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Barbour AJ, Gourmaud S, Lancaster E, Li X, Stewart DA, Hoag KF, Irwin DJ, Talos DM, Jensen FE. Seizures exacerbate excitatory: inhibitory imbalance in Alzheimer's disease and 5XFAD mice. Brain 2024; 147:2169-2184. [PMID: 38662500 PMCID: PMC11146435 DOI: 10.1093/brain/awae126] [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: 09/05/2023] [Revised: 03/02/2024] [Accepted: 03/24/2024] [Indexed: 05/14/2024] Open
Abstract
Approximately 22% of Alzheimer's disease (AD) patients suffer from seizures, and the co-occurrence of seizures and epileptiform activity exacerbates AD pathology and related cognitive deficits, suggesting that seizures may be a targetable component of AD progression. Given that alterations in neuronal excitatory:inhibitory (E:I) balance occur in epilepsy, we hypothesized that decreased markers of inhibition relative to those of excitation would be present in AD patients. We similarly hypothesized that in 5XFAD mice, the E:I imbalance would progress from an early stage (prodromal) to later symptomatic stages and be further exacerbated by pentylenetetrazol (PTZ) kindling. Post-mortem AD temporal cortical tissues from patients with or without seizure history were examined for changes in several markers of E:I balance, including levels of the inhibitory GABAA receptor, the sodium potassium chloride cotransporter 1 (NKCC1) and potassium chloride cotransporter 2 (KCC2) and the excitatory NMDA and AMPA type glutamate receptors. We performed patch-clamp electrophysiological recordings from CA1 neurons in hippocampal slices and examined the same markers of E:I balance in prodromal 5XFAD mice. We next examined 5XFAD mice at chronic stages, after PTZ or control protocols, and in response to chronic mTORC1 inhibitor rapamycin, administered following kindled seizures, for markers of E:I balance. We found that AD patients with comorbid seizures had worsened cognitive and functional scores and decreased GABAA receptor subunit expression, as well as increased NKCC1/KCC2 ratios, indicative of depolarizing GABA responses. Patch clamp recordings of prodromal 5XFAD CA1 neurons showed increased intrinsic excitability, along with decreased GABAergic inhibitory transmission and altered glutamatergic neurotransmission, indicating that E:I imbalance may occur in early disease stages. Furthermore, seizure induction in prodromal 5XFAD mice led to later dysregulation of NKCC1/KCC2 and a reduction in GluA2 AMPA glutamate receptor subunit expression, indicative of depolarizing GABA receptors and calcium permeable AMPA receptors. Finally, we found that chronic treatment with the mTORC1 inhibitor, rapamycin, at doses we have previously shown to attenuate seizure-induced amyloid-β pathology and cognitive deficits, could also reverse elevations of the NKCC1/KCC2 ratio in these mice. Our data demonstrate novel mechanisms of interaction between AD and epilepsy and indicate that targeting E:I balance, potentially with US Food and Drug Administration-approved mTOR inhibitors, hold therapeutic promise for AD patients with a seizure history.
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Affiliation(s)
- Aaron J Barbour
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sarah Gourmaud
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eunjoo Lancaster
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Xiaofan Li
- 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
| | - Keegan F Hoag
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, 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
| | - 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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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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3
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Zhang P, Catterson JH, Grönke S, Partridge L. Inhibition of S6K lowers age-related inflammation and increases lifespan through the endolysosomal system. NATURE AGING 2024; 4:491-509. [PMID: 38413780 PMCID: PMC11031405 DOI: 10.1038/s43587-024-00578-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 01/24/2024] [Indexed: 02/29/2024]
Abstract
Suppression of target of rapamycin complex 1 (TORC1) by rapamycin ameliorates aging in diverse species. S6 kinase (S6K) is an essential mediator, but the mechanisms involved are unclear. Here we show that activation of S6K specifically in Drosophila fat-body blocked extension of lifespan by rapamycin, induced accumulation of multilamellar lysosomes and blocked age-associated hyperactivation of the NF-κB-like immune deficiency (IMD) pathway, indicative of reduced inflammaging. Syntaxin 13 mediated the effects of TORC1-S6K signaling on lysosome morphology and inflammaging, suggesting they may be linked. Inflammaging depended on the IMD receptor regulatory isoform PGRP-LC, and repression of the IMD pathway from midlife extended lifespan. Age-related inflammaging was higher in females than in males and was not lowered in males by rapamycin treatment or lowered S6K. Rapamycin treatment also elevated Syntaxin 12/13 levels in mouse liver and prevented age-related increase in noncanonical NF-κB signaling, suggesting that the effect of TORC1 on inflammaging is conserved from flies to mammals.
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Affiliation(s)
- Pingze Zhang
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - James H Catterson
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK
- Centre for Discovery Brain Sciences, UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | | | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK.
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4
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Yeh CY, Chini LC, Davidson JW, Garcia GG, Gallagher MS, Freichels IT, Calubag MF, Rodgers AC, Green CL, Babygirija R, Sonsalla MM, Pak HH, Trautman M, Hacker TA, Miller RA, Simcox J, Lamming DW. Late-life isoleucine restriction promotes physiological and molecular signatures of healthy aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.02.06.527311. [PMID: 36798157 PMCID: PMC9934591 DOI: 10.1101/2023.02.06.527311] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
In defiance of the paradigm that calories from all sources are equivalent, we and others have shown that dietary protein is a dominant regulator of healthy aging. The restriction of protein or the branched-chain amino acid isoleucine promotes healthspan and extends lifespan when initiated in young or adult mice. However, many interventions are less efficacious or even deleterious when initiated in aged animals. Here, we investigate the physiological, metabolic, and molecular consequences of consuming a diet with a 67% reduction of all amino acids (Low AA), or of isoleucine alone (Low Ile), in male and female C57BL/6J.Nia mice starting at 20 months of age. We find that both diet regimens effectively reduce adiposity and improve glucose tolerance, which were benefits that were not mediated by reduced calorie intake. Both diets improve specific aspects of frailty, slow multiple molecular indicators of aging rate, and rejuvenate the aging heart and liver at the molecular level. These results demonstrate that Low AA and Low Ile diets can drive youthful physiological and molecular signatures, and support the possibility that these dietary interventions could help to promote healthy aging in older adults.
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Affiliation(s)
- Chung-Yang Yeh
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
| | - Lucas C.S. Chini
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
| | - Jessica W. Davidson
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
| | - Gonzalo G. Garcia
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI 48109
| | - Meredith S. Gallagher
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
| | - Isaac T. Freichels
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
| | - Mariah F. Calubag
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
- Graduate Program in Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706
| | - Allison C. Rodgers
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- Cardiovascular Physiology Core Facility, University of Wisconsin-Madison, Madison, WI 53706
| | - Cara L. Green
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
| | - Reji Babygirija
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
- Nutrition and Metabolism Graduate Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Michelle M. Sonsalla
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
- Comparative Biomedical Sciences Graduate Training Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Heidi H. Pak
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
- Nutrition and Metabolism Graduate Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Michaela Trautman
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
- Nutrition and Metabolism Graduate Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Timothy A. Hacker
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- Cardiovascular Physiology Core Facility, University of Wisconsin-Madison, Madison, WI 53706
| | - Richard A Miller
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI 48109
| | - Judith Simcox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
- Howard Hughes Medical Institute, Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Dudley W. Lamming
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
- Graduate Program in Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706
- Nutrition and Metabolism Graduate Program, University of Wisconsin-Madison, Madison, WI 53706
- Comparative Biomedical Sciences Graduate Training Program, University of Wisconsin-Madison, Madison, WI 53706
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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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6
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Kaeberlein TL, Green AS, Haddad G, Hudson J, Isman A, Nyquist A, Rosen BS, Suh Y, Zalzala S, Zhang X, Blagosklonny MV, An JY, Kaeberlein M. Evaluation of off-label rapamycin use to promote healthspan in 333 adults. GeroScience 2023; 45:2757-2768. [PMID: 37191826 PMCID: PMC10187519 DOI: 10.1007/s11357-023-00818-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/02/2023] [Indexed: 05/17/2023] Open
Abstract
Rapamycin (sirolimus) is an FDA-approved drug with immune-modulating and growth-inhibitory properties. Preclinical studies have shown that rapamycin extends lifespan and healthspan metrics in yeast, invertebrates, and rodents. Several physicians are now prescribing rapamycin off-label as a preventative therapy to maintain healthspan. Thus far, however, there is limited data available on side effects or efficacy associated with use of rapamycin in this context. To begin to address this gap in knowledge, we collected data from 333 adults with a history of off-label use of rapamycin by survey. Similar data were also collected from 172 adults who had never used rapamycin. Here, we describe the general characteristics of a patient cohort using off-label rapamycin and present initial evidence that rapamycin can be used safely in adults of normal health status.
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Affiliation(s)
- Tammi L Kaeberlein
- Department of Oral Health Sciences, University of Washington, Seattle, WA, 98195, USA
| | | | | | - Johnny Hudson
- Department of Oral Health Sciences, University of Washington, Seattle, WA, 98195, USA
| | | | | | | | - Yousin Suh
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | | | - Xingyu Zhang
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, 15219, USA
| | | | - Jonathan Y An
- Department of Oral Health Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Matt Kaeberlein
- Optispan Geroscience, Seattle, WA, 98168, USA.
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA.
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7
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Xie K, Ehninger D. Ageing-associated phenotypes in mice. Mech Ageing Dev 2023; 214:111852. [PMID: 37454704 DOI: 10.1016/j.mad.2023.111852] [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: 04/21/2023] [Revised: 06/22/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Ageing is a continuous process in life featuring progressive damage accumulation that leads to physiological decline, functional deterioration and ultimately death of an organism. Based on the relatively close anatomical and physiological similarity to humans, the mouse has been proven as a valuable model organism in ageing research over the last decades. In this review, we survey methods and tools currently in use to assess ageing phenotypes in mice. We summarize a range of ageing-associated alterations detectable at two major levels of analysis: (1) physiology and pathophysiology and (2) molecular biomarkers. Age-sensitive phenotypes provided in this article may serve to inform future studies targeting various aspects of organismal ageing in mice. In addition, we discuss conceptual and technical challenges faced by previous ageing studies in mice and, where possible, provide recommendations on how to resolve some of these issues.
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Affiliation(s)
- Kan Xie
- Translational Biogerontology Lab, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1/99, 53127 Bonn, Germany
| | - Dan Ehninger
- Translational Biogerontology Lab, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1/99, 53127 Bonn, Germany.
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8
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Metaxakis A, Pavlidis M, Tavernarakis N. Neuronal atg1 Coordinates Autophagy Induction and Physiological Adaptations to Balance mTORC1 Signalling. Cells 2023; 12:2024. [PMID: 37626835 PMCID: PMC10453232 DOI: 10.3390/cells12162024] [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: 07/11/2023] [Revised: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/27/2023] Open
Abstract
The mTORC1 nutrient-sensing pathway integrates metabolic and endocrine signals into the brain to evoke physiological responses to food deprivation, such as autophagy. Nevertheless, the impact of neuronal mTORC1 activity on neuronal circuits and organismal metabolism remains obscure. Here, we show that mTORC1 inhibition acutely perturbs serotonergic neurotransmission via proteostatic alterations evoked by the autophagy inducer atg1. Neuronal ATG1 alters the intracellular localization of the serotonin transporter, which increases the extracellular serotonin and stimulates the 5HTR7 postsynaptic receptor. 5HTR7 enhances food-searching behaviour and ecdysone-induced catabolism in Drosophila. Along similar lines, the pharmacological inhibition of mTORC1 in zebrafish also stimulates food-searching behaviour via serotonergic activity. These effects occur in parallel with neuronal autophagy induction, irrespective of the autophagic activity and the protein synthesis reduction. In addition, ectopic neuronal atg1 expression enhances catabolism via insulin pathway downregulation, impedes peptidergic secretion, and activates non-cell autonomous cAMP/PKA. The above exert diverse systemic effects on organismal metabolism, development, melanisation, and longevity. We conclude that neuronal atg1 aligns neuronal autophagy induction with distinct physiological modulations, to orchestrate a coordinated physiological response against reduced mTORC1 activity.
