疏肝健脾方药对非酒精性脂肪性肝病大鼠肝细胞P13K p85α蛋白表达的影响

目的 观察疏肝健脾方药对非酒精件脂肪性肝病(NAFLD)大鼠肝细胞磷脂酰肌醇-3-激酶n85α(PI3K p85α)表达的影响.方法 以高脂饮食12周建立大鼠NAFLD模型后,造模组大鼠再随机分为模型组、疏肝组、健脾组、综合组和自然恢复组等5组.治疗组分别给予相应药物灌胃,其他组给予等量蒸馏水灌胃,模型组继续高脂饮食,其余均予基础饲料喂养.治疗8周后,用3%戊巴比妥腹腔麻醉,腹主动脉取血,全自动生化仪检测血脂及肝功,稳态模型法评价胰岛素抵抗程度,光镜下观察各组肝脏病理改变,免疫组化方法 检测肝细胞内PI3K p85α蛋白的表达情况.结果 与模型组相比,药物治疗各组及自然恢复组肝脏脂变程度明显减轻,肝功、血脂、胰岛素抵抗均有显著改善(P＜0.05或P＜0.01),肝细胞内PI3K p85α蛋白的表达明显减少(P＜0.05).与自然恢复组相比,药物治疗各组肝功、血脂、血糖的改善无显著差异,但肝脏脂变程度减轻,胰岛素抵抗指数明显下降(P＜0.05),肝细胞内PI3K p85α蛋白的表达显著降低(P＜0.05).结论 疏肝健脾方药对高脂饮食诱导的大鼠NAFLD有较好的治疗作用,其机制可能是与其降低肝细胞PI3K p85α的表达有关.     

疏肝健脾方药对非酒精性脂肪性肝病大鼠肝细胞PI3K p85α蛋白表达的影响

目的观察疏肝健脾方药对非酒精性脂肪性肝病（NAFLD）大鼠肝细胞磷脂酰肌醇-3-激酶p85α（PI3K p85α）表达的影响。方法以高脂饮食12周建立大鼠NAFLD模型后,造模组大鼠再随机分为模型组、疏肝组、健脾组、综合组和自然恢复组等5组。治疗组分别给予相应药物灌胃,其他组给予等量蒸馏水灌胃,模型组继续高脂饮食,其余均予基础饲料喂养。治疗8周后,用3%戊巴比妥腹腔麻醉,腹主动脉取血,全自动生化仪检测血脂及肝功,稳态模型法评价胰岛素抵抗程度,光镜下观察各组肝脏病理改变,免疫组化方法检测肝细胞内PI3K p85α蛋白的表达情况。结果与模型组相比,药物治疗各组及自然恢复组肝脏脂变程度明显减轻,肝功、血脂、胰岛素抵抗均有显著改善（P〈0.05或P〈0.01）,肝细胞内PI3K p85α蛋白的表达明显减少（P〈0.05）。与自然恢复组相比,药物治疗各组肝功、血脂、血糖的改善无显著差异,但肝脏脂变程度减轻,胰岛素抵抗指数明显下降（P〈0.05）,肝细胞内PI3K p85α蛋白的表达显著降低（P〈0.05）。结论疏肝健脾方药对高脂饮食诱导的大鼠NAFLD有较好的治疗作用,其机制可能是与其降低肝细胞PI3K p85α的表达有关。     

