NOD1在肥胖糖尿病患者脂肪细胞中的表达及对胰岛素抵抗的作用

【目的】探讨肥胖糖尿病（DM）患者脂肪细胞免疫受体核苷酸结合寡聚化结构域蛋白1（nucleotide-binding oligomerization domain-containing protein,NOD1）的表达与胰岛素抵抗的关系。【方法】取10例肥胖 DM患者（DM组）及10例非DM肥胖患者（NDM组）腹部皮下脂肪细胞,采用Real-time PCR方法检测两组脂肪细胞受体 NOD1的表达,加入 NOD1受体激动剂 iE-DAP,用酶联免疫吸附法（ELISA）检测两组细胞炎性细胞因子白细胞介素（IL）-6、IL-8及单核细胞趋化因子1（MCP-1）水平,2-脱氧-3 H-D-葡萄糖摄入法观察基础状态和 iE-DAP刺激状态的葡萄糖摄取率。【结果】DM组脂肪细胞 NOD1 mRNA的表达显著高于 NDM组（P＜0．05）;iE-DAP刺激下DM组 IL-6、IL-8及 MCP-1的分泌水平均显著高于 NDM组（P ＜0．05）,DM组胰岛素刺激状态下脂肪细胞葡萄糖摄取率显著低于 NDM组（P＜0．05）。【结论】NOD1介导的炎症反应可能参与肥胖糖尿病胰岛素抵抗的发生。     

Insulin receptor binding to monocytes and erythrocytes during normal human pregnancy

In normal human pregnancy glucose tolerance deteriorates gradually in spite of a steady increase in plasma insulin levels. To see whether this change in insulin resistance is accompanied by changes in insulin receptor binding, insulin binding to monocytes and erythrocytes was measured serially during pregnancy and again post-partum in fifteen normal women. Insulin binding to monocytes increased from week 12 to week 24 of gestation (P less than 0.001) and it decreased from week 32 to week 36 (P less than 0.05). After delivery a new increase in insulin binding to monocytes was seen (P less than 0.05). Insulin binding to erythrocytes increased from week 30-32 to week 36 (P less than 0.05), decreased from week 36 to delivery (P less than 0.01) and decreased further post-partum (P less than 0.001). Insulin receptor binding was not significantly correlated to plasma insulin, estradiol, estriol, progesterone or cortisol. The insulin receptor binding to monocytes, but not to erythrocytes, paralleled the insulin resistance found in human pregnancy.     

肥胖患者胰岛素抵抗和血浆vWF水平的变化

目的：研究肥胖患者体脂参数、代谢异常、胰岛素抵抗的程度及血浆vWF水平的变化。探讨肥胖患者的代谢特点、胰岛素抵抗与血管内皮损伤的关系。方法：测定59例肥胖患者和49份正常人的血压、体脂参数、血糖、血脂谱、血浆vWF水平；采用稳定模式评估法评价胰岛素抵抗的程度。结果：肥胖组腰围、臀围、腰臀围比、血压、TC、TG、LDL水平均高于正常对照组，HDL低于对照组（P＜0．001），FIN和HOMA－IR明显高于对照组（P＝0．000）。肥胖组vWF水平与对照组比较有显著差异（P＜0．05）。肥胖组经性别分层后，除HDL男性低于女性、TG男性高于女性外（P＜0．05），其余各项指数在男女之间无显著差异。结论：肥胖患者存在明显体脂分布异常、胰岛素抵抗、血压改变及代谢紊乱，代表血管内皮损伤的血浆vWF水平的增高，提示肥胖病人有血管内皮损伤存在，血管内皮损伤可能是胰岛素抵抗的一个原因。     

Comparative measurements of plasma binding capacity and concentration of human sex hormone binding globulin

Comparisons are made of the plasma binding capacity and concentration of sex hormone binding globulin. Concentration was measured by electroimmunodiffusion standardised in terms of mass of the protein and binding capacity by two methods measuring the binding of 5 alpha-dihydrotestosterone. Isolation of steroid bound by SHBG was by either ammonium sulphate precipitation or cellulose filter discs. Both binding methods correlate highly with electroimmunodiffusion indicating they respond similarly to changes in the plasma concentration of the protein. However, they do not equally reflect the actual concentration. Estimates of the molecular mass of the protein of 188000 and 100000 from the precipitation and disc methods respectively, suggest the former measures less of the protein present than does the latter. A parallel reduction in binding capacity and concentration is seen in obese post-menopausal females. This previously unreported finding suggests that the reduced plasma binding capacity of sex hormone binding globulin in obesity is not due to altered or impaired steroid binding.     

