1
|
Zhao W, Zhang W, Hu Y, Zhou Y, Zhao J, Li Y, Xu Z. AdipoRon Ameliorates Synaptic Dysfunction and Inhibits tau Hyperphosphorylation through the AdipoR/AMPK/mTOR Pathway in T2DM Mice. Neurochem Res 2024; 49:2075-2086. [PMID: 38819697 DOI: 10.1007/s11064-024-04162-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 02/20/2024] [Accepted: 05/22/2024] [Indexed: 06/01/2024]
Abstract
There is growing evidence showing that adiponectin (APN) can improve Alzheimer's disease(AD)-like pathological changes by improving insulin resistance. However, the role of AdipoRon (an Adiponectin receptor agonist) on synaptic plasticity and cognitive dysfunction in the early stages of type 2 diabetes mellitus(T2DM) remains unknown. In this study, we investigated the neuroprotective effect and the molecular mechanism underlying the effect of AdipoRon in T2DM mice. We found that AdipoRon significantly restored the cognitive deficits in T2DM mice, including shorter escape latency, more crossing times, increased distances, and percentage of time in the target quadrant. In addition, AdipoRon treatment up-regulated synaptic proteins (PSD95, SYN, GAP43, and SYP), increased the number of hippocampal synapses and attenuated synaptic damage, including the length, the number and the density of dendritic spines in CA1 and DG regions. Furthermore, AdipoRon attenuated Tau phosphorylation at multiple AD-related sites (p-tau 205, p-tau 396, p-tau 404) by promoting AdipoR expression and activating the AMPK/mTOR pathway. Our data suggests that AdipoRon exerts neuroprotective effects on the T2DM mice, which may be mediated by the activation of the AdipoR/AMPK/mTOR signaling pathway.
Collapse
Affiliation(s)
- Wenyan Zhao
- Department of Neuropsychology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Wei Zhang
- Department of Neuropsychology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Yingying Hu
- Department of Neuropsychology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Yuliang Zhou
- Department of Neuropsychology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Jinying Zhao
- Department of Neuropsychology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Yahong Li
- Department of Applied Psychology, South-Central Minzu University, Wuhan, Hubei, China.
| | - Zhipeng Xu
- Department of Neuropsychology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China.
| |
Collapse
|
2
|
Abyadeh M, Gupta V, Paulo JA, Mahmoudabad AG, Shadfar S, Mirshahvaladi S, Gupta V, Nguyen CTO, Finkelstein DI, You Y, Haynes PA, Salekdeh GH, Graham SL, Mirzaei M. Amyloid-beta and tau protein beyond Alzheimer's disease. Neural Regen Res 2024; 19:1262-1276. [PMID: 37905874 DOI: 10.4103/1673-5374.386406] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 09/07/2023] [Indexed: 11/02/2023] Open
Abstract
ABSTRACT The aggregation of amyloid-beta peptide and tau protein dysregulation are implicated to play key roles in Alzheimer's disease pathogenesis and are considered the main pathological hallmarks of this devastating disease. Physiologically, these two proteins are produced and expressed within the normal human body. However, under pathological conditions, abnormal expression, post-translational modifications, conformational changes, and truncation can make these proteins prone to aggregation, triggering specific disease-related cascades. Recent studies have indicated associations between aberrant behavior of amyloid-beta and tau proteins and various neurological diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, as well as retinal neurodegenerative diseases like Glaucoma and age-related macular degeneration. Additionally, these proteins have been linked to cardiovascular disease, cancer, traumatic brain injury, and diabetes, which are all leading causes of morbidity and mortality. In this comprehensive review, we provide an overview of the connections between amyloid-beta and tau proteins and a spectrum of disorders.
Collapse
Affiliation(s)
| | - Vivek Gupta
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW, Australia
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | | | - Sina Shadfar
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW, Australia
| | - Shahab Mirshahvaladi
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW, Australia
| | - Veer Gupta
- School of Medicine, Deakin University, Geelong, VIC, Australia
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, School of Health Sciences, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne, Parkville, VIC, Australia
| | - David I Finkelstein
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Yuyi You
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW, Australia
| | - Paul A Haynes
- School of Natural Sciences, Macquarie University, Macquarie Park, NSW, Australia
| | - Ghasem H Salekdeh
- School of Natural Sciences, Macquarie University, Macquarie Park, NSW, Australia
| | - Stuart L Graham
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW, Australia
| | - Mehdi Mirzaei
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW, Australia
| |
Collapse
|
3
|
Yang X, Liu S, Wang C, Fan H, Zou Q, Pu Y, Cai Z. Dietary salt promotes cognition impairment through GLP-1R/mTOR/p70S6K signaling pathway. Sci Rep 2024; 14:7970. [PMID: 38575652 PMCID: PMC10995169 DOI: 10.1038/s41598-024-57998-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 03/25/2024] [Indexed: 04/06/2024] Open
Abstract
Dietary salt has been associated with cognitive impairment in mice, possibly related to damaged synapses and tau hyperphosphorylation. However, the mechanism underlying how dietary salt causes cognitive dysfunction remains unclear. In our study, either a high-salt (8%) or normal diet (0.5%) was used to feed C57BL/6 mice for three months, and N2a cells were cultured in normal medium, NaCl medium (80 mM), or NaCl (80 mM) + Liraglutide (200 nM) medium for 48 h. Cognitive function in mice was assessed using the Morris water maze and shuttle box test, while anxiety was evaluated by the open field test (OPT). Western blotting (WB), immunofluorescence, and immunohistochemistry were utilized to assess the level of Glucagon-like Peptide-1 receptor (GLP-1R) and mTOR/p70S6K pathway. Electron microscope and western blotting were used to evaluate synapse function and tau phosphorylation. Our findings revealed that a high salt diet (HSD) reduced the level of synaptophysin (SYP) and postsynaptic density 95 (PSD95), resulting in significant synaptic damage. Additionally, hyperphosphorylation of tau at different sites was detected. The C57BL/6 mice showed significant impairment in learning and memory function compared to the control group, but HSD did not cause anxiety in the mice. In addition, the level of GLP-1R and autophagy flux decreased in the HSD group, while the level of mTOR/p70S6K was upregulated. Furthermore, liraglutide reversed the autophagy inhibition of N2a treated with NaCl. In summary, our study demonstrates that dietary salt inhibits the GLP-1R/mTOR/p70S6K pathway to inhibit autophagy and induces synaptic dysfunction and tau hyperphosphorylation, eventually impairing cognitive dysfunction.
