%0 Journal Article
%~ PubMed
%A Arnaiz, Isabel
%A Johnson, Mh
%A Cook, David I
%A Day, Margot L
%T Changing expression of chloride channels during pre-implantation mouse development.
%B Reproduction
%D 2013
%C United Kingdom
%I BioScientifica Ltd.
%V 145
%N 1
%P 73-84
%@ 1741-7899
%X 
%Z FOR Codes: 60103 60602 111404


%0 Journal Article
%~ PubMed
%A Poon, Connie E
%A Madawala, Romanthi J
%A Day, Margot L
%A Murphy, Christopher R
%T Claudin 7 is reduced in uterine epithelial cells during early pregnancy in the rat.
%B Histochemistry and Cell Biology
%D 2013
%C Germany
%I Springer
%V 139
%N 4
%P 583-593
%@ 1432-119X
%X 
%Z FOR Codes: 60802


%0 Journal Article
%~ PubMed
%A Kaneko, Yui
%A Day, Margot L
%A Murphy, Christopher R
%T Uterine epithelial cells: Serving two masters.
%B The International Journal of Biochemistry & Cell Biology
%D 2013
%C United Kingdom
%I Pergamon
%V 45
%N 2
%P 359-363
%@ 1357-2725
%X 
%Z FOR Codes: 60110


%0 Journal Article
%~ PubMed
%A Kaneko, Yui
%A Murphy, Christopher R
%A Day, Margot L
%T Extracellular matrix proteins secreted from both the endometrium and the embryo are required for attachment: A study using a co-culture model of rat blastocysts and Ishikawa cells.
%B Journal of Morphology
%D 2012
%C United States
%I John Wiley & Sons, Inc.
%V 274
%N 1
%P 63-72
%@ 1097-4687
%X 
%Z FOR Codes: 60602


%0 Journal Article
%~ PubMed
%A Kaneko, Yui
%A Lecce, Laura
%A Day, Margot L
%A Murphy, Christopher R
%T Focal adhesion kinase localizes to sites of cell-to-cell contact in vivo and increases apically in rat uterine luminal epithelium and the blastocyst at the time of implantation.
%B Journal of Morphology
%D 2012
%C United States
%I John Wiley & Sons, Inc.
%V 273
%N 6
%P 639-650
%@ 1097-4687
%X Focal adhesions play an important role in promoting embryo invasion; in particular, focal adhesions disassemble at the time of implantation in the rat, facilitating the detachment of the uterine luminal epithelium to allow the embryo to invade the endometrium. This study investigated focal adhesion protein, focal adhesion kinase (FAK) in the rat uterine luminal, and glandular epithelial cells to understand the dynamics of focal adhesions during early pregnancy. FAK undergoes extensive distributional change during early pregnancy, and surprisingly, FAK was not localized at the site of focal adhesions, instead being localized to the site of cell-to-cell contact and colocalizing with ZO-1 on day 1 of pregnancy. At the time of implantation, FAK increases in the apical region of the uterine luminal epithelial cells which was regulated by progesterone. Using an in vitro co-culture model of rat blastocysts attached to Ishikawa cells, FAK was present apically both in the rat blastocyst and the Ishikawa cells, suggesting a role in attachment andin mediating signal transduction between these two genetically different cell types.
%Z FOR Codes: 111601


%0 Journal Article
%~ PubMed
%A Kaneko, Yui
%A Lecce, Laura
%A Day, Margot L
%A Murphy, Christopher R
%T β(1) and β(3) integrins disassemble from basal focal adhesions and β(3) integrin is later localised to the apical plasma membrane of rat uterine luminal epithelial cells at the time of implantation.
%B Reproduction, fertility, and development
%D 2011
%C Australia
%I CSIRO Publishing
%V 23
%N 3
%P 481-95
%@ 1031-3613
%X The present study investigated the expression of integrin subunits that are known to be associated with focal adhesions, namely ??(1) and ??(3) integrins in rat uterine luminal epithelial cells during early pregnancy. The ??(1) and ??(3) integrins were concentrated along the basal cell surface and were colocalised and structurally interacted with talin, a principal focal adhesion protein, on Day 1 of pregnancy. At the time of implantation, ??(1) and ??(3) integrins disassembled from the site of focal adhesions, facilitating the removal of uterine luminal epithelial cells for embryo invasion. Also at this time, ??(3) integrin markedly increased along the apical membrane, suggesting a role in embryo attachment. This distributional change in ??(1) and ??(3) integrins seen at the time of implantation was predominantly under the influence of progesterone. Taken together, ??(1) and ??(3) integrin disassembly from focal adhesions and the increase in ??(3) integrin apically are key components of hormonally regulated endometrial receptivity.
%Z FOR Codes: 111601


