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Usha KC, Suma HN, Appaji A. Regional-based static and dynamic alterations in Alzheimer disease: a longitudinal study. ARQUIVOS DE NEURO-PSIQUIATRIA 2024; 82:1-11. [PMID: 38977265 DOI: 10.1055/s-0044-1787761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
BACKGROUND Alzheimer disease (AD) leads to cognitive decline and alters functional connectivity (FC) in key brain regions. Resting-state functional magnetic resonance imaging (rs-fMRI) assesses these changes using static-FC for overall correlation and dynamic-FC for temporal variability. OBJECTIVE In AD, there is altered FC compared to normal conditions. The present study investigates possible region-specific functional abnormalities occurring longitudinally over 1 year. Our aim is to evaluate the potential usefulness of the static and dynamic approaches in identifying biomarkers of AD progression. METHODS The study involved 15 AD and 20 healthy participants from the Alzheimer's Disease Neuroimaging Initiative 2 (ADNI2) database, tracked over 2 visits within 1 year. Using constrained-independent component analysis, we assessed FC changes across 80-regions of interest in AD over the year, examining both static and dynamic conditions. RESULTS The average regional FC decreased in AD compared to healthy subjects at baseline and after 1 year. The dynamic condition identifies similarities with a few additional changes in the FC compared to the static condition. In both analyses, the baseline assessment revealed reduced connectivity between the following regions: right-middle-occipital and left-superior-occipital, left-hippocampus and right-postcentral, left-lingual and left-fusiform, and precuneus and left-thalamus. Additionally, increased connectivity was found between the left-superior-occipital and precuneus regions. In the 1-year AD assessment, increased connectivity was noted between the right-superior-temporal-pole and right-insular, right-hippocampus and left-caudate, right-middle-occipital and right-superior-temporal-pole, and posterior-cingulate-cortex and middle-temporal-pole regions. CONCLUSION Significant changes were observed at baseline in the frontal, occipital, and core basal-ganglia regions, progressing towards the temporal lobe and subcortical regions in the following year. After 1 year, we observed the aforementioned region-specific neurological differences in AD, significantly aiding diagnosis and disease tracking.
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Affiliation(s)
- Kuppe Channappa Usha
- B.M.S. College of Engineering, Department of Electronics and Communication Engineering, Bengaluru Karnataka, India
| | | | - Abhishek Appaji
- B.M.S. College of Engineering, Department of Medical Electronics, Bengaluru Karnataka, India
- Maastricht University, University Eye Clinic Maastricht, Maastricht, Netherlands
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2
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Ho K, Bodi NE, Sharma TP. Normal-Tension Glaucoma and Potential Clinical Links to Alzheimer's Disease. J Clin Med 2024; 13:1948. [PMID: 38610712 PMCID: PMC11012506 DOI: 10.3390/jcm13071948] [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: 02/19/2024] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 04/14/2024] Open
Abstract
Glaucoma is a group of optic neuropathies and the world's leading cause of irreversible blindness. Normal-tension glaucoma (NTG) is a subtype of glaucoma that is characterized by a typical pattern of peripheral retinal loss, in which the patient's intraocular pressure (IOP) is considered within the normal range (<21 mmHg). Currently, the only targetable risk factor for glaucoma is lowering IOP, and patients with NTG continue to experience visual field loss after IOP-lowering treatments. This demonstrates the need for a better understanding of the pathogenesis of NTG and underlying mechanisms leading to neurodegeneration. Recent studies have found significant connections between NTG and cerebral manifestations, suggesting NTG as a neurodegenerative disease beyond the eye. Gaining a better understanding of NTG can potentially provide new Alzheimer's Disease diagnostics capabilities. This review identifies the epidemiology, current biomarkers, altered fluid dynamics, and cerebral and ocular manifestations to examine connections and discrepancies between the mechanisms of NTG and Alzheimer's Disease.
