Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Up-regulation of endometrial oxytocin receptor (OTR) expression followed by an increase in pulsatile endometrial prostaglandin (PG) F(2alpha) secretion causes luteolysis in cattle. Inhibition of luteolysis is essential for the maternal recognition of pregnancy but also occurs in association with endometritis. The factors regulating OTR expression at this time are unclear. The OTR gene promoter region contains binding elements for acute phase proteins but their function has not been established. This study investigated the effects of various cytokines on OTR expression and on PGF(2alpha) and PGE(2) production in explant cultures of bovine endometrium. Endometrium was collected in the late luteal phase (mean day of cycle 15.4+/-0.50) or early luteolysis (mean day of cycle 16.4+/-0.24) as determined by the initial concentration of endometrial OTR. Explants were treated for 48 h with: (i) lipopolysaccharide (LPS) and/or dexamethasone (DEX), (ii) ovine interferon-tau (oIFN-tau), or (iii) human recombinant interleukin (IL)-1alpha, -2 or -6. OTR mRNA was then measured in the explants by in situ hybridisation and the medium was collected for measurement of PGF(2alpha) and PGE(2) by RIA. LPS treatment stimulated production of PGF(2alpha), whereas DEX either alone or in combination with LPS was inhibitory to both PGF(2alpha) and PGE(2). Neither of these treatments altered OTR mRNA expression. oIFN-tau reduced OTR mRNA expression but stimulated production of both PGF(2alpha) and PGE(2). In endometrial samples collected in the late luteal phase, IL-1alpha, -2 and -6 all inhibited OTR mRNA expression, but IL-1alpha and -2 both stimulated PGF(2alpha) production. In contrast, when endometrium was collected in early luteolysis, none of the interleukins altered OTR expression or caused a significant stimulation of PGF(2alpha) production but IL-2 increased PGE(2). Neither IL-1alpha nor -2 altered OTR promoter activity in Chinese hamster ovary cells transfected with a bovine OTR promoter/chloramphenicol acetyl transferase reporter gene construct. In conclusion, the action of interleukins on both OTR mRNA expression and endometrial prostaglandin production alters around luteolysis. Pro-inflammatory interleukins suppress OTR expression in the late luteal phase, while LPS stimulates PGF(2alpha) without altering OTR mRNA expression. IL-I and -2 and LPS are therefore unlikely to initiate luteolysis but may cause raised production of PGF(2alpha) during uterine infection.
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PMID:The effects of lipopolysaccharide and interleukins-1alpha, -2 and -6 on oxytocin receptor expression and prostaglandin production in bovine endometrium. 1124 Nov 81

Natural killer (NK) cells are essential for establishment of human and rodent pregnancies. The function of these and other cytotoxic T cells (CTL) is controlled by stimulatory and inhibitory signaling. A role for cytotoxic cells during early pregnancy in cattle has not been described, but regulation of their function at the fetal-maternal interface is thought to be critical for conceptus survival. The hypothesis that the relative abundance of CTL and expression of inhibitory signaling molecules is increased by the conceptus during early pregnancy was tested. The proportions of lymphoid lineage cells and expression of inhibitory signaling molecules in the endometrium during early pregnancy in dairy heifers were determined using flow cytometry, immunofluorescence, and real-time PCR on days 17 and 20 of pregnancy and day 17 of the estrous cycle. Results revealed an increased percentage of NKp46+ and CD8+ cells in the uterus of pregnant heifers. Furthermore, a large percentage of uterine immune cells coexpressed these proteins. Compared to cyclic heifers, CD45+ uterine cells from pregnant heifers exhibited greater degranulation. Endometrium from pregnant heifers had greater mRNA abundance for the inhibitory molecules, CD274 and lymphocyte activating gene 3 (LAG3), and greater cytotoxic T lymphocyte-associated protein 4 (CTLA4), molecules that can interact with receptors on antigen-presenting cells and induce lymphocyte tolerance. This study demonstrates a dynamic regulation of both cytotoxic immune cells and tolerogenic molecules during the peri-implantation period that may be required to support establishment of pregnancy and placentation.
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PMID:Effects of early pregnancy on uterine lymphocytes and endometrial expression of immune-regulatory molecules in dairy heifers. 2863 89