Project description:Stem cell biology has garnered much attention due to its potential to impact human health through disease modeling and cell replacement therapy. This is especially pertinent to myelin-related disorders such as multiple sclerosis and leukodystrophies where restoration of normal oligodendrocyte function could provide an effective treatment. Progress in myelin repair has been constrained by the difficulty in generating pure populations of oligodendrocyte progenitor cells (OPCs) in sufficient quantities. Pluripotent stem cells theoretically provide an unlimited source of OPCs but significant advances are currently hindered by heterogeneous differentiation strategies that lack reproducibility. Here we provide a platform for the directed differentiation of pluripotent mouse epiblast stem cells (EpiSCs) through a defined series of developmental transitions into a pure population of highly expandable OPCs in ten days. These OPCs robustly differentiate into myelinating oligodendrocytes both in vitro and in vivo. Our results demonstrate that pluripotent stem cells can provide a pure population of clinically-relevant, myelinogenic oligodendrocytes and offer a tractable platform for defining the molecular regulation of oligodendrocyte development, drug screening, and potential cell-based remyelinating therapies. 6 total samples were analyzed. Pluripotent epiblast stem cells (EpiSCs) were differentiated to patterned neural rosettes, oligodendrocyte progenitor cells (OPCs), and oligodendrocytes. OPCs and oligodedrocytes were analyzed at two separate passages (3 and 11).
Project description:Cell-based therapies for myelin disorders, such as multiple sclerosis and leukodystrophies, require technologies to generate functional oligodendrocyte progenitor cells. Here we describe direct conversion of mouse embryonic and lung fibroblasts to ‘induced’ oligodendrocyte progenitor cells (iOPCs) using sets of either eight or three defined transcription factors. iOPCs exhibit a bipolar morphologyical and global gene expression profile molecular features consistent with bona fide OPCs. They can be expanded in vitro for at least five passages while retaining the ability to differentiate into induced multiprocessed oligodendrocytes. When transplanted to hypomyelinated mice, iOPCs are capable of ensheathing host axons and generating compact myelinmyelinating axons both in vitro and in vivo. Lineage conversion of somatic cells to expandable iOPCs provides a strategy to study the molecular control of oligodendrocyte lineage identity and may facilitate neurological disease modeling and autologous remyelinating therapies. 6 total samples were analyzed. MEFs were either untreated or infected with inducible lentiviral vectors containing the open reading frames of transcription factors. Samples were compared to bona fide OPCs.
Project description:Many studies have already shown the reprogramming of somatic cells into other cell types such as neural stem cells, blood progenitor cells, and hepatocytes by inducing combinations of transcription factors. One of the recent development in cellular reprogramming is the direct reprogramming, that can change cell fate towards different lineages. This strategy provides an alternative to the use of pluripotent stem cells ruling out the concerns of tumorigenicity caused by undifferentiated cell populations. Here, we generated induced oligodendrocyte progenitor cells (iOPCs) from mouse fibroblasts by direct reprogramming. The generated iOPCs are homogenous, self-renewing, and multipotent. Once differentiated, the somatic stem cells exhibit morphological and molecular characteristics of oligodendrocyte progenitor cells (OPCs). Thus, we demonstrated that terminally differentiated somatic cells can be converted into functional iOPCs by induction of transcription factors offering a new strategies to cure myelin disorders. To identify the global gene expression profiles of iOPCs, we analyzed total 6 samples.
Project description:Cell-based therapies for myelin disorders, such as multiple sclerosis and leukodystrophies, require technologies to generate functional oligodendrocyte progenitor cells. Here we describe direct conversion of mouse embryonic and lung fibroblasts to ‘induced’ oligodendrocyte progenitor cells (iOPCs) using sets of either eight or three defined transcription factors. iOPCs exhibit a bipolar morphologyical and global gene expression profile molecular features consistent with bona fide OPCs. They can be expanded in vitro for at least five passages while retaining the ability to differentiate into induced multiprocessed oligodendrocytes. When transplanted to hypomyelinated mice, iOPCs are capable of ensheathing host axons and generating compact myelinmyelinating axons both in vitro and in vivo. Lineage conversion of somatic cells to expandable iOPCs provides a strategy to study the molecular control of oligodendrocyte lineage identity and may facilitate neurological disease modeling and autologous remyelinating therapies.
Project description:Stem cell biology has garnered much attention due to its potential to impact human health through disease modeling and cell replacement therapy. This is especially pertinent to myelin-related disorders such as multiple sclerosis and leukodystrophies where restoration of normal oligodendrocyte function could provide an effective treatment. Progress in myelin repair has been constrained by the difficulty in generating pure populations of oligodendrocyte progenitor cells (OPCs) in sufficient quantities. Pluripotent stem cells theoretically provide an unlimited source of OPCs but significant advances are currently hindered by heterogeneous differentiation strategies that lack reproducibility. Here we provide a platform for the directed differentiation of pluripotent mouse epiblast stem cells (EpiSCs) through a defined series of developmental transitions into a pure population of highly expandable OPCs in ten days. These OPCs robustly differentiate into myelinating oligodendrocytes both in vitro and in vivo. Our results demonstrate that pluripotent stem cells can provide a pure population of clinically-relevant, myelinogenic oligodendrocytes and offer a tractable platform for defining the molecular regulation of oligodendrocyte development, drug screening, and potential cell-based remyelinating therapies.
