analyses indicate that thepopulation of Vravrona is associated with a species subgroupwhich includes populations found in the Cycladic islands ofSikinos, Folegandros and Thira; its source is probably relatedto certain samples from Sikinos.

 

Gourgou E, Aggeli IK, Beis I, Gaitanaki C. (2010). Hyperthermia-induced Hsp70 and MT20 transcriptional upregulation are mediated by p38-MAPK and JNKs in Mytilus galloprovincialis (Lamarck); a pro-survival response. J. Exp. Biol. 213 ( 2): 347-357.

Abstract: In the present study we investigated the signal transduction cascades triggered by acute thermal stress in Mytilus galloprovincialis gills. This particular species has been reported to exhibit a significant tolerance to high temperatures; thus, it was intriguing to examine the molecular mechanisms responsible for this extraordinary trait. In particular, exposure to 30 degrees C was found to cause a significant and sustained stimulation of p38-MAPK phosphorylation while the activation profile of JNKs was transient and relatively moderate. We also observed that hyperthermia induced apoptosis as a delayed response, with both MAPK subfamilies rapidly translocating to the nucleus. The phosphorylation of cJun, ATF2 and NFkappaB was detected next. Using selective inhibitors, phosphorylation of these transcription factors was established to be dependent on p38-MAPK or JNKs. Subsequently, potential changes in gene expression were assessed. In this context, hyperthermia resulted in the transcriptional upregulation of Hsp70 and MT20 genes with a widely known salutary effect, preserving mussel fitness and performance under adverse environmental conditions. Interestingly, p38-MAPK and JNKs were found to mediate the hyperthermia-induced Hsp70 and MT20 upregulation as well as the delayed induction of apoptosis under the interventions studied. Overall this is, to our knowledge, the first time that an insight into the compensatory survival ;programme' initiated in Mytilus galloprovincialis gills, contributing to this organism's exceptional tolerance to thermal stress, has been gained. In particular, we provide evidence demonstrating the principal role of p38-MAPK and JNKs in transducing the stress signal via mobilization of specific transcription factors and the transcriptional upregulation of cytoprotective genes.

 

Gournas C, Amillis S, Vlanti A, Diallinas G (2010). Transport-dependent endocytosis and turnover of a uric acid-xanthine permease. Mol Microbiol. 75:246-260.

Abstract: In this work we unmask a novel downregulation mechanism of the uric acid/xanthine transporter UapA, the prototype member of the ubiquitous Nucleobase-Ascorbate Transporter family, directly related to its function. In the presence of substrates, UapA is endocytosed, sorted into the multivesicular body pathway and degraded in vacuoles. Substrate-induced endocytosis, unlike ammonium-induced turnover, is absolutely dependent on UapA activity and several lines of evidence showed that the signal for increased endocytosis is the actual translocation of substrates through the UapA protein. The use of several UapA functional mutants with altered kinetics and specificity has further shown that transport-dependent UapA endocytosis occurs through a mechanism, which senses subtle conformational changes associated with the transport cycle. We also show that distinct mechanisms of UapA endocytosis necessitate ubiquitination of a single Lys residue (K572) by HulARsp5. Finally, we demonstrate that in the presence of substrates, non-functional UapA versions can be endocytosed in trans if expressed in the simultaneous presence of active UapA versions, even if the latter cannot be endocytosed themselves.

 

Kadis C, Georghiou K (2010). Seed dispersal and germination behavior of three threatened endemic labiates of Cyprus. Plant Species Biology, 25: 77-84.

Abstract: The present study examined seed dispersal and germination in three of the most threatened endemic labiates of Cyprus: Origanum cordifolium, Phlomis brevibracteata and Phlomis cypria ssp. occidentalis. Some common traits in these taxa can be correlated with their overall survival strategy. Seeds mature in mid to late summer, but most seeds remain on the mother plants until the beginning of the rainy season. The opening of the calyces containing the seeds seems to be caused by absorption of moisture. Water is also the most important dispersal factor because the seeds are dispersed by rain. Seed germination occurs at relatively low temperatures that prevail in the field at the beginning of the rainy season. This behavior provides the plants with ecological advantages because their seeds are exposed on the soil at the most appropriate period (mid to late autumn) for germination and seedling survival. The present study contributes substantially to in situ and ex situ conservation of these threatened plants.

 

Kadis C, Kounnamas C, Georghiou K (2010). Seed germination and conservation of endemic, rare and threatened aromatic plants of Cyprus. Israel J. of Plant Sciences 58 (in press).

 

Kallimanis AS, Panitsa M, Bergmeier E, Georghiou K, Delipetrou P, Dimopoulos P (2010). Biogeographical determinants for total and endemic species richness in a continental archipelago. Biodiversity and Conservation, 19: 1225-1235.

Abstract: We examined the relationship between plant species richness and biogeographical variables (island area, island maximum elevation, distance from nearest inhabited island, distance from nearest mainland) using a data set comprising 201 islands of the Aegean archipelago. We found that endemic species richness was strongly correlated to total species richness. Single-island endemic species richness was most strongly correlated to island maximum elevation, and then to island area, with an apparent small island effect for islands smaller than 47 km2. Total species richness was most strongly correlated to island area (with no apparent small island effect), and less strongly correlated to island maximum elevation. Distance from the mainland or other inhabited islands displayed limited predictive value in our data set. The slope of the relationship between species richness and geographical factors (island area, elevation, distance from island/mainland) was steeper for endemic species richness than for total richness. Finally, the different scales of endemicity (single-island endemics, island group endemics and Aegean regional endemics) displayed similar qualitative trends and only differed quantitatively. Thus, we conclude that different biogeographical factors act as drivers for total species richness than for endemic species richness.

 

Kapiris K, Thessalou-Legaki M, Petrakis G, Conides A (2010). Ontogenetic shifts and temporal changes in the trophic patterns of deep-sea red shrimp Aristaeomorpha foliacea (Decapods: Aristeidae) in the E. Ionian Sea (E. Mediterranean). Marine Ecology Vol. 31 (2):  341 – 354.

Abstract: The purpose of this paper is to provide the first detailed data concerning the diet and feeding activity of the giant red shrimp, Aristaeomorpha foliacea, in the Eastern Ionian Sea (Eastern Mediterranean), in relation to season, size class and sex. Feeding activity in A. foliacea was intense, based on its low vacuity index and high prey diversity, with a diet dominated by mesopelagic prey and less frequent occurrence of benthic taxa. Giant red shrimp displayed a highly diversified diet that exhibited slight seasonal fluctuations. The diets of both sexes consisted of 60 different prey categories belonging chiefly to three groups: crustaceans (e.g. decapods, such as Plesionika spp. and Pasiphaeidae, amphipods), cephalopods (mainly Enoploteuthidae) and fishes (Myctophidae, Macrouridae). These three prey categories accounted for 72–82% of the relative abundance and total occurrence for males and 70–88% for females, respectively. Variation in food availability, as well as increased energy demands related to gonad development and breeding activity, appear to be critical factors driving temporal changes in feeding strategy. Feeding activity increased during spring and summer, which coincides with reproductive activities (mating, gonad maturation, egg-laying). Females seem to be more active predators than males, consuming prey with greater swimming ability. However, ontogenetic shifts in diet were also apparent, despite high dietary overlap among small, medium and large females. Large individuals, which are more efficient predators, selected highly mobile prey (e.g. fishes), whereas small individuals consumed low-mobility prey (e.g. copepods, ostracods, tanaids and sipunculans).

 

Karayanni H, Kormas KAr, Cragg S, Nicolaidou A (2010) Establishment and Succession of an Epibiotic Community on Chromated Copper Arsenate-Treated Wood in Mediterranean Waters Arch. Environ. Contam.  Toxic.58: 71-78.

Abstract: Colonization and succession of an epibiotic animal community on chromated copper arsenate (CCA)-treated wood were studied for 18 months in the eastern Mediterranean (Saronikos Gulf, Aegean Sea). Pine wood panels, 200 x 100 x 25 mm, impregnated with CCA at retentions of 0, 12, 24, and 48 kg m(-3) were used. The abundance or surface coverage of the most characteristic taxa (polychaetes, mollusca, crustacea bryozoa, sponges, ascidians) was measured in situ, while 12 months after submersion two panels of each retention were removed and examined in the laboratory. A total of 26 taxa were identified, among which polychaetes of the family Serpulidae dominated. The controls carried the largest number of species (17) but the lowest number of individuals. On panels with CCA retentions of 12 and 24 kg m(-3), 14 and 16 species were observed, respectively, while at 48 kg m(-3), only 9 species were found. Only the controls were affected by boring bivalves of the family Teredinidae and started to break up within 3 months of submersion. Statistically significant differences in barnacle and polychaete abundance were found between treated and untreated panels. There were no significant differences among panels treated at the three CCA loadings. Ordination by nonmetric multidimensional scaling showed a seasonal effect on the colonization of the treated panels, with the highest recruitment during the warmer months of the study.

