Simulated microgravity maintains the undifferentiated state and enhances the neural repair potential of bone marrow stromal cells.

Recently, regenerative medicine with bone marrow stromal cells (BMSCs) has gained significant attention for the treatment of central nervous system diseases. Here, we investigated the activity of BMSCs under simulated microgravity conditions. Mouse BMSCs (mBMSCs) were isolated from C57BL/6 mice and harvested in 1G condition. Subjects were divided into 4 groups: cultured under simulated microgravity and 1G condition in growth medium and neural differentiation medium. After 7 days of culture, the mBMSCs were used for morphological analysis, reverse transcription (RT)–polymerase chain reaction, immunostaining analysis, and grafting. Neural-induced mBMSCs cultured under 1G conditions exhibited neural differentiation, whereas those cultured under simulated microgravity did not. Moreover, under simulated microgravity conditions, mBMSCs could be cultured in an undifferentiated state. Next, we intravenously injected cells into a mouse model of cerebral contusion. Graft mBMSCs cultured under simulated microgravity...