title: P2X7 receptor as sensitive flow sensor for ERK activation in osteoblasts.
abstract: The involvement of the P2 receptor in the activation of ERK induced by a short transient fluid flow stimulation in MC3T3-E1 osteoblasts was examined in the current study. The ERK activation induced by this transient fluid flow stimulation was followed by an increase in c-fos mRNA expression. Suramin, a non-selective P2 receptor antagonist, and two different P2X7 receptor (P2X7R) antagonists, ATP analogue (oxidized ATP) and dye (Brilliant blue G), inhibited fluid flow-induced ERK activation. However, the P2Y receptor pathway inhibitor U73122 did not abolish this ERK activation. The P2X7R agonist 2',3'-O-(4-benzoylbenzoyl)-ATP (BzATP) significantly increased ERK activation and this activation could be completely inhibited by oxidized ATP and Brilliant blue G. Our results suggest that P2X7R is a highly sensitive P2 receptor for fluid flow-induced ERK activation in osteoblasts.
authors.affiliation: Department of Anatomy and Developmental Biology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-0841, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Okumura
authors.forename: Dai
authors.initials: D
authors.lastname: Shiba
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Kubo
authors.forename: Takahiko
authors.initials: T
authors.lastname: Yokoyama
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D004963:Estrenes / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D011760:Pyrrolidinones / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D058486:Receptors, Purinergic P2X7; D013314:Stress, Mechanical; D013498:Suramin / Q000494:pharmacology
chemical_list: D004963:Estrenes; C546469:P2rx7 protein, mouse; D016760:Proto-Oncogene Proteins c-fos; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D011760:Pyrrolidinones; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; D058486:Receptors, Purinergic P2X7; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; C033901:3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate; D013498:Suramin; D000255:Adenosine Triphosphate; D048049:Extracellular Signal-Regulated MAP Kinases