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Yazdani M. Cellular and Molecular Responses to Mitochondrial DNA Deletions in Kearns-Sayre Syndrome: Some Underlying Mechanisms. Mol Neurobiol 2024; 61:5665-5679. [PMID: 38224444 DOI: 10.1007/s12035-024-03938-7] [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] [Indexed: 01/16/2024]
Abstract
Kearns-Sayre syndrome (KSS) is a rare multisystem mitochondrial disorder. It is caused by mitochondrial DNA (mtDNA) rearrangements, mostly large-scale deletions of 1.1-10 kb. These deletions primarily affect energy supply through impaired oxidative phosphorylation and reduced ATP production. This impairment gives rise to dysfunction of several tissues, in particular those with high energy demand like brain and muscles. Over the past decades, changes in respiratory chain complexes and energy metabolism have been emphasized, whereas little attention has been paid to other reports on ROS overproduction, protein synthesis inhibition, myelin vacuolation, demyelination, autophagy, apoptosis, and involvement of lipid raft and oligodendrocytes in KSS. Therefore, this paper draws attention towards these relatively underemphasized findings that might further clarify the pathologic cascades following deletions in the mtDNA.
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Affiliation(s)
- Mazyar Yazdani
- Department of Medical Biochemistry, Oslo University Hospital, Rikshospitalet, Oslo, 0027, Norway.
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2
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D'Alessandro A, Lukens JR, Zimring JC. The role of PIMT in Alzheimer's disease pathogenesis: A novel hypothesis. Alzheimers Dement 2023; 19:5296-5302. [PMID: 37157118 DOI: 10.1002/alz.13115] [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: 03/09/2023] [Accepted: 04/11/2023] [Indexed: 05/10/2023]
Abstract
There are multiple theories of Alzheimer's disease pathogenesis. One major theory is that oxidation of amyloid beta (Aβ) promotes plaque deposition that directly contributes to pathology. A competing theory is that hypomethylation of DNA (due to altered one carbon metabolism) results in pathology through altered gene regulation. Herein, we propose a novel hypothesis involving L-isoaspartyl methyltransferase (PIMT) that unifies the Aβ and DNA hypomethylation hypotheses into a single model. Importantly, the proposed model allows bidirectional regulation of Aβ oxidation and DNA hypomethylation. The proposed hypothesis does not exclude simultaneous contributions by other mechanisms (e.g., neurofibrillary tangles). The new hypothesis is formulated to encompass oxidative stress, fibrillation, DNA hypomethylation, and metabolic perturbations in one carbon metabolism (i.e., methionine and folate cycles). In addition, deductive predictions of the hypothesis are presented both to guide empirical testing of the hypothesis and to provide candidate strategies for therapeutic intervention and/or nutritional modification. HIGHLIGHTS: PIMT repairs L-isoaspartyl groups on amyloid beta and decreases fibrillation. SAM is a common methyl donor for PIMT and DNA methyltransferases. Increased PIMT activity competes with DNA methylation and vice versa. The PIMT hypothesis bridges a gap between plaque and DNA methylation hypotheses.
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Affiliation(s)
- Angelo D'Alessandro
- University of Colorado Denver-Anschutz Medical Campus, Aurora, Colorado, USA
| | - John R Lukens
- Carter Immunology Center and Center for Brain Immunology and Glia, University of Virginia Departments of Pathology and Neuroscience, Charlottesville, Virginia, USA
| | - James C Zimring
- Carter Immunology Center and Center for Brain Immunology and Glia, University of Virginia Departments of Pathology and Neuroscience, Charlottesville, Virginia, USA
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Salvador CL, Oppebøen M, Vassli AØ, Pfeiffer HCV, Varhaug KN, Elgstøen KBP, Yazdani M. Increased Sphingomyelin and Free Sialic Acid in Cerebrospinal Fluid of Kearns-Sayre Syndrome: New Findings Using Untargeted Metabolomics. Pediatr Neurol 2023; 143:68-76. [PMID: 37018879 DOI: 10.1016/j.pediatrneurol.2023.02.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 01/10/2023] [Accepted: 02/25/2023] [Indexed: 04/07/2023]
Abstract
BACKGROUND Kearns-Sayre syndrome (KSS) is caused by duplications and/or deletions of mitochondrial DNA (mtDNA) and is typically diagnosed based on a classic triad of symptoms with chronic progressive external ophthalmoplegia (CPEO), retinitis pigmentosa, and onset before age 20 years. The present study aimed to diagnose two patients, on suspicion of KSS. METHODS One of the patients went through a diagnostic odyssey, with normal results from several mtDNA analyses, both in blood and muscle, before the diagnosis was confirmed genetically. RESULTS Two patients presented increased tau protein and low 5-methyltetrahydrofolate (5-MTHF) levels in the cerebrospinal fluid (CSF). Untargeted metabolomics on CSF samples also showed an increase in the levels of free sialic acid and sphingomyelin C16:0 (d18:1/C16:0), compared with four control groups (patients with mitochondrial disorders, nonmitochondrial disorders, low 5-MTHF, or increased tau proteins). CONCLUSIONS It is the first time that elevated sphingomyelin C16:0 (d18:1/C16:0) and tau protein in KSS are reported. Using an untargeted metabolomics approach and standard laboratory methods, the study could shed new light on metabolism in KSS to better understand its complexity. In addition, the findings may suggest the combination of elevated free sialic acid, sphingomyelin C16:0 (d18:1/C16:0), and tau protein as well as low 5-MTHF as new biomarkers in the diagnostics of KSS.
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Affiliation(s)
| | - Mari Oppebøen
- Department of Pediatrics, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Anja Østeby Vassli
- Department of Medical Biochemistry, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Helle Cecilie Viekilde Pfeiffer
- Department of Pediatrics, Oslo University Hospital, Rikshospitalet, Oslo, Norway; Department of Pediatrics, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Kristin Nielsen Varhaug
- The Mitochondrial Medicine and Neurogenetics (MMN) Group, Department of Clinical Medicine, University of Bergen, Bergen, Norway; Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | | | - Mazyar Yazdani
- Department of Medical Biochemistry, Oslo University Hospital, Rikshospitalet, Oslo, Norway
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Carey A, Fossati S. Hypertension and hyperhomocysteinemia as modifiable risk factors for Alzheimer's disease and dementia: New evidence, potential therapeutic strategies, and biomarkers. Alzheimers Dement 2023; 19:671-695. [PMID: 36401868 PMCID: PMC9931659 DOI: 10.1002/alz.12871] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/04/2022] [Accepted: 10/17/2022] [Indexed: 11/21/2022]
Abstract
This review summarizes recent evidence on how mid-life hypertension, hyperhomocysteinemia (HHcy) and blood pressure variability, as well as late-life hypotension, exacerbate Alzheimer's disease (AD) and dementia risk. Intriguingly, HHcy also increases the risk for hypertension, revealing the importance of understanding the relationship between comorbid cardiovascular risk factors. Hypertension-induced dementia presents more evidently in women, highlighting the relevance of sex differences in the impact of cardiovascular risk. We summarize each major antihypertensive drug class's effects on cognitive impairment and AD pathology, revealing how carbonic anhydrase inhibitors, diuretics modulating cerebral blood flow, have recently gained preclinical evidence as promising treatment against AD. We also report novel vascular biomarkers for AD and dementia risk, highlighting those associated with hypertension and HHcy. Importantly, we propose that future studies should consider hypertension and HHcy as potential contributors to cognitive impairment, and that uncovering the underlying molecular mechanisms and biomarkers would aid in the identification of preventive strategies.
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Affiliation(s)
- Ashley Carey
- Alzheimer’s Center at Temple, Department of Neural Sciences, Temple University Lewis Katz School of Medicine, Philadelphia
| | - Silvia Fossati
- Alzheimer’s Center at Temple, Department of Neural Sciences, Temple University Lewis Katz School of Medicine, Philadelphia
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Shams H, Matsunaga A, Ma Q, Mofrad MR, Didonna A. Methylation at a conserved lysine residue modulates tau assembly and cellular functions. Mol Cell Neurosci 2022; 120:103707. [DOI: 10.1016/j.mcn.2022.103707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/14/2022] [Accepted: 02/22/2022] [Indexed: 11/30/2022] Open
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Reffo A, Gabelli C. Hyperhomocysteinemia and Dementia Associated With Severe Cortical Atrophy, but No Amyloid Burden. J Geriatr Psychiatry Neurol 2022; 35:57-61. [PMID: 33461371 DOI: 10.1177/0891988720988910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We report a case of a 77 years old patient who was admitted to our memory clinic because of progressive gait impairment and amnestic cognitive decline associated with extrapyramidal symptoms and behavioral changes. The clinical picture was consistent with a possible diagnosis of Alzheimer's Disease associated with parkinsonian symptoms or with a Parkinson Plus syndrome. After a complete investigation, she was found to have a high plasma level of homocysteine due to homozygous methylene-tetrahydrofolate reductase (MTHFR) gene C665 T polymorphism, cognitive and motor impairment were associated with a severe cortical atrophy and mild subcortical vascular disease. PET neuroimaging excluded a significant amyloid load. Clinically, she showed improvement of the movement disorder and functional status after folate integration plus levodopa and memantine administration. We concluded for a primary degenerative dementia with movement impairment associated with persistent hyperhomocysteinemia. We hypothesized that neurodegeneration is driven by mechanisms linked to homocysteine metabolism possibly associated with tauopathy.
