Expression of intermediate filament in endoometrial glands changes with the onset of pregnancy and in endometriosis

Abstract

Appropriate endometrial differentiation is believed to be a prerequisite for pregnancy success. This study investigates the expression of two intermediate filament proteins, cytokeratin and vimentin, in human endometrium and first trimester decidua and in ectopic endometrium from women with endometriosis. Stromal elements, including vascular endothelial cells, were consistently vimentin-positive and cytokeratin-negative. Surface and glandular epithelial cells of human endometrium co-expressed vimentin and cytokeratin during all stages of the menstrual cycle, but failed to express vimentin after the onset of pregnancy. This suggests that intermediate filaments, and especially vimentin, may have a role to play in the proliferation and/or differentiation of the endometrial glands during decidualization. Ectopic endometrium showed a staining pattern similar to normal endometrium.