Optimization of reverse chemical ecology method: false positive binding of Aenasius bambawalei odorant binding protein 1 caused by uncertain binding mechanism

Odorant binding proteins (OBPs) are considered as the core molecular targets in reverse chemical ecology, which is a convenient and efficient method by which to screen potential semiochemicals. Herein, we identified a classic OBP, AbamOBP1 from Aenasius bambawalei, which showed high mRNA expression in male antennae. Fluorescence competitive binding assay (FCBA) results demonstrated that AbamOBP1 has higher binding affinity with ligands at acid pH, suggesting the physiologically inconsistent binding affinity of this protein. Amongst the four compounds with the highest binding affinities at acid pH, 2, 4, 4‐trimethyl‐2‐pentene and 1‐octen‐3‐one were shown to have attractant activity for male adults, whereas (?)‐limonene and an analogue of 1‐octen‐3‐ol exhibited nonbehavioural activity. Further homology modelling and fluorescence quenching experiments demonstrated that the stoichiometry of the binding of this protein to these ligands was not 1: 1, suggesting that the results of FCBA were false. In contrast, the apparent association constants (Ka) of fluorescence quenching experiments seemed to be more reliable, because 2, 4, 4‐trimethyl‐2‐pentene and 1‐octen‐3‐one had observably higher Ka than (?)‐limonene and 1‐octen‐3‐ol at neutral pH. Based on the characteristics of different OBPs, various approaches should be applied to study their binding affinities with ligands, which could modify and complement the results of FCBA and contribute to the application of reverse chemical ecology.     

肥胖患者脂联素与胰岛素抵抗、内皮依赖性舒张功能相关性研究

目的：探讨肥胖患者脂联素变化及与胰岛素抵抗、内皮依赖性舒张功能之间的关系。方法：采用彩色多普勒超声检测仪检测肥胖组（O）53例和正常对照组（C）24例右肱动脉内皮依赖性舒张功能、颈总动脉内膜-中层厚度（IMT），并测定血脂、血糖、空腹胰岛素（HNS）、血管性血友病因子（vWF）、纤溶酶原激活剂抑制物-1（PAI-1）和脂联素（adiponectin）。采用稳态模式（HOMA-IR）评价胰岛素抵抗。结果：O组腰臀比（WHR）、体重指数（BMI）、体内脂肪含量（BF）、收缩压（SBP）、舒张压（DBP）、载脂蛋白B（ApoB）、空腹血糖（FBG）、FINS和HOMA-IR高于C组（P〈0．05），脂联素明显低于C组（P〈0．05）。脂联素与性别（男=1，女=2）、高密度脂蛋白-胆固醇（HDL-C）呈正相关（r分别为0．354、0．438，P值分别为0．027、0．005）；与体重、腰围（W）、甘油三酯（TG）、WHR、F1NS和HOMA-IR呈负相关（r分别为-0．358、-0．359、-0．449、-0．375、-0．363、-0．319，P值分别为0．025、0．025、0．004、0、019、0．027、0．054）。多元逐步回归分析显示，BMI和BF是影响脂联素独立的危险因素。结论：肥胖患者脂联素降低，并且与胰岛素抵抗密切相关。     

Intraspecific nucleotide variation at the pheromone binding protein locus in the turnip moth, Agrotis segetum

Inter- and intraspecific amino acid variability in the pheromone binding proteins (PBPs) of the Lepidoptera is believed to contribute to a molecular mechanism of pheromone blend discrimination. Messenger RNA coding for PBP sequence in Agrotis segetum (Noctuidae) was cloned, and nucleotide and inferred amino acid variation across a 769-bp region of a PBP locus was studied in two populations. A single gene copy was fully sequenced, revealing an intron/exon structure conserved with distant saturniids. While several nucleotide substitutions are predicted to result in amino acid replacement, tests for the presence of natural selection suggest that the observed variation is neutral. A phylogenetic analysis provides evidence that the two populations are in the process of genetic isolation.     

