Potential apoptotic effect of ultraviolet-A irradiation during cross-linking: a study on ex vivo cultivated limbal epithelial cells. Issue 10 (1st September 2012)

• Record Type: Journal Article
• Authors: Matalia, Himanshu; Shetty, Rohit; Dhamodaran, Kamesh; Subramani, Murali; Arokiaraj, Vincent; Das, Debashish
• Is Part Of: British journal of ophthalmology. Volume 96:Issue 10(2012)
• Page Start: 1339
• Page End: 1345
• Publication Date: 2012-09-01
• Subjects: Stem Cells -- Biochemistry -- Cornea; Ophthalmology -- Periodicals; 617.7
• DOI: 10.1136/bjophthalmol-2012-301811
• Languages: English
• ISSNs: 0007-1161

Abstract

Abstract : Aim/background: To study the effects of ultraviolet-A (UV-A) irradiation, in the presence or absence of riboflavin, on ex vivo cultured limbal epithelial cells (LECs). Methods: The study was carried out in a super specialty ophthalmic hospital. Ex vivo cultured LECs were grown on denuded amniotic membranes and exposed to similar levels of UV-A radiation used during corneal cross-linking (CXL), in the presence or absence of the photosensitiser, riboflavin. These cells were then used for extraction of RNA, cDNA conversion, and antibody staining. Quantitative PCR and immunofluorescence staining were performed to evaluate the apoptotic state of treated and non-treated LECs. Statistical analyses were evaluated using a Student's t test. Results: We found that bcl-2, an antiapoptotic gene, was downregulated, whereas, bax, a proapoptotic gene, was upregulated. After LECs were exposed to UV-A radiation, a significant upregulation of both caspase 3 and caspase 9 was observed in treated cells when compared with untreated LECs. Conclusions: These results indicate that exposure of LECs to UV-A dosages similar to those used in the CXL procedure promotes the expression of genes known to promote apoptosis. In the presence of riboflavin, the damage caused by UV-A treatment was marginalised, but not totally blocked.