Biochemical and immunological properties of related small ruminant trophoblast interferons

Newton, G. R.; Ott, Troy L.; Woldesenbet, Selamawit; Shelton, A.M.; Bazer, Fuller W.

doi:10.1016/0093-691x(96)00222-1

Cited by 27 publications

(18 citation statements)

References 26 publications

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“…Intrauterine injections of ovine IFNT into sheep (Godkin et al 1984b ;Vallet et al 1988 ;Ott et al 1993 ), as well as cattle (Knickerbocker et al 1986a ;Knickerbocker et al 1986b ;Thatcher et al 1986 ;Meyer et al 1995 ;Thatcher et al 2001 ) and goats (Newton et al 1996 ), abrogate the development of the endometrial luteolytic mechanism and extend CL lifespan and the interestrous interval. It must be noted that the same mechanism(s) involved in IFNT action in sheep may be slightly different from those in the cow (Thatcher et al 1992 ;Hansen et al 1999 ).…”

Section: Antiluteolytic Effects Of Ifntmentioning

confidence: 99%

Implantation and Establishment of Pregnancy in Ruminants

Spencer

Hansen

2015

Advances in Anatomy, Embryology and Cell Biology

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The establishment of pregnancy in ruminants occurs during the peri-implantation period and involves the suppression of the endometrial luteolytic mechanism to maintain progesterone production by the corpus luteum (CL). Reciprocal interactions between the elongating conceptus (embryo/fetus and associated extraembryonic membranes) and endometrium culminate in implantation. Antiluteolytic effects of the conceptus are due to the production of interferon tau (IFNT) by the trophoblast that has a paracrine effect to inhibit the upregulation of oxytocin receptors in the endometrial epithelia, thereby disrupting uterine release of luteolytic prostaglandin F2 alpha (PGF) pulses. Additionally, IFNT is released into the uterine vein and has endocrine actions to induce ISGs in peripheral tissues. For example, IFNT may induce luteal resistance to PGF, thereby ensuring survival of the CL and maintenance of pregnancy. Survival of the blastocyst and elongation of the conceptus requires embryotrophic factors from the epithelia of the uterus, and those embryotrophic factors are regulated by ovarian progesterone as well as conceptus-derived factors including IFNT and prostaglandins. This review provides new concepts on mechanisms of the establishment of pregnancy and implantation in ruminants with emphasis on conceptus-maternal signaling associated with elongation of the blastocyst and endometrial responses to the presence of a conceptus.

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Section: Antiluteolytic Effects Of Ifntmentioning

confidence: 99%

Implantation and Establishment of Pregnancy in Ruminants

Spencer

Hansen

2015

Advances in Anatomy, Embryology and Cell Biology

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“…We produced a synthetic gene for IFNT, expressed it in the Pichia pastoris yeast system, and showed that its biological activities were equivalent to those of native IFNT (Ott et al 1991 ;VanHeeke et al 1996 ). We also conducted experiments to unravel the mechanism whereby IFNT prevents luteal regression to allow the establishment of pregnancy in ewes (see Thatcher et al 1989 ;Meyer et al 1995 ;Newton et al 1996 ; Bazer 2013a , b ) using Dr. John McCracken's model of the "progesterone block" for the regulation of the estrous cycle in ewes (Schramm et al 1983 ). Results supported our hypotheses relevant to mechanisms whereby IFNT acts to signal pregnancy recognition in sheep and other ruminant species.…”

Section: Pregnancymentioning

confidence: 97%

History of Maternal Recognition of Pregnancy

Bazer

2015

Regulation of Implantation and Establishment of Pregnancy in Mammals

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The mechanism for signaling pregnancy recognition is highly variable among species, and the signaling molecule itself varies between estrogens in pigs to chorionic gonadotrophin in primates. This chapter provides insight into the menstrual cycle of women and estrous cycles of rodents, dog, cat, pigs, sheep, rabbits, and marsupials, as well as the hormones required for pregnancy recognition. Pregnancy recognition involves specific hormones such as prolactin in rodents or interferons in ruminants and estrogens in pigs that in their own way ensure the maintenance of the corpus luteum and its secretion of progesterone which is the hormone of pregnancy. However, these pregnancy recognition signals may also modify gene expression in a cell-specific and temporal manner to ensure the growth and development of the conceptus. This chapter provides some historical aspects of the development of understanding of mechanisms for the establishment and maintenance of pregnancy in several species of mammals.

