1
|
Singh NAK, Prasad S. Ellagic Acid Reverses Alterations in the Expression of AMPA Receptor and Its Scaffolding Proteins in the Cerebral Cortex and Memory Decline in STZ-sporadic Alzheimer' s Disease Mouse Model. Psychopharmacology (Berl) 2024:10.1007/s00213-024-06622-9. [PMID: 38842699 DOI: 10.1007/s00213-024-06622-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 05/18/2024] [Indexed: 06/07/2024]
Abstract
RATIONALE Alzheimer's disease (AD), an age-dependent devastating neuropsychiatric disorder, is a leading cause of learning, memory and intellectual disabilities. Current therapeutic approaches for the amelioration of the anomalies of AD are not effective. OBJECTIVE In the present study, the molecular mechanisms underlying sporadic AD (sAD), the memory related behavioral analysis and neuroprotective effects of Ellagic acid (EA) were investigated. METHOD sAD mouse model was developed by intracerebroventricular (ICV) injection of Streptozotocin (STZ). The efficacy of EA, a naturally occurring polyphenol, in amelioration of anomalies associated with sAD was assessed. EA was administered once daily for 28 days at a dose of 75 mg/kg body weight followed by neurobehavioral, biochemical, molecular and neuronal count analysis to delineate the mode of action of EA. RESULT The ICV injection of STZ in mice significantly increased the expression of AD biomarkers in addition to enhanced oxidative stress. A decline in the discrimination index in Novel Object Recognition Test was observed indicating the compromise of recognition memory in AD. Studies on the expression of genes involved in synaptic plasticity reveal the dysregulation of the α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) of the glutamate and its scaffolding proteins in the postsynaptic density and thereby synaptic plasticity in AD. ICV-STZ led to significant upregulation of apoptotic markers which led to decrease in neuronal density of the cerebral cortex. EA significantly reversed the above and improved anomalies of sAD. CONCLUSION EA was observed to profoundly modulate the genes involved in AD pathophysiology, restored antioxidant enzymes activity, reduced lipid peroxidation and neuronal loss in the sAD brain. Further, EA was observed to effectively modulate the genes involved in apoptosis and synaptic plasticity. Therefore, EA possesses promising anti-AD properties, which may improve AD-associated anomalies by modulating synaptic plasticity via AMPAR signaling.
Collapse
Affiliation(s)
- Nidhi Anand K Singh
- Biochemistry and Molecular Biology Laboratory, Centre of Advanced Study in Zoology, Institute of Science, Banaras Hindu University, Varanasi, 211005, Uttar Pradesh, India
| | - S Prasad
- Biochemistry and Molecular Biology Laboratory, Centre of Advanced Study in Zoology, Institute of Science, Banaras Hindu University, Varanasi, 211005, Uttar Pradesh, India.
| |
Collapse
|
2
|
Barbour AJ, Gourmaud S, Lancaster E, Li X, Stewart DA, Hoag KF, Irwin DJ, Talos DM, Jensen FE. Seizures exacerbate excitatory: inhibitory imbalance in Alzheimer's disease and 5XFAD mice. Brain 2024; 147:2169-2184. [PMID: 38662500 PMCID: PMC11146435 DOI: 10.1093/brain/awae126] [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: 09/05/2023] [Revised: 03/02/2024] [Accepted: 03/24/2024] [Indexed: 05/14/2024] Open
Abstract
Approximately 22% of Alzheimer's disease (AD) patients suffer from seizures, and the co-occurrence of seizures and epileptiform activity exacerbates AD pathology and related cognitive deficits, suggesting that seizures may be a targetable component of AD progression. Given that alterations in neuronal excitatory:inhibitory (E:I) balance occur in epilepsy, we hypothesized that decreased markers of inhibition relative to those of excitation would be present in AD patients. We similarly hypothesized that in 5XFAD mice, the E:I imbalance would progress from an early stage (prodromal) to later symptomatic stages and be further exacerbated by pentylenetetrazol (PTZ) kindling. Post-mortem AD temporal cortical tissues from patients with or without seizure history were examined for changes in several markers of E:I balance, including levels of the inhibitory GABAA receptor, the sodium potassium chloride cotransporter 1 (NKCC1) and potassium chloride cotransporter 2 (KCC2) and the excitatory NMDA and AMPA type glutamate