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Affiliation(s)
- Alessandro Reffo
- Department of Medicine (DIMED), Geriatrics Division, University of Padova, Padova, Italy
| | - Carlo Gabelli
- Regionale Brain Aging Center, Department of Medicine (DIMED), University of Padova, Padova, Italy
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Zhang L, Xie X, Sun Y, Zhou F. Blood and CSF Homocysteine Levels in Alzheimer's Disease: A Meta-Analysis and Meta-Regression of Case-Control Studies. Neuropsychiatr Dis Treat 2022; 18:2391-2403. [PMID: 36276430 PMCID: PMC9586177 DOI: 10.2147/ndt.s383654] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 09/25/2022] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE Hyperhomocysteinemia (HHcy), as an important risk factor for Alzheimer's disease (AD), would aggravate cognitive dysfunction. This study aimed to investigate whether and to what degree the homocysteine (Hcy) levels in blood and cerebrospinal fluid (CSF) were elevated in AD patients compared with healthy controls and to explore the factors related to the elevated Hcy levels in AD patients. METHODS PubMed and Embase databases were searched to identify eligible studies, and study quality was evaluated using the Newcastle-Ottawa Quality Assessment Scale. Ratio of mean (RoM) Hcy concentrations was used as a measure of fold-change between AD patients and healthy control subjects. RESULTS We identified 35 eligible studies, consisting a total of 2172 patients with AD and 2289 healthy controls. The pooled results showed that patients with AD had a significantly higher blood level of Hcy (RoM, 1.32; 95% CI, 1.25-1.40; p<0.001) than controls did, with large heterogeneity across studies (I2=81.4%, p<0.001). Hcy level in CSF did not differ significantly between patients with AD than controls (RoM, 1.12; 95% CI, 0.90-1.39, p=0.293; I2=69.4%, p=0.02). A random effects meta-regression analysis revealed that there was an inverse correlation between the blood levels of Hcy and folate (p=0.006). There was no link found between the blood levels of vitamin B12, or the Mini-Mental Status Examination scores reflecting the degree of cognitive impairment, and blood levels of Hcy. CONCLUSION Regardless of dementia severity, there is an approximate one-third increase in blood Hcy in AD patients, which is robustly associated with a decreased level of blood folate in AD, but not with that of blood vitamin B12 nor the degree of dementia. Future investigation on the cause-and-effect link between Hcy and folate is warranted to clarify this issue.
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Affiliation(s)
- Ling Zhang
- School of Basic Medicine, Gannan Medical University, Ganzhou, People's Republic of China
| | - Xinhua Xie
- Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases of Ministry of Education, Gannan Medical University, Ganzhou, People's Republic of China
| | - Yangyan Sun
- School of Basic Medicine, Gannan Medical University, Ganzhou, People's Republic of China
| | - Futao Zhou
- School of Basic Medicine, Gannan Medical University, Ganzhou, People's Republic of China
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Pautova A, Burnakova N, Revelsky A. Metabolic Profiling and Quantitative Analysis of Cerebrospinal Fluid Using Gas Chromatography-Mass Spectrometry: Current Methods and Future Perspectives. Molecules 2021; 26:3597. [PMID: 34208377 PMCID: PMC8231178 DOI: 10.3390/molecules26123597] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 11/17/2022] Open
Abstract
Cerebrospinal fluid is a key biological fluid for the investigation of new potential biomarkers of central nervous system diseases. Gas chromatography coupled to mass-selective detectors can be used for this investigation at the stages of metabolic profiling and method development. Different sample preparation conditions, including extraction and derivatization, can be applied for the analysis of the most of low-molecular-weight compounds of the cerebrospinal fluid, including metabolites of tryptophan, arachidonic acid, glucose; amino, polyunsaturated fatty and other organic acids; neuroactive steroids; drugs; and toxic metabolites. The literature data analysis revealed the absence of fully validated methods for cerebrospinal fluid analysis, and it presents opportunities for scientists to develop and validate analytical protocols using modern sample preparation techniques, such as microextraction by packed sorbent, dispersive liquid-liquid microextraction, and other potentially applicable techniques.
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Affiliation(s)
- Alisa Pautova
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Laboratory of Human Metabolism in Critical States, Negovsky Research Institute of General Reanimatology, Petrovka str. 25-2, 107031 Moscow, Russia
| | - Natalia Burnakova
- Laboratory of Mass Spectrometry, Chemistry Department, Lomonosov Moscow State University, GSP-1, Leninskie Gory, 1-3, 119991 Moscow, Russia; (N.B.); (A.R.)
| | - Alexander Revelsky
- Laboratory of Mass Spectrometry, Chemistry Department, Lomonosov Moscow State University, GSP-1, Leninskie Gory, 1-3, 119991 Moscow, Russia; (N.B.); (A.R.)
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Hooshmand B, Refsum H, Smith AD, Kalpouzos G, Mangialasche F, von Arnim CAF, Kåreholt I, Kivipelto M, Fratiglioni L. Association of Methionine to Homocysteine Status With Brain Magnetic Resonance Imaging Measures and Risk of Dementia. JAMA Psychiatry 2019; 76:1198-1205. [PMID: 31339527 PMCID: PMC6659152 DOI: 10.1001/jamapsychiatry.2019.1694] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
IMPORTANCE Impairment of methylation status (ie, methionine to homocysteine ratio) may be a modifiable risk factor for structural brain changes and incident dementia. OBJECTIVE To investigate the association of serum markers of methylation status and sulfur amino acids with risk of incident dementia, Alzheimer disease (AD), and the rate of total brain tissue volume loss during 6 years. DESIGN, SETTING, AND PARTICIPANTS This population-based longitudinal study was performed from March 21, 2001, to October 10, 2010, in a sample of 2570 individuals aged 60 to 102 years from the Swedish Study on Aging and Care in Kungsholmen who were dementia free at baseline and underwent comprehensive examinations and structural brain magnetic resonance imaging (MRI) on 2 to 3 occasions during 6 years. Data analysis was performed from March 1, 2018, to October 1, 2018. MAIN OUTCOMES AND MEASURES Incident dementia, AD, and the rate of total brain volume loss. RESULTS This study included 2570 individuals (mean [SD] age, 73.1 [10.4] years; 1331 [56.5%] female). The methionine to homocysteine ratio was higher in individuals who consumed vitamin supplements (median, 1.9; interquartile range [IQR], 1.5-2.6) compared with those who did not (median, 1.8; IQR, 1.3-2.3; P < .001) and increased per each quartile increase of vitamin B12 or folate. In the multiadjusted model, an elevated baseline serum total homocysteine level was associated with an increased risk of dementia and AD during 6 years: for the highest homocysteine quartile compared with the lowest, the hazard ratios (HRs) were 1.60 (95% CI, 1.01-2.55) for dementia and 2.33 (95% CI, 1.26-4.30) for AD. In contrast, elevated concentrations of methionine were associated with a decreased risk of dementia (HR, 0.54; 95% CI, 0.36-0.81) for the highest quartile compared with the lowest. Higher values of the methionine to homocysteine ratio were significantly associated with lower risk of dementia and AD: for the fourth methionine-homocysteine quartile compared with the first quartile, the HR was 0.44 (95% CI, 0.27-0.71) for incident dementia and 0.43 (95% CI, 0.23-0.80) for AD. In the multiadjusted linear mixed models, a higher methionine to homocysteine ratio was associated with a decreased rate of total brain tissue volume loss during the study period (β [SE] per 1-SD increase, 0.038 [0.014]; P = .007). CONCLUSIONS AND RELEVANCE The methionine to homocysteine status was associated with dementia development and structural brain changes during the 6-year study period, suggesting that a higher methionine to homocysteine ratio may be important in reducing the rate of brain atrophy and decreasing the risk of dementia in older adults.
