Mesenchymal stem cells-derived exosomes attenuate radiation-induced pulmonary fibrosis by inhibiting the NF-κB signaling pathway

WANG Li-li; LIU Yu; YANG Zi-en; OUYANG Ming-yue; XING Si-ning; YIN Zong-tao; YU Hui-ying

doi:10.16048/j.issn.2095-5561.2024.05.09

Abstract：Objective To explore the effect and potential mechanism of mesenchymal stem cells-derived exosomes(MSCs-EXO)on radiation-induced pulmonary fibrosis(RIPF).Methods Human umbilical cord derived MSCs were isolated and cultured,and their exosomes(EXO)were collected.Exosomes were identified by western blot,nanoparticle tracking analysis and transmission electron microscopy.Fifteen SD rats were randomly divided into control group,irradiation(IR)group and IR+MSCs-EXO(IR+EXO)group,with five rats in each group.The rats in IR group and IR+EXO group were given a single dose of 30 Gy to the right lung.At 1 h and 14 d after irradiation,1×109 exosomes/kg were injected via tail vein in IR+EXO group.Rats in the control group and IR group were simultaneously injected with equal volume of normal saline via tail vein.The rats in each group were sacrificed at 12th week after irradiation,and the fresh lung tissues on the right side of the rats were collected.He and Masson staining were used to detect the pathological damage and collagen fiber deposition of lung tissue.Immunohistochemical staining and RT-qPCR were used to detect the expression of fibrosis related molecules α-SMA and COL1A1 in lung tissue.Western blot was used to detect the expression of NF-κB signaling pathway related molecules in lung tissue.Results At 12th week after irradiation,compared with IR group,the pathological damage of lung tissue in IR+EXO group was significantly reduced,and the Ashcroft score was significantly lower than that in IR group(P<0.001).The deposition of collagen fibers in lung tissue of IR+EXO was significantly reduced,and the collagen volume fraction was significantly lower than that of IR group(P<0.001).The positive expression levels of α-SMA and COL1A1 proteins in the IR+EXO group were significantly lower than those in the IR group,and the mRNA expression levels of α-SMA and COL1A1 were also significantly lower than those in the IR group(P<0.01).Compared with the IR group,the p-NF-κB p65(Ser536)protein expression in the IR+EXO group was significantly downregulated(P<0.01),the expression of α-SMA and COL1A1 proteins was also significantly downregulated(P<0.01).Conclusion MSCs-EXO may alleviate radiation-induced pulmonary fibrosis by inhibiting NF-κB signaling pathway.