BACKGROUND: Platelet-derived growth factor (PDGF) is a potent mitogen and chemoattractant for vascular smooth muscle cells (SMCs). Three isotypes of PDGF (BB, AB, and AA) have been identified; each of these isotypes may have differing effects on the behaviour of vascular SMCs. In this study we evaluated the influence of PDGF isotypes on proliferation and migration of human venous SMCs and explored the signaling pathways through which these effects are mediated. METHODS: Proliferation was measured by a 72-hour assay of cell number, and migration was evaluated by a 4-hour microchemotaxis assay. The effects of PDGF isotypes on the activities of the signaling proteins mitogen-activated protein kinase (MAP-K), p 125 focal adhesion kinase (p125FAK), and tensin were measured by immunoprecipitation of these proteins and subsequent phosphorylation on myelin basic protein (in MAP-K) and Western blotting with antiphosphotyrosine (in tensin and p125FAK). RESULTS: All three isotypes stimulated SMC proliferation (PDGF-BB > AB > AA). PDGF-BB and -AB, but not -AA, stimulated chemotaxis. All three isotypes activated MAP-K with an intensity that corresponded to their proliferative effects. PDGF-BB and -AB tyrosine phosphorylated tensin and p125FAK, whereas PDGF-AA had no effect on either of these proteins. CONCLUSIONS: For human vascular SMCs the physiologic effects and the signaling pathways that mediate these effects are specific for each of the three PDGF isotypes. These data also suggest an association between MAP-K and SMC proliferation and between the proteins, p125FAK and tensin, and migration.
BACKGROUND: Platelet-derived growth factor (PDGF) is a potent mitogen and chemoattractant for vascular smooth muscle cells (SMCs). Three isotypes of PDGF (BB, AB, and AA) have been identified; each of these isotypes may have differing effects on the behaviour of vascular SMCs. In this study we evaluated the influence of PDGF isotypes on proliferation and migration of human venous SMCs and explored the signaling pathways through which these effects are mediated. METHODS: Proliferation was measured by a 72-hour assay of cell number, and migration was evaluated by a 4-hour microchemotaxis assay. The effects of PDGF isotypes on the activities of the signaling proteins mitogen-activated protein kinase (MAP-K), p 125 focal adhesion kinase (p125FAK), and tensin were measured by immunoprecipitation of these proteins and subsequent phosphorylation on myelin basic protein (in MAP-K) and Western blotting with antiphosphotyrosine (in tensin and p125FAK). RESULTS: All three isotypes stimulated SMC proliferation (PDGF-BB > AB > AA). PDGF-BB and -AB, but not -AA, stimulated chemotaxis. All three isotypes activated MAP-K with an intensity that corresponded to their proliferative effects. PDGF-BB and -AB tyrosine phosphorylated tensin and p125FAK, whereas PDGF-AA had no effect on either of these proteins. CONCLUSIONS: For human vascular SMCs the physiologic effects and the signaling pathways that mediate these effects are specific for each of the three PDGF isotypes. These data also suggest an association between MAP-K and SMC proliferation and between the proteins, p125FAK and tensin, and migration.
Authors: A D Schecter; P L Giesen; O Taby; C L Rosenfield; M Rossikhina; B S Fyfe; D S Kohtz; J T Fallon; Y Nemerson; M B Taubman Journal: J Clin Invest Date: 1997-11-01 Impact factor: 14.808
Authors: Emily H Hall; Jeremy L Balsbaugh; Kristie L Rose; Jeffrey Shabanowitz; Donald F Hunt; David L Brautigan Journal: Mol Cell Proteomics Date: 2010-08-26 Impact factor: 5.911
Authors: Nafiseh Nili; Asim N Cheema; Frank J Giordano; Alan W Barolet; Saeid Babaei; Reed Hickey; Mohammad R Eskandarian; Mirjam Smeets; Jagdish Butany; Gerard Pasterkamp; Bradley H Strauss Journal: Am J Pathol Date: 2003-09 Impact factor: 4.307
Authors: Shirling Tsai; Scott T Hollenbeck; Evan J Ryer; Rachel Edlin; Dai Yamanouchi; Rishi Kundi; Chunjie Wang; Bo Liu; K Craig Kent Journal: Am J Physiol Heart Circ Physiol Date: 2009-06-12 Impact factor: 4.733