Chen Yao, Bangash Abdul Basit, Song Juan, Zhong Wei, Wang Cuiping, Shao Chen, Wang Zhongqun, Yan Jinchuan
Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu Province 212001, PR China.
The School of Clinical Medicine, Jiangsu University, Zhenjiang, Jiangsu Province 212001, PR China.
Int J Cardiol. 2017 Mar 1;230:198-203. doi: 10.1016/j.ijcard.2016.12.174. Epub 2016 Dec 30.
Vascular calcification is a characteristic feature of atherosclerosis and is considered as an independent predictor of cardiovascular risk. CD137 signaling has previously shown to be involved in atherosclerosis. However, the possible role of CD137 signaling in regulation of vascular calcification has not been reported. In the present study, we investigated the effect of CD137 signaling on vascular calcification in ApoE mice and in vascular smooth muscle cells (VSMCs) of mice.
Calcium deposition and muscle fibers in vivo or vitro were identified by von-Kossa and Masson's trichrome staining respectively. Alkaline phosphatase (ALP) activity was measured by the ALP assay Kit. The presence of bone morphogenic protein 2 (BMP2) and runt-related transcription factor 2 (Runx2) was detected by real-time PCR, Western blot and immunofluorescence in vitro or vivo.
Our data shows that activation of CD137 signaling by intraperitoneal injection of agonist-CD137 antibody increased the areas of vascular calcification. Activation of CD137 signaling also increased the expression of BMP2 and Runx2 in the atherosclerotic plaques. In vitro, activation of CD137 signaling also aggravated VSMC calcification, while blocking CD137 signaling could alleviate agonist-CD137 induced VSMC calcification. In addition, the levels of calcium, BMP2 and Runx2, indicators of calcification, were all significantly elevated in agonist-CD137 group in VSMCs.
Our data revealed a previously unrecognized role of CD137 signaling in vascular calcification in vivo and vitro and provides a novel target for prevention and treatment of atherosclerosis in the future.
血管钙化是动脉粥样硬化的一个特征性表现，被认为是心血管风险的独立预测因子。先前已表明CD137信号传导参与动脉粥样硬化。然而，CD137信号传导在血管钙化调节中的可能作用尚未见报道。在本研究中，我们研究了CD137信号传导对载脂蛋白E基因敲除（ApoE）小鼠及小鼠血管平滑肌细胞（VSMC）血管钙化的影响。
分别通过冯科萨（von-Kossa）染色和马松三色（Masson's trichrome）染色鉴定体内或体外的钙沉积和肌纤维。通过碱性磷酸酶（ALP）检测试剂盒测定ALP活性。通过实时聚合酶链反应（PCR）、蛋白质免疫印迹法（Western blot）和免疫荧光法在体内或体外检测骨形态发生蛋白2（BMP2）和 runt相关转录因子2（Runx2）的存在情况。
我们的数据表明，通过腹腔注射激动剂CD137抗体激活CD137信号传导会增加血管钙化面积。CD137信号传导的激活还会增加动脉粥样硬化斑块中BMP2和Runx2的表达。在体外，CD137信号传导的激活也会加重VSMC钙化，而阻断CD137信号传导可减轻激动剂CD137诱导的VSMC钙化。此外，在VSMC的激动剂CD137组中，钙化指标钙、BMP2和Runx2的水平均显著升高。
我们的数据揭示了CD137信号传导在体内和体外血管钙化中一个先前未被认识的作用，并为未来动脉粥样硬化的预防和治疗提供了一个新靶点。
