Effect of human amnion-derived multipotent progenitor cells on hematopoietic recovery after total body irradiation in C57BL/6 mice

Background: The hematopoie c system is sensi ve to the adverse effects of ionizing radia on. Cellular therapies u lizing mesenchymal stem cells or vascular endothelial cells have been explored as poten al countermeasures for radia on hematopoie c injuries. We inves gated cells cultured from amnion (Amnion-derived Mul potent Progenitor cells, AMPs) for effects on hematopoie c recovery following total body irradia on in mice. Materials and Methods: C57BL/6J mice were sham-irradiated or exposed to 60 Co irradia on (7.75 – 7.90 Gy, 0.6 Gy/min). Either AMPs (5 × 10 6 cells/animal) or vehicle were administered 24 h pos rradia on via intraperitoneal injec on. Results: We observed a 13% and 20% improvement in 30-day survival of mice treated with AMPs compared with treatment with vehicle following irradia on at 7.75 and 7.90 Gy, respec vely. AMP treatment was characterized by a trend toward accelerated recovery of white blood cells, neutrophils, re culocytes, and monocytes, measured through day 40 pos rradia on a9er 7.75 Gy. AMP treatment enhanced hematopoie c cell repopula on of spleen and femoral bone marrow as measured by total nucleated cell and hematopoie c progenitor cell counts in comparison to vehicle-treated animals. FACS analysis showed that AMPs treatment significantly mi gated the reduc on in CD11b + /Gr-1 int and CD11b + /Gr-1 high bone marrow cell popula ons at the nadir, and improved recovery of these cell types. Conclusion: Together, our data indicate that AMPs reduced hematopoie c toxicity induced by ionizing radia on when infused within 24 h a9er radia on injury.