1
|
Zhang S, Lu J, Jin Z, Xu H, Zhang D, Chen J, Wang J. Gut microbiota metabolites: potential therapeutic targets for Alzheimer's disease? Front Pharmacol 2024; 15:1459655. [PMID: 39355779 PMCID: PMC11442227 DOI: 10.3389/fphar.2024.1459655] [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] [Received: 07/04/2024] [Accepted: 09/05/2024] [Indexed: 10/03/2024] Open
Abstract
Background Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive decline in cognitive function, which significantly increases pain and social burden. However, few therapeutic interventions are effective in preventing or mitigating the progression of AD. An increasing number of recent studies support the hypothesis that the gut microbiome and its metabolites may be associated with upstream regulators of AD pathology. Methods In this review, we comprehensively explore the potential mechanisms and currently available interventions targeting the microbiome for the improvement of AD. Our discussion is structured around modern research advancements in AD, the bidirectional communication between the gut and brain, the multi-target regulatory effects of microbial metabolites on AD, and therapeutic strategies aimed at modulating gut microbiota to manage AD. Results The gut microbiota plays a crucial role in the pathogenesis of AD through continuous bidirectional communication via the microbiota-gut-brain axis. Among these, microbial metabolites such as lipids, amino acids, bile acids and neurotransmitters, especially sphingolipids and phospholipids, may serve as central components of the gut-brain axis, regulating AD-related pathogenic mechanisms including β-amyloid metabolism, Tau protein phosphorylation, and neuroinflammation. Additionally, interventions such as probiotic administration, fecal microbiota transplantation, and antibiotic use have also provided evidence supporting the association between gut microbiota and AD. At the same time, we propose an innovative strategy for treating AD: a healthy lifestyle combined with targeted probiotics and other potential therapeutic interventions, aiming to restore intestinal ecology and microbiota balance. Conclusion Despite previous efforts, the molecular mechanisms by which gut microbes act on AD have yet to be fully described. However, intestinal microorganisms may become an essential target for connecting the gut-brain axis and improving the symptoms of AD. At the same time, it requires joint exploration by multiple centers and multiple disciplines.
Collapse
Affiliation(s)
- Shanshan Zhang
- The School to Changchun University of Chinese Medicine, Changchun, China
| | - Jing Lu
- Research Center of Traditional Chinese Medicine, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China
| | - Ziqi Jin
- The School to Changchun University of Chinese Medicine, Changchun, China
| | - Hanying Xu
- Department of Encephalopathy, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China
| | - Dongmei Zhang
- Research Center of Traditional Chinese Medicine, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China
| | - Jianan Chen
- The School to Changchun University of Chinese Medicine, Changchun, China
| | - Jian Wang
- Department of Encephalopathy, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China
| |
Collapse
|
2
|
Gao Y, Zhang H, Hu Y. Baseline serum glutamate: Implications for diagnosis and prediction in mild cognitive impairment and Alzheimer's disease of the Alzheimer's Disease Neuroimaging Initiative. J Clin Neurosci 2024; 129:110828. [PMID: 39265358 DOI: 10.1016/j.jocn.2024.110828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 07/28/2024] [Accepted: 09/04/2024] [Indexed: 09/14/2024]
Abstract
PURPOSE Numerous studies have highlighted a close link between metabolic imbalances and Alzheimer's Disease (AD). The advancement of metabolomics has recently enabled the exploration of characteristic metabolic changes associated with AD. Studies indicate that serum glutamate (Glu) levels may correlate with mild cognitive impairment (MCI) and AD. This study aims to further elucidate the characteristics of baseline serum Glu levels in MCI and AD. METHODS This study included 783 participants from the Alzheimer's Disease Neuroimaging Initiative-1 (ADNI-1) cohort, categorized into cognitively normal (CN, n = 224), stable MCI (sMCI, n = 181), progressive MCI (pMCI, n = 193), and AD (n = 185). The study aimed to analyze the diagnostic value of baseline serum Glu, to explore its predictive capability for the progression from CN to MCI or AD, and from MCI to AD, and to analyze the relationship between serum Glu and cerebrospinal fluid (CSF) biomarkers and cognitive functions in different diagnostic groups. RESULTS Compared to the CN and sMCI groups, the pMCI group showed significantly lower levels of serum Glu, and the AD group also had lower Glu levels compared to the sMCI group. However, serum Glu did not show significant diagnostic value for MCI and AD. Lower levels of serum Glu could predict the progression from MCI to AD. CONCLUSION Serum Glu levels can predict the progression from MCI to AD, suggesting that it could provide new insights into the pathophysiological mechanisms of AD. However, serum Glu may not be an ideal peripheral biomarker for AD.
Collapse
Affiliation(s)
- Ying Gao
- Department of General Medical Wards Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Engineering Research Center of Stem Cell Therapy. Chongqing 400014, China
| | - Hua Zhang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Yuming Hu
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
| |
Collapse
|
3
|
Dadi P, Pauling CW, Shrivastava A, Shah DD. Synthesis of versatile neuromodulatory molecules by a gut microbial glutamate decarboxylase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.02.583032. [PMID: 38915512 PMCID: PMC11195143 DOI: 10.1101/2024.03.02.583032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Dysbiosis of the microbiome correlates with many neurological disorders, yet very little is known about the chemistry that controls the production of neuromodulatory molecules by gut microbes. Here, we found that an enzyme glutamate decarboxylase (BfGAD) of a gut microbe Bacteroides fragilis forms multiple neuromodulatory molecules such as γ-aminobutyric acid (GABA), hypotaurine, taurine, homotaurine, and β-alanine. We evolved BfGAD and doubled its taurine productivity. Additionally, we increased its specificity towards the substrate L-glutamate. Here, we provide a chemical strategy via which the BfGAD activity could be fine-tuned. In future, this strategy could be used to modulate the production of neuromodulatory molecules by gut microbes.
Collapse
Affiliation(s)
- Pavani Dadi
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ 85281
- School of Life Sciences, Arizona State University, Tempe, AZ 85281
| | - Clint W. Pauling
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ 85281
- School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ 85306
| | - Abhishek Shrivastava
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ 85281
- School of Life Sciences, Arizona State University, Tempe, AZ 85281
| | - Dhara D. Shah
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ 85281
- School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ 85306
| |
Collapse
|
4
|
Salcedo C, Pozo Garcia V, García-Adán B, Ameen AO, Gegelashvili G, Waagepetersen HS, Freude KK, Aldana BI. Increased glucose metabolism and impaired glutamate transport in human astrocytes are potential early triggers of abnormal extracellular glutamate accumulation in hiPSC-derived models of Alzheimer's disease. J Neurochem 2024; 168:822-840. [PMID: 38063257 DOI: 10.1111/jnc.16014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 10/27/2023] [Accepted: 11/01/2023] [Indexed: 05/19/2024]
Abstract
Glutamate recycling between neurons and astrocytes is essential to maintain neurotransmitter homeostasis. Disturbances in glutamate homeostasis, resulting in excitotoxicity and neuronal death, have been described as a potential mechanism in Alzheimer's disease (AD) pathophysiology. However, glutamate neurotransmitter metabolism in different human brain cells, particularly astrocytes, has been poorly investigated at the early stages of AD. We sought to investigate glucose and glutamate metabolism in AD by employing human induced pluripotent stem cell (hiPSC)-derived astrocytes and neurons carrying mutations in the amyloid precursor protein (APP) or presenilin-1 (PSEN-1) gene as found in familial types of AD (fAD). Methods such as live-cell bioenergetics and metabolic mapping using [13C]-enriched substrates were used to examine metabolism in the early stages of AD. Our results revealed greater glycolysis and glucose oxidative metabolism in astrocytes and neurons with APP or PSEN-1 mutations, accompanied by an elevated glutamate synthesis compared to control WT cells. Astrocytes with APP or PSEN-1 mutations exhibited reduced expression of the excitatory amino acid transporter 2 (EAAT2), and glutamine uptake increased in mutated neurons, with enhanced glutamate release specifically in neurons with a PSEN-1 mutation. These results demonstrate a hypermetabolic phenotype in astrocytes with fAD mutations possibly linked to toxic glutamate accumulation. Our findings further identify metabolic imbalances that may occur in the early phases of AD pathophysiology.
Collapse
Affiliation(s)
- Claudia Salcedo
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Victoria Pozo Garcia
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bernat García-Adán
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Aishat O Ameen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Georgi Gegelashvili
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
| | - Helle S Waagepetersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kristine K Freude
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Blanca I Aldana
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
5
|
Yao X, Xu X, Hu K, Yang Z, Deng S. BANF1 promotes glutamate-induced apoptosis of HT-22 hippocampal neurons. Mol Biol Rep 2023; 50:9441-9452. [PMID: 37838622 DOI: 10.1007/s11033-023-08889-1] [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: 04/13/2023] [Accepted: 10/04/2023] [Indexed: 10/16/2023]
Abstract
BACKGROUND Glutamate exposure was fatal to HT-22 neuronal cells that derived from mouse hippocampus. This is often used as a model for hippocampus neurodegeneration in vitro. The targets relevant to glutamate-induced neuronal toxicity is not fully understood. In this study, we aimed to identify crucial factors associated with glutamate-induced cytotoxicity in HT-22 cells. METHODS HT-22 cells were treated with 7.5 mM glutamate for 24 h and isobaric tags for relative and absolute quantitation (iTRAQ) proteomic analysis conducted to identify the differentially expressed proteins. Differential proteins were subjected to Gene Ontology analyses. Upregulation of barrier to autointegration factor (BANF1/BANF1) protein was confirmed by RT-qPCR and western blotting. Cell viability was measured by CKK-8 and MTT assays. Cell apoptosis rates and intracellular reactive oxygen species (ROS) levels were detected using flow cytometry. RESULTS A total of 5811 proteins were quantified by iTRAQ, 50 of which were recognized as significantly differential proteins (fold change ≥ 1.5 and P ≤ 0.05); 26 proteins were up-regulated and 24 were down-regulated after exposure to glutamate. GO enrichment analysis showed that the apoptotic signaling pathway was involved in cell death induced by glutamate. BANF1 expression level was markedly increased in HT-22 cells after glutamate treatment. Further, knockdown of BANF1 alleviated glutamate-mediated cell death with lower ROS levels. CONCLUSIONS In conclusion, we successfully filtered out differential proteins relevant to glutamate-mediated cytotoxicity. BANF1 upregulation promoted glutamate-induced apoptosis of HT-22 cells by enhancing ROS generation.
Collapse
Affiliation(s)
- Xinyu Yao
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Xiaoyi Xu
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, Guangdong, China
| | - Kunhua Hu
- Proteomics Research Center, Sun Yat-Sen Medical College of Sun Yat-Sen University, Guangzhou, 510080, China
| | - Zhaoshou Yang
- The First Affiliated Hospital/School of Clinical Medicine of Guangdong Pharmaceutical University, Guangdong Pharmaceutical University, Guangzhou, 510080, China.
| | - Shaodong Deng
- The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, 523710, Guangdong, China.