 

Karkoulis PK, Stravopodis DJ, Margaritis LH, Voutsinas GE. (2010). 17-Allylamino-17-demethoxygeldanamycin induces downregulation of critical Hsp90 protein clients and results in cell cycle arrest and apoptosis of human urinary bladder cancer cells. BMC Cancer. 9;10:481.

Abstract: BACKGROUND: 17-Allylamino-17-demethoxygeldanamycin (17-AAG), a benzoquinone ansamycin antibiotic, specifically targets heat shock protein 90 (Hsp90) and interferes with its function as a molecular chaperone that maintains the structural and functional integrity of various protein clients involved in cellular signaling. In this study, we have investigated the effect of 17-AAG on the regulation of Hsp90-dependent signaling pathways directly implicated in cell cycle progression, survival and motility of human urinary bladder cancer cell lines. METHODS: We have used MTT-based assays, FACS analysis, Western blotting, semi-quantitative RT-PCR, immunocytochemistry and scratch-wound assay in RT4, RT112 and T24 human urinary bladder cancer cell lines. RESULTS: We have demonstrated that, upon 17-AAG treatment, bladder cancer cells are arrested in the G1 phase of the cell cycle and eventually undergo apoptotic cell death in a dose-dependent manner. Furthermore, 17-AAG administration was shown to induce a pronounced downregulation of multiple Hsp90 protein clients and other downstream effectors, such as IGF-IR, Akt, IKK-α, IKK-β, FOXO1, ERK1/2 and c-Met, resulting in sequestration-mediated inactivation of NF-κB, reduced cell proliferation and decline of cell motility. CONCLUSIONS: In total, we have clearly evinced a dose-dependent and cell type-specific effect of 17-AAG on cell cycle progression, survival and motility of human bladder cancer cells, due to downregulation of multiple Hsp90 clients and subsequent disruption of signaling integrity.

 

Katsanevakis S, Poursanidis D, Issaris Y, Tsiamis K, Salomidi M, Maroulakis M, Kytinou E, Thessalou-Legaki M, Zenetos Α (2010). The invasive crab Percnon gibbesi (Crustacea: Decapoda: Plagusiidae) is spreading in the Aegean and Ionian Seas. Marine Biodiversity Records(in press) [doi:10.1017/S1755267210000163]

Abstract: Percnon gibbesi is an opportunistic feeder, feeding primarily on algae, of the shallow infra-littoral rocky shores. It was first observed in 1999 in the Mediterranean Sea and has rapidly spread since then. The range expansion of the species in the Aegean and Ionian Seas was recorded and evidence of its further establishment in Greek waters was provided. Established populations were observed in areas where it had not been previously reported: the Saronikos Gulf (central Aegean Sea), Chios Island (central Aegean Sea), Milos Island (central Aegean Sea), Zakynthos Island (central Ionian Sea) and Syvota (north-eastern coast of the Ionian Sea). The species was also observed in new sites in the Messiniakos Gulf, Crete and Rhodes Island, where it had been previously reported. The species keeps spreading in the Mediterranean Sea with a high rate of expansion.

 

Kosti V, Papageorgiou I, Diallinas G (2010). Dynamic elements at both cytoplasmic- and extracellular-facing sides of the UapA transporter selectively control the accessibility of substrates to their translocation pathway. J Mol Biol. (in press).

Abstract: In the UapA uric acid-xanthine permease of Aspergillus nidulans subtle interactions between key residues of the putative substrate binding pocket, located in the TMS8-9 loop, and a specificity filter, implicating residues in TMS12 and the TMS1-2 loop, are critical for function and specificity. By using a strain lacking all transporters involved in adenine uptake (DeltaazgA DeltafcyB DeltauapC) and carrying a mutation which partially inactivates the UapA specificity filter (F528S), we obtained 28 mutants capable of UapA-mediated growth on adenine. 72% of mutants concern replacements of a single residue, R481, in the putative cytoplasmic loop TMS10-11. Five different missense mutations are located in TMS9, TMS10 or in loops TMS1-2 and TMS8-9. Mutations in the latter loops concern residues previously shown to enlarge UapA specificity (Q113L) or to be part of a motif involved in substrate binding (F406Y). In all mutants the ability of UapA to transport its physiological substrates remains intact, whereas the increased capacity for transport of adenine and other purines seems to be due to the elimination of elements that hinder the translocation of non-physiological substrates through UapA, rather than to an increase in relevant binding affinities. The additive effect of most novel mutations with F528S and allele-specific interactions of mutation R481G (TMS10-11 loop) with Q113L (TMS1-2 loop) or T526M (TMS12) establish specific interdomain synergy as a critical determinant for substrate selection. Our results strongly suggest that distinct domains at both sides of UapA act as selective dynamic gates controlling substrate access to their translocation pathway.

 

Koussoulakou D, Margaritis LH, Koussoulakos S (2010). Antagonists of retinoic acid and BMP4 affect fetal mouse osteogenesis and odontoblast differentiation. Pathophysiology (Epub ahead of print).

Abstract: Retinoic acid and bone morphogenetic protein (BMP4) are endogenous factors indispensable for the physiological development of vertebrates. The proximate aim of the present study was to investigate whether the natural compound citral (a retinoic acid synthesis inhibitor) and a monoclonal, anti-BMP4 antibody, administered to pregnant mice affect in the fetuses cranial osteogenesis and odontoblast differentiation. The present investigation was motivated by the fact that, retinoic acid inhibitors and BMP4 neutralizers may frequently contact human tissues (both intentional and unintentional, and/or unconsciously) inducing unanticipated effects. Our ultimate goal is the prevention of side effects and, future clinical implementation of the results. To this end, pregnant, white mice (balb-c Mus musculus) were intra-abdominally injected with either citral or anti-BMP4 antibody at the 9th gestational day. Newborns were processed within 5h, postnatal. Results were evaluated (a) macroscopically, (b) stereoscopically, following histochemical double staining of cartilage and osseous tissues and, (c) microscopically after (c(1)) histological staining of paraffin sections, and, (c(2)) immunohistochemical detection of apoptosis. Data indicate that in vivo administration of citral (biomimicking hypovitaminosis A) caused restriction/retardation of cranial chondrogenesis and osteogenesis. Apoptosis was not detected in teeth tissues. In vivo administration of anti-BMP4 antibody resulted in a transitory interference with the normal course of odontoblast differentiation and the production of pre-dentin, whereas, delay in the ossification also included the alveoli. Animals inspected in adulthood displayed a fairly normal phenotype. It is concluded that those two substances, under their concentrations experienced, are quite safe for the public.

 

Kyriakou, E., Zouros, E. and Rodakis, G. C. (2010). The atypical presence of the paternal mitochondrial DNA in somatic tissues of male and female individuals of the blue mussel species Mytilus galloprovincialis. BMC Res. Notes 3: 222.

Abstract: BACKGROUND: In animals mtDNA inheritance is maternal except in certain molluscan bivalve species which have a paternally inherited mitochondrial genome (genome M) along with the standard maternal one (genome F). Normally, the paternal genome occurs in the male gonad, but it can be often found, as a minority, in somatic tissues of males and females. This may happen in two ways. One is through "sperm mtDNA leakage" into somatic tissues, a deviation from the normal situation in which the sperm mtDNA vanishes in females or ends up exclusively in the germ line of males. The other is through "egg heteroplasmy", when the egg contains, in small quantities, the paternal genome in addition to maternal genome. FINDINGS: To test the two hypotheses, we compared the sequences of one of the most variable domains of the M molecule in a somatic tissue (foot) and in the sperm of ten male and in the foot of ten female individuals of M. galloprovincialis. Presence of the M genome was rarer in the foot of females than males. The M genome in the sperm and in the foot of males was identical. CONCLUSIONS: Given that the surveyed region differs from individual to individual, the identity of the M genome in the foot and the sperm of males supports strongly the hypothesis that, at least for the tissue examined, the presence of the M genome is due to sperm mtDNA leakage.

 

Lecanidou R, Papantonis A (2010). Modeling bidirectional transcription using silkmoth chorion gene promoters. Organogenesis 6: 14-18.

