目的:评价正常小鼠血清对小鼠放射性肺炎的治疗作用并探讨其可能的作用机制。
方法:由胸部辐射暴露引起的放射性肺炎的小鼠模型在暴露后立即给予100μL正常小鼠血清或生理盐水的静脉内注射,随后每隔一天注射一次,共注射8次。在照射后的第15天,使用HE染色检查小鼠肺的组织病理学变化,TNF-α的水平,TGF-β,ELISA法检测肺组织和血清中IL-1α和IL-6,用流式细胞术分析肺组织中淋巴细胞的百分比。进行外泌体miRNA的高粗测序以探索信号通路的变化。qRT-PCR检测免疫相关基因的mRNA表达水平,talin-1、tensin2、FAK、维古林,蛋白质印迹法检测粘着斑信号通路中的α-肌动蛋白和桩蛋白。
结果:在小鼠放射性肺炎模型中,注射正常小鼠血清显著降低肺脏器系数,降低了TNF-α的水平,TGF-β,血清和肺组织中的IL-1α和IL-6,和改善CD45+的浸润,肺组织中CD4+和Treg淋巴细胞(均P<0.05)。Egfr和Pik3cd基因在mRNA和蛋白水平上的表达水平以及talin-1,tensin2,FAK,维古林,α?在正常小鼠血清处理后,小鼠模型中的actinin和paxillin均显着下调。
结论:正常小鼠血清通过抑制黏着斑信号通路中关键蛋白的表达来改善小鼠放射性肺炎。
OBJECTIVE: To evaluate the therapeutic effect of normal mouse serum on radiation pneumonitis in mice and explore the possible mechanism.
METHODS: Mouse models of radiation pneumonitis induced by thoracic radiation exposure were given intravenous injections of 100 μL normal mouse serum or normal saline immediately after the exposure followed by injections once every other day for a total of 8 injections. On the 15th day after irradiation, histopathological changes of the lungs of the mice were examined using HE staining, the levels of TNF-α, TGF-β, IL-1α and IL-6 in the lung tissue and serum were detected using ELISA, and the percentages of lymphocytes in the lung tissue were analyzed with flow cytometry. Highth-roughput sequencing of exosome miRNA was carried out to explore the changes in the signaling pathways. The mRNA expression levels of the immune-related genes were detected by qRT-PCR, and the protein expressions of talin-1, tensin2, FAK, vinculin, α-actinin and paxillin in the focal adhesion signaling pathway were detected with Western blotting.
RESULTS: In the mouse models of radiation pneumonitis, injections of normal mouse serum significantly decreased the lung organ coefficient, lowered the levels of TNF-α, TGF-β, IL-1α and IL-6 in the serum and lung tissues, and ameliorated infiltration of CD45+, CD4+ and Treg lymphocytes in the lung tissue (all P < 0.05). The expression levels of Egfr and Pik3cd genes at both the mRNA and protein levels and the protein expressions of talin-1, tensin2, FAK, vinculin, α?actinin and paxillin were all significantly down-regulated in the mouse models after normal mouse serum treatment.
CONCLUSIONS: Normal mouse serum ameliorates radiation pneumonitis in mice by inhibiting the expressions of key proteins in the Focal adhesion signaling pathway.