高强度间歇运动降低2型糖尿病小鼠海马神经元坏死性凋亡及炎症反应的研究

关键词：2型糖尿病  坏死性凋亡  神经炎症  高强度间歇运动

Keywords:type 2 diabetes mellitus  necroptosis  neuroinflammation  high intensity interval exercise

摘要：

      摘要 目的：观察高强度间歇运动（high intensity interval exercise， HIIT）对2型糖尿病（type 2 diabete mellitus， T2DM）小鼠海马神经元坏死性凋亡及神经炎症的影响。 方法：雄性C57BL/6小鼠高脂饲养10周后腹腔注射链脲佐菌素（streptozotocin， STZ），制备T2DM小鼠模型。小鼠分组如下：健康对照组（CON，n=10），T2DM模型组（T2DM，n=10），T2DM运动组（HIIT，n=10）。HIIT组小鼠进行7周跑台训练。实验结束后，乳酸脱氢酶（lactate dehydrogenase， LDH）含量和碘化丙啶（propidium iodide， PI）染色，观察各组小鼠海马神经元细胞坏死情况；免疫荧光染色观察各组小鼠Nod样受体蛋白3（the NOD-like receptor protein 3， NLRP3）水平；应用qRT-PCR（quantitative real-time polymerase chain reaction）检测各组小鼠海马组织肿瘤坏死因子-α（tumor necrosis factor-α， TNF-α）、白细胞介素-1β（interleukin-1β， IL-1β）mRNA表达。Western Blot观察各组小鼠海马组织坏死性凋亡及炎症因子相关蛋白的表达情况。 结果：与CON组相比，T2DM组小鼠海马LDH释放水平显著增加（P<0.0001），PI染色阳性细胞数量、坏死性凋亡相关蛋白表达水平增加；NLRP3荧光强度增加（P<0.05），NLRP3、caspase-1、Cleaved caspase-1蛋白及炎症因子iNOS、IL-6、TNF-α、IL-1β表达明显增加（P<0.05）。7周HIIT干预后，与T2DM组相比，HIIT组小鼠海马LDH释放水平显著降低（P<0.0001），PI染色阳性细胞数量减少，坏死性凋亡相关蛋白表达水平降低；NLRP3荧光强度降低（P<0.05）、NLRP3、caspase-1、Cleaved caspase-1蛋白及促炎因子的表达水平明显降低（P<0.05）。 结论：T2DM小鼠海马组织中存在坏死性凋亡，HIIT可抑制T2DM小鼠海马坏死性凋亡，降低海马组织炎症反应。

Abstract:

      Abstract Objective： To investigate the effect of high-intensity interval exercise （HIIT） on necroptosis and neuroinflammation in hippocampus of type 2 diabetes mellitus （T2DM） mice. Method： Male C57BL/6 mice fed with high-fat for ten weeks and then injected with streptozotocin （STZ） to establish the model of T2DM mice. Mice were divided into normal control group （CON， n=10）， T2DM model group （T2DM， n=10）, and T2DM exercise group （HIIT， n=10）. Mice in HIIT group received treadmill training for 7 weeks. At the end of the experiment， the necroptosis of hippocampal neurons was determined by lactate dehydrogenase （LDH） content and propidium iodide （PI） staining. The NOD-like receptor protein 3 （NLRP3） level was examined by immunofluorescence staining. The mRNA expressions of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β） in hippocampus were evaluate by quantitative real-time polymerase chain reaction （qRT-PCR）. The level of necroptosis and inflammatory cytokines related proteins in hippocampus were measured by the Western Blot. Result： Compared with the CON group， the LDH release level was significantly increased （P<0.0001）， the number of PI-stained positive cells and the expression level of necroptosis related proteins were increased in T2DM group. The fluorescence intensity of NLRP3， the expression of NLRP3， caspase-1， cleaved caspase-1 protein and inflammatory cytokines iNOS， IL-6， TNF-α and IL-1β were significantly increased （P<0.05） in T2DM group. After 7 weeks of the HIIT intervention，the hippocampal LDH release level of HIIT group was significantly lower than T2DM group （P<0.0001）, the number of PI-stained positive cells and the expressions level of necroptosis related proteins was also decreased. The fluorescence intensity of NLRP3 and the expression of NLRP3， caspase-1， Cleaved caspase-1 protein and the expression levels of proinflammatory factor were all decreased in HIIT group compared to the T2DM group (P<0.05). Conclusion： Necroptosis was found in the hippocampal tissue of T2DM mice. HIIT can inhibit the necroptosis and eventually reduce the inflammatory response in the hippocampal tissue of T2DM mice.