[38]

   A 3D-clinostat is a multi-directional gravity device for simulating microgravity. By controlled rotation of two axes, a 3D-clinostat minimizes the cumulative gravity vector in cells cultured at the center of the device and makes 10^-3 G average over time.  Bone marrow-derived cells (BMCs) are reported to differentiate into the cells of neural lineages as well as mesenchymal cells such as bone, cartilage, and muscles etc. in a media (neural differentiation medium).  Culture of BMCs under the state of simulated microgravity may inhibit differentiation into these various types of cells.  Therefore, we investigated the effect of simulated microgravity on differentiation of mouse BMCs using the 3D-clinostat, which special reference to neural differentiation.

   BMCs were isolated from BALB/cBy mice and allowed to proliferate in normal 1G condition.  Proliferated cells were, then, cultured under the neural differentiation conditions in 3D-clinostat or normal 1G environment for 7 days.  The cells were examined for their growth pattern, morphology and expression of neuronal marker mRNA (neurofilament).  The cell number was decreased 1.6 times more in 3D-clinostat than 1G environment.  However, differentiation of the cells into neural lineages was inhibited: the cells extending processes and expressing neural maker mRNA were scarcely found.  Here we show that mouse BMCs proliferate better and remain more undifferentiated in culture in a 3D-clinostat.