RESUMEN
Sepsis is a lifethreatening multiple organ failure disease caused by an uncontrolled inflammatory response and can progress to acute lung injury (ALI). Heatshock protein B8 (HSPB8) serves a cytoprotective role in multiple types of diseases; however, to the best of our knowledge, the regulatory role of HSPB8 in sepsisinduced ALI remains unclear. A549 human alveolar type II epithelial cells were treated with lipopolysaccharide (LPS) for 24 h to simulate a sepsisinduced ALI model. Cell transfection was performed to overexpress HSPB8, and cells were treated with mitochondrial division inhibitor1 (Mdivi1) for 2 h before LPS induction to assess the underlying mechanism. Protein expression was evaluated using western blotting and an immunofluorescence assay. Cytokines were examined using ELISA assay kits and antioxidant enzymes were examined using their detection kits. Cell apoptosis was detected using flow cytometry. The mitochondrial membrane potential was detected by JC1 staining. HSPB8 was upregulated in A549 cells treated with LPS and HSPB8 overexpression attenuated LPSinduced inflammatory cytokine levels, oxidative stress and apoptosis in A549 cells. LPS inhibited mitophagy and reduced the mitochondrial membrane potential in A549 cells, which was partly inhibited by HSPB8 overexpression. Furthermore, Mdivi1 decreased the inhibitory effect of HSPB8 on the inflammatory response, oxidative stress and apoptosis in LPStreated A549 cells. In conclusion, HSPB8 overexpression attenuated the LPSmediated inflammatory response, oxidative stress and apoptosis in A549 cells by promoting mitophagy, indicating HSPB8 as a potential therapeutic target in sepsisinduced ALI.