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Swerdlow NR, Joshi YB, Sprock J, Talledo J, Molina JL, Delano-Wood L, Iwanaga D, Kotz JE, Huege S, Léger GC, Light GA. Preliminary Evidence that Memantine Enhances Prepulse Effects on Startle Magnitude and Latency in Patients with Alzheimer's Disease. J Alzheimers Dis 2023; 91:355-362. [PMID: 36404550 DOI: 10.3233/jad-220769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The uncompetitive NMDA antagonist, memantine (MEM), enhances prepulse inhibition of startle (PPI) across species. MEM is used to treat Alzheimer's disease (AD); conceivably, its acute impact on PPI might be used to predict a patient's sensitivity to MEM's therapeutic effects. OBJECTIVE To begin to test this possibility, we studied MEM effects on PPI and related measures in AD patients. METHODS 18 carefully screened individuals with AD (mean age = 72.8 y; M:F=9 : 9) completed double-blind order-balanced testing with MEM (placebo versus 20 mg), assessing acoustic startle magnitude, habituation, PPI, and latency. RESULTS Fifteen out of 18 participants exhibited reliable startle responses. MEM did not significantly impact startle magnitude or habituation. Compared to placebo responses, PPI was significantly increased after MEM (p < 0.04; d = 0.40); this comparison reached a large effect size for the 60 ms interval (d = 0.62), where maximal MEM effects on PPI were previously detected. Prepulses reduced peak startle latency ("latency facilitation") and this effect was amplified after MEM (p = 0.03; d = 0.41; for 60 ms intervals, d = 0.69). No effects of MEM were detected on cognition, nor were MEM effects on startle associated with cognitive or clinical measures. CONCLUSION MEM enhances prepulse effects on startle magnitude and latency in AD; these changes in PPI and latency facilitation with MEM suggest that these measures can be used to detect an AD patient's neural sensitivity to acute MEM challenge. Studies in progress will determine whether such a "biomarker" measured at the outset on treatment can predict sensitivity to MEM's therapeutic effects.
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Affiliation(s)
- Neal R Swerdlow
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA.,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Yash B Joshi
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA.,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Joyce Sprock
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA.,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Jo Talledo
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Juan L Molina
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA.,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Lisa Delano-Wood
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Dylan Iwanaga
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Juliana E Kotz
- Department of Health Policy and Management, Fielding School of Public Health, University of California, Los Angeles, CA, USA
| | - Steven Huege
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Gabriel C Léger
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Gregory A Light
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA.,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
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Sun C, Cao XC, Liu ZY, Ma CL, Li BM. Polygalasaponin F protects hippocampal neurons against glutamate-induced cytotoxicity. Neural Regen Res 2022; 17:178-184. [PMID: 34100454 PMCID: PMC8451577 DOI: 10.4103/1673-5374.314321] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Excess extracellular glutamate leads to excitotoxicity, which induces neuronal death through the overactivation of N-methyl-D-aspartate receptors (NMDARs). Excitotoxicity is thought to be closely related to various acute and chronic neurological disorders, such as stroke and Alzheimer’s disease. Polygalasaponin F (PGSF) is a triterpenoid saponin monomer that can be isolated from Polygala japonica, and has been reported to protect cells against apoptosis. To investigate the mechanisms underlying the neuroprotective effects of PGSF against glutamate-induced cytotoxicity, PGSF-pretreated hippocampal neurons were exposed to glutamate for 24 hours. The results demonstrated that PGSF inhibited glutamate-induced hippocampal neuron death in a concentration-dependent manner and reduced glutamate-induced Ca2+ overload in the cultured neurons. In addition, PGSF partially blocked the excess activity of NMDARs, inhibited both the downregulation of NMDAR subunit NR2A expression and the upregulation of NMDAR subunit NR2B expression, and upregulated the expression of phosphorylated cyclic adenosine monophosphate-responsive element-binding protein and brain-derived neurotrophic factor. These findings suggest that PGSF protects cultured hippocampal neurons against glutamate-induced cytotoxicity by regulating NMDARs. The study was approved by the Institutional Animal Care Committee of Nanchang University (approval No. 2017-0006) on December 29, 2017.
