Study Of Theraputic Effect And Related Mechanism Of Syn-HSCT In T1DM Mice

Objection:1.To establish T1DM animal model in C57BL/6J mice of inbred line by low dose STZ continuous intraperitoneal injection.2.To observe theraputic effect of Syn-HSCT in T1DM mice.3.To observe the change of CD4⁺/CD8⁺,CD19⁺,NK,Th1/Th2 and Treg cell proportion before and after Syn-HSCT and approach the possible mechanism of effectiveness.Section 1:Establishing T1DM mouse model.Methods:C57BL/6J mice were injected intraperitoneally with 40 mg/kg body weight of streptozotocin for 5 consecutive days to induce T1D. Diabetic status was confirmed by measurement of blood glucose from day 8 after the first SZ injection.Mice were classified diabetic when fasting blood glucose was＞13.9 mM(250 mg/dl)for 2 consecutive days.Results:The level of blood glucose of normal mice is unchanged,and the weight of mice is increasing.On day 8 after the first SZ injection,fasting blood glucose was＞13.9 mM,and mice have symptom of high blood glucose.Before administration,fasting blood glucose of two group is 6.77±1.46 and 6.28±1.29,p＞0.05.After administration,fasting blood glucose of normal mice is 6.37±1.31 while sickness is 16.71±2.40, P＜0.05.Mortality of establishing T1DM mouse model is about 5%, achievement ratio is about 70%.Section 2:Effect of management to T1DM mice model by Syn-HSCT and changes of proportion of CD⁴+/CD8⁺ CD19⁺ NK cell in T1DM mice before and after treatmentMethods:T1DM mice were randomly divide into two group- disease and transplantation.Syn-HSCT was carried out following the pretreatment of 8Gy ⁶⁰Co y rays radiation;then,prepared bone marrow cells from normal mice were infused into T1DM mice.Normal mice and T1DM mice were control groups.The level of blood glucose of all mice were observed continuously;the proportion of CD19⁺ CD4⁺/CD8⁺ NK lymphocyte subpopulation in peripheral blood were tested by flow cytometry on the 120th day after Syn-HSCTResults:The level of blood glucose descend markedly compared with T1DM control group(P＜0.05),and there are significant descend in the proportion of CD4/CD8 and NK cell while significant raise in CD19 in peripheral blood between before and after Syn-HSCT in T1DM mice.Section 3:Changes of proportion of CD4⁺CD25⁺Foxp3 Thl/Th2 cell in T1DM mice before and after Syn-HSCTMethods:T1DM mice were randomly divide into two group- disease and transplantation.Syn-HSCT was carried out following the pretreatment of 8Gy ⁶⁰Co y rays radiation;Then,prepared bone marrow cells from normal mice were infused into T1DM mice.Normal mice and T1DM mice were control groups.The proportion of Treg and Th1/Th2 lymphocyte subpopulation in spleen were tested by flow cytometry on the 120th day after Syn-HSCTResults:There are significant ascend in the proportion of Treg and Th1 cell before Syn-HSCT in T1DM mice and significant descend after that in spleen.Conclusion1.We established T 1DM mouse model with C57BL/6J mice of inbred line by low dose STZ continuous intraperitoneal injection.2.It is effective to treat T1DM mice by Syn-HSCT.3.There are significant descend in the proportion of CD4/CD8,NK Th1/Th2 and Treg cell while significant ascend in the proportion of CD19 positive cell in T1DM mouse model after Syn-HSCT.It is maybe concerned with the mechanism of effectiveness.