Related Experiment Video
Updated: Dec 31, 2025
A Novel Light Damage Paradigm for Use in Retinal Regeneration Studies in Adult Zebrafish
Published on: October 24, 2013
IL-1β induces rod degeneration through the disruption of retinal glutamate homeostasis
Hugo Charles-Messance1, Guillaume Blot1, Aude Couturier1,2
1Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France.
Background:
Age-related macular degeneration is characterized by the accumulation of subretinal macrophages and the degeneration of cones, but mainly of rods. We have previously shown that Mononuclear Phagocytes-derived IL-1β induces rod photoreceptor cell death during experimental subretinal inflammation and in retinal explants exposed to IL-1β but the mechanism is unknown.
Methods:
Retinal explants were culture in the presence of human monocytes or IL-1β and photoreceptor cell survival was analyzed by TUNEL labeling. Glutamate concentration and transcription levels of gene involved in the homeostasis of glutamate were analyzed in cell fractions of explant cultured or not in the presence of IL-1β. Glutamate receptor antagonists were evaluated for their ability to reduce photoreceptor cell death in the presence of IL1-β or monocytes.
Results:
We here show that IL-1β does not induce death in isolated photoreceptors, suggesting an indirect effect. We demonstrate that IL-1β leads to glutamate-induced rod photoreceptor cell death as it increases the extracellular glutamate concentrations in the retina through the inhibition of its conversion to glutamine in Müller cells, increased release from Müller cells, and diminished reuptake. The inhibition of non-NMDA receptors completely and efficiently prevented rod apoptosis in retinal explants cultured in the presence of IL-1β or, more importantly, in vivo, in a model of subretinal inflammation.
Conclusions:
Our study emphasizes the importance of inflammation in the deregulation of glutamate homeostasis and provides a comprehensive mechanism of action for IL-1β-induced rod degeneration.
Insights
Interleukin-1 beta (IL-1β) causes rod cell death in age-related macular degeneration by disrupting glutamate balance in the retina. Blocking glutamate receptors prevents this degeneration, offering a potential therapeutic target.
Area of Science:
- Ophthalmology
- Neuroscience
- Immunology
Background:
- Age-related macular degeneration (AMD) involves subretinal macrophages and photoreceptor degeneration, primarily rods.
- Interleukin-1 beta (IL-1β), produced by mononuclear phagocytes, is implicated in rod cell death during retinal inflammation, but the mechanism remains unclear.
Purpose of the Study:
- To elucidate the mechanism by which IL-1β induces rod photoreceptor cell death in the context of subretinal inflammation.
- To investigate the role of glutamate homeostasis in IL-1β-mediated retinal degeneration.
Main Methods:
- Retinal explants were treated with human monocytes or IL-1β, and photoreceptor survival was assessed via TUNEL labeling.
- Glutamate concentrations and gene expression related to glutamate metabolism were analyzed.
- The efficacy of glutamate receptor antagonists in preventing photoreceptor death was evaluated.
Main Results:
- IL-1β did not directly kill isolated photoreceptors, indicating an indirect mechanism.
- IL-1β increased extracellular glutamate by inhibiting its conversion to glutamine in Müller cells, enhancing its release, and reducing reuptake.
- Inhibition of non-NMDA receptors effectively prevented rod apoptosis in vitro and in vivo models of subretinal inflammation.
Conclusions:
- Inflammation significantly disrupts glutamate homeostasis in the retina.
- IL-1β induces rod degeneration by creating a glutamate-excitotoxic environment, highlighting a novel therapeutic pathway for AMD.
More Related Videos
06:27Müller Glia Cell Activation in a Laser-induced Retinal Degeneration and Regeneration Model in Zebrafish
Published on: October 27, 2017
12:48In Vivo Dynamics of Retinal Microglial Activation During Neurodegeneration: Confocal Ophthalmoscopic Imaging and Cell Morphometry in Mouse Glaucoma
Published on: May 11, 2015
