scholarly journals Epigenomic Remodeling in Huntington’s Disease—Master or Servant?

Epigenomes ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 15
Author(s):  
Geraldine Zimmer-Bensch
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Neurodegenerative Disorder ◽  
Genetic Defect ◽  
Neuronal Loss ◽  
Histone Variants ◽  
Therapeutic Concepts ◽  
Exon 1 ◽  
Epigenetic Signatures ◽  
Neuronal Physiology

In light of our aging population, neurodegenerative disorders are becoming a tremendous challenge, that modern societies have to face. They represent incurable, progressive conditions with diverse and complex pathological features, followed by catastrophic occurrences of massive neuronal loss at the later stages of the diseases. Some of these disorders, like Huntington’s disease (HD), rely on defined genetic factors. HD, as an incurable, fatal hereditary neurodegenerative disorder characterized by its mid-life onset, is caused by the expansion of CAG trinucleotide repeats coding for glutamine (Q) in exon 1 of the huntingtin gene. Apart from the genetic defect, environmental factors are thought to influence the risk, onset and progression of HD. As epigenetic mechanisms are known to readily respond to environmental stimuli, they are proposed to play a key role in HD pathogenesis. Indeed, dynamic epigenomic remodeling is observed in HD patients and in brains of HD animal models. Epigenetic signatures, such as DNA methylation, histone variants and modifications, are known to influence gene expression and to orchestrate various aspects of neuronal physiology. Hence, deciphering their implication in HD pathogenesis might open up new paths for novel therapeutic concepts, which are discussed in this review.

scholarly journals Esculetin Provides Neuroprotection against Mutant Huntingtin-Induced Toxicity in Huntington’s Disease Models

2021 ◽  
Vol 14 (10) ◽  
pp. 1044
Author(s):  
Letizia Pruccoli ◽  
Carlo Breda ◽  
Gabriella Teti ◽  
Mirella Falconi ◽  
Flaviano Giorgini ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Neuronal Death ◽  
Trinucleotide Repeat ◽  
Neurodegenerative Disorder ◽  
Positive Impact ◽  
Neuroprotective Effects ◽  
Drosophila Model ◽  
Exon 1 ◽  
Transgenic Drosophila

Huntington’s disease (HD) is a neurodegenerative disorder caused by an abnormal CAG trinucleotide repeat expansion within exon 1 of the huntingtin (HTT) gene. This mutation leads to the production of mutant HTT (mHTT) protein which triggers neuronal death through several mechanisms. Here, we investigated the neuroprotective effects of esculetin (ESC), a bioactive phenolic compound, in an inducible PC12 model and a transgenic Drosophila melanogaster model of HD, both of which express mHTT fragments. ESC partially inhibited the progression of mHTT aggregation and reduced neuronal death through its ability to counteract the oxidative stress and mitochondria impairment elicited by mHTT in the PC12 model. The ability of ESC to counteract neuronal death was also confirmed in the transgenic Drosophila model. Although ESC did not modify the lifespan of the transgenic Drosophila, it still seemed to have a positive impact on the HD phenotype of this model. Based on our findings, ESC may be further studied as a potential neuroprotective agent in a rodent transgenic model of HD.

scholarly journals Non-Cell Autonomous and Epigenetic Mechanisms of Huntington’s Disease

2021 ◽  
Vol 22 (22) ◽  
pp. 12499
Author(s):  
Chaebin Kim ◽  
Ali Yousefian-Jazi ◽  
Seung-Hye Choi ◽  
Inyoung Chang ◽  
Junghee Lee ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Trinucleotide Repeat ◽  
Neurodegenerative Disorder ◽  
Involuntary Movement ◽  
Therapeutic Approaches ◽  
Exon 1 ◽  
Human Chromosome 4 ◽  
The Brain