肥胖患者外周血单个核细胞Toll样受体4表达及活性研究

目的研究肥胖患者外周血单个核细胞（PBMCs）Toll样受体4（11LR4）表达及活性。方法收集16例肥胖患者和16例正常对照者的PBMCs,蛋白印迹法检测PBMCsTLR4及IKBct蛋白表达,实时荧光定量PCR检测PBMCsTLR4及白细胞介素6（IL-6）mRNA表达,并测定空腹血糖、空腹胰岛素、血游离脂肪酸（FFA）、IL-6及肿瘤坏死因子仪（TNF-a）。结果与正常对照组比较,肥胖组血FFA、IL-6、TNF-a及稳态模型评估的胰岛素抵抗指数（HOMA-IR）明显增高[FFA：（879±64）、（458±48）umoL／L,t=24．613、P=0．000;IL-6：（2．20±0．35）、（1．264-0．25）ng／L,t=14．993、P=0．000;TNF—a（1．964-0．32）、（1．384-0．24）ng／L,t=9．128、P=0．000;HOMA．IR：1．84-0．2、0．44-0．1,t=32．254、P=0．000];肥胖组PBMCsTLR4mRNA及蛋白表达显著升高（TLR4mRNA：3．13±0．21与0．99±0．03,f=54．758,P〈0．05;TLR4蛋白：7．04±0．42与2．53±0．17,t：77．450,P〈0．05）;肥胖组PBMCsIKBet蛋白表达显著降低（2．52±0．16与4．00±0．30,t=23．284,P〈0．05）,IL-6mRNA表达显著升高（2．55±0．15与1．03±O．11,t=53．981,P〈0．05）。结论肥胖患者PBMCsTLR4表达及活性显著增加,可能在肥胖患者胰岛素抵抗的发生、发展中具有重要作用。     

Plasma retinol-binding protein is not a marker of insulin resistance in overweight subjects: a three year longitudinal study

Objectives

This longitudinal study investigated whether or not plasma retinol-binding protein (RBP), recently referred to as RBP4, was a marker of insulin resistance in overweight subjects.

Methods

We measured anthropometric markers as well as RBP, fasting glucose and insulin in 206 overweight subjects and repeated these measurements 36 months later. Subjects were grouped according to fasting plasma glucose concentration at baseline and 36 months.

Results

Subjects (n = 51) with a normal basal fasting glucose (< 5.6 mmol/L) who developed impaired fasting glucose (IFG) 3 years later (≥ 5.6 mmol/L) showed a highly significant increase in both fasting insulin and insulin resistance, but importantly no change in plasma RBP. This group had a significant increase in body mass index (BMI). Subjects (n = 101) with a normal fasting glucose at both baseline (< 5.6 mmol/L) and 36 months showed no significant change in fasting insulin, insulin resistance, RBP or BMI. The remaining subjects had impaired basal fasting glucose and were not analysed on a group-wise basis. Overall, RBP correlated significantly, but inversely, with anthropometric measures, but not with fasting glucose, insulin or insulin resistance.

Conclusions

This is the first report of a long-term longitudinal study on RBP and the major finding is that subjects who developed insulin resistance showed no change in plasma RBP. On the basis of our results we consider that RBP cannot be construed as a marker of insulin resistance in overweight humans.     

Age‐specific differences in binding of heparin to plasma proteins

Summary. Background: Clinically significant age‐related differences in the anticoagulation effect of heparin have previously been established in vitro as well as in different clinical settings in vivo. These differences were hypothesized to be due to the age‐specific differences in binding of heparin to plasma proteins. Objectives: The aim of this project was to investigate global age‐related differences in heparin binding to plasma proteins. Patients/Methods: Heparin‐binding proteins were identified by incubating heparin‐coated magnetic beads with plasma samples from neonates, children and adults, and purifying the proteins that were bound to the beads in this reaction system. Results: These results provide the first preliminary evidence of age‐related differences in the total number and concentration of proteins bound to heparin. The results also suggest, for the first time, that there are age‐related differences of heparin binding to antithrombin and thrombin. Conclusions: The results of this study, although preliminary, support and contribute to the explanation of the mechanism of age‐related differences in the effect of heparin observed previously in vitro and in vivo.     

