Ritchie, Michael2013-03-012013-03-012012-01https://hdl.handle.net/11299/145560Universiversity of Minnesota M.S. thesis. January 2012. Major: Stem Cell Biology. Advisor: Dr. Walter Low PhD. 1 computer file (PDF); v, 41 pages.The most prevalent approach of attempted direct reprogramming of cells is the insertion and expression of genes using lentiviral transduction. This often, if not always results in an incompletely reprogrammed cellular phenotype. To determine what other factors might be manipulated we focused on two novel methods for direct differentiation; induction with extracellular matrix and miRNA manipulation. For the first approach we developed a decellularization protocol and produced mouse brain and cochlear decellularized extracellular matrix. After staining and analysis of the matrices we applied murine neural stem cells to determine if they adhere and begin to differentiate. The cells adhered to the extracellular matrix faster than with either fibronectin or gelatin coated surfaces without the decellularized tissue. The second approach is miRNA manipulation. There have been many recent studies that use miRNA much like a transduced gene to increase reprogramming efficiency. However they have never been used alone without the insertion of additional factors or via endogenous miRNA knockdown. We identified a list of genes plausibly up-regulated in dopaminergic neurons. We then found that multiple miRNA all down-regulate this cluster of genes. To this end our approach is to down-regulate the miRNA that target the genes on our target list, allowing natural transcription and translation of endogenous protein to then cause a shift in phenotype towards the dopaminergic neuron of the substantia nigra pars compacta.en-USThesis or Dissertation