Exploring the involvement of the alternative complement pathway in non-infectious uveitis pathogenesis

Area of Science:

• Ophthalmology
• Immunology
• Molecular Biology

Background:

• Non-infectious uveitis is a leading cause of vision loss globally, characterized by intraocular inflammation.
• The triggers and recurrence factors of non-infectious uveitis remain largely unknown.
• The complement system is implicated in various inflammatory conditions.

Purpose of the Study:

• To investigate the role of the alternative complement pathway in the pathogenesis of non-infectious uveitis.
• To analyze the expression of complement components and regulatory microRNAs in uveitis patients.

Main Methods:

• Quantitative PCR was used to assess gene and microRNA expression in peripheral leukocytes of anterior and posterior uveitis patients.
• Multiplex ELISA measured complement components (C3b, factor B, CFH) in aqueous humor.
• Western blotting validated ELISA findings in aqueous and vitreous humor.

Main Results:

• Downregulation of C3 and CFH mRNA was observed in anterior uveitis, with opposite findings in posterior uveitis.
• Elevated C3b and CFH protein levels were detected in the aqueous humor of uveitis patients compared to controls.
• Increased C3b to CFH ratio and downregulated miR-146a and miR-155-5p were observed in uveitis patients, correlating with complement activation.

Conclusions:

• The alternative complement pathway, specifically factor H, is involved in the pathogenesis of non-infectious uveitis.
• Findings suggest a potential link between complement dysregulation and disease development.
• Further research is needed to explore the therapeutic potential of targeting this pathway.