Notch信号通路调控巨噬细胞极化在大鼠纤维化型饲鸽者肺的作用

Role of Notch signal pathway in regulating macrophage polarization in the lung of rats with fibrotic pigeon feeder

目的探讨Notch信号通路调控巨噬细胞极化方向与大鼠纤维化型饲鸽者肺的关系。方法选取正常SD大鼠(Ctrl组),通过观察病理、CT,检测纤维化标记物构建纤维化型过敏性肺炎大鼠模型(M组),予以γ分泌酶(DAPT)抑制Notch信号通路(M+DAPT组),通过荧光定量PCR技术检测阻断Notch信号通路对巨噬细胞极化方向的影响。结果正常大鼠气道内滴注致敏原冻干粉20周后,病理及CT可见纤维化形成,且α-SMA、TGF-β1表达水平增高,证实造模成功;M组与Ctrl组比较:纤维化型过敏性肺炎大鼠肺组织Notch信号通路关键蛋白配体,DLL1、DLL4、JAG1、JAG2及受体Notch1、Notch2的蛋白表达水平增高;应用DAPT抑制Notch信号通路后DLL4、JAG1、JAG2及受体Notch1均下降(P<0.05);M组较Ctrl组比较:M1型巨噬细胞标记基因肿瘤坏死因子(TNF-α)、诱导型一氧化氮合酶(iNOS)mRNA表达量下降;M2型巨噬细胞标记基因甘露糖受体C2(Mrc2)、重组人精氨酸酶1(Arg-1)mRNA表达量升高(P<0.05),应用DAPT抑制剂后TNF-α、iNOS基因mRNA的相对表达量升高,Mrc2、Arg-1基因mRNA的相对表达量降低(P<0.05)。结论Notch信号通路调控巨噬细胞极化方向,给予DAPT抑制剂后,抑制巨噬细胞向M2型极化,有效延缓纤维化形成。

Objective To explore the relationship between the Notch signaling pathway regulating the polarization direction of macrophages and the lungs of rat fibrotic pigeon feeders.Methods Normal SD rats(the control group)were selected,and a fibrotic allergic pneumonia rat model(the M group)was constructed by observing pathology,CT,and detecting fibrotic markers.γsecretory enzymes(DAPT)inhibiting the Notch signaling pathway was taken as the M+DAPT group.It used fluorescence quantitative PCR technology to detect the effect of blocking the Notch pathway on the polarization direction of macrophages.Results 20 weeks after intratracheal instillation of allergen freeze-dried powder in normal rats,fibrosis formation was observed in pathology and CT,and the levels ofα-SMA and TGF-β1 increased,which confirmed the successful modeling.The protein expression levels of the key protein ligands DLL1,DLL4,JAG1,JAG2 in the Notch signaling pathway and the receptors Notch1 and Notch2 in the lung tissue of rats with fibrotic allergic pneumonia increased.The application of DAPT to inhibit the Ntoch signaling pathway resulted in a decrease in DLL4,JAG1,JAG2,and receptor Notch1(P<0.05).Compared with the control group,the expression levels of M1 type macrophage marker genes TNF-a and iNOS mRNA decreased in the M group.The mRNA expression levels of M2 macrophage marker genes Mrc2 and Arg-1 increased(P<0.05),and the relative expression levels of TNF-αand iNOS gene mRNA increased after the use of DAPT inhibitors,while the relative expression levels of Mrc2 and Arg-1 gene mRNA decreased(P<0.05).Conclusion The Notch signaling pathway regulates the polarization direction of macrophages,and administration of DAPT inhibitors inhibits macrophage polarization towards M2 type,effectively delaying fibrosis formation.