First Author | Nozaki M | Year | 2006 |
Journal | J Clin Invest | Volume | 116 |
Issue | 2 | Pages | 422-9 |
PubMed ID | 16453023 | Mgi Jnum | J:105442 |
Mgi Id | MGI:3615081 | Doi | 10.1172/JCI26316 |
Citation | Nozaki M, et al. (2006) Loss of SPARC-mediated VEGFR-1 suppression after injury reveals a novel antiangiogenic activity of VEGF-A. J Clin Invest 116(2):422-9 |
abstractText | VEGF-A promotes angiogenesis in many tissues. Here we report that choroidal neovascularization (CNV) incited by injury was increased by excess VEGF-A before injury but was suppressed by VEGF-A after injury. This unorthodox antiangiogenic effect was mediated via VEGFR-1 activation and VEGFR-2 deactivation, the latter via Src homology domain 2-containing (SH2-containing) tyrosine phosphatase-1 (SHP-1). The VEGFR-1-specific ligand placental growth factor-1 (PlGF-1), but not VEGF-E, which selectively binds VEGFR-2, mimicked these responses. Excess VEGF-A increased CNV before injury because VEGFR-1 activation was silenced by secreted protein, acidic and rich in cysteine (SPARC). The transient decline of SPARC after injury revealed a temporal window in which VEGF-A signaling was routed principally through VEGFR-1. These observations indicate that therapeutic design of VEGF-A inhibition should include consideration of the level and activity of SPARC. |