1. Key role of PI3K? in monocyte chemotactic protein-1-mediated amplification of PDGF-induced aortic smooth muscle cell migration
- Author
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Fougerat, Anne, Smirnova, Natalia, Gayral, Stéphanie, Malet, Nicole, Hirsch, Emilio, Wymann, Matthias, Perret, Bertrand, Martinez, Laurent, Douillon, Monique, Laffargue, Muriel, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Genetics, Biology and Biochemistry, Université de Turin, Institute of Biochemistry and Genetics, and Simon, Marie Francoise
- Subjects
Receptors, CCR2 ,Swine ,MESH: Mice, Transgenic ,MESH: Aorta, Thoracic ,MESH: Class Ib Phosphatidylinositol 3-Kinase ,Myocytes, Smooth Muscle ,Aorta, Thoracic ,Mice, Transgenic ,[SDV.BC]Life Sciences [q-bio]/Cellular Biology ,MESH: Recombinant Proteins ,Mice ,Cell Movement ,MESH: Mice, Inbred C57BL ,MESH: Receptors, CCR2 ,Animals ,Class Ib Phosphatidylinositol 3-Kinase ,MESH: Animals ,[SDV.BC] Life Sciences [q-bio]/Cellular Biology ,MESH: Swine ,MESH: Cell Movement ,MESH: Chemokine CCL2 ,MESH: Mice ,Cells, Cultured ,Chemokine CCL2 ,Platelet-Derived Growth Factor ,MESH: Proto-Oncogene Proteins c-akt ,MESH: Platelet-Derived Growth Factor ,MESH: Myocytes, Smooth Muscle ,Research Papers ,Recombinant Proteins ,Mice, Inbred C57BL ,cardiovascular system ,Proto-Oncogene Proteins c-akt ,MESH: Cells, Cultured - Abstract
International audience; BACKGROUND AND PURPOSE: Vascular smooth muscle cell (SMC) migration within the arterial wall is a crucial event in atherogenesis and restenosis. Monocyte chemotactic protein-1/CC-chemokine receptor 2 (MCP-1/CCR2) signalling is involved in SMC migration processes but the molecular mechanisms have not been well characterized. We investigated the role of PI3Kγ in SMC migration induced by MCP-1. EXPERIMENTAL APPROACHES: A pharmacological PI3Kγ inhibitor, adenovirus encoding inactive forms of PI3Kγ and genetic deletion of PI3Kγ were used to investigate PI3Kγ functions in the MCP-1 and platelet-derived growth factor (PDGF) signalling pathway and migration process in primary aortic SMC. KEY RESULTS: The γ isoform of PI3K was shown to be the major signalling molecule mediating PKB phosphorylation in MCP-1-stimulated SMC. Using a PI3Kγ inhibitor and an adenovirus encoding a dominant negative form of PI3Kγ, we demonstrated that PI3Kγ is essential for SMC migration triggered by MCP-1. PDGF receptor stimulation induced MCP-1 mRNA and protein accumulation in SMCs. Blockade of the MCP-1/CCR2 pathway or pharmacological inhibition of PI3Kγ reduced PDGF-stimulated aortic SMC migration by 50%. Thus PDGF promotes an autocrine loop involving MCP-1/CCR2 signalling which is required for PDGF-mediated SMC migration. Furthermore, SMCs isolated from PI3Kγ-deficient mice (PI3Kγ(-/-)), or mice expressing an inactive PI3Kγ (PI3Kγ(KD/KD)), migrated less than control cells in response to MCP-1 and PDGF. CONCLUSIONS AND IMPLICATIONS: PI3Kγ is essential for MCP-1-stimulated aortic SMC migration and amplifies cell migration induced by PDGF by an autocrine/paracrine loop involving MCP-1 secretion and CCR2 activation. PI3Kγ is a promising target for the treatment of aortic fibroproliferative pathologies.
- Published
- 2012
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