1
|
Chang J, Li Y, Shan X, Chen X, Yan X, Liu J, Zhao L. Neural stem cells promote neuroplasticity: a promising therapeutic strategy for the treatment of Alzheimer's disease. Neural Regen Res 2024; 19:619-628. [PMID: 37721293 PMCID: PMC10581561 DOI: 10.4103/1673-5374.380874] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 04/04/2023] [Accepted: 06/10/2023] [Indexed: 09/19/2023] Open
Abstract
Recent studies have demonstrated that neuroplasticity, such as synaptic plasticity and neurogenesis, exists throughout the normal lifespan but declines with age and is significantly impaired in individuals with Alzheimer's disease. Hence, promoting neuroplasticity may represent an effective strategy with which Alzheimer's disease can be alleviated. Due to their significant ability to self-renew, differentiate, and migrate, neural stem cells play an essential role in reversing synaptic and neuronal damage, reducing the pathology of Alzheimer's disease, including amyloid-β, tau protein, and neuroinflammation, and secreting neurotrophic factors and growth factors that are related to plasticity. These events can promote synaptic plasticity and neurogenesis to repair the microenvironment of the mammalian brain. Consequently, neural stem cells are considered to represent a potential regenerative therapy with which to improve Alzheimer's disease and other neurodegenerative diseases. In this review, we discuss how neural stem cells regulate neuroplasticity and optimize their effects to enhance their potential for treating Alzheimer's disease in the clinic.
Collapse
Affiliation(s)
- Jun Chang
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| | - Yujiao Li
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| | - Xiaoqian Shan
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| | - Xi Chen
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| | - Xuhe Yan
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| | - Jianwei Liu
- Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Lan Zhao
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| |
Collapse
|
2
|
Dias-Carvalho A, Sá SI, Carvalho F, Fernandes E, Costa VM. Inflammation as common link to progressive neurological diseases. Arch Toxicol 2024; 98:95-119. [PMID: 37964100 PMCID: PMC10761431 DOI: 10.1007/s00204-023-03628-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 10/12/2023] [Indexed: 11/16/2023]
Abstract
Life expectancy has increased immensely over the past decades, bringing new challenges to the health systems as advanced age increases the predisposition for many diseases. One of those is the burden of neurologic disorders. While many hypotheses have been placed to explain aging mechanisms, it has been widely accepted that the increasing pro-inflammatory status with advanced age or "inflammaging" is a main determinant of biological aging. Furthermore, inflammaging is at the cornerstone of many age-related diseases and its involvement in neurologic disorders is an exciting hypothesis. Indeed, aging and neurologic disorders development in the elderly seem to share some basic pathways that fundamentally converge on inflammation. Peripheral inflammation significantly influences brain function and contributes to the development of neurological disorders, including Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Understanding the role of inflammation in the pathogenesis of progressive neurological diseases is of crucial importance for developing effective treatments and interventions that can slow down or prevent disease progression, therefore, decreasing its social and economic burden.
Collapse
Affiliation(s)
- Ana Dias-Carvalho
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal.
- UCIBIO- Applied Molecular Biosciences Unit, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal.
| | - Susana Isabel Sá
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine, University of Porto, Porto, Portugal
- CINTESIS@RISE, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Félix Carvalho
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
- UCIBIO- Applied Molecular Biosciences Unit, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Eduarda Fernandes
- LAQV, REQUIMTE, Laboratory of Applied Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Vera Marisa Costa
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal.
- UCIBIO- Applied Molecular Biosciences Unit, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal.
| |
Collapse
|
3
|
Sha A, Liu Y, Qiu X, Xiong B. Polysaccharide from Paris polyphylla improves learning and memory ability in D-galactose-induced aging model mice based on antioxidation, p19/p53/p21, and Wnt/β-catenin signaling pathways. Int J Biol Macromol 2023; 251:126311. [PMID: 37579895 DOI: 10.1016/j.ijbiomac.2023.126311] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 07/30/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
The current study aimed to investigate the effects and mechanisms of Paris polyphylla polysaccharide component 1 (PPPm-1) to improve learning and memory in D-galactose-induced aging model mice. We determined the effects of PPPm-1 on the brain, organ index, and behavior in the aging model mice induced by D-galactose to study learning and memory improvement. UV-Vis spectrophotometry helped determine the PPPm-1 effect on antioxidant parameters associated with learning and memory in the brain and related organs of aging mice. Moreover, in the hippocampi of aging model mice, PPPm-1 effect on the mRNA and protein expressions of p19, p53, p21, P16, Rb, Wnt/1, β-catenin, CyclinD1, TCF-4, and GSK-3β were detected using the quantitative real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. The results indicated that PPPm-1 could increase the brain and organ indexes, the avoidance latency, the total distance and average speed in the water maze, and the SOD and GSH-PX activities in the brain, liver tissues, and plasma. Moreover, the mRNA and protein expressions of Wnt/1, β-catenin, CyclinD1, and TCF-4 were also elevated in the hippocampi of aging model mice. However, the error times in step-through tests, the MDA content in the brain and liver tissues, the AChE activity in the brain tissue, the protein expressions of P16, Rb in the hippocampi, and the mRNA and protein expressions of p19, p53, p21, and GSK-3β in the hippocampi of aging model mice were significantly decreased. Thus, PPPm-1 significantly enhanced the learning and memory impairment induced by D-galactose in mice. The action mechanisms were associated with anti-oxidative stress, cholinergic nervous system function regulation, LTP enhancement in long-term memory, down-regulated expression of p19/p53/p21 signaling pathway factors, and Wnt/β-catenin signaling pathway activation.