Abstract: Bidirectional transcription is an interesting feature of eukaryotic genomes; yet not all aspects of its mechanism are understood. Silkmoth choriogenesis is a model system for studying transcriptional regulation at the initiation level. As chorion genes comprise a large group of divergently transcribed gene pairs, we are presented with the possibility of investigating the intricacies of bidirectional transcription. Τheir well characterized 5’ regulatory regions and expression profiles lay the foundation for investigating protein:protein and protein:DNA interactions, and RNA polymerase function during oocyte development. In this article we summarize current knowledge on chorion gene regulation and propose an approach to modeling bidirectional transcription using chorion promoters.

 

Lecanidou R, Papantonis A (2010). Silkmoth chorion gene regulation revisited: promoter architecture as a key player. Insect Molecular Biology 19: 141-151

Abstract: Regulation of silkmoth chorion genes has long been used as a model system for studying differential gene expression. The large numbers of genes, their overlapping expression patterns and the overall complexity of the system hinted towards an elaborate mechanism for transcriptional control. Recent studies, however, offer evidence of a molecular pathway governed by the interplay between two general transcription factors, CCAAT enhancer binding proteins (C/EBP) and GATA, an architectural protein, high mobility group A and a chromatin remodeller, chromo-helicase/ATPase-DNA binding protein 1. In this review we present a parsimonious model that adequately describes regulation of transcription across all temporally regulated chorion genes, and propose a role for promoter architecture.

 

Leung J, Karachaliou M, Alves C, Diallinas G, Byrne B (2010). Expression and purification of a functional uric acid-xanthine transporter (UapA) Protein Expr Purif. 72(1):139-46.

Abstract: The Nucleobase-Ascorbate Transporters (NATs) family includes carriers with fundamental functions in uptake of key cellular metabolites, such as uric acid or vitamin C. The best studied example of a NAT transporter is the uric acid-xanthine permease (UapA) from the model ascomycete Aspergillus nidulans. Detailed genetic and biochemical analyses have revealed much about the mechanism of action of this protein; however, the difficulties associated with handling eukaryotic membrane proteins have limited efforts to elucidate the precise structure-function relationships of UapA by structural analysis. In this manuscript, we describe the heterologous overexpression of functional UapA as a fusion with GFP in different strains of Saccharomyces cerevisiae. The UapA-GFP construct expressed to 2.3 mg/L in a pep4Delta deletion strain lacking a key vacuolar endopeptidase and 3.8 mg/L in an npi1-1 mutant strain with defective Rsp5 ubiquitin ligase activity. Epifluorescence microscopy revealed that the UapA-GFP was predominately localized to the plasma membrane in both strains, although a higher intensity of fluorescence was observed for the npi1-1 mutant strain plasma membrane. In agreement with these observations, the npi1-1 mutant strain demonstrated a approximately 5-fold increase in uptake of [(3)H]-xanthine compared to the pep4Delta deletion strain. Despite yielding the best results for functional expression, in-gel fluorescence of the UapA-GFP expressed in the npi1-1 mutant strain revealed that the protein was subject to significant proteolytic degradation. Large scale expression of the protein using the pep4Delta deletion strain followed by purification produced mg quantities of pure, monodispersed protein suitable for further structural and functional studies. In addition, this work has generated a yeast cell based system for performing reverse genetics and other targeted approaches, in order to further understand the mechanism of action of this important model protein.

 

Lhullier C, Falkenberg M, Ioannou E, Quesada A, Papazafiri P, Horta P, Schenkel E, Vagias C, Roussis V (2010). Cytotoxic Halogenated Metabolites from the Brazilian Red Alga Laurencia catarinensis. J Nat Prod. 73 (1): 27–32 - doi: 10.1021/np900627r

Abstract: Seven new (1−7) and seven previously reported (8−14) halogenated metabolites were isolated from the organic extract of the Brazilian red alga Laurencia catarinensis. The structure elucidation and the assignment of the relative configurations of the new natural products were based on detailed NMR and MS spectroscopic analyses, whereas the structure of metabolite 6 was confirmed by single-crystal X-ray diffraction analysis. The absolute configuration of metabolite 1 was determined using the modified Mosher’s method. The in vitro cytotoxicity of compounds 1−14 was evaluated against HT29, MCF7, and A431 cell lines.

 

Litridis I, Kapnoulas N, Natisvili T, Agiannitopoulos K, Peraki O, Ntostis P, Lamnissou K (2010). A polymorphism in the CYP17 gene and recurrent spontaneous abortions. Archives of Gynaecology and Obstetric [Epub ahead of print].

Abstract: Purpose: The CYP17 gene encodes the enzyme cytochrome P450c17α, which functions at key steps in the synthesis process of human sex steroid hormones. A T/C polymorphism in the 5′ promoter region of the CYP17 gene has been described previously. Serum levels of androgens and estrogens have been shown to be elevated in individuals who carry the C substitution (Α2 allele). We hypothesized that variability in genes that control the sex hormone (estrogens, testosterone) biosynthesis might affect the pregnancy outcome. In the present study, we investigated the possible association between the T/C polymorphism of the promoter of CYP17 gene and the risk of recurrent spontaneous abortions in the Greek population. Methods: In the prospective case-control study, 148 patients and 134 healthy controls were studied. Women who had at least three unexplained spontaneous abortions before 20 weeks of gestation were included in the patient group. The PCR–RFLP method was used to genotype the subjects. Results: The frequencies of A1A1, A1A2, A2A2 genotypes were 0.34, 0.52, 0.14, respectively, in the patient group and 0.32, 0.47, 0.21, respectively, in the control group. The allele frequencies were 0.595 and 0.405 for A1 and A2, in the patient group and 0.555 and 0.445 for A1 and A2, respectively, in the control group. The data between the two groups were analyzed by χ2 test. Our results showed that there are no significant differences in genotype (P = 0.3883) or in allele frequencies (P = 0.3800) between the patient and the control group. Conclusion: The T/C promoter polymorphism of the CYP17 gene is not associated with the risk for recurrent spontaneous abortions in our Caucasian population.

 

Lymperopoulou DS, Kormas KA, Moustaka-Gouni M, Karagouni AD (2010). Diversity of cyanobacterial phylotypes in a Mediterranean drinking water reservoir (Marathonas, Greece). Environmental Monitoring and Assessment (in press).

Abstract: The structure of the cyanobacterial community in a large drinking water reservoir (Marathonas, Greece) was investigated in October 2007 and September 2008. Cyanobacteria-specific primers were used for the PCR amplification of cyanobacterial 16S rDNAs from three water column sites and the water collection tank. In total, 199 clones were sequenced representing 52 unique cyanobacterial, including chloroplast-related, and 11 non-cyanobacterial phylotypes. All cyanobacterial phylotypes belonged to the order Chroococcales. Cluster analysis showed that the cyanobacterial communities in 2007 in the three water column sites showed high similarity between the stations and low diversity (H = 1.17 - 1.44), due to the occurring common phylotypes, while all sites in 2008 had very low similarities between them and higher diversity (H = 1.56 - 2.40). Some of the most abundant phylotypes were closely related (>98%) to members of the genus Gloeocapsa and a potentially toxin-producing strain of Microcystis aeruginosa. The non-cyanobacterial phylotypes were either unaffiliated or belonged to the Verrucomicrobia, and were related with sequences originating from lake water habitats.

 

Malagoli D, Abdalla FC, Cao Y, Feng Q, Fujisaki K, Gregorc A, Matsuo T, Nezis IP, Papassideri IS, Sass M, da Silva-Zacarin EM, Tettamanti G, Umemiya-Shirafuji R (2010). Autophagy and its physiological relevance in arthropods: current knowledge and perspectives. Autophagy 6(5):575-588.

Abstract: The autophagic process is one of the best examples of a conserved mechanism of survival in eukaryotes. At the molecular level there are impressive similarities between unicellular and multicellular organisms, but there is increasing evidence that the same process may be used for different ends, i.e., survival or death, at least at the cellular level. Arthropods encompass a wide variety of invertebrates such as insects, crustaceans and spiders, and thus represent the taxon in which most of the investigations on autophagy in nonmammalian models are performed. The present review is focused on the genetic basis and the physiological meaning of the autophagic process in key models of arthropods. The involvement of autophagy in programmed cell death, especially during oogenesis and development, is also discussed.

 

Mavridis K, Avgeris M, Koutalellis G, Stravodimos K, Scorilas A. (2010). Expression analysis and study of the KLK15 mRNA splice variants in prostate cancer and benign prostatic hyperplasia. Cancer Sci. 101: 693–699.