receptors. We performed patch-clamp electrophysiological recordings from CA1 neurons in hippocampal slices and examined the same markers of E:I balance in prodromal 5XFAD mice. We next examined 5XFAD mice at chronic stages, after PTZ or control protocols, and in response to chronic mTORC1 inhibitor rapamycin, administered following kindled seizures, for markers of E:I balance. We found that AD patients with comorbid seizures had worsened cognitive and functional scores and decreased GABAA receptor subunit expression, as well as increased NKCC1/KCC2 ratios, indicative of depolarizing GABA responses. Patch clamp recordings of prodromal 5XFAD CA1 neurons showed increased intrinsic excitability, along with decreased GABAergic inhibitory transmission and altered glutamatergic neurotransmission, indicating that E:I imbalance may occur in early disease stages. Furthermore, seizure induction in prodromal 5XFAD mice led to later dysregulation of NKCC1/KCC2 and a reduction in GluA2 AMPA glutamate receptor subunit expression, indicative of depolarizing GABA receptors and calcium permeable AMPA receptors. Finally, we found that chronic treatment with the mTORC1 inhibitor, rapamycin, at doses we have previously shown to attenuate seizure-induced amyloid-β pathology and cognitive deficits, could also reverse elevations of the NKCC1/KCC2 ratio in these mice. Our data demonstrate novel mechanisms of interaction between AD and epilepsy and indicate that targeting E:I balance, potentially with US Food and Drug Administration-approved mTOR inhibitors, hold therapeutic promise for AD patients with a seizure history.
Collapse
Affiliation(s)
- Aaron J Barbour
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sarah Gourmaud
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eunjoo Lancaster
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Xiaofan Li
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David A Stewart
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Duke University School of Medicine, Durham, NC 27708, USA
| | - Keegan F Hoag
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David J Irwin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Penn Frontotemporal Degeneration Center, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Delia M Talos
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Frances E Jensen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
3
|
Martin SP, Leeman-Markowski BA. Proposed mechanisms of tau: relationships to traumatic brain injury, Alzheimer's disease, and epilepsy. Front Neurol 2024; 14:1287545. [PMID: 38249745 PMCID: PMC10797726 DOI: 10.3389/fneur.2023.1287545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/30/2023] [Indexed: 01/23/2024] Open
Abstract
Traumatic brain injury (TBI), Alzheimer's disease (AD), and epilepsy share proposed mechanisms of injury, including neuronal excitotoxicity, cascade signaling, and activation of protein biomarkers such as tau. Although tau is typically present intracellularly, in tauopathies, phosphorylated (p-) and hyper-phosphorylated (hp-) tau are released extracellularly, the latter leading to decreased neuronal stability and neurofibrillary tangles (NFTs). Tau cleavage at particular sites increases susceptibility to hyper-phosphorylation, NFT formation, and eventual cell death. The relationship between tau and inflammation, however, is unknown. In this review, we present evidence for an imbalanced endoplasmic reticulum (ER) stress response and inflammatory signaling pathways resulting in atypical p-tau, hp-tau and NFT formation. Further, we propose tau as a biomarker for neuronal injury severity in TBI, AD, and epilepsy. We present a hypothesis of tau phosphorylation as an initial acute neuroprotective response to seizures/TBI. However, if the underlying seizure pathology or TBI recurrence is not effectively treated, and the pathway becomes chronically activated, we propose a "tipping point" hypothesis that identifies a transition of tau phosphorylation from neuroprotective to injurious. We outline the role of amyloid beta (Aβ) as a "last ditch effort" to revert the cell to programmed death signaling, that, when fails, transitions the mechanism from injurious to neurodegenerative. Lastly, we discuss targets along these pathways for therapeutic intervention in AD, TBI, and epilepsy.
