Transforming growth factor-beta isoforms and receptors in endometriotic cysts of the human ovary

PROBLEM: The present study examined the presence and cellular distribution of transforming growth factor-beta 1, 2, and 3 isoforms and their type I an d II receptors in endometriotic cysts of the ovary, relative to their prese nce in normal endometrial tissue. METHOD OF STUDY: Thirteen control samples of normal endometrium in the prol iferative phase and 11 ovarian endometriotic cysts were examined by immunoh istochemistry for transforming growth factor-beta 1, 2, and 3 isoforms and their type I and II receptors. RESULTS: Immunoreactivity for all ligands and receptors was detected in bot h normal endometrium and endometriotic cysts. Isoform-specific differences in immunostaining were not detected. Expression of all ligands and receptor s was significantly increased in epithelial cells of endometriotic cysts co mpared with those of normal endometrium. On the other hand, stromal cells i n normal endometrium and endometriotic cysts were only faintly immunostaine d. Inflammatory cells infiltrating among endometriotic stromal cells contai ned the highest immunostaining intensity for all ligands and receptors. We identified nearly all inflammatory cells as macrophages using a specific an tibody. CONCLUSIONS: These findings suggest that macrophages in endometriotic tissu e are a major source of transforming growth factor-beta, which may be an im portant regulator of cell proliferation in endometriotic cysts through para crine and autocrine actions.