Effect Of Transforming Growth Factor-β1on The Activation Of Hepatic Stellate Cells And Its Mechanism

Objective:To vestigate the effect of transforming growth factor-β1(TGF-β1) on the activation of hepatic stellate cells (HSCs)and its mechanism, further reveal the pathogenesis of liver fibrosis, and provide the new targets for cirrhosis of the liver.Methods:Hepatic stellate cells lines with different concentration of TGF-β1(final concentration were0.2,1.0, and5.0ng/ml) were cultured for48h.Expression of a-smooth muscle actin (a-SMA) in HSCs were measured by conventional cells immunohistochemistry (SABC).The content of asymmetric dimethylarginine(ADMA) in cell cultures was measured by high performance liquid chromatography(HPLC).Activity of dimethylarginine dimethylaminohydrolase (DDAH) in HSCs was estimated by directly measuring the amount of ADMA metabolized by the enzyme.Messenger RNA levels of DDAH1in the HSCs were mearsured using RT-PCR, researching TGF-β1to the HSCs’activation function and whether DDAH/ADMA pathways involved.Results:1. Immunohistochemical results show that TGF-β1can increase expression levels of a-SMA in a concentration-dependent manner,and promote the HSCs’activation.2. RT-PCR detect changes of hepatic stellate cells DDAH1mRNA.finding that TGF-β1can downregulate the DDAH1mRNA level in a concentration-dependent manner.3.The results of high performance liquid chromatography show that TGF-β1may lower the activity of DDAH1, promote the synthesis of ADMA with increasing of concentration.Conclusion:1.TGF-β1still has strong effect on activated HSCs, and the effect is concentration-dependent.2. DDAH/ADMA pathways exist in HSC.3. TGF-β1to the HSCs’ activation function may be related to DDAH/ADMA pathways.