scholarly journals Hippocampal Neurogenesis, Cognitive Deficits and Affective Disorder in Huntington's Disease

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mark I. Ransome ◽  
Thibault Renoir ◽  
Anthony J. Hannan

Huntington’s disease (HD) is a neurodegenerative disorder caused by a tandem repeat expansion encoding a polyglutamine tract in the huntingtin protein. HD involves progressive psychiatric, cognitive, and motor symptoms, the selective pathogenesis of which remains to be mechanistically elucidated. There are a range of different brain regions, including the cerebral cortex and striatum, known to be affected in HD, with evidence for hippocampal dysfunction accumulating in recent years. In this review we will focus on hippocampal abnormalities, in particular, deficits of adult neurogenesis. We will discuss potential molecular mechanisms mediating disrupted hippocampal neurogenesis, and how this deficit of cellular plasticity may in turn contribute to specific cognitive and affective symptoms that are prominent in HD. The generation of transgenic animal models of HD has greatly facilitated our understanding of disease mechanisms at molecular, cellular, and systems levels. Transgenic HD mice have been found to show progressive behavioral changes, including affective, cognitive, and motor abnormalities. The discovery, in multiple transgenic lines of HD mice, that adult hippocampal neurogenesis and synaptic plasticity is disrupted, may help explain specific aspects of cognitive and affective dysfunction. Furthermore, these mouse models have provided insight into potential molecular mediators of adult neurogenesis deficits, such as disrupted serotonergic and neurotrophin signaling. Finally, a number of environmental and pharmacological interventions which are known to enhance adult hippocampal neurogenesis have been found to have beneficial affective and cognitive effects in mouse models, suggesting common molecular targets which may have therapeutic utility for HD and related diseases.

2019 ◽  
Vol 29 (2) ◽  
pp. 216-227
Author(s):  
Sheridan L Roberts ◽  
Tracey Evans ◽  
Yi Yang ◽  
Yuhua Fu ◽  
Robert W Button ◽  
...  

Abstract Huntington’s disease (HD) is a neurodegenerative disorder caused by an expanded polyglutamine tract in the huntingtin (HTT) protein. Mutant HTT (mHTT) toxicity is caused by its aggregation/oligomerization. The striatum is the most vulnerable region, although all brain regions undergo neuronal degeneration in the disease. Here we show that the levels of Bim, a BH3-only protein, are significantly increased in HD human post-mortem and HD mouse striata, correlating with neuronal death. Bim reduction ameliorates mHTT neurotoxicity in HD cells. In the HD mouse model, heterozygous Bim knockout significantly mitigates mHTT accumulation and neuronal death, ameliorating disease-associated phenotypes and lifespan. Therefore, Bim could contribute to the progression of HD.


Author(s):  
Margaux Lebouc ◽  
Quentin Richard ◽  
Maurice Garret ◽  
Jérôme Baufreton

Huntington's disease (HD) is an inherited neurodegenerative disorder that usually starts during midlife with progressive alterations of motor and cognitive functions. The disease is caused by a CAG repeat expansion within the huntingtin gene leading to severe striatal neurodegeneration. Recent studies conducted on pre-HD children highlight early striatal developmental alterations starting as soon as 6 years old, the earliest age assessed. These findings, in line with data from mouse models of HD, raise the question of when during development do the first disease-related striatal alterations emerge or whether they contribute to the later appearance of the neurodegenerative features of the disease. In this review we will describe the different stages of striatal network development and then discuss recent evidence for its alterations in rodent models of the disease. We argue that a better understanding of the striatum’s development should help in assessing aberrant neurodevelopmental processes linked to the HD mutation.


2004 ◽  
Vol 51 (2) ◽  
pp. 415-430 ◽  
Author(s):  
Anthony J Hannan

Huntington's disease (HD) is an autosomal dominant disorder in which there is progressive neurodegeneration producing motor, cognitive and psychiatric symptoms. HD is caused by a trinucleotide (CAG) repeat mutation, encoding an expanded polyglutamine tract in the huntingtin protein. At least eight other neurodegenerative diseases are caused by CAG/glutamine repeat expansions in different genes. Recent evidence suggests that environmental factors can modify the onset and progression of Huntington's disease and possibly other neurodegenerative disorders. This review outlines possible molecular and cellular mechanisms mediating the polyglutamine-induced toxic 'gain of function' and associated gene-environment interactions in HD. Key aspects of pathogenesis shared with other neurodegenerative diseases may include abnormal protein-protein interactions, selective disruption of gene expression and 'pathological plasticity' of synapses in specific brain regions. Recent discoveries regarding molecular mechanisms of pathogenesis are guiding the development of new therapeutic approaches. Knowledge of gene-environment interactions, for example, could lead to development of 'enviromimetics' which mimic the beneficial effects of specific environmental stimuli. The effects of environmental enrichment on brain and behaviour will also be discussed, together with the general implications for neuroscience research involving animal models.