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Affiliation(s)
- Athanasios Metaxakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Nikolaou Plastira 100, 70013 Heraklion, Crete, Greece
| | - Michail Pavlidis
- Department of Biology, University of Crete, 71409 Heraklion, Crete, Greece;
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Nikolaou Plastira 100, 70013 Heraklion, Crete, Greece
- Department of Basic Sciences, Faculty of Medicine, University of Crete, 71110 Heraklion, Crete, Greece
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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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10
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Gaspar-Silva F, Trigo D, Magalhaes J. Ageing in the brain: mechanisms and rejuvenating strategies. Cell Mol Life Sci 2023; 80:190. [PMID: 37354261 DOI: 10.1007/s00018-023-04832-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/31/2023] [Accepted: 06/07/2023] [Indexed: 06/26/2023]
Abstract
Ageing is characterized by the progressive loss of cellular homeostasis, leading to an overall decline of the organism's fitness. In the brain, ageing is highly associated with cognitive decline and neurodegenerative diseases. With the rise in life expectancy, characterizing the brain ageing process becomes fundamental for developing therapeutic interventions against the increased incidence of age-related neurodegenerative diseases and to aim for an increase in human life span and, more importantly, health span. In this review, we start by introducing the molecular/cellular hallmarks associated with brain ageing and their impact on brain cell populations. Subsequently, we assess emerging evidence on how systemic ageing translates into brain ageing. Finally, we revisit the mainstream and the novel rejuvenating strategies, discussing the most successful ones in delaying brain ageing and related diseases.
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Affiliation(s)
- Filipa Gaspar-Silva
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
| | - Diogo Trigo
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Joana Magalhaes
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal.
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11
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Bitto A, Grillo AS, Ito TK, Stanaway IB, Nguyen BMG, Ying K, Tung H, Smith K, Tran N, Velikanje G, Urfer SR, Snyder JM, Barton J, Sharma A, Kayser EB, Wang L, Smith DL, Thompson JW, DuBois L, DePaolo W, Kaeberlein M. Acarbose suppresses symptoms of mitochondrial disease in a mouse model of Leigh syndrome. Nat Metab 2023; 5:955-967. [PMID: 37365290 DOI: 10.1038/s42255-023-00815-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 05/04/2023] [Indexed: 06/28/2023]
Abstract
Mitochondrial diseases represent a spectrum of disorders caused by impaired mitochondrial function, ranging in severity from mortality during infancy to progressive adult-onset disease. Mitochondrial dysfunction is also recognized as a molecular hallmark of the biological ageing process. Rapamycin, a drug that increases lifespan and health during normative ageing, also increases survival and reduces neurological symptoms in a mouse model of the severe mitochondrial disease Leigh syndrome. The Ndufs4 knockout (Ndufs4-/-) mouse lacks the complex I subunit NDUFS4 and shows rapid onset and progression of neurodegeneration mimicking patients with Leigh syndrome. Here we show that another drug that extends lifespan and delays normative ageing in mice, acarbose, also suppresses symptoms of disease and improves survival of Ndufs4-/- mice. Unlike rapamycin, acarbose rescues disease phenotypes independently of inhibition of the mechanistic target of rapamycin. Furthermore, rapamycin and acarbose have additive effects in delaying neurological symptoms and increasing maximum lifespan in Ndufs4-/- mice. We find that acarbose remodels the intestinal microbiome and alters the production of short-chain fatty acids. Supplementation with tributyrin, a source of butyric acid, recapitulates some effects of acarbose on lifespan and disease progression, while depletion of the endogenous microbiome in Ndufs4-/- mice appears to fully recapitulate the effects of acarbose on healthspan and lifespan in these animals. To our knowledge, this study provides the first evidence that alteration of the gut microbiome plays a significant role in severe mitochondrial disease and provides further support for the model that biological ageing and severe mitochondrial disorders share underlying common mechanisms.
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Affiliation(s)
- Alessandro Bitto
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Anthony S Grillo
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Takashi K Ito
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- RIKEN Center for Sustainable Resource Science, Saitama, Japan
| | - Ian B Stanaway
- Division of Nephrology, School of Medicine, University of Washington, Seattle, WA, USA
- Harborview Medical Center, Kidney Research Institute, Seattle, WA, USA
| | - Bao M G Nguyen
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Kejun Ying
- T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | | | | | - Ngoc Tran
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Gunnar Velikanje
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Silvan R Urfer
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Jessica M Snyder
- Department of Comparative Medicine, University of Washington, Seattle, WA, USA
| | - Jacob Barton
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Ayush Sharma
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | | | - Lu Wang
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Daniel L Smith
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - J Will Thompson
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC, USA
| | - Laura DuBois
- Department of Biostatistics and Bioinformatics, Duke University, Durham, NC, USA
| | - William DePaolo
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Matt Kaeberlein
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA.
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12
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Knufinke M, MacArthur MR, Ewald CY, Mitchell SJ. Sex differences in pharmacological interventions and their effects on lifespan and healthspan outcomes: a systematic review. FRONTIERS IN AGING 2023; 4:1172789. [PMID: 37305228 PMCID: PMC10249017 DOI: 10.3389/fragi.2023.1172789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/10/2023] [Indexed: 06/13/2023]
Abstract
With an increasing aging population, the burden of age-related diseases magnifies. To alleviate this burden, geroprotection has been an area of intense research focus with the development of pharmacological interventions that target lifespan and/or healthspan. However, there are often sex differences, with compounds mostly tested in male animals. Given the importance of considering both sexes in preclinical research, this neglects potential benefits for the female population, as interventions tested in both sexes often show clear sexual dimorphisms in their biological responses. To further understand the prevalence of sex differences in pharmacological geroprotective intervention studies, we performed a systematic review of the literature according to the PRISMA guidelines. Seventy-two studies met our inclusion criteria and were classified into one of five subclasses: FDA-repurposed drugs, novel small molecules, probiotics, traditional Chinese medicine, and antioxidants, vitamins, or other dietary supplements. Interventions were analyzed for their effects on median and maximal lifespan and healthspan markers, including frailty, muscle function and coordination, cognitive function and learning, metabolism, and cancer. With our systematic review, we found that twenty-two out of sixty-four compounds tested were able to prolong both lifespan and healthspan measures. Focusing on the use of female and male mice, and on comparing their outcomes, we found that 40% of studies only used male mice or did not clarify the sex. Notably, of the 36% of pharmacologic interventions that did use both male and female mice, 73% of these studies showed sex-specific outcomes on healthspan and/or lifespan. These data highlight the importance of studying both sexes in the search for geroprotectors, as the biology of aging is not the same in male and female mice. Systematic Review Registration: [website], identifier [registration number].
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13
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Salazar AM, Aparicio R, Clark RI, Rera M, Walker DW. Intestinal barrier dysfunction: an evolutionarily conserved hallmark of aging. Dis Model Mech 2023; 16:dmm049969. [PMID: 37144684 PMCID: PMC10184675 DOI: 10.1242/dmm.049969] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023] Open
Abstract
A major challenge in the biology of aging is to understand how specific age-onset pathologies relate to the overall health of the organism. The integrity of the intestinal epithelium is essential for the wellbeing of the organism throughout life. In recent years, intestinal barrier dysfunction has emerged as an evolutionarily conserved feature of aged organisms, as reported in worms, flies, fish, rodents and primates. Moreover, age-onset intestinal barrier dysfunction has been linked to microbial alterations, elevated immune responses, metabolic alterations, systemic health decline and mortality. Here, we provide an overview of these findings. We discuss early work in the Drosophila model that sets the stage for examining the relationship between intestinal barrier integrity and systemic aging, then delve into research in other organisms. An emerging concept, supported by studies in both Drosophila and mice, is that directly targeting intestinal barrier integrity is sufficient to promote longevity. A better understanding of the causes and consequences of age-onset intestinal barrier dysfunction has significant relevance to the development of interventions to promote healthy aging.
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Affiliation(s)
- Anna M. Salazar
- Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, VA 23606, USA
| | - Ricardo Aparicio
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA
| | - Rebecca I. Clark
- Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | - Michael Rera
- Université de Paris, Inserm U1284, Center for Research and Interdisciplinarity, Paris 75004, France
| | - David W. Walker
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA
- Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
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14
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Lee H, Wilson D, Bunting KV, Kotecha D, Jackson T. Repurposing digoxin for geroprotection in patients with frailty and multimorbidity. Ageing Res Rev 2023; 86:101860. [PMID: 36682465 DOI: 10.1016/j.arr.2023.101860] [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: 09/07/2022] [Revised: 12/22/2022] [Accepted: 01/18/2023] [Indexed: 01/21/2023]
Abstract
The geroscience hypothesis proposes biological hallmarks of ageing are modifiable. Increasing evidence supports targeting these hallmarks with therapeutics could prevent and ameliorate age-related conditions - collectively termed "geroprotector drugs". Cellular senescence is a hallmark with considerable potential to be modified with geroprotector drugs. Senotherapeutics are drugs that target cellular senescence for therapeutic benefit. Repurposing commonly used medications with secondary geroprotector properties is a strategy of interest to promote incorporation of geroprotector drugs into clinical practice. One candidate is the cardiac glycoside digoxin. Evidence in mouse models of pulmonary fibrosis, Alzheimer's disease, arthritis and atherosclerosis support digoxin as a senotherapeutic agent. Proposed senolytic mechanisms are upregulation of intrinsic apoptotic pathways and promoting intracellular acidification. Digoxin also appears to have a senomorphic mechanism - altering the T cell pool to ameliorate pro-inflammatory SASP. Despite being widely prescribed to treat atrial fibrillation and heart failure, often in multimorbid older adults, it is not known whether digoxin exerts senotherapeutic effects in humans. Further cellular and animal studies, and ultimately clinical trials with participation of pre-frail older adults, are required to identify whether digoxin has senotherapeutic effect at low dose. This paper reviews the biological mechanisms identified in preliminary cellular and animal studies that support repurposing digoxin as a geroprotector in patients with frailty and multimorbidity.
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Affiliation(s)
- Helena Lee
- Institute of Inflammation and Ageing, University of Birmingham Research Laboratories, Queen Elizabeth Hospital, Mindelsohn Way, Edgbaston, Birmingham B15 2WD, UK.
| | - Daisy Wilson
- Institute of Inflammation and Ageing, University of Birmingham Research Laboratories, Queen Elizabeth Hospital, Mindelsohn Way, Edgbaston, Birmingham B15 2WD, UK
| | - Karina V Bunting
- Institute of Cardiovascular Sciences, University of Birmingham, Medical School, Vincent Drive, Birmingham B15 2TT, UK; University Hospitals Birmingham NHS Foundation Trust, Institute of Translational Medicine, Queen Elizabeth Hospital, Mindelsohn Way, Birmingham B15 2GW, UK
| | - Dipak Kotecha
- Institute of Cardiovascular Sciences, University of Birmingham, Medical School, Vincent Drive, Birmingham B15 2TT, UK; University Hospitals Birmingham NHS Foundation Trust, Institute of Translational Medicine, Queen Elizabeth Hospital, Mindelsohn Way, Birmingham B15 2GW, UK
| | - Thomas Jackson
- Institute of Inflammation and Ageing, University of Birmingham Research Laboratories, Queen Elizabeth Hospital, Mindelsohn Way, Edgbaston, Birmingham B15 2WD, UK
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15
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Li Z, Tian M, Wang G, Cui X, Ma J, Liu S, Shen B, Liu F, Wu K, Xiao X, Zhu C. Senotherapeutics: An emerging approach to the treatment of viral infectious diseases in the elderly. Front Cell Infect Microbiol 2023; 13:1098712. [PMID: 37065192 PMCID: PMC10094634 DOI: 10.3389/fcimb.2023.1098712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/06/2023] [Indexed: 03/31/2023] Open
Abstract
In the context of the global COVID-19 pandemic, the phenomenon that the elderly have higher morbidity and mortality is of great concern. Existing evidence suggests that senescence and viral infection interact with each other. Viral infection can lead to the aggravation of senescence through multiple pathways, while virus-induced senescence combined with existing senescence in the elderly aggravates the severity of viral infections and promotes excessive age-related inflammation and multiple organ damage or dysfunction, ultimately resulting in higher mortality. The underlying mechanisms may involve mitochondrial dysfunction, abnormal activation of the cGAS-STING pathway and NLRP3 inflammasome, the role of pre-activated macrophages and over-recruited immune cells, and accumulation of immune cells with trained immunity. Thus, senescence-targeted drugs were shown to have positive effects on the treatment of viral infectious diseases in the elderly, which has received great attention and extensive research. Therefore, this review focused on the relationship between senescence and viral infection, as well as the significance of senotherapeutics for the treatment of viral infectious diseases.
