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OUP accepted manuscript. Brain 2022; 145:2250-2275. [DOI: 10.1093/brain/awac096] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 01/21/2022] [Accepted: 01/23/2022] [Indexed: 11/13/2022] Open
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Li J, Zheng C, Ge Q, Yan S, Paranjpe MD, Hu S, Zhou Y. Association between long-term donepezil treatment and brain regional amyloid and tau burden among individuals with mild cognitive impairment assessed using 18 F-AV-45 and 18 F-AV-1451 PET. J Neurosci Res 2021; 100:670-680. [PMID: 34882830 DOI: 10.1002/jnr.24995] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 10/16/2021] [Accepted: 11/06/2021] [Indexed: 11/06/2022]
Abstract
This study aims to investigate the association between long-term donepezil treatment and brain neuropathological burden and cognitive function in mild cognitive impairment (MCI) patients. Preprocessed 18 F-AV-45 amyloid and 18 F-AV-1451 tau positron emission tomography (PET) images, magnetic resonance imaging images (MRIs), demographic information, and donepezil use status were downloaded from 255 MCI participants enrolled in the Alzheimer's Disease Neuroimaging Initiative database. Partial volume correction was applied to all PET images. Structural MRIs were used for PET spatial normalization. Regions of interest (ROIs) were defined in standard space, and standardized uptake value ratio (SUVR) images relative to the cerebellum were computed. Multiple linear regression with the least absolute shrinkage selector operator was performed to analyze the effect of long-term donepezil treatment on (a) the SUVR of each 18 F-AV-45 or 18 F-AV-1451 brain PET ROI after adjusting for age, sex, education, ApoE ε4 status, and AD-associated disease risk factors; and (b) cognitive performance after adjusting for age, sex education, ApoE ε4 status, AD-associated disease risk factors, and regional amyloid or tau burden. In adjusted models, long-term donepezil treatment was associated with greater amyloid load in the orbital frontal, superior frontal, parietal, posterior precuneus, posterior cingulate, lateral temporal, inferior temporal and fusiform regions, and tau burden in the posterior cingulate, entorhinal and parahippocampal gyrus. Long-term donepezil treatment was also associated with worse performance on the 13-item Alzheimer's Disease Assessment Scale-Cognitive subscale after adjusting for AD-related risk factors and regional brain amyloid or tau load. These results indicate that long-term donepezil treatment is associated with increased regional amyloid and tau burden and worse cognitive performance among individuals with MCI. Our study highlights the importance of using noninvasive and quantitative 18 F-AV-45 and 18 F-AV-1451 PET to elucidate the consequences of drug administration in AD studies.
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Affiliation(s)
- Jian Li
- Department of Nuclear Medicine (PET Center), Xiangya Hospital Central South University, Changsha, China.,Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Chaojie Zheng
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA.,Central Research Institute, United Imaging Healthcare Group Co., Ltd, Shanghai, China
| | - Qi Ge
- Central Research Institute, United Imaging Healthcare Group Co., Ltd, Shanghai, China
| | - Shaozhen Yan
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Manish D Paranjpe
- Harvard-MIT Program in Health Sciences and Technology, Harvard Medical School, Boston, MA, USA
| | - Shuo Hu
- Department of Nuclear Medicine (PET Center), Xiangya Hospital Central South University, Changsha, China.,Key Laboratory of Biological Nanotechnology of National Health Commission, Xiangya Hospital Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital Central South University, Changsha, China
| | - Yun Zhou
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA.,Central Research Institute, United Imaging Healthcare Group Co., Ltd, Shanghai, China
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Kehoe PG, Hibbs E, Palmer LE, Miners JS. Angiotensin-III is Increased in Alzheimer's Disease in Association with Amyloid-β and Tau Pathology. J Alzheimers Dis 2018; 58:203-214. [PMID: 28387670 DOI: 10.3233/jad-161265] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Hyperactivity of the renin-angiotensin system (RAS) is associated with the pathogenesis of Alzheimer's disease (AD) believed to be mediated by angiotensin-II (Ang-II) activation of the angiotensin type 1 receptor (AT1R). We previously showed that angiotensin-converting enzyme-1 (ACE-1) activity, the rate-limiting enzyme in the production of Ang-II, is increased in human postmortem brain tissue in AD. Angiotensin-III (Ang-III) activates the AT1R and angiotensin type-2 receptor (AT2R), but its potential role in the pathophysiology of AD remains unexplored. We measured Ang-II and Ang-III levels by ELISA, and the levels and activities of aminopeptidase-A (AP-A) and aminopeptidase-N (AP-N) (responsible for the production and metabolism of Ang-III, respectively) in human postmortem brain tissue in the mid-frontal cortex (Brodmann area 9) in a cohort of AD (n = 90) and age-matched non-demented controls (n = 59), for which we had previous measurements of ACE-1 activity, Aβ level, and tau pathology (also in the mid-frontal cortex). We found that both Ang-II and Ang-III levels were significantly higher in AD compared to age-matched controls and that Ang-III, rather than Ang-II, was strongly associated with Aβ load and tau load. Levels of AP-A were significantly reduced in AD but AP-A enzyme activity was unchanged whereas AP-N activity was reduced in AD but AP-N protein level was unchanged. Together, these data indicate that the APA/Ang-III/APN/Ang-IV/AT4R pathway is dysregulated and that elevated Ang-III could contribute to the pathogenesis of AD.