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Affiliation(s)
- Chong Sun
- Laboratory of Cognitive Function and Disorder, Institute of Life Science, Nanchang University, Nanchang, Jiangxi Province, China
| | - Xin-Cheng Cao
- Laboratory of Cognitive Function and Disorder, Institute of Life Science, Nanchang University, Nanchang, Jiangxi Province, China
| | - Zhi-Yang Liu
- Laboratory of Cognitive Function and Disorder, Institute of Life Science, Nanchang University, Nanchang, Jiangxi Province, China
| | - Chao-Lin Ma
- Laboratory of Cognitive Function and Disorder, Institute of Life Science, Nanchang University, Nanchang, Jiangxi Province, China
| | - Bao-Ming Li
- Laboratory of Cognitive Function and Disorder, Institute of Life Science, Nanchang University, Nanchang, Jiangxi Province; Institute of Brain Science and Department of Psychology, School of Education, Hangzhou Normal University, Hangzhou, Zhejiang Province, China
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Swerdlow NR, Kotz JE, Joshi YB, Talledo J, Sprock J, Molina JL, Huisa B, Huege SF, Romero JA, Walsh MJ, Delano-Wood L, Light GA. Using Biomarkers to Predict Memantine Effects in Alzheimer's Disease: A Proposal and Proof-Of-Concept Demonstration. J Alzheimers Dis 2021; 84:1431-1438. [PMID: 34690144 DOI: 10.3233/jad-215029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Memantine's benefits in Alzheimer's disease (AD) are modest and heterogeneous. We tested the feasibility of using sensitivity to acute memantine challenge to predict an individual's clinical response. Eight participants completed a double-blind challenge study of memantine (placebo versus 20 mg) effects on autonomic, subjective, cognitive, and neurophysiological measures, followed by a 24-week unblinded active-dose therapeutic trial (10 mg bid). Study participation was well tolerated. Subgroups based on memantine sensitivity on specific laboratory measures differed in their clinical response to memantine, some by large effect sizes. It appears feasible to use biomarkers to predict clinical sensitivity to memantine.
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Affiliation(s)
- Neal R Swerdlow
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Juliana E Kotz
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Yash B Joshi
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA.,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Jo Talledo
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Joyce Sprock
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA.,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Juan L Molina
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA.,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Branko Huisa
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Steven F Huege
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jairo Alberto Romero
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Michael J Walsh
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Lisa Delano-Wood
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Gregory A Light
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA.,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
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Swerdlow NR, Bhakta SG, Talledo J, Kotz J, Roberts BZ, Clifford RE, Thomas ML, Joshi YB, Molina JL, Light GA. Memantine effects on auditory discrimination and training in schizophrenia patients. Neuropsychopharmacology 2020; 45:2180-2188. [PMID: 32961542 PMCID: PMC7784956 DOI: 10.1038/s41386-020-00865-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 09/08/2020] [Accepted: 09/11/2020] [Indexed: 12/16/2022]
Abstract
The uncompetitive low-affinity NMDA receptor antagonist, memantine, acutely increases electrophysiological measures of auditory information processing in both healthy subjects (HS) and patients with schizophrenia. Memantine effects on functional measures of auditory discrimination performance and learning are not known; conceivably, beneficial effects on these measures might suggest a role for memantine in augmenting the cognitive and functional impact of auditory targeted cognitive training (TCT). Here, carefully characterized HS (n = 20) and schizophrenia patients (n = 22) were tested in measures of auditory discrimination performance (words-in-noise (WIN), quick speech-in-noise (QuickSIN), gaps-in-noise) and auditory frequency modulation learning (a component of TCT) on 2 days about a week apart, after ingesting either placebo or 20 mg memantine po, in a double-blind, within-subject cross-over random order design. Memantine modestly enhanced functional measures of auditory discrimination in both schizophrenia patients (WIN) and HS (WIN and QuickSIN), as well as auditory frequency modulation learning in schizophrenia patients. These findings converge with a growing literature showing that memantine can enhance a range of metrics of auditory function. These properties could contribute to the apparent benefits of memantine as an adjunctive treatment in schizophrenia, and suggest that memantine might augment learning and potentially clinical gains from auditory-based TCT.
