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ORIGINAL RESEARCH article

Front. Endocrinol.

Sec. Clinical Diabetes

Volume 16 - 2025 | doi: 10.3389/fendo.2025.1615103

This article is part of the Research TopicDiabetes Complications: Navigating Challenges and Unveiling New SolutionsView all 7 articles

A key role of the PGC-1α/ERR-α pathway in regulation of angiogenic factors in proliferative diabetic retinopathy

Provisionally accepted
  • 1King Saud University Medical City, Riyadh, Saudi Arabia
  • 2College of Medicine, King Saud University, Riyadh, Saudi Arabia
  • 3University Hospitals Leuven, Leuven, Brussels, Belgium

The final, formatted version of the article will be published soon.

Background: PGC-1α is induced by hypoxia and interacts with the receptor ERR-α to stimulate angiogenic factors expression and promote angiogenesis. We investigated the possible role of PGC-1α/ERR-α pathway in regulating angiogenic factors expression in proliferative diabetic retinopathy (PDR).We analysed vitreous fluid samples from PDR and non-diabetic patients and epiretinal fibrovascular membranes from PDR patients. Streptozotocin-treated rats were used as a model of diabetic retinopathy. Vitreous samples, epiretinal membranes, rat retinas, human retinal Müller glial cells and human retinal microvascular endothelial cells (HRMECs) were studied by Western blot analysis, ELISA and immunohistochemistry. Levels of reactive oxygen species (ROS) were determined with spectrofluorometric analysis.Results: Immunohistochemical analysis demonstrated co-expression of PGC-1α and ERR-α in endothelial cells and leukocytes in epiretinal membranes. Angiogenic activity, determined by the numbers of CD31-positive vessels, correlated significantly with PGC-1α and ERR-α expression levels. PGC-1α, ERR-α and the angiogenic biomarkers vascular endothelial growth (VEGF) and angiopoietin 2 were significantly increased in PDR vitreous samples. Diabetes induced upregulation of PGC-1α and ERR-α immunoreactive proteoforms in rat retinas. Cultured Müller cells and HRMECs constitutively expressed PGC-1α and ERR-α. In Müller cells, the PGC-1α inhibitor SR-18292 and the ERR-α selective inverse agonist XCT790 significantly attenuated VEGF, angiopoietin 2 and MCP-1/CCL2 upregulation induced by diabetic mimetic conditions. Treatment of Müller cells with the PGC-1α activator XLN005 induced significant upregulation of VEGF and attenuated ROS production induced by diabetic mimetic conditions. Conclusions: Our findings suggest that suppression of PGC-1α/ERR-α pathway might impair the upregulation of angiogenic factors in PDR.

Keywords: proliferative diabetic retinopathy, Angiogenesis, PGC1-α, ERR-α, VEGF

Received: 20 Apr 2025; Accepted: 30 Jun 2025.

Copyright: © 2025 Abu El-Asrar, NAWAZ, Ahmad, Siddiquei, Allegaert, Gikandi, De Hertogh and Opdenakker. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Ahmed M. Abu El-Asrar, King Saud University Medical City, Riyadh, Saudi Arabia

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