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Faulkner ME, Gong Z, Bilgel M, Laporte JP, Guo A, Bae J, Palchamy E, Kaileh M, Bergeron CM, Bergeron J, Church S, D’Agostino J, Ferrucci L, Bouhrara M. Evidence of association between higher cardiorespiratory fitness and higher cerebral myelination in aging. Proc Natl Acad Sci U S A 2024; 121:e2402813121. [PMID: 39159379 PMCID: PMC11363304 DOI: 10.1073/pnas.2402813121] [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: 02/13/2024] [Accepted: 07/10/2024] [Indexed: 08/21/2024] Open
Abstract
Emerging evidence suggests that altered myelination is an important pathophysiologic correlate of several neurodegenerative diseases, including Alzheimer and Parkinson's diseases. Thus, improving myelin integrity may be an effective intervention to prevent and treat age-associated neurodegenerative pathologies. It has been suggested that cardiorespiratory fitness (CRF) may preserve and enhance cerebral myelination throughout the adult lifespan, but this hypothesis has not been fully tested. Among cognitively normal participants from two well-characterized studies spanning a wide age range, we assessed CRF operationalized as the maximum rate of oxygen consumption (VO2max) and myelin content defined by myelin water fraction (MWF) estimated through our advanced multicomponent relaxometry MRI method. We found significant positive correlations between VO2max and MWF across several white matter regions. Interestingly, the effect size of this association was higher in brain regions susceptible to early degeneration, including the frontal lobes and major white matter fiber tracts. Further, the interaction between age and VO2max exhibited i) a steeper positive slope in the older age group, suggesting that the association of VO2max with MWF is stronger at middle and older ages and ii) a steeper negative slope in the lower VO2max group, indicating that lower VO2max levels are associated with lower myelination with increasing age. Finally, the nonlinear pattern of myelin maturation and decline is VO2max-dependent with the higher VO2max group reaching the MWF peak at later ages. This study provides evidence of an interconnection between CRF and cerebral myelination and suggests therapeutic strategies for promoting brain health and attenuating white matter degeneration.
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Affiliation(s)
- Mary E. Faulkner
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD21224
| | - Zhaoyuan Gong
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD21224
| | - Murat Bilgel
- Laboratory of Behavioral Neuroscience, National Institute on Aging, NIH, Baltimore, MD21224
| | - John P. Laporte
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD21224
| | - Alex Guo
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD21224
| | - Jonghyun Bae
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD21224
| | - Elango Palchamy
- Translational Gerontology Branch, National Institute on Aging, NIH, Baltimore, MD21224
| | - Mary Kaileh
- Clinical Research Core, National Institute on Aging, NIH, Baltimore, MD21224
| | | | - Jan Bergeron
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD21224
| | - Sarah Church
- Clinical Research Core, National Institute on Aging, NIH, Baltimore, MD21224
| | - Jarod D’Agostino
- Clinical Research Core, National Institute on Aging, NIH, Baltimore, MD21224
| | - Luigi Ferrucci
- Translational Gerontology Branch, National Institute on Aging, NIH, Baltimore, MD21224
| | - Mustapha Bouhrara
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD21224
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Faulkner ME, Gong Z, Guo A, Laporte JP, Bae J, Bouhrara M. Harnessing myelin water fraction as an imaging biomarker of human cerebral aging, neurodegenerative diseases, and risk factors influencing myelination: A review. J Neurochem 2024. [PMID: 38973579 DOI: 10.1111/jnc.16170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 06/12/2024] [Accepted: 06/19/2024] [Indexed: 07/09/2024]
Abstract
Myelin water fraction (MWF) imaging has emerged as a promising magnetic resonance imaging (MRI) biomarker for investigating brain function and composition. This comprehensive review synthesizes the current state of knowledge on MWF as a biomarker of human cerebral aging, neurodegenerative diseases, and risk factors influencing myelination. The databases used include Web of Science, Scopus, Science Direct, and PubMed. We begin with a brief discussion of the theoretical foundations of MWF imaging, including its basis in MR physics and the mathematical modeling underlying its calculation, with an overview of the most adopted MRI methods of MWF imaging. Next, we delve into the clinical and research applications that have been explored to date, highlighting its advantages and limitations. Finally, we explore the potential of MWF to serve as a predictive biomarker for neurological disorders and identify future research directions for optimizing MWF imaging protocols and interpreting MWF in various contexts. By harnessing the power of MWF imaging, we may gain new insights into brain health and disease across the human lifespan, ultimately informing novel diagnostic and therapeutic strategies.
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Affiliation(s)
- Mary E Faulkner
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Zhaoyuan Gong
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Alex Guo
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - John P Laporte
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Jonghyun Bae
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Mustapha Bouhrara
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
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Abdel-Halim NHM, Eid EA, Yehya YM, Taha M, Mosa AAH, Ammar O, Nasr ANA, Hussin E, Hussein AM. Effect of New Antidiabetics on Steatosis in Nerve Tissues and Nerve Conduction Velocity: Possible Role of Nerve Growth Factor (NGF)/Synaptophysin and Nrf2/HO-1 Pathways. Cureus 2024; 16:e65726. [PMID: 39211670 PMCID: PMC11358857 DOI: 10.7759/cureus.65726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2024] [Indexed: 09/04/2024] Open
Abstract
OBJECTIVES The current study aims to investigate the impact of the GLP1 analog (semaglutide) and SGLT2 inhibitor (dapagliflozin) on nerve functions, morphology, and the underlying mechanisms involving nerve growth factor (NGF)/synaptophysin and Nrf2/HO-1 pathways in obese rats. METHODS Forty male Sprague Dawley rats, aged six to eight weeks, were classified into five groups; normal group (high-fat diet {HFD} for 12 weeks, metformin group (HFD for 12 weeks + metformin in last four weeks), dapagliflozin group (HFD for 12 weeks +dapagliflozin in last four weeks, semaglutide group (HFD for 12 weeks + semaglutide in last four weeks). At the end of the experiment, the sciatic nerve was collected for nerve conduction study, oxidative stress marker (malondialdehyde, i.e., MDA), real-time polymerase chain reaction (PCR) study (for HO-1 and Nrf2), oil red O staining, electron microscopic examination and immunohistochemistry for NGF and synaptophysin. RESULTS The HFD group showed a significant rise in blood glucose, serum lipids, homeostatic model assessment (HOMA) index, lipid deposition in nerve tissues, and lipid peroxidation (MDA) in nerve tissues with significant attenuation in nerve conduction velocity (NCV), the expression of Nrf2 and HO-1 genes and significant attenuation in area stained with NGF and synaptophysin. On the other hand, pretreatment with either dapagliflozin or semaglutide led to considerable enhancement in the deteriorated serum and nerve tissue parameters and reversed the pathological changes. CONCLUSION New antidiabetic drugs like SGLT2 inhibitors (more powerful) and GLP1 analog might have neuroprotective beneficial effects besides controlling the glycemic state in obese rats. This effect may result from reduced oxidative stress and increased Nrf2 levels, HO-1, synaptophysin, and NGF in the nerve tissues of obese rats.