%0 Journal Article
%~ PubMed
%A Kaneko, Yui
%A Day, Margot L
%A Murphy, Christopher R
%T Integrin {beta}3 in rat blastocysts and epithelial cells is essential for implantation in vitro: studies with Ishikawa cells and small interfering RNA transfection.
%B Human reproduction (Oxford, England)
%D 2011
%C United Kingdom
%I Oxford University Press
%V 26
%N 7
%P 1665-74
%@ 1460-2350
%X Integrins are involved in the process of embryo-endometrium interaction during implantation. We investigated the localization of integrin ??3 in the rat blastocyst and Ishikawa cells using an in vitro co-culture model of implantation.
%Z FOR Codes: 111601


%0 Journal Article
%~ PubMed
%A Li, Yan
%A O'Neill, Chris
%A Day, Margot
%T Activation of a Chloride Channel by a Trophic Ligand Is Required for Development of the Mouse Preimplantation Embryo In Vitro.
%B Biology of reproduction
%D 2009
%C United States
%I Society for the Study of Reproduction
%V 81
%N 4
%P 759-67
%@ 1529-7268
%X Platelet-activating factor (1-o-alkyl-2-acetyl-sn-gylcero-3-phosphocholine [PAF]) is one of several autocrine trophic factors supporting the development of the preimplantation embryo. PAF acts on the embryo to induce receptor-mediated intracellular calcium (Ca(2+))(i) transients, and these coincide with a marked membrane hyperpolarization. Patch-clamp analysis of 2-cell embryos showed that these Ca(2+)(i) transients resulted in an outward membrane current. The present study characterizes this current and assesses its role in embryo development. The outward current was dependent upon the presence of anions in the extracellular medium and occurred as a consequence of the PAF-induced Ca(2+)(i) transients. The anion current induced by PAF was inhibited by niflumic acid (NFA), a selective blocker of Ca(2+)-activated Cl(-) channels, but this drug did not block the PAF-induced Ca(2+)(i) transients. Voltage ramp analysis showed that the Cl(-) conductance was outwardly rectifying and inactivated at holding potentials more positive than +30 mV. Culture in NFA or 4,4''-diisothiocyanatostilbene-2,2''-disulfonic acid (a broad-specificity anion channel blocker) from the zygote stage significantly reduced development to blastocysts, with most arresting at the 4-cell and 8-cell stages. Niflumic acid exposure only from the zygote to the late 2-cell stage also reduced the subsequent development to blastocysts. By contrast, treatment from the late 2-cell stage or the 8-cell stage had no effect on development to the blastocyst stage. This study demonstrates the activation of a Ca(2+)-sensitive Cl(-) channel in the 2-cell embryo by PAF and shows that this current activity during the zygote to 2-cell stage is required for normal embryo development in vitro.
%Z FOR Codes: 111401


%0 Journal Article
%~ PubMed
%A Lee, Il-Ha
%A Campbell, Craig R
%A Song, Sung-Hee
%A Day, Margot L
%A Kumar, Sharad
%A Cook, David I
%A Dinudom, Anuwat
%T The activity of the epithelial sodium channels is regulated by caveolin-1 via a Nedd4-2-dependent mechanism.
%B Journal of Biological Chemistry
%D 2009
%C United States
%I American Society for Biochemistry and Molecular Bi
%V 284
%N 19
%P 12663-12669
%@ 0021-9258
%X It has recently been shown that the epithelial Na(+) channel (ENaC) is compartmentalized in caveolin-rich lipid rafts and that pharmacological depletion of membrane cholesterol, which disrupts lipid raft formation, decreases the activity of ENaC. Here we show, for the first time, that a signature protein of caveolae, caveolin-1 (Cav-1), down-regulates the activity and membrane surface expression of ENaC. Physical interaction between ENaC and Cav-1 was also confirmed in a coimmunoprecipitation assay. We found that the effect of Cav-1 on ENaC requires the activity of Nedd4-2, a ubiquitin protein ligase of the Nedd4 family, which is known to induce ubiquitination and internalization of ENaC. The effect of Cav-1 on ENaC requires the proline-rich motifs at the C termini of the beta- and gamma-subunits of ENaC, the binding motifs that mediate interaction with Nedd4-2. Taken together, our data suggest that Cav-1 inhibits the activity of ENaC by decreasing expression of ENaC at the cell membrane via a mechanism that involves the promotion of Nedd4-2-dependent internalization of the channel.
%Z FOR Codes: 60602 111601


