Coupling of CFTR-mediated anion secretion to nucleoside transporters and adenosine homeostasis in calu-3 cells

Coupling of CFTR-mediated anion secretion to nucleoside transporters and adenosine homeostasis in... The purpose of this study was to characterize the role of adenosine-dependent regulation of anion secretion in Calu-3 cells. RT-PCR studies showed that Calu-3 cells expressed mRNA for A2a and A2B but not A1 or A3 receptors, and for hENTl, hENT2 and hCNT3 but not hCNTl or hCNT2 nucleoside transporters. Short-circuit current measurements indicated that A2b receptors were present in both apical and basolateral membranes, whereas A2a receptors were detected only in basolateral membranes. Uptake studies demonstrated that the majority of adenosine transport was mediated by hENTl, which was localized to both apical and basolateral membranes, with a smaller hENT2-mediated component in basolateral membranes. Whole-cell current measurements showed that application of extracellular nitrobenzylmercaptopurine ribonucleoside (NBMPR), a selective inhibitor of hENTl-mediated transport, had similar effects on whole-cell currents as the application of exogenous adenosine. Inhibitors of adenosine kinase and 5′-nucleotidase increased and decreased, respectively, whole-cell currents, whereas inhibition of adenosine deaminase had no effect. Single-channel studies showed that NBMPR and adenosine kinase inhibitors activated CFTR Cl- channels. These results suggested that the equilibrative nucleoside transporters (hENTl, hENT2) together with adenosine kinase and 5′-nucleotidase play a crucial role in the regulation of CFTR through an adenosine-dependent pathway in human airway epithelia. The Journal of Membrane Biology Springer Journals

Coupling of CFTR-mediated anion secretion to nucleoside transporters and adenosine homeostasis in calu-3 cells

Loading next page...
Copyright © 2003 by Springer-Verlag
Life Sciences; Biochemistry, general; Human Physiology
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial