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1.
背景:脂联素对胰岛素抵抗、代谢综合征有着重要的调节作用,其合成受过氧化物酶体增殖物活化受体γ活性的调节,研究表明部分血管紧张素受体拮抗剂可通过激活过氧化物酶体增殖物活化受体γ影响脂联素代谢,但具体机制尚不清楚。 目的:探讨替米沙坦对脂肪细胞脂联素表达和分泌的影响,并与坎地沙坦进行比较。 方法:体外培养、诱导分化3T3-L1脂肪细胞,分别用空白培养液、坎地沙坦(10 μmol/L)和替米沙坦(10 μmol/L)干预3T3-L1脂肪细胞,采用RT-PCR法、Western blot法和ELISA法检测脂肪细胞脂联素mRNA和蛋白表达及培养液中脂联素的分泌水平。 结果与结论:与空白组和坎地沙坦组相比,替米沙坦组脂肪细胞脂联素的mRNA和蛋白表达水平明显增加(P < 0.05或P < 0.01),但各组间脂肪细胞培养液中脂联素的分泌水平差异无显著性意义(P > 0.05)。说明替米沙坦可以明显增加脂肪细胞脂联素的表达,但并不增加脂联素的分泌水平,其促进脂联素表达的作用优于坎地沙坦。  相似文献   

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背景:残粒脂蛋白可诱导大鼠脂肪间充质干细胞分化为成熟的脂肪细胞。 目的:观察残粒脂蛋白对人脂肪间充质干细胞成脂分化和氧化物酶体增殖物激活受体γ、脂联素基因表达的影响。 方法:采用成脂诱导剂刺激人脂肪间充质干细胞,油红O染色鉴定脂肪细胞。分离高三酰甘油血症患者高脂餐后4 h抗凝血浆中的残粒脂蛋白,分别将0,50,100,150,200 mg/L残粒脂蛋白与10 mg/L胰岛素联合刺激脂肪间充质干细胞。 结果与结论:油红O染色发现0,50 mg/L 残粒脂蛋白组有微量脂滴形成。100~200 mg/L残粒脂蛋白组红色脂滴逐渐增加,以200mg/L组红色脂滴最多。在50~200 mg/L质量浓度范围内,细胞氧化物酶体增殖物激活受体γ mRNA与脂联素mRNA表达随残粒脂蛋白浓度增加而逐渐增强(P < 0.05)。200 mg/L残粒脂蛋白组脂联素 mRNA表达量显著低于150 mg/L组(P < 0.05),但与100 mg/L 残粒脂蛋白组差异未达到显著性意义。表明残粒脂蛋白通过激活氧化物酶体增殖物激活受体γ诱导人脂肪间充质干细胞的成脂分化,并上调脂联素mRNA的表达。  相似文献   

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背景:研究表明小檗碱可用于治疗2型糖尿病,但小檗碱治疗糖尿病胰岛素抵抗尤其是肝脏脂诱性胰岛素抵抗的分子机制仍不明确。 目的:观察小檗碱对2型糖尿病中国地鼠模型肝脏过氧化物酶体增殖体激活受体及其靶基因表达的影响。 方法:以高脂饮食及结合小剂量链脲菌素的方法建立胰岛素抵抗和2型糖尿病中国地鼠模型。建模后随机分成4组:对照组给予普通饮食,胰岛素抵抗组给予高脂饮食,2型糖尿病组给予高脂饮食+小剂量链脲菌素,2型糖尿病小檗碱治疗组给予高脂饮食+小剂量链脲菌素+小檗碱,治疗9周。 结果与结论:实时定量PCR结果显示与对照组相比,胰岛素抵抗及2型糖尿病组地鼠肝脏过氧化物酶体增殖体激活受体α,β/d,酰基辅酶A氧化酶,肉碱棕榈酰转移酶1和中链酰基辅酶A脱氢酶的表达降低(P < 0.05),而固醇调节元件结合蛋白1c,2,过氧化物酶体增殖体激活受体γ,脂蛋白脂酶,脂肪酸转运者(FAT/CD36)和脂肪酸结合蛋白(ap2)的表达增加(P < 0.05)。结果证实,小檗碱可改善胰岛素抵抗,并逆转了氧化物酶体增殖体激活的受体及其靶基因表达的改变,小檗碱治疗2型糖尿病地鼠脂诱性胰岛素抵抗的分子机制与氧化物酶体增殖体激活的受体及其靶基因表达的改变相关。  相似文献   

