Department of Anesthesiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences and Guangdong Cardiovascular Institute, No.102, Zhongshan 2nd Road, Yuexiu District, Guangzhou, 510080, Guangdong Province, People's Republic of China.
Department of Anesthesiology, The University of Hong Kong, Pok Fu Lam, 999077, Hong Kong SAR, People's Republic of China.
Acta Diabetol. 2021 Sep;58(9):1251-1267. doi: 10.1007/s00592-021-01713-x. Epub 2021 Apr 27.
Diabetic cardiomyopathy (DCM) is a specific myocardial alteration in patients with diabetics. LncRNA KCNQ1OT1 has been previously demonstrated to be involved in various diabetic complications. Our aims are to further investigate the underlying regulatory mechanisms/pathways of KCNQ1OT1 in DCM.
In vitro and in vivo models of DCM were established in high glucose (HG)-treated human cardiomyocytes and in streptozotocin (STZ)-induced diabetic mice, respectively. Gene and protein expressions were examined by qPCR, western blotting and ELISA. Cell proliferation and apoptosis were determined by CCK8 assay, flow cytometry and TUNEL staining. The association between KCNQ1OT1 and miR-181a-5p, miR-181a-5p and PDCD4 was predicted using bioinformatics methods and subsequently confirmed by dual luciferase reporter and RNA immunoprecipitation assays. Mouse cardiac tissues were collected and analysed using HE staining, Masson's staining and immunohistochemical analysis.
KCNQ1OT1 and PDCD4 were upregulated in HG-treated human cardiomyocytes, while miR-181a-5p was downregulated. In addition, KCNQ1OT1 could negatively regulate miR-181a-5p expression; meanwhile, miR-181a-5p also negatively regulated PDCD4 expression. KCNQ1OT1 silencing suppressed the expression of inflammatory cytokines and cell apoptosis in vitro, whereas inhibition of miR-181a-5p abrogated those effects of KCNQ1OT1 knockdown. Moreover, overexpressed PDCD4 abolished the inhibition on inflammation and apoptosis caused by miR-181a-5p overexpression. Finally, KCNQ1OT1 knockdown reduced the expression of PDCD4 via regulating miR-181a-5p and inhibited myocardial inflammation and cardiomyocyte apoptosis in the in vivo DCM model.
Our findings suggest that KCNQ1OT1 and its target gene miR-181a-5p regulate myocardial inflammation and cardiomyocyte apoptosis by modulating PDCD4 in DCM.
糖尿病心肌病（DCM）是糖尿病患者特有的心肌改变。先前已经证明长链非编码 RNA KCNQ1OT1 参与了各种糖尿病并发症。我们的目的是进一步研究 KCNQ1OT1 在 DCM 中的潜在调节机制/途径。
分别在高糖（HG）处理的人心肌细胞和链脲佐菌素（STZ）诱导的糖尿病小鼠中建立 DCM 的体外和体内模型。通过 qPCR、western blot 和 ELISA 检测基因和蛋白表达。通过 CCK8 测定、流式细胞术和 TUNEL 染色测定细胞增殖和凋亡。使用生物信息学方法预测 KCNQ1OT1 与 miR-181a-5p、miR-181a-5p 与 PDCD4 之间的关联，随后通过双荧光素酶报告基因和 RNA 免疫沉淀测定进行验证。收集并分析小鼠心脏组织，采用 HE 染色、Masson 染色和免疫组织化学分析。
HG 处理的人心肌细胞中 KCNQ1OT1 和 PDCD4 上调，而 miR-181a-5p 下调。此外，KCNQ1OT1 可以负调控 miR-181a-5p 的表达；同时，miR-181a-5p 也负调控 PDCD4 的表达。KCNQ1OT1 沉默抑制了体外炎症细胞因子和细胞凋亡的表达，而抑制 miR-181a-5p 则消除了 KCNQ1OT1 敲低的这些作用。此外，过表达 PDCD4 消除了 miR-181a-5p 过表达引起的炎症和凋亡抑制作用。最后，KCNQ1OT1 敲低通过调节 miR-181a-5p 降低 PDCD4 的表达，并抑制体内 DCM 模型中的心肌炎症和心肌细胞凋亡。
我们的研究结果表明，KCNQ1OT1 及其靶基因 miR-181a-5p 通过调节 PDCD4 来调节 DCM 中的心肌炎症和心肌细胞凋亡。
