Fig. 3

Quantitative mapping and expression of choroid plexus transporters. a RNAseq of rat choroid plexus revealed transport proteins with high transcript abundance. Of a total of 233 genes in the filtered ion transporter category, see "Methods" section, the luminally expressed Na⁺/K⁺ ATPase (NKA) subunit α1, NBCe2, and NKCC1 were in the top 6% of highest expressed transporters with rank numbers of 4, 5, and 13, with NHE1 at a much lower abundance; ranked 131. b Relative mRNA expression levels of NKCC1 (0.52 ± 0.06), the NKA subunit α1 (0.52 ± 0.08), NBCe2 (0.06 ± 0.01), and NHE1 (0.002 ± 0.000) in rat choroid plexus, n = 5. c mRNA expression levels in rat lateral choroid plexus of Na⁺/K⁺-ATPase subunit α1, α2, α3, \(\beta\)1, \(\beta\)2, and \(\beta\) 3 relative to reference genes, n = 5. d Quantification of Na⁺/K⁺-ATPase subunit α1, α2, and α3 protein in choroid plexus and brain normalized to GAPDH loading control. Data are shown as choroid plexus expression relative to brain expression, n = 4. Inset: Representative Western blots of Na⁺/K⁺-ATPase subunit α1, α2, and α3 in lateral choroid plexus or whole brain tissue (see intact Western blots in Additional file 1: Fig. S4d). e Immunostaining of Na⁺/K⁺-ATPase subunit α1 (green) in rat choroid plexus (CP) and brain parenchyma. Cell nuclei visualized with Hoechst (blue), scalebar = 20 μm