补肾通脉方对伴胰岛素抵抗的多囊卵巢综合征大鼠肝脏和脂肪组织磷脂酰肌醇-3激酶蛋白表达的影响

目的 观察补肾通脉方对伴胰岛素抵抗(insulin resistance,IR)的多囊卵巢综合征(polycystic ovarian syndrome,PCOS)大鼠肝脏和脂肪组织中磷脂酰肌醇-3激酶(PI-3K)p85α亚基蛋白表达的影响.方法 23日龄雌性SD大鼠皮下注射硫酸普拉睾酮钠9 mg/(100 g·d),共20 d,联合高脂饮食喂养80 d建立IR的PCOS大鼠模型,成模大鼠随机分为模型组和治疗组,另设15只为正常对照组.治疗组大鼠以补肾通脉方进行干预.光镜下观察大鼠排卵情况;通过葡萄糖氧化酶法测定空腹血糖(FPG);以放射免疫法测定空腹血清胰岛素(FINS);采用Western blot技术检测肝脏和脂肪组织中PI-3K p85α的蛋白表达.结果 与模型组比较,治疗组平均排卵数及排卵率明显增加(P＜0.01),FINS浓度显著降低(P＜0.01).治疗组肝脏和脂肪组织中PI-3K p85α的蛋白表达水平均较模型组明显增加(P＜0.01,P＜0.05).结论 补肾通脉方可改善伴IR的PCOS大鼠的胰岛素抵抗,其机制可能与其上调肝脏和脂肪组织中PI-3K p85α蛋白的表达有关.     

复方贞术调脂方对HepG2细胞胰岛素抵抗的作用及机制研究

目的 观察复方贞术调脂方（FTZ）对胰岛素抵抗（IR） HepG2细胞的作用,为开拓FTZ的治疗范围,阐明FTZ调节糖脂代谢的机制提供实验依据.方法 用高浓度胰岛素诱导HepG2细胞使其产生胰岛素抵抗,用高、中、低3个剂量的FTZ干预后,葡萄糖氧化酶法检测HepG2细胞培养液上清液中葡萄糖的含量,实时荧光定量PCR检测HepG2细胞胰岛素信号PI-3Kp85 mRNA的表达,Western blot检测HepG2细胞胰岛素信号转导蛋白IRS1表达.结果 模型细胞培养基上清液中葡萄糖含量高于正常细胞（P＜0.05）.给予FTZ（1、25、100μg/mL）后,HepG2细胞培养基上清液中葡萄糖含量均低于模型细胞葡萄糖含量（P＜0.05）.胰岛素抵抗细胞与正常细胞相比PI-3Kp85 mRNA和IRS1的蛋白表达显著降低（P＜0.05）.给予FTZ干预后,与胰岛素抵抗细胞相比PI-3Kp85 mRNA和IRS1的蛋白表达显著增加（P＜0.05）.结论 FTZ可改善胰岛素抵抗HepG2细胞对葡萄糖的摄取.其改善胰岛素抵抗的作用机制之一可能是通过上调胰岛素信号PI-3Kp85 mRNA和IRSl蛋白质在胰岛素抵抗HepG2细胞的表达.     

肉桂醛对糖尿病大鼠腓肠肌IRS-1和P85α表达的影响

目的:研究肉桂醛(Cin)降糖调脂作用及其对胰岛素受体底物1(IRS-1)和磷脂酰肌醇3激酶调节亚基P85α的影响。方法:Wistar大鼠,雄性,随机分为3组:正常对照组、糖尿病组(T2DM,高脂饮食诱导8周后,腹腔注射35mg/kg链脲佐菌素建立的糖尿病大鼠模型)和Cin+糖尿病组[T2DM+Cin,肉桂醛40mg/(kg·d),灌胃]。药物干预4周后,观察一般情况,检测体重、血糖血脂、胰岛素,采用免疫组化检测大鼠腓肠肌IRS-1和P85α蛋白水平。结果:实验末,T2DM+Cin组体重、血糖、胰岛素、甘油三酯、低密度脂蛋白均显著低于T2DM组(P<0.01),高密度脂蛋白高于T2DM组(P<0.05);T2DM+Cin组腓肠肌的IRS-1高于T2DM组,P85α低于T2DM组,差别有统计学意义(P<0.05)。结果:肉桂醛的降糖调脂作用可能与升高糖尿病大鼠腓肠肌中IRS-1和降低P85α水平有关。     

