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Immunofluorescent localization of cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) in human sweat ducts
Author(s) -
Brown Mary Beth,
Vincent Karla K,
MillardStafford Mindy,
McCarty Nael A
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.796.30
Subject(s) - epithelial sodium channel , cystic fibrosis transmembrane conductance regulator , cystic fibrosis , transepithelial potential difference , staining , apical membrane , chemistry , chloride channel , pathology , epithelium , microbiology and biotechnology , biology , ion transporter , medicine , sodium , biochemistry , organic chemistry , membrane
A functional link between the chloride channel cystic fibrosis transmembrane conductance regulator (CFTR) and the epithelial Na + channel (ENaC), has been suggested based on evidence from electrophysiological and biochemical methods in heterologous expression systems. Their interaction in native tissue is not clearly defined but is implicated in the pathophysiology of cystic fibrosis. The present study utilized immunofluorescence and laser confocal microscopy on cryosections of healthy human skin specimens to characterize CFTR and ENaC localization in sweat ducts. Ductal segment morphology was identified with 4',6‐diamidino‐2‐phenylindole nuclear staining. Throughout the duct there was one to two fold less staining of CFTR compared to ENaC. The proportion of lumen‐specific staining was significantly (one to ten fold) greater for CFTR than for the more ubiquitous ENaC, but varied widely between tissue samples. There is additional corroborating evidence of some co‐localization of CFTR and ENaC confined primarily to the ductal lumen, a principal site of transepithelial NaCl reabsorption. This study is the first example of immunofluorescent staining for CFTR and ENaC localization in native human tissue. Future studies will help identify the spatial relationship between these two channel proteins, and how their potential interaction correlates to fluid and electrolyte transport in health and disease.