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Affiliation(s)
- Neal R. Swerdlow
- grid.266100.30000 0001 2107 4242Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA USA
| | - Savita G. Bhakta
- grid.266100.30000 0001 2107 4242Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA USA
| | - Jo Talledo
- grid.266100.30000 0001 2107 4242Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA USA
| | - Juliana Kotz
- grid.266100.30000 0001 2107 4242Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA USA
| | - Benjamin Z. Roberts
- grid.266100.30000 0001 2107 4242Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA USA
| | - Royce Ellen Clifford
- grid.266100.30000 0001 2107 4242Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA USA
| | - Michael L. Thomas
- grid.47894.360000 0004 1936 8083Department of Psychology, Colorado State University, Fort Collins, CO USA
| | - Yash B. Joshi
- grid.266100.30000 0001 2107 4242Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA USA ,grid.410371.00000 0004 0419 2708VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA USA
| | - Juan L. Molina
- grid.266100.30000 0001 2107 4242Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA USA
| | - Gregory A. Light
- grid.266100.30000 0001 2107 4242Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA USA ,grid.410371.00000 0004 0419 2708VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA USA
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Patnode CD, Perdue LA, Rossom RC, Rushkin MC, Redmond N, Thomas RG, Lin JS. Screening for Cognitive Impairment in Older Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA 2020; 323:764-785. [PMID: 32096857 DOI: 10.1001/jama.2019.22258] [Citation(s) in RCA: 138] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
IMPORTANCE Early identification of cognitive impairment may improve patient and caregiver health outcomes. OBJECTIVE To systematically review the test accuracy of cognitive screening instruments and benefits and harms of interventions to treat cognitive impairment in older adults (≥65 years) to inform the US Preventive Services Task Force. DATA SOURCES MEDLINE, PubMed, PsycINFO, and Cochrane Central Register of Controlled Trials through January 2019, with literature surveillance through November 22, 2019. STUDY SELECTION Fair- to good-quality English-language studies of cognitive impairment screening instruments, and pharmacologic and nonpharmacologic treatments aimed at persons with mild cognitive impairment (MCI), mild to moderate dementia, or their caregivers. DATA EXTRACTION AND SYNTHESIS Independent critical appraisal and data abstraction; random-effects meta-analyses and qualitative synthesis. MAIN OUTCOMES AND MEASURES Sensitivity, specificity; patient, caregiver, and clinician decision-making; patient function, quality of life, and neuropsychiatric symptoms; caregiver burden and well-being. RESULTS The review included 287 studies with more than 280 000 older adults. One randomized clinical trial (RCT) (n = 4005) examined the direct effect of screening for cognitive impairment on patient outcomes, including potential harms, finding no significant differences in health-related quality of life at 12 months (effect size, 0.009 [95% CI, -0.063 to 0.080]). Fifty-nine studies (n = 38 531) addressed the accuracy of 49 screening instruments to detect cognitive impairment. The Mini-Mental State Examination was the most-studied instrument, with a pooled sensitivity of 0.89 (95% CI, 0.85 to 0.92) and specificity of 0.89 (95% CI, 0.85 to 0.93) to detect dementia using a cutoff of 23 or less or 24 or less (15 studies, n = 12 796). Two hundred twenty-four RCTs and 3 observational studies including more than 240 000 patients or caregivers addressed the treatment of MCI or mild to moderate dementia. None of the treatment trials were linked with a screening program; in all cases, participants were persons with known cognitive impairment. Medications approved to treat Alzheimer disease (donepezil, galantamine, rivastigmine, and memantine) improved scores on the ADAS-Cog 11 by 1 to 2.5 points over 3 months to 3 years. Psychoeducation interventions for caregivers resulted in a small benefit for caregiver burden (standardized mean difference, -0.24 [95% CI, -0.36 to -0.13) over 3 to 12 months. Intervention benefits were small and of uncertain clinical importance. CONCLUSIONS AND RELEVANCE Screening instruments can adequately detect cognitive impairment. There is no empirical evidence, however, that screening for cognitive impairment improves patient or caregiver outcomes or causes harm. It remains unclear whether interventions for patients or caregivers provide clinically important benefits for older adults with earlier detected cognitive impairment or their caregivers.
