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Zhang J, Zhang Y, Wang J, Xia Y, Zhang J, Chen L. Recent advances in Alzheimer's disease: Mechanisms, clinical trials and new drug development strategies. Signal Transduct Target Ther 2024; 9:211. [PMID: 39174535 PMCID: PMC11344989 DOI: 10.1038/s41392-024-01911-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 03/18/2024] [Accepted: 07/02/2024] [Indexed: 08/24/2024] Open
Abstract
Alzheimer's disease (AD) stands as the predominant form of dementia, presenting significant and escalating global challenges. Its etiology is intricate and diverse, stemming from a combination of factors such as aging, genetics, and environment. Our current understanding of AD pathologies involves various hypotheses, such as the cholinergic, amyloid, tau protein, inflammatory, oxidative stress, metal ion, glutamate excitotoxicity, microbiota-gut-brain axis, and abnormal autophagy. Nonetheless, unraveling the interplay among these pathological aspects and pinpointing the primary initiators of AD require further elucidation and validation. In the past decades, most clinical drugs have been discontinued due to limited effectiveness or adverse effects. Presently, available drugs primarily offer symptomatic relief and often accompanied by undesirable side effects. However, recent approvals of aducanumab (1) and lecanemab (2) by the Food and Drug Administration (FDA) present the potential in disrease-modifying effects. Nevertheless, the long-term efficacy and safety of these drugs need further validation. Consequently, the quest for safer and more effective AD drugs persists as a formidable and pressing task. This review discusses the current understanding of AD pathogenesis, advances in diagnostic biomarkers, the latest updates of clinical trials, and emerging technologies for AD drug development. We highlight recent progress in the discovery of selective inhibitors, dual-target inhibitors, allosteric modulators, covalent inhibitors, proteolysis-targeting chimeras (PROTACs), and protein-protein interaction (PPI) modulators. Our goal is to provide insights into the prospective development and clinical application of novel AD drugs.
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Affiliation(s)
- Jifa Zhang
- Department of Neurology, Laboratory of Neuro-system and Multimorbidity and State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yinglu Zhang
- Department of Neurology, Laboratory of Neuro-system and Multimorbidity and State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jiaxing Wang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, 38163, TN, USA
| | - Yilin Xia
- Department of Neurology, Laboratory of Neuro-system and Multimorbidity and State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jiaxian Zhang
- Department of Neurology, Laboratory of Neuro-system and Multimorbidity and State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Lei Chen
- Department of Neurology, Laboratory of Neuro-system and Multimorbidity and State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
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2
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Clouston SAP, Muñiz Terrera G, Rodgers JL, O'Keefe P, Mann F, Lewis NA, Wänström L, Kaye J, Hofer SM. Cohort and Period Effects as Explanations for Declining Dementia Trends and Cognitive Aging. POPULATION AND DEVELOPMENT REVIEW 2021; 47:611-637. [PMID: 36937313 PMCID: PMC10021404 DOI: 10.1111/padr.12409] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Studies have reported that the age-adjusted incidence of cognitive impairment and dementia may have decreased over the past two decades. Aging is the predominant risk factor for Alzheimer's disease and related dementias and for neurocognitive decline. However, aging cannot explain changes in overall age-adjusted incidence of dementia. The objective of this position paper was to describe the potential for cohort and period effects in cognitive decline and incidence of dementia. Cohort effects have long been reported in demographic literature, but starting in the early 1980s, researchers began reporting cohort trends in cognitive function. At the same time, period effects have emerged in economic factors and stressors in early and midlife that may result in reduced cognitive dysfunction. Recognizing that aging individuals today were once children and adolescents, and that research has clearly noted that childhood cognitive performance is a primary determinant of old-age cognitive performance, this is the first study that proposes the need to connect known cohort effects in childhood cognition with differences in late-life functioning.
