scholarly journals CYP46A1 gene therapy deciphers the role of brain cholesterol metabolism in Huntington’s disease

Brain ◽  
2019 ◽  
Vol 142 (8) ◽  
pp. 2432-2450 ◽  
Author(s):  
Radhia Kacher ◽  
Antonin Lamazière ◽  
Nicolas Heck ◽  
Vincent Kappes ◽  
Coline Mounier ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Large Scale ◽  
Cholesterol Metabolism ◽  
Cholesterol Homeostasis ◽  
Synaptic Activity ◽  
Critical Event ◽  
Brain Cholesterol ◽  
The Brain

AbstractDysfunctions in brain cholesterol homeostasis have been extensively related to brain disorders. The main pathway for brain cholesterol elimination is its hydroxylation into 24S-hydroxycholesterol by the cholesterol 24-hydrolase, CYP46A1. Increasing evidence suggests that CYP46A1 has a role in the pathogenesis and progression of neurodegenerative disorders, and that increasing its levels in the brain is neuroprotective. However, the mechanisms underlying this neuroprotection remain to be fully understood. Huntington’s disease is a fatal autosomal dominant neurodegenerative disease caused by an abnormal CAG expansion in huntingtin’s gene. Among the multiple cellular and molecular dysfunctions caused by this mutation, altered brain cholesterol homeostasis has been described in patients and animal models as a critical event in Huntington’s disease. Here, we demonstrate that a gene therapy approach based on the delivery of CYP46A1, the rate-limiting enzyme for cholesterol degradation in the brain, has a long-lasting neuroprotective effect in Huntington’s disease and counteracts multiple detrimental effects of the mutated huntingtin. In zQ175 Huntington’s disease knock-in mice, CYP46A1 prevented neuronal dysfunctions and restored cholesterol homeostasis. These events were associated to a specific striatal transcriptomic signature that compensates for multiple mHTT-induced dysfunctions. We thus explored the mechanisms for these compensations and showed an improvement of synaptic activity and connectivity along with the stimulation of the proteasome and autophagy machineries, which participate to the clearance of mutant huntingtin (mHTT) aggregates. Furthermore, BDNF vesicle axonal transport and TrkB endosome trafficking were restored in a cellular model of Huntington’s disease. These results highlight the large-scale beneficial effect of restoring cholesterol homeostasis in neurodegenerative diseases and give new opportunities for developing innovative disease-modifying strategies in Huntington’s disease.

scholarly journals Insights into kinetics, release, and behavioral effects of brain-targeted hybrid nanoparticles for cholesterol delivery in Huntington’s disease

2020 ◽  
Author(s):  
Giulia Birolini ◽  
Marta Valenza ◽  
Ilaria Ottonelli ◽  
Alice Passoni ◽  
Monica Favagrossa ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Neurodegenerative Disorder ◽  
Polymeric Nanoparticles ◽  
Cholesterol Biosynthesis ◽  
Hybrid Nanoparticles ◽  
Neural Cells ◽  
Peripheral Tissues ◽  
Brain Cholesterol ◽  
The Brain

AbstractSupplementing brain cholesterol is emerging as a potential treatment for Huntington’s disease (HD), a genetic neurodegenerative disorder characterized, among other abnormalities, by inefficient brain cholesterol biosynthesis. However, delivering cholesterol to the brain is challenging due to the bloodbrain barrier (BBB), which prevents it from reaching the striatum, especially, with therapeutically relevant doses.Here we describe the distribution, kinetics, release, and safety of novel hybrid polymeric nanoparticles made of PLGA and cholesterol which were modified with an heptapeptide (g7) for BBB transit (hybrid-g7-NPs-chol). We show that these NPs rapidly reach the brain and target neural cells. Moreover, deuterium-labeled cholesterol from hybrid-g7-NPs-chol is released in a controlled manner within the brain and accumulates over time, while being rapidly removed from peripheral tissues and plasma. We confirm that systemic and repeated injections of the new hybrid-g7-NPs-chol enhanced endogenous cholesterol biosynthesis, prevented cognitive decline, and ameliorated motor defects in HD animals, without any inflammatory reaction.In summary, this study provides insights about the benefits and safety of cholesterol delivery through advanced brain-permeable nanoparticles for HD treatment.

scholarly journals Cholesteryl ester levels are elevated in the caudate and putamen of Huntington’s disease patients