Huntington’s disease (HD) is a rare neurodegenerative disorder caused by an expansion of CAG trinucleotide repeat located in the exon 1 of Huntingtin (HTT) gene in human chromosome 4. The HTT protein is ubiquitously expressed in the brain. Specifically, mutant HTT (mHTT) protein-mediated toxicity leads to a dramatic degeneration of the striatum among many regions of the brain. HD symptoms exhibit a major involuntary movement followed by cognitive and psychiatric dysfunctions. In this review, we address the conventional role of wild type HTT (wtHTT) and how mHTT protein disrupts the function of medium spiny neurons (MSNs). We also discuss how mHTT modulates epigenetic modifications and transcriptional pathways in MSNs. In addition, we define how non-cell autonomous pathways lead to damage and death of MSNs under HD pathological conditions. Lastly, we overview therapeutic approaches for HD. Together, understanding of precise neuropathological mechanisms of HD may improve therapeutic approaches to treat the onset and progression of HD.

scholarly journals Westphal Variant of Huntington's Disease

2017 ◽  
Vol 17 (01) ◽  
pp. 028-030
Author(s):  
L. Cabarcas-Castro ◽  
J. Ramón-Gómez ◽  
A. Zarante-Bahamón ◽  
O. Bernal-Pacheco ◽  
E. Espinosa-García ◽  
...  
Keyword(s):  
Family History ◽  
Huntington's Disease ◽  
Movement Disorder ◽  
Huntington’S Disease ◽  
Neurodegenerative Disorder ◽  
Cag Repeats ◽  
Molecular Evidence ◽  
Exon 1 ◽  
History Of

AbstractA Westphal variant of Huntington's disease (HD) is an infrequent presentation of this inherited neurodegenerative disorder. Here, we describe a 14-year-old girl who developed symptoms at the age of 7, with molecular evidence of abnormally expanded Cytosine-Adenine-Guanine (CAG) repeats in exon 1 of the Huntingtin gene. We briefly review the classical features of this variant highlighting the importance of suspecting HD in a child with parkinsonism and a family history of movement disorder or dementia.

scholarly journals Purinergic Signaling in the Pathophysiology and Treatment of Huntington’s Disease

2021 ◽  
Vol 15 ◽  
Author(s):  
Melissa Talita Wiprich ◽  
Carla Denise Bonan
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Neurodegenerative Disorder ◽  
Early Stage ◽  
Purinergic Signaling ◽  
Neuronal Loss ◽  
Movement Control ◽  
Motor Dysfunction ◽  
Purine Nucleotides ◽  
Psychiatric Disturbance

Huntington’s disease (HD) is a devastating, progressive, and fatal neurodegenerative disorder inherited in an autosomal dominant manner. This condition is characterized by motor dysfunction (chorea in the early stage, followed by bradykinesia, dystonia, and motor incoordination in the late stage), psychiatric disturbance, and cognitive decline. The neuropathological hallmark of HD is the pronounced neuronal loss in the striatum (caudate nucleus and putamen). The striatum is related to the movement control, flexibility, motivation, and learning and the purinergic signaling has an important role in the control of these events. Purinergic signaling involves the actions of purine nucleotides and nucleosides through the activation of P2 and P1 receptors, respectively. Extracellular nucleotide and nucleoside-metabolizing enzymes control the levels of these messengers, modulating the purinergic signaling. The striatum has a high expression of adenosine A2A receptors, which are involved in the neurodegeneration observed in HD. The P2X7 and P2Y2 receptors may also play a role in the pathophysiology of HD. Interestingly, nucleotide and nucleoside levels may be altered in HD animal models and humans with HD. This review presents several studies describing the relationship between purinergic signaling and HD, as well as the use of purinoceptors as pharmacological targets and biomarkers for this neurodegenerative disorder.

scholarly journals D1R- and D2R-Medium-Sized Spiny Neurons Diversity: Insights Into Striatal Vulnerability to Huntington’s Disease Mutation

