Abstract
Purpose :
Purpose- Non-infectious uveitis (NIU) is a complex disease characterized by intraocular inflammation of the uveal tract. However, what triggers the inflammation and contributes to its recurrence remains unclear. Complement system has been linked to various immunological and inflammatory conditions such as rheumatoid arthritis and retinal degenerative diseases etc. In the present study, we have systematically evaluated the role of the alternate complement pathway in the pathogenesis of NIU.
Methods :
Methods- Multiplex ELISA was performed in the aqueous humor (AqH) of NIU, infectious uveitis (IU) patients and controls (N=10) in each category to investigate the role of major alternate complement pathway proteins like C3, factor B and CFH. Western blotting was performed to validate these results in the AqH and vitreous humor (vitH) of NIU patients (n=15) in each category. Their gene expression was also assessed by q PCR in both anterior and posterior non-infectious uveitis vs. controls (N=10). Besides, the expression of hsa-miRNA-146 and hsa-miRNA-155 that regulate CFH, was also evaluated. (N=10). Statistical significance was calculated using ANOVA with a p value<0.05 considered significant.
Results :
Results- On Multiplex ELISA analysis, both IU and NIU showed significant increase (p-value <0.05 and fold change (FC) >2) in the C3 and CFH proteins in AqH samples as compared to controls which was further confirmed by western blotting. However, in the VitH, only C3 protein was significantly increased as compared to controls with p-value <0.05 while, the CFH was downregulated. At mRNA level, C3 (FC -4.4; *p = 0.04) and CFH genes (FC -1.6 p = 0.5) were significantly downregulated in anterior uveitis (AU), however both were upregulated among PU though the differences were not statistically significant. Both miRNAs (hsa-miRNA146 and has-miRNA155) were downregulated in both the categories [ hsa-miR-146 (AU vs control; FC -2.8; *p-value = 0.03; PU vs control; FC -3.3 *p- value = 0.05) and hsa-miR155 (AU vs control; FC -2.1 p = 0.2; PU vs. control FC -4.2 p = 0.4)].
Conclusions :
Conclusion- The systematic approach adopted in the present study confirmed the involvement of alternative complement pathway in the noninfectious uveitis. Dysregulation in hsa-miR-155 and has-miR-146 seems to contribute to the activation of alternative complement pathway leading to inflammation and disease pathogenesis.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.