Original Article Hypoxically preconditioned human peripheral blood mononuclear cells improve blood flow in hindlimb ischemia xenograft model

* Equal contributors. Received August 8, 2014; Accepted August 31, 2014; Epub October 11, 2014; Published October 15, 2014 Abstract: Transplantation of peripheral blood mononuclear cells (PBMNCs) is a promising therapeutic approach for the treatment of hindlimb ischemia. However, insufficient angiogenesis in ischemic hindlimb after cell transplanta - tion reduces the importance and practicality of this approach. Previously, we demonstrated using mouse models that hypoxic preconditioning augmented the cellular functions of rodent PBMNCs, such as increased cell adhesion capacity and accelerated neovascularization in ischemic hindlimb. To test the clinical application of this therapeu- tic strategy in this study, we investigated whether the protocol of hypoxic preconditioning, which was established in a condition of 2% O 2 for 24 h, can be made available for human PBMNCs (hPBMNCs). In addition, we grafted preconditioned hPBMNCs in a hindlimb ischemia mouse model. Hypoxic preconditioning enhanced cell adhesion capacity and oxidative stress resistance in hPBMNCs. We also observed an up-regulation of platelet endothelial cell adhesion molecule-1 (PECAM-1) in hPBMNCs by hypoxic preconditioning. Furthermore, preconditioned hPBMNCs significantly recovered limb blood flow in ischemic mice after transplantation. These results indicate that our estab - lished preconditioning protocol is available for hPBMNCs to effectively reinforce multiple cellular functions. Taken together with our series of study, we believe that this simple but powerful therapeutic strategy will be helpful in cur- ing patients with severe hindlimb ischemia.