Foxp3在小鼠肺发育中的动态表达及意义

Dynamic expression and significance of Foxp3 in the development of mouse lung

目的:通过分析叉头样转录因子3(forkhead box protein 3,Foxp3)在小鼠肺发育过程中的表达及其与肺发育相关标志物之间的关系,探讨Foxp3在肺发育中的可能作用。方法:根据小鼠肺发育的进程,选取胎鼠及新生鼠分为6组,分别于孕17.5 d及出生后1、4、7、14、21 d留取肺组织,HE染色观察肺组织形态,免疫组织化学染色检测CD31含量并观察肺微血管密度。qRT-PCR检测Foxp3及肺表面活性蛋白C(surfactant protein C,SP-C)、血管内皮生长因子A(vascular endothelial growth factor A,VEGF-A)、血管生成素-1(angiopoietin 1,Ang-1)mRNA表达,蛋白质印迹法检测Foxp3及SP-C、VEGF-A、Ang-1蛋白表达。结果:肺组织内Foxp3 mRNA在孕17.5 d小管期表达最高,后呈现不断减少趋势。SP-C mRNA在小鼠出生后1 d表达最高,随后逐渐减弱,直至肺泡化晚期。VEGF-A、Ang-1 mRNA在孕17.5 d表达最高,之后呈现不断减少趋势,最终趋于稳定。Foxp3蛋白在小管期已有表达,且在小管期及囊泡期表达最高,其后逐渐趋于平稳,VEGF-A及Ang-1在小管期及囊泡期表达亦最高,后逐渐减少;SP-C表达于出生后1 d达到最高,随后逐渐减少,并于肺泡化中晚期趋于平稳。相关性分析显示,Foxp3与SP-C、VEGF-A及Ang-1存在相关性(r分别为0.661、0.630和0.738)。结论:Foxp3在胎肺期及出生后早期呈现动态表达,Foxp3在小管期及囊泡早中期的高表达与SP-C、VEGF-A及Ang-1呈正相关,提示Foxp3可能促进肺泡上皮细胞及肺血管内皮细胞的增殖,参与肺发育过程。

Objective:To explore the possible role of forkhead box protein 3(Foxp3)in lung development by analyzing the dynamic expression of Foxp3 during mouse lung development and its relationship with lung development related markers.Methods:According to the process of lung development,fetal and newborn mice were divided into 6 groups.Lung tissues were taken at 17.5 days of pregnancy and 1 day,4 days,7 days,14 days and 21 days after birth.Lung morphology was observed by HE staining,CD31 content was detected by immunohistochemical staining and pulmonary microvessel density was observed.The expression of Foxp3 and surfactant protein C(SP-C),vascular endothelial growth factor A(VEGF-A),angiopoietin 1(Ang-1)mRNA was detected by qRT-PCR,and the protein expression of Foxp3 and SP-C,VEGF-A,Ang-1 was detected by Western blotting.Results:The expression of Foxp3 mRNA in lung tissue was the highest in the tubule stage at E17.5 d,and then decreased continuously.The expression of SP-C mRNA was the highest at 1 day after birth,and then decreased gradually until the late stage of alveolization.The expression of VEGF-A and Ang-1 mRNA was the highest at E17.5 d,then decreased gradually,and finally tended to be stable.The expression of Foxp3 protein was found in the tubule stage,and the expression was the highest in the tubule phase and vesicular phase,and then gradually stabilized.The expression of VEGF-A and Ang-1 was also the highest in the tubule and vesicular phase,and then decreased gradually,while the expression of SP-C reached the peak at 1 day after birth,then decreased gradually,and tended to be stable in the middle and late stage of alveoli.Correlation analysis showed that Foxp3 was correlated with SP-C,VEGF-A and Ang-1(r=0.661,0.630 and 0.738).Conclusion:Foxp3 showed dynamic expression in fetal lung and early postnatal stage.The high expression of Foxp3 in tubule stage and early and middle vesicle stage was positively correlated with SP-C,VEGF-A and Ang-1,suggesting that Foxp3 may promote the proliferation of alveolar epithelial cells and pulmonary vascular endothelial cells and participate in the process of lung development.