Oral Presentation 6th Annual Meeting for Australasian Society for Stem Cell Research 2013

Direct Reprogramming of Adult Human Fibroblasts to Neural Precursor-like Cells. (#12)

Bronwen Connor 1
  1. University of Auckland, Auckland, New Zealand

Direct reprogramming of human fibroblasts to mature neurons by the introduction of defined neural genes has become well established and holds potential use in the areas of neurological disease modeling and drug development. However, use of induced neurons for large-scale drug screening and cell-based replacement strategies is limited due to their inability to expand once reprogrammed. We proposed it would be more desirable to induce expandable neural precursor cells directly from human fibroblasts. To date a number of pluripotent and neural transcription factors have been shown to be capable of converting mouse fibroblasts to neural stem/precursor-like cells. We have extended these findings and demonstrate that over-expression of the transcription factors Sox2 and Pax6 in adult human fibroblasts allows the efficient generation of induced neural precursor (iNP) colonies expressing a wide range of neural stem and pro-neural genes. Quantitative PCR of multiple iNP lines further demonstrated the expression of neuronal positional markers in iNP cells including those of the dorsal forebrain (Gli3, Pax6, Ngn2, Emx2, Tbr2), ventral forebrain (Dlx2, Mash1, Olig2), midbrain (FoxA1, Lmx1A, Nurr1, Pitx3) and hindbrain (HoxB9), indicating a potential to generate neurons specific to different regions of the brain. Upon differentiation, iNP cells give rise to GFAP+ astrocytes and high yields of electrophysiologically active neurons expressing TuJ1, MAP2, NSE, and subtype specific markers TH, calbindin, DARRP32 and GAD65/67. Our reprogramming method has direct application for ‘disease modelling in a dish’, and we have successfully derived TH+ human neurons from aHDFs obtained from a patient with Parkinson’s disease. Such research will provide novel insights into disease progression and cellular mechanisms not able to be examined using current models with potential for the identification of new therapeutic targets.