Collapse
Affiliation(s)
- Ailong Sha
- School of Teacher Education, Chongqing Three Gorges University, Chongqing 404120, China; School of biology and food engineering, Chongqing Three Gorges University, Chongqing, 404120, China.
| | - Yi Liu
- School of biology and food engineering, Chongqing Three Gorges University, Chongqing, 404120, China
| | - Xinyu Qiu
- School of biology and food engineering, Chongqing Three Gorges University, Chongqing, 404120, China
| | - Binbing Xiong
- School of biology and food engineering, Chongqing Three Gorges University, Chongqing, 404120, China
| |
Collapse
|
4
|
Anglada-Huguet M, Endepols H, Sydow A, Hilgers R, Neumaier B, Drzezga A, Kaniyappan S, Mandelkow E, Mandelkow EM. Reversal of Tau-Dependent Cognitive Decay by Blocking Adenosine A1 Receptors: Comparison of Transgenic Mouse Models with Different Levels of Tauopathy. Int J Mol Sci 2023; 24:ijms24119260. [PMID: 37298211 DOI: 10.3390/ijms24119260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023] Open
Abstract
The accumulation of tau is a hallmark of several neurodegenerative diseases and is associated with neuronal hypoactivity and presynaptic dysfunction. Oral administration of the adenosine A1 receptor antagonist rolofylline (KW-3902) has previously been shown to reverse spatial memory deficits and to normalize the basic synaptic transmission in a mouse line expressing full-length pro-aggregant tau (TauΔK) at low levels, with late onset of disease. However, the efficacy of treatment remained to be explored for cases of more aggressive tauopathy. Using a combination of behavioral assays, imaging with several PET-tracers, and analysis of brain tissue, we compared the curative reversal of tau pathology by blocking adenosine A1 receptors in three mouse models expressing different types and levels of tau and tau mutants. We show through positron emission tomography using the tracer [18F]CPFPX (a selective A1 receptor ligand) that intravenous injection of rolofylline effectively blocks A1 receptors in the brain. Moreover, when administered to TauΔK mice, rolofylline can reverse tau pathology and synaptic decay. The beneficial effects are also observed in a line with more aggressive tau pathology, expressing the amyloidogenic repeat domain of tau (TauRDΔK) with higher aggregation propensity. Both models develop a progressive tau pathology with missorting, phosphorylation, accumulation of tau, loss of synapses, and cognitive decline. TauRDΔK causes pronounced neurofibrillary tangle assembly concomitant with neuronal death, whereas TauΔK accumulates only to tau pretangles without overt neuronal loss. A third model tested, the rTg4510 line, has a high expression of mutant TauP301L and hence a very aggressive phenotype starting at ~3 months of age. This line failed to reverse pathology upon rolofylline treatment, consistent with a higher accumulation of tau-specific PET tracers and inflammation. In conclusion, blocking adenosine A1 receptors by rolofylline can reverse pathology if the pathological potential of tau remains below a threshold value that depends on concentration and aggregation propensity.