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Affiliation(s)
- Babak Hooshmand
- Aging Research Center, Karolinska Institute, Stockholm, Sweden,Department of Neurology, Ulm University Hospital, Ulm, Germany
| | - Helga Refsum
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom,Institute of Nutrition, University of Oslo, Oslo, Norway
| | - A. David Smith
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | | | | | | | | | - Miia Kivipelto
- Division of Clinical Geriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden,Theme Aging, Karolinska University Hospital, Stockholm, Sweden,Stockholms Sjukhem, Research & Development Unit, Stockholm, Sweden,Neuroepidemiology and Ageing Research Unit, School of Public Health, Imperial College London, London, United Kingdom,Department of Neurology, University of Eastern Finland, Kuopio, Finland
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Didonna A, Cantó E, Shams H, Isobe N, Zhao C, Caillier SJ, Condello C, Yamate-Morgan H, Tiwari-Woodruff SK, Mofrad MRK, Hauser SL, Oksenberg JR. Sex-specific Tau methylation patterns and synaptic transcriptional alterations are associated with neural vulnerability during chronic neuroinflammation. J Autoimmun 2019; 101:56-69. [PMID: 31010726 PMCID: PMC6561733 DOI: 10.1016/j.jaut.2019.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 04/03/2019] [Accepted: 04/04/2019] [Indexed: 12/19/2022]
Abstract
The molecular events underlying the transition from initial inflammatory flares to the progressive phase of multiple sclerosis (MS) remain poorly understood. Here, we report that the microtubule-associated protein (MAP) Tau exerts a gender-specific protective function on disease progression in the MS model experimental autoimmune encephalomyelitis (EAE). A detailed investigation of the autoimmune response in Tau-deficient mice excluded a strong immunoregulatory role for Tau, suggesting that its beneficial effects are presumably exerted within the central nervous system (CNS). Spinal cord transcriptomic data show increased synaptic dysfunctions and alterations in the NF-kB activation pathway upon EAE in Tau-deficient mice as compared to wildtype animals. We also performed the first comprehensive characterization of Tau post-translational modifications (PTMs) in the nervous system upon EAE. We report that the methylation levels of the conserved lysine residue K306 are significantly decreased in the chronic phase of the disease. By combining biochemical assays and molecular dynamics (MD) simulations, we demonstrate that methylation at K306 decreases the affinity of Tau for the microtubule network. Thus, the down-regulation of this PTM might represent a homeostatic response to enhance axonal stability against an autoimmune CNS insult. The results, altogether, position Tau as key mediator between the inflammatory processes and neurodegeneration that seems to unify many CNS diseases.
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Affiliation(s)
- Alessandro Didonna
- Department of Neurology and Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, 94158, USA.
| | - Ester Cantó
- Department of Neurology and Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Hengameh Shams
- Department of Neurology and Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Noriko Isobe
- Department of Neurology and Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Chao Zhao
- Department of Neurology and Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Stacy J Caillier
- Department of Neurology and Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Carlo Condello
- Department of Neurology and Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, 94158, USA; Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
| | - Hana Yamate-Morgan
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA, 92521, USA; Neuroscience Graduate Program, University of California Riverside, Riverside, CA, 92521, USA
| | - Seema K Tiwari-Woodruff
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA, 92521, USA; Neuroscience Graduate Program, University of California Riverside, Riverside, CA, 92521, USA; Center for Glial-Neuronal Interactions, UCR School of Medicine, CA, 92506, USA
| | - Mohammad R K Mofrad
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, CA, 94720, USA; Physical Biosciences Division, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA
| | - Stephen L Hauser
- Department of Neurology and Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Jorge R Oksenberg
- Department of Neurology and Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, 94158, USA
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Bihaqi SW. Early life exposure to lead (Pb) and changes in DNA methylation: relevance to Alzheimer’s disease. REVIEWS ON ENVIRONMENTAL HEALTH 2019; 34:187-195. [DOI: 10.1515/reveh-2018-0076] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 01/09/2019] [Indexed: 05/08/2023]
Abstract
Abstract
Recent advances in neuroepigenetics have revealed its essential role in governing body function and disease. Epigenetics regulates an array of mechanisms that are susceptible to undergoing alteration by intracellular or extracellular factors. DNA methylation, one of the most extensively studied epigenetic markers is involved in the regulation of gene expression and also plays a vital role in neuronal development. The epigenome is most vulnerable during early the embryonic stage and perturbation in DNA methylation during this period can result in a latent outcome which can persist during the entire lifespan. Accumulating evidence suggests that environmental insults during the developmental phase can impart changes in the DNA methylation landscape. Based on reports on human subjects and animal models this review will explore the evidence on how developmental exposure of the known environmental pollutant, lead (Pb), can induce changes in the DNA methylation of genes which later can induce development of neurodegenerative disorders like Alzheimer’s disease (AD).
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Affiliation(s)
- Syed Waseem Bihaqi
- George and Anne Ryan Institute for Neuroscience , University of Rhode Island , Avedisian Hall, Lab: 390, 7 Greenhouse Road , Kingston, RI 02881 , USA
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Haijes HA, van der Ham M, Gerrits J, van Hasselt PM, Prinsen HCMT, de Sain-van der Velden MGM, Verhoeven-Duif NM, Jans JJM. Direct-infusion based metabolomics unveils biochemical profiles of inborn errors of metabolism in cerebrospinal fluid. Mol Genet Metab 2019; 127:51-57. [PMID: 30926434 DOI: 10.1016/j.ymgme.2019.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/11/2019] [Accepted: 03/14/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND For inborn errors of metabolism (IEM), metabolomics is performed for three main purposes: 1) development of next generation metabolic screening platforms, 2) identification of new biomarkers in predefined patient cohorts and 3) for identification of new IEM. To date, plasma, urine and dried blood spots are used. We anticipate that cerebrospinal fluid (CSF) holds additional - valuable - information, especially for IEM with neurological involvement. To expand metabolomics to CSF, we here tested whether direct-infusion high-resolution mass spectrometry (DI-HRMS) based non-quantitative metabolomics could correctly capture the biochemical profile of patients with an IEM in CSF. METHODS Eleven patient samples, harboring eight different IEM, and thirty control samples were analyzed using DI-HRMS. First we assessed whether the biochemical profile of the control samples represented the expected profile in CSF. Next, each patient sample was assigned a 'most probable diagnosis' by an investigator blinded for the known diagnoses of the patients. RESULTS the biochemical profile identified using DI-HRMS in CSF samples resembled the known profile, with - among others - the highest median intensities for mass peaks annotated with glucose, lactic acid, citric acid and glutamine. Subsequent analysis of patient CSF profiles resulted in correct 'most probable diagnoses' for all eleven patients, including non-ketotic hyperglycinaemia, propionic aciduria, purine nucleoside phosphorylase deficiency, argininosuccinic aciduria, tyrosinaemia type I, hyperphenylalaninemia and hypermethioninaemia. CONCLUSION We here demonstrate that DI-HRMS based non-quantitative metabolomics accurately captures the biochemical profile of this set of patients in CSF, opening new ways for using metabolomics in CSF in the metabolic diagnostic laboratory.
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Affiliation(s)
- Hanneke A Haijes
- Section Metabolic Diagnostics, Department of Biomedical Genetics, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht University, Lundlaan 6, 3584 EA Utrecht, The Netherlands; Section Metabolic Diseases, Department of Child Health, Wilhelmina Children's Hospital, University Medical Centre Utrecht, Utrecht University, Lundlaan 6, 3584 EA Utrecht, The Netherlands
| | - Maria van der Ham
- Section Metabolic Diagnostics, Department of Biomedical Genetics, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht University, Lundlaan 6, 3584 EA Utrecht, The Netherlands
| | - Johan Gerrits
- Section Metabolic Diagnostics, Department of Biomedical Genetics, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht University, Lundlaan 6, 3584 EA Utrecht, The Netherlands
| | - Peter M van Hasselt
- Section Metabolic Diseases, Department of Child Health, Wilhelmina Children's Hospital, University Medical Centre Utrecht, Utrecht University, Lundlaan 6, 3584 EA Utrecht, The Netherlands
| | - Hubertus C M T Prinsen
- Section Metabolic Diagnostics, Department of Biomedical Genetics, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht University, Lundlaan 6, 3584 EA Utrecht, The Netherlands
| | - Monique G M de Sain-van der Velden
- Section Metabolic Diagnostics, Department of Biomedical Genetics, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht University, Lundlaan 6, 3584 EA Utrecht, The Netherlands
| | - Nanda M Verhoeven-Duif
- Section Metabolic Diagnostics, Department of Biomedical Genetics, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht University, Lundlaan 6, 3584 EA Utrecht, The Netherlands
| | - Judith J M Jans
- Section Metabolic Diagnostics, Department of Biomedical Genetics, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht University, Lundlaan 6, 3584 EA Utrecht, The Netherlands.
