Background/aims: Hepatic stellate cells are predominantly responsible for the increased extracellular matrix seen in cirrhosis. The cytokine oncostatin M has been implicated in fibrogenesis in vitro in other cell types and in vivo in other tissues, although its effect on hepatic stellate cells or in cirrhosis is unknown.
Methods: To examine the effect of oncostatin M on collagen production by human hepatic stellate cells in culture, collagen protein was measured and collagen alpha2(1) mRNA was quantified by Northern analysis. Tissue inhibitor of metalloproteinase-1 (an inhibitor of collagen degradation) mRNA was measured in response to oncostation M stimulation. To explore the potential biological significance of this work to human liver disease, oncostatin M messenger RNA in normal and cirrhotic human liver was measured.
Results: Oncostatin M induced in a 2-fold increase in collagen secretion. The potency of induction of collagen protein secretion was equal to that observed after transforming growth factor beta stimulation. An increase in endogenous collagen alpha2(1) mRNA could not be detected. This suggested a post-transcriptional mechanism for the increase in collagen protein. In response to oncostatin M stimulation, there was a 2-fold increase in the tissue inhibitor or metalloproteinase-1 mRNA. Oncostatin M mRNA was detected in 6/6 cirrhotic livers and 1/7 normal livers after 28 PCR cycles.
Conclusion: These results suggest that oncostatin M expression is upregulated in cirrhosis where it may have a role as a profibrogenic cytokine in hepatic stellate cells.