scholarly journals Insulin Stimulates GLUT4 Trafficking to the Syncytiotrophoblast Basal Plasma Membrane in the Human Placenta

2019 ◽  
Vol 104 (9) ◽  
pp. 4225-4238 ◽  
Author(s):  
Laura B James-Allan ◽  
Jaron Arbet ◽  
Stephanie B Teal ◽  
Theresa L Powell ◽  
Thomas Jansson
Keyword(s):  
Plasma Membrane ◽  
Protein Expression ◽  
Membrane Trafficking ◽  
Human Placenta ◽  
Plasma Membranes ◽  
Glucose Transporter ◽  
Maternal Obesity ◽  
Normal Body Mass Index ◽  
Basal Plasma Membrane ◽  
Basal Plasma

AbstractContextPlacental transport capacity influences fetal glucose supply. The syncytiotrophoblast is the transporting epithelium in the human placenta, expressing glucose transporters (GLUTs) and insulin receptors (IRs) in its maternal-facing microvillous plasma membrane (MVM) and fetal-facing basal plasma membrane (BM).ObjectiveThe objectives of this study were to (i) determine the expression of the insulin-sensitive GLUT4 glucose transporter and IR in the syncytiotrophoblast plasma membranes across gestation in normal pregnancy and in pregnancies complicated by maternal obesity, and (ii) assess the effect of insulin on GLUT4 plasma membrane trafficking in human placental explants.Design, Setting, and ParticipantsPlacental tissue was collected across gestation from women with normal body mass index (BMI) and mothers with obesity with appropriate for gestational age and macrosomic infants. MVM and BM were isolated.Main Outcome MeasuresProtein expression of GLUT4, GLUT1, and IR were determined by western blot.ResultsGLUT4 was exclusively expressed in the BM, and IR was predominantly expressed in the MVM, with increasing expression across gestation. BM GLUT1 expression was increased and BM GLUT4 expression was decreased in women with obesity delivering macrosomic babies. In placental villous explants, incubation with insulin stimulated Akt (S473) phosphorylation (+76%, P = 0.0003, n = 13) independent of maternal BMI and increased BM GLUT4 protein expression (+77%, P = 0.0013, n = 7) in placentas from lean women but not women with obesity.ConclusionWe propose that maternal insulin stimulates placental glucose transport by promoting GLUT4 trafficking to the BM, which may enhance glucose transfer to the fetus in response to postprandial hyperinsulinemia in women with normal BMI.

scholarly journals l-Arginine Transport across the Basal Plasma Membrane of the Syncytiotrophoblast of the Human Placenta from Normal and Preeclamptic Pregnancies

2003 ◽  
Vol 88 (9) ◽  
pp. 4287-4292 ◽  
Author(s):  
P. F. Speake ◽  
J. D. Glazier ◽  
P. T.-Y. Ayuk ◽  
M. Reade ◽  
C. P. Sibley ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Human Placenta ◽  
Arginine Transport ◽  
Basal Plasma Membrane ◽  
Basal Plasma

scholarly journals Protein expression of fatty acid transporter 2 is polarized to the trophoblast basal plasma membrane and increased in placentas from overweight/obese women

Placenta ◽  
2016 ◽  
Vol 40 ◽  
pp. 60-66 ◽  
Author(s):  
Susanne Lager ◽  
Vanessa I. Ramirez ◽  
Francesca Gaccioli ◽  
Brian Jang ◽  
Thomas Jansson ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Fatty Acid ◽  
Protein Expression ◽  
Obese Women ◽  
Basal Plasma Membrane ◽  
Basal Plasma ◽  
Fatty Acid Transporter ◽  
Acid Transporter

Evidence for carrier-mediated bilirubin transport across the basal plasma membrane of human placenta trophoblast at term

1998 ◽  
Vol 28 ◽  
pp. 125
Author(s):  
L. Pascolo ◽  
J.E. Bayón ◽  
M.A. Serrano ◽  
D. Ostrow ◽  
C. Tiribelli ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Human Placenta ◽  
Basal Plasma Membrane ◽  
Basal Plasma

scholarly journals Folding of the syncytiotrophoblast basal plasma membrane increases the surface area available for exchange in human placenta

Placenta ◽  
2021 ◽  
Author(s):  
Stanimir A. Tashev ◽  
Daisy Parsons ◽  
Cameron Hillman ◽  
Shelley Harris ◽  
Emma M. Lofthouse ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Surface Area ◽  
Human Placenta ◽  
Basal Plasma Membrane ◽  
Basal Plasma

ATP independent calcium transport and binding by basal plasma membrane of human placenta

Placenta ◽  
1994 ◽  
Vol 15 (2) ◽  
pp. 147-155 ◽  
Author(s):  
S.G. Kamath ◽  
N. Haider ◽  
C.H. Smith
Keyword(s):  
Plasma Membrane ◽  
Human Placenta ◽  
Calcium Transport ◽  
Basal Plasma Membrane ◽  
Basal Plasma

Alanine transport systems in isolated basal plasma membrane of human placenta

1989 ◽  
Vol 256 (3) ◽  
pp. C630-C637 ◽  
Author(s):  
S. D. Hoeltzli ◽  
C. H. Smith
Keyword(s):  
Amino Acids ◽  
Plasma Membrane ◽  
Plasma Membranes ◽  
Transport Systems ◽  
Acid Uptake ◽  
Plasma Membrane Vesicles ◽  
Basal Plasma Membrane ◽  
Sodium Dependent ◽  
Basal Plasma ◽  
System 2