Collapse
Affiliation(s)
- Samantha P. Martin
- Comprehensive Epilepsy Center, New York University Langone Health, New York, NY, United States
- Department of Neurology, New York University Langone Health, New York, NY, United States
- New York University Grossman School of Medicine, New York, NY, United States
- VA New York Harbor Healthcare System, New York, NY, United States
| | - Beth A. Leeman-Markowski
- Comprehensive Epilepsy Center, New York University Langone Health, New York, NY, United States
- Department of Neurology, New York University Langone Health, New York, NY, United States
- VA New York Harbor Healthcare System, New York, NY, United States
| |
Collapse
|
4
|
Xing A, Li X, Jiang C, Chen Y, Wu S, Zhang J, An L. As a Histone Deacetylase Inhibitor, γ-Aminobutyric Acid Upregulates GluR2 Expression: An In Vitro and In Vivo Study. Mol Nutr Food Res 2019; 63:e1900001. [PMID: 31090246 DOI: 10.1002/mnfr.201900001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 04/20/2019] [Indexed: 12/13/2022]
Abstract
SCOPE γ-Aminobutyric acid (GABA) possesses extensive physiological functions and can be directly obtained from foods. GABA-enriched functional foods have been developed and the commercial demands for GABA are increasing. GABA is widely recognized as a central nervous system inhibitory neurotransmitter and plays an important role in some diseases by binding to its receptors. However, some of the functions of GABA are not explained by neurotransmission or GABA receptor pathways. Therefore, this study investigates whether GABA has the potential to inhibit histone deacetylase (HDAC). METHODS AND RESULTS It is found that GABA inhibits HDAC1/2/3 expression and upregulates histone acetylation levels (Ace-H3K9/Ace-H4K12) in SH-SY5Y cells (which express GABA receptors), 3T3-L1 cells (which do not express GABA receptors), and the cerebral cortex in mice. Glutamate receptor 2 (GluR2) is a subunit of the α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor and is implicated in the pathogenesis of some neurological diseases. It is also found that GABA increases GluR2 expression by inhibiting HDAC1/2 but not HDAC3. CONCLUSION A novel role for GABA is demonstrated in which it acts as an HDAC inhibitor. The present study expands the horizons for exploring the non-neurotransmitter functions of GABA.
Collapse
Affiliation(s)
- Aiping Xing
- The School of Public Health, China Medical University, Shenyang, China
| | - Xinhui Li
- The School of Public Health, China Medical University, Shenyang, China
| | - Congmin Jiang
- The School of Public Health, China Medical University, Shenyang, China
| | - Yanqiu Chen
- The School of Public Health, China Medical University, Shenyang, China
| | - Sining Wu
- The School of Public Health, China Medical University, Shenyang, China
| | - Jingzhu Zhang
- The School of Public Health, China Medical University, Shenyang, China
| | - Li An
- The School of Public Health, China Medical University, Shenyang, China
| |
Collapse
|
5
|
Yin H, Wang W, Yu W, Li J, Feng N, Wang L, Wang X. Changes in Synaptic Plasticity and Glutamate Receptors in Type 2 Diabetic KK-Ay Mice. J Alzheimers Dis 2018; 57:1207-1220. [PMID: 28304288 DOI: 10.3233/jad-160858] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In the present study, the progressive alteration of cognition and the mechanisms of reduction in long-term potentiation (LTP) in spontaneous obese KK-Ay type 2 diabetic mice were investigated. In the study, 3-, 5-, and 7-month-old KK-Ay mice were used. The results indicated that KK-Ay mice showed cognitive deficits in the Morris water maze test beginning at the age of 3 months. LTP was significantly impaired in KK-Ay mice during whole study period (3 to 7 months). The above deficits were reversible at an early stage (3 to 5 months old) by diet intervention. Moreover, we found the underlying mechanisms of LTP impairment in KK-Ay mice might be attributed to abnormal phosphorylation or expression of postsynaptic glutamate receptor subunits instead of alteration of basal synaptic transmission. The expression levels of NR1, NR2A, and NR2B subunits of N-methyl-d-aspartate receptors (NMDARs) were unchanged while the Tyr-dependent phosphorylation of both NR2A and NR2B subunits were significantly reduced in KK-Ay mice. The level of p-Src expression mediating this process was decreased, and the level of αCaMKII autophosphorylation was also reduced. Meanwhile, the GluR1 of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) was decreased, and GluR2 was significantly increased. These data suggest that deficits in synaptic plasticity in KK-Ay mice may arise from the abnormal phosphorylation of the NR2 subunits and the alteration of subunit composition of AMPARs. Diet intervention at an early stage of diabetes might alleviate the cognitive deficits and LTP reduction in KK-Ay mice.
