scholarly journals Membrane trafficking directed by VAMP2 and syntaxin 3 in uterine epithelial cells

Reproduction ◽  
2020 ◽  
Vol 160 (4) ◽  
pp. 533-546
Author(s):  
Sadaf N Kalam ◽  
Louise Cole ◽  
Laura Lindsay ◽  
Christopher R Murphy
Keyword(s):  
Epithelial Cells ◽  
Early Pregnancy ◽  
Membrane Trafficking ◽  
Snare Proteins ◽  
Apical Surface ◽  
Uterine Receptivity ◽  
Uterine Epithelial Cells ◽  
Syntaxin 3 ◽  
Cytoskeletal Disruption

Luminal uterine epithelial cells (UEC) have a surge in vesicular activity during early uterine receptivity. It has been predicted these vesicles exit the UEC via exocytosis resulting in secretion and membrane trafficking. The present study investigated the changes in SNARE proteins VAMP2 (v-SNARE) and syntaxin 3 (t-SNARE) localisation and abundance in UECs during early pregnancy in the rat. We found VAMP2 and syntaxin 3 are significantly higher on day 5.5 compared to day 1 of pregnancy. On day 5.5, VAMP2 is perinuclear and syntaxin 3 is concentrated in the apical cytoplasm compared to a cytoplasmic localisation on day 1. This change in localisation and abundance show VAMP2 and syntaxin 3 are involved in vesicular movement and membrane trafficking in UECs during early pregnancy. This study also investigated the influence of cytoskeletal disruption of microtubules and actin filaments on VAMP2 and syntaxin 3 in UECs grown in vitro, since microtubules and actin influence vesicle trafficking. As expected, this study found disruption to microtubules with colchicine and actin with cytochalasin D impacted VAMP2 and syntaxin 3 localisation. These results suggest VAMP2 and syntaxin 3 are involved in the timely trafficking of vesicular membranes to the apical surface in UECs during early pregnancy, as are of microtubules and actin.

312. THE DISTRIBUTION OF PROMININ-1 IN THE RAT UTERUS DURING EARLY PREGNANCY

2010 ◽  
Vol 22 (9) ◽  
pp. 112
Author(s):  
S. N. Dowland ◽  
L. A. Lindsay ◽  
C. R. Murphy
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Early Pregnancy ◽  
Cell Types ◽  
Apical Plasma Membrane ◽  
Apical Surface ◽  
Uterine Epithelial Cells ◽  
Uterine Epithelial Cell ◽  
Terminal Web ◽  
Blastocyst Implantation

Prominin-1 is a recently discovered pentaspan membrane protein present in characteristic cholesterol-based vesicles and associated with microvilli. These vesicles are used to deliver prominin-1 to the apical plasma membrane in a number of cell types. Previous work on uterine epithelial cells has demonstrated a loss of microvilli and the presence of large, cholesterol-based vesicles at the time of implantation. Thus this study aims to determine a role for prominin-1 in rat uterine epithelial cells during early pregnancy. Immunofluorescence microscopy reveals punctate and diffuse prominin-1 staining below the apical plasma membrane on day 1 of pregnancy. At the time of blastocyst implantation (day 6) however, prominin-1 appears concentrated at the apical surface of the cell. Western blotting of isolated uterine epithelial cell lysate revealed a change in prominin-1 glycosylation during early pregnancy. Prominin-1 was determined to be glycosylated on day 1 of pregnancy, but these carbohydrate side chains were lost by the time of attachment. Results seen in the present study indicate that prominin-containing vesicles may be prevented from reaching the apical plasma membrane by the terminal web on day 1 of pregnancy. On day 6, the loss of the terminal web may allow the vesicles to approach and incorporate into the apical plasma membrane, as seen with other uterine vesicles. The deglycosylation of prominin-1 at this time is suggested to allow the protein to bind its ligand and activate downstream signalling pathways that permit implantation. This study constitutes the first reported observation of prominin in endometrial lumenal epithelial cells. These preliminary results, in consideration with previous reports of prominin expression in trophoblast cells, suggest an important role for this protein in early pregnancy.

