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Charles A. Thornton

Bio: Charles A. Thornton is an academic researcher from University of Rochester Medical Center. The author has contributed to research in topics: Myotonic dystrophy & MBNL1. The author has an hindex of 71, co-authored 182 publications receiving 17195 citations. Previous affiliations of Charles A. Thornton include University of Rochester & University of Florida.


Papers
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Journal ArticleDOI
TL;DR: This work proposes that DM1 disease is caused by aberrant recruitment of the EXP proteins to the DMPK transcript (CUG)n expansion, and identifies the triplet repeat expansion (EXP) RNA‐binding proteins as candidate sequestered factors.
Abstract: Myotonic dystrophy (DM1) is an autosomal dominant neuromuscular disorder associated with a (CTG)n expansion in the 3′-untranslated region of the DM1 protein kinase (DMPK) gene. To explain disease pathogenesis, the RNA dominance model proposes that the DM1 mutation produces a gain-of-function at the RNA level in which CUG repeats form RNA hairpins that sequester nuclear factors required for proper muscle development and maintenance. Here, we identify the triplet repeat expansion (EXP) RNA-binding proteins as candidate sequestered factors. As predicted by the RNA dominance model, binding of the EXP proteins is specific for dsCUG RNAs and proportional to the size of the triplet repeat expansion. Remarkably, the EXP proteins are homologous to the Drosophila muscleblind proteins required for terminal differentiation of muscle and photoreceptor cells. EXP expression is also activated during mammalian myoblast differentiation, but the EXP proteins accumulate in nuclear foci in DM1 cells. We propose that DM1 disease is caused by aberrant recruitment of the EXP proteins to the DMPK transcript (CUG)n expansion.

890 citations

Journal ArticleDOI
12 Dec 2003-Science
TL;DR: It is shown that disruption of the mouse Mbnl1 gene leads to muscle, eye, and RNAsplicing abnormalities that are characteristic of DM disease.
Abstract: The neuromuscular disease myotonic dystrophy (DM) is caused by microsatellite repeat expansions at two different genomic loci. Mutant DM transcripts are retained in the nucleus together with the muscleblind (Mbnl) proteins, and these abnormal RNAs somehow interfere with pre-mRNA splicing regulation. Here, we show that disruption of the mouse Mbnl1 gene leads to muscle, eye, and RNAsplicing abnormalities that are characteristic of DM disease. Our results support the hypothesis that manifestations of DM can result from sequestration of specific RNAbinding proteins by a repetitive element expansion in a mutant RNA.

718 citations

Journal ArticleDOI
08 Sep 2000-Science
TL;DR: In this paper, an untranslated CUG repeat in an unrelated mRNA in transgenic mice was found to be sufficient to generate a myotonic dystrophy phenotype, whereas mice expressing a nonexpanded repeat did not.
Abstract: Myotonic dystrophy (DM), the most common form of muscular dystrophy in adult humans, results from expansion of a CTG repeat in the 3' untranslated region of the DMPK gene. The mutant DMPK messenger RNA (mRNA) contains an expanded CUG repeat and is retained in the nucleus. We have expressed an untranslated CUG repeat in an unrelated mRNA in transgenic mice. Mice that expressed expanded CUG repeats developed myotonia and myopathy, whereas mice expressing a nonexpanded repeat did not. Thus, transcripts with expanded CUG repeats are sufficient to generate a DM phenotype. This result supports a role for RNA gain of function in disease pathogenesis.

692 citations

Journal ArticleDOI
TL;DR: Using skeletal muscle from a transgenic mouse model of DM, it is shown that expression of expanded CUG repeats reduces the transmembrane chloride conductance to levels well below those expected to cause myotonia.

637 citations

Journal ArticleDOI
TL;DR: Examination of post-mortem DM1 tissue by fluorescence in situ hybridization indicates that CNS impairment in DM1 may result from a deleterious gain-of-function by mutant DMPK mRNA, and a subset of neuronal pre-mRNAs show abnormal regulation of alternative splicing.
Abstract: Myotonic dystrophy type 1 (DM1) is caused by expansion of a CTG repeat in the DMPK gene. In skeletal muscles, DM1 may involve a novel, RNA-dominant disease mechanism in which transcripts from the mutant DMPK allele accumulate in the nucleus and compromise the regulation of alternative splicing. Here we show evidence for a similar disease mechanism in brain. Examination of post-mortem DM1 tissue by fluorescence in situ hybridization indicates that the mutant DMPK mRNA, with its expanded CUG repeat in the 3'-untranslated region, is widely expressed in cortical and subcortical neurons. The mutant transcripts accumulate in discrete foci within neuronal nuclei. Proteins in the muscleblind family are recruited into the RNA foci and depleted elsewhere in the nucleoplasm. In parallel, a subset of neuronal pre-mRNAs show abnormal regulation of alternative splicing. These observations suggest that CNS impairment in DM1 may result from a deleterious gain-of-function by mutant DMPK mRNA.

493 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: The evidence reviewed in this Position Stand is generally consistent with prior American College of Sports Medicine statements on the types and amounts of physical activity recommended for older adults as well as the recently published 2008 Physical Activity Guidelines for Americans.
Abstract: The purpose of this Position Stand is to provide an overview of issues critical to understanding the importance of exercise and physical activity in older adult populations. The Position Stand is divided into three sections: Section 1 briefly reviews the structural and functional changes that characterize normal human aging, Section 2 considers the extent to which exercise and physical activity can influence the aging process, and Section 3 summarizes the benefits of both long-term exercise and physical activity and shorter-duration exercise programs on health and functional capacity. Although no amount of physical activity can stop the biological aging process, there is evidence that regular exercise can minimize the physiological effects of an otherwise sedentary lifestyle and increase active life expectancy by limiting the development and progression of chronic disease and disabling conditions. There is also emerging evidence for significant psychological and cognitive benefits accruing from regular exercise participation by older adults. Ideally, exercise prescription for older adults should include aerobic exercise, muscle strengthening exercises, and flexibility exercises. The evidence reviewed in this Position Stand is generally consistent with prior American College of Sports Medicine statements on the types and amounts of physical activity recommended for older adults as well as the recently published 2008 Physical Activity Guidelines for Americans. All older adults should engage in regular physical activity and avoid an inactive lifestyle.

4,264 citations

Journal ArticleDOI
TL;DR: This Review describes special events in the lifetimes of lncRNAs — before, during and after transcription — and discusses how these events ultimately shape the unique characteristics and functional roles of lNCRNAs.
Abstract: Long non-coding RNAs (lncRNAs) are a diverse class of RNAs that engage in numerous biological processes across every branch of life. Although initially discovered as mRNA-like transcripts that do not encode proteins, recent studies have revealed features of lncRNAs that further distinguish them from mRNAs. In this Review, we describe special events in the lifetimes of lncRNAs - before, during and after transcription - and discuss how these events ultimately shape the unique characteristics and functional roles of lncRNAs.

2,568 citations

Journal ArticleDOI
TL;DR: Sarcopenia should be considered in all older patients who present with observed declines in physical function, strength, or overall health, and patients who meet these criteria should further undergo body composition assessment using dual energy x-ray absorptiometry with sarcopenia being defined using currently validated definitions.

2,378 citations