Sustained Wnt/β-catenin signalling causes neuroepithelial aberrations through the accumulation of aPKC at the apical pole

ABSTRACT Rotaviruses are characterized by polarized release from the apical side of infected enterocytes, and the rotavirus VP4 spike protein specifically binds to the actin network at the apical pole of differentiated enterocytic cells. To determine the functional consequences of this VP4-actin interaction, fluorescence recovery after photobleaching experiments were carried out to measure the diffusional mobility of VP4 associated with the microfilaments. Results show that VP4 binds to barbed ends of microfilaments by using actin treadmilling. Actin treadmilling inhibition results in the loss of rotavirus apical preferential release, suggesting a major role for actin in polarized rotavirus release.

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Accumulation and Oriented Transport of Ampicillin in Caco-2 Cells from Its Pivaloyloxymethylester Prodrug, Pivampicillin

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.4.1279-1288.2005 ◽

2005 ◽

Vol 49 (4) ◽

pp. 1279-1288 ◽

Cited By ~ 16

Author(s):

Hugues Chanteux ◽

Françoise Van Bambeke ◽

Marie-Paule Mingeot-Leclercq ◽

Paul M. Tulkens

Keyword(s):

Multidrug Resistance ◽

Drug Release ◽

Intestinal Epithelium ◽

Atp Depletion ◽

Intestinal Cells ◽

Apical Pole ◽

Cell Lysate ◽

Nitrophenyl Phosphate ◽

Significant Release ◽

Esterase Inhibitor

ABSTRACT Pivampicillin (PIVA), an acyloxymethylester of ampicillin, is thought to enhance the oral bioavailability of ampicillin because of its greater lipophilicity compared to that of ampicillin. The fate of PIVA in intestinal cells and the exact location of its conversion into ampicillin have, however, never been unambiguously established. Polarized Caco-2 cells have been used to examine the handling of PIVA and the release of ampicillin from PIVA by the intestinal epithelium. Experiments were limited to 3 h. Cells incubated with PIVA (apical pole) showed a fast accumulation of ampicillin and transport toward the basolateral medium, whereas PIVA itself was only poorly accumulated and transported. Cells incubated with free ampicillin accumulated and transported only minimal amounts of this drug. Release of ampicillin from cells incubated with PIVA was unaffected by PEPT1 and OCTN2 inhibitors but was sharply decreased after ATP depletion or addition of bis(4-nitrophenyl)-phosphate (BNPP; an esterase inhibitor). PIVA incubated with Caco-2 lysates released free ampicillin, and this release was inhibited by BNPP. Efflux studies showed that the ampicillin that accumulated in cells after incubation with PIVA was preferentially transported out of the cells through the basolateral pole. This efflux was decreased by multidrug resistance-associated protein (MRP) inhibitors (probenecid, MK-571) and by ATP depletion. A phthalimidomethylester of ampicillin that resists cellular esterases failed to cause any significant release (cell lysate) or transport (polarized Caco-2 cells) of ampicillin. These results show that when PIVA is given to Caco-2 cells from their apical pole, ampicillin is released intracellularly and that ampicillin is thereafter preferentially effluxed into the basolateral medium through an MRP-like transporter.

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Characterization of actin microfilaments at the apical pole of thyroid cells

Cell Biology International Reports ◽

10.1016/0309-1651(80)90010-7 ◽

1980 ◽

Vol 4 (1) ◽

pp. 59-68 ◽

Cited By ~ 17

Author(s):

J GABRION ◽

F TRAVERS ◽

Y BENYAMIN ◽

P SENTEIN ◽

N VANTHOAI

Keyword(s):

Actin Microfilaments ◽

Thyroid Cells ◽

Apical Pole

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Comparative study of the oospore morphology of two populations of a rare species Chara baueri A. Braun in Cedynia (Poland) and Batzlow (Germany)

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2012.012 ◽

2012 ◽

Vol 81 (2) ◽

pp. 131-136 ◽

Cited By ~ 9

Author(s):

