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We compared the characteristics of neural cells derived from induced pluripotent stem (iPS) cells from a patient with multiple sclerosis versus neurally differentiated control iPS cells of a healthy individual. The iPS cells were differentiated toward the oligodendrocyte lineage using a four-step protocol established for the differentiation of embryonic stem cells. The resulting cell population was immunostained on day 112 of differentiation for the presence of oligodendrocytes and analyzed by transmission electron microscopy (TEM). Both patient and control samples resembled a mixed population of neural cells rather than oligodendroglia of high purity, including neural stem cell-like cells and possibly oligodendrocytes demonstrable by TEM.

The recent introduction of technologies capable of reprogramming human somatic cells into induced pluripotent stem (iPS) cells offers a unique opportunity to study many aspects of neurodegenerative diseases in vitro that could ultimately lead to novel drug development and testing. Here, we report for the first time that human dermal fibroblasts from a patient with relapsing-remitting Multiple Sclerosis (MS) were reprogrammed to pluripotency by retroviral transduction using defined factors (OCT4, SOX2, KLF4, and c-MYC). The MSiPS cell lines resembled human embryonic stem (hES) cell-like colonies in morphology and gene expression and exhibited silencing of the retroviral transgenes after four passages. MSiPS cells formed embryoid bodies that expressed markers of all three germ layers by immunostaining and Reverse Transcriptase (RT)-PCR. The injection of undifferentiated iPS cell colonies into immunodeficient mice formed teratomas, thereby demonstrating pluripotency. The MSiPS cells were successfully differentiated into mature astrocytes, oligodendrocytes and neurons with normal karyotypes. Although MSiPS-derived neurons displayed some differences in their electrophysiological characteristics as compared to the control cell line, they exhibit properties of functional neurons, with robust resting membrane potentials, large fast tetrodotoxin-sensitive action potentials and voltage-gated sodium currents. This study provides for the first time proof of concept that disease cell lines derived from skin cells obtained from an MS patient can be generated and successfully differentiated into mature neural lineages. This represents an important step in a novel approach for the study of MS pathophysiology and potential drug discovery., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Background: Transplantation of neural stem cells (NSCs) is a promising novel approach to the treatment of neuroinflammatory diseases such as multiple sclerosis (MS). NSCs can be derived from primary central nervous system (CNS) tissue or obtained by neural differentiation of embryonic stem (ES) cells, the latter having the advantage of readily providing an unlimited number of cells for therapeutic purposes. Using a mouse model of MS, we evaluated the therapeutic potential of NSCs derived from ES cells by two different neural differentiation protocols that utilized adherent culture conditions and compared their effect to primary NSCs derived from the subventricular zone (SVZ)., Methodology/principal Findings: The proliferation and secretion of pro-inflammatory cytokines by antigen-stimulated splenocytes was reduced in the presence of SVZ-NSCs, while ES cell-derived NSCs exerted differential immunosuppressive effects. Surprisingly, intravenously injected NSCs displayed no significant therapeutic impact on clinical and pathological disease outcomes in mice with experimental autoimmune encephalomyelitis (EAE) induced by recombinant myelin oligodendrocyte glycoprotein, independent of the cell source. Studies tracking the biodistribution of transplanted ES cell-derived NSCs revealed that these cells were unable to traffic to the CNS or peripheral lymphoid tissues, consistent with the lack of cell surface homing molecules. Attenuation of peripheral immune responses could only be achieved through multiple high doses of NSCs administered intraperitoneally, which led to some neuroprotective effects within the CNS., Conclusion/significance: Systemic transplantation of these NSCs does not have a major influence on the clinical course of rMOG-induced EAE. Improving the efficiency at which NSCs home to inflammatory sites may enhance their therapeutic potential in this model of CNS autoimmunity.