title: Possible role of cell surface H+ -ATP synthase in the extracellular ATP synthesis and proliferation of human umbilical vein endothelial cells.
abstract: Extracellular ATP synthesis on human umbilical vein endothelial cells (HUVECs) was examined, and it was found that HUVECs possess high ATP synthesis activity on the cell surface. Extracellular ATP generation was detected within 5 s after addition of ADP and inorganic phosphate and reached a maximal level at 15 s. This type of ATP synthesis was almost completely inhibited by mitochondrial H(+)-ATP synthase inhibitors (e.g., efrapeptins, resveratrol, and piceatannol), which target the F(1) catalytic domain. Oligomycin and carbonyl cyanide m-chlorophenylhydrazone, but not potassium cyanide, also inhibited extracellular ATP synthesis on HUVECs, suggesting that cell surface ATP synthase employs the transmembrane electrochemical potential difference of protons to synthesize ATP as well as mitochondrial H(+)-ATP synthase. The F(1)-targeting H(+)-ATP synthase inhibitors markedly inhibited the proliferation of HUVECs, but intracellular ATP levels in HUVECs treated with these inhibitors were only slightly affected, as shown by comparison with the control cells. Interestingly, piceatannol inhibited only partially the activation of Syk (a nonreceptor tyrosine kinase), which has been shown to play a role in a number of endothelial cell functions, including cell growth and migration. These findings suggest that H(+)-ATP synthase-like molecules on the surface of HUVECs play an important role not only in extracellular ATP synthesis but also in the proliferation of HUVECs. The present results demonstrate that the use of small molecular H(+)-ATP synthase inhibitors targeting the F(1) catalytic domain may lead to significant advances in potential antiangiogenic cancer therapies.
authors.affiliation: Faculty of Pharmaceutical Sciences, University of Tokushima, Shomachi, Tokushima, Japan. arakaki@ph.tokushima-u.ac.jp
authors.forename: Naokatu
authors.initials: N
authors.lastname: Arakaki
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nagao
authors.forename: Rie
authors.initials: R
authors.lastname: Niki
authors.forename: Ayako
authors.initials: A
authors.lastname: Toyofuku
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kuramoto
authors.forename: Yuka
authors.initials: Y
authors.lastname: Emoto
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Shibata
authors.forename: Koji
authors.initials: K
authors.lastname: Magota
authors.forename: Tomihiko
authors.initials: T
authors.lastname: Higuti
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D004792:Enzyme Precursors / Q000096:biosynthesis; D005110:Extracellular Space / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D009840:Oligomycins / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D011190:Potassium Cyanide / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000502:physiology; D000077185:Resveratrol; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors; D013267:Stilbenes / Q000494:pharmacology; D000072377:Syk Kinase; D014471:Umbilical Veins / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D004792:Enzyme Precursors; D047908:Intracellular Signaling Peptides and Proteins; D009840:Oligomycins; D010455:Peptides; D013267:Stilbenes; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C012953:efrapeptin; C041525:3,3',4,5'-tetrahydroxystilbene; D000255:Adenosine Triphosphate; D012264:Ribonucleotide Reductases; D011505:Protein-Tyrosine Kinases; C000606896:SYK protein, human; D000072377:Syk Kinase; D006180:Proton-Translocating ATPases; D011190:Potassium Cyanide; D000077185:Resveratrol