- Scientific Research Platform, The Second Clinical Medical College, Guangdong Medical University, Dongguan, 523808, China.
| |
Collapse
|
6
|
Xie D, Song C, Qin T, Zhai Z, Cai J, Dai J, Sun T, Xu Y. Moschus ameliorates glutamate-induced cellular damage by regulating autophagy and apoptosis pathway. Sci Rep 2023; 13:18586. [PMID: 37903904 PMCID: PMC10616123 DOI: 10.1038/s41598-023-45878-7] [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: 11/16/2022] [Accepted: 10/25/2023] [Indexed: 11/01/2023] Open
Abstract
Alzheimer's disease (AD), a neurodegenerative disorder, causes short-term memory and cognition declines. It is estimated that one in three elderly people die from AD or other dementias. Chinese herbal medicine as a potential drug for treating AD has gained growing interest from many researchers. Moschus, a rare and valuable traditional Chinese animal medicine, was originally documented in Shennong Ben Cao Jing and recognized for its properties of reviving consciousness/resuscitation. Additionally, Moschus has the efficacy of "regulation of menstruation with blood activation, relief of swelling and pain" and is used for treating unconsciousness, stroke, coma, and cerebrovascular diseases. However, it is uncertain whether Moschus has any protective effect on AD patients. We explored whether Moschus could protect glutamate (Glu)-induced PC12 cells from cellular injury and preliminarily explored their related action mechanisms. The chemical compounds of Moschus were analyzed and identified by GC-MS. The Glu-induced differentiated PC12 cell model was thought to be the common AD cellular model. The study aims to preliminarily investigate the intervention effect of Moschus on Glu-induced PC12 cell damage as well as their related action mechanisms. Cell viability, lactate dehydrogenase (LDH), mitochondrial reactive oxygen species, mitochondrial membrane potential (MMP), cell apoptosis, autophagic vacuoles, autolysosomes or autophagosomes, proteins related to apoptosis, and the proteins related to autophagy were examined and analyzed. Seventeen active compounds of the Moschus sample were identified based on GC-MS analysis. In comparison to the control group, Glu stimulation increased cell viability loss, LDH release, mitochondrial damage, loss of MMP, apoptosis rate, and the number of cells containing autophagic vacuoles, and autolysosomes or autophagosomes, while these results were decreased after the pretreatment with Moschus and 3-methyladenine (3-MA). Furthermore, Glu stimulation significantly increased cleaved caspase-3, Beclin1, and LC3II protein expression, and reduced B-cell lymphoma 2/BAX ratio and p62 protein expression, but these results were reversed after pretreatment of Moschus and 3-MA. Moschus has protective activity in Glu-induced PC12 cell injury, and the potential mechanism might involve the regulation of autophagy and apoptosis. Our study may promote research on Moschus in the field of neurodegenerative diseases, and Moschus may be considered as a potential therapeutic agent for AD.
Collapse
Affiliation(s)
- Danni Xie
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Caiyou Song
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Tao Qin
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Zhenwei Zhai
- School of Medical Information Engineering, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jie Cai
- School of Medical Information Engineering, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jingyi Dai
- School of Medical Information Engineering, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Tao Sun
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
- School of Medical Information Engineering, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
| | - Ying Xu
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, China.
| |
Collapse
|
7
|
Hu X, Jin X, Cao X, Liu B. The Anaphase-Promoting Complex/Cyclosome Is a Cellular Ageing Regulator. Int J Mol Sci 2022; 23:ijms232315327. [PMID: 36499653 PMCID: PMC9740938 DOI: 10.3390/ijms232315327] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/11/2022] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a complicated cellular component that plays significant roles in regulating the cell cycle process of eukaryotic organisms. The spatiotemporal regulation mechanisms of APC/C in distinct cell cycle transitions are no longer mysterious, and the components of this protein complex are gradually identified and characterized. Given the close relationship between the cell cycle and lifespan, it is urgent to understand the roles of APC/C in lifespan regulation, but this field still seems to have not been systematically summarized. Furthermore, although several reviews have reported the roles of APC/C in cancer, there are still gaps in the summary of its roles in other age-related diseases. In this review, we propose that the APC/C is a novel cellular ageing regulator based on its indispensable role in the regulation of lifespan and its involvement in age-associated diseases. This work provides an extensive review of aspects related to the underlying mechanisms of APC/C in lifespan regulation and how it participates in age-associated diseases. More comprehensive recognition and understanding of the relationship between APC/C and ageing and age-related diseases will increase the development of targeted strategies for human health.
Collapse
Affiliation(s)
- Xiangdong Hu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
| | - Xuejiao Jin
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
| | - Xiuling Cao
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
- Correspondence: (X.C.); (B.L.)
| | - Beidong Liu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41390 Gothenburg, Sweden
- Correspondence: (X.C.); (B.L.)
| |
Collapse
|
8
|
Abulseoud OA, Alasmari F, Hussein AM, Sari Y. Ceftriaxone as a Novel Therapeutic Agent for Hyperglutamatergic States: Bridging the Gap Between Preclinical Results and Clinical Translation. Front Neurosci 2022; 16:841036. [PMID: 35864981 PMCID: PMC9294323 DOI: 10.3389/fnins.2022.841036] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 06/07/2022] [Indexed: 12/02/2022] Open
Abstract
Dysregulation of glutamate homeostasis is a well-established core feature of neuropsychiatric disorders. Extracellular glutamate concentration is regulated by glutamate transporter 1 (GLT-1). The discovery of a beta-lactam antibiotic, ceftriaxone (CEF), as a safe compound with unique ability to upregulate GLT-1 sparked the interest in testing its efficacy as a novel therapeutic agent in animal models of neuropsychiatric disorders with hyperglutamatergic states. Indeed, more than 100 preclinical studies have shown the efficacy of CEF in attenuating the behavioral manifestations of various hyperglutamatergic brain disorders such as ischemic stroke, amyotrophic lateral sclerosis (ALS), seizure, Huntington’s disease, and various aspects of drug use disorders. However, despite rich and promising preclinical data, only one large-scale clinical trial testing the efficacy of CEF in patients with ALS is reported. Unfortunately, in that study, there was no significant difference in survival between placebo- and CEF-treated patients. In this review, we discussed the translational potential of preclinical efficacy of CEF based on four different parameters: (1) initiation of CEF treatment in relation to induction of the hyperglutamatergic state, (2) onset of response in preclinical models in relation to onset of GLT-1 upregulation, (3) mechanisms of action of CEF on GLT-1 expression and function, and (4) non-GLT-1-mediated mechanisms for CEF. Our detailed review of the literature brings new insights into underlying molecular mechanisms correlating the preclinical efficacy of CEF. We concluded here that CEF may be clinically effective in selected cases in acute and transient hyperglutamatergic states such as early drug withdrawal conditions.
Collapse
Affiliation(s)
- Osama A. Abulseoud
- Department of Psychiatry and Psychology, Alex School of Medicine at Mayo Clinic, Phoenix, AZ, United States
- *Correspondence: Osama A. Abulseoud,
| | - Fawaz Alasmari
- Department of Pharmacology and Experimental Therapeutics, University of Toledo, Toledo, OH, United States
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Abdelaziz M. Hussein
- Department of Medical Physiology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Youssef Sari
- Department of Pharmacology and Experimental Therapeutics, University of Toledo, Toledo, OH, United States
- Youssef Sari,
| |
Collapse
|
9
|
Targa Dias Anastacio H, Matosin N, Ooi L. Neuronal hyperexcitability in Alzheimer's disease: what are the drivers behind this aberrant phenotype? Transl Psychiatry 2022; 12:257. [PMID: 35732622 PMCID: PMC9217953 DOI: 10.1038/s41398-022-02024-7] [Citation(s) in RCA: 86] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/01/2022] [Accepted: 06/08/2022] [Indexed: 12/13/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder leading to loss of cognitive abilities and ultimately, death. With no cure available, limited treatments mostly focus on symptom management. Identifying early changes in the disease course may provide new therapeutic targets to halt or reverse disease progression. Clinical studies have shown that cortical and hippocampal hyperactivity are a feature shared by patients in the early stages of disease, progressing to hypoactivity during later stages of neurodegeneration. The exact mechanisms causing neuronal excitability changes are not fully characterized; however, animal and cell models have provided insights into some of the factors involved in this phenotype. In this review, we summarize the evidence for neuronal excitability changes over the course of AD onset and progression and the molecular mechanisms underpinning these differences. Specifically, we discuss contributors to aberrant neuronal excitability, including abnormal levels of intracellular Ca2+ and glutamate, pathological amyloid β (Aβ) and tau, genetic risk factors, including APOE, and impaired inhibitory interneuron and glial function. In light of recent research indicating hyperexcitability could be a predictive marker of cognitive dysfunction, we further argue that the hyperexcitability phenotype could be leveraged to improve the diagnosis and treatment of AD, and present potential targets for future AD treatment development.
Collapse
Affiliation(s)
- Helena Targa Dias Anastacio
- grid.510958.0Illawarra Health and Medical Research Institute, Wollongong, NSW 2522 Australia ,grid.1007.60000 0004 0486 528XMolecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Natalie Matosin
- grid.510958.0Illawarra Health and Medical Research Institute, Wollongong, NSW 2522 Australia ,grid.1007.60000 0004 0486 528XMolecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia. .,Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia.
| |
Collapse
|
10
|
Rafiee Z, García-Serrano AM, Duarte JMN. Taurine Supplementation as a Neuroprotective Strategy upon Brain Dysfunction in Metabolic Syndrome and Diabetes. Nutrients 2022; 14:1292. [PMID: 35334949 PMCID: PMC8952284 DOI: 10.3390/nu14061292] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 02/07/2023] Open
Abstract
Obesity, type 2 diabetes, and their associated comorbidities impact brain metabolism and function and constitute risk factors for cognitive impairment. Alterations to taurine homeostasis can impact a number of biological processes, such as osmolarity control, calcium homeostasis, and inhibitory neurotransmission, and have been reported in both metabolic and neurodegenerative disorders. Models of neurodegenerative disorders show reduced brain taurine concentrations. On the other hand, models of insulin-dependent diabetes, insulin resistance, and diet-induced obesity display taurine accumulation in the hippocampus. Given the possible cytoprotective actions of taurine, such cerebral accumulation of taurine might constitute a compensatory mechanism that attempts to prevent neurodegeneration. The present article provides an overview of brain taurine homeostasis and reviews the mechanisms by which taurine can afford neuroprotection in individuals with obesity and diabetes. We conclude that further research is needed for understanding taurine homeostasis in metabolic disorders with an impact on brain function.
Collapse
Affiliation(s)
- Zeinab Rafiee
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, 22100 Lund, Sweden; (Z.R.); (A.M.G.-S.)
- Wallenberg Centre for Molecular Medicine, Lund University, 22100 Lund, Sweden
| | - Alba M. García-Serrano
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, 22100 Lund, Sweden; (Z.R.); (A.M.G.-S.)
- Wallenberg Centre for Molecular Medicine, Lund University, 22100 Lund, Sweden
| | - João M. N. Duarte
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, 22100 Lund, Sweden; (Z.R.); (A.M.G.-S.)
- Wallenberg Centre for Molecular Medicine, Lund University, 22100 Lund, Sweden
| |
Collapse
|
11
|
Mather M. Noradrenaline in the aging brain: Promoting cognitive reserve or accelerating Alzheimer's disease? Semin Cell Dev Biol 2021; 116:108-124. [PMID: 34099360 PMCID: PMC8292227 DOI: 10.1016/j.semcdb.2021.05.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 12/19/2022]
Abstract
Many believe that engaging in novel and mentally challenging activities promotes brain health and prevents Alzheimer's disease in later life. However, mental stimulation may also have risks as well as benefits. As neurons release neurotransmitters, they often also release amyloid peptides and tau proteins into the extracellular space. These by-products of neural activity can aggregate into the tau tangle and amyloid plaque signatures of Alzheimer's disease. Over time, more active brain regions accumulate more pathology. Thus, increasing brain activity can have a cost. But the neuromodulator noradrenaline, released during novel and mentally stimulating events, may have some protective effects-as well as some negative effects. Via its inhibitory and excitatory effects on neurons and microglia, noradrenaline sometimes prevents and sometimes accelerates the production and accumulation of amyloid-β and tau in various brain regions. Both α2A- and β-adrenergic receptors influence amyloid-β production and tau hyperphosphorylation. Adrenergic activity also influences clearance of amyloid-β and tau. Furthermore, some findings suggest that Alzheimer's disease increases noradrenergic activity, at least in its early phases. Because older brains clear the by-products of synaptic activity less effectively, increased synaptic activity in the older brain risks accelerating the accumulation of Alzheimer's pathology more than it does in the younger brain.
