Immunohistochemical Localization of Prostaglandin E receptor Subtypes and Prostaglandin E synthase - 1 Within Synovium of Patients with Joint Trauma, Osteoarthritis, and Rheumatoid Arthritis.

Abstract

Synovium membrane can become irritated and thickened in inflammatory conditions such as rheumatoid arthritis. Prostaglandins are involved in the inflammatory response, PGE; receptors have been classified into four subtypes, designated the EP 1, EP2, EP3, and EP4 receptors. In addition, microsomal prostaglandin E2 synthase-1 (1nPGES-1) is induced by proinflammatoiy mediators and is down-regulated by glucocorticoids in various cells. Although, there is a growing body of data suggesting that PGE2 are implicated in arthritic diseases via its receptors, the exact cell types and disease-specific differences in the occurrence of EP receptors subtypes have not been examined so far. In the present study, we have (28) samples, were taken from (28) patients ( 9 patients with RA, 9 patients with OA, and 10 patients with JT). Light immunohistochemistry and immunoflourescence confocal microscopy analysis revealed that EPl, EP2, EP3, EP4 were expressed mostly by macrophage-like (CD68+) and fibroblast-like (P4PF) cells within synovium tissue of IT patients. However, in synovial tissue from OA patients, these receptor subtypes were mostly expressed by fibroblast-like (P4H+) cells. In synovial tissue from RA patients, these receptor subtypes were mostly expressed by fibroblast-like (P4}F) and plasma cells. Parallel to the severity