Abstract: Prostate cancer is the most commonly diagnosed malignancy in male populations in the Western world. The KLK15 gene, the newest member of the kallikrein family, is expressed in the prostate gland. The purpose of this study is the expression analysis and the clinical evaluation of the KLK15 mRNA spliced variants in prostate cancer (CaP) and benign prostatic hyperplasia (BPH) patients. Total RNA was isolated from 104 CaP and BPH tissue specimens. After testing the quality of the RNA, cDNA was produced by reverse transcription, and PCR was performed for the amplification of the KLK15 mRNA transcripts. GAPDH and HPRT genes were used as endogenous controls Our data revealed that mRNA spliced variants of KLK15 were differentially expressed in prostate tissue specimens. Analysis of data showed a statistically significant (P < 0.001) increase in the frequency of overexpression of KLK15 transcripts encoding for both the active isoform and for the isoform 3 in CaP compared to BPH samples. Furthermore, KLK15 transcripts were found to be highly expressed in more aggressive tumors (P = 0.017). These results suggest that KLK15 expression analysis could be employed as a valuable tool for the discrimination between BPH and CaP tissue specimens and as an unfavorable prognostic marker for prostate cancer.

 

Mavridis K, Talieri M, Scorilas A (2010). KLK5 gene expression is severely upregulated in androgen independent prostate cancer cells after treatment with the chemotherapeutic agents docetaxel and mitoxantrone. Biol Chem. 391 (4).

Abstract: Kallikrein-related peptidases (KLKs), including KLK5, have been proposed as promising biomarkers for prostate cancer diagnosis and prognosis. In the present study, we report that distinct augmentations (up to 6.4-fold) of KLK5 mRNA expressional levels, calculated via quantitative real-time PCR, occur after treatment of DU145 cells with appropriate concentrations, determined by the MTT method, of docetaxel and mitoxantrone. Our data reveal the endogenous need of prostate cancer cells for modified KLK5 expression to cope with the administration of chemotherapeutic drugs. Furthermore, it is proposed that the expression profile of KLK5 could serve as a putative biomarker for monitoring the treatment response in hormone refractory prostate cancer patients.

 

Meintanis C, Chalkou KI, Kormas KA, Lymperopoulou DS, Katsifas EA, Karagouni AD (2010). The use of trpB gene in resolving phylogenetic diversity within the group of Streptomyces. Current Trends in Microbiology (in press).

Abstract: In the present work, we investigated the ability of trpB gene, which encodes a primary metabolism enzyme involved in the tryptophan synthesis, to be used as an alternative to 16S rRNA for sequence similarity analysis in the actinobacteria group. trpB DNAs (504 bp) were amplified from 13 Actinobacteria type strains, in addition to 24 environmental streptomycete isolates with different BOX-PCR profiles. The sequences and the phylogenetic tree of trpB were compared to those obtained from 16S rRNA gene analysis, for the total of the examined bacteria. The results demonstrated between 93 – 100 % (16S rRNA) and 86 – 100 % (trpB) similarity among the examined bacteria of the genus Streptomyces and suggested that trpB sequence similarity analysis allows a more accurate discrimination of the species within Streptomyces genus than the more commonly used 16S rRNA. Furthermore, DGGE analysis was also applied in habitats which exhibit a high degree of streptomycete diversity. The biodiversity patterns produced led to similar estimation of diversity, whether using 16S Actinobacteria group specific primers or the trpB novel primers. In conclusion, our study suggested that trpB sequence similarity analysis is a powerful tool for discrimination between species within the ecologically and industrially important strains of Streptomyces genus.

 

Mountrakis C, Georgaki S, Manolis SK (2010). A Trephined Late Bronze Age Skull from Peloponnesus, Greece. Mediterranean Archaeology  and Archaeometry (accepted).

 

Mountrakis, C., Eliopoulos, C., Koilias C.G., and S.K. Manolis (2010) Sex Determination by using the metric analysis of the metatarsals in the Athens Collection. Forensic Science International. Vol. 200, Iss. 1-3, 178.e1-178.e7

Abstract: The determination of sex in skeletal remains performed by forensic anthropologists or bioarchaeologists typically relies on the analysis of quantitative and qualitative characteristics of the skeleton. In this regard, the most widely used features belong to the pelvic and cranial areas, but these are often not available in forensic or archaeological contexts. The objective of this study is to determine the extent of dimorphism exhibited by the metatarsal bones in order to examine their utility in the metric determination of sex in skeletal remains of Greek origin. A further objective is the development of linear discriminant function equations for sex determination based on the metatarsals from a contemporary Greek population. The skeletal sample used in this study is comprised of 1595 metatarsals (left and right), corresponding to 186 adult individuals (97 males, 89 females) and belongs to the documented collection of the University of Athens. The results suggest that metatarsal bones exhibit significant sexual dimorphism and the accuracy of the discriminant function equations for sex determination range from 80.7% to 90.1% (or 77.9–86.4% cross-validated). Thus, metatarsal bones may be used for sex determination in skeletal remains from Greece in addition to other sexing techniques.

 

Panagopoulos DJ, Chavdoula ED, Margaritis LH. (2010) Bioeffects of mobile telephony radiation in relation to its intensity or distance from the antenna. Int J Radiat Biol. 86(5):345-57.

Abstract: PURPOSE: To examine the bioactivity of GSM 900 and 1800 (Global System for Mobile Telecommunications) radiations, in relation to the distance from the antenna or to the radiation-field intensities. MATERIALS AND METHODS: Drosophila melanogaster adult insects were exposed to the radiation of a GSM 900/1800 mobile phone antenna at different distances ranging from 0 to 100 cm, and the effect on their reproductive capacity and cell death induction in the gonads by the use of TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) assay, was studied. RESULTS: These radiations/fields decreased the reproductive capacity by cell death induction, at all the different distances tested. The effect diminished with the distance/decreasing intensities. An increased bioactivity 'window' was revealed at distances of 20-30 cm from the mobile phone antenna, (radiation intensity around 10 microW/cm(2)) where the effect became highest, in relation to smaller or longer distances. The effect diminished considerably for distances longer than 40-50 cm and became not evident for distances longer than 1 m or radiation intensities smaller than 1 microW/cm(2). CONCLUSIONS: GSM bioactivity is highest for intensities down to less than 10 microW/cm(2) and still evident until 1 microW/cm(2) exhibiting 'window' effects.

 

Panagopoulos DJ, Margaritis LH. (2010). The effect of exposure duration on the biological activity of mobile telephony radiation. Mutat Res. 699(1-2):17-22.

Abstract: In the present experiments we studied the effects of different durations of a single (continuous), daily exposure, ranging from 1 min up to 21 min, to the two established systems of digital mobile telephony radiation that are commonly used in Europe, viz. GSM 900 MHz (Global System for Mobile telecommunications) and DCS 1800 MHz (Digital Cellular System-referred to also as GSM 1800 MHz), on a well-tested biological model, the reproductive capacity of the insect Drosophila melanogaster. The insects were exposed to each type of radiation at an intensity of about 10 microW/cm(2), corresponding to a distance of 20 or 30 cm from the antenna of a DCS 1800 or a GSM 900 mobile phone handset, respectively. At these distances the bioactivity of mobile telephony radiation was found to be at a maximum due to the existence of a "window" of increased bioactivity around this value, as we have shown recently [1-4]. The results show that the reproductive capacity decreases almost linearly with increasing exposure duration to both GSM 900 and DCS 1800 radiation, suggesting that short-term exposures to these radiations have cumulative effects on living organisms. Additionally, our results show again that GSM 900 MHz radiation is slightly more bioactive than DCS 1800 MHz radiation, at the same exposure durations and under equal radiation intensities, as shown in our previous experiments [5].

 

Panagopoulos DJ, Margaritis LH. (2010). The identification of an intensity 'window' on the bioeffects of mobile telephony radiation. Int J Radiat Biol. 86(5):358-66.

Abstract: PURPOSE: The increased bioactivity 'windows' of GSM 900 and 1800 MHz radiations, (Global System for Mobile telecommunications) revealed recently by us and published in this issue, manifesting themselves as a maximum decrease in the reproductive capacity of the insect Drosophila melanogaster, were examined to discover whether they depend on the intensity of radiation-fields. METHODS: In each experiment, one group of insects were exposed to the GSM 900 or 1800 radiation at 30 or 20 cm distances, respectively, from the antenna of a mobile phone, where the bioactivity 'window' appears for each type of radiation and another group was exposed at 8 or 5 cm, respectively, behind a metal grid, shielding both microwave radiation and the extremely low frequency (ELF) electric and magnetic fields for both types of radiation in a way that radiation and field intensities were roughly equal between the two groups. Then the effect on reproductive capacity was compared between groups for each type of radiation. RESULTS: The decrease in the reproductive capacity did not differ significantly between the two groups. CONCLUSIONS: The bioactivity window seems to be due to the intensity of radiation-field (10 microW/cm(2), 0.6-0.7 V/m) at 30 or 20 cm from the GSM 900 or 1800 mobile phone antenna, respectively.