Concentrative transfer of amino acids from mother to fetus is affected by transport across both microvillous (maternal-facing) and basal (fetal-facing) plasma membranes of the human placental syncytiotrophoblast. Isolated basal plasma membrane vesicles were used to elucidate transport systems for neutral amino acids across this membrane. The concentration dependence and inhibition of zero-trans-alanine uptake were studied and four pathways for alanine uptake were defined as follows: 1) a sodium-dependent system shared by methylaminoisobutyric acid, which has the characteristics of an A system; 2) a sodium-dependent system resistant to inhibition by methylaminoisobutyric acid, which has the characteristics of an ASC system; 3) a sodium-independent system which may resemble an L system; 4) nonsaturable uptake. The microvillous membrane of the syncytiotrophoblast possesses systems similar to 1 and 3, but system 2 is unique to the basal plasma membrane. Active and passive transport of amino acids across both microvillous and basal plasma membranes may contribute to trophoblast amino acid uptake and nutrition and to the transfer of amino acids to the fetus.

scholarly journals Comparative ultrastructure of cells and cuticle in the anterior chamber and papillate region of Porcellio scaber (Crustacea, Isopoda) hindgut

ZooKeys ◽  
2018 ◽  
Vol 801 ◽  
pp. 427-458 ◽  
Author(s):  
Urban Bogataj ◽  
Monika Praznik ◽  
Polona Mrak ◽  
Jasna Štrus ◽  
Magda Tušek-Žnidarič ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Anterior Chamber ◽  
Plasma Membranes ◽  
Cell Junctions ◽  
Apical Plasma Membrane ◽  
Septate Junctions ◽  
Basal Plasma Membrane ◽  
Basal Plasma ◽  
Cuticle Ultrastructure

Isopod hindgut consists of two anatomical and functional parts, the anterior chamber, and the papillate region. This study provides a detailed ultrastructural comparison of epithelial cells in the anterior chamber and the papillate region with focus on cuticle ultrastructure, apical and basal plasma membrane labyrinths, and cell junctions. Na+/K+-ATPase activity in the hindgut epithelial cells was demonstrated by cytochemical localisation. The main difference in cuticle ultrastructure is in the thickness of epicuticle which is almost as thick as the procuticle in the papillate region and only about one sixth of the thickness of procuticle in the anterior chamber. The apical plasma membrane in both hindgut regions forms an apical plasma membrane labyrinth of cytoplasmic strands and extracellular spaces. In the papillate region the membranous infoldings are deeper and the extracellular spaces are wider. The basal plasma membrane is extensively infolded and associated with numerous mitochondria in the papillate region, while it forms relatively scarce basal infoldings in the anterior chamber. The junctional complex in both hindgut regions consists of adherens and septate junctions. Septate junctions are more extensive in the papillate region. Na+/K+-ATPase was located mostly in the apical plasma membranes in both hindgut regions. The ultrastructural features of hindgut cuticle are discussed in comparison to exoskeletal cuticle and to cuticles of other arthropod transporting epithelia from the perspective of their mechanical properties and permeability. The morphology of apical and basal plasma membranes and localisation of Na+/K+-ATPase are compared with other arthropod-transporting epithelia according to different functions of the anterior chamber and the papillate region.

scholarly journals Insulin Stimulates Membrane Fusion and GLUT4 Accumulation in Clathrin Coats on Adipocyte Plasma Membranes

2007 ◽  
Vol 27 (9) ◽  
pp. 3456-3469 ◽  
Author(s):  
Shaohui Huang ◽  
Larry M. Lifshitz ◽  
Christine Jones ◽  
Karl D. Bellve ◽  
Clive Standley ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Fusion ◽  
Insulin Signaling ◽  
Plasma Membranes ◽  
Glucose Transporter ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Tirf Microscopy ◽  
Adipocyte Plasma Membranes ◽  
Kinetics Of

ABSTRACT Total internal reflection fluorescence (TIRF) microscopy reveals highly mobile structures containing enhanced green fluorescent protein-tagged glucose transporter 4 (GLUT4) within a zone about 100 nm beneath the plasma membrane of 3T3-L1 adipocytes. We developed a computer program (Fusion Assistant) that enables direct analysis of the docking/fusion kinetics of hundreds of exocytic fusion events. Insulin stimulation increases the fusion frequency of exocytic GLUT4 vesicles by ∼4-fold, increasing GLUT4 content in the plasma membrane. Remarkably, insulin signaling modulates the kinetics of the fusion process, decreasing the vesicle tethering/docking duration prior to membrane fusion. In contrast, the kinetics of GLUT4 molecules spreading out in the plasma membrane from exocytic fusion sites is unchanged by insulin. As GLUT4 accumulates in the plasma membrane, it is also immobilized in punctate structures on the cell surface. A previous report suggested these structures are exocytic fusion sites (Lizunov et al., J. Cell Biol. 169:481-489, 2005). However, two-color TIRF microscopy using fluorescent proteins fused to clathrin light chain or GLUT4 reveals these structures are clathrin-coated patches. Taken together, these data show that insulin signaling accelerates the transition from docking of GLUT4-containing vesicles to their fusion with the plasma membrane and promotes GLUT4 accumulation in clathrin-based endocytic structures on the plasma membrane.

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