Dataset Information

Drusen proteome analysis: an approach to the etiology of age-related macular degeneration.

ABSTRACT: Drusen are extracellular deposits that accumulate below the retinal pigment epithelium on Bruch's membrane and are risk factors for developing age-related macular degeneration (AMD). The progression of AMD might be slowed or halted if the formation of drusen could be modulated. To work toward a molecular understanding of drusen formation, we have developed a method for isolating microgram quantities of drusen and Bruch's membrane for proteome analysis. Liquid chromatography tandem MS analyses of drusen preparations from 18 normal donors and five AMD donors identified 129 proteins. Immunocytochemical studies have thus far localized approximately 16% of these proteins in drusen. Tissue metalloproteinase inhibitor 3, clusterin, vitronectin, and serum albumin were the most common proteins observed in normal donor drusen whereas crystallin was detected more frequently in AMD donor drusen. Up to 65% of the proteins identified were found in drusen from both AMD and normal donors. However, oxidative protein modifications were also observed, including apparent crosslinked species of tissue metalloproteinase inhibitor 3 and vitronectin, and carboxyethyl pyrrole protein adducts. Carboxyethyl pyrrole adducts are uniquely generated from the oxidation of docosahexaenoate-containing lipids. By Western analysis they were found to be more abundant in AMD than in normal Bruch's membrane and were found associated with drusen proteins. Carboxymethyl lysine, another oxidative modification, was also detected in drusen. These data strongly support the hypothesis that oxidative injury contributes to the pathogenesis of AMD and suggest that oxidative protein modifications may have a critical role in drusen formation.

SUBMITTER: Crabb JW

PROVIDER: S-EPMC137479 | biostudies-literature | 2002 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Drusen proteome analysis: an approach to the etiology of age-related macular degeneration.

Crabb John W JW Miyagi Masaru M Gu Xiaorong X Shadrach Karen K West Karen A KA Sakaguchi Hirokazu H Kamei Motohiro M Hasan Azeem A Yan Lin L Rayborn Mary E ME Salomon Robert G RG Hollyfield Joe G JG

Proceedings of the National Academy of Sciences of the United States of America 20021021 23

Drusen are extracellular deposits that accumulate below the retinal pigment epithelium on Bruch's membrane and are risk factors for developing age-related macular degeneration (AMD). The progression of AMD might be slowed or halted if the formation of drusen could be modulated. To work toward a molecular understanding of drusen formation, we have developed a method for isolating microgram quantities of drusen and Bruch's membrane for proteome analysis. Liquid chromatography tandem MS analyses of ...[more]

PMID: 12391305

Similar Datasets

Project description:PURPOSE: To assess the association of gender, cigarette smoking, body-mass index, and nine genetic risk variants with cuticular drusen (CD), a well recognized subtype of age-related macular degeneration (AMD). METHODS: A total of 757 patients with AMD, including 217 patients with CD, and 553 control individuals were interviewed with a questionnaire and underwent an ophthalmic examination. Venous blood samples were obtained for genomic DNA extraction, and genotyping was performed of single nucleotide polymorphisms previously associated with AMD. Odds ratios were calculated for patients with CD, using unaffected control individuals as a reference. Furthermore, odds ratios in patients with CD were compared to those in patients with "non-CD" AMD. RESULTS: The CD subtype of AMD was significantly associated with current smoking as well as variants in the complement factor H (CFH), age-related maculopathy susceptibility 2 (ARMS2), complement factor B/complement component 2 (CFB/C2), complement component 3 (C3), and apolipoprotein E (APOE) genes. In patients with CD, the association with the CFH Y402H risk allele was significantly higher (p=0.022), whereas the association with current smoking was significantly lower (p<0.001) than in the heterogeneous group of patients with "non-CD" AMD. CONCLUSIONS: The AMD subtype of CD was associated with previously identified genetic AMD risk factors. However, the association with the CFH Y402H risk allele appeared to be stronger, whereas the association with smoking was less pronounced when compared to AMD as a whole. This study suggests a more important role for genetic factors than environmental factors in the development of this well defined subtype of AMD. These findings stress the importance of detailed phenotyping in AMD to identify homogeneous AMD subtypes, which may be associated with different risk factors and disease mechanisms. Such studies will improve the accuracy of predictive models and the effectiveness of preventive and therapeutic options in AMD.

Project description:BackgroundTo identify novel biomarkers related to the pathogenesis of dry age-related macular degeneration (AMD), we adopted a human retinal pigment epithelial (RPE) cell culture model that mimics some features of dry AMD including the accumulation of intra- and sub-RPE deposits. Then, we investigated the aqueous humor (AH) proteome using a data-independent acquisition method (sequential window acquisition of all theoretical fragment ion mass spectrometry) for dry AMD patients and controls.MethodsAfter uniformly pigmented polarized monolayers of human fetal primary RPE (hfRPE) cells were established, the cells were exposed to 4-hydroxy-2-nonenal (4-HNE), followed by Western blotting, immunofluorescence analysis and ELISA of cells or conditioned media for several proteins of interest. Data-dependent acquisition for identification of the AH proteome and SWATH-based mass spectrometry were performed for 11 dry AMD patients according to their phenotypes (including soft drusen and reticular pseudodrusen [RPD]) and 2 controls (3 groups).ResultsIncreased intra- and sub-RPE deposits were observed in 4-HNE-treated hfRPE cells compared with control cultures based on APOA1, cathepsin D, and clusterin immunoreactivity. Additionally, the differential abundance of proteins in apical and basal chambers with or without 4-HNE treatment confirmed the polarized secretion of proteins from hfRPE cells. A total of 119 proteins were quantified in dry AMD patients and controls by SWATH-MS. Sixty-five proteins exhibited significantly altered abundance among the three groups. A two-dimensional principal component analysis plot was generated to identify typical proteins related to the pathogenesis of dry AMD. Among the identified proteins, eight proteins, including APOA1, CFHR2, and CLUS, were previously considered major components or regulators of drusen. Three proteins (SERPINA4, LUM, and KERA proteins) have not been previously described as components of drusen or as being related to dry AMD. Interestingly, the LUM and KERA proteins, which are related to extracellular matrix organization, were upregulated in both RPD and soft drusen.ConclusionsDifferential protein expression in the AH between patients with drusen and RPD was quantified using SWATH-MS in the present study. Detailed proteomic analyses of dry AMD patients might provide insights into the in vivo biology of drusen and RPD.

Dataset Information

Drusen proteome analysis: an approach to the etiology of age-related macular degeneration.

Publications

Drusen proteome analysis: an approach to the etiology of age-related macular degeneration.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets