Transcription des genes de proteines plasmatiques dans le foie au cours de l'inflammation aigue systemique

In the acute phase of a systemic inflammatory response, the so-called proinflammatory cytokines (interleukin-1 [IL-1]; IL-6) trigger significant changes in protein sytheses in liver. The hepatocyte is a source for most plasma proteins. Among the latter, many display a transient, up- (positive proteins) or down-regulated (negative proteins) synthesis during the acute phase. These regulations take place mostly at a transcriptional level and involve several families of nuclear factors. Some factors are primarily responsible for a basal and specific gene expression in liver (i.e. HNF factors and some factors of the C/EBP and STAT families). Other nuclear factors are mediators for the IL-1- (i.e. some factors of C/EBP family) or IL-6-regulated pathways (some factors of STAT family; glucocorticoid receptor), This paper reviews our knowledge of the molecular events (binding sites and factors in a given gene; synergism or antagonism between factors for gene binding; synergism in gene activation) that regulate the transcription of some genes coding for positive or negative plasma proteins. The equal importance of the NF-κB and C/EBP factors in the IL-1-driven gene response, the growing number of STAT factors involved in the IL-6-driven one as well as, in some instances, the simultaneous involvement of both sets of IL 1- or IL-6-associated factors are outlined.