Collapse
Affiliation(s)
- Xu Yang
- Department of Neurology, Affiliated Hospital of Southwest Medical University, Sichuan, 646000, People's Republic of China
- Department of Neurology, Chongqing General Hospital, Chongqing university, No. 118, Xingguang Avenue, Liangjiang New Area, Chongqing, 401147, People's Republic of China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing No. 312, Zhongshan First Road, Yuzhong District, Chongqing, 400013, People's Republic of China
| | - Shu Liu
- Department of Neurology, Chongqing General Hospital, Chongqing university, No. 118, Xingguang Avenue, Liangjiang New Area, Chongqing, 401147, People's Republic of China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing No. 312, Zhongshan First Road, Yuzhong District, Chongqing, 400013, People's Republic of China
| | - Chuanling Wang
- Department of Neurology, Chongqing General Hospital, Chongqing university, No. 118, Xingguang Avenue, Liangjiang New Area, Chongqing, 401147, People's Republic of China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing No. 312, Zhongshan First Road, Yuzhong District, Chongqing, 400013, People's Republic of China
- Department of Pathophysiology, School of Basic Medicine, Chongqing Medical University, No. 1 Yixueyuan Road, Yuzhong District, Chongqing, 400016, People's Republic of China
| | - Haixia Fan
- Department of Neurology, Chongqing General Hospital, Chongqing university, No. 118, Xingguang Avenue, Liangjiang New Area, Chongqing, 401147, People's Republic of China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing No. 312, Zhongshan First Road, Yuzhong District, Chongqing, 400013, People's Republic of China
| | - Qian Zou
- Department of Neurology, Chongqing General Hospital, Chongqing university, No. 118, Xingguang Avenue, Liangjiang New Area, Chongqing, 401147, People's Republic of China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing No. 312, Zhongshan First Road, Yuzhong District, Chongqing, 400013, People's Republic of China
| | - Yingshuang Pu
- Department of Neurology, Chongqing General Hospital, Chongqing university, No. 118, Xingguang Avenue, Liangjiang New Area, Chongqing, 401147, People's Republic of China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing No. 312, Zhongshan First Road, Yuzhong District, Chongqing, 400013, People's Republic of China
| | - Zhiyou Cai
- Department of Neurology, Affiliated Hospital of Southwest Medical University, Sichuan, 646000, People's Republic of China.
- Department of Neurology, Chongqing General Hospital, Chongqing university, No. 118, Xingguang Avenue, Liangjiang New Area, Chongqing, 401147, People's Republic of China.
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing No. 312, Zhongshan First Road, Yuzhong District, Chongqing, 400013, People's Republic of China.
- Department of Neurology, Chongqing General Hospital, No. 312 Zhongshan First Road, Yuzhong District, Chongqing, 400013, People's Republic of China.
| |
Collapse
|
4
|
Gupta S, Jinka SKA, Khanal S, Bhavnani N, Almashhori F, Lallo J, Mathias A, Al-Rhayyel Y, Herman D, Holden JG, Fleming SM, Raman P. Cognitive dysfunction and increased phosphorylated tau are associated with reduced O-GlcNAc signaling in an aging mouse model of metabolic syndrome. J Neurosci Res 2023; 101:1324-1344. [PMID: 37031439 DOI: 10.1002/jnr.25196] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 12/15/2022] [Accepted: 03/21/2023] [Indexed: 04/10/2023]
Abstract
Metabolic syndrome (MetS), characterized by hyperglycemia, obesity, and hyperlipidemia, can increase the risk of developing late-onset dementia. Recent studies in patients and mouse models suggest a putative link between hyperphosphorylated tau, a component of Alzheimer's disease-related dementia (ADRD) pathology, and cerebral glucose hypometabolism. Impaired glucose metabolism reduces glucose flux through the hexosamine metabolic pathway triggering attenuated O-linked N-acetylglucosamine (O-GlcNAc) protein modification. The goal of the current study was to investigate the link between cognitive function, tau pathology, and O-GlcNAc signaling in an aging mouse model of MetS, agouti KKAy+/- . Male and female C57BL/6, non-agouti KKAy-/- , and agouti KKAy+/- mice were aged 12-18 months on standard chow diet. Body weight, blood glucose, total cholesterol, and triglyceride were measured to confirm the MetS phenotype. Cognition, sensorimotor function, and emotional reactivity were assessed for each genotype followed by plasma and brain tissue collection for biochemical and molecular analyses. Body weight, blood glucose, total cholesterol, and triglyceride levels were significantly elevated in agouti KKAy+/- mice versus C57BL/6 controls and non-agouti KKAy-/- . Behaviorally, agouti KKAy+/- revealed impairments in sensorimotor and cognitive function versus age-matched C57BL/6 and non-agouti KKAy-/- mice. Immunoblotting demonstrated increased phosphorylated tau accompanied with reduced O-GlcNAc protein expression in hippocampal-associated dorsal midbrain of female agouti KKAy+/- versus C57BL/6 control mice. Together, these data demonstrate that impaired cognitive function and AD-related pathology are associated with reduced O-GlcNAc signaling in aging MetS KKAy+/- mice. Overall, our study suggests that interaction of tau pathology with O-GlcNAc signaling may contribute to MetS-induced cognitive dysfunction in aging.