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Affiliation(s)
- Sean A P Clouston
- Program in Public Health and Department of Family, Population, and Preventive Medicine, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
| | - Graciela Muñiz Terrera
- Biostatistics and Epidemiology, Center for Dementia Prevention, University of Edinburgh, Edinburgh, UK
| | - Joseph Lee Rodgers
- Department of Psychology and Human Development, Vanderbilt University, Nashville, TN, USA
| | | | - Frank Mann
- Program in Public Health and Department of Family, Population, and Preventive Medicine, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
| | - Nathan A Lewis
- Department of Psychology, University of Victoria, Victoria, BC
| | - Linda Wänström
- Department of Computer and Informational Science, Linköping University, Linköping, Sweden
| | - Jeffrey Kaye
- Oregon Center for Aging and Technology, Oregon Health and Sciences University, and NIA-Layton Aging & Alzheimer's Disease Center, Portland, OR, USA
| | - Scott M Hofer
- Department of Psychology, University of Victoria, Victoria, BC
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3
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Polis B, Karasik D, Samson AO. Alzheimer's disease as a chronic maladaptive polyamine stress response. Aging (Albany NY) 2021; 13:10770-10795. [PMID: 33811757 PMCID: PMC8064158 DOI: 10.18632/aging.202928] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 03/27/2021] [Indexed: 12/21/2022]
Abstract
Polyamines are nitrogen-rich polycationic ubiquitous bioactive molecules with diverse evolutionary-conserved functions. Their activity interferes with numerous genes' expression resulting in cell proliferation and signaling modulation. The intracellular levels of polyamines are precisely controlled by an evolutionary-conserved machinery. Their transient synthesis is induced by heat stress, radiation, and other traumatic stimuli in a process termed the polyamine stress response (PSR). Notably, polyamine levels decline gradually with age; and external supplementation improves lifespan in model organisms. This corresponds to cytoprotective and reactive oxygen species scavenging properties of polyamines. Paradoxically, age-associated neurodegenerative disorders are characterized by upsurge in polyamines levels, indicating polyamine pleiotropic, adaptive, and pathogenic roles. Specifically, arginase overactivation and arginine brain deprivation have been shown to play an important role in Alzheimer's disease (AD) pathogenesis. Here, we assert that a universal short-term PSR associated with acute stimuli is beneficial for survival. However, it becomes detrimental and maladaptive following chronic noxious stimuli, especially in an aging organism. Furthermore, we regard cellular senescence as an adaptive response to stress and suggest that PSR plays a central role in age-related neurodegenerative diseases' pathogenesis. Our perspective on AD proposes an inclusive reassessment of the causal relationships between the classical hallmarks and clinical manifestation. Consequently, we offer a novel treatment strategy predicated upon this view and suggest fine-tuning of arginase activity with natural inhibitors to preclude or halt the development of AD-related dementia.
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Affiliation(s)
- Baruh Polis
- Drug Discovery Laboratory, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - David Karasik
- Hebrew SeniorLife, Hinda and Arthur Marcus Institute for Aging Research, Boston, MA 02131, USA
- Musculoskeletal Genetics Laboratory, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Abraham O. Samson
- Drug Discovery Laboratory, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
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Garrett MD. Multiple Causes of Dementia as Engineered Senescence. EUROPEAN JOURNAL OF MEDICAL AND HEALTH SCIENCES 2020; 2. [DOI: 10.24018/ejmed.2020.2.2.227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
All traumas—cranial, cardiovascular, hormone, viral, bacterial, fungi, parasites, misfolded protein, genetic, behavior, environmental and medication—affect the brain. This paper itemizes studies showing the many different causes of dementia including Alzheimer’s disease. Causes interact with each other, act sequentially by preparing the optimal conditions for its successor, initiate other diseases, allow for other traumas to accumulate and degrade protective features of the brain. Since such age-related cognitive impairment is not exclusively a human attribute there might be support for an evolutionary theory of dementia. Relying on theories of antagonistic pleiotropy and polymorphism, the brain has been designed to sequester trauma. Because of increased longevity, the short-term tactic of sequestering trauma becomes a long-term liability. We are engineered to sequester these insults until a tipping point is reached. Dementia is an evolutionary trade-off for longevity. We cannot cure dementia without understanding the overall biology of aging.
