Protection of exosomes derived from bone marrow mesenchymal stem cells of different mouse ages on radiation-induced lung injury

Zhang Tingting; Li Yalong; Yue Haodi; Li Yanjun; Geng Xiwen; Zhang Yuwei; Liu Xiaozhuan

doi:10.12307/2025.575

Abstract：BACKGROUND:Mesenchymal stem cells show extremely therapeutic potential for radiation-induced lung injury through delivering exosomes.Age is a primary factor affecting the function and biological efficacy of mesenchymal stem cells. OBJECTIVE:To investigate the protective effects of exosomes derived from bone marrow mesenchymal stem cells of different mouse ages on radiation-induced lung injury in mice. METHODS:Bone marrow mesenchymal stem cells of young mice and old mice were obtained by whole bone marrow adherent culture.The exosomes were isolated from the supernatant of passage 3 bone marrow mesenchymal stem cells.Ten 2-month-old C57BL/6J mice were randomly selected as the control group after anesthesia and not irradiated.The remaining 30 2-month-old C57BL/6J mice were used to establish a mouse radiation-induced lung injury model and were randomly divided into three groups.Exosomes derived from bone marrow mesenchymal stem cells of young mice,exosomes derived from bone marrow mesenchymal stem cells of old mice,and PBS were injected through the tail vein,respectively.The survival rate of mice was monitored.The lung function,lung inflammation and fibrosis were assessed at 1 and 12 weeks after irradiation. RESULTS AND CONCLUSION:(1)The concentrations of particles and proteins in exosomes derived from bone marrow mesenchymal stem cells of young mice were higher than those in exosomes derived from bone marrow mesenchymal stem cells of old mice.(2)Compared with the control group,the survival rate of mice in the PBS group was low,and lung inflammation was obvious at week 1 after irradiation,and the levels and mRNA expressions of interleukin-1β,interleukin-6,and tumor necrosis factor-α were increased.Collagen deposition in lung tissues was observed at week 12 after irradiation,and the mRNA level of E-cadherin was decreased,while the mRNA levels of α-smooth muscle actin,transforming growth factor-β1,and β-catenin were increased.(3)Compared with the PBS group,the survival rate of mice in the exosome group was significantly improved,and the level of proinflammatory factors and their mRNA expression were reduced at week 1 after irradiation,the mRNA level of E-cadherin was increased,and the mRNA levels of α-smooth muscle actin,transforming growth factor β1 and β-catenin were reduced at week 12 after irradiation.(4)Among all the above indicators,the therapeutic effect of exosomes derived from bone marrow mesenchymal stem cells of young mice was better than that of exosomes derived from bone marrow mesenchymal stem cells of old mice.(5)The results showed that exosomes derived from bone marrow mesenchymal stem cells of young mice contained more particles and proteins,and the effect of alleviating early inflammation and late fibrosis of radiation-induced lung injury in mice was better than that of exosomes derived from bone marrow mesenchymal stem cells of old mice.