RESUMO
Polyglutamine (polyQ) repeat diseases are a class of neurodegenerative disorders caused by CAG-repeat expansion. There are diverse cellular mechanisms behind the pathogenesis of polyQ disorders, including transcriptional dysregulation. Interestingly, we find that levels of the long isoform of nuclear paraspeckle assembly transcript 1 (Neat1L) are elevated in the brains of mouse models of spinocerebellar ataxia types 1, 2, 7 and Huntington's disease (HD). Neat1L was also elevated in differentiated striatal neurons derived from HD knock-in mice and in HD patient brains. The elevation was mutant Huntingtin (mHTT) dependent, as knockdown of mHTT in vitro and in vivo restored Neat1L to normal levels. In additional studies, we found that Neat1L is repressed by methyl CpG binding protein 2 (MeCP2) by RNA-protein interaction but not by occupancy of MeCP2 at its promoter. We also found that NEAT1L overexpression protects from mHTT-induced cytotoxicity, while reducing it enhanced mHTT-dependent toxicity. Gene set enrichment analysis of previously published RNA sequencing data from mouse embryonic fibroblasts and cells derived from HD patients shows that loss of NEAT1L impairs multiple cellular functions, including pathways involved in cell proliferation and development. Intriguingly, the genes dysregulated in HD human brain samples overlap with pathways affected by a reduction in NEAT1, confirming the correlation of NEAT1L and HD-induced perturbations. Cumulatively, the role of NEAT1L in polyQ disease model systems and human tissues suggests that it may play a protective role in CAG-repeat expansion diseases.
Assuntos
Doença de Huntington/genética , Proteína 2 de Ligação a Metil-CpG/genética , RNA Longo não Codificante/genética , Ataxias Espinocerebelares/genética , Processamento Alternativo/genética , Animais , Diferenciação Celular/genética , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Técnicas de Introdução de Genes , Humanos , Proteína Huntingtina/genética , Doença de Huntington/fisiopatologia , Camundongos , Neurônios/metabolismo , Neurônios/patologia , Peptídeos/genética , Regiões Promotoras Genéticas , Isoformas de Proteínas/genética , Proteínas de Ligação a RNA/genética , Ataxias Espinocerebelares/fisiopatologia , Expansão das Repetições de Trinucleotídeos/genéticaRESUMO
Adeno-associated virus-mediated gene replacement is emerging as a safe and effective means of correcting single-gene mutations affecting the CNS. AAV-mediated progranulin gene (GRN) delivery has been proposed as a treatment for GRN-deficient frontotemporal dementia and neuronal ceroid lipofuscinosis, and recent studies using intraparenchymal AAV-Grn delivery to brain have shown moderate success in histopathologic and behavioral rescue in mouse models. Here, we used AAV9 to deliver GRN to the lateral ventricle to achieve widespread expression in the Grn null mouse brain. We found that, despite a global increase in progranulin, overexpression resulted in dramatic and selective hippocampal toxicity and degeneration affecting neurons and glia. Hippocampal degeneration was preceded by T cell infiltration and perivascular cuffing. GRN delivery with an ependymal-targeting AAV for selective secretion of progranulin into the cerebrospinal fluid similarly resulted in T cell infiltration, as well as ependymal hypertrophy. Interestingly, overexpression of GRN in wild-type animals also provoked T cell infiltration. These results call into question the safety of GRN overexpression in the CNS, with evidence for both a region-selective immune response and cellular proliferative response. Our results highlight the importance of careful consideration of target gene biology and cellular response to overexpression prior to progressing to the clinic.
Assuntos
Dependovirus/genética , Progranulinas/metabolismo , Linfócitos T/metabolismo , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Feminino , Demência Frontotemporal/genética , Demência Frontotemporal/terapia , Terapia Genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Modelos Teóricos , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/terapia , Progranulinas/líquido cefalorraquidiano , Progranulinas/deficiência , Progranulinas/genéticaRESUMO
Site-specific genome editing provides a promising approach for achieving long-term, stable therapeutic gene expression. Genome editing has been successfully applied in a variety of preclinical models, generally focused on targeting the diseased locus itself; however, limited targeting efficiency or insufficient expression from the endogenous promoter may impede the translation of these approaches, particularly if the desired editing event does not confer a selective growth advantage. Here we report a general strategy for liver-directed protein replacement therapies that addresses these issues: zinc finger nuclease (ZFN) -mediated site-specific integration of therapeutic transgenes within the albumin gene. By using adeno-associated viral (AAV) vector delivery in vivo, we achieved long-term expression of human factors VIII and IX (hFVIII and hFIX) in mouse models of hemophilia A and B at therapeutic levels. By using the same targeting reagents in wild-type mice, lysosomal enzymes were expressed that are deficient in Fabry and Gaucher diseases and in Hurler and Hunter syndromes. The establishment of a universal nuclease-based platform for secreted protein production would represent a critical advance in the development of safe, permanent, and functional cures for diverse genetic and nongenetic diseases.
