Neurotrophic Schwann-cell factors induce neural differentiation of bone marrow stromal cells.

Neural transdifferentiation of bone marrow stromal cells has been questioned, because cell fusion could explain the development of new cell types, misinterpreted as transdifferentiated cells. We performed here cocultures of bone marrow stromal cells and Schwann cells, without possibility that both cell types can establish contact. In these conditions, bone marrow stromal cells expressed nestin 4 h after beginning cocultures, and strong expression of neuronal markers was disclosed at 72 h, increasing at 1 and 2 weeks. Our results support that neural transdifferentiation of bone marrow stromal cells is induced by soluble factors provided by glial cells, and suggest that cell fusion should not be significant when local bone marrow stromal cells administration for neural repair is considered.