Relationship Between Toll‐like Receptor‐4 and mPGES‐1 Gene Expression in Local Lesions of Endometriosis Patients

Abstract

Toll-like receptors (TLRs) are innate immune receptors that mediate the pattern recognition of, and response toward, pathogens and host-derived danger signals. We reported that cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase (mPGES) mRNA were expressed in cases of endometriosis. The relationship between COX-2, mPGES-1, and TLR4 in endometriotic lesions has yet to be determined. Endometriosis samples were obtained from 37 patients with endometrial cysts. Endometrial tissues were obtained from patients undergoing surgical procedures for benign gynecological conditions. COX-2, mPGES-1, and TLR4 mRNA expressions were examined by real-time quantitative reverse transcription PCR (qRT-PCR) and mPGES-1, and TLR4 protein localization was examined by immunohistochemistry. TLR4 proteins were mostly located to the glandular epithelium. The immunoreactivities of TLR4 and mPGES-1 from endometriosis lesions were significantly higher than those in eutopic endometrium in the proliferative phase. The expression levels of mPGES-1 mRNA in peritoneal endometriosis were higher than those in eutopic endometrium in the proliferative phase. The expression of TLR4 mRNA correlates with that of mPGES-1 mRNA and not with that of COX-2 in endometriotic lesions. Relationship between TLR4 and mPGES-1 mRNA in endometriotic lesions indicate that innate immunity may play an important role in the pathogenesis of endometriosis.