诱导回输胰岛素分泌细胞对大鼠糖尿病的疗效

目的:研究胰岛素分泌细胞的体外诱导方法及其对大鼠糖尿病的疗效.方法:分离培养大鼠骨髓干细胞,用尼克酰胺及肠促胰岛素类似物诱导其分化为胰岛素分泌细胞.将24只Wistar大鼠随机分为对照组、糖尿病组和诱导组.后两组建立糖尿病模型,将该胰岛素分泌细胞回输至诱导组体内,监测大鼠体重、血糖(空腹及OGTT 120分血糖)及空腹...     

罗格列酮联合胰岛素对糖尿病大鼠氧化应激及血脂水平的影响

摘要 目的：探讨罗格列酮（RSG）联合胰岛素（INS）对糖尿病大鼠的氧化应激和血脂水平的影响。方法：30只健康雄性Wistar大鼠,随机分为3组：健康对照组、DM模型组和RSG+INS组,每组10只。采用链脲佐菌素（STZ）造模法进行糖尿病大鼠模型诱导。此后以RSG （3 mg/kg/day）灌胃,INS （2.25 U/kg/day）皮下注射,均连续给药8周,对RSG+INS组大鼠进行干预治疗。每2周定期记录各组大鼠的体重和血糖值1次;药物干预治疗8周后,取各组大鼠血清,对血清总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL）、高密度脂蛋白（HDL）、糖化血红蛋白（HbA1c）和丙二醛（MDA）的含量以及超氧化物歧化酶（SOD）和谷胱甘肽（GSH）的活性进行检测;应用苏木素碱性复红苦昧酸（HBFP）染色分析心肌形态变化。结果：RSG联合INS组治疗糖尿病大鼠,导致血糖发生时间依赖性下降（均P<0.05）;药物干预处理8周后,RSG+INS组大鼠的血清TC、TG、LDL和HbA1c水平均显著低于DM模型组,而HDL显著高于DM模型组（均P<0.05）;与DM模型组相比,RSG+INS组大鼠的血清MDA含量显著下降,而SOD和GSH活性则显著升高（均P<0.05）;与DM模型组相比,RSG+INS组心肌缺血/氧程度减轻。结论：RSG联合INS可有效对抗糖尿病大鼠体内的氧化应激损伤,改善糖尿病大鼠的脂代谢异常情况,并对心肌组织有一定的保护作用。     

石榴皮多酚对妊娠期糖尿病大鼠胰岛素抵抗及氧化应激损伤的影响

摘要 目的：探讨石榴皮多酚（PPPs）对妊娠期糖尿病（GDM）大鼠胰岛素抵抗（IR）及氧化应激损伤的影响。方法：45只孕鼠随机分为对照组、模型组和PPPs组,各15只。模型组和PPPs组孕鼠经腹腔注射45 mg/kg链脲佐菌素制备GDM模型大鼠,对照组经腹腔注射生理盐水。模型制备成功后给予PPPs组大鼠按300 mg/kg PPPs灌胃,对照组和模型组灌胃等体积生理盐水。给药14 d后检测空腹尾静脉血中糖化血红蛋白（HbA1c）、空腹血糖（FBG）、空腹胰岛素（FINS）、肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）、IL-6、超氧化物歧化酶（SOD）、超敏C反应蛋白（hs-CRP）、丙二醛（MDA）、过氧化氢酶（CAT）、尿酸（UA）、尿素氮（BUN）、血清肌酐（SCr）和尿液β-N-乙酰氨基葡萄糖苷酶（NAG）、肾损伤分子1（KIM-1）水平,计算稳态模型的胰岛素抵抗指数（HOMA-IR）。结果：模型组和PPPs组大鼠血清HbA1c、FBG、FINS、TNF-α、IL-1β、IL-6、hs-CRP、MDA、UA、BUN、SCr和尿液NAG、KIM-1水平以及HOMA-IR显著高于对照组,SOD和CAT活性显著低于对照组（P<0.05）。PPPs组大鼠血清HbA1c、FBG、FINS、TNF-α、IL-1β、IL-6、hs-CRP、MDA、UA、BUN、SCr和尿液NAG、KIM-1水平以及HOMA-IR均显著低于模型组,SOD和CAT活性显著高于对照组（P<0.05）。结论：PPPs能够显著减轻妊娠期糖尿病大鼠胰岛素抵抗、氧化应激水平,改善血糖和肾损伤。     

