Toxicity and detoxification of lipid-derived aldehydes in cultured retinal pigmented epithelial cells
Toxicity and detoxification of lipid-derived aldehydes in cultured retinal pigmented epithelial cells
复制标题
DOI：
10.1016/j.taap.2004.08.023
复制
发表时间：
2005-04-15
影响因子：
3.8
通讯作者：
Ansari, NH
中科院分区：
文献类型：
--
作者：
Choudhary, S;Xiao, T;Ansari, NH
年龄相关性黄斑变性（ARMD）是发达国家致盲的主要原因，但其发病机制尚不清楚。视网膜具有高水平的多不饱和脂肪酸（PUFAs），并在氧化应激条件下发挥作用。为了研究PUFAs过氧化产物是否诱导视网膜色素上皮细胞（RPE）凋亡并可能导致ARMD，我们将人视网膜色素上皮细胞（ARPE-19）暴露于微摩尔浓度的H2O2、4-羟基壬烯醛（HNE）和4-羟基己烯醛（HHE）中。通过ELISA、流式细胞术和Hoechst染色检测DNA片段，观察到H2O2-、HNE-和hhe诱导的细胞凋亡的浓度和时间依赖性增加。广谱细胞凋亡抑制剂Z-VAD抑制细胞凋亡。在暴露于H2O2或HNE之前，用硫蛋白肽处理RPE细胞可减少蛋白质-HNE加合物的形成，并改变线粒体膜电位和凋亡。利用3h - fine，研究了ARPE-19细胞对HNE解毒的各种代谢途径。采用高效液相色谱法分离代谢产物，电喷雾电离质谱（ESI-MS）和气相色谱-质谱（ms）对代谢产物进行表征。检测出HNE解毒的三种主要代谢途径：(1)与谷胱甘肽（GSH）结合形成GS-HNE，由谷胱甘肽- s -转移酶（GST）催化，(2)醛糖还原酶催化GS-HNE还原，(3)醛脱氢酶（ALDH）催化HNE氧化。通过抗氧化剂、硫肽清除HNE和caspase抑制剂抑制细胞凋亡的联合策略来预防视网膜退化可能是一种限制ARMD视网膜变性的潜在治疗方法。(c) 2004 Elsevier Inc.版权所有。
Age-related macular degeneration (ARMD) is the leading cause of blindness in the developed world and yet its pathogenesis remains poorly understood. Retina has high levels of polyunsaturated fatty acids (PUFAs) and functions under conditions of oxidative stress. To investigate whether peroxidative products of PUFAs induce apoptosis in retinal pigmented epithelial (RPE) cells and possibly contribute to ARMD, human retinal pigmented epithelial cells (ARPE-19) were exposed to micromolar concentrations of H2O2, 4-hydroxynonenal (HNE) and 4-hydroxyhexenal (HHE). A concentration- and time-dependent increase in H2O2-, HNE-, and HHE-induced apoptosis was observed when monitored by quantifying DNA fragmentation as determined by ELISA, flow cytometry, and Hoechst staining. The broad-spectrum inhibitor of apoptosis Z-VAD inhibited apoptosis. Treatment of RPE cells with a thionein peptide prior to exposure to H2O2 or HNE reduced the formation of protein-HNE adducts as well as alteration in mitochondrial membrane potential and apoptosis. Using 3 H-FINE, various metabolic pathways to detoxify HNE by ARPE-19 cells were studied. The metabolites were separated by HPLC and characterized by ElectroSpray Ionization-Mass Spectrometry (ESI-MS) and gas chromatography-MS. Three main metabolic routes of HNE detoxification were detected: (1) conjugation with glutathione (GSH) to form GS-HNE, catalyzed by glutathione-S-transferase (GST), (2) reduction of GS-HNE catalyzed by aldose reductase, and (3) oxidation of HNE catalyzed by aldehyde dehydrogenase (ALDH). Preventing HNE fort-nation by a combined strategy of antioxidants, scavenging HNE by thionein peptide, and inhibiting apoptosis by caspase inhibitors may offer a potential therapy to limit retinal degeneration in ARMD. (c) 2004 Elsevier Inc. All rights reserved.