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Pomilio C, Presa J, Oses C, Vinuesa A, Bentivegna M, Gregosa A, Riudavets M, Sevlever G, Galvan V, Levi V, Beauquis J, Saravia F. Loss of Direct Vascular Contact to Astrocytes in the Hippocampus as an Initial Event in Alzheimer's Disease. Evidence from Patients, In Vivo and In Vitro Experimental Models. Mol Neurobiol 2024; 61:5142-5160. [PMID: 38172288 DOI: 10.1007/s12035-023-03897-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 12/20/2023] [Indexed: 01/05/2024]
Abstract
Alzheimer's disease (AD) is characterized by the accumulation of aggregated amyloid peptides in the brain parenchyma and within the walls of cerebral vessels. The hippocampus-a complex brain structure with a pivotal role in learning and memory-is implicated in this disease. However, there is limited data on vascular changes during AD pathological degeneration in this susceptible structure, which has distinctive vascular traits. Our aim was to evaluate vascular alterations in the hippocampus of AD patients and PDAPP-J20 mice-a model of AD-and to determine the impact of Aβ40 and Aβ42 on endothelial cell activation. We found a loss of physical astrocyte-endothelium interaction in the hippocampus of individuals with AD as compared to non-AD donors, along with reduced vascular density. Astrocyte-endothelial interactions and levels of the tight junction protein occludin were altered early in PDAPP-J20 mice, preceding any signs of morphological changes or disruption of the blood-brain barrier in these mice. At later stages, PDAPP-J20 mice exhibited decreased vascular density in the hippocampus and leakage of fluorescent tracers, indicating dysfunction of the vasculature and the BBB. In vitro studies showed that soluble Aβ40 exposure in human brain microvascular endothelial cells (HBMEC) was sufficient to induce NFκB translocation to the nucleus, which may be linked with an observed reduction in occludin levels. The inhibition of the membrane receptor for advanced glycation end products (RAGE) prevented these changes in HBMEC. Additional results suggest that Aβ42 indirectly affects the endothelium by inducing astrocytic factors. Furthermore, our results from human and mouse brain samples provide evidence for the crucial involvement of the hippocampal vasculature in Alzheimer's disease.
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Affiliation(s)
- C Pomilio
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
- Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - J Presa
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
- Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - C Oses
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - A Vinuesa
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
- Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - M Bentivegna
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
- Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - A Gregosa
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
- Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - M Riudavets
- FLENI, Instituto de Investigaciones Neurológicas Dr Raúl Carrea, Buenos Aires, Argentina
| | - G Sevlever
- FLENI, Instituto de Investigaciones Neurológicas Dr Raúl Carrea, Buenos Aires, Argentina
| | - V Galvan
- Department of Biochemistry and Molecular Biology and Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences, Oklahoma City, OK, 73104, USA
| | - V Levi
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - J Beauquis
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
- Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - F Saravia
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina.
- Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina.
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Zhang Y, Li D, Gao H, Zhao H, Zhang S, Li T. Rapamycin Alleviates Neuronal Injury and Modulates Microglial Activation After Cerebral Ischemia. Mol Neurobiol 2024; 61:5699-5717. [PMID: 38224443 DOI: 10.1007/s12035-023-03904-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/21/2023] [Indexed: 01/16/2024]
Abstract
Neurons and microglia are sensitive to cerebral microcirculation and their responses play a crucial part in the pathological processes, while they are also the main target cells of many drugs used to treat brain diseases. Rapamycin exhibits beneficial effects in many diseases; however, whether it can affect neuronal injury or alter the microglial activation after global cerebral ischemia remains unclear. In this study, we performed global cerebral ischemia combined with rapamycin treatment in CX3CR1GFP/+ mice and explored the effects of rapamycin on neuronal deficit and microglial activation. Our results showed that rapamycin reduced neuronal loss, neurodegeneration, and ultrastructural damage after ischemia by histological staining and transmission electron microscopy (TEM). Interestingly, rapamycin suppressed de-ramification and proliferation of microglia and reduced the density of microglia. Immunofluorescence staining indicated that rapamycin skewed microglial polarization toward an anti-inflammatory state. Furthermore, rapamycin as well suppressed the activation of astrocytes. Meanwhile, quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed a significant reduction of pro-inflammatory factors as well as an elevation of anti-inflammatory factors upon rapamycin treatment. As a result of these effects, behavioral tests showed that rapamycin significantly alleviated the brain injury after stroke. Together, our study suggested that rapamycin attenuated neuronal injury, altered microglial activation state, and provided a more beneficial immune microenvironment for the brain, which could be used as a promising therapeutic approach to treat ischemic cerebrovascular diseases.
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Affiliation(s)
- Yue Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Donghai Li
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China
| | - Hao Gao
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China
| | - Haiyu Zhao
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China
| | - Shengxiang Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China.
| | - Ting Li
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China.
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3
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Xie PL, Zheng MY, Han R, Chen WX, Mao JH. Pharmacological mTOR inhibitors in ameliorating Alzheimer's disease: current review and perspectives. Front Pharmacol 2024; 15:1366061. [PMID: 38873415 PMCID: PMC11169825 DOI: 10.3389/fphar.2024.1366061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 04/25/2024] [Indexed: 06/15/2024] Open
Abstract
Traditionally, pharmacological mammalian/mechanistic targets of rapamycin (mTOR) kinase inhibitors have been used during transplantation and tumor treatment. Emerging pre-clinical evidence from the last decade displayed the surprising effectiveness of mTOR inhibitors in ameliorating Alzheimer's Disease (AD), a common neurodegenerative disorder characterized by progressive cognitive function decline and memory loss. Research shows mTOR activation as an early event in AD development, and inhibiting mTOR may promote the resolution of many hallmarks of Alzheimer's. Aberrant protein aggregation, including amyloid-beta (Aβ) deposition and tau filaments, and cognitive defects, are reversed upon mTOR inhibition. A closer inspection of the evidence highlighted a temporal dependence and a hallmark-specific nature of such beneficial effects. Time of administration relative to disease progression, and a maintenance of a functional lysosomal system, could modulate its effectiveness. Moreover, mTOR inhibition also exerts distinct effects between neurons, glial cells, and endothelial cells. Different pharmacological properties of the inhibitors also produce different effects based on different blood-brain barrier (BBB) entry capacities and mTOR inhibition sites. This questions the effectiveness of mTOR inhibition as a viable AD intervention strategy. In this review, we first summarize the different mTOR inhibitors available and their characteristics. We then comprehensively update and discuss the pre-clinical results of mTOR inhibition to resolve many of the hallmarks of AD. Key pathologies discussed include Aβ deposition, tauopathies, aberrant neuroinflammation, and neurovascular system breakdowns.
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Affiliation(s)
- Pei-Lun Xie
- University College London, London, United Kingdom
| | | | - Ran Han
- Dongfang Hospital of Beijing University of Chinese Medicine, Beijing, China
| | - Wei-Xin Chen
- Dongfang Hospital of Beijing University of Chinese Medicine, Beijing, China
| | - Jin-Hua Mao
- Beijing University of Chinese Medicine, Beijing, China
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4
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Davoody S, Asgari Taei A, Khodabakhsh P, Dargahi L. mTOR signaling and Alzheimer's disease: What we know and where we are? CNS Neurosci Ther 2024; 30:e14463. [PMID: 37721413 PMCID: PMC11017461 DOI: 10.1111/cns.14463] [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: 07/07/2022] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023] Open
Abstract
Despite the great body of research done on Alzheimer's disease, the underlying mechanisms have not been vividly investigated. To date, the accumulation of amyloid-beta plaques and tau tangles constitutes the hallmark of the disease; however, dysregulation of the mammalian target of rapamycin (mTOR) seems to be significantly involved in the pathogenesis of the disease as well. mTOR, as a serine-threonine protein kinase, was previously known for controlling many cellular functions such as cell size, autophagy, and metabolism. In this regard, mammalian target of rapamycin complex 1 (mTORC1) may leave anti-aging impacts by robustly inhibiting autophagy, a mechanism that inhibits the accumulation of damaged protein aggregate and dysfunctional organelles. Formation and aggregation of neurofibrillary tangles and amyloid-beta plaques seem to be significantly regulated by mTOR signaling. Understanding the underlying mechanisms and connection between mTOR signaling and AD may suggest conducting clinical trials assessing the efficacy of rapamycin, as an mTOR inhibitor drug, in managing AD or may help develop other medications. In this literature review, we aim to elaborate mTOR signaling network mainly in the brain, point to gaps of knowledge, and define how and in which ways mTOR signaling can be connected with AD pathogenesis and symptoms.
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Affiliation(s)
- Samin Davoody
- Student Research Committee, School of MedicineShahid Beheshti University of Medical SciencesTehranIran
| | - Afsaneh Asgari Taei
- Neuroscience Research CenterShahid Beheshti University of Medical SciencesTehranIran
| | - Pariya Khodabakhsh
- Department of NeurophysiologyInstitute of Physiology, Eberhard Karls University of TübingenTübingenGermany
| | - Leila Dargahi
- Neurobiology Research CenterShahid Beheshti University of Medical SciencesTehranIran
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Lei T, Yang Z, Li H, Qin M, Gao H. Interactions between nanoparticles and pathological changes of vascular in Alzheimer's disease. Adv Drug Deliv Rev 2024; 207:115219. [PMID: 38401847 DOI: 10.1016/j.addr.2024.115219] [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: 10/30/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024]
Abstract
Emerging evidence suggests that vascular pathological changes play a pivotal role in the pathogenesis of Alzheimer's disease (AD). The dysfunction of the cerebral vasculature occurs in the early course of AD, characterized by alterations in vascular morphology, diminished cerebral blood flow (CBF), impairment of the neurovascular unit (NVU), vasculature inflammation, and cerebral amyloid angiopathy. Vascular dysfunction not only facilitates the influx of neurotoxic substances into the brain, triggering inflammation and immune responses but also hampers the efflux of toxic proteins such as Aβ from the brain, thereby contributing to neurodegenerative changes in AD. Furthermore, these vascular changes significantly impact drug delivery and distribution within the brain. Therefore, developing targeted delivery systems or therapeutic strategies based on vascular alterations may potentially represent a novel breakthrough in AD treatment. This review comprehensively examines various aspects of vascular alterations in AD and outlines the current interactions between nanoparticles and pathological changes of vascular.
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Affiliation(s)
- Ting Lei
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, West China School of Pharmacy, Mental Health Center and National Chengdu Center for Safety Evaluation of Drugs, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Zixiao Yang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, West China School of Pharmacy, Mental Health Center and National Chengdu Center for Safety Evaluation of Drugs, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Hanmei Li
- School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China
| | - Meng Qin
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, West China School of Pharmacy, Mental Health Center and National Chengdu Center for Safety Evaluation of Drugs, West China Hospital, Sichuan University, Chengdu 610041, China.
| | - Huile Gao
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, West China School of Pharmacy, Mental Health Center and National Chengdu Center for Safety Evaluation of Drugs, West China Hospital, Sichuan University, Chengdu 610041, China.
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6
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Owens CD, Bonin Pinto C, Detwiler S, Olay L, Pinaffi-Langley ACDC, Mukli P, Peterfi A, Szarvas Z, James JA, Galvan V, Tarantini S, Csiszar A, Ungvari Z, Kirkpatrick AC, Prodan CI, Yabluchanskiy A. Neurovascular coupling impairment as a mechanism for cognitive deficits in COVID-19. Brain Commun 2024; 6:fcae080. [PMID: 38495306 PMCID: PMC10943572 DOI: 10.1093/braincomms/fcae080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/08/2024] [Accepted: 03/05/2024] [Indexed: 03/19/2024] Open
Abstract
Components that comprise our brain parenchymal and cerebrovascular structures provide a homeostatic environment for proper neuronal function to ensure normal cognition. Cerebral insults (e.g. ischaemia, microbleeds and infection) alter cellular structures and physiologic processes within the neurovascular unit and contribute to cognitive dysfunction. COVID-19 has posed significant complications during acute and convalescent stages in multiple organ systems, including the brain. Cognitive impairment is a prevalent complication in COVID-19 patients, irrespective of severity of acute SARS-CoV-2 infection. Moreover, overwhelming evidence from in vitro, preclinical and clinical studies has reported SARS-CoV-2-induced pathologies in components of the neurovascular unit that are associated with cognitive impairment. Neurovascular unit disruption alters the neurovascular coupling response, a critical mechanism that regulates cerebromicrovascular blood flow to meet the energetic demands of locally active neurons. Normal cognitive processing is achieved through the neurovascular coupling response and involves the coordinated action of brain parenchymal cells (i.e. neurons and glia) and cerebrovascular cell types (i.e. endothelia, smooth muscle cells and pericytes). However, current work on COVID-19-induced cognitive impairment has yet to investigate disruption of neurovascular coupling as a causal factor. Hence, in this review, we aim to describe SARS-CoV-2's effects on the neurovascular unit and how they can impact neurovascular coupling and contribute to cognitive decline in acute and convalescent stages of the disease. Additionally, we explore potential therapeutic interventions to mitigate COVID-19-induced cognitive impairment. Given the great impact of cognitive impairment associated with COVID-19 on both individuals and public health, the necessity for a coordinated effort from fundamental scientific research to clinical application becomes imperative. This integrated endeavour is crucial for mitigating the cognitive deficits induced by COVID-19 and its subsequent burden in this especially vulnerable population.