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Kiernan MC, Ziemann U, Eisen A. Amyotrophic lateral sclerosis: Origins traced to impaired balance between neural excitation and inhibition in the neonatal period. Muscle Nerve 2019; 60:232-235. [PMID: 31233613 DOI: 10.1002/mus.26617] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 06/17/2019] [Accepted: 06/18/2019] [Indexed: 12/14/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is an adult onset disease but with an increasingly recognized preclinical prodrome. A wide spectrum of investigative approaches has identified loss of inhibitory function at the heart of ALS. In developing an explanation for the onset of ALS, it remains a consideration that ALS has its origins in neonatal derangement of the γ-aminobutyric acid (GABA)-ergic system, with delayed conversion from excitatory to mature inhibitory GABA and impaired excitation/inhibition balance. If this is so, the resulting chronic excitotoxicity could marginalize cortical network functioning very early in life, laying the path for neurodegeneration. The possibility that adult-onset neurodegenerative conditions might have their roots in early developmental derangements is worthy of consideration, particularly in relation to current models of disease pathogenesis. Unraveling the very early molecular events will be crucial in developing a better understanding of ALS and other adult neurodegenerative disorders. Muscle Nerve, 2019.
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Affiliation(s)
- Matthew C Kiernan
- The University of Sydney School of Medicine Brain and Mind Centre, Building F, Level 4, 94 Mallett Street, Camperdown, New South Wales, 2050, Australia
- Department of Neurology, Royal Prince Alfred Hospital, Sydney, Australia
| | - Ulf Ziemann
- Department of Neurology & Stroke, and Hertie-Institute for clinical brain research, University of Tübingen, Tübingen, Germany
| | - Andrew Eisen
- Division of Neurology (Emeritus), Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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Fox M, Knorr DA, Haptonstall KM. Alzheimer's disease and symbiotic microbiota: an evolutionary medicine perspective. Ann N Y Acad Sci 2019; 1449:3-24. [PMID: 31180143 DOI: 10.1111/nyas.14129] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/19/2019] [Accepted: 05/03/2019] [Indexed: 12/15/2022]
Abstract
Microorganisms resident in our bodies participate in a variety of regulatory and pathogenic processes. Here, we describe how etiological pathways implicated in Alzheimer's disease (AD) may be regulated or disturbed by symbiotic microbial activity. Furthermore, the composition of symbiotic microbes has changed dramatically across human history alongside the rise of agriculturalism, industrialization, and globalization. We postulate that each of these lifestyle transitions engendered progressive depletion of microbial diversity and enhancement of virulence, thereby enhancing AD risk pathways. It is likely that the human life span extended into the eighth decade tens of thousands of years ago, yet little is known about premodern geriatric epidemiology. We propose that microbiota of the gut, oral cavity, nasal cavity, and brain may modulate AD pathogenesis, and that changes in the microbial composition of these body regions across history suggest escalation of AD risk. Dysbiosis may promote immunoregulatory dysfunction due to inadequate education of the immune system, chronic inflammation, and epithelial barrier permeability. Subsequently, proinflammatory agents-and occasionally microbes-may infiltrate the brain and promote AD pathogenic processes. APOE genotypes appear to moderate the effect of dysbiosis on AD risk. Elucidating the effect of symbiotic microbiota on AD pathogenesis could contribute to basic and translational research.
