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The Tau protein (Tubulin Associated Unit) is a phosphoprotein of the microtubule-associated protein family (MAPs). Its role is the regulation of the microtubule polymerization. The Tau protein is naturally present in brain, heart, muscle, lung, kidney, pancreas and liver. An expression of Tau protein and RNA messengers was also highlighted in the testis that is an organ rich in microtubules. The role of microtubules is essential in the stabilization of the cellular shape and in cell divisions. In the testis, Tau protein could be involved in the division process of the spermatogenesis by acting on the microtubular dynamics in the arrangement of the spermatozoon polarity. This review synthesizes the current knowledge, the localization and the main functions of the Tau protein focused on the testis. The localization and the potential roles of the Tau protein during the spermatogenesis are discussed by emphasizing the link with the microtubular structures of seminiferous tubules., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Introduction: OMICS is the term used to designate new biological sciences investigating a large group of molecules in biological samples. For instance, genomics and transcriptomics study changes in genome and transcription expression respectively. Numerous others OMICS are emerging (e.g. epigen-, prote-, metabol-, lipid-, glucid-OMICS). Support from bioinformatics and biostatistics, together with new molecular biology technologies for screening these large molecular groups (i.e. high-throughput biological arrays), has led to the development of these scientific fields. They help to draw relevant molecular identity cards of tumors., State of the Art: Glial tumors form a heterogeneous morphological and clinical tumor group including astrocytomas (from grade I to IV), oligodendrogliomas and oligoastrocytomas (grades II and III). OMICS has enabled a better understanding of clinical and biological behavior of these tumors identifying new molecular abnormalities and relevant biomarkers (i.e. diagnostic, prognostic, predictive of response to treatments and predisposing to gliomas). BRAF abnormalities are diagnostic markers in pilocytic astrocytomas and pleomorphic xanthoastrocytomas (duplication with rearrangement and V600E mutation, respectively). Translocation (1;19)(q10;p10) is associated with oligodendroglial phenotype and better prognosis in gliomas. MGMT promoter methylation is predictive of response to chemotherapy in grade IV astrocytomas (GBM). In GBM, high-throughput studies have discovered: genetic and genomic disruption of tyrosine kinase receptors, TP53 and RB signaling pathways in the vast majority of cases; several transcriptomic (e.g. neural, proneural, classic and mesenchymal), epigenomic (e.g. CpG Island Methylator phenotype versus non methylator phenotype) and proteomic (e.g. EGFR, PDGFR and NF1) patterns with biological and/or clinical impacts. Finally, OMICS have identified recurrent IDH1/IDH2 mutations with prognostic significance in glial tumors and five single nucleotide polymorphisms associated with susceptibility to gliomas (e.g. TERT, CCDC26, PHLDB1, RTEL1 and CDKN2A/CDKN2B). These latter data combined with already known inherited cancer syndromes (i.e. Turcot type 1, Cowden, melanoma-astrocytoma, Li-Fraumeni, tuberous sclerosis complex, type I and II neurofibromatosis) improve our knowledge of genetic predisposition to gliomas., Perspectives: Data generated by OMICS are huge, multidimensional and promising. Bioinformatics and biostatistics will allow their integration (integromics) toward a precise dissection of their clinical of biological significance in neuro-oncology., Conclusions: OMICS have a growing impact in neuro-oncology improving basic research in brain tumors and clinical management of patients through the discovery of biomarkers., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

Aims: To study the immunohistochemical expression of HHV8 in Kaposi's lesions and in other vascular lesions and to determine the utility of this technique in differentiating between Kaposi's disease (KD) and other vascular lesions., Methods: Fixed, paraffin-embedded tissue sections from 25 cases of KD, 9 cases of hemangioma, 2 cases of angiolymphoid hyperplasia with eosinophilia and 9 cases of angiosarcoma were examined immunohistochemically using the monoclonal antibody monoclonal LNA 53 (ABI). Strong, nuclear and granular staining in at least a cell was considered as a positive result., Results: Sixteen cases of KD showed positive staining, whereas all cases of hemangioma, angiolymphoid hyperplasia with eosinophilia and angiosarcoma were negative for this antigen, Conclusion: Immunohistochemical detection of the human herpesvirus-8 latent nuclear antigen-1 is a useful for differentiating between KD and other vascular lesions.