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Bachurin SO, Bovina EV, Ustyugov AA. Drugs in Clinical Trials for Alzheimer's Disease: The Major Trends. Med Res Rev 2017; 37:1186-1225. [PMID: 28084618 DOI: 10.1002/med.21434] [Citation(s) in RCA: 209] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 10/18/2016] [Accepted: 11/24/2016] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD) is characterized by a chronic and progressive neurodegenerative process resulting from the intracellular and extracellular accumulation of fibrillary proteins: beta-amyloid and hyperphosphorylated Tau. Overaccumulation of these aggregates leads to synaptic dysfunction and subsequent neuronal loss. The precise molecular mechanisms of AD are still not fully understood but it is clear that AD is a multifactorial disorder and that advanced age is the main risk factor. Over the last decade, more than 50 drug candidates have successfully passed phase II clinical trials, but none has passed phase III. Here, we summarize data on current "anti-Alzheimer's" agents currently in clinical trials based on findings available in the Thomson Reuters «Integrity» database, on the public website www.clinicaltrials.gov, and on database of the website Alzforum.org. As a result, it was possible to outline some major trends in AD drug discovery: (i) the development of compounds acting on the main stages of the pathogenesis of the disease (the so-called "disease-modifying agents") - these drugs could potentially slow the development of structural and functional abnormalities in the central nervous system providing sustainable improvements of cognitive functions, which persist even after drug withdrawal; (ii) focused design of multitargeted drugs acting on multiple molecular targets involved in the pathogenesis of the disease; (3) finally, the repositioning of old drugs for new (anti-Alzheimer's) application offers a very attractive approach to facilitate the completion of clinical trials.
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Affiliation(s)
- Sergey O Bachurin
- Institute of Physiologically Active Compounds, Russian Academy of Sciences, Severny proezd 1, Chernogolovka, Moscow region, 142432, Russia
| | - Elena V Bovina
- Institute of Physiologically Active Compounds, Russian Academy of Sciences, Severny proezd 1, Chernogolovka, Moscow region, 142432, Russia
| | - Aleksey A Ustyugov
- Institute of Physiologically Active Compounds, Russian Academy of Sciences, Severny proezd 1, Chernogolovka, Moscow region, 142432, Russia
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Kehoe PG, Wong S, Al Mulhim N, Palmer LE, Miners JS. Angiotensin-converting enzyme 2 is reduced in Alzheimer's disease in association with increasing amyloid-β and tau pathology. ALZHEIMERS RESEARCH & THERAPY 2016; 8:50. [PMID: 27884212 PMCID: PMC5123239 DOI: 10.1186/s13195-016-0217-7] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 10/20/2016] [Indexed: 12/14/2022]
Abstract
BACKGROUND Hyperactivity of the classical axis of the renin-angiotensin system (RAS), mediated by angiotensin II (Ang II) activation of the angiotensin II type 1 receptor (AT1R), is implicated in the pathogenesis of Alzheimer's disease (AD). Angiotensin-converting enzyme-2 (ACE-2) degrades Ang II to angiotensin 1-7 (Ang (1-7)) and counter-regulates the classical axis of RAS. We have investigated the expression and distribution of ACE-2 in post-mortem human brain tissue in relation to AD pathology and classical RAS axis activity. METHODS We measured ACE-2 activity by fluorogenic peptide substrate assay in mid-frontal cortex (Brodmann area 9) in a cohort of AD (n = 90) and age-matched non-demented controls (n = 59) for which we have previous data on ACE-1 activity, amyloid β (Aβ) level and tau pathology, as well as known ACE1 (rs1799752) indel polymorphism, apolipoprotein E (APOE) genotype, and cerebral amyloid angiopathy severity scores. RESULTS ACE-2 activity was significantly reduced in AD compared with age-matched controls (P < 0.0001) and correlated inversely with levels of Aβ (r = -0.267, P < 0.001) and phosphorylated tau (p-tau) pathology (r = -0.327, P < 0.01). ACE-2 was reduced