Related Experiment Video
Updated: May 8, 2025
Retinal Pigment Epithelium Transplantation in a Non-human Primate Model for Degenerative Retinal Diseases
Published on: June 14, 2021
Correction to: Triamcinolone Acetonide Protects Against Light-Induced Retinal Degeneration by Activating
Xiangcheng Tang1, Wei Liu2, Jia Liang1
1Shenzhen Eye Hospital, Shenzhen Eye Institute, JinanUniversity, 18 Zetian Road, Shenzhen, 518040, Guangdong, China.
Abstract:
Microglia are highly specialized resident macrophages in the central nervous system that play a pivotal role in modulating neuroinflammation. Microglial plasticity is essential for their function, allowing them to polarize into proinflammatory M1-like or anti-inflammatory M2-like phenotypes. However, the mechanisms driving M1 and M2 microglial induction during retinal degeneration remain largely unexplored. In addition, drugs that regulate retinal microglial polarity have not been fully investigated. The synthetic glucocorticoid triamcinolone acetonide (TA) is widely utilized in ophthalmology clinics for its anti-inflammatory properties. Here, we investigated microglial polarity in a light-induced retinal degeneration mouse model, along with the effects and mechanisms of intravitreal injection of TA on microglial polarity, retinal inflammation, and visual function following light damage (LD). Our findings demonstrated that LD induced a pro-inflammatory M1 microglial signature, with levels of M1 marker proteins in the retina increasing in a time-dependent manner following LD. Intravitreal TA treatment mitigated LD-induced retinal inflammation, photoreceptor death, and retinal blood vessel leakage, and preserved retinal responsiveness to light stimuli. Mechanistically, TA suppressed the proinflammatory microglial phenotype while promoting the anti-inflammatory phenotype by activating the signal transducer and activator of transcription 6/arginase1 (STAT6/Arg1) signaling pathway. These results reveal a new mechanism by which TA protects the retina from LD by shifting microglia toward an anti-inflammatory state through the STAT6/Arg1 axis.
Insights
Light damage triggers pro-inflammatory microglia in the retina. Triamcinolone acetonide (TA) treatment shifts microglia to an anti-inflammatory state, protecting vision and reducing retinal damage.
Area of Science:
- Neuroscience
- Immunology
- Ophthalmology
Context:
- Microglia, the central nervous system's resident macrophages, are crucial for neuroinflammation.
- Microglial plasticity allows polarization into M1 (pro-inflammatory) or M2 (anti-inflammatory) phenotypes.
- Mechanisms of microglial polarization in retinal degeneration and therapeutic regulation are underexplored.
Purpose:
- Investigate microglial polarity in a light-induced retinal degeneration (LD) mouse model.
- Evaluate the effects and mechanisms of intravitreal triamcinolone acetonide (TA) on microglial polarity, retinal inflammation, and visual function post-LD.
- Elucidate TA's role in modulating microglial phenotypes and protecting the retina.
Summary:
- Light damage (LD) induced a time-dependent increase in M1 pro-inflammatory microglial markers in the retina.
- Intravitreal TA treatment reduced LD-induced retinal inflammation, photoreceptor cell death, and vascular leakage.
- TA treatment preserved retinal responsiveness to light stimuli and shifted microglial polarization.
- TA activated the signal transducer and activator of transcription 6/arginase1 (STAT6/Arg1) pathway, suppressing M1 and promoting M2 phenotypes.
Impact:
- Reveals a novel mechanism of retinal protection by TA through microglial polarization.
- Demonstrates TA's therapeutic potential in mitigating retinal degeneration.
- Highlights the STAT6/Arg1 signaling pathway as a key mediator of TA's protective effects in the retina.
