Prostaglandin secretion by perifused porcine endometrium: further evidence for an endocrine versus exocrine secretion of prostaglandins.
ABSTRACT Bilateral perifusion devices were utilized for measurement of prostaglandin secretion by luminal and myometrial surfaces of porcine endometrium. Tissues were collected from Days 10, 12 and 14 pregnant, Day 14 cyclic and Day 14 estrogen-induced pseudopregnant gilts. Each tissue was placed into duplicate perifusion devices and perifused with Krebs-Ringer Bicarbonate solution at 3 ml/10 min for 2 h, fractions collected every 10 min and oxytocin (1 IU/ml) perifused during fractions 6-10 to the luminal side of one chamber and to the myometrial side of the other chamber. Secretion rates of PGF were higher (P less than 0.05) than PGE2 for each status. Secretion rates of PGF and PGE2 were higher (P less than 0.01) from the luminal side for Day 12 pregnant, Day 14 pregnant and Day 14 pseudo-pregnant gilts, whereas secretion was higher from the myometrial side for Day 10 pregnant and Day 14 cyclic gilts. Oxytocin increased (P less than 0.01) prostaglandin secretion from the luminal side regardless of reproductive status. Pregnancy at Day 12 and Day 14, as well as estrogen treatment, were associated with prostaglandin secretion in a luminal (exocrine) orientation versus a myometrial (endocrine) orientation for Day 14 cyclic and Day 10 pregnant gilts. These data indicate an estrogen associated switch between Days 10 and 12 of pregnancy from an endocrine to an exocrine secretion of prostaglandins.
- [show abstract] [hide abstract]
ABSTRACT: I developed a passion for reproductive biology when taking a course in Physiology of Reproduction at Louisiana State University while preparing to apply for Veterinary School at Texas A&M University. My career path changed. I entered graduate school, obtained a Ph.D. and have enjoyed an academic career conducting research in uterine biology and pregnancy in animal science departments at the University of Florida and at Texas A&M University. My contributions to science include: (1) identification of molecules secreted by or transported by uterine epithelia into the uterine lumen that are critical to successful establishment and maintenance of pregnancy, (2) discovery of steroids and proteins required for pregnancy-recognition signalling and their mechanisms of action in pigs and ruminants, (3) patterns of fetal-placental development and placental transport of nutrients, (4) identification of links between nutrients and components of histotroph that affect fetal-placental development, (5) characterising aspects of the endocrinology of pregnancy and (6) contributing to efforts to exploit the therapeutic value of interferon tau, particularly for treatment of autoimmune and inflammatory diseases. Current research focuses on select nutrients in the uterine lumen, specifically amino acids, glucose and fructose, that affect conceptus development, the therapeutic potential for interferon tau, stromal-epithelial cell signalling whereby progesterone and oestrogen act via steroid receptors in uterine stromal cells to stimulate secretion of growth factors (e.g. fibroblast growth factors and hepatocyte growth factor) that regulate uterine epithelial cells and conceptus trophectoderm, and roles of toll-like receptors expressed by uterine epithelia and conceptus trophectoderm in pregnancy.Reproduction Fertility and Development 12/2012; 25(1):129-47. · 2.58 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: The aim of this study was to develop immortalized cell lines from porcine uterus. Endometrial cells including luminal epithelium (LE), glandular epithelium (GE), stroma (ST), and myometrium (MYO) were enzymatically isolated from the uterus of a day 12 pregnant gilt. Primary cultures were immortalized by transduction with a retroviral vector containing the E6 and E7 open reading frames of human papillomavirus type 16 (LXSN-16E6E7) packaged by the amphotropic fibroblast line PA-317. Cells having integrated the vector were selected by resistance to the neomycin analog G418 (0.4-1.5 mg/ml). Surviving cells were maintained in complete culture medium containing G418 (0.1 mg/ml) and subcultured for 1 yr. Expression of the E7 protein was confirmed in all cell lines by Western blotting. Phase contrast microscopy revealed that LE and GE cells exhibited cobblestone morphology, whereas ST and MYO cells exhibited spindle-shaped morphology. The epithelial origin of LE and GE was confirmed by positive immunostaining for cytokeratin. Stromal and MYO cells were vimentin-positive, but cytokeratin-negative. The MYO cell lines were positive for smooth muscle alpha-actin staining, whereas LE, GE, and ST cell lines were negative for alpha-actin. Western blotting indicated that all cell lines expressed both estrogen and progesterone receptors, but only GE cells secreted uteroferrin (UF). Collectively, these porcine uterine cell lines provide an in vitro model for studying cell type-specific actions of hormones and cytokines, signal transduction pathways, cell-cell interactions, and gene expression.In Vitro Cellular & Developmental Biology - Animal 04/2012; 36(10):650-6. · 1.29 Impact Factor
Article: Uterine biology in pigs and sheep.[show abstract] [hide abstract]
ABSTRACT: There is a dialogue between the developing conceptus (embryo-fetus and associated placental membranes) and maternal uterus which must be established during the peri-implantation period for pregnancy recognition signaling, implantation, regulation of gene expression by uterine epithelial and stromal cells, placentation and exchange of nutrients and gases. The uterus provide a microenvironment in which molecules secreted by uterine epithelia or transported into the uterine lumen represent histotroph required for growth and development of the conceptus and receptivity of the uterus to implantation. Pregnancy recognition signaling mechanisms sustain the functional lifespan of the corpora lutea (CL) which produce progesterone, the hormone of pregnancy essential for uterine functions that support implantation and placentation required for a successful outcome of pregnancy. It is within the peri-implantation period that most embryonic deaths occur due to deficiencies attributed to uterine functions or failure of the conceptus to develop appropriately, signal pregnancy recognition and/or undergo implantation and placentation. With proper placentation, the fetal fluids and fetal membranes each have unique functions to ensure hematotrophic and histotrophic nutrition in support of growth and development of the fetus. The endocrine status of the pregnant female and her nutritional status are critical for successful establishment and maintenance of pregnancy. This review addresses the complexity of key mechanisms that are characteristic of successful reproduction in sheep and pigs and gaps in knowledge that must be the subject of research in order to enhance fertility and reproductive health of livestock species.Journal of animal science and biotechnology. 01/2012; 3(1):23.