内脏脂肪、炎症与胰岛素抵抗的相关基础及临床研究

发布时间：2018-03-16 23:22

本文选题：胰岛素抵抗　切入点：脂肪细胞　出处：《南京医科大学》2017年博士论文　论文类型：学位论文

【摘要】：目的:脂肪组织中巨噬细胞分泌的炎症因子可明显改变脂肪细胞功能,诱导炎症反应,降低胰岛素敏感性。然而,关于脂肪组织中巨噬细胞分泌的微囊泡在巨噬细胞和脂肪细胞间信号传递中的作用尚未明确。但已有研究发现,单核巨噬细胞分泌的微囊泡可上调人呼吸道上皮细胞炎症介质的合成,在炎性疾病的发生中起一定的作用。所以,本研究主要探讨炎性巨噬细胞分泌的微囊泡对人脂肪细胞胰岛素抵抗的影响。方法:通过刺激M1型和M2型THP-1巨噬细胞产生各自的微囊泡,将这些微囊泡分别与人的原代成熟脂肪细胞和由人前脂肪细胞分化而来的成熟脂肪细胞共培养,然后通过Western Blot方法检测人脂肪细胞中Akt磷酸化水平;运用2-NBDG评估人脂肪细胞对葡萄糖的摄取。同时,我们还提取了被处理的人脂肪细胞的质膜,通过Western Blot方法检测细胞膜上GLUT4表达水平;通过核萃取和Western Blot方法检测NF-κB核转运水平。结果:与M2型巨噬细胞分泌的微囊泡(M2 MVs)相比,M1型巨噬细胞分泌的微囊泡(M1 MVs)可明显减少人脂肪细胞中磷酸化Akt水平。通过2-NBDG检测人脂肪细胞对糖的摄取,我们发现用M1 MVs处理人脂肪细胞后,人脂肪细胞对胰岛素依赖的葡萄糖摄取减少,而用M2 MVs处理人脂肪细胞后,人脂肪细胞对胰岛素依赖的葡萄糖摄取增加。与M2 MVs相比,用M1 MVs处理人脂肪细胞后,可引起人脂肪细胞NF-κB核转位增加,Akt磷酸化和GLUT4膜转运减少,而这些改变可被NF-κB的特异性抑制剂——BAY 11-7085逆转。结论:促炎的M1型巨噬细胞分泌的微囊泡可能是肥胖引起的胰岛素抵抗的原因之一,其机制可能是通过激活NF-κB,减少人脂肪细胞胰岛素信号转导,降低细胞葡萄糖摄取。目的:探讨艾塞那肽对肥胖2型糖尿病患者内脏脂肪的影响。方法:将36名单用二甲双胍治疗血糖控制不达标的肥胖2型糖尿病患者随机分别接受艾塞那肽+二甲双胍治疗(GLP-1组)或阿卡波糖+二甲双胍治疗(对照组)3个月。观察两组患者试验前后内脏脂肪含量的变化,以及空腹血糖、糖化血红蛋白、空腹胰岛素、血脂、体重指数和炎症因子的改变。结果:GLP-1组患者的内脏脂肪含量试验后较试验前明显减少(前:17947±5804mm2后:13717士3628mm2,P=0.001),而对照组内脏脂肪含量试验前后无明显变化(P = 0.197)。试验后,GLP-1组患者内脏脂肪含量较对照组更低(P=0.043)。两组患者试验后的血糖控制和胰岛素抵抗较试验前均明显改善,HbA1c(GLP-1 组:前 9.72±1.38%后 7.09±0.60%,P0.001;对照组:前 9.46±1.25%后 7.42±0.84%,P0.001),LN(HOMA-IR)(GLP-1 组:前 1.58±0.40后 1.01±0.33,P0.001;对照组:前 1.53±0.57后 1.10±0.33,P=0.003)。但试验后,两组间HbA1c和LN(HOMA-IR)比较无明显差异。GLP-1组试验后TNF-α,IL-6和瘦素较试验前明显降低,脂联素明显升高(P0.05),而对照组试验前后均无明显改变。试验后,两组间TNF-α,IL-6和瘦素水平无明显不同,而GLP-1组脂联素水平较对照组更高(P = 0.025)。结论:艾塞那肽在控制血糖同时,还可减少肥胖糖尿病患者的内脏脂肪含量、改善肥胖患者的胰岛素抵抗和炎症状态。
[Abstract]:Objective: inflammatory cytokines secreted by macrophages in adipose tissue can markedly alter adipocyte function, inducing inflammation, reduce insulin sensitivity. However, on macrophages in adipose tissue secretion were soaked in macrophages and adipocytes in signal transduction are not yet clear. But studies have found that the synthesis of microencapsulated mononuclear macrophage foam on the epithelial cells of human respiratory tract inflammatory mediators, play a role in inflammatory diseases. Therefore, this study focused on the inflammatory macrophage foam microcapsule effects on insulin resistance in human adipose cells. Methods: the vesicles through the stimulation of M1 type and M2 type THP-1 macrophages, these microvesicles were primary adipocytes and the differentiation of human preadipocytes to mature adipocytes were cultured, and then through the Western Blot Method for detection of human fat cells in Akt phosphorylation; use of glucose uptake in 2-NBDG assessment of fat cells. At the same time, we also extracted human adipocytes treated membrane, through the cell membrane to detect Western Blot method on the expression level of GLUT4; through nuclear extraction and Western Blot method to detect NF- kappa B nuclear translocation. Results: Microcystis secretion and M2 macrophages (M2 MVs) compared to the global, M1 type macrophage foam microcapsules (M1 MVs) can significantly reduce the