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Affiliation(s)
- Cameron D Owens
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Camila Bonin Pinto
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Sam Detwiler
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Lauren Olay
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Ana Clara da C Pinaffi-Langley
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Peter Mukli
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Anna Peterfi
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Zsofia Szarvas
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Judith A James
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Arthritis & Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Veronica Galvan
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Stefano Tarantini
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
- The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Anna Csiszar
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Zoltan Ungvari
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Angelia C Kirkpatrick
- Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
- Cardiovascular Section, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Calin I Prodan
- Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
- Department of Neurology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Andriy Yabluchanskiy
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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Cai J, Xie D, Kong F, Zhai Z, Zhu Z, Zhao Y, Xu Y, Sun T. Effect and Mechanism of Rapamycin on Cognitive Deficits in Animal Models of Alzheimer's Disease: A Systematic Review and Meta-analysis of Preclinical Studies. J Alzheimers Dis 2024; 99:53-84. [PMID: 38640155 DOI: 10.3233/jad-231249] [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] [Indexed: 04/21/2024]
Abstract
Background Alzheimer's disease (AD), the most common form of dementia, remains long-term and challenging to diagnose. Furthermore, there is currently no medication to completely cure AD patients. Rapamycin has been clinically demonstrated to postpone the aging process in mice and improve learning and memory abilities in animal models of AD. Therefore, rapamycin has the potential to be significant in the discovery and development of drugs for AD patients. Objective The main objective of this systematic review and meta-analysis was to investigate the effects and mechanisms of rapamycin on animal models of AD by examining behavioral indicators and pathological features. Methods Six databases were searched and 4,277 articles were retrieved. In conclusion, 13 studies were included according to predefined criteria. Three authors independently judged the selected literature and methodological quality. Use of subgroup analyses to explore potential mechanistic effects of rapamycin interventions: animal models of AD, specific types of transgenic animal models, dosage, and periodicity of administration. Results The results of Morris Water Maze (MWM) behavioral test showed that escape latency was shortened by 15.60 seconds with rapamycin therapy, indicating that learning ability was enhanced in AD mice; and the number of traversed platforms was increased by 1.53 times, indicating that the improved memory ability significantly corrected the memory deficits. CONCLUSIONS Rapamycin therapy reduced age-related plaque deposition by decreasing AβPP production and down-regulating β-secretase and γ-secretase activities, furthermore increased amyloid-β clearance by promoting autophagy, as well as reduced tau hyperphosphorylation by up-regulating insulin-degrading enzyme levels.
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Affiliation(s)
- Jie Cai
- School of Intelligent Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Danni Xie
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Fanjing Kong
- School of Intelligent Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Zhenwei Zhai
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Zhishan Zhu
- School of Intelligent Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Yanru Zhao
- School of Intelligent Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Ying Xu
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Tao Sun
- School of Intelligent Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
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Fang X, Fan F, Border JJ, Roman RJ. Cerebrovascular Dysfunction in Alzheimer's Disease and Transgenic Rodent Models. JOURNAL OF EXPERIMENTAL NEUROLOGY 2024; 5:42-64. [PMID: 38434588 PMCID: PMC10906803 DOI: 10.33696/neurol.5.087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
Alzheimer's Disease (AD) and Alzheimer's Disease-Related Dementia (ADRD) are the primary causes of dementia that has a devastating effect on the quality of life and is a tremendous economic burden on the healthcare system. The accumulation of extracellular beta-amyloid (Aβ) plaques and intracellular hyperphosphorylated tau-containing neurofibrillary tangles (NFTs) in the brain are the hallmarks of AD. They are also thought to be the underlying cause of inflammation, neurodegeneration, brain atrophy, and cognitive impairments that accompany AD. The discovery of APP, PS1, and PS2 mutations that increase Aβ production in families with early onset familial AD led to the development of numerous transgenic rodent models of AD. These models have provided new insight into the role of Aβ in AD; however, they do not fully replicate AD pathology in patients. Familial AD patients with mutations that elevate the production of Aβ represent only a small fraction of dementia patients. In contrast, those with late-onset sporadic AD constitute the majority of cases. This observation, along with the failure of previous clinical trials targeting Aβ or Tau and the modest success of recent trials using Aβ monoclonal antibodies, has led to a reappraisal of the view that Aβ accumulation is the sole factor in the pathogenesis of AD. More recent studies have established that cerebral vascular dysfunction is one of the earliest changes seen in AD, and 67% of the candidate genes linked to AD are expressed in the cerebral vasculature. Thus, there is an increasing appreciation of the vascular contribution to AD, and the National Institute on Aging (NIA) and the Alzheimer's Disease Foundation recently prioritized it as a focused research area. This review summarizes the strengths and limitations of the most commonly used transgenic AD animal models and current views about the contribution of Aβ accumulation versus cerebrovascular dysfunction in the pathogenesis of AD.
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Affiliation(s)
- Xing Fang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Fan Fan
- Department of Physiology, Augusta University, Augusta, GA 30912, USA
| | - Jane J. Border
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Richard J. Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216, USA
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Gianessi L, Magini A, Dominici R, Giovagnoli S, Dolcetta D. A Stable Micellar Formulation of RAD001 for Intracerebroventricular Delivery and the Treatment of Alzheimer's Disease and Other Neurological Disorders. Int J Mol Sci 2023; 24:17478. [PMID: 38139306 PMCID: PMC10744130 DOI: 10.3390/ijms242417478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 11/30/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
A large body of evidence, replicated in many mouse models of Alzheimer's disease (AD), supports the therapeutic efficacy of the oral mammalian target of rapamycin inhibitors (mTOR-Is). Our preliminary data show that intracerebroventricular (ICV) administration of everolimus (RAD001) soon after clinical onset greatly diminished cognitive impairment and the intracellular beta amyloid and neurofibrillary tangle load. However, RAD001 shows >90% degradation after 7 days in solution at body temperature, thus hampering the development of proper therapeutic regimens for patients. To overcome such a drawback, we developed a stable, liquid formulation of mTOR-Is by loading RAD001 into distearoylphosphatidylethanolamine-polyethylene glycol 2000 (DSPE-PEG2000) micelles using the thin layer evaporation method. The formulation showed efficient encapsulation of RAD001 and a homogeneous colloidal size and stabilised RAD001, with over 95% of activity preserved after 14 days at 37 °C with a total decay only occurring after 98 days. RAD001-loaded DSPE-PEG2000 micelles were unchanged when stored at 4 and 25 °C over the time period investigated. The obtained formulation may represent a suitable platform for expedited clinical translation and effective therapeutic regimens in AD and other neurological diseases.
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Affiliation(s)
- Laura Gianessi
- Department of Pharmaceutical Sciences, University of Perugia, 06123 Perugia, Italy (S.G.)
| | | | - Roberto Dominici
- Department of Biochemistry, Desio Hospital, ASST-Brianza, 20832 Desio, Italy
| | - Stefano Giovagnoli
- Department of Pharmaceutical Sciences, University of Perugia, 06123 Perugia, Italy (S.G.)
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10
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Awad H, Ajalik R, Alenchery R, Linares I, Wright T, Miller B, McGrath J. Human tendon-on-a-chip for modeling vascular inflammatory fibrosis. RESEARCH SQUARE 2023:rs.3.rs-3722255. [PMID: 38168335 PMCID: PMC10760304 DOI: 10.21203/rs.3.rs-3722255/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Understanding vascular inflammation and myofibroblast crosstalk is critical to developing therapies for fibrotic diseases. Here we report the development of a novel human Tendon-on-a-Chip (hToC) to model this crosstalk in peritendinous adhesions, a debilitating fibrotic condition affecting flexor tendon, which currently lacks biological therapies. The hToC enables cellular and paracrine interactions between a vascular compartment harboring endothelial cells and monocytes with a tissue hydrogel compartment containing tendon fibroblasts and macrophages. We find that the hToC replicates in vivo inflammatory and fibrotic phenotypes in preclinical and clinical samples, including myofibroblast differentiation and tissue contraction, excessive ECM deposition, and inflammatory cytokines secretion. We further show that the fibrotic phenotypes are driven by the transmigration of monocytes from the vascular to the tissue compartments of the chip. We demonstrate significant overlap in fibrotic transcriptional signatures in the hToC with human tenolysis samples, including mTOR signaling, a regulatory nexus of fibrosis across various organs. Treatment with rapamycin suppressed the fibrotic phenotype on the hToC, which validates the hToC as a preclinical alternative for investigating fibrosis and testing therapeutics.
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11
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Bu LL, Yuan HH, Xie LL, Guo MH, Liao DF, Zheng XL. New Dawn for Atherosclerosis: Vascular Endothelial Cell Senescence and Death. Int J Mol Sci 2023; 24:15160. [PMID: 37894840 PMCID: PMC10606899 DOI: 10.3390/ijms242015160] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/01/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023] Open
Abstract
Endothelial cells (ECs) form the inner linings of blood vessels, and are directly exposed to endogenous hazard signals and metabolites in the circulatory system. The senescence and death of ECs are not only adverse outcomes, but also causal contributors to endothelial dysfunction, an early risk marker of atherosclerosis. The pathophysiological process of EC senescence involves both structural and functional changes and has been linked to various factors, including oxidative stress, dysregulated cell cycle, hyperuricemia, vascular inflammation, and aberrant metabolite sensing and signaling. Multiple forms of EC death have been documented in atherosclerosis, including autophagic cell death, apoptosis, pyroptosis, NETosis, necroptosis, and ferroptosis. Despite this, the molecular mechanisms underlying EC senescence or death in atherogenesis are not fully understood. To provide a comprehensive update on the subject, this review examines the historic and latest findings on the molecular mechanisms and functional alterations associated with EC senescence and death in different stages of atherosclerosis.
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Affiliation(s)
- Lan-Lan Bu
- School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; (L.-L.B.); (D.-F.L.)
| | - Huan-Huan Yuan
- College of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (H.-H.Y.); (L.-L.X.); (M.-H.G.)
| | - Ling-Li Xie
- College of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (H.-H.Y.); (L.-L.X.); (M.-H.G.)
- Departments of Biochemistry and Molecular Biology and Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Min-Hua Guo
- College of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (H.-H.Y.); (L.-L.X.); (M.-H.G.)
| | - Duan-Fang Liao
- School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; (L.-L.B.); (D.-F.L.)
| | - Xi-Long Zheng
- Departments of Biochemistry and Molecular Biology and Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
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12
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Hou SJ, Zhang SX, Li Y, Xu SY. Rapamycin Responds to Alzheimer's Disease: A Potential Translational Therapy. Clin Interv Aging 2023; 18:1629-1639. [PMID: 37810956 PMCID: PMC10557994 DOI: 10.2147/cia.s429440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/25/2023] [Indexed: 10/10/2023] Open
Abstract
Alzheimer's disease (AD) is a sporadic or familial neurodegenerative disease of insidious onset with progressive cognitive decline. Although numerous studies have been conducted or are underway on AD, there are still no effective drugs to reverse the pathological features and clinical manifestations of AD. Rapamycin is a macrolide antibiotic produced by Streptomyces hygroscopicus. As a classical mechanistic target of rapamycin (mTOR) inhibitor, rapamycin has been shown to be beneficial in a variety of AD mouse and cells models, both before the onset of disease symptoms and the early stage of disease. Although many basic studies have demonstrated the therapeutic effects of rapamycin in AD, many questions and controversies remain. This may be due to the variability of experimental models, different modes of administration, dose, timing, frequency, and the availability of drug-targeting vehicles. Rapamycin may delay the development of AD by reducing β-amyloid (Aβ) deposition, inhibiting tau protein hyperphosphorylation, maintaining brain function in APOE ε4 gene carriers, clearing chronic inflammation, and improving cognitive dysfunction. It is thus expected to be one of the candidates for the treatment of Alzheimer's disease.
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Affiliation(s)
- Si-Jia Hou
- Department of Neurology, Headache Center, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, 030001, People’s Republic of China
| | - Sheng-Xiao Zhang
- Department of Rheumatology, The Second Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, 030009, People’s Republic of China
| | - Yang Li
- Department of Neurology, Headache Center, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, 030001, People’s Republic of China
| | - Sui-Yi Xu
- Department of Neurology, Headache Center, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, 030001, People’s Republic of China
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13
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Konopka AR, Lamming DW. Blazing a trail for the clinical use of rapamycin as a geroprotecTOR. GeroScience 2023; 45:2769-2783. [PMID: 37801202 PMCID: PMC10643772 DOI: 10.1007/s11357-023-00935-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/04/2023] [Indexed: 10/07/2023] Open
Abstract
Treatment with rapamycin, an inhibitor of the mechanistic Target Of Rapamycin Complex One (mTORC1) protein kinase, has been repeatedly demonstrated to extend lifespan and prevent or delay age-related diseases in diverse model systems. Concerns over the risk of potentially serious side effects in humans, including immunosuppression and metabolic disruptions, have cautiously limited the translation of rapamycin and its analogs as a treatment for aging associated conditions. During the last decade, we and others have developed a working model that suggests that while inhibition of mTORC1 promotes healthy aging, many of the negative side effects of rapamycin are associated with "off-target" inhibition of a second mTOR complex, mTORC2. Differences in the kinetics and molecular mechanisms by which rapamycin inhibits mTORC1 and mTORC2 suggest that a therapeutic window for rapamycin could be exploited using intermittent dosing schedules or alternative rapalogs that may enable more selective inhibition of mTORC1. However, the optimal dosing schedules and the long-term efficacy of such interventions in humans are unknown. Here, we highlight ongoing or upcoming clinical trials that will address outstanding questions regarding the safety, pharmacokinetics, pharmacodynamics, and efficacy of rapamycin and rapalogs on several clinically oriented outcomes. Results from these early phase studies will help guide the design of phase 3 clinical trials to determine whether rapamycin can be used safely to inhibit mTORC1 for the treatment and prevention of age-related diseases in humans.
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Affiliation(s)
- Adam R Konopka
- Division of Geriatrics, Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA.
