Effect of circACAP2 on myocardial injury in rats with myocardial infarction by regulating miR-421/BTG2 axis
Li Shanshan
Xu Wen
Yang Xi
Tu Lin
Zhou Haiyan
Abstract：Objective To investigate the effect of circular RNA(circRNA)ACAP2 on myocardial injury in MI rats by regulating the miR-421/B cell translocation gene 2(BTG2)axis.Methods A rat MI model and an H9c2 myocardial cell model were constructed.A total of 80 rats were divided into sham operation group,MI group,small interfering RNA-negative control(si-NC)group,si-circACAP2 group,overexpression control(pcDNA3.1)group,pCDNA3.1-circACAP2 group,pCDNA3.1-circACAP2+mimic NC group,and pCDNA3.1-circACAP2+miR-421 mimic group,with 10 rats in each group.H9c2 cells were divided into hypoxia group,hypoxia+si-NC group,hypoxia+si-circACAP2 group,hypoxia+pcDNA3.1 group,hypoxia+pcDNA3.1 circACAP2 group,hypoxia+pcDNA3.1 circACAP2+mimic NC group,hypoxia+pcDNA3.1 circACAP2+miR-421 mimic group,and control group.LVEF,LVFS,myocardial infarction,pathological chan-ges of myocardial tissue,and circACAP2,miR-421 and BTG2 mRNA expression,LDH,CK-MB activity,H9c2 cardiomyocyte viability and apoptosis,BTG2 protein expression in myocardial tis-sue,and BTG2 protein expression in H9c2 cardiomyocytes were detected in each group.Results Compared with the sham operation group,higher mRNA levels of circACAP2(1.84±0.21 vs 1.00±0.10)and BTG2(1.68±0.17 vs 1.00±0.10),larger infarct size,stronger activities of CK-MB and LDH,while decreased expression of miR-421(0.49±0.05 vs 1.00±0.11)and LVFS and LVEF values were observed in the MI group(P＜0.05).Compared with the si-NC group,the si-circACAP2 group had alleviated myocardial injury,increased LVFS and LVEF values,and decreased infarct size and CK-MB and LDH activities(P＜0.05).Significantly increased cell via-bility,and reduced apoptotic rate and CK-MB and LDH activities were observed in the hypoxia+si-circACAP2 group than the hypoxia+si-NC group(P＜0.05).Compared with the pcDNA3.1 group,myocardial injury was aggravated,LVFS and LVEF were decreased,and infarct size and CK-MB and LDH activities were increased in the pcDNA3.1-circACAP2 group(P＜0.05);Com-pared with the hypoxia+pcDNA3.1 group,the hypoxia+PCDNA3.1-circACAP2 group signifi-cantly decreased cell viability,and enhanced apoptotic rate and CK-MB and LDH activities(P＜0.05).Conclusion circACAP2 is up-regulated in MI rats and H9c2 cells,and silencing circACAP2 may improve cardiac function,reduce myocardial injury,and increase cardiomyocyte viability by regulating miR-421/BTG2 axis.
Keywords：myocytescardiacmyocardial injurymiR-421/BTG2 axiscircRNA CAP2rats with myocardial infarction
Publication Date：2024-06-15
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 688-693 )