高氧诱导早产鼠肺纤维化中结缔组织生长因子的表达及其意义

Expression and role of connective tissue growth factor mRNA in premature rats with hyperoxia-induced chronic lung disease

摘要:

目的：结缔组织生长因子（CTGF）是新近发现与纤维化发生密切相关的一种因子，但其与早产儿慢性肺疾病（CLD）的肺纤维化有何关系，迄今未见报道。该文旨在阐明CTGF在高氧致早产鼠CLD发生、发展的表达规律，并探讨其在纤维化中表达及意义。方法：采用高浓度氧诱导早产鼠CLD模型，应用酶联免疫吸附法（ELISA）、免疫组织化学及反转录聚合酶链反应（RT-PCR）等技术，动态观察CTGF mRNA表达，并同时测定肺成纤维细胞的增殖性细胞核抗原（PCNA）指数及肺组织 Ⅰ 型胶原的含量和TGF-β1蛋白表达水平。结果：生后1 d，3 d，两组 Ⅰ 型胶原、PCNA指数、TGF-β1蛋白及CTGF mRNA表达水平无差异（P>0.05）；实验组肺组织TGF-β1蛋白表达7 d升高（P<0.05），Ⅰ 型胶原、PCNA指数及CTGF mRNA表达14 d升高（P<0.05），21 d均达高峰（P<0.01）；肺组织CTGF mRNA表达与 Ⅰ 型胶原呈明显正相关（γ=0.89, P<0.01）。结论： 高氧致CLD早产鼠肺组织CTGF mRNA表达水平与肺组织纤维化的程度相一致，CTGF与CLD的肺纤维化密切相关。［中国当代儿科杂志，2007，9（5）：449-452］

Abstract:

OBJECTIVE: To investigate the role of connective tissue growth factor (CTGF) in pulmonary fibrosis in rats with hyperoxia-induced chronic lung disease (CLD). METHODS: Eighty premature rats were randomly exposed to hyperxia (FiO2=0.90) or room air (control group) (n=40 each). CLD was induced by hyperoxia exposure. The expression of CTGF mRNA and transforming growth factor-β 1 (TGF-β 1), the levels of type I collagen and the proliferating cell nuclear antigen (PCNA) index were assayed with enzyme linked immunoadsorbent (ELISA), immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) on days 1, 3, 7, 14 and 21 after exposure. RESULTS: There were no differences in the levels of type I collagen, PCNA index, TGF-β 1 protein and CTGF mRNA between the CLD and the control groups within 3 days after exposure. In the CLD group, the expression of TGF-β 1 protein increased on the 7th day, remained at a higher level on the 14th and 21st day after exposure; the higher levels of type I collagen, PCNA index and CTGF mRNA were detected on the 14th day and peaked on the 21st day after exposure when comparing the control group. CTGF mRNA expression was positively correlated with type I collagen levels in the CLD group (r=0.89, P< 0.01). CONCLUSIONS: The expression of CTGF in lung tissues is associated with pulmonary fibrosis in CLD rats.