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Smith AD, Refsum H, Bottiglieri T, Fenech M, Hooshmand B, McCaddon A, Miller JW, Rosenberg IH, Obeid R. Homocysteine and Dementia: An International Consensus Statement. J Alzheimers Dis 2019; 62:561-570. [PMID: 29480200 PMCID: PMC5836397 DOI: 10.3233/jad-171042] [Citation(s) in RCA: 191] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Identification of modifiable risk factors provides a crucial approach to the prevention of dementia. Nutritional or nutrient-dependent risk factors are especially important because dietary modifications or use of dietary supplements may lower the risk factor level. One such risk factor is a raised concentration of the biomarker plasma total homocysteine, which reflects the functional status of three B vitamins (folate, vitamins B12, B6). A group of experts reviewed literature evidence from the last 20 years. We here present a Consensus Statement, based on the Bradford Hill criteria, and conclude that elevated plasma total homocysteine is a modifiable risk factor for development of cognitive decline, dementia, and Alzheimer’s disease in older persons. In a variety of clinical studies, the relative risk of dementia in elderly people for moderately raised homocysteine (within the normal range) ranges from 1.15 to 2.5, and the Population Attributable risk ranges from 4.3 to 31%. Intervention trials in elderly with cognitive impairment show that homocysteine-lowering treatment with B vitamins markedly slows the rate of whole and regional brain atrophy and also slows cognitive decline. The findings are consistent with moderately raised plasma total homocysteine (>11 μmol/L), which is common in the elderly, being one of the causes of age-related cognitive decline and dementia. Thus, the public health significance of raised tHcy in the elderly should not be underestimated, since it is easy, inexpensive, and safe to treat with B vitamins. Further trials are needed to see whether B vitamin treatment will slow, or prevent, conversion to dementia in people at risk of cognitive decline or dementia.
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Affiliation(s)
- A David Smith
- OPTIMA, Department of Pharmacology, University of Oxford, Oxford, UK
| | - Helga Refsum
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Norway
| | - Teodoro Bottiglieri
- Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX, USA
| | - Michael Fenech
- Genome Health and Personalised Nutrition Laboratory, CSIRO Health and Biosecurity, Adelaide BC, SA, Australia
| | - Babak Hooshmand
- Aging Research Centre, Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Stockholm, Sweden
| | - Andrew McCaddon
- Cardiff University, School of Medicine, Gwenfro Units 6/7, Wrexham, UK
| | - Joshua W Miller
- Department of Nutritional Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Irwin H Rosenberg
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA
| | - Rima Obeid
- Department of Clinical Chemistry and Laboratory Medicine, University Hospital of the Saarland, Germany
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14
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Craenen K, Verslegers M, Baatout S, Abderrafi Benotmane M. An appraisal of folates as key factors in cognition and ageing-related diseases. Crit Rev Food Sci Nutr 2019; 60:722-739. [PMID: 30729795 DOI: 10.1080/10408398.2018.1549017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Folic acid (FA) is often consumed as a food supplement and can be found in fortified staple foods in various western countries. Even though FA supplementation during pregnancy is known to prevent severe congenital anomalies in the developing child (e.g., neural tube defects), much less is known about its influence on cognition and neurological functioning. In this review, we address the advances in this field and situate how folate intake during pregnancy, postnatal life, adulthood and in the elderly affects cognition. In addition, an association between folate status and ageing, dementia and other neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis is discussed. While its role in the incidence and severity of these diseases is becoming apparent, the underlying action of folates and related metabolites remains elusive. Finally, the potential of FA as a nutraceutical has been proposed, although the efficacy will highly depend on the interplay with other micronutrients, the disease stage and the duration of supplementation. Hence, the lack of consistent data urges for more animal studies and (pre)clinical trials in humans to ascertain a potential beneficial role for folates in the treatment or amelioration of cognitive decline and ageing-related disorders.
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Affiliation(s)
- Kai Craenen
- Radiobiology Unit, Belgian Nuclear Research Centre SCK•CEN, Mol, Belgium.,Biology Department, Research Group Neural Circuit Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Mieke Verslegers
- Radiobiology Unit, Belgian Nuclear Research Centre SCK•CEN, Mol, Belgium
| | - Sarah Baatout
- Radiobiology Unit, Belgian Nuclear Research Centre SCK•CEN, Mol, Belgium
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15
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Abstract
The biosynthesis of B12, involving up to 30 different enzyme-mediated steps, only occurs in bacteria. Thus, most eukaryotes require an external source of B12, and yet the vitamin appears to have only two functions in eukaryotes: as a cofactor for the enzymes methionine synthase and methylmalonylCoA mutase. These two functions are crucial for normal health in humans, and in particular, the formation of methionine is essential for providing methyl groups for over 100 methylation processes. Interference with the methionine synthase reaction not only depletes the body of methyl groups but also leads to the accumulation of homocysteine, a risk factor for many diseases. The syndrome pernicious anemia, characterized by lack of intrinsic factor, leads to a severe, sometimes fatal form of B12 deficiency. However, there is no sharp cutoff for B12 deficiency; rather, there is a continuous inverse relationship between serum B12 and a variety of undesirable outcomes, including neural tube defects, stroke, and dementia. The brain is particularly vulnerable; in children, inadequate B12 stunts brain and intellectual development. Suboptimal B12 status (serum B12<300pmol/L) is very common, occurring in 30%-60% of the population, in particular in pregnant women and in less-developed countries. Thus, many tens of millions of people in the world may suffer harm from having a poor B12 status. Public health steps are urgently needed to correct this inadequacy.
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Affiliation(s)
- A David Smith
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom.
| | - Martin J Warren
- School of Biosciences, University of Kent, Canterbury, Kent, United Kingdom
| | - Helga Refsum
- Department of Nutrition, University of Oslo, Oslo, Norway
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16
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Peng Y, Wang Z. Red blood cell folate concentrations and coronary heart disease prevalence: A cross-sectional study based on 1999-2012 National Health and Nutrition Examination Survey. Nutr Metab Cardiovasc Dis 2017; 27:1015-1020. [PMID: 28844321 DOI: 10.1016/j.numecd.2017.07.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 06/28/2017] [Accepted: 07/17/2017] [Indexed: 01/09/2023]
Abstract
BACKGROUND AND AIM Folate is involved in a number of metabolic pathways. Red blood cell (RBC) folate is a well-established indicator of folate intake. However, studies focused on the association between RBC folate and coronary heart disease (CHD) are limited. The aim of the current study was to investigate the effect of RBC folate concentrations on the presence of CHD in a nationally representative sample of American adults. METHODS AND RESULTS In the 1999-2012 National Health and Nutrition Examination Survey (NHANES), 22,499 subjects aged 30-74 years with RBC folate concentrations, CHD status and responses to co-variates questions were included; 822 (3.65%) participants were identified as having CHD. Bio-Rad Quanta Phase II radioassay and microbiological assay were used to measure RBC folate concentrations. Firstly, we treated RBC folate as a categorical variable, based on RBC folate tertiles, and used logistic regression analysis to display the RBC folate and CHD relationship. Secondly, we explored associations using a combination of restricted cubic spline and logistic regression models, stratified by sex. After adjusting for several well-established traditional CHD risk factors, RBC folate was positively related to CHD presence in the total population and the association was more pronounced among males than females. A J-shaped pattern was observed in RBC folate concentrations for females. CONCLUSION Elevated RBC folate concentrations were associated with higher CHD risk. Further investigation is needed to test the association in large-scale follow-up studies.