- William S. Middleton Memorial Veterans Hospital, Madison, WI, 53705, USA.
- Division of Geriatrics and Gerontology, Department of Medicine, Geriatric Research Education and Clinical Center (GRECC), William S. Middleton Memorial Veterans Hospital, University of Wisconsin-Madison, 2500 Overlook Terrace, Madison, WI, 53705, USA.
| | - Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI, 53705, USA
- Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA
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14
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Melanis K, Stefanou MI, Themistoklis KM, Papasilekas T. mTOR pathway - a potential therapeutic target in stroke. Ther Adv Neurol Disord 2023; 16:17562864231187770. [PMID: 37576547 PMCID: PMC10413897 DOI: 10.1177/17562864231187770] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 06/27/2023] [Indexed: 08/15/2023] Open
Abstract
Stroke is ranked as the second leading cause of death worldwide and a major cause of long-term disability. A potential therapeutic target that could offer favorable outcomes in stroke is the mammalian target of rapamycin (mTOR) pathway. mTOR is a serine/threonine kinase that composes two protein complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), and is regulated by other proteins such as the tuberous sclerosis complex. Through a significant number of signaling pathways, the mTOR pathway can modulate the processes of post-ischemic inflammation and autophagy, both of which play an integral part in the pathophysiological cascade of stroke. Promoting or inhibiting such processes under ischemic conditions can lead to apoptosis or instead sustained viability of neurons. The purpose of this review is to examine the pathophysiological role of mTOR in acute ischemic stroke, while highlighting promising neuroprotective agents such as hamartin for therapeutic modulation of this pathway. The therapeutic potential of mTOR is also discussed, with emphasis on implicated molecules and pathway steps that warrant further elucidation in order for their neuroprotective properties to be efficiently tested in future clinical trials.
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Affiliation(s)
- Konstantinos Melanis
- Second Department of Neurology, School of Medicine and ‘Attikon’ University Hospital, National and Kapodistrian University of Athens, Rimini 1 Chaidari, Athens 12462, Greece
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Maria-Ioanna Stefanou
- Second Department of Neurology, School of Medicine and ‘Attikon’ University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Konstantinos M. Themistoklis
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- Department of Neurosurgery, ‘Korgialenio, Benakio, H.R.C’. General Hospital of Athens, Athens, Greece
| | - Themistoklis Papasilekas
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- Department of Neurosurgery, ‘Korgialenio, Benakio, H.R.C’. General Hospital of Athens, Athens, Greece
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15
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Carosi JM, Sargeant TJ. Rapamycin and Alzheimer disease: a hypothesis for the effective use of rapamycin for treatment of neurodegenerative disease. Autophagy 2023; 19:2386-2390. [PMID: 36727410 PMCID: PMC10351443 DOI: 10.1080/15548627.2023.2175569] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/03/2023] Open
Abstract
In 2019 we summarized work relating to the potential use of rapamycin for treating Alzheimer disease (AD). We considered the commentary necessary because use of rapamycin in people with AD is a very real prospect and we wanted to present a balanced view of the likely consequences of MTOR (mechanistic target of rapamycin kinase) inhibition in the AD brain. We concluded that use of rapamycin, an MTOR inhibitor that increases macroautophagy/autophagy, could hold promise for prevention of AD if used early enough. However, MTOR inhibition appeared ineffectual in resolving existing amyloid pathology in AD mouse models. In this View article, we update these observations with new studies that have used rapamycin in AD models and provide evidence both for and against its use in AD. We also discuss rapamycin in the light of new research that describes rapamycin-induced autophagic stress in the aging brain and autophagic stress as the origin of the amyloid plaque itself. We conclude that rapamycin will have complex effects on the brain in AD. Further, we hypothesize that lysosomal degradative capacity in the brain will likely determine how effective or detrimental rapamycin will be as a treatment of AD.Abbreviations: AD: Alzheimer disease; APP: amyloid beta precursor protein; MAPT/tau: microtubule associated protein tau; MTOR: mechanistic target of rapamycin kinase; MTORC1: mechanistic target of rapamycin kinase complex 1.
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Affiliation(s)
- Julian M Carosi
- Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Timothy J Sargeant
- Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
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16
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Van Skike CE, DeRosa N, Galvan V, Hussong SA. Rapamycin restores peripheral blood flow in aged mice and in mouse models of atherosclerosis and Alzheimer's disease. GeroScience 2023; 45:1987-1996. [PMID: 37052770 PMCID: PMC10400743 DOI: 10.1007/s11357-023-00786-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 03/19/2023] [Indexed: 04/14/2023] Open
Abstract
Peripheral artery disease (PAD), defined as reduced blood flow to the lower limbs, is a serious disorder that can lead to loss of function in the lower extremities and even loss of limbs. One of the main risk factors for PAD is age, with up to 25% of adults over the age of 55 and up to 40% over the age of 80 presenting with some form of the disease. While age is the largest risk factor for PAD, other risk factors include atherosclerosis, smoking, hypertension, and diabetes. Furthermore, previous studies have suggested that the incidence of PAD is significantly increased in patients with Alzheimer's disease (AD). Attenuation of mTOR with rapamycin significantly improves cerebral blood flow and heart function in aged rodents as well as in mouse models of atherosclerosis, atherosclerosis-driven cognitive impairment, and AD. In this study, we show that rapamycin treatment improves peripheral blood flow in aged mice and in mouse models of atherosclerosis and AD. Inhibition of mTOR with rapamycin ameliorates deficits in baseline hind paw perfusion in aged mice and restores levels of blood flow to levels indistinguishable from those of young controls. Furthermore, rapamycin treatment ameliorates peripheral blood flow deficits in mouse models of atherosclerosis and AD. These data indicate that mTOR is causally involved in the reduction of blood flow to lower limbs associated with aging, atherosclerosis, and AD-like progression in model mice. Rapamycin or other mTOR inhibitors may have potential as interventions to treat peripheral artery disease and other peripheral circulation-related conditions.
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Affiliation(s)
- Candice E Van Skike
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center San Antonio, San Antonio, TX, 78229, USA
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center San Antonio, San Antonio, TX, 78229, USA
| | - Nicholas DeRosa
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center San Antonio, San Antonio, TX, 78229, USA
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center San Antonio, San Antonio, TX, 78229, USA
| | - Veronica Galvan
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
- Oklahoma City Veterans Health Care System, Oklahoma City, OK, 73104, USA.
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
| | - Stacy A Hussong
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- Oklahoma City Veterans Health Care System, Oklahoma City, OK, 73104, USA
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17
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Riordan R, Rong W, Yu Z, Ross G, Valerio J, Dimas-Muñoz J, Heredia V, Magnusson K, Galvan V, Perez VI. Effect of Nrf2 loss on senescence and cognition of tau-based P301S mice. GeroScience 2023; 45:1451-1469. [PMID: 36976489 PMCID: PMC10400516 DOI: 10.1007/s11357-023-00760-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 02/20/2023] [Indexed: 03/29/2023] Open
Abstract
Cellular senescence may contribute to chronic inflammation involved in the progression of age-related diseases such as Alzheimer's disease (AD), and its removal prevents cognitive impairment in a model of tauopathy. Nrf2, the major transcription factor for damage response pathways and regulators of inflammation, declines with age. Our previous work showed that silencing Nrf2 gives rise to premature senescence in cells and mice. Others have shown that Nrf2 ablation can exacerbate cognitive phenotypes of some AD models. In this study, we aimed to understand the relationship between Nrf2 elimination, senescence, and cognitive impairment in AD, by generating a mouse model expressing a mutant human tau transgene in an Nrf2 knockout (Nrf2KO) background. We assessed senescent cell burden and cognitive decline of P301S mice in the presence and absence of Nrf2. Lastly, we administered 4.5-month-long treatments with two senotherapeutic drugs to analyze their potential to prevent senescent cell burden and cognitive decline: the senolytic drugs dasatinib and quercetin (DQ) and the senomorphic drug rapamycin. Nrf2 loss accelerated the onset of hind-limb paralysis in P301S mice. At 8.5 months of age, P301S mice did not exhibit memory deficits, while P301S mice without Nrf2 were significantly impaired. However, markers of senescence were not elevated by Nrf2 ablation in any of tissues that we examined. Neither drug treatment improved cognitive performance, nor did it reduce expression of senescence markers in brains of P301S mice. Contrarily, rapamycin treatment at the doses used delayed spatial learning and led to a modest decrease in spatial memory. Taken together, our data suggests that the emergence of senescence may be causally associated with onset of cognitive decline in the P301S model, indicate that Nrf2 protects brain function in a model of AD through mechanisms that may include, but do not require the inhibition of senescence, and suggest possible limitations for DQ and rapamycin as therapies for AD.
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Affiliation(s)
- Ruben Riordan
- Department of Biochemistry and Biophysics, Linus Pauling Institute, Oregon State University, 351 Linus Pauling Science Center, Corvallis, OR, 97331, USA
- Linus Pauling Institute, Oregon State University, Corvallis, OR, USA
| | - Wang Rong
- Department of Biochemistry and Biophysics, Linus Pauling Institute, Oregon State University, 351 Linus Pauling Science Center, Corvallis, OR, 97331, USA
- Linus Pauling Institute, Oregon State University, Corvallis, OR, USA
| | - Zhen Yu
- Department of Biochemistry and Biophysics, Linus Pauling Institute, Oregon State University, 351 Linus Pauling Science Center, Corvallis, OR, 97331, USA
- Linus Pauling Institute, Oregon State University, Corvallis, OR, USA
| | - Grace Ross
- Department of Biochemistry and Biophysics, Linus Pauling Institute, Oregon State University, 351 Linus Pauling Science Center, Corvallis, OR, 97331, USA
- Linus Pauling Institute, Oregon State University, Corvallis, OR, USA
| | - Juno Valerio
- Department of Biochemistry and Biophysics, Linus Pauling Institute, Oregon State University, 351 Linus Pauling Science Center, Corvallis, OR, 97331, USA
- Linus Pauling Institute, Oregon State University, Corvallis, OR, USA
| | - Jovita Dimas-Muñoz
- Department of Biochemistry and Biophysics, Linus Pauling Institute, Oregon State University, 351 Linus Pauling Science Center, Corvallis, OR, 97331, USA
- Linus Pauling Institute, Oregon State University, Corvallis, OR, USA
| | - Valeria Heredia
- Department of Biochemistry and Biophysics, Linus Pauling Institute, Oregon State University, 351 Linus Pauling Science Center, Corvallis, OR, 97331, USA
- Linus Pauling Institute, Oregon State University, Corvallis, OR, USA
| | - Kathy Magnusson
- Linus Pauling Institute, Oregon State University, Corvallis, OR, USA
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | - Veronica Galvan
- Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 740 Stanton L. Young Bvd BMSB 821, Oklahoma City, OK, 73104, USA.
- Oklahoma City VA Medical Center, US Department of Veterans Affairs, Oklahoma City, OK, USA.
| | - Viviana I Perez
- Department of Biochemistry and Biophysics, Linus Pauling Institute, Oregon State University, 351 Linus Pauling Science Center, Corvallis, OR, 97331, USA.
- Linus Pauling Institute, Oregon State University, Corvallis, OR, USA.
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18
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Hussong SA, Banh AQ, Van Skike CE, Dorigatti AO, Hernandez SF, Hart MJ, Ferran B, Makhlouf H, Gaczynska M, Osmulski PA, McAllen SA, Dineley KT, Ungvari Z, Perez VI, Kayed R, Galvan V. Soluble pathogenic tau enters brain vascular endothelial cells and drives cellular senescence and brain microvascular dysfunction in a mouse model of tauopathy. Nat Commun 2023; 14:2367. [PMID: 37185259 PMCID: PMC10126555 DOI: 10.1038/s41467-023-37840-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 03/31/2023] [Indexed: 05/17/2023] Open
Abstract
Vascular mechanisms of Alzheimer's disease (AD) may constitute a therapeutically addressable biological pathway underlying dementia. We previously demonstrated that soluble pathogenic forms of tau (tau oligomers) accumulate in brain microvasculature of AD and other tauopathies, including prominently in microvascular endothelial cells. Here we show that soluble pathogenic tau accumulates in brain microvascular endothelial cells of P301S(PS19) mice modeling tauopathy and drives AD-like brain microvascular deficits. Microvascular impairments in P301S(PS19) mice were partially negated by selective removal of pathogenic soluble tau aggregates from brain. We found that similar to trans-neuronal transmission of pathogenic forms of tau, soluble tau aggregates are internalized by brain microvascular endothelial cells in a heparin-sensitive manner and induce microtubule destabilization, block endothelial nitric oxide synthase (eNOS) activation, and potently induce endothelial cell senescence that was recapitulated in vivo in microvasculature of P301S(PS19) mice. Our studies suggest that soluble pathogenic tau aggregates mediate AD-like brain microvascular deficits in a mouse model of tauopathy, which may arise from endothelial cell senescence and eNOS dysfunction triggered by internalization of soluble tau aggregates.
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Affiliation(s)
- Stacy A Hussong
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Oklahoma City Veterans Health Care System, 921 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Andy Q Banh
- South Texas Medical Scientist Training Program, University of Texas Health San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Candice E Van Skike
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Angela O Dorigatti
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Stephen F Hernandez
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Matthew J Hart
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Center for Therapeutic Science, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
| | - Beatriz Ferran
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
| | - Haneen Makhlouf
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
| | - Maria Gaczynska
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
| | - Pawel A Osmulski
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
| | - Salome A McAllen
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Mitchell Center for Neurodegenerative Disease, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Sealy Center for Vaccine Development, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
| | - Kelly T Dineley
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Mitchell Center for Neurodegenerative Disease, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Sealy Center for Vaccine Development, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
| | - Zoltan Ungvari
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Department of Neurosurgery, University of Oklahoma Health Sciences Center, 800 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine, Department of Public Health, Semmelweis University, H-1085 Budapest, Üllői út 26, Budapest, Hungary
| | | | - Rakez Kayed
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Mitchell Center for Neurodegenerative Disease, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Sealy Center for Vaccine Development, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
| | - Veronica Galvan
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA.