Collapse
Affiliation(s)
- Shreya Gupta
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
- Biomedical Sciences Graduate Program, Kent State University, Kent, Ohio, USA
| | - Sanjay K A Jinka
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Saugat Khanal
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
- Biomedical Sciences Graduate Program, Kent State University, Kent, Ohio, USA
| | - Neha Bhavnani
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
- Biomedical Sciences Graduate Program, Kent State University, Kent, Ohio, USA
| | - Fayez Almashhori
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
- Biomedical Sciences Graduate Program, Kent State University, Kent, Ohio, USA
| | - Jason Lallo
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Amy Mathias
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Yasmine Al-Rhayyel
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Danielle Herman
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - John G Holden
- Department of Psychology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Sheila M Fleming
- Biomedical Sciences Graduate Program, Kent State University, Kent, Ohio, USA
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Priya Raman
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
- Biomedical Sciences Graduate Program, Kent State University, Kent, Ohio, USA
| |
Collapse
|
5
|
Wu M, Liao W, Zhang R, Gao Y, Chen T, Hua L, Cai F. PTP1B Inhibitor Claramine Rescues Diabetes-Induced Spatial Learning and Memory Impairment in Mice. Mol Neurobiol 2023; 60:524-544. [PMID: 36319905 DOI: 10.1007/s12035-022-03079-9] [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: 05/25/2022] [Accepted: 10/05/2022] [Indexed: 11/05/2022]
Abstract
Accumulating clinical and epidemiological studies indicate that learning and memory impairment is more prevalent among people with diabetes mellitus (DM). PTP1B is a member of protein tyrosine phosphatase family and participates in a variety of pathophysiological effects including inflammatory, insulin signaling pathway, and learning and memory. This study was aimed to investigate the effects of CA, a specific inhibitor of PTP1B, on spatial learning and memory impairment in diabetic mice caused by high-fat diet and injection of streptozotocin. We found that the protein expressions of PTP1B increased in hippocampal CA1, CA3, and PFC regions of diabetic mice. Network pharmacology results showed that PTP1B might be one of the key targets between diabetes and cognitive dysfunction, and CA might alleviate DM-induced cognitive dysfunction. Animal experiments showed that CA ameliorated DM-induced spatial learning and memory impairment, and improved glucose and lipid metabolic disorders. Moreover, administration of CA alleviated hippocampal structure damage and enhanced the expressions of synaptic proteins, including PSD-95, SYN-1, and SYP in diabetic mice. Furthermore, CA treatment not only significantly down-regulated the expressions of PTP1B and NLRP3 inflammatory related proteins (NLRP3, ASC, Caspase-1, COX-2, IL-1β, and TNF-α), but also significantly up-regulated the expressions of insulin signaling pathway-related proteins (p-IRS1, p-PI3K, p-AKT, and p-GSK-3β) in diabetic mice. Taken together, these results suggested that PTP1B might be a targeted strategy to rescue learning and memory deficits in DM, possibly through inhibition of NLRP3 inflammasome and regulation of insulin signaling pathway.
Collapse
Affiliation(s)
- Mengyu Wu
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, 437100, China
- Xianning Medical College, Hubei University of Science and Technology, Xianning, 437100, China
| | - Wenli Liao
- Xianning Medical College, Hubei University of Science and Technology, Xianning, 437100, China
| | - Ruyi Zhang
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, 437100, China
- Xianning Medical College, Hubei University of Science and Technology, Xianning, 437100, China
| | - Yuting Gao
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, 437100, China
- Xianning Medical College, Hubei University of Science and Technology, Xianning, 437100, China
| | - Tao Chen
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, 437100, China
- Xianning Medical College, Hubei University of Science and Technology, Xianning, 437100, China
| | - Liangliang Hua
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, 437100, China
- Xianning Medical College, Hubei University of Science and Technology, Xianning, 437100, China
| | - Fei Cai
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, 437100, China.
- Xianning Medical College, Hubei University of Science and Technology, Xianning, 437100, China.
| |
Collapse
|
6
|
Wee AS, Nhu TD, Khaw KY, San Tang K, Yeong KY. Linking Diabetes to Alzheimer's Disease: Potential Roles of Glucose Metabolism and Alpha-Glucosidase. Curr Neuropharmacol 2023; 21:2036-2048. [PMID: 36372924 PMCID: PMC10556372 DOI: 10.2174/1570159x21999221111102343] [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: 02/20/2022] [Revised: 05/31/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's disease (AD) and type 2 diabetes mellitus (DM) are more prevalent with ageing and cause a substantial global socio-economic burden. The biology of these two conditions is well elaborated, but whether AD and type 2 DM arise from coincidental roots in ageing or are linked by pathophysiological mechanisms remains unclear. Research findings involving animal models have identified mechanisms shared by both AD and type 2 DM. Deposition of β-amyloid peptides and formation of intracellular neurofibrillary tangles are pathological hallmarks of AD. Type 2 DM, on the other hand, is a metabolic disorder characterised by hyperglycaemia and insulin resistance. Several studies show that improving type 2 DM can delay or prevent the development of AD, and hence, prevention and control of type 2 DM may reduce the risk of AD later in life. Alpha-glucosidase is an enzyme that is commonly associated with hyperglycaemia in type 2 DM. However, it is uncertain if this enzyme may play a role in the progression of AD. This review explores the experimental evidence that depicts the relationship between dysregulation of glucose metabolism and AD. We also delineate the links between alpha-glucosidase and AD and the potential role of alpha-glucosidase inhibitors in treating AD.
