scholarly journals Histone deacetylase (HDAC) inhibitors targeting HDAC3 and HDAC1 ameliorate polyglutamine-elicited phenotypes in model systems of Huntington's disease

2012 ◽  
Vol 46 (2) ◽  
pp. 351-361 ◽  
Author(s):  
Haiqun Jia ◽  
Judit Pallos ◽  
Vincent Jacques ◽  
Alice Lau ◽  
Bin Tang ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Histone Deacetylase ◽  
Hdac Inhibitors ◽  
Model Systems

Evaluation of 5-(Trifluoromethyl)-1,2,4-oxadiazole-Based Class IIa HDAC Inhibitors for Huntington’s Disease

2021 ◽  
Author(s):  
Andrew J. Stott ◽  
Michel C. Maillard ◽  
Vahri Beaumont ◽  
David Allcock ◽  
Omar Aziz ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Hdac Inhibitors

scholarly journals The Contribution of Somatic Expansion of the CAG Repeat to Symptomatic Development in Huntington’s Disease: A Historical Perspective

2021 ◽  
Vol 10 (1) ◽  
pp. 7-33
Author(s):  
Darren G. Monckton
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Human Genetics ◽  
Age At Onset ◽  
Cag Repeat ◽  
Model Systems ◽  
Causative Mutation ◽  
Inverse Association ◽  
Independent Manner ◽  
Dna Mismatch

The discovery in the early 1990s of the expansion of unstable simple sequence repeats as the causative mutation for a number of inherited human disorders, including Huntington’s disease (HD), opened up a new era of human genetics and provided explanations for some old problems. In particular, an inverse association between the number of repeats inherited and age at onset, and unprecedented levels of germline instability, biased toward further expansion, provided an explanation for the wide symptomatic variability and anticipation observed in HD and many of these disorders. The repeats were also revealed to be somatically unstable in a process that is expansion-biased, age-dependent and tissue-specific, features that are now increasingly recognised as contributory to the age-dependence, progressive nature and tissue specificity of the symptoms of HD, and at least some related disorders. With much of the data deriving from affected individuals, and model systems, somatic expansions have been revealed to arise in a cell division-independent manner in critical target tissues via a mechanism involving key components of the DNA mismatch repair pathway. These insights have opened new approaches to thinking about how the disease could be treated by suppressing somatic expansion and revealed novel protein targets for intervention. Exciting times lie ahead in turning these insights into novel therapies for HD and related disorders.

scholarly journals N6-Furfuryladenine is protective in Huntington’s disease models by signaling huntingtin phosphorylation

2018 ◽  
Vol 115 (30) ◽  
pp. E7081-E7090 ◽  
Author(s):  
Laura E. Bowie ◽  
Tamara Maiuri ◽  
Melanie Alpaugh ◽  
Michelle Gabriel ◽  
Nicolas Arbez ◽  
...  
Keyword(s):  
Dna Damage ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Oxidative Dna Damage ◽  
Model Systems ◽  
Protective Effects ◽  
Mutant Huntingtin ◽  
Naturally Occurring ◽  
Phosphate Donor ◽  
High Content Analysis

The huntingtin N17 domain is a modulator of mutant huntingtin toxicity and is hypophosphorylated in Huntington’s disease (HD). We conducted high-content analysis to find compounds that could restore N17 phosphorylation. One lead compound from this screen was N6-furfuryladenine (N6FFA). N6FFA was protective in HD model neurons, and N6FFA treatment of an HD mouse model corrects HD phenotypes and eliminates cortical mutant huntingtin inclusions. We show that N6FFA restores N17 phosphorylation levels by being salvaged to a triphosphate form by adenine phosphoribosyltransferase (APRT) and used as a phosphate donor by casein kinase 2 (CK2). N6FFA is a naturally occurring product of oxidative DNA damage. Phosphorylated huntingtin functionally redistributes and colocalizes with CK2, APRT, and N6FFA DNA adducts at sites of induced DNA damage. We present a model in which this natural product compound is salvaged to provide a triphosphate substrate to signal huntingtin phosphorylation via CK2 during low-ATP stress under conditions of DNA damage, with protective effects in HD model systems.

scholarly journals KEAP1-modifying small molecule reveals muted NRF2 signaling responses in neural stem cells from Huntington's disease patients

2017 ◽  
Vol 114 (23) ◽  
pp. E4676-E4685 ◽  
Author(s):  
Luisa Quinti ◽  
Sharadha Dayalan Naidu ◽  
Ulrike Träger ◽  
Xiqun Chen ◽  
Kimberly Kegel-Gleason ◽  
...  
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Adaptor Protein ◽  
Negative Regulator ◽  
Model Systems ◽  
Human Model ◽  
Selective Activation ◽  
Primary Mouse

