Interactome Mapping Guided by Tissue-Specific Phosphorylation in Age-Related Macular Degeneration

Abstract

The current study aims to determine the molecular mechanisms of age-related macular degeneration (AMD) using the phosphorylation network. Specifically, we examined novel biomarkers for oxidative stress by protein interaction mapping using in vitro and in vivo models that mimic the complex and progressive characteristics of AMD. We hypothesized that the early apoptotic reactions could be initiated by protein phosphorylation in region-dependent (peripheral retina vs. macular) and tissue-dependent (retinal pigment epithelium vs. retina) manner under chronic oxidative stress. The analysis of protein interactome and oxidative biomarkers showed the presence of tissue-and region-specific post-translational mechanisms that contribute to AMD progression and suggested new therapeutic targets that include ubiquitin, erythropoietin, * Address correspondence to: Wan Jin Jahng, Retina Proteomics Laboratory and Organic Chemistry Laboratory, Department of Petroleum Chemistry, American University of Nigeria, Yola, Nigeria, Tel +234 805 550 1032. wan.jahng@aun.edu.ng; Diana R. Gutsaeva, Department of Ophthalmology, Augusta University, Augusta, GA, USA, Tel +1 706 721 7910. dgutsaeva@augusta.edu. COMPETING INTERESTS None AUTHORS' CONTRIBUTIONS (/P) HHS Public AccessAuthor manuscript Int J Sci Eng Res. Author manuscript; available in PMC 2017 May 31. Author Manuscript Author ManuscriptAuthor ManuscriptAuthor Manuscript vitronectin, MMP2, crystalline, nitric oxide, and prohibitin. Phosphorylation of specific target proteins in RPE cells is a central regulatory mechanism as a survival tool under chronic oxidative imbalance. The current interactome map demonstrates a positive correlation between oxidative stress-mediated phosphorylation and AMD progression and provides a basis for understanding oxidative stress-induced cytoskeletal changes and the mechanism of aggregate formation induced by protein phosphorylation. This information could provide an effective therapeutic approach to treat age-related neurodegeneration.

Mitochondrial quality control in AMD: does mitophagy play a pivotal role?

“…The alteration of protein phosphorylation induced by oxidative stress has been recently studied in RPE cells in interactome network scale [163]. Phosphorylation is a survival mechanism for proteins in chronic oxidative stress.…”

Proteomics of Human Retinal Pigment Epithelium (RPE) Cells

“…The proteome in H 2 O 2 -treated D407 cells showed upregulation of several proteins including heat shock proteins, peroxiredoxins, elongation factor Tu, and RNA helicase DDX3X. Findings from this study were expanded in subsequent investigations that applied global and targeted proteomics approaches in the context of interactomics and phosphoproteomics [ 44 , 45 , 46 ].…”

Mechanistic Dissection of Macular Degeneration Using the Phosphorylation Interactome

“…Cells were grown on sterile glass cover slips using DMEM/F12 medium with 10% FBS and 1% penicillin/streptomycin (Hyclone) in 5% CO 2 incubator at 37°C. Cells were treated under oxidative stress or intense light as previously reported [9][10][11][18][19][20]. Cells were washed with PBS and incubated with MitoTracker Orange CMTMRos (100 nM, Molecular Probes, Carlsbad, CA) in serum-free culture medium (30 min, 37°C), followed by washing (PBS) and fixing (10% formaldehyde, 30 min, room temperature).…”

“…Phosphoproteomes of macula (I), peripheral retina (II), central RPE (III), and peripheral RPE (IV) were compared to age-matched control donor eyes to determine region-specific, senescence-associated molecular mechanisms during AMD progression. Phosphoproteins were enriched by charge-based spin column chromatography and resolved by 2D gel electrophoresis as previously reported [11,16]. Trypsin-digested phosphopeptides from whole lysates were enriched using Ga 3+ /TiO 2 immobilized metal ion chromatography.…”