Collapse
Affiliation(s)
- Ai Sze Wee
- School of Pharmacy, Monash University Malaysia, Bandar Sunway, 47500, Selangor, Malaysia
- Faculty of Medicine, SEGi University, Kota Damansara, 47810 Selangor, Malaysia
| | - Thao Dinh Nhu
- Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Kooi Yeong Khaw
- School of Pharmacy, Monash University Malaysia, Bandar Sunway, 47500, Selangor, Malaysia
| | - Kim San Tang
- School of Pharmacy, Monash University Malaysia, Bandar Sunway, 47500, Selangor, Malaysia
| | - Keng Yoon Yeong
- School of Science, Monash University Malaysia, Bandar Sunway, 47500 , Selangor, Malaysia
- Tropical Medicine and Biology (TMB) Multidisciplinary Platform, Monash University Malaysia, Bandar Sunway 47500 Selangor, Malaysia
| |
Collapse
|
7
|
FDA-Approved Kinase Inhibitors in Preclinical and Clinical Trials for Neurological Disorders. Pharmaceuticals (Basel) 2022; 15:ph15121546. [PMID: 36558997 PMCID: PMC9784968 DOI: 10.3390/ph15121546] [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: 10/10/2022] [Revised: 12/09/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
Cancers and neurological disorders are two major types of diseases. We previously developed a new concept termed "Aberrant Cell Cycle Diseases" (ACCD), revealing that these two diseases share a common mechanism of aberrant cell cycle re-entry. The aberrant cell cycle re-entry is manifested as kinase/oncogene activation and tumor suppressor inactivation, which are hallmarks of both tumor growth in cancers and neuronal death in neurological disorders. Therefore, some cancer therapies (e.g., kinase inhibition, tumor suppressor elevation) can be leveraged for neurological treatments. The United States Food and Drug Administration (US FDA) has so far approved 74 kinase inhibitors, with numerous other kinase inhibitors in clinical trials, mostly for the treatment of cancers. In contrast, there are dire unmet needs of FDA-approved drugs for neurological treatments, such as Alzheimer's disease (AD), intracerebral hemorrhage (ICH), ischemic stroke (IS), traumatic brain injury (TBI), and others. In this review, we list these 74 FDA-approved kinase-targeted drugs and identify those that have been reported in preclinical and/or clinical trials for neurological disorders, with a purpose of discussing the feasibility and applicability of leveraging these cancer drugs (FDA-approved kinase inhibitors) for neurological treatments.
Collapse
|
8
|
Wu Q, Dong J, Bai X, Jiang Y, Li J, Fan S, Cheng Y, Jiang G. Propionate ameliorates diabetes-induced neurological dysfunction through regulating the PI3K/Akt/eNOS signaling pathway. Eur J Pharmacol 2022; 925:174974. [PMID: 35490725 DOI: 10.1016/j.ejphar.2022.174974] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 03/31/2022] [Accepted: 04/19/2022] [Indexed: 11/24/2022]
Abstract
A large body of research has established diabetes-related cognitive deterioration, sometimes known as "diabetic encephalopathy". Current evidence supports that oxidative stress, neuronal apoptosis, and cerebral microcirculation weakness are associated with cognition deficits induced by diabetes. The present study explores the effect of propionate on neurological deficits, cerebral blood flow, and oxidative stress in diabetic mice. Propionate in different doses (37.5, 75 and 150 mg/kg) was orally administrated daily. Here, we show that propionate can markedly improve neurological function, which is correlated with its capabilities of stimulating nitrogen monoxide (NO) production, increasing cerebral microcirculation, suppressing oxidative stress, and reducing neuron loss in the hippocampus. In addition, the results of Western Blotting indicated that the brain-protective function of propionate in streptozocin (STZ)-induced type 1 diabetes mellitus (T1DM) mice is related to phosphoinositide 3-kinase (PI3K)/serine-threonine protein kinase (Akt)/endothelial nitrogen monoxide synthase (eNOS) signaling pathway. In a diabetic mouse model, propionate reduces cerebral microcirculation, hippocampus apoptosis, and neurological impairment. Thus, propionate, now employed as a food preservative, may also help slow diabetes-induced cognitive loss.
Collapse
Affiliation(s)
- Qin Wu
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining, Zhejiang, PR China
| | - Jiajun Dong
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining, Zhejiang, PR China
| | - Xinying Bai
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan University, Wuhan, Hubei, PR China
| | - Yuan Jiang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan University, Wuhan, Hubei, PR China
| | - Jinjin Li
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan University, Wuhan, Hubei, PR China
| | - Shiqi Fan
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan University, Wuhan, Hubei, PR China
| | - Yahong Cheng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan University, Wuhan, Hubei, PR China.
| | - Gaofeng Jiang
- Center for Translational Medicine, Tianyou Hospital, Wuhan University of Science and Technology, Wuhan, Hubei, PR China.
| |
Collapse
|
9
|
Hippocampal mTOR Dysregulation and Morphological Changes in Male Rats after Fetal Growth Restriction. Nutrients 2022; 14:nu14030451. [PMID: 35276811 PMCID: PMC8839133 DOI: 10.3390/nu14030451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 02/04/2023] Open
Abstract
Fetal growth restriction (FGR) has been linked to long-term neurocognitive impairment, especially in males. To determine possible underlying mechanisms, we examined hippocampal cellular composition and mTOR signaling of male rat FGR offspring during main brain growth and development (postnatal days (PND) 1 and 12). FGR was either induced by a low-protein diet throughout pregnancy, experimental placental insufficiency by bilateral uterine vessel ligation or intrauterine stress by “sham” operation. Offspring after unimpaired gestation served as common controls. Low-protein diet led to a reduced cell density in the molecular dentate gyrus subregion, while intrauterine surgical stress was associated with increased cell density in the cellular CA2 subregion. Experimental placental insufficiency caused increased mTOR activation on PND 1, whereas intrauterine stress led to mTOR activation on PND 1 and 12. To determine long-term effects, we additionally examined mTOR signaling and Tau phosphorylation, which is altered in neurodegenerative diseases, on PND 180, but did not find any changes among the experimental groups. Our findings suggest that hippocampal cellular proliferation and mTOR signaling are dysregulated in different ways depending on the cause of FGR. While a low-protein diet induced a decreased cell density, prenatal surgical stress caused hyperproliferation, possibly via increased mTOR signaling.