胰岛素分泌细胞移植治疗Ⅰ型糖尿病的研究进展

Ⅰ型糖尿病(typeⅠ diabetes mellitus,T1DM)是目前严重危害人类健康的常见病、多发病,全世界约有2%~5%的人患有此种疾病,且呈逐年增长趋势,多见于儿童和青少年。从降糖药物到胰岛素,从胰腺移植到胰岛移植,T1DM的治疗经历了一个漫长的过程。近年来研究发现,由胚胎干细胞(embryonicstemcells,ESC)、胰腺干细胞及其它组织干细胞等诱导分化为胰岛素分泌细胞(insulin-serectingcells,ISC),可望解决移植过程中存在的供体不足的问题。着重介绍了几种ISC的来源和诱导分化途径,分析了各种途径的优势及不足。     

不同负荷的运动干预对糖尿病大鼠血清脂联素的影响

目的:观察不同运动强度下糖尿病大鼠血清脂联素的影响,并初步探讨血清脂联素与血清胰岛素的关系。方法:将SD大鼠分为5组:正常对照组(CON组)、糖尿病非运动组(DM0组)、糖尿病小强度运动组(DM1组)、糖尿病中等强度运动组(DM2组)和糖尿病大强度运动组(DM3组),每组6只。采用高糖高脂饮食饲养4周后一次性腹腔注射链脲佐菌素(Streptozotocin)制备糖尿病大鼠模型。6周跑台运动前后检测大鼠尾静脉空腹血清胰岛素(FINS)、血清脂联素(ADIPO)水平。结果 :小强度FINS和APIDO无明显变化,中强度FINS和APIDO明显升高,大强度运动组FINS和APIDO明显升高。脂联素与胰岛素水平相关性分析:DM1组无明显相关性,DM2组和DM3组有正相关性。结论:不同运动强度下糖尿病大鼠血清脂联素水平不一致,而且胰岛素水平与脂联素水平存在一定的变化关系。     

胰腺β细胞的离子通道和胰岛素分泌

1 .胰腺β细胞膜上几种重要的离子通道和动作电位β细胞内的离子通道特性和胰岛素分泌的机制研究是深入了解糖尿病的基础。 2 0世纪 70年代初 ,胰岛 (ｉｓｌｅｔ)电生理研究表明 ,葡萄糖刺激伴随着β细胞膜电势的变化 ,并推测其与胰岛素分泌相关[1] 。 2 0世纪 70年代末 ,Ｎｅｈｅｒ等[2 ] 发明了膜片钳记录技术 ,大大促进了包括β细胞在内的单细胞电生理的研究。1 .1　Ｋ 通道　　 2 0世纪 80年代前期 ,各种不同膜片钳构型的研究都表明 ,葡萄糖刺激下β细胞的膜电势变化源于膜上一种Ｋ 通道活性的改变 ,因其可直接被ＡＴＰ关闭而被命名为…     

高糖高脂致家兔糖尿病的实验模型探讨

目的　建立饮食诱导新西兰兔糖尿病模型 ,探讨脂肪毒性和葡萄糖毒性在 2型糖尿病发病中的意义。方法　将雄性新西兰兔 30只按血糖血脂浓度随机分为 2组 ,15只饲以基础饲料作为正常对照组 (C组 ) ;15只饲以高糖高脂饲料作为实验组 (DD组 ) ,共观察 32周 ,每 4周从禁食过夜的兔耳静脉抽取血样 ,测定血清中血糖、胰岛素、甘油三酯。于 32周时 ,全部处死动物 ,取动物胰腺。取部分胰腺用 10 %中性甲醛液固定 ,常规石蜡包埋切片 ,H、E染色 ,光学显微镜下观察 ;另一部分胰腺用 2 5 %戊二醛固定 ,常规电镜样品制备 ,透射电镜下观察并照相。结果　实验组 4周后即出现高血糖、高甘油三酯 ,并随着喂养时间延长 ,而有所升高 ,基础饲料组血糖、甘油三酯未见明显升高 ,两组比较差异具有显著性意义 (P <0 0 1)。以不同喂养时间作方差分析 ,整体上差异具有显著性意义。实验组血清胰岛素水平整体上差异没有显著性意义 (P >0 0 5 )。实验组胰腺组织表现为胰岛萎缩 ,胰岛边缘皱缩 ,胰岛数目减少 ,胰岛内细胞数量亦减少 ,多数细胞呈梭形 ,细胞核呈杆状 ,胰岛周围少量淋巴细胞浸润。透射电镜下观察到实验组胰岛 β细胞体积略小 ,核较小 ,部分分泌颗粒呈空泡状 ,细胞内可见局部结构较模糊 ,粗面内质网少 ,未见明显淀粉样变     

