Scholarlink

<p>Early-onset inherited retinal degenerations (IRDs), such as Leber congenital amaurosis (LCA) caused by pathogenic variants in the <i>NMNAT1</i> gene, lead to severe vision loss in children. Despite its ubiquitous expression, reduced <i>NMNAT1</i> function primarily affects photoreceptor cells (PRs) of the retina, yet the mechanisms underlying their vulnerability remain incompletely understood. Here, we demonstrate that reduced NMNAT1 enzyme function due to the p.V9M mutation leads to DNA damage in PRs, characterized by the progressive accumulation of the oxidative DNA adduct 8-oxo-dG in <i>Nmnat1</i><sup>V9M/V9M</sup> mutant mice. Cells with oxidative DNA damage also demonstrate DNA double-strand breaks, as evidenced by co-staining with antibodies to phosphorylated H2AX (γH2A.X). This DNA damage correlates with apoptosis-driven PR degeneration, as evidenced by caspase-9 activation and TUNEL staining in the PRs of the <i>Nmnat1</i><sup>V9M/V9M</sup> mutant mice, while alternative cell death pathways such as necroptosis and parthanatos were not significantly activated. Treatment with the antioxidant N-acetylcysteine (NAC) reduced oxidative DNA damage and retinal immune responses, mitigated apoptosis, and preserved cone PRs. Longitudinal assessment via optical coherence tomography (OCT) and electroretinography (ERG) revealed sustained structural and functional protection of the retina in NAC-treated mice. These findings establish oxidative DNA damage as a key driver of PR degeneration in the <i>Nmnat1</i><sup>V9M/V9M</sup> model and highlight NAC’s potential as a therapeutic strategy for <i>NMNAT1</i>-associated IRD and potentially other IRDs in which oxidative DNA damage contributes to disease pathogenesis.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Oxidative DNA damage drives apoptotic photoreceptor loss in NMNAT1-associated inherited retinal degeneration: a therapeutic opportunity

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年4月2日

查看全文
  • Hanmeng Zhang,
  • Kevin Valestil,
  • Rossano M. Butcher,
  • Eric A. Pierce

摘要

Early-onset inherited retinal degenerations (IRDs), such as Leber congenital amaurosis (LCA) caused by pathogenic variants in the NMNAT1 gene, lead to severe vision loss in children. Despite its ubiquitous expression, reduced NMNAT1 function primarily affects photoreceptor cells (PRs) of the retina, yet the mechanisms underlying their vulnerability remain incompletely understood. Here, we demonstrate that reduced NMNAT1 enzyme function due to the p.V9M mutation leads to DNA damage in PRs, characterized by the progressive accumulation of the oxidative DNA adduct 8-oxo-dG in Nmnat1V9M/V9M mutant mice. Cells with oxidative DNA damage also demonstrate DNA double-strand breaks, as evidenced by co-staining with antibodies to phosphorylated H2AX (γH2A.X). This DNA damage correlates with apoptosis-driven PR degeneration, as evidenced by caspase-9 activation and TUNEL staining in the PRs of the Nmnat1V9M/V9M mutant mice, while alternative cell death pathways such as necroptosis and parthanatos were not significantly activated. Treatment with the antioxidant N-acetylcysteine (NAC) reduced oxidative DNA damage and retinal immune responses, mitigated apoptosis, and preserved cone PRs. Longitudinal assessment via optical coherence tomography (OCT) and electroretinography (ERG) revealed sustained structural and functional protection of the retina in NAC-treated mice. These findings establish oxidative DNA damage as a key driver of PR degeneration in the Nmnat1V9M/V9M model and highlight NAC’s potential as a therapeutic strategy for NMNAT1-associated IRD and potentially other IRDs in which oxidative DNA damage contributes to disease pathogenesis.