scholarly journals CrossTalk proposal: Apical NKCC1 of choroid plexus epithelial cells works in the net inward flux mode under basal conditions, maintaining intracellular Cl − and cell volume

2020 ◽  
Vol 598 (21) ◽  
pp. 4733-4736 ◽  
Author(s):  
Francisco J. Alvarez‐Leefmans
Keyword(s):  
Epithelial Cells ◽  
Choroid Plexus ◽  
Cell Volume ◽  
Flux Mode ◽  
Choroid Plexus Epithelial

scholarly journals Genetic and pharmacological inactivation of apical Na+-K+-2Cl− cotransporter 1 in choroid plexus epithelial cells reveals the physiological function of the cotransporter

2019 ◽  
Vol 316 (4) ◽  
pp. C525-C544 ◽  
Author(s):  
Jeannine M. C. Gregoriades ◽  
Aaron Madaris ◽  
Francisco J. Alvarez ◽  
Francisco J. Alvarez-Leefmans
Keyword(s):  
Epithelial Cells ◽  
Choroid Plexus ◽  
Basolateral Membrane ◽  
Water Volume ◽  
Water Fluxes ◽  
Membrane Location ◽  
Flux Mode ◽  
Choroid Plexus Epithelial

Choroid plexus epithelial cells (CPECs) secrete cerebrospinal fluid (CSF). They express Na+-K+-ATPase and Na+-K+-2Cl− cotransporter 1 (NKCC1) on their apical membrane, deviating from typical basolateral membrane location in secretory epithelia. Given this peculiarity, the direction of basal net ion fluxes mediated by NKCC1 in CPECs is controversial, and cotransporter function is unclear. Determining the direction of basal NKCC1-mediated fluxes is critical to understanding the function of apical NKCC1. If NKCC1 works in the net efflux mode, it may be directly involved in CSF secretion. Conversely, if NKCC1 works in the net influx mode, it would have an absorptive function, contributing to intracellular Cl− concentration ([Cl−]i) and cell water volume (CWV) maintenance needed for CSF secretion. We resolve this long-standing debate by electron microscopy (EM), live-cell-imaging microscopy (LCIM), and intracellular Na+ and Cl− measurements in single CPECs of NKCC1+/+ and NKCC1−/− mouse. NKCC1-mediated ion and associated water fluxes are tightly linked, thus their direction is inferred by measuring CWV changes. Genetic or pharmacological NKCC1 inactivation produces CPEC shrinkage. EM of NKCC1−/− CPECs in situ shows they are shrunken, forming large dilations of their basolateral extracellular spaces, yet remaining attached by tight junctions. Normarski LCIM shows in vitro CPECs from NKCC1−/− are ~17% smaller than NKCC1+/+. CWV measurements in calcein-loaded CPECs show that bumetanide (10 μM) produces ~16% decrease in CWV in NKCC1+/+ but not in NKCC1−/− CPECs. Our findings suggest that under basal conditions apical NKCC1 is continuously active and works in the net inward flux mode maintaining [Cl−]i and CWV needed for CSF secretion.

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.

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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