Wei Bing, Liu Yi-Song, Guan Hai-Xia
Department of Endocrinology, Daqing Oil Field General Hospital, Daqing, Heilongjiang 163411, P.R. China.
Dental Department, Daqing Oil Field General Hospital, Daqing, Heilongjiang 163411, P.R. China.
Exp Ther Med. 2020 Mar;19(3):1915-1924. doi: 10.3892/etm.2020.8427. Epub 2020 Jan 7.
MicroRNAs (miRNAs/miRs) are considered to serve essential roles in podocyte apoptosis, and to be critical in the development of diabetic nephropathy (DN). Activation of the Notch signaling pathway has been demonstrated to serve an important role in DN development; however, its regulatory mechanisms are not fully understood. The present study used a high glucose (HG)-induced apoptosis model using mouse podocytes. Expression levels of miR-145-5p and its target, Notch1, and other key factors involved in the apoptosis signaling pathway were detected and measured by reverse transcription-quantitative PCR and western blotting. A luciferase reporter assay was performed to elucidate the miRNA-target interactions. The functions of miR-145-5p in apoptosis were detected using flow cytometry and TUNEL staining. The present study demonstrated that in HG conditions, miR-145-5p overexpression inhibited Notch1, Notch intracellular domain, Hes1 and Hey1 expression at the mRNA and protein levels. Notch1 was identified as a direct target of miR-145-5p. Furthermore, cleaved caspase-3, Bcl-2 and Bax levels were reduced significantly by miR-145-5p overexpression. These results indicate that miR-145-5p overexpression inhibited the Notch signaling pathway and podocyte lesions induced by HG. In conclusion, the results of the present study suggested that miR-145-5p may be a regulator of DN. Additionally, miR-145-5p inhibited HG-induced apoptosis by directly targeting Notch1 and dysregulating apoptotic factors, including cleaved caspase-3, Bcl-2 and Bax. The results of the present study provided evidence that miR-145-5p may offer a novel approach for the treatment of DN.
微小RNA（miRNA/miR）被认为在足细胞凋亡中起重要作用，并且在糖尿病肾病（DN）的发展中至关重要。Notch信号通路的激活已被证明在DN发展中起重要作用；然而，其调控机制尚未完全阐明。本研究使用高糖（HG）诱导的小鼠足细胞凋亡模型。通过逆转录定量PCR和蛋白质印迹法检测并测量miR-145-5p及其靶标Notch1以及凋亡信号通路中其他关键因子的表达水平。进行荧光素酶报告基因测定以阐明miRNA-靶标相互作用。使用流式细胞术和TUNEL染色检测miR-145-5p在凋亡中的功能。本研究表明，在HG条件下，miR-145-5p过表达在mRNA和蛋白质水平上抑制Notch1、Notch细胞内结构域、Hes1和Hey1的表达。Notch1被鉴定为miR-145-5p的直接靶标。此外，miR-145-5p过表达显著降低了裂解的caspase-3、Bcl-2和Bax水平。这些结果表明，miR-145-5p过表达抑制了HG诱导的Notch信号通路和足细胞损伤。总之，本研究结果表明miR-145-5p可能是DN的一个调节因子。此外，miR-145-5p通过直接靶向Notch1并失调包括裂解的caspase-3、Bcl-2和Bax在内的凋亡因子来抑制HG诱导的凋亡。本研究结果提供了证据，表明miR-145-5p可能为DN的治疗提供一种新方法。