Collapse
Affiliation(s)
- Mara Mather
- Leonard Davis School of Gerontology, Department of Psychology, & Department of Biomedical Engineering, University of Southern California, 3715 McClintock Ave, Los Angeles, CA 90089, United States.
| |
Collapse
|
12
|
Kuroda M, Matsuwaki T, Tanaka Y, Yamanouchi K, Nishihara M. Convulsive responses to seizure-inducible drugs are exacerbated in progranulin-deficient mice. Neuroreport 2021; 31:478-483. [PMID: 32168097 DOI: 10.1097/wnr.0000000000001425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Progranulin (PGRN) is a glycoprotein that is widely expressed among organs, including the central nervous system. PGRN insufficiency is involved in various neurodegenerative disorders such as frontotemporal dementia, Alzheimer's disease, and neuronal ceroid lipofuscinosis. One of the major causes of neuronal damage is hyperactivation of the cerebrum triggered by upregulation of excitatory systems. In the present study, we examined the possible involvement of PGRN in modulating excitability of the cerebrum using wild type and PGRN-deficient mice. First, we treated wild type and PGRN-deficient mice with seizure-inducible drugs, bicuculline or N-methyl-D-aspartate (NMDA), which provoke hyperexcitement of neurons. PGRN-deficient mice showed higher intensity of seizure and longer duration of convulsive behavior when treated with either bicuculline or NMDA. Next, we quantified the expression of NMDA receptor subunits in the hippocampus and cerebral cortex. The expression level of NR2A subunit protein was significantly higher in the hippocampus of PGRN-deficient mice, while no difference was observed in the cerebral cortex. On the other hand, mRNA levels of NMDA receptor subunits in the hippocampus were comparable or even lower in PGRN-deficient mice. These results suggest that PGRN modulates the excitability of the cerebrum by regulating at least partially the protein level of NMDA receptors in the hippocampus.
Collapse
Affiliation(s)
- Machi Kuroda
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo
| | - Takashi Matsuwaki
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo
| | - Yoshinori Tanaka
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo.,Biochemistry Unit, Faculty of Veterinary Medicine, Okayama University of Science, Ehime, Japan
| | - Keitaro Yamanouchi
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo
| | - Masugi Nishihara
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo
| |
Collapse
|
13
|
Ding Y, Wang X, Ji J, Zhang X, Chen M, Li S, Zhang Q, Liu P. (( E)- N-(4-(((2-Amino-5-phenylpyridin-3-yl)imino)methyl)pyridin-2-yl)cyclopropanecarboxamide) Ameliorated Aβ 1-42-Induced Alzheimer's Disease in SD Rats by Inhibiting Oxidative Stress and Apoptosis. ACS Chem Neurosci 2021; 12:640-650. [PMID: 33517657 DOI: 10.1021/acschemneuro.0c00655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Our study investigated the protective effects of ((E)-N-(4-(((2-amino-5-phenylpyridin-3-yl)imino)methyl)pyridin-2-yl)cyclopropanecarboxamide) 9b, a novel glycogen synthase kinase-3β (GSK-3β) inhibitor, on the learning and memory function of rats with amyloid-β1-42 (Aβ1-42)-induced Alzheimer's disease (AD) and explored the possible mechanisms. Sixty male Sprague-Dawley (SD) rats were randomly divided into five groups: the control, Aβ, donepezil, and low-dose and high-dose 9b groups. The rats in the Aβ, donepezil, and two 9b intervention groups received a single microinjection of 10 μg of Aβ1-42 into the hippocampus followed by intragastric administration of 0.5% sodium carboxymethyl cellulose (CMC-Na), 12 (mg/kg)/d donepezil hydrochloride and 6 or 18 (mg/kg)/d compound 9b for 28 days, while the rats in the control group were treated with the vehicles. Learning and memory impairment were attenuated, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), acetylcholinesterase (AChE), and adenosine triphosphatase (ATPase) in the brain tissue were significantly increased (p < 0.05), and the concentrations of Aβ1-42, phospho-tau (p-tau), and malondialdehyde (MDA) in the brain tissue were significantly decreased (p < 0.05) in the compound 9b group compared to the Aβ group. In addition, compound 9b regulated the imbalance in the concentrations of neurotransmitters and alleviated severe damage and apoptosis in the brains of the rats exposed to Aβ1-42. The novel GSK-3β inhibitor 9b could improve learning and memory dysfunction caused by Aβ1-42 through its antioxidant and antiapoptotic effects.
Collapse
Affiliation(s)
- Yun Ding
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Xin Wang
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Jing Ji
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Xuejiao Zhang
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Mengdi Chen
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Shuling Li
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Qiongyao Zhang
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Ping Liu
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| |
Collapse
|
14
|
Oh SJ, Lee HJ, Jeong YJ, Nam KR, Kang KJ, Han SJ, Lee KC, Lee YJ, Choi JY. Evaluation of the neuroprotective effect of taurine in Alzheimer's disease using functional molecular imaging. Sci Rep 2020; 10:15551. [PMID: 32968166 PMCID: PMC7511343 DOI: 10.1038/s41598-020-72755-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/04/2020] [Indexed: 01/22/2023] Open
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disorder and the leading cause of dementia, but therapeutic treatment options are limited. Taurine has been reported to have neuroprotective properties against dementia, including AD. The present study aimed to investigate the treatment effect of taurine in AD mice by functional molecular imaging. To elucidate glutamate alterations by taurine, taurine was administered to 5xFAD transgenic mice from 2 months of age, known to apear amyloid deposition. Then, we performed glutamate positron emission tomography (PET) imaging studies for three groups (wild-type, AD, and taurine-treated AD, n = 5 in each group). As a result, brain uptake in the taurine-treated AD group was 31-40% higher than that in the AD group (cortex: 40%, p < 0.05; striatum: 32%, p < 0.01; hippocampus: 36%, p < 0.01; thalamus: 31%, p > 0.05) and 3-14% lower than that in the WT group (cortex: 10%, p > 0.05; striatum: 15%, p > 0.05; hippocampus: 14%, p > 0.05; thalamus: 3%, p > 0.05). However, we did not observe differences in Aβ pathology between the taurine-treated AD and AD groups in immunohistochemistry experiments. Our results reveal that although taurine treatment did not completely recover the glutamate system, it significantly increased metabolic glutamate receptor type 5 brain uptake. Therefore, taurine has therapeutic potential against AD.
Collapse
Affiliation(s)
- Se Jong Oh
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812, Korea
| | - Hae-June Lee
- Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Ye Ji Jeong
- Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Kyung Rok Nam
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812, Korea
| | - Kyung Jun Kang
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812, Korea
| | - Sang Jin Han
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812, Korea
| | - Kyo Chul Lee
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812, Korea
| | - Yong Jin Lee
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812, Korea
| | - Jae Yong Choi
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812, Korea.
| |
Collapse
|
15
|
Significance of Blood and Cerebrospinal Fluid Biomarkers for Alzheimer's Disease: Sensitivity, Specificity and Potential for Clinical Use. J Pers Med 2020; 10:jpm10030116. [PMID: 32911755 PMCID: PMC7565390 DOI: 10.3390/jpm10030116] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 08/21/2020] [Accepted: 09/01/2020] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) is the most common type of dementia, affecting more than 5 million Americans, with steadily increasing mortality and incredible socio-economic burden. Not only have therapeutic efforts so far failed to reach significant efficacy, but the real pathogenesis of the disease is still obscure. The current theories are based on pathological findings of amyloid plaques and tau neurofibrillary tangles that accumulate in the brain parenchyma of affected patients. These findings have defined, together with the extensive neurodegeneration, the diagnostic criteria of the disease. The ability to detect changes in the levels of amyloid and tau in cerebrospinal fluid (CSF) first, and more recently in blood, has allowed us to use these biomarkers for the specific in-vivo diagnosis of AD in humans. Furthermore, other pathological elements of AD, such as the loss of neurons, inflammation and metabolic derangement, have translated to the definition of other CSF and blood biomarkers, which are not specific of the disease but, when combined with amyloid and tau, correlate with the progression from mild cognitive impairment to AD dementia, or identify patients who will develop AD pathology. In this review, we discuss the role of current and hypothetical biomarkers of Alzheimer's disease, their specificity, and the caveats of current high-sensitivity platforms for their peripheral detection.
Collapse
|
16
|
Tondo M, Wasek B, Escola-Gil JC, de Gonzalo-Calvo D, Harmon C, Arning E, Bottiglieri T. Altered Brain Metabolome Is Associated with Memory Impairment in the rTg4510 Mouse Model of Tauopathy. Metabolites 2020; 10:metabo10020069. [PMID: 32075035 PMCID: PMC7074477 DOI: 10.3390/metabo10020069] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/01/2020] [Accepted: 02/05/2020] [Indexed: 01/03/2023] Open
Abstract
Alzheimer’s disease (AD) is characterized, amongst other features, by the pathologic accumulation of abnormally phosphorylated tau filaments in neurons that lead to neurofibrillary tangles. However, the molecular mechanisms by which the abnormal processing of tau leads to neurodegeneration and cognitive impairment remain unknown. Metabolomic techniques can comprehensively assess disturbances in metabolic pathways that reflect changes downstream from genomic, transcriptomic and proteomic systems. In the present study, we undertook a targeted metabolomic approach to determine a total of 187 prenominated metabolites in brain cortex tissue from wild type and rTg4510 animals (a mice model of tauopathy), in order to establish the association of metabolic pathways with cognitive impairment. This targeted metabolomic approach revealed significant differences in metabolite concentrations of transgenic mice. Brain glutamine, serotonin and sphingomyelin C18:0 were found to be predictors of memory impairment. These findings provide informative data for future research on AD, since some of them agree with pathological alterations observed in diseased humans.
Collapse
Affiliation(s)
- Mireia Tondo
- Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75226, USA; (M.T.); (B.W.); (C.H.); (E.A.)
- Servei de Bioquímica, Laboratori Sant Pau, Hospital de la Santa Creu i Sant Pau, 08041 Barcelona, Spain
| | - Brandi Wasek
- Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75226, USA; (M.T.); (B.W.); (C.H.); (E.A.)
| | - Joan Carles Escola-Gil
- Research Institute, Hospital de la Santa Creu i Sant Pau and CIBERDEM, Institute of Health Carlos III, 08041 Barcelona, Spain;
| | - David de Gonzalo-Calvo
- Institute of Biomedical Research of Barcelona (IIBB)—Spanish National Research Council (CSIC), Biomedical Research Institute Sant Pau (IIB Sant Pau) and CIBERCV, Institute of Health Carlos III, 08036 Barcelona, Spain;
| | - Clinton Harmon
- Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75226, USA; (M.T.); (B.W.); (C.H.); (E.A.)
| | - Erland Arning
- Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75226, USA; (M.T.); (B.W.); (C.H.); (E.A.)
| | - Teodoro Bottiglieri
- Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75226, USA; (M.T.); (B.W.); (C.H.); (E.A.)