in individuals possessing an APOE ε4 allele (P < 0.05) and was associated with ACE1 indel polymorphism (P < 0.05), with lower ACE-2 activity in individuals homozygous for the ACE1 insertion AD risk allele. ACE-2 activity correlated inversely with ACE-1 activity (r = -0.453, P < 0.0001), and the ratio of ACE-1 to ACE-2 was significantly elevated in AD (P < 0.0001). Finally, we show that the ratio of Ang II to Ang (1-7) (a proxy measure of ACE-2 activity indicating conversion of Ang II to Ang (1-7)) is reduced in AD. CONCLUSIONS Together, our findings indicate that ACE-2 activity is reduced in AD and is an important regulator of the central classical ACE-1/Ang II/AT1R axis of RAS, and also that dysregulation of this pathway likely plays a significant role in the pathogenesis of AD.
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Affiliation(s)
- Patrick Gavin Kehoe
- Dementia Research Group, University of Bristol, Level 1, Learning and Research, Southmead Hospital, Bristol, BS10 5NB, UK.
| | - Steffenny Wong
- Dementia Research Group, University of Bristol, Level 1, Learning and Research, Southmead Hospital, Bristol, BS10 5NB, UK
| | - Noura Al Mulhim
- Dementia Research Group, University of Bristol, Level 1, Learning and Research, Southmead Hospital, Bristol, BS10 5NB, UK
| | - Laura Elyse Palmer
- Dementia Research Group, University of Bristol, Level 1, Learning and Research, Southmead Hospital, Bristol, BS10 5NB, UK
| | - J Scott Miners
- Dementia Research Group, University of Bristol, Level 1, Learning and Research, Southmead Hospital, Bristol, BS10 5NB, UK.
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Bachurin SO. A review of drugs for treatment of Alzheimer’s disease in clinical trials: main trends. Zh Nevrol Psikhiatr Im S S Korsakova 2016. [DOI: 10.17116/jnevro20161168177-87] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Kukharsky MS, Ovchinnikov RK, Bachurin SO. Molecular aspects of the pathogenesis and current approaches to pharmacological correction of Alzheimer’s disease. Zh Nevrol Psikhiatr Im S S Korsakova 2015; 115:103-114. [DOI: 10.17116/jnevro20151156103-114] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Miners JS, Renfrew R, Swirski M, Love S. Accumulation of α-synuclein in dementia with Lewy bodies is associated with decline in the α-synuclein-degrading enzymes kallikrein-6 and calpain-1. Acta Neuropathol Commun 2014; 2:164. [PMID: 25476568 PMCID: PMC4271448 DOI: 10.1186/s40478-014-0164-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 11/20/2014] [Indexed: 12/29/2022] Open
Abstract
Kallikrein-6 and calpain-1 are amongst a small group of proteases that degrade α-synuclein. We have explored the possibility that reduction in the level or activity of these enzymes contributes to the accumulation of α-synuclein in Lewy body diseases. We measured calpain-1 activity by fluorogenic activity assay, kallikrein-6 level by sandwich ELISA, and levels of α-synuclein and α-synuclein phosphorylated at serine 129 (α-synuclein-P129), in post-mortem brain tissue in pure dementia with Lewy bodies (DLB, n = 12), Alzheimer’s disease (AD, n = 20) and age-matched controls (n = 19). Calpain-1 activity was significantly reduced in DLB within the cingulate and parahippocampal cortex, regions with highest α-synuclein and α-synuclein-P129 load, and correlated inversely with the levels of α-synuclein and α-synuclein-P129. Calpain-1 was unaltered in the thalamus and frontal cortex, regions with less α-synuclein pathology. Kallikrein-6 level was reduced in the cingulate cortex in the DLB cohort, and correlated inversely with α-synuclein and α-synuclein-P129. Kallikrein-6 was also reduced in DLB in the thalamus but not in relation to α-synuclein or α-synuclein-P129 load and was unaltered in the frontal and parahippocampal cortex. In SH-SY5Y cells overexpressing wild-type α-synuclein there was partial co-localisation of kallikrein-6 and calpain-1 with α-synuclein, and siRNA-mediated knock-down of kallikrein-6 and calpain-1 increased the amount of α-synuclein in cell lysates. Our results indicate that reductions in kallikrein-6 and calpain-1 may contribute to the accumulation of α-synuclein in DLB.
