Effect of midazolam on lipopolysaccharide-induced alveolar epithelial cell injury by regulating the AMPK/NRF2/HO-1 signaling pathway

Abstract: This study aimed to investigate the effect of midazolam (MDZ) on lipopolysaccharide (LPS)-induced alveolar epithelial cell injury by regulating the adenosine monophosphate-activated protein kinase (AMPK)/nuclear factor erythroid 2-related factor 2 (NRF2)/heme oxygenase-1 (HO-1) signaling pathway. mouse alveolar epithelial cells (MLE-12 cells) were divided into five groups: control group, LPS group, low-dose MDZ group (6 µmol/L), high-dose MDZ group (12 µmol/L), and high-dose MDZ + AMPK inhibitor DOR group. The cell proliferation, apoptosis, levels of inflammatory factors and oxidative stress indices, as well as the protein expressions of phosphorylated AMPK (p-AMPK), total AMPK, NRF2 and HO-1 were detected by MTT, Annexin V-FITC, ELISA and Western blot, respectively. The results showed that compared with the LPS group, both low and high-doses of MDZ significantly increased the cell viability, superoxide dismutase (SOD) activity, and the ratios of p-AMPK to AMPK as well as the protein levels of NRF2 and HO-1 (P < 0.05), while decreased the apoptosis rate and the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and reactive oxygen species (ROS) (P < 0.05). Moreover, DOR reversed the ameliorating effects of high-dose MDZ on the above indicators (P < 0.05). In conclusion, MDZ can alleviate LPS-induced alveolar epithelial cell injury by activating the AMPK/NRF2/HO-1 signaling pathway.