GENETIC CORRECTION OF HUNTINGTON'S DISEASE PHENOTYPES IN INDUCED PLURIPOTENT STEM CELLS
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ABSTRACT: Huntington's Disease (HD) is caused by a CAG expansion in the huntingtin gene. Expansion of the polyglutamine tract in the huntingtin protein results in massive cell death in the striatum of HD patients. We report that human induced pluripotent stem cells (iPSCs) derived from HD patient fibroblasts can be corrected by replacing the expanded CAG repeat with a normal repeat using homologous recombination, and that the correction persists in iPSC differentiation into DARPP-32 positive neurons in vitro and vivo. Further, correction of the HD-iPSCs normalized pathogenic HD signaling pathways (cadherin, TGF-?, BNDF, caspase activation), and reversed disease phenotypes such as susceptibility to cell death and altered mitochondrial bioenergetics in neural stem cells. The ability to make patient-specific, genetically corrected iPSCs from HD patients will provide relevant disease models in identical genetic backgrounds and is a critical step for the eventual use of these cells in cell replacement therapy. 16 experimental samples were used overall. There were 8 replicates per group, with one group being the control, and the other being the experimental. Comparison was carried out on the Nimblegen platform.
Project description:Huntington's Disease (HD) is caused by a CAG expansion in the huntingtin gene. Expansion of the polyglutamine tract in the huntingtin protein results in massive cell death in the striatum of HD patients. We report that human induced pluripotent stem cells (iPSCs) derived from HD patient fibroblasts can be corrected by replacing the expanded CAG repeat with a normal repeat using homologous recombination, and that the correction persists in iPSC differentiation into DARPP-32 positive neurons in vitro and vivo. Further, correction of the HD-iPSCs normalized pathogenic HD signaling pathways (cadherin, TGF-β, BNDF, caspase activation), and reversed disease phenotypes such as susceptibility to cell death and altered mitochondrial bioenergetics in neural stem cells. The ability to make patient-specific, genetically corrected iPSCs from HD patients will provide relevant disease models in identical genetic backgrounds and is a critical step for the eventual use of these cells in cell replacement therapy.
Project description:Huntington’s disease (HD) is an incurable hereditary neurodegenerative disorder, which manifests itself as a loss of GABAergic medium spiny (GABA MS) neurons in the striatum and caused by an expansion of the CAG repeat in exon 1 of the huntingtin gene. There is no cure for HD, existing pharmaceutical can only relieve its symptoms. Here, induced pluripotent stem cells were established from patients with low CAG repeat expansion in the huntingtin gene, and were then efficiently differentiated into GABA MS-like neurons under defined culture conditions. Analysis of differentially expressed genes between Huntington’s disease and wild type iPSCs derived GABA MS-like neurons has been performed.
Project description:Huntington’s Disease (HD) is caused by a CAG repeat expansion in the gene encoding Huntingtin (HTT). While normal HTT function appears impacted by the mutation, the specific pathways unique to CAG repeat expansion versus loss of normal function are unclear. To understand the impact of the CAG repeat expansion, we evaluated biological signatures of HTT knockout (HTT KO) versus those that occur from the CAG repeat expansion by applying multi-omics, live cell imaging, survival analysis and a novel feature- based pipeline to study cortical neurons (eCNs) derived from an isogenic human embryonic stem cell series (RUES2). HTT KO and the CAG repeat expansion influence developmental trajectories of eCNs, with opposing effects on the growth. Network analyses of differentially expressed genes and proteins associated with enriched epigenetic motifs identified subnetworks common to CAG repeat expansion and HTT KO that include neuronal differentiation, cell cycle regulation, and mechanisms related to transcriptional repression and may represent gain-of-function mechanisms that cannot be explained by HTT loss of function alone. A combination of dominant and loss-of-function mechanisms are likely involved in the aberrant neurodevelopmental and neurodegenerative features of HD that can help inform therapeutic strategies.
Project description:Huntington’s Disease (HD) is caused by a CAG repeat expansion in the gene encoding Huntingtin (HTT). While normal HTT function appears impacted by the mutation, the specific pathways unique to CAG repeat expansion versus loss of normal function are unclear. To understand the impact of the CAG repeat expansion, we evaluated biological signatures of HTT knockout (HTT KO) versus those that occur from the CAG repeat expansion by applying multi-omics, live cell imaging, survival analysis and a novel feature- based pipeline to study cortical neurons (eCNs) derived from an isogenic human embryonic stem cell series (RUES2). HTT KO and the CAG repeat expansion influence developmental trajectories of eCNs, with opposing effects on the growth. Network analyses of differentially expressed genes and proteins associated with enriched epigenetic motifs identified subnetworks common to CAG repeat expansion and HTT KO that include neuronal differentiation, cell cycle regulation, and mechanisms related to transcriptional repression and may represent gain-of-function mechanisms that cannot be explained by HTT loss of function alone. A combination of dominant and loss-of-function mechanisms are likely involved in the aberrant neurodevelopmental and neurodegenerative features of HD that can help inform therapeutic strategies.
