The Role of 2% Rebamipide Eye Drops Related to Conjunctival Differentiation in Superoxide Dismutase-1 (Sod1) Knockout Mice

Abstract

Citation: Kojima T, Simsek C, Igarashi A, et al. The role of 2% rebamipide eye drops related to conjunctival differentiation in superoxide dismutase-1 (Sod1) knockout mice. Invest Ophthalmol Vis Sci. 2018;59:1675-1681. https://doi.org/10.1167/iovs.17-23213 PURPOSE. The superoxide dismutase-1 knockout (Sod1 À/À ) mouse is an age-related dry eye mouse model. We evaluated the role of 2% rebamipide ophthalmic solution on the conjunctiva and ocular surface alterations in Sod1 À/À mice. METHODS.Rebamipide eye drops (2%) were instilled in six 50-week-old male Sod1 À/À mice and six C57BL/6 strain wild-type (WT) male mice four times a day for 2 weeks. Aqueous tear secretion quantity and tear film breakup time measurements as well as vital stainings were performed. Immunohistochemistry staining of the conjunctiva was performed using SAM pointed domain-containing ETS transcription factor (SPDEF), transglutaminase-1, and involucrin antibodies. Quantitative RT-PCR was carried out to study mRNA expression of the same markers.RESULTS. The mean tear quantities showed no significant changes in both mice strains after treatment (P ¼ 0.24). The mean tear film breakup time (P ¼ 0.003) and vital staining scores significantly improved in the Sod1 À/À mice after treatment. Treatment with 2% rebamipide eye drops significantly decreased the corneal fluorescein (P ¼ 0.0093) and Rose Bengal (P ¼ 0.002) staining scores in the Sod1 À/À mice. We showed a notable increase in SPDEF and a marked decrease in transglutaminase-1 and involucrin immunohistochemistry stainings, together with a significant increase in SPDEF (P ¼ 0.0003) and a significant decline in transglutaminase-1 (P ¼ 0.0072) and involucrin (P ¼ 0.009) mRNA expression after treatment in the Sod1 À/À mice.CONCLUSIONS. Topical use of 2% rebamipide drops was observed to improve conjunctival epithelial differentiation and suppress keratinization in the Sod1 À/À mice.

The Efficacy of 2% Topical Rebamipide on Conjunctival Squamous Metaplasia and Goblet Cell Density in Dry Eye Disease

“…It has been reported that topical administration of rebamipide significantly improves symptoms, corneal fluorescein staining, conjunctival lissamine green staining, and tear film breakup time in DED. 7,10,17 Previous animal studies have shown that rebamipide instillation also improved ocular surface epithelial differentiation with a FIG. 2.…”

“…*Represents P < 0.05, **Represents P < 0.01. reduction in keratinization. 10 Additionally, Kinoshita et al have shown that even short-term rebamipide instillation has favorable therapeutic effects on corneal staining scores. Moreover, they also have demonstrated that administration of rebamipide ophthalmic solution results in significant improvement in both the objective signs and subjective symptoms of DED.…”

“…39,40 Previous human and animal studies demonstrated that rebamipide increases the density of periodic acid-Schiff-positive goblet cells and mucin levels in the cornea and conjunctival epithelial cells. 2,6,10,41 Additionally, Ohguchi et al demonstrated that 2% rebamipide application increased the goblet cell density as well as Muc5AC mRNA expression in an SOD1 knockout mouse model. 5 The mean of the goblet cell density along with corneal epithelial cell density showed a notable increase with 2% rebamipide application in this study and this result was consistent with findings of previous studies Our study is the initial investigation looking into cytological changes at the ocular surface by employing impression cytology and in vivo confocal microscopy.…”

“…4,6,8 Experimental studies after 2011 disclosed effects related to improvement of the ocular surface ultrastructural environment, increased secretion of membrane-bound mucins, and improvement of the epithelial barrier. [9][10][11] Squamous metaplasia of the keratoconjunctival epithelium, loss of goblet cells, and lid wiper epitheliopathy (LWE) have been demonstrated to be associated with DED. [12][13][14][15][16] Additionally, squamous metaplasia resulting from disturbances in healthy epithelial differentiation has been already reported in dry eye patients.…”

The Effects of Rebamipide 2% Ophthalmic Solution Application on Murine Subbasal Corneal Nerves After Environmental Dry Eye Stress

“…Although the effects of rebamipide eye drops on the ocular surface epithelium, tear function, and the conjunctiva have been investigated previously [14,15,20,21,22], its effects on corneal subbasal nerves have not yet been examined. Moreover, there is a paucity of studies which have evaluated rebamipide eye drops in VDT animal models.…”