Unlabelled: Although antiplatelet therapy with ASA-clopidogrel reduces the risk of cardiovascular episodes after PCI, a substantial number of events occur during follow-up. Sustained platelet reactivity under dual antiplatelet therapy was recently associated with increased risk of recurrent atherothrombotic events after PCI. Whereas it appears significant to determine clopidogrel responsiveness, the accurate platelet function assay is still under investigation., Objectives: (i) to determine the proportion of "low-responders" or "resistants" patients during coronary syndrome (ii) to identify determinants of interindividual variability response to clopidogrel (iii) to compare aggregometry and VASP phosphorylation measured by flow cytometry. Patients were treated by clopidogrel (300 mg loading dose and 75 mg maintenance dose) and ASA (160 mg) (N=27). Additional treatment by GPIIbIIIa antagonists was given to high-risk patients (N=9). Platelet function was monitored by ADP aggregometry (5, 10, 20 microM) and VASP phosphorylation before any treatment by clopidogrel (d0) and at least five days after (d5). The platelet reactivity index (PRI), expressed as percentage, is the difference in VASP fluorescence intensity between resting (+ PGE1) and activated (ADP) platelets. At d5, low responsiveness to clopidogrel was defined by either (i) a PRI > 67.3% corresponding to the mean value -2SD measured in untreated patients (dO) (ii) or an absolute change (delta d0-d5) in aggregation (ADP 10 microM) < to 30%., Results: PRI, platelet aggregometry to ADP was significantly reduced following clopidogrel treatment (P < 0.01). A wide inter-individual variability to clopidogrel was observed at d5 (PRI from 11 to 83%). Whatever the platelet function used, a large proportion of patients were detected as "low-responders" (37% by VASP, 44% by ADP aggregometry). Absolute change in ADP aggregation was correlated to the variation of PRI (R = 0.559; P = 0.02). Contrary to ADP aggregometry, PRI was not influenced by GPIIbIIIa antagonists or prior administration of ASA. However, the conformity of the two methods to evaluate clopidogrel responsiveness was only 66%. No differences in platelet aggregometry could be observed at d5 between "low" and "good-responders" defined by VASP analysis. At d5, a higher PRI value could be detected in male and patients with history of dyslipemia., Conclusion: During coronary syndrome, impaired platelet responsiveness to clopidogrel was observed in a large proportion of patients whatever the platelet function assay used. VASP analysis was found insensitive to GPIIbIIIa or aspirin administration. Possible mechanisms linking clopidogrel "resistance" measured by VASP assay and enhanced thrombogenicity remain to be characterized. Indeed, clopidogrel "resistance" defined by VASP analysis was not associated with higher platelet aggregation.

Stathmin family proteins interact with tubulin and negatively regulate its assembly in microtubules. One stathmin molecule forms a complex with two alphabeta tubulin heterodimers in an interaction that is weakened upon stathmin phosphorylation. The X-ray structure of crystals of the complex reveals a head-to-tail arrangement of the two tubulins which are connected by a long stathmin alpha helix. By holding tubulins in a curved complex that is not incorporated in microtubules, stathmin lowers the pool of "assembly competent" tubulin. An alternate mechanism has been also proposed to account for the stathmin action in vivo; it involves a direct interaction of stathmin with microtubule (+) ends. More experiments are needed to evaluate the relative contribution of this alternative mechanism to the regulation of tubulin assembly by stathmin.

