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Zhou J, Wearn A, Huck J, Hughes C, Baracchini G, Tremblay-Mercier J, Poirier J, Villeneuve S, Tardif CL, Chakravarty MM, Daugherty AM, Gauthier CJ, Turner GR, Spreng RN. Iron Deposition and Distribution Across the Hippocampus Is Associated with Pattern Separation and Pattern Completion in Older Adults at Risk for Alzheimer's Disease. J Neurosci 2024; 44:e1973232024. [PMID: 38388425 PMCID: PMC11079967 DOI: 10.1523/jneurosci.1973-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 12/16/2023] [Accepted: 01/03/2024] [Indexed: 02/24/2024] Open
Abstract
Elevated iron deposition in the brain has been observed in older adult humans and persons with Alzheimer's disease (AD), and has been associated with lower cognitive performance. We investigated the impact of iron deposition, and its topographical distribution across hippocampal subfields and segments (anterior, posterior) measured along its longitudinal axis, on episodic memory in a sample of cognitively unimpaired older adults at elevated familial risk for AD (N = 172, 120 females, 52 males; mean age = 68.8 ± 5.4 years). MRI-based quantitative susceptibility maps were acquired to derive estimates of hippocampal iron deposition. The Mnemonic Similarity Task was used to measure pattern separation and pattern completion, two hippocampally mediated episodic memory processes. Greater hippocampal iron load was associated with lower pattern separation and higher pattern completion scores, both indicators of poorer episodic memory. Examination of iron levels within hippocampal subfields across its long axis revealed topographic specificity. Among the subfields and segments investigated here, iron deposition in the posterior hippocampal CA1 was the most robustly and negatively associated with the fidelity memory representations. This association remained after controlling for hippocampal volume and was observed in the context of normal performance on standard neuropsychological memory measures. These findings reveal that the impact of iron load on episodic memory performance is not uniform across the hippocampus. Both iron deposition levels as well as its spatial distribution, must be taken into account when examining the relationship between hippocampal iron and episodic memory in older adults at elevated risk for AD.
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Affiliation(s)
- Jing Zhou
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Alfie Wearn
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Julia Huck
- Physics Department, Concordia University, Montreal, Quebec H4B 1R6, Canada
- Department of Radiology, Université de Sherbrooke, Sherbrooke, Quebec J1G 1E4, Canada
- Sherbrooke Connectivity Imaging Lab (SCIL), Computer Science Department, Faculty of Science, University of Sherbrooke, Quebec J1K 0A5, Canada
| | - Colleen Hughes
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Giulia Baracchini
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | | | - Judes Poirier
- StoP-AD Centre, Douglas Mental Health Institute Research Centre, Montreal, Quebec H4H 1R3, Canada
- Department of Psychiatry, McGill University, Montreal, Quebec H3A 1A1, Canada
| | - Sylvia Villeneuve
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
- StoP-AD Centre, Douglas Mental Health Institute Research Centre, Montreal, Quebec H4H 1R3, Canada
- Department of Psychiatry, McGill University, Montreal, Quebec H3A 1A1, Canada
| | - Christine Lucas Tardif
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
- Department of Biomedical Engineering, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - M Mallar Chakravarty
- Department of Psychiatry, McGill University, Montreal, Quebec H3A 1A1, Canada
- Department of Biomedical Engineering, McGill University, Montreal, Quebec H3A 2B4, Canada
- Cerebral Imaging Centre, Douglas Mental Health Institute Research Centre, Montreal, Quebec H4H 1R3, Canada
| | - Ana M Daugherty
- Department of Psychology and Institute of Gerontology, Wayne State University, Detroit, Michigan 48202
| | - Claudine J Gauthier
- Physics Department, Concordia University, Montreal, Quebec H4B 1R6, Canada
- Montreal Heart Institute, Montreal, Quebec H1T 1C8, Canada
| | - Gary R Turner
- Department of Psychology, York University, Toronto, ON M3J 1P3, Canada
| | - R Nathan Spreng
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
- StoP-AD Centre, Douglas Mental Health Institute Research Centre, Montreal, Quebec H4H 1R3, Canada
- Department of Psychiatry, McGill University, Montreal, Quebec H3A 1A1, Canada
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, Montréal, Quebec H3A 1A1, Canada
- Departments of Psychiatry and Psychology, McGill University, Montréal, Quebec H3A 1G1, Canada
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Ekanayake A, Peiris S, Ahmed B, Kanekar S, Grove C, Kalra D, Eslinger P, Yang Q, Karunanayaka P. A Review of the Role of Estrogens in Olfaction, Sleep and Glymphatic Functionality in Relation to Sex Disparity in Alzheimer's Disease. Am J Alzheimers Dis Other Demen 2024; 39:15333175241272025. [PMID: 39116421 PMCID: PMC11311174 DOI: 10.1177/15333175241272025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
Several risk factors contribute to the development of Alzheimer's disease (AD), including genetics, metabolic health, cardiovascular history, and diet. It has been observed that women appear to face a higher risk of developing AD. Among the various hypotheses surrounding the gender disparity in AD, one pertains to the potential neuroprotective properties of estrogen. Compared to men, women are believed to be more susceptible to neuropathology due to the significant decline in circulating estrogen levels following menopause. Studies have shown, however, that estrogen replacement therapies in post-menopausal women do not consistently reduce the risk of AD. While menopause and estrogen levels are potential factors in the elevated incidence rates of AD among women, this review highlights the possible roles estrogen has in other pathways that may also contribute to the sex disparity observed in AD such as olfaction, sleep, and glymphatic functionality.
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Affiliation(s)
- Anupa Ekanayake
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
- Grodno State Medical University, Grodno, Belarus
| | - Senal Peiris
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Biyar Ahmed
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Sangam Kanekar
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Cooper Grove
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Deepak Kalra
- Department of Neurology, Penn State University College of Medicine, Hershey, PA, USA
| | - Paul Eslinger
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
- Department of Neurology, Penn State University College of Medicine, Hershey, PA, USA
| | - Qing Yang
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
- Department of Neurosurgery, Penn State University College of Medicine, Hershey, PA, USA
| | - Prasanna Karunanayaka
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
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3
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Madden DJ, Merenstein JL. Quantitative susceptibility mapping of brain iron in healthy aging and cognition. Neuroimage 2023; 282:120401. [PMID: 37802405 PMCID: PMC10797559 DOI: 10.1016/j.neuroimage.2023.120401] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/14/2023] [Accepted: 09/30/2023] [Indexed: 10/10/2023] Open
Abstract
Quantitative susceptibility mapping (QSM) is a magnetic resonance imaging (MRI) technique that can assess the magnetic properties of cerebral iron in vivo. Although brain iron is necessary for basic neurobiological functions, excess iron content disrupts homeostasis, leads to oxidative stress, and ultimately contributes to neurodegenerative disease. However, some degree of elevated brain iron is present even among healthy older adults. To better understand the topographical pattern of iron accumulation and its relation to cognitive aging, we conducted an integrative review of 47 QSM studies of healthy aging, with a focus on five distinct themes. The first two themes focused on age-related increases in iron accumulation in deep gray matter nuclei versus the cortex. The overall level of iron is higher in deep gray matter nuclei than in cortical regions. Deep gray matter nuclei vary with regard to age-related effects, which are most prominent in the putamen, and age-related deposition of iron is also observed in frontal, temporal, and parietal cortical regions during healthy aging. The third theme focused on the behavioral relevance of iron content and indicated that higher iron in both deep gray matter and cortical regions was related to decline in fluid (speed-dependent) cognition. A handful of multimodal studies, reviewed in the fourth theme, suggest that iron interacts with imaging measures of brain function, white matter degradation, and the accumulation of neuropathologies. The final theme concerning modifiers of brain iron pointed to potential roles of cardiovascular, dietary, and genetic factors. Although QSM is a relatively recent tool for assessing cerebral iron accumulation, it has significant promise for contributing new insights into healthy neurocognitive aging.
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Affiliation(s)
- David J Madden
- Brain Imaging and Analysis Center, Duke University Medical Center, Box 3918, Durham, NC 27710, USA; Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA; Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, USA.
| | - Jenna L Merenstein
- Brain Imaging and Analysis Center, Duke University Medical Center, Box 3918, Durham, NC 27710, USA
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Lee SY, Paolillo EW, Saloner R, Cobigo Y, Diaz VE, Gontrum EQ, VandeBunte A, Chatterjee A, Tucker M, Kramer JH, Casaletto KB. Moderating role of physical activity on hippocampal iron deposition and memory outcomes in typically aging older adults. Neurobiol Aging 2023; 131:124-131. [PMID: 37633118 DOI: 10.1016/j.neurobiolaging.2023.07.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 06/23/2023] [Accepted: 07/26/2023] [Indexed: 08/28/2023]
Abstract
Physical activity (PA) is linked to better cognitive and brain health, though its mechanisms are unknown. While brain iron is essential for normal function, levels increase with age and, when excessive, can cause detrimental neural effects. We examined how objectively measured PA relates to cerebral iron deposition and memory functioning in normal older adults. Sixty-eight cognitively unimpaired older adults from the UCSF Memory and Aging Center completed neuropsychological testing and brain magnetic resonance imaging, followed by 30-day Fitbit monitoring. Magnetic resonance imaging quantitative susceptibility mapping (QSM) quantified iron deposition. PA was operationalized as average daily steps. Linear regression models examined memory as a function of hippocampal QSM, PA, and their interaction. Higher bilateral hippocampal iron deposition correlated with worse memory but was not strongly related to PA. Covarying for demographics, PA moderated the relationship between bilateral hippocampal iron deposition and memory such that the negative effect of hippocampal QSM on memory performances was no longer significant above 9120 daily steps. PA may mitigate adverse iron-related pathways for memory health.
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Affiliation(s)
- Shannon Y Lee
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Emily W Paolillo
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Rowan Saloner
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Yann Cobigo
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Valentina E Diaz
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Eva Q Gontrum
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Anna VandeBunte
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Ankita Chatterjee
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Miwa Tucker
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Joel H Kramer
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Kaitlin B Casaletto
- Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA.
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5
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Zhang C, Chen H, Rodriguez Y, Ma X, Swerdlow RH, Zhang J, Ding WX. A perspective on autophagy and transcription factor EB in Alcohol-Associated Alzheimer's disease. Biochem Pharmacol 2023; 213:115576. [PMID: 37127251 PMCID: PMC11009931 DOI: 10.1016/j.bcp.2023.115576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 05/03/2023]
Abstract
Alzheimer's disease (AD) is the most common form of progressive dementia and there is no truly efficacious treatment. Accumulating evidence indicates that impaired autophagic function for removal of damaged mitochondria and protein aggregates such as amyloid and tau protein aggregates may contribute to the pathogenesis of AD. Epidemiologic studies have implicated alcohol abuse in promoting AD, yet the underlying mechanisms are poorly understood. In this review, we discuss mechanisms of selective autophagy for mitochondria and protein aggregates and how these mechanisms are impaired by aging and alcohol consumption. We also discuss potential genetic and pharmacological approaches for targeting autophagy/mitophagy, as well as lysosomal and mitochondrial biogenesis, for the potential prevention and treatment of AD.
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Affiliation(s)
- Chen Zhang
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Hao Chen
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Yssa Rodriguez
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Xiaowen Ma
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Russell H Swerdlow
- Department of Neurology, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Jianhua Zhang
- Department of Pathology, Division of Molecular Cellular Pathology, University of Alabama at Birmingham, 901 19th street South, Birmingham, AL 35294, USA
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA; Department of Internal Medicine, Division of Gastroenterology, Hepatology & Motility, The University of Kansas Medical Center, Kansas City, KS 66160, USA.
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6
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Guardia T, Mazloum-Farzaghi N, Olsen RK, Tsvetanov KA, Campbell KL. Associative memory is more strongly predicted by age-related differences in the prefrontal cortex than medial temporal lobes. NEUROIMAGE: REPORTS 2023. [DOI: 10.1016/j.ynirp.2023.100168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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7
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Tian Y, Xie Y, Guo Z, Feng P, You Y, Yu Q. 17β-oestradiol inhibits ferroptosis in the hippocampus by upregulating DHODH and further improves memory decline after ovariectomy. Redox Biol 2023; 62:102708. [PMID: 37116254 PMCID: PMC10163677 DOI: 10.1016/j.redox.2023.102708] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/20/2023] [Accepted: 04/20/2023] [Indexed: 04/30/2023] Open
Abstract
Ovariectomy (OVX) conducted before the onset of natural menopause is considered to bringing forward and accelerate the process of ageing-associated neurodegeneration. However, the mechanisms underlying memory decline and other cognitive dysfunctions following OVX are unclear. Given that iron accumulates during ageing and after OVX, we hypothesized that excess iron accumulation in the hippocampus would cause ferroptosis-induced increased neuronal degeneration and death associated with memory decline. In the current study, female rats that underwent OVX showed decreased dihydroorotate dehydrogenase (DHODH) expression and reduced performance in the Morris water maze (MWM). We used primary cultured hippocampal cells to explore the ferroptosis resistance-inducing effect of 17β-oestradiol (E2). The data supported a vital role of DHODH in neuronal ferroptosis. Specifically, E2 alleviated ferroptosis induced by erastin and ferric ammonium citrate (FAC), which can be blocked by brequinar (BQR). Further in vitro studies showed that E2 reduced lipid peroxidation levels and improved the behavioural performance of OVX rats. Our research interprets OVX-related neurodegeneration with respect to ferroptosis, and both our in vivo and in vitro data show that E2 supplementation exerts beneficial antiferroptotic effects by upregulating DHODH. Our data demonstrate the utility of E2 supplementation after OVX and provide a potential target, DHODH, for which hormone therapy has not been available.