The activity of the transcription factor nuclear factor-erythroid 2 p45-derived factor 2 (NRF2) is orchestrated and amplified through enhanced transcription of antioxidant and antiinflammatory target genes. The present study has characterized a triazole-containing inducer of NRF2 and elucidated the mechanism by which this molecule activates NRF2 signaling. In a highly selective manner, the compound covalently modifies a critical stress-sensor cysteine (C151) of the E3 ligase substrate adaptor protein Kelch-like ECH-associated protein 1 (KEAP1), the primary negative regulator of NRF2. We further used this inducer to probe the functional consequences of selective activation of NRF2 signaling in Huntington's disease (HD) mouse and human model systems. Surprisingly, we discovered a muted NRF2 activation response in human HD neural stem cells, which was restored by genetic correction of the disease-causing mutation. In contrast, selective activation of NRF2 signaling potently repressed the release of the proinflammatory cytokine IL-6 in primary mouse HD and WT microglia and astrocytes. Moreover, in primary monocytes from HD patients and healthy subjects, NRF2 induction repressed expression of the proinflammatory cytokines IL-1, IL-6, IL-8, and TNFα. Together, our results demonstrate a multifaceted protective potential of NRF2 signaling in key cell types relevant to HD pathology.

scholarly journals HDAC inhibition imparts beneficial transgenerational effects in Huntington's disease mice via altered DNA and histone methylation

2014 ◽  
Vol 112 (1) ◽  
pp. E56-E64 ◽  
Author(s):  
Haiqun Jia ◽  
Charles D. Morris ◽  
Roy M. Williams ◽  
Jeanne F. Loring ◽  
Elizabeth A. Thomas
Keyword(s):  
Dna Methylation ◽  
Transgenic Mice ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Hdac Inhibitors ◽  
Hdac Inhibition ◽  
Transgenerational Effects ◽  
Treated Male ◽  
Disease Phenotypes ◽  
Cpg Sites

Increasing evidence has demonstrated that epigenetic factors can profoundly influence gene expression and, in turn, influence resistance or susceptibility to disease. Epigenetic drugs, such as histone deacetylase (HDAC) inhibitors, are finding their way into clinical practice, although their exact mechanisms of action are unclear. To identify mechanisms associated with HDAC inhibition, we performed microarray analysis on brain and muscle samples treated with the HDAC1/3-targeting inhibitor, HDACi 4b. Pathways analyses of microarray datasets implicate DNA methylation as significantly associated with HDAC inhibition. Further assessment of DNA methylation changes elicited by HDACi 4b in human fibroblasts from normal controls and patients with Huntington’s disease (HD) using the Infinium HumanMethylation450 BeadChip revealed a limited, but overlapping, subset of methylated CpG sites that were altered by HDAC inhibition in both normal and HD cells. Among the altered loci of Y chromosome-linked genes, KDM5D, which encodes Lys (K)-specific demethylase 5D, showed increased methylation at several CpG sites in both normal and HD cells, as well as in DNA isolated from sperm from drug-treated male mice. Further, we demonstrate that first filial generation (F1) offspring from drug-treated male HD transgenic mice show significantly improved HD disease phenotypes compared with F1 offspring from vehicle-treated male HD transgenic mice, in association with increased Kdm5d expression, and decreased histone H3 Lys4 (K4) (H3K4) methylation in the CNS of male offspring. Additionally, we show that overexpression of Kdm5d in mutant HD striatal cells significantly improves metabolic deficits. These findings indicate that HDAC inhibitors can elicit transgenerational effects, via cross-talk between different epigenetic mechanisms, to have an impact on disease phenotypes in a beneficial manner.

scholarly journals New developments in Huntington’s disease and other triplet repeat diseases: DNA repair turns to the dark side

2020 ◽  
Vol 4 (4) ◽  
Author(s):  
Robert S. Lahue
Keyword(s):  
Dna Repair ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Cag Repeat ◽  
Model Systems ◽  
Triplet Repeat ◽  
Maximal Effect ◽  
Huntingtin Protein ◽  
Dna Repair Proteins ◽  
Repeat Expansions

Abstract Huntington’s disease (HD) is a fatal, inherited neurodegenerative disease that causes neuronal death, particularly in medium spiny neurons. HD leads to serious and progressive motor, cognitive and psychiatric symptoms. Its genetic basis is an expansion of the CAG triplet repeat in the HTT gene, leading to extra glutamines in the huntingtin protein. HD is one of nine genetic diseases in this polyglutamine (polyQ) category, that also includes a number of inherited spinocerebellar ataxias (SCAs). Traditionally it has been assumed that HD age of onset and disease progression were solely the outcome of age-dependent exposure of neurons to toxic effects of the inherited mutant huntingtin protein. However, recent genome-wide association studies (GWAS) have revealed significant effects of genetic variants outside of HTT. Surprisingly, these variants turn out to be mostly in genes encoding DNA repair factors, suggesting that at least some disease modulation occurs at the level of the HTT DNA itself. These DNA repair proteins are known from model systems to promote ongoing somatic CAG repeat expansions in tissues affected by HD. Thus, for triplet repeats, some DNA repair proteins seem to abandon their normal genoprotective roles and, instead, drive expansions and accelerate disease. One attractive hypothesis—still to be proven rigorously—is that somatic HTT expansions augment the disease burden of the inherited allele. If so, therapeutic approaches that lower levels of huntingtin protein may need blending with additional therapies that reduce levels of somatic CAG repeat expansions to achieve maximal effect.

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