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Hogan DB. Long-term efficacy and toxicity of cholinesterase inhibitors in the treatment of Alzheimer disease. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2014; 59:618-23. [PMID: 25702360 PMCID: PMC4304580 DOI: 10.1177/070674371405901202] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Though the symptoms of Alzheimer disease go on for years, the phase 3 trials of the cholinesterase inhibitors (ChEIs), the current mainstay of symptomatic pharmacotherapy for this condition, were typically of only 3- to 6-months' duration. We have limited data on long-term (that is, a year or more) therapy with these agents. In this review, we explore the available information on the biological and clinical effects of long-term ChEI therapy, what happens when these agents are discontinued, and examine what others have recommended An individualized approach to deciding on whether to carry on with a ChEI should be taken. If continued, treatment goals should be clarified and patients monitored over time, for both drug-related benefits and adverse effects.
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Affiliation(s)
- David B Hogan
- Brenda Strafford Foundation Chair in Geriatric Medicine, University of Calgary, Calgary, Alberta
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Swirski M, Miners JS, de Silva R, Lashley T, Ling H, Holton J, Revesz T, Love S. Evaluating the relationship between amyloid-β and α-synuclein phosphorylated at Ser129 in dementia with Lewy bodies and Parkinson's disease. ALZHEIMERS RESEARCH & THERAPY 2014; 6:77. [PMID: 25452767 PMCID: PMC4248436 DOI: 10.1186/s13195-014-0077-y] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Accepted: 10/14/2014] [Indexed: 01/12/2023]
Abstract
Introduction Lewy body and Alzheimer-type pathologies often co-exist.
Several studies suggest a synergistic relationship between amyloid-β (Aβ)
and α-synuclein (α-syn) accumulation. We have explored the relationship
between Aβ accumulation and the phosphorylation of α-syn at serine-129
(pSer129 α-syn), in post-mortem human brain tissue and in SH-SY5Y
neuroblastoma cells transfected to overexpress human α-syn. Methods We measured levels of Aβ40, Aβ42, α-syn and pSer129 α-syn by
sandwich enzyme-linked immunosorbent assay, in soluble and insoluble
fractions of midfrontal, cingulate and parahippocampal cortex and
thalamus, from cases of Parkinson’s disease (PD) with (PDD; n = 12) and
without dementia (PDND; n = 23), dementia with Lewy bodies (DLB; n = 10)
and age-matched controls (n = 17). We also examined the relationship of
these measurements to cognitive decline, as measured by time-to-dementia
and the mini-mental state examination (MMSE) score in the PD patients,
and to Braak tangle stage. Results In most brain regions, the concentration of insoluble
pSer129 α-syn correlated positively, and soluble pSer129 α-syn
negatively, with the levels of soluble and insoluble Aβ. Insoluble
pSer129 α-syn also correlated positively with Braak stage. In most
regions, the levels of insoluble and soluble Aβ and the proportion of
insoluble α-syn that was phosphorylated at Ser129 were significantly
higher in the PD and DLB groups than the controls, and higher in the PDD
and DLB groups than the PDND brains. In PD, the MMSE score correlated
negatively with the level of insoluble pSer129 α-syn. Exposure of SH-SY5Y
cells to aggregated Aβ42 significantly increased the proportion of α-syn
that was phosphorylated at Ser129 (aggregated Aβ40 exposure had a
smaller, non-significant effect). Conclusions Together, these data show that the concentration of pSer129
α-syn in brain tissue homogenates is directly related to the level of Aβ
and Braak tangle stage, and predicts cognitive status in Lewy body
diseases. Electronic supplementary material The online version of this article (doi:10.1186/s13195-014-0077-y) contains supplementary material, which is available to
authorized users.