Collapse
|
10
|
Chen X, Gao F, Lin C, Chen A, Deng J, Chen P, Lin M, Xie B, Liao Y, Gong C, Zheng X. mTOR-mediated autophagy in the hippocampus is involved in perioperative neurocognitive disorders in diabetic rats. CNS Neurosci Ther 2021; 28:540-553. [PMID: 34784444 PMCID: PMC8928925 DOI: 10.1111/cns.13762] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 10/25/2021] [Accepted: 11/01/2021] [Indexed: 12/14/2022] Open
Abstract
Introduction Perioperative neurocognitive disorders (PND) are common neurological complications after surgery. Diabetes mellitus (DM) has been reported to be an independent risk factor for PND, but little is known about its mechanism of action. Mammalian target of rapamycin (mTOR) signaling is crucial for neuronal growth, development, apoptosis, and autophagy, but the dysregulation of mTOR signaling leads to neurological disorders. The present study investigated whether rapamycin can attenuate PND by inhibiting mTOR and activating autophagy in diabetic rats. Methods Male diabetic Sprague‐Dawley rats underwent tibial fracture surgery under isoflurane anesthesia to establish a PND model. Cognitive functions were examined using the Morris water maze test. The levels of phosphorylated mTOR (p‐mTOR), phosphorylated tau (p‐tau), autophagy‐related proteins (Beclin‐1, LC3), and apoptosis‐related proteins (Bax, Bcl‐2, cleaved caspase‐3) in the hippocampus were examined on postoperative days 3, 7, and 14 by Western blot. Hippocampal amyloid β (Aβ) levels were examined by immunohistochemistry. Results The data showed that surgical trauma and/or DM impaired cognitive function, induced mTOR activation, and decreased Beclin‐1 levels and the LC3‐II/I ratio. The levels of Aβ and p‐tau and the hippocampal apoptotic responses were significantly higher in diabetic or surgery‐treated rats than in control rats and were further increased in diabetic rats subjected to surgery. Pretreatment of rats with rapamycin inhibited mTOR hyperactivation and restored autophagic function, effectively decreasing tau hyperphosphorylation, Aβ deposition, and apoptosis in the hippocampus. Furthermore, surgical trauma‐induced neurocognitive disorders were also reversed by pretreatment of diabetic rats with rapamycin. Conclusion The results demonstrate that mTOR hyperactivation regulates autophagy, playing a critical role in the mechanism underlying PND, and reveal that the modulation of mTOR signaling could be a promising therapeutic strategy for PND in patients with diabetes.
Collapse
Affiliation(s)
- Xiaohui Chen
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China
| | - Fei Gao
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China
| | - Cuicui Lin
- Department of Anesthesiology, Fuzhou Second Hospital Affiliated to Xiamen University, Fuzhou, China
| | - Andi Chen
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China
| | - Jianhui Deng
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China
| | - Pinzhong Chen
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China
| | - Mingxue Lin
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China
| | - Bingxin Xie
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China
| | - Yanling Liao
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China
| | - Cansheng Gong
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China
| | - Xiaochun Zheng
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China.,Fujian Provincial Institute of Emergency Medicine, Fujian Provincial Key Laboratory of Emergency Medicine, Fuzhou, China
| |
Collapse
|
11
|
Notch1 participates in the activation of autophagy in the hippocampus of type I diabetic mice. Neurochem Int 2021; 150:105156. [PMID: 34389314 DOI: 10.1016/j.neuint.2021.105156] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 01/01/2023]
Abstract
Notch1 not only plays a key role in the development of the nervous system but also modulates synaptic plasticity and memory. However, the role of Notch1 in the brain of diabetes is still unclear. We hypothesize that Notch1 is involved in type I diabetes-induced cognitive dysfunction. In this study, adult male C57BL/6J mice carrying a heterozygous null mutation in the Notch1 gene (Notch1+/-) and wild-type littermate controls were used in this experiment. They were subjected to streptozocin (55 mg/kg, i.p.) for consecutive five days. After 12 weeks, the cognitive function of all mice was detected by novel object recognition (NOR) test and electrophysiological recording. Our results demonstrated that the levels of Notch1 mRNA and Notch1 receptor were increased in the hippocampus of the wild-type diabetic mice at 12 weeks. It suggested that the Notch1 signal pathway was activated. Compared with the wild-type diabetic mice, the discrimination index and the long-term potentiation was further decreased in the Notch1+/- diabetic group, the impairment of neuronal ultrastructure was exacerbated in the hippocampus of the Notch1+/- diabetic mice, and the number of synapses and autophagic vacuoles were significantly reduced in the Notch1+/- diabetic group. Moreover, some postsynaptic associated protein expressions were down-regulated, as well as the Beclin1 expression and the ratio of LC3II/LC3I were reduced in the hippocampus of the Notch1+/- diabetic mice. Interestingly, the phosphorylation of mTOR, Akt, and ERK1/2 were all inhibited in the Notch1+/- diabetic group. Taken together, these results suggest that Notch1 deficiency deteriorates the synaptic plasticity and inhibits the activation of autophagy partly via the mTOR-independent signal pathway in the hippocampus of type I diabetic mice.
Collapse
|
12
|
Lu C, Zhao Y, Cao Y, Liu L, Wu S, Li D, Liu S, Xiao S, Wei Y, Li X. MALAT1 Regulated mTOR-Mediated Tau Hyperphosphorylation by Acting as a ceRNA of miR144 in Hippocampus Cells Exposed to High Glucose. Clin Interv Aging 2021; 16:1185-1191. [PMID: 34188461 PMCID: PMC8236260 DOI: 10.2147/cia.s304827] [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: 02/22/2021] [Accepted: 06/03/2021] [Indexed: 11/23/2022] Open
Abstract
Aim High glucose (HG)-induced activation of mTOR promotes tau phosphorylation and leads to diabetes-associated dementia. This study aimed to explore the role of metastasis associated in lung adenocarcinoma transcript 1 (MALAT1) in HG-induced neuronal cell injury. Methods Hippocampus cells were isolated from C57BL/6J mice. After 6 days of culture, the cells were incubated with 5.5 mM glucose in normal medium or 75 mM glucose for 4 days. Cells were transfected with miR-144 mimic, miR-144 inhibitor, siRNA for MALAT1 or corresponding controls. Gene expression was detected by PCR and Western blot analysis. Results HG increased the levels of MALAT1 and p-tau in hippocampal cells. Knockdown of MALAT1 partially reversed the effects of HG on mTOR activity and p-tau protein levels. MALAT1 functioned as competing endogenous RNA (ceRNA) for miR-144, and pre-treatment with MALAT1 siRNA decreased mTOR activity and p-tau protein level in HG-treated hippocampal cells, which was significantly attenuated by miR-144 mimics. Moreover, miR-144 negatively regulated the expression of mTOR and knockdown of MALAT1 suppressed mTOR, while overexpression of mTOR abrogated protective effects of MALAT1 knockdown in HG-treated hippocampal cells. Conclusion MALAT1 knockdown prevented HG-induced mTOR activation and inhibited tau phosphorylation. MALAT1 may be a therapy target for diabetes associated dementia.