2005 ◽  
Vol 93 (5) ◽  
pp. 2565-2574 ◽  
Author(s):  
Marjorie A. Ariano ◽  
Carlos Cepeda ◽  
Christopher R. Calvert ◽  
Jorge Flores-Hernández ◽  
Elizabeth Hernández-Echeagaray ◽  
...  

Huntington's disease (HD) is a neurodegenerative disorder that mainly affects the projection neurons of the striatum and cerebral cortex. Genetic mouse models of HD have shown that neurons susceptible to the mutation exhibit morphological and electrophysiological dysfunctions before and during development of the behavioral phenotype. We used HD transgenic mouse models to examine inwardly and outwardly rectifying K+ conductances, as well as expression of some related K+ channel subunits. Experiments were conducted in slices and dissociated cells from two mouse models, the R6/2 and TgCAG100, at the beginning and after full development of overt behavioral phenotypes. Striatal medium-sized spiny neurons (MSNs) from symptomatic transgenic mice had increased input resistances, depolarized resting membrane potentials, and reductions in both inwardly and outwardly rectifying K+ currents. These changes were more dramatic in the R6/2 model than in the TgCAG100. Parallel immunofluorescence studies detected decreases in the expression of K+ channel subunit proteins, Kir2.1, Kir2.3, and Kv2.1 in MSNs, which contribute to the formation of the channel ionophores for these currents. Attenuation in K+ conductances and channel subunit expression contribute to altered electrophysiological properties of MSNs and may partially account for selective cellular vulnerability in the striatum.


2010 ◽  
Vol 90 (3) ◽  
pp. 905-981 ◽  
Author(s):  
Chiara Zuccato ◽  
Marta Valenza ◽  
Elena Cattaneo

Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG repeat expansion in the gene encoding for huntingtin protein. A lot has been learned about this disease since its first description in 1872 and the identification of its causative gene and mutation in 1993. We now know that the disease is characterized by several molecular and cellular abnormalities whose precise timing and relative roles in pathogenesis have yet to be understood. HD is triggered by the mutant protein, and both gain-of-function (of the mutant protein) and loss-of-function (of the normal protein) mechanisms are involved. Here we review the data that describe the emergence of the ancient huntingtin gene and of the polyglutamine trait during the last 800 million years of evolution. We focus on the known functions of wild-type huntingtin that are fundamental for the survival and functioning of the brain neurons that predominantly degenerate in HD. We summarize data indicating how the loss of these beneficial activities reduces the ability of these neurons to survive. We also review the different mechanisms by which the mutation in huntingtin causes toxicity. This may arise both from cell-autonomous processes and dysfunction of neuronal circuitries. We then focus on novel therapeutical targets and pathways and on the attractive option to counteract HD at its primary source, i.e., by blocking the production of the mutant protein. Strategies and technologies used to screen for candidate HD biomarkers and their potential application are presented. Furthermore, we discuss the opportunities offered by intracerebral cell transplantation and the likely need for these multiple routes into therapies to converge at some point as, ideally, one would wish to stop the disease process and, at the same time, possibly replace the damaged neurons.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Valentina Fodale ◽  
Roberta Pintauro ◽  
Manuel Daldin ◽  
Roberta Altobelli ◽  
Maria Carolina Spiezia ◽  
...  

AbstractHuntington’s disease (HD) is a monogenetic neurodegenerative disorder that is caused by the expansion of a polyglutamine region within the huntingtin (HTT) protein, but there is still an incomplete understanding of the molecular mechanisms that drive pathology. Expression of the mutant form of HTT is a key aspect of diseased tissues, and the most promising therapeutic approaches aim to lower expanded HTT levels. Consequently, the investigation of HTT expression in time and in multiple tissues, with assays that accurately quantify expanded and non-expanded HTT, are required to delineate HTT homeostasis and to best design and interpret pharmacodynamic readouts for HTT lowering therapeutics. Here we evaluate mutant polyglutamine-expanded (mHTT) and polyglutamine-independent HTT specific immunoassays for validation in human HD and control fibroblasts and use to elucidate the CSF/brain and peripheral tissue expression of HTT in preclinical HD models.


2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Lucía Gabriela García-Lara ◽  
Adriana Morales-Martínez ◽  
Quetzalli Denisse Angeles-López ◽  
Hilda Pedraza-Espitia ◽  
Iván Pérez-Neri ◽  
...  

