title: The P2Y2nucleotide receptor is an inhibitor of vascular calcification.
abstract: Mutations in the 5'-nucleotidase ecto (NT5E) gene that encodes CD73, a nucleotidase that converts AMP to adenosine, are linked to arterial calcification. However, the role of purinergic receptor signaling in the pathology of intimal calcification is not well understood. In this study, we examined whether extracellular nucleotides acting via P2Y2receptor (P2Y2R) modulate arterial intimal calcification, a condition highly correlated with cardiovascular morbidity.
  
  
  
  Apolipoprotein E, P2Y2R double knockout mice (ApoE-/-P2Y2R-/-) were used to determine the effect of P2Y2R deficiency on vascular calcification in vivo. Vascular smooth muscle cells (VSMC) isolated from P2Y2R-/-mice grown in high phosphate medium were used to assess the role of P2Y2R in the conversion of VSMC into osteoblasts. Luciferase-reporter assays were used to assess the effect of P2Y2R on the transcriptional activity of Runx2.
  
  
  
  P2Y2R deficiency in ApoE-/-mice caused extensive intimal calcification despite a significant reduction in atherosclerosis and macrophage plaque content. The ectoenzyme apyrase that degrades nucleoside di- and triphosphates accelerated high phosphate-induced calcium deposition in cultured VSMC. Expression of P2Y2R inhibits calcification in vitro inhibited the osteoblastic trans-differentiation of VSMC. Mechanistically, expression of P2Y2R inhibited Runx2 transcriptional activation of an osteocalcin promoter driven luciferase reporter gene.
  
  
  
  This study reveals a role for vascular P2Y2R as an inhibitor of arterial intimal calcification and provides a new mechanistic insight into the regulation of the osteoblastic trans-differentiation of SMC through P2Y2R-mediated Runx2 antagonism. Given that calcification of atherosclerotic lesions is a significant clinical problem, activating P2Y2R may be an effective therapeutic approach for treatment or prevention of vascular calcification.
authors.affiliation: Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Shaomin
authors.initials: S
authors.lastname: Qian
authors.affiliation: Medicine/Endocrinology, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Jenna N
authors.initials: JN
authors.lastname: Regan
authors.affiliation: Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Maxwell T
authors.initials: MT
authors.lastname: Shelton
authors.affiliation: Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: April
authors.initials: A
authors.lastname: Hoggatt
authors.affiliation: Medicine/Endocrinology, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Khalid S
authors.initials: KS
authors.lastname: Mohammad
authors.affiliation: Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Herring
authors.affiliation: Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA. Electronic address: cseye@iu.edu.
authors.forename: Cheikh I
authors.initials: CI
authors.lastname: Seye
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000378:metabolism / Q000473:pathology; D001018:Aortic Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D001057:Apolipoproteins E / Q000172:deficiency / Q000235:genetics; D050197:Atherosclerosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D054338:Cell Transdifferentiation; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D058851:GPI-Linked Proteins / Q000378:metabolism; D020022:Genetic Predisposition to Disease; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000378:metabolism* / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology; D010006:Osteoblasts / Q000378:metabolism / Q000473:pathology; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D011401:Promoter Regions, Genetic; D058473:Receptors, Purinergic P2Y2 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D061205:Vascular Calcification / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*
chemical_list: D001057:Apolipoproteins E; D050659:Core Binding Factor Alpha 1 Subunit; D058851:GPI-Linked Proteins; C546386:P2ry2 protein, mouse; D058473:Receptors, Purinergic P2Y2; C493716:Runx2 protein, mouse; D015675:Osteocalcin; D015720:5'-Nucleotidase; C548242:Nt5e protein, mouse
keywords: ATP; Atherosclerosis; Inflammation; Nucleotide receptor; Vascular calcification