Platelet-rich plasma releasate promotes angiogenesis in vitro and in vivo

Platelet-rich plasma (PRP) is a plasma fraction in which several growth factors are concentrated at high levels. In recent years, the biological effects on various cells of the active soluble releasate that is isolated following platelet activation of PRP [PRP-releasate (PRPr)] have been reported. The purpose of this study was to determine the angiogenic effects of human PRPr in vitro and in vivo. PRPr was prepared from human whole blood using the double spin method and was activated with CaCl2 and autologous thrombin. PRPr stimulated proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) and in vivo angiogenesis-inducing ability in nude mice. PRPr led to the phosphorylation of Erk1/2 and Akt in HUVECs, and the induction of proliferation and migration by PRPr was suppressed by PRPr inhibitors PD98059 and LY294002. PRPr induces angiogenesis in vitro and in vivo, and the present findings suggest that the mechanism for this is activation of the ERK and phosphatidylinositol-3-kinase-Akt pathways. Our results demonstrate that PRPr is a promising autologous source for therapeutic angiogenesis in treating cardiovascular disease.