Toll-Like Receptors in InflammAging at Ocular Surface.

Abstract

Purpose: To evaluate changes in Toll Like Receptors expression at the ocular surface of healthy control volunteers within age. Methods: 51 volunteers were enrolled in a pilot observational study. Clinical (OSDI questionnaire, Schirmer test and BUT) and Biomolecular (ICAM1, Goblet cells) biomarkers were assessed in all subjects. Temporal Conjunctival imprints were used for molecular analysis while nasal ones were harvested for epifluorescence microscopy. Results: Within the age in our sample OSDI score increases, T-BUT values decrease, and goblet cells showed a decreasing trend. Relative real time PCR detected up-regulation of TLR2 and down-regulation of TLR7, TLR8 and MyD88 transcripts. Immunofluorescence data corroborated the PCR results reporting increased TLR2 and decreased TLR7 and TLR8 expression in elder population. A direct correlation was showed between increasing ICAM and increasing TLR2 changes with age. Conclusion: Changes in TLR expression are associated with aging, suggesting physiological role of TLRs in modulating innate and adaptive ocular surface immunity. TLRs age related changes may participate to the failure of ocular surface homeostatic mechanisms with inflammAging.