Regulatory Effect Of Metformin On Bleomycin Induced Systemic Sclerosis Mice

Objective: Establishing the SSc mouse model to investigate the therapeutic effect of different doses of Metformin and explore the regulation of Metformin on balance of Th17/Treg in SSc.Methods: 1.Grouping and approach: All mice were divided into normal control group(group A),model control group(group B),high dosage(200mg/kg)MET group(group C),middle dosage(100mg/kg)MET group(group D)and low dosage(50mg/kg)MET group(group E).Daily 0.1 ml normal saline was injected intracutaneously into the backs of group A,and others were injected with 0.1 ml(100?g/0.1ml)BLM.Two hours later,group C,D,E were injected intraperitoneally with corresponding concentrations of MET,group A and group B were injected 0.1 ml normal saline.2.Index determination: All animals need to be put to death after four weeks and keep skin tissue.Observing the pathological changes of skin tissue by HE and Masson staining.The content of hygroxyproline were measured and the levers changes of the ?-SMA,IL-17 and Foxp3 were detected by immunohistochemical.Results: 1.HE staining: Compared with the control group,the skin thickness of model group and treatment group were increased(p<0.05),especially model group,collagen fiber obviously swelled,accompanied by inflammatory cells infiltration.Compared with the model group,the skin thickness of high and middle dosage MET group were decreased(p<0.05),but the differences between the model group and low dosage MET group was not statistically significant(p>0.05).2.Masson staning: Compared with the control group,the collagen thickness of model group and treatment group were increased(p<0.05).Compared with the model group,the collagen thickness of high dosage MET group and middle dosage MET group were decreased(p<0.05),but the differences between model group and low dosage MET group was not statistically significant(p>0.05).3.The expression of ?-SMA: Compared with the control group,the expression of ?-SMA of model group and treatment group were increased(p<0.05).Compared with the model group,the expression of ?-SMA of high dosage MET group was decreased(p<0.05),but the differences between model group,middle dosage MET group and low dosage MET group was not statistically significant(p>0.05).4.Content of hygroxyproline: Compared with the control group,the content of hygroxyproline of model group,middle dosage MET group and low dosage MET group were increased(p<0.05),but the differences between control group and high dosage MET group was not statistically significant(p>0.05).Compared with the model group,the content of hygroxyproline of high group was decreased(p<0.05),but the differences between model group,middle dosage MET group and low dosage MET group was not statistically significant(p>0.05).5.The expression of IL-17: Compared with the control group,the expression of IL-17 of model group,middle dosage MET group and low dosage MET group were increased(p<0.05).Compared with the model group,the expression of IL-17 of high dosage MET group and middle dosage MET group were decreased(p<0.05),but the differences between model group and low dosage MET group was not statistically significant(p>0.05). 6.The expression of Foxp3: Compared with the control group,the expression of Foxp3 of model group,middle dosage MET group and low dosage MET group were decreased(p<0.05).Compared with the model group,the expression of Foxp3 of treatment group were increased(p<0.05),but the differences between the treatment groups was not statistically significant(p>0.05).7.The ratio of IL-17/Foxp3: Compared with the control group,the ratio of IL-17/Foxp3 of model group,middle dosage MET group and low dosage MET group were increased(p<0.05).Compared with the model group,the ratio of IL-17/Foxp3 of middle dosage MET group and low dosage MET group were decreased(p<0.05),and middle dosage MET group were decreased than low dosage MET group(p<0.05).Conclusion: 1.Metformin can effectively alleviate the skin fibrosis of SSc mouse which in a dose-dependent manner.2.Metformin can relieve symptoms and decreaes skin fibrosis of SSc mouse by modulating the balance of Th17 and Treg effectively.