Collapse
Affiliation(s)
- Chong Lu
- Department of Neurology, Heilongjiang Provincial Hospital, Harbin, People's Republic of China
| | - Yikui Zhao
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, People's Republic of China
| | - Yan Cao
- Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Li Liu
- Department of Neurology, Heilongjiang Provincial Hospital, Harbin, People's Republic of China
| | - Shanshan Wu
- Department of Neurology, Heilongjiang Provincial Hospital, Harbin, People's Republic of China
| | - Dongbin Li
- Department of Neurology, Heilongjiang Provincial Hospital, Harbin, People's Republic of China
| | - Shuang Liu
- Department of Neurology, Heilongjiang Provincial Hospital, Harbin, People's Republic of China
| | - Shuyuan Xiao
- Department of Neurology, Heilongjiang Provincial Hospital, Harbin, People's Republic of China
| | - Yafen Wei
- Department of Neurology, Heilongjiang Provincial Hospital, Harbin, People's Republic of China
| | - Xinyu Li
- Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| |
Collapse
|
13
|
Ding Y, Liu H, Cen M, Tao Y, Lai C, Tang Z. Rapamycin Ameliorates Cognitive Impairments and Alzheimer's Disease-Like Pathology with Restoring Mitochondrial Abnormality in the Hippocampus of Streptozotocin-Induced Diabetic Mice. Neurochem Res 2021; 46:265-275. [PMID: 33140268 DOI: 10.1007/s11064-020-03160-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 10/22/2020] [Accepted: 10/26/2020] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) and diabetes mellitus (DM) share common pathophysiological findings, in particular, the mammalian target of rapamycin (mTOR) has been strongly implied to link to AD, while it also plays a key role in the insulin signaling pathway. However, the mechanism of how DM and AD is coupled remains elusive. In the present study, we found that streptozotocin (STZ)-induced DM mice significantly increased the levels P-mTOR Ser2448, P-p70S6K Thr389, P-tau Ser356 and Aβ levels (Aβ oligomer/monomer), as well as the levels of Drp1 and p-Drp1 S616 (mitochondrial fission proteins) are increased, whereas no change was found in the expression of Opa1, Mfn1 and Mfn2 (mitochondrial fusion proteins) compared with control mice. Moreover, the expression of 4-HNE and 8-OHdG showed an aberrant increase in the hippocampus of STZ-induced DM mice that is associated with a decreased capacity of spatial memory and a loss of synapses. Rapamycin, an inhibitor of mTOR, rescued the STZ-induced increases in mTOR/p70S6K activities, tau phosphorylation and Aβ levels, as well as mitochondria abnormality and cognitive impairment in mice. These findings imply that rapamycin prevents cognitive impairment and protects hippocampus neurons from AD-like pathology and mitochondrial abnormality, and also that rapamycin treatment could normalize these STZ-induced alterations by decreasing hippocampus mTOR/p70S6K hyperactivity.
Collapse
Affiliation(s)
- Yuanting Ding
- Department of Clinical Research Center, The First Affliated Hospital of Guizhou University of Traditional Chinese Medicine, Baoshan Road No.71, Guiyang, 550001, Guizhou, China
| | - Heng Liu
- Department of Anesthesiology, Tongren Municipal People's Hospital, Tongren, 554300, Guizhou, China
| | - Mofei Cen
- Department of Clinical Research Center, The First Affliated Hospital of Guizhou University of Traditional Chinese Medicine, Baoshan Road No.71, Guiyang, 550001, Guizhou, China
| | - Yuxiang Tao
- Department of Clinical Research Center, The First Affliated Hospital of Guizhou University of Traditional Chinese Medicine, Baoshan Road No.71, Guiyang, 550001, Guizhou, China
| | - Chencen Lai
- Department of Clinical Research Center, The First Affliated Hospital of Guizhou University of Traditional Chinese Medicine, Baoshan Road No.71, Guiyang, 550001, Guizhou, China
| | - Zhi Tang
- Department of Clinical Research Center, The First Affliated Hospital of Guizhou University of Traditional Chinese Medicine, Baoshan Road No.71, Guiyang, 550001, Guizhou, China.
| |
Collapse
|
14
|
Glaucocalyxin A as a natural product increases amyloid β clearance and decreases tau phosphorylation involving the mammalian target of rapamycin signaling pathway. Neuroreport 2019; 30:310-316. [PMID: 30688759 DOI: 10.1097/wnr.0000000000001202] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder correlated with age, characterized by the accumulation of amyloid β (Aβ) plaques and neurofibrillary tangles. The mammalian target of rapamycin (mTOR) is an important protein that regulates Aβ clearance and tau phosphorylation. Therefore, mTOR has become a pivotal therapeutic target for AD treatment. In this study, we discovered a natural product, glaucocalyxin A (GLA), as a new mTOR inhibitor based on a high-throughput screening platform with α-screen technology against our natural product library. Further study showed that GLA increased Aβ clearance involving the protein kinase B/mTOR/autophagy signaling pathway and inhibited tau phosphorylation involving the mTOR/70-kDa ribosomal protein S6 kinase pathway, which highlighted the therapeutic potential of GLA for the AD treatment.