Collapse
|
6
|
Chong JR, Chai YL, Lee JH, Howlett D, Attems J, Ballard CG, Aarsland D, Francis PT, Chen CP, Lai MKP. Increased Transforming Growth Factor β2 in the Neocortex of Alzheimer's Disease and Dementia with Lewy Bodies is Correlated with Disease Severity and Soluble Aβ42 Load. J Alzheimers Dis 2018; 56:157-166. [PMID: 27911312 DOI: 10.3233/jad-160781] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Of the three transforming growth factor (TGF)-β isoforms known, TGFβ1 deficits have been widely reported in Alzheimer's disease (AD) and studied as a potential therapeutic target. In contrast, the status of TGFβ2, which has been shown to mediate amyloid-β (Aβ)-mediated neuronal death, are unclear both in AD and in Lewy body dementias (LBD) with differential neuritic plaque and neurofibrillary tangle burden. OBJECTIVE To measure neocortical TGFβ2 levels and their correlations with neuropathological and clinical markers of disease severity in a well-characterized cohort of AD as well as two clinical subtypes of LBD, dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD), known to manifest relatively high and low Aβ plaque burden, respectively. METHODS Postmortem samples from temporal cortex (BA21) were measured for TGFβ2 using a Luminex-based platform, and correlated with scores for neuritic plaques, neurofibrillary tangles, α-synuclein pathology, dementia severity (as measured by annual decline of Mini-Mental State Examination scores) as well as soluble and total fractions of brain Aβ42. RESULTS TGFβ2 was significantly increased in AD and DLB, but not in PDD. TGFβ2 also correlated with scores for neurofibrillary tangles, Lewy bodies (within the LBD group), dementia severity, and soluble Aβ42 concentration, but not with neuritic plaque scores, total Aβ42, or monomeric α-synuclein immunoreactivity. CONCLUSIONS TGFβ2 is increased in the temporal cortex of AD and DLB, and its correlations with neuropathological and clinical markers of disease severity as well as with soluble Aβ42 load suggest a potential pathogenic role in mediating the neurotoxicity of non-fibrillar Aβ. Our study also indicates the potential utility of targeting TGFβ2 in pharmacotherapeutic approaches to AD and DLB.
Collapse
Affiliation(s)
- Joyce R Chong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Yuek Ling Chai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Jasinda H Lee
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - David Howlett
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - Johannes Attems
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Clive G Ballard
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - Dag Aarsland
- Department of Neurobiology, Ward Sciences and Society, Karolinska Institute, Stockholm, Sweden.,Centre for Age-Related Medicine, Stavanger University Hospital, Stavanger, Norway
| | - Paul T Francis
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - Christopher P Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| |
Collapse
|
7
|
Datta A, Chai YL, Tan JM, Lee JH, Francis PT, Chen CP, Sze SK, Lai MKP. An iTRAQ-based proteomic analysis reveals dysregulation of neocortical synaptopodin in Lewy body dementias. Mol Brain 2017; 10:36. [PMID: 28800743 PMCID: PMC5553757 DOI: 10.1186/s13041-017-0316-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 07/21/2017] [Indexed: 02/08/2023] Open
Abstract
Lewy body dementias are the second most common cause of neurodegenerative dementia in the elderly after Alzheimer's disease (AD). The two clinical subgroups of Lewy body dementias, namely, dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD), are differentiated by the chronology of cognitive symptoms relative to parkinsonism. At present, there remains a debate on whether DLB and PDD are separate disease entities, or fall within the same spectrum of Lewy body dementias. In this study, we compared the detergent-soluble proteome via an 8-plex isobaric tag for relative and absolute quantitation (iTRAQ) analysis of pooled lysates from the prefrontal cortex (BA9) of DLB (n = 19) and PDD (n = 21) patients matched a priori for amyloid (total Aβ42) burden, semi-quantitative scores for Lewy bodies and neurofibrillary tangles together with age-matched control (n = 21) subjects. A total of 1914 proteins were confidently identified by iTRAQ (false discovery rate = 0%). None of the proteins showed a significant yet opposite regulation in between DLB and PDD when compared to aged controls in the proteomic data set as well as following immunoblot analysis of the pooled and individual lysates involving all 61 subjects. The postsynaptic protein, synaptopodin (SYNPO) was significantly down-regulated in both DLB and PDD subgroups, suggesting a defective synaptic transmission in the demented patients. In conclusion, the largely similar proteome of DLB and PDD matched for amyloid burden suggests that variations in concomitant AD-related pathology, abnormal post-translational modifications or protein-protein interactions, defective intracellular trafficking or misfolding of proteins could play a part in driving the clinically observed differences between these two subgroups of Lewy body dementias. This further indicates that amyloid-targeting therapeutic strategies may show different efficacies in DLB versus PDD.
