Li Yong, Sun Wei, Saaoud Fatma, Wang Yuzhen, Wang Quanyi, Hodge Johnie, Hui Yvonne, Yin Sophia, Lessner Susan M, Kong Xiangqing, Fan Daping
Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA.
Department of Cardiology and Department of Cardiothoracic Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
J Cell Mol Med. 2021 Jan;25(1):535-548. doi: 10.1111/jcmm.16107. Epub 2020 Nov 18.
microRNA-155 (miR155) is pro-atherogenic; however, its role in vascular calcification is unknown. In this study, we aim to examine whether miR155 regulates vascular calcification and to understand the underlying mechanism. Quantitative real-time PCR showed that miR155 is highly expressed in human calcific carotid tissue and positively correlated with the expression of osteogenic genes. Wound-healing assay and TUNEL staining showed deletion of miR155 inhibited vascular smooth muscle cell (VSMC) migration and apoptosis. miR155 deficiency attenuated calcification of cultured mouse VSMCs and aortic rings induced by calcification medium, whereas miR155 overexpression promoted VSMC calcification. Compared with wild-type mice, miR155 mice showed significant resistance to vitamin D3 induced vascular calcification. Protein analysis showed that miR155 deficiency alleviated the reduction of Rictor, increased phosphorylation of Akt at S473 and accelerated phosphorylation and degradation of FOXO3a in cultured VSMCs and in the aortas of vitamin D3-treated mice. A PI3K inhibitor that suppresses Akt phosphorylation increased, whereas a pan-caspase inhibitor that suppresses apoptosis reduced VSMC calcification; and both inhibitors diminished the protective effects of miR155 deficiency on VSMC calcification. In conclusion, miR155 deficiency attenuates vascular calcification by increasing Akt phosphorylation and FOXO3a degradation, and thus reducing VSMC apoptosis induced by calcification medium.
微小RNA-155（miR155）具有促动脉粥样硬化作用；然而，其在血管钙化中的作用尚不清楚。在本研究中，我们旨在探讨miR155是否调节血管钙化并了解其潜在机制。定量实时聚合酶链反应显示，miR155在人类钙化颈动脉组织中高表达，且与成骨基因的表达呈正相关。伤口愈合试验和TUNEL染色显示，miR155缺失抑制血管平滑肌细胞（VSMC）迁移和凋亡。miR155缺乏减弱了钙化培养基诱导的培养小鼠VSMC和主动脉环的钙化，而miR155过表达则促进VSMC钙化。与野生型小鼠相比，miR155基因敲除小鼠对维生素D3诱导的血管钙化具有显著抗性。蛋白质分析表明，miR155缺乏减轻了Rictor的减少，增加了培养的VSMC和维生素D3处理小鼠主动脉中Akt在S473位点的磷酸化，并加速了FOXO3a的磷酸化和降解。抑制Akt磷酸化的PI3K抑制剂增加了VSMC钙化，而抑制凋亡的泛半胱天冬酶抑制剂减少了VSMC钙化；两种抑制剂均减弱了miR155缺乏对VSMC钙化的保护作用。总之，miR155缺乏通过增加Akt磷酸化和FOXO3a降解来减轻血管钙化，从而减少钙化培养基诱导的VSMC凋亡。