 

Pantazi.A, Tzonis P, Perros G, Graphou O, Keramitsoglou T, Koussoulakos S, Margaritis LH, Varla-Leftherioti M (2010). Comparative analysis of peripheral Natural Killer (NK) cells in the two phases of the ovarian cycle. Am J Reprod Immunol 63: 46-53.

Abstract: Problem: Changes in endometrial Natural Killer (NK) cells during the luteal phase of the ovarian cycle are important in initiating/maintaining a subsequent pregnancy. In the present study it was investigated whether during the menstrual cycle changes occur also in peripheral blood (PB) NKs. Method of study: Blood samples during the follicular and the luteal phase were collected from 30 women without fertility problems. Samples were analyzed by flow-cytometry for: (1) NK cells (CD3CD16+CD56+) and (2) intracellular production of interferon-γ (IFN-γ) by NK cells. For the comparison and correlation of the two populations between the two phases, Wilcoxon signed-rank test and Spearman's Coefficient were used. Results: The differences in percentages of CD3CD16+CD56+ cells and that of CD3CD16+CD56+/IFN-γ+ cells between the follicular and the luteal phase were not statistically significant (10.61 ± 5.11 versus 9.76 ± 4.57 and 6.48 ± 7.90 versus 7.30 ± 6.77, respectively, P > 0.05). The correlation between the two variables (NK% and NK/IFN-γ%) was weakly positive (P = 0.07) only in the follicular phase. Conclusion: The study did not reveal menstrual cycle-depended changes in PB NK cells. Thus, a suggestion to measure these cells in a specific phase of the cycle in order to predict the outcome of a subsequent pregnancy in women with fertility problems is objected.

 

Papanastasis VP, Arianoutsou M, Papanastasis K, Environmental conservation in classical Greece. Journal of Biological Research (accepted).

 

Papandreou, NC, Iconomidou, VA, Willis, JH, Hamodrakas, SJ (2010). A possible structural model of members of the CPF family of cuticular proteins implicating binding to components other than chitin. J Insect Physiol., 56(10), 1420-1426

Abstract: The physical properties of cuticle are determined by the structure of its two major components, cuticular proteins (CPs) and chitin, and, also, by their interactions. A common consensus region (extended R&R Consensus) found in the majority of cuticular proteins, the CPRs, binds to chitin. Previous work established that beta-pleated sheet predominates in the Consensus region and we proposed that it is responsible for the formation of helicoidal cuticle. Remote sequence similarity between CPRs and a lipocalin, bovine plasma retinol binding protein (RBP), led us to suggest an antiparallel beta-sheet half-barrel structure as the basic folding motif of the R&R Consensus. There are several other families of cuticular proteins. One of the best defined is CPF. Its four members in Anopheles gambiae are expressed during the early stages of either pharate pupal or pharate adult development, suggesting that the proteins contribute to the outer regions of the cuticle, the epi- and/or exo-cuticle. These proteins did not bind to chitin in the same assay used successfully for CPRs. Although CPFs are distinct in sequence from CPRs, the same lipocalin could also be used to derive homology models for one A. gambiae and one Drosophila melanogaster CPF. For the CPFs, the basic folding motif predicted is an eight-stranded, antiparallel beta-sheet, full-barrel structure. Possible implications of this structure are discussed and docking experiments were carried out with one possible Drosophila ligand, 7(Z),11(Z)-heptacosadiene.

 

Parmakelis A, Moustaka M, Poulakakis N, Louis C, Slotman MA, Marshall JC, Awono-Ambene PH, Antonio-Nkondjio C, Simard F, Caccone A, Powell JR (2010). Anopheles immune genes and amino acid sites evolving under the effect of positive selection. PLoS ONE 5(1):8885.

Abstract: Background: It has long been the goal of vector biology to generate genetic knowledge that can be used to “manipulate” natural populations of vectors to eliminate or lessen disease burden. While long in coming, progress towards reaching this goal has been made. Aiming to increase our understanding regarding the interactions between Plasmodium and the Anopheles immune genes, we investigated the patterns of genetic diversity of four anti-Plasmodium genes in the Anopheles gambiae complex of species. Methodology/Principal Findings: Within a comparative phylogenetic and population genetics framework, the evolutionary history of four innate immunity genes within the An. gambiae complex (including the two most important human malaria vectors, An. gambiae and An. arabiensis) is reconstructed. The effect of natural selection in shaping the genes' diversity is examined. Introgression and retention of ancestral polymorphisms are relatively rare at all loci. Despite the potential confounding effects of these processes, we could identify sites that exhibited dN/dS ratios greater than 1. Conclusions/Significance: In two of the studied genes, CLIPB14 and FBN8, several sites indicated evolution under positive selection, with CLIPB14 exhibiting the most consistent evidence. Considering only the sites that were consistently identified by all methods, two sites in CLIPB14 are adaptively driven. However, the analysis inferring the lineage -specific evolution of each gene was not in favor of any of the Anopheles lineages evolving under the constraints imposed by positive selection. Nevertheless, the loci and the specific amino acids that were identified as evolving under strong evolutionary pressure merit further investigation for their involvement in the Anopheles defense against microbes in general.

 

Paululat T, Kulik A, Hausmann H, Karagouni A.D, Zinecker H, Imhoff JF, Fiedler HP (2010). Grecocyclines, new Angucyclines from Streptomyces sp. Acta 1362. European Journal of Organic Chemistry 2244-2350.

Abstract: Two novel angucyclines were isolated from the streptomycete Acta 1362. The strain was of particular interest regarding the production of characteristic metabolites that were detected by HPLC-diode array profiling of the extracts. Grecocycline A and B were isolated and their structures were determined. Grecocycline A shows cytotoxic activity and grecocycline B inhibits protein tyrosine phosphatase 1B. Moreover, shunt product grecocyline C was isolated and its structure was determined.

 

Petroutsa E, Manolis SK (2010). Reconstructing late Bronze Age Diet in mainland Greece using stable isotope analysis. Journal of Archaeological Science 37: 614–620.

Abstract: The Late Bronze Age is a period of great importance in prehistoric Greece, due to the rise of the Mycenaean and Minoan civilizations. Settlements, palatial complexes and cemeteries have been excavated whilst a plethora of findings among which wall paintings and artifacts provided a large amount of information regarding the period. In this paper we examine the sources of dietary protein of four populations, from mainland Greece, in light of documentary and archaeological evidence in an effort to identify dietary trends within and between groups that reflect everyday behavior. These are being studied with the aid of biomolecular archaeology using stable isotope analysis in human and faunal remains. Isotopic data to date suggests a rather homogeneous diet mainly based on C3 plant and animal protein. There are no individuals with δ13C and δ15N values that could represent important marine protein intake, despite proximity to the Aegean Sea.

 

Petza D, Katsanevakis S, Lykouri N, Spiliotis V, Verriopoulos G (2010). Investigation of the potential effect of diet, body mass and maturity on growth and feed performance of common octopus Octopus vulgaris: an information theory approach. Aquaculture Nutrition (in press).

Abstract: The potential effect of body mass (m), maturity stage (ms), food type (ft), food protein (p) and lipid (li) content, and food protein-to-energy ratio, P/E (pe) on Specific Growth Rate (SGR, % day[minus]1), Absolute Feeding Rate (AFR, g day[minus]1), Feed Efficiency (FE, %), Assimilation Efficiency (AE, %), and Protein Retention Efficiency (PRE, %) in the common octopus was investigated. Six food types were provided ad libitum: shrimp, squid, hake, mussel, sardine and artificial one (gels made of hydrated squid flour agglutinated with sodium alginate). Estimated SGRs, AFRs, FEs, AEs and PREs were modelled with General Linear Models based on an information theory approach, using m, ms, ft, p, li and pe as potential predictor variables. SGR decreased when m increased; octopuses fed on shrimps showed the highest SGRs and the ones fed on mussels showed the lowest SGRs. AFR increased with m. Maximum and minimum FEs were observed, when food provided was shrimps and mussels, respectively. Maximum PRE was performed by octopuses fed on shrimps or sardines and minimum PRE by octopuses fed on mussels. Octopuses fed on artificial diet reached satisfactory levels of SGR (0.50% day[minus]1) and FE (12.3%).

 

Polymeni R, SpanakisE, Argiropoulos A, Rhizopoulou S (2010). Aspects on the relief of living surfaces using atomic force microscopy allow “art” to imitate nature. Integrative Zoology 5: 218-225.

