Low glutathione levels are associated with crystallin oxidation in age-related nuclear cataract. To understand the role of cysteine residue oxidation, we used the novel approach of comparing human cataracts with glutathionedepleted LEGSKO mouse lenses for intra-versus intermolecular disulfide crosslinks using 2D-PAGE and proteomics, and then systematically identified in vivo and in vitro all disulfide forming sites using ICAT labeling method coupled with proteomics. Crystallins rich in intramolecular disulfides were abundant at young age in human and WT mouse lens but shifted to multimeric intermolecular disulfides at older age. The shift was 4x accelerated in LEGSKO lens. Most cysteine disulfides in β-crystallins (except βA4 in human) were highly conserved in mouse and human and could be generated by oxidation with H 2 O 2 , whereas γ-crystallin oxidation selectively affected γC23/42/79/80/154, γD42/33, and γS83/115/130 in human cataracts, and γB79/80/110, γD19/109, γF19/79, γE19, γS83/130, and γN26/128 in mouse. Analysis based on available crystal structure suggests that conformational changes are needed to expose Cys42, Cys79/80, Cys154 in γC; Cys42, Cys33 in γD, and Cys83, Cys115, and Cys130 in γS. In conclusion, the β-crystallin disulfidome is highly conserved in age-related nuclear cataract and LEGSKO mouse, and reproducible by in vitro oxidation, whereas some of the disulfide formation sites in γ-crystallins necessitate prior conformational changes. Overall, the LEGSKO mouse model is closely reminiscent of age- Aging lens crystallins accumulate post-synthetic modifications that can be broadly classified into three categories, namely (1) protein backbone changes, such as racemization and truncation (1-3), (2) conversion of one amino acid into another, such as deamidation of asparagine into aspartate or deguanidination of arginine into ornithine, deamination of lysine into allysine and 2-aminoadipic acid (4 -6), and (3) amino acid residue damage from reactive carbonyls and reactive oxygen species (7,8). Carbonyl damage results from the Maillard Reaction by glucose, methylglyoxal, or oxidation products of ascorbate, tryptophan or lipids which form adducts and crosslinks with nucleophilic group of lysine, arginine and cysteine. Examples include carboxymethyl-lysine, pentosidine, methylglyoxal hydroimidazolones, HNE-cysteine adducts and kynurenine (7,9 -12). Oxidative damage results from reactive oxygen species that directly damage amino acid residues, e.g. oxidizing tryptophan into N-formyl kynurenine and kynurenine, methionine into its sulfoxide, and cysteine into cysteine disulfides or cysteic acid (13)(14)(15).Because of their relevance to age-related cataract, the impact of each of these modifications on crystallin structure and stability is the subject of intense investigation. Importantly, Benedek proposed that high molecular weight (HMW) 1 crystallin aggregates the size of 50 million daltons are needed in order for lens opacification to be visible (16,17). Crystallin aggregation conceivably occurs by o...

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

SummaryAge‐related cataractogenesis is associated with disulfide‐linked high molecular weight (HMW) crystallin aggregates. We recently found that the lens crystallin disulfidome was evolutionarily conserved in human and glutathione‐depleted mouse (LEGSKO) cataracts and that it could be mimicked by oxidation in vitro (Mol. Cell Proteomics, 14, 3211‐23 (2015)). To obtain a comprehensive blueprint of the oxidized key regulatory and cytoskeletal proteins underlying cataractogenesis, we have now used the same approach to determine, in the same specimens, all the disulfide‐forming noncrystallin proteins identified by ICAT proteomics. Seventy‐four, 50, and 54 disulfide‐forming proteins were identified in the human and mouse cataracts and the in vitro oxidation model, respectively, of which 17 were common to all three groups. Enzymes with oxidized cysteine at critical sites include GAPDH (hGAPDH, Cys247), glutathione synthase (hGSS, Cys294), aldehyde dehydrogenase (hALDH1A1, Cys126 and Cys186), sorbitol dehydrogenase (hSORD, Cys140, Cys165, and Cys179), and PARK7 (hPARK7, Cys46 and Cys53). Extensive oxidation was also present in lens‐specific intermediate filament proteins, such as BFSP1 and BFSP12 (hBFSP1 and hBFSP12, Cys167, Cys65, and Cys326), vimentin (mVim, Cys328), and cytokeratins, as well as microfilament and microtubule filament proteins, such as tubulin and actins. While the biological impact of these modifications for lens physiology remains to be determined, many of these oxidation sites have already been associated with either impaired metabolism or cytoskeletal architecture, strongly suggesting that they have a pathogenic role in cataractogenesis. By extrapolation, these findings may be of broader significance for age‐ and disease‐related dysfunctions associated with oxidant stress.

