Objective To explore the influence of remimazolam (REM) on lipopolysaccharide (LPS)-induced pyroptosis of alveolar epithelial cells by regulating high mobility group box-1 protein (HMGB1)/Toll-like receptor 4 (TLR4)/nuclear factor κB (NF-κB) signaling pathway.

Methods Human alveolar epithelial cells HPAEpiC were cultured in vitro and divided into 7 groups, control group (normal culture), LPS group (10 mg/L LPS), LPS+pcDNA3.1 group (10 mg/L LPS+transfected with pcDNA3.1 plasmid), LPS+pcDNA3.1-HMGB1 group (10 mg/L LPS+transfected with pcDNA3.1-HMGB1 plasmid), LPS+REM group (10 mg/L LPS+150 μg/mL REM), LPS+REM+pcDNA3.1 group (10 mg/L LPS+150 μg/mL REM+transfected with pcDNA3.1 plasmid), and LPS+REM+pcDNA3.1-HMGB1 group (10 mg/L LPS+150 μg/mL REM+transfected with pcDNA3.1-HMGB1 plasmid), the morphological changes of HPAEpiC cells in each group were observed under scanning electron microscope; the survival rate of HPAEpiC cells in each group was detected by CCK-8 method; the release of lactate dehydrogenase (LDH) and the levels of interleukin (IL)-1β and IL-18 in HPAEpiC cells in each group were detected; the expression levels of nucleotide-binding oligomerization domain-like receptor family 3 (NLRP3), Caspase-1, cleaved N-terminal gasdermin D-N (GSDMD-N) pyroptosis-related proteins, and TLR4 and NF-κB proteins in HPAEpiC cells in each group were detected by Western blotting; and the expression level of HMGB1 mRNA in HPAEpiC cells in each group was detected by qRT-PCR.

Results Compared with the control group, HPAEpiC cells in the LPS group showed obvious features of pyroptosis, the cells were swollen or even ruptured, larger air bubbles were generated on the plasma membrane, the cell viability decreased, the LDH release, NLRP3, Caspase-1, GSDMD-N protein expression, IL-1β and IL-18 levels, HMGB1 mRNA and TLR4, nuclear NF-κB protein expression increased; compared with the LPS group, the above phenomena were aggravated in the LPS+pcDNA3.1-HMGB1 group, and were improved in the LPS+REM group; compared with the LPS+REM group, the above phenomena of HPAEpiC cells in the LPS+REM+pcDNA3.1-HMGB1 group were aggravated (P < 0.05 to P < 0.01).

Conclusions REM can alleviate LPS-induced inflammatory response and inhibit the pyroptosis of HPAEpiC cells, which may be related to the inhibition of HMGB1/TLR4/NF-κB signaling pathway.