- Correspondence:
| |
Collapse
|
17
|
Choroid plexus LAT2 and SNAT3 as partners in CSF amino acid homeostasis maintenance. Fluids Barriers CNS 2020; 17:17. [PMID: 32046769 PMCID: PMC7014681 DOI: 10.1186/s12987-020-0178-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 02/01/2020] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Cerebrospinal fluid (CSF) is mainly produced by the choroid plexus (CP) located in brain ventricles. Although derived from blood plasma, it is nearly protein-free (~ 250-fold less) and contains about 2-20-fold less free amino acids, with the exception of glutamine (Gln) which is nearly equal. The aim of this study was to determine which amino acid transporters are expressed in mouse CP epithelium in order to gain understanding about how this barrier maintains the observed amino acid concentration gradient. METHODS Expression of amino acid transporters was assessed in isolated choroid plexuses (CPs) by qRT-PCR followed by localization studies using immunofluorescence with specific antibodies. The impact of LAT2 (Slc7a8) antiporter deletion on CSF amino acids was determined. RESULTS The purity of isolated choroid plexuses was tested on the mRNA level using specific markers, in particular transthyretin (Ttr) that was enriched 330-fold in CP compared to cerebral tissue. In a first experimental round, 14 out of 32 Slc amino acid transporters tested on the mRNA level by qPCR were selected for further investigation. Out of these, five were considered highly expressed, SNAT1 (Slc38a1), SNAT3 (Slc38a3), LAT2 (Slc7a8), ASC1 (Slc7a10) and SIT1 (Slc6a20b). Three of them were visualized by immunofluorescence: SNAT1 (Slc38a1), a neutral amino acid-Na+ symporter, found at the blood side basolateral membrane of CP epithelium, while SNAT3 (Slc38a3), an amino acid-Na+ symporter and H+ antiporter, as well as LAT2 (Slc7a8), a neutral amino acid antiporter, were localized at the CSF-facing luminal membrane. In a LAT2 knock-out mouse model, CSF Gln was unchanged, whereas other amino acids normally 2-20-fold lower than in plasma, were increased, in particular the LAT2 uptake substrates leucine (Leu), valine (Val) and tryptophan (Trp) and some other amino acids such as glutamate (Glu), glycine (Gly) and proline (Pro). CONCLUSION These results suggest that Gln is actively transported by SNAT1 from the blood into CP epithelial cells and then released luminally into CSF via SNAT3 and LAT2. Its efflux via LAT2 may drive the reuptake from the CSF of essential amino acid substrates of this antiporter and thereby participates to maintaining the amino acid gradient between plasma and CSF.
Collapse
|
18
|
Lloret A, Monllor P, Esteve D, Cervera-Ferri A, Lloret MA. Obesity as a Risk Factor for Alzheimer's Disease: Implication of Leptin and Glutamate. Front Neurosci 2019; 13:508. [PMID: 31191220 PMCID: PMC6540965 DOI: 10.3389/fnins.2019.00508] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/02/2019] [Indexed: 12/22/2022] Open
Abstract
Obesity is known to induce leptin and insulin resistance. Leptin is a peptide hormone synthesized in adipose tissue that mainly regulates food intake. It has been shown that insulin stimulates the production of leptin when adipocytes are exposed to glucose to encourage satiety; while leptin, via a negative feedback, decreases the insulin release and enhances tissue sensitivity to it, leading to glucose uptake for energy utilization or storage. Therefore, resistance to insulin is closely related to leptin resistance. Obesity in middle age has also been related to Alzheimer's disease (AD). In recent years, the relation between impaired leptin signaling pathway and the onset of AD has been studied. In all this context the role of the blood brain barrier (BBB) is crucial. Slow excitotoxicity happens in AD due to an excess of the neurotransmitter glutamate. Since leptin has been shown to regulate N-methyl-D-aspartate (NMDA) receptors, we want to review the link between these pathological pathways, and how they are affected by other AD triggering factors and its role in the onset of AD.
Collapse
Affiliation(s)
- Ana Lloret
- Department of Physiology, Faculty of Medicine, University of Valencia, Health Research Institute INCLIVA, Valencia, Spain
| | - Paloma Monllor
- Department of Physiology, Faculty of Medicine, University of Valencia, Health Research Institute INCLIVA, Valencia, Spain
| | - Daniel Esteve
- Department of Physiology, Faculty of Medicine, University of Valencia, Health Research Institute INCLIVA, Valencia, Spain
| | - Ana Cervera-Ferri
- Department of Human Anatomy and Embryology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Maria-Angeles Lloret
- Department of Clinic Neurophysiology, University Clinic Hospital of Valencia, Valencia, Spain
| |
Collapse
|
19
|
Calabrese EJ, Rubio-Casillas A. Biphasic effects of THC in memory and cognition. Eur J Clin Invest 2018; 48:e12920. [PMID: 29574698 DOI: 10.1111/eci.12920] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/11/2018] [Indexed: 12/20/2022]
Abstract
A generally undesired effect of cannabis smoking is a reversible disruption of short-term memory induced by delta-9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis. However, this paradigm has been recently challenged by a group of scientists who have shown that THC is also able to improve neurological function in old animals when chronically administered at low concentrations. Moreover, recent studies demonstrated that THC paradoxically promotes hippocampal neurogenesis, prevents neurodegenerative processes occurring in animal models of Alzheimer's disease, protects from inflammation-induced cognitive damage and restores memory and cognitive function in old mice. With the aim to reconcile these seemingly contradictory facts, this work will show that such paradox can be explained within the framework of hormesis, defined as a biphasic dose-response.
Collapse
Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, University of Massachusetts, Amherst, MA, USA
| | - Alberto Rubio-Casillas
- Laboratorio de Biologia, Escuela Preparatoria Regional de Autlán, Universidad de Guadalajara, Jalisco, México
| |
Collapse
|
20
|
Madeira C, Vargas-Lopes C, Brandão CO, Reis T, Laks J, Panizzutti R, Ferreira ST. Elevated Glutamate and Glutamine Levels in the Cerebrospinal Fluid of Patients With Probable Alzheimer's Disease and Depression. Front Psychiatry 2018; 9:561. [PMID: 30459657 PMCID: PMC6232456 DOI: 10.3389/fpsyt.2018.00561] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/17/2018] [Indexed: 12/05/2022] Open
Abstract
Recent evidence suggests that Alzheimer's disease (AD) and depression share common mechanisms of pathogenesis. In particular, deregulation of glutamate-mediated excitatory signaling may play a role in brain dysfunction in both AD and depression. We have investigated levels of glutamate and its precursor glutamine in the cerebrospinal fluid (CSF) of patients with a diagnosis of probable AD or major depression compared to healthy controls and patients with hydrocephalus. Patients with probable AD or major depression showed significantly increased CSF levels of glutamate and glutamine compared to healthy controls or hydrocephalus patients. Furthermore, CSF glutamate and glutamine levels were inversely correlated to the amyloid tau index, a biomarker for AD. Results suggest that glutamate and glutamine should be further explored as potential CSF biomarkers for AD and depression.
Collapse
Affiliation(s)
- Caroline Madeira
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Charles Vargas-Lopes
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carlos Otávio Brandão
- Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Taylor Reis
- Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jerson Laks
- Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rogerio Panizzutti
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Sergio T Ferreira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
21
|
Bai W, Zhou YG. Homeostasis of the Intraparenchymal-Blood Glutamate Concentration Gradient: Maintenance, Imbalance, and Regulation. Front Mol Neurosci 2017; 10:400. [PMID: 29259540 PMCID: PMC5723322 DOI: 10.3389/fnmol.2017.00400] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/20/2017] [Indexed: 12/25/2022] Open
Abstract
It is widely accepted that glutamate is the most important excitatory neurotransmitter in the central nervous system (CNS). However, there is also a large amount of glutamate in the blood. Generally, the concentration gradient of glutamate between intraparenchymal and blood environments is stable. However, this gradient is dramatically disrupted under a variety of pathological conditions, resulting in an amplifying cascade that causes a series of pathological reactions in the CNS and peripheral organs. This eventually seriously worsens a patient’s prognosis. These two “isolated” systems are rarely considered as a whole even though they mutually influence each other. In this review, we summarize what is currently known regarding the maintenance, imbalance and regulatory mechanisms that control the intraparenchymal-blood glutamate concentration gradient, discuss the interrelationships between these systems and further explore their significance in clinical practice.
Collapse
Affiliation(s)
- Wei Bai
- Molecular Biology Center, State Key Laboratory of Trauma, Burn, and Combined Injury, Research Institute of Surgery and Daping Hospital, Third Military Medical University, Chongqing, China
| | - Yuan-Guo Zhou
- Molecular Biology Center, State Key Laboratory of Trauma, Burn, and Combined Injury, Research Institute of Surgery and Daping Hospital, Third Military Medical University, Chongqing, China
| |
Collapse
|
22
|
Miyamoto T, Stein L, Thomas R, Djukic B, Taneja P, Knox J, Vossel K, Mucke L. Phosphorylation of tau at Y18, but not tau-fyn binding, is required for tau to modulate NMDA receptor-dependent excitotoxicity in primary neuronal culture. Mol Neurodegener 2017; 12:41. [PMID: 28526038 PMCID: PMC5438564 DOI: 10.1186/s13024-017-0176-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 04/26/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Hyperexcitability of neuronal networks can lead to excessive release of the excitatory neurotransmitter glutamate, which in turn can cause neuronal damage by overactivating NMDA-type glutamate receptors and related signaling pathways. This process (excitotoxicity) has been implicated in the pathogenesis of many neurological conditions, ranging from childhood epilepsies to stroke and neurodegenerative disorders such as Alzheimer's disease (AD). Reducing neuronal levels of the microtubule-associated protein tau counteracts network hyperexcitability of diverse causes, but whether this strategy can also diminish downstream excitotoxicity is less clear. METHODS We established a cell-based assay to quantify excitotoxicity in primary cultures of mouse hippocampal neurons and investigated the role of tau in exicitotoxicity by modulating neuronal tau expression through genetic ablation or transduction with lentiviral vectors expressing anti-tau shRNA or constructs encoding wildtype versus mutant mouse tau. RESULTS We demonstrate that shRNA-mediated knockdown of tau reduces glutamate-induced, NMDA receptor-dependent Ca2+ influx and neurotoxicity in neurons from wildtype mice. Conversely, expression of wildtype mouse tau enhances Ca2+ influx and excitotoxicity in tau-deficient (Mapt -/-) neurons. Reconstituting tau expression in Mapt -/- neurons with mutant forms of tau reveals that the tau-related enhancement of Ca2+ influx and excitotoxicity depend on the phosphorylation of tau at tyrosine 18 (pY18), which is mediated by the tyrosine kinase Fyn. These effects are most evident at pathologically elevated concentrations of glutamate, do not involve GluN2B-containing NMDA receptors, and do not require binding of Fyn to tau's major interacting PxxP motif or of tau to microtubules. CONCLUSIONS Although tau has been implicated in diverse neurological diseases, its most pathogenic forms remain to be defined. Our study suggests that reducing the formation or level of pY18-tau can counteract excitotoxicity by diminishing NMDA receptor-dependent Ca2+ influx.
Collapse
Affiliation(s)
- Takashi Miyamoto
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA.,Department of Neurology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Liana Stein
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA.,Department of Neurology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Reuben Thomas
- Gladstone Institutes, Convergence Zone, 1650 Owens Street, San Francisco, CA, 94158, USA
| | - Biljana Djukic
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA
| | - Praveen Taneja
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA
| | - Joseph Knox
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA
| | - Keith Vossel
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA.,Department of Neurology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Lennart Mucke
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA. .,Department of Neurology, University of California, San Francisco, San Francisco, CA, 94158, USA.
| |
Collapse
|
23
|
New Functions of APC/C Ubiquitin Ligase in the Nervous System and Its Role in Alzheimer's Disease. Int J Mol Sci 2017; 18:ijms18051057. [PMID: 28505105 PMCID: PMC5454969 DOI: 10.3390/ijms18051057] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/05/2017] [Accepted: 05/09/2017] [Indexed: 12/16/2022] Open
Abstract
The E3 ubiquitin ligase Anaphase Promoting Complex/Cyclosome (APC/C) regulates important processes in cells, such as the cell cycle, by targeting a set of substrates for degradation. In the last decade, APC/C has been related to several major functions in the nervous system, including axon guidance, synaptic plasticity, neurogenesis, and neuronal survival. Interestingly, some of the identified APC/C substrates have been related to neurodegenerative diseases. There is an accumulation of some degradation targets of APC/C in Alzheimer’s disease (AD) brains, which suggests a dysregulation of the protein complex in the disorder. Moreover, recently evidence has been provided for an inactivation of APC/C in AD. It has been shown that oligomers of the AD-related peptide, Aβ, induce degradation of the APC/C activator subunit cdh1, in vitro in neurons in culture and in vivo in the mouse hippocampus. Furthermore, in the AD mouse model APP/PS1, lower cdh1 levels were observed in pyramidal neurons in CA1 when compared to age-matched wildtype mice. In this review, we provide a complete list of APC/C substrates that are involved in the nervous system and we discuss their functions. We also summarize recent studies that show neurobiological effects in cdh1 knockout mouse models. Finally, we discuss the role of APC/C in the pathophysiology of AD.