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA.
- Oklahoma City Veterans Health Care System, 921 NE 13th Street, Oklahoma City, OK, 73104, USA.
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Bensalem J, Hein LK, Hassiotis S, Trim PJ, Proud CG, Heilbronn LK, Sargeant TJ. Modifying Dietary Protein Impacts mTOR Signaling and Brain Deposition of Amyloid β in a Knock-In Mouse Model of Alzheimer Disease. J Nutr 2023; 153:1407-1419. [PMID: 36870538 DOI: 10.1016/j.tjnut.2023.02.035] [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: 11/21/2022] [Revised: 01/24/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
BACKGROUND Alzheimer disease (AD) is a neurodegenerative condition defined by the build-up of amyloid plaques in the brain and intraneuronal tangles of the protein tau. Autophagy is a cellular cleaning process involved in the degradation of proteins, including proteins directly responsible for amyloid plaques, but its activity is compromised in AD. The mechanistic target of rapamycin complex (mTORC) 1 inhibits autophagy when activated by amino acids. OBJECTIVES We hypothesized that reducing amino acid intake by decreasing dietary protein could promote autophagy, which in turn could prevent amyloid plaque deposition in AD mice. METHODS Homozygote (2-mo-old) and heterozygote (4-mo-old) amyloid precursor protein NL-G-F mice, a model of brain amyloid deposition, were used in this study to test this hypothesis. Male and female mice were fed with isocaloric low-protein, control, or high-protein diets for 4 mo and killed for analysis. Locomotor performance was measured using the inverted screen test, and body composition was measured using EchoMRI. Samples were analyzed using western blotting, enzyme-linked immunosorbent assay, mass spectrometry, and immunohistochemical staining. RESULTS mTORC1 activity in the cerebral cortex was inversely covaried with protein consumption in both homozygote and heterozygote mice. Low-protein diet improved metabolic parameters and restored locomotor performance only in male homozygous mice. Dietary protein adjustment did not affect amyloid deposition in homozygous mice. However, in the heterozygous amyloid precursor protein NL-G-F mice, amyloid plaque was lower in male mice consuming the low protein compared with that in mice fed with the control diet. CONCLUSIONS This study showed that reducing protein intake reduces mTORC1 activity and may prevent amyloid accumulation, at least in male mice. Moreover, dietary protein is a tool that can be used to change mTORC1 activity and amyloid deposition in the mouse brain, and the murine brain's response to dietary protein is sex specific.
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Affiliation(s)
- Julien Bensalem
- Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia; Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Leanne K Hein
- Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Sofia Hassiotis
- Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Paul J Trim
- Proteomics, Metabolomics and MS-Imaging Core Facility, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Christopher G Proud
- Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Leonie K Heilbronn
- Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia; Nutrition, Metabolism & Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Timothy J Sargeant
- Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia; Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia.
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20
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Al-Kuraishy HM, Al-Gareeb AI, Alsayegh AA, Hakami ZH, Khamjan NA, Saad HM, Batiha GES, De Waard M. A Potential Link Between Visceral Obesity and Risk of Alzheimer's Disease. Neurochem Res 2023; 48:745-766. [PMID: 36409447 DOI: 10.1007/s11064-022-03817-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/05/2022] [Accepted: 11/08/2022] [Indexed: 11/22/2022]
Abstract
Alzheimer's disease (AD) is the most common type of dementia characterized by the deposition of amyloid beta (Aβ) plaques and tau-neurofibrillary tangles in the brain. Visceral obesity (VO) is usually associated with low-grade inflammation due to higher expression of pro-inflammatory cytokines by adipose tissue. The objective of the present review was to evaluate the potential link between VO and the development of AD. Tissue hypoxia in obesity promotes tissue injury, production of adipocytokines, and release of pro-inflammatory cytokines leading to an oxidative-inflammatory loop with induction of insulin resistance. Importantly, brain insulin signaling is involved in the pathogenesis of AD and lower cognitive function. Obesity and enlargement of visceral adipose tissue are associated with the deposition of Aβ. All of this is consonant with VO increasing the risk of AD through the dysregulation of adipocytokines which affect the development of AD. The activated nuclear factor kappa B (NF-κB) pathway in VO might be a potential link in the development of AD. Likewise, the higher concentration of advanced glycation end-products in VO could be implicated in the pathogenesis of AD. Taken together, different inflammatory signaling pathways are activated in VO that all have a negative impact on the cognitive function and progression of AD except hypoxia-inducible factor 1 which has beneficial and neuroprotective effects in mitigating the progression of AD. In addition, VO-mediated hypoadiponectinemia and leptin resistance may promote the progression of Aβ formation and tau phosphorylation with the development of AD. In conclusion, VO-induced AD is mainly mediated through the induction of oxidative stress, inflammatory changes, leptin resistance, and hypoadiponectinemia that collectively trigger Aβ formation and neuroinflammation. Thus, early recognition of VO by visceral adiposity index with appropriate management could be a preventive measure against the development of AD in patients with VO.
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Affiliation(s)
- Hayder M Al-Kuraishy
- Department of Pharmacology, Toxicology and Medicine, Medical Faculty, College of Medicine, Al-Mustansiriyah University, P.O. Box 14132, Baghdad, Iraq
| | - Ali I Al-Gareeb
- Department of Pharmacology, Toxicology and Medicine, Medical Faculty, College of Medicine, Al-Mustansiriyah University, P.O. Box 14132, Baghdad, Iraq
| | - Abdulrahman A Alsayegh
- Clinical Nutrition Department, Applied Medical Sciences College, Jazan University, Jazan, 82817, Saudi Arabia
| | - Zaki H Hakami
- Medical Laboratory Technology Department Applied Medical Sciences College, Jazan University, Jazan, 82817, Saudi Arabia
| | - Nizar A Khamjan
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia
| | - Hebatallah M Saad
- Department of Pathology, Faculty of Veterinary Medicine, Matrouh University, Marsa Matruh, 51744, Egypt.
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, 22511, Egypt.
| | - Michel De Waard
- Smartox Biotechnology, 6 rue des Platanes, 38120, Saint-Egrève, France.,L'institut du thorax, INSERM, CNRS, UNIV NANTES, 44007, Nantes, France.,LabEx «Ion Channels, Science & Therapeutics», Université de Nice Sophia-Antipolis, 06560, Valbonne, France
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21
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Cipolla MJ. Therapeutic Induction of Collateral Flow. Transl Stroke Res 2023; 14:53-65. [PMID: 35416577 PMCID: PMC10155807 DOI: 10.1007/s12975-022-01019-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 01/31/2023]
Abstract
Therapeutic induction of collateral flow as a means to salvage tissue and improve outcome from acute ischemic stroke is a promising approach in the era in which endovascular therapy is no longer time-dependent but collateral-dependent. The importance of collateral flow enhancement as a therapeutic for acute ischemic stroke extends beyond those patients with large amounts of salvageable tissue. It also has the potential to extend the time window for reperfusion therapies in patients who are ineligible for endovascular thrombectomy. In addition, collateral enhancement may be an important adjuvant to neuroprotective agents by providing a more robust vascular route for which treatments can gain access to at risk tissue. However, our understanding of collateral hemodynamics, including under comorbid conditions that are highly prevalent in the stroke population, has hindered the efficacy of collateral flow augmentation for improving stroke outcome in the clinical setting. This review will discuss our current understanding of pial collateral function and hemodynamics, including vasoactivity that is critical for enhancing penumbral perfusion. In addition, mechanisms by which collateral flow can be increased during acute ischemic stroke to limit ischemic injury, that may be different depending on the state of the brain and vasculature prior to stroke, will also be reviewed.
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Affiliation(s)
- Marilyn J Cipolla
- Department of Neurological Sciences, University of Vermont Robert Larner College of Medicine, 149 Beaumont Ave, HSRF 416A, Burlington, VT, USA.
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont Larner College of Medicine, Burlington, VT, USA.
- Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT, USA.
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22
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Zhang L, Wong LR, Wong P, Shen W, Yang S, Huang L, Lim YA, Ho PCL. Chronic treatment with baicalein alleviates behavioural disorders and improves cerebral blood flow via reverting metabolic abnormalities in a J20 transgenic mouse model of Alzheimer's disease. Brain Behav Immun Health 2023; 28:100599. [PMID: 36817510 PMCID: PMC9931920 DOI: 10.1016/j.bbih.2023.100599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 01/21/2023] [Accepted: 01/29/2023] [Indexed: 02/01/2023] Open
Abstract
Baicalein (BE) has both antioxidant and anti-inflammatory effects. It has also been reported able to improve cerebral blood circulation in brain ischemic injury. However, its chronic efficacy and metabolomics in Alzheimer's disease (AD) remain unknown. In this study, BE at 80 mg/kg was administrated through the oral route in J20 AD transgenic mice aged from aged 4 months to aged 10 months. Metabolic- and neurobehavioural phenotyping was done before and after 6 months' treatment to evaluate the drug efficacy and the relevant mechanisms. Meanwhile, molecular docking was used to study the binding affinity of BE and poly (ADP-ribose) polymerase-1 (PARP-1) which is related to neuronal injury. The open field test showed that BE could suppress hyperactivity in J20 mice and increase the frequency of the target quadrant crossing in the Morris Water Maze test. More importantly, BE restored cerebral blood flow back to the normal level after the chronic treatment. A 1H NMR-based metabolomics study showed that BE treatment could restore the tricarboxylic acid cycle in plasma. And such a treatment could suppress oxidative stress, inhibit neuroinflammation, alleviate mitochondrial dysfunction, improve neurotransmission, and restore amino homeostasis via starch and sucrose metabolism and glycolipid metabolism in the cortex and hippocampus, which could affect the behavioural and cerebral blood flow. These findings showed that BE is a potential therapeutic agent for AD.
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Affiliation(s)
- Li Zhang
- Integrative Sciences and Engineering Programme, NUS Graduate School, National University of Singapore, Singapore, 117583, Singapore,Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, 117543, Singapore
| | - Ling Rong Wong
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, 117543, Singapore
| | - Peiyan Wong
- Neuroscience Phenotyping Core, Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 117456, Singapore
| | - Wanxiang Shen
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 117543, Singapore
| | - Shili Yang
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, 117543, Singapore
| | - Lizhen Huang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Yun-An Lim
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Paul Chi-Lui Ho
- Integrative Sciences and Engineering Programme, NUS Graduate School, National University of Singapore, Singapore, 117583, Singapore,Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, 117543, Singapore,Monash University Malaysia, School of Pharmacy, Subang Jaya, 47500, Selangor, Malaysia,Corresponding author. Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, 117543, Singapore.
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23
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Huang W, Xia Q, Zheng F, Zhao X, Ge F, Xiao J, Liu Z, Shen Y, Ye K, Wang D, Li Y. Microglia-Mediated Neurovascular Unit Dysfunction in Alzheimer's Disease. J Alzheimers Dis 2023; 94:S335-S354. [PMID: 36683511 PMCID: PMC10473143 DOI: 10.3233/jad-221064] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2022] [Indexed: 01/21/2023]
Abstract
The neurovascular unit (NVU) is involved in the pathological changes in Alzheimer's disease (AD). The NVU is a structural and functional complex that maintains microenvironmental homeostasis and metabolic balance in the central nervous system. As one of the most important components of the NVU, microglia not only induce blood-brain barrier breakdown by promoting neuroinflammation, the infiltration of peripheral white blood cells and oxidative stress but also mediate neurovascular uncoupling by inducing mitochondrial dysfunction in neurons, abnormal contraction of cerebral vessels, and pericyte loss in AD. In addition, microglia-mediated dysfunction of cellular components in the NVU, such as astrocytes and pericytes, can destroy the integrity of the NVU and lead to NVU impairment. Therefore, we review the mechanisms of microglia-mediated NVU dysfunction in AD. Furthermore, existing therapeutic advancements aimed at restoring the function of microglia and the NVU in AD are discussed. Finally, we predict the role of pericytes in microglia-mediated NVU dysfunction in AD is the hotspot in the future.
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Affiliation(s)
- Wenhao Huang
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Qing Xia
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Feifei Zheng
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Xue Zhao
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Fangliang Ge
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Jiaying Xiao
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Zijie Liu
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Yingying Shen
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Ke Ye
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Dayong Wang
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
- Basic Medical Institute, Heilongjiang Medical Science Academy, Harbin, Heilongjiang Province, China
- Translational Medicine Center of Northern China, Harbin, Heilongjiang Province, China
- Key Laboratory of Heilongjiang Province for Genetically Modified Animals, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Yanze Li
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
- Basic Medical Institute, Heilongjiang Medical Science Academy, Harbin, Heilongjiang Province, China
- Translational Medicine Center of Northern China, Harbin, Heilongjiang Province, China
- Key Laboratory of Heilongjiang Province for Genetically Modified Animals, Harbin Medical University, Harbin, Heilongjiang Province, China
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24
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mTOR contributes to endothelium-dependent vasorelaxation by promoting eNOS expression and preventing eNOS uncoupling. Commun Biol 2022; 5:726. [PMID: 35869262 PMCID: PMC9307829 DOI: 10.1038/s42003-022-03653-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 06/24/2022] [Indexed: 11/08/2022] Open
Abstract
Clinically used inhibitors of mammalian target of rapamycin (mTOR) negatively impacts endothelial-dependent vasodilatation (EDD) through unidentified mechanisms. Here we show that either the endothelium-specific deletion of Mtor to inhibit both mTOR complexes, or depletion of Raptor or Rictor to disrupt mTORC1 or mTORC2, causes impaired EDD, accompanied by reduced NO in the serum of mice. Consistently, inhibition of mTOR decreases NO production by human and mouse EC. Specifically, inhibition of mTORC1 suppresses eNOS gene expression, due to impairment in p70S6K-mediated posttranscriptional regulation of the transcription factor KLF2 expression. In contrast to mTORC1 inhibition, a positive-feedback between MAPK (p38 and JNK) activation and Nox2 upregulation contributes to the excessive generation of reactive oxygen species (ROS), which causes eNOS uncoupling and decreased NO bioavailability in mTORC2-inhibited EC. Adeno-associated virus-mediated EC-specific overexpression of KLF2 or suppression of Nox2 restores EDD function in endothelial mTORC1- or mTORC2-inhibited mice. The endothelium-specific inhibition of either of mammalian target of rapamycin (mTOR) complexes impairs endothelial-dependent vasodilatation (EDD), accompanied by decreased nitric oxide bioavailability in both human and mice endothelial cells.
