RESUMEN
Peripheral blood mononuclear cells (PBMCs) contain a cell fraction of mononuclear progenitor cells (MPCs), which own significant angiogenic potential. Autologous transplant of PBMC and/or platelet-rich plasma (PRP) promotes endothelial cells differentiation in experimental lower limb ischemia, which is considered a safe and effective strategy to support revascularization, either in animal models or clinical trials. In addition, thrombin has been proposed to enrich biological scaffolds, hence increasing MPC viability after intramuscular administration, whereas proangiogenic mediators such as vascular endothelial growth factor (VEGF), tumor necrosis factor alpha (TNF-α), inhibitor of the plasminogen activator-1 (PAI-1), and chemokine (CXCL1; GRO-α) participate in the endothelial response to ischemia, through their proangiogenic effects over endothelial cells proliferation, survival, migration, endothelial integrity maintenance, and physiologic vascular response to injury. In the present study, we describe the effect of autologous PBMCs transplant and PRP, either with or without thrombin, over proangiogenic mediators (measured by enzyme-linked immunosorbent assay) and revascularization response (angiographic vascular pattern at 30 days after vascular occlusion) in a rat model of lower limb ischemia. The group treated with PBMC + PRP significantly induced PAI-1, an effect that was prevented by the addition of thrombin. Furthermore, treatment with PBMC + PRP + thrombin resulted in the induction of VEGF. GRO-α showed a sensitive induction of all proangiogenic mediators. All treatments significantly stimulated revascularization, according to angiographic assessment, whereas higher effect was observed with PBMC + PRP treatment (p < .0001). In conclusion, autologous PBMC transplant stimulates revascularization during experimental ischemia of the lower limb, whereas particular effects over proangiogenic and fibrinolytic mediators may be attributed to PBMCs and its combination with PRP and thrombin.
