SiRNA targeting SHP-1 accelerates angiogenesis in a rat model of hindlimb ischemia.
Vascular endothelial growth factor (VEGF) receptor-2 (KDR/flk-1) has a tyrosine kinase domain, and once activated, induces the autophosphorylation of the tyrosine residues, which is essential for angiogenesis. SHP-1, a cytoplasmic protein tyrosine phosphatase, plays a negative regulatory role in signal transduction pathways by dephosphorylation of the receptors to which it binds. Thus, therapeutic angiogenesis designed to inhibit expression of SHP-1 would be beneficial in hindlimb ischemia. In in vitro, the inhibition of SHP-1 by SHP-1 siRNA impaired the ability of TNF to block the tyrosine phosphorylation of KDR/flk-1 induced by VEGF and showed an increase in endothelial cell growth. In in vivo, SHP-1 mRNA, SHP-1 protein levels and VEGF were increased in a rat model of hindlimb ischemia. Upon injection to the ischemic adductor muscle, vector-based siRNA reduced SHP-1, increased phosphorylation of KDR/flk-1, and markedly increased capillary density. Our data demonstrated in vivo the potential use of siRNA targeting SHP-1 as therapy for peripheral ischemic diseases.
Sugano
Masahiro
M
Department of Molecular and Cellular Biology, Division of Molecular and Clinical Gerontology, Medical Institute of Bioregulation, Kyushu University, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan. massy@tsurumi.beppu.kyushu-u.ac.jp
Tsuchida
Keiko
K
Maeda
Toyoki
T
Makino
Naoki
N
D000818:Animals; D002478:Cells, Cultured; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000187:drug effects*; D015316:Genetic Therapy; D006801:Humans; D007511:Ischemia / Q000503:physiopathology* / Q000628:therapy; D008297:Male; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D016491:Peripheral Vascular Diseases / Q000503:physiopathology* / Q000628:therapy; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6 / Q000187:drug effects* / Q000235:genetics; D034741:RNA, Small Interfering / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014471:Umbilical Veins; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D034741:RNA, Small Interfering; D042461:Vascular Endothelial Growth Factor A; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; C509250:Ptpn6 protein, rat