Abstract:

Objective To investigate the effects of miR-483-3p on hypoxia/reoxygenation （H/R）-induced apoptosis and pyroptosis of H9c2 cardiomyocytes and its possible mechanism. Methods Rat H9c2 cardiomyocytes were cultured in vitro，adeno-associated virus-infected H9c2 and the H/R model were constructed by triple-air incubator， and the cells were randomly divided into blank control （Sham） group， model （H/R） group， AAV-miR-483-3p mimic+H/R （AAV-miR-483-3p） group， AAV-miR-483-3p negative control+H/R （AAV-NC） group. The growth status of cells in each group was observed using an inverted microscope； cell proliferation activity was detected by cell counting kit-8 （CCK-8）； LDH release by lactate dehydrogenase （LDH） kit； apoptosis rate by flow cytometry； apoptosis by notched end labeling （TUNEL）.Western blot （WB） was used to detect the expression levels of IL-1β and GSDMD proteins in each group. Results Compared with the Sham group， the H/R group showed abnormal cell status and increased cell death， decreased cell activity， increased LDH release， increased apoptosis rate and apoptosis level， and increased expression levels of IL-1β and GSDMD proteins （P < 0.05）； compared with the H/R group， the AAV-miR-483-3p group showed improved cell status and less cell death， increased cell proliferation activity， increased LDH release， and increased IL-1β and GSDMD protein expression levels （P < 0.05）. Compared with the H/R group， the AAV-miR-483-3p group showed improved cell status and less cell death， increased cell proliferation activity， decreased LDH release， decreased apoptosis rate and apoptosis level， and decreased expression of IL-1β and GSDMD proteins （P < 0.05）. Conclusion Over-expression of miR-483-3p can improve H/R-inducedH9c2 cardiomyocyte injury by enhancing cell activity and cell metabolism， and inhibiting apoptosis and cell charring.

Key words: miR-483-3p, myocardial ischemia-reperfusion injury, apoptosis, cellular pyroptosis