Uridine-5'-triphosphate and adenosine triphosphate gammaS induce mucin secretion via Ca2+-dependent pathways in human nasal epithelial cells.
OBJECTIVE
Nucleotides such as adenosine triphosphate (ATP) and uridine-5'-triphosphate (UTP) play fundamental roles in the early stage of secretion in nasal epithelial cells via the P2Y receptor. In this study, we examined the expression pattern of P2Y subtypes and their functions on Ca2+ influx ([Ca2+]i) in normal human nasal epithelial (NHNE) cells. We also examined the effect of UTP (an agonist for P2Y2) and ATPgammaS (an agonist for P2Y11) on mucin secretion and mucin gene expression.


METHODS
The expression pattern of P2Y receptors and the mRNA levels of MUC5AC, MUC5B and MUC8 were examined after treatment with UTP and ATPgammaS by means of reverse transcriptase polymerase chain reaction. Mucin was quantified by an immunoblotting assay. We measured [Ca2+]i in NHNE cells using a double perfusion chamber.


RESULTS
Two uracil-sensitive receptors (P2Y2, P2Y4) and two adenine-selective receptors (P2Y1, P2Y11) were expressed in NHNE cells. UTP and ATPgammaS increased [Ca2+]i via caffeine-sensitive pathways, and these two agonists stimulated mucin secretion to a similar magnitude without their gene enhancement. In addition, the mucin stimulatory effects subsided when the intracellular Ca2+ was removed by 2-bis-(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester.


CONCLUSIONS
This study showed that P2Y2 and P2Y11 receptors were expressed in NHNE cells and that their agonists, UTP and ATPgammaS, act as secretogogues on mucin secretion via Ca2+-dependent pathways.
Choi
Jae Young
JY
Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea.
Namkung
Wan
W
Shin
Ji-Hyun
JH
Yoon
Joo-Heon
JH
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D018929:Cell Culture Techniques; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D009077:Mucins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D009297:Nasal Mucosa / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D011983:Receptors, Purinergic / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D014544:Uridine Triphosphate / Q000494:pharmacology*
D009077:Mucins; D012333:RNA, Messenger; D011983:Receptors, Purinergic; D000255:Adenosine Triphosphate; D002118:Calcium; D014544:Uridine Triphosphate