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Affiliation(s)
- Molly Fox
- Department of Anthropology, University of California Los Angeles, Los Angeles, California.,Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California
| | - Delaney A Knorr
- Department of Anthropology, University of California Los Angeles, Los Angeles, California
| | - Kacey M Haptonstall
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California
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Fox M. 'Evolutionary medicine' perspectives on Alzheimer's Disease: Review and new directions. Ageing Res Rev 2018; 47:140-148. [PMID: 30059789 PMCID: PMC6195455 DOI: 10.1016/j.arr.2018.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/24/2018] [Accepted: 07/24/2018] [Indexed: 10/28/2022]
Abstract
Evolution by natural selection eliminates maladaptive traits from a species, and yet Alzheimer's Disease (AD) persists with rapidly increasing prevalence globally. This apparent paradox begs an explanation within the framework of evolutionary sciences. Here, I summarize and critique previously proposed theories to explain human susceptibility to AD, grouped into 8 distinct hypotheses based on the concepts of novel extension of the lifespan; lack of selective pressure during the post-reproductive phase; antagonistic pleiotropy; rapid brain evolution; delayed neuropathy by selection for grandmothering; novel alleles selected to delay neuropathy; by-product of selection against cardiovascular disease; and thrifty genotype. Subsequently, I describe a new hypothesis inspired by the concept of mismatched environments. Many of the factors that enhance AD risk today may have been absent or functioned differently before the modern era, potentially making AD a less common affliction for age-matched individuals before industrialization and for the majority of human history. Future research is needed to further explore whether changes in environments and lifestyles across human history moderate risk factors and susceptibility to AD.
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Affiliation(s)
- Molly Fox
- Department of Psychiatry & Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA; Department of Anthropology, University of California Los Angeles, Los Angeles, CA, 90095, USA.
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8
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Huang A, Zhang L, Li W, Ma Z, Shuo S, Yao T. Controlled fluorescence quenching by antibody-conjugated graphene oxide to measure tau protein. ROYAL SOCIETY OPEN SCIENCE 2018; 5:171808. [PMID: 29765647 PMCID: PMC5936912 DOI: 10.1098/rsos.171808] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 03/09/2018] [Indexed: 05/31/2023]
Abstract
We report an ultrasensitive immunoassay for tau protein-a key marker of Alzheimer's disease. This sensing platform relies on graphene oxide (GO) surfaces conjugated with anti-human tau antibody to provide quantitative binding sites for the tau protein. The GO quenches standard fluorescein isothiocyanate labelled tau (tau-FITC) when tau protein and tau-FITC are both present and compete for the binding sites. This change in fluorescence signal can be used to quantitate tau protein. In contrast with traditional enzyme-linked immunosorbent assay (ELISA), our method does not require enzyme-linked secondary antibodies for protein recognition nor does it require an enzyme substrate for optical signal generation. This requires fewer reagents and has less systematic error than the antigen-antibody recognition steps in ELISA. Our method has a tau protein detection limit of 0.14 pmol ml-1 in buffer. This approach could be developed into a promising biosensor for the detection of tau protein and may be useful in the clinical diagnosis of tau-induced neurodegeneration syndromes.
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Affiliation(s)
- Ao Huang
- Authors for correspondence: Ao Huang e-mail:
| | | | | | | | - Shi Shuo
- Authors for correspondence: Shi Shuo e-mail:
| | - Tianming Yao
- Authors for correspondence: Tianming Yao e-mail:
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9
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Gulisano W, Maugeri D, Baltrons MA, Fà M, Amato A, Palmeri A, D’Adamio L, Grassi C, Devanand D, Honig LS, Puzzo D, Arancio O. Role of Amyloid-β and Tau Proteins in Alzheimer's Disease: Confuting the Amyloid Cascade. J Alzheimers Dis 2018; 64:S611-S631. [PMID: 29865055 PMCID: PMC8371153 DOI: 10.3233/jad-179935] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The "Amyloid Cascade Hypothesis" has dominated the Alzheimer's disease (AD) field in the last 25 years. It posits that the increase of amyloid-β (Aβ) is the key event in AD that triggers tau pathology followed by neuronal death and eventually, the disease. However, therapeutic approaches aimed at decreasing Aβ levels have so far failed, and tau-based clinical trials have not yet produced positive findings. This begs the question of whether the hypothesis is correct. Here we have examined literature on the role of Aβ and tau in synaptic dysfunction, memory loss, and seeding and spreading of AD, highlighting important parallelisms between the two proteins in all of these phenomena. We discuss novel findings showing binding of both Aβ and tau oligomers to amyloid-β protein precursor (AβPP), and the requirement for the presence of this protein for both Aβ and tau to enter neurons and induce abnormal synaptic function and memory. Most importantly, we propose a novel view of AD pathogenesis in which extracellular oligomers of Aβ and tau act in parallel and upstream of AβPP. Such a view will call for a reconsideration of therapeutic approaches directed against Aβ and tau, paving the way to an increased interest toward AβPP, both for understanding the pathogenesis of the disease and elaborating new therapeutic strategies.
