Expression of collagen genes in the liver
Brenner, D.A.; Alcorn, J.M.; Feitelberg, S.P.; Leffert, H.L.; Chojkier, M.
Molecular Biology and Medicine 7(2): 105-115
1990
ISSN/ISBN: 0735-1313 PMID: 2342427 Document Number: 349448
Hepatic production of type I collagen is markedly increased in liver cirrhosis. Previous studies using primary liver cell cultures have demonstrated that hepatocytes, lipocytes and endothelial cells are all capable of producing collagen. In this study in situ hybridization and hepatic cell sorting have been used to identify which cells are expressing the type I collagen gene, .alpha.1(I), in normal rat liver. Northern blotting of mRNAs from purified hepatic cell populations demonstrated that both hepatocytes and several types of non-parenchymal cells express the collagen .alpha.1(I) gene. Calculations based on cell numbers, yields of mRNA, and cellular mRNA concentration demonstrated that the majority of collagen .alpha.1(I) mRNA originates from the hepatocytes in the normal liver. Localization of a collagen .alpha.1(I) mRNA by in situ hybridization confirmed that both hepatocytes and non-parenchymal cells express this gene. Furthermore, collagen .alpha.1(I) gene expression in hepatocytes was obtained by transfecting a reporter gene driven by the collagen .alpha.1(I) 5' regulatory segment in primary liver cells cultures. Future experiments will further characterize the regulation of collagen .alpha.1(I) gene expression in the liver.