School of Kinesiology, University of Michigan, Ann Arbor, MI 48109, USA.
Centre of Inflammation and Metabolism and Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, DK-2100 Copenhagen, Denmark.
Nutrients. 2019 Mar 1;11(3):532. doi: 10.3390/nu11030532.
The purpose of this investigation was to evaluate the effects of experimental hyperglycemia on oxidative damage (OX), advanced glycation end products (AGEs), and the receptor for AGEs (RAGE) through an in vivo approach. Obese subjects ( = 10; 31.2 ± 1.2 kg·m; 56 ± 3 years) underwent 24 h of hyperglycemic clamp (+5.4 mM above basal), where plasma at basal and after 2 h and 24 h of hyperglycemic challenge were assayed for OX (methionine sulfoxide, MetSO, and aminoadipic acid, AAA) and AGE-free adducts (N-carboxymethyllysine, CML; N-carboxyethyllysine, CEL; glyoxal hydroimidazolone-1, GH-1; methylglyoxal hydroimidazolone-1, MG-H1; and 3-deoxyglucosone hydroimidazolone, 3DG-H) via liquid chromatography⁻tandem mass spectrometry (LC⁻MS/MS). Urine was also analyzed at basal and after 24 h for OX and AGE-free adducts and plasma soluble RAGE (sRAGE) isoforms (endogenous secretory RAGE, esRAGE, and cleaved RAGE, cRAGE), and inflammatory markers were determined via enzyme-linked immunosorbent assay (ELISA). Skeletal muscle tissue collected via biopsy was probed at basal, 2 h, and 24 h for RAGE and OST48 protein expression. Plasma MetSO, AAA, CEL, MG-H1, and G-H1 decreased (-18% to -47%; < 0.05), while CML increased (72% at 24 h; < 0.05) and 3DG-H remained unchanged ( > 0.05) with the hyperglycemic challenge. Renal clearance of MetSO, AAA, and G-H1 increased (599% to 1077%; < 0.05), CML decreased (-30%; < 0.05), and 3DG-H, CEL, and MG-H1 remained unchanged ( > 0.05). Fractional excretion of MetSO, AAA, CEL, G-H1, and MG-H1 increased (5.8% to 532%; < 0.05) and CML and 3DG-H remained unchanged ( > 0.05). Muscle RAGE and OST48 expression, plasma sRAGE, IL-1β, IL-1Ra, and TNFα remained unchanged ( > 0.05), while IL-6 increased (159% vs. basal; > 0.05). These findings suggest that individuals who are obese but otherwise healthy have the capacity to prevent accumulation of OX and AGEs during metabolic stress by increasing fractional excretion and renal clearance.
本研究旨在通过体内方法评估实验性高血糖对氧化损伤 (OX)、晚期糖基化终产物 (AGEs) 和 AGEs 受体 (RAGE) 的影响。肥胖受试者（n=10；31.2±1.2kg·m；56±3 岁）接受了 24 小时高血糖钳夹（比基础水平高 5.4mM），在基础水平和高血糖挑战 2 小时和 24 小时后，测定血浆中 OX（甲硫氨酸亚砜、MetSO 和氨基己二酸、AAA）和 AGE 无缀合物（N-羧甲基赖氨酸、CML；N-羧乙基赖氨酸、CEL；乙二醛羟咪唑啉-1、GH-1；甲基乙二醛羟咪唑啉-1、MG-H1；和 3-脱氧葡萄糖醛酮羟咪唑啉、3DG-H），采用液相色谱-串联质谱法（LC-MS/MS）。在基础水平和 24 小时后，还通过酶联免疫吸附试验（ELISA）测定尿液中的 OX 和 AGE 无缀合物以及血浆可溶性 RAGE（内源性分泌型 RAGE、esRAGE 和裂解型 RAGE、cRAGE），并通过酶联免疫吸附试验（ELISA）测定炎症标志物。在基础水平、2 小时和 24 小时时，通过活检采集的骨骼肌组织检测 RAGE 和 OST48 蛋白表达。随着高血糖挑战，血浆 MetSO、AAA、CEL、MG-H1 和 G-H1 减少（-18%至-47%；<0.05），而 CML 增加（24 小时时增加 72%；<0.05），3DG-H 保持不变（>0.05）。MetSO、AAA 和 G-H1 的肾清除率增加（599%至 1077%；<0.05），CML 减少（-30%；<0.05），而 3DG-H、CEL 和 MG-H1 保持不变（>0.05）。MetSO、AAA、CEL、G-H1 和 MG-H1 的尿分数排泄增加（5.8%至 532%；<0.05），CML 和 3DG-H 保持不变（>0.05）。肌肉 RAGE 和 OST48 表达、血浆 sRAGE、IL-1β、IL-1Ra 和 TNFα 保持不变（>0.05），而 IL-6 增加（159%，与基础值相比；>0.05）。这些发现表明，肥胖但其他方面健康的个体有能力通过增加分数排泄和肾清除率来防止代谢应激期间 OX 和 AGEs 的积累。