Project description:Many studies have already shown the reprogramming of somatic cells into other cell types such as neural stem cells, blood progenitor cells, and hepatocytes by inducing combinations of transcription factors. One of the recent development in cellular reprogramming is the direct reprogramming, that can change cell fate towards different lineages. This strategy provides an alternative to the use of pluripotent stem cells ruling out the concerns of tumorigenicity caused by undifferentiated cell populations. Here, we generated induced oligodendrocyte progenitor cells (iOPCs) from mouse fibroblasts by direct reprogramming. The generated iOPCs are homogenous, self-renewing, and multipotent. Once differentiated, the somatic stem cells exhibit morphological and molecular characteristics of oligodendrocyte progenitor cells (OPCs). Thus, we demonstrated that terminally differentiated somatic cells can be converted into functional iOPCs by induction of transcription factors offering a new strategies to cure myelin disorders.
Project description:Conversion of fibroblasts into skeletal muscle cells by overexpression of the transcription factor MyoD has been widely employed over past decades in a multitude of experimental settings. However, the potential of additional myogenic regulatory factors such as Myf5, Myf6 and Myog to elicit a myogenic conversion has been significantly less studied. To address this disparity, we set out to investigate the role of MRFs in fibroblast conversion into skeletal muscle stem and differentiated cells. Surprisingly, we found that Myf6, a transcription factor associated with postnatal late-stage myogenesis, efficiently converted fibroblasts into myotubes alone, or alternatively into expandable Pax7-expressing induced myogenic progenitor cells (iMPCs) in the presence of defined small molecules. To investigate reprogramming dynamics in a tightly regulated system, we generated an inducible Myf6 overexpression transgenic mouse model, which enabled dissection of transcription and epigenetic dynamics unique to iMPC formation. Mechanistically, we characterized the chromatin binding of Myf6, as well as its protein binding partners, during iMPC reprogramming and conventional transdifferentiation, revealing shared and different targets and binding partners. To further investigate its role, we surprisingly found that endogenous Myf6 is dispensable for iMPC formation by MyoD and small molecules. In accordance with this observation, we demonstrated that subjecting MyoD-KO fibroblasts to reprogramming with Myf6 and small molecules gave rise to expandable MyoD-KO iMPCs, indicating that MyoD is similarly dispensable for iMPC formation and self-renewal. Multi-omics analyses of Myf6-derived MyoD-KO iMPCs uncovered upregulated genes that compensated for the lack of MyoD, whose downregulation during iMPC production mitigated Pax7 expression, highlighting their roles as reprogramming regulators. Collectively, these results illustrate a redundancy between MRFs’ function in myogenic cellular conversions, highlighting an unexpected potency for Myf6 in the induction of a muscle stem cell fate in vitro.
Project description:Conversion of fibroblasts into skeletal muscle cells by overexpression of the transcription factor MyoD has been widely employed over past decades in a multitude of experimental settings. However, the potential of additional myogenic regulatory factors such as Myf5, Myf6 and Myog to elicit a myogenic conversion has been significantly less studied. To address this disparity, we set out to investigate the role of MRFs in fibroblast conversion into skeletal muscle stem and differentiated cells. Surprisingly, we found that Myf6, a transcription factor associated with postnatal late-stage myogenesis, efficiently converted fibroblasts into myotubes alone, or alternatively into expandable Pax7-expressing induced myogenic progenitor cells (iMPCs) in the presence of defined small molecules. To investigate reprogramming dynamics in a tightly regulated system, we generated an inducible Myf6 overexpression transgenic mouse model, which enabled dissection of transcription and epigenetic dynamics unique to iMPC formation. Mechanistically, we characterized the chromatin binding of Myf6, as well as its protein binding partners, during iMPC reprogramming and conventional transdifferentiation, revealing shared and different targets and binding partners. To further investigate its role, we surprisingly found that endogenous Myf6 is dispensable for iMPC formation by MyoD and small molecules. In accordance with this observation, we demonstrated that subjecting MyoD-KO fibroblasts to reprogramming with Myf6 and small molecules gave rise to expandable MyoD-KO iMPCs, indicating that MyoD is similarly dispensable for iMPC formation and self-renewal. Multi-omics analyses of Myf6-derived MyoD-KO iMPCs uncovered upregulated genes that compensated for the lack of MyoD, whose downregulation during iMPC production mitigated Pax7 expression, highlighting their roles as reprogramming regulators. Collectively, these results illustrate a redundancy between MRFs’ function in myogenic cellular conversions, highlighting an unexpected potency for Myf6 in the induction of a muscle stem cell fate in vitro.