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Affiliation(s)
- Ying Tian
- Department of Obstetrics and Gynecology, National Clinical Research Center for Obstetric & Gynecologic Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Peking Union Medical College Hospital (Dongdan Campus), No.1 Shuaifuyuan Wangfujing Dongcheng District, Beijing, 100730, China.
| | - Yuan Xie
- Department of Obstetrics and Gynecology, National Clinical Research Center for Obstetric & Gynecologic Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Peking Union Medical College Hospital (Dongdan Campus), No.1 Shuaifuyuan Wangfujing Dongcheng District, Beijing, 100730, China.
| | - Zaixin Guo
- Department of Obstetrics and Gynecology, National Clinical Research Center for Obstetric & Gynecologic Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Peking Union Medical College Hospital (Dongdan Campus), No.1 Shuaifuyuan Wangfujing Dongcheng District, Beijing, 100730, China.
| | - Penghui Feng
- Department of Obstetrics and Gynecology, National Clinical Research Center for Obstetric & Gynecologic Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Peking Union Medical College Hospital (Dongdan Campus), No.1 Shuaifuyuan Wangfujing Dongcheng District, Beijing, 100730, China.
| | - Yang You
- Department of Obstetrics and Gynecology, National Clinical Research Center for Obstetric & Gynecologic Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Peking Union Medical College Hospital (Dongdan Campus), No.1 Shuaifuyuan Wangfujing Dongcheng District, Beijing, 100730, China.
| | - Qi Yu
- Department of Obstetrics and Gynecology, National Clinical Research Center for Obstetric & Gynecologic Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Peking Union Medical College Hospital (Dongdan Campus), No.1 Shuaifuyuan Wangfujing Dongcheng District, Beijing, 100730, China.
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8
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Iron Deposition in Brain: Does Aging Matter? Int J Mol Sci 2022; 23:ijms231710018. [PMID: 36077413 PMCID: PMC9456423 DOI: 10.3390/ijms231710018] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/30/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
The alteration of iron homeostasis related to the aging process is responsible for increased iron levels, potentially leading to oxidative cellular damage. Iron is modulated in the Central Nervous System in a very sensitive manner and an abnormal accumulation of iron in the brain has been proposed as a biomarker of neurodegeneration. However, contrasting results have been presented regarding brain iron accumulation and the potential link with other factors during aging and neurodegeneration. Such uncertainties partly depend on the fact that different techniques can be used to estimate the distribution of iron in the brain, e.g., indirect (e.g., MRI) or direct (post-mortem estimation) approaches. Furthermore, recent evidence suggests that the propensity of brain cells to accumulate excessive iron as a function of aging largely depends on their anatomical location. This review aims to collect the available data on the association between iron concentration in the brain and aging, shedding light on potential mechanisms that may be helpful in the detection of physiological neurodegeneration processes and neurodegenerative diseases such as Alzheimer's disease.
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9
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Tu J, Yan J, Liu J, Liu D, Wang X, Gao F. Iron deposition in the precuneus is correlated with mild cognitive impairment in patients with cerebral microbleeds: A quantitative susceptibility mapping study. Front Neurosci 2022; 16:944709. [PMID: 36003962 PMCID: PMC9395124 DOI: 10.3389/fnins.2022.944709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 07/08/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to define whether mild cognitive impairment (MCI) is associated with iron deposition in rich-club nodes distant from cerebral microbleeds (CMBs) in patients with cerebral small vessel disease (CSVD). Methods A total of 64 participants underwent magnetic resonance imaging (MRI) scanning and were separated into three groups, namely, CMB(+), CMB(–), and healthy controls (HCs). We compared their characteristics and susceptibility values of rich-club nodes [e.g., superior frontal gyrus (SFG), precuneus, superior occipital gyrus (SOG), thalamus, and putamen]. We then divided the CMB(+) and CMB(–) groups into subgroups of patients with or without MCI. Then, we analyzed the relationship between iron deposition and MCI by comparing the susceptibility values of rich-club nodes. We assessed cognitive functions using the Montreal Cognitive Assessment (MoCA) and quantified iron content using quantitative susceptibility mapping (QSM). Results In the putamen, the CMB(+) and CMB(–) groups had significantly different susceptibility values. Compared with the HCs, the CMB(+) and CMB(–) groups had significantly different susceptibility values for the SFG and SOG. In addition, we found significant differences in the putamen susceptibility values of the CMB(+)MCI(+) group and the two CMB(–) groups. The CMB(+)MCI(+) and CMB(+)MCI(–) groups had significantly different precuneus susceptibility values. The binary logistic regression analysis revealed that only higher susceptibility values of precuneus were associated with a cognitive decline in patients with CMBs, and it indicated statistical significance. Conclusion Iron deposition in the precuneus is an independent risk factor for MCI in patients with CMBs. CMBs might influence iron content in remote rich-club nodes and be relevant to MCI.
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Affiliation(s)
- Jing Tu
- Department of Neurology, The First Affiliated Hospital of Xi'an Medical University, Xi'an, China
- Xi'an Medical University, Xi'an, China
| | - Jin Yan
- Department of Radiology, The First Affiliated Hospital of Xi'an Medical University, Xi'an, China
| | - Juan Liu
- Department of Neurology, The First Affiliated Hospital of Xi'an Medical University, Xi'an, China
| | - Dandan Liu
- Department of Neurology, The First Affiliated Hospital of Xi'an Medical University, Xi'an, China
| | - Xiaomeng Wang
- Department of Neurology, The First Affiliated Hospital of Xi'an Medical University, Xi'an, China
| | - Fei Gao
- Department of Neurology, The First Affiliated Hospital of Xi'an Medical University, Xi'an, China
- *Correspondence: Fei Gao
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10
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Sonnenschein SF, Parr AC, Larsen B, Calabro FJ, Foran W, Eack SM, Luna B, Sarpal DK. Subcortical brain iron deposition in individuals with schizophrenia. J Psychiatr Res 2022; 151:272-278. [PMID: 35523067 DOI: 10.1016/j.jpsychires.2022.04.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 04/01/2022] [Accepted: 04/18/2022] [Indexed: 11/28/2022]
Abstract
Subcortical structures play a critical role the pathophysiology and treatment of schizophrenia (SZ), yet underlying neurophysiological processes, in vivo, remain largely unexplored. Brain tissue iron, which can be measured with magnetic resonance-based methods, is a crucial component of a variety of neuronal functions including neurotransmitter synthesis. Here we used a proxy measure of tissue iron to examine basal ganglia and thalamic structures in an adult cohort of individuals with chronic SZ. A publicly available dataset of 72 individuals with SZ between ages 18 and 65, and a matched sample of 74 healthy control (HC) participants were included. A novel method that calculated the inverse-normalized T2*-weighted contrast (1/nT2*) was used to estimate brain iron within the basal ganglia and thalamus. Between group, age- and sex-related differences in 1/nT2* were examined, in addition to correlations with measures of psychopathology and cognition. Individuals with SZ showed greater 1/nT2* (iron index) compared to HCs in the thalamus (p < 0.01, FWE corrected). Age-related 1/nT2* accumulation was noted in regions of the basal ganglia, coinciding with prior work, and prominent sex-differences were noted in the caudate and thalamus (p < 0.01, FWE corrected). No significant relationship was observed between 1/nT2* and measures of neurocognition or psychopathology. Overall, our findings characterize a non-invasive proxy measure of tissue iron in SZ and highlight thalamic iron accumulation as a potential marker of illness.
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Affiliation(s)
| | | | - Bart Larsen
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA
| | | | | | - Shaun M Eack
- Department of Psychiatry, USA; School of Social Work, USA
| | - Beatriz Luna
- Department of Psychiatry, USA; Department of Psychology, USA; Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
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11
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Luo A, Xie Z, Wang Y, Wang X, Li S, Yan J, Zhan G, Zhou Z, Zhao Y, Li S. Type 2 diabetes mellitus-associated cognitive dysfunction: Advances in potential mechanisms and therapies. Neurosci Biobehav Rev 2022; 137:104642. [PMID: 35367221 DOI: 10.1016/j.neubiorev.2022.104642] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 03/24/2022] [Accepted: 03/27/2022] [Indexed: 12/22/2022]
Abstract
Type 2 diabetes (T2D) and its target organ injuries cause distressing impacts on personal health and put an enormous burden on the healthcare system, and increasing attention has been paid to T2D-associated cognitive dysfunction (TDACD). TDACD is characterized by cognitive dysfunction, delayed executive ability, and impeded information-processing speed. Brain imaging data suggest that extensive brain regions are affected in patients with T2D. Based on current findings, a wide spectrum of non-specific neurodegenerative mechanisms that partially overlap with the mechanisms of neurodegenerative diseases is hypothesized to be associated with TDACD. However, it remains unclear whether TDACD is a consequence of T2D or a complication that co-occurs with T2D. Theoretically, anti-diabetes methods are promising neuromodulatory approaches to reduce brain injury in patients with T2D. In this review, we summarize potential mechanisms underlying TDACD and promising neurotropic effects of anti-diabetes methods and some neuroprotective natural compounds. Constructing screening or diagnostic tools and developing targeted treatment and preventive strategies would be expected to reduce the burden of TDACD.
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Affiliation(s)
- Ailin Luo
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology.
| | - Zheng Xie
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology.
| | - Yue Wang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology.
| | - Xuan Wang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology.
| | - Shan Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology.
| | - Jing Yan
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology.
| | - Gaofeng Zhan
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology.
| | - Zhiqiang Zhou
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology.
| | - Yilin Zhao
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology.
| | - Shiyong Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology.
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12
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Gustavsson J, Papenberg G, Falahati F, Laukka EJ, Kalpouzos G. Contributions of the Catechol-O-Methyltransferase Val158Met Polymorphism to Changes in Brain Iron Across Adulthood and Their Relationships to Working Memory. Front Hum Neurosci 2022; 16:838228. [PMID: 35571998 PMCID: PMC9091601 DOI: 10.3389/fnhum.2022.838228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 03/16/2022] [Indexed: 11/13/2022] Open
Abstract
Ageing is associated with excessive free brain iron, which may induce oxidative stress and neuroinflammation, likely causing cognitive deficits. Lack of dopamine may be a factor behind the increase of iron with advancing age, as it has an important role in cellular iron homoeostasis. We investigated the effect of COMT Val 158 Met (rs4680), a polymorphism crucial for dopamine degradation and proxy for endogenous dopamine, on iron accumulation and working memory in a longitudinal lifespan sample (n = 208, age 20–79 at baseline, mean follow-up time = 2.75 years) using structural equation modelling. Approximation of iron content was assessed using quantitative susceptibility mapping in striatum and dorsolateral prefrontal cortex (DLPFC). Iron accumulated in both striatum and DLPFC during the follow-up period. Greater iron accumulation in DLPFC was associated with more deleterious change in working memory. Older (age 50–79) Val homozygotes (with presumably lower endogenous dopamine) accumulated more iron than older Met carriers in both striatum and DLPFC, no such differences were observed among younger adults (age 20–49). In conclusion, individual differences in genetic predisposition related to low dopamine levels increase iron accumulation, which in turn may trigger deleterious change in working memory. Future studies are needed to better understand how dopamine may modulate iron accumulation across the human lifespan.
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Affiliation(s)
- Jonatan Gustavsson
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
- *Correspondence: Jonatan Gustavsson,
| | - Goran Papenberg
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Farshad Falahati
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Erika J. Laukka
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
- Stockholm Gerontology Research Center, Stockholm, Sweden
| | - Grégoria Kalpouzos
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
- Grégoria Kalpouzos,
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13
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Howard CM, Jain S, Cook AD, Packard LE, Mullin HA, Chen N, Liu C, Song AW, Madden DJ. Cortical iron mediates age-related decline in fluid cognition. Hum Brain Mapp 2022; 43:1047-1060. [PMID: 34854172 PMCID: PMC8764476 DOI: 10.1002/hbm.25706] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 01/19/2023] Open
Abstract
Brain iron dyshomeostasis disrupts various critical cellular functions, and age-related iron accumulation may contribute to deficient neurotransmission and cell death. While recent studies have linked excessive brain iron to cognitive function in the context of neurodegenerative disease, little is known regarding the role of brain iron accumulation in cognitive aging in healthy adults. Further, previous studies have focused primarily on deep gray matter regions, where the level of iron deposition is highest. However, recent evidence suggests that cortical iron may also contribute to cognitive deficit and neurodegenerative disease. Here, we used quantitative susceptibility mapping (QSM) to measure brain iron in 67 healthy participants 18-78 years of age. Speed-dependent (fluid) cognition was assessed from a battery of 12 psychometric and computer-based tests. From voxelwise QSM analyses, we found that QSM susceptibility values were negatively associated with fluid cognition in the right inferior temporal gyrus, bilateral putamen, posterior cingulate gyrus, motor, and premotor cortices. Mediation analysis indicated that susceptibility in the right inferior temporal gyrus was a significant mediator of the relation between age and fluid cognition, and similar effects were evident for the left inferior temporal gyrus at a lower statistical threshold. Additionally, age and right inferior temporal gyrus susceptibility interacted to predict fluid cognition, such that brain iron was negatively associated with a cognitive decline for adults over 45 years of age. These findings suggest that iron may have a mediating role in cognitive decline and may be an early biomarker of neurodegenerative disease.
