UNASSIGNED: @entity1 and @entity19 endometrium undergo dramatic cellular reorganization during pregnancy and postpartum. Somatic stem cells maintain homeostasis of the tissue by providing a cell reservoir for regeneration. We hypothesized that endometrial cells with quiescent properties (stem/progenitor cells) were involved in the regeneration of the endometrial tissue. Given that stem cells divide infrequently, they can retain the DNA synthesis label [ @entity1603 ( @entity1603 )] after a prolonged chase period. In this study, prepubertal @entity19 were pulsed with @entity1603 and after a 6-week chase a small population of label-retaining stromal cells (LRSC) was located primarily beneath the luminal epithelium, adjacent to blood vessels, and near the endometrial-myometrial junction. Marker analyses suggested that they were of mesenchymal origin expressing @entity3844 (+), @entity3512 (+), @entity5232 (+), CD146(+), and @entity17776 (+). During pregnancy, nonproliferating LRSC predominately resided at the interimplantation/placental loci of the gestational endometrium. Immediately after parturition, a significant portion of the LRSC underwent proliferation ( @entity1603 (+)/Ki-67(+)) and expressed total and active b-catenin. The b-catenin expression in the LRSC was transiently elevated at @entity227 ( @entity227 ) 1. The proliferation of LRSC resulted in a significant decline in the proportion of LRSC in the postpartum uterus. The LRSC returned to dormancy at PPD7, and the percentage of LRSC remained stable thereafter until 11 weeks. This study demonstrated that LRSC can respond efficiently to physiological stimuli upon initiation of uterine involution and return to its quiescent state after postpartum repair.

Label-Retaining Stromal Cells in XXXX Endometrium Awaken for Expansion and Repair After Parturition.

@entity1 :: ('9606', 'Species') :: ['Human'] @entity1603 :: ('MESH:D001973', 'Chemical') :: ['BrdU', 'bromodeoxyuridine'] @entity17776 :: ('20238(Tax:10090)', 'Gene') :: ['Sca-1'] @entity227 :: ('MESH:D014786', 'Disease') :: ['PPD', 'postpartum day'] @entity19 :: ('10090', 'Species') :: ['mice', 'mouse'] @entity3512 :: ('21838(Tax:10090)', 'Gene') :: ['CD90'] @entity5232 :: ('18596(Tax:10090)', 'Gene') :: ['CD140b'] @entity3844 :: ('12505(Tax:10090)', 'Gene') :: ['CD44']
@entity19 :: (10090,Species) :: ['Mouse']