亚硒酸钠对糖尿病肾病大鼠肾脏脂联素表达的影响

目的:探讨亚硒酸钠对糖尿病肾病大鼠肾脏脂联素表达的影响及二者间的关系,从而研究亚硒酸钠和脂联素在糖尿病肾病中的作用机制。 方法:通过链脲佐菌素法并给予高脂饮食诱导模拟大鼠糖尿病肾病模型,实验设空白对照组、糖尿病肾病对照组、亚硒酸钠干预组,每组10只。亚硒酸钠干预组每日给予亚硒酸钠溶液1 μg/kg灌胃,其他各组给予等量盐水溶液灌胃。灌胃10周后处死大鼠,取大鼠血、尿标本测相关生化指标。快速切取小块肾皮质组织,4%戊二醛固定,制电镜切片扫描电镜观察超微结构。取肾脏组织标本制石蜡切片光镜下观察病理改变及免疫组化分析定位蛋白表达,定量PCR法检测脂联素的mRNA表达、蛋白质印迹法检测脂联素蛋白表达。结果:亚硒酸钠干预组大鼠基本状况和生化指标较糖尿病肾病对照组明显改善,光镜下亚硒酸钠干预组病理改变和电镜下超微结构较糖尿病肾病对照组明显减轻。免疫组化分析,亚硒酸钠干预组脂联素蛋白着色较糖尿病肾病对照组明显增强,且肾小管、肾小球内均有着色。亚硒酸钠干预组脂联素mRNA是空白对照组的2.043倍,糖尿病肾病对照组脂联素mRNA是空白对照组的1.373倍。亚硒酸钠干预组脂联素蛋白表达水平高于糖尿病肾病对照组及空白对照组,差异有统计学意义(P<0.05)。结论:亚硒酸钠通过抗氧化应激、增加外周组织对胰岛素的敏感性从而促进肾脏脂联素表达,表明亚硒酸钠和脂联素在延缓和防治糖尿病肾病的发生发展中可能起重要作用。     

Roux-en-Y胃旁路术缓解2型糖尿病GK大鼠肝脏胰岛素抵抗的机制

 目的研究Roux-en-Y胃旁路术（RYGB）后GK大鼠肝脏胰岛素抵抗缓解的机制。方法10只GK大鼠行RYGB（RYGB组）,10只GK大鼠（GK组）和10只Wistar大鼠（WIS组）行假手术,检测RYGB手术前后大鼠体质量、空腹血糖、胰岛素抵抗指数的变化,检测手术前后大鼠血浆脂联素、肝细胞脂联素受体2、肝细胞内腺苷酸活化蛋白激酶（AMPK）、胰岛素受体底物2（IRS-2）的变化。结果 术前RYGB组与GK组大鼠存在明显的胰岛素抵抗, RYGB组术后血糖、胰岛素抵抗指数（HOMA-IR）基本恢复至正常水平,血浆脂联素水平升高。与WIS组比较,RYGB组大鼠肝细胞的AMPKα2 mRNA水平上调1.81倍（P＜0.05）,IRS-2 mRNA水平上调3.24倍（P＜0.05）。结论RYGB后脂联素升高,通过脂联素受体作用于AMPK信号通路,增加葡萄糖利用,减少肝糖原异生,并通过上调IRS-2,达到缓解胰岛素抵抗的作用。     

Ghrelin改善骨骼肌细胞胰岛素抵抗的机制研究

目的观察酰化ghrelin和非酰化ghrelin分别对胰岛素抵抗（insulinresistance,IR）骨骼肌细胞的胰岛素受体后信号通路关键因子P13Kp85α、Akt／PKB及GLUT4的影响。方法大鼠L6成肌细胞经棕榈酸诱导分化,建立IR模型成功后入选实验,分为酰化ghrelin组（AG组）、非酰化ghrelin组（UAG组）、P13K抑制剂（LY）＋酰化ghrelin组（LY＋AG组）、LY＋非酰化ghrelin组（LY＋UAG组）和对照组（IR—CO组）。各组经处理因素干预24h后,激光共聚焦和流式细胞术检测各组骨骼肌细胞在胰岛素刺激下对荧光葡萄糖的摄取能力,免疫印迹法检测骨骼肌组织的磷酸化／总P13Kp85α、磷酸化／总Akt、细胞膜／总GLUT4的蛋白表达,实时荧光定量PCR法检测骨骼肌组织P13Kp85α、Akt、GLUT4mRNA的表达。结果L6成肌细胞诱导分化及IR模型建立成功;AG组和UAG组的细胞在胰岛素刺激下的葡萄糖摄取分别是IR—CO组的1．25和1．28倍,磷酸形总P13Kp85α相对蛋白表达量分别是IR-CO组的1．78和1．89倍,磷酸化／总Akt、细胞膜／总GLUT4的蛋白表达是IR—CO组的1．84和1．80倍,细胞P13Kp85α、Akt／PKB、GLUT4的mRNA表达均较对照组显著升高,LY＋AG组和LY＋UAG组细胞的上述指标较单独使用酰化ghrelin或非酰化ghrelin作用时显著下降。结论酰化ghrelin和非酰化ghrelin均能改善骨骼肌细胞的IR,增加骨骼肌细胞在胰岛素刺激下的葡萄糖摄取;能够上调骨骼肌细胞的磷酸化P13Kp85α、磷酸化Akt／PKB、细胞膜GLUT4的相对蛋白表达和3者的mRNA表达,PI3K抑制剂LY294002能够抑制酰化和非酰化ghrelin的上述改善作用。     

