Inhibition of the Tyrosine Phosphatase SHP-2 Suppresses Angiogenesis in vitro and in vivo

Abstract

Endothelial cell survival is indispensable to maintain endothelial integrity and initiate new vessel formation. We investigated the role of SHP-2 in endothelial cell survival and angiogenesis in vitro as well as in vivo. SHP-2 function in cultured human umbilical vein and human dermal microvascular endothelial cells was inhibited by either silencing the protein expression with antisense-oligodesoxynucleotides or treatment with a pharmacological inhibitor (PtpI IV). SHP-2 inhibition impaired capillary-like structure formation (p < 0.01; n = 8) in vitroas well as new vessel growth ex vivo(p < 0.05; n = 10) and in vivo in the chicken chorioallantoic membrane (p < 0.01, n = 4). Additionally, SHP-2 knock-down abrogated fibroblast growth factor 2 (FGF-2)-dependent endothelial proliferation measured by MTT reduction (p < 0.01; n = 12). The inhibitory effect of SHP-2 knock-down on vessel growth was mediated by increased endothelial apoptosis (annexin V staining, p < 0.05, n = 9), which was associated with reduced FGF-2-induced phosphorylation of phosphatidylinositol 3-kinase (PI3-K), Akt and extracellular regulated kinase 1/2 (ERK1/2) and involved diminished ERK1/2 phosphorylation after PI3-K inhibition (n = 3). These results suggest that SHP-2 regulates endothelial cell survival through PI3-K-Akt and mitogen-activated protein kinase pathways thereby strongly affecting new vessel formation. Thus, SHP-2 exhibits a pivotal role in angiogenesis and may represent an interesting target for therapeutic approaches controlling vessel growth.

Role of tyrosine phosphatase SHP-1 in the mechanism of endorepellin angiostatic activity

“…In contrast, PP2-mediated block of Src, a small tyrosine kinase implicated in integrin-mediated activation of tyrosine phosphatases and phosphorylation of FAK, did not affect the endorepellin-induced block of migration (data not shown). Knockdown of SHP-2 ( Figure 5B) caused a general delay in endothelial cell migration in line with previous reports, 29 but it did not dampen the response to endorepellin ( Figure 5D). …”

The Kaposi's Sarcoma-Associated Herpesvirus G Protein-Coupled Receptor Contains an Immunoreceptor Tyrosine-Based Inhibitory Motif That Activates Shp2

“…The scratch assay in Fig. 4C shows that the vGPCR-ITIM mutant is also deficient at stimulating endothelial cell migration, consistent with a role for Shp2 in angiogenesis (3,13). The presence of functional ITIMs in GPCRs has so far received little attention (9,22,24).…”

“…In addition to the many growth-related pathways involving Shp2 mentioned above, recent data also support a role for Shp2 in angiogenesis (13). Indeed, one of the most striking functional consequences of vGPCR signaling in endothelial cells in vitro and in animal models is angiogenesis.…”

Site directed vascular gene delivery in vivo by ultrasonic destruction of magnetic nanoparticle coated microbubbles

“…Phosphorothioate-modified oligodeoxynucleotides (ODN) were purchased from MWG Biotech (Ebersberg, Germany) and sequences were as described previously. 15 Mouse anti-SHP-2 antibody was from Santa Cruz biotechnology (Heidelberg, Germany) and mouse anti-GAPDH antibody was purchased from Chemicon (Hampshire, England).…”