Science: Human Stem Cells Remyelinate a Rat

Pouya et al. Human Induced Pluripotent Stem Cells Differentiation into Oligodendrocyte Progenitors and Transplantation in a Rat Model of Optic Chiasm Demyelination PLoS ONE: 2011 10.1371/journal.pone.0027925

Background: This study aims to differentiate human induced pluripotent (grow into and cell type) stem cells (hiPSCs) into oligodendrocyte precursors and assess their recovery potential in a demyelinated optic chiasm model in rats.

Methodology/Principal Findings: We generated a cell population of oligodendrocyte progenitors from hiPSCs by using embryoid body formation in a defined medium supplemented with a combination of factors, positive selection and mechanical enrichment. Real-time polymerase chain reaction and immunofluorescence analyses showed that stage-specific markers, were expressed following the differentiation procedure, and enrichment of the oligodendrocyte lineage. These results are comparable with the expression of stage-specific markers in human embryonic stem cell-derived oligodendrocyte lineage cells. Transplantation of hiPSC-derived oligodendrocyte progenitors into the lysolecithin-induced demyelinated optic chiasm of the rat model resulted in recovery from signsand integration and differentiation into oligodendrocytes were detected by immunohistofluorescence staining against myelin protiens, and measurements of the visual evoked potentials (nerve signals from eye to the brain).


Conclusions/Significance: These results showed that oligodendrocyte progenitors generated efficiently from hiPSCs can be used in future biomedical studies once safety issues have been overcome.

"The use of stem cells offers promise to promote myelin repair. Use of embryonic stem cells not only has ethical issues but also means that the recipient will need to be on transplant rejection drugs for the rest of their lives as the immune response of the recipient may reject the stem cells or their progeny. Induced pluripotent stem cells can be made from adult cells and could be made from any individual and so could be taylored to each individual and so would avoid the above problems". The studies used stem cell lines are encouraging, but this approach was active in early lesions and it needs to be shown whether these cells can remyelinate gliotic long established lesions as may be needed in MS. This approach is not without risks as some can become tumours, so as we learn more about how we can avoid these risks we will be in a better state to move forward with human trials."