细胞外基质对哮喘大鼠气道平滑肌细胞PI3Kp85表达的影响

目的:研究细胞外基质(ECM)对哮喘大鼠气道平滑肌细胞(ASMCs)磷脂酰肌醇-3-激酶p85(PI3Kp85)表达的影响。方法:卵白蛋白(OVA)致敏法复制大鼠哮喘模型,将培养后的大鼠叶支气管ASMCs分别种植在涂覆有纤维连接蛋白、Ⅰ型胶原及层粘蛋白的培养瓶中培养,Western blot检测各组ASMCs中PI3Kp85蛋白表达,Real-time PCR检测其mRNA。另取12只正常大鼠做对照。结果:哮喘纤维连接蛋白组、层粘蛋白组、Ⅰ型胶原蛋白组ASMCs中PI3Kp85 mRNA的表达分别是(7.63±0.61)、(9.73±0.68)、(16.22±0.88),均明显高于对照组(5.93±0.75)(P<0.01);蛋白表达情况与mRNA趋势一致。结论:纤维连接蛋白、Ⅰ型胶原及层粘蛋白可以上调哮喘大鼠气道平滑肌细胞中PI3Kp85表达。     

非诺贝特对胰岛素抵抗大鼠血清脂联素及肿瘤坏死因子-α的影响

目的：观察非诺贝特对胰岛素抵抗（IR）大鼠血清脂联素、肿瘤坏死因子-α（TNF-α）的影响,探讨非诺贝特改善IR的机制。方法：36只Wistar大鼠随机分为正常对照组（12只）和高脂组（24只）,分别给予普通饮食和高脂饮食;6周后高脂组大鼠分为非诺贝特组（F组）和高脂对照组（HF组）,每组12只,分别给予非诺贝特和蒸馏水灌胃4周。以高胰岛素-正常葡萄糖钳夹技术评价胰岛素敏感性;ELLSA法检测血清脂联素和TNF～仅的水平。结果：HF组大鼠血清脂联素水平明显降低（P〈0．05）,而TNF-α水平显著升高（P〈0．01）,胰岛素敏感性显著下降（P〈0．01）。非诺贝特治疗后,血清脂联素水平明显升高,而TNF-α水平明显下降（P〈0．05）,胰岛素敏感性显著增加（P〈0．01）。结论：非诺贝特增加IR大鼠血清脂联素水平而降低TNF-α水平,改善IR。     

青春期胰岛素抵抗及青春期2型糖尿病动物模型的特点

目的：分析高脂饮食诱导的青春期胰岛素抵抗大鼠及青春期2型糖尿病大鼠的特点。方法：通过正常血糖-高血浆胰岛素钳夹实验评估两种大鼠模型的胰岛素敏感性；对两种模型大鼠的雄激素与胰岛素敏感性的相关性进行研究，并与高脂饮食的成年期大鼠比较异同。结果：青春期胰岛素抵抗雄性大鼠的睾酮水平显著降低，且与胰岛素敏感性呈相关关系；小剂量链佐菌素（STZ）并不明显破坏胰岛细胞，但可使青春期胰岛素抵抗大鼠发生糖尿病（2型糖尿病）；青春期大鼠高脂饮食后仅仅甘油三酯（TG）和低密度脂蛋白胆固醇（LDL-C）升高，而成年胰岛素抵抗大鼠血脂代谢已经全面异常。结论：高脂饮食诱导的青春期大鼠胰岛素抵抗及2型糖尿病的发生可能与其血浆睾酮水平异常有关。     

