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Updated: Jun 8, 2026
Real-Time Analysis of Bioenergetics in Primary Human Retinal Pigment Epithelial Cells Using High-Resolution Respirometry
Published on: February 3, 2023
Retinal aging and sirtuins
Yoko Ozawa1, Shunsuke Kubota, Toshio Narimatsu
1Laboratory of Retinal Cell Biology, Keio University School of Medicine, Tokyo, Japan. yoko-o@sc.itc.keio.ac.jp
Abstract:
The process of aging involves the accumulating changes in the microenvironment that lead to cell senescence or apoptosis, and subsequent tissue or organ dysfunction. Multiple extrinsic and intrinsic events that cause DNA instability are associated with aging. Cells containing unstable DNA are biologically vulnerable, and if the DNA damage is too great for the cell to repair, it becomes senescent or dies by apoptosis. Thus, the cell's capacity to repair its DNA determines the progress of aging, at least in part. Here, we focus on the sirtuins, the mammalian homologs of the yeast life-span-extending molecule, Sir2. Among the sirtuin family proteins in mammals, the one most similar to yeast Sir2 is SIRT1, which is involved in multiple pathways, including the repair of DNA double-strand breaks. Although the role of SIRT1 in mammalian longevity is not clear, it is expressed throughout the retina, where it may suppress aging. In fact, a mutant mouse model of retinal degeneration shows an abnormal subcellular localization of SIRT1 protein and accelerated retinal cell apoptosis. Further analyses are required to elucidate the mechanism of DNA damage and repair, including the contributions of the sirtuins, in the aged or diseased retinas, which will help us understand the mechanisms of retinal aging.
Insights
Aging involves DNA damage and repair. Sirtuin 1 (SIRT1) may protect retinal cells from aging by aiding DNA repair, but further research is needed to confirm its role in retinal aging.
Area of Science:
- Cellular and Molecular Biology
- Gerontology
- Ophthalmology
Background:
- Aging is characterized by accumulating cellular damage, including DNA instability, leading to senescence or apoptosis and organ dysfunction.
- DNA repair capacity is a key determinant in the aging process.
- Sirtuins, particularly SIRT1, are mammalian homologs of yeast Sir2 and are involved in DNA repair pathways.
Purpose of the Study:
- To investigate the role of SIRT1 in retinal aging and its potential protective mechanisms against DNA damage.
- To explore the link between SIRT1, DNA repair, and retinal cell apoptosis in aging and disease models.
Main Methods:
- Focus on sirtuins, specifically SIRT1, as mammalian homologs of yeast Sir2.
- Examined SIRT1 expression and localization in the retina.
- Utilized a mutant mouse model of retinal degeneration to study SIRT1's role in accelerated apoptosis.
Main Results:
- SIRT1 is expressed in the retina and may play a role in suppressing aging.
- A mouse model of retinal degeneration exhibited abnormal SIRT1 subcellular localization and increased retinal cell apoptosis.
- These findings suggest a potential link between SIRT1 dysfunction and retinal aging.
Conclusions:
- SIRT1 is implicated in retinal aging, potentially through its involvement in DNA repair mechanisms.
- Further research is necessary to fully elucidate the mechanisms of DNA damage and repair involving sirtuins in aged or diseased retinas.
- Understanding these mechanisms is crucial for comprehending retinal aging and developing potential interventions.
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