老年2型糖尿病合并脂肪肝与肥胖、血脂紊乱及胰岛素抵抗的关系

目的 :探讨老年 2型糖尿病 (T2 DM )合并脂肪肝患者与肥胖、血脂紊乱及胰岛素抵抗 (IR)的关系。方法 :对 6 4例老年T2 DM合并或无脂肪肝患者进行血脂水平、空腹血糖 (FBG)及空腹胰岛素 (FINS)的测定 ,并计算体重指数 (BMI) ,腰、髋比值及胰岛素敏感指数 (ISI) ,并进行分析。结果 :老年T2 DM并脂肪肝组 (A组 )与无脂肪肝组 (B组 )相比 ,体重指数 (BMI) ,腰、髋比值 ,甘油三酯 (TG) ,载脂蛋白B(APOB) ,FINS明显升高 (P <0 .0 5～ 0 .0 1) ,ISI、高密度脂蛋白胆固醇 (HPL -C)明显降低 (P<0 .0 5 )。结论 :老年T2 DM合并脂肪肝与胰岛素抵抗、血脂紊乱、肥胖有关。     

2型糖尿病肥胖患者口服降糖药失效启用胰岛素治疗方案的探讨

目的探讨2型糖尿病肥胖患者在口服降糖药继发失效的情况下启用胰岛素治疗方案的选择。方法选择2009年1月2010年12月间40例口服降糖药失效的2型糖尿病肥胖患者,随机分为两组,每组20例。A组原口服药不变,睡前联用长效胰岛素（商品名：来得时）治疗,B组停用口服药,于早晚餐前使用预混胰岛素（商品名：诺和灵30R）,治疗共3个月,分别于治疗前后观察空腹血糖、餐后2h血糖、糖化血红蛋白、血脂、血压、体质量指数的变化,记录低血糖发生次数,并填写问卷调查表,评估患者对治疗方案的满意度和接受度。结果两个组治疗后空腹血糖、餐后2h血糖、糖化血红蛋白均较治疗前明显下降（P〈0.01）,而血脂、血压变化不大;但B组体质量指数有轻微升高（P〉0.05）,且每日胰岛素用量较A组更大（P〈0.01）,低血糖反应更多（P〈0.05）,满意度和接受度不如A组高（P〉0.05）。结论对2型糖尿病肥胖患者在口服降糖药继发失效的情况下启用胰岛素治疗,选用口服降糖药联合基础胰岛素的治疗方案具有作用佳、安全性好,体重增加不明显,患者依从性更高的特点。     

Regional variation in high-density lipoprotein binding to human adipocyte plasma membranes of massively obese subjects

Obesity is associated with significant changes in cholesterol and lipoprotein metabolism. High density lipoprotein (HDL) cholesterol is often reduced and adipose tissue cholesterol stores are increased in obese individuals. This prompted a study on the binding of HLD fractions (HDL2 and HDL3) to adipocyte plasma membranes obtained from massively obese subjects (BMI greater than 37 kg m-2) undergoing gastroplasty. Regional variation in HDL binding to these adipocyte plasma membranes was demonstrated. Membranes derived from the abdominal subcutaneous depot exhibited similar binding affinity (Kd) but higher binding capacity (Bmax) for HDL2 and HDL3 than that from the omental depot. There was significant inter-individual variation in Bmax but the amount of HDL2 or HDL3 bound to the two depots of the same individual was positively correlated (HDL2, r = 0.66, P less than 0.05; HDL3, r = 0.88, P less than 0.01). While HDL2 binding showed a higher affinity (lower Kd) than HDL3, a significant positive correlation existed between HDL2 and HDL3 binding to the same adipocyte membranes (r = 0.89, P less than 0.01). A significant inverse correlation (P less than 0.05) was also observed between HDL2 and HDL3 binding to adipocyte membranes and plasma HDL-cholesterol concentration. These results suggest that adipose tissue is an important site of HDL metabolism and the subcutaneous fat depot may play a proportionally more significant role due to its higher HDL binding capacity. It is further suggested that increased HDL binding and metabolism by the expanded adipose tissue mass may contribute to reduced plasma HDL-cholesterol levels frequently associated with obesity.     