visfatin对体外脂肪细胞胰岛素受体底物和PI3K表达的影响

目的：从胰岛素经典信号传导通路磷脂酰肌醇-3-激酶（PI3K）角度探讨内脏脂肪素（visfatin）与2型糖尿病（T2DM）胰岛素抵抗（IR）的关系。方法：复苏、传代和诱导分化人源T2DM前脂肪细胞,构建 visfatin过表达载体,进行载体转化、培养和提取;以4个不同表达梯度（0.0、1.0、2.5和5.0 μg）转染传代脂肪细胞,以0.0 μg组为对照组,其余3组为观察组;Q-PCR法检测visfatin 、胰岛素受体底物1（IRS-1）、胰岛素受体底物2（IRS-2）和 PI3K（P85α） mRNA表达水平,Western blotting法检测visfatin、IRS-1、IRS-2和PI3K（P85α） 蛋白表达水平及IRS-1和IRS-2酪氨酸磷酸化水平,[³H]-2-脱氧-D-葡萄糖摄取法测定细胞葡萄糖摄取率的变化。结果：各组 visfatin mRNA及蛋白表达水平随转染浓度梯度升高而升高（P<0.01）,所构建visfatin过表达载体有效。随visfatin表达增加,各组IRS-1和PI3K（P85α） mRNA和蛋白表达水平以及IRS-1磷酸化程度均明显升高（P< 0.01）,但IRS-2 mRNA和蛋白表达水平未出现明显变化（P>0.05）。脂肪细胞的葡萄糖摄取率随visfatin表达增加而升高（P<0.05）。结论：体外脂肪细胞visfatin过表达可增加IRS-1和PI3K的表达水平。     

Effect of berberine on expression of hepatocyte nuclear factor-4α in rats with fructose-induced insulin resistance

The effects of berberine on the expression of hepatocyte nuclear factor-4α （HNF-4α） in liver of rats with fructose-induced insulin resistance and the molecular mechanism of berberine preventing insulin resistance were investigated. The experimental animals were divided into two groups of 16 animals each. The control group received a control routine diet containing 60% carbohydrate, and the study group a high-fructose diet containing 60% fructose as the sole source of carbohydrate. At the end of 6 weeks these were each subdivided into two groups. One was administered with berberine [187.5 mg/（kg·d） in 5 g/L carboxymethyl cellulose] by intragastric intubation and the other group was treated with a vehicle （5 g/L carboxymethyl cellulose）. The rats were fed on the same dietary regimen for the next 4 weeks. After the experimental period of 10 weeks, plasma glucose, insulin and triglyceride levels were measured. HOMA insulin resistance index （HOMA-IR） was assayed. Immunohistochemistry, semiquantitative RT-PCR and western blot were used to detect the expression of HNF-4α in liver. Compared with control diet, fructose feeding induced hyperinsulinemia, HOMA-IR and increased triglyceride （all P〈0.01）. Berberine prevented the rise in plasma insulin （P〈0.01）, HOMA-IR （P〈0.01） and triglyceride （P〈0.05） in the fructose-fed rats. No change in plasma glucose was seen among these groups. The mRNA and protein expression of HNF-4α was decreased in the fructose-fed rats, but berberine could promote its expression. It was concluded that berberine could prevent fructose-induced insulin resistance in rats possibly by promoting the expression HNF-4α in liver.     