Huntington’s disease (HD) is a hereditary neurodegenerative disorder of the central nervous system that mainly affects the basal ganglia and has no cure. The mutation is located at an abnormal expansion of the CAG triplet in the Huntingtin gene. Humans show psychiatric, behavioural and motor disorders. Transgenic animal models are essential to the study of HD since the disease only affects humans. Therefore, the aim of this article was to describe the formation and maintenance of and to validate the progressive neurological phenotype of an R6/1 transgenic mouse colony. To achieve our objective, the colony founder was imported from Jackson Laboratories, and the mice were kept under controlled environmental conditions. The animals were bred at the vivarium of the Instituto Nacional de Neurología y Neurocirugía Man­uel Velasco Suárez. The R6/1 transgenic mice were successfully bred and showed genetic and phenotypic characteristics similar to the ones previously reported. Our colony is currently established and validated with the condi­tions of our vivarium and has produced more than four generations of R6/1 mice. The establishment of the R6/1 colony and its maintenance through generation is an advantage since it allows us to follow the authenticity of the transgenic mice regarding their phenotypic and motor behaviours. Fur­thermore, these animals can be compared with other transgenic mice that reproduce some of the main characteristics of the disease manifested in hu­mans, making these transgenic R6/1 mice a useful tool for the study of HD.


2022 ◽  
Vol 2022 ◽  
pp. 1-18
Author(s):  
Stefano Farioli-Vecchioli ◽  
Valentina Ricci ◽  
Silvia Middei

The mammalian hippocampal dentate gyrus is a niche for adult neurogenesis from neural stem cells. Newborn neurons integrate into existing neuronal networks, where they play a key role in hippocampal functions, including learning and memory. In the ageing brain, neurogenic capability progressively declines while in parallel increases the risk for developing Alzheimer’s disease (AD), the main neurodegenerative disorder associated with memory loss. Numerous studies have investigated whether impaired adult neurogenesis contributes to memory decline in AD. Here, we review the literature on adult hippocampal neurogenesis (AHN) and AD by focusing on both human and mouse model studies. First, we describe key steps of AHN, report recent evidence of this phenomenon in humans, and describe the specific contribution of newborn neurons to memory, as evinced by animal studies. Next, we review articles investigating AHN in AD patients and critically examine the discrepancies among different studies over the last two decades. Also, we summarize researches investigating AHN in AD mouse models, and from these studies, we extrapolate the contribution of molecular factors linking AD-related changes to impaired neurogenesis. Lastly, we examine animal studies that link impaired neurogenesis to specific memory dysfunctions in AD and review treatments that have the potential to rescue memory capacities in AD by stimulating AHN.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243052
Author(s):  
Taneli Heikkinen ◽  
Timo Bragge ◽  
Niina Bhattarai ◽  
Teija Parkkari ◽  
Jukka Puoliväli ◽  
...  

Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by severe disruption of cognitive and motor functions, including changes in posture and gait. A number of HD mouse models have been engineered that display behavioral and neuropathological features of the disease, but gait alterations in these models are poorly characterized. Sensitive high-throughput tests of fine motor function and gait in mice might be informative in evaluating disease-modifying interventions. Here, we describe a hypothesis-free workflow that determines progressively changing locomotor patterns across 79 parameters in the R6/2 and Q175 mouse models of HD. R6/2 mice (120 CAG repeats) showed motor disturbances as early as at 4 weeks of age. Similar disturbances were observed in homozygous and heterozygous Q175 KI mice at 3 and 6 months of age, respectively. Interestingly, only the R6/2 mice developed forelimb ataxia. The principal components of the behavioral phenotypes produced two phenotypic scores of progressive postural instability based on kinematic parameters and trajectory waveform data, which were shared by both HD models. This approach adds to the available HD mouse model research toolbox and has a potential to facilitate the development of therapeutics for HD and other debilitating movement disorders with high unmet medical need.


Metabolites ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 113 ◽  
Author(s):  
Stefano Patassini ◽  
Paul Begley ◽  
Jingshu Xu ◽  
Stephanie Church ◽  
Nina Kureishy ◽  
...  

Huntington’s disease (HD) is a neurodegenerative disorder caused by an expanded CAG repeat in exon 1 of the HTT gene. HD usually manifests in mid-life with loss of GABAergic projection neurons from the striatum accompanied by progressive atrophy of the putamen followed by other brain regions, but linkages between the genetics and neurodegeneration are not understood. We measured metabolic perturbations in HD-human brain in a case-control study, identifying pervasive lowering of vitamin B5, the obligatory precursor of coenzyme A (CoA) that is essential for normal intermediary metabolism. Cerebral pantothenate deficiency is a newly-identified metabolic defect in human HD that could potentially: (i) impair neuronal CoA biosynthesis; (ii) stimulate polyol-pathway activity; (iii) impair glycolysis and tricarboxylic acid cycle activity; and (iv) modify brain-urea metabolism. Pantothenate deficiency could lead to neurodegeneration/dementia in HD that might be preventable by treatment with vitamin B5.


Sign in / Sign up

Export Citation Format

Share Document