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Affiliation(s)
- Y Peng
- Centre for Chronic Disease, Centre for Clinical Research, The University of Queensland, Herston, Queensland 4029, Australia.
| | - Z Wang
- Centre for Chronic Disease, Centre for Clinical Research, The University of Queensland, Herston, Queensland 4029, Australia
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17
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Dayon L, Guiraud SP, Corthésy J, Da Silva L, Migliavacca E, Tautvydaitė D, Oikonomidi A, Moullet B, Henry H, Métairon S, Marquis J, Descombes P, Collino S, Martin FPJ, Montoliu I, Kussmann M, Wojcik J, Bowman GL, Popp J. One-carbon metabolism, cognitive impairment and CSF measures of Alzheimer pathology: homocysteine and beyond. ALZHEIMERS RESEARCH & THERAPY 2017. [PMID: 28623948 PMCID: PMC5473969 DOI: 10.1186/s13195-017-0270-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Background Hyperhomocysteinemia is a risk factor for cognitive decline and dementia, including Alzheimer disease (AD). Homocysteine (Hcy) is a sulfur-containing amino acid and metabolite of the methionine pathway. The interrelated methionine, purine, and thymidylate cycles constitute the one-carbon metabolism that plays a critical role in the synthesis of DNA, neurotransmitters, phospholipids, and myelin. In this study, we tested the hypothesis that one-carbon metabolites beyond Hcy are relevant to cognitive function and cerebrospinal fluid (CSF) measures of AD pathology in older adults. Methods Cross-sectional analysis was performed on matched CSF and plasma collected from 120 older community-dwelling adults with (n = 72) or without (n = 48) cognitive impairment. Liquid chromatography-mass spectrometry was performed to quantify one-carbon metabolites and their cofactors. Least absolute shrinkage and selection operator (LASSO) regression was initially applied to clinical and biomarker measures that generate the highest diagnostic accuracy of a priori-defined cognitive impairment (Clinical Dementia Rating-based) and AD pathology (i.e., CSF tau phosphorylated at threonine 181 [p-tau181]/β-Amyloid 1–42 peptide chain [Aβ1–42] >0.0779) to establish a reference benchmark. Two other LASSO-determined models were generated that included the one-carbon metabolites in CSF and then plasma. Correlations of CSF and plasma one-carbon metabolites with CSF amyloid and tau were explored. LASSO-determined models were stratified by apolipoprotein E (APOE) ε4 carrier status. Results The diagnostic accuracy of cognitive impairment for the reference model was 80.8% and included age, years of education, Aβ1–42, tau, and p-tau181. A model including CSF cystathionine, methionine, S-adenosyl-L-homocysteine (SAH), S-adenosylmethionine (SAM), serine, cysteine, and 5-methyltetrahydrofolate (5-MTHF) improved the diagnostic accuracy to 87.4%. A second model derived from plasma included cystathionine, glycine, methionine, SAH, SAM, serine, cysteine, and Hcy and reached a diagnostic accuracy of 87.5%. CSF SAH and 5-MTHF were associated with CSF tau and p-tau181. Plasma one-carbon metabolites were able to diagnose subjects with a positive CSF profile of AD pathology in APOE ε4 carriers. Conclusions We observed significant improvements in the prediction of cognitive impairment by adding one-carbon metabolites. This is partially explained by associations with CSF tau and p-tau181, suggesting a role for one-carbon metabolism in the aggregation of tau and neuronal injury. These metabolites may be particularly critical in APOE ε4 carriers. Electronic supplementary material The online version of this article (doi:10.1186/s13195-017-0270-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Loïc Dayon
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland.
| | - Seu Ping Guiraud
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - John Corthésy
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - Laeticia Da Silva
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - Eugenia Migliavacca
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - Domilė Tautvydaitė
- Old Age Psychiatry, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Aikaterini Oikonomidi
- Old Age Psychiatry, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Barbara Moullet
- Old Age Psychiatry, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Hugues Henry
- Department of Laboratories, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Sylviane Métairon
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - Julien Marquis
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - Patrick Descombes
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - Sebastiano Collino
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - François-Pierre J Martin
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - Ivan Montoliu
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - Martin Kussmann
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland.,Present address: Liggins Institute, University of Auckland, Auckland, New Zealand
| | | | - Gene L Bowman
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, Bâtiment H, 1015, Lausanne, Switzerland
| | - Julius Popp
- Old Age Psychiatry, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
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18
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Oikonomidi A, Lewczuk P, Kornhuber J, Smulders Y, Linnebank M, Semmler A, Popp J. Homocysteine metabolism is associated with cerebrospinal fluid levels of soluble amyloid precursor protein and amyloid beta. J Neurochem 2016; 139:324-332. [PMID: 27507672 DOI: 10.1111/jnc.13766] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 06/15/2016] [Accepted: 07/29/2016] [Indexed: 01/05/2023]
Abstract
Disturbed homocysteine metabolism may contribute to amyloidogenesis by modulating the amyloid precursor protein (APP) production and processing. The objective of this study was to investigate the relationships between cerebral amyloid production and both blood and cerebrospinal fluid (CSF) markers of the homocysteine metabolism. We assessed CSF concentrations of soluble APPα, soluble APPβ, and amyloid β1-42 (Aβ1-42), as well as plasma levels of homocysteine (Hcys), total vitamin B12, and folate, and CSF concentrations of homocysteine (Hcys-CSF), 5-methyltetrahydrofolate (5-MTHF), S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) in 59 subjects with normal cognition. Linear regression analyses were performed to assess associations between homocysteine metabolism parameters and amyloid production. The study was approved by the Ethical Committee of the University of Bonn. After controlling for age, gender, APOEe4 status, and albumin ratio (Qalb), higher Aβ1-42 CSF levels were associated with high Hcys and low vitamin B12 plasma levels as well as with high Hcys, high SAH, and low 5-MTHF CSF levels. Higher CSF concentrations of sAPPα and sAPPβ were associated with high SAH levels. The results suggest that disturbed homocysteine metabolism is related to increased CSF levels of sAPP forms and Aβ1-42, and may contribute to the accumulation of amyloid pathology in the brain. Disturbed homocysteine metabolism may contribute to amyloidogenesis by modulating the amyloid precursor protein (APP) production and processing. We found associations between CSF levels of soluble APP forms and Aβ1-42, and markers of the homocysteine metabolism in both plasma and CSF in adults with normal cognition. Disturbed homocysteine metabolism may represent a target for preventive and early disease-modifying interventions in Alzheimer's disease.
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Affiliation(s)
- Aikaterini Oikonomidi
- Department of Psychiatry, Division of Old Age Psychiatry, University Hospital of Lausanne, Lausanne, Switzerland
| | - Piotr Lewczuk
- Department of Psychiatry and Psychotherapy, University of Erlangen, Erlangen, Germany.,Department of Neurodegeneration Diagnostics, Medical University of Bialystok, Bialystok, Poland
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, University of Erlangen, Erlangen, Germany
| | - Yvo Smulders
- Department of Internal Medicine, VU University Medical Centre, Amsterdam, The Netherlands.,Institute for Cardiovascular Research ICaR-VU, VU University Medical Centre, Amsterdam, The Netherlands
| | - Michael Linnebank
- Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Alexander Semmler
- Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Julius Popp
- Department of Psychiatry, Division of Old Age Psychiatry, University Hospital of Lausanne, Lausanne, Switzerland. .,Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany.
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19
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Affiliation(s)
- A. David Smith
- OPTIMA, Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom;
| | - Helga Refsum
- OPTIMA, Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom;
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, 0316 Oslo, Norway;
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20
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McCaddon A, Miller JW. Assessing the association between homocysteine and cognition: reflections on Bradford Hill, meta-analyses, and causality. Nutr Rev 2015; 73:723-35. [DOI: 10.1093/nutrit/nuv022] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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21
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Hooshmand B, Polvikoski T, Kivipelto M, Tanskanen M, Myllykangas L, Erkinjuntti T, Mäkelä M, Oinas M, Paetau A, Scheltens P, van Straaten ECW, Sulkava R, Solomon A. Plasma homocysteine, Alzheimer and cerebrovascular pathology: a population-based autopsy study. ACTA ACUST UNITED AC 2013; 136:2707-16. [PMID: 23983028 DOI: 10.1093/brain/awt206] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Elevated plasma total homocysteine is associated with increased risk of dementia/Alzheimer's disease, but underlying pathophysiological mechanisms are not fully understood. This study investigated possible links between baseline homocysteine, and post-mortem neuropathological and magnetic resonance imaging findings up to 10 years later in the Vantaa 85+ population including people aged ≥85 years. Two hundred and sixty-five individuals had homocysteine and autopsy data, of which 103 had post-mortem brain magnetic resonance imaging scans. Methenamine silver staining was used for amyloid-β and modified Bielschowsky method for neurofibrillary tangles and neuritic plaques. Macroscopic infarcts were identified from cerebral hemispheres, brainstem and cerebellum slices. Standardized methods were used to determine microscopic infarcts, cerebral amyoloid angiopathy, and α-synuclein pathology. Magnetic resonance imaging was used for visual ratings of the degree of medial temporal lobe atrophy, and periventricular and deep white matter hyperintensities. Elevated baseline homocysteine was associated with increased neurofibrillary tangles count at the time of death: for the highest homocysteine quartile, odds ratio (95% confidence interval) was 2.60 (1.28-5.28). The association was observed particularly in people with dementia, in the presence of cerebral infarcts, and with longer time between the baseline homocysteine assessment and death. Also, elevated homocysteine tended to relate to amyloid-β accumulation, but this was seen only with longer baseline-death interval: odds ratio (95% confidence interval) was 2.52 (0.88-7.19) for the highest homocysteine quartile. On post-mortem magnetic resonance imaging, for the highest homocysteine quartile odds ratio (95% confidence interval) was 3.78 (1.12-12.79) for more severe medial temporal atrophy and 4.69 (1.14-19.33) for more severe periventricular white matter hyperintensities. All associations were independent of several potential confounders, including common vascular risk factors. No relationships between homocysteine and cerebral macro- or microinfarcts, cerebral amyoloid angiopathy or α-synuclein pathology were detected. These results suggest that elevated homocysteine in adults aged ≥85 years may contribute to increased Alzheimer-type pathology, particularly neurofibrillary tangles burden. This effect seems to be more pronounced in the presence of cerebrovascular pathology. Randomized controlled trials are needed to determine the impact of homocysteine-lowering treatments on dementia-related pathology.
