过氧化物酶增殖体激活受体β在急性肺损伤大鼠肺组织的表达及其意义

Expression of peroxisome proliferation activated receptor-β in lung of rats with acute lung injury by lipopolysaccharide

目的观察内毒素(lipopolysaccharide,LPS)复制的急性肺损伤(acutelunginjury,ALI)大鼠肺组织过氧化物酶增殖体激活受体β(peroxisomeproliferationactivatedreceptorβ,PPARβ)表达的变化,探讨PPARβ在ALI中可能的作用。方法将40只雄性Wistar大鼠随机分为对照组、LPS致伤1、2、4h组和8h组。用LPS(5mg/kg)静脉注射复制大鼠ALI模型,分别在LPS致伤后1、2、4、8h时活杀大鼠,测定各组肺组织湿/干重比(W/D)及肺组织病理变化;采用RTPCR法检测肺组织中PPARβmRNA的表达;采用免疫组化法检测肺组织中PPARβ的表达。结果LPS致伤后2、4、8h肺组织W/D较对照组均显著升高(F=19.61,P<0.01);LPS致伤后1、2、4hPPARβmRNA表达分别较对照组显著升高(F=86.96,P<0.01);而LPS致伤后2、4、8h组PPARβ表达阳性细胞光密度值较对照组显著升高(F=6.89,P<0.05)。结论PPARβ在ALI大鼠肺组织表达升高,提示其可能参与了急性肺损伤的发生发展。

Objective To investigate the expression and role of peroxisome proliferation activated receptor- β （PPARβ） in lung of rats stimulated with lipopolysaccharide （LPS）. Methods Thirty-two male Wistar rats were established into acute lung injury models by venous injection of LPS and another eight LPS were injected with normal saline as controls. All rats were sacrificed at 1 , 2, 4, 8 h after injection of 5 mg/kg LPS. The ratio of lung wet/dry weight were measured. Semi-quantitative reverse transcription polymerase chain reaction （ RTPCR） and immunohistochemical method were used to measure the expression of PPARβ mRNA and PPARβ protein in the lung. Results The ratio of lung wet/dry weight in rats killed at 2 h, 4 h and 8 h after LPS injection was significantly higher than that of control group （ F = 19.61, P 〈 0. 01 ）. The expression of PPARβ mRNA （IOD） in rats killed at 1 h, 2 h and 4 h after LPS injection was significantly higher than that in control group （F = 86.96, P 〈0. 01 ） and PPARβ（IOD） at 2 h, 4 h and 8 h were significantly higher than that in control group （F = 6.89, P 〈 0. 05）. Conclusion Our data showed the expression of PPARβ was high in rat lung and PPARβ maybe play a major role in acute lung injury.