Aging Research Center, Ce.S.I., G. d'Annunzio University Foundation, Chieti-Pescara, Italy.
J Nephrol. 2011 Jul-Aug;24(4):453-64. doi: 10.5301/JN.2011.8342.
Carbonylation is an irreversible modification caused by the introduction into proteins of carbonyl derivatives (aldehydes and ketones), which can alter protein structure and function and lead to cellular dysfunction and tissue damage. Chronic uremia may be associated with an increased carbonyl overload ("carbonyl stress"), though carbonyl formation has been proposed so far for major plasma proteins only. In this study we looked for evidence and for the targets of plasma protein carbonylation in patients on hemodialysis. We also examined the effect of in vitro carbonylated albumin on mRNA levels of endothelial cell adhesion molecules involved in early atherogenesis.
Carbonylated proteins in uremic plasma were detected by a covalent hydrazine bait strategy and identified by combining electrophoretic separation with mass spectrometry analysis of tryptic digests. Some plasma samples were first depleted of albumin and immunoglobulins to improve detection of lower abundance proteins. The functional impact of carbonylation was assessed in human vein endothelial cells by studying models of modified human serum albumin.
Post-dialysis plasma carbonylated protein levels were significantly increased compared to pre-dialysis levels. Susceptibility to carbonyl formation was described on a open-platform investigation for a number of plasma proteins, albumin being the main scavenger of carbonyl reactive species. Incubation of endothelial cells with low doses of carbonylated albumin caused a significant increase in intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 mRNA levels.
Chronic uremia appears as a state of "carbonyl stress" targeting several different plasma proteins. Carbonylated albumin displayed biological effects that may be relevant to uremic atherosclerosis.
羰基化是一种由蛋白质中羰基衍生物（醛和酮）的引入引起的不可逆修饰，可改变蛋白质结构和功能，导致细胞功能障碍和组织损伤。慢性尿毒症可能与羰基负荷增加（“羰基应激”）有关，尽管迄今为止仅提出了主要血浆蛋白的羰基形成。在这项研究中，我们在血液透析患者中寻找血浆蛋白羰基化的证据和靶标。我们还研究了体外羰基化白蛋白对参与早期动脉粥样硬化形成的内皮细胞黏附分子的 mRNA 水平的影响。
通过共价肼诱饵策略检测尿毒症血浆中的羰基化蛋白，并通过电泳分离与胰蛋白酶消化物的质谱分析相结合来鉴定。一些血浆样品首先耗尽白蛋白和免疫球蛋白，以提高对低丰度蛋白的检测。通过研究改性人血清白蛋白模型，在人静脉内皮细胞中评估羰基化的功能影响。
与透析前水平相比，透析后血浆羰基化蛋白水平显著升高。对几种血浆蛋白进行了开放式平台调查，描述了它们对羰基形成的易感性，白蛋白是羰基反应性物质的主要清除剂。用低剂量的羰基化白蛋白孵育内皮细胞会导致细胞间黏附分子-1 和血管细胞黏附分子-1 的 mRNA 水平显著增加。
慢性尿毒症似乎是一种针对几种不同血浆蛋白的“羰基应激”状态。羰基化白蛋白表现出可能与尿毒症性动脉粥样硬化相关的生物学效应。