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Affiliation(s)
- Babak Hooshmand
- Ageing Research Centre, Department of Neurobiology, Care Sciences, and Society, Karolinska Institute, 11330 Stockholm, Sweden.
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22
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Muratore CR, Hodgson NW, Trivedi MS, Abdolmaleky HM, Persico AM, Lintas C, De La Monte S, Deth RC. Age-dependent decrease and alternative splicing of methionine synthase mRNA in human cerebral cortex and an accelerated decrease in autism. PLoS One 2013; 8:e56927. [PMID: 23437274 PMCID: PMC3577685 DOI: 10.1371/journal.pone.0056927] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 01/16/2013] [Indexed: 12/22/2022] Open
Abstract
The folate and vitamin B12-dependent enzyme methionine synthase (MS) is highly sensitive to cellular oxidative status, and lower MS activity increases production of the antioxidant glutathione, while simultaneously decreasing more than 200 methylation reactions, broadly affecting metabolic activity. MS mRNA levels in postmortem human cortex from subjects across the lifespan were measured and a dramatic progressive biphasic decrease of more than 400-fold from 28 weeks of gestation to 84 years was observed. Further analysis revealed alternative splicing of MS mRNA, including deletion of folate-binding domain exons and age-dependent deletion of exons from the cap domain, which protects vitamin B12 (cobalamin) from oxidation. Although three species of MS were evident at the protein level, corresponding to full-length and alternatively spliced mRNA transcripts, decreasing mRNA levels across the lifespan were not associated with significant changes in MS protein or methionine levels. MS mRNA levels were significantly lower in autistic subjects, especially at younger ages, and this decrease was replicated in cultured human neuronal cells by treatment with TNF-α, whose CSF levels are elevated in autism. These novel findings suggest that rather than serving as a housekeeping enzyme, MS has a broad and dynamic role in coordinating metabolism in the brain during development and aging. Factors adversely affecting MS activity, such as oxidative stress, can be a source of risk for neurological disorders across the lifespan via their impact on methylation reactions, including epigenetic regulation of gene expression.
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Affiliation(s)
- Christina R. Muratore
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, Massachusetts, United States of America
| | - Nathaniel W. Hodgson
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, Massachusetts, United States of America
| | - Malav S. Trivedi
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, Massachusetts, United States of America
| | - Hamid M. Abdolmaleky
- Genetics Program, School of Medicine, Boston University, Boston, Massachusetts, United States of America
| | - Antonio M. Persico
- Laboratory of Molecular Psychiatry and Neurogenetics, University Campus Bio-Medico, Rome, Italy
| | - Carla Lintas
- Laboratory of Molecular Psychiatry and Neurogenetics, University Campus Bio-Medico, Rome, Italy
| | - Suzanne De La Monte
- Department of Medicine and Pathology, Rhode Island Hospital and Warren Alpert School of Medicine at Brown University, Providence, Rhode Island, United States of America
| | - Richard C. Deth
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, Massachusetts, United States of America
- * E-mail:
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23
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Abstract
Hydrogen sulfide is an environmental toxicant and gaseous neurotransmitter. It is produced enterically by sulfur-reducing bacteria and invasive pathogens including Streptococcus anginosus group, Salmonella and Citrobacter. We describe putative focal hydrogen sulfide neurotoxicity after Streptococcus constellatus meningitis, treated with adjunctive sodium nitrite and hyperbaric oxygen therapy.
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24
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McCaddon A. Vitamin B12 in neurology and ageing; clinical and genetic aspects. Biochimie 2012; 95:1066-76. [PMID: 23228515 DOI: 10.1016/j.biochi.2012.11.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 11/27/2012] [Indexed: 01/13/2023]
Abstract
The classic neurological and psychiatric features associated with vitamin B12 deficiency have been well described and are the subject of many excellent review articles. The advent of sensitive diagnostic tests, including homocysteine and methylmalonic acid assays, has revealed a surprisingly high prevalence of a more subtle 'subclinical' form of B12 deficiency, particularly within the elderly. This is often associated with cognitive impairment and dementia, including Alzheimer's disease. Metabolic evidence of B12 deficiency is also reported in association with other neurodegenerative disorders including vascular dementia, Parkinson's disease and multiple sclerosis. These conditions are all associated with chronic neuro-inflammation and oxidative stress. It is possible that these clinical associations reflect compromised vitamin B12 metabolism due to such stress. Physicians are also increasingly aware of considerable inter-individual variation in the clinical response to B12 replacement therapy. Further research is needed to determine to what extent this is attributable to genetic determinants of vitamin B12 absorption, distribution and cellular uptake.
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Affiliation(s)
- Andrew McCaddon
- School of Medicine, Cardiff University, Gwenfro Units 6/7, Wrexham Technology Park, Wrexham LL17 7YP, Wales, United Kingdom.
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25
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Smach MA, Naffeti S, Charfeddine B, Ben Abdallah J, Othmen LB, Letaef A, Limem K. [Homocysteine, vitamin B-12, folic acid and the cognitive decline in the elderly]. ACTA ACUST UNITED AC 2012; 61:184-92. [PMID: 22647793 DOI: 10.1016/j.patbio.2012.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 04/18/2012] [Indexed: 11/25/2022]
Abstract
Hyperhomocysteinemia is a risk factor for neurological diseases, but the underlying pathophysiology has not been adequately explained. Mild hyperhomocysteinemia, which is sometimes associated with a low plasma level of vitamin B9, B12 and folic acid, is responsible in the toxicity in neural cell by activating NMDA receptor. Indeed, even if vitamin supplementation has clearly proven its efficiency on lowering plasma levels of homocysteine, recent studies do not show any positive effect of vitamin therapy on cognitive function. The hypothesis that this therapy is inefficient has been recently reinforced by two randomized trials on the effects of vitamin supplementation. Several hypotheses still need to be explored: Mechanisms of homocysteine toxicity and that of total uselessness of vitamin supplementation; the possible need to complete the actual data with further, more powerful studies in order to prove the role of homocysteine in the development of neurodegenerative diseases and a clinical effect of vitamin therapy.
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Affiliation(s)
- M A Smach
- Department of Biochemistry, Faculty of Medicine of Sousse, 4002 Sousse, Tunisie.
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26
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Obeid R, Schlundt J, Umanskaya N, Herrmann W, Herrmann M. Folate is related to phosphorylated neurofilament-H and P-tau (Ser396) in rat brain. J Neurochem 2011; 117:1047-54. [PMID: 21517845 DOI: 10.1111/j.1471-4159.2011.07280.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Protein phosphatase PP2A dephosphorylates phosphorylated tau (P-tau) and neurofilaments (pNFs). PP2A is S-adenosylmethionine (SAM)-dependent and might thus link methylation with neurodegeneration. Low SAM and increased S-adenosylhomocysteine (SAH) can enhance the risk of dementia. We studied the effect of hyperhomocysteinemia on P-tau (Ser396), pNF-H (heavy chain), and PP2A-activity and level (the C subunit) in rat brain. Wistar rats (total n=55) were fed either on a standard, a homocystine 1.7% or a methionine 2.4%-rich diet for 5 months. P-tau was tested in 21 frontal cortex tissue slices using immuno-fluorescence. Concentrations of pNF-H and the activity and level of PP2A were measured in brain extracts. Concentrations of homocysteine, SAM and SAH strongly increased in plasma of rats on the modified diets. The diets caused lowering of plasma folate and vitamin B12 and a significant increase in P-tau (Ser396) in brain tissues but PP2A activity and level were unchanged. Plasma folate correlated to brain tissue PP2A activity (r=0.28), pNF-H (r=-0.30), and P-tau (Ser396) staining (r=-0.57) all p<0.05. Phosphorylation of brain functional proteins was related to folate. The effect of the diet on P-tau and pNF-H seemed not to be explained by a lower activity or protein level of PP2A. Folate might prove protective against multiple steps in the process of neurodegeneration.
