Heat shock protein 47 and renal fibrogenesis.

Recent research has greatly increased our knowledge regarding the molecular mechanisms of collagen synthesis and processing. Heat specific shock protein (HSP47) is a collagen-specific molecular chaperone, and helps in post-translational modifications of procollagens, during biosynthesis of collagen. Both in vivo and in vitro studies have convincingly demonstrated that HSP47 is localized in the endoplasmic reticulum of collagen-producing cells, and that its synthesis is closely associated with the rate of procollagen assembly. Recent studies are directed towards the pathological relevance of HSP47 in tissue scarring, a process that is characterized by excessive accumulation of collagens. It appears likely that increased levels of HSP47 in fibrotic diseases assist in increased assembly of procollagen, and thereby help in excessive accumulation of collagens in the fibrotic mass. Such profibrotic effects of HSP47 suggest that modulation of HSP47 expression in scarring diseases might alter the course of fibrotic diseases. In this brief article, we review the role of HSP47 in renal fibrotic diseases and its relevance to other scarring diseases.