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Affiliation(s)
- Kathleen Ho
- Eugene and Marilyn Glick Eye Institute, Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
| | - Nicole E. Bodi
- Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
| | - Tasneem P. Sharma
- Eugene and Marilyn Glick Eye Institute, Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
- Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
- Stark Neurosciences Research Institute, Indianapolis, IN 46202, USA
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3
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Sendi MS, Zendehrouh E, Fu Z, Liu J, Du Y, Mormino E, Salat DH, Calhoun VD, Miller RL. Disrupted Dynamic Functional Network Connectivity Among Cognitive Control Networks in the Progression of Alzheimer's Disease. Brain Connect 2023; 13:334-343. [PMID: 34102870 PMCID: PMC10442683 DOI: 10.1089/brain.2020.0847] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Background: Alzheimer's disease (AD) is the most common age-related dementia that promotes a decline in memory, thinking, and social skills. The initial stages of dementia can be associated with mild symptoms, and symptom progression to a more severe state is heterogeneous across patients. Recent work has demonstrated the potential for functional network mapping to assist in the prediction of symptomatic progression. However, this work has primarily used static functional connectivity (sFC) from resting-state functional magnetic resonance imaging. Recently, dynamic functional connectivity (dFC) has been recognized as a powerful advance in functional connectivity methodology to differentiate brain network dynamics between healthy and diseased populations. Methods: Group independent component analysis was applied to extract 17 components within the cognitive control network (CCN) from 1385 individuals across varying stages of AD symptomology. We estimated dFC among 17 components within the CCN, followed by clustering the dFCs into 3 recurring brain states, and then estimated a hidden Markov model and the occupancy rate for each subject. Then, we investigated the link between CCN dFC features and AD progression. Also, we investigated the link between sFC and AD progression and compared its results with dFC results. Results: Progression of AD symptoms was associated with increases in connectivity within the middle frontal gyrus. Also, the very mild AD (vmAD) showed less connectivity within the inferior parietal lobule (in both sFC and dFC) and between this region and the rest of CCN (in dFC analysis). Also, we found that within-middle frontal gyrus connectivity increases with AD progression in both sFC and dFC results. Finally, comparing with vmAD, we found that the normal brain spends significantly more time in a state with lower within-middle frontal gyrus connectivity and higher connectivity between the hippocampus and the rest of CCN, highlighting the importance of assessing the dynamics of brain connectivity in this disease. Conclusion: Our results suggest that AD progress not only alters the CCN connectivity strength but also changes the temporal properties in this brain network. This suggests the temporal and spatial pattern of CCN as a biomarker that differentiates different stages of AD.
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Affiliation(s)
- Mohammad S.E. Sendi
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta, Georgia, USA
- Department of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science, Georgia State University, Georgia Institute of Technology, Emory University, Atlanta, Georgia, USA
| | - Elaheh Zendehrouh
- Department of Computer Science, Georgia State University, Atlanta, Georgia, USA
| | - Zening Fu
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science, Georgia State University, Georgia Institute of Technology, Emory University, Atlanta, Georgia, USA
| | - Jingyu Liu
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science, Georgia State University, Georgia Institute of Technology, Emory University, Atlanta, Georgia, USA
- Department of Computer Science, Georgia State University, Atlanta, Georgia, USA
| | - Yuhui Du
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science, Georgia State University, Georgia Institute of Technology, Emory University, Atlanta, Georgia, USA
- School of Computer and Information Technology, Shanxi University, Taiyuan, China
| | | | - David H. Salat
- Harvard Medical School, Cambridge, Massachusetts, USA
- Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Vince D. Calhoun
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta, Georgia, USA
- Department of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science, Georgia State University, Georgia Institute of Technology, Emory University, Atlanta, Georgia, USA
- Department of Computer Science, Georgia State University, Atlanta, Georgia, USA
| | - Robyn L. Miller
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science, Georgia State University, Georgia Institute of Technology, Emory University, Atlanta, Georgia, USA
- Department of Computer Science, Georgia State University, Atlanta, Georgia, USA
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4
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Chauhan N, Choi BJ. Classification of Alzheimer's Disease Using Maximal Information Coefficient-Based Functional Connectivity with an Extreme Learning Machine. Brain Sci 2023; 13:1046. [PMID: 37508978 PMCID: PMC10377329 DOI: 10.3390/brainsci13071046] [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: 06/21/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive chronic illness that leads to cognitive decline and dementia. Neuroimaging technologies, such as functional magnetic resonance imaging (fMRI), and deep learning approaches offer promising avenues for AD classification. In this study, we investigate the use of fMRI-based functional connectivity (FC) measures, including the Pearson correlation coefficient (PCC), maximal information coefficient (MIC), and extended maximal information coefficient (eMIC), combined with extreme learning machines (ELM) for AD classification. Our findings demonstrate that employing non-linear techniques, such as MIC and eMIC, as features for classification yields accurate results. Specifically, eMIC-based features achieve a high accuracy of 94% for classifying cognitively normal (CN) and mild cognitive impairment (MCI) individuals, outperforming PCC (81%) and MIC (85%). For MCI and AD classification, MIC achieves higher accuracy (81%) compared to PCC (58%) and eMIC (78%). In CN and AD classification, eMIC exhibits the best accuracy of 95% compared to MIC (90%) and PCC (87%). These results underscore the effectiveness of fMRI-based features derived from non-linear techniques in accurately differentiating AD and MCI individuals from CN individuals, emphasizing the potential of neuroimaging and machine learning methods for improving AD diagnosis and classification.