%0 Journal Article
%~ PubMed
%A Li, Yan
%A Day, Margot L
%A O'neill, Chris
%T Autocrine activation of ion currents in the two-cell mouse embryo.
%B Experimental cell research
%D 2007
%C United States
%I Academic Press
%V 313
%N 13
%P 2786-94
%@ 0014-4827
%X The actions of autocrine ligands are required for the normal development of the preimplantation embryo in vitro. These ligands act as survival factors for the preimplantation stage embryo. One autocrine ligand, paf (1-o-alkyl-2-acetyl-sn-gylcero-3-phosphocholine), induced a dihydropyridine-sensitive calcium transient in the zygote and two-cell embryo, and these transients were required for the normal preimplantation stage survival. Paf induces an influx of external calcium through a dihydropyridine-sensitive channel. Dihydropyridine-sensitive currents are voltage-regulated, yet to date there is no evidence of membrane voltage depolarization in the two-cell embryo. To define the paf-induced calcium influx we have examined the response of the membrane potential and ion currents to paf in two-cell embryos. An initial response to paf challenge was the expression of an ion current (-15.6+/-1.6 pA) that was dependent upon extracellular calcium, was not voltage-gated but was dihydropyridine (nifedipine)-sensitive. This calcium current was followed (91+/-6 s after paf) by a net outward current (284+/-59 pA) that was composed of 4,4''-diisothiocyanatostilbene-2,2''-disulfonate-sensitive (anion channel blocker) and tetraethylammonium chloride-sensitive (K(+) channel blocker) currents. This current corresponded temporally with a marked paf-induced transient hyperpolarization of the membrane potential (-8.4+/-1.2 mV) that was dependent upon the generation of the calcium transient. The results directly demonstrate the activation of a voltage-independent calcium current in response to paf and show for the first time the expression of an afterhyperpolarization that occurs as a response to the calcium transient.
%Z FOR Codes: 111601


%0 Journal Article
%~ PubMed
%A Li, Yan
%A Chandrakanthan, Vashe
%A Day, Margot L
%A O'Neill, Chris
%T Direct evidence for the action of phosphatidylinositol (3,4,5)-trisphosphate-mediated signal transduction in the 2-cell mouse embryo.
%B Biology of reproduction
%D 2007
%C US
%I Society for the Study of Reproduction
%V 77
%N 5
%P 813-821
%@ 0006-3363
%X Paf (1-o-alkyl-2-acetyl-sn-gylcero-3-phosphocholine) is a putative autocrine survival factor for the preimplantation embryo. It acts to induce receptor-mediated calcium transients in the early embryo. Inhibitors of 1-o-phosphatidylinositol-3-kinase (PI3kinase), such as wortmannin and LY 294002, blocked these calcium transients, implicating the generation of phosphatidylinositol (3,4,5)-trisphosphate (PIP3) in autocrine signal transduction in the early embryo. Perfusion of the embryo cytoplasm with a blocking antibody to PIP3 inhibited paf-induced calcium transients and hyperpolarization of the membrane potential. Furthermore, direct infusion of PIP3 into the embryo induced a nifedipine (10 mumol/L)- and diltiazem (10 mumol/L)-sensitive calcium current in the 2-cell embryo. PIP3 acts as a docking site on membranes for proteins that contain pleckstrin homology domains, such as the thymoma viral proto-oncogene protein (AKT) and phospholipase C gamma. The 2-cell embryo expressed three genes for AKT (Akt 1-3) and two genes for phospholipase C gamma (Plcg1 and Plcg2), and we confirmed the expression of both AKT and phospholipase C gamma 1 by immunolocalization. Paf induced increased accumulation of serine 473-phosphorylated AKT in the region of the plasma membrane, consistent with its recruitment to membrane PIP3. Inhibitors of PI3kinase, such as LY294002, and of AKT, e.g., deguelin and AKT-inhibitor, reduced zygote development in a dose-dependent manner, and this inhibition was partially reversed by the addition of paf to the culture medium. These results provide the first direct evidence that PIP3 and its responsive signaling pathways act in the 2-cell embryo. Since signal transduction via PI3kinase has important roles in governing the cell survival pathways, these results support the hypothesis that autocrine embryotropins, such as paf, act as survival factors.
%Z FOR Codes: 111601