Collapse
|
24
|
Corso G, Cristofano A, Sapere N, la Marca G, Angiolillo A, Vitale M, Fratangelo R, Lombardi T, Porcile C, Intrieri M, Di Costanzo A. Serum Amino Acid Profiles in Normal Subjects and in Patients with or at Risk of Alzheimer Dementia. Dement Geriatr Cogn Dis Extra 2017. [PMID: 28626469 PMCID: PMC5471778 DOI: 10.1159/000466688] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Background/Aims Abnormalities in the plasma amino acid profile have been reported in Alzheimer disease (AD), but no data exist for the prodromal phase characterized by subjective memory complaint (SMC). It was our aim to understand if serum amino acid levels change along the continuum from normal to AD, and to identify possible diagnostic biomarkers. Methods Serum levels of 15 amino acids and 2 organic acids were determined in 4 groups of participants – 29 with probable AD, 18 with mild cognitive impairment (MCI), 24 with SMC, and 46 cognitively healthy subjects (HS) – by electrospray tandem mass spectrometry. Results Glutamate, aspartate, and phenylalanine progressively decreased, while citrulline, argininosuccinate, and homocitrulline progressively increased, from HS over SMC and MCI to AD. The panel including these 6 amino acids and 4 ratios (glutamate/citrulline, citrulline/phenylalanine, leucine plus isoleucine/phenylalanine, and arginine/phenylalanine) discriminated AD from HS with about 96% accuracy. Other panels including 20 biomarkers discriminated SMC or MCI from AD or HS with an accuracy ranging from 88 to 75%. Conclusion Amino acids contribute to a characteristic metabotype during the progression of AD along the continuum from health to frank dementia, and their monitoring in elderly individuals might help to detect at-risk subjects.
Collapse
Affiliation(s)
- Gaetano Corso
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Adriana Cristofano
- Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio," University of Molise, Campobasso, Italy
| | - Nadia Sapere
- Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio," University of Molise, Campobasso, Italy
| | - Giancarlo la Marca
- Newborn Screening, Biochemistry and Pharmacology Laboratories, Clinic of Pediatric Neurology, Meyer Children's Hospital, Florence, Italy.,Department of Neurosciences, Psychology, Pharmacology, and Child Health, University of Florence, Florence, Italy
| | - Antonella Angiolillo
- Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio," University of Molise, Campobasso, Italy
| | - Michela Vitale
- Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio," University of Molise, Campobasso, Italy
| | - Roberto Fratangelo
- Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio," University of Molise, Campobasso, Italy
| | - Teresa Lombardi
- Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio," University of Molise, Campobasso, Italy
| | - Carola Porcile
- Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio," University of Molise, Campobasso, Italy
| | - Mariano Intrieri
- Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio," University of Molise, Campobasso, Italy
| | - Alfonso Di Costanzo
- Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio," University of Molise, Campobasso, Italy
| |
Collapse
|
25
|
Bruno D, Nierenberg J, Cooper TB, Marmar CR, Zetterberg H, Blennow K, Hashimoto K, Pomara N. The recency ratio is associated with reduced CSF glutamate in late-life depression. Neurobiol Learn Mem 2017; 141:14-18. [PMID: 28323201 DOI: 10.1016/j.nlm.2017.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 02/27/2017] [Accepted: 03/15/2017] [Indexed: 11/30/2022]
Abstract
Glutamate is the principal excitatory neurotransmitter in the central nervous system, and is thought to be involved in the process of memory encoding and storage. Glutamate disturbances have also been reported in psychiatric disorders, such as schizophrenia and major depressive disorder (MDD), and in Alzheimer's disease. In this paper, we set out to study the relationship between cerebrospinal fluid (CSF) glutamate levels and memory performance, which we believe has not been reported previously. In particular, we focused on recall performance broken down by serial position. Our prediction was that the recency ratio (Rr), a novel cognitive marker of intellectual impairment, would be linked with CSF glutamate levels. We studied data from a group of cognitively intact elderly individuals, 28 of whom had MDD, while 19 were controls. Study results indicated that Rr levels, but no other memory score, were inversely correlated with CSF glutamate levels, although this was found only in individuals with late-life MDD. For comparison, glutamine or GABA were not correlated with any memory performance measure.
Collapse
Affiliation(s)
- Davide Bruno
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK.
| | - Jay Nierenberg
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA; Department of Psychiatry, School of Medicine, New York University, New York City, NY, USA
| | - Thomas B Cooper
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA; Department of Psychiatry, Medical Center, Columbia University, New York City, NY, USA
| | - Charles R Marmar
- Department of Psychiatry, School of Medicine, New York University, New York City, NY, USA
| | - Henrik Zetterberg
- Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden; UCL Institute of Neurology, London, UK
| | - Kaj Blennow
- Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden
| | - Kenji Hashimoto
- Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan
| | - Nunzio Pomara
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA; Department of Psychiatry, School of Medicine, New York University, New York City, NY, USA
| |
Collapse
|
26
|
Watt G, Karl T. In vivo Evidence for Therapeutic Properties of Cannabidiol (CBD) for Alzheimer's Disease. Front Pharmacol 2017; 8:20. [PMID: 28217094 PMCID: PMC5289988 DOI: 10.3389/fphar.2017.00020] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/10/2017] [Indexed: 12/19/2022] Open
Abstract
Alzheimer's disease (AD) is a debilitating neurodegenerative disease that is affecting an increasing number of people. It is characterized by the accumulation of amyloid-β and tau hyperphosphorylation as well as neuroinflammation and oxidative stress. Current AD treatments do not stop or reverse the disease progression, highlighting the need for new, more effective therapeutics. Cannabidiol (CBD) is a non-psychoactive phytocannabinoid that has demonstrated neuroprotective, anti-inflammatory and antioxidant properties in vitro. Thus, it is investigated as a potential multifunctional treatment option for AD. Here, we summarize the current status quo of in vivo effects of CBD in established pharmacological and transgenic animal models for AD. The studies demonstrate the ability of CBD to reduce reactive gliosis and the neuroinflammatory response as well as to promote neurogenesis. Importantly, CBD also reverses and prevents the development of cognitive deficits in AD rodent models. Interestingly, combination therapies of CBD and Δ9-tetrahydrocannabinol (THC), the main active ingredient of cannabis sativa, show that CBD can antagonize the psychoactive effects associated with THC and possibly mediate greater therapeutic benefits than either phytocannabinoid alone. The studies provide “proof of principle” that CBD and possibly CBD-THC combinations are valid candidates for novel AD therapies. Further investigations should address the long-term potential of CBD and evaluate mechanisms involved in the therapeutic effects described.
Collapse
Affiliation(s)
- Georgia Watt
- Karl Group, Behavioural Neuroscience, Western Sydney University Campbelltown, NSW, Australia
| | - Tim Karl
- Karl Group, Behavioural Neuroscience, Western Sydney UniversityCampbelltown, NSW, Australia; Neuroscience Research AustraliaRandwick, NSW, Australia
| |
Collapse
|
27
|
Phelan MM, Caamaño-Gutiérrez E, Gant MS, Grosman RX, Madine J. Using an NMR metabolomics approach to investigate the pathogenicity of amyloid-beta and alpha-synuclein. Metabolomics 2017; 13:151. [PMID: 29142509 PMCID: PMC5661010 DOI: 10.1007/s11306-017-1289-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/23/2017] [Indexed: 01/04/2023]
Abstract
INTRODUCTION The pathogenicity at differing points along the aggregation pathway of many fibril-forming proteins associated with neurodegenerative diseases is unclear. Understanding the effect of different aggregation states of these proteins on cellular processes is essential to enhance understanding of diseases and provide future options for diagnosis and therapeutic intervention. OBJECTIVES To establish a robust method to probe the metabolic changes of neuronal cells and use it to monitor cellular response to challenge with three amyloidogenic proteins associated with neurodegenerative diseases in different aggregation states. METHOD Neuroblastoma SH-SY5Y cells were employed to design a robust routine system to perform a statistically rigorous NMR metabolomics study into cellular effects of sub-toxic levels of alpha-synuclein, amyloid-beta 40 and amyloid-beta 42 in monomeric, oligomeric and fibrillar conformations. RESULTS This investigation developed a rigorous model to monitor intracellular metabolic profiles of neuronal cells through combination of existing methods. This model revealed eight key metabolites that are altered when neuroblastoma cells are challenged with proteins in different aggregation states. Metabolic pathways associated with lipid metabolism, neurotransmission and adaptation to oxidative stress and inflammation are the predominant contributors to the cellular variance and intracellular metabolite levels. The observed metabolite changes for monomer and oligomer challenge may represent cellular effort to counteract the pathogenicity of the challenge, whereas fibrillar challenge is indicative of system shutdown. This implies that although markers of stress are more prevalent under oligomeric challenge the fibrillar response suggests a more toxic environment. CONCLUSION This approach is applicable to any cell type that can be cultured in a laboratory (primary or cell line) as a method of investigating how protein challenge affects signalling pathways, providing additional understanding as to the role of protein aggregation in neurodegenerative disease initiation and progression.
Collapse
Affiliation(s)
- M. M. Phelan
- 0000 0004 1936 8470grid.10025.36Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - E. Caamaño-Gutiérrez
- 0000 0004 1936 8470grid.10025.36Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - M. S. Gant
- 0000 0004 1936 8470grid.10025.36Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - R. X. Grosman
- 0000 0004 1936 8470grid.10025.36Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - J. Madine
- 0000 0004 1936 8470grid.10025.36Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| |
Collapse
|
28
|
Fuchsberger T, Martínez-Bellver S, Giraldo E, Teruel-Martí V, Lloret A, Viña J. Aβ Induces Excitotoxicity Mediated by APC/C-Cdh1 Depletion That Can Be Prevented by Glutaminase Inhibition Promoting Neuronal Survival. Sci Rep 2016; 6:31158. [PMID: 27514492 PMCID: PMC4981891 DOI: 10.1038/srep31158] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 07/15/2016] [Indexed: 02/08/2023] Open
Abstract
The E3 ubiquitin ligase anaphase-promoting complex/cyclosome (APC/C) is activated by the fizzy-related protein homolog/CDC20-like protein 1 (cdh1) in post-mitotic neurons. Growing evidence suggests that dysregulation of APC/C-Cdh1 is involved in neurodegenerative diseases. Here we show in neurons that oligomers of amyloid beta (Aβ), a peptide related to Alzheimer’s disease, cause proteasome-dependent degradation of cdh1. This leads to a subsequent increase in glutaminase (a degradation target of APC/C-Cdh1), which causes an elevation of glutamate levels and further intraneuronal Ca2+ dysregulation, resulting in neuronal apoptosis. Glutaminase inhibition prevents glutamate excitotoxicity and apoptosis in Aβ treated neurons. Furthermore, glutamate also decreases cdh1 and leads to accumulation of glutaminase, suggesting that there may be a positive feedback loop of cdh1 inactivation. We confirmed the main findings in vivo using microinjection of either Aβ or glutamate in the CA1 region of the rat hippocampus. We show here for the first time in vivo that both Aβ and glutamate cause nuclear exclusion of cdh1 and an increase in glutaminase. These results show that maintaining normal APC/C-Cdh1 activity may be a useful target in Alzheimer’s disease treatment.
