Comprehensive proteomic and phosphoproteomic analysis of retinal pigment epithelium reveals multiple pathway alterations in response to the inflammatory stimuli

Juha Song, Dohyun Han, Heonyi Lee, Jung Da Kim, Joo Youn Cho, Jae Hak Park, Seung Hyeok Seok

Research output: Contribution to journalArticle


Overwhelming and persistent inflammation of retinal pigment epithelium (RPE) induces destructive changes in the retinal environment. However, the precise mechanisms remain unclear. In this study, we aimed to investigate RPE-specific biological and metabolic responses against intense inflammation and identify the molecular characteristics determining pathological progression. We performed quantitative analyses of the proteome and phosphoproteome of the human-derived RPE cell line ARPE-19 after treatment with lipopolysaccharide (LPS) for 45 min or 24 h using the latest isobaric tandem-mass tags (TMTs) labeling approach. This approach led to the identification of 8984 proteins, of which 261 showed a 1.5-fold change in abundance after 24 h of treatment with LPS. A parallel phosphoproteome analysis identified 20,632 unique phosphopeptides from 3207 phosphoproteins with 3103 phosphorylation sites. Integrated proteomic and phosphoproteomic analyses showed significant downregulation of proteins related to mitochondrial respiration and cell cycle checkpoint, while proteins related to lipid metabolism, amino acid metabolism, cell-matrix adhesion, and endoplasmic reticulum (ER) stress were upregulated after LPS stimulation. Further, phosphorylation events in multiple pathways, including MAPKK and Wnt/β-catenin signalings, were identified as involved in LPS-triggered pathobiology. In essence, our findings reveal multiple integrated signals exerted by RPE under inflammation and are expected to give insight into the development of therapeutic interventions for RPE disorders.

Original languageEnglish
Article number3037
JournalInternational Journal of Molecular Sciences
Issue number9
StatePublished - 1 May 2020



  • ARPE-19
  • Inflammation
  • Lipopolysaccharide (LPS)
  • Phosphoproteomics
  • Proteomics
  • Tandem-mass tags (TMTs)

Cite this