Andrzej Pukacz ◽

Patrycja Boszke ◽

Mariusz J. Pełechaty ◽

Uwe Raabe

Keyword(s):

Comparative Analysis ◽

Comparative Study ◽

Rare Species ◽

Polar Axis ◽

German Population ◽

Apical Pole ◽

Equatorial Diameter ◽

Habitat Differentiation ◽

Two Populations ◽

Species Ecology

Morphological features of oospores of Chara baueri A. Braun, one of the rarest charophyte species worldwide, were studied based on 100 oospores collected from a small and temporarily dried mid-field pond near Cedynia, Western Poland. This is the first Polish and fifth presently known locality of this species. For comparison 67 oospores from a German population (similar pond localized near Batzlow, Germany) were also measured. So far, data on morphology of C. baueri oospores as well as the species ecology are limited. The only more detailed study of oospores for this species was earlier performed on 15 oospores from Kazakhstan. Largest polar axis (LPA, length), largest equatorial diameter (LED, width), isopolarity index (ISI = LPA/LED × 100), number of ridges, width of fossa, distance from apical pole to LED (AND) and anisipolarity index (ANI = AND/LPA × 100) were measured. The comparative analysis revealed that the oospores from Poland are generally bigger and more prolate than the German ones. The differences for most of studied parameters were statistically significant. The finding is discussed in the context of habitat differentiation of both studied sites. Moreover, the results obtained of oospore measurements for both populations differs from most of the data known so far from the literature.

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Cell-lineage specificity of primary cilia during epididymis post-natal development

10.1101/288977 ◽

2018 ◽

Author(s):

Agathe Bernet ◽

Alexandre Bastien ◽

Denis Soulet ◽

Olivia Jerczynski ◽

Christian Roy ◽

...

Keyword(s):

Epithelial Cells ◽

Hedgehog Signaling ◽

Primary Cilia ◽

Cell Lineage ◽

Basal Cells ◽

Myoid Cells ◽

Apical Pole ◽

Lineage Specificity ◽

Spatio Temporal ◽

Temporal Localization

AbstractPrimary cilia are sensory organelles that orchestrate major signaling pathways during organ development and homeostasis. By using a double Arl13b/mCherry-Cetn2/GFP transgenic mouse model, we characterized the spatio-temporal localization of primary cilia in the epididymis, from birth to adulthood. We report here a constitutive localisation of primary cilia in peritubular myoid cells and a dynamic profiling in differentiated epithelial cells throughout post-natal development. While primary cilia are present at the apical pole of the undifferentiated epithelial cells from birth to puberty, they are absent from the apical pole of the epithelium in adults, where they appear exclusively associated with cytokeratin 5-positive basal cells. Exogenous labeling of primary cilia marker Arl13b and IFT88 confirmed the cell lineage specific localization of primary cilia in basal cells and myoid cells in human epididymides. From whole epididymis tissues and serum-free cultures of DC2 murine epididymal principal cell lines we determined that primary cilia from the epididymis are associated with the polycystic kidney disease-related proteins polycystin 1 (PC1) and polycystin 2 (PC2), and Gli3 Hedgehog signaling transcription factor. Thus, our findings unveil the existence of primary cilia sensory organelles, which have the potential to mediate mechano/ chemo-signaling events in the epididymis.

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Seed Morphometry of Native Indonesian Orchids in the Genus Dendrobium

Scientifica ◽

10.1155/2020/3986369 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Sucipto Hariyanto ◽

Intan Ayu Pratiwi ◽

Edy Setiti Wida Utami

Keyword(s):