交泰丸通过骨骼肌磷脂酰肌醇(-3)激酶通路提高糖尿病大鼠胰岛素信号强度

Objective: To investigate the effect of Jiaotai Pill (交泰丸, JTP) at different constitutional proportions on insulin signaling through phosphatidylinositol 3-kinase (PI3K) pathway in the skeletal muscle of diabetic rats. Methods: The rat model of type 2 diabetes mellitus (T2DM) was established by intravenous injection of a small dose of streptozotoein plus high fat diet feeding. JTP at the same dosage of cinnamon and the increasing dosage of Coptis chinensis was administered to diabetic rats for nine weeks respectively. Plasma glucose and insulin levels were assayed. The expressions of proteins were determined by Western blot method. Results: All the three formulations of JTP decreased plasma glucose and fasting insulin levels as well as increased the protein expressions of insulin receptor β (InsRβ) subunit, insulin receptor substrate-1 (IRS-1), PI3K p85 subunit and glucose transporter 4 (GLUT4) in skeletal muscle. Meanwhile, JTP increased the tyrosine phosphorylation of InsRβ subunit and IRS-1, and reduced the serine phosphorylation of IRS-1 in skeletal muscle. Interestingly, the effect of JTP on improving insulin sensitivity was not dose-dependent. In contrast, JTP containing the least amount of Coptis chinensis exhibited the best effect. Conclusion: JTP at different constitutional proportions attenuates the development of diabetes in a rat model of T2DM. The mechanism might be associated with enhancing insulin signaling through PI3K pathway in the skeletal muscle.     

Regulation of leptin on insulin secretion and sulfonulurea receptor 1 transcription level in isolated rats pancreatic islets

Objective To investigate the regulation of leptin on insulin secretion and expression of ATP-sensitive potassium channel subunit sulfonulurea receptor 1 (SUR1) mRNA, and to determine whether the effects of leptin are mediated through known intracellular signaling transduction.Methods Pancreatic islets were isolated by the collagenase method from male SD rats. The purified islets were incubated with different concentrations of leptin for 2 h in the presence of different concentrations of glucose. Insulin release was measured using radioimmunoassay. Expression of SUR1 mRNA was detected by RT-PCR.Results In the presence of leptin 2 nmol/L, insulin release was significantly inhibited at either 11.1 or 16.7 mmol/L glucose concentration (both P<0.05), but insulin release was not altered at glucose of 5. 6 mmol/L physiological concentration. The dose-response experiment showed that the maximal effect of leptin on insulin secretion achieved at 2 nmol/L. Exposure of islets to 2 nmol/L leptin induced a significan     

磷脂酰肌醇3激酶在卵巢癌组织中的表达

目的:探讨磷脂酰肌醇3激酶(PI3K)在卵巢癌组织中的表达。方法:选取20例卵巢癌组织和20例正常卵巢组织,通过Western blot法检测PI3K的亚单位p85蛋白表达,并通过逆转录-聚合酶链式反应检测PI3K mRNA的表达。结果:卵巢癌组织p85蛋白及PI3K mRNA的表达高于正常卵巢组织,差异具有统计学意义。结论:PI3K/Akt信号转导通路可能参与了卵巢癌的发生和发展。     

Chronic Hyperinsulinism Induced Down-regulation of Insulin Post-Recentor Signaling Transduction in Hep G2 Cells

Summary: To study the regulatory effect of acute and chronic insulin treatment on insulin post-re-ceptor signaling transduction pathway in a human hepatoma cell line (Hep G2), Hep G2 cells wereincubated in the presence or absence of insulin with different concentrations in serum free mediafor 16 h and then stimulated with 100 nmol/L insulin for 1 min. Protein levels of insulin receptorβ-subunit (IRβ), insulin receptor substrate-1 (IRS-1) and p85 subunit of phosphatidylinositol 3-kinase (PI 3-kinase) were determined in total cell lysates by Western-immunoblot. Phosphorylat-ed proteins IRβ, IRS-1 and interaction of PI 3-kinase with IRS-1 were determined by immunopre-cipitation. Results showed that 1-min insulin stimulation rapidly induced tyrosine phosphorylationof IRβ and IRS-l, which in turn, resulting in association of PI 3-kinase with IRS-1. 1-100 nmol/L chronic insulin treatment induced a dose-dependent decrease in the protein level of IRβ and aslight decrease in the protein level of IRS-1. There wass more marked reduction in the phospho-rylation of IRβ, IRS-1, reaching a nadir of 22 % (P＜0. 01) and 15 % (P＜0. 01) of control lev-els, respectively, after 16 h treatment with 100 nmol/L insulin. The association between IRS-1and PI 3-kinase was decreased by 66 % (P＜0. 01). There was no significant change in PI 3-ki-nase protein levels. These data suggest that chronic insulin treatment can induce alterations ofIRβ, IRS-1 and PI 3-kinase three early steps in insulin action, which contributes significantly toinsulin resistance, and may account for desensitization of insulin action.