Neural stem cells may provide long-term treatment of neurodegenerative diseases such as Parkinson's by cell replacement or trophic factor secretion.
Treating disorders of the nervous system has long posed a formidable challenge given the complexity of the underlying pathologies. But neural stem cell therapy offers a potentially game-changing approach to cure thus far intractable diseases. Previously, we showed how stem cells can treat ischemic stroke. Here, we summarize the latest developments in the field of neural stem cell therapy based on a recent review by Pruszak.
The justification for the neural stem cell approach is in part motivated by the shortcomings of traditional approaches including pharmacological therapies, neurostimulation and RNA interference-type approaches for preventing protein aggregates. While these approaches can yield short term functional improvements, more durable structural and functional repair of neural circuits by means of cell replacement is preferable.
Among the candidates for neural stem cell therapy are those associated with aging, injury, genetic and developmental disorders. One of the most commonly attempted therapies is for Parkinson’s disease. This movement disorder is rooted in the ventral midbrain with axonal projections to target cells in the striatum. The treatment strategy for Parkinson’s includes replacement of deficient dopamine.
Successful neural stem cell therapy would offer significantly enhanced clinical outcome. Source cells for such therapy may eventually include neural stem and precursor cells, astro- or oligodendroglia or postmitotic neurons.
Neural cell preparations can survive long-term, restore function and alleviate neurological disease. It has also been suggested that non-neural cells could further serve as vehicles for trophic factor release or gene delivery as an enhancement to primary neural cell replacement.
The functional replacement of the dopaminergic neuronal subset by engrafting fetal midbrain tissue has been demonstrated although this not an equivalent substitute for actual therapeutic agents from pluripotent or multipotent sources.
Some research milestones still lay ahead. These include refinement of parameters for identification of best-candidate diseases, appropriate patient collectives, and optimal disease stages in which to intervene. In addition, the conditions of the host/ recipient tissue at the implantation site, appropriate means of delivery, diagnostic assessments, and the avoidance of unwanted side-effects must be considered.
Regulatory criteria will likely contribute significantly to guiding future developments. Optimized protocols will generate increasingly safe neural stem cell preparations. In this way repairing the nervous system might be possible even before we fully understand how it works or how the new neural stem cells are incorporated. We at HemaCare, are proud to offer a line of mesenchymal stem cells that can contribute to this exciting line of life-saving research.
 Pruszak, J Molecular and Cellular Therapies 2014, 2:2 doi:10.1186/2052-8426-2-2