Induction of oligodendrocyte lineage cells by direct cellular reprogramming.

点击翻译按钮获取中文摘要

Direct reprogramming is a recent and exciting technology in the field of regenerative medicine that is used to convert abundant and easily accessible cells (e.g. fibroblasts) directly into different cell-types of interest. Similar to the generation of induced pluripotent stem cells, forced expression of a defined set of transcription factors is used to induce the desired switch of cellular-identity. The first reports of direct reprogramming of fibroblasts into different neuronal cell-types as well as into neural stem cells have now been published. To date, there are no reports about direct reprogramming of fibroblasts into glial cells. However, oligodendrocytes, one of the principal glial cell-types of ectodermal origin, are critical for neuronal function. They engage tightly with nerve cell axons and endow these with myelin-sheaths, a prerequisite for rapid signal-propagation in the nervous system.In this research proposal I hypothesise that overexpression of a distinct set of transcription factors is sufficient to induce the direct conversion of fibroblasts (and pluripotent stem cells) into cells of the oligodendrocyte-lineage. My own preliminary data strongly support the feasibility of this approach. Reporter mouse fibroblasts will be used as starting cell population to define the most efficient combination of transcription factors to induce the reprogramming process. Induced cells will be characterised extensively both in vitro and in vivo. Furthermore, fluorescent reporters that are expressed under the control of stage-specific markers will allow the definition of transcription factor-combinations that mediate a conversion into distinct stages of the oligodendrocyte-lineage (i.e. oligodendrocyte precursor cells versus differentiated oligodendrocytes). Subsequently, the results will be translated into the human system, where pluripotent stem cells will serve as initial starting population. Gene-targeting methods will be applied to derive human pluripotent reporter cell-lines that will facilitate the study of induced human oligodendrocyte-lineage cells.Once a robust human oligodendrocyte-culture system has been established, a number of follow-up projects will follow. Directly reprogrammed oligodendrocytes need to be compared with their counterparts derived by conventional directed differentiation from embryonic stem cells. Comparison of reprogrammed cells derived from wild-type versus leukodystrophy-patients will allow in-vitro modelling of demyelinating disease and pave the way for drug- and toxicology testing as well as transplantation studies.