Abstract
Abstract: :
Purpose: In the mucosal immune system, epithelial cells comprise a physiological and immunological barrier. The ocular surface epithelium is also part of the mucosal defense; moreover, in the conjunctival sac or on the eyelid edge that contacts the ocular surface there are normal bacterial flora, including coagulase–negative staphylococci (CNS), Propionibacterium acnes and others. However, ocular surface epithelium does not respond to normal bacterial flora. On the other hand, NF–kB is well known as an important transcriptional factor related to inflammation and induced via stimulation of LPS or inflammatory cytokines such as IL–1 and TNF–a in macrophages. Moreover, it is well known that the IkB family comprises negative regulators of NF–kB. In the present study, we found the IkB family to be expressed on the ocular surface. Methods: IkB family expression was examined in mouse cornea and conjunctiva using RT–PCR. Localization of the new IkB family IkB z mRNA on the ocular surface was examined via in situ hybridization. Result: Such IkB family members as IkB a, IkB b and IkB z were expressed on mouse cornea and conjunctiva. New IkB family member IkB z mRNA was expressed on ocular surface epithelium mainly in in situ hybridization. Discussion: Healthy ocular surface epithelium is almost always free of signs of inflammation, although there are commensal bacteria on the ocular surface. It seems possible that the presence of IkB family expression contributes to the ocular surface’s unresponsiveness to commensal bacteria.
Keywords: in situ hybridization • conjunctiva • cornea: epithelium