Collapse
|
15
|
Yang B, Cai Z, Zhang W, Yin D, Zhao W, Yang M. Autophagy alleviates the decrease in proliferation of amyloid β1‑42‑treated bone marrow mesenchymal stem cells via the AKT/mTOR signaling pathway. Mol Med Rep 2019; 19:4091-4100. [PMID: 30896831 PMCID: PMC6471277 DOI: 10.3892/mmr.2019.10069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 01/14/2019] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease (AD) and osteoporosis (OP) are 2 common progressive age-associated diseases, primarily affecting the elderly worldwide. Accumulating evidence has demonstrated that patients with AD are more likely to suffer from bone mass loss and even OP, but whether it is a pathological feature of AD or secondary to motor dysfunction remains poorly understood. The present study aimed to investigate whether amyloid-β1–42 (Aβ1–42), the typical pathological product of AD, exhibited a negative effect on the proliferation of bone marrow mesenchymal stem cells (BMSCs) and the role of autophagy. The proliferation of BMSCs was measured using a Cell Counting Kit-8 assay, cell cycle analysis and 5-ethynyl-2′-deoxyuridine (EdU) staining. The autophagy-associated proteins microtubule-associated proteins 1A/1B light chain 3B and sequestosome 1 (p62) were evaluated by western blot analysis and autophagosomes were detected by transmission electron microscopy and immunofluorescence. The activity of the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway was measured using western blot analysis, and the autophagy inducer rapamycin (RAPA), inhibitor 3-methyladenine (3-MA) and the AKT activator SC79 were also used to investigate the role of AKT/mTOR signaling pathway and autophagy in the proliferation of BMSCs. The results suggested that the proliferation of BMSCs treated with Aβ1–42 was inhibited, with the autophagy level increasing following treatment with Aβ1–42 in a dose-dependent manner, while the AKT/mTOR signaling pathway participated in the regulation of the autophagy level. Activation of autophagy using RAPA inhibited the decrease in proliferation of BMSCs, while suppression of autophagy by 3-MA and activation of the AKT/mTOR signaling pathway increased the decrease in proliferation of BMSCs caused by Aβ1–42. It was concluded that Aβ1–42, as an external stimulus, suppressed the proliferation of BMSCs directly and that the AKT/mTOR signaling pathway participated in the regulation of the level of autophagy. Concomitantly, autophagy may serve as a resistance mechanism in inhibiting the decreased proliferation of BMSCs treated with Aβ1–42.
Collapse
Affiliation(s)
- Bo Yang
- Department of Orthopedics, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Zhenyu Cai
- Department of Orthopedics, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Weilin Zhang
- Department of Orthopedics, The Fourth Hospital of China Medical University, Shenyang, Liaoning 110032, P.R. China
| | - Dali Yin
- Department of Orthopedics, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Wei Zhao
- Department of Orthopedics, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Maowei Yang
- Department of Orthopedics, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| |
Collapse
|
16
|
Castellani RJ, Perry G. Tau Biology, Tauopathy, Traumatic Brain Injury, and Diagnostic Challenges. J Alzheimers Dis 2019; 67:447-467. [PMID: 30584140 PMCID: PMC6398540 DOI: 10.3233/jad-180721] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2018] [Indexed: 12/12/2022]
Abstract
There is considerable interest in the pathobiology of tau protein, given its potential role in neurodegenerative diseases and aging. Tau is an important microtubule associated protein, required for the assembly of tubulin into microtubules and maintaining structural integrity of axons. Tau has other diverse cellular functions involving signal transduction, cellular proliferation, developmental neurobiology, neuroplasticity, and synaptic activity. Alternative splicing results in tau isoforms with differing microtubule binding affinity, differing representation in pathological inclusions in certain disease states, and differing roles in developmental biology and homeostasis. Tau haplotypes confer differing susceptibility to neurodegeneration. Tau phosphorylation is a normal metabolic process, critical in controlling tau's binding to microtubules, and is ongoing within the brain at all times. Tau may be hyperphosphorylated, and may aggregate as detectable fibrillar deposits in tissues, in both aging and neurodegenerative disease. The hypothesis that p-tau is neurotoxic has prompted constructs related to isomers, low-n assembly intermediates or oligomers, and the "tau prion". Human postmortem studies have elucidated broad patterns of tauopathy, with tendencies for those patterns to differ as a function of disease phenotype. However, there is extensive overlap, not only between genuine neurodegenerative diseases, but also between aging and disease. Recent studies highlight uniqueness to pathological patterns, including a pattern attributed to repetitive head trauma, although clinical correlations have been elusive. The diagnostic process for tauopathies and neurodegenerative diseases in general is challenging in many respects, and may be particularly problematic for postmortem evaluation of former athletes and military service members.
Collapse
Affiliation(s)
- Rudy J. Castellani
- Departments of Pathology and Neuroscience, West Virginia University School of Medicine, Morgantown, WV, USA
| | - George Perry
- College of Sciences, University of Texas, San Antonio, San Antonio, TX, USA
| |
Collapse
|
17
|
Heard DS, Tuttle CSL, Lautenschlager NT, Maier AB. Repurposing Proteostasis-Modifying Drugs to Prevent or Treat Age-Related Dementia: A Systematic Review. Front Physiol 2018; 9:1520. [PMID: 30425653 PMCID: PMC6218672 DOI: 10.3389/fphys.2018.01520] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/09/2018] [Indexed: 12/21/2022] Open
Abstract
Background: Dementia has a significant impact on quality of life of older individuals. Impaired proteostasis has been implicated as a potential cause of dementia, that can be therapeutically targeted to improve patient outcomes. This review aimed to collate all current evidence of the potential for targeting proteostasis with repurposed drugs as an intervention for age-related dementia and cognitive decline. Methods: PubMed, Web of Science and Embase databases were searched from inception until 4th July 2017 for studies published in English. Interventional studies of repurposed proteostasis-modifying drugs in Alzheimer's disease (AD), Parkinson's disease (PD), Lewy Body disease, vascular dementia, and cognitive aging, in either animal models or humans with change in cognition as the outcome were included. The SYRCLE and Cochrane tools were used to assess risk of bias for included studies. Results: Overall 47 trials, 38 animal and 9 human, were isolated for inclusion in this review. Drugs tested in animals and humans included lithium, rapamycin, rifampicin, and tyrosine kinase inhibitors. Drugs tested only in animals included Macrophage and Granulocyte-Macrophage Colony Stimulating Factors, methylene blue, dantrolene, geranylgeranylacetone, minocycline and phenylbutyric acid. Lithium (n = 10 animal, n = 6 human) and rapamycin (n = 12 animal, n = 1 human) were the most studied proteostasis modifying drugs influencing cognition. Nine of ten animal studies of lithium showed a statistically significant benefit in Alzheimer's models. Rapamycin demonstrated a significant benefit in models of vascular dementia, aging, and Alzheimer's, but may not be effective in treating established Alzheimer's pathology. Lithium and nilotinib had positive outcomes in human studies including Alzheimer's and Parkinson's patients respectively, while a human study of rifampicin in Alzheimer's failed to demonstrate benefit. Microdose lithium showed a strongly significant benefit in both animals and humans. While the risk of bias was relatively low in human studies, the risk of bias in animal studies was largely unclear. Conclusion: Overall, the collective findings support the hypothesis that targeting proteostasis for treatment of dementia may be beneficial, and therefore future studies in humans with repurposed proteostasis modifying drugs are warranted. Larger human clinical trials focusing on safety, efficacy, tolerability, and reproducibility are required to translate these therapeutics into clinical practice.
