MicroRNA146a overexpression alleviates intestinal ischemia/reperfusioninduced acute lung injury in mice

Previous studies have shown that microRNAs (miRs), such as miR146a play an important role in the pathogenesis of intestinal ischemia/reperfusion (I/R)induced injury; however, the role of miR146a in intestinal I/Rinduced acute lung injury has not been elucidated. An intestinal I/Rinduced injury mouse model was established in the present study by clamping the superior mesenteric artery and expression levels of miR146a in intestinal and lung tissue samples were evaluated using reverse transcriptionquantitative PCR (RTqPCR). Intestinal and lung histopathological characteristics in mice with intestinal I/Rinduced injury were assessed by hematoxylin and eosin staining, and mRNA and protein expression levels in intestinal and lung tissue samples were evaluated using RTqPCR and western blotting, respectively. miR146a expression was significantly downregulated in the intestinal and lung tissue samples of mice with intestinal I/Rinduced injury. Intestinal I/R injuryinduced histopathological changes in the lung and intestines, and pulmonary edema in mice transduced with an adenoviral miR146aoverexpression vector (the miR146a overexpression group) were alleviated. mRNA expression levels of TNFα, IL1β, IFNγ and TGFβ1, and protein expression levels of TNF receptorassociated factor 6, phosphorylatedp65 NFκB, cleaved caspase3 and cleaved caspase9 in lung and intestinal tissue samples were downregulated in I/RmiR146aoverexpressing mice, compared with those from the I/Rnegative control group. Thus, the present study identified that pretreatment with the miR146a overexpression vector alleviated intestinal I/Rinduced acute lung injury in mice.