Department of Cardiology, The First College of Clinical Medical Science, China Three Gorges University & Yichang Central People's Hospital, Yichang 443003, China; Department of Central Experimental Laboratory, The First College of Clinical Medical Science, China Three Gorges University & Yichang Central People's Hospital, Yichang 443003, China; Yichang Key Laboratory of Ischemic Cardiovascular and Cerebrovascular Disease Translational Medicine, China.
Department of Cardiology, The First College of Clinical Medical Science, China Three Gorges University & Yichang Central People's Hospital, Yichang 443003, China; Department of Central Experimental Laboratory, The First College of Clinical Medical Science, China Three Gorges University & Yichang Central People's Hospital, Yichang 443003, China.
Nutr Metab Cardiovasc Dis. 2019 Jun;29(6):621-632. doi: 10.1016/j.numecd.2019.03.002. Epub 2019 Mar 13.
The vascular remodeling plays a crucial role in pathogenesis of diabetic cardiovascular complications. In this study, we intended to explore the effects and potential mechanisms of microRNA-24 (miR-24) on vascular remodeling under diabetic conditions.
MiR-24 recombinant adenovirus (Ad-miR-24-GFP) was used to induce miR-24 overexpression either in carotid arteries or high glucose (HG)-induced vascular smooth muscle cells (VSMCs). Cell proliferation was analyzed using CCK-8 method. Cell migration was examined using wound-healing and transwell assay. mRNA and protein expressions of critical factors were, respectively, measured by real-time PCR and western blot as follows: qRT-PCR for the levels of miR-24, PIK3R1; western blot for the protein levels of PI3K (p85α), Akt, p-Akt, mTOR, p-mTOR, 4E-BP1, p-4E-BP1, p70s6k, p-p70s6k, MMP 2, MMP 9, collagen Ⅰ, as well as collagen Ⅲ. Carotid arteries in diabetic rats suffered balloon injury were harvested and examined by HE, immunohistochemical and Masson trichrome staining. The expression of miR-24 was decreased in HG-stimulated VSMCs and balloon-injured carotid arteries of diabetic rats, accompanied by increased mRNA expression of PIK3R1. The up-regulation of miR-24 suppressed VSMCs proliferation, migration, collagen deposition not only induced by HG in vitro, but also in balloon-injured diabetic rats, which were related to inactivation of PI3K/Akt signaling pathway.
The up-regulation of miR-24 significantly attenuated vascular remodeling both in balloon-injured diabetic rats and HG-stimulated VSMCs via suppression of proliferation, migration and collagen deposition by acting on PIK3R1 gene that modulated the PI3K/Akt/mTOR axes.
血管重构在糖尿病心血管并发症的发病机制中起着关键作用。在这项研究中，我们旨在探讨 microRNA-24（miR-24）在糖尿病条件下对血管重构的影响及其潜在机制。
利用 miR-24 重组腺病毒（Ad-miR-24-GFP）在颈动脉或高糖（HG）诱导的血管平滑肌细胞（VSMCs）中诱导 miR-24 过表达。采用 CCK-8 法分析细胞增殖。采用划痕愈合和 Transwell 实验检测细胞迁移。分别采用实时 PCR 和 Western blot 法检测关键因子的 mRNA 和蛋白表达：qRT-PCR 检测 miR-24、PIK3R1 水平；Western blot 检测 PI3K（p85α）、Akt、p-Akt、mTOR、p-mTOR、4E-BP1、p-4E-BP1、p70s6k、p-p70s6k、MMP2、MMP9、胶原Ⅰ和胶原Ⅲ的蛋白水平。对糖尿病大鼠球囊损伤后的颈动脉进行 HE、免疫组化和 Masson 三色染色。HG 刺激的 VSMCs 和糖尿病大鼠球囊损伤的颈动脉中 miR-24 表达降低，同时 PIK3R1mRNA 表达增加。miR-24 的上调不仅抑制了体外 HG 刺激的 VSMCs 的增殖和迁移，还抑制了球囊损伤的糖尿病大鼠的增殖和迁移，这与 PI3K/Akt 信号通路的失活有关。
miR-24 的上调通过作用于调节 PI3K/Akt/mTOR 轴的 PIK3R1 基因，显著减轻了糖尿病大鼠球囊损伤和 HG 刺激的 VSMCs 中的血管重构，从而抑制了增殖、迁移和胶原沉积。