Collapse
Affiliation(s)
- Marta Anglada-Huguet
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
| | - Heike Endepols
- Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Straße, 52428 Jülich, Germany
| | - Astrid Sydow
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
| | - Ronja Hilgers
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
| | - Bernd Neumaier
- Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Straße, 52428 Jülich, Germany
- Max Planck Institute for Metabolism Research, 50931 Cologne, Germany
| | - Alexander Drzezga
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Molecular Organization of the Brain (INM-2), Wilhelm-Johnen-Straße, 52428 Jülich, Germany
| | - Senthilvelrajan Kaniyappan
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- MPI Neurobiology Behavior-caesar, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
- Department of Neurodegenerative Diseases and Geriatric Psychiatry, University of Bonn, 53127 Bonn, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- MPI Neurobiology Behavior-caesar, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
- Department of Neurodegenerative Diseases and Geriatric Psychiatry, University of Bonn, 53127 Bonn, Germany
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- MPI Neurobiology Behavior-caesar, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| |
Collapse
|
5
|
Shixing X, Xueyan H, Yuan R, Wei T, Wei W. Enriched environment can reverse chronic sleep deprivation-induced damage to cellular plasticity in the dentate gyrus of the hippocampus. Transl Neurosci 2023; 14:20220280. [PMID: 36969794 PMCID: PMC10031502 DOI: 10.1515/tnsci-2022-0280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/15/2023] [Accepted: 02/24/2023] [Indexed: 03/24/2023] Open
Abstract
Objective We studied whether enriched environment (EE), a classic epigenetics paradigm, can prevent cellular plasticity damage caused by chronic sleep deprivation (SD). Methods We performed SD in mice by a modified multi-platform method (MMPM). Mice in the SD group were deprived of sleep for 18 h a day. In addition, half of the mice in the chronic SD group were exposed to EE stimuli for 6 h per day. Immunostaining analyzed neurogenesis and neural progenitor cell-differentiated phenotypes in the hippocampal dentate gyrus (DG) region. Result At 13 weeks, compared with the control group, SD severely impaired the proliferation and differentiation of neural stem cells, and EE completely reversed the process. SD can induce gliosis in the mouse hippocampus, and EE can delay the process. Conclusion: Our results suggest that chronic SD may damage the neurogenesis in the DG of the hippocampus. However, enrichment stimulation can reverse the processing by promoting neuronal repair related to neuronal plasticity.
Collapse
Affiliation(s)
- Xue Shixing
- Department of Neurology, Affiliated Xinhua Hospital of Dalian University, Dalian, Liaoning Province, China
| | - Hou Xueyan
- Department of Medical Imaging, Affiliated Xinhua Hospital of Dalian University, Dalian, Liaoning Province, China
| | - Ren Yuan
- Department of Neurology, Affiliated Xinhua Hospital of Dalian University, Dalian, Liaoning Province, China
| | - Tang Wei
- Department of Neurology, Affiliated Xinhua Hospital of Dalian University, Dalian, Liaoning Province, China
| | - Wang Wei
- Department of Rehabilitation Medicine, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning Province, China
| |
Collapse
|
6
|
Squarcio F, Hitrec T, Piscitiello E, Cerri M, Giovannini C, Martelli D, Occhinegro A, Taddei L, Tupone D, Amici R, Luppi M. Synthetic torpor triggers a regulated mechanism in the rat brain, favoring the reversibility of Tau protein hyperphosphorylation. Front Physiol 2023; 14:1129278. [PMID: 36969585 PMCID: PMC10034179 DOI: 10.3389/fphys.2023.1129278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/28/2023] [Indexed: 03/11/2023] Open
Abstract
Introduction: Hyperphosphorylated Tau protein (PPTau) is the hallmark of tauopathic neurodegeneration. During "synthetic torpor" (ST), a transient hypothermic state which can be induced in rats by the local pharmacological inhibition of the Raphe Pallidus, a reversible brain Tau hyperphosphorylation occurs. The aim of the present study was to elucidate the - as yet unknown - molecular mechanisms underlying this process, at both a cellular and systemic level. Methods: Different phosphorylated forms of Tau and the main cellular factors involved in Tau phospho-regulation were assessed by western blot in the parietal cortex and hippocampus of rats induced in ST, at either the hypothermic nadir or after the recovery of euthermia. Pro- and anti-apoptotic markers, as well as different systemic factors which are involved in natural torpor, were also assessed. Finally, the degree of microglia activation was determined through morphometry. Results: Overall, the results show that ST triggers a regulated biochemical process which can dam PPTau formation and favor its reversibility starting, unexpectedly for a non-hibernator, from the hypothermic nadir. In particular, at the nadir, the glycogen synthase kinase-β was largely inhibited in both regions, the melatonin plasma levels were significantly increased and the antiapoptotic factor Akt was significantly activated in the hippocampus early after, while a transient neuroinflammation was observed during the recovery period. Discussion: Together, the present data suggest that ST can trigger a previously undescribed latent and regulated physiological process, that is able to cope with brain PPTau formation.