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Affiliation(s)
- Walter Gulisano
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, Catania, Italy
| | - Daniele Maugeri
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, Catania, Italy
| | - Marian A. Baltrons
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
- Department of Biochemistry and Molecular Biology and Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Mauro Fà
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Arianna Amato
- Department of Anaesthesiology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Agostino Palmeri
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, Catania, Italy
| | - Luciano D’Adamio
- Department of Pharmacology, Physiology and Neuroscience, Rutgers University, Newark, NJ, USA
| | - Claudio Grassi
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - D.P. Devanand
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Lawrence S. Honig
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Daniela Puzzo
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, Catania, Italy
| | - Ottavio Arancio
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
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Cooper EL, Ma MJ. Alzheimer Disease: Clues from traditional and complementary medicine. J Tradit Complement Med 2017; 7:380-385. [PMID: 29034183 PMCID: PMC5634730 DOI: 10.1016/j.jtcme.2016.12.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 12/06/2016] [Accepted: 12/08/2016] [Indexed: 02/07/2023] Open
Abstract
Despite modern medicine's incredible innovation and resulting accumulation of valuable knowledge, many of the world's most problematic diseases such as Alzheimer Disease (AD) still lack effective cures and treatments. Western medicine has revealed many genetic, cellular, and molecular processes that characterize AD such as protein aggregation and inflammation. As the need for novel and effective treatments increases, researchers have turned towards traditional medicine as a resource. Modern, evidence based research examining traditional and complementary remedies for AD has generated promising results within the last decade. Animal based products inhibiting cellular toxicity, anti-inflammatory nutraceuticals such as omega-3 fatty acids, and plant based compounds derived from herbal medicine demonstrate viability as neuroprotective treatments and possible application in developing pharmaceuticals. Analysis of antioxidant, anti-inflammatory, and neuroprotective phytochemicals used in various traditional medicines around the world reveal potential to ameliorate and prevent the devastating neurodegeneration observed in AD.
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Affiliation(s)
- Edwin L. Cooper
- Laboratory of Comparative Immunology, Department of Neurobiology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095-1763, USA
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Garcia-Ruiz PJ, Espay AJ. Parkinson Disease: An Evolutionary Perspective. Front Neurol 2017; 8:157. [PMID: 28507529 PMCID: PMC5410593 DOI: 10.3389/fneur.2017.00157] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 04/03/2017] [Indexed: 01/09/2023] Open
Abstract
There are two central premises to this evolutionary view of Parkinson disease (PD). First, PD is a specific human disease. Second, the prevalence of PD has increased over the course of human history. Several lines of evidence may explain why PD appears to be restricted to the human species. The major manifestations of PD are the consequence of degeneration in the dopamine-synthesizing neurons of the mesostriatal neuronal pathway. It is of note the enormous expansion of the human dopamine mesencephalic neurons onto the striatum compared with other mammals. Hence, an evolutionary bottle neck was reached with the expansion of the massive nigrostriatal axonal arborization. This peculiar nigral overload may partly explain the selective fragility of the human dopaminergic mesencephalic neurotransmission and the unique presence of PD in humans. On the other hand, several facts may explain the increasing prevalence of PD over the centuries. The apparently low prevalence of PD before the twentieth century may be related to the shorter life expectancy and survival compared to present times. In addition, changes in lifestyle over the course of human history might also account for the increasing burden of PD. Our hunter-gatherers ancestors invested large energy expenditure on a daily basis, a prototypical physical way of life for which our genome remains adapted. Technological advances have led to a dramatic reduction of physical exercise. Since the brain release of neurotrophic factors (including brain-derived neurotrophic factor) is partially exercise related, the marked reduction in exercise may contribute to the increasing prevalence of PD.
