Calcium-pump inhibitors induce functional surface expression of Delta F508-CFTR protein in cystic fibrosis epithelial cells

Nat Med. 2002 May;8(5):485-92. doi: 10.1038/nm0502-485.


The most common mutation in cystic fibrosis, Delta F508, results in a cystic fibrosis transmembrane conductance regulator (CFTR) protein that is retained in the endoplasmic reticulum (ER). Retention is dependent upon chaperone proteins, many of which require Ca(++) for optimal activity. Interfering with chaperone activity by depleting ER Ca(++) stores might allow functional Delta F508-CFTR to reach the cell surface. We exposed several cystic fibrosis cell lines to the ER Ca(++) pump inhibitor thapsigargin and evaluated surface expression of Delta F508-CFTR. Treatment released ER-retained Delta F508-CFTR to the plasma membrane, where it functioned effectively as a Cl(-) channel. Treatment with aerosolized calcium-pump inhibitors reversed the nasal epithelial potential defect observed in a mouse model of Delta F508-CFTR expression. Thus, ER calcium-pump inhibitors represent a potential target for correcting the cystic fibrosis defect.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amiloride / pharmacology
  • Calcium Channel Blockers / pharmacology*
  • Cell Membrane / drug effects
  • Cell Membrane / physiology*
  • Cells, Cultured
  • Cystic Fibrosis / physiopathology*
  • Cystic Fibrosis Transmembrane Conductance Regulator / genetics*
  • Epithelial Cells / drug effects
  • Epithelial Cells / physiology*
  • Gene Expression Regulation / drug effects*
  • Humans
  • Isoproterenol / pharmacology
  • Patch-Clamp Techniques
  • Sequence Deletion
  • Thapsigargin / pharmacology*


  • CFTR protein, human
  • Calcium Channel Blockers
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Thapsigargin
  • Amiloride
  • Isoproterenol