trp-lys-tyr-met-val-met and Ischemia

WKYMVm hexapeptide has been identified as a strong FPR2 agonist through a library screening of synthetic peptides. The FPR2 has been reported to play a crucial role in inflammation and angiogenic responses via stimulation of chemotaxis, migration, cell proliferation, wound healing and vessel growth. Recently, the therapeutic effects of WKYMVm have been reported in various disease models. In cutaneous wound model in diabetic mice, WKYMVm facilitated wound healing processes by stimulating the formation of capillary and arteriole and re-epithelialization. In coronary artery stenosis model, WKYMVm coating on stent promoted re-endothelialization and lowered restenosis rate. In hindlimb ischemia mouse model, intramuscular injection of WKYMVm promoted homing of exogenously transplanted endothelial colony-forming cells and neovascularization, resulting in salvaging hindlimb. Furthermore, a single injection of WKYMVm encapsulated in poly (lactide-co-glycolide) microspheres was demonstrated to be as efficient as multiple injections of WKYMVm in restoring blood flow in hindlimb ischemia model. These observations may open up promising biomedical applications of WKYMVm for tissue repairs and regenerations.

Topics: Animals; Coronary Restenosis; Humans; Ischemia; Neovascularization, Physiologic; Oligopeptides; Skin; Stents; Wound Healing

Formyl peptide receptor-2 (FPR-2) is expressed in various cell types, such as phagocytes, fibroblasts, and endothelial cells. FPR-2 has been reported to play a significant role in inflammation and angiogenic response, and synthetic WKYMVm peptide has been identified as a novel peptide agonist for the FPR-2. In this study, we demonstrate that WKYMVm peptides stimulate the angiogenic potential of outgrowth endothelial cells (OECs). Upon WKYMVm peptide exposure, migration and proliferation of OECs were stimulated. WKYMVm effectively stimulated angiogenesis in tube formation assay and aortic ring assay. Furthermore, we fabricated injectable poly (lactide-co-glycolide) (PLGA) microspheres encapsulating WKYMVm peptides, which showed sustained release of cargo molecule. When WKYMVm peptide encapsulated microspheres were injected into the hind limb ischemia model, a single injection of microspheres was as effective as multiple injections of WKYMVm peptide in restoring blood flow from ischemic injury and promoting capillary growth. These results demonstrate that sustained release of WKYMVm peptide from microspheres in the application to ischemic hind limb extended angiogenic stimulation.. Formyl peptide receptor (FPR) has been reported to play an important role in inflammation and angiogenic response. A synthetic WKYMVm peptide has been identified as a novel peptide activating the FPR-2 that is expressed in a various cell types, such as phagocytes, fibroblasts, and endothelial cells. In this manuscript we explored a unique property of high-affinity ligand for formyl peptide receptors-2 (FPR-2) (i.e., WKYMVm). WKYMVm-induced activation of FPR2 has been reported to be crucial in host defense and inflammation by activation of phagocytes, monocytes, and lymphocytes. In this study, highlight the efficacy of WKYMVm peptide's role in inducing neovascularization in vivo hind limb ischemia model when the peptide was released from injected PLGA microspheres in sustained manner. Our results demonstrate that sustained release of WKYMVm peptide from microspheres have extended angiogenic stimulation capacity.

Topics: Animals; Aorta; Cell Movement; Cell Proliferation; Disease Models, Animal; Emulsions; Gene Expression Regulation; Hindlimb; Humans; In Vitro Techniques; Injections; Ischemia; Lactic Acid; Limb Salvage; Male; Mice, Inbred BALB C; Microspheres; Neovascularization, Physiologic; Oligopeptides; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer

Endothelial colony-forming cells (ECFCs) are recruited to the sites of ischemic injury in order to contribute to neovascularization and repair of injured tissues. However, therapeutic potential of ECFCs is limited due to low homing and engraftment efficiency of transplanted ECFCs. The G-protein-coupled formyl peptide receptor (FPR) 2 has been implicated in regulation of inflammation and angiogenesis, while the role of FPR2 in homing and engraftment of ECFCs and neovascularization in ischemic tissues has not been fully defined. This study was undertaken to investigate the effects of WKYMVm, a selective FPR2 agonist isolated by screening synthetic peptide libraries, on homing ability of ECFCs and vascular regeneration of ischemic tissues. WKYMVm stimulated chemotactic migration, angiogenesis, and proliferation ability of human ECFCs in vitro. Small interfering RNA-mediated silencing of FPR2, but not FPR3, abrogated WKYMVm-induced migration and angiogenesis of ECFCs. Intramuscular injection of WKYMVm resulted in attenuation of severe hind limb ischemia and promoted neovascularization in ischemic limb. ECFCs transplanted via tail vein into nude mice were incorporated into capillary vessels in the ischemic hind limb, resulting in augmented neovascularization and improved ischemic limb salvage. Intramuscular injection of WKYMVm promoted homing of exogenously administered ECFCs to the ischemic limb and ECFC-mediated vascular regeneration. Silencing of FPR2 expression in ECFCs resulted in abrogation of WKYMVm-induced in vivo homing of exogenously transplanted ECFCs to the ischemic limb, neovascularization, and ischemic limb salvage. These results suggest that WKYMVm promotes repair of ischemic tissues by stimulating homing of ECFCs and neovascularization via a FPR2-dependent mechanism.

Topics: Animals; Cell Movement; Cell Proliferation; Colony-Forming Units Assay; Disease Models, Animal; Endothelial Cells; Hindlimb; Humans; Injections, Intramuscular; Ischemia; Limb Salvage; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Neovascularization, Physiologic; Oligopeptides; Perfusion; Receptors, Formyl Peptide; Recovery of Function