Abstract: The visualization of the surface of biological samples using an atomic force microscope reveals features of the external relief and can resolve very fine and detailed features of the surface. We examined specimens from the skin of the amphibians Salamandra salamandra, Lyciasalamandra luschani basoglui and Mesotriton alpestris, and from the surface of pollen grains of the plant species Cyclamen graecum and Cistus salviifolius, which exhibit certain interesting features, imaged at the nanoscale level. It is likely that the relief influences the attributes of the interfaces between the tissues and the environment. We found that the microsculpture increases in size the surface of the examined tissues and this may be particularly important for their performance in the field. Microsculpturing of amphibians’ skin may affect water regulation, dehydration and rehydration, and cutaneous gas exchange. While, pollen grain relief may affect the firmness of the contact between pollen surface and water droplets. High resolution imaging of the external relief showed that roughening may induce wetting and influence the water status of the specimens. Also, roughness affects the radius of water droplets retained in between the projections of the external relief. Roughness of the tissues was highly correlated with their vertical distance; while, surface distances were highly correlated with horizontal distances. By enabling a more detailed characterization of the external sculptures, via sophisticated techniques, a more comprehensive examination of the samples indicates similarities among different living tissues, originated from different kingdoms, which can be attributed to environmental conditions and physiological circumstances.

 

Porichi O, Nikolaidou ME, Apostolaki A, Arnogiannaki N, Papassideri I, Chatonidis I, Tserkezoglou A, Vorgias G, Kassanos D, Panotopoulou E. (2010). Isomorph expression of BAG-1 gene, ER and PR in endometrial cancer. Anticancer Res. 30(10):4103-8.

Abstract: BACKGROUND: BAG-1 isomorphs are regulating proteins with antiapoptotic action in endometrium. ERa and PRA isomorphs seem to have an important role in endometrial cancer. PATIENTS AND METHODS: We investigated the expression of BAG-1, ERa and PRA isomorphs in endometrioid adenocarcinoma and we correlated them with clinicopathological findings of the tumor. Fresh endometrial tissues were obtained from 33 patients with endometrial carcinoma and 191 paraffin-embedded tissues were analyzed by real-time PCR and immunochemistry for BAG-1, ER and PR. RESULTS: BAG-1 protein is expressed in both nucleus and cytoplasm. Grade 3 tumors were considered to have the highest intensity. Only 4 out of 79 samples showed intense expression of ERa, while 37 samples out of 72 samples strongly expressed PRA. CONCLUSION: BAG-1 nuclear isomorph appeared more frequently in grade 2 tumors than in grade 1 and 3 tumors, and the cytoplasmatic isomorph was expressed more strongly than the nuclear one.

 

Radea C, Kazanis D, Arianoutsou M. (2010). Effects of Fire History Upon Soil Macroarthropod Communities in Pinus Halepensis Stands in Attica, Greece. Israel Journal of Ecology and Evolution, Vol. 56, No.2, 165-179.

Abstract: The composition of the soil macroarthropod community was studied in three forest stands which constitute a gradient of increased fire frequency. All stands were adjacent to each other, on the foothills of Mt. Penteli, Attica, Greece, and they shared similar physiography, climate, altitude, while their original pre-fire vegetation was a well-developed Pinus halepensis forest. The stands were severely burned by a large fire early in summer 1995. Two of them had been burned previously: the first in 1978 and the second in 1978 and 1987. Sampling was carried out during the 2nd year after the last fire event. Although the phenology of soil macroarthropods was not altered in frequently burned stands, the number of taxa collected, as well as their population size, was extremely low. Canonical Correspondence Analysis showed that fire frequency does not directly affect soil arthropod communities, but influences them through increased abundance of specific plant groups, i.e., phrygana vegetation and legumes. Seasonality of climate seemed to be another significant factor controlling the structure of macroarthropod communities in the stands studied.

 

Radea C, Louvrou I,  Pantazidou Α, Economou-Amilli Α (2010). Photosynthetic microorganisms as epibionts and euendoliths on biotic substrates in a thermal spring with ferric-iron deposits. Fottea 10(1) (in press).

Abstract: Rust–coloured shells of the aquatic gastropod Ventrosia ventrosa, a new record for eastern Greece, indicating presence of iron (EDAX analysis) were studied for detection of iron–encrusted photosynthetic epibionts in a Greek brackish–water thermal spring (38 °C). Microscopic analyses (LM, SEM) revealed the presence of a biofilm consisted of mostly facultative micro–epibionts, i.e. a) 5 periphytic taxa of coccal and filamentous cyanobacteria, including a taxonomically and ecologically interesting morphospecies, Xenococcus cf. pyriformis, dominated exclusively on the shell surface, and b) pennate diatoms with higher species richness (18 periphytic taxa of the genera Amphora, Brachysira, Cymbella, Diatoma, Encyonema, Navicula, Nitzschia, Pleurosigma, Synedra, Ulnaria; 5 taxa as new records for Greece), most of them emerging only after acid treatment of whole gastropod shells. The abundant diatoms thriving directly or nearby the iron–coatings (Cocconeis placentula var. euglypta and Achnanthes brevipes sensu lato) exhibited different modes of attachment (‘adnate’ and ‘pendunculate’, respectively). Two euendolithic cyanobacteria (Hyella sp. and Leptolyngbya terebrans; the former with special taxonomic interest) were also found perforating the delicate gastropod shells, with no distinct differentiation in the extent of infestation between live and dead gastropod shells. Moreover, the possible impact of these encrusted photosynthetic assemblages on V. ventrosa was investigated; statistical analysis showed that a) there is no ‘drag effect’, induced by the epibionts, influencing the gastropod growth (i.e. shell length), b) shell size enlargement provides a favourable space and promotes the intense fouling by both micro–epibionts and macro–epibionts (egg–capsules), and c) the detachment prevention of egg–capsules is attributed to the biofilm development.

 

Anna Runemark, Bengt Hansson, Panayiotis Pafilis, Efstratios D Valakosand Erik I Svensson (2010). Island biology and morphological divergence of the Skyros wall lizard Podarcis gaigeae: a combined role for local selection and genetic drift on color morph frequency divergence? BMC Evolutionary Biology 10:269

Abstract: Background: Patterns of spatial variation in discrete phenotypic traits can be used to draw inferences about theadaptive significance of traits and evolutionary processes, especially when compared to patterns of neutral geneticvariation. Population divergence in adaptive traits such as color morphs can be influenced by both local ecology and stochastic factors such as genetic drift or founder events. Here, we use quantitative color measurements of males and females of Skyros wall lizard, Podarcis gaigeae, to demonstrate that this species is polymorphic with respect to throat color, and the morphs form discrete phenotypic clusters with limited overlap between categories.We use divergence in throat color morph frequencies and compare that to neutral genetic variation to infer the evolutionary processes acting on islet- and mainland populations. Results: Geographically close islet- and mainland populations of the Skyros wall lizard exhibit strong divergence in throat color morph frequencies. Population variation in throat color morph frequencies between islets was higher than that between mainland populations, and the effective population sizes on the islets were small (Ne:s < 100). Population divergence (FST) for throat color morph frequencies fell within the neutral FST-distribution estimated from microsatellite markers, and genetic drift could thus not be rejected as an explanation for the pattern.Moreover, for both comparisons among mainland-mainland population pairs and between mainland-islet population pairs, morph frequency divergence was significantly correlated with neutral divergence, further pointing to some role for genetic drift in divergence also at the phenotypic level of throat color morphs. Conclusions: Genetic drift could not be rejected as an explanation for the pattern of population divergence in morph frequencies. In spite of an expected stabilising selection, throat color frequencies diverged in the islet populations. These results suggest that there is an interaction between selection and genetic drift causing divergence even at a phenotypic level in these small, subdivided populations.

 

Satagopam, V.P., Theodoropoulou, M.C., Stampolakis, C.K., Pavlopoulos, G.A., Papandreou, N.C., Bagos, P.G., Schneider, R., Hamodrakas, S.J. (2010) GPCRs, G-proteins, Effectors and their interactions: Human-gpDB, a database employing advanced visualization tools and data integration techniques. Database (Oxford), 2010.

Abtstract: G-protein coupled receptors (GPCRs) are a major family of membrane receptors in eukaryotic cells. They play a crucial role in the communication of a cell with the environment. Ligands bind to GPCRs on the outside of the cell, activating them by causing a conformational change, and allowing them to bind to G-proteins. Through their interaction with G-proteins, several effector molecules are activated leading to many kinds of cellular and physiological responses. The great importance of GPCRs and their corresponding signal transduction pathways is indicated by the fact that they take part in many diverse disease processes and that a large part of efforts towards drug development today is focused on them. We present Human-gpDB, a database which currently holds information about 713 human GPCRs, 36 human G-proteins and 99 human effectors. The collection of information about the interactions between these molecules was done manually and the current version of Human-gpDB holds information for about 1663 connections between GPCRs and G-proteins and 1618 connections between G-proteins and effectors. Major advantages of Human-gpDB are the integration of several external data sources and the support of advanced visualization techniques. Human-gpDB is a simple, yet a powerful tool for researchers in the life sciences field as it integrates an up-to-date, carefully curated collection of human GPCRs, G-proteins, effectors and their interactions. The database may be a reference guide for medical and pharmaceutical research, especially in the areas of understanding human diseases and chemical and drug discovery. Database URLs: schneider.embl.de/human_gpdb; bioinformatics.biol.uoa.gr/human_gpdb/

 

Tovey SC, Dedos SG, Rahman T, Taylor EJA, Pantazaka E, Taylor CW (2010). Regulation of IP3 receptors by cyclic AMP. J. Biol. Chem. 285: 12979-12989.

