Abstract
BACKGROUND Acute lung injury (ALI) results from damage to the alveolar capillary endothelial cells and can result in acute respiratory distress syndrome (ARDS). This study aimed to investigate murine lung vascular endothelial cells (MLECs) damage in a murine model of lipopolysaccharide (LPS)-induced ALI. MATERIAL AND METHODS Mice were injected with LPS to induce an acute lung injury model. An adenovirus transfection system was used to overexpress or knockdown DUSP12 in mice. MLECs were isolated, cultured and transfected with DUSP12-overexpressing adenovirus or with DUSP12 siRNA to knockdown DUSP12. LPS was used to establish a cell injury model. ELISA and RT-PCR were used to examine cell inflammation. LPS-induced oxidative stress was also evaluated using commercial kits. RESULTS A decreased level of DUSP12 was observed in MLECs treated with LPS. DUSP12 overexpression in mice attenuated LPS-induced lung inflammation and lung injury, as reflected by reduced levels of proinflammatory cytokines. Mice with DUSP12 knockdown exhibited worsened lung inflammation and injury. In vitro, DUSP12 overexpression in endothelial cells ameliorated LPS-induced inflammation, apoptosis, and oxidative stress. DUSP12 silencing in endothelial cells aggravated LPS-induced inflammation, apoptosis, and oxidative stress. Furthermore, we found that DUSP12 directly bound to apoptosis signal-regulating kinase 1 (ASK1) to inhibit Jun N-terminal kinase activation (JNK). A JNK1/2 inhibitor and ASK1 siRNA ameliorated the exacerbating effects of DUSP12 knockdown in vitro. CONCLUSIONS Our data demonstrated that DUSP12 suppressed MLEC injury in response to LPS insult by regulating the ASK1/JNK pathway.