Microglia Preserve Visual Function in a Mouse Model of Retinitis Pigmentosa with Rhodopsin-P23H Mutant
Chen Yu1, Daniel R Saban2,3
1Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA.
Abstract:
Most forms of outer retinal degenerative diseases involve the ectopic accumulation of microglia/macrophages in the subretinal space, including retinitis pigmentosa. However, their role in the loss of photoreceptor function during retinal degeneration remains unknown. Here, we examined the effect of conditional microglial depletion on photoreceptor numbers and visual function in mice with the rhodopsin P23H mutation, a dominant form of retinitis pigmentosa in humans. We found that microglial depletion led to an elevated level of rhodopsin and increased photoreceptor layer thickness. However, overall electrophysiological functions of the retina were reduced with microglial depletion. Therefore, these results identify an essential role of microglia specially in preserving visual function in outer retinal degeneration.
Insights
Microglia play a crucial role in preserving visual function in outer retinal degenerative diseases like retinitis pigmentosa. Depleting microglia in P23H mice elevated rhodopsin but reduced overall retinal electrophysiological function.
Area of Science:
- Ophthalmology
- Neuroscience
- Immunology
Background:
- Outer retinal degenerative diseases, including retinitis pigmentosa, are characterized by microglia/macrophage accumulation in the subretinal space.
- The specific role of these immune cells in photoreceptor dysfunction during retinal degeneration is not fully understood.
Purpose of the Study:
- To investigate the impact of conditional microglial depletion on photoreceptor integrity and visual function.
- To elucidate the role of microglia in a mouse model of dominant retinitis pigmentosa (rhodopsin P23H mutation).
Main Methods:
- Utilized a conditional depletion strategy to eliminate microglia in P23H mutant mice.
- Assessed photoreceptor numbers, retinal layer thickness, and retinal electrophysiological function.
Main Results:
- Microglial depletion resulted in elevated rhodopsin levels and increased photoreceptor layer thickness.
- Despite structural changes, overall electrophysiological function of the retina was significantly reduced following microglial depletion.
Conclusions:
- Microglia are essential for maintaining visual function in the context of outer retinal degeneration.
- These findings highlight a critical neuroprotective role for microglia in retinitis pigmentosa and related diseases.