Abstract: In HEK cells stably expressing type 1 receptors for parathyroid hormone (PTH), PTH causes a sensitization of IP3 receptors (IP3R) to IP3 that is entirely mediated by cAMP and requires cAMP to pass directly from type 6 adenylyl cyclase (AC6) to IP3R2. Using DT40 cells expressing single subtypes of mammalian IP3R, we demonstrate that high concentrations of cAMP similarly sensitize all IP3R isoforms to IP3 by a mechanism that does not require cAMP-dependent protein kinase (PKA). IP3 binding to IP3R2 is unaffected by cAMP, and sensitization is not mediated by the site through which ATP potentiates responses to IP3. In single channel recordings from excised nuclear patches of cells expressing IP3R2, cAMP alone had no effect, but it increased the open probability of IP3R2 activated by a submaximal concentration of IP3 alone or in combination with a maximally effective concentration of ATP. These results establish that cAMP itself increases the sensitivity of all IP3R subtypes to IP3. For IP3R2, this sensitization results from cAMP binding to a novel site that increases the efficacy of IP3. Using stably expressed short-hairpin RNA to reduce expression of the G-protein, Gαs, we demonstrate that attenuation of AC activity by loss of Gαs more substantially reduces sensitization of IP3R by PTH than does comparable direct inhibition of AC. This suggests that Gαs may also specifically associate with each AC-IP3R complex. We conclude that all three subtypes of IP3R are regulated by cAMP independent of PKA. In HEK cells, where IP3R2 selectively associates with AC6, Gαs also associates with the AC-IP3R signaling junction.

 

Trougakos IP, Chondrogianni N, Amarantos I, Blake J, Schwager C, Wirkner U, Ansorge W, Gonos ES. (2010). Genome-wide transcriptome profile of the human osteosarcoma Sa OS and U-2 OS cell lines. Cancer Genet Cytogenet. 196(2):109-18.

Abstract: With the use of genome-wide cDNA microarrays, we investigated the transcriptome profile of the human osteosarcoma Sa OS and U-2 OS cell lines. In all, 1,098 chip entries were differentially regulated in the two cell lines; of these, 796 entries corresponded to characterized mRNAs. The identified genes are mostly expressed in epithelial tissues and localize on chromosomes 1, 10, and 20. Furthermore, signaling cascades for cell cycle, glycolysis, and gluconeogenesis, the p53 pathway, cell communication, and focal adhesion were found to be differently regulated in the two cell lines. The transcriptome profiles reported here provide novel information about the considerable molecular differences between these two widely used human osteosarcoma cell lines.

 

Tsachaki M, Ghiso J, Rostagno A, Efthimiopoulos S (2010). BRI2 homodimerizes with the involvement of intermolecular disulfide bonds. Neurobiol Aging 31: 88-98.

Abstract: Familial British and Familial Danish Dementia (FBD and FDD) are two dominantly inherited neurodegenerative diseases that present striking similarities with Alzheimer's disease. The genetic defects underlying those dementias are mutations in the gene that encodes for BRI2 protein. Cleavage of mutated BRI2 by furin releases the peptides ABri or ADan, which accumulate in the brains of patients. BRI2 normal function is yet unknown. To unwind aspects of its cellular role, we investigated the possibility that BRI2 forms dimers, based on structural elements of the protein, the GXXXG motif within its transmembrane domain and the odd number of cysteine residues. We found that BRI2 dimerizes in cells and that dimers are held via non-covalent interactions and via disulfide bridges between the cysteines at position 89. Additionally, we showed that BRI2 dimers are formed in the ER and appear at the cell surface. Finally, BRI2 dimers were found to exist in mouse brain. Revealing the physiological properties of BRI2 is critical in the elucidation of the deviations that lead to neurodegeneration.

 

Tsagkamilis P, Danielidis D, Dring MJ, Katsaros C (2010). Removal of phosphate from sewage effluents by Ulva lactuca L. (Chlorophyta).J. Appl. Phycol. 22:331–339 [DOI 10.1007/s10811-009-9463-4].

Abstract: In the present study, the use of seaweeds for phosphate absorption was examined as a tertiary treatment in sewage treatment plants, to improve the water quality and reduce eutrophication risks. The data came from both laboratory and field experiments that took place on Ios Island sewage treatment plant. Three different macroalgae were tested and Ulva lactuca was finally chosen thanks to its high survivability in low salinity waters. Since the main restrictive factor was low salinity, we initially established the ratio of seawater:effluent that combined satisfactory viability with maximum phosphate absorption. The biomass growth under these conditions was also examined. Based on the above results, we designed a continuous-flow system with a 1/4 volume per hour water turnover, in a mixture of 60% sewage effluent: 40% sea water and 30 g L-1 initial biomass of U. lactuca that must be renewed every 10 days. Under these conditions and time frame, the phosphate content of the effluent was reduced by about 50%.

 

Tsangaris C, Cotou E, Papathanassiou E, Nicolaidou A (2010) Assessment of contaminant impacts in a semi-enclosed estuary (Amvrakikos Gulf, NW Greece): Bioenergetics and biochemical biomarkers in mussels Envir. Monitor. Assess 161: 259-269.

Abstract: A combination of bioenergetics and biochemical biomarkers in mussels was applied to assess possible pollution impacts in a protected semi-enclosed estuary (Amvrakikos Gulf, NW Greece) that receives pesticide discharges through riverine transport. Scope for growth, a physiological condition index representing the energy budget of the organism, was applied to detect general stress effects on the health status of mussels. The low energy budgets of mussels revealed stress conditions and provided early warning signals of possible consequences at higher levels of biological organization. Biochemical markers of exposure confirmed a risk of pesticide contamination. Decreased acetylcholinesterase activities indicated exposure to organophosphate and carbamate pesticides. Responses of the antioxidant enzyme glutathione peroxidase suggested the presence of contaminants capable of reactive oxygen species production that could be related to organochlorine pesticide contamination in the area. On the other hand, metallothionein levels implied low metal contamination.

 

Tsaousis, G.N., Tsirigos, K.D., Andrianou, X.D., Liakopoulos, T.D., Bagos, P.G., Hamodrakas, S.J.(2010) ExTopoDB: A database of experimentally derived topological models of transmembrane proteins. Bioinformatics, 26(19): 2490–2492.

Abstract: ExTopoDB is a publicly accessible database of experimentally derived topological models of transmembrane proteins. It contains information collected from studies in the literature that report the use of biochemical methods for the determination of the topology of α-helical transmembrane proteins. Transmembrane protein topology is highly important in order to understand their function and ExTopoDB provides an up to date, complete and comprehensive dataset of experimentally determined topologies of α-helical transmembrane proteins. Topological information is combined with transmembrane topology prediction resulting in more reliable topological models. Availability: bioinformatics.biol.uoa.gr/ExTopoDB.

 

Tsiamis K, Montesanto B, Panayotidis P, Katsaros C, Verlaque M (2010). Updated records and range expansion of alien marine macrophytes in Greece. Mediterranean Marine Science (in press).

Abstract: In the present study the list of alien marine macrophytes already recorded on Greek coasts has been revised in the light of recent studies and new observations. In comparison to 2008, the total number consists of 32 taxa, and the classification as established, casual and debatable species has been modified, with a total of 14, 5 and 13 species respectively. An interesting increase in established species from 9 taxa in 2008 to 14 taxa in 2009 is noted. With 23 taxa listed, Rhodobionta is the best represented group, followed by Chlorobionta (4 taxa) and Chromobionta (4 taxa), while seagrasses (Streptobionta) are represented by only one species. Several new records, one new entry and two putative additions are considered here, while two other taxa previously assumed introduced are excluded from the list of aliens.

 

Tsiamis K., Montesanto B., Panayotidis P. & Katsaros C., (2010). Notes on new records of Ceramiales red algae from the Aegean Sea (Greece, Eastern Mediterranean). Cryptogamie, Algologie (submitted).

