Lee Wanda, Wells Tracy, Kantorow Marc
Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA.
Mol Vis. 2007 Aug 27;13:1469-74.
Peroxiredoxin III (PRDX3) is a mitochondrial peroxidase that defends cells against oxidative damage and therefore could play a role in cataract formation. To establish a possible role for PRDX3 in lens function, PRDX3 was localized to specific human lens sub-regions and the levels of PRDX3 in human lens cells and rat lenses exposed to exogenously-added oxidative stress determined.
PRDX3 levels were monitored by RT-PCR, western analysis, and immunofluorescence. PRDX3 levels in human lens epithelial cells and whole rat lenses exposed to H2O2, TBHP, and heat-treatment were also examined relative to untreated controls by RT-PCR and western analysis.
Significant levels of PRDX3 mRNA and protein were detected in human lens epithelia and fiber cells. PRDX3 was localized to the mitochondria in human lens epithelial cells. PRDX3 was highly induced in human lens epithelial cells by as little as 2 microM H2O2 and by 50 microM H2O2 in cultured rat lenses. Induction of PRDX3 was specific for H2O2 in cultured lens cells since sub-lethal levels of TBHP or heat-shock did not result in detectable increases in the level of PRDX3.
These data demonstrate that PRDX3 is present throughout the lens and localized to the mitochondria in lens epithelial cells. PRDX3 was specifically induced by low levels of H2O2 in human lens epithelial cells and rat lenses suggesting that induction of PRDX3 is an acute response of the lens to increased H2O2 levels. These data provide evidence for an important role for PRDX3 in lens H2O2-detoxification, mitochondrial maintenance, and possibly cataract formation.
过氧化物酶体增殖物激活受体γ辅激活因子1α(PRDX3)是一种线粒体过氧化物酶,可保护细胞免受氧化损伤,因此可能在白内障形成中发挥作用。为了确定PRDX3在晶状体功能中的可能作用,将PRDX3定位到特定的人晶状体亚区域,并测定人晶状体细胞和暴露于外源性氧化应激的大鼠晶状体中PRDX3的水平。
通过逆转录聚合酶链反应(RT-PCR)、蛋白质印迹分析和免疫荧光监测PRDX3水平。还通过RT-PCR和蛋白质印迹分析,相对于未处理的对照,检测暴露于过氧化氢(H2O2)、叔丁基过氧化氢(TBHP)和热处理的人晶状体上皮细胞和整个大鼠晶状体中的PRDX3水平。
在人晶状体上皮细胞和纤维细胞中检测到显著水平的PRDX3信使核糖核酸(mRNA)和蛋白质。PRDX3定位于人晶状体上皮细胞的线粒体中。在培养的大鼠晶状体中,低至2微摩尔/升的H2O2和50微摩尔/升的H2O2可使人晶状体上皮细胞中的PRDX3高度诱导。由于亚致死水平的TBHP或热休克不会导致PRDX3水平的可检测增加,因此在培养的晶状体细胞中,PRDX3的诱导对H2O2具有特异性。
这些数据表明,PRDX3存在于整个晶状体中,并定位于晶状体上皮细胞的线粒体中。低水平的H2O2在人晶状体上皮细胞和大鼠晶状体中特异性诱导PRDX3,这表明PRDX3的诱导是晶状体对H2O2水平升高的急性反应。这些数据为PRDX3在晶状体H2O2解毒、线粒体维持以及可能的白内障形成中的重要作用提供了证据。