Collapse
Affiliation(s)
- T Fuchsberger
- Department of Physiology, Faculty of Medicine, University of Valencia, INCLIVA Avda. Blasco Ibañez 15, 46010 Valencia, Spain
| | - S Martínez-Bellver
- Department of Anatomy and Human Embriology, Faculty of Medicine, University of Valencia, Avda. Blasco Ibañez 15, 46010 Valencia, Spain.,Department of Cellular Biology and Parasitology, Faculty of Biology, University of Valencia, Avda. Doctor Moliner 50, 46100 Valencia, Spain
| | - E Giraldo
- Department of Physiology, Faculty of Medicine, University of Valencia, INCLIVA Avda. Blasco Ibañez 15, 46010 Valencia, Spain
| | - V Teruel-Martí
- Department of Anatomy and Human Embriology, Faculty of Medicine, University of Valencia, Avda. Blasco Ibañez 15, 46010 Valencia, Spain
| | - A Lloret
- Department of Physiology, Faculty of Medicine, University of Valencia, INCLIVA Avda. Blasco Ibañez 15, 46010 Valencia, Spain
| | - J Viña
- Department of Physiology, Faculty of Medicine, University of Valencia, INCLIVA Avda. Blasco Ibañez 15, 46010 Valencia, Spain
| |
Collapse
|
29
|
Ellis B, Hye A, Snowden SG. Metabolic Modifications in Human Biofluids Suggest the Involvement of Sphingolipid, Antioxidant, and Glutamate Metabolism in Alzheimer's Disease Pathogenesis. J Alzheimers Dis 2016; 46:313-27. [PMID: 25835424 DOI: 10.3233/jad-141899] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative dementia, with the accumulation of extracellular amyloid-β and formation of neurofibrillary tau tangles as leading explanations of pathology. With the difficulties of studying the brain directly, it is hoped that identifying the effect of AD on the metabolite composition of biofluids will provide insights into underlying mechanisms of pathology. The present review identified 705 distinct metabolite reports representing 448 structurally distinct metabolites in six human biofluids, with 147 metabolites increased and 214 metabolites decreased with AD, while 80 metabolites showed inconsistent shifts. Sphingolipid, antioxidant, and glutamate metabolism were found to be strongly associated with AD and were selected for detailed investigation of their role in pathogenesis. In plasma, two ceramides increased and eight sphingomyelins decreased with AD, with total ceramides shown to increase in both serum and cerebrospinal fluid. In general antioxidants were shown to be depleted, with oxidative stress markers elevated in a range of biofluids in patients suggesting AD produces a pro-oxidative environment. Shifts in glutamate and glutamine and elevation of 4-hydroxy-2-nonenal suggests peroxidation of the astrocyte lipid bilayer resulting in reduced glutamate clearance from the synaptic cleft, suggesting a excitotoxicity component to AD pathology; however, due to inconsistencies in literature reports, reliable interpretation is difficult. The present review has shown that metabolite shifts in biofluids can provide valuable insights into potential pathological mechanisms in the brain, with sphingolipid, antioxidant, and glutamate metabolism being implicated in AD pathology.
Collapse
Affiliation(s)
- Ben Ellis
- Kings College London, School of Medicine, London, UK
| | - Abdul Hye
- Institute of Psychiatry, Department of Old Age Psychiatry, Kings College London, London, UK
| | - Stuart G Snowden
- Institute of Psychiatry, Department of Old Age Psychiatry, Kings College London, London, UK
| |
Collapse
|
30
|
Hashimoto K, Bruno D, Nierenberg J, Marmar CR, Zetterberg H, Blennow K, Pomara N. Abnormality in glutamine-glutamate cycle in the cerebrospinal fluid of cognitively intact elderly individuals with major depressive disorder: a 3-year follow-up study. Transl Psychiatry 2016; 6:e744. [PMID: 26926880 PMCID: PMC4872461 DOI: 10.1038/tp.2016.8] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/07/2016] [Accepted: 01/14/2016] [Indexed: 12/17/2022] Open
Abstract
Major depressive disorder (MDD), common in the elderly, is a risk factor for dementia. Abnormalities in glutamatergic neurotransmission via the N-methyl-D-aspartate receptor (NMDA-R) have a key role in the pathophysiology of depression. This study examined whether depression was associated with cerebrospinal fluid (CSF) levels of NMDA-R neurotransmission-associated amino acids in cognitively intact elderly individuals with MDD and age- and gender-matched healthy controls. CSF was obtained from 47 volunteers (MDD group, N=28; age- and gender-matched comparison group, N=19) at baseline and 3-year follow-up (MDD group, N=19; comparison group, N=17). CSF levels of glutamine, glutamate, glycine, L-serine and D-serine were measured by high-performance liquid chromatography. CSF levels of amino acids did not differ across MDD and comparison groups. However, the ratio of glutamine to glutamate was significantly higher at baseline in subjects with MDD than in controls. The ratio decreased in individuals with MDD over the 3-year follow-up, and this decrease correlated with a decrease in the severity of depression. No correlations between absolute amino-acid levels and clinical variables were observed, nor were correlations between amino acids and other biomarkers (for example, amyloid-β42, amyloid-β40, and total and phosphorylated tau protein) detected. These results suggest that abnormalities in the glutamine-glutamate cycle in the communication between glia and neurons may have a role in the pathophysiology of depression in the elderly. Furthermore, the glutamine/glutamate ratio in CSF may be a state biomarker for depression.
Collapse
Affiliation(s)
- K Hashimoto
- Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan
| | - D Bruno
- Department of Psychology, Liverpool Hope University, Liverpool, UK
| | - J Nierenberg
- Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY, USA
| | - C R Marmar
- Department of Psychiatry, New York University Langone Medical Center, New York, NY, USA
| | - H Zetterberg
- Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - K Blennow
- Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | - N Pomara
- Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY, USA
| |
Collapse
|
31
|
Lewerenz J, Maher P. Chronic Glutamate Toxicity in Neurodegenerative Diseases-What is the Evidence? Front Neurosci 2015; 9:469. [PMID: 26733784 PMCID: PMC4679930 DOI: 10.3389/fnins.2015.00469] [Citation(s) in RCA: 468] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/24/2015] [Indexed: 12/13/2022] Open
Abstract
Together with aspartate, glutamate is the major excitatory neurotransmitter in the brain. Glutamate binds and activates both ligand-gated ion channels (ionotropic glutamate receptors) and a class of G-protein coupled receptors (metabotropic glutamate receptors). Although the intracellular glutamate concentration in the brain is in the millimolar range, the extracellular glutamate concentration is kept in the low micromolar range by the action of excitatory amino acid transporters that import glutamate and aspartate into astrocytes and neurons. Excess extracellular glutamate may lead to excitotoxicity in vitro and in vivo in acute insults like ischemic stroke via the overactivation of ionotropic glutamate receptors. In addition, chronic excitotoxicity has been hypothesized to play a role in numerous neurodegenerative diseases including amyotrophic lateral sclerosis, Alzheimer's disease and Huntington's disease. Based on this hypothesis, a good deal of effort has been devoted to develop and test drugs that either inhibit glutamate receptors or decrease extracellular glutamate. In this review, we provide an overview of the different pathways that are thought to lead to an over-activation of the glutamatergic system and glutamate toxicity in neurodegeneration. In addition, we summarize the available experimental evidence for glutamate toxicity in animal models of neurodegenerative diseases.
Collapse
Affiliation(s)
- Jan Lewerenz
- Department of Neurology, Ulm UniversityUlm, Germany
| | - Pamela Maher
- Cellular Neurobiology Laboratory, Salk Institute for Biological StudiesLa Jolla, CA, USA
| |
Collapse
|
32
|
Getting to NO Alzheimer's Disease: Neuroprotection versus Neurotoxicity Mediated by Nitric Oxide. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2016:3806157. [PMID: 26697132 PMCID: PMC4677236 DOI: 10.1155/2016/3806157] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/16/2015] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder involving the loss of neurons in the brain which leads to progressive memory loss and behavioral changes. To date, there are only limited medications for AD and no known cure. Nitric oxide (NO) has long been considered part of the neurotoxic insult caused by neuroinflammation in the Alzheimer's brain. However, focusing on early developments, prior to the appearance of cognitive symptoms, is changing that perception. This has highlighted a compensatory, neuroprotective role for NO that protects synapses by increasing neuronal excitability. A potential mechanism for augmentation of excitability by NO is via modulation of voltage-gated potassium channel activity (Kv7 and Kv2). Identification of the ionic mechanisms and signaling pathways that mediate this protection is an important next step for the field. Harnessing the protective role of NO and related signaling pathways could provide a therapeutic avenue that prevents synapse loss early in disease.
Collapse
|
33
|
Akanuma SI, Sakurai T, Tachikawa M, Kubo Y, Hosoya KI. Transporter-mediated L-glutamate elimination from cerebrospinal fluid: possible involvement of excitatory amino acid transporters expressed in ependymal cells and choroid plexus epithelial cells. Fluids Barriers CNS 2015; 12:11. [PMID: 25925580 PMCID: PMC4425921 DOI: 10.1186/s12987-015-0006-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 04/11/2015] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND L-Glutamate (L-Glu) is the major excitatory neurotransmitter in the CNS, and its level in cerebrospinal fluid (CSF) is reported to be increased in neuroexcitatory diseases such as epilepsy. Since L-Glu concentration in the CSF is reported to be lower than that in plasma, it has been proposed that some mechanisms of L-Glu clearance from the CSF operate in the brain. The purpose of this study was to elucidate the major pathway of L-Glu elimination from rat CSF and the transporters responsible. METHODS Protein expression and localization of excitatory amino acid transporters were examined by immunohistochemical analysis using specific antibodies. In vivo elimination of L-Glu from rat CSF was evaluated by intracerebroventricular administration. An L-Glu uptake study by using primary-cultured rat ependymal cells and isolated rat choroid plexus was performed to characterize L-Glu transport mechanisms. RESULTS An immunohistochemical analysis has shown that excitatory amino acid transporter (EAAT) 1 and EAAT3, which are D-aspartate-sensitive and kainate-insensitive L-Glu transporters, are localized on the CSF-side of rat ependymal cells and choroid plexus epithelial cells, respectively. In contrast, the kainate-sensitive L-Glu transporter, EAAT2, is not expressed in these cells. In vivo L-Glu elimination clearance from the rat CSF (189 μL/(min · rat)) was 23-fold higher than the CSF bulk flow rate, indicating that facilitative process(es) are involved in L-Glu elimination from the CSF. The in vivo [(3)H]L-Glu elimination from the CSF was significantly inhibited by unlabeled L-Glu and D-aspartate, but not kainate. Moreover, unlabeled L-Glu and D-aspartate inhibited [(3)H]L-Glu uptake by rat ependymal cells and choroid plexus epithelial cells, whereas kainate had little effect. CONCLUSION It is suggested that EAAT1 in ependymal cells and EAAT3 in choroid plexus epithelial cells participate in L-Glu elimination from the CSF.
Collapse
Affiliation(s)
- Shin-ichi Akanuma
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
| | - Tatsuhiko Sakurai
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
| | - Masanori Tachikawa
- Division of Membrane Transport and Drug Targeting, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan.
| | - Yoshiyuki Kubo
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
| | - Ken-ichi Hosoya
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
| |
Collapse
|
34
|
SUN11602 has basic fibroblast growth factor-like activity and attenuates neuronal damage and cognitive deficits in a rat model of Alzheimer׳s disease induced by amyloid β and excitatory amino acids. Brain Res 2014; 1585:159-66. [DOI: 10.1016/j.brainres.2014.08.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 05/22/2014] [Accepted: 08/10/2014] [Indexed: 11/23/2022]
|
35
|
Cheng D, Low JK, Logge W, Garner B, Karl T. Chronic cannabidiol treatment improves social and object recognition in double transgenic APPswe/PS1∆E9 mice. Psychopharmacology (Berl) 2014; 231:3009-17. [PMID: 24577515 DOI: 10.1007/s00213-014-3478-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 01/27/2014] [Indexed: 10/25/2022]
Abstract
RATIONALE Patients suffering from Alzheimer's disease (AD) exhibit a decline in cognitive abilities including an inability to recognise familiar faces. Hallmark pathological changes in AD include the aggregation of amyloid-β (Aβ), tau protein hyperphosphorylation as well as pronounced neurodegeneration, neuroinflammation, neurotoxicity and oxidative damage. OBJECTIVES The non-psychoactive phytocannabinoid cannabidiol (CBD) exerts neuroprotective, anti-oxidant and anti-inflammatory effects and promotes neurogenesis. CBD also reverses Aβ-induced spatial memory deficits in rodents. MATERIALS AND METHODS Thus we determined the therapeutic-like effects of chronic CBD treatment (20 mg/kg, daily intraperitoneal injections for 3 weeks) on the APPswe/PS1∆E9 (APPxPS1) transgenic mouse model for AD in a number of cognitive tests, including the social preference test, the novel object recognition task and the fear conditioning paradigm. We also analysed the impact of CBD on anxiety behaviours in the elevated plus maze. RESULTS Vehicle-treated APPxPS1 mice demonstrated impairments in social recognition and novel object recognition compared to wild type-like mice. Chronic CBD treatment reversed these cognitive deficits in APPxPS1 mice without affecting anxiety-related behaviours. CONCLUSIONS This is the first study to investigate the effect of chronic CBD treatment on cognition in an AD transgenic mouse model. Our findings suggest that CBD may have therapeutic potential for specific cognitive impairments associated with AD.
