M S Razzaque1, T Taguchi. 1. Second Department of Pathology, Nagasaki University School of Medicine, Japan.
Abstract
BACKGROUND: Heat shock protein 47 (hsp47) is a collagen-specific stress protein and is shown to be involved in the synthesis/assembly of various collagens as a molecular chaperone. This study was undertaken to investigate the possible role of hsp47 in dietary-induced hypercholesterolemic rat kidneys, which showed glomerular hypercellularity with expansion of mesangial matrix. METHODS: Dietary-induced hypercholesterolemia was induced in male Wistar rats by giving 2% cholesterol diet for four months. Immunohistochemistry was used for localization of protein products for collagens (types I, III, and IV). alpha-smooth muscle actin, vimentin, desmin, and ED-1, a macrophage/monocyte marker, and hsp47 in control and hypercholesterolemic rat kidneys. RESULTS: Compared with the control, increased accumulation of collagens was accompanied with increased expression of hsp47 in hypercholesterolemic rat kidneys, with predominant expression in the glomeruli. By double immunostaining, desmin-positive glomerular epithelial cells were found to be the main source of hsp47 in hypercholesterolemic rat kidneys. CONCLUSION: From these results, it is concluded that induced expression of hsp47 by phenotypically altered glomerular epithelial cells might play a role in the excessive assembly/synthesis of collagens and could thereby contribute to the glomerulosclerosis found in dietary-induced hypercholesterolemic rat kidneys.
BACKGROUND: Heat shock protein 47 (hsp47) is a collagen-specific stress protein and is shown to be involved in the synthesis/assembly of various collagens as a molecular chaperone. This study was undertaken to investigate the possible role of hsp47 in dietary-induced hypercholesterolemicrat kidneys, which showed glomerular hypercellularity with expansion of mesangial matrix. METHODS: Dietary-induced hypercholesterolemia was induced in male Wistar rats by giving 2% cholesterol diet for four months. Immunohistochemistry was used for localization of protein products for collagens (types I, III, and IV). alpha-smooth muscle actin, vimentin, desmin, and ED-1, a macrophage/monocyte marker, and hsp47 in control and hypercholesterolemicrat kidneys. RESULTS: Compared with the control, increased accumulation of collagens was accompanied with increased expression of hsp47 in hypercholesterolemicrat kidneys, with predominant expression in the glomeruli. By double immunostaining, desmin-positive glomerular epithelial cells were found to be the main source of hsp47 in hypercholesterolemicrat kidneys. CONCLUSION: From these results, it is concluded that induced expression of hsp47 by phenotypically altered glomerular epithelial cells might play a role in the excessive assembly/synthesis of collagens and could thereby contribute to the glomerulosclerosis found in dietary-induced hypercholesterolemicrat kidneys.
Authors: Gereon Poschmann; Barbara Sitek; Bence Sipos; Anna Ulrich; Sebastian Wiese; Christian Stephan; Bettina Warscheid; Günter Klöppel; Ann Vander Borght; Frans C S Ramaekers; Helmut E Meyer; Kai Stühler Journal: Mol Cell Proteomics Date: 2009-01-27 Impact factor: 5.911