脂联素对肾性高血压小鼠心脏的影响

目的研究脂联素对肾性高血压小鼠心肌炎症、纤维化与心脏功能的影响,并探讨其作用机制。方法选择脂联素基因敲除纯合子小鼠60只(A组),野生型小鼠120只(平均分为2组,B组60例,C组60例),分别制作肾血管性高血压模型(A1、B1、C1)与假手术模型(对照组,A2、B2、C2),其中C组接受外源性脂联素干预。免疫组织化学染色方法(SP法)检测心肌组织切片中性粒细胞浸润数量,天狼星红(VG)染色法检测心肌胶原沉积纤维化程度,Western blot法检测心肌组织中炎症与致纤维化因子AngⅡ、IL-6、TNF-α、TGF-β水平,ELISA方法检测各组小鼠BNP,观察体外培养心肌细胞在脂联素、AngⅡ干预下的凋亡指数。结果肾性高血压模型组的BNP、心肌中性粒细胞数、心肌胶原及AngⅡ、IL-6、TNF-α、TGF-β水平高于假手术对照组,且A1组高于B1组,B1组高于B2组,差异均有统计学意义(P<0.05或P<0.01)。AngⅡ干预组心肌细胞凋亡指数高于空白对照组、脂联素干预组及共同干预组(P<0.01)。结论脂联素可以通过抗炎症、抗纤维化、抗细胞凋亡的途径保护肾性高血压小鼠的心肌结构与心功能。     

脂联素干预TNF-α作用后的巨噬细胞脂联素受体mRNA表达水平及其吞噬脂质变化

目的探讨脂联素干预TNF-α作用后的巨噬细胞表面脂联素受体mRNA表达水平及其吞噬脂质的变化。方法单核巨噬细胞系用佛波酯诱导,使之分化为巨噬细胞;进而采用不同浓度的TNF-α(0、0.1、1、10、100ng/ml)作用24h(以TNF-α0ng/ml为空白对照组),采用RT-PCR技术观察巨噬细胞表面脂联素受体R1、R2mRNA表达水平。选择0、10ng/ml浓度TNF-α作用后的巨噬细胞,用0.2mg/ml低密度脂蛋白混悬生长液作用24h,油红O染色和比色定量检测巨噬细胞吞噬脂质变化;同时TNF-α作用后的巨噬细胞,进一步用人重组脂联素20μg/ml干预24h,再次观察巨噬细胞表达脂联素受体mRNA水平及吞噬脂质变化。结果巨噬细胞用不同浓度的TNF-α作用后,随着TNF-α浓度梯度增加,脂联素受体R1、R2mRNA表达水平逐渐下降(P<0.05)。TNF-α10ng/ml作用后的巨噬细胞吞噬脂质的量明显高于TNF-α空白对照组(P<0.05);同时10ng/mlTNF-α作用后的巨噬细胞,进一步用脂联素干预,巨噬细胞表达脂联素受体R1、R2mRNA水平均较干预前上调(P<0.05),吞噬脂质的量较干预前减少(P<0.05)。结论脂联素及其受体在调节巨噬细胞吞噬脂质过程中产生重要作用,该作用可能成为预防和治疗动脉粥样硬化发生发展的新靶标。     

