Hexokinase 2 inhibits LPS-induced mitochondria-dependent apoptosis in human lung epithelial BEAS-2B cells

AIM: To explore the effect of hexokinase 2 (HK2) on lipopolysaccharide (LPS)-induced apoptosis of human lung epithelial BEAS-2B cells and the underlying mechanisms.METHODS: BEAS-2B cells were treated with LPS to induce cell injury, and the cell viability was examined by CCK-8 assay. Hoechst 33342 staining and Annexin V/PI double staining were used to analyze the apoptosis. The apoptotic pathway was identified by the specific inhibitor for caspase-8 or caspase-9. The releases of key mediators in mitochondrial apoptosis pathway were examined by Western blot. The effects of HK2 in these process were confirmed by HK2 over-expression followed by LPS treatment.RESULTS: CCK-8 assay showed that LPS treatment decreased the viability of BEAS-2B cells in a dose/time-dependent manner (P<0.01). The apoptosis of BEAS-2B cells was manifested by Hoechst 33342 and Annexin V/PI double staining. Pretreatment with z-LEHD-fmk, but not z-IETD-fmk, reversed the decreased cell viability under LPS stimulation. HK2 down-regulation was involved in LPS-induced apoptosis of the BEAS-2B cells. After HK2 over-expression, the cell viability was increased after LPS treatment. Releases of cytochrome C and apoptosis-inducing factor from mitochondrion to cytoplasm during apoptosis were also inhibited by HK2 over-expression.CONCLUSION: Hexokinase 2 inhibits LPS-induced mitochondria-dependent apoptosis in human lung epithelial cells.