Localization and H2O2-specific induction of PRDX3 inthe eye lens

[摘要] Purpose: Peroxiredoxin III (PRDX3) is a mitochondrial peroxidasethat defends cells against oxidative damage and therefore could play arole in cataract formation. To establish a possible role for PRDX3 inlens function, PRDX3 was localized to specific human lens sub-regionsand the levels of PRDX3 in human lens cells and rat lenses exposed toexogenously-added oxidative stress determined.Methods: PRDX3 levels were monitored by RT-PCR, western analysis,and immunofluorescence. PRDX3 levels in human lens epithelial cells andwhole rat lenses exposed to H2O2, TBHP, and heat-treatmentwere also examined relative to untreated controls by RT-PCR and westernanalysis.Results: Significant levels of PRDX3 mRNA and protein were detectedin human lens epithelia and fiber cells. PRDX3 was localized to themitochondria in human lens epithelial cells. PRDX3 was highly induced inhuman lens epithelial cells by as little as 2 μM H2O2 andby 50 μM H2O2 in cultured rat lenses. Induction of PRDX3was specific for H2O2 in cultured lens cells sincesub-lethal levels of TBHP or heat-shock did not result in detectableincreases in the level of PRDX3.Conclusions: These data demonstrate that PRDX3 is present throughoutthe lens and localized to the mitochondria in lens epithelial cells.PRDX3 was specifically induced by low levels of H2O2 inhuman lens epithelial cells and rat lenses suggesting that induction ofPRDX3 is an acute response of the lens to increased H2O2levels. These data provide evidence for an important role for PRDX3 inlens H2O2-detoxification, mitochondrial maintenance, andpossibly cataract formation.

[学科分类] 生物化学/生物物理