罗格列酮对2型糖尿病大鼠肾脏脂联素受体1表达的影响

目的观察罗格列酮对2型糖尿病大鼠肾脏脂联素受体1(AdipoR1)表达的影响,探讨罗格列酮对2型糖尿病大鼠肾脏保护作用及机制。方法雄性Wistar大鼠随机分为A组(健康对照组)、B组(糖尿病组)和C组(糖尿病罗格列酮治疗组)。用高脂高糖饲料加小剂量链尿佐菌素制备2型糖尿病大鼠模型。造模成功后,C组给予罗格列酮(3mg·kg-1·d-1)灌胃12周。实验结束时,用免疫组织化学法测定肾脏组织中AdipoR1和转化生长因子-β1(TGF-β1)的表达,用反转录-聚合酶链反应(RT-PCR)法测定肾脏AdipoR1 mRNA表达。结果与A组比较,B组糖尿病大鼠血糖、血脂、血肌酐、尿素氮、尿白蛋白排泄率、肾脏指数和TGF-β1表达均显著升高(P<0.05),罗格列酮干预后,C组上述指标均较B组显著降低(P<0.05)。B组糖尿病大鼠肾组织AdipoR1 mRNA表达显著低于A组(P<0.01);罗格列酮干预后,C组大鼠AdipoR1 mRNA表达较B组显著升高(P<0.01)。免疫组织化学结果显示,B组糖尿病大鼠肾脏AdipoR1表达较A组显著降低(P<0.01),经罗格列酮干预后,C组大鼠肾脏AdipoR1表达较B组显著升高(P<0.01)。结论2型糖尿病大鼠肾脏AdipoR1表达降低。罗格列酮通过上调肾脏AdipoR1表达,降低TGF-β1表达,减轻肾脏肥大,产生肾脏保护作用。     

咖啡豆提取物对肥胖大鼠血清瘦素、脂联素水平及脂联素受体表达水平的影响

目的 研究咖啡豆提取物对高脂饮食肥胖大鼠的瘦素(Leptin,LP)、脂联素(APN)及脂联素受体表达的影响。方法 给予高脂饲料建立SD大鼠肥胖模型,灌胃给予咖啡豆提取物(800,267,133 mg·kg^-1),连续6周。测量大鼠体质量及脂体比,测定大鼠血浆总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)、血清LP、APN;检测肝组织脂联素受体表达。结果 与正常对照组相比,给予高脂饲料6周的大鼠体质量明显增加(P<0.01),提示SD大鼠肥胖模型建立。与模型组比较,咖啡豆提取物给药后大鼠体质量、脂体比和LP水平下降(P<0.01或P<0.05),血清APN水平、APN受体的mRNA和蛋白表达显著增加(P<0.01或P<0.05)。结论 咖啡豆提取物对高脂饮食肥胖大鼠的体质量具有改善作用,作用机制可能是升高血清APN水平,降低LP水平及上调肝脏脂联素受体的mRNA和蛋白表达。     

大鼠脂联素和脂联素受体R2 mRNA表达水平和与胰岛素抵抗

目的 研究脂联素及脂联素受体R2 mRNA水平与胰岛素抵抗的关系.方法 普通级雄性Wistar大鼠24只,随机分为高糖高脂组(A组)、罗格列酮组(B组)和正常对照组(C组).检测空腹血糖、空腹胰岛素和胰岛素抵抗指数(HOMA-IR);应用RT-PCR方法测定大鼠肝组织脂联素受体R2 mRNA的表达;ELISA法测定血浆脂联素水平.结果 与C组相比,A组脂联素及脂联素受体R2 mRNA水平均显著降低(P<0.05);B组的脂联素及其受体水平较高糖高脂组有所升高,但仅脂联素的升高差异有显著性(P<0.05);脂联素受体R2 mRNA与HOMA-IR负相关(r=-0.652,P<0.01).结论 脂联素参与胰岛素抵抗的发生,脂联素受体R2可能介导了该效应.     

脂联素及其受体2mRNA在非酒精性脂肪性肝炎大鼠的表达及替米沙坦的干预作用

目的探讨替米沙坦对非酒精性脂肪性肝炎(NASH)大鼠肝组织脂联素及其受体R2mRNA表达的影响。方法 35只雄性SD大鼠随机分为正常对照组(NC组,n=10)、模型组(FC组,n=15)和替米沙坦干预组(FT组,n=10)。FC和FT组给予高脂饲料喂养16周诱发脂肪性肝炎,其中FT组于高脂喂养12周后,给予替米沙坦(5mg·kg-1·d-1)灌胃治疗4周。取肝组织测肝指数;检测血清ALT及AST,RT-PCR方法测定大鼠肝组织脂联素及其受体R2mRNA的表达。结果与NC组相比,FC组血清ALT、AST均明显升高(P<0.01),脂联素及其受体R2mRNA水平均显著降低(P<0.01);FT组的血清ALT显著降低(P<0.01),脂联素及其受体R2mRNA水平较FC组均升高(P<0.05)。结论替米沙坦对实验性非酒精性脂肪肝大鼠具有一定的治疗作用,其作用机制之一是促进肝脏脂联素及其受体R2mRNA的表达。     

