Leukocyte distribution in the pseudopregnant mouse uterus

Pleiotropic effects of Hoxa10 on the functional development of peri-implantation endometrium

Hoxa10, a homeodomain transcription factor, is dynamically expressed in adult uterine endometrium where it is necessary for embryo implantation. Endometrial Hoxa10 expression is driven by estrogen and progesterone. High levels of endometrial Hoxa10 expression coincide with high progesterone levels and development of endometrial receptivity. Although, progesterone is sufficient for endometrial differentiation and implantation, the molecular mechanisms by which progesterone mediates endometrial receptivity are not known. To determine if Hoxa10 mediates the developmental effects of progesterone in the endometrial cell compartments, we performed in vivo uterine transfection using pcDNA3.1/Hoxa10 in estrogen-primed, ovariectomized mice and compared results to mice treated with progesterone. Additional control mice were treated with either estrogen alone or empty vector pcDNA3.1. By using ovariectomized mice, we were able to determine specific developmental effects resultant from Hoxa10 treatment and distinguish them from those mediated by the regulation of multiple endogenous genes (including Hoxa10) by ovarian progesterone. Treatment with either Hoxa10 or progesterone resulted in diminished uterine weight and increased expression of characteristic cell-type specific differentiation markers such as epithelial calcitonin and stromal prolactin, suggesting that Hoxa10 likely mediates progesterone induced functional differentiation of endometrial epithelium and stroma. However, progesterone treatment suppressed endometrial eosinophil infiltration and degranulation compared to that seen with Hoxa10 treatment. Besides mediating progestational effects, Hoxa10 may activate distinct developmental pathways leading to endometrial differentiation. Functional differentiation in regenerative adult tissues may depend on timed expression of embryonic selector genes. Mol. Reprod. Dev. 67: 8-14, 2004.

Expression and regulation of chemokine genes in the mouse uterus during pregnancy

Leukocytes accumulate in the pregnant mouse uterus following mating, during implantation and during placental development. Changes in leukocyte number are primarily due to recruitment from the blood, not local proliferation, but the underlying recruitment mechanisms are poorly understood. Mating-induced granulocyte and macrophage recruitment is due in part to pro-inflammatory and chemotactic factors present in seminal plasma. Accumulation of macrophages later in pregnancy appears to be caused in part by ovarian hormone-stimulated CSF-1 production and in part by other as yet unidentified uterine chemotactic factors. The current study was performed to assess chemokine production in the uterus during pregnancy. Northern blotting was used to demonstrate NSI/KC (KC), macrophage chemotactic protein-1 (MCP-1), macrophage inflammatory protein one alpha (MIP1alpha) and regulated inactivation, normal T expressed and secreted protein (RANTES) mRNA in the uterus. Oestrogen and progesterone induced intrauterine production of all four chemokines and may have done so through the autocrine/paracrine activities of IL-1. The data suggest that C-C chemokines play a role in accumulation of macrophages in the uterus during pregnancy.

Inflammatory response in the pig uterus induced by seminal plasma

The immunological and physiological influence of seminal plasma on the local uterine environment was investigated by immunohistochemical and flow cytometrical studies on uterine tissues and lymph nodes taken from gilts after mating with a vasectomised boar and from control, unmated gilts. These studies revealed that mating with a vasectomised boar induces an acute transient inflammatory response in the endometrium resulting in marked changes in the presence and distribution of leukocytes and extensive proliferation of the endometrial glands. At the same time there was an increase in CD8L and sIg+ cells and an up-regulation of MHC class II and IL-2 receptor expression in the uterine lymph nodes of mated pigs. This would suggest that seminal plasma deposited in the uterus can activate cells in the local draining lymph nodes. Together, these results demonstrate in utero that pronounced immunological and physiological changes are induced in vivo by seminal plasma.