Collapse
Affiliation(s)
- Arnab Datta
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore. .,Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, Building 10 Room 6N318, Bethesda, MD 20814, USA.
| | - Yuek Ling Chai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore
| | - Jing Min Tan
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore
| | - Jasinda H Lee
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore
| | - Paul T Francis
- Wolfson Centre for Age-related Diseases, King's College London, Guy's Campus, St Thomas Street, London SE1 1UL, UK
| | - Christopher P Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore. .,Wolfson Centre for Age-related Diseases, King's College London, Guy's Campus, St Thomas Street, London SE1 1UL, UK.
| |
Collapse
|
8
|
Xing H, Lim YA, Chong JR, Lee JH, Aarsland D, Ballard CG, Francis PT, Chen CP, Lai MKP. Increased phosphorylation of collapsin response mediator protein-2 at Thr514 correlates with β-amyloid burden and synaptic deficits in Lewy body dementias. Mol Brain 2016; 9:84. [PMID: 27609071 PMCID: PMC5016931 DOI: 10.1186/s13041-016-0264-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/05/2016] [Indexed: 11/11/2022] Open
Abstract
Collapsin response mediator protein-2 (CRMP2) regulates axonal growth cone extension, and increased CRMP2 phosphorylation may lead to axonal degeneration. Axonal and synaptic pathology is an important feature of Lewy body dementias (LBD), but the state of CRMP2 phosphorylation (pCRMP2) as well as its correlations with markers of neurodegeneration have not been studied in these dementias. Hence, we measured CRMP2 phosphorylation at Thr509, Thr514 and Ser522, as well as markers of β-amyloid (Aβ), tau-phosphorylation, α-synuclein and synaptic function in the postmortem neocortex of a longitudinally assessed cohort of LBD patients characterized by low (Parkinson’s disease dementia, PDD) and high (dementia with Lewy bodies, DLB) burden of Alzheimer type pathology. We found specific increases of pCRMP2 at Thr514 in DLB, but not PDD. The increased CRMP2 phosphorylation correlated with fibrillogenic Aβ as well as with losses of markers for axon regeneration (β-III-tubulin) and synaptic integrity (synaptophysin) in LBD. In contrast, pCRMP2 alterations did not correlate with tau-phosphorylation or α-synuclein, and also appear unrelated to immunoreactivities of putative upstream kinases glycogen synthase kinase 3β and cyclin-dependent kinase 5, as well as to protein phosphatase 2A. In conclusion, increased pCRMP2 may underlie the axonal pathology of DLB, and may be a novel therapeutic target. However, antecedent signaling events as well as the nature of pCRMP2 association with Aβ and other neuropathologic markers require further study.