Collapse
Affiliation(s)
- Fabio Squarcio
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Timna Hitrec
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Emiliana Piscitiello
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
- Centre for Applied Biomedical Research—CRBA, St. Orsola Hospital, University of Bologna, Bologna, Italy
| | - Matteo Cerri
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Catia Giovannini
- Centre for Applied Biomedical Research—CRBA, St. Orsola Hospital, University of Bologna, Bologna, Italy
- Department of Experimental, Diagnostic and Specialty Medicines, University of Bologna, Bologna, Italy
| | - Davide Martelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Alessandra Occhinegro
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
- Centre for Applied Biomedical Research—CRBA, St. Orsola Hospital, University of Bologna, Bologna, Italy
| | - Ludovico Taddei
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Domenico Tupone
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, United States
| | - Roberto Amici
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Marco Luppi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
- Centre for Applied Biomedical Research—CRBA, St. Orsola Hospital, University of Bologna, Bologna, Italy
| |
Collapse
|
7
|
Lehmann DJ, Elshorbagy A, Hurley MJ. Many Paths to Alzheimer's Disease: A Unifying Hypothesis Integrating Biological, Chemical, and Physical Risk Factors. J Alzheimers Dis 2023; 95:1371-1382. [PMID: 37694367 DOI: 10.3233/jad-230295] [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: 09/12/2023]
Abstract
Sporadic Alzheimer's disease (AD) is a complex, multifactorial disease. We should therefore expect to find many factors involved in its causation. The known neuropathology seen at autopsy in patients dying with AD is not consistently seen in all patients with AD and is sometimes seen in patients without dementia. This suggests that patients follow different paths to AD, with different people having slightly different combinations of predisposing physical, chemical and biologic risk factors, and varying neuropathology. This review summarizes what is known of the biologic and chemical predisposing factors and features in AD. We postulate that, underlying the neuropathology of AD is a progressive failure of neurons, with advancing age or other morbidity, to rid themselves of entropy, i.e., the disordered state resulting from brain metabolism. Understanding the diverse causes of AD may allow the development of new therapies targeted at blocking the paths that lead to dementia in each subset of patients.
Collapse
Affiliation(s)
- Donald J Lehmann
- Oxford Project to Investigate Memory and Ageing (OPTIMA), Department of Pharmacology, University of Oxford, Oxford, UK
| | - Amany Elshorbagy
- Department of Pharmacology, University of Oxford, Oxford, UK
- Department of Physiology, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Michael J Hurley
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| |
Collapse
|
8
|
Culig L, Chu X, Bohr VA. Neurogenesis in aging and age-related neurodegenerative diseases. Ageing Res Rev 2022; 78:101636. [PMID: 35490966 PMCID: PMC9168971 DOI: 10.1016/j.arr.2022.101636] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 04/14/2022] [Accepted: 04/25/2022] [Indexed: 12/11/2022]
Abstract
Adult neurogenesis, the process by which neurons are generated in certain areas of the adult brain, declines in an age-dependent manner and is one potential target for extending cognitive healthspan. Aging is a major risk factor for neurodegenerative diseases and, as lifespans are increasing, these health challenges are becoming more prevalent. An age-associated loss in neural stem cell number and/or activity could cause this decline in brain function, so interventions that reverse aging in stem cells might increase the human cognitive healthspan. In this review, we describe the involvement of adult neurogenesis in neurodegenerative diseases and address the molecular mechanistic aspects of neurogenesis that involve some of the key aggregation-prone proteins in the brain (i.e., tau, Aβ, α-synuclein, …). We summarize the research pertaining to interventions that increase neurogenesis and regulate known targets in aging research, such as mTOR and sirtuins. Lastly, we share our outlook on restoring the levels of neurogenesis to physiological levels in elderly individuals and those with neurodegeneration. We suggest that modulating neurogenesis represents a potential target for interventions that could help in the fight against neurodegeneration and cognitive decline.
Collapse
Affiliation(s)
- Luka Culig
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Xixia Chu
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Vilhelm A Bohr
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
| |
Collapse
|
9
|
Zheng J. Hippocampal neurogenesis and pro‐neurogenic therapies for Alzheimer's disease. Animal Model Exp Med 2022; 5:3-14. [PMID: 35229998 PMCID: PMC8879631 DOI: 10.1002/ame2.12212] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/24/2021] [Accepted: 01/18/2022] [Indexed: 01/01/2023] Open
Abstract
Adult hippocampal neurogenesis (AHN) facilitates hippocampal circuits plasticity and regulates hippocampus‐dependent cognition and emotion. However, AHN malfunction has been widely reported in both human and animal models of Alzheimer's disease (AD), the most common form of dementia in the elderly. Pro‐neurogenic therapies including rescuing innate AHN, cell engraftment and glia‐neuron reprogramming hold great potential for compensating the neuronal loss and rewiring the degenerated neuronal network in AD, but there are still great challenges to be overcome. This review covers recent advances in unraveling the involvement of AHN in AD and highlights the prospect of emerging pro‐neurogenic remedies.