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血浆脂联素与超敏C反应蛋白在脑梗塞中的临床意义   总被引:1,自引:0,他引:1  
脂联素(adiponectin,APN)是脂肪细胞分泌的一种蛋白质,近年来研究显示,脂肪组织专一表达的脂联素通过其受体调节内皮功能、免疫功能、糖脂代谢、动脉硬化,与肥胖、胰岛素抵抗、2型糖尿病、缺血性血管病有一定相关性,超敏C反应蛋白(high-sensitirity-reactive protein HsCRP)作为炎症因子,其水平与血管性疾病有着密切的联系。本研究旨在探讨APN及HsCRP在脑梗塞中的临床意义。  相似文献   

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背景:目前关于脂肪细胞分化的分子作用机制的研究较少。过氧化物酶增殖物激活受体和CCAAT/增强子结合蛋白家族的转录调控因子可诱导前脂肪细胞表达促进其分化成熟的多个转录因子,但其作用机制却罕见报道。 目的:观察小鼠3T3-L1前脂肪细胞分化为成熟脂肪细胞过程中过氧化物酶增殖物激活受体γ和CCAAT/增强子结合蛋白α的表达,以及在脂肪细胞分化过程中的变化。 方法:体外培养3T3-L1前脂肪细胞,采用经典激素鸡尾酒诱导法诱导细胞分化,诱导剂为1-甲基-3-异丁基-黄嘌呤、地塞米松和胰岛素。诱导后0,2,4,6和8 d,用油红O染色和染色比色法分析脂肪细胞的分化程度,采用实时PCR和Western blot技术检测不同时间点的过氧化物酶增殖物激活受体γ和CCAAT/增强子结合蛋白α的表达。 结果与结论:在前体脂肪细胞的分化过程中,随时间的延长相对脂肪含量、过氧化物酶增殖物激活受体γ与CCAAT/增强子结合蛋白α表达水平均明显升高(P < 0.01)。说明在小鼠3T3-L1前脂肪细胞分化为成熟脂肪细胞过程中,过氧化物酶增殖物激活受体γ与CCAAT/增强子结合蛋白α对细胞分化可能起促进作用。 关键词:脂肪细胞;细胞培养;细胞分化;过氧化物酶增殖物激活受体γ;CCAAT/增强子结合蛋白α  相似文献   

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背景:阿托伐他汀作为过氧化酶体增殖体激活受体γ的激动剂,不仅可以调节脂质代谢,而且能够抑制炎症递质生产,减轻缺血性炎症损伤,但其具体作用机制尚不明确。 目的:观察原代培养的人单核细胞中阿托伐他汀对过氧化物酶增殖体激活受体的影响和抗炎作用。 方法:将原代培养的人单核细胞随机分为对照组,10,1,0.1 µmol/L阿托伐他汀组和抗过氧化酶体增殖体激活受体γ抗体组;预先被肿瘤坏死因子α激活的人单核细胞随机分为对照组,0.1,1,10 µmol/L阿托伐他汀组,分别和不同浓度的阿托伐他汀共同孵育24 h,通过电泳迁移率变化分析抗过氧化酶体增殖体激活受体γ蛋白的表达情况,通过酶联免疫吸附实验测定肿瘤坏死因子α、单核细胞趋化蛋白1、明胶酶B的水平,并且通过氧电极法测定细胞氧耗量。 结果与结论:在未被肿瘤坏死因子α激活的单核细胞中,阿托伐他汀可以呈浓度依赖性激活抗过氧化酶体增殖体激活受体γ,降低单核细胞趋化蛋白1、降低明胶酶B的水平,但对肿瘤坏死因子α的水平没有明显影响。而在预先被肿瘤坏死因子α激活的单核细胞中,阿托伐他汀使抗过氧化酶体增殖体激活受体γ上调的作用并不明显,但仍可浓度依赖性降低肿瘤坏死因子α、单核细胞趋化蛋白1 和明胶酶B的水平,同时阿托伐他汀呈浓度依赖性降低细胞氧耗量达41%。说明阿托伐他汀具有确切的抗炎效果,但这种作用并不完全依赖于过氧化物酶体增殖体激活受体γ途径。  相似文献   

