Huang Li, Yappert Marta C, Jumblatt Marcia M, Borchman Douglas
Department of Ophthalmology and Visual Science, University of Louisville, Louisville, Kentucky, USA.
Curr Eye Res. 2008 Jul;33(7):575-86. doi: 10.1080/02713680802167554.
Thyroxine-treated human lens epithelial cells, HLE B-3, were grown in either a normoxic or hyperoxic atmosphere as a first step in identifying factors related to their increased viability. Reactive oxygen species, ROS, and the apparent mitochondrial membrane potential, Delta Psi(m), were measured using fluorescent probes. ROS were significantly higher in HLE B-3 cells grown in a hyperoxic atmosphere for both thyroxine-treated and untreated samples. However, treatment with thyroxine produced 40% lower ROS levels than untreated cells. A mitochondrial uncoupler concomitantly reduced ROS generation. In cells that were grown in a hyperoxic atmosphere, the Delta Psi(m) was significantly higher for samples treated with thyroxine compared to those that were untreated. ROS generation correlated inversely with the apparent Delta Psi(m) and the amount of cardiolipin, and correlated with the amount of lipid oxidation products. These correlations were valid whether cardiolipin and the Delta Psi(m) were decreased as a result of oxygen or increased as a result of thyroxine treatment. Therapies that protect mitochondria from damage and reduce damaging ROS generation may potentially ameliorate the effects of oxidation that occur in aging tissues and in diseases such as cataract.
作为确定与其活力增加相关因素的第一步，用甲状腺素处理过的人晶状体上皮细胞（HLE B-3）在常氧或高氧环境中培养。使用荧光探针测量活性氧（ROS）和表观线粒体膜电位（ΔΨm）。对于甲状腺素处理和未处理的样本，在高氧环境中培养的HLE B-3细胞中的ROS均显著更高。然而，与未处理的细胞相比，甲状腺素处理使ROS水平降低了40%。线粒体解偶联剂同时减少了ROS的产生。在高氧环境中培养的细胞中，与未处理的样本相比，甲状腺素处理的样本的ΔΨm显著更高。ROS的产生与表观ΔΨm和心磷脂的量呈负相关，与脂质氧化产物的量呈正相关。无论心磷脂和ΔΨm是因氧气而降低还是因甲状腺素处理而升高，这些相关性都是成立的。保护线粒体免受损伤并减少有害ROS产生的疗法可能会改善衰老组织和白内障等疾病中发生的氧化作用的影响。
