Thyroid hormone stimulates the renal Na/H exchanger NHE3 by transcriptional activation

Citation
A. Cano et al., Thyroid hormone stimulates the renal Na/H exchanger NHE3 by transcriptional activation, AM J P-CELL, 45(1), 1999, pp. C102-C108
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
ISSN journal
0363-6143 → ACNP
Volume
45
Issue
1
Year of publication
1999
Pages
C102 - C108
Database
ISI
SICI code
0363-6143(199901)45:1<C102:THSTRN>2.0.ZU;2-N
Abstract
Thyroid hormone stimulates renal proximal tubule NaCl and NaHCo3 absorption in part by activating the apical membrane Na/H exchanger NHE3. We used a r enal epithelial cell Line, the opossum kidney (OK) cell, to define the mech anism by which 3,5,3'-triiodothyronine (T-3) increases NHE3 activity. T-3 s timulated NKE3 activity, an effect that was blocked by inhibition of cellul ar transcription or translation. The increase in activity was associated wi th increases in steady-state cell surface and total cellular NHE3 protein a nd NHE3 transcript abundance. T-3 stimulated transcription of the NHE3 gene and had no effect on NHE3 transcript stability. The transcriptional activi ty of the 5'-flanking region of the rat NHE3 gene was stimulated by Ts when expressed in OK cells. When heterologously expressed rat NKE3 transcript l evels were clamped constant with a constitutive promoter in OK cells, T-3 h as no effect on rat NHE3 protein abundance, suggesting the absence of regul ar ion of NHE3 protein stability or translation. These studies demonstrate that T-3 stimulates NHE3 activity by activating NKE3 gene transcription and increasing NHE3 transcript and protein abundance.