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Affiliation(s)
| | - Alberto J Espay
- James J. and Joan A. Gardner Family Center for Parkinson's Disease and Movement Disorders, University of Cincinnati, Cincinnati, OH, USA
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Nesse RM, Finch CE, Nunn CL. Does selection for short sleep duration explain human vulnerability to Alzheimer's disease? Evol Med Public Health 2017; 2017:39-46. [PMID: 28096295 PMCID: PMC5381352 DOI: 10.1093/emph/eow035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/15/2016] [Accepted: 12/29/2016] [Indexed: 01/17/2023] Open
Abstract
Compared with other primates, humans sleep less and have a much higher prevalence of Alzheimer 's disease (AD) pathology. This article reviews evidence relevant to the hypothesis that natural selection for shorter sleep time in humans has compromised the efficacy of physiological mechanisms that protect against AD during sleep. In particular, the glymphatic system drains interstitial fluid from the brain, removing extra-cellular amyloid beta (eAβ) twice as fast during sleep. In addition, melatonin - a peptide hormone that increases markedly during sleep - is an effective antioxidant that inhibits the polymerization of soluble eAβ into insoluble amyloid fibrils that are associated with AD. Sleep deprivation increases plaque formation and AD, which itself disrupts sleep, potentially creating a positive feedback cycle. These and other physiological benefits of sleep may be compromised by short sleep durations. Our hypothesis highlights possible long-term side effects of medications that reduce sleep, and may lead to potential new strategies for preventing and treating AD.
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Affiliation(s)
| | - Caleb E Finch
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
| | - Charles L Nunn
- Department of Evolutionary Anthropology and Duke Global Health Institute, Duke University, Durham, NC 27708
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13
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Campbell CE, Strassmann BI. The blemishes of modern society? Acne prevalence in the Dogon of Mali. Evol Med Public Health 2016; 2016:325-337. [PMID: 27651516 PMCID: PMC5046992 DOI: 10.1093/emph/eow027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Non-communicable diseases may reflect an evolutionary mismatch between our human ancestry and modern environments. To explore the mismatch hypothesis for Acne vulgaris, we studied the prevalence and severity of acne in Dogon adolescents in Mali, West Africa. METHODOLOGY We graded the prevalence and severity of acne in 1182 Dogon adolescents aged 11-18 years from nine villages using facial photos taken as part of a prospective cohort study. Eighty-nine (89%) of the individuals in the cohort migrated to the city during adolescence, enabling us to assess the effect of urban migration. Using multivariable logistic regression, we estimated the effect of predictor variables on the presence of acne. RESULTS The prevalence of acne in the cohort was 28%, with 90% of cases being mild or very mild. Thus, the prevalence and severity of acne was much lower than for adolescents in high-income countries. Controlling for age, puberty, and body mass index (BMI), the odds of boys developing acne was 85% lower in the city than in the villages (P = 0.002). CONCLUSION AND IMPLICATIONS Acne is similar to the 'diseases of civilization' in being promoted by the pro-inflammatory properties of modern diets. The low prevalence and severity of acne in the Dogon supports the mismatch hypothesis and suggests that acne should join the list of diseases of modern lifestyles. However, we also observed an unexpected decrease in acne in urban boys. Future research is needed for a deeper mechanistic understanding of the interplay between diet, inflammation, immune function and other environmental exposures that differ between urban and rural environments.