Collapse
Affiliation(s)
- Huayang Xing
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, 117599, Singapore
| | - Yun-An Lim
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, 117599, Singapore.,Memory, Ageing and Cognition Centre, National University Health System, Kent Ridge, Singapore
| | - Joyce R Chong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, 117599, Singapore
| | - Jasinda H Lee
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, 117599, Singapore
| | - Dag Aarsland
- Department of Neurobiology, Care Sciences and Society, Alzheimer's Disease Research Centre, Karolinska Institutet, Novum, Stockholm, Sweden.,Center for Age-Related Diseases, Stavanger University Hospital, Stavanger, Norway
| | - Clive G Ballard
- King's College London, Wolfson Centre for Age-Related Diseases, London, UK
| | - Paul T Francis
- King's College London, Wolfson Centre for Age-Related Diseases, London, UK
| | - Christopher P Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, 117599, Singapore.,Memory, Ageing and Cognition Centre, National University Health System, Kent Ridge, Singapore
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, 117599, Singapore. .,Memory, Ageing and Cognition Centre, National University Health System, Kent Ridge, Singapore. .,King's College London, Wolfson Centre for Age-Related Diseases, London, UK.
| |
Collapse
|
9
|
Umeda K, Kotake Y, Miyara M, Ishida K, Sanoh S, Ohta S. Methoxychlor and fenvalerate induce neuronal death by reducing GluR2 expression. J Toxicol Sci 2016; 41:255-64. [DOI: 10.2131/jts.41.255] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Kanae Umeda
- Graduate School of Biomedical and Health Sciences, Hiroshima University
| | - Yaichiro Kotake
- Graduate School of Biomedical and Health Sciences, Hiroshima University
| | - Masatsugu Miyara
- Graduate School of Biomedical and Health Sciences, Hiroshima University
- Research Fellow of the Japan Society for the Promotion of Science
| | - Keishi Ishida
- Graduate School of Biomedical and Health Sciences, Hiroshima University
- Research Fellow of the Japan Society for the Promotion of Science
| | - Seigo Sanoh
- Graduate School of Biomedical and Health Sciences, Hiroshima University
| | - Shigeru Ohta
- Graduate School of Biomedical and Health Sciences, Hiroshima University
| |
Collapse
|
10
|
Sugiyama C, Kotake Y, Yamaguchi M, Umeda K, Tsuyama Y, Sanoh S, Okuda K, Ohta S. Development of a simple measurement method for GluR2 protein expression as an index of neuronal vulnerability. Toxicol Rep 2015; 2:450-460. [PMID: 28962381 PMCID: PMC5598506 DOI: 10.1016/j.toxrep.2014.12.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 12/20/2014] [Accepted: 12/20/2014] [Indexed: 11/28/2022] Open
Abstract
In vitro estimating strategies for potential neurotoxicity are required to screen multiple substances. In a previous study, we showed that exposure to low-concentrations of some chemicals, such as organotin, decreased the expression of GluR2 protein, which is a subunit of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptors, and led to neuronal vulnerability. This result suggested that GluR2 decreases as an index of neuronal cell sensitivity and vulnerability to various toxic insults. Accordingly, we developed a versatile method that is a large scale determination of GluR2 protein expression in the presence of environmental chemicals by means of AlphaLISA technology. Various analytical conditions were optimized, and then GluR2 protein amount was measured by the method using AlphaLISA. The GluR2 amounts were strongly correlated with that of measured by western blotting, which is currently used to determine GluR2 expression. An ideal standard curve could be written with the authentic GluR2 protein from 0 ng to 100 ng. Subsequently, twenty environmental chemicals were screened and nitenpyram was identified as a chemical which lead to decrease in GluR2 protein expression. This assay may provide a tool for detecting neurotoxic chemicals according to decreases in GluR2 protein expression.