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Affiliation(s)
- Nishant Chauhan
- Department of Electronic Engineering, Daegu University, Gyeongsan 38453, Republic of Korea
| | - Byung-Jae Choi
- Department of Electronic Engineering, Daegu University, Gyeongsan 38453, Republic of Korea
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Hua L, Gao F, Xia X, Guo Q, Zhao Y, Huang S, Yuan Z. Individual-specific functional connectivity improves prediction of Alzheimer's disease's symptoms in elderly people regardless of APOE ε4 genotype. Commun Biol 2023; 6:581. [PMID: 37258640 PMCID: PMC10232409 DOI: 10.1038/s42003-023-04952-6] [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: 02/15/2023] [Accepted: 05/18/2023] [Indexed: 06/02/2023] Open
Abstract
To date, reliable biomarkers remain unclear that could link functional connectivity to patients' symptoms for detecting and predicting the process from normal aging to Alzheimer's disease (AD) in elderly people with specific genotypes. To address this, individual-specific functional connectivity is constructed for elderly participants with/without APOE ε4 allele. Then, we utilize recursive feature selection-based machine learning to reveal individual brain-behavior relationships and to predict the symptom transition in different genotypes. Our findings reveal that compared with conventional atlas-based functional connectivity, individual-specific functional connectivity exhibits higher classification and prediction performance from normal aging to AD in both APOE ε4 groups, while no significant performance is detected when the data of two genotyping groups are combined. Furthermore, individual-specific between-network connectivity constitutes a major contributor to assessing cognitive symptoms. This study highlights the essential role of individual variation in cortical functional anatomy and the integration of brain and behavior in predicting individualized symptoms.
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Affiliation(s)
- Lin Hua
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau, SAR 999078, China
- Centre for Cognitive and Brain Sciences, University of Macau, Avenida da Universidade, Taipa, Macau, SAR 999078, China
| | - Fei Gao
- Institute of Modern Languages and Linguistics, Fudan University, Shanghai, 200433, China
| | - Xiaoluan Xia
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau, SAR 999078, China
- Centre for Cognitive and Brain Sciences, University of Macau, Avenida da Universidade, Taipa, Macau, SAR 999078, China
| | - Qiwei Guo
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau, SAR 999078, China
- Centre for Cognitive and Brain Sciences, University of Macau, Avenida da Universidade, Taipa, Macau, SAR 999078, China
| | - Yonghua Zhao
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Avenida da Universidade, Taipa, Macau, SAR 999078, China
| | - Shaohui Huang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhen Yuan
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau, SAR 999078, China.
- Centre for Cognitive and Brain Sciences, University of Macau, Avenida da Universidade, Taipa, Macau, SAR 999078, China.
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6
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Liu Y, Liu S, Tang C, Tang K, Liu D, Chen M, Mao Z, Xia X. Transcranial alternating current stimulation combined with sound stimulation improves cognitive function in patients with Alzheimer's disease: Study protocol for a randomized controlled trial. Front Aging Neurosci 2023; 14:1068175. [PMID: 36698862 PMCID: PMC9869764 DOI: 10.3389/fnagi.2022.1068175] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/14/2022] [Indexed: 01/12/2023] Open
Abstract
Background The number of patients with Alzheimer's disease (AD) worldwide is increasing yearly, but the existing treatment methods have poor efficacy. Transcranial alternating current stimulation (tACS) is a new treatment for AD, but the offline effect of tACS is insufficient. To prolong the offline effect, we designed to combine tACS with sound stimulation to maintain the long-term post-effect. Materials and methods To explore the safety and effectiveness of tACS combined with sound stimulation and its impact on the cognition of AD patients. This trial will recruit 87 patients with mild to moderate AD. All patients were randomly divided into three groups. The change in Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) scores from the day before treatment to the end of treatment and 3 months after treatment was used as the main evaluation index. We will also explore the changes in the brain structural network, functional network, and metabolic network of AD patients in each group after treatment. Discussion We hope to conclude that tACS combined with sound stimulation is safe and tolerable in 87 patients with mild to moderate AD under three standardized treatment regimens. Compared with tACS alone or sound alone, the combination group had a significant long-term effect on cognitive improvement. To screen out a better treatment plan for AD patients. tACS combined with sound stimulation is a previously unexplored, non-invasive joint intervention to improve patients' cognitive status. This study may also identify the potential mechanism of tACS combined with sound stimulation in treating mild to moderate AD patients. Clinical Trial Registration Clinicaltrials.gov, NCT05251649. Registered on February 22, 2022.
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Affiliation(s)
- Yang Liu
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | | | - Can Tang
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Keke Tang
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Di Liu
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Meilian Chen
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Zhiqi Mao
- Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China
| | - Xuewei Xia
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
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7
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Moffat G, Zhukovsky P, Coughlan G, Voineskos AN. Unravelling the relationship between amyloid accumulation and brain network function in normal aging and very mild cognitive decline: a longitudinal analysis. Brain Commun 2022; 4:fcac282. [PMID: 36415665 PMCID: PMC9678202 DOI: 10.1093/braincomms/fcac282] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 07/29/2022] [Accepted: 10/31/2022] [Indexed: 06/27/2024] Open
Abstract
Pathological changes in the brain begin accumulating decades before the appearance of cognitive symptoms in Alzheimer's disease. The deposition of amyloid beta proteins and other neurotoxic changes occur, leading to disruption in functional connections between brain networks. Discrete characterization of the changes that take place in preclinical Alzheimer's disease has the potential to help treatment development by targeting the neuropathological mechanisms to prevent cognitive decline and dementia from occurring entirely. Previous research has focused on the cross-sectional differences in the brains of patients with mild cognitive impairment or Alzheimer's disease and healthy controls or has concentrated on the stages immediately preceding cognitive symptoms. The present study emphasizes the early preclinical phases of neurodegeneration. We use a longitudinal approach to examine the brain changes that take place during the early stages of cognitive decline in the Open Access Series of Imaging Studies-3 data set. Among 1098 participants, 274 passed the inclusion criteria (i.e. had at least two cognitive assessments and two amyloid scans). Over 90% of participants were healthy at baseline. Over 8-10 years, some participants progressed to very mild cognitive impairment (n = 48), while others stayed healthy (n = 226). Participants with cognitive decline show faster amyloid accumulation in the lateral temporal, motor and parts of the lateral prefrontal cortex. These changes in amyloid levels were linked to longitudinal increases in the functional connectivity of select networks, including default mode, frontoparietal and motor components. Our findings advance the understanding of amyloid staging and the corresponding changes in functional organization of large-scale brain networks during the progression of early preclinical Alzheimer's disease.
