Bimatoprost-Induced Calcium Signaling in Human T-Cells does not Involve Prostanoid FP or TP Receptors

Abstract

Purpose: The prostamide bimatoprost and prostanoid FP receptor agonists are highly efficacious drugs for glaucoma treatment. The presence of both prostamide and prostanoid FP receptors in bimatoprost-sensitive preparations has made prostamide receptor classification difficult. This study investigated a novel bimatoprost-sensitive preparation. Methods: Human peripheral blood T lymphoblasts (Molt-3) and human osteoblasts (hFOB) were cultured for intracellular calcium signaling studies and quantitative real-time PCR analysis of RNA. Results: Bimatoprost stimulated concentration-related increases in [Ca2 +]i in a human T-cell line that does not express human FP receptor/variants, according to PCR analysis. The calcium signal induced by bimatoprost was not antagonized by prostanoid FP receptor antagonist/partial agonist AL-8810 or selective TP receptor antagonist SQ 29548. Conversely, bimatoprost did not elevate [Ca2 +]i in human osteoblasts, which were confirmed to contain RNA of human FP receptor/variants. Conclusions: Molt-3 cells have been identified as a bimatoprost-sensitive preparation in which the activity of bimatoprost is independent of prostanoid FP receptors.