奥美沙坦对胰岛素抵抗大鼠血清肿瘤坏死因子-α和脂联素的影响

目的探讨奥美沙坦对胰岛素抵抗大鼠血清TNF-α及脂联素的影响。方法正常Sprague-Dawley雄性大鼠39只,随机分为正常对照组(n=9)和造模组(n=30)。高脂喂养6周后尾静脉采血查空腹血糖(FBG)、空腹胰岛素(FINS),并计算胰岛素敏感指数(ISI),确定27只胰岛素抵抗大鼠模型建立。将胰岛素抵抗大鼠再随机分为3组:①模型组(n=9):给予高脂饮食;②二甲双胍组(n=9):在高脂饮食的基础上加用二甲双胍(300mg·kg-1·d-1);③奥美沙坦组(n=9):在高脂饮食的基础上加用奥美沙坦(3mg·kg-1·d-1)。干预6周后,测定FBG、FINS,计算ISI;测定TNF-α及脂联素水平。结果奥美沙坦组与模型组比较,TNF-α明显减低(P<0.01),脂联素明显增高(P<0.05)。结论奥美沙坦可能通过降低TNF-α,增高脂联素水平而改善胰岛素抵抗。     

脂联素对高糖环境下肾小球系膜细胞转化生长因子β1及细胞间粘附分子1表达的影响

目的研究脂联素(ADPN)对高糖培养的大鼠肾小球系膜细胞转化生长因子β1(TGF-β1)及细胞间粘附分子1(ICAM-1)表达的影响。方法以培养的大鼠HBZY-1肾小球系膜细胞(MCs)为受试对象,将MCs分为3组:正常对照组(5.5mmol/L葡萄糖,NG组),高糖组(30mmol/L葡萄糖,HG组),高糖+不同浓度的脂联素组(30mmol/L葡萄糖,2.5、5.0、7.5、10.0、15.0、20.0μg/mlADPN)分别作用48h后,用ELISA法测定细胞内TGF-β1及ICAM-1表达。结果作用48h后,高糖明显上调细胞内TGF-β1及ICAM-1表达。加入低浓度脂联素对于TGF-β1、ICAM-1表达影响不大,而随着脂联素浓度的升高,TGF-β1及ICAM-1的表达明显下降,与高糖组相比,浓度为10～20mg/L的脂联素组TGF-β1及ICAM-1的表达差异有统计学意义(P<0.05)。结论中等以上浓度的脂联素能下调TGF-β1及ICAM-1表达,提示脂联素可能通过阻抑TGF-β1及ICAM-1表达起到抗纤维化,从而发挥对糖尿病肾脏的保护作用。     

非酒精性脂肪性肝病患者肝组织脂联素表达及其意义

目的探讨肝组织脂联素表达在非酒精性脂肪性肝病（NAFLD）发病机制中的作用及地位,为NAFLD的预防及治疗提供新的思路。方法47例NAFLD患者及20例正常对照均测量身高、体重,计算体重指数（BMI）;分别应用ELISA方法测定血清脂联素（adiponectin）浓度、血清肿瘤坏死因子-α（TNF-α）浓度;采用稳态模式评估法,计算胰岛素抵抗指数（HOMA-IR）;对肝组织进行HE、Masson染色及脂联素免疫组化染色,对脂联素表达量进行半定量分析。结果非酒精性脂肪性肝炎（NASH）组肝组织脂联素表达较对照组及单纯性脂肪肝组显著减少（P〈0.05）,与血清脂联素浓度呈显著正相关（P〈0.01）,与血清TNF-α浓度、ALT、HOMA-IR及肝组织炎症、纤维化程度呈负相关（P〈0.01）,而与脂变程度不相关（P〉0.05）。多元线性逐步回归分析显示,肝组织脂联素表达是肝组织炎症及纤维化发生的保护因素。结论肝组织脂联素表达在NAFLD患者肝组织炎症及纤维化发生发展中起保护性作用。     

