Electroacupuncture Enhances The Anti-Pulmonary Fibrosis Effect Of Bone Marrow Mesenchymal Stem Cells In Rats

Objective To study whether electroacupuncture at Zusanli and Feishu points can enhance the role of bone marrow mesenchymal stem cells(MSC)in alleviating bleomycin-induced pulmonary fibrosis(PF)in rats.Methods 6-week-old clean male SD rats were randomly divided into 5 groups(n= 6 in each group): control group(group C),pulmonary fibrosis group(group B),pulmonary fibrosis + MSC group(BM group),pulmonary fibrosis + electroacupuncture stimulation group(BE group)and pulmonary fibrosis + electroacupuncture + MSC group(BME group).Except for the normal control group,the pulmonary fibrosis models were established by aerosol inhalation of bleomycin 5mg/kg in other groups.On the 15 th day after human bleomycin inhalation,the rats in BM group and BME group were injected with 1ml PBS medium containing 106 MSC through tail vein,while the rats in group B were injected with the same volume of PBS at the corresponding time point.In BE group and BME group,bilateral Zusanli and Feishu acupoints were selected for electroacupuncture stimulation(sparse dense wave,frequency 2/15 Hz,stimulation intensity was suitable for slight tremor of limbs),30min/ days,a total of 28 days.On the 28 th day after inhalation of bleomycin or normal saline,all rats were killed to detect the pathomorphological changes of lung tissue,to evaluate the degree of pulmonary fibrosis according to Ashcroft score,to determine the content of hydroxyproline(HYP)in lung tissue,the content of TNF-α,IL-6 and IL-10 in bronchoalveolar lavage fluid(BALF),and the content of MDA,SOD activity,MPO activity and Nrf2 protein expression in lung tissue..Results Compared with group C,Ashcoft score,hydroxyproline content,MDA content,SOD activity,Nrf2 protein expression and MPO activity in group B were significantly higher than those in group C(P<0.05).the contents of TNF-α and IL-6 in BALF were significantly increased(P<0.05),but there was no significant difference in IL-10 content(P﹥0.05).Compared with group B,Ashcoft score,hydroxyproline content,MDA content,SOD activity and MPO activity in lung tissue of BE group and BM group decreased significantly(P<0.05),while the expression of Nrf2 protein had no significant difference(P﹥0.05).The contents of TNF-α and IL-6 in BALF decreased significantly,while the content of IL-10 increased significantly(P<0.05).Compared with BME group,Ashcoft score,hydroxyproline content,MDA content,SOD activity,Nrf2 protein expression and MPO activity in lung tissue of BE group and BM group were significantly increased(P<0.05),while TNF-α and IL-6 content in BALF were significantly increased,while IL-10 content was significantly decreased(P<0.05).Conclusion Electroacupuncture can enhance the role of MSC in alleviating BLM-induced pulmonary fibrosis in rats.The mechanism may be related to up-regulating the expression of Nrf2 and enhancing the ability of anti-oxidation and anti-inflammation..