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Affiliation(s)
- Zhiqiang Li
- Department of Clinical Laboratory, Institute of Translational Medicine, Renmin Hospital of Wuhan University, Wuhan, China
| | - Mingfu Tian
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Guolei Wang
- Department of Clinical Laboratory, Institute of Translational Medicine, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xianghua Cui
- Department of Clinical Laboratory, Institute of Translational Medicine, Renmin Hospital of Wuhan University, Wuhan, China
| | - Jun’e Ma
- Department of Clinical Laboratory, Institute of Translational Medicine, Renmin Hospital of Wuhan University, Wuhan, China
| | - Siyu Liu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Bingzheng Shen
- Department of Pharmacy, Renmin Hospital of Wuhan University, Wuhan, China
| | - Fang Liu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Kailang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xuan Xiao
- Department of Clinical Laboratory, Institute of Translational Medicine, Renmin Hospital of Wuhan University, Wuhan, China
- *Correspondence: Chengliang Zhu, ; Xuan Xiao,
| | - Chengliang Zhu
- Department of Clinical Laboratory, Institute of Translational Medicine, Renmin Hospital of Wuhan University, Wuhan, China
- *Correspondence: Chengliang Zhu, ; Xuan Xiao,
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16
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Li JB, Hu XY, Chen MW, Xiong CH, Zhao N, Ge YH, Wang H, Gao XL, Xu NJ, Zhao LX, Yu ZH, Chen HZ, Qiu Y. p85S6K sustains synaptic GluA1 to ameliorate cognitive deficits in Alzheimer's disease. Transl Neurodegener 2023; 12:1. [PMID: 36624510 PMCID: PMC9827685 DOI: 10.1186/s40035-022-00334-w] [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: 07/03/2022] [Accepted: 12/26/2022] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Ribosomal protein S6 kinase 1 (S6K1) is a serine-threonine kinase that has two main isoforms: p70S6K (70-kDa isoform) and p85S6K (85-kDa isoform). p70S6K, with its upstream mammalian target of rapamycin (mTOR), has been shown to be involved in learning and memory and participate in the pathophysiology of Alzheimer's disease (AD). However, the function of p85S6K has long been neglected due to its high similarity to p70S6k. The role of p85S6K in learning and memory is still largely unknown. METHODS We fractionated the postsynaptic densities to illustrate the differential distribution of p85S6K and p70S6K. Coimmunoprecipitation was performed to unveil interactions between p85S6K and the GluA1 subunit of AMPA receptor. The roles of p85S6K in synaptic targeting of GluA1 and learning and memory were evaluated by specific knockdown or overexpression of p85S6K followed by a broad range of methodologies including immunofluorescence, Western blot, in situ proximity ligation assay, morphological staining and behavioral examination. Further, the expression level of p85S6K was measured in brains from AD patients and AD model mice. RESULTS p85S6K, but not p70S6K, was enriched in the postsynaptic densities. Moreover, knockdown of p85S6K resulted in defective spatial and recognition memory. In addition, p85S6K could interact with the GluA1 subunit of AMPA receptor through synapse-associated protein 97 and A-kinase anchoring protein 79/150. Mechanistic studies demonstrated that p85S6K could directly phosphorylate GluA1 at Ser845 and increase the amount of GluA1 in synapses, thus sustaining synaptic function and spine densities. Moreover, p85S6K was found to be specifically decreased in the synaptosomal compartment in the brains of AD patients and AD mice. Overexpression of p85S6K ameliorated the synaptic deficits and cognitive impairment in transgenic AD model mice. CONCLUSIONS These results strongly imply a significant role for p85S6K in maintaining synaptic and cognitive function by interacting with GluA1. The findings provide an insight into the rational targeting of p85S6K as a therapeutic potential for AD.
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Affiliation(s)
- Jia-Bing Li
- grid.16821.3c0000 0004 0368 8293Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Xiao-Yu Hu
- grid.16821.3c0000 0004 0368 8293Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Mu-Wen Chen
- grid.16821.3c0000 0004 0368 8293Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Cai-Hong Xiong
- grid.16821.3c0000 0004 0368 8293Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Na Zhao
- grid.16821.3c0000 0004 0368 8293Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Yan-Hui Ge
- grid.16821.3c0000 0004 0368 8293Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Hao Wang
- grid.16821.3c0000 0004 0368 8293Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Xiao-Ling Gao
- grid.16821.3c0000 0004 0368 8293Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Nan-Jie Xu
- grid.16821.3c0000 0004 0368 8293Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Lan-Xue Zhao
- grid.16821.3c0000 0004 0368 8293Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Zhi-Hua Yu
- grid.16821.3c0000 0004 0368 8293Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Hong-Zhuan Chen
- Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China. .,Institute of Interdisciplinary Integrative Biomedical Research, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 201210, China.
| | - Yu Qiu
- Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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17
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Life on Magnet: Long-Term Exposure of Moderate Static Magnetic Fields on the Lifespan and Healthspan of Mice. Antioxidants (Basel) 2022; 12:antiox12010108. [PMID: 36670970 PMCID: PMC9854752 DOI: 10.3390/antiox12010108] [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: 11/24/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 01/04/2023] Open
Abstract
All living organisms on the Earth live and evolve in the presence of the weak geomagnetic field, a quasi-uniform static magnetic field (SMF). In the meantime, although the effects of moderate and high SMFs have been investigated on multiple aspects of a living organism, a long-term SMF exposure of more than 1 year has never been reported. Here, we investigated the influence of a moderate SMF (70-220 mT head-to-toe) long-term continuous exposure (1.7 years) to two different SMF directions on healthy male C57BL/6 mice. We found that not only was the lifespan of the mice prolonged, but their healthspan was also improved. The elevated plus maze test and open field test show that SMFs could significantly improve the exploratory and locomotive activities of the aged mice. The Morris water maze test shows that SMFs could improve their spatial learning ability and spatial memory. Tissue examinations reveal that SMFs have an ameliorative effect on oxidative stress in the brain of aged mice, which was reinforced by the cellular assays, showing that SMFs could protect the PC12 cells from D-gal-induced senescence by increasing superoxide dismutase, catalase, and reducing the malonaldehyde levels. Therefore, our data show that the 1.7-year SMF exposure can improve both the lifespan and healthspan of naturally aged mice due to reduced oxidative stress, which indicates that SMFs have the potential to be used as an adjuvant physical therapy to reduce the ageing-induced health risks to benefit animals, and even humans.
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18
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The landscape of aging. SCIENCE CHINA LIFE SCIENCES 2022; 65:2354-2454. [PMID: 36066811 PMCID: PMC9446657 DOI: 10.1007/s11427-022-2161-3] [Citation(s) in RCA: 97] [Impact Index Per Article: 48.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 07/05/2022] [Indexed: 02/07/2023]
Abstract
Aging is characterized by a progressive deterioration of physiological integrity, leading to impaired functional ability and ultimately increased susceptibility to death. It is a major risk factor for chronic human diseases, including cardiovascular disease, diabetes, neurological degeneration, and cancer. Therefore, the growing emphasis on “healthy aging” raises a series of important questions in life and social sciences. In recent years, there has been unprecedented progress in aging research, particularly the discovery that the rate of aging is at least partly controlled by evolutionarily conserved genetic pathways and biological processes. In an attempt to bring full-fledged understanding to both the aging process and age-associated diseases, we review the descriptive, conceptual, and interventive aspects of the landscape of aging composed of a number of layers at the cellular, tissue, organ, organ system, and organismal levels.
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19
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New Trends in Aging Drug Discovery. Biomedicines 2022; 10:biomedicines10082006. [PMID: 36009552 PMCID: PMC9405986 DOI: 10.3390/biomedicines10082006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/13/2022] [Accepted: 08/15/2022] [Indexed: 11/17/2022] Open
Abstract
Aging is considered the main risk factor for many chronic diseases that frequently appear at advanced ages. However, the inevitability of this process is being questioned by recent research that suggests that senescent cells have specific features that differentiate them from younger cells and that removal of these cells ameliorates senescent phenotype and associated diseases. This opens the door to the design of tailored therapeutic interventions aimed at reducing and delaying the impact of senescence in life, that is, extending healthspan and treating aging as another chronic disease. Although these ideas are still far from reaching the bedside, it is conceivable that they will revolutionize the way we understand aging in the next decades. In this review, we analyze the main and well-validated cellular pathways and targets related to senescence as well as their implication in aging-associated diseases. In addition, the most relevant small molecules with senotherapeutic potential, with a special emphasis on their mechanism of action, ongoing clinical trials, and potential limitations, are discussed. Finally, a brief overview of alternative strategies that go beyond the small molecule field, together with our perspectives for the future of the field, is provided.
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Pharmacological Approaches to Decelerate Aging: A Promising Path. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:4201533. [PMID: 35860429 PMCID: PMC9293537 DOI: 10.1155/2022/4201533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 05/24/2022] [Accepted: 06/26/2022] [Indexed: 11/17/2022]
Abstract
Biological aging or senescence is a course in which cellular function decreases over a period of time and is a consequence of altered signaling mechanisms that are triggered in stressed cells leading to cell damage. Aging is among the principal risk factors for many chronic illnesses such as cancer, cardiovascular disorders, and neurodegenerative diseases. Taking this into account, targeting fundamental aging mechanisms therapeutically may effectively impact numerous chronic illnesses. Selecting ideal therapeutic options in order to hinder the process of aging and decelerate the progression of age-related diseases is valuable. Along therapeutic options, life style modifications may well render the process of aging. The process of aging is affected by alteration in many cellular and signaling pathways amid which mTOR, SIRT1, and AMPK pathways are the most emphasized. Herein, we have discussed the mechanisms of aging focusing mainly on the mentioned pathways as well as the role of inflammation and autophagy in aging. Moreover, drugs and natural products with antiaging properties are discussed in detail.
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21
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Culig L, Chu X, Bohr VA. Neurogenesis in aging and age-related neurodegenerative diseases. Ageing Res Rev 2022; 78:101636. [PMID: 35490966 PMCID: PMC9168971 DOI: 10.1016/j.arr.2022.101636] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 04/14/2022] [Accepted: 04/25/2022] [Indexed: 12/11/2022]
Abstract
Adult neurogenesis, the process by which neurons are generated in certain areas of the adult brain, declines in an age-dependent manner and is one potential target for extending cognitive healthspan. Aging is a major risk factor for neurodegenerative diseases and, as lifespans are increasing, these health challenges are becoming more prevalent. An age-associated loss in neural stem cell number and/or activity could cause this decline in brain function, so interventions that reverse aging in stem cells might increase the human cognitive healthspan. In this review, we describe the involvement of adult neurogenesis in neurodegenerative diseases and address the molecular mechanistic aspects of neurogenesis that involve some of the key aggregation-prone proteins in the brain (i.e., tau, Aβ, α-synuclein, …). We summarize the research pertaining to interventions that increase neurogenesis and regulate known targets in aging research, such as mTOR and sirtuins. Lastly, we share our outlook on restoring the levels of neurogenesis to physiological levels in elderly individuals and those with neurodegeneration. We suggest that modulating neurogenesis represents a potential target for interventions that could help in the fight against neurodegeneration and cognitive decline.
