scholarly journals Multiple Na,K-ATPase Subunits Colocalize in the Brush Border of Mouse Choroid Plexus Epithelial Cells

2021 ◽  
Vol 22 (4) ◽  
pp. 1569
Author(s):  
Inga Baasch Christensen ◽  
Lei Cheng ◽  
Jonathan R. Brewer ◽  
Udo Bartsch ◽  
Robert A. Fenton ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Choroid Plexus ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Full Range ◽  
Stimulated Emission ◽  
Actin Binding ◽  
Pcr Analysis ◽  
Atpase Subunits ◽  
Choroid Plexus Epithelial

(1) Background: The unusual accumulation of Na,K-ATPase complexes in the brush border membrane of choroid plexus epithelial cells have intrigued researchers for decades. However, the full range of the expressed Na,K-ATPase subunits and their relation to the microvillus cytoskeleton remains unknown. (2) Methods: RT-PCR analysis, co-immunoprecipitation, native PAGE, mass spectrometry, and differential centrifugation were combined with high-resolution immunofluorescence histochemistry, proximity ligase assays, and stimulated emission depletion (STED) microscopy on mouse choroid plexus cells or tissues in order to resolve these issues. (3) Results: The choroid plexus epithelium expresses Na,K-ATPase subunits α1, α2, β1, β2, β3, and phospholemman. The α1, α2, β1, and β2, subunits are all localized to the brush border membrane, where they appear to form a complex. The ATPase complexes may stabilize in the brush border membrane via anchoring to microvillar actin indirectly through ankyrin-3 or directly via other co-precipitated proteins. Aquaporin 1 (AQP1) may form part of the proposed multi-protein complexes in contrast to another membrane protein, the Na-K-2Cl cotransporter 1 (NKCC1). NKCC1 expression seems necessary for full brush border membrane accumulation of the Na,K-ATPase in the choroid plexus. (4) Conclusion: A multitude of Na,K-ATPase subunits form molecular complexes in the choroid plexus brush border, which may bind to the cytoskeleton by various alternative actin binding proteins.

Na+-dependent HCO3− uptake into the rat choroid plexus epithelium is partially DIDS sensitive

2005 ◽  
Vol 289 (6) ◽  
pp. C1448-C1456 ◽  
Author(s):  
Elena V. Bouzinova ◽  
Jeppe Praetorius ◽  
Leila V. Virkki ◽  
Søren Nielsen ◽  
Walter F. Boron ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Choroid Plexus ◽  
Brush Border Membrane ◽  
Bicarbonate Transport ◽  
Excitation Wavelength ◽  
Membrane Domain ◽  
Choroid Plexus Epithelium ◽  
Transport Inhibitor ◽  
Acid Loading ◽  
Choroid Plexus Epithelial

Several studies suggest the involvement of Na+ and HCO3− transport in the formation of cerebrospinal fluid. Two Na+-dependent HCO3− transporters were recently localized to the epithelial cells of the rat choroid plexus (NBCn1 and NCBE), and the mRNA for a third protein was also detected (NBCe2) (Praetorius J, Nejsum LN, and Nielsen S. Am J Physiol Cell Physiol 286: C601–C610, 2004). Our goal was to immunolocalize the NBCe2 to the choroid plexus by immunohistochemistry and immunogold electronmicroscopy and to functionally characterize the bicarbonate transport in the isolated rat choroid plexus by measurements of intracellular pH (pHi) using a dual-excitation wavelength pH-sensitive dye (BCECF). Both antisera derived from COOH-terminal and NH2-terminal NBCe2 peptides localized NBCe2 to the brush-border membrane domain of choroid plexus epithelial cells. Steady-state pHi in choroidal cells increased from 7.03 ± 0.02 to 7.38 ± 0.02 ( n = 41) after addition of CO2/HCO3− into the bath solution. This increase was Na+ dependent and inhibited by the Cl− and HCO3− transport inhibitor DIDS (200 μM). This suggests the presence of Na+-dependent, partially DIDS-sensitive HCO3− uptake. The pHi recovery after acid loading revealed an initial Na+ and HCO3−-dependent net base flux of 0.828 ± 0.116 mM/s ( n = 8). The initial flux in the presence of CO2/HCO3− was unaffected by DIDS. Our data support the existence of both DIDS-sensitive and -insensitive Na+- and HCO3−-dependent base loader uptake into the rat choroid plexus epithelial cells. This is consistent with the localization of the three base transporters NBCn1, Na+-driven Cl− bicarbonate exchanger, and NBCe2 in this tissue.

scholarly journals Porcine Choroid Plexus Epithelial Cells Induce Streptococcus suis Bacteriostasis In Vitro

2004 ◽  
Vol 72 (5) ◽  
pp. 3084-3087 ◽  
Author(s):  
Rüdiger A. Adam ◽  
Tobias Tenenbaum ◽  
Peter Valentin-Weigand ◽  
Maurice Laryea ◽  
Bernd Schwahn ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Bacterial Meningitis ◽  
Choroid Plexus ◽  
Host Defense ◽  
Streptococcus Suis ◽  
Active Role ◽  
Necrosis Factor Alpha ◽  
Ifn Γ ◽  
Choroid Plexus Epithelial