Collapse
Affiliation(s)
- Jie Zheng
- Department of Pharmacology Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education Key Laboratory of Basic Pharmacology of Guizhou Province Zunyi Medical University Zunyi China
| |
Collapse
|
10
|
An Q, Sun C, Li R, Chen S, Gu X, An S, Wang Z. Calcitonin gene-related peptide regulates spinal microglial activation through the histone H3 lysine 27 trimethylation via enhancer of zeste homolog-2 in rats with neuropathic pain. J Neuroinflammation 2021; 18:117. [PMID: 34020664 PMCID: PMC8139106 DOI: 10.1186/s12974-021-02168-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 05/05/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Calcitonin gene-related peptide (CGRP) as a mediator of microglial activation at the transcriptional level may facilitate nociceptive signaling. Trimethylation of H3 lysine 27 (H3K27me3) by enhancer of zeste homolog 2 (EZH2) is an epigenetic mark that regulates inflammatory-related gene expression after peripheral nerve injury. In this study, we explored the relationship between CGRP and H3K27me3 in microglial activation after nerve injury, and elucidated the underlying mechanisms in the pathogenesis of chronic neuropathic pain. METHODS Microglial cells (BV2) were treated with CGRP and differentially enrichments of H3K27me3 on gene promoters were examined using ChIP-seq. A chronic constriction injury (CCI) rat model was used to evaluate the role of CGRP on microglial activation and EZH2/H3K27me3 signaling in CCI-induced neuropathic pain. RESULTS Overexpressions of EZH2 and H3K27me3 were confirmed in spinal microglia of CCI rats by immunofluorescence. CGRP treatment induced the increased of H3K27me3 expression in the spinal dorsal horn and cultured microglial cells (BV2) through EZH2. ChIP-seq data indicated that CGRP significantly altered H3K27me3 enrichments on gene promoters in microglia following CGRP treatment, including 173 gaining H3K27me3 and 75 losing this mark, which mostly enriched in regulation of cell growth, phagosome, and inflammation. qRT-PCR verified expressions of representative candidate genes (TRAF3IP2, BCL2L11, ITGAM, DAB2, NLRP12, WNT3, ADAM10) and real-time cell analysis (RTCA) verified microglial proliferation. Additionally, CGRP treatment and CCI increased expressions of ITGAM, ADAM10, MCP-1, and CX3CR1, key mediators of microglial activation in spinal dorsal horn and cultured microglial cells. Such increased effects induced by CCI were suppressed by CGRP antagonist and EZH2 inhibitor, which were concurrently associated with the attenuated mechanical and thermal hyperalgesia in CCI rats. CONCLUSION Our findings highly indicate that CGRP is implicated in the genesis of neuropathic pain through regulating microglial activation via EZH2-mediated H3K27me3 in the spinal dorsal horn.
Collapse
Affiliation(s)
- Qi An
- Department of Human Anatomy, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Chenyan Sun
- Department of Human Anatomy, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Ruidi Li
- Department of Human Anatomy, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Shuhui Chen
- Department of Human Anatomy, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Xinpei Gu
- Department of Human Anatomy, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Shuhong An
- Department of Human Anatomy, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China.
| | - Zhaojin Wang
- Department of Human Anatomy, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China.
| |
Collapse
|
11
|
Houben S, Homa M, Yilmaz Z, Leroy K, Brion JP, Ando K. Tau Pathology and Adult Hippocampal Neurogenesis: What Tau Mouse Models Tell us? Front Neurol 2021; 12:610330. [PMID: 33643196 PMCID: PMC7902892 DOI: 10.3389/fneur.2021.610330] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/06/2021] [Indexed: 12/18/2022] Open
Abstract
Adult hippocampal neurogenesis (AHN) has been widely confirmed in mammalian brains. A growing body of evidence points to the fact that AHN sustains hippocampal-dependent functions such as learning and memory. Impaired AHN has been reported in post-mortem human brain hippocampus of Alzheimer's disease (AD) and is considered to contribute to defects in learning and memory. Neurofibrillary tangles (NFTs) and amyloid plaques are the two key neuropathological hallmarks of AD. NFTs are composed of abnormal tau proteins accumulating in many brain areas during the progression of the disease, including in the hippocampus. The physiological role of tau and impact of tau pathology on AHN is still poorly understood. Modifications in AHN have also been reported in some tau transgenic and tau-deleted mouse models. We present here a brief review of advances in the relationship between development of tau pathology and AHN in AD and what insights have been gained from studies in tau mouse models.
