Submitted to: Trade Journal Publication
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2004
Publication Date: 8/6/2004
Citation: Wang, Z., Stoltenberg, M., Jo, S.M., Huang, L., Larsen, A., Dahlstrom, A., Danscher, G. 2004. Dynamic zinc pools in mouse choroid plexus. NeuroReport, 15:1801-1804, Lippincott, Williams & Wilkins.
Interpretive Summary: To get zinc from foods that we eat into the cells that need it, the body relies on proteins known as zinc transporters. Two families of zinc-transporter proteins, ZnT (Zinc Transporter, SLC30) and ZIP (ZRT1, IRT1-like protein, SLC39) have been identified in mammals. The ZnT proteins function in transport of zinc out of cells or in sequestration of zinc into intracellular compartments. Eight family members, ZnT1-7, have been cloned and characterized. These transporter proteins play different roles in zinc homeostasis in normal and pathological conditions in different tissues. The choroid plexus is a neuroepithelial-lined papillary projection of the ventricular ependyma, a structure that produces cerebrospinal fluid (CSF) in brain. Several studies have suggested that the choroid plexus is involved in the biodynamics of zinc ions in the central nervous system (CNS). In the present study, we investigated the detailed distributions of ZnT1, ZnT3, ZnT4, and ZnT6 proteins and zinc ions in rat choroid epithelium with immunohistochemistry and zinc selenide autometallography (ZnSeAMG) methods. Our results indicated that the choroids epithelium is involved in regulation of the zinc concentration in the cerebrospinal fluid.
Technical Abstract: We examined the presence of Zn-transporters (ZnT1, ZnT3, ZnT4, and ZnT6) proteins and zinc ions in rat choroid epithelium with immunohistochemistry and zinc selenide autometallography (ZnSeAMG).The four ZnT proteins were all expressed in the choroid epithelial cells.ZnT3 immunostaining was found invesicle membranes in the apical part of the cells, associated to the microvillus membrane. Correspondingly, the ZnSeAMG technique revealed zinc ions in small vesicles, in microvilli, and multivesicular bodies in the epithelial cells.Traceable zinc ions were also found in lysosome like organelles of fenestrated endothelial cells, but here no corresponding ZnT3 immunostaining was seen. The observations suggests that the choroid plexus is instrumental to regulation of the level of zinc ions in the cerebrospinal fluid.