Characterization of CFTR expression and chloride channel activity in human endothelia.
The cystic fibrosis transmembrane conductance regulator (CFTR) functions as a low-conductance, cAMP-regulated chloride (Cl-) channel in a variety of cell types, such as exocrine epithelial cells. Our results demonstrate that human primary endothelial cells isolated from umbilical vein (HUVEC) and lung microvasculature (HLMVEC) also express CFTR as determined via RT-PCR and immunohistochemical and immunoprecipitation analyses. Moreover, Cl- efflux and whole cell patch-clamp analyses reveal that HUVEC (n = 6 samples, P < 0.05) and HLMVEC (n = 5 samples, P < 0.05) display cyclic nucleotide-stimulated Cl- transport that is inhibited by the CFTR selective Cl- channel blocker glibenclamide but not by the blocker DIDS, indicative of CFTR Cl- channel activity. Taken together, these findings demonstrate that human endothelial cells derived from multiple organ systems express CFTR and that CFTR functions as a cyclic nucleotide-regulated Cl- channel in human endothelia.
Tousson
A
A
Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
Van Tine
B A
BA
Naren
A P
AP
Shaw
G M
GM
Schwiebert
L M
LM
D001483:Base Sequence; D002478:Cells, Cultured; D018118:Chloride Channels / Q000502:physiology*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008833:Microcirculation / Q000502:physiology; D008969:Molecular Sequence Data; D009712:Nucleotides, Cyclic / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D011233:Precipitin Tests; D011652:Pulmonary Circulation / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014471:Umbilical Veins / Q000166:cytology / Q000378:metabolism
C505032:CFTR protein, human; D018118:Chloride Channels; D009712:Nucleotides, Cyclic; D012333:RNA, Messenger; D019005:Cystic Fibrosis Transmembrane Conductance Regulator