A sensitive method for monitoring the migration of mesenchymal stem cells from bone marrow in murine models

Objetive: Mesenchymal stem cells (MSCs) are commonly used in regenerative therapy of human diseases. In murine models, in which human MSCs are transplanted, distinguishing the origin of the identified MSCs in the organs of mice is important. The objective of this study was to determine the performance of PCR-based analysis of human Alu sequences to detect human DNA after infusion of human bone marrow stem cells (hBMSCs) in immunodeficient mice. Material and method: HBMSCs were obtained from the femoral head of patients undergoing hip replacement surgery. 10(6) hBMSCs were infused intravenously by injection into the retro-orbital sinus of NOD/SCID mice. The presence of human DNA in lung, liver and bone was then assessed. Results: In in vitro DNA mixtures, human DNA was easily detected with a good logarithmic-linear relationship. Similarly, when human and mouse osteoblasts were mixed, 1-10 cells were easily detected among 10(5) mouse cells. Likewise, human DNA was detected in the lungs 1 and 7 days after cell infusions in NOD/SCID mice. However, human DNA was inconsistently detected in the liver and bones. Conclusion: Detecting Alu sequences is an effective procedure to observe human DNA. The results confirm that most intravenously injected hBMSCs are trapped in the lungs. Thus, for the treatment of skeletal disorders, procedures are needed to increase the migration of these cells to the bone.