No abstract

Purpose: Evaluating outcomes in patients receiving intravitreal antivascular endothelial growth factor (VEGF) inhibitors for neovascular age-related macular degeneration whom experience a lapse in treatment. Methods: A retrospective chart review evaluating 3,304 patients ≥18 years who experienced treatment lapses ≥3 months compared with control counterparts. Demographic information, macular thickness as measured by central subfield thickness, and visual acuity were collected at baseline, the first postlapse appointment, and at 3, 6, and 12 months after the lapse for the study group. Results: Lapse (n = 241) and control patients (n = 241) had similar baseline visual acuity and central subfield thickness (Early Treatment Diabetic Retinopathy Study: 58.9 ± 20.2 [20/63] vs. 59.2 ± 20.1 [20/63]; central subfield thickness: 252.4 ± 63.2 µm vs. 259.8 ± 66.2 µm, P = 0.21). Analysis revealed that lapse patients experienced a significant increase in central subfield thickness after lapse when compared with controls (279.4 ± 86.9 µm vs. 253.7 ± 65.9 µm, P < 0.01), which normalized on resumption of treatment (259.1 ± 79 µm vs. 246.8 ± 57.6 µm, P = 0.06). Study patients also experienced loss in the visual acuity after lapse when compared with controls (52.9 ± 23.6 Early Treatment Diabetic Retinopathy Study [20/100] vs. 59.9 ± 20.8 [20/63] Early Treatment Diabetic Retinopathy Study, P < 0.01) that did not recover through 12 months of follow-up. Conclusion: Patients with neovascular age-related macular degeneration who have lapses in care are at risk for poorer outcomes. Although macular thickness normalizes on resumption of treatment, their decline in the visual acuity does not recover.

Background/aimsThe efficacy of mineralocorticoid receptor antagonist eplerenone to treat chronic central serous chorioretinopathy (CSCR) has been established. However, previous studies have been limited by small cohort size and short follow-up duration. This study aims to report 3-year clinical outcomes of patients treated with eplerenone for chronic CSCR.MethodsInstitutional review board-approved retrospective chart analysis at a single institution from 2012 to 2018. Baseline best-corrected visual acuity and anatomical measurements related to degree of subretinal fluid (SRF) were collected at eplerenone initiation. Follow-up data were collected at the closest date to 12, 24 and 36 months.ResultsData were obtained for 100 eyes of 83 patients at 1-year (mean 11.18 ± 4.00 months), 49 eyes at 2-year (24.01 ± 3.33 months) and 33 eyes at 3-year (mean 35.5 ± 7.89 months) follow-up visits. The rate of complete SRF resolution was 31%, 28% and 33%, respectively. At final follow-up, logarithm of the minimum angle of resolution visual acuity change from baseline was +0.10 ± 0.24 (p = 0.130). Average change from baseline at final follow-up for central subfield thickness was −97 ± 140.6 µm (p < 0.001), cube volume was –1.07 ± 1.71 mm3 (p < 0.001), macular thickness –28. 5 ± 47.5 µm (p < 0.001), maximum SRF height was −95.6 ± 160.5 µm (p < 0.001) and maximum SRF diameter was −1169.0 ± 1638.7 µm (p = 0.008).ConclusionAnatomical improvement occurs primarily within the first year of eplerenone treatment for chronic CSCR.

No abstract

No abstract