TY - JOUR
T1 - Purinergic regulation of CFTR and Ca2+ -activated Cl- channels and K+ channels in human pancreatic duct epithelium
AU - Wang, Jing
AU - Haanes, Kristian A
AU - Novak, Ivana
PY - 2013/4/1
Y1 - 2013/4/1
N2 - Purinergic agonists have been considered for the treatment of respiratory epithelia in cystic fibrosis (CF) patients. The pancreas, one of the most seriously affected organs in CF, expresses various purinergic receptors. Studies on the rodent pancreas show that purinergic signaling regulates pancreatic secretion. In the present study we aim to identify Cl- and K+ channels in human pancreatic ducts and their regulation by purinergic receptors. Human pancreatic duct epithelia formed by Capan-1 or CFPAC-1 cells were studied in open-circuit Ussing chambers. In Capan-1 cells, ATP/UTP effects were dependent on intracellular Ca2+. Apically applied ATP/UTP stimulated CF transmembrane conductance regulator (CFTR) and Ca2+-activated Cl- (CaCC) channels, which were inhibited by CFTRinh-172 and niflumic acid, respectively. The basolaterally applied ATP stimulated CFTR. In CFPAC-1 cells, which have mutated CFTR, basolateral ATP and UTP had negligible effects. In addition to Cl- transport in Capan-1 cells, the effects of 5, 6-dichloro-1-ethyl-1, 3-dihydro-2H-benzimidazol-2-one (DC-EBIO) and clotrimazole indicated functional expression of the intermediate conductance K+ channels (IK, KCa3.1). The apical effects of ATP/UTP were greatly potentiated by the IK channel opener DC-EBIO. Determination of RNA and protein levels revealed that Capan-1 cells have high expression of TMEM16A (ANO1), a likely CaCC candidate. We conclude that in human pancreatic duct cells ATP/UTP regulates via purinergic receptors both Cl- channels (TMEM16A/ANO1 and CFTR) and K+ channels (IK). The K+ channels provide the driving force for Cl--channel-dependent secretion, and luminal ATP provided locally or secreted from acini may potentiate secretory processes. Future strategies in augmenting pancreatic duct function should consider sidedness of purinergic signaling and the essential role of K+ channels.
AB - Purinergic agonists have been considered for the treatment of respiratory epithelia in cystic fibrosis (CF) patients. The pancreas, one of the most seriously affected organs in CF, expresses various purinergic receptors. Studies on the rodent pancreas show that purinergic signaling regulates pancreatic secretion. In the present study we aim to identify Cl- and K+ channels in human pancreatic ducts and their regulation by purinergic receptors. Human pancreatic duct epithelia formed by Capan-1 or CFPAC-1 cells were studied in open-circuit Ussing chambers. In Capan-1 cells, ATP/UTP effects were dependent on intracellular Ca2+. Apically applied ATP/UTP stimulated CF transmembrane conductance regulator (CFTR) and Ca2+-activated Cl- (CaCC) channels, which were inhibited by CFTRinh-172 and niflumic acid, respectively. The basolaterally applied ATP stimulated CFTR. In CFPAC-1 cells, which have mutated CFTR, basolateral ATP and UTP had negligible effects. In addition to Cl- transport in Capan-1 cells, the effects of 5, 6-dichloro-1-ethyl-1, 3-dihydro-2H-benzimidazol-2-one (DC-EBIO) and clotrimazole indicated functional expression of the intermediate conductance K+ channels (IK, KCa3.1). The apical effects of ATP/UTP were greatly potentiated by the IK channel opener DC-EBIO. Determination of RNA and protein levels revealed that Capan-1 cells have high expression of TMEM16A (ANO1), a likely CaCC candidate. We conclude that in human pancreatic duct cells ATP/UTP regulates via purinergic receptors both Cl- channels (TMEM16A/ANO1 and CFTR) and K+ channels (IK). The K+ channels provide the driving force for Cl--channel-dependent secretion, and luminal ATP provided locally or secreted from acini may potentiate secretory processes. Future strategies in augmenting pancreatic duct function should consider sidedness of purinergic signaling and the essential role of K+ channels.
KW - Adenosine Triphosphate
KW - Calcium
KW - Cell Line
KW - Chloride Channels
KW - Cystic Fibrosis Transmembrane Conductance Regulator
KW - Epithelial Cells
KW - Gene Expression Regulation
KW - Humans
KW - Pancreatic Ducts
KW - Potassium Channels, Calcium-Activated
KW - Receptors, Purinergic P2X
KW - Receptors, Purinergic P2Y
KW - Uridine Triphosphate
U2 - 10.1152/ajpcell.00196.2012
DO - 10.1152/ajpcell.00196.2012
M3 - Journal article
C2 - 23364268
SN - 0363-6143
VL - 304
SP - C673-84
JO - American Journal of Physiology: Cell Physiology
JF - American Journal of Physiology: Cell Physiology
IS - 7
ER -