降钙素基因相关肽对肺纤维化大鼠肺组织eIF3a、p27表达的影响  

Effects of calcitonin gene-related peptide on e IF3a and p27 expression in bleomycin-induced pulmonary fibrosis of rats

作　　者：李先伟[1] 左东泽 沈媛媛[1] 郝伟[1] LI Xian-wei ZUO Dong-ze SHEN Yuan-yuan HAO Wei(Department of Pharmacology, Wannan Medical College, Wuhu 241002, China)

机构地区：[1]皖南医学院药理学教研室,安徽芜湖241002

出　　处：《中国应用生理学杂志》2017年第1期16-21,共6页Chinese Journal of Applied Physiology

基　　金：安徽省自然科学基金资助项目(1408085QH168)

摘　　要：目的:观察降钙素基因相关肽(CGRP)对肺纤维化大鼠肺组织真核翻译起始因子3a(e IF3a)、p27表达的影响,探讨CGRP在肺纤维化中的作用及机制。方法:雄性SD大鼠,体重180~220 g,随机分为3组(n=8):对照组、博莱霉素组、博莱霉素+辣椒素组。采用气管内注射博莱霉素(5 mg/kg)诱导肺纤维化大鼠模型。造模前4 d大鼠皮下注射辣椒素(Capsaicin)(50 mg/kg·d),造模后第28天处死动物,颈动脉采血ELISA法测定血浆CGRP含量。细胞实验分6组(n=9):Control组,转化生长因子-β1(TGF-β1)组,CGRP(1、10、100 nmol/L)组,CGRP8-37 1μmol/L和CGRP 100 nmol/L组。细胞用CGRP和(或)CGRP8-37预处理1 h,再用TGF-β1(5 ng/ml)处理48 h。5-溴脱氧尿嘧啶核苷(Brd U)法检测细胞增殖。免疫组化、real-time PCR和(或)Western blot检测e IF3a、p27、α-平滑肌肌动蛋白(α-SMA)、collagenⅠm RNA及蛋白表达。结果:博莱霉素诱发肺纤维化动物肺组织e IF3a、α-SMA及Ⅰ胶原表达增高,CGRP及p27的表达明显降低。外源性CGRP可剂量依赖性的抑制TGF-β1诱导的肺成纤维细胞增殖,明显抑制e IF3a、α-SMA、Ⅰ胶原的表达,上调p27的表达,这些作用可以被CGRP阻断剂CGRP8-37所取消。结论:CGRP在博莱霉素诱导的肺纤维化中起着重要作用,可能通过抑制e IF3a、上调p27的表达而抑制肺成纤维细胞的增殖,进而抑制肺纤维化的形成与发展。Objective： To observe the effects of calcitonin gene-related peptide（ CGRP） on eukaryotic translation initiation factor3a（ e IF3a） and p27 expression in bleomycin-induced pulmonary fibrosis of rats and its possible mechanism. Methods： Twenty-four male SD rats weighing 180 - 220 g were randomly divided into three groups（ n = 8） ： control group,bleomycin group,bleomycin plus capsaicin group. Bleomycin（ 5 mg / kg） was used to induce pulmonary fibrosis rat model. Rats were given capsaicin（ 50 mg / kg·d）by subcutaneous injections 4 days before to deplete endogenous CGRP. At the end of experiments,blood samples were collected from carotid artery to determinate the plasma levels of CGRP by ELISA. The cells were divided into 6 groups as follows： control group,transforming growth factor-β1（ TGF-β1） group,＋ CGRP（ 1,10,100 nmol / L） group,＋ CGRP 100 nmol / L and CGRP8-37 1 μmol /L group respectively（ n = 9）. TGF-β1（ 5 ng / ml） stimulated proliferation of pulmonary fibroblasts and proliferation was measured by Brd U marking. The expression levels of e IF3 a,p27,α-smooth muscle actin（ α-SMA） and collagen Ⅰ were detected by immunohistochemisty,real-time PCR or Western blot. Results： The expressions of e IF3 a,α-SMA,and collagen I were increased and the expression of p27 was decreasing in pulmonary fibrosis rats induced by bleomycin. Exogenous application of CGRP significantly inhibited TGF-β1-induced proliferation and differentiation of pulmonary fibroblasts and the expressions of α-SMA,collagen I and e IF3 a,and upregulated the expression of p27. All these effects of CGRP were abolished in the presence of CGRP8-37. Conclusion： These results suggest that endogenous CGRP is related to the development of pulmonary fibrosis induced by bleomycin,and the inhibitory effect of CGRP on proliferation of lung fibroblasts involves the e IF3 a / p27 signaling pathway.

关 键 词：降钙素基因相关肽 肺纤维化 肺成纤维细胞 eIF3a P27 大鼠 

分 类 号：R966[医药卫生—药理学]