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Affiliation(s)
- Nehal H M Abdel-Halim
- Department of Medical Physiology, Faculty of Medicine, Mansoura University, Mansoura, EGY
| | - Elsayed A Eid
- Department of Internal Medicine, Faculty of Medicine, Delta University for Science and Technology, Gamasa, EGY
| | - Yomna M Yehya
- Department of Medical Physiology, Faculty of Medicine, Mansoura University, Mansoura, EGY
| | - Medhat Taha
- Department of Anatomy, Umm Al-Qura University, Al-Qunfudhah, SAU
- Department of Anatomy and Embryology, Faculty of Medicine, Mansoura University, Mansoura, EGY
| | - Ahmed A H Mosa
- Department of Neurology, Faculty of Medicine, Delta University for Science and Technology, Gamasa, EGY
| | - Omar Ammar
- Department of Basic Sciences, Delta University for Science and Technology, Gamasa, EGY
| | - Ahmed N A Nasr
- Department of Anatomy and Embryology, Faculty of Medicine, Mansoura University, Mansoura, EGY
| | - Emadeldeen Hussin
- Department of Anatomy and Embryology, Faculty of Medicine, Mansoura University, Mansoura, EGY
| | - Abdelaziz M Hussein
- Department of Medical Physiology, Faculty of Medicine, Mansoura University, Mansoura, EGY
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Ahmed M, Lai AY, Hill ME, Ribeiro JA, Amiraslani A, McLaurin J. Obesity differentially effects the somatosensory cortex and striatum of TgF344-AD rats. Sci Rep 2024; 14:7235. [PMID: 38538727 PMCID: PMC10973391 DOI: 10.1038/s41598-024-57953-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 03/23/2024] [Indexed: 04/04/2024] Open
Abstract
Lifestyle choices leading to obesity, hypertension and diabetes in mid-life contribute directly to the risk of late-life Alzheimer's disease (AD). However, in late-life or in late-stage AD conditions, obesity reduces the risk of AD and disease progression. To examine the mechanisms underlying this paradox, TgF344-AD rats were fed a varied high-carbohydrate, high-fat (HCHF) diet to induce obesity from nine months of age representing early stages of AD to twelve months of age in which rats exhibit the full spectrum of AD symptomology. We hypothesized regions primarily composed of gray matter, such as the somatosensory cortex (SSC), would be differentially affected compared to regions primarily composed of white matter, such as the striatum. We found increased myelin and oligodendrocytes in the somatosensory cortex of rats fed the HCHF diet with an absence of neuronal loss. We observed decreased inflammation in the somatosensory cortex despite increased AD pathology. Compared to the somatosensory cortex, the striatum had fewer changes. Overall, our results suggest that the interaction between diet and AD progression affects myelination in a brain region specific manner such that regions with a lower density of white matter are preferentially affected. Our results offer a possible mechanistic explanation for the obesity paradox.
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Affiliation(s)
- Minhal Ahmed
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Aaron Y Lai
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
| | - Mary E Hill
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
| | - Jessica A Ribeiro
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
| | - Ashley Amiraslani
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - JoAnne McLaurin
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada.
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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Sun J, Zeng N, Hui Y, Li J, Liu W, Zhao X, Zhao P, Chen S, Wu S, Wang Z, Lv H. Association of variability in body size with neuroimaging metrics of brain health: a population-based cohort study. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2024; 44:101015. [PMID: 38328337 PMCID: PMC10848022 DOI: 10.1016/j.lanwpc.2024.101015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/02/2024] [Accepted: 01/10/2024] [Indexed: 02/09/2024]
Abstract
Background The relationship between the fluctuation in body size and brain health is poorly understood. This study aimed to examine the associations of long-term variability in body mass index (BMI) and waist-to-hip ratio (WHR) with neuroimaging metrics that approximate brain health. Methods This cohort study recruited 1114 participants aged 25-83 years from a multicenter, community-based cohort study in China. We modeled the BMI and WHR trajectories of participants during 2006-2018 and assessed the BMI and WHR variability (direction and speed of change) by calculating the slope. Generalized linear models were applied to investigate the associations of BMI and WHR variability with MRI markers of brain tissue volume, white matter microstructural integrity, white matter hyperintensity (WMH), and cerebral small vessel disease (CSVD). Findings Progressive weight gain during follow-up was associated with lower global fractional anisotropy (beta = -0.18, 95% confidence interval [CI] -0.34 to -0.02), higher mean diffusivity (beta = 0.15, 95% CI 0.01-0.30) and radial diffusivity (beta = 0.17, 95% CI 0.02-0.32). Weight loss was also associated with a lower burden of periventricular WMH (beta = -0.26, 95% CI -0.48 to -0.03) and a lower risk of moderate-to-severe basal ganglia enlarged perivascular spaces (BG-EPVS, odds ratio [OR] = 0.41, 95% CI 0.20-0.83). Among overweight populations, weight loss was linked with smaller volumes of WMH (beta = -0.47, 95% CI -0.79 to -0.15), periventricular WMH (beta = -0.57, 95% CI -0.88 to -0.26), and deep WMH (beta = -0.36, 95% CI -0.69 to -0.03), as well as lower risk of CSVD (OR = 0.22, 95% CI 0.08-0.62), lacune (OR = 0.12, 95% CI 0.01-0.91) and moderate-to-severe BG-EPVS (OR = 0.24, 95% CI 0.09-0.61). In adults with central obesity, WHR loss was positively associated with larger gray matter volume (beta = 0.50, 95% CI 0.11-0.89), hippocampus volume (beta = 0.62, 95% CI 0.15-1.09), and parahippocampal gyrus volume (beta = 0.85, 95% CI 0.34-1.37). The sex-stratification and age-stratification analyses revealed similar findings with the main results, with the pattern of associations significantly presented in the individuals at mid-life and late-life. Interpretation Long-term stability of BMI level is essential for maintaining brain health. Progressive weight gain is associated with impaired white matter microstructural integrity. Weight and WHR losses are associated with improved general brain health. Our results contribute to a better understanding of the integrated associations between variations in obesity measures and brain health. Funding This study was supported by grants No. 62171297 (Han Lv) and 61931013 (Zhenchang Wang) from the National Natural Science Foundation of China, No. 7242267 from the Beijing Natural Science Foundation (Han Lv), and No. [2015] 160 from the Beijing Scholars Program (Zhenchang Wang).
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Affiliation(s)
- Jing Sun
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yongan Road, Xicheng District, Beijing 100050, China
| | - Na Zeng
- School of Public Health, Peking University, Beijing 100191, China
| | - Ying Hui
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yongan Road, Xicheng District, Beijing 100050, China
| | - Jing Li
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yongan Road, Xicheng District, Beijing 100050, China
| | - Wenjuan Liu
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yongan Road, Xicheng District, Beijing 100050, China
| | - Xinyu Zhao
- Clinical Epidemiology and Evidence-based Medicine Unit, Capital Medical University, No. 95 Yongan Road, Xicheng District, Beijing 100050, China
| | - Pengfei Zhao
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yongan Road, Xicheng District, Beijing 100050, China
| | - Shuohua Chen
- Department of Cardiology, Kailuan General Hospital, Tangshan, Hebei 063000, China
| | - Shouling Wu
- Department of Cardiology, Kailuan General Hospital, Tangshan, Hebei 063000, China
| | - Zhenchang Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yongan Road, Xicheng District, Beijing 100050, China
| | - Han Lv
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yongan Road, Xicheng District, Beijing 100050, China
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Cao HL, Wei W, Meng YJ, Deng RH, Li XJ, Deng W, Liu YS, Tang Z, Du XD, Greenshaw AJ, Li ML, Li T, Guo WJ. Interactions between overweight/obesity and alcohol dependence impact human brain white matter microstructure: evidence from DTI. Eur Arch Psychiatry Clin Neurosci 2024:10.1007/s00406-024-01760-9. [PMID: 38403735 DOI: 10.1007/s00406-024-01760-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 01/13/2024] [Indexed: 02/27/2024]
Abstract
There is inconsistent evidence for an association of obesity with white matter microstructural alterations. Such inconsistent findings may be related to the cumulative effects of obesity and alcohol dependence. This study aimed to investigate the possible interactions between alcohol dependence and overweight/obesity on white matter microstructure in the human brain. A total of 60 inpatients with alcohol dependence during early abstinence (44 normal weight and 16 overweight/obese) and 65 controls (42 normal weight and 23 overweight/obese) were included. The diffusion tensor imaging (DTI) measures [fractional anisotropy (FA) and radial diffusivity (RD)] of the white matter microstructure were compared between groups. We observed significant interactive effects between alcohol dependence and overweight/obesity on DTI measures in several tracts. The DTI measures were not significantly different between the overweight/obese and normal-weight groups (although widespread trends of increased FA and decreased RD were observed) among controls. However, among the alcohol-dependent patients, the overweight/obese group had widespread reductions in FA and widespread increases in RD, most of which significantly differed from the normal-weight group; among those with overweight/obesity, the alcohol-dependent group had widespread reductions in FA and widespread increases in RD, most of which were significantly different from the control group. This study found significant interactive effects between overweight/obesity and alcohol dependence on white matter microstructure, indicating that these two controllable factors may synergistically impact white matter microstructure and disrupt structural connectivity in the human brain.
