髓系细胞特异性敲除G-CSFR对小鼠急性放射性肺炎进程的影响研究OA

Objective To investigate the impact of myeloid cell-specific knockout of the granulocyte colony-stimulating factor receptor(G-CSFR)on the progression of acute radiation pneumonitis.Methods Myeloid cell-specific G-CSFR knockout(G-CSFR-/-,Lyz2-cre)mice were constructed.G-CSFR-/-,Lyz2-cre and C57BL/6N mice underwent a single whole-body irradiation with 6.5 Gy of 60Co γ-rays to establish a model of radiation injury.The lung function of mice was assessed using a mouse lung function test system at 3,7 and 14-days post γ-ray irradiation.Pathological changes in the lung tissue were analyzed via hematoxylin and eosin(HE)staining of paraffin sections.Tumor necrosis factor-α(TNF-α)and interleukin-10(IL-10)levels were measured via radioimmunoassay.IL-8 and its receptor CXCR2 were quantified using enzyme-linked immunosorbent assay(ELISA).The infiltration of neutrophils in lung tissue was evaluated by immunohistochemical detection of myeloperoxidase.Results At 3-,7-and 14-days post-irradiation with 6.5 Gy of 60Co γ-rays,there were no significant differences observed in lung function or interstitial inflammatory lesions between G-CSFR-/-,Lyz2-cre mice and C57BL/6N mice.However,the infiltration of neutrophils in lung tissue of G-CSFR-/-,Lyz2-cre mice was significantly reduced(P＜0.01),and the levels of IL-8,CXCR2 and TNF-α in lung tissues were markedly lower than in C57BL/6N mice(P＜0.05).Conclusion The myeloid cell-specific knockout of G-CSFR can effectively diminish neutrophil infiltration as well as inflammatory cytokine levels in lung tissues following radiation exposure.