Collapse
Affiliation(s)
- Sarah Houben
- Laboratory of Histology, Neuroanatomy and Neuropathology, UNI (ULB Neuroscience Institute), Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Mégane Homa
- Laboratory of Histology, Neuroanatomy and Neuropathology, UNI (ULB Neuroscience Institute), Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Zehra Yilmaz
- Laboratory of Histology, Neuroanatomy and Neuropathology, UNI (ULB Neuroscience Institute), Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Karelle Leroy
- Laboratory of Histology, Neuroanatomy and Neuropathology, UNI (ULB Neuroscience Institute), Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Jean-Pierre Brion
- Laboratory of Histology, Neuroanatomy and Neuropathology, UNI (ULB Neuroscience Institute), Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Kunie Ando
- Laboratory of Histology, Neuroanatomy and Neuropathology, UNI (ULB Neuroscience Institute), Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| |
Collapse
|
12
|
Kent SA, Spires-Jones TL, Durrant CS. The physiological roles of tau and Aβ: implications for Alzheimer's disease pathology and therapeutics. Acta Neuropathol 2020; 140:417-447. [PMID: 32728795 PMCID: PMC7498448 DOI: 10.1007/s00401-020-02196-w] [Citation(s) in RCA: 197] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 01/18/2023]
Abstract
Tau and amyloid beta (Aβ) are the prime suspects for driving pathology in Alzheimer's disease (AD) and, as such, have become the focus of therapeutic development. Recent research, however, shows that these proteins have been highly conserved throughout evolution and may have crucial, physiological roles. Such functions may be lost during AD progression or be unintentionally disrupted by tau- or Aβ-targeting therapies. Tau has been revealed to be more than a simple stabiliser of microtubules, reported to play a role in a range of biological processes including myelination, glucose metabolism, axonal transport, microtubule dynamics, iron homeostasis, neurogenesis, motor function, learning and memory, neuronal excitability, and DNA protection. Aβ is similarly multifunctional, and is proposed to regulate learning and memory, angiogenesis, neurogenesis, repair leaks in the blood-brain barrier, promote recovery from injury, and act as an antimicrobial peptide and tumour suppressor. This review will discuss potential physiological roles of tau and Aβ, highlighting how changes to these functions may contribute to pathology, as well as the implications for therapeutic development. We propose that a balanced consideration of both the physiological and pathological roles of tau and Aβ will be essential for the design of safe and effective therapeutics.
Collapse
Affiliation(s)
- Sarah A. Kent
- Translational Neuroscience PhD Programme, Centre for Discovery Brain Sciences and the UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ Scotland, UK
| | - Tara L. Spires-Jones
- Centre for Discovery Brain Sciences and the UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ Scotland, UK
| | - Claire S. Durrant
- Centre for Discovery Brain Sciences and the UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ Scotland, UK
| |
Collapse
|
13
|
S Narasimhan KK, Devarajan A, Karan G, Sundaram S, Wang Q, van Groen T, Monte FD, Rajasekaran NS. Reductive stress promotes protein aggregation and impairs neurogenesis. Redox Biol 2020; 37:101739. [PMID: 33242767 PMCID: PMC7695986 DOI: 10.1016/j.redox.2020.101739] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 09/23/2020] [Indexed: 12/20/2022] Open
Abstract
Redox homeostasis regulates key cellular signaling in both physiology and pathology. While perturbations result in shifting the redox homeostasis towards oxidative stress are well documented, the influence of reductive stress (RS) in neurodegenerative diseases and its mechanisms are unknown. Here, we postulate that a redox shift towards the reductive arm (through the activation of Nrf2 signaling) will damage neurons and impair neurogenesis. In proliferating and differentiating neuroblastoma (Neuro 2a/N2a) cells, sulforaphane-mediated Nrf2 activation resulted in increased transcription/translation of antioxidants and glutathione (GSH) production along with significantly declined ROS in a dose-dependent manner leading to a reductive-redox state (i.e. RS). Interestingly, this resulted in endoplasmic reticulum (ER) stress leading to subsequent protein aggregation/proteotoxicity in neuroblastoma cells. Under RS, we also observed elevated Tau/α-synuclein and their co-localization with other protein aggregates in these cells. Surprisingly, we noticed that acute RS impaired neurogenesis as evidenced from reduced neurite outgrowth/length. Furthermore, maintaining the cells in a sustained RS condition (for five consecutive generations) dramatically reduced their differentiation and prevented the formation of axons (p < 0.05). This impairment in RS mediated neurogenesis occurs through the alteration of Tau dynamics i.e. RS activates the pathogenic GSK3β/Tau cascade thereby promoting the phosphorylation of Tau leading to proteotoxicity. Of note, intermittent withdrawal of sulforaphane from these cells suppressed the proteotoxic insult and re-activated the differentiation process. Overall, this results suggest that either acute or chronic RS could hamper neurogenesis through GSK3β/TAU signaling and proteotoxicity. Therefore, investigations identifying novel redox mechanisms impacting proteostasis are crucial to preserve neuronal health.