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Affiliation(s)
- Hai-Ling Cao
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Wei Wei
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310063, China
| | - Ya-Jing Meng
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Ren-Hao Deng
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Xiao-Jing Li
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310063, China
| | - Wei Deng
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310063, China
| | - Yan-Song Liu
- Department of Clinical Psychology, Suzhou Psychiatric Hospital, The Affiliated Guangji Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Zhen Tang
- Department of Clinical Psychology, Suzhou Psychiatric Hospital, The Affiliated Guangji Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Xiang-Dong Du
- Department of Clinical Psychology, Suzhou Psychiatric Hospital, The Affiliated Guangji Hospital of Soochow University, Suzhou, Jiangsu, China
| | | | - Ming-Li Li
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Tao Li
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310063, China
| | - Wan-Jun Guo
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310063, China.
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-Machine Integration, State Key Laboratory of Brain-Machine Intelligence, Zhejiang University, 1369 West Wenyi Road, Hangzhou, 311121, China.
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Kim MS, Pickering TA, Cotter DL, Fraga NR, Luo S, Won CY, Geffner ME, Herting MM. Neural Correlates of Obesity and Inflammation in Children and Adolescents with Congenital Adrenal Hyperplasia. Horm Res Paediatr 2024:000537847. [PMID: 38373413 PMCID: PMC11331025 DOI: 10.1159/000537847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 02/11/2024] [Indexed: 02/21/2024] Open
Abstract
INTRODUCTION Patients with classical congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency exhibit an increased prevalence of obesity from childhood including central adiposity and inflammation. There is also an emerging affected brain phenotype in CAH, with decreased cortico-limbic gray matter volumes and white matter abnormalities. We aimed to study the relationship between brain structure, obesity, and inflammation in children and adolescents with CAH compared to controls. METHODS 27 CAH (12.6±3.4y, 16 females) and 35 controls (13.0±2.8y, 20 females) had MRI of gray matter regions of interest [prefrontal cortex (PFC), amygdala, hippocampus] and white matter microstructure [fornix, stria terminalis (ST)]. Anthropometric measures and lab analytes were obtained. Relaimpo analyses (relative importance for linear regression; percent variance) identified which brain structures were most different between groups. Subsequent regressions further quantified the magnitude and direction of these relationships. Correlations analyzed relationships between brain structure, obesity, and inflammation in the context of CAH status. RESULTS PFC (13.3% variance) and its superior frontal (SF) subregion (14%) were most different between CAH and controls for gray matter; ST (16%) for white matter. Patients with CAH had lower caudal middle frontal [β = -0.56, (-0.96, -0.15)] and superior frontal [β = -0.58 (-0.92, -0.25)] subregion volumes, increased orientation dispersion index in the fornix [β = 0.56 (0.01, 1.10)] and ST [β = 0.85 (0.34, 1.36)], and decreased fractional anisotropy in the fornix [β = -0.91 (-1.42, -0.42)] and ST [β = -0.83 (-1.34, -0.33)] (all p's <0.05) indicating axonal disorganization, reduced myelin content, and/or higher microglial density within the affected white matter tracts. For the full cohort, SF was correlated with MCP-1 (r=-0.41), visceral adipose tissue (r=-0.25), and waist-to-height ratio (r=-0.27, all p's <0.05); ST was correlated with MCP-1 (r=0.31) and TNF-α (r= 0.29, all p's <0.05); however, after adjusting for CAH status, almost all correlations were attenuated for significance. CONCLUSIONS Relationships among key brain structures, body composition and inflammatory markers in pediatric patients with CAH could be largely driven by having CAH, with implications for obesity and neuroinflammation in this high-risk population.
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Affiliation(s)
- Mimi S. Kim
- Children’s Hospital Los Angeles, Center for Endocrinology, Diabetes and Metabolism, Los Angeles, CA, USA
- The Saban Research Institute at Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Department of Pediatrics, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - Trevor A. Pickering
- Department of Population and Public Health Sciences, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
| | - Devyn L. Cotter
- Department of Population and Public Health Sciences, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
| | - Nicole R. Fraga
- Children’s Hospital Los Angeles, Center for Endocrinology, Diabetes and Metabolism, Los Angeles, CA, USA
| | - Shan Luo
- Department of Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
- Department of Psychology, University of Southern California, Los Angeles, CA, USA
| | - Cindy Y. Won
- Children’s Hospital Los Angeles, Center for Endocrinology, Diabetes and Metabolism, Los Angeles, CA, USA
| | - Mitchell E. Geffner
- Children’s Hospital Los Angeles, Center for Endocrinology, Diabetes and Metabolism, Los Angeles, CA, USA
- The Saban Research Institute at Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Department of Pediatrics, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - Megan M. Herting
- Department of Population and Public Health Sciences, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
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Burzynska AZ, Anderson C, Arciniegas DB, Calhoun V, Choi IY, Mendez Colmenares A, Kramer AF, Li K, Lee J, Lee P, Thomas ML. Correlates of axonal content in healthy adult span: Age, sex, myelin, and metabolic health. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2024; 6:100203. [PMID: 38292016 PMCID: PMC10827486 DOI: 10.1016/j.cccb.2024.100203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 02/01/2024]
Abstract
As the emerging treatments that target grey matter pathology in Alzheimer's Disease have limited effectiveness, there is a critical need to identify new neural targets for treatments. White matter's (WM) metabolic vulnerability makes it a promising candidate for new interventions. This study examined the age and sex differences in estimates of axonal content, as well the associations of with highly prevalent modifiable health risk factors such as metabolic syndrome and adiposity. We estimated intra-axonal volume fraction (ICVF) using the Neurite Orientation Dispersion and Density Imaging (NODDI) in a sample of 89 cognitively and neurologically healthy adults (20-79 years). We showed that ICVF correlated positively with age and estimates of myelin content. The ICVF was also lower in women than men, across all ages, which difference was accounted for by intracranial volume. Finally, we found no association of metabolic risk or adiposity scores with the current estimates of ICVF. In addition, the previously observed adiposity-myelin associations (Burzynska et al., 2023) were independent of ICVF. Although our findings confirm the vulnerability of axons to aging, they suggest that metabolic dysfunction may selectively affect myelin content, at least in cognitively and neurologically healthy adults with low metabolic risk, and when using the specific MRI techniques. Future studies need to revisit our findings using larger samples and different MRI approaches, and identify modifiable factors that accelerate axonal deterioration as well as mechanisms linking peripheral metabolism with the health of myelin.