替米沙坦对非酒精性脂肪性肝炎大鼠脂联素及PPAR-γ表达的影响

目的 探讨替米沙坦对非酒精性脂肪性肝炎大鼠脂联素及PPAR-γmRNA表达的影响. 方法 35只雄性SD大鼠随机分为正常对照组(n=10)、模型组(n=15)和替米沙坦干预组(n=10). 模型和药物干预组给予高脂饲料喂养16周诱发脂肪性肝炎,其中药物干预组于高脂喂养12周后,给予替米沙坦(5 mg&#8226;kg-1&#8226;d-1)灌胃治疗4周. 检测空腹血糖、空腹胰岛素和胰岛素抵抗指数(HOMA-IR);应用逆转录 聚合酶链反应(RT-PCR)方法 测定大鼠肝组织脂联素及PPAR-γmRNA的表达;ELISA法测定血清脂联素水平. 结果与正常对照组比较,模型组空腹血糖、空腹胰岛素和HOMA-IR均显著性升高(P<0.01),药物干预组上述指标较模型组显著下降(P<0.01). 与正常对照组比较,模型组血清脂联素及肝组织脂联素、PPAR-γmRNA水平均显著降低(P<0.01);药物干预组的血清脂联素及肝组织脂联素、PPAR-γmRNA较模型组均升高(P<0.05). 结论 替米沙坦对非酒精性脂肪性肝炎有防治作用.     

Targeting adiponectin for cardioprotection

Adiponectin is an adipose tissue-derived plasma protein which has a reduced concentration in subjects with obesity-related diseases. Adiponectin has antidiabetic and anti-inflammatory characteristics, which lead to beneficial actions on various obesity-linked complications. Recent experimental findings have shown that adiponectin contributes to protection against cardiac remodelling after pressure overload and cardiac injury following ischaemia–reperfusion. Thus, adiponectin could emerge as a potential cardioprotective agent for the treatment of several pathological heart conditions.     

脂联素的研究进展

本文综述了脂联素的结构、生理功能、影响因素，以及与脂联素功能失调相关的疾病。     

Targeting adiponectin for cardioprotection

Adiponectin is an adipose tissue-derived plasma protein which has a reduced concentration in subjects with obesity-related diseases. Adiponectin has antidiabetic and anti-inflammatory characteristics, which lead to beneficial actions on various obesity-linked complications. Recent experimental findings have shown that adiponectin contributes to protection against cardiac remodelling after pressure overload and cardiac injury following ischaemia-reperfusion. Thus, adiponectin could emerge as a potential cardioprotective agent for the treatment of several pathological heart conditions.     

Effect of N-acetylcysteine on plasma adiponectin and renal adiponectin receptors in streptozotocin-induced diabetic rats

