This article appears in the following Human Molecular Genetics issue: Stem Cells and Regeneration [View the issue table of contents]
Stem cell-based strategies for treating pediatric disorders of myelin
1 Division of Cell and Gene Therapy and Center for Translational Neuromedicine, Department of Neurology and Neurosurgery 2 Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY 14642, USA
* To whom correspondence should be addressed at: Department of Neurology and Department of Neurosurgery, University of Rochester Medical Center, 601 Elmwood Avenue/MRBX, Box 645, Rochester, NY 14642, USA. Tel: +1 5852759550; Fax: +1 5852760232; Email: steven_goldman{at}urmc.rochester.edu
Received January 11, 2008; Revised January 11, 2008; Accepted February 13, 2008
The pediatric leukodystrophies comprise a category of disease manifested by neonatal or childhood deficiencies in myelin production or maintenance; these may be due to hereditary defects in one or more genes critical to the initiation of myelination, as in Pelizaeus–Merzbacher Disease, or to enzymatic deficiencies with aberrant substrate accumulation-related dysfunction, as in the lysosomal storage disorders. Despite differences in both phenotype and natural history, these disorders are all essentially manifested by a profound deterioration in neurological function with age. A congenital deficit in forebrain myelination is also noted in children with the periventricular leukomalacia of cerebral palsy, another major source of neurological morbidity. In light of the wide range of disorders to which congenital hypomyelination and/or postnatal demyelination may contribute, and the relative homogeneity of central oligodendrocytes and their progenitors, the pediatric leukodystrophies may be especially attractive targets for cell-based therapeutic strategies. As a result, glial progenitor cells (GPCs), which can give rise to new myelinogenic oligodendrocytes, have become of great interest as potential therapeutic vectors for the restoration of myelin to the hypomyelinated or dysmyelinated childhood CNS. In addition, by distributing themselves throughout the deficient host neuraxis after perinatal allograft, and giving rise to astrocytes as well as oligodendrocytes, glial progenitors appear to be of potential great utility in rectifying enzymatic deficiencies. In this review, we focus on current efforts to develop the use of isolated human GPCs as transplantable agents both for mediating enzymatic restoration to the enzyme-deficient brain and for therapeutic myelination in the disorders of congenital hypomyelination.