小窝蛋白1脚手架区多肽减轻LPS诱导的小鼠急性肺损伤

Effects of caveolin-1 scaffolding domain peptide on LPS-induced acute lung injury in mice

目的:探究人工合成的小窝蛋白1(caveolin-1,Cav-1)脚手架区多肽cavtratin对血红素加氧酶1(heme oxygenase-1,HO-1)活性及脂多糖(lipopolysaccharide,LPS)诱导的小鼠急性肺损伤的作用。方法:成年雄性BALB/c小鼠随机分为6组,每组8~10只,实验分为对照(control)组、触足肽内化序列(Antennapedia internalization sequence,AP)组、LPS组、LPS+血晶素(hemin)组、LPS+hemin+cavtratin组和LPS+hemin+cavtratin+锌原卟啉(zinc protoporphyrin IX,Zn PP)组。小鼠气管滴注LPS 24 h后,苏木素-伊红染色观察肺组织病理形态变化;检测肺组织湿/干重比、肺泡灌洗液中细胞数和血清中乳酸脱氢酶活性。免疫荧光观察HO-1和Cav-1的结合情况并检测HO-1活性;实时荧光定量PCR检测炎症因子(IL-1β、IL-6、TNF-α、MCP-1和i NOS)的mRNA水平。结果:组织免疫荧光以及HO-1活性检测发现,与LPS组比较,LPS+hemin+cavtratin组HO-1与细胞膜Cav-1的结合减少,HO-1的活性增高(P<0.05);与LPS组比较,LPS+hemin+cavtratin组肺组织受损程度明显减轻,肺湿/干重比、肺泡灌洗液细胞数和血清中乳酸脱氢酶活性显著降低(P<0.05);与LPS组比较,LPS+hemin+cavtratin组炎症因子的mRNA表达降低(P<0.05);HO-1活性抑制剂Zn PP可以消除cavtratin的保护作用。结论:Cavtratin可以通过减少HO-1与细胞膜Cav-1的结合使得HO-1活性增加,进而减轻LPS诱导的小鼠急性肺损伤。

AIM:To investigate the effects of caveolin-1(Cav-1)scaffolding domain peptide,cavtratin,on lipopolysaccharide(LPS)-induced mouse acute lung injury and heme oxygenase-1(HO-1)activity.METHODS:Adult male BALB/c mice were randomly divided into6groups(n=8to10):control,Antennapedia internalization sequence(AP),LPS,LPS+hemin,LPS+hemin+cavtratin and LPS+hemin+cavtratin+zinc protoporphyrin IX(ZnPP)groups.After LPS administration for24h,the lung pathological changes,the wet/dry weight(W/D)ratio of lung tissues,total cell number in bronchoalveolar lavage fluid and serum lactate dehydrogenase activity were measured.The co-localization of HO-1and Cav-1was displayed by immunofluorescence,and the HO-1activity were detected.The mRNA expression of pro-inflammatory cytokines IL-1β,IL-6,TNF-α,MCP-1and iNOS was detected by real-time PCR.RESULTS:The mice in LPS+hemin+cavtratin group had the decreased interaction between HO-1and Cav-1,and the increased HO-1activity compare with LPS group(P<0.05).Compared with LPS group,the pulmonary damage was attenuated in LPS+hemin+cavtratin group,and the injury indexes,including W/D ratio,total cell number in bronchoalveolar lavage fluid and lactate dehydrogenase activity in the serum,and the mRNA expression of inflammatory cytokines all decreased(P<005).HO-1activity inhibitor ZnPP abolished the above protective effect of cavtratin on the lung tissues with LPS-induced acute lung injury.CONCLUSION:Cavtratin has beneficial effects on the lung with LPS-induced acute injury by restoring the HO-1activity.