Project description:Huntington’s Disease (HD) is caused by a CAG repeat expansion in the gene encoding Huntingtin (HTT). While normal HTT function appears impacted by the mutation, the specific pathways unique to CAG repeat expansion versus loss of normal function are unclear. To understand the impact of the CAG repeat expansion, we evaluated biological signatures of HTT knockout (HTT KO) versus those that occur from the CAG repeat expansion by applying multi-omics, live cell imaging, survival analysis and a novel feature- based pipeline to study cortical neurons (eCNs) derived from an isogenic human embryonic stem cell series (RUES2). HTT KO and the CAG repeat expansion influence developmental trajectories of eCNs, with opposing effects on the growth. Network analyses of differentially expressed genes and proteins associated with enriched epigenetic motifs identified subnetworks common to CAG repeat expansion and HTT KO that include neuronal differentiation, cell cycle regulation, and mechanisms related to transcriptional repression and may represent gain-of-function mechanisms that cannot be explained by HTT loss of function alone. A combination of dominant and loss-of-function mechanisms are likely involved in the aberrant neurodevelopmental and neurodegenerative features of HD that can help inform therapeutic strategies.
Project description:Huntington’s Disease (HD) is caused by a CAG repeat expansion in the gene encoding Huntingtin (HTT). While normal HTT function appears impacted by the mutation, the specific pathways unique to CAG repeat expansion versus loss of normal function are unclear. To understand the impact of the CAG repeat expansion, we evaluated biological signatures of HTT knockout (HTT KO) versus those that occur from the CAG repeat expansion by applying multi-omics, live cell imaging, survival analysis and a novel feature- based pipeline to study cortical neurons (eCNs) derived from an isogenic human embryonic stem cell series (RUES2). HTT KO and the CAG repeat expansion influence developmental trajectories of eCNs, with opposing effects on the growth. Network analyses of differentially expressed genes and proteins associated with enriched epigenetic motifs identified subnetworks common to CAG repeat expansion and HTT KO that include neuronal differentiation, cell cycle regulation, and mechanisms related to transcriptional repression and may represent gain-of-function mechanisms that cannot be explained by HTT loss of function alone. A combination of dominant and loss-of-function mechanisms are likely involved in the aberrant neurodevelopmental and neurodegenerative features of HD that can help inform therapeutic strategies.
Project description:Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that is characterized by motor, cognitive, and psychiatric alterations. The mutation responsible for this disease is an abnormally expanded and unstable CAG repeat within the coding region of the gene encoding huntingtin (Htt). Knock-in mouse models of HD with human exon 1 containing expanded CAG repeats inserted in the murine huntingtin gene (Hdh) provide a genetic reconstruction of the human causative mutation within the mouse model. The goal of this study is RNA expression profiling by RNA sequencing (RNA-seq) in 2, 6, and 10 month old knock-in mice with CAG lengths of 20, 80, 92, 111, 140, 175 along with littermate control wild-type animals miRNA expression profiles were obtained via RNA-seq analysis performed on tissue samples from the liver of 2, 6, and 10 month old knock-in mice with CAG lengths of 20, 80, 92, 111, 140, 175 along with littermate control wild-type animals.
Project description:Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that is characterized by motor, cognitive, and psychiatric alterations. The mutation responsible for this disease is an abnormally expanded and unstable CAG repeat within the coding region of the gene encoding huntingtin (Htt). Knock-in mouse models of HD with human exon 1 containing expanded CAG repeats inserted in the murine huntingtin gene (Hdh) provide a genetic reconstruction of the human causative mutation within the mouse model. The goal of this study is RNA expression profiling by RNA sequencing (RNA-seq) in 2, 6, and 10 month old knock-in mice with CAG lengths of 20, 80, 92, 111, 140, 175 along with littermate control wild-type animals miRNA expression profiles were obtained via RNA-seq analysis performed on tissue samples from the striatum of 2, 6, and 10 month old knock-in mice with CAG lengths of 20, 80, 92, 111, 140, 175 along with littermate control wild-type animals.
Project description:Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that is characterized by motor, cognitive, and psychiatric alterations. The mutation responsible for this disease is an abnormally expanded and unstable CAG repeat within the coding region of the gene encoding huntingtin (Htt). Knock-in mouse models of HD with human exon 1 containing expanded CAG repeats inserted in the murine huntingtin gene (Hdh) provide a genetic reconstruction of the human causative mutation within the mouse model. The goal of this study is RNA expression profiling by RNA sequencing (RNA-seq) in 2, 6, and 10 month old knock-in mice with CAG lengths of 20, 80, 92, 111, 140, 175 along with littermate control wild-type animals mRNA expression profiles were obtained via RNA-seq analysis performed on tissue samples from the liver of 2, 6, and 10 month old knock-in mice with CAG lengths of 20, 80, 92, 111, 140, 175 along with littermate control wild-type animals.
Project description:Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that is characterized by motor, cognitive, and psychiatric alterations. The mutation responsible for this disease is an abnormally expanded and unstable CAG repeat within the coding region of the gene encoding huntingtin (Htt). Knock-in mouse models of HD with human exon 1 containing expanded CAG repeats inserted in the murine huntingtin gene (Hdh) provide a genetic reconstruction of the human causative mutation within the mouse model. The goal of this study is RNA expression profiling by RNA sequencing (RNA-seq) in 2, 6, and 10 month old knock-in mice with CAG lengths of 20, 80, 92, 111, 140, 175 along with littermate control wild-type animals mRNA expression profiles were obtained via RNA-seq analysis performed on tissue samples from the striatum of 2, 6, and 10 month old knock-in mice with CAG lengths of 20, 80, 92, 111, 140, 175 along with littermate control wild-type animals.