THE PLASMA MEMBRANE TRANSFORMATION: A KEY CONCEPT IN UTERINE RECEPTIVITY

2001 ◽  
Vol 9 (3) ◽  
pp. 197-208 ◽  
Author(s):  
CR Murphy
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Early Pregnancy ◽  
Fetal Tissue ◽  
Human Beings ◽  
Human Uterus ◽  
Uterine Receptivity ◽  
Uterine Epithelial Cells ◽  
Considerable Body ◽  
Membrane Transformation

The first site of contact between maternal and fetal tissue at the beginning of blastocyst attachment and implantation is the plasma membrane of uterine epithelial cells. Indeed, as has been noted often, regardless of the mode of placentation which ultimately occurs, contact between this plasma membrane and that of the trophoblast is a common beginning to implantation in most species studied so far, which now range from viviparous lizards to human beings. The similarities in these early events of uterine receptivity and placentation go further than mere contact between opposing surfaces however. A considerable body of evidence indicates that the behaviour of the plasma membrane of uterine epithelial cells during early pregnancy has many common aspects across species including humans. This review pays special attention to events in the human uterus and the epithelial cells in particular, but examines them within the wider context of uterine receptivity for implantation across species.

scholarly journals Localization of phosphatidylinositol phosphate kinase IIγ in kidney to a membrane trafficking compartment within specialized cells of the nephron

2008 ◽  
Vol 295 (5) ◽  
pp. F1422-F1430 ◽  
Author(s):  
Jonathan H. Clarke ◽  
Piers C. Emson ◽  
Robin F. Irvine
Keyword(s):  
Epithelial Cells ◽  
Membrane Trafficking ◽  
Kidney Cell ◽  
Collecting Duct ◽  
Thick Ascending Limb ◽  
Phosphatidylinositol Phosphate ◽  
The Matrix ◽  
Phosphatidylinositol 4

PIP4Ks (type II phosphatidylinositol 4-phosphate kinases) are phosphatidylinositol 5-phosphate (PtdIns5P) 4-kinases, believed primarily to regulate cellular PtdIns5P levels. In this study, we investigated the expression, localization, and associated biological activity of the least-studied PIP4K isoform, PIP4Kγ. Quantitative RT-PCR and in situ hybridization revealed that compared with PIP4Kα and PIP4Kβ, PIP4Kγ is expressed at exceptionally high levels in the kidney, especially the cortex and outer medulla. A specific antibody was raised to PIP4Kγ, and immunohistochemistry with this and with antibodies to specific kidney cell markers showed a restricted expression, primarily distributed in epithelial cells in the thick ascending limb and in the intercalated cells of the collecting duct. In these cells, PIP4Kγ had a vesicular appearance, and transfection of kidney cell lines revealed a partial Golgi localization (primarily the matrix of the cis-Golgi) with an additional presence in an unidentified vesicular compartment. In contrast to PIP4Kα, bacterially expressed recombinant PIP4Kγ was completely inactive but did have the ability to associate with active PIP4Kα in vitro. Overall our data suggest that PIP4Kγ may have a function in the regulation of vesicular transport in specialized kidney epithelial cells.

310. CAVEOLIN 1 AND 2 IN THE UTERUS DURING EARLY PREGNANCY

2010 ◽  
Vol 22 (9) ◽  
pp. 110
Author(s):  
R. J. Madawala ◽  
C. R. Murphy
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Protein Expression ◽  
Early Pregnancy ◽  
Basolateral Membrane ◽  
Membrane Curvature ◽  
Major Protein ◽  
Uterine Epithelial Cells ◽  
Caveolin 1 ◽  
Blastocyst Implantation

