Pak Jhang Ho, Kim Tae-im, Joon Kim Myoung, Yong Kim Jae, Choi Hyun-jeung, Kim Seon Ah, Tchah Hungwon
Department of Ophthalmology and Asan Institute for Life Sciences, University of Ulsan College of Medicine, Asan Medical Center, Songpa-gu, Seoul 138-736, South Korea.
Exp Eye Res. 2006 May;82(5):899-906. doi: 10.1016/j.exer.2005.10.017. Epub 2005 Dec 20.
1-cys peroxiredoxin (1-cysPrx), a member of the peroxiredoxin family with a single conserved cysteine residue, reduces a broad spectrum of hydroperoxides. This study was undertaken to examine changes in 1-cysPrx expression in human cataract samples, human lens epithelial (HLE B3) cell line, and rat organ-cultured lenses in response to oxidative insult induced by H2O2 or transforming growth factor-beta1 (TGF-beta1). Expression of 1-cysPrx mRNA and protein in HLE B3 cells increased in response to 2-8 ng ml(-1) TGF-beta1 and 50-75 microm H2O2 and then decreased below the control level at high doses (10 ng ml(-1) TGF-beta1 and 100-150 microm H2O2), as determined by Northern blot and immunoblot analysis. This reduction coincided with the decrease of cell viability. Immunoreactive 1-cysPrx protein was measured in capsulorrhexis specimens obtained from patients with anterior subcapsular cataract (ASC), nuclear sclerosis (NS), cortical spokes (CS), posterior subcapsular cataract (PSC), or white mature cataract (WC) at the time of cataract surgery. Significant reduction of 1-cysPrx protein was observed in ASC, PSC, and WC samples, but there was no statistical difference in CS and NS samples relative to normal control. Also, rat lens explants were cultured with 10 ng ml(-1) TGF-beta1 for approximately 5 days or 500 microm H2O2 for approximately 2 days. Subsequently, expression of 1-cysPrx mRNA and protein in the lens capsules was evaluated. Rat lens explants treated with TGF-beta1 or H2O2 developed a cataract similar to human ASC or WC, respectively, which resulted in a markedly decreased expression of 1-cysPrx mRNA and protein. Collectively, these findings show that expression patterns of 1-cysPrx gene in the lens are changed in response to oxidative stress, a major factor in the etiology of cataract.
1-半胱氨酸过氧化物酶（1-cysPrx）是过氧化物酶家族的成员，有一个单一的保守半胱氨酸残基，能还原多种氢过氧化物。本研究旨在检测人白内障样本、人晶状体上皮（HLE B3）细胞系以及大鼠器官培养晶状体中1-cysPrx的表达变化，这些样本是对由过氧化氢（H2O2）或转化生长因子-β1（TGF-β1）诱导的氧化损伤做出的反应。通过Northern印迹和免疫印迹分析确定，HLE B3细胞中1-cysPrx mRNA和蛋白的表达在2-8 ng/ml TGF-β1和50-75 μM H2O2刺激下增加，然后在高剂量（10 ng/ml TGF-β1和100-150 μM H2O2）时降至对照水平以下。这种降低与细胞活力的下降一致。在白内障手术时，对从前囊下白内障（ASC）、核硬化（NS）、皮质辐轮状混浊（CS）、后囊下白内障（PSC）或白色成熟白内障（WC）患者获得的撕囊标本中的免疫反应性1-cysPrx蛋白进行了检测。在ASC、PSC和WC样本中观察到1-cysPrx蛋白显著减少，但CS和NS样本与正常对照相比无统计学差异。此外，将大鼠晶状体外植体用10 ng/ml TGF-β1培养约5天或用500 μM H2O2培养约2天。随后，评估晶状体囊膜中1-cysPrx mRNA和蛋白的表达。用TGF-β1或H2O2处理的大鼠晶状体外植体分别形成了类似于人ASC或WC的白内障，这导致1-cysPrx mRNA和蛋白的表达明显降低。总的来说，这些发现表明晶状体中1-cysPrx基因的表达模式会因氧化应激而改变，氧化应激是白内障病因中的一个主要因素。
