Project description:The identification of a marker that is expressed in the conjunctival epithelium but not in the corneal epithelium has been a growing need. A more specific marker of limbal and conjunctival epithelia would be necessary to detect non-corneal epithelial cells on the corneal surface. To search for conjunctival specific marker(s), we first performed preferential gene profiling in the conjunctiva in direct comparison to that in the cornea using microarray technique.
Project description:The identification of a marker that is expressed in the conjunctival epithelium but not in the corneal epithelium has been a growing need. A more specific marker of limbal and conjunctival epithelia would be necessary to detect non-corneal epithelial cells on the corneal surface. To search for conjunctival specific marker(s), we first performed preferential gene profiling in the conjunctiva in direct comparison to that in the cornea using microarray technique. The study consisted of gene expression profiles comparing the cornea and conjunctiva.
Project description:Purpose: To investigate the mechanism for developing dry eye disease in the Pinkie mouse strain with a loss of function RXR mutation. Methods: Measures of dry eye disease were assessed in the cornea and conjunctiva. Expression profiling by single-cell RNA sequencing (scRNA-seq)was performed to compare gene expression in conjunctival immune cells. Conjunctival immune cells were immunophenotyped by flow cytometry and confocal microscopy. Activity of RXR ligand 9-cis retinoic acid (RA) was evaluated in cultured monocytes and T cells. Results: Compared to wild type (WT) C57BL/6, Pinkie has increased signs of dry eye disease, including corneal barrier disruption, conjunctival cornification and goblet cell loss, and corneal vascularization, opacification, and ulceration with aging. scRNA-seq of conjunctival immune cells identified T cells as the predominant IL-17 expressing population in both strains and there is a 4-fold increased percentage of T cells in Pinkie. Compared to WT, significantly increased expression of IL-17a and IL-17f in conventional T cells and IL-17f in T cells was found in Pinkie. Flow cytometry and immunostaining revealed an increased number of IL-17+ T cells in Pinkie. Tear concentration of the IL-17 inducer IL-23 is significantly higher in Pinkie. 9-cis RA treatment suppresses stimulated IL-17 production by T and stimulatory activity of monocyte supernatant on T cell IL-17 production. Compared to WT bone marrow chimeras, Pinkie chimeras have increased IL-17+ T cells in the conjunctiva after desiccating stress and anti-IL-17 treatment suppresses dry eye induced corneal MMP-9 production/activity and conjunctival goblet cell loss. Conclusion: These findings indicate that RXR suppresses generation of dry eye disease inducing T17 cells in the conjunctiva and identifies RXR as a potential therapeutic target in dry eye.