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脂肪组织能分泌一系列脂肪细胞因子,包括瘦素、肿瘤坏死因子-α、纤溶酶原激活剂抑制物-1、白介素-6、抵抗素、脂联素等,这些脂肪细胞因子共同参与了机体的能量代谢,并通过胰岛素抵抗等多种途径参与了脑血管病的发生、发展,成为代谢综合征及其大血管并发症发病的共同土壤。  相似文献   

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背景:过氧化物酶体增殖物激活受体γ是细胞分化重要的调控因子,通过调节其他转录因子的表达,参与调节骨髓间充质干细胞的分化。 目的:构建pEGFP-N1-过氧化物酶体增殖物激活受体γ真核表达载体,体外转染兔骨髓间充质干细胞,为过氧化物酶体增殖物激活受体γ受体功能和基于过氧化物酶体增殖物激活受体γ受体靶点的药物筛选提供分子研究平台。 设计、时间及地点:单一样本观察,于2007-09/2008-07在南华大学附属一医院临床研究所完成。 材料:选择雄性2~5月龄新西兰大白兔,用于分离培养骨髓间充质干细胞。 方法:应用密度梯度离心法分离骨髓间充质干细胞,贴壁法不断纯化。从正常小鼠的肝组织中提取总RNA,反转录-聚合酶链反应法获得过氧化物酶体增殖物激活受体γcDNA,经Xho Ⅰ,Apa Ⅰ双酶切,定向克隆到真核表达载体pEGFP-N1,构建重组质粒pEGFP-N1-过氧化物酶体增殖物激活受体γ。 主要观察指标:经酶切分析和测序鉴定重组质粒中过氧化物酶体增殖物激活受体γ基因的完整性和真实性,脂质体介导下体外转染骨髓间充质干细胞,荧光倒置显微镜下观察瞬时表达及转染效率,提取总RNA和总蛋白,进行反转录-聚合酶链反应和Western blot检测。 结果:获得的过氧化物酶体增殖物激活受体γ基因片段经酶切和测序鉴定正确,重组质粒经酶切和测序鉴定证实构建正确,成功转染骨髓间充质干细胞,在其中检测到目的基因及蛋白表达。 结论:实验成功构建了pEGFP-N1-过氧化物酶体增殖物激活受体γ重组质粒,同时在转染的骨髓间充质干细胞中获得了过氧化物酶体增殖物激活受体γ的高效表达。  相似文献   

