α1-肾上腺素受体对胶原诱导性关节炎小鼠Treg细胞功能的影响

Effects of α1-adrenoreceptor on Treg cell function in collagen-induced arthritis

目的:利用胶原诱导性关节炎(CIA)模型小鼠,探讨去甲肾上腺素(NE)及其α1-肾上腺素受体(AR)对CIA小鼠Treg细胞的作用。方法:雄性DBA/1小鼠32只,随机分为对照组(n=8)和CIA模型组(n=24)。II型胶原(CII)乳剂100μl尾根部注射DBA/1小鼠制备CIA小鼠模型,在初次免疫后第41日,用免疫荧光法检测小鼠脾脏中CD4^(+)T与α1-AR的共定位情况;用Western blot法检测小鼠踝关节和脾脏中α1-AR的蛋白表达。分离纯化CIA小鼠脾脏中CD4^(+)T细胞,用抗CD3和抗CD28的单克隆抗体刺激CD4^(+)T细胞,进行细胞培养,分为未加药组和加药组,加药组用NE或α1-AR激动剂苯肾上腺素(phenylephrine)处理细胞,用流式细胞术检测CIA小鼠CD4^(+)T细胞中Treg的细胞数;用Western blot法检测CIA小鼠CD4^(+)T中转化生长因子-β(TGF-β)和IL-10的蛋白表达。结果:CD4^(+)T细胞能够表达α1-AR;与对照组相比,CIA小鼠踝关节和脾脏中α1-AR的蛋白表达显著降低(P<0.01);与未加药的CIA小鼠的CD4^(+)T细胞相比,NE加入后的CIA小鼠CD4^(+)T细胞中Treg细胞的功能显著增强(P<0.01);α1-AR激动剂phenylephrine加入后的CIA小鼠CD4^(+)T细胞中Treg细胞的功能显著增强(P<0.01)。结论:激活CIA小鼠CD4^(+)T细胞上的α1-AR可增强Treg细胞的功能,促进CD4^(+)T细胞向Treg细胞方向分化,发挥抗炎作用。

Objective:An animal model of collagen-induced arthritis(CIA)was used to investigate the effects of norepinephrine(NE)and α1-adrenoreceptor( α1-AR)on Treg cells in CIA.Methods:Thirty-two male DBA/1 mice were randomly divided into control group and CIA model group.CIA was prepared by intradermal injection of collagen type II(CII,100μl)at the tail base of DBA/1 mice.On the 41 th day following primary immunization,co-expression of CD4^(+)T and α1-AR in mouse spleens was observed.Protein expressions of α1-AR in the ankle joints and the spleens of mice were measured by Western blot analysis.The CD4^(+)T cells were isolated from the mouse spleen tissues in CIA mice and treated with NE or α1-AR agonist phenylephrine.Percentage of Treg cells in mouse CD4^(+)T cells of CIA mice was determined by flow cytometry.Expressions of α1-AR,transforming growth factor-β(TGF-β)and IL-10 in CD4^(+)T cells of CIA mice were assessed by Western blot.Results:Co-expression of CD4 and α1-AR was observed in spleens of both intact and CIA mice.Compared with intace mice, α1-AR expressions in the ankle joints and spleens were down-regulated in CIA mice.NE increased the function of Treg cells in CD4^(+)T cells of CIA mice compared with that of nothing-treated CD4^(+)T cells of CIA mice.Moreover,the α1-AR agonist phenylephrine increased the Treg cell function in CD4^(+)T cells of CIA mice relative to that of nothing-treated CD4^(+)T cells of CIA mice.Conclusion:Activating α1-AR on CD4^(+)T cells of CIA mice enhances Treg cell function,facilitating a shift of CD4^(+)T cells toward Treg polarization.