CircHECTD1 promoted MIRI‐associated inflammation via inhibiting miR‐138‐5p and upregulating ROCK2

Abstract Myocardial ischemia–reperfusion injury (MIRI) was often observed after surgeries, causing a lot of suffering to patients. Inflammation and apoptosis were critical determinants during MIRI. We conveyed experiments to reveal the regulatory functions of circHECTD1 in MIRI development. The Rat MIRI model was established and determined by 2,3,5‐triphenyl tetrazolium chloride (TTC) staining. We analyzed cell apoptosis using TUNEL and flow cytometry. Proteins expression was evaluated by western blot. The RNA level was determined by qRT‐PCR. Secreted inflammatory factors were analyzed by ELISA assay. To predict the interaction sequences on circHECTD1, miR‐138‐5p, and ROCK2, bioinformatics analysis was performed. Dual‐luciferase assay was used to confirm these interaction sequences. CircHECTD1 and ROCK2 were upregulated in the rat MIRI model, while miR‐138‐5p was decreased. CircHECTD1 knockdown alleviated H/R‐induced inflammation in H9c2 cells. Direct interaction and regulation of circHECTD1/miR‐138‐5p and miR‐138‐5p/ROCK2 were confirmed by dual‐luciferase assay. CircHECTD1 promoted H/R‐induced inflammation and cell apoptosis by inhibiting miR‐138‐5p. miR‐138‐5p alleviated H/R‐induced inflammation, while ectopic ROCK2 antagonized such effect of miR‐138‐5p. Our research suggested that the circHECTD1‐modulated miR‐138‐5p suppressing is responsible for ROCK2 activation during H/R‐induced inflammatory response, providing a novel insight into MIRI‐associated inflammation.