Endometriosis is generally associated with an immunoinflammatory process that takes place in the peritoneal cavity of patients. Interleukin (IL)-6, a multifunctional cytokine involved in numerous immunological and proliferative processes, has been found at high concentrations in the peritoneal fluid of endometriosis patients. The purpose of this study was to investigate the ability of endometriotic cells to produce IL-y and to assess the regulation of its secretion by proinflammatory cytokines and sex steroids. Cultures of human endometriotic cells were exposed to different concentrations of cytokines and sex steroid hormones for varying periods of time. IL-6 secretion was measured using an enzyme-linked immunosorbent assay. Endometriotic cells spontaneously released IL-6 in culture. IL-1 beta and tumour necrosis factor (TNF)-alpha (0.1-100.0 ng/ ml) potentiated IL-y secretion in a time- and dose-dependent manner. Interferon-gamma (0.4-400 ng/ml) induced a dose-related increase in IL-6 secretion and showed a synergistic effect on that secretion in combination with TNF-alpha (10 ng/ ml). Either spontaneous or cytokine-induced IL-6 secretion was inhibited by progesterone (10(-8)-10(-5) M) and danazol (10(-6) M), whereas oestradiol (10(-8)-10(-5) M) had a limited inhibitory effect. The antiprogestin RU486 (10(-8)-10(-4) M) antagonized the inhibitory effects of progesterone and danazol, but showed agonist action when used alone. These findings indicate that endometriotic tissue may actively contribute to the biological changes observed in the peritoneal fluid of endometriosis patients. They also provide new insights into the mechanisms of action of progesterone and those of danazol and RU486 used in the treatment of endometriosis.
The kinin B(1) receptor (B(1)R) gene is strongly upregulated following tissue injury and inflammation. In an attempt to define the regulatory elements that account for the control of B(1)R gene expression, we have conducted in vivo footprinting analysis of the B(1)R gene promoter region in three human cell types: embryonic lung fibroblast cells (IMR-90), embryonic kidney cells (HEK-293), and primary cultures of vascular umbilical smooth muscle cells. Initial in vitro delineation of the B(1)R gene promoter by transient transfection experiments with a reporter gene indicated that a 1.4-kb region, located just upstream of the transcription initiation site, bears all the characteristics of a core promoter with a functional TATA box and additional positive and negative control elements, as some of them could be tissue-specific. In vivo ultraviolet and dimethylsulfate footprinting analyses of the 1.4-kb region revealed no difference between the footprint patterns in the three cell types studied. We found that even in the noninduced state, the B(1)R gene promoter is possibly bound by several sequence-specific DNA binding proteins (GATA-1, PEA3, AP-1, CAAT, Sp1, Pit-1a, Oct-1, CREB). Some other footprints were detected on sequences that do not correspond to any known transcription factor binding site. No additional changes in protein-DNA complexes were observed upon treatment with interleukin-1 beta (IL-1beta) or bacterial lipopolysaccharide, shown previously to induce B(1)R gene expression. These results indicate that complex protein-DNA interactions exist at the B(1)R gene promoter prior to induction by external stimuli even in cells (HEK-293) that do not express a functional B(1)R.
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