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25
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Effects of lifespan-extending interventions on cognitive healthspan. Expert Rev Mol Med 2022; 25:e2. [PMID: 36377361 DOI: 10.1017/erm.2022.36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ageing is known to be the primary risk factor for most neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease and Huntington's disease. They are currently incurable and worsen over time, which has broad implications in the context of lifespan and healthspan extension. Adding years to life and even to physical health is suboptimal or even insufficient, if cognitive ageing is not adequately improved. In this review, we will examine how interventions that have the potential to extend lifespan in animals affect the brain, and if they would be able to thwart or delay the development of cognitive dysfunction and/or neurodegeneration. These interventions range from lifestyle (caloric restriction, physical exercise and environmental enrichment) through pharmacological (nicotinamide adenine dinucleotide precursors, resveratrol, rapamycin, metformin, spermidine and senolytics) to epigenetic reprogramming. We argue that while many of these interventions have clear potential to improve cognitive health and resilience, large-scale and long-term randomised controlled trials are needed, along with studies utilising washout periods to determine the effects of supplementation cessation, particularly in aged individuals.
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26
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Hunt NJ, Wahl D, Westwood LJ, Lockwood GP, Le Couteur DG, Cogger VC. Targeting the liver in dementia and cognitive impairment: Dietary macronutrients and diabetic therapeutics. Adv Drug Deliv Rev 2022; 190:114537. [PMID: 36115494 PMCID: PMC10125004 DOI: 10.1016/j.addr.2022.114537] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 09/04/2022] [Accepted: 09/07/2022] [Indexed: 01/24/2023]
Abstract
Many people living with dementia and cognitive impairment have dysfunctional mitochondrial and insulin-glucose metabolism resembling type 2 diabetes mellitus and old age. Evidence from human trials shows that nutritional interventions and anti-diabetic medicines that target nutrient-sensing pathways overcome these deficits in glucose and energy metabolism and can improve cognition and/or reduce symptoms of dementia. The liver is the main organ that mediates the systemic effects of diets and many diabetic medicines; therefore, it is an intermediate target for such dementia interventions. A challenge is the efficacy of these treatments in older age. Solutions include the targeted hepatic delivery of diabetic medicines using nanotechnologies and titration of macronutrients to optimize hepatic energy metabolism.
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Affiliation(s)
- Nicholas J Hunt
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2008, Australia; Charles Perkins Centre, The University of Sydney, Sydney, NSW 2008, Australia; Sydney Nano Institute, The University of Sydney, Sydney, NSW 2008, Australia; ANZAC Research Institute & Centre for Education and Research on Ageing, Concord Repatriation General Hospital, Concord, NSW 2139, Australia
| | - Devin Wahl
- Department of Health and Exercise Science & Centre for Healthy Aging, Colorado State University, CO 80523, United States
| | - Lara J Westwood
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2008, Australia; ANZAC Research Institute & Centre for Education and Research on Ageing, Concord Repatriation General Hospital, Concord, NSW 2139, Australia
| | - Glen P Lockwood
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2008, Australia; ANZAC Research Institute & Centre for Education and Research on Ageing, Concord Repatriation General Hospital, Concord, NSW 2139, Australia
| | - David G Le Couteur
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2008, Australia; Charles Perkins Centre, The University of Sydney, Sydney, NSW 2008, Australia; ANZAC Research Institute & Centre for Education and Research on Ageing, Concord Repatriation General Hospital, Concord, NSW 2139, Australia
| | - Victoria C Cogger
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2008, Australia; ANZAC Research Institute & Centre for Education and Research on Ageing, Concord Repatriation General Hospital, Concord, NSW 2139, Australia.
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27
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Yang Y, Zhao X, Zhu Z, Zhang L. Vascular dementia: A microglia's perspective. Ageing Res Rev 2022; 81:101734. [PMID: 36113763 DOI: 10.1016/j.arr.2022.101734] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 08/28/2022] [Accepted: 09/11/2022] [Indexed: 01/31/2023]
Abstract
Vascular dementia (VaD) is a second most common form of age-related dementia. It is characterized by cognitive impairment associated with vascular pathology, symptoms mainly caused by cerebral damage due to inadequate blood flow to the brain. The pathogenesis of VaD is complex, and a growing body of literature emphasizes on the involvement of microglia in disease development and progression. Here, we review the current knowledge on the role of microglia in regulating neuroinflammation under the pathogenesis of VaD. The commonly used animal and cell models for understanding the disease pathogenesis were summarized. The mechanisms by which microglia contribute to VaD are multifactorial, and we specifically focus on some of the predominant functions of microglia, including chemotaxis, secretory property, phagocytosis, and its crosstalk with other neurovascular unit cells. Finally, potential therapeutic strategies targeting microglia-modulated neuroinflammation are discussed.
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Affiliation(s)
- Yi Yang
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; Hangzhou Key Laboratory of Medical Neurobiology, Hangzhou Normal University, Hangzhou 311121, China; Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China.
| | - Xinyuan Zhao
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; Hangzhou Key Laboratory of Medical Neurobiology, Hangzhou Normal University, Hangzhou 311121, China
| | - Zirui Zhu
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; Hangzhou Key Laboratory of Medical Neurobiology, Hangzhou Normal University, Hangzhou 311121, China
| | - Lihui Zhang
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; Hangzhou Key Laboratory of Medical Neurobiology, Hangzhou Normal University, Hangzhou 311121, China; Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China.
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28
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Shi Q, Chang C, Saliba A, Bhat MA. Microglial mTOR Activation Upregulates Trem2 and Enhances β-Amyloid Plaque Clearance in the 5XFAD Alzheimer's Disease Model. J Neurosci 2022; 42:5294-5313. [PMID: 35672148 PMCID: PMC9270922 DOI: 10.1523/jneurosci.2427-21.2022] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 05/04/2022] [Accepted: 05/05/2022] [Indexed: 02/08/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) signaling pathway plays a major role in key cellular processes including metabolism and differentiation; however, the role of mTOR in microglia and its importance in Alzheimer's disease (AD) have remained largely uncharacterized. We report that selective loss of Tsc1, a negative regulator of mTOR, in microglia in mice of both sexes, caused mTOR activation and upregulation of Trem2 with enhanced β-Amyloid (Aβ) clearance, reduced spine loss, and improved cognitive function in the 5XFAD AD mouse model. Combined loss of Tsc1 and Trem2 in microglia led to reduced Aβ clearance and increased Aβ plaque burden revealing that Trem2 functions downstream of mTOR. Tsc1 mutant microglia showed increased phagocytosis with upregulation of CD68 and Lamp1 lysosomal proteins. In vitro studies using Tsc1-deficient microglia revealed enhanced endocytosis of the lysosomal tracker indicator Green DND-26 suggesting increased lysosomal activity. Incubation of Tsc1-deficient microglia with fluorescent-labeled Aβ revealed enhanced Aβ uptake and clearance, which was blunted by rapamycin, an mTOR inhibitor. In vivo treatment of mice of relevant genotypes in the 5XFAD background with rapamycin, affected microglial activity, decreased Trem2 expression and reduced Aβ clearance causing an increase in Aβ plaque burden. Prolonged treatment with rapamycin caused even further reduction of mTOR activity, reduction in Trem2 expression, and increase in Aβ levels. Together, our findings reveal that mTOR signaling in microglia is critically linked to Trem2 regulation and lysosomal biogenesis, and that the upregulation of Trem2 in microglia through mTOR activation could be exploited toward better therapeutic avenues to Aβ-related AD pathologies.SIGNIFICANCE STATEMENT Mechanistic target of rapamycin (mTOR) signaling pathway is a key regulator for major cellular metabolic processes. However, the link between mTOR signaling and Alzheimer's disease (AD) is not well understood. In this study, we provide compelling in vivo evidence that mTOR activation in microglia would benefit β-Amyloid (Aβ)-related AD pathologies, as it upregulates Trem2, a key receptor for Aβ plaque uptake. Inhibition of mTOR pathway with rapamycin, a well-established immunosuppressant, downregulated Trem2 in microglia and reduced Aβ plaque clearance indicating that mTOR inactivation may be detrimental in Aβ-associated AD patients. This finding will have a significant public health impact and benefit, regarding the usage of rapamycin in AD patients, which we believe will aggravate the Aβ-related AD pathologies.
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Affiliation(s)
- Qian Shi
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health Science Center, San Antonio, Texas 78229
| | - Cheng Chang
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health Science Center, San Antonio, Texas 78229
| | - Afaf Saliba
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health Science Center, San Antonio, Texas 78229
| | - Manzoor A Bhat
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health Science Center, San Antonio, Texas 78229
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29
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Khonsari F, Heydari M, Sharifzadeh M, Valizadeh H, Dinarvand R, Atyabi F. Transferrin decorated-nanostructured lipid carriers (NLCs) are a promising delivery system for rapamycin in Alzheimer's disease: An in vivo study. BIOMATERIALS ADVANCES 2022; 137:212827. [PMID: 35929260 DOI: 10.1016/j.bioadv.2022.212827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/06/2022] [Accepted: 04/21/2022] [Indexed: 06/15/2023]
Abstract
Alzheimer's disease (AD), the most common neurodegenerative disorder, is characterized by progressive cognitive impairment and memory loss. The mammalian target of rapamycin (mTOR) signaling pathway could regulate learning and memory. The effect of rapamycin (Rapa) on mTOR activity could slow or prevent the progression of AD by affecting various essential cellular processes. Previously, we prepared transferrin (Tf) decorated-nanostructured lipid carriers (NLCs) for rapamycin (150 ± 9 nm) to protect the drug from chemical and enzymatic degradation and for brain targeted delivery of rapamycin. Herein, the effect of Tf-NLCs compared to untargeted anionic-NLCs and free rapamycin, were studied in amyloid beta (Aβ) induced rat model of AD. Behavioral test revealed that the Rapa Tf-NLCs were able to significantly improve the impaired spatial memory induced by Aβ. Histopathological studies of hippocampus also showed neural survival in Rapa Tf-NLCs treated group. The immunosuppressive, and delayed wound healing adverse effects in the rapamycin solution treated group were abolished by incorporating the drug into NLCs. The Aβ induced oxidative stress was also reduced by Rapa Tf-NLCs. Molecular studies on the level of Aβ, autophagy (LC3) and apoptotic (caspase-3) markers, and mTOR activity revealed that the Rapa Tf-NLCs decreased the Aβ level and suppressed the toxic effects of Aβ plaques by modulating the mTOR activity and autophagy, and decreasing the apoptosis level. As a conclusion, the designed Tf-NLCs could be an appropriate and a safe brain delivery system for rapamycin and make this drug more efficient in AD for improving memory and neuroprotection.
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Affiliation(s)
- Fatemeh Khonsari
- Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mostafa Heydari
- Department of Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sharifzadeh
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
| | - Hadi Valizadeh
- Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran; Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Rassoul Dinarvand
- Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; School of Pharmacy, De Mont Fort University, Leicester, UK
| | - Fatemeh Atyabi
- Department of Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
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Blood-brain barrier leakage in Alzheimer's disease: From discovery to clinical relevance. Pharmacol Ther 2022; 234:108119. [PMID: 35108575 PMCID: PMC9107516 DOI: 10.1016/j.pharmthera.2022.108119] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 12/16/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia. AD brain pathology starts decades before the onset of clinical symptoms. One early pathological hallmark is blood-brain barrier dysfunction characterized by barrier leakage and associated with cognitive decline. In this review, we summarize the existing literature on the extent and clinical relevance of barrier leakage in AD. First, we focus on AD animal models and their susceptibility to barrier leakage based on age and genetic background. Second, we re-examine barrier dysfunction in clinical and postmortem studies, summarize changes that lead to barrier leakage in patients and highlight the clinical relevance of barrier leakage in AD. Third, we summarize signaling mechanisms that link barrier leakage to neurodegeneration and cognitive decline in AD. Finally, we discuss clinical relevance and potential therapeutic strategies and provide future perspectives on investigating barrier leakage in AD. Identifying mechanistic steps underlying barrier leakage has the potential to unravel new targets that can be used to develop novel therapeutic strategies to repair barrier leakage and slow cognitive decline in AD and AD-related dementias.
