Benefit of combined extracorporeal shock wave and bone marrow-derived endothelial progenitor cells in protection against critical limb ischemia in rats

Objectives: We hypothesized that combined treatment with extracorporeal shock wave and bone marrow-derived endothelial progenitor cells might exert enhanced protection against critical limb ischemia in rats. Methods: Male Sprague-Dawley rats (n = 9 for laser Doppler study and n = 6 for laboratory examinations in each group) were divided into group 1 (sham control), group 2 (critical limb ischemia treated with culture medium), group 3 (critical limb ischemia treated with intramuscular bone marrow-derived endothelial progenitor cells [2.0 × 10 cells]), group 4 (critical limb ischemia treated with extracorporeal shock wave [280 impulses at 0.1 mJ/mm]), and group 5 (combined bone marrow-derived endothelial progenitor cell-extracorporeal shock wave) after critical limb ischemia induction. Results: By day 21, laser Doppler showed substantially lower ratios of ischemic/normal blood flow in group 2 compared with other groups (p < .001). The protein expressions of mitochondrial cytochrome c, stromal cell-derived factor-1, C-X-C chemokine receptor type 4, vascular endothelial growth factor, and endothelial nitric oxide synthase were remarkably higher in group 5 than in groups 2 to 4, and notably higher in groups 3 and 4 than in group 2 (all p < .01). The messenger RNA expressions of proinflammatory and apoptotic biomarkers and oxidative stress were reduced in group 5 compared with groups 2 to 4, and notably lower in groups 3 and 4 than in group 2 (all p < .01). The messenger RNA expressions of anti-inflammatory and antiapoptotic biomarkers were lower in group 2 than in other groups (all p < .01). Immunofluorescent staining showed higher numbers of CD31+ stromal cell-derived factor-1+, chemokine receptor type 4+, and von Willebrand factor+ cells, and vessels in the ischemic area in group 5 than in groups 2 to 4, and in groups 3 and 4 than in group 2 (all p < .04). Conclusion: Combined treatment with bone marrow-derived endothelial progenitor cells and extracorporeal shock wave is superior to either bone marrow-derived endothelial progenitor cells or extracorporeal shock wave alone in improving ischemia in rodent critical limb ischemia.