2021 ◽  
Vol 15 ◽  
Author(s):  
Guendalina Bergonzoni ◽  
Jessica Döring ◽  
Marta Biagioli
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Neurodegenerative Disorder ◽  
Neuronal Population ◽  
Specific Gene ◽  
Spiny Neurons ◽  
Loss Of Autonomy ◽  
Exon 1 ◽  
Cell Type Specific ◽  
Gene Expression Dysregulation

Huntington’s disease (HD) is a devastating neurodegenerative disorder caused by an aberrant expansion of the CAG tract within the exon 1 of the HD gene, HTT. HD progressively impairs motor and cognitive capabilities, leading to a total loss of autonomy and ultimate death. Currently, no cure or effective treatment is available to halt the disease. Although the HTT gene is ubiquitously expressed, the striatum appears to be the most susceptible district to the HD mutation with Medium-sized Spiny Neurons (MSNs) (D1R and D2R) representing 95% of the striatal neuronal population. Why are striatal MSNs so vulnerable to the HD mutation? Particularly, why do D1R- and D2R-MSNs display different susceptibility to HD? Here, we highlight significant differences between D1R- and D2R-MSNs subpopulations, such as morphology, electrophysiology, transcriptomic, functionality, and localization in the striatum. We discuss possible reasons for their selective degeneration in the context of HD. Our review suggests that a better understanding of cell type-specific gene expression dysregulation within the striatum might reveal new paths to therapeutic intervention or prevention to ameliorate HD patients’ life expectancy.

scholarly journals Nuclear translocation of AMPK-α1 potentiates striatal neurodegeneration in Huntington’s disease

2011 ◽  
Vol 194 (2) ◽  
pp. 209-227 ◽  
Author(s):  
Tz-Chuen Ju ◽  
Hui-Mei Chen ◽  
Jiun-Tsai Lin ◽  
Ching-Pang Chang ◽  
Wei-Cheng Chang ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Energy Homeostasis ◽  
Nuclear Translocation ◽  
Neurodegenerative Disorder ◽  
Neuronal Loss ◽  
Adenosine Monophosphate ◽  
Cag Repeats ◽  
Nuclear Accumulation ◽  
Striatal Neurons

Adenosine monophosphate–activated protein kinase (AMPK) is a major energy sensor that maintains cellular energy homeostasis. Huntington’s disease (HD) is a neurodegenerative disorder caused by the expansion of CAG repeats in the huntingtin (Htt) gene. In this paper, we report that activation of the α1 isoform of AMPK (AMPK-α1) occurred in striatal neurons of humans and mice with HD. Overactivation of AMPK in the striatum caused brain atrophy, facilitated neuronal loss, and increased formation of Htt aggregates in a transgenic mouse model (R6/2) of HD. Such nuclear accumulation of AMPK-α1 was activity dependent. Prevention of nuclear translocation or inactivation of AMPK-α1 ameliorated cell death and down-regulation of Bcl2 caused by mutant Htt (mHtt). Conversely, enhanced expression of Bcl2 protected striatal cells from the toxicity evoked by mHtt and AMPK overactivation. These data demonstrate that aberrant activation of AMPK-α1 in the nuclei of striatal cells represents a new toxic pathway induced by mHtt.

scholarly journals Huntington’s Disease Pathogenesis: Two Sequential Components

2021 ◽  
Vol 10 (1) ◽  
pp. 35-51 ◽  
Author(s):  
Eun Pyo Hong ◽  
Marcy E. MacDonald ◽  
Vanessa C. Wheeler ◽  
Lesley Jones ◽  
Peter Holmans ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Human Genetics ◽  
Neurodegenerative Disorder ◽  
Genetic Defect ◽  
Genome Project ◽  
Dna Polymorphisms ◽  
Genetic Linkage Analysis ◽  
Abnormal Movements ◽  
Hd Gene

