Efficacy of trabodenoson in a mouse keratoconjunctivitis sicca (KCS) model for dry-eye syndrome

Abstract

PURPOSE. To determine the efficacy of trabodenoson, an adenosine mimetic with highly selective adenosine A 1 receptor binding properties, in a preclinical mouse model for dry-eye disease. METHODS. Dry-eye disease was induced in adult male C57BL/6 mice using a combination of desiccating environment and transdermal administration of scopolamine. Mice were treated concurrently and twice daily with either vehicle, 6% trabodenoson, or 0.05% cyclosporine (Restasis). Efficacy (P <0.05 versus vehicle) was determined by clinical assessment of dry-eye symptoms using corneal fluorescein staining and tear volumes and histopathologically by quantifying lacrimal gland pathology and conjunctival goblet cells. RESULTS. Twice-daily topical (ocular) administration of trabodenoson increased tear levels and reduced corneal fluorescein staining (P <0.05) as compared with vehicle-treated eyes in a mouse model of dry-eye disease. Furthermore, significant infiltration of immune cells in the lacrimal gland and reduced number of mucin-producing conjunctival goblet cells were noted in both untreated and vehicle-treated eyes. Comparatively, trabodenoson treatment significantly reduced lacrimal gland infiltration and increased the number of goblet cells (P <0.05 for both versus vehicle). These trabodenoson-related effects on lacrimal gland pathology and goblet cells were similar to or better than the effects observed with cyclosporine treatment. CONCLUSIONS. Topical ocular delivery of trabodenoson significantly improves the clinical and histopathological signs associated with dry-eye disease in mice. This improvement appears to be related to anti-inflammatory effects from targeting adenosine signaling and represents a novel therapeutic approach to develop for the management of dry-eye disease.