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Affiliation(s)
- Agnieszka Z Burzynska
- The BRAiN lab, Department of Human Development and Family Studies/Molecular, Cellular and Integrative Neurosciences, Colorado State University, Fort Collins, CO, USA
| | - Charles Anderson
- Department of Computer Science, Colorado State University, Fort Collins, CO, USA
| | - David B. Arciniegas
- Marcus Institute for Brain Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Vince Calhoun
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science (TReNDS), Georgia State, Georgia Tech, Emory, Atlanta, GA, USA
| | - In-Young Choi
- Department of Neurology, Department of Radiology, Hoglund Biomedical Imaging Center, University of Kansas Medical Center, Kansas City, KS, USA
| | - Andrea Mendez Colmenares
- The BRAiN lab, Department of Human Development and Family Studies/Molecular, Cellular and Integrative Neurosciences, Colorado State University, Fort Collins, CO, USA
| | - Arthur F Kramer
- Beckman Institute for Advanced Science and Technology at the University of Illinois, IL, USA
- Center for Cognitive & Brain Health, Northeastern University, Boston, MA, USA
| | - Kaigang Li
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Jongho Lee
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, Republic of Korea
| | - Phil Lee
- Department of Radiology, Hoglund Biomedical Imaging Center, University of Kansas Medical Center, Kansas City, KS, USA
| | - Michael L Thomas
- Department of Psychology, Colorado State University, Fort Collins, CO, USA
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Kueck PJ, Morris JK, Stanford JA. Current Perspectives: Obesity and Neurodegeneration - Links and Risks. Degener Neurol Neuromuscul Dis 2023; 13:111-129. [PMID: 38196559 PMCID: PMC10774290 DOI: 10.2147/dnnd.s388579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 12/21/2023] [Indexed: 01/11/2024] Open
Abstract
Obesity is increasing in prevalence across all age groups. Long-term obesity can lead to the development of metabolic and cardiovascular diseases through its effects on adipose, skeletal muscle, and liver tissue. Pathological mechanisms associated with obesity include immune response and inflammation as well as oxidative stress and consequent endothelial and mitochondrial dysfunction. Recent evidence links obesity to diminished brain health and neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Both AD and PD are associated with insulin resistance, an underlying syndrome of obesity. Despite these links, causative mechanism(s) resulting in neurodegenerative disease remain unclear. This review discusses relationships between obesity, AD, and PD, including clinical and preclinical findings. The review then briefly explores nonpharmacological directions for intervention.
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Affiliation(s)
- Paul J Kueck
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Jill K Morris
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- University of Kansas Alzheimer’s Disease Research Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - John A Stanford
- University of Kansas Alzheimer’s Disease Research Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- Landon Center on Aging, University of Kansas Medical Center, Kansas City, KS, 66160, USA
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10
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Kilpatrick LA, Zhang K, Dong TS, Gee GC, Beltran-Sanchez H, Wang M, Labus JS, Naliboff BD, Mayer EA, Gupta A. Mediation of the association between disadvantaged neighborhoods and cortical microstructure by body mass index. COMMUNICATIONS MEDICINE 2023; 3:122. [PMID: 37714947 PMCID: PMC10504354 DOI: 10.1038/s43856-023-00350-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 08/21/2023] [Indexed: 09/17/2023] Open
Abstract
BACKGROUND Living in a disadvantaged neighborhood is associated with worse health outcomes, including brain health, yet the underlying biological mechanisms are incompletely understood. We investigated the relationship between neighborhood disadvantage and cortical microstructure, assessed as the T1-weighted/T2-weighted ratio (T1w/T2w) on magnetic resonance imaging, and the potential mediating roles of body mass index (BMI) and stress, as well as the relationship between trans-fatty acid intake and cortical microstructure. METHODS Participants comprised 92 adults (27 men; 65 women) who underwent neuroimaging and provided residential address information. Neighborhood disadvantage was assessed as the 2020 California State area deprivation index (ADI). The T1w/T2w ratio was calculated at four cortical ribbon levels (deep, lower-middle, upper-middle, and superficial). Perceived stress and BMI were assessed as potential mediating factors. Dietary data was collected in 81 participants. RESULTS Here, we show that worse ADI is positively correlated with BMI (r = 0.27, p = .01) and perceived stress (r = 0.22, p = .04); decreased T1w/T2w ratio in middle/deep cortex in supramarginal, temporal, and primary motor regions (p < .001); and increased T1w/T2w ratio in superficial cortex in medial prefrontal and cingulate regions (p < .001). Increased BMI partially mediates the relationship between worse ADI and observed T1w/T2w ratio increases (p = .02). Further, trans-fatty acid intake (high in fried fast foods and obesogenic) is correlated with these T1w/T2w ratio increases (p = .03). CONCLUSIONS Obesogenic aspects of neighborhood disadvantage, including poor dietary quality, may disrupt information processing flexibility in regions involved in reward, emotion regulation, and cognition. These data further suggest ramifications of living in a disadvantaged neighborhood on brain health.
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Affiliation(s)
- Lisa A Kilpatrick
- Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
- Goodman-Luskin Microbiome Center, University of California, Los Angeles, CA, USA.
- G. Oppenheimer Center for Neurobiology of Stress and Resilience, University of California, Los Angeles, CA, USA.
| | - Keying Zhang
- Goodman-Luskin Microbiome Center, University of California, Los Angeles, CA, USA
| | - Tien S Dong
- Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Goodman-Luskin Microbiome Center, University of California, Los Angeles, CA, USA
- G. Oppenheimer Center for Neurobiology of Stress and Resilience, University of California, Los Angeles, CA, USA
- Division of Gastroenterology, Hepatology and Parenteral Nutrition, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Gilbert C Gee
- Department of Community Health Sciences, Fielding School of Public Health, University of California, Los Angeles, CA, USA
- California Center for Population Research, University of California, Los Angeles, CA, USA
| | - Hiram Beltran-Sanchez
- Department of Community Health Sciences, Fielding School of Public Health, University of California, Los Angeles, CA, USA
- California Center for Population Research, University of California, Los Angeles, CA, USA
| | - May Wang
- Department of Community Health Sciences, Fielding School of Public Health, University of California, Los Angeles, CA, USA
| | - Jennifer S Labus
- Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Goodman-Luskin Microbiome Center, University of California, Los Angeles, CA, USA
- G. Oppenheimer Center for Neurobiology of Stress and Resilience, University of California, Los Angeles, CA, USA
| | - Bruce D Naliboff
- Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Goodman-Luskin Microbiome Center, University of California, Los Angeles, CA, USA
- G. Oppenheimer Center for Neurobiology of Stress and Resilience, University of California, Los Angeles, CA, USA
| | - Emeran A Mayer
- Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Goodman-Luskin Microbiome Center, University of California, Los Angeles, CA, USA
- G. Oppenheimer Center for Neurobiology of Stress and Resilience, University of California, Los Angeles, CA, USA
| | - Arpana Gupta
- Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
- Goodman-Luskin Microbiome Center, University of California, Los Angeles, CA, USA.
- G. Oppenheimer Center for Neurobiology of Stress and Resilience, University of California, Los Angeles, CA, USA.
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11
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Gong Z, Khattar N, Kiely M, Triebswetter C, Bouhrara M. REUSED: A deep neural network method for rapid whole-brain high-resolution myelin water fraction mapping from extremely under-sampled MRI. Comput Med Imaging Graph 2023; 108:102282. [PMID: 37586261 PMCID: PMC10528830 DOI: 10.1016/j.compmedimag.2023.102282] [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: 01/05/2023] [Revised: 07/23/2023] [Accepted: 07/24/2023] [Indexed: 08/18/2023]
Abstract
Changes in myelination are a cardinal feature of brain development and the pathophysiology of several central nervous system diseases, including multiple sclerosis and dementias. Advanced magnetic resonance imaging (MRI) methods have been developed to probe myelin content through the measurement of myelin water fraction (MWF). However, the prolonged data acquisition and post-processing times of current MWF mapping methods pose substantial hurdles to their clinical implementation. Recently, fast steady-state MRI sequences have been implemented to produce high-spatial resolution whole-brain MWF mapping within ∼20 min. Despite the subsequent significant advances in the inversion algorithm to derive MWF maps from steady-state MRI, the high-dimensional nature of such inversion does not permit further reduction of the acquisition time by data under-sampling. In this work, we present an unprecedented reduction in the computation (∼30 s) and the acquisition time (∼7 min) required for whole-brain high-resolution MWF mapping through a new Neural Network (NN)-based approach, named NN-Relaxometry of Extremely Under-SamplEd Data (NN-REUSED). Our analyses demonstrate virtually similar accuracy and precision in derived MWF values using NN-REUSED compared to results derived from the fully sampled reference method. The reduction in the acquisition and computation times represents a breakthrough toward clinically practical MWF mapping.
