Altered gene expression and secretion of interleukin-6 in stromal cells derived from endometriotic tissues

Objective: To compare the expression of interleukin-6 (IL-6) in endometrial and endometriotic cells. Design: Prospective study. Setting: Department of Obstetrics and Gynecology, Tottori University Hospit al, Yonago, Japan. Patient(s): Twenty patients who underwent either hysterectomy or laparoscop ic surgery. Intervention(s): Endometrial and endometriotic stromal cells were obtained from normal endometrium and from chocolate cyst linings of the ovary. Perit oneal macrophages were isolated from peritoneal fluids. Cells were cultured in the presence or absence of tumor necrosis factor-alpha. Main Outcome Measure(s): Gene expression of IL-6 was examined by Northern b lot analysis. Interleukin-6 protein production was examined by immunocytoch emical staining and ELISA. Result(s): A single IL-6 messenger RNA band of approximately 1.3 kilobases was detected in endometriotic stromal cells. Tumor necrosis factor-alpha in creased the expression of IL-6 messenger RNA in endometriotic cells in a do se-dependent manner. In endometrial stromal cells, IL-6 messenger RNA signa ls were much weaker. Endometriotic stromal cells produced significantly lar ger amounts of IL-6 compared with endometrial stromal cells under basal con ditions and after stimulation with tumor necrosis factor-alpha. Interleukin -6 protein was detected in cells isolated from endometriotic tissues by imm unocytochemical staining. Interleukin-6 production by cultured macrophages from patients with endometriosis and endometriotic stromal cells was compar able. Conclusion(s): Altered gene expression and protein secretion of IL-6 in pat ients with endometriosis may contribute to the pathogenesis of the disease and/or to endometriosis-associated infertility. (Fertil Steril(R) 2000; 73: 205-11. (C) 2000 by American Society for Reproductive Medicine.)