Widespread selenium deficiency in the brain of cases with Huntington's disease presents a new potential therapeutic target.
EBioMedicine 2023;
97:104824. [PMID:
37806287 PMCID:
PMC10667115 DOI:
10.1016/j.ebiom.2023.104824]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 09/21/2023] [Accepted: 09/21/2023] [Indexed: 10/10/2023] Open
Abstract
BACKGROUND
Huntington or Huntington's disease (HD) is an autosomal dominant neurodegenerative disease characterised by both progressive motor and cognitive dysfunction; its pathogenic mechanisms remain poorly understood and no treatment can currently slow, stop, or reverse its progression. There is some evidence of metallomic dysfunction in limited regions of the HD brain; we hypothesised that these alterations are more widespread than the current literature suggests and may contribute to pathogenesis in HD.
METHODS
We measured the concentrations of eight essential metals (sodium, potassium, magnesium, calcium, iron, zinc, copper, and manganese) and the metalloid selenium across 11 brain regions in nine genetically confirmed, clinically manifest cases of HD and nine controls using inductively-coupled plasma mass spectrometry. Case-control differences were assessed by non-parametric Mann-Whitney U test (p < 0.05), risk ratios, E-values, and effect sizes.
FINDINGS
We observed striking decreases in selenium levels in 11 out of 11 investigated brain regions in HD, with risk ratios and effect sizes ranging 2.3-9.0 and 0.7-1.9, respectively. Increased sodium/potassium ratios were observed in every region (risk ratio = 2.5-8.0; effect size = 1.2-5.8) except the substantia nigra (risk ratio = 0.25; effect size = 0.1). Multiple regions showed increased calcium and/or zinc levels, and localised decreases in iron, copper, and manganese were present in the globus pallidus, cerebellum, and substantia nigra, respectively.
INTERPRETATION
The observed metallomic alterations in the HD brain may contribute to several pathogenic mechanisms, including mitochondrial dysfunction, oxidative stress, and blood-brain barrier dysfunction. Selenium supplementation may represent a potential, much-needed therapeutic pathway for the treatment of HD that would not require localised delivery in the brain due to the widespread presence of selenium deficiency in regions that show both high and low levels of neurodegeneration.
FUNDING
In Acknowledgments, includes the Lee Trust, the Endocore Research Trust, Cure Huntington's Disease Initiative, the Oakley Mental Health Research Foundation, the Medical Research Council (MRC), the New Zealand Neurological Foundation, and others.
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