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Affiliation(s)
- Zhaoyuan Gong
- Magnetic Resonance Physics of Aging and Dementia Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
| | | | - Matthew Kiely
- Magnetic Resonance Physics of Aging and Dementia Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Curtis Triebswetter
- Magnetic Resonance Physics of Aging and Dementia Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Mustapha Bouhrara
- Magnetic Resonance Physics of Aging and Dementia Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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Burzynska AZ, Anderson C, Arciniegas DB, Calhoun V, Choi IY, Colmenares AM, Hiner G, Kramer AF, Li K, Lee J, Lee P, Oh SH, Umland S, Thomas ML. Metabolic syndrome and adiposity: Risk factors for decreased myelin in cognitively healthy adults. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2023; 5:100180. [PMID: 38162292 PMCID: PMC10757180 DOI: 10.1016/j.cccb.2023.100180] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 08/11/2023] [Accepted: 08/17/2023] [Indexed: 01/03/2024]
Abstract
Metabolic syndrome (MetS) is a cluster of conditions that affects ∼25% of the global population, including excess adiposity, hyperglycemia, dyslipidemia, and elevated blood pressure. MetS is one of major risk factors not only for chronic diseases, but also for dementia and cognitive dysfunction, although the underlying mechanisms remain poorly understood. White matter is of particular interest in the context of MetS due to the metabolic vulnerability of myelin maintenance, and the accumulating evidence for the importance of the white matter in the pathophysiology of dementia. Therefore, we investigated the associations of MetS risk score and adiposity (combined body mass index and waist circumference) with myelin water fraction measured with myelin water imaging. In 90 cognitively and neurologically healthy adults (20-79 years), we found that both high MetS risk score and adiposity were correlated with lower myelin water fraction in late-myelinating prefrontal and associative fibers, controlling for age, sex, race, ethnicity, education and income. Our findings call for randomized clinical trials to establish causality between MetS, adiposity, and myelin content, and to explore the potential of weight loss and visceral adiposity reduction as means to support maintenance of myelin integrity throughout adulthood, which could open new avenues for prevention or treatment of cognitive decline and dementia.
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Affiliation(s)
- Agnieszka Z Burzynska
- The BRAiN lab, Department of Human Development and Family Studies/Molecular, Cellular and Integrative Neurosciences, Colorado State University, Fort Collins, CO, USA
| | - Charles Anderson
- Department of Computer Science, Colorado State University, Fort Collins, CO, USA
| | - David B Arciniegas
- Marcus Institute for Brain Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Psychiatry and Behavioral Sciences, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Vince Calhoun
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science (TReNDS), Georgia State, Georgia Tech, Emory, Atlanta, GA, USA
| | - In-Young Choi
- Department of Neurology, Department of Radiology, Hoglund Biomedical Imaging Center, University of Kansas Medical Center, Kansas City, KS, USA
| | - Andrea Mendez Colmenares
- The BRAiN lab, Department of Human Development and Family Studies/Molecular, Cellular and Integrative Neurosciences, Colorado State University, Fort Collins, CO, USA
| | - Grace Hiner
- The BRAiN lab, Department of Human Development and Family Studies/Molecular, Cellular and Integrative Neurosciences, Colorado State University, Fort Collins, CO, USA
| | - Arthur F Kramer
- Beckman Institute for Advanced Science and Technology at the University of Illinois, IL, USA
- Center for Cognitive & Brain Health, Northeastern University, Boston, MA, USA
| | - Kaigang Li
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Jongho Lee
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, Republic of Korea
| | - Phil Lee
- Department of Radiology, Hoglund Biomedical Imaging Center, University of Kansas Medical Center, Kansas City, KS, USA
| | - Se-Hong Oh
- Division of Biomedical Engineering, Hankuk University of Foreign Studies, Gyeonggi-do, Republic of Korea
| | - Samantha Umland
- The BRAiN lab, Department of Human Development and Family Studies/Molecular, Cellular and Integrative Neurosciences, Colorado State University, Fort Collins, CO, USA
| | - Michael L Thomas
- Michael Thomas, Department of Psychology, Colorado State University, Fort Collins, CO, USA
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Laporte JP, Faulkner ME, Gong Z, Akhonda MA, Ferrucci L, Egan JM, Bouhrara M. Hypertensive Adults Exhibit Lower Myelin Content: A Multicomponent Relaxometry and Diffusion Magnetic Resonance Imaging Study. Hypertension 2023; 80:1728-1738. [PMID: 37283066 PMCID: PMC10355798 DOI: 10.1161/hypertensionaha.123.21012] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/11/2023] [Indexed: 06/08/2023]
Abstract
BACKGROUND It is unknown whether hypertension plays any role in cerebral myelination. To fill this knowledge gap, we studied 90 cognitively unimpaired adults, age range 40 to 94 years, who are participants in the Baltimore Longitudinal Study of Aging and the Genetic and Epigenetic Signatures of Translational Aging Laboratory Testing to look for potential associations between hypertension and cerebral myelin content across 14 white matter brain regions. METHODS Myelin content was probed using our advanced multicomponent magnetic resonance relaxometry method of myelin water fraction, a direct and specific magnetic resonance imaging measure of myelin content, and longitudinal and transverse relaxation rates (R1 and R2), 2 highly sensitive magnetic resonance imaging metrics of myelin content. We also applied diffusion tensor imaging magnetic resonance imaging to measure fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity values, which are metrics of cerebral microstructural tissue integrity, to provide context with previous magnetic resonance imaging findings. RESULTS After adjustment of age, sex, systolic blood pressure, smoking status, diabetes status, and cholesterol level, our results indicated that participants with hypertension exhibited lower myelin water fraction, fractional anisotropy, R1 and R2 values and higher mean diffusivity, radial diffusivity, and axial diffusivity values, indicating lower myelin content and higher impairment to the brain microstructure. These associations were significant across several white matter regions, particularly in the corpus callosum, fronto-occipital fasciculus, temporal lobes, internal capsules, and corona radiata. CONCLUSIONS These original findings suggest a direct association between myelin content and hypertension and form the basis for further investigations including longitudinal assessments of this relationship.