Collapse
Key Words
- AMPA receptor
- AMPA receptor, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor
- AlphaLISA
- Cell-based assay
- DMEM, Dulbecco's modified Eagle's medium
- DMSO, dimethyl sulfoxide
- EDTA, ethylenediaminetetraacetic acid
- FCS, fetal calf serum
- Glu, glutamate
- GluR2
- HS, horse serum
- MAP2, microtubule-associated protein 2
- NAS, 1-naphthylacetylspermine
- Neurotoxicity
- Nitenpyram
- PBS, phosphate-buffered saline
- TBT, tributyltin
- WST-1, 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium
Collapse
Affiliation(s)
- Chihiro Sugiyama
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Yaichiro Kotake
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Masafumi Yamaguchi
- Faculty of Pharmaceutical Sciences, Hiroshima International University, 5-1-1 Hirokoshinkai, Kure, Hiroshima 737-0112, Japan
| | - Kanae Umeda
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Yumi Tsuyama
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Seigo Sanoh
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Katsuhiro Okuda
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Shigeru Ohta
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| |
Collapse
|
11
|
Datta A, Qian J, Chong R, Kalaria RN, Francis P, Lai MKP, Chen CP, Sze SK. Novel pathophysiological markers are revealed by iTRAQ-based quantitative clinical proteomics approach in vascular dementia. J Proteomics 2014; 99:54-67. [PMID: 24448401 PMCID: PMC4024194 DOI: 10.1016/j.jprot.2014.01.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 12/10/2013] [Accepted: 01/08/2014] [Indexed: 12/14/2022]
Abstract
UNLABELLED Vascular dementia (VaD) is a leading cause of dementia in the elderly together with Alzheimer's disease with limited treatment options. Poor understanding of the pathophysiology underlying VaD is hindering the development of new therapies. Hence, to unravel its underlying molecular pathology, an iTRAQ-2D-LC-MS/MS strategy was used for quantitative analysis of pooled lysates from Brodmann area 21 of pathologically confirmed cases of VaD and matched non-neurological controls. A total of 144 differentially expressed proteins out of 2281 confidently identified proteins (false discovery rate=0.3%) were shortlisted for bioinformatics analysis. Western blot analysis of selected proteins using samples from individual patients (n=10 per group) showed statistically significant increases in the abundance of SOD1 and NCAM and reduced ATP5A in VaD. This suggested a state of hypometabolism and vascular insufficiency along with an inflammatory condition during VaD. Elevation of SOD1 and increasing trend for iron-storage proteins (FTL, FTH1) may be indicative of an oxidative imbalance that is accompanied by an aberrant iron metabolism. The synaptic proteins did not exhibit a generalized decrease in abundance (e.g. syntaxin) in the VaD subjects. This reported proteome offers a reference data set for future basic or translational studies on VaD. BIOLOGICAL SIGNIFICANCE Our study is the first quantitative clinical proteomic study where iTRAQ-2D-LC-MS/MS strategy has been used to identify the differential proteome in the VaD cortex by comparing VaD and matched control subjects. We generate testable hypothesis about the involvement of various proteins in the vascular and parenchymal events during the evolution of VaD that finally leads to malfunction and demise of brain cells. This study also establishes quantitative proteomics as a complementary approach and viable alternative to existing neurochemical, electron microscopic and neuroimaging techniques that are traditionally being used to understand the molecular pathology of VaD. Our study could inspire fellow researchers to initiate similar retrospective studies targeting various ethnicities, age-groups or sub-types of VaD using brain samples available from brain banks across the world. Meta-analysis of these studies in the future may be able to shortlist candidate proteins or pathways for rationale exploration of therapeutic targets or biomarkers for VaD.
Collapse
Affiliation(s)
- Arnab Datta
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jingru Qian
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Ruifen Chong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Raj N Kalaria
- Institute for Ageing Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK
| | - Paul Francis
- Wolfson Centre for Age-related Diseases, King's College London, London, UK
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Memory, Aging and Cognition Centre, National University Health System, Singapore
| | - Christopher P Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Memory, Aging and Cognition Centre, National University Health System, Singapore.
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, Singapore.
| |
Collapse
|
12
|
Mohamed NE, Howlett DR, Ma L, Francis PT, Aarsland D, Ballard CG, McKeith IG, Chen CP, Lai MKP. Decreased immunoreactivities of neocortical AMPA receptor subunits correlate with motor disability in Lewy body dementias. J Neural Transm (Vienna) 2013; 121:71-8. [DOI: 10.1007/s00702-013-1067-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 07/02/2013] [Indexed: 10/26/2022]
|
13
|
Sheng Y, Lee JH, Medhurst AD, Wilcock GK, Esiri M, Wong PTH, Chen CP, Lai MK. Preservation of cortical histamine H3 receptors in ischemic vascular and mixed dementias. J Neurol Sci 2012; 315:110-4. [DOI: 10.1016/j.jns.2011.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 10/11/2011] [Accepted: 11/04/2011] [Indexed: 11/26/2022]
|