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31
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Zhu WM, Neuhaus A, Beard DJ, Sutherland BA, DeLuca GC. Neurovascular coupling mechanisms in health and neurovascular uncoupling in Alzheimer's disease. Brain 2022; 145:2276-2292. [PMID: 35551356 PMCID: PMC9337814 DOI: 10.1093/brain/awac174] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/05/2022] [Accepted: 05/07/2022] [Indexed: 11/25/2022] Open
Abstract
To match the metabolic demands of the brain, mechanisms have evolved to couple neuronal activity to vasodilation, thus increasing local cerebral blood flow and delivery of oxygen and glucose to active neurons. Rather than relying on metabolic feedback signals such as the consumption of oxygen or glucose, the main signalling pathways rely on the release of vasoactive molecules by neurons and astrocytes, which act on contractile cells. Vascular smooth muscle cells and pericytes are the contractile cells associated with arterioles and capillaries, respectively, which relax and induce vasodilation. Much progress has been made in understanding the complex signalling pathways of neurovascular coupling, but issues such as the contributions of capillary pericytes and astrocyte calcium signal remain contentious. Study of neurovascular coupling mechanisms is especially important as cerebral blood flow dysregulation is a prominent feature of Alzheimer’s disease. In this article we will discuss developments and controversies in the understanding of neurovascular coupling and finish by discussing current knowledge concerning neurovascular uncoupling in Alzheimer’s disease.
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Affiliation(s)
- Winston M Zhu
- Oxford Medical School, University of Oxford, Oxford, UK
| | - Ain Neuhaus
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Daniel J Beard
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia
| | - Brad A Sutherland
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Gabriele C DeLuca
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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32
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Natural Products from Plants and Algae for Treatment of Alzheimer’s Disease: A Review. Biomolecules 2022; 12:biom12050694. [PMID: 35625622 PMCID: PMC9139049 DOI: 10.3390/biom12050694] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 12/14/2022] Open
Abstract
Neurodegenerative disorders including Parkinson’s disease (PD), Huntington’s disease (HD) and the most frequent, Alzheimer’s disease (AD), represent one of the most urgent medical needs worldwide. Despite a significantly developed understanding of disease development and pathology, treatments that stop AD progression are not yet available. The recent approval of sodium oligomannate (GV-971) for AD treatment in China emphasized the potential value of natural products for the treatment of neurodegenerative disorders. Many current clinical studies include the administration of a natural compound as a single and combination treatment. The most prominent mechanisms of action are anti-inflammatory and anti-oxidative activities, thus preserving cellular survival. Here, we review current natural products that are either approved or are in testing for a treatment of neurodegeneration in AD. In addition to the most important compounds of plant origin, we also put special emphasis on compounds from algae, given their neuroprotective activity and their underlying mechanisms of neuroprotection.
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Rahman MA, Rahman MDH, Mamun-Or-Rashid ANM, Hwang H, Chung S, Kim B, Rhim H. Autophagy Modulation in Aggresome Formation: Emerging Implications and Treatments of Alzheimer's Disease. Biomedicines 2022; 10:1027. [PMID: 35625764 PMCID: PMC9138936 DOI: 10.3390/biomedicines10051027] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is one of the most prevailing neurodegenerative diseases in the world, which is characterized by memory dysfunction and the formation of tau and amyloid β (Aβ) aggregates in multiple brain regions, including the hippocampus and cortex. The formation of senile plaques involving tau hyperphosphorylation, fibrillar Aβ, and neurofibrillary tangles (NFTs) is used as a pathological marker of AD and eventually produces aggregation or misfolded protein. Importantly, it has been found that the failure to degrade these aggregate-prone proteins leads to pathological consequences, such as synaptic impairment, cytotoxicity, neuronal atrophy, and memory deficits associated with AD. Recently, increasing evidence has suggested that the autophagy pathway plays a role as a central cellular protection system to prevent the toxicity induced by aggregation or misfolded proteins. Moreover, it has also been revealed that AD-related protein aggresomes could be selectively degraded by autophagosome and lysosomal fusion through the autophagy pathway, which is known as aggrephagy. Therefore, the regulation of autophagy serve as a useful approach to modulate the formation of aggresomes associated with AD. This review focuses on the recent improvements in the application of natural compounds and small molecules as a potential therapeutic approach for AD prevention and treatment via aggrephagy.
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Affiliation(s)
- Md Ataur Rahman
- Department of Pathology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
- Korean Medicine-Based Drug Repositioning Cancer Research Center, College of Korean Medicine, Kyung Hee University, 1-5, Hoegidong, Dongdaemungu, Seoul 02447, Korea
- Global Biotechnology & Biomedical Research Network (GBBRN), Department of Biotechnology and Genetic Engineering, Faculty of Biological Sciences, Islamic University, Kushtia 7003, Bangladesh
| | - M D Hasanur Rahman
- Department of Pathology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - A N M Mamun-Or-Rashid
- Anti-Aging Medical Research Center and Glycation Stress Research Center, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto 602-8566, Japan
| | - Hongik Hwang
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Korea
| | - Sooyoung Chung
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Korea
| | - Bonglee Kim
- Department of Pathology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
- Korean Medicine-Based Drug Repositioning Cancer Research Center, College of Korean Medicine, Kyung Hee University, 1-5, Hoegidong, Dongdaemungu, Seoul 02447, Korea
| | - Hyewhon Rhim
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Korea
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Korea
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Gourmaud S, Stewart DA, Irwin DJ, Roberts N, Barbour AJ, Eberwine G, O’Brien WT, Vassar R, Talos DM, Jensen FE. The role of mTORC1 activation in seizure-induced exacerbation of Alzheimer's disease. Brain 2022; 145:324-339. [PMID: 34264340 PMCID: PMC9126019 DOI: 10.1093/brain/awab268] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/04/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
The risk of seizures is 10-fold higher in patients with Alzheimer's disease than the general population, yet the mechanisms underlying this susceptibility and the effects of these seizures are poorly understood. To elucidate the proposed bidirectional relationship between Alzheimer's disease and seizures, we studied human brain samples (n = 34) from patients with Alzheimer's disease and found that those with a history of seizures (n = 14) had increased amyloid-β and tau pathology, with upregulation of the mechanistic target of rapamycin (mTOR) pathway, compared with patients without a known history of seizures (n = 20). To establish whether seizures accelerate the progression of Alzheimer's disease, we induced chronic hyperexcitability in the five times familial Alzheimer's disease mouse model by kindling with the chemoconvulsant pentylenetetrazol and observed that the mouse model exhibited more severe seizures than the wild-type. Furthermore, kindled seizures exacerbated later cognitive impairment, Alzheimer's disease neuropathology and mTOR complex 1 activation. Finally, we demonstrated that the administration of the mTOR inhibitor rapamycin following kindled seizures rescued enhanced remote and long-term memory deficits associated with earlier kindling and prevented seizure-induced increases in Alzheimer's disease neuropathology. These data demonstrated an important link between chronic hyperexcitability and progressive Alzheimer's disease pathology and suggest a mechanism whereby rapamycin may serve as an adjunct therapy to attenuate progression of the disease.
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Affiliation(s)
- Sarah Gourmaud
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David A Stewart
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Duke University School of Medicine, Durham, NC 27708, USA
| | - David J Irwin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Penn Frontotemporal Degeneration Center, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicholas Roberts
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Aaron J Barbour
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Grace Eberwine
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William T O’Brien
- Neurobehavior Testing Core, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert Vassar
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Delia M Talos
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Frances E Jensen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Lai C, Chen Z, Ding Y, Chen Q, Su S, Liu H, Ni R, Tang Z. Rapamycin Attenuated Zinc-Induced Tau Phosphorylation and Oxidative Stress in Rats: Involvement of Dual mTOR/p70S6K and Nrf2/HO-1 Pathways. Front Immunol 2022; 13:782434. [PMID: 35197970 PMCID: PMC8858937 DOI: 10.3389/fimmu.2022.782434] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 01/13/2022] [Indexed: 01/01/2023] Open
Abstract
Alzheimer’s disease is pathologically characterized by abnormal accumulation of amyloid-beta plaques, neurofibrillary tangles, oxidative stress, neuroinflammation, and neurodegeneration. Metal dysregulation, including excessive zinc released by presynaptic neurons, plays an important role in tau pathology and oxidase activation. The activities of mammalian target of rapamycin (mTOR)/ribosomal S6 protein kinase (p70S6K) are elevated in the brains of patients with Alzheimer’s disease. Zinc induces tau hyperphosphorylation via mTOR/P70S6K activation in vitro. However, the involvement of the mTOR/P70S6K pathway in zinc-induced oxidative stress, tau degeneration, and synaptic and cognitive impairment has not been fully elucidated in vivo. Here, we assessed the effect of pathological zinc concentrations in SH-SY5Y cells by using biochemical assays and immunofluorescence staining. Rats (n = 18, male) were laterally ventricularly injected with zinc, treated with rapamycin (intraperitoneal injection) for 1 week, and assessed using the Morris water maze. Evaluation of oxidative stress, tau phosphorylation, and synaptic impairment was performed using the hippocampal tissue of the rats by biochemical assays and immunofluorescence staining. The results from the Morris water maze showed that the capacity of spatial memory was impaired in zinc-treated rats. Zinc sulfate significantly increased the levels of P-mTOR Ser2448, P-p70S6K Thr389, and P-tau Ser356 and decreased the levels of nuclear factor erythroid 2-related factor-2 (Nrf2) and heme oxygenase-1 (HO-1) in SH-SY5Y cells and in zinc-treated rats compared with the control groups. Increased expression of reactive oxygen species was observed in zinc sulfate-induced SH-SY5Y cells and in the hippocampus of zinc-injected rats. Rapamycin, an inhibitor of mTOR, rescued zinc-induced increases in mTOR/p70S6K activation, tau phosphorylation, and oxidative stress, and Nrf2/HO-1 inactivation, cognitive impairment, and synaptic impairment reduced the expression of synapse-related proteins in zinc-injected rats. In conclusion, our findings imply that rapamycin prevents zinc-induced cognitive impairment and protects neurons from tau pathology, oxidative stress, and synaptic impairment by decreasing mTOR/p70S6K hyperactivity and increasing Nrf2/HO-1 activity.
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Affiliation(s)
- Chencen Lai
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education & Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
- Department of Nosocomial Infection, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Zhuyi Chen
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education & Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
| | - Yuanting Ding
- Department of Nosocomial Infection, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Qian Chen
- Department of Nosocomial Infection, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Songbai Su
- Department of Nosocomial Infection, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Heng Liu
- Department of Anesthesiology, Tongren Municipal People’s Hospital, Tongren, China
| | - Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, Eidgenössische Technische Hochschule Zürich (ETH) and University of Zurich, Zurich, Switzerland
| | - Zhi Tang
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education & Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
- *Correspondence: Zhi Tang,
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36
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Autophagy in Alzheimer's disease pathogenesis: Therapeutic potential and future perspectives. Ageing Res Rev 2021; 72:101464. [PMID: 34551326 DOI: 10.1016/j.arr.2021.101464] [Citation(s) in RCA: 101] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 09/01/2021] [Accepted: 09/16/2021] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative disease in the elderly and the most common cause of human dementia. AD is characterized by accumulation of abnormal protein aggregates including amyloid plaques (composed of beta-amyloid (Aβ) peptides) and neurofibrillary tangles (formed by hyper-phosphorylated tau protein). Synaptic plasticity, neuroinflammation, calcium signaling etc. also show dysfunction in AD patients. Autophagy is an evolutionarily conserved lysosome-dependent cellular event in eukaryotes. It is closely linked to modulation of protein metabolism, through which damaged organelles and mis-folded proteins are degraded and then recycled to maintain protein homeostasis. Accumulating evidence has shown that impaired autophagy also contributes to AD pathogenesis. In the present review, we highlight the role of autophagy, including bulk and selective autophagy, in regulating metabolic circuits in AD pathogenesis. We also discuss the potential and future perspectives of autophagy-inducing strategies in AD therapeutics.
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37
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Gonzales MM, Krishnamurthy S, Garbarino V, Daeihagh AS, Gillispie GJ, Deep G, Craft S, Orr ME. A geroscience motivated approach to treat Alzheimer's disease: Senolytics move to clinical trials. Mech Ageing Dev 2021; 200:111589. [PMID: 34687726 PMCID: PMC9059898 DOI: 10.1016/j.mad.2021.111589] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/04/2021] [Accepted: 10/18/2021] [Indexed: 12/29/2022]
Abstract
The pathogenic processes driving Alzheimer's disease (AD) are complex. An incomplete understanding of underlying disease mechanisms has presented insurmountable obstacles for developing effective disease-modifying therapies. Advanced chronological age is the greatest risk factor for developing AD. Intervening on biological aging may alter disease progression and represents a novel, complementary approach to current strategies. Toward this end, cellular senescence has emerged as a promising target. This complex stress response harbors damaged cells in a cell cycle arrested, apoptosis-resistant cell state. Senescent cells accumulate with age where they notoriously secrete molecules that contribute to chronic tissue dysfunction and disease. Thus, benefits of cell survival in a senescent fate are countered by their toxic secretome. The removal of senescent cells improves brain structure and function in rodent models at risk of developing AD, and in those with advanced Aβ and tau pathology. The present review describes the path to translating this promising treatment strategy to AD clinical trials. We review evidence for senescent cell accumulation in the human brain, considerations and strategies for senescence-targeting trials specific to AD, approaches to detect senescent brain cells in biofluids, and summarize the goals of the first senolytic trials for the treatment of AD (NCT04063124 and NCT04685590). This article is part of the Special Issue - Senolytics - Edited by Joao Passos and Diana Jurk.
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Affiliation(s)
- Mitzi M Gonzales
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Sudarshan Krishnamurthy
- Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA; Bowman Gray Center for Medical Education, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Valentina Garbarino
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Ali S Daeihagh
- Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Gregory J Gillispie
- Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Gagan Deep
- Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Suzanne Craft
- Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA; Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Miranda E Orr
- Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA; Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, NC, USA; Salisbury VA Medical Center, Salisbury, NC, USA.