Collapse
Affiliation(s)
- Kishore Kumar S Narasimhan
- Cardiac Aging & Redox Signaling Laboratory, Molecular and Cellular Pathology, Department of Pathology, Birmingham, AL, USA
| | - Asokan Devarajan
- Department of Medicine, Division of Cardiology, Cardiac Arrhythmia Center and Neurocardiology Research Center of Excellence, University of California, Los Angeles, CA, United States
| | - Goutam Karan
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Sandhya Sundaram
- Department of Pathology, Sri Ramachandra Medical University & Research Institute, Chennai, India
| | - Qin Wang
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Thomas van Groen
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Federica Del Monte
- Gazes Cardiac Research Institute, Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Namakkal S Rajasekaran
- Cardiac Aging & Redox Signaling Laboratory, Molecular and Cellular Pathology, Department of Pathology, Birmingham, AL, USA; Division of Cardiovascular Medicine, Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA; Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
| |
Collapse
|
14
|
Yang Y, Zhang Z. Microglia and Wnt Pathways: Prospects for Inflammation in Alzheimer's Disease. Front Aging Neurosci 2020; 12:110. [PMID: 32477095 PMCID: PMC7241259 DOI: 10.3389/fnagi.2020.00110] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/30/2020] [Indexed: 01/27/2023] Open
Abstract
Alzheimer’s disease (AD) has been a major health issue for more than one century since it was first reported in 1906. As one of the most common neurodegenerative diseases, AD is characterized by the presence of senile plaques and neurofibrillary tangles (NFTs) in the affected brain area. Microglia are the major regulators of neuroinflammation in the brain, and neuroinflammation has become recognized as the core pathophysiological process of various neurodegenerative diseases. In the central nervous system (CNS), microglia play a dual role in AD development. For one thing, they degrade amyloid β (Aβ) to resist its deposition; for another, microglia release pro-inflammatory and inflammatory factors, contributing to neuroinflammation as well as the spreading of Aβ and tau pathology. Wnt pathways are important regulators of cell fate and cell activities. The dysregulation of Wnt pathways is responsible for both abnormal tau phosphorylation and synaptic loss in AD. Recent studies have also confirmed the regulatory effect of Wnt signaling on microglial inflammation. Thus, the study of microglia, Wnt pathways, and their possible interactions may open up a new direction for understanding the mechanisms of neuroinflammation in AD. In this review, we summarize the functions of microglia and Wnt pathways and their roles in AD in order to provide new ideas for understanding the pathogenesis of AD.
Collapse
Affiliation(s)
- Yunying Yang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| |
Collapse
|
15
|
Interneuron Accumulation of Phosphorylated tau Impairs Adult Hippocampal Neurogenesis by Suppressing GABAergic Transmission. Cell Stem Cell 2020; 26:331-345.e6. [PMID: 31978364 DOI: 10.1016/j.stem.2019.12.015] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/27/2019] [Accepted: 12/12/2019] [Indexed: 12/27/2022]
Abstract
Phospho-tau accumulation and adult hippocampal neurogenesis (AHN) impairment both contribute importantly to the cognitive decline in Alzheimer's disease (AD), but whether and how tau dysregulates AHN in AD remain poorly understood. Here, we found a prominent accumulation of phosphorylated tau in GABAergic interneurons in the dentate gyrus (DG) of AD patients and mice. Specific overexpression of human tau (hTau) in mice DG interneurons induced AHN deficits but increased neural stem cell-derived astrogliosis, associating with a downregulation of GABA and hyperactivation of neighboring excitatory neurons. Chemogenetic inhibition of excitatory neurons or pharmacologically strengthening GABAergic tempos rescued the tau-induced AHN deficits and improved contextual cognition. These findings evidenced that intracellular accumulation of tau in GABAergic interneurons impairs AHN by suppressing GABAergic transmission and disinhibiting neural circuits within the neurogenic niche, suggesting a potential of GABAergic potentiators for pro-neurogenic or cell therapies of AD.
Collapse
|
16
|
Jia L, Piña-Crespo J, Li Y. Restoring Wnt/β-catenin signaling is a promising therapeutic strategy for Alzheimer's disease. Mol Brain 2019; 12:104. [PMID: 31801553 PMCID: PMC6894260 DOI: 10.1186/s13041-019-0525-5] [Citation(s) in RCA: 163] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 11/26/2019] [Indexed: 01/01/2023] Open
Abstract
Alzheimer’s disease (AD) is an aging-related neurological disorder characterized by synaptic loss and dementia. Wnt/β-catenin signaling is an essential signal transduction pathway that regulates numerous cellular processes including cell survival. In brain, Wnt/β-catenin signaling is not only crucial for neuronal survival and neurogenesis, but it plays important roles in regulating synaptic plasticity and blood-brain barrier integrity and function. Moreover, activation of Wnt/β-catenin signaling inhibits amyloid-β production and tau protein hyperphosphorylation in the brain. Critically, Wnt/β-catenin signaling is greatly suppressed in AD brain via multiple pathogenic mechanisms. As such, restoring Wnt/β-catenin signaling represents a unique opportunity for the rational design of novel AD therapies.
