| First Author | Yaung J | Year | 2007 |
| Journal | Mol Vis | Volume | 13 |
| Pages | 566-77 | PubMed ID | 17438522 |
| Mgi Jnum | J:121617 | Mgi Id | MGI:3710733 |
| Citation | Yaung J, et al. (2007) alpha-Crystallin distribution in retinal pigment epithelium and effect of gene knockouts on sensitivity to oxidative stress. Mol Vis 13:566-77 |
| abstractText | PURPOSE: To investigate the susceptibility of retinal pigment epithelium (RPE) from alphaA (-/-) and alphaB (-/-) mice to oxidative stress, and the subcellular changes of alphaA and alphaB-crystallins under oxidative stress. METHODS: The effect of hydrogen peroxide (H(2)O(2)) on apoptosis in RPE from alphaA (-/-), alphaB (-/-), and wild type (wt) mice was assessed by TUNEL and AnnexinV/Propidium Iodide assays. H(2)O(2)-induced changes in caspase-3 activity and mitochondrial permeability transition (MPT) were determined. Human RPE in early passages (2-4) were starved in 1% FBS-containing Dulbecco's modified Eagle medium (DMEM) and treated with H(2)O(2) for 24 h. Gene expression was quantitated by real time PCR. Confocal microscopy was used to examine alpha-crystallin compartmentalization. Whole cell and mitochondrial alpha-crystallin protein amounts were examined by transmission electron microscopy (TEM) and Western blot analysis. RESULTS: RPE from alphaA (-/-), alphaB (-/-) mice exhibited increased susceptibility to apoptosis induced by H(2)O(2), increased caspase-3 activation, and increased MPT. Treatment of human RPE with H(2)O(2) resulted in a dose-dependent decrease in alphaB-crystallin mRNA expression. Confocal microscopy and subcellular fractionation of RPE showed that H(2)O(2) treatment decreased cytosolic and mitochondrial pools of alphaB-crystallin but caused no change in alphaA-crystallin content. TEM confirmed changes in expression of alphaA and alphaB-crystallins with oxidative stress. CONCLUSIONS: Lack of alpha-crystallins renders RPE cells more susceptible to apoptosis from oxidative stress. Mitochondrial alpha-crystallins may play an important role in the protection from increased susceptibility of RPE in oxidative stress. |
