Sodium Iodate-Induced Degeneration Results in Local Complement Changes and Inflammatory Processes in Murine Retina

Area of Science:

• Ophthalmology
• Neuroscience
• Immunology

Background:

• Age-related macular degeneration (AMD) is a leading cause of blindness, with no current treatment for the dry form (geographic atrophy).
• Understanding the pathology of geographic atrophy is crucial for developing effective therapies.

Purpose of the Study:

• To investigate the molecular and cellular mechanisms underlying retinal degeneration in a mouse model of geographic atrophy induced by sodium iodate (NaIO3).
• To identify key pathways involved in NaIO3-induced retinal pigment epithelium (RPE) atrophy.

Main Methods:

• Induction of RPE atrophy using NaIO3 in a mouse model.
• Analysis of retinal tissue using RNA sequencing (RNA-seq), qRT-PCR, Western blot, and immunohistochemistry.
• Multiplex ELISA was used to analyze mouse serum.

Main Results:

• NaIO3 treatment caused RPE loss and photoreceptor thinning, characteristic of geographic atrophy.
• Retinal expression and deposition of complement components (C1s, C3, CFH, CFB) were significantly increased.
• Pro-inflammatory mediators (CCL2, CCL3, CCL5, IL-1β, IL-33, TGF-β) were upregulated, while VEGF-A mRNA was reduced.
• Macrophages, microglia, and Müller cells were identified as potential sources of local inflammation.

Conclusions:

• Systemic NaIO3 administration effectively models key degenerative and inflammatory aspects of geographic atrophy.
• The study highlights the involvement of the complement system and inflammatory pathways in RPE degeneration.
• This mouse model provides a valuable tool for studying dry AMD and testing potential therapeutic interventions.