Urate Transport via Paracellular Route across Epithelial Cells.
Biol Pharm Bull
; 42(1): 43-49, 2019.
Article
em En
| MEDLINE
| ID: mdl-30606989
ABSTRACT
Urate is the final oxidation product of purine metabolism in humans. We have recently reported that the paracellular route is the major urate transport pathway across the blood-placental barrier. In this study, the mechanism of urate paracellular transport was investigated in several epithelial cell lines including Madin-Darby canine kidney (MDCK) type I, Lilly Laboratories cell-porcine kidney 1 (LLC-PK1) and Caco-2 cells. Very little urate passed through MDCK and LLC-PK1 cell layers. In contrast, one of the Caco-2 cell lines was found to be urate-permeable. This urate paracellular movement across Caco-2 cell layer was not inhibited by the urate transporter inhibitor benzbromarone but was partially inhibited by 4,4'-diisothiocyanato-2,2'-stilbenedisulfonic acid (DIDS), which inhibits chloride transport. Detection and quantification of claudin proteins that are important for paracellular transport of ions were performed by LC/MS. Claudins 1, 3, 4, 6, 7 and 12 were detected in urate-permeable cell lines, BeWo cells and Caco-2 cells. We compared claudin expression patterns in urate-permeable and urate-non-permeable Caco-2 cells by LC/MS and found that claudin 12 had a higher expression level in urate-permeable Caco-2 cells. Overexpression of these claudins in MDCK cells did not increase urate paracellular transport. Although there were differences in claudin expression pattern between urate-permeable and non-permeable cells, increased expression of single claudin alone did not explain paracellular permeability of urate.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ácido Úrico
/
Junções Íntimas
/
Células Epiteliais
/
Claudinas
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Biol Pharm Bull
Assunto da revista:
BIOQUIMICA
/
FARMACOLOGIA
Ano de publicação:
2019
Tipo de documento:
Article