小窝蛋白1脚手架区多肽减轻LPS诱导的小鼠急性肺损伤

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(P0.05);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(P0.05);与LPS组比较,LPS+hemin+cavtratin组炎症因子的mRNA表达降低(P0.05);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。

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

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 into 6 groups (n=8 to 10):control, Antennapedia internalization sequence (AP), LPS, LPS+hemin, LPS+ hemin+cavtratin and LPS+hemin+cavtratin+zinc protoporphyrin IX (ZnPP) groups. After LPS administration for 24 h, 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-1 and Cav-1 was displayed by immunofluorescence, and the HO-1 activity were detected. The mRNA expression of pro-inflammatory cytokines IL-1β, IL-6, TNF-α, MCP-1 and iNOS was detected by real-time PCR. RESULTS: The mice in LPS+hemin+cavtratin group had the decreased interaction between HO-1 and Cav-1, and the increased HO-1 activity 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-1 activity 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-1 activity.