Cytokine and Complement Response in the Glaucomatous βB1-CTGF Mouse Model.

Area of Science:

• Ophthalmology
• Immunology
• Neuroscience

Background:

• Glaucoma is a neurodegenerative disease causing retinal ganglion cell (RGC) and optic nerve axon loss.
• Complement system activation is implicated in RGC cell death in glaucoma.
• The βB1-CTGF mouse model exhibits elevated intraocular pressure and RGC loss.

Purpose of the Study:

• To investigate the initiation of the complement system and cytokine response in the βB1-CTGF glaucoma mouse model.
• To analyze complement factor expression and cytokine profiles in relation to RGC loss.

Main Methods:

• Quantitative real-time PCR and immunohistological experiments were conducted on βB1-CTGF mice and wildtypes (WT) at 5, 10, and 15 weeks of age.
• Expression levels of complement system components (C3, Hc, C5ar, C5ar1, C1q) and cytokines (Infg, Cxcl1, Cxcl2, Cxcl10) were analyzed.

Main Results:

• Upregulation of terminal complement pathway components (C3, Hc) and C5a receptor (C5ar, C5ar1) mRNA was observed in βB1-CTGF mice.
• Increased C3+ and membrane attack complex+ cells were detected in transgenic retinas.
• All three complement activation pathways were elevated, with significant C1q increase (classical pathway) at all ages.
• Upregulation of interferon-γ (Infg), Cxcl1, Cxcl2, and Cxcl10 mRNA indicated a pro-inflammatory cytokine response.

Conclusions:

• Complement activation, primarily via the classical pathway, and a distinct cytokine response are key contributors to RGC cell death in the βB1-CTGF mouse model.
• These findings highlight the role of the complement system and inflammatory cytokines in glaucoma pathogenesis.
• The study provides insights into the molecular mechanisms underlying glaucoma progression.