Rat uterine epithelial cells undergo many changes during early pregnancy in order to become receptive to blastocyst implantation. These changes include basolateral folding and the presence of vesicles of various sizes which are at their greatest number during the pre-implantation period. The present study investigated the possible role that caveolin 1 and 2 plays in this remodelling specifically days 1, 3, 6, 7, and 9 of pregnancy. Caveolin is a major protein in omega shaped invaginations of the plasma membrane called caveolae that are considered to be specialised plasma membrane subdomains. Caveolae are rich in cholesterol, glycosphingolipids, and GPI anchored proteins and are involved in endocytosis and membrane curvature. Immunofluorescence microscopy has shown caveolin 1 and 2 on day 1 of pregnancy are localised to the cytoplasm of luminal uterine epithelial cells, and by day 6 of pregnancy (the time of implantation), it concentrates basally. By day 9 of pregnancy, expression of both caveolin 1 and 2 in luminal uterine epithelia is cytoplasmic as seen on day 1 of pregnancy. A corresponding increase in protein expression of caveolin 1 on day 6 of pregnancy in luminal uterine epithelia was observed. Interestingly however, caveolin 2 protein expression decreases at the time of implantation as found by western blot analysis. Both caveolin 1 and 2 were localised to blood vessels within the endometrium and myometrium and also the muscle of the myometrium in all days of pregnancy studied. In addition, both caveolin 1 and 2 were absent from glandular epithelium, which is interesting considering that they do not undergo the plasma membrane transformation. The localisation and expression of caveolin 1 and 2 in rat luminal uterine epithelium at the time of implantation suggest possible roles in trafficking of cholesterol and/or various proteins for either degradation or relocation. Caveolins may contribute to the morphology of the basolateral membrane seen on day 6 of pregnancy. All of which may play an important role during successful blastocyst implantation.

Human duodenal mucosal brush border Na+/H+ exchangers NHE2 and NHE3 alter net bicarbonate movement

2001 ◽  
Vol 281 (1) ◽  
pp. G159-G163 ◽  
Author(s):  
Maltin Repishti ◽  
Daniel L. Hogan ◽  
Vijaya Pratha ◽  
Laura Davydova ◽  
Mark Donowitz ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Brush Border ◽  
Polyclonal Antibodies ◽  
Duodenal Mucosa ◽  
Transport Processes ◽  
Apical Surface ◽  
Luminal Perfusion ◽  
Significant Step

The proximal duodenal mucosa secretes HCO[Formula: see text] that serves to protect the epithelium from injury. In isolated human duodenal enterocytes in vitro, multiple luminal membrane proteins are involved in acid/base transport. We postulated that one or more isoforms of the Na+/H+ exchanger (NHE) family is located on the apical surface of human duodenal mucosal epithelial cells and thereby contributes to duodenal mucosal HCO[Formula: see text] transport. Duodenal biopsies were obtained from human volunteers, and the presence of NHE2 and NHE3 was determined by using previously characterized polyclonal antibodies (Ab 597 for NHE2 and Ab 1381 for NHE3). In addition, proximal duodenal mucosal HCO[Formula: see text] transport was measured in humans in vivo in response to luminal perfusion of graded doses of amiloride; 10−5–10−4 M amiloride was used to inhibit NHE2 and 10−3 M amiloride to inhibit NHE3. Both NHE2 and NHE3 were localized principally to the brush border of duodenal villus cells. Sequential doses of amiloride resulted in significant, step-wise increases in net duodenal HCO[Formula: see text] output. Inhibition of NHE2 with 10−5 M and 10−4 M amiloride significantly increased net HCO[Formula: see text] output. Moreover, there was an additional, equivalent increase ( P < 0.05) in duodenal HCO[Formula: see text] output with 10−3 M amiloride, which inhibited NHE3. We conclude that 1) NHE2 and NHE3 are localized principally to the brush border of human duodenal villus epithelial cells; 2) sequential inhibition of NHE2 and NHE3 isoforms resulted in step-wise increases in net HCO[Formula: see text]output; 3) NHE2 and NHE3 participate in human duodenal villus cell HCO[Formula: see text] transport; and 4) the contribution of NHE-related transport events should be considered when studying duodenal HCO[Formula: see text] transport processes.

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