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Affiliation(s)
- Luka Culig
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Xixia Chu
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Vilhelm A Bohr
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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22
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He CF, Xue WJ, Xu XD, Wang JT, Wang XR, Feng Y, Zhou HG, Guo JC. Knockdown of NRSF Alleviates Ischemic Brain Injury and Microvasculature Defects in Diabetic MCAO Mice. Front Neurol 2022; 13:869220. [PMID: 35645950 PMCID: PMC9136417 DOI: 10.3389/fneur.2022.869220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/04/2022] [Indexed: 11/26/2022] Open
Abstract
Diabetes is one of the well-established risk factors of stroke and is associated with a poor outcome in patients with stroke. Previous studies have shown that the expression of neuron restrictive silencer factor (NRSF) is elevated in diabetes as well as ischemic stroke. However, the role of NRSF in regulating an outcome of diabetic ischemic stroke has not been completely understood. Here, we hypothesized that diabetes-induced NRSF elevation can aggravate brain injury and cognition impairment in ischemic stroke. The diabetic ischemic stroke mice model was established by 8 weeks of high-fat-diet feeding and 5 days of streptozotocin injection followed by 30 min of middle cerebral artery occlusion (MCAO). We found that diabetes enhanced the MCAO-induced elevation of NRSF in the hippocampus in accompany with an elevation of its corepressors, HDAC1, and mSin3A, and decrease of β-TrCP. By using histological/immunofluorescence staining and neurobehavioral testing, our results showed that the brain damage and learning/memory impairment were aggravated in diabetic ischemic mice but significantly attenuated after stereotaxic injection of NRSF-shRNA. Meanwhile, by performing whole-brain clearing with PEGASOS, microvascular reconstruction, western blotting, and ELISA, we found that NRSF-shRNA markedly alleviated the vasculature disorders and rescued the suppression of NRP-1, VEGF, and VEGFR2 in the hippocampus of diabetic ischemic mice. Therefore, our results demonstrated for the first time that the elevation of hippocampal NRSF plays an important role in alleviating brain injury and cognitive disabilities in diabetic ischemic mice, potentially via the reduction of NRP-1/VEGF signaling.
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Affiliation(s)
- Cheng-Feng He
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Translational Neuroscience, Jing'an District Centre Hospital of Shanghai, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Wen-Jiao Xue
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Translational Neuroscience, Jing'an District Centre Hospital of Shanghai, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Xiao-Die Xu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Translational Neuroscience, Jing'an District Centre Hospital of Shanghai, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Jian-Tao Wang
- Department of Geriatric Neurology of Huashan Hospital, National Clinical Research Center for Aging and Medicine, Fudan University, Shanghai, China
| | - Xin-Ru Wang
- Department of Geriatric Neurology of Huashan Hospital, National Clinical Research Center for Aging and Medicine, Fudan University, Shanghai, China
| | - Yi Feng
- State Key Laboratory of Medical Neurobiology, Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, Fudan Institutes of Integrative Medicine, Fudan University, Shanghai, China
- *Correspondence: Yi Feng
| | - Hou-Guang Zhou
- Department of Geriatric Neurology of Huashan Hospital, National Clinical Research Center for Aging and Medicine, Fudan University, Shanghai, China
- Hou-Guang Zhou
| | - Jing-Chun Guo
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Translational Neuroscience, Jing'an District Centre Hospital of Shanghai, Institutes of Brain Science, Fudan University, Shanghai, China
- Jing-Chun Guo
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23
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Regulation of Aging and Longevity by Ion Channels and Transporters. Cells 2022; 11:cells11071180. [PMID: 35406743 PMCID: PMC8997527 DOI: 10.3390/cells11071180] [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: 02/01/2022] [Revised: 03/22/2022] [Accepted: 03/29/2022] [Indexed: 12/10/2022] Open
Abstract
Despite significant advances in our understanding of the mechanisms that underlie age-related physiological decline, our ability to translate these insights into actionable strategies to extend human healthspan has been limited. One of the major reasons for the existence of this barrier is that with a few important exceptions, many of the proteins that mediate aging have proven to be undruggable. The argument put forth here is that the amenability of ion channels and transporters to pharmacological manipulation could be leveraged to develop novel therapeutic strategies to combat aging. This review delves into the established roles for ion channels and transporters in the regulation of aging and longevity via their influence on membrane excitability, Ca2+ homeostasis, mitochondrial and endolysosomal function, and the transduction of sensory stimuli. The goal is to provide the reader with an understanding of emergent themes, and prompt further investigation into how the activities of ion channels and transporters sculpt the trajectories of cellular and organismal aging.
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Rapaka D, Bitra VR, Challa SR, Adiukwu PC. mTOR signaling as a molecular target for the alleviation of Alzheimer's disease pathogenesis. Neurochem Int 2022; 155:105311. [PMID: 35218870 DOI: 10.1016/j.neuint.2022.105311] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/12/2022] [Accepted: 02/20/2022] [Indexed: 10/19/2022]
Abstract
Mechanistic/mammalian target of rapamycin (mTOR) belongs to the phosphatidylinositol kinase-related kinase (PIKK) family. mTOR signaling is required for the commencement of essential cell functions including autophagy. mTOR primarily governs cell growth in response to favourable nutrients and other growth stimuli. However, it also influences aging and other aspects of nutrient-related physiology such as protein synthesis, ribosome biogenesis, and cell proliferation in adults with very limited growth. The major processes for survival such as synaptic plasticity, memory storage and neuronal recovery involve a significant mTOR activity. mTOR dysregulation is becoming a prevalent motif in a variety of human diseases, including cancer, neurological disorders, and other metabolic syndromes. The use of rapamycin to prolong life in different animal models may be attributable to the multiple roles played by mTOR signaling in various processes involved in ageing, protein translation, autophagy, stem cell pool turnover, inflammation, and cellular senescence. mTOR activity was found to be altered in AD brains and rodent models, supporting the notion that aberrant mTOR activity is one of the key events contributing to the onset and progression of AD hallmarks This review assesses the molecular association between the mTOR signaling pathway and pathogenesis of Alzheimer's disease. The research data supporting this theme are also reviewed.
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Affiliation(s)
- Deepthi Rapaka
- A.U. College of Pharmaceutical Sciences, Andhra University, Visakhapatnam, 530003, India.
| | | | - Siva Reddy Challa
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine, Peoria, IL, 61614, USA.
| | - Paul C Adiukwu
- School of Pharmacy, University of Botswana, Gaborone, 0022, Botswana.
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25
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Querfurth H, Marshall J, Parang K, Rioult-Pedotti MS, Tiwari R, Kwon B, Reisinger S, Lee HK. A PDK-1 allosteric agonist neutralizes insulin signaling derangements and beta-amyloid toxicity in neuronal cells and in vitro. PLoS One 2022; 17:e0261696. [PMID: 35061720 PMCID: PMC8782417 DOI: 10.1371/journal.pone.0261696] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 12/08/2021] [Indexed: 01/09/2023] Open
Abstract
The Alzheimer's brain is affected by multiple pathophysiological processes, which include a unique, organ-specific form of insulin resistance that begins early in its course. An additional complexity arises from the four-fold risk of Alzheimer's Disease (AD) in type 2 diabetics, however there is no definitive proof of causation. Several strategies to improve brain insulin signaling have been proposed and some have been clinically tested. We report findings on a small allosteric molecule that reverses several indices of insulin insensitivity in both cell culture and in vitro models of AD that emphasize the intracellular accumulation of β-amyloid (Aβi). PS48, a chlorophenyl pentenoic acid, is an allosteric activator of PDK-1, which is an Akt-kinase in the insulin/PI3K pathway. PS48 was active at 10 nM to 1 μM in restoring normal insulin-dependent Akt activation and in mitigating Aβi peptide toxicity. Synaptic plasticity (LTP) in prefrontal cortical slices from normal rat exposed to Aβ oligomers also benefited from PS48. During these experiments, neither overstimulation of PI3K/Akt signaling nor toxic effects on cells was observed. Another neurotoxicity model producing insulin insensitivity, utilizing palmitic acid, also responded to PS48 treatment, thus validating the target and indicating that its therapeutic potential may extend outside of β-amyloid reliance. The described in vitro and cell based-in vitro coupled enzymatic assay systems proved suitable platforms to screen a preliminary library of new analogs.
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Affiliation(s)
- Henry Querfurth
- Department of Neurology, Tufts Medical Center, Boston, MA, United States of America
| | - John Marshall
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States of America
| | - Keykavous Parang
- Center for Targeted Drug Delivery, Chapman University, School of Pharmacology, Irvine, CA United States of America
| | - Mengia S. Rioult-Pedotti
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States of America
- Department of Neurology, Clinical Neurorehabilitation, University of Zurich, Zurich, Switzerland
| | - Rakesh Tiwari
- Center for Targeted Drug Delivery, Chapman University, School of Pharmacology, Irvine, CA United States of America
| | - Bumsup Kwon
- Department of Neurology, Rhode Island Hospital, Providence, RI, United States of America
| | | | - Han-Kyu Lee
- Department of Neurology, Tufts Medical Center, Boston, MA, United States of America
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26
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Liu T, Liang X, Sun Y, Yang S. Rapamycin suppresses the PI3K/AKT/mTOR signaling pathway by targeting SIRT1 in esophageal cancer. Exp Ther Med 2021; 22:1190. [PMID: 34475980 PMCID: PMC8406672 DOI: 10.3892/etm.2021.10624] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 06/29/2021] [Indexed: 12/13/2022] Open
Abstract
Rapamycin, a secondary metabolite produced by Streptomyces hygroscopicus, is known for its pharmacological effects, especially antitumor and immunosuppressive activities. However, the antitumoral effects of rapamycin in human esophageal cancer (EC) are still poorly understood. To investigate the potential of rapamycin in EC treatment, sirtuin 1 (SIRT1) mRNA expression was quantified in the tissue of patients with EC or in EC cell lines using reverse transcription-quantitative PCR. The protein levels of SIRT1 and PI3K/AKT/mTOR were measured via western blotting. Furthermore, cell viability, migration and invasion were investigated by Cell Counting Kit-8, wound healing and Transwell assays, respectively. The present results suggested that SIRT1 expression was upregulated in EC. In vitro, the inhibitory effect of rapamycin on cell viability in EC was strengthened or weakened after small interfering (si)-SIRT1 or pcDNA3.1/SIRT1 transfection. Furthermore, SIRT1 rescued the inhibitory effect of rapamycin on the migration and invasion of EC cells. In vivo, si-SIRT1 or SIRT1 overexpression in mice could enhance or rescue the inhibitory effects of rapamycin on tumor growth. In addition, SIRT1 transfection rescued the decreased level of phosphorylated (p)-PI3K, p-AKT and p-mTOR induced by rapamycin treatment. Taken together, the present results suggested that rapamycin suppressed the cell viability, migration, invasion and PI3K/AKT/mTOR signaling pathway in EC by negatively regulating SIRT1.