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Affiliation(s)
- Carrie D Patnode
- Kaiser Permanente Evidence-based Practice Center, Center for Health Research, Kaiser Permanente, Portland, Oregon
| | - Leslie A Perdue
- Kaiser Permanente Evidence-based Practice Center, Center for Health Research, Kaiser Permanente, Portland, Oregon
| | | | - Megan C Rushkin
- Kaiser Permanente Evidence-based Practice Center, Center for Health Research, Kaiser Permanente, Portland, Oregon
| | - Nadia Redmond
- Kaiser Permanente Evidence-based Practice Center, Center for Health Research, Kaiser Permanente, Portland, Oregon
| | - Rachel G Thomas
- Kaiser Permanente Evidence-based Practice Center, Center for Health Research, Kaiser Permanente, Portland, Oregon
| | - Jennifer S Lin
- Kaiser Permanente Evidence-based Practice Center, Center for Health Research, Kaiser Permanente, Portland, Oregon
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Kishi T, Matsunaga S, Oya K, Nomura I, Ikuta T, Iwata N. Memantine for Alzheimer's Disease: An Updated Systematic Review and Meta-analysis. J Alzheimers Dis 2018; 60:401-425. [PMID: 28922160 DOI: 10.3233/jad-170424] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND The clinical benefit of memantine for Alzheimer's disease (AD) remains inconclusive. OBJECTIVE We performed an updated systematic review and meta-analysis of the efficacy/safety of memantine in AD. METHODS We included randomized trials of memantine for AD patients. Cognitive function scores (CF), behavioral disturbances scores (BD), and all-cause discontinuation were used as primary measures. Effect size based on a random-effects model was evaluated in the meta-analyses. RESULTS Thirty studies (n = 7,567; memantine versus placebo: N = 11, n = 3,298; memantine + cholinesterase inhibitors (M+ChEIs) versus ChEIs: N = 17, n = 4,175) were identified. Memantine showed a significant improvement in CF [standardized mean difference (SMD) = -0.24, 95% confidence intervals (95% CIs) = -0.34, -0.15, p < 0.00001, I2 = 35% ] and BD (SMD = -0.16, 95% CIs = -0.29, -0.04, p = 0.01, I2 = 52%) compared with placebo. In the sensitivity analysis including only patients with moderate-severe AD, memantine was superior to the placebo in reducing BD without considerable heterogeneity (SMD = -0.20, 95% CIs = -0.34, -0.07, p = 0.003, I2 = 36%). Compared with ChEIs, M+ChEIs showed a greater reduction in BD (SMD = -0.20, 95% CIs = -0.36, -0.03, p = 0.02, I2 = 77%) and a trend of CF improvement (SMD = -0.11, 95% CIs = -0.22, 0.01, p = 0.06, I2 = 56%). However, in the sensitivity analysis of double-blind, placebo-controlled studies only, M+ChEIs showed a significant reduction in BD compared with ChEIs without considerable heterogeneity (SMD = -0.11, 95% CIs = -0.21, -0.01, p = 0.04, I2 = 40%). When performing the sensitivity analysis of donepezil studies only, M+ChEIs was superior to ChEIs in improving CF without considerable heterogeneity (SMD = -0.18, 95% CIs = -0.31, -0.05, p = 0.006, I2 = 49%). No differences were detected in all-cause discontinuation between the groups. CONCLUSIONS The meta-analyses suggest the credible efficacy and safety of memantine in treating AD when used alone or in combination with ChEIs.
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Affiliation(s)
- Taro Kishi
- Department of Psychiatry, Fujita Health University School of Medicine, Kutsukake-cho, Toyoake, Aichi, Japan
| | - Shinji Matsunaga
- Department of Psychiatry, Fujita Health University School of Medicine, Kutsukake-cho, Toyoake, Aichi, Japan
| | - Kazuto Oya
- Department of Psychiatry, Fujita Health University School of Medicine, Kutsukake-cho, Toyoake, Aichi, Japan
| | - Ikuo Nomura
- Department of Psychiatry, Fujita Health University School of Medicine, Kutsukake-cho, Toyoake, Aichi, Japan
| | - Toshikazu Ikuta
- Department of Communication Sciences and Disorders, School of Applied Sciences, University of Mississippi, University MS, USA
| | - Nakao Iwata
- Department of Psychiatry, Fujita Health University School of Medicine, Kutsukake-cho, Toyoake, Aichi, Japan
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Memantine, a Low-Affinity NMDA Receptor Antagonist, Protects against Methylmercury-Induced Cytotoxicity of Rat Primary Cultured Cortical Neurons, Involvement of Ca2+ Dyshomeostasis Antagonism, and Indirect Antioxidation Effects. Mol Neurobiol 2016; 54:5034-5050. [DOI: 10.1007/s12035-016-0020-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 08/01/2016] [Indexed: 01/20/2023]
