Exposure to a MRI-Type High-Strength Static Magnetic Field Stimulates Megakaryocytic/Erythroid Hematopoiesis in CD34+ Cells From Human Placental and Umbilical Cord Blood

The biological response after exposure to a high-strength static magnetic field (SMF) has recently been widely discussed from the perspective of possible health benefits as well as potential adverse effects. To clarify this issue, CD34 cells from human placental and Umbilical cord blood were exposed under conditions of high-strength SMF in vitro. The high-strength SMF exposure system was comprised of a magnetic field generator with a helium-free superconducting magnet with built-in CO, incubator. Freshly prepared CD34 cells were exposed to a 5 tesla (T) SMF with the strongest magnetic field gradient (41.7 T/m) or a 10 T SMF without magnetic field gradient for 4 or 16 h. In the harvested cells after exposure to 10 T SMF for 16 h, a significant increase of hematopoietic progenitors in the total burst-forming unit erythroid- and megakaryocytic progenitor cells-derived colony formation was observed, thus producing 1.72- and 1.77-fold higher than the control, respectively. Furthermore, early hematopoiesis-related and cell cycle-related genes were found to be significantly up-regulated by exposure to SMF. These results suggest that the 10 T SMF exposure may change gene expressions and result in the specific enhancement of megakaryocytic/erythroid progenitor (MEP) differentiation from pluripotent hematopoietic stem cells and/or the proliferation of bipotent MER Bioelectromagnetics 30:280-285, 2009. (C) 2009 Wiley-Liss. Inc.