Collapse
Affiliation(s)
- Lin Jia
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA.,Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, 361102, China
| | - Juan Piña-Crespo
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Yonghe Li
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA.
| |
Collapse
|
17
|
Das R, Chinnathambi S. Microglial priming of antigen presentation and adaptive stimulation in Alzheimer's disease. Cell Mol Life Sci 2019; 76:3681-3694. [PMID: 31093687 PMCID: PMC11105582 DOI: 10.1007/s00018-019-03132-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 12/21/2022]
Abstract
The prominent pathological consequences of Alzheimer's disease (AD) are the misfolding and mis-sorting of two cellular proteins, amyloid-β and microtubule-associated protein Tau. The accumulation of toxic phosphorylated Tau inside the neurons induces the increased processing of amyloid-β-associated signaling cascade and vice versa. Neuroinflammation-driven synaptic depletion and cognitive decline are substantiated by the cross talk of activated microglia and astroglia, leading to neuron degeneration. Microglia are the brain-resident immune effectors that prove their diverse functions in maintaining CNS homeostasis via collaboration with astrocytes and T lymphocytes. Age-related senescence and chronic inflammation activate microglia with increased pro-inflammatory markers, oxidative damage and phagocytosis. But the improper processing of misfolded protein via lysosomal pathway destines the spreading of 'seed' constituents to the nearby healthy neurons. Primed microglia process and present self-antigen such as amyloid-β and modified Tau to the infiltrated T lymphocytes through MHC I/II molecules. After an effective conversation with CD4+ T cells, microglial phenotype can be altered from pro-active M1 to neuro-protective M2 type, which corresponds to the tissue remodeling and homeostasis. In this review, we are focusing on the change in functionality of microglia from innate to adaptive immune response in the context of neuroprotection, which may help in the search of novel immune therapy in AD.
Collapse
Affiliation(s)
- Rashmi Das
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Pune, 411008, India
| | - Subashchandrabose Chinnathambi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India.
- Academy of Scientific and Innovative Research (AcSIR), Pune, 411008, India.
| |
Collapse
|
18
|
Li H, Liu CC, Zheng H, Huang TY. Amyloid, tau, pathogen infection and antimicrobial protection in Alzheimer's disease -conformist, nonconformist, and realistic prospects for AD pathogenesis. Transl Neurodegener 2018; 7:34. [PMID: 30603085 PMCID: PMC6306008 DOI: 10.1186/s40035-018-0139-3] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 12/02/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is a fatal disease that threatens the quality of life of an aging population at a global scale. Various hypotheses on the etiology of AD have been developed over the years to guide efforts in search of therapeutic strategies. MAIN BODY In this review, we focus on four AD hypotheses currently relevant to AD onset: the prevailing amyloid cascade hypothesis, the well-recognized tau hypothesis, the increasingly popular pathogen (viral infection) hypothesis, and the infection-related antimicrobial protection hypothesis. In briefly reviewing the main evidence supporting each hypothesis and discussing the questions that need to be addressed, we hope to gain a better understanding of the complicated multi-layered interactions in potential causal and/or risk factors in AD pathogenesis. As a defining feature of AD, the existence of amyloid deposits is likely fundamental to AD onset but is insufficient to wholly reproduce many complexities of the disorder. A similar belief is currently also applied to hyperphosphorylated tau aggregates within neurons, where tau has been postulated to drive neurodegeneration in the presence of pre-existing Aβ plaques in the brain. Although infection of the central nerve system by pathogens such as viruses may increase AD risk, it is yet to be determined whether this phenomenon is applicable to all cases of sporadic AD and whether it is a primary trigger for AD onset. Lastly, the antimicrobial protection hypothesis provides insight into a potential physiological role for Aβ peptides, but how Aβ/microbial interactions affect AD pathogenesis during aging awaits further validation. Nevertheless, this hypothesis cautions potential adverse effects in Aβ-targeting therapies by hindering potential roles for Aβ in anti-viral protection. CONCLUSION AD is a multi-factor complex disorder, which likely requires a combinatorial therapeutic approach to successfully slow or reduce symptomatic memory decline. A better understanding of how various causal and/or risk factors affecting disease onset and progression will enhance the likelihood of conceiving effective treatment paradigms, which may involve personalized treatment strategies for individual patients at varying stages of disease progression.
Collapse
Affiliation(s)
- Hongmei Li
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL USA
| | - Chia-Chen Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL USA
| | - Hui Zheng
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX USA
| | - Timothy Y. Huang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA USA
| |
Collapse
|
19
|
Chauderlier A, Gilles M, Spolcova A, Caillierez R, Chwastyniak M, Kress M, Drobecq H, Bonnefoy E, Pinet F, Weil D, Buée L, Galas MC, Lefebvre B. Tau/DDX6 interaction increases microRNA activity. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:762-772. [DOI: 10.1016/j.bbagrm.2018.06.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 06/27/2018] [Accepted: 06/27/2018] [Indexed: 12/17/2022]
|