ABSTRACT The involvement of the choroid plexus in host defense during bacterial meningitis is unclear. Aiming to elucidate possible antibacterial mechanisms, we stimulated primary porcine choroid plexus epithelial cells (pCPEC) with proinflammatory cytokines and challenged them with various Streptococcus suis strains. In the supernatant of gamma interferon (IFN-γ)-stimulated pCPEC, streptococcal growth was markedly suppressed. Costimulation with tumor necrosis factor alpha enhanced this bacteriostatic effect, while supplementation of l-tryptophan completely eliminated it. We also demonstrate that an activation of indoleamine 2,3-dioxygenase in the pCPEC seems to be responsible for the IFN-γ-induced bacteriostasis. This supports the hypothesis of an active role of the choroid plexus in host defense against bacterial meningitis.

scholarly journals Unique Regulation of Enterocyte Brush Border Membrane Na-Glutamine and Na-Alanine Co-Transport by Peroxynitrite during Chronic Intestinal Inflammation

2019 ◽  
Vol 20 (6) ◽  
pp. 1504 ◽  
Author(s):  
Subha Arthur ◽  
Palanikumar Manoharan ◽  
Shanmuga Sundaram ◽  
M Rahman ◽  
Balasubramanian Palaniappan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial Cells ◽  
Rabbit Model ◽  
Intestinal Epithelial ◽  
Mechanism Of Inhibition ◽  
Chronic Intestinal Inflammation

Na-amino acid co-transporters (NaAAcT) are uniquely affected in rabbit intestinal villus cell brush border membrane (BBM) during chronic intestinal inflammation. Specifically, Na-alanine co-transport (ASCT1) is inhibited secondary to a reduction in the affinity of the co-transporter for alanine, whereas Na-glutamine co-transport (B0AT1) is inhibited secondary to a reduction in BBM co-transporter numbers. During chronic intestinal inflammation, there is abundant production of the potent oxidant peroxynitrite (OONO). However, whether OONO mediates the unique alteration in NaAAcT in intestinal epithelial cells during chronic intestinal inflammation is unknown. In this study, ASCT1 and B0AT1 were inhibited by OONO in vitro. The mechanism of inhibition of ASCT1 by OONO was secondary to a reduction in the affinity of the co-transporter for alanine, and secondary to a reduction in the number of co-transporters for B0AT1, which were further confirmed by Western blot analyses. In conclusion, peroxynitrite inhibited both BBM ASCT1 and B0AT1 in intestinal epithelial cells but by different mechanisms. These alterations in the villus cells are similar to those seen in the rabbit model of chronic enteritis. Therefore, this study indicates that peroxynitrite may mediate the inhibition of ASCT1 and B0AT1 during inflammation, when OONO levels are known to be elevated in the mucosa.

Characterization of two splice variants of human organic anion transporting polypeptide 3A1 isolated from human brain

2007 ◽  
Vol 292 (2) ◽  
pp. C795-C806 ◽  
Author(s):  
Robert D. Huber ◽  
Bo Gao ◽  
Marguerite-Anne Sidler Pfändler ◽  
Wenting Zhang-Fu ◽  
Simone Leuthold ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Brain ◽  
Frontal Cortex ◽  
Choroid Plexus ◽  
Splice Variants ◽  
Organic Anion ◽  
Xenopus Laevis Oocytes ◽  
Organic Anion Transporting Polypeptide ◽  
Human Frontal Cortex ◽  
Choroid Plexus Epithelial

In the present study we isolated two splice variants of organic anion transporting polypeptide 3A1 (OATP3A1_v1 and OATP3A1_v2) from human brain. OATP3A1_v2 lacks 18 amino acids (aa) at the COOH-terminal end (692 aa) but is otherwise similar in sequence to OATP3A1_v1 (710 aa). OATP3A1_v1 exhibits a wide tissue distribution, with expression in testis, various brain regions, heart, lung, spleen, peripheral blood leukocytes, and thyroid gland, whereas OATP3A1_v2 is predominantly expressed in testis and brain. On the cellular and subcellular levels OATP3A1_v1 could be immunolocalized in testicular germ cells, the basolateral plasma membrane of choroid plexus epithelial cells, and neuroglial cells of the gray matter of human frontal cortex. Immunolocalization of OATP3A1_v2 included Sertoli cells in testis, apical and/or subapical membranes in choroid plexus epithelial cells, and neurons (cell bodies and axons) of the gray and white matter of human frontal cortex. The rodent ortholog Oatp3a1 was also widely distributed in rat brain, and its localization included somatoneurons as well as astroglial cells. Transport studies in cRNA-injected Xenopus laevis oocytes and in stably transfected Chinese hamster ovary FlpIn cells revealed a similar broad substrate specificity for both splice variants. Transported substrates include prostaglandin (PG)E1 and PGE2, thyroxine, and the cyclic oligopeptides BQ-123 (endothelin receptor antagonist) and vasopressin. These studies provide further evidence for the involvement of OATPs in oligopeptide transport. They specifically suggest that OATP3A1 variants might be involved in the regulation of extracellular vasopressin concentration in human brain and thus might influence the neuromodulation of neurotransmission by cerebral neuropeptides such as vasopressin.

Choroid plexus epithelial cells co-express the long and short form of the leptin receptor

2006 ◽  
Vol 393 (2-3) ◽  
pp. 269-272 ◽  
Author(s):  
Beatriz Merino ◽  
Carmen Díez-Fernández ◽  
Mariano Ruiz-Gayo ◽  
Beatriz Somoza
Keyword(s):  
Epithelial Cells ◽  
Choroid Plexus ◽  
Leptin Receptor ◽  
Short Form ◽  
Choroid Plexus Epithelial
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