DAPL1 deficiency in mice impairs antioxidant defenses in the RPE and leads to retinal degeneration with AMD-like features.

Abstract

The decreased antioxidant capacity in the retinal pigment epithelium (RPE) is the hallmark of retinal degenerative diseases including age-related macular degeneration (AMD). Nevertheless, the exact regulatory mechanisms underlying the pathogenesis of retinal degenerations remain largely unknown. Here we show in mice that deficiencies in Dapl1, a susceptibility gene for human AMD, impair the antioxidant capacity of the RPE and lead to age-related retinal degeneration in the 18-month-old mice homozygous for a partial deletion of Dapl1. Dapl1-deficiency is associated with a reduction of the RPE's antioxidant capacity, and experimental re-expression of Dapl1 reverses this reduction and protects the retina from oxidative damage. Mechanistically, DAPL1 directly binds the transcription factor E2F4 and inhibits the expression of MYC, leading to upregulation of the transcription factor MITF and its targets NRF2 and PGC1α, both of which regulate the RPE's antioxidant function. When MITF is experimentally overexpressed in the RPE of DAPL1 deficient mice, antioxidation is restored and retinas are protected from degeneration. These findings suggest that the DAPL1-MITF axis functions as a novel regulator of the antioxidant defense system of the RPE and may play a critical role in the pathogenesis of age-related retinal degenerative diseases.

• Authors: Xiaoyin Ma, Huaicheng Chen, Shuhui Jian, Junhao He, Youjia Liu, Shuxian Han, Lifu Chang, Pingping Li, Ying-Ao Chen, Xiaoyan Liu, Xiaojuan Hu, Yu Chen, Ling Hou
• Journal: Redox biology (Redox Biol) Vol. 62 Pg. 102675 (06 2023) ISSN: 2213-2317 [Electronic] Netherlands
• PMID: 36933392 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.

Chemical References

• Antioxidants
• Membrane Proteins
• Transcription Factors
• early epithelial differentiation-associated protein, mouse
• Mitf protein, mouse

Topics

• Animals
• Mice
• Antioxidants (metabolism)
• Cell Line
• Macular Degeneration (genetics, pathology)
• Membrane Proteins (metabolism)
• Oxidative Stress
• Retinal Degeneration (metabolism)
• Retinal Pigment Epithelium (metabolism)
• Transcription Factors (metabolism)