This study investigated the effect of N-acetylcysteine on plasma adiponectin, renal adiponectin receptors, lipid metabolism and oxidative stress in streptozotocin-induced diabetic rats. Metabolic parameters, plasma adiponectin level, renal protein expression of adiponectin receptors were analyzed in controls and diabetic rats treated with or without N-acetylcysteine in drinking water for 8 weeks. Plasma lipid, creatinine and free 5-F(2t)-isoprostane levels, urine protein excretion rate, mesangial matrix expansion index, and protein expression of renal connective tissue growth factor (CTGF) were increased in diabetic rats. The decreased plasma adiponectin levels and renal protein expression of adiponectin receptor 1 were accompanied by the decreased renal phosphorylation of adenosine monophosphate (AMP)-activated protein kinase (AMPK)-alpha (Thr172) and protein expression of phospho-acetyl coenzyme A carboxylase (ACC) (Ser79) which led to the increased renal triglyceride levels in diabetic rats. There was no difference in the protein expression of renal adiponectin receptor 2 between control and diabetic rats. N-acetylcysteine treatment attenuated the increased oxidative stress, plasma and renal lipids, urine protein excretion rate, mesangial matrix expansion index, and protein expression of renal CTGF, but did not affect plasma adiponectin levels, renal protein expression of adiponectin receptor 1, phosphorylation of AMPK-alpha (Thr172) and renal protein expression of phospho-ACC (Ser79) in diabetic rats. These results suggested that the decreased plasma adiponectin and renal adiponectin receptor 1 result in the increased renal triglyceride that stimulates renal CTGF expression leading to the renal hypertrophy and the deteriorated renal function in the diabetic rats. N-acetylcysteine treatment attenuates the increased oxidative stress, but has no effect on the decreased plasma adiponectin and renal adiponectin receptor 1 in diabetic rats, indicating that oxidative stress may not contribute to the decreased plasma adiponectin and renal adiponectin receptor 1 protein expression in diabetic rats.     

罗格列酮对糖耐量受损大鼠血清脂联素和肝脏脂联素受体表达的影响

目的探讨罗格列酮对糖耐量受损大鼠血清脂联素和肝脏脂联素受体-1表达的影响。方法60只Wistar雄性大鼠随机分为对照组(普通饲料喂养)和高脂组(高脂饲料喂养)。每周记录体质量变化,每2周作1次糖耐量试验;用HOMA胰岛素抵抗指数评价胰岛素抵抗程度,用反转录聚合酶链反应和蛋白印迹法分别测定脂联素受体1 mRNA和蛋白在肝脏的表达,成模后用罗格列酮干预4周。结果①12周时高脂组有18只大鼠成模,其2 h血糖均值达到了糖耐量受损的诊断标准,空腹血糖高于对照组(P<0.05),但未达到空腹血糖受损的诊断标准;②成模组大鼠体质量明显增加,空腹胰岛素和HOMA-IR指数高于对照组(P<0.05);③罗格列酮干预4周后血清脂联素水平较模型组升高(P<0.05),肝脏组织脂联素受体1 mRNA和蛋白的表达与模型组相比差异无统计学意义(P>0.05)。结论脂联素表达的下降在高脂饮食导致的胰岛素抵抗的发生中起着重要作用,罗格列酮可升高血清脂联素水平,但不影响肝脏脂联素受体-1的表达。     

2型糖尿病患者血浆脂联素水平与血脂代谢的关系探讨

目的探讨不同体重指数的2型糖尿病病人血浆脂联素水平的变化以及与血脂代谢的关系。方法运用放射免疫测定30例正常非肥胖、37例单纯性肥胖（体重指数≥25kg／m^2）、52例2型糖尿病病人（24例体重指数〈25kg／m^2和28例体重指数≥25kg／m^2）血浆脂联素水平，统计分析脂联素与总胆固醇、甘油三酯、高密度脂蛋白和低密度脂蛋白的关系。结果体重指数≥25kg／m^2单纯性肥胖和2型糖尿病个体的脂联素水平显著低于低重指数〈25kg／m^2的正常个体和2型糖尿病的水平，而前二者之间和后二者之间血浆脂联素水平无显著性差异（P〉0．05）。本组统计结果提示脂联素与总胆固醇、甘油三酯、高密度脂蛋白和低密度脂蛋白无相关性（P〉0．05）。结论脂联素作为一种脂肪细胞因子，体重水平的不同影响它在人群的分泌的差异，与血脂代谢关系仍需进一步探讨。     

beta-adrenoceptor agonists downregulate adiponectin, but upregulate adiponectin receptor 2 and tumor necrosis factor-alpha expression in adipocytes

