高氧致慢性肺疾病新生大鼠肺组织中ERK1/2变化的研究

Expression of ERK1/2 protein in lung tissues of newborn rats with hyperoxia-induced chronic lung disease

摘要:

目的：探讨细胞外信号调节激酶（ERK）1/2在高氧致慢性肺疾病（CLD）新生大鼠肺组织中的表达及作用。方法：将48 只新生Wistar大鼠随机分为高氧组和对照组，每组 24 只。高氧组生后即置于氧箱中，维持氧浓度为 0.90，诱导CLD；对照组生后置于空气中。于生后3 d、7 d和14 d采集肺组织标本，应用免疫组化、Western blot及Real-time PCR方法检测ERK1/2蛋白及mRNA表达，同时测定肺组织纤维化评分。结果：免疫组化及Western blot结果显示7 d、14 d时高氧组肺组织p-ERK1/2蛋白的表达均明显高于同时间点对照组（P<0.01）。Western blot结果同时显示各组间ERK1/2总蛋白的表达差异无统计学意义。Real-time PCR结果表明各组间ERK1、ERK2 mRNA水平差异无统计学意义（P＞0.05）。结论：新生大鼠持续吸入高氧后，ERK1/2蛋白磷酸化活化，参与了高氧致CLD肺纤维化的形成过程。

Abstract:

OBJECTIVE: To study the expression of extracellular signal regulated protein kinase (ERK) 1/2 in lung tissues of newborn rats with chronic lung disease (CLD) caused by hyperoxia. METHODS: Forty-eight full-term newborn rats were randomly divided into two groups: hyperoxia and control. The two groups were exposed to a hyperoxic gas mixture (0.90 O2) for an induction of CLD and room air within 12 hrs after birth, respectively. The levels of ERK1/2 protein and mRNA in lung tissues were measured using immunohistochemistry, Western blot and real-time PCR methods on postnatal days 3, 7 and 14. The severity of pulmonary fibrosis was evaluated. RESULTS: The expression of p-ERK protein in lung tissues in the hyperoxia group was significantly higher than that in the control group on postnatal days 7 and 14 (P<0.01). There were no significant differences in the levels of total ERK1/2 protein and ERK1/2 mRNA. CONCLUSIONS: The activation of phosphorated ERK1/2 may lead to lung fibrosis caused by hyperoxia in newborn rats.