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Affiliation(s)
- John P. Laporte
- Laboratory of Clinical Investigation (J.P.L., M.E.F., Z.G., M.A.B.S.A., J.M.E., M.B.), National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Mary E. Faulkner
- Laboratory of Clinical Investigation (J.P.L., M.E.F., Z.G., M.A.B.S.A., J.M.E., M.B.), National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Zhaoyuan Gong
- Laboratory of Clinical Investigation (J.P.L., M.E.F., Z.G., M.A.B.S.A., J.M.E., M.B.), National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Mohammad A.B.S. Akhonda
- Laboratory of Clinical Investigation (J.P.L., M.E.F., Z.G., M.A.B.S.A., J.M.E., M.B.), National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Luigi Ferrucci
- Translational Gerontology Branch (L.F.), National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Josephine M. Egan
- Laboratory of Clinical Investigation (J.P.L., M.E.F., Z.G., M.A.B.S.A., J.M.E., M.B.), National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Mustapha Bouhrara
- Laboratory of Clinical Investigation (J.P.L., M.E.F., Z.G., M.A.B.S.A., J.M.E., M.B.), National Institute on Aging, National Institutes of Health, Baltimore, MD
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Gong Z, Bilgel M, Kiely M, Triebswetter C, Ferrucci L, Resnick SM, Spencer RG, Bouhrara M. Lower myelin content is associated with more rapid cognitive decline among cognitively unimpaired individuals. Alzheimers Dement 2023; 19:3098-3107. [PMID: 36720000 PMCID: PMC10387505 DOI: 10.1002/alz.12968] [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: 10/15/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 02/01/2023]
Abstract
INTRODUCTION The influence of myelination on longitudinal changes in cognitive performance remains unclear. METHODS For each participant (N = 123), longitudinal cognitive scores were calculated. Myelin content was probed using myelin water fraction (MWF) or longitudinal relaxation rate (R1 ); both are MRI measures sensitive to myelin, with MWF being specific. RESULTS Lower MWF was associated with steeper declines in executive function (p < .02 in all regions) and lower R1 was associated with steeper declines in verbal fluency (p < .03 in all regions). Additionally, lower R1 was associated with steeper declines in executive function (p < .02 in all regions) and memory (p < .04 in occipital and cerebral white matter) but did not survive Bonferroni correction. DISCUSSION We demonstrate significant relationships between myelin content and the rates of change in cognitive performance among cognitively normal individuals. These findings highlight the importance of myelin in cognitive functioning and suggest MWF and R1 as imaging biomarkers to predict cognitive changes.
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Affiliation(s)
- Zhaoyuan Gong
- Magnetic Resonance Physics of Aging and Dementia (MRPAD) Unit, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, USA
| | - Murat Bilgel
- Brain Aging and Behavior Section, NIA, NIH, Baltimore, Maryland, USA
| | - Matthew Kiely
- Magnetic Resonance Physics of Aging and Dementia (MRPAD) Unit, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, USA
| | - Curtis Triebswetter
- Magnetic Resonance Physics of Aging and Dementia (MRPAD) Unit, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, USA
| | - Luigi Ferrucci
- Longitudinal Studies Section, NIA, NIH, Baltimore, Maryland, USA
| | - Susan M. Resnick
- Brain Aging and Behavior Section, NIA, NIH, Baltimore, Maryland, USA
| | - Richard G. Spencer
- Magnetic Resonance Imaging and Spectroscopy Section, NIA, NIH, Baltimore, Maryland, USA
| | - Mustapha Bouhrara
- Magnetic Resonance Physics of Aging and Dementia (MRPAD) Unit, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, USA
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García-García I, Michaud A, Jurado MÁ, Dagher A, Morys F. Mechanisms linking obesity and its metabolic comorbidities with cerebral grey and white matter changes. Rev Endocr Metab Disord 2022; 23:833-843. [PMID: 35059979 DOI: 10.1007/s11154-021-09706-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/14/2021] [Indexed: 02/07/2023]
Abstract
Obesity is a preventable risk factor for cerebrovascular disorders and it is associated with cerebral grey and white matter changes. Specifically, individuals with obesity show diminished grey matter volume and thickness, which seems to be more prominent among fronto-temporal regions in the brain. At the same time, obesity is associated with lower microstructural white matter integrity, and it has been found to precede increases in white matter hyperintensity load. To date, however, it is unclear whether these findings can be attributed solely to obesity or whether they are a consequence of cardiometabolic complications that often co-exist with obesity, such as low-grade systemic inflammation, hypertension, insulin resistance, or dyslipidemia. In this narrative review we aim to provide a comprehensive overview of the potential impact of obesity and a number of its cardiometabolic consequences on brain integrity, both separately and in synergy with each other. We also identify current gaps in knowledge and outline recommendations for future research.
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Affiliation(s)
- Isabel García-García
- Department of Clinical Psychology and Psychobiology, Universitat de Barcelona, Barcelona, Spain.
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain.
| | | | - María Ángeles Jurado
- Department of Clinical Psychology and Psychobiology, Universitat de Barcelona, Barcelona, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, Esplugues de Llobregat, Spain
| | - Alain Dagher
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Filip Morys
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
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Henn RE, Noureldein MH, Elzinga SE, Kim B, Savelieff MG, Feldman EL. Glial-neuron crosstalk in health and disease: A focus on metabolism, obesity, and cognitive impairment. Neurobiol Dis 2022; 170:105766. [PMID: 35584728 PMCID: PMC10071699 DOI: 10.1016/j.nbd.2022.105766] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/28/2022] [Accepted: 05/11/2022] [Indexed: 12/12/2022] Open
Abstract
Dementia is a complex set of disorders affecting normal cognitive function. Recently, several clinical studies have shown that diabetes, obesity, and components of the metabolic syndrome (MetS) are associated with cognitive impairment, including dementias such as Alzheimer's disease. Maintaining normal cognitive function is an intricate process involving coordination of neuron function with multiple brain glia. Well-orchestrated bioenergetics is a central requirement of neurons, which need large amounts of energy but lack significant energy storage capacity. Thus, one of the most important glial functions is to provide metabolic support and ensure an adequate energy supply for neurons. Obesity and metabolic disease dysregulate glial function, leading to a failure to respond to neuron energy demands, which results in neuronal damage. In this review, we outline evidence for links between diabetes, obesity, and MetS components to cognitive impairment. Next, we focus on the metabolic crosstalk between the three major glial cell types, oligodendrocytes, astrocytes, and microglia, with neurons under physiological conditions. Finally, we outline how diabetes, obesity, and MetS components can disrupt glial function, and how this disruption might impair glia-neuron metabolic crosstalk and ultimately promote cognitive impairment.
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Affiliation(s)
- Rosemary E Henn
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America; Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
| | - Mohamed H Noureldein
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America; Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
| | - Sarah E Elzinga
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America; Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
| | - Bhumsoo Kim
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America; Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
| | - Masha G Savelieff
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America.
| | - Eva L Feldman
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America; Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
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Triebswetter C, Kiely M, Khattar N, Ferrucci L, Resnick SM, Spencer RG, Bouhrara M. Differential associations between apolipoprotein E alleles and cerebral myelin content in normative aging. Neuroimage 2022; 251:118988. [PMID: 35150834 PMCID: PMC8940662 DOI: 10.1016/j.neuroimage.2022.118988] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/20/2022] [Accepted: 02/08/2022] [Indexed: 11/29/2022] Open
Abstract
Mounting evidence indicates that myelin breakdown may represent an early phenomenon in neurodegeneration, including Alzheimer's disease (AD). Understanding the factors influencing myelin synthesis and breakdown will be essential for the development and evaluation of therapeutic interventions. In this work, we assessed associations between genetic variance in apolipoprotein E (APOE) and cerebral myelin content. Quantitative magnetic resonance imaging (qMRI) was performed on a cohort of 92 cognitively unimpaired adults ranging in age from 24 to 94 years. We measured whole-brain myelin water fraction (MWF), a direct measure of myelin content, as well as longitudinal and transverse relaxation rates (R1 and R2), sensitive measures of myelin content, in carriers of the APOE ε4 or APOE ε2 alleles and individuals with the ε33 genotype. Automated brain mapping algorithms and statistical models were used to evaluate the relationships between MWF or relaxation rates and APOE isoforms, accounting for confounding variables including age, sex, and race, in several cerebral structures. Our results indicate that carriers of APOE ε2 exhibited significantly higher myelin content, that is, higher MWF, R1 or R2 values, in most brain regions investigated as compared to noncarriers, while ε4 carriers exhibited trends toward lower myelin content compared to noncarriers. Finally, all qMRI metrics exhibited quadratic, inverted U-shape, associations with age; attributed to the development of myelination from young to middle age followed by progressive loss of myelin afterwards. Sex and race effects on myelination were, overall, nonsignificant. These findings suggest that individual genetic background may influence cerebral myelin maintenance. Although preliminary, this work lays the foundation for further investigations to clarify the relationship between APOE genotype and myelination, which may suggest potential targets in treatment or prevention of AD.
