Mdivi-1 attenuates lipopolysaccharide-induced acute lung injury by inhibiting MAPKs, oxidative stress and apoptosis

Sepsis is among the most devastating events in intensive care units. As a complication of sepsis, acute lung injury (ALI) is common and highly associated with poor outcome. The present study demonstrated that abnormal mitochondrial dynamics play a pivotal role in lipopolysaccharide (LPS)-induced ALI. Inhibiting the mitochondrial fission with the specific inhibitor-1 (Mdivi-1) ameliorated ALI as assessed by hematoxylin and eosin (H&E) staining and wet/dry ratio. Furthermore, Mdivi-1 reduced mitogen-activated protein kinases (MAPKs) activation, oxidative stress and apoptosis in the lungs. Plasma pro-inflammation cytokines were also reduced significantly in Mdivi-1-treated mice. In vitro study revealed that Mdivi-1 protected the macrophages from LPSinduced MAPKs activation, oxidative stress and cell apoptosis. Mdivi-1 also inhibited the release of pro-inflammatory cytokines. Morphological analysis showed that Mdivi-1 rescued the macrophages from LPS-induced mitochondrial fragmentation. Moreover, LPS treatment induced significant phosphorylation of Drp1 at Ser616, dephosphorylation at Ser637 and translocation of Drp1 from the cytoplasm to mitochondria, while Mdivi-1 inhibited those effects. Thus, modification of fission to rebuild mitochondrial homeostasis may offer an innovative opportunity for developing therapeutic strategies against ALI.