Project description:Direct cell reprogramming has enabled the direct conversion of skin fibroblasts into functional neurons and oligodendrocytes using a minimal set of cell lineage-specific transcription factors. This approach has substantial advantages since it is rapid and simple, generating the cell type of interest in a single step. However, it remains unknown whether this technology can be applied for directly reprogramming skin cells into astrocytes, the third neural lineage. Astrocytes play crucial roles in neuronal homeostasis and their dysfunctions contribute to the origin and progression of multiple human diseases. Herein, we carried out a screening using several transcription factors involved in defining the astroglial cell fate and identified NFIA, NFIB and SOX9 to be sufficient to convert with high efficiency embryonic and post-natal mouse fibroblasts into astrocytes (iAstrocytes). We proved both by gene expression profiling and functional tests that iAstrocytes are comparable to native brain astrocytes. This protocol can be then employed to generate functional iAstrocytes for a wide range of experimental applications. Induced astrocytes (iAstro) were compared to Fibroblasts (Fibro) as negative control and to primary astrocytes (astro) as positive control. Three biological replicates were analyzed for each experimental group.
Project description:Mitochondria account for essential cellular pathways, from ATP production to nucleotide metabolism, and their deficits lead to neurological disorders and contribute to the onset of age-related diseases. Direct neuronal reprogramming aims at replacing neurons lost in such conditions, but almost nothing is known about the impact of mitochondrial dysfunction in human cell direct reprogramming. Here we explore the defects and how to improve the neuronal reprogramming of iPSC-derived astrocytes carrying mutations in NDUFS4 gene, important for Complex I and associated to Leigh Sydrome. This led to the identification of the unfolded protein response as a major hurdle in the direct neuronal conversion of not only patient, but also control astrocytes and fibroblasts. Our data highlight mitochondria-ER stress-mediated inhibition of translation as a key hurdle in direct neuronal reprogramming, emphasizing how disease modelling using patient cells can contribute to unravel novel pathways in human glia cell reprogramming.
Project description:Mitochondria account for essential cellular pathways, from ATP production to nucleotide metabolism, and their deficits lead to neurological disorders and contribute to the onset of age-related diseases. Direct neuronal reprogramming aims at replacing neurons lost in such conditions, but almost nothing is known about the impact of mitochondrial dysfunction in human cell direct reprogramming. Here we explore the defects and how to improve the neuronal reprogramming of iPSC-derived astrocytes carrying mutations in NDUFS4 gene, important for Complex I and associated to Leigh Sydrome. This led to the identification of the unfolded protein response as a major hurdle in the direct neuronal conversion of not only patient, but also control astrocytes and fibroblasts. Our data highlight mitochondria-ER stress-mediated inhibition of translation as a key hurdle in direct neuronal reprogramming, emphasizing how disease modelling using patient cells can contribute to unravel novel pathways in human glia cell reprogramming.
Project description:Mitochondria account for essential cellular pathways, from ATP production to nucleotide metabolism, and their deficits lead to neurological disorders and contribute to the onset of age-related diseases. Direct neuronal reprogramming aims at replacing neurons lost in such conditions, but almost nothing is known about the impact of mitochondrial dysfunction in human cell direct reprogramming. Here we explore the defects and how to improve the neuronal reprogramming of iPSC-derived astrocytes carrying mutations in NDUFS4 gene, important for Complex I and associated to Leigh Sydrome. This led to the identification of the unfolded protein response as a major hurdle in the direct neuronal conversion of not only patient, but also control astrocytes and fibroblasts. Our data highlight mitochondria-ER stress-mediated inhibition of translation as a key hurdle in direct neuronal reprogramming, emphasizing how disease modelling using patient cells can contribute to unravel novel pathways in human glia cell reprogramming.
Project description:Ectopic expression of the reprogramming factors OCT4, SOX2, or NANOG into human astrocytes in specific cytokine/culture conditions activated the neural stem gene program and induced generation of cells expressing neural stem/precursor markers. Here we compare the whole gene expression profile of primary human astrocytes (Astro) with neural stem cells (HNSC) derived from astrocytes reprogramming
Project description:Spinal cord-derived astrocytes underwent direct neuronal reprogramming following the activation of Ascl1ERT2 and Neurog2ERT2 for 24 hours