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Affiliation(s)
- Gemma Moffat
- Kimel Family Translational Imaging-Genetics Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada
| | - Peter Zhukovsky
- Kimel Family Translational Imaging-Genetics Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Gillian Coughlan
- Rotman Research Institute, Baycrest Hospital, Toronto, ON, M6A 2E1, Canada
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02129, USA
| | - Aristotle N Voineskos
- Kimel Family Translational Imaging-Genetics Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada
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8
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Network synchronization deficits caused by dementia and Alzheimer's disease serve as topographical biomarkers: a pilot study. Brain Struct Funct 2022; 227:2957-2969. [PMID: 35997832 PMCID: PMC9396580 DOI: 10.1007/s00429-022-02554-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 08/09/2022] [Indexed: 11/24/2022]
Abstract
Mild cognitive impairment (MCI) is known as an early stage of cognitive decline. Amnestic MCI (aMCI) is considered as the preliminary stage of dementia which may progress to Alzheimer’s disease (AD). While some aMCI patients may stay in this condition for years, others might develop dementia associated with AD. Early detection of MCI allows for potential treatments to prevent or decelerate the process of developing dementia. Standard methods of diagnosing MCI and AD employ structural (imaging), behavioral (cognitive tests), and genetic or molecular (blood or CSF tests) techniques. Our study proposes network-level neural synchronization parameters as topographical markers for diagnosing aMCI and AD. We conducted a pilot study based on EEG data recorded during an olfactory task from a group of elderly participants consisting of healthy individuals and patients of aMCI and AD to assess the value of different indicators of network-level phase and amplitude synchronization in differentiating the three groups. Significant differences were observed in the percent phase locking value, theta-gamma phase-amplitude coupling, and amplitude coherence between the groups, and classifiers were developed to differentiate the three groups based on these parameters. The observed differences in these indicators of network-level functionality of the brain can help explain the underlying processes involved in aMCI and AD.
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Combined functional and structural imaging of brain white matter reveals stage-dependent impairment in multiple system atrophy of cerebellar type. NPJ Parkinsons Dis 2022; 8:105. [PMID: 35977953 PMCID: PMC9385720 DOI: 10.1038/s41531-022-00371-2] [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: 12/06/2021] [Accepted: 07/26/2022] [Indexed: 12/04/2022] Open
Abstract
Advances in fMRI of brain white matter (WM) have established the feasibility of understanding how functional signals of WM evolve with brain diseases. By combining functional signals with structural features of WM, the current study characterizes functional and structural impairments of WM in cerebelar type multiple system atrophy, with the goal to derive new mechanistic insights into the pathological progression of this disease. Our analysis of 30 well-diagnosed patients revealed pronounced decreases in functional connectivity in WM bundles of the cerebellum and brainstem, and concomitant local structural alterations that depended on the disease stage. The novel findings implicate a critical time point in the pathological evolution of the disease, which could guide optimal therapeutic interventions. Furthermore, fMRI signals of impaired WM bundles exhibited superior sensitivity in differentiating initial disease development, which demonstrates great potential of using these signals to inform disease management.