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Affiliation(s)
- Tao Liu
- Department of Cardiothoracic Surgery, Guangxi International Zhuang Medical Hospital, Nanning, Guangxi 530201, P.R. China
- Department of Cardiothoracic Surgery, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530007, P.R. China
| | - Xiangsen Liang
- Department of Cardiothoracic Surgery, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530007, P.R. China
| | - Yu Sun
- Department of Cardiothoracic Surgery, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530007, P.R. China
| | - Shengzhuang Yang
- Department of Cardiothoracic Surgery, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530007, P.R. China
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27
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Yang N, Liu X, Niu X, Wang X, Jiang R, Yuan N, Wang J, Zhang C, Lim KL, Lu L. Activation of Autophagy Ameliorates Age-Related Neurogenesis Decline and Neurodysfunction in Adult Mice. Stem Cell Rev Rep 2021; 18:626-641. [PMID: 34546510 DOI: 10.1007/s12015-021-10265-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2021] [Indexed: 01/10/2023]
Abstract
Adult neurogenesis is the ongoing generation of functional new neurons from neural progenitor cells (NPCs) in the mammalian brain. However, this process declines with aging, which is implicated in the recession of brain function and neurodegeneration. Understanding the mechanism of adult neurogenesis and stimulating neurogenesis will benefit the mitigation of neurodegenerative diseases. Autophagy, a highly conserved process of cellular degradation, is essential for maintaining cellular homeostasis and normal function. Whether and how autophagy affects adult neurogenesis remains poorly understood. In present study, we revealed a close connection between impaired autophagy and adult neurogenetic decline. Expression of autophagy-related genes and autophagic activity were significantly declined in the middle-adult subventricular/subgranular zone (SVZ/SGZ) homogenates and cultured NPCs, and inhibiting autophagy by siRNA interference resulted in impaired proliferation and differentiation of NPCs. Conversely, stimulating autophagy by rapamycin not only revitalized the viability of middle-adult NPCs, but also facilitated the neurogenesis in middle-adult SVZ/SGZ. More importantly, autophagic activation by rapamycin also ameliorated the olfactory sensitivity and cognitional capacities in middle-adult mice. Taken together, our results reveal that compromised autophagy is involved in the decline of adult neurogenesis, which could be reversed by autophagy activation. It also shed light on the regulation of adult neurogenesis and paves the way for developing a therapeutic strategy for aging and neurodegenerative diseases.
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Affiliation(s)
- Na Yang
- Department of Anatomy, Shanxi Medical University, 030001, Taiyuan, People's Republic of China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, 030001, Taiyuan, People's Republic of China
| | - Xueqin Liu
- Department of Anatomy, Shanxi Medical University, 030001, Taiyuan, People's Republic of China
| | - Xiaojie Niu
- Department of Anatomy, Shanxi Medical University, 030001, Taiyuan, People's Republic of China
| | - Xiaoqiang Wang
- Department of Anatomy, Shanxi Medical University, 030001, Taiyuan, People's Republic of China
| | - Rong Jiang
- Department of Anatomy, Shanxi Medical University, 030001, Taiyuan, People's Republic of China
| | - Na Yuan
- Hematology Center of Cyrus Tang Medical Institute, Soochow University School of Medicine, 215123, Suzhou, People's Republic of China
| | - Jianrong Wang
- Hematology Center of Cyrus Tang Medical Institute, Soochow University School of Medicine, 215123, Suzhou, People's Republic of China
| | - Chengwu Zhang
- Institute of Advanced Materials, Nanjing Tech University, 211816, Nanjing, People's Republic of China
| | - Kah-Leong Lim
- Lee Kong Chian School of Medicine, Nanyang Technological University, 308232, Singapore, Singapore.
| | - Li Lu
- Department of Anatomy, Shanxi Medical University, 030001, Taiyuan, People's Republic of China. .,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, 030001, Taiyuan, People's Republic of China.
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28
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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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29
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Traxler L, Lagerwall J, Eichhorner S, Stefanoni D, D'Alessandro A, Mertens J. Metabolism navigates neural cell fate in development, aging and neurodegeneration. Dis Model Mech 2021; 14:dmm048993. [PMID: 34345916 PMCID: PMC8353098 DOI: 10.1242/dmm.048993] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
An uninterrupted energy supply is critical for the optimal functioning of all our organs, and in this regard the human brain is particularly energy dependent. The study of energy metabolic pathways is a major focus within neuroscience research, which is supported by genetic defects in the oxidative phosphorylation mechanism often contributing towards neurodevelopmental disorders and changes in glucose metabolism presenting as a hallmark feature in age-dependent neurodegenerative disorders. However, as recent studies have illuminated roles of cellular metabolism that span far beyond mere energetics, it would be valuable to first comprehend the physiological involvement of metabolic pathways in neural cell fate and function, and to subsequently reconstruct their impact on diseases of the brain. In this Review, we first discuss recent evidence that implies metabolism as a master regulator of cell identity during neural development. Additionally, we examine the cell type-dependent metabolic states present in the adult brain. As metabolic states have been studied extensively as crucial regulators of malignant transformation in cancer, we reveal how knowledge gained from the field of cancer has aided our understanding in how metabolism likewise controls neural fate determination and stability by directly wiring into the cellular epigenetic landscape. We further summarize research pertaining to the interplay between metabolic alterations and neurodevelopmental and psychiatric disorders, and expose how an improved understanding of metabolic cell fate control might assist in the development of new concepts to combat age-dependent neurodegenerative diseases, particularly Alzheimer's disease.
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Affiliation(s)
- Larissa Traxler
- Neural Aging Laboratory, Institute of Molecular Biology, CMBI, Leopold-Franzens-University Innsbruck, Tyrol 6020, Austria
| | - Jessica Lagerwall
- Neural Aging Laboratory, Institute of Molecular Biology, CMBI, Leopold-Franzens-University Innsbruck, Tyrol 6020, Austria
| | - Sophie Eichhorner
- Neural Aging Laboratory, Institute of Molecular Biology, CMBI, Leopold-Franzens-University Innsbruck, Tyrol 6020, Austria
| | - Davide Stefanoni
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, CO 80045, USA
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, CO 80045, USA
| | - Jerome Mertens
- Neural Aging Laboratory, Institute of Molecular Biology, CMBI, Leopold-Franzens-University Innsbruck, Tyrol 6020, Austria
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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30
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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: 104] [Impact Index Per Article: 34.7] [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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31
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Rapamycin alleviates memory deficit against pentylenetetrazole-induced neural toxicity in Wistar male rats. Mol Biol Rep 2021; 48:5083-5091. [PMID: 34165769 DOI: 10.1007/s11033-021-06504-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/17/2021] [Indexed: 10/21/2022]
Abstract
Numerous studies have reported that epilepsy causes memory deficits. The present study was aimed at studying the effect of rapamycin against the memory deficiency of the pentylenetetrazole (PTZ)-kindled animal model of epilepsy. In the present experiment, we randomly chose thirty male rats from the species of Wistar and categorized them in groups of control and experiment (6 for each group). The groups of experiment received the injection of rapamycin (0.5, 1 and 2 mg/kg) intraperitoneally (i.p.) and the group of control received normal saline (0.9%) treatment. Through the PTZ's sub-threshold dose (35 mg kg-1, i.p.), all groups were kindled 12 times. Passive avoidance test (PAT) was used for gauging the memory function and the seizure behaviors after the kindling procedure. The rodents were sacrificed at the end of the trial and their brains were scooped for measuring the expression of Gabra1 and Pras40 genes. Statistical analysis unveiled that rapamycin delayed the kindling development and the onset of seizures which are tonic-clonic. Moreover, the administration of rapamycin significantly prevented memory dysfunction in epileptic rats. Finally, it was shown that rapamycin resulted in an increase in the expression levels of Gabra1 and Pras40 genes at the brain tissues. The current research design indicated that rapamycin has beneficial effects for the prevention of memory impairment against PTZ-kindling epilepsy in rats. Such promising outcomes could be attributed to its impact on the Gabra1 and Pras40 genes.
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32
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Gibbs NH, Michalski H, Promislow DEL, Kaeberlein M, Creevy KE. Reasons for Exclusion of Apparently Healthy Mature Adult and Senior Dogs From a Clinical Trial. Front Vet Sci 2021; 8:651698. [PMID: 34150883 PMCID: PMC8206478 DOI: 10.3389/fvets.2021.651698] [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: 01/10/2021] [Accepted: 04/27/2021] [Indexed: 11/14/2022] Open
Abstract
Background: Interventional clinical trials intended to maintain health in aging dogs are unusual and require particular attention to exclusion criteria. Objectives: To describe reasons for exclusion when a mature adult and senior canine population with normal health status was sought. Animals: Fifty six companion dogs nominated for a randomized controlled trial (RCT). Procedures: Exclusions occurred within Stage 1 (S1): owner-provided survey information; Stage 2 (S2): medical records review; and Stage 3 (S3): screening examination and within Owner, Dog, or Other factor categories. Results: Of 56 nominated dogs, 39 were excluded at S1 (n = 19), S2 (n = 5), and S3 (n = 15), respectively. Dogs were excluded for Owner (n = 4), Dog (n = 27), Other (n = 6), and concurrent (Owner + Dog; n = 2) factors. The most common exclusion period was S1 (n = 19), with weight outside the target range being the most common exclusion factor in that stage (n = 10). Heart murmurs were the second most common exclusion factor (S1: n = 1; S3: n = 5); suspected or confirmed systemic illness was third most common (S1: n = 2; S2: n = 3; S3: n = 2). Among dogs who passed S1 and S2 screening (n = 32), 15 dogs (48%) were excluded at S3, for heart murmur > grade II/VI (n = 5), cardiac arrhythmias (n = 2), and clinicopathologic abnormalities (n = 2). Conclusions and Clinical Relevance: Dogs nominated for a clinical trial for healthy mature adult and senior dogs were excluded for size, previous diagnoses, and newly discovered cardiac abnormalities. For future interventions in mature adult and senior dogs of normal health status, it is important to define expected age-related abnormalities to ensure that meaningful exclusion criteria are used.
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Affiliation(s)
- Nicole H Gibbs
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | - Hannah Michalski
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | - Daniel E L Promislow
- Department of Laboratory Medicine & Pathology, University of Washington School of Medicine, Seattle, WA, United States.,Department of Biology, University of Washington, Seattle, WA, United States
| | - Matt Kaeberlein
- Department of Laboratory Medicine & Pathology, University of Washington School of Medicine, Seattle, WA, United States
| | - Kate E Creevy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
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33
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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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34
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Poole RL, Curry PDK, Marcinkute R, Brewer C, Coman D, Hobson E, Johnson D, Lynch SA, Saggar A, Searle C, Scurr I, Turnpenny PD, Vasudevan P, Tatton-Brown K. Delineating the Smith-Kingsmore syndrome phenotype: Investigation of 16 patients with the MTOR c.5395G > A p.(Glu1799Lys) missense variant. Am J Med Genet A 2021; 185:2445-2454. [PMID: 34032352 DOI: 10.1002/ajmg.a.62350] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/16/2021] [Indexed: 01/06/2023]
Abstract
Smith-Kingsmore Syndrome (SKS) is a rare genetic syndrome associated with megalencephaly, a variable intellectual disability, autism spectrum disorder, and MTOR gain of function variants. Only 30 patients with MTOR missense variants are published, including 14 (47%) with the MTOR c.5395G>A p.(Glu1799Lys) variant. Limited phenotypic data impacts the quality of information delivered to families and the robustness of interpretation of novel MTOR missense variation. This study aims to improve our understanding of the SKS phenotype through the investigation of 16 further patients with the MTOR c.5395G>A p.(Glu1799Lys) variant. Through the careful phenotypic evaluation of these 16 patients and integration with data from 14 previously reported patients, we have defined major (100% patients) and frequent (>15%) SKS clinical characteristics and, using these data, proposed guidance for evidence-based management. In addition, in the absence of functional studies, we suggest that the combination of the SKS major clinical features of megalencephaly (where the head circumference is at least 3SD) and an intellectual disability with a de novo MTOR missense variant (absent from population databases) should be considered diagnostic for SKS.