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Song G, Li Y, Lin L, Cao Y. Anti-autophagic and anti-apoptotic effects of memantine in a SH-SY5Y cell model of Alzheimer's disease via mammalian target of rapamycin-dependent and -independent pathways. Mol Med Rep 2015; 12:7615-22. [PMID: 26459718 PMCID: PMC4626184 DOI: 10.3892/mmr.2015.4382] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 07/17/2015] [Indexed: 11/23/2022] Open
Abstract
Memantine non-competitively blocks the N-methyl-d-aspartate receptor in order to inhibit beta-amyloid (Aβ) secretion, and has been used to treat moderate-to-severe Alzheimer's disease (AD). However, the mechanisms underlying the role of memantine in the autophagy and apoptosis of neuronal cells in AD, as well as the association between neuronal autophagy and apoptosis have yet to be elucidated. The present study aimed to establish an AD cell model overexpressing the 695-amino-acid Swedish mutant of Aβ precursor protein (APP695swe) in order to observe the effects of memantine on the cell viability, autophagy and apoptosis of SH-SY5Y cells in the AD model, and to investigate the associated underlying mechanisms. A pcDNA3.1-APP695 plasmid was transfected into the SH-SY5Y cells. Reverse transcription-quantitative polymerase chain reaction and western blot analyses demonstrated that the AD cell model was successfully established. MTT assays demonstrated that memantine was able to upregulate neuronal cell survival, and acridine orange staining and flow cytometry demonstrated that memantine (5 µM) was able to inhibit neuronal autophagy and apoptosis. Following neuronal autophagy induction by rapamycin, cell apoptosis rates increased significantly. Further experiments revealed that memantine was able to upregulate the expression of signaling molecules phosphorylated (p)-phosphoinositide 3-kinase, p-Akt and p-mammalian target of rapamycin (mTOR), and also inhibited the phosphorylation of the B-cell lymphoma 2/Beclin-1 complex via mitogen-activated protein kinase 8. In conclusion, the results of the present study demonstrated that in the AD cell model, autophagy was able to promote apoptosis. Memantine exerted anti-autophagic and anti-apoptotic functions, and mTOR-dependent as well as-independent autophagic signaling pathways were involved in this process. Therefore, these results of the present study strongly supported the use of memantine as a potential therapeutic strategy for AD treatment.
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Affiliation(s)
- Guijun Song
- Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yu Li
- Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Lulu Lin
- Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yunpeng Cao
- Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
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Atri A, Stern TA. Psychopharmacologic Agents to Enhance Cognition in Alzheimer’s Disease. Psychiatr Ann 2015. [DOI: 10.3928/00485713-20150626-07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Jiang J, Jiang H. Efficacy and adverse effects of memantine treatment for Alzheimer's disease from randomized controlled trials. Neurol Sci 2015; 36:1633-41. [PMID: 25899425 DOI: 10.1007/s10072-015-2221-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 04/15/2015] [Indexed: 01/02/2023]
Abstract
The role of memantine as a treatment for Alzheimer's disease (AD) has been controversial. In clinical trials, a high dropout rate and numerous adverse events associated with memantine have been observed. However, given the relative scarcity of effective treatments for AD it would seem prudent to re-examine existing evidence to determine whether or not memantine should be used. Eight databases were utilized for randomized controlled trials that were published prior to December 31, 2013 and were according with the inclusion criteria. Trial methods, clinical characteristics, outcomes, and adverse events were extracted and analyzed with Review Manager 5.2. We obtained 2293 studies and determined that 13 of those studies met the inclusion criteria. Memantine therapy showed significant benefits to cognition, mental state, activities of daily life, the clinician's global impression in term with MMSE, SIB, NPI, ADCS-ADL19, CIBIC-Plus, respectively. Memantine therapy did not significantly increase the incidence of total adverse events, serious adverse events, death but it did increase the risk for somnolence.