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Affiliation(s)
- Cortney M. Howard
- Center for Cognitive NeuroscienceDuke UniversityDurhamNorth CarolinaUSA
- Brain Imaging and Analysis CenterDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Shivangi Jain
- Brain Imaging and Analysis CenterDuke University Medical CenterDurhamNorth CarolinaUSA
- Present address:
Department of Psychological and Brain SciencesUniversity of IowaIowa CityIowaUSA
| | - Angela D. Cook
- Brain Imaging and Analysis CenterDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Lauren E. Packard
- Brain Imaging and Analysis CenterDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Hollie A. Mullin
- Brain Imaging and Analysis CenterDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Nan‐kuei Chen
- Brain Imaging and Analysis CenterDuke University Medical CenterDurhamNorth CarolinaUSA
- Present address:
Department of Biomedical EngineeringUniversity of ArizonaTucsonArizonaUSA
| | - Chunlei Liu
- Brain Imaging and Analysis CenterDuke University Medical CenterDurhamNorth CarolinaUSA
- Present address:
Department of Electrical Engineering and Computer SciencesUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Allen W. Song
- Brain Imaging and Analysis CenterDuke University Medical CenterDurhamNorth CarolinaUSA
| | - David J. Madden
- Center for Cognitive NeuroscienceDuke UniversityDurhamNorth CarolinaUSA
- Brain Imaging and Analysis CenterDuke University Medical CenterDurhamNorth CarolinaUSA
- Department of Psychiatry and Behavioral SciencesDuke University Medical CenterDurhamNorth CarolinaUSA
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14
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Venkatesh A, Daugherty AM, Bennett IJ. Neuroimaging measures of iron and gliosis explain memory performance in aging. Hum Brain Mapp 2021; 42:5761-5770. [PMID: 34520095 PMCID: PMC8559505 DOI: 10.1002/hbm.25652] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/18/2021] [Accepted: 08/21/2021] [Indexed: 11/13/2022] Open
Abstract
Evidence from animal and histological studies has indicated that accumulation of iron in the brain results in reactive gliosis that contributes to cognitive deficits. The current study extends these findings to human cognitive aging and suggests that magnetic resonance imaging (MRI) techniques like quantitative relaxometry can be used to study iron and its effects in vivo. The effects of iron on microstructure and memory performance were examined using a combination of quantitative relaxometry and multicompartment diffusion imaging in 35 young (21.06 ± 2.18 years) and 28 older (72.58 ± 6.47 years) adults, who also completed a memory task. Replicating past work, results revealed age‐related increases in iron content (R2*) and diffusion, and decreases in memory performance. Independent of age group, iron content was significantly related to restricted (intracellular) diffusion in regions with low‐moderate iron (hippocampus, caudate) and to all diffusion metrics in regions with moderate‐high iron (putamen, globus pallidus). This pattern is consistent with different stages of iron‐related gliosis, ranging from astrogliosis that may influence intracellular diffusion to microglial proliferation and increased vascular permeability that may influence all sources of diffusion. Further, hippocampal restricted diffusion was significantly related to memory performance, with a third of this effect related to iron content; consistent with the hypothesis that higher iron‐related astrogliosis in the hippocampus is associated with poorer memory performance. These results demonstrate the sensitivity of MRI to iron‐related gliosis and extend our understanding of its impact on cognition by showing that this relationship also explains individual differences in memory performance.
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Affiliation(s)
- Anu Venkatesh
- Department of Neuroscience, University of California Riverside, Riverside, California, USA
| | - Ana M Daugherty
- Department of Psychology, Wayne State University, Detroit, Michigan, USA
| | - Ilana J Bennett
- Department of Neuroscience, University of California Riverside, Riverside, California, USA.,Department of Psychology, University of California Riverside, Riverside, California, USA
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15
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Wearn AR, Nurdal V, Saunders-Jennings E, Knight MJ, Madan CR, Fallon SJ, Isotalus HK, Kauppinen RA, Coulthard EJ. T2 heterogeneity as an in vivo marker of microstructural integrity in medial temporal lobe subfields in ageing and mild cognitive impairment. Neuroimage 2021; 238:118214. [PMID: 34116150 PMCID: PMC8350145 DOI: 10.1016/j.neuroimage.2021.118214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/19/2021] [Accepted: 05/25/2021] [Indexed: 11/19/2022] Open
Abstract
A better understanding of early brain changes that precede loss of independence in diseases like Alzheimer's disease (AD) is critical for development of disease-modifying therapies. Quantitative MRI, such as T2 relaxometry, can identify microstructural changes relevant to early stages of pathology. Recent evidence suggests heterogeneity of T2 may be a more informative MRI measure of early pathology than absolute T2. Here we test whether T2 markers of brain integrity precede the volume changes we know are present in established AD and whether such changes are most marked in medial temporal lobe (MTL) subfields known to be most affected early in AD. We show that T2 heterogeneity was greater in people with mild cognitive impairment (MCI; n = 49) compared to healthy older controls (n = 99) in all MTL subfields, but this increase was greatest in MTL cortices, and smallest in dentate gyrus. This reflects the spatio-temporal progression of neurodegeneration in AD. T2 heterogeneity in CA1-3 and entorhinal cortex and volume of entorhinal cortex showed some ability to predict cognitive decline, where absolute T2 could not, however further studies are required to verify this result. Increases in T2 heterogeneity in MTL cortices may reflect localised pathological change and may present as one of the earliest detectible brain changes prior to atrophy. Finally, we describe a mechanism by which memory, as measured by accuracy and reaction time on a paired associate learning task, deteriorates with age. Age-related memory deficits were explained in part by lower subfield volumes, which in turn were directly associated with greater T2 heterogeneity. We propose that tissue with high T2 heterogeneity represents extant tissue at risk of permanent damage but with the potential for therapeutic rescue. This has implications for early detection of neurodegenerative diseases and the study of brain-behaviour relationships.
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Affiliation(s)
- Alfie R Wearn
- Bristol Medical School, University of Bristol, Institute of Clinical Neurosciences, Learning & Research Building at Southmead Hospital, Bristol BS10 5NB, UK.
| | - Volkan Nurdal
- Bristol Medical School, University of Bristol, Institute of Clinical Neurosciences, Learning & Research Building at Southmead Hospital, Bristol BS10 5NB, UK
| | - Esther Saunders-Jennings
- Bristol Medical School, University of Bristol, Institute of Clinical Neurosciences, Learning & Research Building at Southmead Hospital, Bristol BS10 5NB, UK
| | - Michael J Knight
- School of Psychological Science, University of Bristol, Bristol, UK
| | | | - Sean-James Fallon
- National Institute for Health Research Bristol Biomedical Research Centre, University Hospitals Bristol, NHS Foundation Trust and University of Bristol, Bristol, UK
| | - Hanna K Isotalus
- Bristol Medical School, University of Bristol, Institute of Clinical Neurosciences, Learning & Research Building at Southmead Hospital, Bristol BS10 5NB, UK
| | | | - Elizabeth J Coulthard
- Bristol Medical School, University of Bristol, Institute of Clinical Neurosciences, Learning & Research Building at Southmead Hospital, Bristol BS10 5NB, UK; Clinical Neurosciences, North Bristol NHS Trust, Bristol, UK
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16
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Zachariou V, Bauer CE, Seago ER, Panayiotou G, Hall ED, Butterfield DA, Gold BT. Healthy dietary intake moderates the effects of age on brain iron concentration and working memory performance. Neurobiol Aging 2021; 106:183-196. [PMID: 34284261 DOI: 10.1016/j.neurobiolaging.2021.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 05/31/2021] [Accepted: 06/16/2021] [Indexed: 11/18/2022]
Abstract
Age-related brain iron accumulation is linked with oxidative stress, neurodegeneration and cognitive decline. Certain nutrients can reduce brain iron concentration in animal models, however, this association is not well established in humans. Moreover, it remains unknown if nutrition can moderate the effects of age on brain iron concentration and/or cognition. Here, we explored these issues in a sample of 73 healthy older adults (61-86 years old), while controlling for several factors such as age, gender, years of education, physical fitness and alcohol-intake. Quantitative susceptibility mapping was used for assessment of brain iron concentration and participants performed an N-Back paradigm to evaluate working memory performance. Nutritional-intake was assessed via a validated questionnaire. Nutrients were grouped into nutrition factors based on previous literature and factor analysis. One factor, comprised of vitamin E, lysine, DHA omega-3 and LA omega-6 PUFA, representing food groups such as nuts, healthy oils and fish, moderated the effects of age on both brain iron concentration and working memory performance, suggesting that these nutrients may slow the rate of brain iron accumulation and working memory declines in aging.
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Affiliation(s)
- Valentinos Zachariou
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, USA.
| | - Christopher E Bauer
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Elayna R Seago
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Georgia Panayiotou
- Department of Psychology and Center for Applied Neuroscience, University of Cyprus, Nicosia, Cyprus
| | - Edward D Hall
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - D Allan Butterfield
- Department of Chemistry, College of Medicine, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Brian T Gold
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, College of Medicine, University of Kentucky, Lexington, KY, USA; Magnetic Resonance Imaging and Spectroscopy Center, College of Medicine, University of Kentucky, Lexington, KY, USA.
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17
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Salami A, Papenberg G, Sitnikov R, Laukka EJ, Persson J, Kalpouzos G. Elevated neuroinflammation contributes to the deleterious impact of iron overload on brain function in aging. Neuroimage 2021; 230:117792. [PMID: 33497770 DOI: 10.1016/j.neuroimage.2021.117792] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/04/2020] [Accepted: 01/16/2021] [Indexed: 01/24/2023] Open
Abstract
Intracellular iron is essential for many neurobiological mechanisms. However, at high concentrations, iron may induce oxidative stress and inflammation. Brain iron overload has been shown in various neurodegenerative disorders and in normal aging. Elevated brain iron in old age may trigger brain dysfunction and concomitant cognitive decline. However, the exact mechanism underlying the deleterious impact of iron on brain function in aging is unknown. Here, we investigated the role of iron on brain function across the adult lifespan from 187 healthy participants (20-79 years old, 99 women) who underwent fMRI scanning while performing a working-memory n-back task. Iron content was quantified using R2* relaxometry, whereas neuroinflammation was estimated using myo-inositol measured by magnetic resonance spectroscopy. Striatal iron increased non-linearly with age, with linear increases at both ends of adulthood. Whereas higher frontostriatal activity was related to better memory performance independent of age, the link between brain activity and iron differed across age groups. Higher striatal iron was linked to greater frontostriatal activity in younger, but reduced activity in older adults. Further mediation analysis revealed that, after age 40, iron provided unique and shared contributions with neuroinflammation to brain activations, such that neuroinflammation partly mediated brain-iron associations. These findings promote a novel mechanistic understanding of how iron may exert deleterious effects on brain function and cognition with advancing age.
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Affiliation(s)
- Alireza Salami
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden; Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, Umeå, Sweden; Wallenberg Center for Molecular Medicine, Umeå University, Umeå, Sweden.
| | - Goran Papenberg
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Rouslan Sitnikov
- MRI Research Center, Karolinska University Hospital, Stockholm, Sweden
| | - Erika J Laukka
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Jonas Persson
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden; School of Law, Psychology and Social Work, Örebro University, Örebro, Sweden
| | - Grégoria Kalpouzos
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
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18
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Foster CM, Kennedy KM, Daugherty AM, Rodrigue KM. Contribution of iron and Aβ to age differences in entorhinal and hippocampal subfield volume. Neurology 2020; 95:e2586-e2594. [PMID: 32938781 PMCID: PMC7682827 DOI: 10.1212/wnl.0000000000010868] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 06/26/2020] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE To test the hypothesis that the combination of elevated global β-AMYLOID (Aβ) burden and greater striatal iron content would be associated with smaller entorhinal cortex (ERC) volume, but not hippocampal subfield volumes, we measured volume and iron content using high-resolution MRI and Aβ using PET imaging in a cross-sectional sample of 70 cognitively normal older adults. METHODS Participants were scanned with florbetapir 18F PET to obtain Aβ standardized uptake value ratios. Susceptibility-weighted MRI was collected and processed to yield R2* images, and striatal regions of interest (ROIs) were manually placed to obtain a measure of striatal iron burden. Ultra-high resolution T2/PD-weighted MRIs were segmented to measure medial temporal lobe (MTL) volumes. Analyses were conducted using mixed-effects models with MTL ROI as a within-participant factor; age, iron content, and Aβ as between-participant factors; and MTL volumes (ERC and 3 hippocampal subfield regions) as the dependent variable. RESULTS The model indicated a significant 4-way interaction among age, iron, Aβ, and MTL region. Post hoc analyses indicated that the 3-way interaction among age, Aβ, and iron content was selective to the ERC (β = -3.34, standard error = 1.33, 95% confidence interval -5.95 to -0.72), whereas a significant negative association between age and ERC volume was present only in individuals with both elevated iron content and Aβ. CONCLUSIONS These findings highlight the importance of studying Aβ in the context of other, potentially synergistic age-related brain factors such as iron accumulation and the potential role for iron as an important contributor to the earliest, preclinical stages of pathologic aging.
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Affiliation(s)
- Chris M Foster
- From the School of Behavioral and Brain Sciences (C.M.F., K.M.K., K.M.R.), Center for Vital Longevity, University of Texas at Dallas; and Department of Psychology (A.M.D.) and Department of Psychiatry and Behavioral Neurosciences, Institute of Gerontology, Wayne State University, Detroit, MI
| | - Kristen M Kennedy
- From the School of Behavioral and Brain Sciences (C.M.F., K.M.K., K.M.R.), Center for Vital Longevity, University of Texas at Dallas; and Department of Psychology (A.M.D.) and Department of Psychiatry and Behavioral Neurosciences, Institute of Gerontology, Wayne State University, Detroit, MI
| | - Ana M Daugherty
- From the School of Behavioral and Brain Sciences (C.M.F., K.M.K., K.M.R.), Center for Vital Longevity, University of Texas at Dallas; and Department of Psychology (A.M.D.) and Department of Psychiatry and Behavioral Neurosciences, Institute of Gerontology, Wayne State University, Detroit, MI
| | - Karen M Rodrigue
- From the School of Behavioral and Brain Sciences (C.M.F., K.M.K., K.M.R.), Center for Vital Longevity, University of Texas at Dallas; and Department of Psychology (A.M.D.) and Department of Psychiatry and Behavioral Neurosciences, Institute of Gerontology, Wayne State University, Detroit, MI.