Pole Position ◽

Yellow Light ◽

Seed Shape ◽

Apical Pole ◽

Light Yellow ◽

Air Space ◽

Yellow Orange ◽

Basal Pole ◽

Qualitative Characters ◽

Seed Morphometry

In this study, seeds of 10 species of epiphytic orchids were examined using light and scanning electron microscope. Quantitative and qualitative characters were analyzed. All the presently investigated seeds showed are transparent with visible embryo and remarkable embryo color variations (such as pale yellow, light yellow, shiny yellow to yellow, orange, and white). The species showed two groups in seed shape (fusiform and filiform), prolate and oval-shaped embryo, positioned at the center of the long axis and near apical pole. Embryo in prolate shaped and near apical pole position was only in D. antennatum. Based on our investigation, there are variations in seed and embryo volume as well as percentage air space in different taxa of orchids. The highest air space percentages were found in D. leporinum. According to the ornamentation of testa cells, 3 types of seeds were discovered in this genus. Additionally, the clear variation in the testa ornamentation pattern includes the species of D. leporinum, where the testa cells were in the medial regular rectangles, but in the apical and basal pole they are polygonal and irregularly oriented; the testa cells of D. antennatum are polygonal and irregularly oriented and those of D. purpureum are longitudinally oriented with regular rectangles.

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Glial Fibrillary Acidic Protein (GFAP)-like Immunoreactivity in Rat Endocrine Pancreas

Journal of Histochemistry & Cytochemistry ◽

10.1177/002215540004800211 ◽

2000 ◽

Vol 48 (2) ◽

pp. 259-265 ◽

Cited By ~ 8

Author(s):

Marì Regoli ◽

Daniela Orazioli ◽

Renato Gerli ◽

Eugenio Bertelli

Keyword(s):

Glial Fibrillary Acidic Protein ◽

Intermediate Filament ◽

Endocrine Cells ◽

Endocrine Pancreas ◽

Polyclonal Antibodies ◽

Islet Of Langerhans ◽

Rat Pancreas ◽

Apical Pole ◽

Fetal Pancreas ◽

Pancreatic Epithelium

The study of intermediate filament expression in the pancreatic epithelium has been previously focused almost exclusively on cytokeratins. Transient vimentin immunoreactivity has also been detected in duct cells of rat fetal pancreas. Here we report that, in rat pancreas, intense GFAP-like immunoreactivity is detectable in a subpopulation of endocrine cells located in the periphery of the islet of Langerhans. In addition, staining appeared to be preferentially localized to the apical pole of the cells. Two different polyclonal antibodies were employed in this study, with analogous results. Staining of consecutive sections with anti-GFAP, anti-glucagon, and anti-somatostatin antibodies demonstrates that GFAP-like immunoreactivity is present in glucagon-secreting cells. The relevance of this finding is discussed.

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A new look at transudation: the apocrine connection

Physiological Research ◽

10.33549/physiolres.934229 ◽

2020 ◽

pp. 227-244

Author(s):

R. Farkaš ◽

M. Beňo ◽

D. Beňová-Liszeková ◽

I. Raška ◽

O. Raška

Keyword(s):

Epithelial Cells ◽

Endosomal Sorting ◽

Common Features ◽

Apical Pole ◽

Secretion Process ◽

Apocrine Secretion ◽

Basolateral Side ◽

A Cell ◽

The Common ◽

New Look

Transcellular trafficking in which various molecules are transported across the interior of a cell, is commonly classified as transcytosis. However, historically this term has been used synonymously with transudation. In both cases transcellular trafficking starts with the internalization of proteins or other compounds on the basal or basolateral side of a cell and continues by their transport across the interior to the apical pole (or vice versa) where they are subsequently released. This allows a cell to release products which are synthesized elsewhere. Here, we discuss the common features of both transcytosis and transudation, and that which differentiates them. It appears that transcytosis and transudation are identical in terms of vesicular import and endosomal sorting of cargo, but completely differ in the re-secretion process. Specialized epithelial cells re-release substantial quantities of the endocytosed material, and often also a great variety. Some recent studies indicate that this is achieved by non-canonical apocrine secretion rather than by the regular vesicular mechanism of exocytosis, and takes place only on the apical pole. This massive re-release of endocytosed proteins, and potentially other compounds via the apocrine mechanism should be considered as transudation, distinct from transcytosis.

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