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Affiliation(s)
- Rebecca L Poole
- NHS Education for Scotland South East Region, South East of Scotland Clinical Genetics Service, Edinburgh, UK.,University College London, London, UK
| | | | - Ruta Marcinkute
- Department of Clinical Genetics, Guys and St Thomas' NHS Foundation Trust, London, UK
| | - Carole Brewer
- Department of Clinical Genetics, Royal Devon & Exeter NHS Foundation Trust, Exeter, UK
| | - David Coman
- Department of Metabolic Medicine, Queensland Children's Hospital, Queensland, Australia
| | - Emma Hobson
- Department of Clinical Genetics, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Diana Johnson
- Department of Clinical Genetics, Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Sally Ann Lynch
- Department of Clinical Genetics, Temple Street Children's University Hospital, Dublin, Ireland
| | - Anand Saggar
- South West Thames Regional Genetics Department, St George's University Hospitals NHS Foundation Trust, London, UK
| | - Claire Searle
- Department of Clinical Genetics, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Ingrid Scurr
- Department of Clinical Genetics, University Hospital Bristol and Western NHS Foundation Trust, Bristol, UK
| | - Peter D Turnpenny
- Department of Clinical Genetics, Royal Devon & Exeter NHS Foundation Trust, Exeter, UK
| | - Pradeep Vasudevan
- Department of Clinical Genetics, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Katrina Tatton-Brown
- St George's University of London, London, UK.,South West Thames Regional Genetics Department, St George's University Hospitals NHS Foundation Trust, London, UK
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35
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Altschuler RA, Kabara L, Martin C, Kanicki A, Stewart CE, Kohrman DC, Dolan DF. Rapamycin Added to Diet in Late Mid-Life Delays Age-Related Hearing Loss in UMHET4 Mice. Front Cell Neurosci 2021; 15:658972. [PMID: 33897373 PMCID: PMC8058174 DOI: 10.3389/fncel.2021.658972] [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: 01/26/2021] [Accepted: 03/11/2021] [Indexed: 01/30/2023] Open
Abstract
Our previous study demonstrated rapamycin added to diet at 4 months of age had significantly less age-related outer hair cell loss in the basal half of the cochlea at 22 months of age compared to mice without rapamycin. The present study tested adding rapamycin to diet later in life, at 14 months of age, and added a longitudinal assessment of auditory brain stem response (ABR). The present study used UMHET4 mice, a 4 way cross in which all grandparental strains lack the Cdh23753A allele that predisposes to early onset, progressive hearing loss. UMHET4 mice typically have normal hearing until 16-17 months, then exhibit threshold shifts at low frequencies/apical cochlea and later in more basal high frequency regions. ABR thresholds at 4, 12, 24, and 48 kHz were assessed at 12, 18, and 24 months of age and compared to baseline ABR thresholds acquired at 5 months of age to determine threshold shifts (TS). There was no TS at 12 months of age at any frequency tested. At 18 months of age mice with rapamycin added to diet at 14 months had a significantly lower mean TS at 4 and 12 kHz compared to mice on control diet with no significant difference at 24 and 48 kHz. At 24 months of age, the mean 4 kHz TS in rapamycin diet group was no longer significantly lower than the control diet group, while the 12 kHz mean remained significantly lower. Mean TS at 24 and 48 kHz in the rapamycin diet group became significantly lower than in the control diet group at 24 months. Hair cell counts at 24 months showed large loss in the apical half of most rapamycin and control diet mice cochleae with no significant difference between groups. There was only mild outer hair cell loss in the basal half of rapamycin and control diet mice cochleae with no significant difference between groups. The results show that a later life addition of rapamycin can decrease age-related hearing loss in the mouse model, however, it also suggests that this decrease is a delay/deceleration rather than a complete prevention.
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Affiliation(s)
- Richard A Altschuler
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States.,VA Ann Arbor Health Care System, Ann Arbor, MI, United States.,Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Lisa Kabara
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Catherine Martin
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Ariane Kanicki
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Courtney E Stewart
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States.,VA Ann Arbor Health Care System, Ann Arbor, MI, United States
| | - David C Kohrman
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
| | - David F Dolan
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
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36
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The potential of rapalogs to enhance resilience against SARS-CoV-2 infection and reduce the severity of COVID-19. LANCET HEALTHY LONGEVITY 2021; 2:e105-e111. [PMID: 33665645 PMCID: PMC7906698 DOI: 10.1016/s2666-7568(20)30068-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
COVID-19 disproportionately affects older people, with likelihood of severe complications and death mirroring that of other age-associated diseases. Inhibition of the mechanistic target of rapamycin complex 1 (mTORC1) has been shown to delay or reverse many age-related phenotypes, including declining immune function. Rapamycin (sirolimus) and rapamycin derivatives are US Food and Drug Administration-approved inhibitors of mTORC1 with broad clinical utility and well established dosing and safety profiles. Based on preclinical and clinical evidence, a strong case can be made for immediate large-scale clinical trials to assess whether rapamycin and other mTORC1 inhibitors can prevent COVID-19 infection in these populations and also to determine whether these drugs can improve outcomes in patients with severe COVID-19.
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37
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Effect of Aging on Homeostasis in the Soft Tissue of the Periodontium: A Narrative Review. J Pers Med 2021; 11:jpm11010058. [PMID: 33477537 PMCID: PMC7831085 DOI: 10.3390/jpm11010058] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/06/2021] [Accepted: 01/15/2021] [Indexed: 12/12/2022] Open
Abstract
Aging is characterized by a progressive decline or loss of physiological functions, leading to increased susceptibility to disease or death. Several aging hallmarks, including genomic instability, cellular senescence, and mitochondrial dysfunction, have been suggested, which often lead to the numerous aging disorders. The periodontium, a complex structure surrounding and supporting the teeth, is composed of the gingiva, periodontal ligament, cementum, and alveolar bone. Supportive and protective roles of the periodontium are very critical to sustain life, but the periodontium undergoes morphological and physiological changes with age. In this review, we summarize the current knowledge of molecular and cellular physiological changes in the periodontium, by focusing on soft tissues including gingiva and periodontal ligament.
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Kelley WJ, Zemans RL, Goldstein DR. Cellular senescence: friend or foe to respiratory viral infections? Eur Respir J 2020; 56:2002708. [PMID: 33033152 PMCID: PMC7758538 DOI: 10.1183/13993003.02708-2020] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/30/2020] [Indexed: 01/26/2023]
Abstract
Cellular senescence permanently arrests the replication of various cell types and contributes to age-associated diseases. In particular, cellular senescence may enhance chronic lung diseases including COPD and idiopathic pulmonary fibrosis. However, the role cellular senescence plays in the pathophysiology of acute inflammatory diseases, especially viral infections, is less well understood. There is evidence that cellular senescence prevents viral replication by increasing antiviral cytokines, but other evidence shows that senescence may enhance viral replication by downregulating antiviral signalling. Furthermore, cellular senescence leads to the secretion of inflammatory mediators, which may either promote host defence or exacerbate immune pathology during viral infections. In this Perspective article, we summarise how senescence contributes to physiology and disease, the role of senescence in chronic lung diseases, and how senescence impacts acute respiratory viral infections. Finally, we develop a potential framework for how senescence may contribute, both positively and negatively, to the pathophysiology of viral respiratory infections, including severe acute respiratory syndrome due to the coronavirus SARS-CoV-2.
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Affiliation(s)
- William J Kelley
- Dept of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- Program in Immunology, University of Michigan, Ann Arbor, MI, USA
- Dept of Microbiology and Immunology, University of Michigan, Ann Arbor, MI USA
| | - Rachel L Zemans
- Dept of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- Program in Immunology, University of Michigan, Ann Arbor, MI, USA
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, USA
| | - Daniel R Goldstein
- Dept of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- Program in Immunology, University of Michigan, Ann Arbor, MI, USA
- Dept of Microbiology and Immunology, University of Michigan, Ann Arbor, MI USA
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Trujillo-Vargas CM, Kutlehria S, Hernandez H, de Souza RG, Lee A, Yu Z, Pflugfelder SC, Singh M, de Paiva CS. Rapamycin Eyedrops Increased CD4 +Foxp3 + Cells and Prevented Goblet Cell Loss in the Aged Ocular Surface. Int J Mol Sci 2020; 21:ijms21238890. [PMID: 33255287 PMCID: PMC7727717 DOI: 10.3390/ijms21238890] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/12/2020] [Accepted: 11/17/2020] [Indexed: 12/13/2022] Open
Abstract
Dry eye disease (DED), one of the most prevalent conditions among the elderly, is a chronic inflammatory disorder that disrupts tear film stability and causes ocular surface damage. Aged C57BL/6J mice spontaneously develop DED. Rapamycin is a potent immunosuppressant that prolongs the lifespan of several species. Here, we compared the effects of daily instillation of eyedrops containing rapamycin or empty micelles for three months on the aged mice. Tear cytokine/chemokine profile showed a pronounced increase in vascular endothelial cell growth factor-A (VEGF-A) and a trend towards decreased concentration of Interferon gamma (IFN)-γ in rapamycin-treated groups. A significant decrease in inflammatory markers in the lacrimal gland was also evident (IFN-γ, IL-12, CIITA and Ctss); this was accompanied by slightly diminished Unc-51 Like Autophagy Activating Kinase 1 (ULK1) transcripts. In the lacrimal gland and draining lymph nodes, we also observed a significant increase in the CD45+CD4+Foxp3+ cells in the rapamycin-treated mice. More importantly, rapamycin eyedrops increased conjunctival goblet cell density and area compared to the empty micelles. Taken together, evidence from these studies indicates that topical rapamycin has therapeutic efficacy for age-associated ocular surface inflammation and goblet cell loss and opens the venue for new investigations on its role in the aging process of the eye.
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Affiliation(s)
- Claudia M. Trujillo-Vargas
- Grupo de Inmunodeficiencias Primarias, Facultad de Medicina, Universidad de Antioquia, UdeA, Medellín 050010, Colombia;
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030, USA; (H.H.); (R.G.d.S.); (Z.Y.); (S.C.P.)
| | - Shallu Kutlehria
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA; (S.K.); (M.S.)
| | - Humberto Hernandez
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030, USA; (H.H.); (R.G.d.S.); (Z.Y.); (S.C.P.)
| | - Rodrigo G. de Souza
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030, USA; (H.H.); (R.G.d.S.); (Z.Y.); (S.C.P.)
| | - Andrea Lee
- Graduate Program in Immunology & Microbiology, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Zhiyuan Yu
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030, USA; (H.H.); (R.G.d.S.); (Z.Y.); (S.C.P.)
| | - Stephen C. Pflugfelder
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030, USA; (H.H.); (R.G.d.S.); (Z.Y.); (S.C.P.)
| | - Mandip Singh
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA; (S.K.); (M.S.)
| | - Cintia S. de Paiva
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030, USA; (H.H.); (R.G.d.S.); (Z.Y.); (S.C.P.)
- Correspondence: ; Tel.: +1-713-798-2124
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40
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Dumas SN, Lamming DW. Next Generation Strategies for Geroprotection via mTORC1 Inhibition. J Gerontol A Biol Sci Med Sci 2020; 75:14-23. [PMID: 30794726 DOI: 10.1093/gerona/glz056] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Indexed: 01/10/2023] Open
Abstract
Inhibition of mTORC1 (mechanistic Target Of Rapamycin Complex 1) with the pharmaceutical rapamycin prolongs the lifespan and healthspan of model organisms including rodents, with evidence now emerging that rapamycin and its analogs may also have rejuvenative effects in dogs and humans. However, the side effects associated with long-term rapamycin treatment, many of which are due to inhibition of a second mTOR complex, mTORC2, have seemed to preclude the routine use of rapamycin as a therapy for age-related diseases. Here, we discuss recent findings suggesting that strong, chronic inhibition of both mTOR complexes may not be necessary to realize the geroprotective effects of rapamycin. Instead, modestly but specifically inhibiting mTORC1 via a variety of emerging techniques, including intermittent or transient treatment with rapamycin derivatives, or specific dietary regimens, may be sufficient to promote health and longevity with reduced side effects. We will also discuss prospects for the development of new molecules that, by harnessing the detailed molecular understanding of mTORC1 signaling developed over the last decade, will provide new routes to the selective inhibition of mTORC1. We conclude that therapies based on the selective inhibition of mTORC1 may soon permit the safer treatment of diseases of aging.
