烧伤小鼠的葡萄糖耐受性长期评估和靶向代谢组学分析

Long-term assessment of glucose tolerance and targeted metabolomics analysis in mice with burn injury

背景烧伤患者预后与健康人群相比具有较高的糖尿病风险。既往研究多聚焦于短期内患者的血糖以及免疫功能的改变。目的观察烧伤小鼠长期的血糖调控和脾T细胞靶向代谢水平,为探讨烧伤患者长期免疫力低下的代谢机制提供初步依据。方法将雄性Balb/c小鼠随机分为对照组(n=7)、假伤组(n=44)和烧伤组(n=46),烧伤组建立小鼠15%全身体表面积(total body surface area,TBSA)烧伤模型,另取7只健康雄性Balb/c小鼠作为对照组。造模24 d时,随机选取对照组2只、假伤组4只、烧伤组6只处死,磁珠分选脾CD3+T细胞,高压液相色谱结合质谱仪检测T细胞靶向代谢产物果糖1,6-二磷酸、磷酸烯醇式丙酮酸、丙酮酸、顺乌头酸、异柠檬酸、琥珀酸、乳酸和腺苷酸荷能。造模3个月时,比较各组小鼠血糖和血浆胰岛素的水平以及对葡萄糖耐受性和对胰岛素的敏感性。结果烧伤后24 d的小鼠脾T细胞的靶向代谢组学的结果显示,与对照组及假伤组相比,烧伤组小鼠T细胞糖酵解途径中的果糖1,6-二磷酸、磷酸烯醇式丙酮酸、丙酮酸、琥珀酸、乳酸和腺苷酸荷能无统计学差异(P>0.05),但三羧酸循环的中间产物顺乌头酸和异柠檬酸减少(P<0.05)。烧伤后3个月烧伤组小鼠的血糖水平高于假伤组小鼠(P=0.022),但血浆胰岛素水平与假伤组小鼠比较无统计学差异(P=0.173)。萄糖耐受性试验中烧伤模型对于烧伤组血糖的影响高于假伤组(P<0.001),但是在胰岛素敏感实验中两组无统计学差异(P=0.683)。结论小鼠烧伤后血糖在较长期处于升高水平,且存在T细胞葡萄糖代谢缺陷的可能。

Background Burn patients have a higher risk of diabetes in terms of prognosis compared to healthy people.Previous studies have focused on short-term changes in blood sugar and immune function in patients.The long-term changes of glucose metabolism in burned mice were investigated in order to provide a new direction for clinical research.Objective To observe the long-term blood glucose regulation and spleen T-cell targeted metabolism level of burned mice,and provide references for exploring the metabolic mechanism of long-term hypoimmunity in burn patients.Methods Male Balb/c mice were randomly divided into sham group and burn group with 40 mice in each group,and 5 healthy Balb/c mice were selected as control group.A total body surface area(TBSA)burn model of 15%of the total body surface area was established in both the sham group and the burn group.Blood glucose and plasma insulin levels,as well as glucose tolerance and insulin sensitivity in each group of mice were compared after 3 months.In addition,sham and burn models were prepared.After 24 days,CD3+T cells of spleen were sorted by magnetic beads,and T cells targeted metabolites were detected by high pressure liquid chromatography combined with mass spectrometer.Results Targeted metabolomics analysis of spleen T cells of mice at 24 days after burn showed no significant difference in the charge energy of fructose 1,6-diphosphate,phosphoenolpyruvate,pyruvate,succinic acid,lactic acid and adenylate in the glycolytic pathway in the burn group compared with the control group and the sham injury group(P>0.05).However,the intermediate products of the tricarboxylic acid cycle,cisaconite and isocitric acid,were decreased(P<0.05).At three months after burn,the blood glucose level of burn group was higher than that of sham injury group(P=0.022),but there was no significant difference in plasma insulin level between burn group and sham injury group(P=0.173).The effect of burn model on blood glucose in the burn group was higher than that in the sham injury group in the glucose tolerance test (P < 0.001), but there was no difference between the two groups in the insulin sensitivity test (P=0.683). Conclusion Burned mice have long-term abnormal blood glucose regulation and T cell glucose metabolism defects.