P2Y(1), P2Y(2), P2Y(4), and P2Y(6) receptors are coupled to Rho and Rho kinase activation in vascular myocytes

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 278; no. 6; pp. H1751 - H1761
• Main Authors: Sauzeau, V, Le Jeune, H, Cario-Toumaniantz, C, Vaillant, N, Gadeau, A P, Desgranges, C, Scalbert, E, Chardin, P, Pacaud, P, Loirand, G
• Format: Journal Article
• Language: English
• Published: United States 01.06.2000
• Subjects: 3T3 Cells; Actins - physiology; Animals; Aorta - cytology; Aorta - drug effects; Aorta - metabolism; Aorta - physiology; Cell Membrane - metabolism; Cells, Cultured; Cytoskeleton - physiology; Enzyme Activation - physiology; Fibroblasts - metabolism; Intracellular Membranes - physiology; Intracellular Signaling Peptides and Proteins; Mice; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - drug effects; Muscle, Smooth, Vascular - metabolism; Muscle, Smooth, Vascular - physiology; Nucleotides - pharmacology; Protein-Serine-Threonine Kinases - metabolism; Protein-Serine-Threonine Kinases - physiology; Purinergic P2 Receptor Agonists; Rats; Rats, Wistar; Receptors, Purinergic P2 - metabolism; rho-Associated Kinases; rhoA GTP-Binding Protein - metabolism; Signal Transduction - physiology; Vasoconstriction - physiology
• ISSN: 0363-6135
• DOI: 10.1152/ajpheart.2000.278.6.H1751

In the cardiovascular system, activation of ionotropic (P2X receptors) and metabotropic (P2Y receptors) P2 nucleotide receptors exerts potent and various responses including vasodilation, vasoconstriction, and vascular smooth muscle cell proliferation. Here we examined the involvement of the small GTPase RhoA in P2Y receptor-mediated effects in vascular myocytes. Stimulation of cultured aortic myocytes with P2Y receptor agonists induced an increase in the amount of membrane-bound RhoA and stimulated actin cytoskeleton organization. P2Y receptor agonist-induced actin stress fiber formation was inhibited by C3 exoenzyme and the Rho kinase inhibitor Y-27632. Stimulation of actin cytoskeleton organization by extracellular nucleotides was also abolished in aortic myocytes expressing a dominant negative form of RhoA. Extracellular nucleotides induced contraction and Y-27632-sensitive Ca(2+) sensitization in aortic rings. Transfection of Swiss 3T3 cells with P2Y receptors showed that Rho kinase-dependent actin stress fiber organization was induced in cells expressing P2Y(1), P2Y(2), P2Y(4), or P2Y(6) receptor subtypes. Our data demonstrate that P2Y(1), P2Y(2), P2Y(4), and P2Y(6) receptor subtypes are coupled to activation of RhoA and subsequently to Rho-dependent signaling pathways.