氧化应激与糖尿病

高血糖引起的自由基产生过多或消除障碍导致氧化应激的出现,氧化应激与糖尿病及其并发症的发生发展密切相关。抗氧化治疗为糖尿病及并发症的防治提供了新的思路。     

氧化应激与2型糖尿病

胰岛素抵抗、胰岛β细胞功能受损是2型糖尿病的主要病因。高血糖、高血脂导致在代谢过程中,线粒体产生大量活性氧,其可损坏线粒体功能,引起氧化应激反应。氧化应激可以激活细胞内的一系列应激信号通路,如JNK／SAPK、p38MAPK、IKKβ／NF-kβ和氨基己醣通路等。这些应激通路的激活可以产生以下结果：（1）阻断胰岛素作用通路,导致胰岛素抵抗;（2）降低胰岛素基因表达水平;（3）抑制胰岛素分泌;（4）促进β细胞凋亡等。本文主要针对活性氧的产生、氧化应激诱导胰岛素抵抗和胰岛β细胞功能受损等机制加以综述,以便进一步阐明2型糖尿病的发病机理。     

胰岛素对糖尿病大鼠肝细胞氧化损伤的影响

利用四氧嘧啶建立糖尿病大鼠模型 ,研究了胰岛素对糖尿病大鼠肝细胞及线粒体氧化损伤的保护作用。结果表明 ,胰岛素 1U kg皮下注射 9d ,能明显降低肝组织谷丙转氨酶、谷草转氨酶、乳酸脱氢酶、黄嘌呤氧化酶的活性 ,显著提高肝组织丙二醛的含量及肝线粒体O· -2 (活性氧自由基 )的生成量 ,显著提高抗氧化酶谷胱甘肽过氧化物酶、超氧化物歧化酶的活性 ,提高肝线粒体H+ ATPase的合成活力 ,从而使受损的肝细胞功能得到改善     

胰岛素对糖尿病大鼠代谢紊乱的调节作用

利用四氧嘧啶建立糖尿病大鼠模型,研究了胰岛素对糖尿病大鼠脂肪、蛋白质、自由基代谢紊乱的调节作用及对机体和肝脏氧化损伤的保护作用。结果表明,胰岛素0．5U/kg皮下注射8周,能明显抑制糖尿病引起大鼠体重的降低。皮下注射6周,显著提高了血清总蛋白、白蛋白、总胆固醇的水平,降低了血清甘油三酯的含量。胰岛素1U／kg皮下注射9d,能显著提高血清超氧化物歧化酶、谷肮甘肽过氧化物酶的活性,降低血清丙二醛的含量及促氧化酶黄嘌呤氧化酶的活性,提高肝线粒体谷胱甘肽过氧化物酶的活性,降低肝线粒体丙二醛的含量。从而调节糖尿病大鼠脂肪、蛋白质、自由基代谢紊乱,减轻机体的氧化损伤,改善肝功能。     

Delta-like Ligand-4-Notch Signaling Inhibition Regulates Pancreatic Islet Function and Insulin Secretion

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人胰腺细胞培养及胰岛素的分泌

人胰腺细胞培养及胰岛素的分泌王石泉,汤国枝,张鹤云,李敏意,金以丰（南京大学生物化学系,南京２１００９３）胰岛β细胞的体外培养获得胰岛素已有报道,但大多采用新生大鼠胰腺,且β细胞成活率低,分泌量少,还处在研究阶段［１－４］．本实验采用人胰腺细胞做较大...     