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背景:研究表明经典的wnt信号途径可通过抑制成脂分化关键因子过氧化物酶体增殖物激活受体γ而抑制细胞向脂肪细胞的分化。 目的:观察紫外光辐射肝组织致创后自然恢复期不同阶段β连环蛋白及过氧化物酶体增殖物激活受体γ的表达。 方法:将雄性SD大鼠随机分4组:激光致创组大鼠是以355 nm紫外激光辐射肝叶形成损伤区,器械致创对照组则以手术剪肝叶致创,假手术组仅做腹部切开及缝合,正常组大鼠仅实施正常喂养。 结果与结论:紫外激光可在肝组织形成边缘整齐的消融区并在周围形成可自然修复的有限致损区域。免疫组织化学图像平面测量表明紫外激光辐射后自然恢复1周大鼠肝组织中β连环蛋白表达低于各对照组(P < 0.01),而自然恢复表达β连环蛋白 辐射区周围组织表达高于正常(P < 0.01)。蛋白印迹结果显示辐射致创组辐射后自然同时过氧化物酶体增殖物激活受体γ蛋白2周 恢复高于1周恢复(P < 0.01),且恢复期肝组织中可同时表达过氧化物酶体增殖物激活受体γ 1及2。结果证实,辐射区旁组织自然恢复各阶段存在不同的β连环蛋白及过氧化物酶体增殖物激活受体γ表达调控,2周自然恢复后辐射区旁组织成脂进程得到加强。  相似文献   

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背景:GATA-1、GATA-2、过氧化物酶体增殖物激活受体γ和干细胞因子基因在骨髓造血及成脂调控机制中起重要作用。 目的:观察GATA-1、GATA-2、过氧化物酶体增殖物激活受体γ和干细胞因子基因在再生障碍性贫血患者及正常人间充质干细胞中的表达。 方法:收集6例再生障碍性贫血患者及6位正常人骨髓液各10 mL,Ficoll贴壁法分离培养骨髓单个核细胞,达70%~80%融合后扩增传代。取传至第3代的间充质干细胞,应用流式细胞仪进行鉴定。提取总RNA,比较各组基因与内参基因之间的差别。荧光定量聚合酶链反应检测GATA-1、GATA-2、过氧化物酶体增殖物激活受体γ和干细胞因子基因在再生障碍性贫血患者及正常人间充质干细胞中的表达量。 结果与结论:与正常人间充质干细胞相比,再生障碍性贫血患者间充质干细胞的GATA-2和干细胞因子基因表达量降低(P=0.012,0.039),过氧化物酶体增殖物激活受体γ基因表达量升高(P=0.035);两组GATA-1基因表达量差异无显著性意义。提示GATA-2、干细胞因子基因的异常表达可能影响AA患者骨髓微环境的造血调控作用;过氧化物酶体增殖物激活受体γ基因的异常表达可能解释再生障碍性贫血患者骨髓易成脂的原因。  相似文献   

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Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer haircell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of efferent axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.  相似文献   

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Tubocurarine (Tc) effect on membrane currents elicited by acetylcholine (ACh) was studied in isolated superior cervical ganglion neurons of rat using patch-clamp method in the whole-cell recording mode. The "use-dependent" block of ACh current by Tc was revealed in the experiments with ACh applications, indicating that Tc blocked the channels opened by ACh. Mean lifetime of Tc-open channel complex, tau, was found to be 9.8 +/- 0.5 s (n = 7) at -50 mV and 20-24 degrees C. tau exponentially increased with membrane hyperpolarization (e-fold change in tau corresponded to the membrane potential shift by 61 mV). Inhibition of the ACh-induced current by Tc (3-30 microM/1) was completely abolished by membrane depolarization to the level of 80-100 mV. Inhibition of ACh-induced current was augmented at increased ACh doses. It is concluded that the open channel block produced by Tc is likely to be the only mechanism for Tc action on nicotinic acetylcholine receptors in superior cervical ganglion neurons of rat.  相似文献   

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Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005  相似文献   

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After a hopeful beginning, the social process of the reintegration of those with severe mental illness has come to a standstill. I am led to wonder whether "the community" really wants to live together with people suffering from severe mental illness, and if so, how closely? As long as the medical treatment of mental illness provided by the general practitioners is fundamentally deficient, as they are not able to prescribe the necessary interventions--such as out-patient psychiatric nursing, and service providers in the out-patient sector are content with offering increasingly intensive forms of care for the less seriously ill at the cost of the Social Welfare System--the reintegration of those with serious mental illness remains an illusion--which is mainly to the benefit of providers of residential care in homes and hostels.  相似文献   

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