Browsing by Subject "Placenta"
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Item Creation of an Instructional Animation Showing the Development of the Human Placenta from Implantation to Term(2013-01-16) Montgomery, James Scott; Calver, Lewis E., MS/CMI/FAMIThis project was created to fill a need in available placental development instructional tools. In the current literature, there are few three-dimensional representations of placental villous tree structure. This animation provides an overview of placental development and includes a three-dimensional depiction of a placental villous tree. Following creation of this animation, a survey was administered to assess the helpfulness of both the animation and the three-dimensional villous tree representations. Survey responses were overwhelmingly positive and show that this tool aids in the development of an accurate mental model of true placental villous tree form.Item Identification of cubilin (p400) as galectin-3 binding protein from the murine utero-placental complex(Texas Tech University, 2000-12) Crider-Pirkle, Sunday Suzanne; Faust, Charles; Weitlauf, Harry M.; Hardy, Daniel; Lee, Vaughan H.; Webster, Daniel R.; Whelly, Sandra M.Galectin-3 is a soluble p-galactoside binding lectin that is present in several cell types within the uteroplacental complex (UPC) of mice. Affinity chromatography with immobilized galectin-3 was used to isolate potential binding partners for the lectin from homogenates of UPC. At least one glycoprotein (Mr 400,000; p400) was isolated that bound galectin-3 in a carbohydrate-dependent manner. Exposure of p400 to glycosidases decreased its apparent size by 10%. Differential migration of p400 in nonreducing and reducing conditions demonstrated that the protein contains intramolecular disulfide bonds. Amino acid sequencing revealed similarity to cubilin, a 400 kDa endocytic receptor. Collectively, the molecular size of p400, its degree of glycosylation, the presence of intramolecular disulfide bonds, and amino acid sequence similarity strongly suggest that p400 is the murine ortholog of cubilin. Immunohistochemistry revealed that cubilin (p400) was present in the yolk sac epithelium from day 8 to term. It was also localized in the perforin-positive granules of uNK cells in metrial gland and decidua basalis. Although cubilin is best known as the receptor for intrinsic factor-vitamin B12 in the ileum, it may also act as an endocytic receptor in the kidney and yolk sac where it presumably mediates transcytosis of multiple ligands. The localization of cubilin to uNK cells is the first demonstration of the protein in an immune or non-epithelial cell type. However, the questions of whether cubilin actually interacts with galectin-3 in vivo, and what role cubilin plays, cannot be answered from our results. Because both galectin-3 and cubilin are present in uNK cells, one intriguing hypothesis is that they interact to modulate the immune function of uNK cells, and thus, that they are a part of a mechanism for protecting the fetus from immune rejection.Item The role of ovine betaretroviruses in uteroplacental function(2009-06-02) Dunlap, Kathrin AnsonEndogenous retroviruses (ERVs) account for a substantial portion of the genetic pool of every animal species (e.g. ~ 8% of the human genome). Despite their overwhelming abundance in nature, many questions on the basic biology of ERVs are unanswered. Sheep harbor approximately 20 copies of endogenous betaretroviruses (enJSRVs), which are related to an exogenous oncogenic virus, Jaagsiekte sheep retrovirus (JSRV). Therefore, they are an attractive model for investigation of the potential beneficial roles of ERVs in reproductive biology. Studies were conducted to determine: 1) expression of enJSRVs envelope (env) and HYAL2 mRNAs in the ovine uterus and conceptus (embryo/fetus and extraembryonic membranes) throughout gestation; 2) regulation of enJSRVs expression by progesterone; and 3) the role of enJSRVs in regulating peri-implantation placental growth and differentiation. Study One determined the localization of enJSRVs env and HYAL2 mRNAs throughout gestation. Results demonstrate that alterations in expression of enJSRVs and HYAL2 in the sheep uterus and placenta suggest the probability of a variety of physiological roles in implantation and placentation. Partial sequencing of the transcriptionally active enJSRVs from ovine uteroplacental tissues revealed expression of multiple enJSRV loci. Study Two assessed the influence of progesterone, interferon tau, and pregnancy stage on enJSRVs expression, as an effort to understand factors that may regulate enJSRVs. Results of this study support the hypothesis that expression of enJSRVs is modulated by progesterone, but not IFN? in vivo. Study Three provides for enJSRVs regulating trophectoderm growth and differentiation in the peri-implantation conceptus. Blocking conceptus enJSRVs Env expression compromised pregnancy by retarding trophoblast outgrowth and differentiation. Inhibition of enJSRVs Env in vitro also reduced proliferation of mononuclear trophectoderm cells. Consequently, these results demonstrate that enJSRVs Env regulates trophectoderm growth and differentiation in the ovine conceptus, strongly supporting the biological significance of ERVs in placental evolution and animal reproduction Collectively, these studies illustrate that enJSRVs play an integral role in success of pregnancy. While the definitive roles of the enJSRVs have not yet been elucidated, it is evident that enJSRVs are an important component of the ovine genome and that they influence recognition and maintenance of pregnancy and placental formation.