Chronic diabetes increases advanced glycation end products on cardiac ryanodine receptors/calcium release channels
Chronic diabetes increases advanced glycation end products on cardiac ryanodine receptors/calcium release channels
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DOI：
10.2337/diabetes.52.7.1825
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发表时间：
2003-07-01
期刊：
影响因子：
7.7
通讯作者：
Besch, HR
中科院分区：
文献类型：
--
作者：
Bidasee, KR;Nallani, K;Besch, HR
心肌收缩力下降是慢性糖尿病的标志。之前我们表明，这种缺陷至少部分是由 2 型兰尼定受体钙释放通道 (RyR2) 功能障碍引起的。 RyR2 功能障碍的机制尚不完全清楚。本研究旨在确定 RyR2 上的非交联晚期糖基化终产物 (AGE) 是否会随着慢性糖尿病而增加，以及这些翻译后复合物的形成是否可以通过胰岛素治疗减弱。用胰蛋白酶过夜消化来自 8 周对照动物 (8C) 的 RyR2，得到 298 种肽，单同位素质量 (M+H+) 大于或等于 500。来自链脲佐菌素诱导的 8 周糖尿病动物 (8D) 的 RyR2 消化产生的肽减少了 21%，而来自 6 周糖尿病/2 周胰岛素治疗动物的 RyR2 产生了 304 个肽。使用内部 PERLscript 算法，搜索矩阵辅助激光解吸电离飞行时间质量数据文件，识别出与理论 RyR2 肽相对应的几个 M+H+ 峰，这些肽具有单个 N-（羧甲基）-赖氨酸、咪唑啉酮 A、咪唑酮 B、吡咯啉或 1-烷基-2-甲酰基-3,4-糖基吡咯修饰，这些峰存在于 8D 中，但不存在于 8C 中。胰岛素治疗可最大限度地减少某些非酶糖化产物的产生。这些数据首次表明，糖尿病期间，AGEs 在细胞内 RyR2 上形成。由于 AGE 复合物已知会损害蛋白质活性，因此这些数据表明糖尿病引起的 RyR2 功能障碍的潜在机制。
Decrease in cardiac contractility is a hallmark of chronic diabetes. Previously we showed that this defect results, at least in part, from a dysfunction of the type 2 ryanodine receptor calcium-release channel (RyR2). The mechanism(s) underlying RyR2 dysfunction is not fully understood. The present study was designed to determine whether non-cross-linking advanced glycation end products (AGEs) on RyR2 increase with chronic diabetes and if formation of these post-translational complexes could be attenuated with insulin treatment. Overnight digestion of RyR2 from 8-week control animals (8C) with trypsin afforded 298 peptides with monoisotopic mass (M+H+) greater than or equal to500. Digestion of RyR2 from 8-week streptozotocin-induced diabetic animals (8D) afforded 21% fewer peptides, whereas RyR2 from 6-week diabetic/2-week insulin-treated animals generated 304 peptides. Using an in-house PERLscript algorithm, search of matrix-assisted laser desorption ionization-time of flight mass data files identified several M+H+ peaks corresponding to theoretical RyR2 peptides with single N-(carboxymethyl)-lysine, imidazolone A, imidazone B, pyrraline, or 1-alkyl-2-formyl-3,4-glycosyl pyrrole modification that were present in 8D but not 8C. Insulin treatment minimized production of some of these nonenzymatic glycation products. These data show for the first time that AGEs are formed on intracellular RyR2 during diabetes. Because AGE complexes are known to compromise protein activity, these data suggest a potential mechanism for diabetes-induced RyR2 dysfunction.