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gabrielle R. Phillips ◽  
Sarah E. Hancock ◽  
Simon H. J. Brown ◽  
Andrew M. Jenner ◽  
Fabian Kreilaus ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Autosomal Dominant ◽  
Cholesterol Metabolism ◽  
Compensatory Mechanism ◽  
Cholesteryl Esters ◽  
Cholesterol Accumulation ◽  
Specific Vulnerability ◽  
The Brain ◽  
Age And Sex

AbstractHuntington’s disease (HD) is an autosomal dominant neurodegenerative illness caused by a mutation in the huntingtin gene (HTT) and subsequent protein (mhtt), to which the brain shows a region-specific vulnerability. Disturbances in neural cholesterol metabolism are established in HD human, murine and cell studies; however, cholesteryl esters (CE), which store and transport cholesterol in the brain, have not been investigated in human studies. This study aimed to identify region-specific alterations in the concentrations of CE in HD. The Victorian Brain Bank provided post-mortem tissue from 13 HD subjects and 13 age and sex-matched controls. Lipids were extracted from the caudate, putamen and cerebellum, and CE were quantified using targeted mass spectrometry. ACAT 1 protein expression was measured by western blot. CE concentrations were elevated in HD caudate and putamen compared to controls, with the elevation more pronounced in the caudate. No differences in the expression of ACAT1 were identified in the striatum. No remarkable differences in CE were detected in HD cerebellum. The striatal region-specific differences in CE profiles indicate functional subareas of lipid disturbance in HD. The increased CE concentration may have been induced as a compensatory mechanism to reduce cholesterol accumulation.

scholarly journals The Controversial Role of 24-S-Hydroxycholesterol in Alzheimer’s Disease

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 740
Author(s):  
Paola Gamba ◽  
Serena Giannelli ◽  
Erica Staurenghi ◽  
Gabriella Testa ◽  
Barbara Sottero ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cholesterol Metabolism ◽  
Amyloid Β ◽  
Cholesterol Homeostasis ◽  
Oxidation Products ◽  
Cholesterol Oxidation ◽  
Brain Cholesterol ◽  
The Brain

The development of Alzheimer’s disease (AD) is influenced by several events, among which the dysregulation of cholesterol metabolism in the brain plays a major role. Maintenance of brain cholesterol homeostasis is essential for neuronal functioning and brain development. To maintain the steady-state level, excess brain cholesterol is converted into the more hydrophilic metabolite 24-S-hydroxycholesterol (24-OHC), also called cerebrosterol, by the neuron-specific enzyme CYP46A1. A growing bulk of evidence suggests that cholesterol oxidation products, named oxysterols, are the link connecting altered cholesterol metabolism to AD. It has been shown that the levels of some oxysterols, including 27-hydroxycholesterol, 7β-hydroxycholesterol and 7-ketocholesterol, significantly increase in AD brains contributing to disease progression. In contrast, 24-OHC levels decrease, likely due to neuronal loss. Among the different brain oxysterols, 24-OHC is certainly the one whose role is most controversial. It is the dominant oxysterol in the brain and evidence shows that it represents a signaling molecule of great importance for brain function. However, numerous studies highlighted the potential role of 24-OHC in favoring AD development, since it promotes neuroinflammation, amyloid β (Aβ) peptide production, oxidative stress and cell death. In parallel, 24-OHC has been shown to exert several beneficial effects against AD progression, such as preventing tau hyperphosphorylation and Aβ production. In this review we focus on the current knowledge of the controversial role of 24-OHC in AD pathogenesis, reporting a detailed overview of the findings about its levels in different AD biological samples and its noxious or neuroprotective effects in the brain. Given the relevant role of 24-OHC in AD pathophysiology, its targeting could be useful for disease prevention or slowing down its progression.

scholarly journals Lovastatin fails to improve motor performance and survival in methyl-CpG-binding protein2-null mice

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Claudia Villani ◽  
Giuseppina Sacchetti ◽  
Renzo Bagnati ◽  
Alice Passoni ◽  
Federica Fusco ◽  
...  
Keyword(s):  
Rett Syndrome ◽  
Potential Role ◽  
Cholesterol Metabolism ◽  
Cholesterol Homeostasis ◽  
Motor Deficits ◽  
Brain Cholesterol ◽  
Background Strain ◽  
Cholesterol Levels ◽  
The Brain

Previous studies provided evidence for the alteration of brain cholesterol homeostasis in 129.Mecp2-null mice, an experimental model of Rett syndrome. The efficacy of statins in improving motor symptoms and prolonging survival of mutant mice suggested a potential role of statins in the therapy of Rett syndrome. In the present study, we show that Mecp2 deletion had no effect on brain and reduced serum cholesterol levels and lovastatin (1.5 mg/kg, twice weekly as in the previous study) had no effects on motor deficits and survival when Mecp2 deletion was expressed on a background strain (C57BL/6J; B6) differing from that used in the earlier study. These findings indicate that the effects of statins may be background specific and raise important issues to consider when contemplating clinical trials. The reduction of the brain cholesterol metabolite 24S-hydroxycholesterol (24S-OHC) found in B6.Mecp2-null mice suggests the occurrence of changes in brain cholesterol metabolism and the potential utility of using plasma levels of 24S-OHC as a biomarker of brain cholesterol homeostasis in RTT.