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Affiliation(s)
- Jue Jiang
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Zhizaoju Road 639, Shanghai, 200011, China,
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Abstract
BACKGROUND During the course of Alzheimer's disease (AD), cognitive processes, including language and communication, become increasingly impaired. The aim of this review was to highlight the impact of communication deficits in AD, and discuss the need for effective treatments. METHOD PubMed was searched for studies relating to language and communication in AD. The publications identified were used as a basis for the commentary in this paper. Studies relating to the clinical effectiveness of pharmacological treatment for language and communication issues were identified systematically. RESULTS Communication deficits are common in AD. From the earliest disease stage, the patient's capacity for communication declines as problems develop with the use of language and all aspects of functional communication. There is a loss of the ability to communicate thoughts and needs, and it becomes increasingly difficult to interact socially and sustain personal relationships with caregivers, family, and friends. It is unsurprising that patients become frustrated at their loss of self-expression, and studies have demonstrated that impaired communication is strongly linked with the development of significant behavioral concerns. Overall, poor communication contributes to caregiver strain, and adds notably to the burden of disease. Clinical data and post-hoc analyses provide preliminary indications that anti-AD therapies (memantine and the cholinesterase inhibitors, ChEIs) and non-pharmacological cognitive-linguistic stimulation techniques may be helpful in addressing communication difficulties. CONCLUSIONS The capacity to treat or slow the progression of communication deficits in AD would prolong patient independence, and have a profound impact on the quality of life of patients and caregivers. The use of pharmacological (anti-AD therapies) and non-pharmacological (cognitive-linguistic stimulation) treatments may be useful management methods and warrant further investigation.
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Wanka L, Iqbal K, Schreiner PR. The lipophilic bullet hits the targets: medicinal chemistry of adamantane derivatives. Chem Rev 2013; 113:3516-604. [PMID: 23432396 PMCID: PMC3650105 DOI: 10.1021/cr100264t] [Citation(s) in RCA: 439] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Lukas Wanka
- Institute of Organic Chemistry, Justus-Liebig University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen, Germany; Fax +49(641)9934309
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314-6399, USA
| | - Khalid Iqbal
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314-6399, USA
| | - Peter R. Schreiner
- Institute of Organic Chemistry, Justus-Liebig University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen, Germany; Fax +49(641)9934309
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Liu W, Xu Z, Deng Y, Xu B, Wei Y, Yang T. Protective effects of memantine against methylmercury-induced glutamate dyshomeostasis and oxidative stress in rat cerebral cortex. Neurotox Res 2013; 24:320-37. [PMID: 23504438 DOI: 10.1007/s12640-013-9386-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 02/25/2013] [Accepted: 03/05/2013] [Indexed: 12/26/2022]
Abstract
Methylmercury (MeHg) is one of the ubiquitous environmental toxicant that leads to long-lasting neurological deficits in animals and humans. The identification of the underlying mechanisms has been a main focus of research in the neurotoxicology field. Glutamate (Glu) dyshomeostasis and oxidative stress have been identified as two critical mechanisms mediating MeHg-induced neurotoxicity. However, little has been known of the interaction between these two mechanisms that play in MeHg poisoning in vivo. We, therefore, developed a rat model of MeHg subchronic poisoning to evaluate its neurotoxic effects and investigated the neuroprotective role of memantine, a low-affinity, noncompetitive N-methyl-D-aspartate receptors (NMDARs) antagonist, against MeHg-induced neurotoxicity. Ninety rats were randomly divided into five groups: control, memantine control, MeHg-treated (4 and 12 μmol/kg), and memantine pretreated. Administration of 12 μmol/kg MeHg for 4 weeks significantly elevated total Hg levels, disrupted Glu metabolism, overexcited NMDARs, and led to intracellular calcium overload, which might be critical to excessive reactive oxygen species (ROS) formation in cerebral cortex. Meanwhile, MeHg administration reduced non-enzymatic (non-protein sulfhydryl, NPSH) and enzymatic (superoxide dismutase, SOD and glutathione peroxidase, GSH-Px) antioxidants; caused lipid, protein, and DNA oxidative damage; and enhanced neurocyte apoptosis in cerebral cortex. Moreover, glutamate/aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) appear to be inhibited by MeHg exposure. Pretreatment with memantine at a dose of 5 μmol/kg significantly prevented MeHg-induced alterations of Glu metabolism and oxidative stress, alleviated neurocyte apoptosis, and pathological injury. In conclusion, the results suggested that Glu dyshomeostasis and oxidative stress resulting from MeHg exposure contributed to neuronal injury. Memantine possesses the ability to attenuate MeHg-induced neurotoxicity through mechanisms involving its NMDARs-binding properties and indirect antioxidation.
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Affiliation(s)
- Wei Liu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110001, Liaoning, People's Republic of China
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