BALB/c小鼠1型糖尿病模型的构建与CD4^+ CD25^+ Treg的检测

Establishment of type 1 diabetic BALB/c mouse models and detection of CD4^+ CD25^+ regulatory T cells

目的探讨链脲佐菌素(streptozotocin,STZ)诱导BALB/c小鼠1型糖尿病模型的方法,检测糖尿病模型中CD4+CD25+调节性T细胞(regulatory T cell,Treg)的变化及意义。方法将60只雄性BALB/c小鼠随机分为A、B、C、D 4组,每组15只,A组采用一次性腹腔注射150 mg/kg STZ,B组采用一次性腹腔注射与A组等量无菌柠檬酸缓冲液,C组采用200 mg/kg STZ分5次腹腔注射,D组采用与C组等量无菌柠檬酸缓冲液分5次腹腔注射,监测不同时点空腹血糖变化,A、B、C、D 4组均自由饮食。用流式细胞术检测成模前后外周血Treg细胞数的变化。结果 A组糖尿病成模率为86.67%,血糖在3周后稳定在较高水平且无明显下降;C组糖尿病成模率为93.33%,血糖的动态变化与A组相似;两组糖尿病成模率相比差异无统计学意义(P>0.05);B、D组无糖尿病成模;非成模组与成模组外周血CD4+CD25+Treg分别为(4.05±0.37)%和(8.68±0.45)%,差异有统计学意义(P<0.05)。结论采用一次性腹腔注射STZ是构建BALB/c小鼠1型糖尿病模型较为理想的方法。外周血CD4+CD25+Treg的比例可作为1型糖尿病模型构建成功的参考指标。

Objective To establish type 1 diabetic BALB/c mouse models and investigate the significance of CD4^＋ CD25 ^＋ regulatory T cells （Treg） in T1DM. Methods Sixty BALB/e mice were randomly divided into four groups （n = 15）. BALB/e mouse diabetic models were established with single intraperitoenal （ip） injection of 150 mg/kg of streptozotocin （STZ） and 5 separated ip injection of 40 mg/kg of STZ in Group A and Group C, respectively, while con- trois were set up with corresponding injections of citrate buffer solution in Group B and Group D, respectively. Blood sugar level was measured. The frequency of CD4 ^＋ CD25^＋ Treg ceils in peripheral blood was determined by flow cytometry. Resuits Type 1 diabetes mellitus （T1DM） was observed in 86. 67% and 93.33% mice of Group A and Group C, respectively, with suspended high blood glucose since the 21 th day. No significant difference was revealed between Group A and C （ P 〉 0. 05 ）. The peripheral CD4 ^＋ CD25^＋ Treg cell proportioh was significantly lower in model groups than that in control group [ （4. 05 ± 0. 37） % vs （8.68 ± 0. 45 ） %, P 〈 0. 05 ]. Conclusion Single intraperitoneal injection of STZ is an effective method in construction of BALB/c T1DM mouse.