Human Mothers Against Decapentaplegic Homolog 7 ELISA kit

Objective: To investigate the effects of tanshinone IIA on the transforming growth factor-beta 1 (TGF-beta 1)/Smads signaling pathway in angiotensin II-treated hepatic stellate cells (HSCs). Methods: HSCs were cultured and treated with angiotensin II (10 mu M) or angiotensin II (10 mu M) plus tanshinone IIA (3, 10, or 30 mu M). Cells were incubated for 48 hours and proliferation was determined with the Cell Counting Kit-8. The relative mRNA expression ofTGF-beta 1,Smad4, andSmad7was measured by quantitative real-time PCR, and the relative protein expression levels were investigated by western blotting. Results: After angiotensin II treatment, cell proliferation was significantly accelerated. Furthermore, both the mRNA and protein expression of TGF-beta 1 and Smad4 was significantly up-regulated, while the mRNA and protein expression of Smad7 was significantly down-regulated compared with the control cells. Tanshinone IIA inhibited the observed effects of angiotensin II in a concentration-dependent manner, with significant inhibition exerted by tanshinone IIA at 10 and 30 mu M. Conclusions: Angiotensin II promotes the proliferation of HSCs, possibly by regulating the expression of components along the TGF-beta 1/Smads signaling pathway. Tanshinone IIA inhibits the angiotensin II-induced activation of this pathway, and may, therefore, have preventive and therapeutic effects in liver fibrosis.

BackgroundBone mesenchymal stem cells (MSCs) can promote liver regeneration and inhibit inflammation and hepatic fibrosis. MSCs also can serve as a vehicle for gene therapy. Smad7 is an essential negative regulatory gene in the TGF-beta 1/Smad signalling pathway. Activation of TGF-beta 1/Smad signalling accelerates liver inflammation and fibrosis; we therefore hypothesized that MSCs overexpressing the Smad7 gene might be a new cell therapy approach for treating liver fibrosis via the inhibition of TGF-beta 1/Smad signalling.MethodsMSCs were isolated from 6-week-old Wistar rats and transduced with the Smad7 gene using a lentivirus vector. Liver cirrhosis was induced by subcutaneous injection of carbon tetrachloride (CCl4) for 8weeks. The rats with established liver cirrhosis were treated with Smad7-MSCs by direct injection of cells into the main lobes of the liver. The expression of Smad7, Smad2/3 and fibrosis biomarkers or extracellular matrix proteins and histopathological change were assessed by quantitative PCR, ELISA and Western blotting and staining.ResultsThe mRNA and protein level of Smad7 in the recipient liver and serum were increased after treating with Smad-MSCs for 7 and 21days (P<0.001). The serum levels of collagen I and III and collagenase I and III were significantly (P<0.001) reduced after the treatment with Smad7-MSCs. The mRNA levels of TGF-beta 1, TGFBR1, alpha -SMA, TIMP-1, laminin and hyaluronic acid were decreased (P<0.001), while MMP-1 increased (P<0.001). The liver fibrosis score and liver function were significantly alleviated after the cell therapy.ConclusionsThe findings suggest that the MSC therapy with Smad7-MSCs is effective in the treatment of liver fibrosis in the CCl4-induced liver cirrhosis model. Inhibition of TGF-beta 1 signalling pathway by enhancement of Smad-7 expression could be a feasible cell therapy approach to mitigate liver cirrhosis.