Berberine inhibits osteogenic differentiation of aortic valve interstitial cells induced by osteogenic induction medium

Abstract

This research focused on the effect and mechanism of berberine on osteogenic differentiation of valve interstitial cells(VICs) induced by osteogenic induction medium, in order to provide new insights into the clinical treatment of calcified aortic valve disease. The expression of osteogenic and fibrotic makers in three cases of calcified valve tissues and one case of normal control was assayed by Western blot. After the porcine aortic VICs were isolated, the effects of different concentrations of berberine on their viability were examined by MTT assay for determining the optimal concentration range. VICs were cultured in osteogenic induction medium and treated with different concentrations of berberine. Western blot and q-PCR were conducted to detect the effects of berberine on the expression of osteogenic and fibrotic makers in VICs. The effects of berberine on osteogenic differentiation of VICs in the early and late stages were separately measured by ALP staining and alizarin red S staining. The effects of berberine on the phosphorylation of ERK1/2 at different time points were assayed by Western blot. And PD98059, an inhibitor of ERK1/2, was added for verification. The results suggested that related osteogenic and fibrotic makers were significantly up-regulated in calcified valve tissues as compared with those in the normal control. The up-regulated fibrosis and osteogenic makers of VICs under osteogenic conditions were reversed by berberine and the ALP activity and calcium deposition in VICs were also reduced obviously. The level of ERK1/2 phosphorylation was decreased. Similarly, the osteogenic and fibrotic makers of VICs induced by osteogenic induction medium were lowered by PD98059. This study has confirmed that berberine is able to inhibit the differentiation of VICs into myofibroblasts or osteoblast-like cells, which may be associated with the inhibition of ERK1/2 signaling pathway.