Localization of the Organic Anion Transporting Polypeptide 2 (Oatp2) in Capillary Endothelium and Choroid Plexus Epithelium of Rat Brain

Abstract

In this study we investigated the distribution of a recently cloned polyspecific organic anion transporting polypeptide (Oatp2) in rat brain by nonradioactive in situ hybridization histochemistry and immunofluorescence microscopy. The results demonstrate that Oatp2 is expressed in brain capillary and in plexus epithelial cells. At the blood-brain barrier (BBB), Oatp2 expression could be co-localized with the endothelial marker vWF (von Willebrand factor) but not with the astrocyte marker GFAP (glial fibrillary acidic protein). In choroid plexus epithelial cells, Oatp2 could be localized to the basolateral cell pole, whereas the first member of the Oatp gene family of membrane transporters to be cloned (Oatp1) co-localized with the alpha(1)-subunit of Na,K-ATPase at the apical plasma membrane domain. Because Oatp1 and Oatp2 have been previously shown to mediate transmembrane transport of a wide variety of amphipathic organic compounds, including many drugs and other xenobiotics, the histochemical localization of Oatp2 at the BBB and of Oatp1 and Oatp2 in the choroid plexus imply a role for these transporters in the active exchange of amphipathic solutes between the blood, brain, and cerebrospinal fluid compartments. (J Histochem Cytochem 47:1255-1263, 1999)

Localization of organic anion transporting polypeptide 3 (oatp3) in mouse brain parenchymal and capillary endothelial cells

“…4, the immunoreactivity was detected in restricted brain regions. In addition, a previous immunohistochemical study showed that anti-oatp2 antibody gave intense immunoreactivity on endothelial cells of cerebral capillaries, whereas this antibody exhibited only a weak band of oatp2 in a similar amount (30 lg) of rat brain membrane fraction by western blotting (Gao et al 1999). mRNA expression of oatp2 in mouse brain is greater than that of oatp3 (Fig.…”

“…3) suggested mouse oatp3 to be localized at the brush-border membrane of choroid plexus. Furthermore, rat oatp2 is localized at the basolateral membrane of choroid plexus epithelial cells (Gao et al 1999), and mouse oatp2 was also detected in choroid plexus (Fig. 1).…”

“…Oatp2 and oatp14 are expressed at brain capillaries and choroid plexus, which form the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB), respectively (Gao et al 1999;Sugiyama et al 2003). We have reported that oatp3 is localized at the rat choroid plexus (Ohtsuki et al 2003) and this finding raises the issue of whether oatp3 is expressed at the brain capillaries.…”

Interaction of protamine with gram‐negative bacteria membranes: possible alternative mechanisms of internalization in Escherichia coli, Salmonella typhimurium and Pseudomonas aeruginosa

“…Most CAPs are cationic by virtue of the presence of lysine, arginine and/or histidine and usually composed of 12-50 amino acids. The bactericidal effect of many CAPs is thought to be due to the action on the cytoplasmic membrane of the susceptible bacteria, possibly through the formation of pores or destabilization of the membrane bilayer structure leading to lysis of the cell [4,5]. Some CAPs such as buforin 11 [6], indolicidin [7], apidaecin [8], PR 39 [9], PR 26 [10], bactenecin [11] and lactoferricin B [12,13] have been reported to have intracellular targets.…”

Molecular cloning and functional characterization of the mouse organic-anion-transporting polypeptide 1 (Oatp1) and mapping of the gene to chromosome X

“…Oatp1 is expressed, in addition to the sinusoidal membrane of hepatocytes [9], in the apical membrane of the proximal tubule [10] and in the apical membrane of the choroid plexus [11]. Oatp2 protein was detected in rat liver hepatocytes, endothelial cells of the blood\brain barrier [12][13][14] and the choroid plexus [12]. On the basis of Northern-blot analysis, Oatp3 is expressed in the kidney, liver and the retina [4].…”