Collapse
Affiliation(s)
- David Cheng
- Neuroscience Research Australia, Barker St, Randwick, NSW, 2031, Australia
| | | | | | | | | |
Collapse
|
36
|
Neuroprotective properties of the excitatory amino acid carrier 1 (EAAC1). Amino Acids 2013; 45:133-42. [PMID: 23462929 DOI: 10.1007/s00726-013-1481-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 02/23/2013] [Indexed: 01/09/2023]
Abstract
Extracellular glutamate should be maintained at low levels to conserve optimal neurotransmission and prevent glutamate neurotoxicity in the brain. Excitatory amino acid transporters (EAATs) play a pivotal role in removing extracellular glutamate in the central nervous system (CNS). Excitatory amino acid carrier 1 (EAAC1) is a high-affinity Na⁺-dependent neuronal EAAT that is ubiquitously expressed in the brain. However, most glutamate released in the synapses is cleared by glial EAATs, but not by EAAC1 in vivo. In the CNS, EAAC1 is widely distributed in somata and dendrites but not in synaptic terminals. The contribution of EAAC1 to the control of extracellular glutamate levels seems to be negligible in the brain. However, EAAC1 can transport not only extracellular glutamate but also cysteine into the neurons. Cysteine is an important substrate for glutathione (GSH) synthesis in the brain. GSH has a variety of neuroprotective functions, while its depletion induces neurodegeneration. Therefore, EAAC1 might exert a critical role for neuroprotection in neuronal GSH metabolism rather than glutamatergic neurotransmission, while EAAC1 dysfunction would cause neurodegeneration. Despite the potential importance of EAAC1 in the brain, previous studies have mainly focused on the glutamate neurotoxicity induced by glial EAAT dysfunction. In recent years, however, several studies have revealed regulatory mechanisms of EAAC1 functions in the brain. This review will summarize the latest information on the EAAC1-regulated neuroprotective functions in the CNS.
Collapse
|
37
|
Effect of bFGF on neuronal damage induced by sequential treatment of amyloid β and excitatory amino acid in vitro and in vivo. Eur J Pharmacol 2012; 695:76-82. [DOI: 10.1016/j.ejphar.2012.09.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 09/04/2012] [Accepted: 09/17/2012] [Indexed: 11/18/2022]
|
38
|
Advances in drug design based on the amino Acid approach: taurine analogues for the treatment of CNS diseases. Pharmaceuticals (Basel) 2012; 5:1128-46. [PMID: 24281261 PMCID: PMC3816653 DOI: 10.3390/ph5101128] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/24/2012] [Accepted: 10/15/2012] [Indexed: 11/17/2022] Open
Abstract
Amino acids are well known to be an important class of compounds for the maintenance of body homeostasis and their deficit, even for the polar neuroactive aminoacids, can be controlled by supplementation. However, for the amino acid taurine (2-aminoethanesulfonic acid) this is not true. Due its special physicochemical properties, taurine is unable to cross the blood-brain barrier. In addition of injured taurine transport systems under pathological conditions, CNS supplementation of taurine is almost null. Taurine is a potent antioxidant and anti-inflammatory semi-essential amino acid extensively involved in neurological activities, acting as neurotrophic factor, binding to GABA A/glycine receptors and blocking the excitotoxicity glutamate-induced pathway leading to be a neuroprotective effect and neuromodulation. Taurine deficits have been implicated in several CNS diseases, such as Alzheimer’s, Parkinson’s, epilepsy and in the damage of retinal neurons. This review describes the CNS physiological functions of taurine and the development of new derivatives based on its structure useful in CNS disease treatment.
Collapse
|
39
|
Karl T, Cheng D, Garner B, Arnold JC. The therapeutic potential of the endocannabinoid system for Alzheimer's disease. Expert Opin Ther Targets 2012; 16:407-20. [PMID: 22448595 DOI: 10.1517/14728222.2012.671812] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Dementia currently affects over 35 million people worldwide. The most common form of dementia is Alzheimer's disease (AD). Currently, treatments for AD do not stop or reverse the progression of the disease and they are accompanied by side effects. AREAS COVERED The main features of AD pathology, treatment options currently available, the endocannabinoid system and its functionality in general and its role in AD pathology in detail will be outlined. A particular focus will be on the therapeutic potential of the phytocannabinoid cannabidiol. EXPERT OPINION Based on the complex pathology of AD, a preventative, multimodal drug approach targeting a combination of pathological AD symptoms appears ideal. Importantly, cannabinoids show anti-inflammatory, neuroprotective and antioxidant properties and have immunosuppressive effects. Thus, the cannabinoid system should be a prime target for AD therapy. The cannabinoid receptor 2 appears to be a promising candidate but its role in AD has to be investigated cautiously. Furthermore, the phytocannabinoid cannabidiol is of particular interest as it lacks the psychoactive and cognition-impairing properties of other cannabinoids. In conclusion, future research should focus on the evaluation of the effects of manipulations to the endocannabinoid system in established animal models for AD, combined with early-phase studies in humans.
Collapse
Affiliation(s)
- Tim Karl
- Neuroscience Research Australia, Randwick, NSW, Australia.
| | | | | | | |
Collapse
|
40
|
Soluble Aβ oligomers inhibit long-term potentiation through a mechanism involving excessive activation of extrasynaptic NR2B-containing NMDA receptors. J Neurosci 2011; 31:6627-38. [PMID: 21543591 DOI: 10.1523/jneurosci.0203-11.2011] [Citation(s) in RCA: 474] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In Alzheimer's disease (AD), dementia severity correlates strongly with decreased synapse density in hippocampus and cortex. Numerous studies report that hippocampal long-term potentiation (LTP) can be inhibited by soluble oligomers of amyloid β-protein (Aβ), but the synaptic elements that mediate this effect remain unclear. We examined field EPSPs and whole-cell recordings in wild-type mouse hippocampal slices. Soluble Aβ oligomers from three distinct sources (cultured cells, AD cortex, or synthetic peptide) inhibited LTP, and this was prevented by the selective NR2B inhibitors ifenprodil and Ro 25-6981. Soluble Aβ enhanced NR2B-mediated NMDA currents and extrasynaptic responses; these effects were mimicked by the glutamate reuptake inhibitor dl-threo-β-benzyloxyaspartic acid. Downstream, an Aβ-mediated rise in p38 mitogen-activated protein kinase (MAPK) activation was followed by downregulation of cAMP response element-binding protein, and LTP impairment was prevented by inhibitors of p38 MAPK or calpain. Thus, soluble Aβ oligomers at low nanomolar levels present in AD brain increase activation of extrasynaptic NR2B-containing receptors, thereby impairing synaptic plasticity.
Collapse
|
41
|
Nilsen LH, Shi Q, Gibson GE, Sonnewald U. Brain [U-13 C]glucose metabolism in mice with decreased α-ketoglutarate dehydrogenase complex activity. J Neurosci Res 2011; 89:1997-2007. [PMID: 21374701 DOI: 10.1002/jnr.22606] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 12/16/2010] [Accepted: 01/09/2011] [Indexed: 01/24/2023]
Abstract
The activity of the α-ketoglutarate dehydrogenase complex (KGDHC), a mitochondrial enzyme complex that mediates the oxidative decarboxylation of α-ketoglutarate in the TCA cycle, is reduced in Alzheimer's disease. We investigated the metabolic effects of a partial KGDHC activity reduction on brain glucose metabolism using mice with disrupted expression of dihydrolipoyl succinyltransferase (DLST; gene encoding the E2k subunit of KGDHC). Brain tissue extracts from cortex and cerebellum of 6-week-old heterozygote DLST knockout mice (DLST+/-) and corresponding wild-type mice injected with [U-(13) C]glucose and decapitated 15 min later were analyzed. An increase in the concentration of glucose in cortex suggested a decrease in the cortical utilization of glucose in DLST+/- mice. Furthermore, the concentration and (13) C labelling of aspartate in cortex were reduced in DLST+/- mice. This decline was likely caused by a decrease in the pool of oxaloacetate. In contrast to results from cell culture studies, no indications of altered glycolysis or GABA shunt activity were found. Glucose metabolism in the cerebellum was unaffected by the decrease in KGDHC activity. Among metabolites not related to glucose metabolism, the concentration of taurine was decreased in the cortex, and that of tyrosine was increased in the cerebellum. These results imply that diminished KGDHC activity has the potential to induce the reduction in glucose utilization that is seen in several neurodegenerative diseases.
Collapse
Affiliation(s)
- Linn Hege Nilsen
- Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | | | | | | |
Collapse
|
42
|
Lockrow J, Boger H, Bimonte-Nelson H, Granholm AC. Effects of long-term memantine on memory and neuropathology in Ts65Dn mice, a model for Down syndrome. Behav Brain Res 2010; 221:610-22. [PMID: 20363261 DOI: 10.1016/j.bbr.2010.03.036] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 12/09/2009] [Accepted: 03/22/2010] [Indexed: 01/22/2023]
Abstract
Memantine is a partial NMDA receptor antagonist that has been shown to improve learning and memory in several animal models, and is approved for the treatment of Alzheimer's disease (AD). Chronic treatments using memantine in animal models of Alzheimer's disease show disease-modifying effects and suggest a potential neuroprotective function. The present study assessed the effects of both short- and long-term memantine treatment in a mouse model of Down syndrome (DS), the Ts65Dn mouse. The Ts65Dn mouse contains a partial trisomy of murine chromosome 16, and exhibits hippocampal-dependent memory deficits, as well as progressive degeneration of basal forebrain cholinergic neurons (BCFNs). Ts65Dn mice were treated with memantine for a period of 6 months, beginning at 4 months of age. At the end of treatment the mice underwent memory testing using novel object recognition and water radial arm maze tasks, and then histologically analyzed for markers of neurodegeneration. Memantine treatment improved spatial and recognition memory performance in the Ts65Dn mice, though not to the level of normosomic littermate controls. Despite these memory improvements, histological analysis found no morphological signs of neuroprotection of basal forebrain cholinergic or locus coeruleus neurons in memantine-treated Ts65Dn mice. However, memantine treatment of Ts65Dn mice gave rise to elevated brain-derived neurotrophic factor expression in the hippocampus and frontal cortex, suggesting a mechanism of behavioral modification. Thus, our findings provide further evidence for memory facilitation of memantine, but suggest pharmacological rather than neuroprotective effects of memantine both after acute and chronic treatment in this mouse model.
