雷帕霉素对肺间质纤维化大鼠IL-17、IL-2、TGF-β和IL-6及调节性T细胞的影响

Augmentation of IL-17,IL-2,TGF-β,IL-6 and CD4^+ CD25^+ Foxp3^+ Regulatory T Cells by rapamycin to repression of pulmonary fibrosis in rats

目的研究雷帕霉素对大鼠肺纤维化的影响及其机制。方法 SD大鼠15只,随机分为博来霉素5只,生理盐水对照组5只,雷帕霉素干预组5只。采用气管内注入博来霉素(5 mg·kg-1)的方法复制大鼠肺纤维化模型。对照组采用气管内注入生理盐水(1.25 mL·kg-1)的方法制造阴性对照。气管灌注博来霉素后第3天给予雷帕霉素干预组大鼠雷帕霉素灌胃(每天1 mg·kg-1),连续10 d达到雷帕霉素对肺纤维化的干预。第28天分别处死动物,肺组织病理切片HE染色,免疫组织化学方法检测IL-17、IL-2、TGF-β和IL-6的表达;流式细胞术检测CD4+调节性T细胞和CD8+调节性T细胞的比例。结果雷帕霉素干预组肺纤维化严重程度较博来霉素组明显减轻,Ashcroft评分存在统计学差异(P<0.01);IL-6、IL-17、TGF-β和IL-2表达水平在博来霉素组较正常对照组和雷帕霉素干预组升高(P<0.01)。雷帕霉素组的IL-17、TGF-β的表达水平较对照组升高(P<0.01),但是较博来霉素组降低(P<0.01)。各组总体样本数据行相关分析提示IL-6和IL-17表达水平具有正相关性,IL-17与TGF-β表达水平也具有正相关性。雷帕霉素干预组CD4+CD25+Foxp3+细胞占CD4+CD25+细胞、CD4+细胞和淋巴细胞百分比较对照组升高,CD8+CD25+Foxp3+细胞的相关比例也较对照组和博来霉素组升高,并具有统计学差异(P<0.05)。博来霉素组CD8+CD25+Foxp3+细胞占CD8+CD25+细胞百分比较对照组高,并具有统计学差异(P<0.01)。结论雷帕霉素具有抑制肺纤维化的作用,其抗纤维化的作用可能通过促进调节性T细胞作者:雨林木风的诱导增殖及其对Th17细胞等效应性细胞的抑制作用发挥来实现。

Objective To study the influence of rapamyeln on pullnonaty fibrosis in rats and its lnechatlisln. Methods Pullnonaty fibro- sis lnodel was induced by using the lnethod of intratracheal instillation of bleomycin （5 mg · kg -1 ）. Control group was treated by intratra- cheal instillation of saline （ 1.25 mL · kg-l ） to obtain the negative cotttroh The rats of the rapamycin treated group were given rapamycin （ 1 mg · kg i per day） by gastric perfusion for consecutive 10 days beginning on the third day after intratracheal instillation of bleomycin. On the day of 28th all rats were sacrificed and the peripheral blood and the lung tissues were harvested. The lung tissue were perforlned HE staini.g. And the severity of pullnoiloi~ fibrosis in rats was assessed by Ashcroft score. The lung tissues were perforlned ilnlnunohisto- chemical staining to detect the expression of IL-6,IL-17,TGF-beta and IL-2. The expression levels were judged by integrated optical den- ally. flOW cytolnetry was used to detect the percentages of CD4 ＋ CD25 ＋ Foxp3 ＋ T cells, CD8 ＋ CD25 ＋ Foxp3 ＋ T cells. Results The severi- ty d ptdlnonary fibrosis was ilnproved in rats d rapamycin group, compared with the rats d bleomycin group. And there was significant difference in Ashcroft score（P 〈 0.01） between rapamycin group and bleomycin group. The expression levels d IL-6, IL-17,TGF-13 and IL-2 increased in bleomycin group,colnpared with the norlnal contrd group. The expression levels of IL-6, IL-17,TGF-13 and IL-2 de- creased in rapamycin group, colnpared with the bleomycin group. Correlation analysis for data suggested a positive correlation between IL- 6 and IL-17 expression levels. And the expression levels of IL-17 were positive correlated with TGF-13. The percentages of CD8 ＋ CD25 ＋ Foxp3 ＂T cells and CIN ＋ CD25 ＋ Foxp3 ＋ T cells increased in rapamycin group, colnpared with the norlnal control group and bleomycin group. Conclusions Rapamycin can prevent bleomycin-induced ptdlnonary fibrosis, and its antifibrotic effect maybe works by the prolno- tion of proliferation and function of regulatory T cells and the inhibition of prdiferation and function of Th17 cells.