Abstract
Complement factor H (CFH) is a central regulator of the complement system and has been implicated in the etiology of age-related macular degeneration (AMD), a leading cause of blindness in the elderly. In view of previous studies showing that reduced expression of CFH in the retina is a risk factor for developing AMD, there is significant interest in understanding how CFH expression is regulated in the retina. In this study, we have shown that the anti-inflammatory cytokine, IL-27, induced CFH expression in mouse retinal cells and human retinal pigmented epithelial cells (RPE) through STAT1-mediated up-regulation of Interferon Regulatory Factor-1 (IRF-1) and IRF-8. We further show that cells in the ganglion and inner-nuclear layers of the retina constitutively express IRF-1 and IRF-8 and enhanced CFH expression in the retina during ocular inflammation correlated with significant increase in the expression of IRF-1, IRF-8 and IL-27 (IL-27p28 and Ebi3). Our data thus reveal a novel role of IL-27 in regulating complement activation through up-regulation of CFH and suggest that defects in IL-27 signaling or expression may contribute to the reduction of CFH expression in the retina of patients with AMD.
Original language | English |
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Pages (from-to) | e45801 |
Number of pages | 9 |
Journal | PloS ONE |
Volume | 7 |
Issue number | 9 |
Early online date | 20 Sep 2012 |
DOIs | |
Publication status | Published - 20 Sep 2012 |
Keywords
- Animals
- Cells, Cultured
- Complement Factor H/genetics
- Gene Expression
- Humans
- Interferon Regulatory Factor-1/genetics
- Interferon Regulatory Factors/genetics
- Interleukins/genetics
- Macular Degeneration/metabolism
- Mice
- Mice, Inbred C57BL
- Papilledema/metabolism
- Primary Cell Culture
- Retina/metabolism
- Retinal Ganglion Cells/metabolism
- Retinal Photoreceptor Cell Inner Segment/metabolism
- Retinal Vasculitis/metabolism
- STAT1 Transcription Factor/metabolism
- Transcriptional Activation
- Uveitis/metabolism