Department of Geriatrics, Institute of Aging and Geriatrics, The Second Xiang-ya Hospital, Central South University, 139 Renmin Road, Changsha 410011, Hunan, PR China.
Department of Geriatrics, Institute of Aging and Geriatrics, The Second Xiang-ya Hospital, Central South University, 139 Renmin Road, Changsha 410011, Hunan, PR China.
Exp Cell Res. 2014 May 1;323(2):352-8. doi: 10.1016/j.yexcr.2014.02.016. Epub 2014 Mar 4.
Vascular calcification is common in patients with peripheral artery diseases and coronary artery diseases. The osteoblastic differentiation of vascular smooth muscle cells (VSMCs) contributes significantly to vascular calcification. Adiponectin has been demonstrated to exert a protective effect in osteoblastic differentiation of VSMCs through regulating mTOR activity. However, the upstream and downstream signaling molecules of adiponectin-regulated mTOR signaling have not been identified in VSMCs with osteoblastic differentiation. In this study, the VSMC differentiation model was established by beta-glycerophosphate (β-GP) induction. The mineralization was identified by Alizarin Red S staining. Protein expression and phosphorylation were detected by Western blot or immunofluorescence. Adiponectin attenuated osteoblastic differentiation and mineralization of β-GP-treated VSMCs. Adiponectin inhibited osteoblastic differentiation of VSMCs through increasing the level of p-AMPKα. Pretreatment of VSMCs with AMPK inhibitor blocked while AMPK activator enhanced the effect of adiponectin on osteoblastic differentiation of VSMCs. Adiponectin upregulated TSC2 expression and downregulated mTOR and S6K1 phosphorylation in β-GP-treated VSMCs. Adiponectin treatment significantly attenuates the osteoblastic differentiation and calcification of VSMCs through modulation of AMPK-TSC2-mTOR-S6K1 signal pathway.
血管钙化在周围血管疾病和冠状动脉疾病患者中很常见。血管平滑肌细胞（VSMCs）的成骨细胞分化对血管钙化有重要贡献。脂联素已被证明通过调节 mTOR 活性在 VSMCs 的成骨细胞分化中发挥保护作用。然而，在成骨细胞分化的 VSMCs 中，脂联素调节 mTOR 信号的上游和下游信号分子尚未确定。在这项研究中，通过β-甘油磷酸（β-GP）诱导建立了 VSMC 分化模型。通过茜素红 S 染色鉴定矿化。通过 Western blot 或免疫荧光检测蛋白表达和磷酸化。脂联素减弱了β-GP 处理的 VSMCs 的成骨细胞分化和矿化。脂联素通过增加 p-AMPKα 的水平抑制 VSMCs 的成骨细胞分化。用 AMPK 抑制剂预处理 VSMCs 可阻断，而 AMPK 激活剂增强了脂联素对 VSMCs 成骨细胞分化的作用。脂联素上调了 TSC2 的表达，降低了β-GP 处理的 VSMCs 中 mTOR 和 S6K1 的磷酸化。脂联素通过调节 AMPK-TSC2-mTOR-S6K1 信号通路显著抑制了 VSMCs 的成骨细胞分化和钙化。
