Signaling pathways transduced through the elastin receptor facilitate proliferation of arterial smooth muscle cells.
In this report we demonstrate that soluble peptides, elastin degradation products stimulate proliferation of arterial smooth muscle cells. We show that these effects are due to generation of intracellular signals transduced through the cell surface elastin receptor, which consists of peripheral 67-kDa elastin-binding protein (EBP) (spliced variant of beta-galactosidase), immobilized to the transmembrane sialidase and the protective protein. We found that elastin receptor-transduced signaling triggers activation of G proteins, opening of l-type calcium channels, and a sequential activation of tyrosine kinases: FAK, c-Src, platelet-derived growth factor-receptor kinase and then Ras-Raf-MEK1/2-ERK1/2 phosphorylation cascade. This, in turn, causes an increase in expression of cyclins and cyclin-dependent kinases, and a consequent increase in cellular proliferation. The EBP-transduced signals also induce tyrosine kinase-dependent phosphorylation of beta-tubulin, LC3, microtubule-associated protein 1, and alpha-actin and troponin-T, which could be linked to reorganization of cytoskeleton. We have also disclosed that induction of these signals can be abolished by anti-EBP antibody or by galactosugars, which cause shedding of EBP from the cell surface. Moreover, elastin-derived peptides did not induce proliferation of EBP-deficient cells derived from patients bearing a nonsense mutation of the beta-galactosidase gene or sialidase-deficient cells from patients with congenital sialidosis.
Mochizuki
Satsuki
S
Cardiovascular Research Program, The Hospital for Sick Children and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5G 1X8, Canada.
Brassart
Bertrand
B
Hinek
Aleksander
A
D000818:Animals; D001158:Arteries / Q000033:anatomy & histology / Q000502:physiology*; D000081247:CSK Tyrosine-Protein Kinase; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002455:Cell Division / Q000502:physiology*; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D016213:Cyclins / Q000378:metabolism; D004549:Elastin / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D016537:Gangliosidosis, GM1 / Q000378:metabolism; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008954:Models, Biological; D009081:Mucolipidoses / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D015737:Nisoldipine / Q000494:pharmacology; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D037342:Pertussis Toxin / Q000494:pharmacology; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013552:Swine; D014443:Tyrosine / Q000378:metabolism; D019061:src-Family Kinases
D002121:Calcium Channel Blockers; D016895:Culture Media, Serum-Free; D016213:Cyclins; D004791:Enzyme Inhibitors; D010455:Peptides; D011956:Receptors, Cell Surface; C054901:elastin-binding proteins; D014443:Tyrosine; D015737:Nisoldipine; D004549:Elastin; D037342:Pertussis Toxin; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D019061:src-Family Kinases; C000631346:CSK protein, human; D018844:Cyclin-Dependent Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D002118:Calcium