CNGA2 contributes to ATP-induced noncapacitative Ca2+ influx in vascular endothelial cells.
OBJECTIVE
ATP can activate several Ca(2+) influx channels in vascular endothelial cells. For example, it stimulates TRPC channels via capacitative and noncapacitative Ca(2+) entry (CCE and non-CCE, respectively) mechanisms; it also directly acts on P2X purinoceptors, resulting in Ca(2+) influx. In the present study, we tested the hypothesis that cyclic nucleotide-gated (CNG) channels also contribute to ATP-induced non-CCE.


METHODS
Two selective inhibitors of CNG channels, L-cis-diltiazem and LY-83583, and CNGA2-specific siRNA were used to study the involvement of CNGA2 in ATP-induced non-CCE in endothelial cells. Ca(2+) influx was studied using Ca(2+)-sensitive fluorescence dyes Fluo-3 and Fluo-4.


CONCLUSIONS
L-cis-diltiazem and LY-83583 markedly reduced ATP-induced non-CCE in 3 types of endothelial cells including the H5V endothelial cell line, the primary cultured bovine aortic endothelial cells and the endothelial cells within isolated mouse aortic strips. The CNGA2-specific siRNA also reduced the ATP-induced non-CCE in H5V endothelial cells. The Ca(2+) influx was inhibited by Rp-8-CPT-cAMPS, MDL-12330A, SQ-22536 and MRS-2179, but not by ODQ or NF-157. Taken together, the present study demonstrated that CNGA2 channels contribute to ATP-induced non-CCE in vascular endothelial cells. It is likely that ATP acts through P2Y(1)receptors and adenylyl cyclases to stimulate CNGA2.
Kwan
Hiu-Yee
HY
Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, SAR, China.
Cheng
Kwong-Tai
KT
Ma
Yan
Y
Huang
Yu
Y
Tang
Nelson L
NL
Yu
Shan
S
Yao
Xiaoqiang
X
D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism; D000634:Aminoquinolines / Q000494:pharmacology; D000814:Aniline Compounds; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects; D002417:Cattle; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004110:Diltiazem / Q000494:pharmacology; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007097:Imines / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D058919:Purinergic P2 Receptor Antagonists; D034622:RNA Interference; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D058472:Receptors, Purinergic P2Y1; D013873:Thionucleotides / Q000494:pharmacology; D013997:Time Factors; D014162:Transfection; D014664:Vasodilation; D014966:Xanthenes
C090860:8-(4-chlorophenylthio)guanosine 3',5'-cyclic monophosphorothioate; D000067956:Adenylyl Cyclase Inhibitors; D000634:Aminoquinolines; D000814:Aniline Compounds; D002121:Calcium Channel Blockers; C518240:Cnga2 protein, mouse; D054815:Cyclic Nucleotide-Gated Cation Channels; D004791:Enzyme Inhibitors; C409648:Fluo 4; D007097:Imines; C111914:N(6)-methyl-2'-deoxyadenosine 3',5'-diphosphate; C546383:P2ry1 protein, mouse; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; D013873:Thionucleotides; D014966:Xanthenes; C017759:9-(tetrahydro-2-furyl)-adenine; C059715:Fluo-3; D000244:Adenosine Diphosphate; C014925:RMI 12330A; D000255:Adenosine Triphosphate; C041715:6-anilino-5,8-quinolinedione; D000262:Adenylyl Cyclases; D004110:Diltiazem; D006152:Cyclic GMP; D000225:Adenine