title: Tissue inhibitor of metalloproteinase-3 inhibits neonatal mouse cardiomyocyte proliferation via EGFR/JNK/SP-1 signaling.
abstract: We have recently demonstrated that tissue inhibitor of metalloproteinase-3 (TIMP-3) decreases neonatal cardiomyocyte proliferation (Hammoud L, Xiang F, Lu X, Brunner F, Leco K, Feng Q. Cardiovasc Res 75: 359-368, 2007). The aim of the present study was to delineate a pathway through which TIMP-3 exerts its antiproliferative effect. Experiments were conducted on neonatal cardiomyocyte cultures and heart tissues isolated from wild-type (WT) and TIMP-3(-/-) mice. Deficiency in TIMP-3 decreased p27 expression and increased cardiomyocyte proliferation in cardiomyocytes and neonatal hearts. A TIMP-3/epidermal growth factor (EGF) receptor (EGFR)/c-Jun NH(2)-terminal kinase (JNK)/SP-1/p27 pathway was investigated. JNK phosphorylation and EGFR protein levels were increased in TIMP-3(-/-) cardiomyocytes and heart tissues. Treatment with recombinant TIMP-3 decreased JNK phosphorylation and EGFR expression/phosphorylation. Inhibition of JNK activity using SP-600125 decreased SP-1 phosphorylation, increased p27 expression, and decreased cardiomyocyte proliferation. Furthermore, treatment with the EGFR specific inhibitor PD-168393 or the EGF-neutralizing antibody decreased cardiomyocyte proliferation as well as phosphorylation of JNK and SP-1 in both WT and TIMP-3(-/-) cardiomyocytes. We conclude that TIMP-3 inhibits neonatal mouse cardiomyocyte proliferation by upregulating p27 expression. The effects of TIMP-3 are mediated via inhibition of EGFR expression/phosphorylation, and decreases in JNK and SP-1 signaling.
authors.affiliation: Department of Physiology, Univ. of Western Ontario, London, Ontario, Canada N6A 5C1.
authors.forename: Lamis
authors.initials: L
authors.lastname: Hammoud
authors.forename: Dylan E
authors.initials: DE
authors.lastname: Burger
authors.forename: Xiangru
authors.initials: X
authors.lastname: Lu
authors.forename: Qingping
authors.initials: Q
authors.lastname: Feng
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000873:Anthracenes / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000201:enzymology*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011799:Quinazolines / Q000494:pharmacology; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D000873:Anthracenes; C493961:Cdkn1b protein, mouse; C509204:PD168393; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D011994:Recombinant Proteins; D016329:Sp1 Transcription Factor; D019717:Tissue Inhibitor of Metalloproteinase-3; D050760:Cyclin-Dependent Kinase Inhibitor p27; C432165:pyrazolanthrone; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D048031:JNK Mitogen-Activated Protein Kinases