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38
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Gonzales MM, Krishnamurthy S, Garbarino V, Daeihagh AS, Gillispie GJ, Deep G, Craft S, Orr ME. A geroscience motivated approach to treat Alzheimer’s disease: Senolytics move to clinical trials. Mech Ageing Dev 2021. [DOI: 10.1016/j.mad.2021.111589
expr 868687188 + 807217478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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39
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Molnár AÁ, Nádasy GL, Dörnyei G, Patai BB, Delfavero J, Fülöp GÁ, Kirkpatrick AC, Ungvári Z, Merkely B. The aging venous system: from varicosities to vascular cognitive impairment. GeroScience 2021; 43:2761-2784. [PMID: 34762274 PMCID: PMC8602591 DOI: 10.1007/s11357-021-00475-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/12/2021] [Indexed: 10/25/2022] Open
Abstract
Aging-induced pathological alterations of the circulatory system play a critical role in morbidity and mortality of older adults. While the importance of cellular and molecular mechanisms of arterial aging for increased cardiovascular risk in older adults is increasingly appreciated, aging processes of veins are much less studied and understood than those of arteries. In this review, age-related cellular and morphological alterations in the venous system are presented. Similarities and dissimilarities between arterial and venous aging are highlighted, and shared molecular mechanisms of arterial and venous aging are considered. The pathogenesis of venous diseases affecting older adults, including varicose veins, chronic venous insufficiency, and deep vein thrombosis, is discussed, and the potential contribution of venous pathologies to the onset of vascular cognitive impairment and neurodegenerative diseases is emphasized. It is our hope that a greater appreciation of the cellular and molecular processes of vascular aging will stimulate further investigation into strategies aimed at preventing or retarding age-related venous pathologies.
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Affiliation(s)
- Andrea Ágnes Molnár
- Heart and Vascular Center, Semmelweis University, Városmajor Street 68, 1121, Budapest, Hungary.
| | | | - Gabriella Dörnyei
- Department of Morphology and Physiology, Health Sciences Faculty, Semmelweis University, Budapest, Hungary
| | | | - Jordan Delfavero
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center On Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Gábor Áron Fülöp
- Heart and Vascular Center, Semmelweis University, Városmajor Street 68, 1121, Budapest, Hungary
| | - Angelia C Kirkpatrick
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Veterans Affairs Medical Center, 921 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Zoltán Ungvári
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center On Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Béla Merkely
- Heart and Vascular Center, Semmelweis University, Városmajor Street 68, 1121, Budapest, Hungary
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40
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Ryan KC, Ashkavand Z, Sarasija S, Laboy JT, Samarakoon R, Norman KR. Increased mitochondrial calcium uptake and concomitant mitochondrial activity by presenilin loss promotes mTORC1 signaling to drive neurodegeneration. Aging Cell 2021; 20:e13472. [PMID: 34499406 PMCID: PMC8520713 DOI: 10.1111/acel.13472] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 06/21/2021] [Accepted: 08/05/2021] [Indexed: 12/21/2022] Open
Abstract
Metabolic dysfunction and protein aggregation are common characteristics that occur in age‐related neurodegenerative disease. However, the mechanisms underlying these abnormalities remain poorly understood. We have found that mutations in the gene encoding presenilin in Caenorhabditis elegans, sel‐12, results in elevated mitochondrial activity that drives oxidative stress and neuronal dysfunction. Mutations in the human presenilin genes are the primary cause of familial Alzheimer's disease. Here, we demonstrate that loss of SEL‐12/presenilin results in the hyperactivation of the mTORC1 pathway. This hyperactivation is caused by elevated mitochondrial calcium influx and, likely, the associated increase in mitochondrial activity. Reducing mTORC1 activity improves proteostasis defects and neurodegenerative phenotypes associated with loss of SEL‐12 function. Consistent with high mTORC1 activity, we find that SEL‐12 loss reduces autophagosome formation, and this reduction is prevented by limiting mitochondrial calcium uptake. Moreover, the improvements of proteostasis and neuronal defects in sel‐12 mutants due to mTORC1 inhibition require the induction of autophagy. These results indicate that mTORC1 hyperactivation exacerbates the defects in proteostasis and neuronal function in sel‐12 mutants and demonstrate a critical role of presenilin in promoting neuronal health.
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Affiliation(s)
- Kerry C. Ryan
- Department of Regenerative and Cancer Cell Biology Albany Medical College Albany New York USA
| | - Zahra Ashkavand
- Department of Regenerative and Cancer Cell Biology Albany Medical College Albany New York USA
| | - Shaarika Sarasija
- Department of Regenerative and Cancer Cell Biology Albany Medical College Albany New York USA
| | - Jocelyn T. Laboy
- Department of Regenerative and Cancer Cell Biology Albany Medical College Albany New York USA
| | - Rohan Samarakoon
- Department of Regenerative and Cancer Cell Biology Albany Medical College Albany New York USA
| | - Kenneth R. Norman
- Department of Regenerative and Cancer Cell Biology Albany Medical College Albany New York USA
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Soliman AM, Das S, Mahakkanukrauh P. Inflammatory Molecular Mediators and Pathways Involved in Vascular Aging and Stroke: A Comprehensive Review. Curr Med Chem 2021; 29:5522-5542. [PMID: 34488579 DOI: 10.2174/0929867328666210901122359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/01/2021] [Accepted: 07/23/2021] [Indexed: 11/22/2022]
Abstract
There is an increase in the incidence of cardiovascular diseases with aging and it is one of the leading causes of death worldwide. The main cardiovascular pathologies include atherosclerosis, stroke, myocardial infarction, hypertension and stroke. Chronic inflammation is one of the significant contributors to the age-related vascular diseases. Therefore, it is important to understand the molecular mechanisms of the persistent inflammatory conditions occurring in the blood vessels as well as the signaling pathways involved. Herein, we performed an extant search of literature involving PubMed, ISI, WoS and Scopus databases for retrieving all relevant articles with the most recent findings illustrating the potential role of various inflammatory mediators along with their proposed activated pathways in the pathogenesis and progression of vascular aging. We also highlight the major pathways contributing to age-related vascular disorders. The outlined molecular mechanisms, pathways and mediators of vascular aging represent potential drug targets that can be utilized to inhibit and/or slow the pathogenesis and progression of vascular aging.
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Affiliation(s)
- Amro M Soliman
- Department of Biological Sciences-Physiology, Cell and Developmental Biology, University of Alberta, Edmonton, AB T6G 2R3. Canada
| | - Srijit Das
- Department of Human & Clinical Anatomy, College of Medicine & Health Sciences, Sultan Qaboos University, P.C. 123, Al Khoud, Muscat. Oman
| | - Pasuk Mahakkanukrauh
- Department of Anatomy & Excellence center of Osteology Research and Training, Cadaveric Surgical and Training Center, Chiang Mai University, Chiang Mai 50200. Thailand
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Sabran-Cohen T, Bright U, Mizrachi Zer-Aviv T, Akirav I. Rapamycin prevents the long-term impairing effects of adolescence Δ-9-tetrahydrocannabinol on memory and plasticity in male rats. Eur J Neurosci 2021; 54:6104-6122. [PMID: 34405459 DOI: 10.1111/ejn.15425] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 07/01/2021] [Accepted: 08/09/2021] [Indexed: 11/27/2022]
Abstract
Long-lasting cognitive impairment is one of the most central negative consequences related to the exposure to cannabis during adolescence and particularly of Δ-9-tetrahydrocannabinol (THC). The aim of this study was to compare the protracted effects of adolescent versus late-adolescent chronic exposure to THC on short-term memory and plasticity and to examine whether rapamycin, a blocker of the mammalian target of rapamycin (mTOR) pathway, can restore THC-induced deficits in memory and plasticity. Male rats were injected with ascending doses of THC [2.5, 5, 10 mg/kg; intraperitoneally (i.p.)] during adolescence and late-adolescence (post-natal days 30-41 and 45-56, respectively), followed by daily injections of rapamycin (1 mg/kg, i.p.) during the first 10 days of cessation from THC. Thirty days after the last injection, rats were tested for short-term and working memory, anxiety-like behaviour, and plasticity in the pathways projecting from the ventral subiculum (vSub) of the hippocampus to the prefrontal cortex (PFC) and nucleus accumbens (NAc). THC exposure in adolescence, but not late-adolescence, was found to induce long-term deficits in object recognition short-term memory and synaptic plasticity in the hippocampal-accumbens pathway. Importantly, rapamycin rescued these persistent effects of THC administered during adolescence. Our findings show that some forms of memory and plasticity are sensitive to chronic THC administration during adolescence and that rapamycin administered during THC cessation may restore cognitive function and plasticity, thus potentially protecting against the possible long-term harmful effects of THC.
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Affiliation(s)
- Talia Sabran-Cohen
- Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel.,The Integrated Brain and Behavior Research Center, University of Haifa, Haifa, Israel
| | - Uri Bright
- Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel.,The Integrated Brain and Behavior Research Center, University of Haifa, Haifa, Israel
| | - Tomer Mizrachi Zer-Aviv
- Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel.,The Integrated Brain and Behavior Research Center, University of Haifa, Haifa, Israel
| | - Irit Akirav
- Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel.,The Integrated Brain and Behavior Research Center, University of Haifa, Haifa, Israel
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43
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Llarena N, Hine C. Reproductive Longevity and Aging: Geroscience Approaches to Maintain Long-Term Ovarian Fitness. J Gerontol A Biol Sci Med Sci 2021; 76:1551-1560. [PMID: 32808646 PMCID: PMC8361335 DOI: 10.1093/gerona/glaa204] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Indexed: 11/12/2022] Open
Abstract
Increases in delayed childbearing worldwide have elicited the need for a better understanding of the biological underpinnings and implications of age-related infertility. In women 35 years and older the incidences of infertility, aneuploidy, and birth defects dramatically increase. These outcomes are a result of age-related declines in both ovarian reserve and oocyte quality. In addition to waning reproductive function, the decline in estrogen secretion at menopause contributes to multisystem aging and the initiation of frailty. Both reproductive and hormonal ovarian function are limited by the primordial follicle pool, which is established in utero and declines irreversibly until menopause. Because ovarian function is dependent on the primordial follicle pool, an understanding of the mechanisms that regulate follicular growth and maintenance of the primordial follicle pool is critical for the development of interventions to prolong the reproductive life span. Multiple pathways related to aging and nutrient-sensing converge in the mammalian ovary to regulate quiescence or activation of primordial follicles. The PI3K/PTEN/AKT/FOXO3 and associated TSC/mTOR pathways are central to the regulation of the primordial follicle pool; however, aging-associated systems such as the insulin-like growth factor-1/growth hormone pathway, and transsulfuration/hydrogen sulfide pathways may also play a role. Additionally, sirtuins aid in maintaining developmental metabolic competence and chromosomal integrity of the oocyte. Here we review the pathways that regulate ovarian reserve and oocyte quality, and discuss geroscience interventions that leverage our understanding of these pathways to promote reproductive longevity.
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Affiliation(s)
- Natalia Llarena
- Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Lerner Research Institute, Ohio
- Reproductive Endocrinology and Infertility, Cleveland Clinic Women’s Health Institute, Ohio
| | - Christopher Hine
- Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Lerner Research Institute, Ohio
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Querfurth H, Lee HK. Mammalian/mechanistic target of rapamycin (mTOR) complexes in neurodegeneration. Mol Neurodegener 2021; 16:44. [PMID: 34215308 PMCID: PMC8252260 DOI: 10.1186/s13024-021-00428-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Novel targets to arrest neurodegeneration in several dementing conditions involving misfolded protein accumulations may be found in the diverse signaling pathways of the Mammalian/mechanistic target of rapamycin (mTOR). As a nutrient sensor, mTOR has important homeostatic functions to regulate energy metabolism and support neuronal growth and plasticity. However, in Alzheimer's disease (AD), mTOR alternately plays important pathogenic roles by inhibiting both insulin signaling and autophagic removal of β-amyloid (Aβ) and phospho-tau (ptau) aggregates. It also plays a role in the cerebrovascular dysfunction of AD. mTOR is a serine/threonine kinase residing at the core in either of two multiprotein complexes termed mTORC1 and mTORC2. Recent data suggest that their balanced actions also have implications for Parkinson's disease (PD) and Huntington's disease (HD), Frontotemporal dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS). Beyond rapamycin; an mTOR inhibitor, there are rapalogs having greater tolerability and micro delivery modes, that hold promise in arresting these age dependent conditions.
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Affiliation(s)
- Henry Querfurth
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA.
| | - Han-Kyu Lee
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA
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Selvarani R, Mohammed S, Richardson A. Effect of rapamycin on aging and age-related diseases-past and future. GeroScience 2021; 43:1135-1158. [PMID: 33037985 PMCID: PMC8190242 DOI: 10.1007/s11357-020-00274-1] [Citation(s) in RCA: 106] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/21/2020] [Indexed: 12/19/2022] Open
Abstract
In 2009, rapamycin was reported to increase the lifespan of mice when implemented later in life. This observation resulted in a sea-change in how researchers viewed aging. This was the first evidence that a pharmacological agent could have an impact on aging when administered later in life, i.e., an intervention that did not have to be implemented early in life before the negative impact of aging. Over the past decade, there has been an explosion in the number of reports studying the effect of rapamycin on various diseases, physiological functions, and biochemical processes in mice. In this review, we focus on those areas in which there is strong evidence for rapamycin's effect on aging and age-related diseases in mice, e.g., lifespan, cardiac disease/function, central nervous system, immune system, and cell senescence. We conclude that it is time that pre-clinical studies be focused on taking rapamycin to the clinic, e.g., as a potential treatment for Alzheimer's disease.
