Lineage reprogramming of adult mouse liver cells and B-lymphocytes to neural stem-like cells using defined factors [expression array]

The overexpression of transcription factors Oct4, Sox2, Klf4, and c-Myc reprograms a somatic nucleus to one that is transcriptionally and epigenetically indistinguishable from an embryonic stem (ES) cell. However, it is still unclear if transcription factors can completely convert the nucleus of a differentiated cell into that of a distantly related cell type such that it maintains complete transcriptional and epigenetic reprogramming in the absence of exogenous factor expression. To test this idea, we screened a library of doxycycline-inducible vectors encoding neural stem cell (NSC)-expressed genes and found that stable, self-maintaining NSC-like cells could be induced under defined growth conditions after transduction of transcription factors. These induced NSCs (iNSCs) were characterized in the absence of exogenous factor induction and were shown to be transcriptionally, epigenetically, and functionally similar to endogenous embryonic cortical NSCs. Importantly, iNSCs could be generated from multiple adult cell types including liver cells and B-cells with genetic rearrangements. Our results show that self-maintaining proliferative neural cells can be induced from non-ectodermal cells by expressing specific combinations of transcription factors.

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