Zhang Yuquan, Liu Shuzhu, Ding Limin, Wang Dawei, Li Qiangqiang, Li Dongdong
Department of Gerontology, The First Hospital of Qiqihar, Qiqihar, Heilongjiang, China.
Department of Gerontology, Affiliated Qiqihar Hospital, Southern Medical University, Qiqihar, Heilongjiang, China.
PeerJ. 2021 Nov 16;9:e11482. doi: 10.7717/peerj.11482. eCollection 2021.
Acute myocardial infarction (MI) is the common clinical manifestation of coronary heart disease. Circular RNAs (circRNAs) act key roles in cardiomyocytes growth and angiogenesis. However, their functions in MI are not entirely clear. This research intended to investigate the role and underlying mechanisms of circ_0030235 in H9c2 cells.
H9c2 cells were conducted to oxygen glucose deprivation/reperfusion (OGD/R) inducement to establish the MI model. Circ_0030235 and miR-526b expression was tested and altered by qRT-PCR and transfection. Cell viability, apoptosis and reactive oxygen species (ROS) injury were tested by CCK-8 assay, TUNEL assay kit, and ROS Detection Assay Kit, respectively. Assessment of cell injury-related factors was performed by employing ELISA, Mitochondrial Viability Staining and the JC-1-Mitochondrial Membrane Potential Assay Kit. The relationship between circ_0030235 and miR-526b was analyzed by dual luciferase reporter assay. The expression of key proteins was analyzed by western blot.
Circ_0030235 was highly expressed in OGD/R-induced H9c2 cells. OGD/R inducement cell viability, while accelerated apoptosis. Besides, the level ROS, cell injury-related factors, mitochondrial membrane potential were notably elevated by OGD/R inducement, while mitochondrial viability was remarkably declined. Whereas, these impacts were all noticeably remitted by circ_0030235 knockdown. miR-526b was a target of circ_0030235. Circ_0030235 knockdown-induced impacts were all notably abrogated by miR-526b inhibition, including the activating impacts on PI3K/AKT and MEK/ERK pathways.
This research implied that circ_0030235 knockdown might remit OGD/R-induced impacts via activation of PI3K/AKT and MEK/ERK pathways and regulation of miR-526b.
急性心肌梗死（MI）是冠心病的常见临床表现。环状RNA（circRNAs）在心肌细胞生长和血管生成中起关键作用。然而，它们在MI中的功能尚不完全清楚。本研究旨在探讨circ_0030235在H9c2细胞中的作用及潜在机制。
对H9c2细胞进行氧糖剥夺/再灌注（OGD/R）诱导以建立MI模型。通过qRT-PCR和转染检测并改变circ_0030235和miR-526b的表达。分别用CCK-8法、TUNEL检测试剂盒和ROS检测试剂盒检测细胞活力、凋亡和活性氧（ROS）损伤。采用ELISA、线粒体活力染色和JC-1线粒体膜电位检测试剂盒评估细胞损伤相关因子。通过双荧光素酶报告基因检测分析circ_0030235与miR-526b之间的关系。通过蛋白质印迹法分析关键蛋白的表达。
circ_0030235在OGD/R诱导的H9c2细胞中高表达。OGD/R诱导降低细胞活力，同时加速细胞凋亡。此外，OGD/R诱导显著提高了ROS水平、细胞损伤相关因子和线粒体膜电位，而线粒体活力显著下降。然而，circ_0030235敲低显著缓解了这些影响。miR-526b是circ_0030235的靶标。miR-526b抑制显著消除了circ_0030235敲低诱导的影响，包括对PI3K/AKT和MEK/ERK通路的激活作用。
本研究表明，circ_0030235敲低可能通过激活PI3K/AKT和MEK/ERK通路以及调节miR-526b来缓解OGD/R诱导的影响。
