Ablation of AMP-activated protein kinase alpha1 and alpha2 from mouse pancreatic beta cells and RIP2.Cre neurons suppresses insulin release in vivo.
Ablation of AMP-activated protein kinase alpha1 and alpha2 from mouse pancreatic beta cells and RIP2.Cre neurons suppresses insulin release in vivo.
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DOI：
10.1007/s00125-010-1692-1
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发表时间：
2010-05
期刊：
影响因子：
8.2
通讯作者：
Rutter, G. A.
中科院分区：
文献类型：
--
作者：
Sun, G.;Tarasov, A. I.;McGinty, J.;McDonald, A.;Xavier, G. da Silva;Gorman, T.;Marley, A.;French, P. M.;Parker, H.;Gribble, F.;Reimann, F.;Prendiville, O.;Carzaniga, R.;Viollet, B.;Leclerc, I.;Rutter, G. A.
amp活化蛋白激酶（AMPK）是一种进化保守的酶，也是包括二甲双胍在内的抗高血糖药物的靶点。然而，该酶在控制胰岛素分泌中的确切作用仍不确定。在大鼠胰岛素启动子作用下，通过培养AMPKα1基因缺失的小鼠，并在小鼠体内表达Cre重组酶，可以选择性地去除AMPK的催化α1和α2亚基在胰腺细胞和下丘脑神经元中的表达。后一个启动子被用来在转基因小鼠的β细胞中选择性地表达组成型活化AMPK。采用代谢笼法测定食物摄取量、体重和尿儿茶酚胺含量。腹腔注射后测定葡萄糖和胰岛素耐量。分别用光学投影断层扫描和共聚焦免疫荧光显微镜分析β细胞质量和形态。用标准技术测量颗粒对接、胰岛素分泌、膜电位和细胞内游离Ca2+。在β细胞中缺乏AMPK α亚基的三基因βAMPKdKO小鼠表现出正常的体重和增加的胰岛素敏感性，但存在严重的胰岛素缺乏。分泌的儿茶酚胺水平没有变化。总β细胞质量不变，而平均胰岛细胞和β细胞体积减小。缺乏ampk的β细胞表现出正常的葡萄糖诱导的膜电位和细胞内游离Ca2+的变化，同时颗粒对接和胰岛素分泌增强。相反，βAMPK转基因小鼠葡萄糖不耐受，并表现出胰岛素分泌缺陷。抑制β细胞内AMPK活性对于葡萄糖刺激胰岛素分泌是必要的，但不是充分的。胰腺外RIP中AMPK的激活。体内表达cre的细胞也可能影响胰岛素分泌
AMP-activated protein kinase (AMPK) is an evolutionarily-conserved enzyme and a target of antihyperglycemic agents including metformin. However, the precise role(s) of the enzyme in controlling insulin secretion remains uncertain. The catalytic α1 and α2 subunits of AMPK were ablated selectively in pancreatic beta cells and hypothalamic neurons by breeding AMPKα1 null mice, bearing flox’d AMPKα2 alleles, with animals expressing Cre recombinase under the rat insulin promoter. The latter promoter was used to express constitutively-activated AMPK selectively in beta cells in transgenic mice. Food intake, body weight and urinary catecholamines were measured using metabolic cages. Glucose and insulin tolerance were determined after intraperitoneal injection. Beta cell mass and morphology were analysed by optical projection tomography and confocal immunofluorescence microscopy, respectively. Granule docking, insulin secretion, membrane potential, and intracellular free Ca2+ were measured with standard techniques. Trigenic βAMPKdKO mice, lacking both AMPK α subunits in the beta cell, displayed normal body weight and increased insulin sensitivity, but were profoundly insulin deficient. Secreted catecholamine levels were unchanged. Total beta cell mass was unaltered whilst mean islet and beta cell volume were reduced. AMPK-deficient beta cells displayed normal glucose-induced changes in membrane potential and intracellular free Ca2+ whilst granule docking and insulin secretion were enhanced. Conversely, βAMPK transgenic mice were glucose-intolerant and displayed defective insulin secretion. Inhibition of AMPK activity within the beta cell is necessary, but not sufficient, for the stimulation of insulin secretion by glucose. AMPK activation in extrapancreatic RIP.Cre-expressing cells might also influence insulin secretion in vivo
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影响因子：
7.7
作者：
McCrimmon, Rory J.;Shaw, Margaret;Sherwin, Robert S.
通讯作者：
Sherwin, Robert S.
影响因子：
4.4
作者：
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通讯作者：
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影响因子：
8.2
作者：
Kefas, BA;Heimberg, H;Casteele, M
通讯作者：
Casteele, M
影响因子：
2.2
作者：
McDonald, Angela;Fogarty, Sarah;Rutter, Guy A.
通讯作者：
Rutter, Guy A.
影响因子：
15.9
作者：
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通讯作者：
Withers, Dominic J.