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Xiao A, Li HJ, Li QY, Liang RB, Shu HY, Ge QM, Liao XL, Pan YC, Wu JL, Su T, Zhang LJ, Zhou Q, Shao Y. Functional Connectivity Hypointensity of Middle Cingulate Gyrus and Thalamus in Age-Related Macular Degeneration Patients: A Resting-State Functional Magnetic Resonance Imaging Study. Front Aging Neurosci 2022; 14:854758. [PMID: 35391752 PMCID: PMC8979908 DOI: 10.3389/fnagi.2022.854758] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 02/14/2022] [Indexed: 11/17/2022] Open
Abstract
Objective Age-related macular degeneration (AMD) causes visual damage and blindness globally. The purpose of this study was to investigate changes in functional connectivity (FC) in AMD patients using resting-state functional magnetic resonance imaging (rs-fMRI). Subjects and Methods A total of 23 patients (12 male, 11 female) with AMD were enrolled to the AMD patients group (AMDs), and 17 healthy age-, sex-, and education-matched controls (9 male, 8 female) to the healthy controls group (HCs). All participants underwent rs-fMRI and mean FC values were compared between the two groups. Results Significantly higher FC values were found in the inferior frontal gyrus (IFG), superior frontal gyrus (SFG), inferior parietal lobule (IPL), rectal gyrus (RTG), and superior parietal lobule (SPL) in AMDs compared with HCs. Conversely, FC values in the cerebellum posterior lobe (CPL), middle cingulate gyrus (MCG), medulla (MDL), cerebellum anterior lobe (CAL), and thalamus (TLM) were significantly lower in AMDs than in HCs. Conclusion This study demonstrated FC abnormalities in many specific cerebral regions in AMD patients, and may provide new insights for exploration of potential pathophysiological mechanism of AMD-induced functional cerebral changes.
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Affiliation(s)
- Ang Xiao
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Hai-Jun Li
- Department of PET Center and Medical Image Center, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qiu-Yu Li
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Rong-Bin Liang
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Hui-Ye Shu
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qian-Min Ge
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xu-Lin Liao
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Yi-Cong Pan
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jie-Li Wu
- Department of Ophthalmology, Xiang’an Hospital of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Eye Institute of Xiamen University, Xiamen University School of Medicine, Xiamen, China
| | - Ting Su
- Department of Ophthalmology, Xiang’an Hospital of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Eye Institute of Xiamen University, Xiamen University School of Medicine, Xiamen, China
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - Li-Juan Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qiong Zhou
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
- *Correspondence: Qiong Zhou,
| | - Yi Shao
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
- Yi Shao,
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Pourabdi L, Küçükkılınç TT, Khoshtale F, Ayazgök B, Nadri H, Farokhi Alashti F, Forootanfar H, Akbari T, Shafiei M, Foroumadi A, Sharifzadeh M, Shafiee Ardestani M, Abaee MS, Firoozpour L, Khoobi M, Mojtahedi MM. Synthesis of New 3-Arylcoumarins Bearing N-Benzyl Triazole Moiety: Dual Lipoxygenase and Butyrylcholinesterase Inhibitors With Anti-Amyloid Aggregation and Neuroprotective Properties Against Alzheimer’s Disease. Front Chem 2022; 9:810233. [PMID: 35127652 PMCID: PMC8812461 DOI: 10.3389/fchem.2021.810233] [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: 11/06/2021] [Accepted: 12/13/2021] [Indexed: 11/13/2022] Open
Abstract
A novel series of coumarin derivatives linked to the N-benzyl triazole group were synthesized and evaluated against 15-lipoxygenase (15-LOX), and acetyl- and butyrylcholinesterase (AChE and BuChE) to find the most potent derivative against Alzheimer’s disease (AD). Most of the compounds showed weak to moderate activity against ChEs. Among the most active BuChE and 15-LOX inhibitors, 8l and 8n exhibited an excellent neuroprotective effect, higher than the standard drug (quercetin) on the PC12 cell model injured by H2O2 and significantly reduced aggregation of amyloid Aβ1-42, with potencies of 1.44 and 1.79 times higher than donepezil, respectively. Compound 8l also showed more activity than butylated hydroxytoluene (BHT) as the reference antioxidant agent in reducing the levels of H2O2 activated by amyloid β in BV2 microglial cells. Kinetic and ligand–enzyme docking studies were also performed for better understanding of the mode of interaction between the best BuChE inhibitor and the enzyme. Considering the acceptable BuChE and 15-LOX inhibition activities as well as significant neuroprotection, and anti-amyloid aggregation activities, 8l and 8n could be considered as potential MTDLs for further modification and studies against AD.