Recently, the insulin-sensitizing adipokine adiponectin and the insulin resistance-inducing adipokine tumor necrosis factor-alpha (TNF-alpha) were reported to inhibit each other's production in adipocytes. We investigated the effects of two beta(3)-adrenoceptor agonists, 5-[(2R)-2-[[(2R)-2-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]-1,3-benzodioxole-2,2-dicarboxylate (CL-316,243) and (+/-)-(R(*),R(*))-[4-[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]phenoxy]acetic acid (BRL37344), on the gene expression of adiponectin, two adiponectin receptors, and TNF-alpha in adipose tissues of C57BL/6J mice. CL-316,243 and BRL37344 downregulated adiponectin, but upregulated adiponectin receptor 2 (not receptor 1) in epididymal or/and subcutaneous white adipose tissues and in brown adipose tissue. TNF-alpha expression was upregulated only in epididymal adipose tissue. To further explore these effects, we treated differentiated 3T3-L1 adipocytes with the non-selective beta-adrenoceptor agonist isoproterenol. As a result, adiponectin receptor 2 (but not receptor 1) gene expression and TNF-alpha protein expression increased, but gene expression and secretion of adiponectin decreased. The upregulation of adiponectin receptor 2 by isoproterenol is most likely via beta(2),beta(3)-adrenoceptors, adenylyl cyclases, and protein kinase A (PKA). However, the accompanying activation of AMP-activated protein kinase (AMPK) may inhibit this upregulation. Our results suggest that upregulation of TNF-alpha and downregulation of adiponectin by beta-adrenoceptor activation may contribute to the pathogenesis of catecholamine-induced insulin resistance, and that upregulation of adiponectin receptor 2 may be a feedback result of reduced adiponectin.     

Associations between 45T/G polymorphism of the adiponectin gene and plasma adiponectin levels with type 2 diabetes

1. The purpose of the present study was to investigate the association between the single nucleotide polymorphism (SNP) 45T/G and plasma adiponectin levels and the prevalence of Type 2 diabetes mellitus (T2DM) in Uygurs of the Xinjiang region, China. 2. We performed a cross-sectional survey in a representative sample of 151 Uygur adults aged 24-80 years. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to determine the distribution of allele and genotype frequency of the SNP45 T/G polymorphism (exon 2) in the adiponectin gene. An ELISA was used to determine plasma adiponectin levels. Logistic regression was used to screen risk factors for T2DM. 3. Compared with the normal glucose tolerance (NGT) group, the T2DM group exhibited a higher distribution of the TG + GG genotype, G allele frequency and lower plasma adiponectin concentrations in TG + GG genotype carriers compared with those with the TT genotype. Compared with SNP45 T carriers, in the NGT group, G carriers had higher levels of systolic and diastolic blood pressure, low density lipoprotein (P < 0.05) and total cholesterol (P < 0.005). In the T2DM group, G carriers had lower levels of homeostasis model assessment (HOMA) of insulin sensitivity (P < 0.05) and higher levels of HOMA of insulin resistance (P < 0.05). 4. Adiponectin SNP 45 is positively correlated with the prevalence of T2DM in Uygurs of Xinjiang. The G allele carriers who have reduced plasma concentrations of adiponectin may have associated insulin resistance.     

脂连素在胰岛素抵抗综合征防治中的作用

脂连素由脂肪细胞分泌,在调节糖脂代谢过程中发挥着重要作用,具有改善胰岛素抵抗、抗炎、抗动脉粥样硬化等多种功能.胰岛素抵抗状态下血浆脂连素水平明显降低,补充脂连素可改善胰岛素抵抗,脂连素将成为胰岛素抵抗综合征极有潜力的防治靶点.本文重点综述脂连素在胰岛素抵抗综合征防治靶点的研究进展.