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Affiliation(s)
- Sabrina N Dumas
- William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin.,Department of Medicine, University of Wisconsin-Madison
| | - Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin.,Department of Medicine, University of Wisconsin-Madison
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41
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Nicaise AM, Willis CM, Crocker SJ, Pluchino S. Stem Cells of the Aging Brain. Front Aging Neurosci 2020; 12:247. [PMID: 32848716 PMCID: PMC7426063 DOI: 10.3389/fnagi.2020.00247] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/20/2020] [Indexed: 12/12/2022] Open
Abstract
The adult central nervous system (CNS) contains resident stem cells within specific niches that maintain a self-renewal and proliferative capacity to generate new neurons, astrocytes, and oligodendrocytes throughout adulthood. Physiological aging is associated with a progressive loss of function and a decline in the self-renewal and regenerative capacities of CNS stem cells. Also, the biggest risk factor for neurodegenerative diseases is age, and current in vivo and in vitro models of neurodegenerative diseases rarely consider this. Therefore, combining both aging research and appropriate interrogation of animal disease models towards the understanding of the disease and age-related stem cell failure is imperative to the discovery of new therapies. This review article will highlight the main intrinsic and extrinsic regulators of neural stem cell (NSC) aging and discuss how these factors impact normal homeostatic functions within the adult brain. We will consider established in vivo animal and in vitro human disease model systems, and then discuss the current and future trajectories of novel senotherapeutics that target aging NSCs to ameliorate brain disease.
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Affiliation(s)
- Alexandra M Nicaise
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, Cambridge, United Kingdom
| | - Cory M Willis
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, Cambridge, United Kingdom
| | - Stephen J Crocker
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, United States
| | - Stefano Pluchino
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, Cambridge, United Kingdom
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42
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Wolff CA, Lawrence MM, Porter H, Zhang Q, Reid JJ, Laurin JL, Musci RV, Linden MA, Peelor FF, Wren JD, Creery JS, Cutler KJ, Carson RH, Price JC, Hamilton KL, Miller BF. Sex differences in changes of protein synthesis with rapamycin treatment are minimized when metformin is added to rapamycin. GeroScience 2020; 43:809-828. [PMID: 32761290 PMCID: PMC8110668 DOI: 10.1007/s11357-020-00243-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 07/29/2020] [Indexed: 12/18/2022] Open
Abstract
Loss of protein homeostasis is a hallmark of the aging process. We and others have previously shown that maintenance of proteostasis is a shared characteristic of slowed-aging models. Rapamycin (Rap) exerts sex-specific effects on murine lifespan, but the combination of Rap with the anti-hyperglycemic drug metformin (Rap + Met) equally increases male and female mouse median lifespan. In the current investigation, we compare the effects of short-term (8 weeks) Rap and Rap + Met treatments on bulk and individual protein synthesis in two key metabolic organs (the liver and skeletal muscle) of young genetically heterogeneous mice using deuterium oxide. We report for the first time distinct effects of Rap and Rap + Met treatments on bulk and individual protein synthesis in young mice. Although there were decreases in protein synthesis as assessed by bulk measurements, individual protein synthesis analyses demonstrate there were nearly as many proteins that increased synthesis as decreased synthesis rates. While we observed the established sex- and tissue-specific effects of Rap on protein synthesis, adding Met yielded more uniform effects between tissue and sex. These data offer mechanistic insight as to how Rap + Met may extend lifespan in both sexes while Rap does not.
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Affiliation(s)
- Christopher A Wolff
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA.,Department of Physiology and Functional Genomics, University of Florida, Gainesville, 32610, USA
| | - Marcus M Lawrence
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA.
| | - Hunter Porter
- Genes and Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Qian Zhang
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Justin J Reid
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Jaime L Laurin
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Robert V Musci
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Melissa A Linden
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA.,Pennington Biomedical Research Foundation, Baton Rouge, LA, 70808, USA
| | - Frederick F Peelor
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Jonathan D Wren
- Genes and Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Joseph S Creery
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602, USA
| | - Kyle J Cutler
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602, USA
| | - Richard H Carson
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602, USA
| | - John C Price
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602, USA
| | - Karyn L Hamilton
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Benjamin F Miller
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
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43
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Sohrabi M, Floden AM, Manocha GD, Klug MG, Combs CK. IGF-1R Inhibitor Ameliorates Neuroinflammation in an Alzheimer's Disease Transgenic Mouse Model. Front Cell Neurosci 2020; 14:200. [PMID: 32719587 PMCID: PMC7348663 DOI: 10.3389/fncel.2020.00200] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 06/08/2020] [Indexed: 01/01/2023] Open
Abstract
Aging is a major risk factor for Alzheimer's disease (AD). Insulin-like growth factor-1 receptor (IGF-1R) regulates general aging and lifespan. However, the contribution of IGF-1 to age-related AD pathology and progression is highly controversial. Based on our previous work, AβPP/PS1 double transgenic mice, which express human mutant amyloid precursor protein (APP) and presenilin-1 (PS-1), demonstrated a decrease in brain IGF-1 levels when they were crossed with IGF-1 deficient Ames dwarf mice (df/df). Subsequently, a reduction in gliosis, amyloid-β (Aβ) plaque deposition, and Aβ1-40/42 concentrations were observed in this mouse model. This supported the hypothesis that IGF-1 may contribute to the progression of the disease. To assess the role of IGF-1 in AD, 9-10-month-old male littermate control wild type and AβPP/PS1 mice were randomly divided into two treatment groups including control vehicle (DMSO) and picropodophyllin (PPP), a selective, competitive, and reversible IGF-1R inhibitor. The brain penetrant inhibitor was given ip. at 1 mg/kg/day. Mice were sacrificed after 7 days of daily injection and the brains, spleens, and livers were collected to quantify histologic and biochemical changes. The PPP-treated AβPP/PS1 mice demonstrated attenuated insoluble Aβ1-40/42. Additionally, an attenuation in microgliosis and protein p-tyrosine levels was observed due to drug treatment in the hippocampus. Our data suggest IGF-1R signaling is associated with disease progression in this mouse model. More importantly, modulation of the brain IGF-1R signaling pathway, even at mid-life, was enough to attenuate aspects of the disease phenotype. This suggests that small molecule therapy targeting the IGF-1R pathway may be viable for late-stage disease treatment.
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Affiliation(s)
- Mona Sohrabi
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Angela M Floden
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Gunjan D Manocha
- Department of Geriatrics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Marilyn G Klug
- Department of Population Health, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Colin K Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
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44
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Partridge L, Fuentealba M, Kennedy BK. The quest to slow ageing through drug discovery. Nat Rev Drug Discov 2020; 19:513-532. [DOI: 10.1038/s41573-020-0067-7] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2020] [Indexed: 02/07/2023]
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45
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Khosla S, Farr JN, Tchkonia T, Kirkland JL. The role of cellular senescence in ageing and endocrine disease. Nat Rev Endocrinol 2020; 16:263-275. [PMID: 32161396 PMCID: PMC7227781 DOI: 10.1038/s41574-020-0335-y] [Citation(s) in RCA: 256] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/14/2020] [Indexed: 12/19/2022]
Abstract
With the ageing of the global population, interest is growing in the 'geroscience hypothesis', which posits that manipulation of fundamental ageing mechanisms will delay (in parallel) the appearance or severity of multiple chronic, non-communicable diseases, as these diseases share the same underlying risk factor - namely, ageing. In this context, cellular senescence has received considerable attention as a potential target in preventing or treating multiple age-related diseases and increasing healthspan. Here we review mechanisms of cellular senescence and approaches to target this pathway therapeutically using 'senolytic' drugs that kill senescent cells or inhibitors of the senescence-associated secretory phenotype (SASP). Furthermore, we highlight the evidence that cellular senescence has a causative role in multiple diseases associated with ageing. Finally, we focus on the role of cellular senescence in a number of endocrine diseases, including osteoporosis, metabolic syndrome and type 2 diabetes mellitus, as well as other endocrine conditions. Although much remains to be done, considerable preclinical evidence is now leading to the initiation of proof-of-concept clinical trials using senolytics for several endocrine and non-endocrine diseases.
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Affiliation(s)
- Sundeep Khosla
- Division of Endocrinology, Mayo Clinic, Rochester, MN, USA.
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA.
| | - Joshua N Farr
- Division of Endocrinology, Mayo Clinic, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Tamara Tchkonia
- Division of Endocrinology, Mayo Clinic, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - James L Kirkland
- Division of Endocrinology, Mayo Clinic, Rochester, MN, USA.
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA.
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46
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Abdallah CG, Averill LA, Gueorguieva R, Goktas S, Purohit P, Ranganathan M, Sherif M, Ahn KH, D'Souza DC, Formica R, Southwick SM, Duman RS, Sanacora G, Krystal JH. Modulation of the antidepressant effects of ketamine by the mTORC1 inhibitor rapamycin. Neuropsychopharmacology 2020; 45:990-997. [PMID: 32092760 PMCID: PMC7162891 DOI: 10.1038/s41386-020-0644-9] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 01/08/2020] [Accepted: 02/12/2020] [Indexed: 02/08/2023]
Abstract
Twenty-four hours after administration, ketamine exerts rapid and robust antidepressant effects that are thought to be mediated by activation of the mechanistic target of rapamycin complex 1 (mTORC1). To test this hypothesis, depressed patients were pretreated with rapamycin, an mTORC1 inhibitor, prior to receiving ketamine. Twenty patients suffering a major depressive episode were randomized to pretreatment with oral rapamycin (6 mg) or placebo 2 h prior to the intravenous administration of ketamine 0.5 mg/kg in a double-blind cross-over design with treatment days separated by at least 2 weeks. Depression severity was assessed using Montgomery-Åsberg Depression Rating Scale (MADRS). Rapamycin pretreatment did not alter the antidepressant effects of ketamine at the 24-h timepoint. Over the subsequent 2-weeks, we found a significant treatment by time interaction (F(8,245) = 2.02, p = 0.04), suggesting a prolongation of the antidepressant effects of ketamine by rapamycin. Two weeks following ketamine administration, we found higher response (41%) and remission rates (29%) following rapamycin + ketamine compared to placebo + ketamine (13%, p = 0.04, and 7%, p = 0.003, respectively). In summary, single dose rapamycin pretreatment failed to block the antidepressant effects of ketamine, but it prolonged ketamine's antidepressant effects. This observation raises questions about the role of systemic vs. local blockade of mTORC1 in the antidepressant effects of ketamine, provides preliminary evidence that rapamycin may extend the benefits of ketamine, and thereby potentially sheds light on mechanisms that contribute to depression relapse after ketamine administration.
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Affiliation(s)
- Chadi G Abdallah
- National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, USA.
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA.
| | - Lynnette A Averill
- National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, USA
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
| | - Ralitza Gueorguieva
- Department of Biostatistics, Yale University School of Public Health, New Haven, CT, USA
| | - Selin Goktas
- National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, USA
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
| | - Prerana Purohit
- National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, USA
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
| | - Mohini Ranganathan
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
| | - Mohamed Sherif
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
| | - Kyung-Heup Ahn
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
| | - Deepak Cyril D'Souza
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
| | - Richard Formica
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Steven M Southwick
- National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, USA
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
| | - Ronald S Duman
- National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, USA
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
| | - Gerard Sanacora
- National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, USA
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
| | - John H Krystal
- National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, USA
- Departments of Psychiatry, Neuroscience, and Psychology Yale University, New Haven, CT, USA
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47
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Bellantuono I, de Cabo R, Ehninger D, Di Germanio C, Lawrie A, Miller J, Mitchell SJ, Navas-Enamorado I, Potter PK, Tchkonia T, Trejo JL, Lamming DW. A toolbox for the longitudinal assessment of healthspan in aging mice. Nat Protoc 2020; 15:540-574. [PMID: 31915391 PMCID: PMC7002283 DOI: 10.1038/s41596-019-0256-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 10/10/2019] [Indexed: 12/11/2022]
Abstract
The number of people aged over 65 is expected to double in the next 30 years. For many, living longer will mean spending more years with the burdens of chronic diseases such as Alzheimer's disease, cardiovascular disease, and diabetes. Although researchers have made rapid progress in developing geroprotective interventions that target mechanisms of aging and delay or prevent the onset of multiple concurrent age-related diseases, a lack of standardized techniques to assess healthspan in preclinical murine studies has resulted in reduced reproducibility and slow progress. To overcome this, major centers in Europe and the United States skilled in healthspan analysis came together to agree on a toolbox of techniques that can be used to consistently assess the healthspan of mice. Here, we describe the agreed toolbox, which contains protocols for echocardiography, novel object recognition, grip strength, rotarod, glucose tolerance test (GTT) and insulin tolerance test (ITT), body composition, and energy expenditure. The protocols can be performed longitudinally in the same mouse over a period of 4-6 weeks to test how candidate geroprotectors affect cardiac, cognitive, neuromuscular, and metabolic health.
