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Updated: Aug 12, 2025
A Novel Light Damage Paradigm for Use in Retinal Regeneration Studies in Adult Zebrafish
Published on: October 24, 2013
Damage-induced senescent immune cells regulate regeneration of the zebrafish retina
Gregory Konar1, Zachary Flickinger1, Shivani Sharma1
1Department of Biological Sciences, Vanderbilt University, Nashville TN, USA.
Abstract:
Zebrafish spontaneously regenerate their retina in response to damage through the action of Müller glia. Even though Müller glia (MG) are conserved in higher vertebrates, the capacity to regenerate retinal damage is lost. Recent work has focused on the regulation of inflammation during tissue regeneration with precise temporal roles for macrophages and microglia. Senescent cells that have withdrawn from the cell cycle have mostly been implicated in aging, but are still metabolically active, releasing proinflammatory signaling molecules as part of the Senescence Associated Secretory Phenotype (SASP). Here, we discover that in response to retinal damage, a subset of cells expressing markers of microglia/macrophages also express markers of senescence. These cells display a temporal pattern of appearance and clearance during retina regeneration. Premature removal of senescent cells by senolytic treatment led to a decrease in proliferation and incomplete repair of the ganglion cell layer after NMDA damage. Our results demonstrate a role for modulation of senescent cell responses to balance inflammation, regeneration, plasticity, and repair as opposed to fibrosis and scarring.
Insights
Senescent microglia/macrophages aid zebrafish retinal regeneration by balancing inflammation. Prematurely removing these cells impairs repair, highlighting their crucial role in healing.
Area of Science:
- Neuroscience
- Immunology
- Regenerative Medicine
Background:
- Zebrafish exhibit remarkable retinal regeneration via Müller glia (MG), a capacity lost in higher vertebrates.
- Inflammation's role in tissue repair is increasingly recognized, with specific temporal functions for immune cells like macrophages and microglia.
- Cellular senescence, characterized by cell cycle arrest and the Senescence Associated Secretory Phenotype (SASP), is typically linked to aging but may influence tissue repair.
Approach:
- Investigated the presence and role of senescent cells in zebrafish retinal regeneration following damage.
- Utilized markers to identify senescent cells co-expressing microglial/macrophial markers.
- Examined the impact of senolytic treatment to prematurely remove senescent cells on the regenerative process.
Key Points:
- A subset of microglia/macrophages in regenerating zebrafish retinas exhibit senescence markers.
- These senescent immune cells appear and are cleared in a temporally regulated manner during regeneration.
- Early elimination of senescent cells using senolytics resulted in reduced cell proliferation and incomplete ganglion cell layer repair after NMDA-induced damage.
Conclusions:
- Senescent cells, specifically within the microglia/macrophage population, play a critical role in zebrafish retinal regeneration.
- Modulating senescent cell responses is key to balancing inflammation, promoting regeneration, plasticity, and repair, while preventing fibrosis.
