1. Hypoxia Induces Metalloproteinase-9 Activation and Human Vascular Smooth Muscle Cell Migration Through Low-Density Lipoprotein Receptor–Related Protein 1–Mediated Pyk2 Phosphorylation
- Author
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Carolina Gálvez-Montón, Lina Badimon, Laura Nasarre, Vicenta Llorente-Cortés, Santiago Roura, Sonia Benitez, José M. Castellano, Elena Revuelta-López, and Antoni Bayes-Genis
- Subjects
Vascular smooth muscle ,LRP1 protein ,Interleukin-1beta ,Myocytes, Smooth Muscle ,Active Transport, Cell Nucleus ,Matrix metalloproteinase ,Biology ,Transfection ,Muscle, Smooth, Vascular ,Proinflammatory cytokine ,Cell Movement ,protein tyrosine kinase Pyk2 ,Humans ,human ,Phosphorylation ,Protein Kinase Inhibitors ,Cells, Cultured ,Chemokine CCL2 ,Interleukin-6 ,hypoxia ,NF-kappa B ,Focal Adhesion Kinase 2 ,LRP1 ,Cell Hypoxia ,Enzyme Activation ,matrix metalloproteinase 1 ,Phenotype ,Matrix Metalloproteinase 9 ,Tyrosine kinase 2 ,LDL receptor ,Cancer research ,Matrix Metalloproteinase 2 ,RNA Interference ,Inflammation Mediators ,Cardiology and Cardiovascular Medicine ,Low Density Lipoprotein Receptor-Related Protein-1 ,Protein Binding ,Signal Transduction - Abstract
Objective— Hypoxia disturbs vascular function by promoting extracellular matrix remodeling. Extracellular matrix integrity and composition are modulated by metalloproteinases (MMPs). Our aim was to investigate the role of low-density lipoprotein receptor–related protein 1 (LRP1) in regulating MMP-9/MMP-2 activation and vascular smooth muscle cells (VSMCs) migration in response to hypoxia, and to elucidate the LRP1-signaling pathways involved in this process. Approach and Results— Western blot analysis showed that hypoxia induced a sustained phosphorylation of proline-rich tyrosine kinase 2 concomitantly with LRP1 overexpression in human VSMCs (hVSMCs). Deletion of LRP1 using small-interfering RNA technology or treatment of hVSMCs with the Src family kinase inhibitor PP2 impaired hypoxia-induced phosphorylation of proline-rich tyrosine kinase 2 levels. Coimmunoprecipitation experiments showed that the higher amounts of phosphorylation of proline-rich tyrosine kinase 2/LRP1β immunoprecipitates in hypoxic hVSMCs were abolished in PP2-treated hVSMCs. Both LRP1 silencing and PP2 treatment were highly effective in the prevention of hypoxia-induced MMP-9 activation and hVSMC migration. Cellular subfractionation experiments revealed that PP2 effects may be caused by impairment of hypoxia-induced nuclear factor-κβ translocation to the nucleus. ELISA measurements showed that LRP1 silencing but not PP2 treatment increased interleukin-1β, interleukin-6, and monocyte chemoattractant protein-1 secretion by hypoxic hVSMCs. Conclusions— Our findings determine a crucial role of LRP1-mediated Pyk2 phosphorylation on hypoxia-induced MMP-9 activation and hVSMC migration and therefore in hypoxia-induced vascular remodeling. Both LRP1 silencing and PP2 treatments also influence hypoxia-induced proinflammatory effects in hVSMCs. Therefore, further studies are required to establish therapeutical strategies that efficiently modulate vascular remodeling and inflammation associated with hypoxia-vascular diseases.
- Published
- 2013
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