Phosphorylation and Degradation of Tomosyn-2 De-represses Insulin Secretion

The abundance and functional activity of proteins involved in the formation of the SNARE complex are tightly regulated for efficient exocytosis. Tomosyn proteins are negative regulators of exocytosis. Tomosyn causes an attenuation of insulin secretion by limiting the formation of the SNARE complex. We hypothesized that glucose-dependent stimulation of insulin secretion from β-cells must involve reversing the inhibitory action of tomosyn. Here, we show that glucose increases tomosyn protein turnover. Within 1 h of exposure to 15 mm glucose, ∼50% of tomosyn was degraded. The degradation of tomosyn in response to high glucose was blocked by inhibitors of the proteasomal pathway. Using ³²P labeling and mass spectrometry, we showed that tomosyn-2 is phosphorylated in response to high glucose, phorbol esters, and analogs of cAMP, all key insulin secretagogues. We identified 11 phosphorylation sites in tomosyn-2. Site-directed mutagenesis was used to generate phosphomimetic (Ser → Asp) and loss-of-function (Ser → Ala) mutants. The Ser → Asp mutant had enhanced protein turnover compared with the Ser → Ala mutant and wild type tomosyn-2. Additionally, the Ser → Asp tomosyn-2 mutant was ineffective at inhibiting insulin secretion. Using a proteomic screen for tomosyn-2-binding proteins, we identified Hrd-1, an E3-ubiquitin ligase. We showed that tomosyn-2 ubiquitination is increased by Hrd-1, and knockdown of Hrd-1 by short hairpin RNA resulted in increased abundance in tomosyn-2 protein levels. Taken together, our results reveal a mechanism by which enhanced phosphorylation of a negative regulator of secretion, tomosyn-2, in response to insulin secretagogues targets it to degradation by the Hrd-1 E3-ubiquitin ligase.     

Reversal of Osteoporotic Changes of Mineral Composition in Femurs of Diabetic Rats by Insulin

Insulin plays an important role in bone prevention of diabetic osteoporosis, but little is known about the relation between the bone mineral density (BMD) increase and the change of mineral element content after treated with insulin. To address this problem, male Wistar rats were randomly divided into three groups: normal group (n = 6), streptozotocin-induced diabetic group (n = 5), and streptozotocin-induced diabetic group with insulin treatment (n = 5). The femoral BMD was measured by dual energy X-ray absorptiometry, and the element content was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The results showed that the femoral BMD in diabetic group was significantly lower than that in normal group (P < 0.01) but restored by insulin treatment (P < 0.01 vs diabetic group). ICP-AES analysis revealed that the element content of calcium (Ca), phosphorous (P), magnesium (Mg), strontium (Sr), and potassium (K) in diabetic group were remarkably lower than those in normal group (P < 0.01) but only Ca, P, and Mg content were significantly increased compared with diabetic group (P < 0.05) after insulin treatment. However, no significant differences were observed in element zinc (Zn) content among three groups. Our findings suggested that the loss of Ca, P, Mg, Sr, and K content accounted for the lower BMD in streptozotocin-induced diabetes rats, insulin treatment could restore BMD by increasing the content of Ca, P, and Mg.     

水凝胶联合胰岛素外用治疗老年糖尿病褥疮的临床效果

目的:探讨水凝胶联合胰岛素外用治疗老年糖尿病褥疮的临床效果。方法:将60例老年糖尿病褥疮患者按数字列表法随机分为观察组和对照组各30例,观察组采用常规换药后,喷洒胰岛素稀释液,涂抹水凝胶治疗;对照组采用常规换药,比较两组患者治疗1周、2周、3周褥疮面积,及治疗3周后治愈率。结果:观察组患者治疗1周、2周、3周褥疮面积明显小于对照组,两组比较差异有统计学意义(P0.05);观察组治疗3周后治愈率为60%(18/30),观察组为26.67%(8/30),观察组治愈率明显高于对照组,两组比较差异有统计学意义(P0.05)。结论:水凝胶联合胰岛素外用治疗老年糖尿病褥疮疗效显著,治愈率高,值得临床推广应用。     

