Purinergic (ATP) signaling stimulates JNK1 but not JNK2 MAPK in osteoblast-like cells: contribution of intracellular Ca2+ release, stress activated and L-voltage-dependent calcium influx, PKC and Src kinases.
This work shows that ATP activates JNK1, but not JNK2, in rat osteoblasts and ROS-A 17/2.8 osteoblast-like cells. In ROS-A 17/2.8 cells ATP induced JNK1 phosphorylation in a dose- and time-dependent manner. JNK1 phosphorylation also increased after osteoblast stimulation with ATPgammaS and UTP, but not with ADPbetaS. RT-PCR studies supported the expression of P2Y(2) receptor subtype. ATP-induced JNK1 activation was reduced by PI-PLC, IP(3) receptor, PKC and Src inhibitors and by gadolinium, nifedipine and verapamil or a Ca(2+)-free medium. ERK 1/2 or p38 MAPK inhibitors diminished JNK1 activation by ATP, suggesting a cross-talk between these pathways. ATP stimulated osteoblast-like cell proliferation consistent with the participation of P2Y(2) receptors. These results show that P2Y(2) receptor stimulation by ATP induces JNK1 phosphorylation in ROS-A 17/2.8 cells in a way dependent on PI-PLC/IP(3)/intracellular Ca(2+) release and Ca(2+) influx through stress activated and L-type voltage-dependent calcium channels and involves PKC and Src kinases.
Katz
Sebastián
S
Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, San Juan 670, B8000ICN Bahía Blanca, Buenos Aires, Argentina.
Boland
Ricardo
R
Santillán
Graciela
G
D000255:Adenosine Triphosphate / Q000008:administration & dosage*; D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000187:drug effects / Q000502:physiology*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D051379:Mice; D048055:Mitogen-Activated Protein Kinase 8 / Q000378:metabolism; D048056:Mitogen-Activated Protein Kinase 9 / Q000378:metabolism; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010770:Phosphotransferases / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D019061:src-Family Kinases / Q000378:metabolism
D020746:Calcium Channels, L-Type; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; D048056:Mitogen-Activated Protein Kinase 9; D019061:src-Family Kinases; D011493:Protein Kinase C; D048055:Mitogen-Activated Protein Kinase 8; D002118:Calcium