| Objective:To investigate the effect and mechanism of Brahma-rela ted gene 1（Brg1）on the number and function of type 2 alveolar e-pith elial cells in C57BL/6 mice.Methods:6-8 weeks female C57BL/6 mice were used as wild type control group（WT）,and Brg1fl/fl group with Brg1 gene knockout in type II alveolar epithelial cells（n=8）.Immunohistochemistry and immunofluorescence was used to determine the number of Surfactantassocia-ted protein C（SFTPC）positive cells in the pulmonary alveoli.The percentage of Prosurfactant Protein C（pro SP-C）cells was analyzed by flow cytometry.Western blot was used to detected the expression levels of pro SP-C、SFTPC、Surfactantassociated protein A（SFTPA）and Surfact-antassociated protein D（SFTPD）in lung tissue of each group.The expression levels of CyclinD1 and the key proteins EGFR,p-EGFR,PI3K,p-PI3K,AKT,p-AKT,NF-κB p65 in the proliferation-related signal transduction pathway were detected by Western blot.Results:Anti-SFTPC immunohistochemistry and immunofluores-ce nce showed that the number of SFTPC positive cells in Brg1fl/fl mice w as significantly higher than that in WT mice（P<0.05）.The flow cyto-m etry showed that the percentage of pro SP-C positive cells significantly increased in the Brg1fl/fl group（p<0.05）.AECIIs secreting functional prot eins pro SP-C,SFTPC,SFTPA and SFTPD were significantly increased in Brg1fl/fl mice（P<0.05）;Knockout of Brg1 promoted the expression of NF-κB p65 and CyclinD1（p<0.05）.The ratios of p-EGFR/EGFR、p-PI3K/PI3K and p-AKT/AKT in Brg1fl/fl mice were significantly increa sed（p<0.05）.Conclusion:Specific knockout of Brg1 in typeⅡalveolar epithelial cells of C57BL/6 mice could increase the number and function of AECIIs.The possible mechanism was that knocking out Brg1 promoted the activation of EGFR/PI3K/AKT/NF-κB signaling pathway,and increasing the expression of the protein CyclinD1,which lead to an increasing in the number and secreted protein of AECIIs in mice. |
PDF Full Text Request