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19
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Spence H, McNeil CJ, Waiter GD. The impact of brain iron accumulation on cognition: A systematic review. PLoS One 2020; 15:e0240697. [PMID: 33057378 PMCID: PMC7561208 DOI: 10.1371/journal.pone.0240697] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/01/2020] [Indexed: 12/31/2022] Open
Abstract
Iron is involved in many processes in the brain including, myelin generation, mitochondrial function, synthesis of ATP and DNA and the cycling of neurotransmitters. Disruption of normal iron homeostasis can result in iron accumulation in the brain, which in turn can partake in interactions which amplify oxidative damage. The development of MRI techniques for quantifying brain iron has allowed for the characterisation of the impact that brain iron has on cognition and neurodegeneration. This review uses a systematic approach to collate and evaluate the current literature which explores the relationship between brain iron and cognition. The following databases were searched in keeping with a predetermined inclusion criterion: Embase Ovid, PubMed and PsychInfo (from inception to 31st March 2020). The included studies were assessed for study characteristics and quality and their results were extracted and summarised. This review identified 41 human studies of varying design, which statistically assessed the relationship between brain iron and cognition. The most consistently reported interactions were in the Caudate nuclei, where increasing iron correlated poorer memory and general cognitive performance in adulthood. There were also consistent reports of a correlation between increased Hippocampal and Thalamic iron and poorer memory performance, as well as, between iron in the Putamen and Globus Pallidus and general cognition. We conclude that there is consistent evidence that brain iron is detrimental to cognitive health, however, more longitudinal studies will be required to fully understand this relationship and to determine whether iron occurs as a primary cause or secondary effect of cognitive decline.
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Affiliation(s)
- Holly Spence
- Aberdeen Biomedical Imaging Centre, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Chris J. McNeil
- Aberdeen Biomedical Imaging Centre, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Gordon D. Waiter
- Aberdeen Biomedical Imaging Centre, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
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20
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Franco CY, Petok JR, Langley J, Hu X, Bennett IJ. Implicit associative learning relates to basal ganglia gray matter microstructure in young and older adults. Behav Brain Res 2020; 397:112950. [PMID: 33017642 DOI: 10.1016/j.bbr.2020.112950] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/11/2020] [Accepted: 09/26/2020] [Indexed: 01/01/2023]
Abstract
Older adults are impaired at implicit associative learning (IAL), or the learning of relationships between stimuli in the environment without conscious awareness. These age effects have been attributed to differential engagement of the basal ganglia (e.g. caudate, globus pallidus) and hippocampus throughout learning. However, no studies have examined gray matter diffusion relations with IAL, which can reveal microstructural properties that vary with age and contribute to learning. In this study, young (18-29 years) and older (65-87 years) adults completed the Triplet Learning Task, in which participants implicitly learn that the location of cues predict the target location on some trials (high frequency triplets). Diffusion imaging was also acquired and multicompartment diffusion metrics were calculated using neurite orientation dispersion and density imaging (NODDI). As expected, results revealed age deficits in IAL (smaller differences in performance to high versus low frequency triplets in the late learning stage) and age-related differences in basal ganglia and hippocampus free, hindered, and restricted diffusion. Significant correlations were seen between restricted caudate diffusion and early IAL and between hindered globus pallidus diffusion and late IAL, which were not moderated by age group. These findings indicate that individual differences in basal ganglia, but not hippocampal, gray matter microstructure contribute to learning, independent of age, further supporting basal ganglia involvement in IAL.
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Affiliation(s)
- Corinna Y Franco
- Department of Psychology, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USA.
| | - Jessica R Petok
- Department of Psychology, St. Olaf College, 1520 St. Olaf Avenue, Northfield, MN 55057, USA
| | - Jason Langley
- Center for Advanced Neuroimaging, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Xiaoping Hu
- Center for Advanced Neuroimaging, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USA; Department of Bioengineering, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Ilana J Bennett
- Department of Psychology, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USA
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21
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Amyloidogenic processing of Alzheimer's disease β-amyloid precursor protein induces cellular iron retention. Mol Psychiatry 2020; 25:1958-1966. [PMID: 32444869 DOI: 10.1038/s41380-020-0762-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 04/15/2020] [Accepted: 04/27/2020] [Indexed: 12/20/2022]
Abstract
The proteolytic cleavage of β-amyloid precursor protein (APP) to form the amyloid beta (Aβ) peptide is related to the pathogenesis of Alzheimer's disease (AD) because APP mutations that influence this processing either induce familial AD or mitigate the risk of AD. Yet Aβ formation itself may not be pathogenic. APP promotes neuronal iron efflux by stabilizing the cell-surface presentation of ferroportin, the only iron export channel of cells. Mislocalization of APP can promote iron retention, thus we hypothesized that changes in endocytotic trafficking associated with altered APP processing could contribute to the neuronal iron elevation and oxidative burden that feature in AD pathology. Here, we demonstrate, using genetic and pharmacological approaches, that endocytotic amyloidogenic processing of APP impairs iron export by destabilizing ferroportin on the cell surface. Conversely, preferential non-amyloidogenic processing of APP at the cell surface promotes ferroportin stabilization to decrease intraneuronal iron. A new Aβ-independent hypothesis emerges where the amyloidogenic processing of APP, combined with age-dependent iron elevation in the tissue, increases pro-oxidant iron burden in AD.
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22
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Zachariou V, Bauer CE, Seago ER, Raslau FD, Powell DK, Gold BT. Cortical iron disrupts functional connectivity networks supporting working memory performance in older adults. Neuroimage 2020; 223:117309. [PMID: 32861788 PMCID: PMC7821351 DOI: 10.1016/j.neuroimage.2020.117309] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 08/19/2020] [Indexed: 12/12/2022] Open
Abstract
Excessive brain iron negatively affects working memory and related processes but the impact of cortical iron on task-relevant, cortical brain networks is unknown. We hypothesized that high cortical iron concentration may disrupt functional circuitry within cortical networks supporting working memory performance. Fifty-five healthy older adults completed an N-Back working memory paradigm while functional magnetic resonance imaging (fMRI) was performed. Participants also underwent quantitative susceptibility mapping (QSM) imaging for assessment of non-heme brain iron concentration. Additionally, pseudo continuous arterial spin labeling scans were obtained to control for potential contributions of cerebral blood volume and structural brain images were used to control for contributions of brain volume. Task performance was positively correlated with strength of task-based functional connectivity (tFC) between brain regions of the frontoparietal working memory network. However, higher cortical iron concentration was associated with lower tFC within this frontoparietal network and with poorer working memory performance after controlling for both cerebral blood flow and brain volume. Our results suggest that high cortical iron concentration disrupts communication within frontoparietal networks supporting working memory and is associated with reduced working memory performance in older adults.
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Affiliation(s)
- Valentinos Zachariou
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY 40536-0298 USA.
| | - Christopher E Bauer
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY 40536-0298 USA
| | - Elayna R Seago
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY 40536-0298 USA
| | - Flavius D Raslau
- Department of Radiology, College of Medicine, University of Kentucky, Lexington, KY 40536-0298 USA
| | - David K Powell
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY 40536-0298 USA; Magnetic Resonance Imaging and Spectroscopy Center, College of Medicine, University of Kentucky, Lexington, KY 40536-0298 USA
| | - Brian T Gold
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY 40536-0298 USA; Sanders-Brown Center on Aging, College of Medicine, University of Kentucky, Lexington, KY 40536-0298 USA; Magnetic Resonance Imaging and Spectroscopy Center, College of Medicine, University of Kentucky, Lexington, KY 40536-0298 USA.
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23
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Hou M, de Chastelaine M, Jayakumar M, Donley BE, Rugg MD. Recollection-related hippocampal fMRI effects predict longitudinal memory change in healthy older adults. Neuropsychologia 2020; 146:107537. [PMID: 32569610 DOI: 10.1016/j.neuropsychologia.2020.107537] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 06/11/2020] [Accepted: 06/12/2020] [Indexed: 02/07/2023]
Abstract
Prior fMRI studies have reported relationships between memory-related activity in the hippocampus and in-scanner memory performance, but whether such activity is predictive of longitudinal memory change remains unclear. Here, we administered a neuropsychological test battery to a sample of cognitively healthy older adults on three occasions, the second and third sessions occurring one month and three years after the first session. Structural and functional MRI data were acquired between the first two sessions. The fMRI data were derived from an associative recognition procedure and allowed estimation of hippocampal effects associated with both successful associative encoding and successful associative recognition (recollection). Baseline memory performance and memory change were evaluated using memory component scores derived from a principal components analysis of the neuropsychological test scores. Across participants, right hippocampal encoding effects correlated significantly with baseline memory performance after controlling for chronological age. Additionally, both left and right hippocampal associative recognition effects correlated negatively with longitudinal memory decline after controlling for age, and the relationship with the left hippocampal effect remained after also controlling for left hippocampal volume. Thus, in cognitively healthy older adults, the magnitude of hippocampal recollection effects appears to be a robust predictor of future memory change.
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Affiliation(s)
- Mingzhu Hou
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA.
| | - Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Manasi Jayakumar
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Brian E Donley
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA; School of Psychology, University of East Anglia, Norwich, NR4 7TJ, UK
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24
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Takeuchi H, Taki Y, Nouchi R, Yokoyama R, Kotozaki Y, Nakagawa S, Sekiguchi A, Iizuka K, Yamamoto Y, Hanawa S, Araki T, Miyauchi CM, Sakaki K, Nozawa T, Ikeda S, Yokota S, Daniele M, Sassa Y, Kawashima R. Association of iron levels in hair with brain structures and functions in young adults. J Trace Elem Med Biol 2020; 58:126436. [PMID: 31760327 DOI: 10.1016/j.jtemb.2019.126436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 11/02/2019] [Accepted: 11/12/2019] [Indexed: 11/18/2022]
Abstract
BACKGROUND Iron plays a critical role in normal brain functions and development, but it has also been known to have adverse neurological effects. METHODS Here, we investigated the associations of iron levels in hair with regional gray matter volume (rGMV), regional cerebral blood flow (rCBF), fractional anisotropy (FA), mean diffusivity (MD), and cognitive differences in a study cohort of 590 healthy young adults. RESULTS Our findings showed that high iron levels were associated with lower rGMV in areas including the hippocampus, lower rCBF in the anterior and posterior parts of the brain, greater FA in areas including the part of the splenium of the corpus callosum, lower MD in the overlapping area including the splenium of the corpus callosum, as well as greater MD in the left hippocampus and areas including the frontal lobe. CONCLUSION These results are compatible with the notion that iron plays diverse roles in neural mechanisms in healthy young adults.
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Affiliation(s)
- Hikaru Takeuchi
- Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
| | - Yasuyuki Taki
- Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan; Division of Medical Neuroimaging Analysis, Department of Community Medical Supports, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan; Department of Radiology and Nuclear Medicine, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Rui Nouchi
- Creative Interdisciplinary Research Division, Frontier Research Institute for Interdisciplinary Science, Tohoku University, Sendai, Japan; Human and Social Response Research Division, International Research Institute of Disaster Science, Tohoku University, Sendai, Japan; Department of Advanced Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | | | - Yuka Kotozaki
- Division of Clinical research, Medical-Industry Translational Research Center, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Seishu Nakagawa
- Department of Human Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan; Division of Psychiatry, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Atsushi Sekiguchi
- Division of Medical Neuroimaging Analysis, Department of Community Medical Supports, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan; Department of Behavioral Medicine, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Kunio Iizuka
- Department of Psychiatry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yuki Yamamoto
- Department of Human Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Sugiko Hanawa
- Department of Human Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | | | - Carlos Makoto Miyauchi
- Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University, Tokyo, Japan
| | - Kohei Sakaki
- Department of Advanced Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Takayuki Nozawa
- Research Center for the Earth Inclusive Sensing Empathizing with Silent Voices, Tokyo Institute of Technology, Tokyo, Japan
| | - Shigeyuki Ikeda
- Department of Ubiquitous Sensing, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Susumu Yokota
- Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Magistro Daniele
- Department of Sport Science, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, United Kingdom
| | - Yuko Sassa
- Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Ryuta Kawashima
- Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan; Department of Advanced Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan; Department of Human Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
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25
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A positive influence of basal ganglia iron concentration on implicit sequence learning. Brain Struct Funct 2020; 225:735-749. [PMID: 32055981 PMCID: PMC7046582 DOI: 10.1007/s00429-020-02032-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 01/22/2020] [Indexed: 12/18/2022]
Abstract
Iron homeostasis is important for maintaining normal physiological brain functioning. In two independent samples, we investigate the link between iron concentration in the basal ganglia (BG) and implicit sequence learning (ISL). In Study 1, we used quantitative susceptibility mapping and task-related fMRI to examine associations among regional iron concentration measurements, brain activation, and ISL in younger and older adults. In Study 2, we examined the link between brain iron and ISL using a metric derived from fMRI in an age-homogenous sample of older adults. Three main findings were obtained. First, BG iron concentration was positively related to ISL in both studies. Second, ISL was robust for both younger and older adults, and performance-related activation was found in fronto-striatal regions across both age groups. Third, BG iron was positively linked to task-related BOLD signal in fronto-striatal regions. This is the first study investigating the relationship among brain iron accumulation, functional brain activation, and ISL, and the results suggest that higher brain iron concentration may be linked to better neurocognitive functioning in this particular task.
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26
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Kagerer SM, van Bergen JMG, Li X, Quevenco FC, Gietl AF, Studer S, Treyer V, Meyer R, Kaufmann PA, Nitsch RM, van Zijl PCM, Hock C, Unschuld PG. APOE4 moderates effects of cortical iron on synchronized default mode network activity in cognitively healthy old-aged adults. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2020; 12:e12002. [PMID: 32211498 PMCID: PMC7085281 DOI: 10.1002/dad2.12002] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 10/21/2019] [Accepted: 11/01/2019] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Apolipoprotein E ε4 (APOE4)-related genetic risk for sporadic Alzheimer's disease is associated with an early impairment of cognitive brain networks. The current study determines relationships between APOE4 carrier status, cortical iron, and cortical network-functionality. METHODS Sixty-nine cognitively healthy old-aged individuals (mean age [SD] 66.1 [± 7.2] years; Mini-Mental State Exam [MMSE] 29.3 ± 1.1) were genotyped for APOE4 carrier-status and received 3 Tesla magnetic resonance imaging (MRI) for blood oxygen level-dependent functional magnetic resonance imaging (MRI) at rest, three-dimensional (3D)-gradient echo (six echoes) for cortical gray-matter, non-heme iron by quantitative susceptibility mapping, and 18F-flutemetamol positron emission tomography for amyloid-β. RESULTS A spatial pattern consistent with the default mode network (DMN) could be identified by independent component analysis. DMN activity was enhanced in APOE4 carriers and related to cortical iron burden. APOE4 and cortical iron synergistically interacted with DMN activity. Secondary analysis revealed a positive, APOE4 associated, relationship between cortical iron and DMN connectivity. DISCUSSION Our findings suggest that APOE4 moderates effects of iron on brain functionality prior to manifestation of cognitive impairment.