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Affiliation(s)
- Marta Swirski
- Dementia Research Group, Institute of Clinical Neurosciences, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - J Scott Miners
- Dementia Research Group, Institute of Clinical Neurosciences, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Rohan de Silva
- Department of Molecular Neuroscience, Reta Lila Weston Institute of Neurological Studies and Queen Square Brain Bank for Neurological Disorders, Institute of Neurology, University College London, London, UK
| | - Tammaryn Lashley
- Department of Molecular Neuroscience, Reta Lila Weston Institute of Neurological Studies and Queen Square Brain Bank for Neurological Disorders, Institute of Neurology, University College London, London, UK
| | - Helen Ling
- Department of Molecular Neuroscience, Reta Lila Weston Institute of Neurological Studies and Queen Square Brain Bank for Neurological Disorders, Institute of Neurology, University College London, London, UK
| | - Janice Holton
- Department of Molecular Neuroscience, Reta Lila Weston Institute of Neurological Studies and Queen Square Brain Bank for Neurological Disorders, Institute of Neurology, University College London, London, UK
| | - Tamas Revesz
- Department of Molecular Neuroscience, Reta Lila Weston Institute of Neurological Studies and Queen Square Brain Bank for Neurological Disorders, Institute of Neurology, University College London, London, UK
| | - Seth Love
- Dementia Research Group, Institute of Clinical Neurosciences, School of Clinical Sciences, University of Bristol, Bristol, UK
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Glennon EBC, Whitehouse IJ, Miners JS, Kehoe PG, Love S, Kellett KAB, Hooper NM. BIN1 is decreased in sporadic but not familial Alzheimer's disease or in aging. PLoS One 2013; 8:e78806. [PMID: 24205320 PMCID: PMC3804620 DOI: 10.1371/journal.pone.0078806] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 09/22/2013] [Indexed: 01/31/2023] Open
Abstract
Bridging integrator 1 (BIN1) has been implicated in sporadic Alzheimer's disease (AD) by a number of genome wide association studies (GWAS) in a variety of populations. Here we measured BIN1 in frontal cortex samples from 24 sporadic AD and 24 age-matched non-dementia brains and correlated the expression of this protein with markers of AD. BIN1 was reduced by 87% (p=0.007) in sporadic AD compared to non-dementia controls, but BIN1 in sporadic AD did not correlate with soluble Aβ (r(s)=-0.084, p=0.698), insoluble Aβ (r(s)=0.237, p=0.269), Aβ plaque load (r(s)=0.063, p=0.771) or phospho-tau load (r(s)=-0.160, p=0.489). In contrast to our findings in sporadic AD, BIN1 was unchanged in the hippocampus from 6 cases of familial AD compared to 6 age-matched controls (p=0.488). BIN1 declined with age in a cohort of non-dementia control cases between 25 and 88 years but the correlation was not significant (rs=-0.449, p=0.081). Although BIN1 is known to have a role in endocytosis, and the processing of the amyloid precursor protein (APP) to form amyloid-β (Aβ) peptides is dependent on endocytosis, knockdown of BIN1 by targeted siRNA or the overexpression of BIN1 in a human neuroblastoma cell line (SH-SY5Y) had no effect on APP processing. These data suggest that the alteration in BIN1 is involved in the pathogenesis of sporadic, but not familial AD and is not a consequence of AD neurodegeneration or the ageing process, a finding in keeping with the numerous GWAS that implicate BIN1 in sporadic AD. However, the mechanism of its contribution remains to be established.
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Affiliation(s)
- Elizabeth B. C. Glennon
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Isobel J. Whitehouse
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - J. Scott Miners
- Dementia Research Group, School of Clinical Sciences, Institute of Clinical Neurosciences, University of Bristol, Bristol, United Kingdom
| | - Patrick G. Kehoe
- Dementia Research Group, School of Clinical Sciences, Institute of Clinical Neurosciences, University of Bristol, Bristol, United Kingdom
| | - Seth Love
- Dementia Research Group, School of Clinical Sciences, Institute of Clinical Neurosciences, University of Bristol, Bristol, United Kingdom
| | - Katherine A. B. Kellett
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Nigel M. Hooper
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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Corbett A, Smith J, Ballard C. New and emerging treatments for Alzheimer's disease. Expert Rev Neurother 2012; 12:535-43. [PMID: 22550982 DOI: 10.1586/ern.12.43] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD) and other dementias represent a significant and increasing clinical challenge. This review highlights current treatment options for AD and the main focusses of therapies currently being evaluated in clinical trials and for future therapeutic development. Existing treatments slow the progression of symptoms of the disease, but their efficacy does not extend to all people with AD, and benefits are not conveyed beyond an average of 6 months. Despite the substantial economic cost and healthcare burden of AD, which is increasing as populations age, there are currently only three therapies being investigated in Phase III clinical trials. This emphasises the substantial caution and underinvestment in treatment development in this area and why it is critical to address the current lack of effective treatments to target the underlying pathology and disease process in Alzheimer's disease.