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Affiliation(s)
- Ramasamy Selvarani
- Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Sabira Mohammed
- Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Arlan Richardson
- Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Oklahoma City VA Medical Center, Oklahoma City, OK, USA.
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Wang C, Ma Z, Wang Z, Ming S, Ding Y, Zhou S, Qian H. Eriodictyol Attenuates MCAO-Induced Brain Injury and Neurological Deficits via Reversing the Autophagy Dysfunction. Front Syst Neurosci 2021; 15:655125. [PMID: 34122022 PMCID: PMC8190663 DOI: 10.3389/fnsys.2021.655125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 04/19/2021] [Indexed: 11/13/2022] Open
Abstract
The present study was designed to investigate the protective effect of eriodictyol on MCAO-induced brain injury and its regulation of neural function and to explore the mechanism of its regulation of autophagy in rats. Brain injury was induced by middle cerebral artery occlusion (MCAO) in adult rats and pretreated with eriodictyol (low dose: 20 mg/kg; medium dose: 40 mg/kg; high dose: 80 mg/kg) or saline. Rats in the treatment group had a smaller volume of infarction and improved neurological outcome and reduced the latency to the platform, increased the time spent in the correct quadrant compared to MCAO rats pretreated with saline. ELISA kits results confirmed that eriodictyol reduced the inflammatory response induced by MCAO. The results of apoptosis and proliferation by Nissl staining and immunofluorescence detection indicated that eriodictyol could inhibit apoptosis and promote the proliferation in MCAO rats. The expressions of LC3, ATG5, p62, and Beclin1 were used to evaluate the autophagy, as well as the reversal of the autophagy activator (rapamycin) on the neuroprotective effect of eriodictyol, which suggested that the protective effect of eriodictyol on brain injury may be related to the inhibition of autophagy. In summary, we, therefore, suggested that eriodictyol could reduce the inflammation response of brain injury and inhibit neuroapoptosis, directly affecting autophagy to alleviate brain injury. It will provide theoretical support for eriodictyol in the treatment of ischemic stroke.
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Affiliation(s)
- Chuanxiang Wang
- Department of Neurology, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China
| | - Zhequan Ma
- Yangxin County Chinese Medicine Hospital, Yangxin, China
| | - Zuqiang Wang
- Yangxin County Chinese Medicine Hospital, Yangxin, China
| | - Shuping Ming
- The First Clinical College of Hubei University of Traditional Chinese Medicine, Wuhan, China
| | - Yanbing Ding
- Department of Neurology, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China
| | - Sufang Zhou
- Department of Emergency, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China
| | - Hongyu Qian
- Department of Neurology, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China
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Stanciu GD, Rusu RN, Bild V, Filipiuc LE, Tamba BI, Ababei DC. Systemic Actions of SGLT2 Inhibition on Chronic mTOR Activation as a Shared Pathogenic Mechanism between Alzheimer's Disease and Diabetes. Biomedicines 2021; 9:biomedicines9050576. [PMID: 34069618 PMCID: PMC8160780 DOI: 10.3390/biomedicines9050576] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/15/2021] [Accepted: 05/17/2021] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease (AD) affects tens of millions of people worldwide. Despite the advances in understanding the disease, there is an increased urgency for pharmacological approaches able of impacting its onset and progression. With a multifactorial nature, high incidence and prevalence in later years of life, there is growing evidence highlighting a relationship between metabolic dysfunction related to diabetes and subject's susceptibility to develop AD. The link seems so solid that sometimes AD and type 3 diabetes are used interchangeably. A candidate for a shared pathogenic mechanism linking these conditions is chronically-activated mechanistic target of rapamycin (mTOR). Chronic activation of unrestrained mTOR could be responsible for sustaining metabolic dysfunction that causes the breakdown of the blood-brain barrier, tau hyperphosphorylation and senile plaques formation in AD. It has been suggested that inhibition of sodium glucose cotransporter 2 (SGLT2) mediated by constant glucose loss, may restore mTOR cycle via nutrient-driven, preventing or even decreasing the AD progression. Currently, there is an unmet need for further research insight into molecular mechanisms that drive the onset and AD advancement as well as an increase in efforts to expand the testing of potential therapeutic strategies aimed to counteract disease progression in order to structure effective therapies.
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Affiliation(s)
- Gabriela Dumitrita Stanciu
- Center for Advanced Research and Development in Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania; (G.D.S.); (V.B.); (L.E.F.)
| | - Razvan Nicolae Rusu
- Pharmacodynamics and Clinical Pharmacy Department, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania; (R.N.R.); (D.C.A.)
| | - Veronica Bild
- Center for Advanced Research and Development in Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania; (G.D.S.); (V.B.); (L.E.F.)
- Pharmacodynamics and Clinical Pharmacy Department, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania; (R.N.R.); (D.C.A.)
| | - Leontina Elena Filipiuc
- Center for Advanced Research and Development in Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania; (G.D.S.); (V.B.); (L.E.F.)
- Department of Pharmacology, Clinical Pharmacology and Algesiology, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Bogdan-Ionel Tamba
- Center for Advanced Research and Development in Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania; (G.D.S.); (V.B.); (L.E.F.)
- Department of Pharmacology, Clinical Pharmacology and Algesiology, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
- Correspondence:
| | - Daniela Carmen Ababei
- Pharmacodynamics and Clinical Pharmacy Department, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania; (R.N.R.); (D.C.A.)
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mTOR Attenuation with Rapamycin Reverses Neurovascular Uncoupling and Memory Deficits in Mice Modeling Alzheimer's Disease. J Neurosci 2021; 41:4305-4320. [PMID: 33888602 DOI: 10.1523/jneurosci.2144-20.2021] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 02/19/2021] [Accepted: 03/02/2021] [Indexed: 02/07/2023] Open
Abstract
Vascular dysfunction is a universal feature of aging and decreased cerebral blood flow has been identified as an early event in the pathogenesis of Alzheimer's disease (AD). Cerebrovascular dysfunction in AD includes deficits in neurovascular coupling (NVC), a mechanism that ensures rapid delivery of energy substrates to active neurons through the blood supply. The mechanisms underlying NVC impairment in AD, however, are not well understood. We have previously shown that mechanistic/mammalian target of rapamycin (mTOR) drives cerebrovascular dysfunction in models of AD by reducing the activity of endothelial nitric oxide synthase (eNOS), and that attenuation of mTOR activity with rapamycin is sufficient to restore eNOS-dependent cerebrovascular function. Here we show mTOR drives NVC impairments in an AD model through the inhibition of neuronal NOS (nNOS)- and non-NOS-dependent components of NVC, and that mTOR attenuation with rapamycin is sufficient to restore NVC and even enhance it above WT responses. Restoration of NVC and concomitant reduction of cortical amyloid-β levels effectively treated memory deficits in 12-month-old hAPP(J20) mice. These data indicate that mTOR is a critical driver of NVC dysfunction and underlies cognitive impairment in an AD model. Together with our previous findings, the present studies suggest that mTOR promotes cerebrovascular dysfunction in AD, which is associated with early disruption of nNOS activation, through its broad negative impact on nNOS as well as on non-NOS components of NVC. Our studies highlight the potential of mTOR attenuation as an efficacious treatment for AD and potentially other neurologic diseases of aging.SIGNIFICANCE STATEMENT Failure of the blood flow response to neuronal activation [neurovascular coupling (NVC)] in a model of AD precedes the onset of AD-like cognitive symptoms and is driven, to a large extent, by mammalian/mechanistic target of rapamycin (mTOR)-dependent inhibition of nitric oxide synthase activity. Our studies show that mTOR also drives AD-like failure of non-nitric oxide (NO)-mediated components of NVC. Thus, mTOR attenuation may serve to treat AD, where we find that neuronal NO synthase is profoundly reduced early in disease progression, and potentially other neurologic diseases of aging with cerebrovascular dysfunction as part of their etiology.
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Towner RA, Gulej R, Zalles M, Saunders D, Smith N, Lerner M, Morton KA, Richardson A. Rapamycin restores brain vasculature, metabolism, and blood-brain barrier in an inflammaging model. GeroScience 2021; 43:563-578. [PMID: 33846885 PMCID: PMC8110648 DOI: 10.1007/s11357-021-00363-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 04/06/2021] [Indexed: 02/08/2023] Open
Abstract
Rapamycin (RAPA) is found to have neuro-protective properties in various neuroinflammatory pathologies, including brain aging. With magnetic resonance imaging (MRI) techniques, we investigated the effect of RAPA in a lipopolysaccharide (LPS)-induced inflammaging model in rat brains. Rats were exposed to saline (control), or LPS alone or LPS combined with RAPA treatment (via food over 6 weeks). Arterial spin labeling (ASL) perfusion imaging was used to measure relative cerebral blood flow (rCBF). MR spectroscopy (MRS) was used to measure brain metabolite levels. Contrast-enhanced MRI (CE-MRI) was used to assess blood-brain barrier (BBB) permeability. Immunohistochemistry (IHC) was used to confirm neuroinflammation. RAPA restored NF-κB and HIF-1α to normal levels. RAPA was able to significantly restore rCBF in the cerebral cortex post-LPS exposure (p < 0.05), but not in the hippocampus. In the hippocampus, RAPA was able to restore total creatine (Cr) acutely, and N-acetyl aspartate (NAA) at 6 weeks, post-LPS. Myo-inositol (Myo-Ins) levels were found to decrease with RAPA treatment acutely post-LPS. RAPA was also able to significantly restore the BBB acutely post-LPS in both the cortex and hippocampus (p < 0.05 for both). RAPA was found to increase the percent change in BOLD signal in the cortex at 3 weeks, and in the hippocampus at 6 weeks post-LPS, compared to LPS alone. RAPA treatment also restored the neuronal and macro-vascular marker, EphB2, back to normal levels. These results indicate that RAPA may play an important therapeutic role in inhibiting neuroinflammation by normalizing brain vascularity, BBB, and some brain metabolites, and has a high translational capability.
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Affiliation(s)
- Rheal A Towner
- Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA.
- Neuroscience Program, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Oklahoma Nathan Shock Center for Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Rafal Gulej
- Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Michelle Zalles
- Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
- Neuroscience Program, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Debra Saunders
- Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Nataliya Smith
- Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Megan Lerner
- Department of Surgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Kathryn A Morton
- Department of Radiology and Imaging Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Arlan Richardson
- Oklahoma Nathan Shock Center for Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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50
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Nyúl-Tóth Á, Tarantini S, DelFavero J, Yan F, Balasubramanian P, Yabluchanskiy A, Ahire C, Kiss T, Csipo T, Lipecz A, Farkas AE, Wilhelm I, Krizbai IA, Tang Q, Csiszar A, Ungvari Z. Demonstration of age-related blood-brain barrier disruption and cerebromicrovascular rarefaction in mice by longitudinal intravital two-photon microscopy and optical coherence tomography. Am J Physiol Heart Circ Physiol 2021; 320:H1370-H1392. [PMID: 33543687 PMCID: PMC8260380 DOI: 10.1152/ajpheart.00709.2020] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/21/2021] [Accepted: 01/21/2021] [Indexed: 12/25/2022]
Abstract
Age-related blood-brain barrier (BBB) disruption and cerebromicrovascular rarefaction contribute importantly to the pathogenesis of both vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). Recent advances in geroscience research enable development of novel interventions to reverse age-related alterations of the cerebral microcirculation for prevention of VCID and AD. To facilitate this research, there is an urgent need for sensitive and easy-to-adapt imaging methods that enable longitudinal assessment of changes in BBB permeability and brain capillarization in aged mice and that could be used in vivo to evaluate treatment efficiency. To enable longitudinal assessment of changes in BBB permeability in aged mice equipped with a chronic cranial window, we adapted and optimized two different intravital two-photon imaging approaches. By assessing relative fluorescence changes over the baseline within a volume of brain tissue, after qualitative image subtraction of the brain microvasculature, we confirmed that, in 24-mo-old C57BL/6J mice, cumulative permeability of the microvessels to fluorescent tracers of different molecular masses (0.3 to 40 kDa) is significantly increased compared with that of 5-mo-old mice. Real-time recording of vessel cross-sections showed that apparent solute permeability of single microvessels is significantly increased in aged mice vs. young mice. Cortical capillary density, assessed both by intravital two-photon microscopy and optical coherence tomography was also decreased in aged mice vs. young mice. The presented methods have been optimized for longitudinal (over the period of 36 wk) in vivo assessment of cerebromicrovascular health in preclinical geroscience research.NEW & NOTEWORTHY Methods are presented for longitudinal detection of age-related increase in blood-brain barrier permeability and microvascular rarefaction in the mouse cerebral cortex by intravital two-photon microscopy and optical coherence tomography.
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Affiliation(s)
- Ádám Nyúl-Tóth
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Jordan DelFavero
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Feng Yan
- Stephenson School of Biomedical Engineering, Gallogly College of Engineering, The University of Oklahoma, Norman, Oklahoma
| | - Priya Balasubramanian
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Andriy Yabluchanskiy
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Chetan Ahire
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Tamas Kiss
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics and Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Tamas Csipo
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Agnes Lipecz
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Attila E Farkas
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Imola Wilhelm
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
- Institute of Life Sciences, Vasile Goldiş Western University of Arad, Arad, Romania
| | - István A Krizbai
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
- Institute of Life Sciences, Vasile Goldiş Western University of Arad, Arad, Romania
| | - Qinggong Tang
- Stephenson School of Biomedical Engineering, Gallogly College of Engineering, The University of Oklahoma, Norman, Oklahoma
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics and Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics and Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
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