NADPH oxidase-2 does not contribute to β-cell glucotoxicity in cultured pancreatic islets from C57BL/6J mice
NADPH oxidase-2 does not contribute to β-cell glucotoxicity in cultured pancreatic islets from C57BL/6J mice
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DOI：
10.1016/j.mce.2016.09.022
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发表时间：
2017-01-05
影响因子：
4.1
通讯作者：
Jonas, Jean-Christophe
中科院分区：
文献类型：
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作者：
de Souza, Arnaldo H.;Santos, Laila R. B.;Jonas, Jean-Christophe
高糖诱导的氧化应激和NADPH氧化酶-2(NOX2)活性增加可能是2型糖尿病患者胰岛β细胞功能进行性下降的原因。为了验证这一假设，我们在雄性NOX2基因敲除小鼠(NOX2-KO)和野生型(WT)C57BL/6J小鼠的胰岛上，用谷胱甘肽氧化(GRX1-ROGFP_2)、硫醇氧化(ROGFP_1)或H_2O_2(RoGFP_2-Orp1)的探针，在体外研究了葡萄糖对细胞内氧化应激(GRX_1-ROGFP_2)、β细胞刺激-分泌偶联事件和β细胞凋亡的影响。当葡萄糖浓度为20-30 mmol/L时，NOX2-KO胰岛的葡萄糖刺激胰岛素分泌能力是WT胰岛的1.7倍，而NAD(P)H和细胞内钙离子浓度([Ca~(2+)](I))升高相似，细胞内GRX1-RoGFP_2氧化作用无明显差异。在G30条件下长时间培养后，随着β细胞的凋亡，roGFP1和roGFP2-Orp1氧化增加，NADPH的葡萄糖敏感性、[Ca~(2+)](I)和胰岛素分泌反应增加，最大[Ca~(2+)](I)反应降低，但最大GSIS保留。这些反应在两种类型的胰岛中几乎是相同的。总而言之，NOX2是C57BL/6J小鼠胰岛最大GSIS的负调节因子，但它在体外糖毒性诱导胞浆氧化应激和改变β细胞的生存和功能方面没有明显的贡献。(C)2016爱思唯尔爱尔兰有限公司。保留所有权利。
High glucose-induced oxidative stress and increased NADPH oxidase-2 (NOX2) activity may contribute to the progressive decline of the functional beta-cell mass in type 2 diabetes. To test that hypothesis, we characterized, in islets from male NOX2 knockout (NOX2-KO) and wild-type (WT) C57BL/6J mice cultured for up to 3 weeks at 10 or 30 mmol/l glucose (G10 or G30), the in vitro effects of glucose on cytosolic oxidative stress using probes sensing glutathione oxidation (GRX1-roGFP2), thiol oxidation (roGFP1) or H2O2 (roGFP2-Orp1), on beta-cell stimulus-secretion coupling events and on beta-cell apoptosis.After 1-2 days of culture in G10, the glucose stimulation of insulin secretion (GSIS) was 1.7-fold higher in NOX2-KO vs. WT islets at 20-30 mmol/l glucose despite similar rises in NAD(P)H and intracellular calcium concentration ([Ca2+](i)) and no differences in cytosolic GRX1-roGFP2 oxidation.After long-term culture at G10, roGFP1 and roGFP2-Orpl oxidation and beta-cell apoptosis remained low, and the glucose-induced rises in NAD(P)H, [Ca2+](i) and GSIS were similarly preserved in both islet types. After prolonged culture at G30, roGFP1 and roGFP2-Orpl oxidation increased in parallel with beta-cell apoptosis, the glucose sensitivity of the NADPH, [Ca2+](i) and insulin secretion responses increased, the maximal [Ca2+](i) response decreased, but maximal GSIS was preserved. These responses were almost identical in both islet types.In conclusion, NOX2 is a negative regulator of maximal GSIS in C57BL/6J mouse islets, but it does not detectably contribute to the in vitro glucotoxic induction of cytosolic oxidative stress and alterations of beta-cell survival and function. (C) 2016 Elsevier Ireland Ltd. All rights reserved.