Increased Insulin Secretion by Muscarinic M1 and M3 Receptor Function from Rat Pancreatic Islets in vitro

Parasympathetic system plays an important role in insulin secretion from the pancreas. Cholinergic effect on pancreatic beta cells exerts primarily through muscarinic receptors. In the present study we investigated the specific role of muscarinic M1 and M3 receptors in glucose induced insulin secretion from rat pancreatic islets in vitro. The involvement of muscarinic receptors was studied using the antagonist atropine. The role of muscarinic M1 and M3 receptor subtypes was studied using subtype specific antagonists. Acetylcholine agonist, carbachol, stimulated glucose induced insulin secretion at low concentrations (10⁻⁸–10⁻⁵ M) with a maximum stimulation at 10⁻⁷ M concentration. Carbachol-stimulated insulin secretion was inhibited by atropine confirming the role of muscarinic receptors in cholinergic induced insulin secretion. Both M1 and M3 receptor antagonists blocked insulin secretion induced by carbachol. The results show that M3 receptors are functionally more prominent at 20 mM glucose concentration when compared to M1 receptors. Our studies suggest that muscarinic M1 and M3 receptors function differentially regulate glucose induced insulin secretion, which has clinical significance in glucose homeostasis.     

Beneficial Effect of Insulin Treatment on Islet Transplantation Outcomes in Akita Mice

Islet transplantation is a promising potential therapy for patients with type 1 diabetes. The outcome of islet transplantation depends on the transplantation of a sufficient amount of β-cell mass. However, the initial loss of islets after transplantation is problematic. We hypothesized the hyperglycemic status of the recipient may negatively affect graft survival. Therefore, in the present study, we evaluated the effect of insulin treatment on islet transplantation involving a suboptimal amount of islets in Akita mice, which is a diabetes model mouse with an Insulin 2 gene missense mutation. Fifty islets were transplanted under the left kidney capsule of the recipient mouse with or without insulin treatment. For insulin treatment, sustained-release insulin implants were implanted subcutaneously into recipient mice 2 weeks before transplantation and maintained for 4 weeks. Islet transplantation without insulin treatment did not reverse hyperglycemia. In contrast, the group that received transplants in combination with insulin treatment exhibited improved fasting blood glucose levels until 18 weeks after transplantation, even after insulin treatment was discontinued. The group that underwent islet transplantation in combination with insulin treatment had better glucose tolerance than the group that did not undergo insulin treatment. Insulin treatment improved graft survival from the acute phase (i.e., 1 day after transplantation) to the chronic phase (i.e., 18 weeks after transplantation). Islet apoptosis increased with increasing glucose concentration in the medium or blood in both the in vitro culture and in vivo transplantation experiments. Expression profile analysis of grafts indicated that genes related to immune response, chemotaxis, and inflammatory response were specifically upregulated when islets were transplanted into mice with hyperglycemia compared to those with normoglycemia. Thus, the results demonstrate that insulin treatment protects islets from the initial rapid loss that is usually observed after transplantation and positively affects the outcome of islet transplantation in Akita mice.     

链脲佐菌素诱导糖尿病恒河猴胰岛细胞数量的变化

目的观察链脲佐菌素（STZ）诱导恒河猴糖尿病动物模型胰岛细胞数量变化和激素表达情况。方法健康恒河猴5只,小剂量（30 mg/kg）多次静脉注射STZ,濒死状态时将动物安乐死。取胰腺制成石蜡切片,用免疫组化染色法显示胰岛A、B、D和PP细胞,并对结果进行图像分析和统计学处理。结果与对照组比较,模型组B细胞数量减少,胰岛素表达降低（P〈0.01）。A细胞增生,胰高血糖素表达增加（P〈0.01）。PP细胞增生,胰多肽表达增加（P〈0.05）。D细胞数量与对照组比较无显著性差异。结论恒河猴糖尿病动物模型胰岛各种细胞的数量和激素表达情况与人类糖尿病类似。