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Affiliation(s)
- Christine E Campbell
- Department of Anthropology & Institute for Social Research, University of Michigan, Ann Arbor, MI, USA
| | - Beverly I Strassmann
- Department of Anthropology & Institute for Social Research, University of Michigan, Ann Arbor, MI, USA
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Ashford JW. Treatment of Alzheimer's Disease: The Legacy of the Cholinergic Hypothesis, Neuroplasticity, and Future Directions. J Alzheimers Dis 2016; 47:149-56. [PMID: 26402763 DOI: 10.3233/jad-150381] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In this issue, an article by Waring et al. provides a meta-analysis of the effects of apo-lipo-protein E (APOE) genotype on the beneficial effect of acetyl-cholinesterase inhibitors (AChEIs) in patients with Alzheimer's disease (AD). There was no significant effect found. As of 2015, AChEI medications are the mainstay of AD treatment, and APOE genotype is the most significant factor associated with AD causation. This lack of a significant effect of APOE is analyzed with respect to the "Cholinergic Hypothesis" of AD, dating from 1976, through the recognition that cholinergic neurons are not the sole target of AD, but rather that AD attacks all levels of neuroplasticity in the brain, an idea originated by Ashford and Jarvik in 1985 and which still provides the clearest explanation for AD dementia. The "Amyloid Hypothesis" is dissected back to the alpha/beta pathway switching mechanism affecting the nexin-amyloid pre-protein (NAPP switch). The NAPP switch may be the critical neuroplasticity component of all learning involving synapse remodeling and subserve all learning mechanisms. The gamma-secretase cleavage is discussed, and its normal complementary products, beta-amyloid and the NAPP intracellular domain (NAICD), appear to be involved in natural synapse removal, but the link to AD dementia may involve the NAICD rather than beta-amyloid. Understanding neuroplasticity and the critical pathways to AD dementia are needed to determine therapies and preventive strategies for AD. In particular, the effect of APOE on AD predisposition needs to be established and a means found to adjust its effect to prevent AD.
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Baker S, Götz J. What we can learn from animal models about cerebral multi-morbidity. ALZHEIMERS RESEARCH & THERAPY 2015; 7:11. [PMID: 25810783 PMCID: PMC4373088 DOI: 10.1186/s13195-015-0097-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Late-onset diseases such as Alzheimer's disease, Parkinson's disease, or frontotemporal lobar degeneration are considered to be protein-folding disorders, with the accumulation of protein deposits causing a gain-of-toxic function. Alzheimer's disease is characterized by two histological hallmark lesions: amyloid-β-containing plaques and tau-containing neurofibrillary tangles. However, signature proteins, including α-synuclein, which are found in an aggregated fibrillar form in the Lewy bodies of Parkinson's disease brains, are also frequently found in Alzheimer's disease. This highlights the fact that, although specific aggregates form the basis for diagnosis, there is a high prevalence of clinical overlap between neuropathological lesions linked to different diseases, a finding known as cerebral co- or multi-morbidity. Furthermore, the proteins forming these lesions interact, and this interaction accelerates an ongoing degenerative process. Here, we review the contribution that transgenic animal models have made to a better mechanistic understanding of the causes and consequences of co- or multi-morbidity. We discuss selected vertebrate and invertebrate models as well as the insight gained from non-transgenic senescence-accelerated mouse-prone mice. This article is part of a series on 'Cerebral multi-morbidity of the aging brain'.
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Affiliation(s)
- Siân Baker
- Clem Jones Centre for Aging Dementia Research, Queensland Brain Institute, The University of Queensland, Upland Road, Building 79, St Lucia Campus, Brisbane, QLD 4072 Australia
| | - Jürgen Götz
- Clem Jones Centre for Aging Dementia Research, Queensland Brain Institute, The University of Queensland, Upland Road, Building 79, St Lucia Campus, Brisbane, QLD 4072 Australia
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Fjell AM, McEvoy L, Holland D, Dale AM, Walhovd KB. What is normal in normal aging? Effects of aging, amyloid and Alzheimer's disease on the cerebral cortex and the hippocampus. Prog Neurobiol 2014; 117:20-40. [PMID: 24548606 DOI: 10.1016/pneurobio.2014.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 12/19/2013] [Accepted: 02/05/2014] [Indexed: 05/28/2023]
Abstract
What can be expected in normal aging, and where does normal aging stop and pathological neurodegeneration begin? With the slow progression of age-related dementias such as Alzheimer's disease (AD), it is difficult to distinguish age-related changes from effects of undetected disease. We review recent research on changes of the cerebral cortex and the hippocampus in aging and the borders between normal aging and AD. We argue that prominent cortical reductions are evident in fronto-temporal regions in elderly even with low probability of AD, including regions overlapping the default mode network. Importantly, these regions show high levels of amyloid deposition in AD, and are both structurally and functionally vulnerable early in the disease. This normalcy-pathology homology is critical to understand, since aging itself is the major risk factor for sporadic AD. Thus, rather than necessarily reflecting early signs of disease, these changes may be part of normal aging, and may inform on why the aging brain is so much more susceptible to AD than is the younger brain. We suggest that regions characterized by a high degree of life-long plasticity are vulnerable to detrimental effects of normal aging, and that this age-vulnerability renders them more susceptible to additional, pathological AD-related changes. We conclude that it will be difficult to understand AD without understanding why it preferably affects older brains, and that we need a model that accounts for age-related changes in AD-vulnerable regions independently of AD-pathology.
