糖尿病大鼠海马肿瘤坏死因子α、白细胞介素10表达与认知功能改变的关系

Relationship between the changes of cognitive function and the expression of tumor necrosis factor alpha, interleukin 10 in hippocampus of diabetic rats

目的 观察糖尿病大鼠认知功能及海马组织肿瘤坏死因子α（TNF-α）、白细胞介素10（IL-10）表达的变化,探讨炎症在糖尿病脑病（DE）发病机制中的作用.方法 30只雄性SD大鼠随机分为对照组和糖尿病组,糖尿病组给予高脂饮食4周后按30 mg/kg注射链脲佐菌素建立2型糖尿病大鼠模型,实验末行水迷宫测试评价两组大鼠认知功能.酶联免疫吸附测定法检测大鼠海马组织的β-淀粉样蛋白（Aβ）的浓度,蛋白质印迹法检测TNF-α和IL-10的表达,免疫组织化学法观察Aβ、TNF-α和IL-10的表达.结果 糖尿病组大鼠在目标象限的探索时间比对照组短[（38.21±3.68）s vs（42.10±2.62）s,t=3.105,P＜0.01],原平台穿越次数较对照组也减少[（2.62±0.77）次vs（3.69±0.95）次,t=3.184,P＜0.01],糖尿病组Aβ和TNF-α表达较对照组高（均P＜0.01）,IL-10表达较对照组低（P＜0.01）,免疫组织化学染色观察糖尿病组Aβ、TNF-α阳性表达明显,IL-10阳性表达较少.结论 糖尿病大鼠认知功能下降,可能与炎症因子表达失衡有关.

Objective To observe changes of cognitive function and the expression of tumor necrosis factor alpha（TNF-α）,interleukin 10（IL-10） in hippocampus of diabetic rats,and assess the role of inflammation in the possible pathogenesis of diabetic encephalopathy （DE）.Methods 30 male SD rats were randomly divided into control group and diabetes mellitus group.After 4 weeks of feeding high fat diet,diabetes mellitus group according to 30mg/kg injected with streptozotocin to establish type 2 diabetic rat model.At the end of the experiment,cognition were evaluated using water maze test.The concentration of beta-amyloid（Aβ） in hippocampus of diabetic rats were detected through enzyme linked immunosorbent assay,and the expression of TNF-α,IL-10 were detected by Western blotting.The expression of Aβ,TNF-α,IL-10 were observed through immunohistochemistry.Results Time spent in the target quadrant in diabetes mellitus group was shorter than that in control group （（38.21± 3.68）s vs （42.10±2.62）s,t=3.105,P＜0.01）.The frequency of crossing original platform site was less than that in control group（（2.62±0.77） vs（3.69±0.95）,t=3.184,P＜0.01）.Compared with control group the expression of Aβ,TNF-α were higher（BothP＜0.01）,and IL-10 were lower（P＜0.01）in diabetes mellitus group.The positive expression of Aβ,TNF-α were obviously and IL-10 were less obviously observed in diabetes mellitus group according to immunohistochemistry.Conclusion The cognitive decline in diabetic rats is possibly related to inflammatory cytokines expressing out of balance.