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Affiliation(s)
- I Bellantuono
- Department of Oncology and Metabolism, Healthy Lifespan Institute and MRC-Arthritis Research UK Centre for Integrated research into Musculoskeletal Ageing, University of Sheffield, Sheffield, UK.
| | - R de Cabo
- Translational Gerontology Branch, National Institutes of Health, Baltimore, MD, USA
| | - D Ehninger
- German Center for Neurodegenerative Diseases (DZNE), Venusberg Campus 1, Bonn, Germany
| | - C Di Germanio
- Translational Gerontology Branch, National Institutes of Health, Baltimore, MD, USA
| | - A Lawrie
- Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - J Miller
- Robert and Arlene KogodCenter on Aging, Mayo Clinic, Rochester, MN, USA
| | - S J Mitchell
- Department of Molecular Medicine, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - I Navas-Enamorado
- Translational Gerontology Branch, National Institutes of Health, Baltimore, MD, USA
| | - P K Potter
- Department of Biological and Life Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxfordshire, UK
| | - T Tchkonia
- Robert and Arlene KogodCenter on Aging, Mayo Clinic, Rochester, MN, USA
| | - J L Trejo
- Department of Translational Neuroscience, Cajal Institute (CSIC), Madrid, Spain
| | - D W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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48
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Ishikawa S, Ishikawa F. Proteostasis failure and cellular senescence in long-term cultured postmitotic rat neurons. Aging Cell 2020; 19:e13071. [PMID: 31762159 PMCID: PMC6974705 DOI: 10.1111/acel.13071] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 10/05/2019] [Accepted: 10/29/2019] [Indexed: 12/31/2022] Open
Abstract
Cellular senescence, a stress-induced irreversible cell cycle arrest, has been defined for mitotic cells and is implicated in aging of replicative tissues. Age-related functional decline in the brain is often attributed to a failure of protein homeostasis (proteostasis), largely in postmitotic neurons, which accordingly is a process distinct by definition from senescence. It is nevertheless possible that proteostasis failure and cellular senescence have overlapping molecular mechanisms. Here, we identify postmitotic cellular senescence as an adaptive stress response to proteostasis failure. Primary rat hippocampal neurons in long-term cultures show molecular changes indicative of both senescence (senescence-associated β-galactosidase, p16, and loss of lamin B1) and proteostasis failure relevant to Alzheimer's disease. In addition, we demonstrate that the senescent neurons exhibit resistance to stress. Importantly, treatment of the cultures with an mTOR antagonist, protein synthesis inhibitor, or chemical compound that reduces the amount of protein aggregates relieved the proteotoxic stresses as well as the appearance of senescence markers. Our data propose mechanistic insights into the pathophysiological brain aging by establishing senescence as a primary cell-autonomous neuroprotective response.
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Affiliation(s)
- Shoma Ishikawa
- Department of Gene Mechanisms Graduate School of Biostudies Kyoto University Kyoto Japan
| | - Fuyuki Ishikawa
- Department of Gene Mechanisms Graduate School of Biostudies Kyoto University Kyoto Japan
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49
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Van Skike CE, Lin A, Roberts Burbank R, Halloran JJ, Hernandez SF, Cuvillier J, Soto VY, Hussong SA, Jahrling JB, Javors MA, Hart MJ, Fischer KE, Austad SN, Galvan V. mTOR drives cerebrovascular, synaptic, and cognitive dysfunction in normative aging. Aging Cell 2020; 19:e13057. [PMID: 31693798 PMCID: PMC6974719 DOI: 10.1111/acel.13057] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 09/03/2019] [Accepted: 10/06/2019] [Indexed: 01/05/2023] Open
Abstract
Cerebrovascular dysfunction and cognitive decline are highly prevalent in aging, but the mechanisms underlying these impairments are unclear. Cerebral blood flow decreases with aging and is one of the earliest events in the pathogenesis of Alzheimer's disease (AD). We have previously shown that the mechanistic/mammalian target of rapamycin (mTOR) drives disease progression in mouse models of AD and in models of cognitive impairment associated with atherosclerosis, closely recapitulating vascular cognitive impairment. In the present studies, we sought to determine whether mTOR plays a role in cerebrovascular dysfunction and cognitive decline during normative aging in rats. Using behavioral tools and MRI-based functional imaging, together with biochemical and immunohistochemical approaches, we demonstrate that chronic mTOR attenuation with rapamycin ameliorates deficits in learning and memory, prevents neurovascular uncoupling, and restores cerebral perfusion in aged rats. Additionally, morphometric and biochemical analyses of hippocampus and cortex revealed that mTOR drives age-related declines in synaptic and vascular density during aging. These data indicate that in addition to mediating AD-like cognitive and cerebrovascular deficits in models of AD and atherosclerosis, mTOR drives cerebrovascular, neuronal, and cognitive deficits associated with normative aging. Thus, inhibitors of mTOR may have potential to treat age-related cerebrovascular dysfunction and cognitive decline. Since treatment of age-related cerebrovascular dysfunction in older adults is expected to prevent further deterioration of cerebral perfusion, recently identified as a biomarker for the very early (preclinical) stages of AD, mTOR attenuation may potentially block the initiation and progression of AD.
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Affiliation(s)
- Candice E. Van Skike
- Department of Cellular and Integrative PhysiologyBarshop Institute for Longevity and Aging StudiesUniversity of Texas Health San AntonioSan AntonioTexas
- The Glenn Biggs Institute for Alzheimer's & Neurodegenerative DiseasesUniversity of Texas Health San AntonioSan AntonioTexas
| | - Ai‐Ling Lin
- Sanders‐Brown Center on AgingDepartment of Pharmacology and Nutritional SciencesDepartment of Biomedical EngineeringDepartment of NeuroscienceUniversity of KentuckyLexingtonKentucky
| | - Raquel Roberts Burbank
- Department of Cellular and Integrative PhysiologyBarshop Institute for Longevity and Aging StudiesUniversity of Texas Health San AntonioSan AntonioTexas
| | - Jonathan J. Halloran
- Department of Cellular and Integrative PhysiologyBarshop Institute for Longevity and Aging StudiesUniversity of Texas Health San AntonioSan AntonioTexas
| | - Stephen F. Hernandez
- Department of Cellular and Integrative PhysiologyBarshop Institute for Longevity and Aging StudiesUniversity of Texas Health San AntonioSan AntonioTexas
- The Glenn Biggs Institute for Alzheimer's & Neurodegenerative DiseasesUniversity of Texas Health San AntonioSan AntonioTexas
| | - James Cuvillier
- Department of Cellular and Integrative PhysiologyBarshop Institute for Longevity and Aging StudiesUniversity of Texas Health San AntonioSan AntonioTexas
- The Glenn Biggs Institute for Alzheimer's & Neurodegenerative DiseasesUniversity of Texas Health San AntonioSan AntonioTexas
- Department of Veterans AffairsSouth Texas Veterans Health Care SystemSan AntonioTexas
| | - Vanessa Y. Soto
- Department of Cellular and Integrative PhysiologyBarshop Institute for Longevity and Aging StudiesUniversity of Texas Health San AntonioSan AntonioTexas
| | - Stacy A. Hussong
- Department of Cellular and Integrative PhysiologyBarshop Institute for Longevity and Aging StudiesUniversity of Texas Health San AntonioSan AntonioTexas
- Department of Veterans AffairsSouth Texas Veterans Health Care SystemSan AntonioTexas
| | - Jordan B. Jahrling
- Department of Cellular and Integrative PhysiologyBarshop Institute for Longevity and Aging StudiesUniversity of Texas Health San AntonioSan AntonioTexas
| | - Martin A. Javors
- Department of PsychiatryUniversity of Texas Health San AntonioSan AntonioTexas
| | - Matthew J. Hart
- Department of Cellular and Integrative PhysiologyBarshop Institute for Longevity and Aging StudiesUniversity of Texas Health San AntonioSan AntonioTexas
- Center for Innovation in Drug DiscoveryCancer Therapy and Research Center, and the Department of BiochemistryUniversity of Texas Health San AntonioSan AntonioTexas
- RNAi/CRISPR High Throughput Screening FacilityGreehey Children's Cancer Research InstituteUniversity of Texas Health San AntonioSan AntonioTexas
| | - Kathleen E. Fischer
- Department of Biology and Nathan Shock Center of Excellence in the Basic Biology of AgingUniversity of Alabama at BirminghamBirminghamAlabama
| | - Steven N. Austad
- Department of Biology and Nathan Shock Center of Excellence in the Basic Biology of AgingUniversity of Alabama at BirminghamBirminghamAlabama
| | - Veronica Galvan
- Department of Cellular and Integrative PhysiologyBarshop Institute for Longevity and Aging StudiesUniversity of Texas Health San AntonioSan AntonioTexas
- The Glenn Biggs Institute for Alzheimer's & Neurodegenerative DiseasesUniversity of Texas Health San AntonioSan AntonioTexas
- Department of Veterans AffairsSouth Texas Veterans Health Care SystemSan AntonioTexas
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50
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Yuan H, Wu G, Zhai X, Lu B, Meng B, Chen J. Melatonin and Rapamycin Attenuate Isoflurane-Induced Cognitive Impairment Through Inhibition of Neuroinflammation by Suppressing the mTOR Signaling in the Hippocampus of Aged Mice. Front Aging Neurosci 2019; 11:314. [PMID: 31803045 PMCID: PMC6877689 DOI: 10.3389/fnagi.2019.00314] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 10/31/2019] [Indexed: 12/26/2022] Open
Abstract
Melatonin exerts neuroprotective effects on isoflurane-induced cognitive impairment. However, the underlying mechanism has yet to be elucidated. The present study sought to determine if melatonin confers its beneficial effects by acting on mammalian target of rapamycin (mTOR) and attenuates the neuroinflammation in the hippocampus of aged mice. A total of 72 male C57BL/6 mice, 16-month-old, were randomly and equally divided into six groups: (1) the control group (CON); (2) the rapamycin group (RAP); (3) the melatonin group (MEL); (4) the isoflurane group (ISO); (5) the rapamycin + isoflurane group (RAP + ISO); and (6) the melatonin + isoflurane group (MEL + ISO). RAP, RAP + ISO, MEL, MEL + ISO groups received 1 mg/kg/day mTOR inhibitor rapamycin solution or 10 mg/kg/day melatonin solution, respectively, intraperitoneally at 5:00 p.m. for 14 days consecutively. Mice in the CON and ISO groups were administered an equivalent volume of saline. Subsequently, ISO, RAP + ISO, and MEL + ISO groups were exposed to inhale 2% isoflurane for 4 h; the CON, RAP, and MEL mice received only the vehicle gas. Then, the memory function and spatial learning of the mice were examined via the Morris water maze (MWM) test. mTOR expression was detected via Western blot, whereas the concentration of inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and that of melatonin was quantified with enzyme-linked immunosorbent assay (ELISA). Melatonin and rapamycin significantly ameliorated the isoflurane-induced cognitive impairment and also led to a decrease in the melatonin levels as well as the expression levels of TNF-α, IL-1β, IL-6, and p-mTOR in the hippocampus. In conclusion, these results showed that melatonin and rapamycin attenuates mTOR expression while affecting the downstream proinflammatory cytokines. Thus, these molecular findings could be associated with an improved cognitive function in mice exposed to isoflurane.
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Affiliation(s)
- Hui Yuan
- Department of Anesthesiology, HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo, China
| | - Guorong Wu
- Department of Anesthesiology, HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo, China
| | - Xiaojie Zhai
- Department of Anesthesiology, HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo, China
| | - Bo Lu
- Department of Anesthesiology, HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo, China
| | - Bo Meng
- Department of Anesthesiology, HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo, China
| | - Junping Chen
- Department of Anesthesiology, HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo, China
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