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Affiliation(s)
- Rima Obeid
- Department of Clinical Chemistry and Laboratory Medicine/Central Laboratory, University Hospital, Saarland University, Homburg, Germany.
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Smach MA, Jacob N, Golmard JL, Charfeddine B, Lammouchi T, Ben Othman L, Dridi H, Bennamou S, Limem K. Folate and Homocysteine in the Cerebrospinal Fluid of Patients with Alzheimer’s Disease or Dementia: A Case Control Study. Eur Neurol 2011; 65:270-8. [DOI: 10.1159/000326301] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 02/21/2011] [Indexed: 11/19/2022]
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Roe CR, Bottiglieri T, Wallace M, Arning E, Martin A. Adult Polyglucosan Body Disease (APBD): Anaplerotic diet therapy (Triheptanoin) and demonstration of defective methylation pathways. Mol Genet Metab 2010; 101:246-52. [PMID: 20655781 DOI: 10.1016/j.ymgme.2010.06.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Accepted: 06/03/2010] [Indexed: 10/19/2022]
Abstract
APBD is a rare disorder most often affecting adults of Ashkenazi Jewish origin due to partial deficiency of the glycogen brancher enzyme (GBE). It is characterized by progressive involvement of both the central and peripheral nervous systems and deposition of amylopectin-like polyglucosan bodies. There have been no metabolic derangements that might suggest effective therapy nor have there been any clinical improvements for control of its relentless progression. The APBD patients, in this study, experienced stabilization of disease progression, and limited functional improvement in most patients with dietary triheptanoin. Due to a plateau in clinical improvement, the reduced plasma creatinine and methionine levels prompted evaluation of other plasma methylation intermediates in this complex integrated pathway system: decreased S-adenosylmethionine (SAM) (p<0.002), increased S-adenosylhomocysteine (p<0.001), elevated creatine (p=0.001) and increased free choline (p<0.001). Plasma levels of homocysteine and guanidinoacetate were normal. Impaired metabolism of choline and creatine may relate to the progressive dysmyelination and progressive muscle weakness associated with APBD. The partial deficiency of GBE appears to produce a secondary energy deficit possibly related to inadequate reserves of normal glycogen for efficient degradation to free glucose. Dysfunctional regulation of glycogen synthase (GS) may result in continued synthesis and deposition of polyglucosan bodies. This investigation has demonstrated, for the first time, arrest of clinical deterioration with limited functional recovery with triheptanoin diet therapy and the existence of significant derangement of methylation pathways that, when corrected, may lead to even greater therapeutic benefits.
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Affiliation(s)
- Charles R Roe
- Baylor Research Institute, Institute of Metabolic Disease, Baylor University Medical Center, Dallas, TX 75226, United States.
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Liu CC, Ho WY, Leu KL, Tsai HM, Yang TH. Effects of S-adenosylhomocysteine and homocysteine on DNA damage and cell cytotoxicity in murine hepatic and microglia cell lines. J Biochem Mol Toxicol 2010; 23:349-56. [PMID: 19827130 DOI: 10.1002/jbt.20298] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Limited research has been performed on S-adenosylhomocysteine (SAH) or homocysteine (Hcy)-evoked cell damage in hepatic and neuronal cells. In this study, we assessed effects of SAH or Hcy on cell cytotoxicity and DNA damage in hepatic and neuronal cells and attempted to find the underlying mechanism. Cell cytotoxicity and DNA damage were evaluated in murine hepatic cells (BNL CL.2 cell line) and microglia cells (BV-2 cell line) with SAH or Hcy treatment for 48 h. The influences of SAH or Hcy on lipid peroxidation and DNA methylation were also measured in both cell lines. SAH (5-20 microM) or Hcy (1-5 mM) dose dependently inhibited cell cytotoxicity and enhanced DNA damage in both types of cells. Furthermore, SAH treatment markedly increased intracellular SAH levels and DNA hypomethylation, whereas Hcy caused minimal effects on these two parameters at much higher concentrations. Hcy significantly induced lipid peroxidation, but not SAH. The present results show that SAH might cause cellular DNA damage in hepatic and microglia cells by DNA hypomethylation, resulting in irreversible DNA damage and increased cell cytotoxicity. In addition, higher Hcy could induce cellular DNA damage through increased lipid peroxidation and DNA hypomethylation. We suggest that SAH is a better marker of cell damage than Hcy in hepatic and microglia cells.
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Affiliation(s)
- Chia-Chyuan Liu
- Department of Cosmetic Science, Chia-Nan University of Pharmacy and Science, Tainan 71710, Taiwan
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L-methylfolate, methylcobalamin, and N-acetylcysteine in the treatment of Alzheimer's disease-related cognitive decline. CNS Spectr 2010; 15:2-5; discussion 6. [PMID: 20397369 DOI: 10.1017/s1092852900027589] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Neuroinflammatory oxidative stress occurs early in AD pathology. Elevated blood Hcy is a useful marker for such neuroinflammation. Hcy contributes to pathological cascades involving AP and NFTs. In AD, Hcy should be lowered by B-vitamin supplements and NAC.
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Alexopoulos P, Günther F, Popp J, Jessen F, Peters O, Wolf S, Kneib T, Kurz A, Richter-Schmidinger T, Lewczuk P, Bleich S, Wiltfang J, Kornhuber J. PLASMA HOMOCYSTEINE AND CEREBROSPINAL FLUID NEURODEGENERATION BIOMARKERS IN MILD COGNITIVE IMPAIRMENT AND DEMENTIA. J Am Geriatr Soc 2009; 57:737-9. [DOI: 10.1111/j.1532-5415.2009.02212.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Viswanathan A, Raj S, Greenberg SM, Stampfer M, Campbell S, Hyman BT, Irizarry MC. Plasma Abeta, homocysteine, and cognition: the Vitamin Intervention for Stroke Prevention (VISP) trial. Neurology 2009; 72:268-72. [PMID: 19153374 DOI: 10.1212/01.wnl.0000339486.63862.db] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Amyloid-beta protein (Abeta) plays a key role in Alzheimer disease (AD) and is also implicated in cerebral small vessel disease. Serum total homocysteine (tHcy) is a risk factor for small vessel disease and cognitive impairment and correlates with plasma Abeta levels. To determine whether this association results from a common pathophysiologic mechanism, we investigated whether vitamin supplementation-induced reduction of tHcy influences plasma Abeta levels in the Vitamin Intervention in Stroke Prevention (VISP) study. METHODS Two groups of 150 patients treated with either the high-dose or low-dose formulation of pyridoxine, cobalamin, and folic acid in a randomized, double-blind fashion were selected among the participants in the VISP study without recurrent stroke during follow-up and in the highest 10% of the distribution for baseline tHcy levels. Concentrations of plasma Abeta with 40 (Abeta40) and 42 (Abeta42) amino acids were measured at baseline and at the 2-year visit. RESULTS tHcy levels significantly decreased with vitamin supplementation in both groups. tHcy were strongly correlated with Abeta40 but not Abeta42 concentrations. There was no difference in the change in Abeta40, Abeta42 (p = 0.40, p = 0.35), or the Abeta42/Abeta40 ratio over time (p = 0.86) between treatment groups. Abeta measures were not associated with cognitive change. CONCLUSIONS This double-blind randomized controlled trial of vitamin therapy demonstrates a strong correlation between serum tHcy and plasma Abeta40 concentrations in subjects with ischemic stroke. Treatment with high dose vitamins does not, however, influence plasma levels of Abeta, despite their effect on lowering tHcy. Our results suggest that although tHcy is associated with plasma Abeta40, they may be regulated by independent mechanisms.
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Affiliation(s)
- A Viswanathan
- Hemorrhagic Stroke Research Program, Massachusetts General Hospital Stroke Research Center, 175 Cambridge Street, Suite 300, Boston, MA 02114, USA.
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Abstract
Vitamin B-12 deficiency is often associated with cognitive deficits. Here we review evidence that cognition in the elderly may also be adversely affected at concentrations of vitamin B-12 above the traditional cutoffs for deficiency. By using markers such as holotranscobalamin and methylmalonic acid, it has been found that cognition is associated with vitamin B-12 status across the normal range. Possible mediators of this relation include brain atrophy and white matter damage, both of which are associated with low vitamin B-12 status. Intervention trials have not been adequately designed to test whether these associations are causal. Pending the outcome of better trials, it is suggested that the elderly in particular should be encouraged to maintain a good, rather than just an adequate, vitamin B-12 status by dietary means.