Dysregulated Brain Cholesterol Metabolism Is Linked to Neuroinflammation in Huntington's Disease

2020 ◽  
Vol 35 (7) ◽  
pp. 1113-1127 ◽  
Author(s):  
Edith González‐Guevara ◽  
Graciela Cárdenas ◽  
Francisca Pérez‐Severiano ◽  
Juan Carlos Martínez‐Lazcano
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Cholesterol Metabolism ◽  
Brain Cholesterol

scholarly journals Abnormal brain cholesterol homeostasis in Alzheimer’s disease—a targeted metabolomic and transcriptomic study

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Vijay R. Varma ◽  
H. Büşra Lüleci ◽  
Anup M. Oommen ◽  
Sudhir Varma ◽  
Chad T. Blackshear ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Brain Tissue ◽  
Cholesterol Metabolism ◽  
Cholesterol Biosynthesis ◽  
Cholesterol Homeostasis ◽  
Transcriptomic Data ◽  
Brain Cholesterol ◽  
Cholesterol Levels

AbstractThe role of brain cholesterol metabolism in Alzheimer’s disease (AD) remains unclear. Peripheral and brain cholesterol levels are largely independent due to the impermeability of the blood brain barrier (BBB), highlighting the importance of studying the role of brain cholesterol homeostasis in AD. We first tested whether metabolite markers of brain cholesterol biosynthesis and catabolism were altered in AD and associated with AD pathology using linear mixed-effects models in two brain autopsy samples from the Baltimore Longitudinal Study of Aging (BLSA) and the Religious Orders Study (ROS). We next tested whether genetic regulators of brain cholesterol biosynthesis and catabolism were altered in AD using the ANOVA test in publicly available brain tissue transcriptomic datasets. Finally, using regional brain transcriptomic data, we performed genome-scale metabolic network modeling to assess alterations in cholesterol biosynthesis and catabolism reactions in AD. We show that AD is associated with pervasive abnormalities in cholesterol biosynthesis and catabolism. Using transcriptomic data from Parkinson’s disease (PD) brain tissue samples, we found that gene expression alterations identified in AD were not observed in PD, suggesting that these changes may be specific to AD. Our results suggest that reduced de novo cholesterol biosynthesis may occur in response to impaired enzymatic cholesterol catabolism and efflux to maintain brain cholesterol levels in AD. This is accompanied by the accumulation of nonenzymatically generated cytotoxic oxysterols. Our results set the stage for experimental studies to address whether abnormalities in cholesterol metabolism are plausible therapeutic targets in AD.

Altered cholesterol homeostasis contributes to enhanced excitotoxicity in Huntington’s disease

2010 ◽  
Vol 115 (1) ◽  
pp. 153-167 ◽  
Author(s):  
Daniel Del Toro ◽  
Xavier Xifró ◽  
Albert Pol ◽  
Sandrine Humbert ◽  
Frédéric Saudou ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Cholesterol Homeostasis

scholarly journals Huntington's Disease: An Immune Perspective

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Annapurna Nayak ◽  
Rafia Ansar ◽  
Sunil K. Verma ◽  
Domenico Marco Bonifati ◽  
Uday Kishore
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Neurodegenerative Disorder ◽  
Typical Feature ◽  
Trinucleotide Repeats ◽  
Mutant Huntingtin Protein ◽  
Unexplored Area ◽  
Cag Trinucleotide Repeats ◽  
The Brain ◽  
Abnormal Expansion

Huntington's disease (HD) is a progressive neurodegenerative disorder that is caused by abnormal expansion of CAG trinucleotide repeats. Neuroinflammation is a typical feature of most neurodegenerative diseases that leads to an array of pathological changes within the affected areas in the brain. The neurodegeneration in HD is also caused by aberrant immune response in the presence of aggregated mutant huntingtin protein. The effects of immune activation in HD nervous system are a relatively unexplored area of research. This paper summarises immunological features associated with development and progression of HD.

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