Exendin-4调控烫伤小鼠T淋巴细胞免疫功能的交感神经机制  

The sympathetic nervous system mechanism of exendin-4 in respect of modulating T cell- mediated immune response to severe burns in mice

作　　者：计小静 郝济伟 王丽雪[1,2] 董宁[2] 祝筱梅[2] 卢中秋[1] 张庆红[2] 姚咏明[1] 

机构地区：[1]温州医科大学附属第一医院急诊中心,浙江省温州325016 [2]解放军总医院第一附属医院创伤研究中心,北京100048

出　　处：《中华急诊医学杂志》2017年第6期644-649,共6页Chinese Journal of Emergency Medicine

基　　金：国家自然科学基金项目（81272089、81372054、81130035）;国家重点基础研究发展计划项目（2012CB518102）;全军“十二五”计划重点项目（BWS12J050）.

摘　　要：目的探讨胰高血糖素样肽（GLP-1）的长效类似物Exendin-4（Ex-4）对烫伤小鼠T淋巴细胞免疫功能的影响以及神经内分泌调控机制。方法BALB/C小鼠随机（随机数方法）分为烫伤组（n＝100）和假伤组（n＝64），行15%总体表面积（TBSA）的Ⅲ度烫伤。磁珠分离CD4＋ T淋巴细胞，采用细胞免疫荧光方法检测GLP-1受体（GLP-1R）表达。（1）体外实验：24 h后分离脾脏单个核细胞，加Ex-4和β儿茶酚胺受体（β-AR）阻断剂普萘洛尔（propranolol，prop），ConA（5 μg/mL）刺激下培养48 h，观察T淋巴细胞功能和分化。（2）体内实验：烫伤前30 min腹腔注射prop（30 mg/kg），伤后立即注射Ex-4（2.4 nmol/kg）。分别在6 h和24 h处死动物留取血清，分离脾脏单个核细胞，观察T淋巴细胞功能改变。结果正常小鼠T淋巴细胞上存在GLP-1R表达。采用单因素方差分析组内差异，体外实验证实，Ex-4对T淋巴细胞功能无明显作用，并不受prop影响。在体内实验中，Ex-4可显著降低烫伤小鼠T淋巴细胞的增殖活性、IL-2分泌水平（P〈0.05），但可被prop恢复。体外及体内实验显示，Ex-4均可促进T淋巴细胞向Th2分化（P〈0.05），而在烫伤组prop体内干预后反而增强了Ex-4的Th2促分化作用。此外，烫伤组动物Ex-4增加去甲肾上腺素的分泌增加，抑制肾上腺素的分泌，prop干预后两种激素的分泌与单独Ex-4处理组相比急剧增加。结论Ex-4可通过交感神经机制抑制脾脏T淋巴细胞的增殖和IL-2分泌，并经由GLP-1R直接作用于T淋巴细胞使其向Th2漂移。ObjectiveTo investigate the potential effect of glucagon-like peptide-1 （GLP-1） analogue exendin-4 （Ex-4） on immune function of T lymphocytes via neuroendocrine modulation mechanism in mice following severe burns.MethodsMale BALB/C mice were randomly（ramdam number） divided into thermal injury group （n=50） and sham-thermal group （n=30）. The thermal injury model was made by exposing the back skin of 15% total body surface area （TBSA） to 95 ℃ water for 7 seconds, while in sham-thermal model the mice were immersed in 37 ℃ water instead. The expression of GLP-1 receptor （GLP-1R） was determined in sorted CD4＋ T cells from normal mice by immunofluorescence method. In ex vivo experiment, the mice were sacrificed at 24 h post-burn, then the mononuclear cells （MNC） from spleen were separated from both groups and cultured in RMPI 1640 with 10%FCS （fetal calf serum） in presence of ConA （concanavalin A, 5 μg/mL）. Cells were pretreated with catecholamine receptor antagonist propranolol （prop） for 1 hour, followed by consecutive dose of Ex-4 for another 48 h. In in vivo experiment, prop （30 mg/kg） was i. p. injected 30 minutes before thermal injury, then Ex-4 （2.4 nmol/kg） was injected i. p. immediately after scalding. Mice were sacrificed at 6 h and 24 h after thermal injury, then the serum and the spleens were collected.ResultsGLP-1R was expressed on splenic CD4＋ T cells from normal mice. Ex-4 exerted no marked effect on the functions of T cells in terms of proliferation and IL-2 secretion at all doses examined ex vivo, which was not affected by pretreatment with prop. In vivo, T cell functions were suppressed by Ex-4 in thermal mice （P〈0.05）, but was restored by pretreatment with prop. Regardless of ex vivo or in vivo, Ex-4 could induce T cells switched to Th2 response （P〈0.05）. Moreover, the Th2 switch by Ex-4 was greatly potentiated by prop intervention in thermal mice in vivo other than ex vivo. Norepinephrine level was increased and epinephrine was

关 键 词：烧伤 胰高血糖素样肽-1 T淋巴细胞 免疫调控 交感神经 

分 类 号：R644[医药卫生—外科学]