Collapse
Affiliation(s)
- Jason Lockrow
- Department of Neuroscience, Center on Aging, Medical University of South Carolina, 173 Ashley Avenue, Ste 410D, Charleston, SC 29425, USA
| | | | | | | |
Collapse
|
43
|
Li S, Shankar GM, Selkoe DJ. How do Soluble Oligomers of Amyloid beta-protein Impair Hippocampal Synaptic Plasticity? Front Cell Neurosci 2010; 4:5. [PMID: 20428510 PMCID: PMC2859875 DOI: 10.3389/fncel.2010.00005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 02/26/2010] [Indexed: 11/13/2022] Open
Affiliation(s)
- Shaomin Li
- Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School Boston, MA, USA
| | | | | |
Collapse
|
44
|
Son MY, Chung SH. Expression of p25, an aberrant cyclin-dependent kinase 5 activator, stimulates basal secretion in PC12 cells. Mol Cells 2010; 29:51-6. [PMID: 20033852 DOI: 10.1007/s10059-010-0016-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 10/13/2009] [Accepted: 11/02/2009] [Indexed: 10/20/2022] Open
Abstract
Although alterations in the functions of neurotransmitter systems have been implicated in the pathology of Alzheimer's disease (AD), the mechanisms that give rise to these alterations are not well understood. The amount of p25, an aberrant cleavage product of p35 that activates cyclin-dependent kinase 5 (Cdk5), is elevated in AD brains. The role of Cdk5 in neurotransmitter release has been well established. In this study, we examined whether p25 was linked to altered neurotransmitter release in AD. Transient or stable expression of p25 significantly increased basal secretion of human growth hormone (hGH) or neurotransmitter in PC12 cells. Expression of a p25 phosphorylation-deficient mutant, T138A, inhibited basal hGH secretion relative to the p25 wild type, suggesting the involvement of Thr138 phosphorylation in secretion. The expression and activity of beta-site amyloid precursor protein cleaving enzyme 1 (BACE1), a key protease in the generation of beta-amyloid, are increased in AD brains. Our previous studies indicated that overexpression of BACE1 enhanced basal secretion of hGH in PC12 cells. Transient coexpression of p25 and BACE1 further stimulated spontaneous basal secretion. These results indicate a novel role for p25 in the secretory pathway and suggest that elevated levels of p25 and BACE1 in AD brains may contribute to altered neurotransmitter pathology of AD through enhancing spontaneous basal secretion.
Collapse
Affiliation(s)
- Mi-Young Son
- Graduate Program in Neuroscience, Institute for Brain Science and Technology, Inje University, Busan, 614-735, Korea
| | | |
Collapse
|
45
|
Li S, Hong S, Shepardson NE, Walsh DM, Shankar GM, Selkoe D. Soluble oligomers of amyloid Beta protein facilitate hippocampal long-term depression by disrupting neuronal glutamate uptake. Neuron 2009; 62:788-801. [PMID: 19555648 DOI: 10.1016/j.neuron.2009.05.012] [Citation(s) in RCA: 728] [Impact Index Per Article: 48.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Revised: 03/06/2009] [Accepted: 05/06/2009] [Indexed: 12/22/2022]
Abstract
In Alzheimer's disease (AD), the impairment of declarative memory coincides with the accumulation of extracellular amyloid-beta protein (Abeta) and intraneuronal tau aggregates. Dementia severity correlates with decreased synapse density in hippocampus and cortex. Although numerous studies show that soluble Abeta oligomers inhibit hippocampal long-term potentiation, their role in long-term synaptic depression (LTD) remains unclear. Here, we report that soluble Abeta oligomers from several sources (synthetic, cell culture, human brain extracts) facilitated electrically evoked LTD in the CA1 region. Abeta-enhanced LTD was mediated by mGluR or NMDAR activity. Both forms of LTD were prevented by an extracellular glutamate scavenger system. Abeta-facilitated LTD was mimicked by the glutamate reuptake inhibitor TBOA, including a shared dependence on extracellular calcium levels and activation of PP2B and GSK-3 signaling. In accord, synaptic glutamate uptake was significantly decreased by soluble Abeta. We conclude that soluble Abeta oligomers perturb synaptic plasticity by altering glutamate recycling at the synapse and promoting synapse depression.
Collapse
Affiliation(s)
- Shaomin Li
- Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | | | | |
Collapse
|
46
|
Neuronal expression of splice variants of "glial" glutamate transporters in brains afflicted by Alzheimer's disease: unmasking an intrinsic neuronal property. Neurochem Res 2009; 34:1748-57. [PMID: 19319679 DOI: 10.1007/s11064-009-9957-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Accepted: 03/11/2009] [Indexed: 01/24/2023]
Abstract
Anomalies in glutamate homeostasis may contribute to the pathological processes involved in Alzheimer's disease (AD). Glutamate released from neurons or glial cells is normally rapidly cleared by glutamate transporters, most of which are expressed at the protein level by glial cells. However, in some patho-physiological situations, expression of glutamate transporters that are normally considered to be glial types, appears to be evoked in populations of distressed neurons. This study analysed the expression of exon-skipping forms of the three predominant excitatory amino acid (glutamate) transporters (EAATs1-3) in brains afflicted with AD. We demonstrate by immunocytochemistry in temporal cortex, the expression of these proteins particularly in limited subsets of neurons, some of which appeared to be dys-morphic. Whilst the neuronal expression of the "glial" glutamate transporters EAAT1 and EAAT2 is frequently considered to represent the abnormal and ectopic expression of such transporters, we suggest this may be a misinterpretation, since neurons such as cortical pyramidal cells normally express abundant mRNA for these EAATs (but little if any EAAT protein expression). We hypothesize instead that distressed neurons in the AD brain can turn on the translation of pre-existent mRNA pools, or suppress the degradation of alternately spliced glutamate transporter protein, leading to the "unmasking" of, rather than evoked expression of "glial" glutamate transporters in stressed neurons.
Collapse
|
47
|
Survey of ALS-associated factors potentially promoting Ca2+ overload of motor neurons. ACTA ACUST UNITED AC 2008; 8:260-5. [PMID: 17917848 DOI: 10.1080/17482960701523124] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The deleterious consequences of Ca(2+) overload are thought to be a probable cause of motoneuronal death in ALS, although the overloading mechanism is currently unclear. In this paper some ALS-linked factors are analysed with regard to their influence on Ca(2+ )influx into neurons. Intensive cortex activity can render motor neurons susceptible to stimulation of calcium-permeable glutamate NMDA-receptors; increase in CSF concentrations of glutamate, glycine, and norepinephrine supposedly can intensify these receptors' activity. Elevated CSF levels of GABA and reduced levels of serotonin can promote Ca(2+ )influx through glutamate AMPA-receptors and voltage-gated channels of L-, N-, and P-type. Additionally, brain ischaemia can contribute to Ca(2+ )overload of motor neurons. Thus, ALS is characterized by the unique combination of factors potentially able to promote the overload of motor neurons with calcium.
Collapse
|
48
|
Waugh WH. Inhibition of Iron-Catalyzed Oxidations by Attainable Uric Acid and Ascorbic Acid Levels: Therapeutic Implications for Alzheimer’s Disease and Late Cognitive Impairment. Gerontology 2008; 54:238-43. [DOI: 10.1159/000122618] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2007] [Accepted: 02/13/2008] [Indexed: 02/04/2023] Open
|
49
|
Joseph A, Robinson R, Paulose CS. Enhanced [3H] Glutamate Binding in the Cerebellum of Insulin-Induced Hypoglycaemic and Streptozotocin-Induced Diabetic Rats. Cell Mol Neurobiol 2007; 27:1085-95. [PMID: 17805958 DOI: 10.1007/s10571-007-9198-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Accepted: 08/07/2007] [Indexed: 10/22/2022]
Abstract
AIM Energy deprivation causes neuronal death affecting the cognitive and memory ability of an individual. The kinetic parameters of glutamate dehydrogenase (GDH), the enzyme involved in the production of glutamate, was studied in the cerebellum and liver and the binding parameters of glutamate receptors in the cerebellum of insulin-induced hypoglycaemic and streptozotocin-induced diabetic rats were studied to reveal the role of glutamate excitotoxicity. METHODS A single intrafemoral dose of streptozotocin was administered to induce diabetes. Hypoglycaemia was induced by appropriate doses of insulin subcutaneously in control and diabetic rats. The kinetic parameters V (max) and K (m) of GDH were studied spectrophotometrically at different substrate concentrations of alpha-ketoglutarate. Glutamate receptor binding assay was done with different concentrations of [3H] Glutamate. RESULTS The GDH enzyme assay showed a significant increase (P < 0.001) in the V (max) of the enzyme in the cerebellum of hypoglycaemic and diabetic rat groups when compared to control. The V (max) of hypoglycaemic groups was significantly increased (P < 0.001) when compared to diabetic group. In the liver, the V (max) of GDH was significantly increased (P < 0.001) in the diabetic and diabetic hypoglycaemia group when compared to control. The V (max) of GDH increased significantly (P < 0.001) in the diabetic hypoglycaemic rats compared to diabetic group, whereas the control hypoglycaemic rats showed a significant decrease in V (max) (P < 0.001) when compared to diabetic and diabetic hypoglycaemic rats. The K (m) showed no significant change amongst the groups in cerebellum and liver. Scatchard analysis showed a significant increase (P < 0.001) in B (max) in the cerebellum of hypoglycaemic and diabetic rats when compared to control. The B (max) of hypoglycaemic rats significantly increased (P < 0.001) when compared to diabetic group. In hypoglycaemic groups, B (max) of the control hypoglycaemic rats showed a significant increase (P < 0.001) compared to diabetic hypoglycaemic rats. The K (d) of the diabetic group decreased significantly (P < 0.01) when compared to control and control hypoglycaemic rats. There was a significant decrease (P < 0.05) in the K (d) of diabetic hypoglycaemic group when compared to the control hypoglycaemic rats. CONCLUSION Our studies demonstrated the increased enzyme activity in the hypoglycaemic rats with increased production of extracellular glutamate. The present study also revealed increased binding parameters of glutamate receptors reflecting an increased receptor number with increase in the affinity. This increased number of receptors and the increased glutamate production will lead to glutamate excitotoxicity and neuronal degeneration which has an impact on the cognitive and memory ability. This has immense clinical significance in the management of diabetes and insulin therapy.
Collapse
Affiliation(s)
- Anu Joseph
- Department of Biotechnology, Cochin University of Science and Technology, Cochin, Kerala, 682 022, India
| | | | | |
Collapse
|
50
|
Fonteh AN, Harrington RJ, Tsai A, Liao P, Harrington MG. Free amino acid and dipeptide changes in the body fluids from Alzheimer's disease subjects. Amino Acids 2006; 32:213-24. [PMID: 17031479 DOI: 10.1007/s00726-006-0409-8] [Citation(s) in RCA: 182] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Accepted: 05/03/2006] [Indexed: 10/24/2022]
Abstract
Our aim was to determine changes in free amino acid (FAA) and dipeptide (DP) concentrations in probable Alzheimer's disease (pAD) subjects compared with control (CT) subjects using liquid chromatography and electrospray ionization tandem mass spectrometry (LCMS2). We recruited gender- and age-matched study participants based on neurological and neuropsychological assessments. We measured FAAs and DPs in cerebrospinal fluid (CSF), plasma and urine using LCMS2 with selected reaction monitoring (SRM). Imidazole-containing FAAs (histidine, methyl-histidine), catecholamines (L-DOPA and dopamine), citrulline, ornithine, glycine and antioxidant DPs (carnosine and anserine) accounted for the major changes between CT and pAD. Carnosine levels were significantly lower in pAD (328.4 +/- 91.31 nmol/dl) than in CT plasma (654.23 +/- 100.61 nmol/dl). In contrast, L-DOPA levels were higher in pAD (1400.84 +/- 253.68) than CT (513.10 +/- 121.61 nmol/dl) plasma. These data underscore the importance of FAA and DP metabolism in the pathogenesis of AD. Since our data show changes in antioxidants, neurotransmitters and their precursors, or FAA associated with urea metabolism in pAD compared with CT, we propose that manipulation of these metabolic pathways may be important in preventing AD progression.
Collapse
Affiliation(s)
- A N Fonteh
- Molecular Neurology Program, Huntington Medical Research Institutes, Pasadena, CA 91101-1830, USA.
| | | | | | | | | |
Collapse
|