Hsp 90 in lupus-prone mice

SIGLEAvailable from British Library Document Supply Centre- DSC:DXN002551 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Interleukin-10 activates heat-shock protein 90β gene expression

Elevated levels of the cytokine interleukin-10 (IL-10) have been reported in patients with active systemic lupus erythematosus (SLE). Any role for IL-10 in the pathogenesis of SLE is likely to involve the activation of expression of specific genes within its target cells. We have previously reported elevated levels of the 90 000 MW heat-shock protein (hsp 90) and autoantibodies to hsp 90 in patients with SLE. Recent studies have shown that the cytokine IL-6 activates hsp 90 gene expression via specific transcription factors that include STAT-3 (signal transducer and activator of transcription 3). In view of the known role of STAT proteins in IL-10 signalling pathways, we have investigated the effect of IL-10 on hsp 90 gene expression. Here we report that IL-10 enhances the expression of hsp 90 in both a human hepatoma cell line (HepG2) stably expressing the human IL-10 receptor and peripheral blood mononuclear cells (PBMC). In reporter gene assays IL-10 is able to activate both the hsp 90α and hsp 90β promoters directly. Furthermore, a short region of the hsp 90β promoter which is activated in response to IL-10, contains a STAT-3 binding site. This element but not a mutant derivative unable to bind STAT-3, is able to confer a response to IL-10 on a heterologous promoter. These results may be understood in terms of the shared signalling mechanisms of IL-10 and IL-6 and provide evidence of a role for IL-10 in the overexpression of hsp 90 in SLE, with possible pathological consequences

A Brief and Informationally Rich Naming System for Oligosaccharide Motifs of Heteroxylans Found in Plant Cell Walls

The one-letter code system proposed here is a simple method to accurately describe structurally diverse oligosaccharides derived from heteroxylans. Substitutions or ‘molecular decoration(s)’ of main-chain d-xylosyl moieties are designated by unique letters. Hence, an oligosaccharide is described by a series of single letters, beginning with the non-reducing d-xylosyl unit. Superscripted numbers are used to indicate the linkage position(s) of main-chain substitution(s) and, where necessary, superscripted lowercase letter(s) indicate the nature of non-glycosidic groups (e.g., methyl, acetyl, or phenolic derivative moieties) that can be present on the substituents. Although relatively simple and practical to use, this abbreviated system lends itself to the naming of a large number of different combinations of structural building blocks and substituents. In its present state, this system is, therefore, adequate to name and differentiate all currently known complex oligosaccharides derived from heteroxylans and is sufficiently flexible to accommodate new structures as they become available