Historically, Huntington’s disease (HD; OMIM #143100) has played an important role in the enormous advances in human genetics seen over the past four decades. This familial neurodegenerative disorder involves variable onset followed by consistent worsening of characteristic abnormal movements along with cognitive decline and psychiatric disturbances. HD was the first autosomal disease for which the genetic defect was assigned to a position on the human chromosomes using only genetic linkage analysis with common DNA polymorphisms. This discovery set off a multitude of similar studies in other diseases, while the HD gene, later renamed HTT, and its vicinity in chromosome 4p16.3 then acted as a proving ground for development of technologies to clone and sequence genes based upon their genomic location, with the growing momentum of such advances fueling the Human Genome Project. The identification of the HD gene has not yet led to an effective treatment, but continued human genetic analysis of genotype-phenotype relationships in large HD subject populations, first at the HTT locus and subsequently genome-wide, has provided insights into pathogenesis that divide the course of the disease into two sequential, mechanistically distinct components.

scholarly journals The Novel Alpha-2 Adrenoceptor Inhibitor Beditin Reduces Cytotoxicity and Huntingtin Aggregates in Cell Models of Huntington’s Disease

2021 ◽  
Vol 14 (3) ◽  
pp. 257
Author(s):  
Elisabeth Singer ◽  
Lilit Hunanyan ◽  
Magda M. Melkonyan ◽  
Jonasz J. Weber ◽  
Lusine Danielyan ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Neurodegenerative Disorder ◽  
Cell Model ◽  
Resonance Energy Transfer ◽  
Neuronal Cell ◽  
Resonance Energy ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Cell Models

Huntington’s disease (HD) is a monogenetic neurodegenerative disorder characterized by the accumulation of polyglutamine-expanded huntingtin (mHTT). There is currently no cure, and therefore disease-slowing remedies are sought to alleviate symptoms of the multifaceted disorder. Encouraging findings in Alzheimer’s and Parkinson’s disease on alpha-2 adrenoceptor (α2-AR) inhibition have shown neuroprotective and aggregation-reducing effects in cell and animal models. Here, we analyzed the effect of beditin, a novel α2- adrenoceptor (AR) antagonist, on cell viability and mHTT protein levels in cell models of HD using Western blot, time-resolved Foerster resonance energy transfer (TR-FRET), lactate dehydrogenase (LDH) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) cytotoxicity assays. Beditin decreases cytotoxicity, as measured by TUNEL staining and LDH release, in a neuronal progenitor cell model (STHdh cells) of HD and decreases the aggregation propensity of HTT exon 1 fragments in an overexpression model using human embryonic kidney (HEK) 293T cells. α2-AR is a promising therapeutic target for further characterization in HD models. Our data allow us to suggest beditin as a valuable candidate for the pharmaceutical manipulation of α2-AR, as it is capable of modulating neuronal cell survival and the level of mHTT.

scholarly journals RNA Sequencing of Human Peripheral Blood Cells Indicates Upregulation of Immune-Related Genes in Huntington's Disease

2020 ◽  
Vol 11 ◽  
Author(s):  
Miguel A. Andrade-Navarro ◽  
Katja Mühlenberg ◽  
Eike J. Spruth ◽  
Nancy Mah ◽  
Adrián González-López ◽  
...  
Keyword(s):  
Gene Expression ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Trinucleotide Repeat ◽  
Neurodegenerative Disorder ◽  
Gene Expression Signature ◽  
Interferon Response ◽  
Peripheral Blood Cells

Huntington's disease (HD) is an autosomal dominantly inherited neurodegenerative disorder caused by a trinucleotide repeat expansion in the Huntingtin gene. As disease-modifying therapies for HD are being developed, peripheral blood cells may be used to indicate disease progression and to monitor treatment response. In order to investigate whether gene expression changes can be found in the blood of individuals with HD that distinguish them from healthy controls, we performed transcriptome analysis by next-generation sequencing (RNA-seq). We detected a gene expression signature consistent with dysregulation of immune-related functions and inflammatory response in peripheral blood from HD cases vs. controls, including induction of the interferon response genes, IFITM3, IFI6 and IRF7. Our results suggest that it is possible to detect gene expression changes in blood samples from individuals with HD, which may reflect the immune pathology associated with the disease.

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