 

Tsiamis K., Verlaque M., Panayotidis P. & Montesanto B., (2010). New macroalgal records for the Aegean Sea (Greece, Eastern Mediterranean). Botanica Marina (submitted).

 

Tsirigos, K.D., Bagos, P.G. and Hamodrakas, S.J. (2010) OMPdb: A database of ?-barrel outer membrane proteins from Gram negative bacteria. Nucleic Acids Res., [Epub ahead of print].

 

Tsopelas P, Slippers B, Gonou-Zagou Z, Wingfield MJ (2010). First report of Diplodia corticola in Greece on kermes oak (Quercus coccifera). Plant Pathology (in press) (IF: 2.152) [DOI: 10.1111/j.1365-3059.2009.02244.x]

 

Varkitzi I, Pagou K, Granéli E, Hatzianestis I, Pyrgaki C, Pavlidou A, Montesanto B, Εconomou-Amilli A (2010). Unbalanced N:P ratios and nutrient stress controlling growth and toxin production of the harmful dinoflagellate Prorocentrum lima (Ehrenberg) Dodge. Harmful Algae, 9: 304-311.

Abstract: The responses of the benthic marine dinoflagellate Prorocentrum lima to nutrient stress induced by unbalanced N:P ratios were the subject of this study. Batch cultures of P. lima cells were grown under NP sufficient (N as nitrate and ammonium) and deficient conditions, and the cell growth and toxicity were followed for eight weeks. P. lima grew slowly in all nutrient conditions and net growth rates ranged from 0.11 to 0.22 divisions day-1. Phosphorus (P) was taken up with high uptake rates in all treatments until the end of exponential phase and reached limitation in the P deficient cultures. Nitrogen (N) did not reach limitation in any treatment. In the cultures with nitrate as exclusive N source, uptake rates of nitrate remained high after the exponential phase, suggesting that P. lima cells continued to accumulate N under surplus N availability. Nitrate was slowly consumed and therefore maintained cell growth, as documented by a prolonged exponential phase and an algal biomass increasing at low rates still after seven weeks of incubation. In the cultures with ammonium as exclusive N source, ammonium was taken up with the highest N uptake rates until the end of exponential phase. However, high initial concentrations of ammonium proved to be toxic to P. lima cells, demonstrating growth inhibition with the lowest algal biomass and okadaic acid (OA) production among treatments. The OA production increased after the exponential phase in all nutrient conditions when cell growth slowed down, suggesting that OA production was regulated by growth limitation. The highest OA cellular content (11.27 ± 3.30 pg OA cell-1) was found in the P deficient cultures, where P decreased to limitation after the exponential phase (P < 0.1 μM). We argue that the severely low P concentrations slowed down the growth rate so as to allow for a higher accumulation of OA in the P. lima cells that continued to produce OA at the same rate.

 

Vervust B, Pafilis P, Valakos ED, Grbac I, Van Damme R (2010) Anatomical and physiological changes associated with a recent dietary shift in the lizard Podarcis sicula. Physiological and Biochemical Zoology 83(4):632-42.

Abstract: Dietary shifts have played a major role in the evolution of many vertebrates. The idea that the evolution of herbivory is physiologically constrained in squamates is challenged by a number of observations that suggest that at least some lizards can overcome the putative physiological difficulties of herbivory on evolutionary and even ecological timescales. We compared a number of morphological and physiological traits purportedly associated with plant consumption between two island populations of the lacertid lizard Podarcis sicula. Previous studies revealed considerable differences in the amount of plant material consumed between those populations. We continued the investigation of this study system and explored the degree of divergence in morphology (dentition, gut morphology), digestive performance (gut passage time, digestive efficiency), and ecology (endosymbiont density). In addition, we also performed a preliminary analysis of the plasticity of some of these modifications. Our results confirm and expand earlier findings concerning divergence in the morphology of feeding structures between two island populations of P. sicula lizards. In addition to the differences in skull dimensions and the prevalence of cecal valves previously reported, these two recently diverged populations also differ in aspects of their dentition (teeth width) and the lengths of the stomach and small intestine. The plasticity experiment suggests that at least some of the changes associated with a dietary shift toward a higher proportion of plant material may be plastic. Our results also show that these morphological changes effectively translate into differences in digestive performance: the population with the longer digestive tract exhibits longer gut passage time and improved digestive efficiency.

 

Vilà M., Basnou C., Pyšek P., Josefsson M., Genovesi P., Gollasch S., Nentwig W., Olenin S., Roques A., Roy D., Hulme P.E., Adriopoulos P., Arianoutsou M., Augustin S., Baccetti N., Bacher S., Bacon J., Bazos I., Bolshagin P., Bretagnolle F., Chiron F., Clergeau P., Cochard P.O., Cocquempot C., Coeur d’Acier A., Cooper J., Daunys D., David M., Delipetrou P., Didžiulis V., Dorkeld F., Essl F., Galil B., Gasquez J., Georghiou K., Gudžinskas Z., Hatzofe O., Hejda M., Hill M., Jarošík V., Kark S., Klotz S., Kobelt M., Kokkoris Y., Kotarac M., Kühn I., Lambdon P., Lange E., Lopez-Vaamonde C., Loustau M.-L., Marcer A., Martinez M., McLoughlin M., Migeon A., Minchin D., Navajas M., Navajas P., Olenina I., Ostler R., Ovcharenko I., Panov V.E., Papacharalambous E., Pascal M., Pergl J., Perglová I., Phillipov A., Pino J., Poboljsaj K., Rabitsch W., Rasplus J.-Y., Rodionova N., Roy H., Sauvard D., Scalera R., Schwartz A., Sedláček O., Shirley S., Trocchi V., Winter M., Yart A., Yiannitsaros A., Zagatti P., Zikos A. (2010).. How well do we understand the impacts of alien species on ecosystem services? A pan-European, cross-taxa assessment. Frontiers in Ecology and Evolution 3(8):135-144 [doi:10.1890/080083]

Abstract: Recent comprehensive data provided through the DAISIE project (www.europe-aliens.org) have facilitated the development of the first pan-European assessment of the impacts of alien plants, vertebrates, and invertebrates – in terrestrial, freshwater, and marine environments – on ecosystem services. There are 1094 species with documented ecological impacts and 1347 with economic impacts. The two taxonomic groups with the most species causing impacts are terrestrial invertebrates and terrestrial plants. The North Sea is the maritime region that suffers the most impacts. Across taxa and regions, ecological and economic impacts are highly correlated. Terrestrial invertebrates create greater economic impacts than ecological impacts, while the reverse is true for terrestrial plants. Alien species from all taxonomic groups affect “supporting”, “provisioning”, “regulating”, and “cultural” services and interfere with human well-being. Terrestrial vertebrates are responsible for the greatest range of impacts, and these are widely distributed across Europe. Here, we present a review of the financial costs, as the first step toward calculating an estimate of the economic consequences of alien species in Europe.

 

Zhong B, Sallman DA, Gilvary DL, Pernazza D, Sahakian E, Fritz D, Cheng JQ, Trougakos I, Wei S, Djeu JY. (2010). Induction of clusterin by AKT--role in cytoprotection against docetaxel in prostate tumor cells. Mol Cancer Ther. 9(6):1831-41. Epub 2010 May 25.

Abstract: Clusterin (CLU), in its cytoplasmic form, is abundant in many advanced cancers and has been established to be cytoprotective against chemotherapeutic agents including docetaxel. However, little is known of the mechanism of its induction. Here, we provide evidence that AKT plays a critical role in upregulating cytoplasmic/secretory sCLU, which is responsible for docetaxel resistance. Western blot analysis indicated that docetaxel-resistant sublines derived from DU145 and PC3 prostate tumor cell lines displayed a markedly increased phospho-AKT level closely accompanied by heightened sCLU expression when compared with parental cells. To examine if AKT has a role in sCLU expression, AKT blockade was done by treatment with a specific inhibitor, API-2, or dominant-negative AKT transduction before analysis of sCLU gene expression. Loss of AKT function resulted in loss of sCLU and was accompanied by chemosensitization to docetaxel and increased cell death via a caspase-3-dependent pathway. To confirm that AKT affected resistance to docetaxel through sCLU and not through other mediators, tumor cells were first transfected with full-length CLU for overexpression and then treated with the AKT inhibitor API-2. We found that once sCLU was overexpressed, API-2 could not chemosensitize the tumor cells to docetaxel. Thus, the chemoresistance to docetaxel is mediated by sCLU and it can be induced by AKT. Lastly, AKT was found to mediate sCLU induction via signal transducer and activator of transcription 1 activation, which we have earlier shown to drive sCLU gene expression. These results identify a previously unrecognized pathway linking AKT to cytoprotection by sCLU in tumor cells.