Shielding retinal pigment epithelium cells from high glucose-induced oxidative stress: the protective effect of phospholipase D (PLD) pathway inhibition

Document Type

Article

Publication Date

1-28-2026

Publication Title

Biochimica et Biophysica Acta

Abstract

The retinal pigment epithelium (RPE) performs key roles in preserving retinal integrity and must continuously manage oxidative stress (OS). We previously demonstrated that the canonical phospholipase D isoforms, PLD1 and PLD2, mediate the RPE inflammatory response triggered by inflammatory injury. This study explores the mechanisms of modulation of OS mediated by PLD inhibition in RPE cells exposed to high glucose (HG) levels. ARPE-19, D407 and the novel human RPE cell line ABC were cultured under HG (33 mM) or normal glucose (NG, 5.5 mM) conditions. To inhibit PLD1, PLD2, and NADPH oxidase (NOX), VU0359595 (PLD1i), VU0285655-1 (PLD2i), and diphenyleneiodonium chloride (DPI) were used, respectively. HG exposure significantly increased reactive oxygen species (ROS) levels and reduced mitochondrial membrane potential (MMP) in ARPE-19 and D407 cells. These effects were prevented by PLD1i and PLD2i in an Nrf-2 and cyclooxygenase-2 -independent manner. In ARPE-19 cells, DPI prevented OS induced by HG as well as the stress triggered by the combination of phosphatidic acid + diacylglycerol, bioactive lipids generated through the PLD pathway-. Similarly, HG elevated ROS levels in ABC cells, and this increase was prevented by PLD1i and DPI. RNAseq analysis showed differential expression of NOX family members (NOX1,2 and 4 and DUOX1 and 2) in ARPE-19 and ABC cells. Our results demonstrate that PLDs inhibition prevent HG-induced OS in RPE cells, possibly by reducing NOX activity. The PLD pathway constitutes a novel pharmacological target to simultaneously mitigate OS and the inflammatory response, two hallmarks of retinal degenerative diseases.

First Page

1

Last Page

17

PubMed ID

41617127

Volume

1873

Issue

3

Rights

© 2026. Published by Elsevier B.V.

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