Li Zhenjie, Jiang Runxia, Yue Qingcai, Peng Haiying
Department of Endocrinology, Linyi People's Hospital, Linyi, Shandong, 276003, China.
Department of General Medicine, Linyi People's Hospital, Linyi, Shandong, 276003, China.
Biochem Biophys Res Commun. 2017 May 20;487(1):15-21. doi: 10.1016/j.bbrc.2017.03.055. Epub 2017 Mar 15.
In our study, we investigated the expression and function of microRNA-29 in myocardial microvascular endothelial cells (MMEVC) in type 2 diabetic Goto-Kakizaki (GK) rats.
MiR-29 gene expression was compared, by qRT-PCR between diabetic GK rat MMEVC and non-diabetic Wistar rat MMEVC. MiR-29 was downregulated in GK MMEVC and its effect on angiogenic properties of proliferation and migration was examined. Potential downstream target gene of miR-29, insulin growth factor 1 (IGF1), was assessed by dual-luciferase reporter assay, qRT-PCR and western blot in GK MMEVC. IGF1 was also downregulated by siRNA in miR-29-downregulated GK MMEVC. Its effect on miR-29-associated angiogenic regulation on MMEVC proliferation and migration was further investigated.
MiR-29 was substantially upregulated in GK MMEVC than in Wistar MMEVC. Transfection of synthetic miR-29 inhibitor successfully downregulate endogenous miR-29 in GK MMEVC, and subsequently promoted angiogenesis by increasing cell proliferation and migration. IGF1 was confirmed to be downstream target gene of miR-29 in GK MMEVC, with its gene and protein expressions both upregulated in miR-29-downregualted GK MMEVC. Conversely, siRNA-mediated IGF1 downregulation reversed the pro-angiogenic effect of miR-29 downregulation in GK MMEVC, as it decreased cell proliferation and migration.
Our study suggests that miR-29 downregulation, through its inverse regulation on downstream target of IGF1 gene, is a pro-angiogenic factor in MMEVC in type 2 diabetic rats.
在我们的研究中，我们调查了微小RNA - 29在2型糖尿病Goto - Kakizaki（GK）大鼠心肌微血管内皮细胞（MMEVC）中的表达和功能。
通过qRT - PCR比较糖尿病GK大鼠MMEVC和非糖尿病Wistar大鼠MMEVC中miR - 29基因的表达。在GK MMEVC中miR - 29表达下调，并检测其对增殖和迁移等血管生成特性的影响。通过双荧光素酶报告基因检测、qRT - PCR和蛋白质印迹法在GK MMEVC中评估miR - 29潜在的下游靶基因胰岛素生长因子1（IGF1）。在miR - 29下调的GK MMEVC中，IGF1也通过小干扰RNA（siRNA）下调。进一步研究其对miR - 29相关的MMEVC增殖和迁移血管生成调节的影响。
与Wistar MMEVC相比，miR - 29在GK MMEVC中显著上调。合成的miR - 29抑制剂转染成功下调了GK MMEVC中的内源性miR - 29，随后通过增加细胞增殖和迁移促进血管生成。IGF1被证实是GK MMEVC中miR - 29的下游靶基因，在miR - 29下调的GK MMEVC中其基因和蛋白表达均上调。相反，siRNA介导的IGF1下调逆转了miR - 29下调对GK MMEVC的促血管生成作用，因为它降低了细胞增殖和迁移。
我们的研究表明，miR - 29下调通过对IGF1基因下游靶点的反向调节，是2型糖尿病大鼠MMEVC中的一种促血管生成因子。