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Affiliation(s)
- Anne Corbett
- Alzheimer's Society, Devon House, London E1W 1JX, UK
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Corbett A, Ballard C. New and emerging treatments for Alzheimer's disease. Expert Opin Emerg Drugs 2012; 17:147-56. [DOI: 10.1517/14728214.2012.675327] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Lane RM, He Y. Butyrylcholinesterase genotype and gender influence Alzheimer's disease phenotype. Alzheimers Dement 2012; 9:e1-73. [PMID: 22402324 DOI: 10.1016/j.jalz.2010.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 09/04/2010] [Accepted: 12/02/2010] [Indexed: 10/28/2022]
Abstract
Retrospective data are presented to support a spectrum of early Alzheimer's disease (AD) along a continuum defined by gender and genotype. The putative neurodegenerative mechanisms driving distinct phenotypes at each end of the spectrum are glial hypoactivity associated with early failure of synaptic cholinergic neurotransmission and glial overactivation associated with loss of neural network connectivity due to accelerated age-related breakdown of myelin. In early AD, male butyrylcholinesterase K-variant carriers with one or two apolipoprotein ɛ4 alleles have prominent medial temporal atrophy, synaptic failure, cognitive decline, and accumulation of aggregated beta-amyloid peptide. Increasing synaptic acetylcholine in damaged but still functional cholinergic synapses improves cognitive symptoms, whereas increasing the ability of glia to support synapses and to clear beta-amyloid peptide might be disease-modifying. Conversely, chronic glial overactivation can also drive degenerative processes and in butyrylcholinesterase K-variant negative females generalized glial overactivation may be the main driver from mild cognitive impairment to AD. Females are more likely than males to have accelerated age-related myelin breakdown, more widespread white matter loss, loss of neural network connectivity, whole brain atrophy, and functional decline. Increasing extracellular acetylcholine levels blocks glial activation, reduces myelin loss and damage to neural network connectivity, and is disease-modifying. Between extremes characterized by gender, genotype, and age, pathophysiology may be mixed and this spectrum may explain much of the heterogeneity of amnestic mild cognitive impairment. Preservation of the functional integrity of the neural network may be an important component of strengthening cognitive reserve and significantly delaying the onset and progression of dementia, particularly in females. Prospective confirmation of these hypotheses is required. Implications for future research and therapeutic opportunities are discussed.
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Affiliation(s)
- Roger M Lane
- Bristol-Myers Squibb Global Clinical Research, Wallingford, CT, USA.
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Fisher A. Cholinergic modulation of amyloid precursor protein processing with emphasis on M1 muscarinic receptor: perspectives and challenges in treatment of Alzheimer’s disease. J Neurochem 2011; 120 Suppl 1:22-33. [DOI: 10.1111/j.1471-4159.2011.07507.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Dome P, Lazary J, Kalapos MP, Rihmer Z. Smoking, nicotine and neuropsychiatric disorders. Neurosci Biobehav Rev 2009; 34:295-342. [PMID: 19665479 DOI: 10.1016/j.neubiorev.2009.07.013] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 07/23/2009] [Accepted: 07/30/2009] [Indexed: 12/20/2022]
Abstract
Tobacco smoking is an extremely addictive and harmful form of nicotine (NIC) consumption, but unfortunately also the most prevalent. Although disproportionately high frequencies of smoking and its health consequences among psychiatric patients are widely known, the neurobiological background of this epidemiological association is still obscure. The diverse neuroactive effects of NIC and some other major tobacco smoke constituents in the central nervous system may underlie this association. This present paper summarizes the pharmacology of NIC and its receptors (nAChR) based on a systematic review of the literature. The role of the brain's reward system(s) in NIC addiction and the results of functional and structural neuroimaging studies on smoking-related states and behaviors (i.e. dependence, craving, withdrawal) are also discussed. In addition, the epidemiological, neurobiological, and genetic aspects of smoking in several specific neuropsychiatric disorders are reviewed and the clinical relevance of smoking in these disease states addressed.
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Affiliation(s)
- Peter Dome
- Department of Clinical and Theoretical Mental Health, Kutvolgyi Clinical Center, Semmelweis University, Faculty of Medicine, Kutvolgyi ut 4, 1125 Budapest, Hungary.
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