Assuntos
Albuminas/genética , Terapia de Reposição de Enzimas , Terapia Genética , Genoma , Fígado/metabolismo , Transgenes/fisiologia , Albuminas/metabolismo , Animais , Dependovirus/genética , Endonucleases , Doença de Fabry/genética , Doença de Fabry/terapia , Fator IX/genética , Fator VIII/genética , Doença de Gaucher/genética , Doença de Gaucher/terapia , Vetores Genéticos/administração & dosagem , Hemofilia A/genética , Hemofilia A/terapia , Hemofilia B/genética , Hemofilia B/terapia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lisossomos/enzimologia , Camundongos , Camundongos Endogâmicos C57BL , Mucopolissacaridose I/genética , Mucopolissacaridose I/terapia , Mucopolissacaridose II/genética , Mucopolissacaridose II/terapia , Regiões Promotoras Genéticas/genética , Edição de RNA , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Dedos de ZincoRESUMO
Mammalian synthetic biology may provide novel therapeutic strategies, help decipher new paths for drug discovery and facilitate synthesis of valuable molecules. Yet, our capacity to genetically program cells is currently hampered by the lack of efficient approaches to streamline the design, construction and screening of synthetic gene networks. To address this problem, here we present a framework for modular and combinatorial assembly of functional (multi)gene expression vectors and their efficient and specific targeted integration into a well-defined chromosomal context in mammalian cells. We demonstrate the potential of this framework by assembling and integrating different functional mammalian regulatory networks including the largest gene circuit built and chromosomally integrated to date (6 transcription units, 27kb) encoding an inducible memory device. Using a library of 18 different circuits as a proof of concept, we also demonstrate that our method enables one-pot/single-flask chromosomal integration and screening of circuit libraries. This rapid and powerful prototyping platform is well suited for comparative studies of genetic regulatory elements, genes and multi-gene circuits as well as facile development of libraries of isogenic engineered cell lines.
Assuntos
Engenharia Celular/métodos , Redes Reguladoras de Genes , Animais , Linhagem Celular , Clonagem Molecular , Biblioteca Gênica , HumanosRESUMO
Introduction: Parkinson's disease (PD) is the second most prevalent neurodegenerative disease. Complementary and alternative therapies are increasingly utilized to address its complex multisystem symptomatology. Art therapy involves motoric action and visuospatial processing while promoting broad biopsychosocial wellness. The process involves hedonic absorption, which provides an escape from otherwise persistent and cumulative PD symptoms, refreshing internal resources. It involves the expression in nonverbal form of multilayered psychological and somatic phenomena; once these are externalized in a symbolic arts medium, they can be explored, understood, integrated, and reorganized through verbal dialogue, effecting relief and positive change. Methods: 42 participants with mild to moderate PD were treated with 20 sessions of group art therapy. They were assessed before and after therapy with a novel arts-based instrument developed to match the treatment modality for maximum sensitivity. The House-Tree-Person PD Scale (HTP-PDS) assesses motoric and visuospatial processing-core PD symptoms-as well as cognition (thought and logic), affect/mood, motivation, self (including body-image, self-image, and self- efficacy), interpersonal functioning, creativity, and overall level of functioning. It was hypothesized that art therapy will ameliorate core PD symptoms and that this will correlate with improvements in all other variables. Results: HTP-PDS scores across all symptoms and variables improved significantly, though causality among variables was indeterminate. Discussion: Art therapy is a clinically efficacious complementary treatment for PD. Further research is warranted to disentangle causal pathways among the aforementioned variables, and additionally, to isolate and examine the multiple, discrete healing mechanisms believed to operate simultaneously in art therapy.