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Affiliation(s)
- Ladan Pourabdi
- Department of Organic Chemistry and Natural Products, Chemistry and Chemical Engineering Research Center of Iran, Tehran, Iran
| | | | - Fatemeh Khoshtale
- Department of Organic Chemistry and Natural Products, Chemistry and Chemical Engineering Research Center of Iran, Tehran, Iran
| | - Beyza Ayazgök
- Faculty of Pharmacy, Department of Biochemistry, Hacettepe University, Ankara, Turkey
| | - Hamid Nadri
- Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Farid Farokhi Alashti
- Department of Organic Chemistry and Natural Products, Chemistry and Chemical Engineering Research Center of Iran, Tehran, Iran
| | - Hamid Forootanfar
- Pharmaceutical Sciences and Cosmetic Products Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Tayebeh Akbari
- Department of Microbiology, Islamic Azad University, North Tehran Branch, Tehran, Iran
| | - Mohammad Shafiei
- Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Alireza Foroumadi
- Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
- Pharmaceutical Sciences Research Center, The institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sharifzadeh
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Shafiee Ardestani
- Department of Radiopharmacy, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - M. Saeed Abaee
- Department of Organic Chemistry and Natural Products, Chemistry and Chemical Engineering Research Center of Iran, Tehran, Iran
| | - Loghman Firoozpour
- Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Khoobi
- Pharmaceutical Sciences Research Center, The institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran
- Department of Radiopharmacy, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
- *Correspondence: Mohammad M. Mojtahedi, ; Mehdi Khoobi, ,
| | - Mohammad M. Mojtahedi
- Department of Organic Chemistry and Natural Products, Chemistry and Chemical Engineering Research Center of Iran, Tehran, Iran
- *Correspondence: Mohammad M. Mojtahedi, ; Mehdi Khoobi, ,
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12
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Khan MNA, Ghafoor U, Yoo HR, Hong KS. Acupuncture enhances brain function in patients with mild cognitive impairment: evidence from a functional-near infrared spectroscopy study. Neural Regen Res 2022; 17:1850-1856. [PMID: 35017448 PMCID: PMC8820726 DOI: 10.4103/1673-5374.332150] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Mild cognitive impairment (MCI) is a precursor to Alzheimer’s disease. It is imperative to develop a proper treatment for this neurological disease in the aging society. This observational study investigated the effects of acupuncture therapy on MCI patients. Eleven healthy individuals and eleven MCI patients were recruited for this study. Oxy- and deoxy-hemoglobin signals in the prefrontal cortex during working-memory tasks were monitored using functional near-infrared spectroscopy. Before acupuncture treatment, working-memory experiments were conducted for healthy control (HC) and MCI groups (MCI-0), followed by 24 sessions of acupuncture for the MCI group. The acupuncture sessions were initially carried out for 6 weeks (two sessions per week), after which experiments were performed again on the MCI group (MCI-1). This was followed by another set of acupuncture sessions that also lasted for 6 weeks, after which the experiments were repeated on the MCI group (MCI-2). Statistical analyses of the signals and classifications based on activation maps as well as temporal features were performed. The highest classification accuracies obtained using binary connectivity maps were 85.7% HC vs. MCI-0, 69.5% HC vs. MCI-1, and 61.69% HC vs. MCI-2. The classification accuracies using the temporal features mean from 5 seconds to 28 seconds and maximum (i.e, max(5:28 seconds)) values were 60.6% HC vs. MCI-0, 56.9% HC vs. MCI-1, and 56.4% HC vs. MCI-2. The results reveal that there was a change in the temporal characteristics of the hemodynamic response of MCI patients due to acupuncture. This was reflected by a reduction in the classification accuracy after the therapy, indicating that the patients’ brain responses improved and became comparable to those of healthy subjects. A similar trend was reflected in the classification using the image feature. These results indicate that acupuncture can be used for the treatment of MCI patients.
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Affiliation(s)
- M N Afzal Khan
- School of Mechanical Engineering, Pusan National University, Busan, Korea
| | - Usman Ghafoor
- School of Mechanical Engineering, Pusan National University, Busan, Korea
| | - Ho-Ryong Yoo
- Department of Neurology Disorders, Dunsan Hospital, Daejeon University, Daejeon, Korea
| | - Keum-Shik Hong
- School of Mechanical Engineering, Pusan National University, Busan, Korea
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13
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Soni N, Ora M, Bathla G, Nagaraj C, Boles Ponto LL, Graham MM, Saini J, Menda Y. Multiparametric magnetic resonance imaging and positron emission tomography findings in neurodegenerative diseases: Current status and future directions. Neuroradiol J 2021; 34:263-288. [PMID: 33666110 PMCID: PMC8447818 DOI: 10.1177/1971400921998968] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Neurodegenerative diseases (NDDs) are characterized by progressive neuronal loss, leading to dementia and movement disorders. NDDs broadly include Alzheimer's disease, frontotemporal lobar degeneration, parkinsonian syndromes, and prion diseases. There is an ever-increasing prevalence of mild cognitive impairment and dementia, with an accompanying immense economic impact, prompting efforts aimed at early identification and effective interventions. Neuroimaging is an essential tool for the early diagnosis of NDDs in both clinical and research settings. Structural, functional, and metabolic imaging modalities, including magnetic resonance imaging (MRI) and positron emission tomography (PET), are widely available. They show encouraging results for diagnosis, monitoring, and treatment response evaluation. The current review focuses on the complementary role of various imaging modalities in relation to NDDs, the qualitative and quantitative utility of newer MRI techniques, novel radiopharmaceuticals, and integrated PET/MRI in the setting of NDDs.
