CFTR upregulates the expression of the basolateral Na(+)-K(+)-2Cl(-) cotransporter in cultured pancreatic duct cells

The purpose of the current experiments was 1) to assess basolateral Na(+)-K(+)-2Cl(-) cotransporter (NKCC1) expression and 2) to ascertain the role of cystic fibrosis transmembrane conductance regulator (CFTR) in the regulation of this transporter in a prototypical pancreatic duct epithelial cell line. Previously validated human pancreatic duct cell lines (CFPAC-1), which exhibit physiological features prototypical of cystic fibrosis, and normal pancreatic duct epithelia (stable recombinant CFTR-bearing CFPAC-1 cells, termed CFPAC-WT) were grown to confluence before molecular and functional studies. High-stringency Northern blot hybridization, utilizing specific cDNA probes, confirmed that NKCC1 was expressed in both cell lines and its mRNA levels were twofold higher in CFPAC-WT cells than in CFPAC-1 cells (P < 0.01, n = 3). Na(+)-K(+)-2Cl(-) cotransporter activity, assayed as the bumetanide-sensitive, Na(+)- and Cl(-)-dependent NH(+)(4) entry into the cell (with NH(+)(4) acting as a substitute for K(+)), increased by approximately 115% in CFPAC-WT cells compared with CFPAC-1 cells (P < 0.01, n = 6). Reducing the intracellular Cl(-) by incubating the cells in a Cl(-)-free medium increased Na(+)-K(+)-2Cl(-) cotransporter activity by twofold (P < 0.01, n = 4) only in CFPAC-WT cells. We concluded that NKCC1 is expressed in pancreatic duct cells and mediates the entry of Cl(-). NKCC1 activity is enhanced in the presence of an inward Cl(-) gradient. The results further indicate that the presence of functional CFTR enhances the expression of NKCC1. We speculate that CFTR regulates this process in a Cl(-)-dependent manner.

Medienart:

E-Artikel

Erscheinungsjahr:

1999

Erschienen:

1999

Enthalten in:

Zur Gesamtaufnahme - volume:277

Enthalten in:

The American journal of physiology - 277(1999), 6 vom: 17. Dez., Seite C1100-10

Sprache:

Englisch

Beteiligte Personen:

Shumaker, H [VerfasserIn]
Soleimani, M [VerfasserIn]

Links:

Volltext

Themen:

126880-72-6
1F7A44V6OU
8MDF5V39QO
9NEZ333N27
CFTR protein, human
Carrier Proteins
Chlorides
Colforsin
Cystic Fibrosis Transmembrane Conductance Regulator
Journal Article
Quaternary Ammonium Compounds
RNA, Messenger
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.
Sodium
Sodium Bicarbonate
Sodium-Potassium-Chloride Symporters

Anmerkungen:

Date Completed 20.01.2000

Date Revised 20.09.2018

published: Print

Citation Status MEDLINE

doi:

10.1152/ajpcell.1999.277.6.C1100

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM105305499