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7-Ketocholesterol Promotes Retinal Pigment Epithelium Senescence and Fibrosis of Choroidal Neovascularization via IQGAP1 Phosphorylation-Dependent Signaling
Accumulation of 7-ketocholesterol (7KC) occurs in age-related macular degeneration (AMD) and was found previously to promote fibrosis, an untreatable cause of vision loss, partly through induction of endothelial-mesenchymal transition. To address the hypothesis that 7KC causes mesenchymal transition...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10299509/ https://www.ncbi.nlm.nih.gov/pubmed/37373423 http://dx.doi.org/10.3390/ijms241210276 |
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author | Wang, Haibo Ramshekar, Aniket Cung, Thaonhi Wallace-Carrete, Chris Zaugg, Chandler Nguyen, Jasmine Stoddard, Gregory J. Hartnett, M. Elizabeth |
author_facet | Wang, Haibo Ramshekar, Aniket Cung, Thaonhi Wallace-Carrete, Chris Zaugg, Chandler Nguyen, Jasmine Stoddard, Gregory J. Hartnett, M. Elizabeth |
author_sort | Wang, Haibo |
collection | PubMed |
description | Accumulation of 7-ketocholesterol (7KC) occurs in age-related macular degeneration (AMD) and was found previously to promote fibrosis, an untreatable cause of vision loss, partly through induction of endothelial-mesenchymal transition. To address the hypothesis that 7KC causes mesenchymal transition of retinal pigment epithelial cells (RPE), we exposed human primary RPE (hRPE) to 7KC or a control. 7KC-treated hRPE did not manifest increased mesenchymal markers, but instead maintained RPE-specific proteins and exhibited signs of senescence with increased serine phosphorylation of histone H3, serine/threonine phosphorylation of mammalian target of rapamycin (p-mTOR), p16 and p21, β-galactosidase labeling, and reduced LaminB1, suggesting senescence. The cells also developed senescence-associated secretory phenotype (SASP) determined by increased IL-1β, IL-6, and VEGF through mTOR-mediated NF-κB signaling, and reduced barrier integrity that was restored by the mTOR inhibitor, rapamycin. 7KC-induced p21, VEGF, and IL-1β were inhibited by an inhibitor of protein kinase C. The kinase regulates IQGAP1 serine phosphorylation. Furthermore, after 7KC injection and laser-induced injury, mice with an IQGAP1 serine 1441-point mutation had significantly reduced fibrosis compared to littermate control mice. Our results provide evidence that age-related accumulation of 7KC in drusen mediates senescence and SASP in RPE, and IQGAP1 serine phosphorylation is important in causing fibrosis in AMD. |
format | Online Article Text |
id | pubmed-10299509 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-102995092023-06-28 7-Ketocholesterol Promotes Retinal Pigment Epithelium Senescence and Fibrosis of Choroidal Neovascularization via IQGAP1 Phosphorylation-Dependent Signaling Wang, Haibo Ramshekar, Aniket Cung, Thaonhi Wallace-Carrete, Chris Zaugg, Chandler Nguyen, Jasmine Stoddard, Gregory J. Hartnett, M. Elizabeth Int J Mol Sci Article Accumulation of 7-ketocholesterol (7KC) occurs in age-related macular degeneration (AMD) and was found previously to promote fibrosis, an untreatable cause of vision loss, partly through induction of endothelial-mesenchymal transition. To address the hypothesis that 7KC causes mesenchymal transition of retinal pigment epithelial cells (RPE), we exposed human primary RPE (hRPE) to 7KC or a control. 7KC-treated hRPE did not manifest increased mesenchymal markers, but instead maintained RPE-specific proteins and exhibited signs of senescence with increased serine phosphorylation of histone H3, serine/threonine phosphorylation of mammalian target of rapamycin (p-mTOR), p16 and p21, β-galactosidase labeling, and reduced LaminB1, suggesting senescence. The cells also developed senescence-associated secretory phenotype (SASP) determined by increased IL-1β, IL-6, and VEGF through mTOR-mediated NF-κB signaling, and reduced barrier integrity that was restored by the mTOR inhibitor, rapamycin. 7KC-induced p21, VEGF, and IL-1β were inhibited by an inhibitor of protein kinase C. The kinase regulates IQGAP1 serine phosphorylation. Furthermore, after 7KC injection and laser-induced injury, mice with an IQGAP1 serine 1441-point mutation had significantly reduced fibrosis compared to littermate control mice. Our results provide evidence that age-related accumulation of 7KC in drusen mediates senescence and SASP in RPE, and IQGAP1 serine phosphorylation is important in causing fibrosis in AMD. MDPI 2023-06-17 /pmc/articles/PMC10299509/ /pubmed/37373423 http://dx.doi.org/10.3390/ijms241210276 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Wang, Haibo Ramshekar, Aniket Cung, Thaonhi Wallace-Carrete, Chris Zaugg, Chandler Nguyen, Jasmine Stoddard, Gregory J. Hartnett, M. Elizabeth 7-Ketocholesterol Promotes Retinal Pigment Epithelium Senescence and Fibrosis of Choroidal Neovascularization via IQGAP1 Phosphorylation-Dependent Signaling |
title | 7-Ketocholesterol Promotes Retinal Pigment Epithelium Senescence and Fibrosis of Choroidal Neovascularization via IQGAP1 Phosphorylation-Dependent Signaling |
title_full | 7-Ketocholesterol Promotes Retinal Pigment Epithelium Senescence and Fibrosis of Choroidal Neovascularization via IQGAP1 Phosphorylation-Dependent Signaling |
title_fullStr | 7-Ketocholesterol Promotes Retinal Pigment Epithelium Senescence and Fibrosis of Choroidal Neovascularization via IQGAP1 Phosphorylation-Dependent Signaling |
title_full_unstemmed | 7-Ketocholesterol Promotes Retinal Pigment Epithelium Senescence and Fibrosis of Choroidal Neovascularization via IQGAP1 Phosphorylation-Dependent Signaling |
title_short | 7-Ketocholesterol Promotes Retinal Pigment Epithelium Senescence and Fibrosis of Choroidal Neovascularization via IQGAP1 Phosphorylation-Dependent Signaling |
title_sort | 7-ketocholesterol promotes retinal pigment epithelium senescence and fibrosis of choroidal neovascularization via iqgap1 phosphorylation-dependent signaling |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10299509/ https://www.ncbi.nlm.nih.gov/pubmed/37373423 http://dx.doi.org/10.3390/ijms241210276 |
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