human fat cells in Akt phosphate level. Based on the detection of glucose uptake in human adipocytes 2-NBDG, we found that M1 MVs treated human fat cells, glucose uptake of people fat cells to insulin dependent decrease, and M2 MVs in human adipocytes, glucose uptake in human adipose cells to insulin dependent increase. Compared with M2 MVs, M1 MVs treated fat cells, can cause Human fat cells NF- kappa B nuclear translocation increased Akt phosphorylation and GLUT4 membrane decreased, and these changes may be a specific inhibitor of NF- kappa B -- BAY 11-7085. Conclusion: the reversal of microencapsulated M1 macrophages inflammatory secretion may be one of the reasons for global obesity induced insulin resistance and its possible mechanism through the activation of NF- kappa B, reduced insulin signal transduction in fat cells, reduce the cell glucose uptake. Objective: To evaluate the effect of exenatide on type 2 diabetes mellitus patients with visceral fat obesity. Methods: 36 list with metformin insufficientlycontrolled blood glucose in obese patients with type 2 diabetes were randomized to receive exenatide and metformin the treatment (group GLP-1) or acarbose and metformin treatment (control group) for 3 months. To observe the changes of visceral fat content of two groups of patients before and after the test, and fasting blood glucose, glycosylated hemoglobin, fasting insulin, Blood lipid, body mass index and inflammatory factor changes. Results: visceral fat content test in GLP-1 group were significantly decreased after more tests before (before: 17947 + 5804mm2 13717 + 3628mm2, P=0.001), while the control group before and after the test of visceral fat content had no significant change (P = 0.197). After the test, patients in group GLP-1 visceral fat content is lower than the control group (P=0.043). The two groups of patients after the test of glucose control and insulin resistance test were significantly improved, HbA1c (group GLP-1: 9.72 + 1.38% 7.09 + 0.60%, P0.001; control group: 9.46 + 1.25% 7.42 + 0.84%, P0.001), LN (HOMA-IR) (group GLP-1: 1.58 + 0.40 1.01 + 0.33, P0.001; control group: 1.53 + 0.57 1.10 + 0.33, P=0.003). But after the experiment, two groups of HbA1c and LN (HOMA-IR) was not significantly different between.GLP-1 group after the test of TNF- alpha, IL-6 and leptin were tested decreased obviously adiponectin was significantly increased (P0.05 ), while the control group had no obvious change before and after the test. After the test, two groups of TNF- alpha, IL-6 and leptin levels were not significantly different, while adiponectin levels higher than the control group GLP-1 group (P = 0.025). Conclusion: exenatide in glycemic control at the same time, also can reduce the content of visceral fat in obese patients. Diabetes in obese patients, improve insulin resistance and inflammation.

【学位授予单位】：南京医科大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R58

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