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Affiliation(s)
- Sonja M. Kagerer
- Institute for Regenerative MedicineUniversity of ZurichZurichSwitzerland
- Department of Psychogeriatric MedicinePsychiatric University Hospital Zurich (PUK)ZurichSwitzerland
| | | | - Xu Li
- The Russell H. Morgan Department of Radiology and Radiological ScienceDivision of MR ResearchThe Johns Hopkins University School of MedicineBaltimoreMarylandUSA
- F.M. Kirby Research Center for Functional Brain ImagingKennedy Krieger InstituteBaltimoreMarylandUSA
| | | | - Anton F. Gietl
- Institute for Regenerative MedicineUniversity of ZurichZurichSwitzerland
- Department of Psychogeriatric MedicinePsychiatric University Hospital Zurich (PUK)ZurichSwitzerland
| | - Sandro Studer
- Institute for Regenerative MedicineUniversity of ZurichZurichSwitzerland
| | - Valerie Treyer
- Institute for Regenerative MedicineUniversity of ZurichZurichSwitzerland
- Department of Nuclear MedicineUniversity Hospital Zurich and University of ZurichZurichSwitzerland
| | - Rafael Meyer
- Institute for Regenerative MedicineUniversity of ZurichZurichSwitzerland
- Department of Psychogeriatric MedicinePsychiatric University Hospital Zurich (PUK)ZurichSwitzerland
| | - Philipp A. Kaufmann
- Department of Nuclear MedicineUniversity Hospital Zurich and University of ZurichZurichSwitzerland
| | - Roger M. Nitsch
- Institute for Regenerative MedicineUniversity of ZurichZurichSwitzerland
- Neuroscience Center ZurichUniversity of Zurich and ETH ZurichZurichSwitzerland
- NeurimmuneSchlierenSwitzerland
| | - Peter C. M. van Zijl
- The Russell H. Morgan Department of Radiology and Radiological ScienceDivision of MR ResearchThe Johns Hopkins University School of MedicineBaltimoreMarylandUSA
- F.M. Kirby Research Center for Functional Brain ImagingKennedy Krieger InstituteBaltimoreMarylandUSA
| | - Christoph Hock
- Institute for Regenerative MedicineUniversity of ZurichZurichSwitzerland
- Neuroscience Center ZurichUniversity of Zurich and ETH ZurichZurichSwitzerland
- NeurimmuneSchlierenSwitzerland
| | - Paul G. Unschuld
- Institute for Regenerative MedicineUniversity of ZurichZurichSwitzerland
- Department of Psychogeriatric MedicinePsychiatric University Hospital Zurich (PUK)ZurichSwitzerland
- Neuroscience Center ZurichUniversity of Zurich and ETH ZurichZurichSwitzerland
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27
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Rodrigue KM, Daugherty AM, Foster CM, Kennedy KM. Striatal iron content is linked to reduced fronto-striatal brain function under working memory load. Neuroimage 2020; 210:116544. [PMID: 31972284 DOI: 10.1016/j.neuroimage.2020.116544] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/10/2020] [Accepted: 01/13/2020] [Indexed: 12/26/2022] Open
Abstract
Non-heme iron accumulation contributes to age-related decline in brain structure and cognition via a cascade of oxidative stress and inflammation, although its effect on brain function is largely unexplored. Thus, we examine the impact of striatal iron on dynamic range of BOLD modulation to working memory load. N = 166 healthy adults (age 20-94) underwent cognitive testing and an imaging session including n-back (0-, 2-, 3-, and 4-back fMRI), R2*-weighted imaging, and pcASL to measure cerebral blood flow. A statistical model was constructed to predict voxelwise BOLD modulation by age, striatal iron content and an age × iron interaction, controlling for cerebral blood flow, sex, and task response time. A significant interaction between age and striatal iron content on BOLD modulation was found selectively in the putamen, caudate, and inferior frontal gyrus. Greater iron was associated with reduced modulation to difficulty, particularly in middle-aged and younger adults with greater iron content. Further, iron-related decreases in modulation were associated with poorer executive function in an age-dependent manner. These results suggest that iron may contribute to differences in functional brain activation prior to older adulthood, highlighting the potential role of iron as an early factor contributing to trajectories of functional brain aging.
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Affiliation(s)
- Karen M Rodrigue
- Center for Vital Longevity, School of Behavioral and Brain Science, The University of Texas at Dallas, Dallas, TX, USA.
| | - Ana M Daugherty
- Department of Psychology, Department of Psychiatry and Behavioral Neurosciences, Institute of Gerontology, Wayne State University, Detroit, MI, USA
| | - Chris M Foster
- Center for Vital Longevity, School of Behavioral and Brain Science, The University of Texas at Dallas, Dallas, TX, USA
| | - Kristen M Kennedy
- Center for Vital Longevity, School of Behavioral and Brain Science, The University of Texas at Dallas, Dallas, TX, USA
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28
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Machado GDB, de Freitas BS, Florian LZ, Monteiro RT, Gus H, Schröder N. G protein-coupled oestrogen receptor stimulation ameliorates iron- and ovariectomy-induced memory impairments through the cAMP/PKA/CREB signalling pathway. J Neuroendocrinol 2019; 31:e12780. [PMID: 31418949 DOI: 10.1111/jne.12780] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/09/2019] [Accepted: 08/13/2019] [Indexed: 12/18/2022]
Abstract
Iron accumulation in the brain has been associated with neurodegenerative disorders, and imaging studies in humans indicate that iron content in brain regions correlates with poor performance in cognitive tasks. In rats, iron overload impairs memory retention in a variety of memory tasks. Although the effects of iron on cognition in rodents are extensively reported, no previous study has been conducted in female rats. The incidence of certain dementias, such as Alzheimer's disease, is higher in women after menopause compared to aged-matched men. The role of oestrogen depletion in memory deficits in menopausal women is still a matter of debate. The present study aimed to characterise the effects of iron overload on memory in female rats by investigating the effects of ovariectomy (OVX, an experimental model of oestrogen depletion) in rats submitted to iron overload, as well as examining the effects of G protein-coupled oestrogen receptor (GPER) agonism on memory impairments induced by iron and OVX. Female rats received iron (30 mg kg-1 , orally) or vehicle at postnatal days 12-14 and were submitted to OVX in adulthood. Results showed that either iron or OVX impaired memory for object placement and inhibitory avoidance. The selective GPER agonist G1, administered immediately after training, reversed both iron- and OVX-induced memory impairments. G1 effects were abolished by protein kinase A (PKA) inhibition, suggesting the involvement of the cAMP/PKA/CREB signalling pathway. The search for novel oestrogen agonists with positive effects on cognition may be promising for the development of treatments for memory disorders.
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Affiliation(s)
- Gustavo Dalto Barroso Machado
- Neurobiology and Developmental Biology Laboratory, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Betânia Souza de Freitas
- Neurobiology and Developmental Biology Laboratory, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Leonardo Zanetti Florian
- Neurobiology and Developmental Biology Laboratory, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Ricardo Tavares Monteiro
- Neurobiology and Developmental Biology Laboratory, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Henrique Gus
- Neurobiology and Developmental Biology Laboratory, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Nadja Schröder
- National Institute of Science and Technology for Translational Medicine (INCT-TM), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasília, Brazil
- Department of Physiology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
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29
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Ferreira A, Neves P, Gozzelino R. Multilevel Impacts of Iron in the Brain: The Cross Talk between Neurophysiological Mechanisms, Cognition, and Social Behavior. Pharmaceuticals (Basel) 2019; 12:ph12030126. [PMID: 31470556 PMCID: PMC6789770 DOI: 10.3390/ph12030126] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 08/26/2019] [Accepted: 08/27/2019] [Indexed: 12/12/2022] Open
Abstract
Iron is a critical element for most organisms, which plays a fundamental role in the great majority of physiological processes. So much so, that disruption of iron homeostasis has severe multi-organ impacts with the brain being particularly sensitive to such modifications. More specifically, disruption of iron homeostasis in the brain can affect neurophysiological mechanisms, cognition, and social behavior, which eventually contributes to the development of a diverse set of neuro-pathologies. This article starts by exploring the mechanisms of iron action in the brain and follows with a discussion on cognitive and behavioral implications of iron deficiency and overload and how these are framed by the social context. Subsequently, we scrutinize the implications of the disruption of iron homeostasis for the onset and progression of psychosocial disorders. Lastly, we discuss the links between biological, psychological, and social dimensions and outline potential avenues of research. The study of these interactions could ultimately contribute to a broader understanding of how individuals think and act under physiological and pathophysiological conditions.
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Affiliation(s)
- Ana Ferreira
- Centro Interdisciplinar de Ciências Sociais (CICS.NOVA), Faculdade de Ciências Sociais e Humanas da Universidade NOVA de Lisboa (NOVA FCSH), 1069-061 Lisbon, Portugal
| | - Pedro Neves
- School of Business and Economics, NOVA University of Lisbon, 2775-405 Lisbon, Portugal
| | - Raffaella Gozzelino
- Chronic Diseases Research Center (CEDOC)/NOVA Medical School, Universidade NOVA de Lisboa, 1180-052, 1150-082 Lisbon, Portugal.
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30
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Sadeh T, Dang C, Gat-Lazer S, Moscovitch M. Recalling the firedog: Individual differences in associative memory for unitized and nonunitized associations among older adults. Hippocampus 2019; 30:130-142. [PMID: 31348573 DOI: 10.1002/hipo.23142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/20/2019] [Accepted: 07/05/2019] [Indexed: 11/10/2022]
Abstract
Memory deficits in aging are characterized by impaired hippocampus-mediated relational binding-the formation of links between items in memory. By reducing reliance on relational binding, unitization of two items into one concept enhances associative recognition among older adults. Can a similar enhancement be obtained when probing memory with recall? This question has yet to be examined, because recall has been assumed to rely predominantly on relational binding. Inspired by recent evidence challenging this assumption, we investigated individual differences in older adults' recall of unitized and nonunitized associations. Compared with successfully aging individuals, older adults with mild memory deficits, typically mediated by the hippocampus, were impaired in recall of paired-associates in a task which relies on relational binding (study: "PLAY-TUNNEL"; test: PLAY-T?). In stark contrast, the two groups showed similar performance when items were unitized into a novel compound word (study: "LOVEGIGGLE"; test: LOVEG?). Thus, boosting nonrelational aspects of recall enhances associative memory among aging individuals with subtle memory impairments to comparable levels as successfully aging older adults.
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Affiliation(s)
- Talya Sadeh
- Department of Cognitive and Brain Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.,Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer Sheva, Israel.,Department of Psychology, Ben-Gurion University of the Negev, Beer Sheva, Israel.,Department of Psychology, University of Toronto, Toronto, Ontario, Canada.,Rotman Research Institute, Baycrest Centre, Toronto, Ontario, Canada
| | - Christa Dang
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada.,Rotman Research Institute, Baycrest Centre, Toronto, Ontario, Canada.,The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia.,Department of Obstetrics & Gynaecology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Sigal Gat-Lazer
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada.,Rotman Research Institute, Baycrest Centre, Toronto, Ontario, Canada.,Chronic Pain Day Care Unit, Rehabilitation Hospital, Sheba Medical Center, Ramat Gan, Israel
| | - Morris Moscovitch
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada.,Rotman Research Institute, Baycrest Centre, Toronto, Ontario, Canada
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31
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Neely CLC, Lippi SLP, Lanzirotti A, Flinn JM. Localization of Free and Bound Metal Species through X-Ray Synchrotron Fluorescence Microscopy in the Rodent Brain and Their Relation to Behavior. Brain Sci 2019; 9:E74. [PMID: 30925761 PMCID: PMC6523809 DOI: 10.3390/brainsci9040074] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 03/23/2019] [Accepted: 03/26/2019] [Indexed: 12/27/2022] Open
Abstract
Biometals in the brain, such as zinc, copper, and iron, are often discussed in cases of neurological disorders; however, these metals also have important regulatory functions and mediate cell signaling and plasticity. With the use of synchrotron X-ray fluorescence, our lab localized total, both bound and free, levels of zinc, copper, and iron in a cross section of one hemisphere of a rat brain, which also showed differing metal distributions in different regions within the hippocampus, the site in the brain known to be crucial for certain types of memory. This review discusses the several roles of these metals in brain regions with an emphasis on hippocampal cell signaling, based on spatial mapping obtained from X-ray fluorescence microscopy. We also discuss the localization of these metals and emphasize different cell types and receptors in regions with metal accumulation, as well as the potential relationship between this physiology and behavior.
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Affiliation(s)
- Caroline L C Neely
- Department of Psychology, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA.
| | - Stephen L P Lippi
- Department of Psychology & Sociology, Angelo State University, 2601 W. Avenue N, ASU Station #10907, San Angelo, TX 76909, USA.
| | - Antonio Lanzirotti
- Center for Advanced Radiation Sources, University of Chicago, 9700 South Cass Avenue, Argonne, IL 60439, USA.
| | - Jane M Flinn
- Department of Psychology, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA.