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Affiliation(s)
- Curtis Triebswetter
- Magnetic Resonance Physics of Aging and Dementia Unit, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, BRC 05C-222, 251 Bayview Blvd., Baltimore, MD 21224, USA
| | - Matthew Kiely
- Magnetic Resonance Physics of Aging and Dementia Unit, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, BRC 05C-222, 251 Bayview Blvd., Baltimore, MD 21224, USA
| | - Nikkita Khattar
- Magnetic Resonance Physics of Aging and Dementia Unit, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, BRC 05C-222, 251 Bayview Blvd., Baltimore, MD 21224, USA
| | - Luigi Ferrucci
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Susan M Resnick
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Richard G Spencer
- Magnetic Resonance Physics of Aging and Dementia Unit, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, BRC 05C-222, 251 Bayview Blvd., Baltimore, MD 21224, USA
| | - Mustapha Bouhrara
- Magnetic Resonance Physics of Aging and Dementia Unit, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, BRC 05C-222, 251 Bayview Blvd., Baltimore, MD 21224, USA.
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Alisch JSR, Egan JM, Bouhrara M. Differences in the choroid plexus volume and microstructure are associated with body adiposity. Front Endocrinol (Lausanne) 2022; 13:984929. [PMID: 36313760 PMCID: PMC9606414 DOI: 10.3389/fendo.2022.984929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 09/26/2022] [Indexed: 11/13/2022] Open
Abstract
The choroid plexus (CP) is a cerebral structure located in the ventricles that functions in producing most of the brain's cerebrospinal fluid (CSF) and transporting proteins and immune cells. Alterations in CP structure and function has been implicated in several pathologies including aging, multiple sclerosis, Alzheimer's disease, and stroke. However, identification of changes in the CP remains poorly characterized in obesity, one of the main risk factors of neurodegeneration, including in the absence of frank central nervous system alterations. Our goal here was to characterize the association between obesity, measured by the body mass index (BMI) or waist circumference (WC) metrics, and CP microstructure and volume, assessed using advanced magnetic resonance imaging (MRI) methodology. This cross-sectional study was performed in the clinical unit of the National Institute on Aging and included a participant population of 123 cognitively unimpaired individuals spanning the age range of 22 - 94 years. Automated segmentation methods from FreeSurfer were used to identify the CP structure. Our analysis included volumetric measurements, quantitative relaxometry measures (T 1 and T 2), and the diffusion tensor imaging (DTI) measure of mean diffusivity (MD). Strong positive associations were observed between WC and all MRI metrics, as well as CP volume. When comparing groups based on the established cutoff point by the National Institutes of Health for WC, a modest difference in MD and a significant difference in T 1 values were observed between obese and lean individuals. We also found differences in T1 and MD between obese and overweight individuals as defined using the BMI cutoff. We conjecture that these observations in CP volume and microstructure are due to obesity-induced inflammation, diet, or, very likely, dysregulations in leptin binding and transport. These findings demonstrate that obesity is strongly associated with a decline in CP microstructural integrity. We expect that this work will lay the foundation for further investigations on obesity-induced alterations in CP structure and function.
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Affiliation(s)
- Joseph S R Alisch
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Josephine M Egan
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Mustapha Bouhrara
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
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19
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Rahmani F, Wang Q, McKay NS, Keefe S, Hantler N, Hornbeck R, Wang Y, Hassenstab J, Schindler S, Xiong C, Morris JC, Benzinger TL, Raji CA. Sex-Specific Patterns of Body Mass Index Relationship with White Matter Connectivity. J Alzheimers Dis 2022; 86:1831-1848. [PMID: 35180116 PMCID: PMC9108572 DOI: 10.3233/jad-215329] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2022] [Indexed: 11/15/2022]
Abstract
BACKGROUND Obesity is an increasingly recognized modifiable risk factor for Alzheimer's disease (AD). Increased body mass index (BMI) is related to distinct changes in white matter (WM) fiber density and connectivity. OBJECTIVE We investigated whether sex differentially affects the relationship between BMI and WM structural connectivity. METHODS A cross-sectional sample of 231 cognitively normal participants were enrolled from the Knight Alzheimer Disease Research Center. Connectome analyses were done with diffusion data reconstructed using q-space diffeomorphic reconstruction to obtain the spin distribution function and tracts were selected using a deterministic fiber tracking algorithm. RESULTS We identified an inverse relationship between higher BMI and lower connectivity in the associational fibers of the temporal lobe in overweight and obese men. Normal to overweight women showed a significant positive association between BMI and connectivity in a wide array of WM fibers, an association that reversed in obese and morbidly obese women. Interaction analyses revealed that with increasing BMI, women showed higher WM connectivity in the bilateral frontoparietal and parahippocampal parts of the cingulum, while men showed lower connectivity in right sided corticostriatal and corticopontine tracts. Subgroup analyses demonstrated comparable results in participants with and without positron emission tomography or cerebrospinal fluid evidence of brain amyloidosis, indicating that the relationship between BMI and structural connectivity in men and women is independent of AD biomarker status. CONCLUSION BMI influences structural connectivity of WM differently in men and women across BMI categories and this relationship does not vary as a function of preclinical AD.
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Affiliation(s)
- Farzaneh Rahmani
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Qing Wang
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Nicole S. McKay
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Sarah Keefe
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Nancy Hantler
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Russ Hornbeck
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Yong Wang
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Jason Hassenstab
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Suzanne Schindler
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Chengjie Xiong
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
| | - John C. Morris
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
- Charles F. and Joanne Knight Alzheimer Disease Research Center (Knight ADRC), Washington University, St. Louis, MO, USA
| | - Tammie L.S. Benzinger
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
- Charles F. and Joanne Knight Alzheimer Disease Research Center (Knight ADRC), Washington University, St. Louis, MO, USA
| | - Cyrus A. Raji
- Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
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20
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Dong D, Wang Y, Long Z, Jackson T, Chang X, Zhou F, Chen H. The Association between Body Mass Index and Intra-Cortical Myelin: Findings from the Human Connectome Project. Nutrients 2021; 13:3221. [PMID: 34579106 PMCID: PMC8469469 DOI: 10.3390/nu13093221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/26/2021] [Accepted: 09/14/2021] [Indexed: 02/07/2023] Open
Abstract
Intra-cortical myelin is a myelinated part of the cerebral cortex that is responsible for the spread and synchronization of neuronal activity in the cortex. Recent animal studies have established a link between obesity and impaired oligodendrocyte maturation vis-à-vis cells that produce and maintain myelin; however, the association between obesity and intra-cortical myelination remains to be established. To investigate the effects of obesity on intra-cortical myelin in living humans, we employed a large, demographically well-characterized sample of healthy young adults drawn from the Human Connectome Project (n = 1066). Intra-cortical myelin was assessed using a novel T1-w/T2-w ratio method. Linear regression analysis was used to investigate the association between body mass index (BMI), an indicator of obesity, and intra-cortical myelination, adjusting for covariates of no interest. We observed BMI was related to lower intra-cortical myelination in regions previously identified to be involved in reward processing (i.e., medial orbitofrontal cortex, rostral anterior cingulate cortex), attention (i.e., visual cortex, inferior/middle temporal gyrus), and salience detection (i.e., insula, supramarginal gyrus) in response to viewing food cues (corrected p < 0.05). In addition, higher BMIs were associated with more intra-cortical myelination in regions associated with somatosensory processing (i.e., the somatosensory network) and inhibitory control (i.e., lateral inferior frontal gyrus, frontal pole). These findings were also replicated after controlling for key potential confounding factors including total intracranial volume, substance use, and fluid intelligence. Findings suggested that altered intra-cortical myelination may represent a novel microstructure-level substrate underlying prior abnormal obesity-related brain neural activity, and lays a foundation for future investigations designed to evaluate how living habits, such as dietary habit and physical activity, affect intra-cortical myelination.
