Molecular characteristics of Human Endogenous Retrovirus type-W in schizophrenia and bipolar disorder.: HERV-W in schizophrenia and bipolar disorder

International audienceEpidemiological and genome-wide association studies of severe psychiatric disorders such as schizophrenia (SZ) and bipolar disorder (BD), suggest complex interactions between multiple genetic elements and environmental factors. The involvement of genetic elements such as Human Endogenous Retroviruses type 'W' family (HERV-W) has consistently been associated with SZ. HERV-W envelope gene (env) is activated by environmental factors and encodes a protein displaying inflammation and neurotoxicity. The present study addressed the molecular characteristics of HERV-W env in SZ and BD. Hundred and thirty-six patients, 91 with BD, 45 with SZ and 73 healthy controls (HC) were included. HERV-W env transcription was found to be elevated in BD (P<10-4) and in SZ (P=0.012) as compared with HC, but with higher values in BD than in SZ group (P<0.01). The corresponding DNA copy number was paradoxically lower in the genome of patients with BD (P=0.0016) or SZ (P<0.0003) than in HC. Differences in nucleotide sequence of HERV-W env were found between patients with SZ and BD as compared with HC, as well as between SZ and BD. The molecular characteristics of HERV-W env also differ from what was observed in Multiple Sclerosis (MS) and may represent distinct features of the genome of patients with BD and SZ. The seroprevalence for Toxoplasma gondii yielded low but significant association with HERV-W transcriptional level in a subgroup of BD and SZ, suggesting a potential role in particular patients. A global hypothesis of mechanisms inducing such major psychoses is discussed, placing HERV-W at the crossroads between environmental, genetic and immunological factors. Thus, particular infections would act as activators of HERV-W elements in earliest life, resulting in the production of an HERV-W envelope protein, which then stimulates pro-inflammatory and neurotoxic cascades. This hypothesis needs to be further explored as it may yield major changes in our understanding and treatment of severe psychotic disorders

Facteurs d'évolution de la peur dentaire chez l'enfant

Malgré une abondante bibliographie sur le sujet, le concept même "de peur ou d'anxiété dentaire" chez l'enfant reste difficile à comprendre. La présente étude vise à évaluer et analyser les facteurs influençant l'évolution de la peur dentaire chez l'enfant. 625 enfants ont été inclus au cours de cette étude réalisée en milieu scolaire dans le cadre du projet "mieux vivre ensemble", projet dans lequel la santé buccodentaire est un indicateur de santé de l'enfant. Au sein des données recueillies en 2005 (Milord 1) et en 2007 (Milors 2) le critère principal étudié dans cette thèse est la peur dentaire, mesurée à l'aide d'une EVA. Entre Milord 1 et Milord 2, il n'y a pas d'évolution globale du niveau de peur quelque soit l'âge ou le sexe. L'exposition au contexte du cabinet dentaire apparaît comme le facteur principal d'évolution du niveau de peur chez l'enfant d'âge scolaire.CLERMONT FD-BCIU Odontol. (631132226) / SudocCLERMONT FD-BCIU-Santé (631132104) / SudocSudocFranceF

A Multilevel Functional Study of a SNAP25 At-Risk Variant for Bipolar Disorder and Schizophrenia

International audienc