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32
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Ashraf A, Alepuz Guillen JA, Aljuhani M, Hubens C, So PW. Low Cerebrospinal Fluid Levels of Melanotransferrin Are Associated With Conversion of Mild Cognitively Impaired Subjects to Alzheimer's Disease. Front Neurosci 2019; 13:181. [PMID: 30906244 PMCID: PMC6419538 DOI: 10.3389/fnins.2019.00181] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 02/14/2019] [Indexed: 11/13/2022] Open
Abstract
The disruption of iron metabolism and iron transport proteins have been implicated in the pathogenesis of Alzheimer's disease (AD). Serum melanotransferrin (MTf), a transferrin homolog capable of reversibly binding iron, has been proposed as a biochemical marker of AD. MTf has also been shown to be elevated in iron-rich reactive microglia near amyloid plaques in AD. We examined the association of CSF MTf to hippocampal volumes and cognitive tests in 86 cognitively normal, 135 mild cognitive impairment (MCI) and 66 AD subjects. CSF was collected at baseline for MTf, Aβ, total-tau and phosphorylated-tau measurements. Serial cognitive testing with ADAS-Cog13, Rey's auditory visual learning test (RAVLT), mini-mental state examination (MMSE) were performed alongside hippocampal MRI volumetric analysis for up to 10 years after baseline measurements. High levels of baseline CSF MTf were positively associated with baseline hippocampal volume (R 2 = 22%, β = 0.202, and p = 0.017) and RAVLT scores (R 2 = 7.30%, β = -0.178, and p = 0.043) and negatively correlated to ADAS-Cog13 (R 2 = 17.3%, β = 0.247, and p = 0.003) scores in MCI subjects. Interestingly, MCI subjects that converted to AD demonstrated significantly lower levels of CSF MTf (p = 0.020) compared to MCI non-converters at baseline. We suggest the diminished CSF MTf observed in MCI-converters to AD may arise from impaired transport of MTf from blood into the brain tissue/CSF and/or increased MTf export from the CSF into the blood arising from attenuated competition with reduced levels of CSF Aβ. Further investigations are required to determine the source of CSF MTf and how brain MTf is regulated by cellular barriers, Aβ and activated microglia that surround plaques in AD pathophysiology. In conclusion, low CSF MTf may identify those MCI individuals at risk of converting to AD.
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Affiliation(s)
- Azhaar Ashraf
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Jose Andres Alepuz Guillen
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Manal Aljuhani
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Chantal Hubens
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Po-Wah So
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
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33
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Nikseresht S, Bush AI, Ayton S. Treating Alzheimer's disease by targeting iron. Br J Pharmacol 2019; 176:3622-3635. [PMID: 30632143 DOI: 10.1111/bph.14567] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/14/2018] [Accepted: 11/27/2018] [Indexed: 12/30/2022] Open
Abstract
No disease modifying drugs have been approved for Alzheimer's disease despite recent major investments by industry and governments throughout the world. The burden of Alzheimer's disease is becoming increasingly unsustainable, and given the last decade of clinical trial failures, a renewed understanding of the disease mechanism is called for, and trialling of new therapeutic approaches to slow disease progression is warranted. Here, we review the evidence and rational for targeting brain iron in Alzheimer's disease. Although iron elevation in Alzheimer's disease was reported in the 1950s, renewed interest has been stimulated by the advancement of fluid and imaging biomarkers of brain iron that predict disease progression, and the recent discovery of the iron-dependent cell death pathway termed ferroptosis. We review these emerging clinical and biochemical findings and propose how this pathway may be targeted therapeutically to slow Alzheimer's disease progression. LINKED ARTICLES: This article is part of a themed section on Therapeutics for Dementia and Alzheimer's Disease: New Directions for Precision Medicine. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.18/issuetoc.
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Affiliation(s)
- Sara Nikseresht
- The Melbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Ashley I Bush
- The Melbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Scott Ayton
- The Melbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
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Fu XY, Xie XT. [Association between iron deficiency and brain developmental disorder in children]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2018; 20:964-967. [PMID: 30477632 PMCID: PMC7389029 DOI: 10.7499/j.issn.1008-8830.2018.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/02/2018] [Indexed: 06/09/2023]
Abstract
Iron deficiency (ID) is the most common trace element deficiency in childhood. Recent studies have shown that late fetus period, neonatal period, and infancy are important periods for brain development, and ID during these periods may cause irreversible damage to brain development, including abnormal emotion and behavior, cognitive decline, and attention deficit, which may still be present in adulthood. Therefore, it should be taken seriously. This article summarizes the research advances in major mechanisms involved in brain developmental disorder due to ID in the early stage of life and related intervention measures.
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Affiliation(s)
- Xiao-Yan Fu
- Department of Pediatrics, Shanghai Luodian Hospital, Shanghai 201908, China.
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Daugherty AM, Hoagey DA, Kennedy KM, Rodrigue KM. Genetic predisposition for inflammation exacerbates effects of striatal iron content on cognitive switching ability in healthy aging. Neuroimage 2018; 185:471-478. [PMID: 30395929 DOI: 10.1016/j.neuroimage.2018.10.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/25/2018] [Accepted: 10/24/2018] [Indexed: 01/04/2023] Open
Abstract
Non-heme iron homeostasis interacts with inflammation bidirectionally, and both contribute to age-related decline in brain structure and function via oxidative stress. Thus, individuals with genetic predisposition for inflammation may be at greater risk for brain iron accumulation during aging and more vulnerable to cognitive decline. We examine this hypothesis in a lifespan sample of healthy adults (N = 183, age 20-94 years) who underwent R2*-weighted magnetic resonance imaging to estimate regional iron content and genotyping of interleukin-1beta (IL-1β), a pro-inflammatory cytokine for which the T allelle of the single nucleotide polymorphism increases risk for chronic neuroinflammation. Older age was associated with greater striatal iron content that in turn accounted for poorer cognitive switching performance. Heterozygote IL-1β T-carriers demonstrated poorer switching performance in relation to striatal iron content as compared to IL-1β C/C counterparts, despite the two groups being of similar age. With increasing genetic inflammation risk, homozygote IL-1β T/T carriers had lesser age-related variance in striatal iron content as compared to the other groups but showed a similar association of greater striatal iron content predicting poorer cognitive switching. Non-heme iron and inflammation, although necessary for normal neuronal function, both promote oxidative stress that when accumulated in excess, drives a complex mechanism of neural and cognitive decline in aging.
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Affiliation(s)
- Ana M Daugherty
- Department of Psychology, Department of Psychiatry and Behavioral Neurosciences, Institute of Gerontology, Wayne State University, Detroit, MI, USA
| | - David A Hoagey
- Center for Vital Longevity, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA
| | - Kristen M Kennedy
- Center for Vital Longevity, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA
| | - Karen M Rodrigue
- Center for Vital Longevity, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA.
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36
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Repeated mild shaking of neonates induces transient cerebral microhemorrhages and anxiety-related behavior in adult rats. Neurosci Lett 2018; 684:29-34. [DOI: 10.1016/j.neulet.2018.06.059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 06/19/2018] [Accepted: 06/30/2018] [Indexed: 01/15/2023]
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Alcalde LA, de Freitas BS, Machado GDB, de Freitas Crivelaro PC, Dornelles VC, Gus H, Monteiro RT, Kist LW, Bogo MR, Schröder N. Iron chelator deferiprone rescues memory deficits, hippocampal BDNF levels and antioxidant defenses in an experimental model of memory impairment. Biometals 2018; 31:927-940. [PMID: 30117045 DOI: 10.1007/s10534-018-0135-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 08/12/2018] [Indexed: 12/18/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) plays a key role in neural development and physiology, as well as in pathological states. Post-mortem studies demonstrate that BDNF is reduced in the brains of patients affected by neurodegenerative diseases. Iron accumulation has also been associated to the pathogenesis of neurodegenerative diseases. In rats, iron overload induces persistent memory deficits, increases oxidative stress and apoptotic markers, and decreases the expression of the synaptic marker, synaptophysin. Deferiprone (DFP) is an oral iron chelator used for the treatment of systemic iron overload disorders, and has recently been tested for Parkinson's disease. Here, we investigated the effects of iron overload on BDNF levels and on mRNA expression of genes encoding TrkB, p75NTR, catalase (CAT) and NQO1. We also aimed at investigating the effects of DFP on iron-induced impairments. Rats received iron or vehicle at postnatal days 12-14 and when adults, received chronic DFP or water (vehicle). Recognition memory was tested 19 days after the beginning of chelation therapy. BDNF measurements and expression analyses in the hippocampus were performed 24 h after the last day of DFP treatment. DFP restored memory and increased hippocampal BDNF levels, ameliorating iron-induced effects. Iron overload in the neonatal period reduced, while treatment with DFP was able to rescue, the expression of antioxidant enzymes CAT and NQO1.
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Affiliation(s)
- Luisa Azambuja Alcalde
- Neurobiology and Developmental Biology Laboratory, Faculty of Biosciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90619-900, Brazil
| | - Betânia Souza de Freitas
- Neurobiology and Developmental Biology Laboratory, Faculty of Biosciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90619-900, Brazil
| | - Gustavo Dalto Barroso Machado
- Neurobiology and Developmental Biology Laboratory, Faculty of Biosciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90619-900, Brazil
| | - Pedro Castilhos de Freitas Crivelaro
- Neurobiology and Developmental Biology Laboratory, Faculty of Biosciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90619-900, Brazil
| | - Victoria Campos Dornelles
- Neurobiology and Developmental Biology Laboratory, Faculty of Biosciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90619-900, Brazil
| | - Henrique Gus
- Neurobiology and Developmental Biology Laboratory, Faculty of Biosciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90619-900, Brazil
| | - Ricardo Tavares Monteiro
- Neurobiology and Developmental Biology Laboratory, Faculty of Biosciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90619-900, Brazil
| | - Luiza Wilges Kist
- Laboratory of Genomics and Molecular Biology, Faculty of Biosciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90619-900, Brazil.,Graduate Program in Medicine and Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90610-000, Brazil
| | - Mauricio Reis Bogo
- Laboratory of Genomics and Molecular Biology, Faculty of Biosciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90619-900, Brazil.,Graduate Program in Medicine and Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, 90610-000, Brazil
| | - Nadja Schröder
- Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite, 500, Porto Alegre, RS, 90050-170, Brazil. .,National Institute of Science and Technology for Translational Medicine (INCT-TM), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasília, 71605-001, Brazil.
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38
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Chen BT, Ghassaban K, Jin T, Patel SK, Ye N, Sun CL, Kim H, Rockne RC, Mark Haacke E, Root JC, Saykin AJ, Ahles TA, Holodny AI, Prakash N, Mortimer J, Waisman J, Yuan Y, Somlo G, Li D, Yang R, Tan H, Katheria V, Morrison R, Hurria A. Subcortical brain iron deposition and cognitive performance in older women with breast cancer receiving adjuvant chemotherapy: A pilot MRI study. Magn Reson Imaging 2018; 54:218-224. [PMID: 30076946 DOI: 10.1016/j.mri.2018.07.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/10/2018] [Accepted: 07/31/2018] [Indexed: 10/28/2022]
Abstract
As the number of older adults in the U.S. increases, so too will the incidence of cancer and cancer-related cognitive impairment (CRCI). However, the exact underlying biological mechanism for CRCI is not yet well understood. We utilized susceptibility-weighted imaging with quantitative susceptibility mapping, a non-invasive MRI-based technique, to assess longitudinal iron deposition in subcortical gray matter structures and evaluate its association with cognitive performance in women age 60+ with breast cancer receiving adjuvant chemotherapy and age-matched women without breast cancer as controls. Brain MRI scans and neurocognitive scores from the NIH Toolbox for Cognition were obtained before chemotherapy (time point 1) and within one month after the last infusion of chemotherapy for the patients and at matched intervals for the controls (time point 2). There were 14 patients age 60+ with breast cancer (mean age 66.3 ± 5.3 years) and 13 controls (mean age 68.2 ± 6.1 years) included in this study. Brain iron increased as age increased. There were no significant between- or within- group differences in neurocognitive scores or iron deposition at time point 1 or between time points 1 and 2 (p > 0.01). However, there was a negative correlation between iron in the globus pallidus and the fluid cognition composite scores in the control group at time point 1 (r = -0.71; p < 0.01), but not in the chemotherapy group. Baseline iron in the putamen was negatively associated with changes in the oral reading recognition scores in the control group (r = 0.74, p < 0.01), but not in the chemotherapy group. Brain iron assessment did not indicate cancer or chemotherapy related short-term differences, yet some associations with cognition were observed. Studies with larger samples and longer follow-up intervals are warranted.