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Affiliation(s)
- Neetu Soni
- University of Iowa Hospitals and Clinics, USA
| | - Manish Ora
- Department of Nuclear Medicine, SGPGIMS, India
| | - Girish Bathla
- Neuroradiology Department, University of Iowa Hospitals and
Clinics, USA
| | - Chandana Nagaraj
- Department of Neuro Imaging and Interventional Radiology,
NIMHANS, India
| | | | - Michael M Graham
- Division of Nuclear Medicine, University of Iowa Hospitals and
Clinics, USA
| | - Jitender Saini
- Department of Neuro Imaging and Interventional Radiology,
NIMHANS, India
| | - Yusuf Menda
- University of Iowa Hospitals and Clinics, USA
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14
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Yuan LQ, Zeng Q, Wang D, Wen XY, Shi Y, Zhu F, Chen SJ, Huang GZ. Neuroimaging mechanisms of high-frequency repetitive transcranial magnetic stimulation for treatment of amnestic mild cognitive impairment: a double-blind randomized sham-controlled trial. Neural Regen Res 2021; 16:707-713. [PMID: 33063732 PMCID: PMC8067941 DOI: 10.4103/1673-5374.295345] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Individuals with amnestic mild cognitive impairment (aMCI) have a high risk of developing Alzheimer’s disease. Although repetitive transcranial magnetic stimulation (rTMS) is considered a potentially effective treatment for cognitive impairment in patients with aMCI, the neuroimaging mechanisms are poorly understood. Therefore, we performed a double-blind randomized sham-controlled trial in which rTMS was applied to the left dorsolateral prefrontal cortex of aMCI patients recruited from a community near the Third Hospital Affiliated to Sun Yat-sen University, China. Twenty-four patients with aMCI were randomly assigned to receive true rTMS (treatment group, n = 12, 6 men and 6 women; age 65.08 ± 4.89 years) or sham stimulation (sham group, n = 12, 5 men and 7 women; age 64.67 ± 4.77 years). rTMS parameters included a stimulation frequency of 10 Hz, stimulation duration of 2 seconds, stimulation interval of 8 seconds, 20 repetitions at 80% of the motor threshold, and 400 pulses per session. rTMS/sham stimulation was performed five times per week over a period of 4 consecutive weeks. Our results showed that compared with baseline, Montreal Cognitive Assessment scores were significantly increased and the value of the amplitude of low-frequency fluctuation (ALFF) was significantly increased at the end of treatment and 1 month after treatment. Compared with the sham group, the ALFF values in the right inferior frontal gyrus, triangular part of the inferior frontal gyrus, right precuneus, left angular gyrus, and right supramarginal gyrus were significantly increased, and the ALFF values in the right superior frontal gyrus were significantly decreased in the treatment group. These findings suggest that high-frequency rTMS can effectively improve cognitive function in aMCI patients and alter spontaneous brain activity in cognitive-related brain areas. This study was approved by the Ethics Committee of Shenzhen Baoan Hospital of Southern Medical University, China (approval No. BYL20190901) on September 3, 2019, and registered in the Chinese Clinical Trials Registry (registration No. ChiCTR1900028180) on December 14, 2019.
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Affiliation(s)
- Li-Qiong Yuan
- Department of Rehabilitation Medicine and Physiotherapy, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong Province, China
| | - Qing Zeng
- Department of Rehabilitation Medicine and Physiotherapy, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong Province, China
| | - Dan Wang
- Department of Rehabilitation Medicine and Physiotherapy, Shenzhen Baoan Hospital of Southern Medical University, Shenzhen, Guangdong Province, China
| | - Xiu-Yun Wen
- Department of Rehabilitation Medicine and Physiotherapy, Shenzhen Baoan Hospital of Southern Medical University, Shenzhen, Guangdong Province, China
| | - Yu Shi
- Department of Rehabilitation Medicine and Physiotherapy, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong Province, China
| | - Fen Zhu
- Department of Rehabilitation Medicine and Physiotherapy, Shenzhen Baoan Hospital of Southern Medical University, Shenzhen, Guangdong Province, China
| | - Shang-Jie Chen
- Department of Rehabilitation Medicine and Physiotherapy, Shenzhen Baoan Hospital of Southern Medical University, Shenzhen, Guangdong Province, China
| | - Guo-Zhi Huang
- Department of Rehabilitation Medicine and Physiotherapy, Zhujiang Hospital of Southern Medical University; Rehabilitation School of Southern Medical University, Guangzhou, Guangdong Province, China
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15
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Feng J, Zhang SW, Chen L, Xia J. Alzheimer’s disease classification using features extracted from nonsubsampled contourlet subband-based individual networks. Neurocomputing 2021. [DOI: 10.1016/j.neucom.2020.09.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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16
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Gramespacher H, Richter N, Edwin Thanarajah S, Jacobs HIL, Dillen KNH, Nellessen N, von Reutern B, Dronse J, Kukolja J, Fink GR, Onur OA. Aberrant frontostriatal connectivity in Alzheimer's disease with positive palmomental reflex. Eur J Neurol 2020; 27:2405-2414. [PMID: 32677282 DOI: 10.1111/ene.14443] [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: 07/07/2020] [Accepted: 07/10/2020] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND PURPOSE Primitive reflexes may reoccur in various neurodegenerative diseases. However, little is known about their structural and functional correlates in the human brain. Notably, the neural mechanisms underlying a positive palmomental reflex (PMR) are poorly understood. As recent studies link Alzheimer's disease (AD)-related primitive reflexes to a dysfunction of the corticostriatal motor circuit (CMC), we conducted the present study to investigate functional and structural correlates of a positive PMR. We hypothesized an involvement of frontostriatal structures and an impairment of the CMC. METHODS Using whole-brain resting-state functional connectivity (FC), hypothesis and FC result-based probabilistic tractography, and voxel-based morphometry analyses, we compared two groups of AD patients with either positive (n = 12) or negative PMR (n = 12). RESULTS No significant differences in grey matter volume or structural connectivity (SC) could be observed between the PMR-positive and PMR-negative groups. In contrast, the PMR-positive group showed a decreased seed-to-voxel FC between the bilateral supplementary motor area and parts of the right-hemispherical caudate nucleus and thalamus and a decreased region of interest (ROI)-to-ROI FC between the left putamen and the left superior frontal gyrus. CONCLUSION Data suggest that dysfunction of the CMC reflected by decreased FC underlies a positive PMR in patients with AD. The lack of significant grey matter or SC differences might reflect that changes in FC appear before changes in SC in the structures of the CMC and brain atrophy.