Insulin resistance is observed in several diseases such as non insulin dependent diabetes mellitus (NIDDM) or polycystic ovarian syndrome (PCOS). To understand genetic determinism of this abnormality we have developed a multidisciplinary approach including selection of phenotypes with insulin resistance confirmed in vivo by minimal model of Bergman and characterization of cellular defects in insulin action on circulating erythrocytes and monocytes. Exploration of variability in candidate genes by direct sequencing in some genetic syndromes of severe insulin resistance and acanthosis nigricans (mainly the Type A syndrome) revealed mutations of the insulin receptor gene associated with major defects in insulin binding or kinase activity. In other rare genetic syndromes or patients affected by NIDDM or PCOS defects appear to be located at post-receptor level, where IRS (insulin receptor substrate) genes are the most attractive candidates. Prevalence of some allelic variants suggested a potential role of IRS genes in insulin resistance, although their involvement in the pathogenesis of NIDDM remains controversial. Genotype-phenotype correlations in first degree relatives of an index case caring the Type A syndrome, suggested that association of allelic variants of IRS-1 and IRS-2 with insulin receptor mutations contribute, by synergistic effects, to phenotypic expression of defects in signal transduction. These mechanisms through genetic epistasis, involving several genes in insulin action, fit better with the polygenic nature of current forms of NIDDM and represent a good model in the study of pathogenesis of insulin resistance.

The small GTPases Cdc42, Rac and RhoA have important regulatory roles in mediating cytoskeletal rearrangements, MAP kinase cascades and induction of G1 cell cycle progression. The activity of the GTPases is regulated by guanine nucleotide exchange factors (GEFs) which accelerate their GDP/GTP exchange rate, and thereby activate them. All the GEFs for the Rho-GTPases family share two conserved domains: the DH domain (for Dbl-homology domain) responsible for the enzymatic activity, and the PH domain, probably responsible for the proper localization of the molecule. Trio is a multifunctional protein that is comprised of two functional Rho-GEFs domains and a serine/threonine kinase domain. We have shown in vitro and in vivo that the first GEF domain (GEFD1) activates Rac1, while the second GEF domain (GEFD2) acts on RhoA. Moreover, the co-expression of both domains induces simultaneously the activation of both GTPases. To our knowledge, this is the first example of a member of the Rho-GEF family, that contains two functional exchange factor domains, with restricted and different specificity. We are currently investigating how these GEF domains are activated, by addressing the role of the PH domains in GTPases activation by Trio. We have shown that: 1) the PH1 of Trio is necessary for Rac activation by the GEFD1; 2) the PH1 of Trio targets the molecule to the cytoskeleton; 3) the GEFD1 domain of Trio binds, in a two-hybrid screen, the actin binding protein filamin. These data suggest that the PH1 targets Trio to the cytoskeleton close to Rac and its effectors, probably via interaction with the actin-binding protein filamin, consistent with a role of Trio in actin cytoskeleton remodeling.

Enzymatic degradation of non collagenic proteins of the organic matrix of bovine teeth by cariogenic Streptococcus mutans has been studied. The activity on glycoaminoglycans of a constitutive bacterial exoenzyme depends on pH. The speed of degradation of each proteic fraction varies depending on the presence of the substrate during the growing phase of the Bacteria.

Xenopus oocytes were prelabeled with 32PO4 and induced to mature by progesterone treatment (1 microM). At the time of the breakdown of the germinal vesicle (nucleus), an alkali stable 45 kDa phosphoprotein appears in the 165 000 X g oocyte supernatant. Phospho-amino acid analysis shows that the 45 kDa protein is phosphorylated at threonine residues.

Gene expression is in great part under the control of proteins associated with DNA: histones which can be phosphorylated and acetylated, non-histone proteins which include enzymes, hormone receptors and other regulatory proteins. Phosphorylation seems to play an important role in chromatin regulation.

Egg lipovitellins of Orchestia gammarella tested by electrophoresis on gels of different acrylamide concentrations, following the procedure of Hedrick and Smith (1968), display a migration pattern identical to that of proteins with molecular weights of congruent to 3.2 x 10(5) (lipovitellin I) and congruent to 5.5 x 10(5) (lipovitellin II) respectively. Since their molecular weight remains constant during embryogenesis, the changes of their relative mobility in disc gels indicates alterations in their ionic charges.