Abstract
Purpose: To investigate the expression of complement factors in pterygium tissues compared to normal conjunctival samples, using next-generation RNA sequencingMethods: Twenty pterygium and 20 healthy conjunctival samples were obtained from 19 patients who consented to pterygium excision and conjunctival autograft surgery. Tissues (pterygium and normal conjunctiva) were analyzed using next-generation RNA sequencing. Significant gene lists were obtained using DAVID, GSEA, and KEGG for enriched pathway analyses of differentially expressed genes. Realtime polymerase chain reaction was performed to validate differential expressions of complement factors.Results: There was 3.15 ± 2.6, 3.21 ± 4.6, 3.03 ± 1.83, 4.28 ± 6.12, and 4.96 ± 1.89-fold increase in the expression of CFH, C2, C1QB, C1QC, and MASP1, respectively, in pterygium samples compared to normal conjunctival samples. Pterygium size correlated well with the expression of CFH, C1QB, C1QC and MASP1.Conclusion: Alternative and lectin complement systems are activated in pterygia samples compared to normal conjunctival samples.Keywords: Pterygium; Complement factor; RNA sequencing
Highlights
Pterygium is an overgrowth of fibrovascular tissue, with a winglike appearance, from the conjunctiva over the cornea [1,2]
We studied the differentially expressed genes using RNA sequencing in eight pterygium samples and their matched healthy conjunctival samples
We found that complement factor H (CFH), C1QA, C1QB, and C1QC were differentially expressed between pterygium and matched conjunctival samples (Table 2) and they were clustered in the complement system
Summary
Pterygium is an overgrowth of fibrovascular tissue, with a winglike appearance, from the conjunctiva over the cornea [1,2]. Several theories on its pathogenesis have been postulated, including immunological mechanisms, infection, and ultraviolet exposure [3,4,5], the definitive cause of pterygium is still not known. Some studies reported that immunological mechanisms such as type 1, 3, and 4 hypersensitivities might contribute to its pathogenesis, and large numbers of infiltrating lymphocytes, predominantly T-cells (CD3+), have been found in the substantia propria of pterygium specimens [6,7]. Complement activation products mediate immune reactions and the expression of many inflammatory cytokines [8,9,10], and the complement pathway has been related with the pathogenesis of many diseases. Variants in several genes, such as complement 2 (C2), complement 3 (C3), complement factor H (CFH), and complement factor B (CFB), encoding complement pathway proteins, have been associated with age-related macular degeneration [11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
