Functional P2Y2 nucleotide receptors mediate uridine 5'-triphosphate-induced intimal hyperplasia in collared rabbit carotid arteries

• Published in: Circulation (New York, N.Y.) Vol. 106; no. 21; pp. 2720 - 2726
• Main Authors: SEYE, Cheikh I, QIONGMAN KONG, ERB, Laurie, GARRAD, Richard C, KRUGH, Brent, MEIFANG WANG, TURNER, John T, STUREK, Michael, GONZALEZ, Fernando A, WEISMAN, Gary A
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 19-11-2002
• Subjects: Adenosine Triphosphate - pharmacology; Animals; Atherosclerosis (general aspects, experimental research); Biological and medical sciences; Blood and lymphatic vessels; Calcium - metabolism; Cardiology. Vascular system; Carotid Arteries - drug effects; Carotid Arteries - metabolism; Carotid Arteries - pathology; Carotid Stenosis - chemically induced; Carotid Stenosis - metabolism; Carotid Stenosis - pathology; Cell Division - drug effects; Cells, Cultured; Disease Models, Animal; Drug Administration Routes; Fluorescent Dyes; Hyperplasia - chemically induced; Hyperplasia - metabolism; Hyperplasia - pathology; Immunoblotting; Inflammation - chemically induced; Inflammation - pathology; Macrophages - pathology; Medical sciences; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - drug effects; Muscle, Smooth, Vascular - metabolism; Osteopontin; Rabbits; Receptors, Purinergic P2 - genetics; Receptors, Purinergic P2 - metabolism; Receptors, Purinergic P2Y2; RNA - metabolism; Sialoglycoproteins - biosynthesis; Tunica Intima - drug effects; Tunica Intima - metabolism; Tunica Intima - pathology; Up-Regulation; Uridine Triphosphate; Cell culture; restenosis; Calcium; Rat; receptors; Pathogenesis; Hyperplasia; nucleotide; Rodentia; Cardiovascular disease; Triphosphates; carotid arteries; Extracellular; Vascular disease; Vertebrata; Mammalia; P2Y2 purinergic receptor; Animal; Carotid; Atherosclerosis; Intima; Uridine; Pyrimidine nucleoside
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/01.CIR.0000038111.00518.35

Extracellular uridine 5'-triphosphate (UTP) induces mitogenic activation of smooth muscle cells (SMCs) through binding to P2Y2 nucleotide receptors. P2Y2 receptor mRNA is upregulated in intimal lesions of rat aorta, but it is unclear how this G-protein-coupled receptor contributes to development of intimal hyperplasia.
This study used a silicone collar placed around rabbit carotid arteries to induce vascular injury and intimal thickening. Collar placement caused rapid upregulation of P2Y2 receptor mRNA in medial SMCs before appearance of neointima. Fura-2 digital imaging of single SMCs was used to measure changes in myoplasmic calcium concentration (Ca(m)) in response to P2Y receptor agonists. In contrast to UDP, activation by UTP or adenosine 5'-triphosphate (ATP) greatly increased Ca(m), which indicates upregulation of functional P2Y2 receptors at which UTP and ATP are equipotent agonists. The number of responsive cells was significantly greater for freshly dispersed SMCs from collared arteries than for controls. Perivascular infusion of UTP (100 micromol/L) within the collar significantly enhanced neointimal development. Intimas that resulted from UTP exposure were infiltrated by macrophages. Moreover, increased expression of osteopontin occurred in response to in situ application of UTP. ATP or UTP also stimulated osteopontin expression in cultured SMCs in a dose-dependent manner. Furthermore, P2Y2 antisense oligonucleotide inhibited osteopontin expression induced by UTP.
These findings indicate for the first time a role for the UTP/ATP receptor, P2Y2, in development of intimal hyperplasia associated with atherosclerosis and restenosis.