Role of aldehyde dehydrogenase isozymes in the defense of rat lens and human lens epithelial cells against oxidative stress
Role of aldehyde dehydrogenase isozymes in the defense of rat lens and human lens epithelial cells against oxidative stress
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DOI：
10.1167/iovs.04-0120
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发表时间：
2005-01-01
影响因子：
4.4
通讯作者：
Ansari, NH
中科院分区：
文献类型：
--
作者：
Choudhary, S;Xiao, TL;Ansari, NH
目的。4-羟基壬烯醛(HNE)是一种亚稳态的脂质过氧化产物，如不解毒，对多种细胞都有很强的毒性。由于其持续暴露在光线下，眼晶状体在氧化应激条件下不断产生活性氧物种，可能导致过度的脂质过氧化，从而形成脂质衍生的醛(LDAs)，如HNE。在晶状体中，乙醛脱氢酶(ALDH)的各种同工酶对LDAs氧化的贡献从未被系统地研究过。本研究旨在探讨ALDH1A1和-3A1在培养的人晶状体上皮细胞(HLECs)和大、小鼠晶状体上皮细胞(HLECs)中HNE代谢和HNE毒性中的作用。使用了适当的对照，包括野生型小鼠晶状体、杂合寡核苷酸和转染剂。将转染的HLECs暴露于氧化应激(Fenton反应)或HNE(30um)中3h。测定细胞存活率、细胞凋亡率、蛋白质-HNE加合物和外源性H-3-HNE的氧化等毒性参数。将针对ALDH1A1的siRNA导入大鼠晶状体，检测H-3-HNE的氧化以及转染组大鼠晶状体对氧化诱导混浊的敏感性。结果：转染ALDH1A1特异性siRNA的大鼠晶状体，或在ALDH抑制剂氰胺/二硫兰存在下培养的大鼠晶状体，在氧化应激下，透明质酸丧失加速，氧化HNE的能力减弱。同样，ALDH1A1特异性反义RNA或siRNA抑制HLECs中的ALDH1A1与减少H-3-HNE的氧化和增加细胞对氧化损伤(包括凋亡)的敏感性有关。此外，在ALDH3A1特异的siRNA或反义RNA处理的大鼠晶状体、HLECs或ALDH3A1缺失的小鼠晶状体中，H-3-HNE的代谢和HNE诱导的毒性不受影响。结论在氧化应激下，晶状体上皮细胞产生的HNE可引起毒性，从而参与氧化性白内障的发生。此外，研究表明，ALDH1A1是维持人、大鼠和小鼠晶状体透明度的关键同工酶。
PURPOSE. 4-Hydroxynonenal (HNE), a metastable lipid peroxidation product, is highly toxic to various cell types if not detoxified. Because of its constant exposure to light, the ocular lens continuously generates reactive oxygen species which, under conditions of oxidative stress, may lead to excessive lipid peroxidation and consequent formation of lipid-derived aldehydes (LDAs) such as HNE. The contribution of various isozymes of aldehyde dehydrogenase (ALDH) to the oxidation of LDAs has never been systematically investigated in the lens. The present study was undertaken to ascertain the role of ALDH1A1 and -3A1 in HNE metabolism and HNE-induced toxicity in cultured human lens epithelial cells (HLECs) and in rat and mouse lenses.METHODS. The metabolism of H-3-HNE was studied in ALDH3A1-knockout mouse lens and in HLECs transfected with ALDH1A1- or -3A1-specific antisense RNA and short interfering (Si) RNA. Appropriate controls were used, including wild-type mouse lens, scrambled oligonucleotides, and a transfection reagent. Transfected HLECs were exposed to oxidative stress (Fenton reaction) or HNE (30 muM) for 3 hours. Toxicity parameters, such as cell viability, apoptosis, and protein-HNE adducts and oxidation of exogenously added H-3-HNE were measured. Rat lenses were transfected with the SiRNA specific to ALDH1A1, and oxidation of H-3-HNE and the susceptibility of the transfected lenses to oxidation-induced opacification were measured.RESULTS. Rat lenses transfected with ALDH1A1- specific SiRNA, or cultured in the presence of the ALDH inhibitor cyanamide/disulfiram and subjected to oxidative stress displayed accelerated loss of transparency and a diminished capacity to oxidize HNE. Similarly, inhibition of ALDH1A1 in HLECs by ALDH1A1-specific antisense RNA or SiRNA was associated with decreased oxidation of H-3-HNE and increased susceptibility of the cells to oxidative damage, including apoptosis. Furthermore, H-3-HNE metabolism and HNE-induced toxicity were not affected in ALDH3A1-specific SiRNA- or antisense RNA-treated rat lenses, HLECs, or ALDH3A1-null mouse lenses.CONCLUSIONS. The results suggest that, under oxidative stress, HNE produced in the lens epithelium can cause toxicity and thus contribute to oxidation-induced cataractogenesis. Furthermore, the studies indicate that ALDH1A1 is a critical isozyme for maintaining clarity in human, rat, and mouse lenses.