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Affiliation(s)
- Bihong T Chen
- Department of Diagnostic Radiology, City of Hope National Medical Center, Duarte, CA, United States; Center for Cancer and Aging, City of Hope National Medical Center, Duarte, CA, United States.
| | | | - Taihao Jin
- Department of Diagnostic Radiology, City of Hope National Medical Center, Duarte, CA, United States
| | - Sunita K Patel
- Department of Population Science, City of Hope National Medical Center, Duarte, CA, United States
| | - Ningrong Ye
- Department of Diagnostic Radiology, City of Hope National Medical Center, Duarte, CA, United States
| | - Can-Lan Sun
- Center for Cancer and Aging, City of Hope National Medical Center, Duarte, CA, United States
| | - Heeyoung Kim
- Center for Cancer and Aging, City of Hope National Medical Center, Duarte, CA, United States
| | - Russell C Rockne
- Division of Mathematical Oncology, City of Hope National Medical Center, Duarte, CA, United States
| | - E Mark Haacke
- Magnetic Resonance Innovations, Inc., Detroit, MI, United States; Department of Biomedical Engineering, Wayne State University, Detroit, MI, United States
| | - James C Root
- Neurocognitive Research Lab, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Andrew J Saykin
- Center for Neuroimaging, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Tim A Ahles
- Neurocognitive Research Lab, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Andrei I Holodny
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, United States
| | - Neal Prakash
- Division of Neurology, City of Hope National Medical Center, Duarte, CA, United States
| | - Joanne Mortimer
- Department of Medical Oncology, City of Hope National Medical Center, Duarte, CA, United States
| | - James Waisman
- Department of Medical Oncology, City of Hope National Medical Center, Duarte, CA, United States
| | - Yuan Yuan
- Department of Medical Oncology, City of Hope National Medical Center, Duarte, CA, United States
| | - George Somlo
- Department of Medical Oncology, City of Hope National Medical Center, Duarte, CA, United States
| | - Daneng Li
- Department of Medical Oncology, City of Hope National Medical Center, Duarte, CA, United States
| | - Richard Yang
- Center for Cancer and Aging, City of Hope National Medical Center, Duarte, CA, United States
| | - Heidi Tan
- Center for Cancer and Aging, City of Hope National Medical Center, Duarte, CA, United States
| | - Vani Katheria
- Center for Cancer and Aging, City of Hope National Medical Center, Duarte, CA, United States
| | - Rachel Morrison
- Center for Cancer and Aging, City of Hope National Medical Center, Duarte, CA, United States
| | - Arti Hurria
- Center for Cancer and Aging, City of Hope National Medical Center, Duarte, CA, United States; Department of Medical Oncology, City of Hope National Medical Center, Duarte, CA, United States
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Li DTH, Hui ES, Chan Q, Yao N, Chua SE, McAlonan GM, Pang SYY, Ho SL, Mak HKF. Quantitative susceptibility mapping as an indicator of subcortical and limbic iron abnormality in Parkinson's disease with dementia. Neuroimage Clin 2018; 20:365-373. [PMID: 30128274 PMCID: PMC6096006 DOI: 10.1016/j.nicl.2018.07.028] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 07/23/2018] [Accepted: 07/26/2018] [Indexed: 01/19/2023]
Abstract
Late stage Parkinson's disease (PD) patients were commonly observed with other non-motor comorbidities such as dementia and psychosis. While abnormal iron level in the substantia nigra was clinically accepted as a biomarker of PD, it was also suggested that the increased iron deposition could impair other brain regions and induce non-motor symptoms. A new Magnetic Resonance Imaging (MRI) called Quantitative Susceptibility Mapping (QSM) has been found to measure iron concentration in the grey matter reliably. In this study, we investigated iron level of different subcortical and limbic structures of Parkinson's disease (PD) patients with and without dementia by QSM. QSM and volumetric analysis by MRI were performed in 10 PD dementia (PDD) patients (73 ± 6 years), 31 PD patients (63 ± 8 years) and 27 healthy controls (62 ± 7 years). No significant differences were observed in the L-Dopa equivalent dosage for the two PD groups (p = 0.125). Putative iron content was evaluated in different subcortical and limbic structures of the three groups, as well as its relationship with cognitive performance. One-way ANCOVA with FDR adjustment at level of 0.05, adjusted for age and gender, showed significant group differences for left and right hippocampus (p = 0.015 & 0.032, respectively, BH-corrected for multiple ROIs) and right thalamus (p = 0.032, BH-corrected). Post-hoc test with Bonferroni's correction suggested higher magnetic susceptibility in PDD patients than healthy controls in the left and right hippocampus (p = 0.001 & 0.047, respectively, Bonferroni's corrected), while PD patients had higher magnetic susceptibility than the healthy controls in right hippocampus and right thalamus (p = 0.006 & 0.005, respectively, Bonferroni's corrected). PDD patients also had higher susceptibility than the non-demented PD patients in left hippocampus (p = 0.046, Bonferroni's corrected). The magnetic susceptibilities of the left and right hippocampus were negatively correlated with the Mini-Mental State Examination score (r = -0.329 & -0.386, respectively; p < 0.05). This study provides support for iron accumulation in limbic structures of PDD and PD patients and its correlation with cognitive performance, however, its putative involvement in development of non-motor cognitive dysfunction in PD pathogenesis remains to be elucidated.
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Affiliation(s)
- Darrell T H Li
- Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong
| | - Edward S Hui
- Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong
| | | | - N Yao
- Department of Psychiatry, Yale University, New Haven, CT, United States,; Department of Psychiatry, The University of Hong Kong, Hong Kong
| | - S E Chua
- Department of Psychiatry, The University of Hong Kong, Hong Kong,; Raffles Counselling Centre, Raffles Hospital, Singapore
| | - Gráinne M McAlonan
- Department of Psychiatry, The University of Hong Kong, Hong Kong,; Department of Forensic and Neurodevelopmental Science, King's College London, London, United Kingdom,; South London and Maudsley NHS Foundation Trust, United Kingdom
| | - Shirley Y Y Pang
- Division of Neurology, Department of Medicine, The University of Hong Kong, Hong Kong
| | - S L Ho
- Division of Neurology, Department of Medicine, The University of Hong Kong, Hong Kong
| | - Henry K F Mak
- Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong,; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong,; Alzheimer's Disease Research Network, The University of Hong Kong, Hong Kong.
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40
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Chung JY, Kim HS, Song J. Iron metabolism in diabetes-induced Alzheimer's disease: a focus on insulin resistance in the brain. Biometals 2018; 31:705-714. [PMID: 30043289 PMCID: PMC6133192 DOI: 10.1007/s10534-018-0134-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 06/18/2018] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is characterized by an excessive accumulation of toxic amyloid beta (Aβ) plaques and memory dysfunction. The onset of AD is influenced by age, genetic background, and impaired glucose metabolism in the brain. Several studies have demonstrated that diabetes involving insulin resistance and glucose tolerance could lead to AD, ultimately resulting in cognitive dysfunction. Even though the relationship between diabetes and AD was indicated by significant evidences, the critical mechanisms and metabolic alterations in diabetes induced AD are not clear until now. Recently, iron metabolism has been shown to play multiple roles in the central nervous system (CNS). Iron deficiency and overload are associated with neurodegenerative diseases. Iron binds to Aβ and subsequently regulates Aβ toxicity in the CNS. In addition, previous studies have shown that iron is involved in the aggravation of insulin resistance. Considering these effects of iron metabolism in CNS, we expect that iron metabolism may play crucial roles in diabetic AD brain. Thus, we review the recent evidence regarding the relationship between diabetes-induced AD and iron metabolism.
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Affiliation(s)
- Ji Yeon Chung
- Department of Neurology, Chosun University School of Medicine and Hospital, Gwangju, 61452, South Korea
| | - Hyung-Seok Kim
- Department of Forensic Medicine, Chonnam National University Medical School, Gwangju, 61469, South Korea.
| | - Juhyun Song
- Department of Anatomy, Chonnam National University Medical School, Gwangju, 61469, South Korea.
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41
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Hosking DE, Ayton S, Beckett N, Booth A, Peters R. More evidence is needed. Iron, incident cognitive decline and dementia: a systematic review. Ther Adv Chronic Dis 2018; 9:241-256. [PMID: 30719269 DOI: 10.1177/2040622318788485] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/07/2018] [Indexed: 12/22/2022] Open
Abstract
Background Our aim was to systematically review the relationship between iron and incident cognitive decline or dementia from midlife onwards. Methods Systematic review of eligible studies using Medline, Embase and PsycINFO® for the period from 1 January 1986 to 2 December 2016 (CRD42016023800), where study populations had a mean age of over 50 years and were free of cognitive impairment or dementia at baseline. Two authors independently extracted data according to eligibility criteria and assessed study characteristics, quality and outcomes. Disagreement was resolved by discussion. Results A total of 1185 relevant records were identified with 12 full-text articles eligible for review. Six studies were excluded, leaving six texts to be included. Sample size ranged from 90 to 7173, with an average follow up of approximately 11.5 years. Baseline iron measures included brain iron (n = 2), iron-related biomarkers in blood and plasma (n = 2), and iron intake estimates from dietary records (n = 2). Outcomes were dementia incidence (n = 2) and longitudinal outcomes on neuropsychological tests (n = 4). Bias was evident across studies in one or more of the following: recruitment, iron exposure, outcome assessments, potential confounders, missing data or attrition. Conclusions Diversity across the small number of identified studies precludes conclusions regarding the role of iron in cognitive decline or dementia. Our review highlights substantial gaps in the evidence base and the need for more comprehensive, higher quality studies in this area.
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Affiliation(s)
- Diane E Hosking
- Centre for Research into Ageing Health and Wellbeing, Australian National University, Canberra, Australia
| | - Scott Ayton
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Nigel Beckett
- Care of the Elderly, Imperial College London, London, UK
| | - Andrew Booth
- School of Health and Related Research, University of Sheffield, Sheffield, UK
| | - Ruth Peters
- Lifecourse Ageing Research Centre, Neuroscience Research Australia, University of New South Wales, Sydney NSW 2031, Australia
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Hect JL, Daugherty AM, Hermez KM, Thomason ME. Developmental variation in regional brain iron and its relation to cognitive functions in childhood. Dev Cogn Neurosci 2018; 34:18-26. [PMID: 29894887 PMCID: PMC6250585 DOI: 10.1016/j.dcn.2018.05.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 05/08/2018] [Accepted: 05/14/2018] [Indexed: 01/18/2023] Open
Abstract
We examine relationship of brain iron and cognition in childhood and adolescence. Estimates of iron in basal ganglia and hippocampus from R2* relaxometry. Age-related increase in non-heme iron content was observed in multiple brain areas. Greater iron content was indicative of improved cognitive ability. Non-heme iron appears to play a critical role in neural and cognitive development.
Non-heme iron is a vital metabolic cofactor for many core processes of brain development including myelination, dendritogenesis, and neurotransmitter synthesis, and accumulates in the brain with age. However, little is known about development-related differences in brain iron and its association with emerging cognitive abilities during formative years. In this study, we estimated brain iron via R2* relaxometry in children ages 7–16 (N = 57; 38 females) and examined its relation to age-related differences in cognitive ability. As we hypothesized, age correlated positively with iron content in the hippocampus and across subregions of the basal ganglia. The magnitude of age differences in iron content differed between regions such that the largest effects were observed in basal ganglia subregions: globus pallidus, substantia nigra, caudate nucleus, and putamen, as compared to values obtained for the hippocampus and red nucleus. We did not observe sex or hemispheric differences in iron content. Notably, greater brain iron content was associated with both faster processing speed and higher general intelligence, and shared 21.4% of the age-related improvement in processing speed and 12.5% of the improvement in general intelligence. These results suggest that non-heme iron plays a central neurobiological role in the development of critical cognitive abilities during childhood.
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Affiliation(s)
- Jasmine L Hect
- Merrill Palmer Skillman Institute for Child and Family Development, Wayne State University, Detroit, MI, 48202, USA.
| | - Ana M Daugherty
- Beckman Institute for Advanced Science and Technology at the University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Klodia M Hermez
- Merrill Palmer Skillman Institute for Child and Family Development, Wayne State University, Detroit, MI, 48202, USA; Michigan State University College of Osteopathic Medicine, East Lansing, MI, 48825, USA
| | - Moriah E Thomason
- Merrill Palmer Skillman Institute for Child and Family Development, Wayne State University, Detroit, MI, 48202, USA; Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, 48202, USA; Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI, 48202, USA
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Darnai G, Nagy SA, Horváth R, Ács P, Perlaki G, Orsi G, Kovács N, Altbäcker A, Plózer E, Tényi D, Weintraut R, Schwarcz A, John F, Varga E, Bereczkei T, Clemens Z, Komoly S, Janszky J. Iron Concentration in Deep Gray Matter Structures is Associated with Worse Visual Memory Performance in Healthy Young Adults. J Alzheimers Dis 2018; 59:675-681. [PMID: 28671115 PMCID: PMC5523837 DOI: 10.3233/jad-170118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Abnormally high deposition of iron can contribute to neurodegenerative disorders with cognitive impairment. Since previous studies investigating cognition-brain iron accumulation relationships focused on elderly people, our aim was to explore the association between iron concentration in subcortical nuclei and two types of memory performances in a healthy young population. Gender difference was found only in the globus pallidus. Our results showed that iron load characterized by R2* value on the MRI in the caudate and putamen was related to visual memory, while verbal memory was unrelated to iron concentration.
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Affiliation(s)
- Gergely Darnai
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary.,Institute of Psychology, University of Pécs, Pécs, Hungary.,Centre for Neuroscience, University of Pécs, Hungary.,MTA-PTE Clinical Neuroscience MR Research Group, Pécs, Hungary
| | - Szilvia Anett Nagy
- Pécs Diagnostic Centre, Pécs, Hungary.,MTA-PTE Clinical Neuroscience MR Research Group, Pécs, Hungary
| | - Réka Horváth
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary
| | - Péter Ács
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary
| | - Gábor Perlaki
- Pécs Diagnostic Centre, Pécs, Hungary.,MTA-PTE Clinical Neuroscience MR Research Group, Pécs, Hungary.,Department of Neurosurgery, University of Pécs, Medical School, Pécs, Hungary
| | - Gergely Orsi
- Pécs Diagnostic Centre, Pécs, Hungary.,MTA-PTE Clinical Neuroscience MR Research Group, Pécs, Hungary.,Department of Neurosurgery, University of Pécs, Medical School, Pécs, Hungary
| | - Norbert Kovács
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary.,MTA-PTE Clinical Neuroscience MR Research Group, Pécs, Hungary
| | - Anna Altbäcker
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary.,Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Enikő Plózer
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary
| | - Dalma Tényi
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary
| | - Rita Weintraut
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary
| | - Attila Schwarcz
- MTA-PTE Clinical Neuroscience MR Research Group, Pécs, Hungary.,Department of Neurosurgery, University of Pécs, Medical School, Pécs, Hungary
| | - Flóra John
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary
| | - Eszter Varga
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary
| | | | - Zsófia Clemens
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary
| | - Sámuel Komoly
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary
| | - József Janszky
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary.,Centre for Neuroscience, University of Pécs, Hungary.,MTA-PTE Clinical Neuroscience MR Research Group, Pécs, Hungary
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44
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Kazantseva IA, Kotov SV, Borodataya EV, Sidorova OP, Borodin AV. Mitochondrial disorders in multiple sclerosis. Zh Nevrol Psikhiatr Im S S Korsakova 2018; 118:5-9. [DOI: 10.17116/jnevro20181180825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Yamada J, Ohgomori T, Jinno S. Alterations in expression of Cat-315 epitope of perineuronal nets during normal ageing, and its modulation by an open-channel NMDA receptor blocker, memantine. J Comp Neurol 2017; 525:2035-2049. [PMID: 28271508 DOI: 10.1002/cne.24198] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/06/2017] [Accepted: 02/24/2017] [Indexed: 02/04/2023]
Abstract
The perineuronal net (PNN), a specialized aggregate of the extracellular matrix, is involved in neuroprotection against oxidative stress, which is now recognized as a major contributor to age-related decline in brain functions. In this study, we investigated the age-related molecular changes of PNNs using monoclonal antibody Cat-315, which recognizes human natural killer-1 (HNK-1) glycan on aggrecan-based PNNs. Western blot analysis showed that the expression levels of Cat-315 epitope in the hippocampus were higher in middle-aged (MA, 12-month-old) mice than in young adult (YA, 2-month-old) mice. Although there were no differences in the expression levels of Cat-315 epitope between old age (OA, 20-month-old) and MA mice, Cat-315 immunoreactivity was also detected in astrocytes of OA mice. To focus on Cat-315 epitope in PNNs, we used YA and MA mice in the following experiments. Optical disector analysis showed that there were no differences in the numbers of Cat-315-positive (Cat-315+ ) PNNs between YA and MA mice. Fluorescence intensity analysis indicated that Cat-315 immunoreactivity in PNNs increased with age in the dorsal hippocampus, which is mainly involved in cognitive functions. Administration of an open-channel blocker of NMDA receptor, memantine, reduced the expression levels of Cat-315 epitope in the hippocampus. Furthermore, the numbers of glutamatergic and GABAergic terminals colocalized with Cat-315 epitope around parvalbumin-positive neurons were decreased by memantine. These findings provide novel insight into the involvement of PNNs in normal brain ageing, and suggest that memantine may counteract the age-related alterations in expression levels of Cat-315 epitope via regulation of its subcellular localization.
