Expression of the na-k-2cl cotransporter, bsc2, in the nervous
system.
Plotkin, M. D., M. R. Kaplan, L. N. Peterson, S. R. Gullans, S. C.
Hebert, and E. Delpire.
Renal Division, Department of Medicine, Brigham and Women's
Hospital
APStracts 3:0300C, 1996.
We used in situ hybridization and immunocytochemistry with polyclonal
antibodies against the mouse bumetanide-sensitive Na-K-2Cl
cotransporter (mBSC2) to determine the location of this cotransporter
in the rat brain. Northern blots and in situ hybridization showed the
presence of cotransporter mRNA in the brain, with an especially high
level of expression in the choroid plexus (CP). Affinity purified
anti-BSC2 antibody identified proteins of 145-155 kDa on western blot
analysis and immunoprecipitation of brain and CP membrane protein.
Indirect immunofluorescence demonstrated that BSC2 protein is located
on the apical surface of the CP and is heterogeneously distributed in
cell bodies and dendrites of neurons in the central and peripheral
nervous system. The apical localization of BSC2 in the CP was
confirmed by 86Rb uptakes in primary cultures of CP cells grown on
permeable filters and confocal immunofluorescence microscopy. The
apical localization of the cotransporter in CP epithelium suggests a
role for the cotransporter in CSF K+ homeostasis. In neurons, the
cotransporter may help regulate intracellular Cl- concentration and
thereby affect neuronal response to GABA.
Received 9 May 1996; accepted in final form 16 August 1996.
APS Manuscript Number C250-6.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996