Expression of Bicarbonate Transporters and Aquaporins in the Choroid Plexus

Activity: Talk or presentation typesLecture and oral contribution

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Jeppe Praetorius - Lecturer

  • Department of Anatomy
Based on the recent localization of two basolateral Na+ dependent HCO3- transporters in the basolateral plasma membrane domain of choroid plexus epithelial cells, we revisited the expression of transport proteins potentially associated with the production of CSF. Using RT-PCR we screened the rat choroid plexus expression of transporters within four gene families: the SLC4, SLC26, SLC9, SCNN and AQP families. AE2, SCL4a10/NCBE, NBCn1, NBCe2/NBC4, SLC26a10, NHE1, AQP1, AQP4 and AQP11 mRNAs are expressed at detectable levels in the choroid plexus among the members of the 5 gene families. There was no expression of ENaC mRNA. High resolution immunocytochemistry revealed that AE2, NCBE, NBCn1 are localized to the basolateral plasma membrane domain, while AQP1 is localized to the apical domain. Preliminary analysis localizes NBCe2 to the apical domain of choroid plexus epithelium. Functionally, we find evidence for both DIDS-sensitive and -insensitive Na+ dependent HCO3 - transport (likely NCBE and/or NBCe2 and NBCn1, respectively) as well as for DIDS-sensitive and -insensitive Cl-/HCO3- exchange (probably AE2 and a SLC26a-type exchanger). We hope that complementing the well established choroid plexus transporters by more transport proteins will help draw a more complete model for cerebrospinal fluid production. This work was supported by the Danish National Research Foundation
5 Apr 2005

Event (Conference)

TitleExperimental Biology 2005
Date05/04/200505/04/2005
CitySan Diego
CountryUnited States

ID: 192197