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Affiliation(s)
- Jun Yamada
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Tomohiro Ohgomori
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Shozo Jinno
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
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Daugherty AM, Raz N. A virtual water maze revisited: Two-year changes in navigation performance and their neural correlates in healthy adults. Neuroimage 2016; 146:492-506. [PMID: 27659539 DOI: 10.1016/j.neuroimage.2016.09.044] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 09/12/2016] [Accepted: 09/17/2016] [Indexed: 11/30/2022] Open
Abstract
Age-related declines in spatial navigation are associated with deficits in procedural and episodic memory and deterioration of their neural substrates. For the lack of longitudinal evidence, the pace and magnitude of these declines and their neural mediators remain unclear. Here we examined virtual navigation in healthy adults (N=213, age 18-77 years) tested twice, two years apart, with complementary indices of navigation performance (path length and complexity) measured over six learning trials at each occasion. Slopes of skill acquisition curves and longitudinal change therein were estimated in structural equation modeling, together with change in regional brain volumes and iron content (R2* relaxometry). Although performance on the first trial did not differ between occasions separated by two years, the slope of path length improvement over trials was shallower and end-of-session performance worse at follow-up. Advanced age, higher pulse pressure, smaller cerebellar and caudate volumes, and greater caudate iron content were associated with longer search paths, i.e. poorer navigation performance. In contrast, path complexity diminished faster over trials at follow-up, albeit less so in older adults. Improvement in path complexity after two years was predicted by lower baseline hippocampal iron content and larger parahippocampal volume. Thus, navigation path length behaves as an index of perceptual-motor skill that is vulnerable to age-related decline, whereas path complexity may reflect cognitive mapping in episodic memory that improves with repeated testing, although not enough to overcome age-related deficits.
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Affiliation(s)
- Ana M Daugherty
- Institute of Gerontology, Wayne State University, Detroit, MI, USA; Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Champaign, IL, USA.
| | - Naftali Raz
- Institute of Gerontology, Wayne State University, Detroit, MI, USA; Department of Psychology, Wayne State University, Detroit, MI, USA
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Chapman SB, Aslan S, Spence JS, Keebler MW, DeFina LF, Didehbani N, Perez AM, Lu H, D'Esposito M. Distinct Brain and Behavioral Benefits from Cognitive vs. Physical Training: A Randomized Trial in Aging Adults. Front Hum Neurosci 2016; 10:338. [PMID: 27462210 PMCID: PMC4939293 DOI: 10.3389/fnhum.2016.00338] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 06/20/2016] [Indexed: 12/16/2022] Open
Abstract
Insidious declines in normal aging are well-established. Emerging evidence suggests that non-pharmacological interventions, specifically cognitive and physical training, may counter diminishing age-related cognitive and brain functions. This randomized trial compared effects of two training protocols: cognitive training (CT) vs. physical training (PT) on cognition and brain function in adults 56-75 years. Sedentary participants (N = 36) were randomized to either CT or PT group for 3 h/week over 12 weeks. They were assessed at baseline-, mid-, and post-training using neurocognitive, MRI, and physiological measures. The CT group improved on executive function whereas PT group's memory was enhanced. Uniquely deploying cerebral blood flow (CBF) and cerebral vascular reactivity (CVR) MRI, the CT cohort showed increased CBF within the prefrontal and middle/posterior cingulate cortex (PCC) without change to CVR compared to PT group. Improvements in complex abstraction were positively associated with increased resting CBF in dorsal anterior cingulate cortex (dACC). Exercisers with higher CBF in hippocampi bilaterally showed better immediate memory. The preliminary evidence indicates that increased cognitive and physical activity improves brain health in distinct ways. Reasoning training enhanced frontal networks shown to be integral to top-down cognitive control and brain resilience. Evidence of increased resting CBF without changes to CVR implicates increased neural health rather than improved vascular response. Exercise did not improve cerebrovascular response, although CBF increased in hippocampi of those with memory gains. Distinct benefits incentivize testing effectiveness of combined protocols to strengthen brain health.
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Affiliation(s)
- Sandra B Chapman
- Center for BrainHealth®, The University of Texas at Dallas Dallas, TX, USA
| | - Sina Aslan
- Center for BrainHealth®, The University of Texas at DallasDallas, TX, USA; Advance MRI, LLCFrisco, TX, USA
| | - Jeffrey S Spence
- Center for BrainHealth®, The University of Texas at Dallas Dallas, TX, USA
| | - Molly W Keebler
- Center for BrainHealth®, The University of Texas at Dallas Dallas, TX, USA
| | | | - Nyaz Didehbani
- Center for BrainHealth®, The University of Texas at DallasDallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical CenterDallas, TX, USA
| | - Alison M Perez
- Center for BrainHealth®, The University of Texas at Dallas Dallas, TX, USA
| | - Hanzhang Lu
- Department of Radiology and Radiological Science, Johns Hopkins University Baltimore, MD, USA
| | - Mark D'Esposito
- Helen Wills Neuroscience Institute, University of California Berkeley, CA, USA
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Steffener J, Gazes Y, Habeck C, Stern Y. The Indirect Effect of Age Group on Switch Costs via Gray Matter Volume and Task-Related Brain Activity. Front Aging Neurosci 2016; 8:162. [PMID: 27468265 PMCID: PMC4942475 DOI: 10.3389/fnagi.2016.00162] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 06/20/2016] [Indexed: 11/13/2022] Open
Abstract
Healthy aging simultaneously affects brain structure, brain function, and cognition. These effects are often investigated in isolation ignoring any relationships between them. It is plausible that age related declines in cognitive performance are the result of age-related structural and functional changes. This straightforward idea is tested in within a conceptual research model of cognitive aging. The current study tested whether age-related declines in task-performance were explained by age-related differences in brain structure and brain function using a task-switching paradigm in 175 participants. Sixty-three young and 112 old participants underwent MRI scanning of brain structure and brain activation. The experimental task was an executive context dual task with switch costs in response time as the behavioral measure. A serial mediation model was applied voxel-wise throughout the brain testing all pathways between age group, gray matter volume, brain activation and increased switch costs, worsening performance. There were widespread age group differences in gray matter volume and brain activation. Switch costs also significantly differed by age group. There were brain regions demonstrating significant indirect effects of age group on switch costs via the pathway through gray matter volume and brain activation. These were in the bilateral precuneus, bilateral parietal cortex, the left precentral gyrus, cerebellum, fusiform, and occipital cortices. There were also significant indirect effects via the brain activation pathway after controlling for gray matter volume. These effects were in the cerebellum, occipital cortex, left precentral gyrus, bilateral supramarginal, bilateral parietal, precuneus, middle cingulate extending to medial superior frontal gyri and the left middle frontal gyri. There were no significant effects through the gray matter volume alone pathway. These results demonstrate that a large proportion of the age group effect on switch costs can be attributed to individual differences in gray matter volume and brain activation. Therefore, age-related neural effects underlying cognitive control are a complex interaction between brain structure and function. Furthermore, the analyses demonstrate the feasibility of utilizing multiple neuroimaging modalities within a conceptual research model of cognitive aging.
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Affiliation(s)
- Jason Steffener
- PERFORM Center, Concordia University, MontrealQC, Canada; Centre de Recherche de l'Institut de Gériatrie de Montréal, MontréalQC, Canada; Department of Psychology, Concordia University, MontrealQC, Canada
| | - Yunglin Gazes
- Cognitive Neuroscience Division, Department of Neurology and Taub Institute for Research on Alzheimer's Disease and The Aging Brain, Columbia University College of Physicians and Surgeons, New York NY, USA
| | - Christian Habeck
- Cognitive Neuroscience Division, Department of Neurology and Taub Institute for Research on Alzheimer's Disease and The Aging Brain, Columbia University College of Physicians and Surgeons, New York NY, USA
| | - Yaakov Stern
- Cognitive Neuroscience Division, Department of Neurology and Taub Institute for Research on Alzheimer's Disease and The Aging Brain, Columbia University College of Physicians and Surgeons, New York NY, USA
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Abstract
UNLABELLED Disruption of iron homeostasis as a consequence of aging is thought to cause iron levels to increase, potentially promoting oxidative cellular damage. Therefore, understanding how this process evolves through the lifespan could offer insights into both the aging process and the development of aging-related neurodegenerative brain diseases. This work aimed to map, in vivo for the first time with an unbiased whole-brain approach, age-related iron changes using quantitative susceptibility mapping (QSM)--a new postprocessed MRI contrast mechanism. To this end, a full QSM standardization routine was devised and a cohort of N = 116 healthy adults (20-79 years of age) was studied. The whole-brain and ROI analyses confirmed that the propensity of brain cells to accumulate excessive iron as a function of aging largely depends on their exact anatomical location. Whereas only patchy signs of iron scavenging were observed in white matter, strong, bilateral, and confluent QSM-age associations were identified in several deep-brain nuclei--chiefly the striatum and midbrain-and across motor, premotor, posterior insular, superior prefrontal, and cerebellar cortices. The validity of QSM as a suitable in vivo imaging technique with which to monitor iron dysregulation in the human brain was demonstrated by confirming age-related increases in several subcortical nuclei that are known to accumulate iron with age. The study indicated that, in addition to these structures, there is a predilection for iron accumulation in the frontal lobes, which when combined with the subcortical findings, suggests that iron accumulation with age predominantly affects brain regions concerned with motor/output functions. SIGNIFICANCE STATEMENT This study used a whole--brain imaging approach known as quantitative susceptibility mapping (QSM) to provide a novel insight into iron accumulation in the brain across the adult lifespan. Validity of the method was demonstrated by showing concordance with ROI analysis and prior knowledge of iron accumulation in subcortical nuclei. We discovered that, beyond these regions, there is extensive involvement of the frontal lobes that has been missed by past ROI analyses. Broadly speaking, therefore, the motor system selectively accumulates iron with age. The results offer insights into the aging process, but also offer a new approach to studying the role of iron dysregulation in the evolution of age-related neurodegenerative diseases.
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Betts MJ, Acosta-Cabronero J, Cardenas-Blanco A, Nestor PJ, Düzel E. High-resolution characterisation of the aging brain using simultaneous quantitative susceptibility mapping (QSM) and R2* measurements at 7T. Neuroimage 2016; 138:43-63. [PMID: 27181761 DOI: 10.1016/j.neuroimage.2016.05.024] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 04/28/2016] [Accepted: 05/07/2016] [Indexed: 12/12/2022] Open
Abstract
Quantitative susceptibility mapping (QSM) has recently emerged as a novel magnetic resonance imaging (MRI) method to detect non-haem iron deposition, calcifications, demyelination and vascular lesions in the brain. It has been suggested that QSM is more sensitive than the more conventional quantifiable MRI measure, namely the transverse relaxation rate, R2*. Here, we conducted the first high-resolution, whole-brain, simultaneously acquired, comparative study of the two techniques using 7Tesla MRI. We asked which of the two techniques would be more sensitive to explore global differences in tissue composition in elderly adults relative to young subjects. Both QSM and R2* revealed strong age-related differences in subcortical regions, hippocampus and cortical grey matter, particularly in superior frontal regions, motor/premotor cortices, insula and cerebellar regions. Within the basal ganglia system-but also hippocampus and cerebellar dentate nucleus-, QSM was largely in agreement with R2* with the exception of the globus pallidus. QSM, however, provided superior anatomical contrast and revealed age-related differences in the thalamus and in white matter, which were otherwise largely undetected by R2* measurements. In contrast, in occipital cortex, age-related differences were much greater with R2* compared to QSM. The present study, therefore, demonstrated that in vivo QSM using ultra-high field MRI provides a novel means to characterise age-related differences in the human brain, but also combining QSM and R2* using multi-gradient recalled echo imaging can potentially provide a more complete picture of mineralisation, demyelination and/or vascular alterations in aging and disease.
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Affiliation(s)
- Matthew J Betts
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.
| | | | - Arturo Cardenas-Blanco
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany; Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany
| | - Peter J Nestor
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Emrah Düzel
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany; Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany; Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AR, UK
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