Striatal medium spiny neurons (MSNs) are the main output from the striatum, a subcortical part of the forebrain, which is the main input of the basal ganglia (BG) system. 96% of the striatum is composed of MSNs. Huntington’s disease (HD) is caused by a progressive loss of MSNs in the striatum. It is caused by polyglutamine expansion in the Huntingtin protein (HTT). This impairs cerebral cortex function and deregulates several genes that play a role in subpallium development. The identification and use of transcription factors (TFs) to direct the differentiation of stem cells to MSNs is described. Microarray data analysis of MSNs, from data in NCBIs Gene Expression Omnibus (GEO), was performed to detect gene expression profiles involved in telencephalon development and striatum maturation. The genes Dlx2, Gsx2, Mash1, Pax6, Sox4 and Foxp1 were found to play roles in neurogenesis, forebrain neuron fate commitment, cell proliferation, anatomical structure morphology, maturation of MSNs and transcriptional activation and repression. A differentiation protocol was developed in which three TFs, DLX2, GSX2 and MASH1, were selected and cloned into expression vectors, in different combinations,to direct the differentiation of stem cells into naïve rosette neural progenitor cells (nrNPCs). These were then terminally differentiated into striatal MSNs. Expression of DLX2, GSX2 and MASH1 in human embryonic stem cell (hESC) and induced pluripotent stem cell (iPSC) lines successfully directed their differentiationinto nrNPCs. iPSC-derived nrNPCs were successfully terminally differentiated into DARPP-32+ve MSNs. However, only overexpression of DLX2 and MASH1 in iPSCderived nrNPCs yielded functionally active MSNs that expressed DARPP-32, CTIP2, FOXP1, EBF1, DRD1, DRD2, GAD2 and CALBIN-1. It was successful and, therefore, could provide a new cell source for disease modeling in vitro, transplantation studies and drug discovery approaches.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:667897 |
| Date | January 2015 |
| Creators | Bagabir, Sali |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/76449/ |
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