title: Ticlopidine in its prodrug form is a selective inhibitor of human NTPDase1.
abstract: Nucleoside triphosphate diphosphohydrolase-1 (NTPDase1), like other ectonucleotidases, controls extracellular nucleotide levels and consequently their (patho)physiological responses such as in thrombosis, inflammation, and cancer. Selective NTPDase1 inhibitors would therefore be very useful. We previously observed that ticlopidine in its prodrug form, which does not affect P2 receptor activity, inhibited the recombinant form of human NTPDase1 (K i = 14 μM). Here we tested whether ticlopidine can be used as a selective inhibitor of NTPDase1. We confirmed that ticlopidine inhibits NTPDase1 in different forms and in different assays. The ADPase activity of intact HUVEC as well as of COS-7 cells transfected with human NTPDase1 was strongly inhibited by 100 µM ticlopidine, 99 and 86%, respectively. Ticlopidine (100 µM) completely inhibited the ATPase activity of NTPDase1 in situ as shown by enzyme histochemistry with human liver and pancreas sections. Ticlopidine also inhibited the activity of rat and mouse NTPDase1 and of potato apyrase. At 100 µM ticlopidine did not affect the activity of human NTPDase2, NTPDase3, and NTPDase8, nor of NPP1 and NPP3. Weak inhibition (10-20%) of NTPDase3 and -8 was observed at 1 mM ticlopidine. These results show that ticlopidine is a specific inhibitor of NTPDase1 that can be used in enzymatic and histochemistry assays.
authors.affiliation: Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada G1V 0A6 ; Centre de Recherche du CHU de Québec, 2705 Boulevard Laurier, Local T1-49, Québec, QC, Canada G1V 4G2.
authors.forename: Joanna
authors.identifier: 0000-0002-7127-4434
authors.initials: J
authors.lastname: Lecka
authors.affiliation: Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada G1V 0A6 ; Centre de Recherche du CHU de Québec, 2705 Boulevard Laurier, Local T1-49, Québec, QC, Canada G1V 4G2.
authors.forename: Michel
authors.identifier: 0000-0002-5673-9360
authors.initials: M
authors.lastname: Fausther
authors.affiliation: Department of Surgery, Klinikum Rechts der Isar, Technische Universität München, 81675 Munich, Germany.
authors.forename: Beat
authors.initials: B
authors.lastname: Künzli
authors.affiliation: Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada G1V 0A6 ; Centre de Recherche du CHU de Québec, 2705 Boulevard Laurier, Local T1-49, Québec, QC, Canada G1V 4G2.
authors.forename: Jean
authors.identifier: 0000-0003-2922-1600
authors.initials: J
authors.lastname: Sévigny
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D001081:Apyrase / Q000378:metabolism*; D019556:COS Cells; D002522:Chlorocebus aethiops; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D011755:Pyrophosphatases / Q000378:metabolism; D013988:Ticlopidine / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D015703:Antigens, CD; D004791:Enzyme Inhibitors; D000251:Adenosine Triphosphatases; D011755:Pyrophosphatases; C027201:ectoATPase; C439652:nucleoside-triphosphate diphosphohydrolase 3; D001081:Apyrase; C067869:CD39 antigen; D013988:Ticlopidine