MiR-802 alleviates lipopolysaccharide-induced acute lung injury by targeting Peli2

INTRODUCTION: Acute respiratory distress syndrome (ARDS) is a life-threatening medical condition. It is characterized by serious lung inflammation or injury. Characterizing novel miRNAs implicated in ARDS pathogenesis may provide new therapeutic strategy for managing ARDS. METHODS: We employed LPS-induced lung injury model to profile miRNAs associated with ARDS. We isolated one miRNA candidate and characterized its role in lipopolysaccharide (LPS)-induced proinflammatory cytokine production in lung macrophages. We further evaluated its functional role in ARDS model by assessing histological change, neutrophil activation, tissue permeability and tumor necrosis factor alpha (TNFα) production. We also characterized its downstream target using luciferase assay, Western blotting, enzyme-linked immunosorbent assay and cell inflammation assay. RESULTS: Microarray profiling revealed miR-802 was significantly downregulated in ARDS mouse model. LPS-induced miR-802 downregulation was confirmed in lung macrophages. Overexpression of miR-802 significantly suppressed LPS-induced inflammatory cytokine production in vitro and alleviates LPS-induced acute lung injury in vivo. Peli2 was identified as a downstream target of miR-802 and found upregulated in ARDS model. Overexpressing Peli2 abolished the antagonizing effect of miR-802 on LPS-mediated inflammatory response. CONCLUSION: MiR-802 carried a protective role against LPS-induced acute lung injury by downregulating Peli2. MiR-802/Peli2 axis may act as intervening targets to manage ARDS.