Xue-Shan Zhao1, Bin Zheng1, Ya Wen2, Yan Sun1, Jin-Kun Wen3, Xin-Hua Zhang4. 1. Department of Biochemistry and Molecular Biology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education of China, Hebei Medical University, Shijiazhuang, Hebei 050017, China. 2. Department of Neurology, the Second Hospital of Hebei Medical University, Hebei Key Laboratory for Neurology, Shijiazhuang, Hebei 050000, China. 3. Department of Biochemistry and Molecular Biology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education of China, Hebei Medical University, Shijiazhuang, Hebei 050017, China. Electronic address: wjk@hebmu.edu.cn. 4. Department of Biochemistry and Molecular Biology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education of China, Hebei Medical University, Shijiazhuang, Hebei 050017, China. Electronic address: xiaomifeng800815@126.com.
Abstract
BACKGROUND: Salvianolic acid B (Sal B), a water-soluble compound extracted from Salvia miltiorrhiza that has been widely used to treat cardiovascular diseases for hundreds of years in China, exerts cardiovascular protection by multiple mechanisms. miR-146a is involved in vascular smooth muscle cell (VSMC) phenotypic modulation and proliferation. However, it has yet to be investigated whether the cardiovascular protective effect of Sal B is mediated by miR-146a. PURPOSE: To determine the relationship among the cardiovascular protective effect of Sal B, miR-146a expression, and VSMC proliferation. METHODS: MTS assay and cell counting were performed to evaluate the effect of Ang II, Sal B and miR-146a on VSMC proliferation. The neointima hyperplasia was assessed by hematoxylin/eosin staining. qRT-PCR was used to detect the expression of miR-146a, KLF5, cyclin D1 and PCNA. Western blot analysis was used to detect the expressions of KLF5, cyclin D1 and PCNA after miR-20b-5p was knocked down or overexpressed in VSMC. RESULTS: Sal B suppressed intimal hyperplasia induced by carotid artery ligation and decreased Ang II-induced VSMC proliferation by down-regulating the positive cell-cycle regulators KLF5 and cyclin D1. Further experiments showed that VSMC proliferation and upregulation of KLF5 and cyclin D1 induced by Ang II were accompanied by elevated miR-146a level. Furthermore, overexpression of miR-146a promoted and knockdown of miR-146a reduced Ang II-induced VSMC proliferation and ameliorated intimal hyperplasia induced by carotid artery ligation. Sal B inhibited Ang II-induced VSMC proliferation by suppressing miR-146a expression. CONCLUSION: Sal B inhibited Ang II-induced VSMC proliferation in vitro and intimal hyperplasia in vivo by downregulating miR-146a expression.
BACKGROUND:Salvianolic acid B (Sal B), a water-soluble compound extracted from Salvia miltiorrhiza that has been widely used to treat cardiovascular diseases for hundreds of years in China, exerts cardiovascular protection by multiple mechanisms. miR-146a is involved in vascular smooth muscle cell (VSMC) phenotypic modulation and proliferation. However, it has yet to be investigated whether the cardiovascular protective effect of Sal B is mediated by miR-146a. PURPOSE: To determine the relationship among the cardiovascular protective effect of Sal B, miR-146a expression, and VSMC proliferation. METHODS: MTS assay and cell counting were performed to evaluate the effect of Ang II, Sal B and miR-146a on VSMC proliferation. The neointima hyperplasia was assessed by hematoxylin/eosin staining. qRT-PCR was used to detect the expression of miR-146a, KLF5, cyclin D1 and PCNA. Western blot analysis was used to detect the expressions of KLF5, cyclin D1 and PCNA after miR-20b-5p was knocked down or overexpressed in VSMC. RESULTS:Sal B suppressed intimal hyperplasia induced by carotid artery ligation and decreased Ang II-induced VSMC proliferation by down-regulating the positive cell-cycle regulators KLF5 and cyclin D1. Further experiments showed that VSMC proliferation and upregulation of KLF5 and cyclin D1 induced by Ang II were accompanied by elevated miR-146a level. Furthermore, overexpression of miR-146a promoted and knockdown of miR-146a reduced Ang II-induced VSMC proliferation and ameliorated intimal hyperplasia induced by carotid artery ligation. Sal B inhibited Ang II-induced VSMC proliferation by suppressing miR-146a expression. CONCLUSION:Sal B inhibited Ang II-induced VSMC proliferation in vitro and intimal hyperplasia in vivo by downregulating miR-146a expression.