Circ_0030235 knockdown protects H9c2 cells against OGD/R-induced injury via regulation of miR-526b

Abstract

Backgrounds 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. Methods 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. Results 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. Conclusions 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.

Analysis of circRNA profiles and clinical value in Stevens‐Johnson syndrome and toxic epidermal necrolysis

“…Hansenet 18 found that the highly expressed circRNA (ciRS‐7) possesses several binding sites to miR‐7 in human and mouse brains and inhibits miR‐7 activity, arguing for the first time that circRNAs can adsorb miRNAs and thus participate in many biological processes. CircRNA has been demonstrated to play a function in numerous intracellular signalling pathways, including apoptosis (phosphatidylinositol 3‐kinase/protein kinase B pathway), cell proliferation (mitogen‐activated protein kinase pathway) and inflammation (nuclear factor‐kappa B pathway), and activation of these pathways can reflect disease severity 19–21 . The above creates a theoretical basis for the function of circRNA in the SJS/TEN pathophysiology 22 …”

“…CircRNA has been demonstrated to play a function in numerous intracellular signalling pathways, including apoptosis (phosphatidylinositol 3-kinase/protein kinase B pathway), cell proliferation (mitogen-activated protein kinase pathway) and inflammation (nuclear factor-kappa B pathway), and activation of these pathways can reflect disease severity. [19][20][21] The above creates a theoretical basis for the function of circRNA in the SJS/TEN pathophysiology. 22 QPCR validation showed that hsa_circ_0000711, hsa_circ_0083619 and hsa_circ_0005615 were abnormally down-regulated and hsa_ circ_0003028 was abnormally up-regulated.…”

Circular RNAs in organ injury: recent development

“…Studies on circRNAs in myocardial I/RI suggested that circRNAs may promote apoptosis and Further analysis suggested that circ_0030235 may act via the miR-526b axis to inhibit the PI3K/Akt and MAPK pathways. As a result, inhibition of the PI3K/Akt pathway led to apoptosis and hence, aggravated myocardial I/RI [30]. Furthermore, a study by Wang et al also suggested a similar biological function of circRNAs in myocardial I/RI.…”

“…The activated Akt then phosphorylates Bcl-2-associated death promoter (BAD) and Bcl-2-associated X protein (Bax) to inhibit their pro-apoptotic effects and thus attenuate apoptosis [29]. An example of circRNAs acting on this axis can be seen from circ_0030235 in myocardial ischemia/reperfusion injury (I/RI) whereby it acts through the miR-526b axis to inhibit PI3K activity to promote apoptosis [30]. Similarly, studies have suggested that circRNAs may regulate this pathway through modulating the expression of B-cell lymphoma-2 (BCL2).…”

“…Ischemia/reperfusion kidney injury circAKT3 upregulated Promotes cell apoptosis [99] circ_001839 upregulated Promotes inflammatory response [100] circ_0023404 upregulated Promotes cell apoptosis and inflammatory response [101] Renal fibrosis circPlekha7 downregulated Promotes cell proliferation [104] Lupus nephritis circHLA-C upregulated Promotes lupus nephritis pathogenesis [106] Heart Myocardial ischemia-reperfusion injury circ_0030235 upregulated Promotes cell apoptosis [30] circ_0001206 downregulated Promotes cell apoptosis [109] circSAMD4A upregulated Promotes cell apoptosis and inflammatory response [110] circFOXO3 downregulated Inhibits inflammatory response [111] circRbms1 upregulated Promotes FOXO1 expression [112] circUBXN7 downregulated Inhibits cell apoptosis and inflammatory response [113] circPostn upregulated Promotes cell apoptosis [115] circHelz upregulated Promotes inflammatory response [116] Cardiac fibrosis circNFIB downregulated Promotes fibroblast proliferation and cardiac fibroblast-to-myofibroblasts differentiation [118] circRNA_000203 upregulated Promotes α-SMA, Col1a2 and CTGF expression [120] circHIPK3 upregulated Promotes α-SMA, Col1a1 and Col3a1 expression [121] Liver Hepatic fibrosis circPSD3 downregulated Promotes inflammatory response [123] circ_0067835 upregulated Promotes cell proliferation [125] Hepatic ischemia-reperfusion injury circRNA_017753 downregulated Activates Jade1 signalling pathway [129] Radiation-induced liver Injury hsa_circ_0071410 upregulated Promotes cell proliferation [131] circTUBD1 upregulated Promotes inflammatory response [133] circRSF1 upregulated Promotes cell proliferation and inflammatory response [136] Intestine Intestinal injury circRNA_Maml2 downregulated Promotes cell proliferation, differentiation and migration [28] circHIPK3 downregulated Inhibits cell proliferation [139] Reproductive system…”