Regulation of Urea Transporters by Tonicity-responsive Enhancer Binding Protein
Electrolytes & Blood Pressure
;
: 28-33, 2007.
Artigo
em Inglês
| WPRIM
| ID: wpr-195947
ABSTRACT
Urea accumulation in the renal inner medulla plays a key role in the maintenance of maximal urinary concentrating ability. Urea transport in the kidney is mediated by transporter proteins that include renal urea transporter (UT-A) and erythrocyte urea transporter (UT-B). UT-A1 and UT-A2 are produced from the same gene. There is an active tonicity-responsive enhancer (TonE) in the promoter of UT-A1, and the UT-A1 promoter is stimulated by hypertonicity via tonicity-responsive enhancer binding protein (TonEBP). The downregulation of UT-A2 raises the possibility that TonEBP also regulates its promoter. There is some evidence that TonEBP regulates expression of UT-A in vivo; (1) during the renal development of the urinary concentrating ability, expression of TonEBP precedes that of UT-A1; (2) in transgenic mice expressing a dominant negative form of TonEBP, expression of UT-A1 and UT-A2 is severely impaired; (3) in treatment with cyclosporine A, TonEBP was significantly downregulated after 28 days. This downregulation involves mRNA levels of UT-A2; (4) in hypokalemic animals, downregulation of TonEBP contributed to the down regulation of UT-A in the inner medulla. These data support that TonEBP directly contributes to the urinary concentration and renal urea recycling by the regulation of urea transporters.
Texto completo:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Ureia
/
RNA Mensageiro
/
Camundongos Transgênicos
/
Proteínas de Transporte
/
Regulação para Baixo
/
Ciclosporina
/
Eritrócitos
/
Reciclagem
/
Rim
Limite:
Animais
Idioma:
Inglês
Revista:
Electrolytes & Blood Pressure
Ano de publicação:
2007
Tipo de documento:
Artigo
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