沙利度胺下调JNK信号通路抑制肺纤维化大鼠Ⅰ型胶原蛋白的过度表达

Thalidomide inhibits the over expression of type I collagen in pulmonary fibrosis rats via inhibiting JNK signaling pathway

目的探讨沙利度胺抑制肺纤维化大鼠I型胶原蛋白的过度表达，从而减轻博莱霉素诱导的大鼠肺间质纤维化的机制。方法将90只健康雄性W[star大鼠随机分为对照组（N组）、模型组（M组）、沙利度胺组（T组）、SP600125组（SP组）和沙利度胺＋SP600125组（T＋SP组）。气管内滴注博莱霉素（BLM）5mg／kg生理盐水诱导肺纤维模型，于造模当日起，各组给予相应药物，第7、14、28天处死大鼠，取肺组织行苏木素一伊红（HE）染色和Masson染色，光镜下观察肺泡炎和肺纤维化程度；碱水解法检测肺组织羟脯氨酸（Hyp）含量；免疫印迹法（Westernblot法）、实时荧光定量PCR法检测肺组织中c—jun氨基末端激酶（JNK）及I型胶原蛋白表达水平。结果M组第7天肺泡炎性程度最严重，第28天形成显著肺纤维化，Hyp含量于第28天达高峰，其p—JNK、I型胶原蛋白含量与对照组比较均明显升高（F=277．87、472．51，均P〈0．01）；T组、SP组和T＋SP组各时间点肺泡炎和纤维化程度均低于M组，p-JNK、I型胶原蛋白含量亦低于M组（F=14．77、61．59、101．73，均P〈0．01；F=10．33、79．12、57．48，均P〈0．01）；SP组P—JNK含量与T＋SP组比较差异无统计学意义。结论沙利度胺可能通过下调JNK信号通路抑制肺纤维化大鼠I型胶原蛋白的过度表达，从而减轻大鼠肺间质纤维化。

Objective To investigate whether thalidomide inhibits the over expression of type I collagen in pulmonary fibrosis rats via inhibiting the JNK signaling pathway, thereby reducing bleomycin-induced pulmonary interstitial fibrosis in rats. Methods 90 healthy male SD rats were randomly divided into normal control group （group N）, model group （group M）, thalidomide group （group T）, SP600125 group （group SP） and thalidomide＋SP600125 group （group T＋SP）. The pulmonary fibrosis models were prepared via intratracheal injection of 5mg/kg bleomycin, and rats in groups were given corresponding drugs from the first day after preparing model. Rats were randomly sacrificed at 7, 14 and 28 days after treatment. The degree of pulmonary alveolitis and fibrosis was evaluated by H^E and trichrome masson stainings. The level of hydroxyproline in the lung tissue was detected by applying alkaline hydrolysis technique, and expression levels of p-JNK and type I collagen were tested by Western bloting for protein expression and real-time polymerase chain reaction （RT- PCR） for mRNA expression. Results In group M, alveolitis was the most serious on day 7; a marked pulmonary fibrosis formed on day 28; the level of hydroxyproline also peaked on day 28, and the contents of p-JNK and type I collagen were higher than in group N（F=277.87,472. ,51, both P~ 0.01）. Group T, SP and T＋SP showed mild alveolitis and fibrosis at all time points, and their levels of hydroxyproline, p-JNK and type 1 collagen were remarkably decreased as compared with group M （F= 14.77, 61.59,101.73, all P〈0.01;F= 10.33,79.12,57.48, all P〈0.01）.No significant difference in p-JNK was found between group SP and group T-uSP. Conclusions Thalidomide may inhibit the over expression of type I collagen in pulmonary fibrosis rats via inhibiting the JNK signaling pathway, thereby reducing bleomyein-induced pulmonary interstitial fibrosis in rats.