Glucose and tolbutamide induce apoptosis in pancreatic β-cells -: A process dependent on intracellular Ca2+ concentration
Glucose and tolbutamide induce apoptosis in pancreatic β-cells -: A process dependent on intracellular Ca2+ concentration
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DOI：
10.1074/jbc.273.50.33501
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发表时间：
1998-12-11
影响因子：
4.8
通讯作者：
Berggren, PO
中科院分区：
文献类型：
--
作者：
Efanova, IB;Zaitsev, SV;Berggren, PO
高浓度的葡萄糖被认为对胰腺β细胞有毒性。然而，β-细胞功能障碍和导致细胞死亡的潜在机制尚未完全表征。在本研究中，我们已经证明，从ob/ob小鼠和Wistar大鼠的胰岛和β细胞与葡萄糖孵育诱导的凋亡β细胞死亡的过程中，所示的DNA梯状，TdT介导的dUTP-生物素缺口末端标记（TUNEL）技术，并通过使用DNA染色染料HOECHST 33342。所获得的结果表明，凋亡细胞的百分比依赖于葡萄糖浓度，在11 mM葡萄糖时最小。在100 μ M的浓度下，金精三羧酸，一种核酸内切酶活性的抑制剂，几乎完全抑制由17 mM葡萄糖引发的细胞凋亡。我们还表明，与100 μ M磺酰脲类药物甲苯磺丁脲长期孵育可引发胰腺β细胞凋亡。高浓度葡萄糖和甲苯磺丁脲诱导的β细胞死亡过程是Ca ~（2+）依赖性的，因为向培养基中引入50 μ M D-600或200 μ M二氮嗪，其阻断葡萄糖和甲苯磺丁脲诱导的[Ca ~（2+）]（i）增加，抑制了细胞凋亡。因此，这项研究首次表明，高葡萄糖浓度和甲苯磺丁脲诱导胰腺β细胞凋亡，这一过程是钙依赖性的。
High concentrations of glucose are considered to be toxic for the pancreatic beta-cell. However, the mechanisms underlying beta-cell dysfunction and resulting cell death are not fully characterized. In the present study we have demonstrated that incubation of pancreatic islets and beta-cells from ob/ob mice and Wistar rats with glucose induced a process of apoptotic beta-cell death, as shown by DNA laddering, TdT-mediated dUTP-biotin nick end-labeling (TUNEL) technique, and by using DNA-staining dye HOECHST 33342. The obtained results show that the percentage of apoptotic cells was dependent on glucose concentration, being minimal at 11 mM glucose. At a concentration of 100 mu M, aurintricarboxylic acid, an inhibitor of endonuclease activity, almost completely inhibited apoptosis triggered by 17 mM glucose. We have also shown that long term incubation with 100 mu M sulfonylurea, tolbutamide, triggered apoptosis in pancreatic beta-cells. The process of beta-cell death induced by high glucose concentration and tolbutamide were Ca2+-dependent, because introduction to the culture medium of 50 mu M D-600 or 200 mu M diazoxide, which blocked glucose- and tolbutamide-induced [Ca2+](i) increase, inhibited apoptosis. Thus, this study shows for the first time that high glucose concentrations and tolbutamide induce apoptosis in pancreatic beta-cells, and that this process is Ca2+-dependent.