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Affiliation(s)
- Anders M Fjell
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway.
| | - Linda McEvoy
- Multimodal Imaging Laboratory, University of California, San Diego, CA, USA
| | - Dominic Holland
- Multimodal Imaging Laboratory, University of California, San Diego, CA, USA; Department of Neurosciences, University of California, San Diego, CA, USA
| | - Anders M Dale
- Multimodal Imaging Laboratory, University of California, San Diego, CA, USA; Department of Radiology, University of California, San Diego, CA, USA; Department of Neurosciences, University of California, San Diego, CA, USA
| | - Kristine B Walhovd
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway
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Fjell AM, McEvoy L, Holland D, Dale AM, Walhovd KB. What is normal in normal aging? Effects of aging, amyloid and Alzheimer's disease on the cerebral cortex and the hippocampus. Prog Neurobiol 2014; 117:20-40. [PMID: 24548606 DOI: 10.1016/j.pneurobio.2014.02.004] [Citation(s) in RCA: 503] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 12/19/2013] [Accepted: 02/05/2014] [Indexed: 01/18/2023]
Abstract
What can be expected in normal aging, and where does normal aging stop and pathological neurodegeneration begin? With the slow progression of age-related dementias such as Alzheimer's disease (AD), it is difficult to distinguish age-related changes from effects of undetected disease. We review recent research on changes of the cerebral cortex and the hippocampus in aging and the borders between normal aging and AD. We argue that prominent cortical reductions are evident in fronto-temporal regions in elderly even with low probability of AD, including regions overlapping the default mode network. Importantly, these regions show high levels of amyloid deposition in AD, and are both structurally and functionally vulnerable early in the disease. This normalcy-pathology homology is critical to understand, since aging itself is the major risk factor for sporadic AD. Thus, rather than necessarily reflecting early signs of disease, these changes may be part of normal aging, and may inform on why the aging brain is so much more susceptible to AD than is the younger brain. We suggest that regions characterized by a high degree of life-long plasticity are vulnerable to detrimental effects of normal aging, and that this age-vulnerability renders them more susceptible to additional, pathological AD-related changes. We conclude that it will be difficult to understand AD without understanding why it preferably affects older brains, and that we need a model that accounts for age-related changes in AD-vulnerable regions independently of AD-pathology.
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Affiliation(s)
- Anders M Fjell
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway.
| | - Linda McEvoy
- Multimodal Imaging Laboratory, University of California, San Diego, CA, USA
| | - Dominic Holland
- Multimodal Imaging Laboratory, University of California, San Diego, CA, USA; Department of Neurosciences, University of California, San Diego, CA, USA
| | - Anders M Dale
- Multimodal Imaging Laboratory, University of California, San Diego, CA, USA; Department of Radiology, University of California, San Diego, CA, USA; Department of Neurosciences, University of California, San Diego, CA, USA
| | - Kristine B Walhovd
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway
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18
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LeBlanc AC. Caspase-6 as a novel early target in the treatment of Alzheimer's disease. Eur J Neurosci 2013; 37:2005-18. [DOI: 10.1111/ejn.12250] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 04/01/2013] [Accepted: 04/06/2013] [Indexed: 12/16/2022]
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