GROWTH-FACTOR EFFECTS ON ENDOMETRIAL EPITHELIAL-CELL DIFFERENTIATION AND PROTEIN-SYNTHESIS IN-VITRO

Objective: To develop a baseline for projected studies of a rat endome triosis model. Design: We investigated the effects of two macrophage-r elated growth factors, platelet-derived growth factor (PDGF) and trans forming growth factor-beta (TGF-beta), on proliferation, in vitro diff erentiation, and protein secretion of uterine epithelial cells from im mature rats. Uterine epithelial cells grown on matrix covered filters were treated with growth factors (GFs) or estrogen and/or P. Incorpora tion of [S-35]methionine by polarized uterine epithelial cell proteins and secretion of labeled proteins into apical and basal culture mediu m were examined. Setting: Department of Cell Biology, Baylor College o f Medicine, Houston, Texas. Main Outcome Measures: Cell associated and secreted proteins were resolved by gel electrophoresis, fluorography, and immunoblotting. Proliferation was quantified by cell counts in pa rallel cultures by hemocytometer. Results: Estrogen and P increase pro tein synthesis by uterine epithelium. Transforming growth factor-beta depressed protein synthesis and secretion in uterine epithelial cells. Platelet-derived growth factor appears to have no effect on epithelia l protein synthesis or secretion and does not modulate the effect of T GF-beta. Estrogen and P increase complement component 3 (C3) productio n by epithelial cells. Conclusion: Macrophage-secreted GFs may play a role in the development and maintenance of ectopic endometrial tissue. Both TGF-beta and ovarian steroids may participate in the dynamic reg ulation of protein synthesis by ectopic uterine epithelium. These mole cules may indirectly affect the macrophage-stromal axis through nonspe cific modulation of C3 secretion. Platelet-derived growth factor appea rs to have no direct effect on uterine epithelial cells. The recognize d effect of PDGF on ectopic endometrial tissue is most likely mediated via the stromal component.