Daily bone marrow cell transplantations for the management of fast neurodegenerative processes.

Cell therapy has been proven to be a promising treatment for fighting neurodegenerative diseases. As neuronal replacement presents undeniable complications, the neuroprotection of live neurons arises as the most suitable therapeutic approach. Accordingly, the earlier the diagnosis and treatment, the better the prognosis. However, these diseases are commonly diagnosed when symptoms have already progressed towards an irreversible degenerative stage. This problem is especially dramatic when neurodegeneration is aggressive and rapidly progresses. One of the most interesting approaches for neuroprotection is the fusion between healthy bone marrow-derived cells and neurons, as the former can provide the latter with regular/protective genes without harming brain parenchyma. So far, this phenomenon has only been identified in Purkinje cells, whose death is the cause of different diseases like cerebellar ataxias. Here we have employed a model of aggressive cerebellar neurodegeneration, the Purkinje Cell Degeneration mouse, to optimize a cell therapy based on bone marrow-derived cell and cell fusion. Our findings show that the substitution of bone marrow in diseased animals by healthy bone marrow, even prior to the onset of neurodegeneration, is not fast enough to stop neuronal loss in time. Conversely, avoiding bone marrow replacement and ensuring a regular supply of healthy cells through continuous, daily transplants, the neurodegenerative milieu of PCD is enough to attract those transplanted elements. Furthermore, in the most affected cerebellar regions, more than a half of surviving neurons undergo a process of cell fusion. Therefore, this method deserves consideration as a means to impede neuronal cell death.