Effect of downregulation of paralemmin-3 on LPS-induced acute lung injury in mice

CHEN Xu-xin; MENG Ji-guang; ZHANG Yan; LIU Zhen-qian; FU Yu-mei; HAN Zhi-hai

Abstract：Objective To investigate the effect of downregulation of paralemmin-3 (PALM3) expression on LPS-induced acute lung injury ( ALI) in mice.Methods Thirty BALB/c mice were randomly divided into 3 groups ( normal group, PALM3 shRNA group and control shRNA group ).At 48 h after transfection, protein expression level of PALM3 in lung tissues was detected by immunohistochemistry and mRNA level of PALM 3 in lung tissues was analyzed by RT -PCR. A second cohort of forty BALB/c mice were randomly divided into 4 groups ( normal group , ALI model group , PALM3 shRNA+ALI group and control shRNA+ALI group) .Lung tissues of all 4 groups were collected at 4 h after introperito-neal injection of LPS (15 mg/kg).Levels of nitric monoxide (NO) and activity of myeloperoxidase (MPO) in lung tissue homogenates, as well as pathological changes in the lung were detected .Results Compared with the normal and control shRNA groups, the PALM3 mRNA and protein expressions were suppressed in the PALM 3 shRNA group (P<0.05).Af-ter intraperitoneal injection of LPS , typical pathological features of ALI were observed in the control shRNA +ALI and ALI model groups, as well as higher lung injury score (P<0.05) and marked increases in pulmonary NO level and MPO ac-tivity (P<0.05).However, in mice given PALM3 shRNA, pathological changes in lung tissues were attenuated (P<0.05).NO production and MPO activity in lung tissue homogenates of the PALM 3 shRNA group were significantly re-duced (P<0.05).Conclusion PALM3 expression in mice lungs was significantly down -regulated by intranasal trans-fection with PALM3 shRNA.Downregulation of pulmonary PALM 3 expression in mice could significantly suppress the in-flammatory reaction to LPS and reduce severity of LPS -induced ALI .