308 research outputs found
C-fos and c-jun Proto-Oncogene Expression Is Decreased in Psoriasis: an In Situ Quantitative Analysis
Psoriasis is a common, sometimes sevcre, non-malignant skin disease characterized by hyperproliferation and abnormal differentiation of keratinocytes. Because proto-oncogenes are implicated in both cell proliferation and differentiation, their expression could be modified in skin diseases such as psoriasis. The c-fos and c-jun proto-oncogenes, whose products associate to form a heterodimeric transcription factor, are among the first genes to be expressed when certain cells are stimulated to either proliferate or differentiate. Recent studies in our laboratory have shown that the c-fos protooncogene is highly expressed in normal human adult skin. In the present study, we used in situ hybridization with RNA to compare the expression and localization of c-fos and c-jun transcripts in 15 lesional and non-lesional psoriatic skin samples. Two clinical variants of psoriasis were studied: the most severe and chronic form or plaque-type psoriasis (N = 10) and rapidly resolutive guttate-type psoriasis (N = 5). Quantitative analysis was performed using a semi-automatic image analyzer and the âStarwise grainâ software program. Our control samples included 10 normal skins and eight specimens from other benign hyperproliferative non-psoriatic skin diseases, consisting of three with inflammation (seborrheic dermatitis and atopic dermatitis), and 5 without inflammation (seborrheic keratoses). Control genes we used for in situ hybridization and RNA integrity were keratin 14, which is expressed in the epidermis and was normally expressed in all tissue analyzed, and ribosomal RNA. Our data showed that c-fos and c-jun were expressed to an equivalent extent, both spatially and quantitatively, in all specimens tested. Expression was significantly decreased in plaque-type but not in guttate-type psoriasis. It was also decreased in the three other benign inflammatory cutaneous hyperproliferative disorders, but not in the five non-inflammatory cases. These results were surprising because hyperproliferation was here associated with a decrease in proto-oncogene expression, thus suggesting that c-fos and c-jun do not play a crucial role in the control of keratinocyte proliferation in vivo. However, their reduced expression in some abnormally differentiated skins indicates that both c-fos and c-jun proto-oncogenes may play a key role in keratinocyte differentiation. Their altered expression correlated with severity of the disease and the presence of an inflammatory infiltrate. These data offer a new insight into the role and regulation of these proto-oncogenes in vivo in humans
Surface organometallic chemistry: a route to well-defined boron heterogeneous co-catalyst for olefin polymerisation
Effect of the nuclearity of perhydrocarbyl Fe(II) complexes on the grafting on oxide supports
Grafting mechanism and olefin metathesis activity of well-defined silica-supported Mo imido alkyl alkylidene complexes
SynthÚse et caractérisation de nouveaux complexes aryloxy à  base de tungstÚne
International audienc
Beyond PrPres Type 1/Type 2 Dichotomy in Creutzfeldt-Jakob Disease
Sporadic Creutzfeldt-Jakob disease (sCJD) cases are currently subclassified according to the methionine/valine polymorphism at codon 129 of the PRNP gene and the proteinase K (PK) digested abnormal prion protein (PrPres) identified on Western blotting (type 1 or type 2). These biochemically distinct PrPres types have been considered to represent potential distinct prion strains. However, since cases of CJD show co-occurrence of type 1 and type 2 PrPres in the brain, the basis of this classification system and its relationship to agent strain are under discussion. Different brain areas from 41 sCJD and 12 iatrogenic CJD (iCJD) cases were investigated, using Western blotting for PrPres and two other biochemical assays reflecting the behaviour of the disease-associated form of the prion protein (PrPSc) under variable PK digestion conditions. In 30% of cases, both type 1 and type 2 PrPres were identified. Despite this, the other two biochemical assays found that PrPSc from an individual patient demonstrated uniform biochemical properties. Moreover, in sCJD, four distinct biochemical PrPSc subgroups were identified that correlated with the current sCJD clinico-pathological classification. In iCJD, four similar biochemical clusters were observed, but these did not correlate to any particular PRNP 129 polymorphism or western blot PrPres pattern. The identification of four different PrPSc biochemical subgroups in sCJD and iCJD, irrespective of the PRNP polymorphism at codon 129 and the PrPres isoform provides an alternative biochemical definition of PrPSc diversity and new insight in the perception of Human TSE agents variability
Pour une démocratie socio-environnementale : cadre pour une plate-forme participative « transition écologique »
Contribution publiĂ©e in Penser une dĂ©mocratie alimentaire Volume II â Proposition Lascaux entre ressources naturelles et besoins fondamentaux, F. Collart Dutilleul et T. BrĂ©ger (dir), Inida, San JosĂ©, 2014, pp. 87-111.International audienceLâanthropocĂšne triomphant actuel, avec ses forçages environnementaux et sociaux, est Ă lâorigine de lâaccĂ©lĂ©ration des dĂ©gradations des milieux de vie sur Terre et de lâaccentuation des tensions sociales et gĂ©opolitiques. Passer Ă un anthropocĂšne de gestion Ă©quitable, informĂ© et sobre vis-Ă -vis de toutes les ressources et dans tous les secteurs dâactivitĂ© (slow anthropocene), impose une analyse prĂ©alable sur lâensemble des activitĂ©s et des rapports humains. Cette transition dite « Ă©cologique », mais en rĂ©alitĂ© Ă la fois sociĂ©tale et Ă©cologique, est tout sauf un ajustement technique de secteurs dits prioritaires et technocratiques. Elle est avant tout culturelle, politique et philosophique au sens propre du terme. Elle est un horizon pour des trajectoires de dĂ©veloppement humain, pour des constructions sociales et Ă©conomiques, censĂ©es redĂ©finir socialement richesse, bien-ĂȘtre, travail etc. La dĂ©nomination « transition Ă©cologique » est largement vĂ©hiculĂ©e, mais ses bases conceptuelles ne sont pas entiĂšrement acquises ni mĂȘme Ă©laborĂ©es. Dans ce contexte, les Ă©tudiants en premiĂšre annĂ©e de Master BioSciences Ă lâEcole Normale SupĂ©rieure (ENS) de Lyon ont prĂ©parĂ© une premiĂšre Ă©tude analytique de ce changement radical et global de sociĂ©tĂ© pour mieux comprendre dans quelle sociĂ©tĂ© ils souhaitent vivre, en donnant du sens aux activitĂ©s humaines prĂ©sentes et Ă venir. Une trentaine de dossiers sur divers secteurs dâactivitĂ©s et acteurs de la sociĂ©tĂ© ont Ă©tĂ© produits et ont servis de support Ă cette synthĂšse. Plus largement, le but est de construire un socle conceptuel et une plate-forme de travail sur lesquels les questions de fond, mais aussi opĂ©rationnelles, peuvent ĂȘtre posĂ©es et Ă©tudiĂ©es en permanence. Cette dĂ©marche participative est ouverte Ă la collectivitĂ© sur le site http://institutmichelserres.ens-lyon.fr/
- âŠ