Abstract 858: Ex vivo Pretreatment of Bone Marrow Mononuclear Cells with the eNOS Enhancer AVE Enhances their Functional Activity for Cell Therapy
Bone marrow mononuclear cells (BMC) and blood-derived endothelial progenitor cells (EPC) from patients with coronary artery disease (CAD) or ischemic cardiomyopathy (ICMP) show a reduced neovascularization capacity in vivo. Nitric oxide (NO) plays an important role in neovascularization and NO bioavailability is typically reduced in patients with CAD. We investigated, whether the impaired capacity of BMC or EPC can be restored by ex vivo pretreatment with the novel endothelial NO synthase (eNOS) transcription enhancer AVE9488 (AVE). Ex vivo treatment of BMC or EPC isolated from patients with ICMP or CAD with AVE (5 μM, 24 hours) significantly increased eNOS mRNA expression (p<0.05). The increased eNOS expression was associated with an enhanced migratory capacity in vitro (140±9.0%; p<0.001). Intravenous administration of AVE-pretreated patient-derived EPC or BMC significantly increased the limb perfusion in a nude mice hind limb ischemia model to 272±9% and 159±14%, respectively (p<0.05). Likewise, the exercise capacity (swimming test) was augmented after infusion of AVE-pretreated patient-derived BMC (p<0.05). The enhancement of limb perfusion by AVE-treated BMC was abrogated by ex vivo pretreatment with the eNOS inhibitor NG-nitro-L-arginine methyl ester. AVE had no effect on the impaired migratory capacity of BMC derived from eNOS-deficient mice documenting the specific involvement of NO. Consistently, infusion of AVE-pretreated BMC also improved heart function in nude mice after acute myocardial infarction. Taken together, these data demonstrate that AVE-pretreatment improved the functional capacity of patient-derived BMC and EPC to augment blood flow recovery and improvement of heart function after myocardial infarction. This strategy might be useful to optimize cell therapy of patients with peripheral and cardiac ischemic diseases.