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“…The theory is based on evidence from a series of studies indicating that 1) IFNT silences transcription of the ESR1 gene and therefore E2-induced expression of OXTR in uterine LE/sGE to abrogate development of the endometrial luteolytic mechanism involving oxytocin-induced luteolytic pulses of PGF, 2) basal production of PGF and PGE2 is higher in pregnant than cyclic ewes because of the continued expression of prostaglandin endoperoxide synthase 2 (PTGS2), 3) IFNT silencing of ESR1 expression prevents E2 from inducing PGR in endometrial epithelia, and 4) loss of PGR by uterine epithelia is required for expression of P4-induced and IFNT-stimulated genes that support development of the conceptus [47,[90][91][92][93][94][95][96][97][98][99][100][101][102]. Caprine IFNT, secreted between Days 16 and 21 of gestation, is the pregnancy recognition signal that prevents pulsatile release of luteolytic PGF and extends life span of the CL in goats [103]. Bovine IFNT, secreted between Days 12 and 38 of pregnancy, also prevents secretion of luteolytic pulses of PGF by uterine epithelia and blocks effects of exogenous E2 and oxytocin to stimulate uterine release of PGF.…”

Section: Pregnancy and Pregnancy Recognition Signalingmentioning

confidence: 99%

“…Interferon tau (IFNT) is the pregnancy recognition hormone in sheep and other ruminants that acts to silence expression of estrogen receptor alpha (ESR1) and, in turn, oxytocin receptor (OXTR) to prevent development of the luteolytic mechanism that required oxytocin (OXT) from the corpus luteum (CL) and posterior pituitary to induce luteolytic pulses of prostaglandin F 2a (PGF). Thus, IFNT blocks the ability of the uterus to develop the luteolytic mechanism but does not inhibit prostaglandin synthase 2 (PTGS2) or the basal production of PGF during pregnancy [91,[94][95][96][97][98][99][100][101][102][103][104][105][106][107][108][109][110][111].…”

Section: Pregnancy and Pregnancy Recognition Signalingmentioning

confidence: 99%

Contributions of an Animal Scientist to Reproductive Biology

Bazer

2011

Biology of Reproduction

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I became interested in biology as an undergraduate in a premedical curriculum but developed a passion for the field of reproductive biology because of a course in physiology of reproduction taken to meet requirements for admission to veterinary school. My career path changed, and I entered graduate school, obtained the Ph.D., and have enjoyed an academic career as a reproductive biologist conducting research in uterine biology and pregnancy in animal science departments at the University of Florida and at Texas A&M University. However, I have never allowed academic boundaries to interfere with research and graduate education as that is contrary to collegiality, the cornerstone of great universities. I consider that my major contributions to science include 1) identification of proteins secreted by cells of the uterine endometrium that are critical to successful establishment and maintenance of pregnancy; 2) discovery of steroids and proteins required for pregnancy recognition signaling and their mechanisms of action in pigs and ruminant species; 3) investigation of fetal-placental development and placental transport of nutrients, including water and electrolytes; 4) identification of linkages between nutrition and fetal-placental development; 5) defining aspects of the endocrinology of pregnancy; and 6) contributing to efforts to exploit the therapeutic value of interferon tau, particularly for treatment of autoimmune diseases. My current studies are focused on the role of select nutrients in the uterine lumen, specifically amino acids and glucose, that affect development and survival of the conceptus and translation of mRNAs and, with colleagues at Seoul National University, gene expression by the avian reproductive tract at key periods postovulation. Another goal is to understand stromal-epithelial cell signaling, whereby progesterone and estrogen act via uterine stromal cells that express receptors for sex steroids to stimulate secretion of growth factors (e.g., fibroblast growth factors and hepatocyte growth factor) that, in turn, regulate functions of uterine epithelial cells and conceptus trophectoderm.

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Biochemical and immunological properties of related small ruminant trophoblast interferons

Cited by 27 publications

References 26 publications

Implantation and Establishment of Pregnancy in Ruminants

Implantation and Establishment of Pregnancy in Ruminants

History of Maternal Recognition of Pregnancy

Contributions of an Animal Scientist to Reproductive Biology

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