AICA-riboside induces apoptosis of pancreatic beta cells through stimulation of AMP-activated protein kinase
AICA-riboside induces apoptosis of pancreatic beta cells through stimulation of AMP-activated protein kinase
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DOI：
10.1007/s00125-002-1030-3
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发表时间：
2003-02-01
期刊：
影响因子：
8.2
通讯作者：
Casteele, M
中科院分区：
文献类型：
--
作者：
Kefas, BA;Heimberg, H;Casteele, M
目的/假设。β细胞长期暴露于低葡萄糖浓度会触发其凋亡，并且已知会激活β细胞系中的AMP活化蛋白激酶（AMPK）。我们研究了AMPK的长期激活是否可以触发啮齿动物β细胞的凋亡。原代β细胞从大鼠、野生型和AMPK（α 2）缺陷型小鼠中进行FACS纯化。β细胞中的AMPK活化由腺苷类似物AICA-核苷诱导，并使用磷酸特异性抗体通过免疫印迹检测。啮齿动物β细胞的凋亡通过β细胞DNA含量的流式细胞仪分析、使用荧光显微镜直接计数凋亡细胞或通过测量它们的半胱天冬酶-3活性来监测。剂量依赖性和时间依赖性的细胞凋亡，伴随着半胱天冬酶-3的活化，被半胱天冬酶抑制剂zVAD-favor和zDEVD-favor抑制。通过加入阻断AICA-核苷诱导的AMPK磷酸化的MAPK抑制剂SB 203580，AICA-核苷诱导的细胞凋亡也被阻止。从AMPK-（α 2）缺陷小鼠分离的β细胞对AICA-核苷诱导的细胞凋亡具有抗性。AICA-核苷持续激活AMPK可触发胰腺β细胞的半胱天冬酶依赖性凋亡。
Aims/hypothesis. Prolonged exposure of beta cells to low glucose concentrations triggers their apoptosis and is known to activate AMP-activated protein kinase (AMPK) in beta cell lines. We examined whether prolonged activation of AMPK can trigger apoptosis in rodent beta cells.Methods. Primary beta cells were FACS-purified from rats, and from wild-type and AMPK(alpha2)-deficient mice. AMPK activation in beta cells was induced by the adenosine analog AICA-riboside and detected by immunoblotting using a phosphospecific antibody. Apoptosis of rodent beta cells was monitored by FACS analysis of beta cell DNA content, by direct counting of apoptotic cells using fluorescence microscopy, or by measurement of their caspase-3 activity.Results. Dose-dependent and time-dependent apoptosis of the cells, concommittant with an activation of caspase-3, were suppressed by the caspase inhibitors zVAD-fmk and zDEVD-fmk. Apoptosis induction by AICA-riboside was also prevented by adding the MAPK-inhibitor SB203580 which blocked the AICA-riboside-induced phosphorylation of AMPK. Beta cells isolated from AMPK-(alpha2)-deficient mice were resistant against AICA-riboside induced apoptosis.Conclusion/interpretation. Sustained activation of AMPK by AICA-riboside can trigger a caspase-dependent apoptosis of pancreatic beta cells.