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Affiliation(s)
- A David Smith
- Oxford Project to Investigate Memory and Ageing, the Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.
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Kuszczyk M, Gordon-Krajcer W, Lazarewicz JW. Homocysteine-induced acute excitotoxicity in cerebellar granule cells in vitro is accompanied by PP2A-mediated dephosphorylation of tau. Neurochem Int 2009; 55:174-80. [DOI: 10.1016/j.neuint.2009.02.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 01/27/2009] [Accepted: 02/17/2009] [Indexed: 12/29/2022]
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Cole PD, Beckwith KA, Vijayanathan V, Roychowdhury S, Smith AK, Kamen BA. Folate homeostasis in cerebrospinal fluid during therapy for acute lymphoblastic leukemia. Pediatr Neurol 2009; 40:34-41. [PMID: 19068252 DOI: 10.1016/j.pediatrneurol.2008.09.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 08/25/2008] [Accepted: 09/03/2008] [Indexed: 10/21/2022]
Abstract
The neurotoxic effects of therapy for childhood acute lymphoblastic leukemia can result in leukoencephalopathy or measurable deficits in cognitive function. However, there are no validated biomarkers that allow the identification of those patients at greatest risk. With the objective of identifying such predictors, cerebrospinal fluid collected from 53 patients over 2.5 years of therapy for childhood acute lymphoblastic leukemia was retrospectively studied. Cerebrospinal fluid folate, concentrated relative to serum folate prior to therapy, dropped during the first month of therapy and remained below baseline throughout treatment. Cerebrospinal fluid homocysteine was inversely related to cognitive function prior to treatment. Oral methotrexate was associated with decreased cerebrospinal fluid folate and increased cerebrospinal fluid homocysteine, but these changes were not seen with oral aminopterin. Of 36 patients who had imaging after completion of therapy, 9 had periventricular or subcortical white matter abnormalities consistent with leukoencephalopathy. Peak cerebrospinal fluid tau concentrations during therapy were higher among patients who had leukoencephalopathy after completion of therapy than among those with normal imaging studies at the end of therapy. If confirmed prospectively, these markers may allow the identification of those patients at greatest risk of developing treatment-induced neurocognitive dysfunction, thus guiding preventive interventions.
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Affiliation(s)
- Peter D Cole
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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Folate deficiency induces in vitro and mouse brain region-specific downregulation of leucine carboxyl methyltransferase-1 and protein phosphatase 2A B(alpha) subunit expression that correlate with enhanced tau phosphorylation. J Neurosci 2008; 28:11477-87. [PMID: 18987184 DOI: 10.1523/jneurosci.2816-08.2008] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Altered folate homeostasis is associated with many clinical and pathological manifestations in the CNS. Notably, folate-mediated one-carbon metabolism is essential for methyltransferase-dependent cellular methylation reactions. Biogenesis of protein phosphatase 2A (PP2A) holoenzyme containing the regulatory B(alpha) subunit, a major brain tau phosphatase, is controlled by methylation. Here, we show that folate deprivation in neuroblastoma cells induces downregulation of PP2A leucine carboxyl methyltransferase-1 (LCMT-1) expression, resulting in progressive accumulation of newly synthesized demethylated PP2A pools, concomitant loss of B(alpha), and ultimately cell death. These effects are further accentuated by overexpression of PP2A methylesterase (PME-1) but cannot be rescued by PME-1 knockdown. Overexpression of either LCMT-1 or B(alpha) is sufficient to protect cells against the accumulation of demethylated PP2A, increased tau phosphorylation, and cell death induced by folate starvation. Conversely, knockdown of either protein accelerates folate deficiency-evoked cell toxicity. Significantly, mice maintained for 2 months on low-folate or folate-deficient diets have brain-region-specific alterations in metabolites of the methylation pathway. Those are associated with downregulation of LCMT-1, methylated PP2A, and B(alpha) expression and enhanced tau phosphorylation in susceptible brain regions. Our studies provide novel mechanistic insights into the regulation of PP2A methylation and tau. They establish LCMT-1- and B(alpha)-containing PP2A holoenzymes as key mediators of the role of folate in the brain. Our results suggest that counteracting the neuronal loss of LCMT-1 and B(alpha) could be beneficial for all tauopathies and folate-dependent disorders of the CNS.
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Herrmann W, Obeid R. Biomarkers of folate and vitamin B(12) status in cerebrospinal fluid. Clin Chem Lab Med 2008; 45:1614-20. [PMID: 17892439 DOI: 10.1515/cclm.2007.310] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Folate and vitamin B(12) are essential cofactors for the methionine/homocysteine cycle in the brain. These vitamins mediate the remethylation of homocysteine (Hcy), which affects the production of the universal methyl donor, S-adenosylmethionine (SAM), in the brain among other organs. Additionally, increased plasma concentrations of total Hcy (tHcy) are associated with cerebrovascular disease and can compromise the blood-brain barrier. tHcy concentrations in the brain and cerebrospinal fluid become increased in several psychiatric and neurological disorders. Disturbances in the transmethylation pathway indicated by abnormal SAM, S-adenosylhomocysteine or their ratio have been reported in many neurodegenerative diseases, such as dementia, depression or Parkinson's disease. Cobalamin is essential for neuronal generation and its deficiency can cause degeneration of the nervous system. Available data emphasize that deficiency of folate and vitamin B(12) can lead to elevated concentrations of tHcy and disturbed methylation potential in the brain. Therefore, acquired or inherited disorders in these metabolic pathways are associated with brain abnormalities and severe neurological symptoms that are mostly irreversible, even after providing the missing cofactors. This review discusses the relationship between brain and blood levels of key vitamins and metabolites related to one carbon metabolism.
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Affiliation(s)
- Wolfgang Herrmann
- Department of Clinical Chemistry and Laboratory Medicine, Faculty of Medicine, University Hospital of Saarland, Homburg/Saar, Germany.
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The potential role of nutritional components in the management of Alzheimer's Disease. Eur J Pharmacol 2008; 585:197-207. [PMID: 18374332 DOI: 10.1016/j.ejphar.2008.01.049] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 12/28/2007] [Accepted: 01/21/2008] [Indexed: 01/30/2023]
Abstract
Epidemiological evidence linking nutrition to the incidence and risk of Alzheimer Disease is rapidly increasing. The specific nutritional deficiencies in Alzheimer patients may suggest a relative shortage of specific macro- and micronutrients. These include omega-3 fatty acids, several B-vitamins and antioxidants such as vitamins E and C. Recent mechanistic studies in cell systems and animal models also support the idea that nutritional components are able to counteract specific aspects of the neurodegenerative and pathological processes in the brain. In addition, it has been shown that several nutritional components can also effectively stimulate membrane formation and synapse formation as well as improve behavior and cerebrovascular health. The suggested synergy between nutritional components to improve neuronal plasticity and function is supported by epidemiological studies as well as experimental studies in animal models. The ability of nutritional compositions to stimulate synapse formation and effectively reduce Alzheimer Disease neuropathology in these preclinical models provides a solid basis to predict potential to modify the disease process, especially during the early phases of Alzheimer Disease.
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Abstract
There is an association between cognitive function and vitamin B12 and folate status. Both vitamins participate in recycling the potentially toxic amino acid homocysteine to methionine and, ultimately, to the methyl donor S-adenosylmethionine (SAM). Consequently, B12 and folate indirectly influence glutathione synthesis – a major intracellular antioxidant. Neuroinflammation and oxidative stress are early features of Alzheimer’s disease (AD). Such stress impairs homocysteine recycling, degrades folate and decreases its cellular retention, resulting in limited SAM availability and increased homocysteine levels. Oxidized homocysteine derivatives, such as homocysteic acid, can initiate a vicious cycle by promoting free-radical formation. Decreased SAM also fosters development of characteristic AD neuropathologies – neurofibrillary tangles and amyloid plaques. The latter generate additional free radicals in a further feed-forward cascade. Future therapies should simultaneously halt neuroinflammation, restore redox homeostasis and replace depleted intracellular B vitamins. Developing early markers for these harmful processes will allow targeting of such therapy before irreversible cellular damage ensues.
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Affiliation(s)
- Andrew McCaddon
- Cardiff University, Cardiff School of Medicine, Gardden Road Surgery, Rhosllanerchrugog, Wrexham, North Wales, LL14 2EN, UK
| | - Peter R Hudson
- Maelor Hospital, Department of Medical Biochemistry, Croesnewydd Road, Wrexham, North Wales, LL13 7TD, UK
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