Andrgrapholide-mediated c-SKI inhibits myocardial fibroblast transdif-ferentiation and myocardial fibrosis

Ming GAO; Huanhuan DING; Lihua ZHENG; Ming WANG

ABSTRACT

AIM:

To investigate the effect of cellular Sloan-Kettering Institute(c-SKI)protein expression on myocardial fibrosis in mice treated with andrgrapholide(Andr).

METHODS:

Male C57 mice were randomly divided into control group,model group[isoprenaline(ISO)group]and ISO+Andr group,with 6 mice per group.The mice in ISO and ISO+Andr groups were subcutaneously injected with ISO,while those in control group were injected with normal sa-line.The mice in ISO+Andr group was intragastrically given Andr,while those in ISO and control groups were given nor-mal saline.The histopathological characteristics of the heart tissue were detected by HE and Masson staining after 8 weeks of administration.The expression levels of c-SKI and extracellular matrix(ECM)-related proteins were detected by immu-nohistochemistry or Western blot.The c-SKI mRNA level was detected by qPCR.Human cardiac fibroblasts(HCFBs)were treated with different concentrations of Andr for 48 h.The cell viability was detected by CCK-8 assay,and the c-SKI and ECM-related protein levels were detected by Western blot.The transdifferentiated cell model was treated with the lowest effective dose of Andr.The cell morphology was observed under a microscope,the levels of c-SKI and ECM-related pro-teins were assessed by Western blot,and the c-SKI mRNA level was detected by qPCR.The transforming growth factor-β1(TGF-β1)-treated HCFBs were treated with the combination of c-SKI knockdown and Andr.The cell viability was detected by CCK-8 assay,and the levels of c-SKI and ECM-related proteins were detected by Western blot.

RESULTS:

After the intervention of Andr,the myocardial fibers in mice were neatly arranged,the morphology of myocardial cells was basically normal,the cell membrane was intact,and the collagen volume fraction was significantly reduced(P＜0.01).The mRNA and protein levels of c-SKI were significantly up-regulated(P＜0.05 or P＜0.01),and the protein levels of fibronectin 1(FN1),α-smooth muscle actin(α-SMA),vimentin and collagen type I(Col I)were significantly down-regulated(P＜0.01).After 50 μmol/L Andr treatment for 48 h,the viability of HCFBs was significantly decreased(P＜0.01),the pro-tein levels of Col I,α-SMA,vimentin and FN1 were significantly down-regulated(P＜0.01),and c-SKI expression was significantly up-regulated(P＜0.01).Compared with PBS group,the number of the HCFBs in TGF-β1 group increased with flattened and irregular morphological change,and the FN1,α-SMA,Col I and vimentin levels were significantly in-creased(P＜0.01),while c-SKI expression was significantly decreased(P＜0.01).After Andr intervention,the induction effect of TGF-β1 on HCFBs was reversed.Knockdown of c-SKI combined with Andr treatment in HCFBs significantly down-regulated c-SKI expression(P＜0.01),significantly up-regulated FN1,α-SMA,vimentin and Col I levels(P＜0.05),and significantly increased the cell viability.

CONCLUSION:

Andrgrapholide may affect the TGF-β1 signaling pathway by regulating c-SKI expression,and inhibit the proliferation of myocardial fibroblasts and ECM deposition,thus inhibiting myocardial fibrosis.