MEF2C Enhances Dopaminergic Neuron Differentiation of Human Embryonic Stem Cells in a Parkinsonian Rat Model

Del E. Webb Center for Neuroscience, Aging, and Stem Cell Research, Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America.
PLoS ONE (Impact Factor: 3.53). 08/2011; 6(8):e24027. DOI: 10.1371/journal.pone.0024027
Source: PubMed

ABSTRACT Human embryonic stem cells (hESCs) can potentially differentiate into any cell type, including dopaminergic neurons to treat Parkinson's disease (PD), but hyperproliferation and tumor formation must be avoided. Accordingly, we use myocyte enhancer factor 2C (MEF2C) as a neurogenic and anti-apoptotic transcription factor to generate neurons from hESC-derived neural stem/progenitor cells (NPCs), thus avoiding hyperproliferation. Here, we report that forced expression of constitutively active MEF2C (MEF2CA) generates significantly greater numbers of neurons with dopaminergic properties in vitro. Conversely, RNAi knockdown of MEF2C in NPCs decreases neuronal differentiation and dendritic length. When we inject MEF2CA-programmed NPCs into 6-hydroxydopamine-lesioned parkinsonian rats in vivo, the transplanted cells survive well, differentiate into tyrosine hydroxylase-positive neurons, and improve behavioral deficits to a significantly greater degree than non-programmed cells. The enriched generation of dopaminergic neuronal lineages from hESCs by forced expression of MEF2CA in the proper context may prove valuable in cell-based therapy for CNS disorders such as PD.

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    ABSTRACT: The myocyte enhancer factor 2 (MEF2) family of transcription factors is highly expressed in the brain and constitutes a key determinant of neuronal survival, differentiation, and synaptic plasticity. However, genome-wide transcriptional profiling of MEF2-regulated genes has not yet been fully elucidated, particularly at the neural stem cell stage. Here we report the results of microarray analysis comparing mRNAs isolated from human neural progenitor/stem cells (hNPCs) derived from embryonic stem cells expressing a control vector versus progenitors expressing a constitutively-active form of MEF2 (MEF2CA), which increases MEF2 activity. Microarray experiments were performed using the Illumina Human HT-12 V4.0 expression beadchip (GEO#: GSE57184). By comparing vector-control cells to MEF2CA cells, microarray analysis identified 1880 unique genes that were differentially expressed. Among these genes, 1121 genes were up-regulated and 759 genes were down-regulated. Our results provide a valuable resource for identifying transcriptional targets of MEF2 in hNPCs.
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    ABSTRACT: There is increasing interest in transplantation of human stem cells for therapeutic purposes. It would benefit future application if one could achieve their long-term acceptance and functional differentiation in allogeneic hosts using minimal immunosuppression. Allogeneic stem cell transplants differ from conventional tissue transplants insofar as not all alloantigens are revealed during tolerance induction. This risks that the immune system tolerized to antigens expressed by progenitors may still remain responsive to antigens expressed later during differentiation. Here we show that brief induction with monoclonal antibody-mediated coreceptor and costimulation blockade enables long-term engraftment and tolerance towards murine ESCs, hESCs, human induced pluripotent stem cells (iPSCs) and hESC-derived progenitors in outbred murine recipients. Tolerance induced to PSC-derived progenitors extends to their differentiated progenies, and sometimes even to different tissues derived from the same donor. Global gene expression profiling identifies clear features in T cells from tolerized grafts that are distinct from those involved in rejection.
    Nature Communications 12/2014; 5:5629. DOI:10.1038/ncomms6629 · 10.74 Impact Factor

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