| First Author | Ding X | Year | 2009 |
| Journal | Invest Ophthalmol Vis Sci | Volume | 50 |
| Issue | 10 | Pages | 4957-66 |
| PubMed ID | 19443712 | Mgi Jnum | J:154545 |
| Mgi Id | MGI:4397528 | Doi | 10.1167/iovs.09-3381 |
| Citation | Ding X, et al. (2009) Enhanced HtrA2/Omi expression in oxidative injury to retinal pigment epithelial cells and murine models of neurodegeneration. Invest Ophthalmol Vis Sci 50(10):4957-66 |
| abstractText | PURPOSE: To investigate the role of HtrA2/Omi, a nuclear-encoded mitochondrial serine protease with a proapoptosis function, under H(2)O(2)-induced oxidative stress in human RPE, in the Ccl2(-)(/)(-)Cx3cr1(-)(/)(-) double-knockout (DKO) mouse retina, and the HtrA2/Omi-deficient mice. METHODS: Oxidative stress was induced in ARPE-19 cells by 1 mM H(2)O(2) for 2 hours. HtrA2/Omi and caspase-3 expression was evaluated using RQ-PCR, immunohistochemistry, or Western blot. Cell viability was detected by MTT assay. HtrA2/Omi expression in the subcellular components and activated caspase-3 were measured. These processes were also evaluated in cells treated with UCF-101, an HtrA2/Omi inhibitor or in cells subjected to RNAi against HtrA2/Omi. Oxidative stress was assayed and compared in retinas of DKO and wild-type (WT) mice by determining serum NADPH oxidase subunits and nitrite levels. Transmission electron microscopy was used to view the retinal ultrastructure of the HtrA2/Omi-deficient mice. RESULTS: H(2)O(2)-induced oxidative damage resulted in HtrA2/Omi translocation from mitochondria to cytosol, leading to RPE cell apoptosis via a caspase-mediated pathway. Treatment of RPE cells with UCF-101 reduced the cytosolic translocation of HtrA2/Omi, attenuated caspase-3 activation, and decreased apoptosis. After specific HtrA2 downregulation, increased cell viability was measured in H(2)O(2)-treated ARPE-19 cells. Retina of DKO mice exhibit increased oxidative stress and upregulation of HtrA2/Omi. Fewer and abnormal mitochondria were found in HtrA2/Omi(-)(/)(-) photoreceptors and RPE. CONCLUSIONS: These findings suggest that HtrA2/Omi is related to RPE apoptosis due to oxidative stress, which may play an important role in the integrity of mitochondria and the pathogenesis of AMD. |