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Affiliation(s)
- Debo Dong
- Key Laboratory of Cognition and Personality, Southwest University (SWU), Ministry of Education, Chongqing 400715, China; (D.D.); (Y.W.); (Z.L.)
- Faculty of Psychology, Southwest University (SWU), Chongqing 400715, China
| | - Yulin Wang
- Key Laboratory of Cognition and Personality, Southwest University (SWU), Ministry of Education, Chongqing 400715, China; (D.D.); (Y.W.); (Z.L.)
- Faculty of Psychology, Southwest University (SWU), Chongqing 400715, China
| | - Zhiliang Long
- Key Laboratory of Cognition and Personality, Southwest University (SWU), Ministry of Education, Chongqing 400715, China; (D.D.); (Y.W.); (Z.L.)
- Faculty of Psychology, Southwest University (SWU), Chongqing 400715, China
| | - Todd Jackson
- Department of Psychology, University of Macau, Taipa 999078, China;
| | - Xuebin Chang
- School of Mathematics and Statistics, Xi’an Jiaotong University, Xi’an 710049, China;
| | - Feng Zhou
- Center for Information in Medicine, MOE Key Lab for Neuroinformation, The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China;
| | - Hong Chen
- Key Laboratory of Cognition and Personality, Southwest University (SWU), Ministry of Education, Chongqing 400715, China; (D.D.); (Y.W.); (Z.L.)
- Faculty of Psychology, Southwest University (SWU), Chongqing 400715, China
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21
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Lycopene abrogates obesity-provoked hyperactivity of neurosignalling enzymes, oxidative stress and hypothalamic inflammation in female Wistar rats. Neurochem Int 2021; 149:105125. [PMID: 34245807 DOI: 10.1016/j.neuint.2021.105125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 06/22/2021] [Accepted: 07/04/2021] [Indexed: 02/06/2023]
Abstract
Obesity, a global epidemic, has been strongly associated with impairment of brain function. Lycopene has several therapeutic properties and can cross the blood-brain barrier. However, its effects on obesity-provoked brain dysfunction remain unexplored. This study evaluated the potential remediating effects of lycopene on obesity-induced neurological derangements. Thirty-six female Wistar rats (150-200g) were distributed in six groups (n = 6); normal control, obese control, obese + lycopene (20 mg/kg), obese + lycopene (40 mg/kg), normal + lycopene (20 mg/kg), and normal + lycopene (40 mg/kg). Obesity was induced by feeding rats with the Western diet for eight weeks, while normal rats received the control diet. Afterwards, the brain was excised and processed for biochemical, gene expression analyses, and histological evaluations. Obesity-induced brain dysfunction was hallmarked by reduced brain organosomatic index, accumulation of lipids in the cerebrum, and hyperactivity of neurotransmitters-metabolizing enzymes (AChE, ADA, MAO-A, 5'-nucleotidase, and NTPdase). Also, obese rats had decreased antioxidant capacity, with increased oxidative damage, while the expressions of NF-κβ p65 and pro-inflammatory cytokines (IL-1β and IL-6) were elevated in the hypothalamus. These observations were validated by histomorphological evaluations, which showed vacuolation in the brain of obese rats. Treatment with lycopene significantly (p < 0.05) reduced the elevated lipid contents and activities of neuronal enzymes, alleviated oxidative stress and inflammation, while improving the histology of the brain, in a dose-dependent manner. Thus, lycopene abrogates obesity-provoked brain dysfunction and may present a safe and viable therapeutic option for the management of neurological perturbations associated with obesity.
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Khattar N, Triebswetter C, Kiely M, Ferrucci L, Resnick SM, Spencer RG, Bouhrara M. Investigation of the association between cerebral iron content and myelin content in normative aging using quantitative magnetic resonance neuroimaging. Neuroimage 2021; 239:118267. [PMID: 34139358 PMCID: PMC8370037 DOI: 10.1016/j.neuroimage.2021.118267] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 12/24/2022] Open
Abstract
Myelin loss and iron accumulation are cardinal features of aging and various neurodegenerative diseases. Oligodendrocytes incorporate iron as a metabolic substrate for myelin synthesis and maintenance. An emerging hypothesis in Alzheimer’s disease research suggests that myelin breakdown releases substantial stores of iron that may accumulate, leading to further myelin breakdown and neurodegeneration. We assessed associations between iron content and myelin content in critical brain regions using quantitative magnetic resonance imaging (MRI) on a cohort of cognitively unimpaired adults ranging in age from 21 to 94 years. We measured whole-brain myelin water fraction (MWF), a surrogate of myelin content, using multicomponent relaxometry, and whole-brain iron content using susceptibility weighted imaging in all individuals. MWF was negatively associated with iron content in most brain regions evaluated indicating that lower myelin content corresponds to higher iron content. Moreover, iron content was significantly higher with advanced age in most structures, with men exhibiting a trend towards higher iron content as compared to women. Finally, relationship between MWF and age, in all brain regions investigated, suggests that brain myelination continues until middle age, followed by degeneration at older ages. This work establishes a foundation for further investigations of the etiology and sequelae of myelin breakdown and iron accumulation in neurodegeneration and may lead to new imaging markers for disease progression and treatment.
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Affiliation(s)
- Nikkita Khattar
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Curtis Triebswetter
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Matthew Kiely
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Luigi Ferrucci
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Susan M Resnick
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Richard G Spencer
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Mustapha Bouhrara
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States.
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23
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Bouhrara M, Cortina LE, Khattar N, Rejimon AC, Ajamu S, Cezayirli DS, Spencer RG. Maturation and degeneration of the human brainstem across the adult lifespan. Aging (Albany NY) 2021; 13:14862-14891. [PMID: 34115614 PMCID: PMC8221341 DOI: 10.18632/aging.203183] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/20/2021] [Indexed: 04/12/2023]
Abstract
Brainstem tissue microstructural properties change across the adult lifespan. However, studies elucidating the biological processes that govern brainstem maturation and degeneration in-vivo are lacking. In the present work, conducted on a large cohort of 140 cognitively unimpaired subjects spanning a wide age range of 21 to 94 years, we implemented a multi-parameter approach to characterize the sex- and age differences. In addition, we examined regional correlations between myelin water fraction (MWF), a direct measure of myelin content, and diffusion tensor imaging indices, and transverse and longitudinal relaxation rates to evaluate whether these metrics provide information complementary to MWF. We observed region-dependent differences in myelin content and axonal density with age and found that both exhibit an inverted U-shape association with age in several brainstem substructures. We emphasize that the microstructural differences captured by our distinct MRI metrics, along with their weak associations with MWF, strongly indicate the potential of using these outcome measures in a multi-parametric approach. Furthermore, our results support the gain-predicts-loss hypothesis of tissue maturation and degeneration in the brainstem. Indeed, our results indicate that myelination follows a temporally symmetric time course across the adult life span, while axons appear to degenerate significantly more rapidly than they mature.
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Affiliation(s)
- Mustapha Bouhrara
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Luis E. Cortina
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Nikkita Khattar
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Abinand C. Rejimon
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Samuel Ajamu
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Defne S. Cezayirli
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Richard G. Spencer
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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