Stem cells have long held potential in the field of regenerative medicine since they hold the ability to turn into any other type of cell. However, laboratory findings have not kept in pace with the practical benefits achieved through stem cell therapy. For example, although pluripotent stem cells (PSCs) derived from mice have been successfully converted to dopamine neurons which have shown efficacy in Parkinson’s disease models, similar levels of efficacy have not been achieved with Human PSCs (note: Parkinson’s results from death of dopamine neurons).
Recently, however, a study published in Nature describes a new strategy for converting Human Stem Cells into dopamine neurons that allow these neurons to easily engraft or easily integrate into the mid-brain of living animals. Their strategy was to induce differentation of Human PSCs (or Embryonic Stem cells) to dopamine neurons by causing differentiation first to mid-brain floor plate precursors (or an immature type of neuron found in the floor plate of the mid-brain, especially during embryogenesis) and then to dopamine neurons via the usage of molecular activators sonic hedgehog (SSH) and canonical WNT signaling. They found that using such a strategy created domapine neurons that easily engrafted or integrated in vivo, even in parkinsonian monkeys (a closer model to humans than mice). This suggests that the dismal success of past studies were mostly due to incomplete specification or transformation of Human PSCs to fully functional domamine neurons as opposed to vulnerability of the cells in vivo. As a result of their findings, stem cell based therapies for Parkinson’s disease have come one step closer to reality and may in the near future make it to clinical usage.