Retinol binding protein 4 and insulin resistance in apparently healthy elderly subjects

BackgroundInsulin resistance (IR) increases with advancing age, yet the underlying mechanism is not well established. Although adipocytokine retinol binding protein 4 (RBP4) was recently shown to be linked to IR, their relationship remains controversial and relatively little information exists regarding their roles in the elderly subjects. We investigated the association between RBP4 and IR in obese and nonobese elderly subjects.MethodsA total of 111 (68 nonobese and 43 obese) apparently healthy elderly subjects, aged 75.9 ± 4.8 y were included. IR was determined by homeostasis model assessment (HOMA-IR). Serum RBP4 was measured by enzyme-linked immunosorbent assay.ResultsIn all subjects, RBP4 levels were positively correlated with fasting insulin, HOMA-IR, and triglycerides. However, after subgroup analysis, RBP4 levels were positively correlated with fasting glucose, fasting insulin, and HOMA-IR in the obese group only. In step-wise multiple linear regression analysis, RBP4 was found to be independently associated with triglyceride levels in the nonobese group and independently associated with HOMA-IR in the obese group.ConclusionsThe reason for the differing metabolic role of RBP4 in obese and nonobese elderly subjects remains uncertain, but our findings suggest that RBP4 may be linked to IR and lipid metabolism, at least in the elderly.     

代谢综合征患者血清抵抗素与血脂、肥胖和胰岛素抵抗关系的研究

目的:探讨代谢综合征患者血清抵抗素水平与血脂、肥胖和胰岛素抵抗的关系。方法: 60 例代谢综合征患者和28 例年龄相匹配的正常对照者,按体重指数将代谢综合征患者分为肥胖组和非肥胖组。采用ELISA方法测定受试者空腹血清抵抗素和瘦素水平,同时检测其身高、体重、腰围、臀围、血压、血糖、血脂及胰岛素水平,并计算体重指数(BMI)、腰臀比(WHR)和胰岛素抵抗指数(HOMA)。结果:代谢综合征患者肥胖组和正常对照组相比其血清抵抗素水平明显升高(28.28±11.7μg/L与19.44±5.79μg/L,P<0.01);非肥胖组和正常对照组相比其血清抵抗素水平明显升高(26.14±11.9μg/L与19.44±5.79μg/L,P<0.05)。肥胖组和正常对照组相比其血清瘦素水平明显升高(1.47±0.57μg/L与0.31±0.13μg/L,P<0.01);非肥胖组和正常对照组相比其血清瘦素水平明显升高(1.35±0.57μg/L与0.31±0.13μg/L,P<0.01)。肥胖组和非肥胖组相比其血清抵抗素、瘦素水平无显著差异。相关分析显示空腹抵抗素水平与腰臀比、空腹胰岛素、胰岛素抵抗指数呈显著正相关(分别为r=0.22,0.22,0.19;P<0.05);与体重指数、腰围、臀围、瘦素呈显著正相关(分别为r=0.31,0.32,0.36,0.28;P<0.01);而与收缩压、舒张压、总胆固醇、甘油三酯、低密度脂蛋白胆固醇(LDL C)、血     

