Distinct expression and subcellular localization patterns of Na+ /HCO3− cotransporter (SLC 4A4) variants NBCe1-A and NBCe1-B in mouse brain

• Published in: Neuroscience Vol. 146; no. 3; pp. 1220 - 1231
• Main Authors: Rickmann, M, Orlowski, B, Heupel, K, Roussa, E
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier 25-05-2007
• Subjects: Animals; Biological and medical sciences; Brain Chemistry - genetics; Cells, Cultured; Cerebellum - cytology; Cerebellum - metabolism; Cerebral Cortex - metabolism; Female; Fundamental and applied biological sciences. Psychology; Hippocampus - cytology; Hippocampus - metabolism; Hydrogen-Ion Concentration; Immunoblotting; Immunoenzyme Techniques; Immunohistochemistry; Mice; Microscopy, Immunoelectron; Nerve Tissue Proteins - biosynthesis; Nerve Tissue Proteins - genetics; Neurology; Neurons - metabolism; Neurons - ultrastructure; Olfactory Bulb - metabolism; Pregnancy; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; Sodium-Bicarbonate Symporters - biosynthesis; Sodium-Bicarbonate Symporters - genetics; Subcellular Fractions - metabolism; Subcellular Fractions - ultrastructure; Vertebrates: nervous system and sense organs; MOPS; day in vitro; CNS; LTP; PFA; phosphate-buffered saline; SLC; pH regulation; NBC; solute carrier; BSA; E17.5; FITC; Tris-buffered saline; sodium dodecyl sulfate; bicarbonate; paraformaldehyde; morpholinepropanesulfonic acid; polymerase chain reaction; fluorescein; long term potentiation; PBS; Na +/HCO 3 − cotransporter; SDS; TBS; ion transport; GFAP; DIV; indocarbocyanin; embryonic day 17.5; CY3; glial fibrillary acidic protein; bovine serum albumin; PCR; Rodentia; Central nervous system; Ion transport; Coupled transport; Encephalon; Hydrogencarbonates; Vertebrata; Mammalia; Sodium; Mouse; Animal; Localization
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/j.neuroscience.2007.02.061

Abstract The electrogenic Na+ /HCO3− cotransporter (NBCe1) has been identified as a key player for regulation of intracellular pH in several cell types. The present study was undertaken to determine expression and subcellular localization of the NH2 -terminal solute carrier (SLC) 4A4 variants NBCe1-A and NBCe1-B in mouse brain using variant-specific antibodies by immunohistochemistry and immunoelectron microscopy. In addition, distribution of NBCe1 variants and activity-dependent regulation was investigated in mouse embryonic day 17.5 (E17.5) hippocampal primary cultures in vitro . The results showed NBCe1-A and NBCe1-B transcript expression in the mouse olfactory bulb, cerebral cortex, hippocampus and cerebellum. NBCe1-A was predominantly expressed in Purkinje cells, granule cells of the dentate gyrus, non-pyramidal cell bodies in cerebral cortex, and in periglomerular and mitral cells in the olfactory bulb. Pyramidal neurons in cerebral cortex and apical cell dendrites in the hippocampus were stained for both NBCe1-A and NBCe1-B. Moreover, NBCe1-B was present in Bergmann glia. At the ultrastructural level, NBCe1-B was preferentially expressed in perivascular astroglial lamellae, whereas both NBCe1 NH2 -terminal variants were localized in pre- and postsynaptic compartments. Except for the olfactory bulb, NBCe1-A was always colocalized with calbindin. Treatment of E17.5 primary hippocampal cultures with KCl, showed dramatic downregulation of NBCe1-B mRNA and protein after 60 min, whereas NBCe1-A expression remained unchanged. These data demonstrate for the first time distinct cellular distribution of NBCe1 NH2 -terminal variants in mouse brain. NBCe1 may be involved in neuronal modulation, and pH regulation during neuronal activity.