Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Hum Mol Genet ; 31(18): 3144-3160, 2022 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-35567413

RESUMO

Myotonic dystrophy (DM) is caused by expansions of C(C)TG repeats in the non-coding regions of the DMPK and CNBP genes, and DM patients often suffer from sudden cardiac death due to lethal conduction block or arrhythmia. Specific molecular changes that underlie DM cardiac pathology have been linked to repeat-associated depletion of Muscleblind-like (MBNL) 1 and 2 proteins and upregulation of CUGBP, Elav-like family member 1 (CELF1). Hypothesis solely targeting MBNL1 or CELF1 pathways that could address all the consequences of repeat expansion in heart remained inconclusive, particularly when the direct cause of mortality and results of transcriptome analyses remained undetermined in Mbnl compound knockout (KO) mice with cardiac phenotypes. Here, we develop Myh6-Cre double KO (DKO) (Mbnl1-/-; Mbnl2cond/cond; Myh6-Cre+/-) mice to eliminate Mbnl1/2 in cardiomyocytes and observe spontaneous lethal cardiac events under no anesthesia. RNA sequencing recapitulates DM heart spliceopathy and shows gene expression changes that were previously undescribed in DM heart studies. Notably, immunoblotting reveals a nearly 6-fold increase of Calsequestrin 1 and 50% reduction of epidermal growth factor proteins. Our findings demonstrate that complete ablation of MBNL1/2 in cardiomyocytes is essential for generating sudden death due to lethal cardiac rhythms and reveal potential mechanisms for DM heart pathogenesis.


Assuntos
Distrofia Miotônica , Processamento Alternativo/genética , Animais , Calsequestrina/genética , Proteínas de Ligação a DNA/genética , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/patologia , Família de Proteínas EGF/genética , Família de Proteínas EGF/metabolismo , Camundongos , Camundongos Knockout , Músculo Esquelético/metabolismo , Miócitos Cardíacos/metabolismo , Distrofia Miotônica/patologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
2.
Sci Transl Med ; 13(617): eabd5991, 2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34705518

RESUMO

The most common cause of amyotrophic lateral sclerosis and frontotemporal dementia (c9ALS/FTD) is an expanded G4C2 RNA repeat [r(G4C2)exp] in chromosome 9 open reading frame 72 (C9orf72), which elicits pathology through several mechanisms. Here, we developed and characterized a small molecule for targeted degradation of r(G4C2)exp. The compound was able to selectively bind r(G4C2)exp's structure and to assemble an endogenous nuclease onto the target, provoking removal of the transcript by native RNA quality control mechanisms. In c9ALS patient­derived spinal neurons, the compound selectively degraded the mutant C9orf72 allele with limited off-targets and reduced quantities of toxic dipeptide repeat proteins (DPRs) translated from r(G4C2)exp. In vivo work in a rodent model showed that abundance of both the mutant allele harboring the repeat expansion and DPRs were selectively reduced by this compound. These results demonstrate that targeted small-molecule degradation of r(G4C2)exp is a strategy for mitigating c9ALS/FTD-associated pathologies and studying disease-associated pathways in preclinical models.


Assuntos
Esclerose Lateral Amiotrófica , Demência Frontotemporal , Esclerose Lateral Amiotrófica/genética , Proteína C9orf72/genética , Expansão das Repetições de DNA , Demência Frontotemporal/genética , Humanos , Ribonucleases
3.
Proc Natl Acad Sci U S A ; 116(16): 7799-7804, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30926669

RESUMO

Myotonic dystrophy type 1 (DM1) is an incurable neuromuscular disorder caused by an expanded CTG repeat that is transcribed into r(CUG)exp The RNA repeat expansion sequesters regulatory proteins such as Muscleblind-like protein 1 (MBNL1), which causes pre-mRNA splicing defects. The disease-causing r(CUG)exp has been targeted by antisense oligonucleotides, CRISPR-based approaches, and RNA-targeting small molecules. Herein, we describe a designer small molecule, Cugamycin, that recognizes the structure of r(CUG)exp and cleaves it in both DM1 patient-derived myotubes and a DM1 mouse model, leaving short repeats of r(CUG) untouched. In contrast, oligonucleotides that recognize r(CUG) sequence rather than structure cleave both long and short r(CUG)-containing transcripts. Transcriptomic, histological, and phenotypic studies demonstrate that Cugamycin broadly and specifically relieves DM1-associated defects in vivo without detectable off-targets. Thus, small molecules that bind and cleave RNA have utility as lead chemical probes and medicines and can selectively target disease-causing RNA structures to broadly improve defects in preclinical animal models.


Assuntos
Bleomicina/análogos & derivados , Distrofia Miotônica/genética , Distrofia Miotônica/metabolismo , Oligonucleotídeos/química , Splicing de RNA/genética , RNA/genética , RNA/metabolismo , Expansão das Repetições de Trinucleotídeos/genética , Animais , Bleomicina/química , Modelos Animais de Doenças , Desenho de Fármacos , Humanos , Camundongos , Oligonucleotídeos/metabolismo
4.
Sci Rep ; 7(1): 10504, 2017 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-28874804

RESUMO

Recapitulation of developmental signals represents a promising strategy for treating intervertebral disc degeneration. During development, embryonic notochord-derived cells (NDCs) are the direct progenitors of cells that populate the adult nucleus pulposus (NP) and are an important source of secreted signaling molecules. The objective of this study was to define global gene expression profiles of NDCs at key stages of embryonic disc formation. NDCs were isolated from Shh-cre;ROSA:YFP mice at embryonic day 12.5 and postnatal day 0, representing opposite ends of the notochord to NP transformation. Differences in global mRNA abundance across this developmental window were established using RNA-Seq. Protein expression of selected molecules was confirmed using immunohistochemistry. Principal component analysis revealed clustering of gene expression at each developmental stage with more than 5000 genes significantly differentially expressed between E12.5 and P0. There was significantly lower mRNA abundance of sonic hedgehog pathway elements at P0 vs E12.5, while abundance of elements of the transforming growth factor-beta and insulin-like growth factors pathways, and extracellular matrix components including collagen 6 and aggrecan, were significantly higher at P0. This study represents the first transcriptome-wide analysis of embryonic NDCs. Results suggest signaling and biosynthesis of NDCs change dramatically as a function of developmental stage.


Assuntos
Perfilação da Expressão Gênica , Notocorda/citologia , Núcleo Pulposo/embriologia , Núcleo Pulposo/metabolismo , Transcriptoma , Animais , Embrião de Mamíferos , Matriz Extracelular/metabolismo , Regulação da Expressão Gênica , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , RNA Mensageiro , Reprodutibilidade dos Testes , Transdução de Sinais , Coluna Vertebral/embriologia , Coluna Vertebral/metabolismo , Fator de Crescimento Transformador beta/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...