Isoflurane Preconditioning Alleviates Hypoxia/Reoxygenation-Induced Cardiomyocyte Injury by Inhibiting miR-195-3p Expression

To investigate the role of microRNA-195-3p (miR-195-3p) in hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury. AC16 human cardiomyocyte cells were cultured and pretreated with different concentrations of isoflurane (ISO) (1%, 2%, and 3%), followed by 6 h each of hypoxia and reoxygenation to construct H/R cell models. The optimum ISO concentration was assessed based on the cell viability. miR-195-3p expression was regulated by in vitro cell transfection. Cell viability was determined by MTT assay, and apoptosis was evaluated by flow cytometry. The levels of myocardial injury and inflammation were determined by enzyme-linked immunosorbent assay. Compared with the control group, the cell viability of the H/R group had significantly decreased and that of ISO pretreatment had increased in a dose-dependent manner. Therefore, we selected a 2% ISO concentration for pretreatment. MiR-195-3p expression had significantly increased in the H/R group and decreased after 2% ISO pretreatment. Additionally, the number of apoptotic cells and the levels of lactate dehydrogenase, creatine kinase-myoglobin binding, cardiac troponin I, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α had increased significantly. ISO preconditioning inhibited H/R-induced AC16 cell damage, whereas miR-195-3p overexpression reversed the protective effects of ISO on cardiomyocytes. The expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) was reduced in the H/R-induced AC16 cells, and PTEN is a downstream target gene of miR-195-3p. Preconditioning with 2% ISO plays a protective role in H/R-induced AC16 cell damage by inhibiting miR-195-3p expression.