Objective To investigate the effect of lidocaine on cardiomyocyte H9C2 injury induced by hypoxia/reoxygenation (H/R) by regulating microRNA -181a (miR-181a).

Methods H9C2 cells were cultured and an H/R model was established as H/R group; normal cultured cells were used as the control (Con) group. H/R-induced H9C2 cells were treated with 1.0, 2.5, 5.0, 10.0 and 20.0 μmol/L lidocaine and were set as 1.0 μmol/L group, 2.5 μmol/L group, 5.0 μmol/L group, 10.0 μmol/L group and 20.0 μmol/L group, respectively. Anti-miR-NC and anti-miR-181a were transfected into H/R-induced H9C2 cells, included in H/R+anti-miR-NC group and H/R+anti-miR-181a group, respectively. The miR-NC and miR-181a were transfected into H/R-induced H9C2 cells, and then treated with 20 μmol/L lidocaine, which were recorded as H/R+miR-NC+20 μmol/L group and H/R+miR-181a+20 μmol/L group, respectively. The cell activity was detected by MTT assay; flow cytometry was used to detect apoptosis; the expression of Caspase-3 protein was detected by Western blot; real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of miR-181a; the content of malondialdehyde (MDA) and the activities of lactate dehydrogenase (LDH) and and superoxide dismutase (SOD) were detected; the levels of inflammatory factors tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β), Interleukin-6 (IL-6) were detected by enzyme-linked immunosorbent assay (ELISA).

Results Compared with the Con group, the cell activity in the H/R group was significantly decreased (P < 0.05). Compared with the H/R group, the cell activity of 5.0 μmol/L group, 10.0 μmol/L group and 20.0 μmol/L group was significantly increased (P < 0.05). Therefore, the experiment was conducted with 20.0 μmol/L lidocaine. Compared with the Con group, apoptosis rate and Caspase-3 protein expression in the H/R group were significantly increased (P < 0.05). Compared with the H/R group, the apoptosis rate and Caspase-3 protein expression in the 20.0 μmol/L group were significantly decreased (P < 0.05). Compared with the Con group, MDA content, LDH activity and inflammatory factor levels in the H/R group were significantly increased, while SOD activity was significantly decreased in the H/R group; compared with the H/R group, MDA content, LDH activity and inflammatory factor level in the 20.0 μmol/L group were significantly decreased, and SOD activity was significantly increased (P < 0.05). Compared with the H/R+anti-miR-NC group, the expression of miR-181a, apoptosis rate and Caspase-3 protein in the H/R+anti-miR-181a group were significantly decreased (P < 0.05). Compared with the H/R+anti-miR-NC group, the MDA content, LDH activity and inflammatory factor levels in the H/R+anti-miR-181a group were significantly decreased, while SOD activity was significantly increased (P < 0.05). Compared with the H/R+miR-NC+20.0 μmol/L group, the apoptosis rate, the contents of Caspase-3 protein as well as MDA content, the activity of LDH and the level of inflammatory factors in the H/R+miR-181a+20.0 μmol/L group were significantly increased, and the SOD activity was significantly decreased (P < 0.05).

Conclusion Lidocaine inhibits H/R-induced cardiomyocyte H9C2 injury by interfering with the expression of miR-181a.