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Affiliation(s)
- H Gramespacher
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - N Richter
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Cognitive Neuroscience, Research Center Jülich, Institute of Neuroscience and Medicine (INM3), Research Centre Juelich, Juelich, Germany
| | - S Edwin Thanarajah
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Max Planck Institute for Metabolism Research, Cologne, Germany.,Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital Frankfurt, Frankfurt, Germany
| | - H I L Jacobs
- Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg; Maastricht University, Maastricht, The Netherlands.,Gordon Center of Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - K N H Dillen
- Cognitive Neuroscience, Research Center Jülich, Institute of Neuroscience and Medicine (INM3), Research Centre Juelich, Juelich, Germany.,Department of Palliative Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - N Nellessen
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - B von Reutern
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Cognitive Neuroscience, Research Center Jülich, Institute of Neuroscience and Medicine (INM3), Research Centre Juelich, Juelich, Germany
| | - J Dronse
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Cognitive Neuroscience, Research Center Jülich, Institute of Neuroscience and Medicine (INM3), Research Centre Juelich, Juelich, Germany
| | - J Kukolja
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Department of Neurology and Clinical Neurophysiology, Helios University Hospital Wuppertal, Wuppertal, Germany.,Faculty of Health, Witten/Herdecke University, Witten, Germany
| | - G R Fink
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Cognitive Neuroscience, Research Center Jülich, Institute of Neuroscience and Medicine (INM3), Research Centre Juelich, Juelich, Germany
| | - O A Onur
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Cognitive Neuroscience, Research Center Jülich, Institute of Neuroscience and Medicine (INM3), Research Centre Juelich, Juelich, Germany
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17
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Royea J, Lacalle-Aurioles M, Trigiani LJ, Fermigier A, Hamel E. AT2R's (Angiotensin II Type 2 Receptor's) Role in Cognitive and Cerebrovascular Deficits in a Mouse Model of Alzheimer Disease. Hypertension 2020; 75:1464-1474. [PMID: 32362228 DOI: 10.1161/hypertensionaha.119.14431] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Antihypertensive medications targeting the renin-angiotensin system have lowered the incidence and progression of Alzheimer disease. Understanding how these medications function could lead to novel therapeutic strategies. AT4Rs (angiotensin IV receptors) have been associated with angiotensin receptor blockers' cognitive, cerebrovascular, and neuroinflammatory rescue in Alzheimer disease models. Yet, whether AT4Rs act alone or with AT2Rs remains unknown. Here, we investigated whether AT2Rs contribute to losartan's benefits and whether chronic AT2R activation could mimic angiotensin receptor blocker benefits in transgenic mice overexpressing familial Alzheimer disease mutations of the human APP (amyloid precursor protein). Losartan-treated mice (10 mg/kg per day, drinking water, 7 months) received intracerebroventricular (1 month) administration of vehicle or AT2R antagonist PD123319 (1.6 nmol/day). PD123319 countered losartan's benefits on spatial learning and memory, neurovascular coupling, and hampered those on oxidative stress and nitric oxide bioavailability. PD123319 did not oppose losartan's benefits on short-term memory and vasodilatory function and had no benefit on neuroinflammation or Aβ (amyloid β) pathology. Mice receiving either vehicle or selective AT2R agonist compound 21 (intracerebroventricular: 1 nmol/day, 1 month or drinking water: 10 mg/kg per day, 7 months), showed no improvement in memory, vasodilatory function, or nitric oxide bioavailability. Compound 21 treatment normalized neurovascular coupling, reduced astrogliosis independent of persisting microgliosis, and exacerbated oxidative stress in APP mice. Compound 21 reduced dense core Aβ plaques, but not diffuse plaques or Aβ species. Our findings suggest that targeting AT2Rs is not an ideal strategy for restoring Aβ-related cognitive and cerebrovascular deficits.
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Affiliation(s)
- Jessika Royea
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Maria Lacalle-Aurioles
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Lianne J Trigiani
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Alice Fermigier
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Edith Hamel
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
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