Insulin resistance: the link between obesity and cardiovascular disease

There seems to be general agreement that the prevalence of obesity is increasing in the United States and that we are in the midst of an obesity epidemic. The disease-related implications of this epidemic have received an enormous amount of publicity in the popular media, but public awareness of the untoward effects of excess weight has not led to an effective approach to dealing with the dilemma. The gravity of the problem is accentuated in light of the report that only approximately 50% of physicians polled provided weight loss counseling. Given the importance of excess adiposity as increasing the risk of CVD, 2DM, and hypertension and the combination of an increase in the prevalence of overweight/obesity and a health care system unprepared to deal with this situation, it is essential that considerable thought be given as to how to best address this dilemma. In this context, it must be emphasized that CVD, 2DM, and hypertension are characterized by resistance to insulin-mediated glucose disposal and that insulin resistance and the compensatory hyperinsulinemia associated with insulin resistance have been shown to be independent predictors of all three clinical syndromes. It has also been apparent for many years that overweight/obese individuals tend to be insulin resistant and become more insulin sensitive with weight loss.25 In light of these observations, it seems reasonable to suggest that insulin resistance is the link between overweight/obesity and the adverse clinical syndromes related to excess adiposity. The evidence summarized in this review shows that the more overweight an individual, the more likely he or she is insulin resistant and at increased risk to develop all the abnormalities associated with this defect in insulin action. Not all overweight/obese individuals are insulin resistant, however, any more than all insulin resistant individuals are overweight/obese. More important, there is compelling evidence that CVD risk factors are present to a significantly greater degree in the subset of overweight/obese individuals that is also insulin resistant. Not surprisingly,we have also demonstrated that an improvement in CVD risk factors with weight loss occurs to a significantly greater degree in those overweight/obese individuals who are also insulin resistant at baseline. In view of the ineffectiveness of current clinical approaches to weight loss, it seems necessary to recognize that not all overweight/obese individuals are at equal risk to develop CVD and that it is clinically useful to identify those at highest risk. The simplest way to achieve this task seems to be focusing on the CVD risk factors that are highly associated with insulin resistance/hyperinsulinemia. If this is done, then intense efforts at weight control can be brought to bear on those who not only need it the most but also have the most to gain by losing weight.     

胰岛素抵抗与肥胖相关性肾病发病情况的相关性分析

目的 探究胰岛素抵抗与肥胖相关性肾病（O RG ）发病情况的相关性。方法 选取2010年3月至2014年3月来本院进行常规肾功能检测的肥胖患者88例,依据检测结果将肾功能正常患者32例作为A组,肾病患者56例作为B组;并于8周后依据治疗效果将B组分为B1组32例（肾功能明显好转组）及B2组24例（肾功能未见好转组）。分别于患者体检时及8周治疗后复诊时检测各组患者的血脂相关指标、肾功能指标、血糖代谢指标及血压。结果 B组患者的总胆固醇（TC）、三酰甘油（TG）、24 h尿蛋白定量（24h‐UP）、血尿素氮（BUN）、空腹血糖（FBG）、餐后2 h血糖（2h‐PBG）、空腹胰岛素（FINS）、胰岛素抵抗指数（HOMA‐IR）及平均动脉压（MAP）均高于A组,B组患者的肌酐清除率（CCR）及高密度脂蛋白胆固醇（HDL‐C）均低于A组,差异有统计学意义（ P ＜0．05）;B1组患者的 TC、TG、24h‐UP、BUN、FBG、HOMA‐IR及MAP均低于B2组,B1组患者的CCR明显高于B2组,差异有统计学意义（ P ＜ 0．05）;通过 Pearson相关分析,患者的HOMA‐IR及MAP水平与24h‐UP及BUN呈明显正相关（ P ＜0．05）,与CCR呈明显负相关（ r ＝－0．159,－0．368,P ＜0．05）。结论 HOMA‐IR及MAP的升高是导致ORG发病的重要原因,可为疾病的治疗指明新的方向。     

Major venom proteins of the fire ant Solenopsis invicta: insights into possible pheromone‐binding function from mass spectrometric analysis

Proteins in the venom of the fire ant Solenopsis invicta have been suggested to function in pheromone binding. Venom from queens and workers contains different isoforms of these proteins, consistent with the differing pheromones they secrete, but questions remain about the venom protein composition and glandular source. We found that the queen venom contains a previously uncharacterized pheromone‐binding protein paralogue known as Sol i 2X1. Using imaging mass spectrometry, we located the main venom proteins in the poison sac, implying that pheromones might have to compete with venom alkaloids for binding. Using the known structure of the worker venom protein Sol i 2w, we generated three‐dimensional homology models of the worker venom protein Sol i 4.02, and of the two main venom proteins in queens and female alates, Sol i 2q and Sol i 2X1. Surprisingly, the models show that the proteins have relatively small internal hydrophobic binding pockets that are blocked by about 10 amino acids of the C‐terminal region. For these proteins to function as carriers of hydrophobic ligands, a conformational change would be required to displace the C‐terminal region, somewhat like the mechanism known to occur in the silk moth pheromone‐binding protein.