Collapse
Affiliation(s)
- Daniel S Heard
- North West Mental Health, Melbourne Health, Melbourne, VIC, Australia
| | - Camilla S L Tuttle
- @AgeMelbourne, Department of Medicine and Aged Care, University of Melbourne, Melbourne, VIC, Australia
| | - Nicola T Lautenschlager
- North West Mental Health, Melbourne Health, Melbourne, VIC, Australia.,Academic Unit for Psychiatry of Old Age, Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia
| | - Andrea B Maier
- @AgeMelbourne, Department of Medicine and Aged Care, University of Melbourne, Melbourne, VIC, Australia.,@AgeAmsterdam, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, Netherlands
| |
Collapse
|
18
|
The autophagic degradation of Cav-1 contributes to PA-induced apoptosis and inflammation of astrocytes. Cell Death Dis 2018; 9:771. [PMID: 29991726 PMCID: PMC6039485 DOI: 10.1038/s41419-018-0795-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 06/04/2018] [Accepted: 06/06/2018] [Indexed: 12/23/2022]
Abstract
The accumulation of palmitic acid (PA), implicated in obesity, can induce apoptotic cell death and inflammation of astrocytes. Caveolin-1 (Cav-1), an essential protein for astrocytes survival, can be degraded by autophagy, which is a double-edge sword that can either promote cell survival or cell death. The aim of this study was to delineate whether the autophagic degradation of Cav-1 is involved in PA-induced apoptosis and inflammation in hippocampal astrocytes. In this study we found that: (1) PA caused apoptotic death and inflammation by autophagic induction; (2) Cav-1 was degraded by PA-induced autophagy and PA induced autophagy in a Cav-1-independent manner; (3) the degradation of Cav-1 was responsible for PA-induced autophagy-dependent apoptotic cell death and inflammation; (4) chronic high-fat diet (HFD) induced Cav-1 degradation, apoptosis, autophagy, and inflammation in the hippocampal astrocytes of rats. Our results suggest that the autophagic degradation of Cav-1 contributes to PA-induced apoptosis and inflammation of astrocytes. Therefore, Cav-1 may be a potential therapeutic target for central nervous system injuries caused by PA accumulation.
Collapse
|
19
|
High glucose forces a positive feedback loop connecting ErbB4 expression and mTOR/S6K pathway to aggravate the formation of tau hyperphosphorylation in differentiated SH-SY5Y cells. Neurobiol Aging 2018; 67:171-180. [DOI: 10.1016/j.neurobiolaging.2018.03.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 02/14/2018] [Accepted: 03/17/2018] [Indexed: 01/04/2023]
|
20
|
Wu J, Zhou SL, Pi LH, Shi XJ, Ma LR, Chen Z, Qu ML, Li X, Nie SD, Liao DF, Pei JJ, Wang S. High glucose induces formation of tau hyperphosphorylation via Cav-1-mTOR pathway: A potential molecular mechanism for diabetes-induced cognitive dysfunction. Oncotarget 2018; 8:40843-40856. [PMID: 28489581 PMCID: PMC5522306 DOI: 10.18632/oncotarget.17257] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 04/07/2017] [Indexed: 12/31/2022] Open
Abstract
The abnormally hyperphosphorylated tau is thought to be implicated in diabetes-associated cognitive deficits. The role of mammalian target of rapamycin (mTOR) / S6 kinase (S6K) signalling in the formation of tau hyperphosphorylation has been previously studied. Caveolin-1 (Cav-1), the essential structure protein of caveolae, promotes neuronal survival and growth, and inhibits glucose metabolism. In this study, we aimed to investigate the role of Cav-1 in the formation of tau hyperphosphorylation under chronic hyperglycemic condition (HGC). Diabetic rats were induced by streptozotocin (STZ). Primary hippocampal neurons with or without molecular intervention such as the transient over-expression or knock-down were subjected to HGC. The obtained experimental samples were analyzed by real time quantitative RT-PCR, Western blot, immunofluorescence or immunohistochemisty. We found: 1) that a chronic HGC directly decreases Cav-1 expression, increases tau phosphorylation and activates mTOR/S6K signalling in the brain neurons of diabetic rats, 2) that overexpression of Cav-1 attenuates tau hyperphosphorylation induced by chronic HGC in primary hippocampal neurons, whereas down-regulation of Cav-1 using Cav-1 siRNA dramatically worsens tau hyperphosphorylation via mTOR/S6K signalling pathway, and 3) that the down-regulation of Cav-1 induced by HGC is independent of mTOR signalling. Our results suggest that tau hyperphosphorylation and the sustained over-activated mTOR signalling under hyperglycemia may be due to the suppression of Cav-1. Therefore, Cav-1 is a potential therapeutic target for diabetes-induced cognitive dysfunction.
Collapse
Affiliation(s)
- Jing Wu
- Department of Endocrinology, Xiang-Ya Hospital, Central South University, Changsha, China
| | - Shan-Lei Zhou
- Department of Endocrinology, Xiang-Ya Hospital, Central South University, Changsha, China
| | - Lin-Hua Pi
- Department of Endocrinology, Xiang-Ya Hospital, Central South University, Changsha, China
| | - Xia-Jie Shi
- Department of Endocrinology, Xiang-Ya Hospital, Central South University, Changsha, China
| | - Ling-Ran Ma
- Department of Pharmaceutical Engineering, College of Chemistry and Chemical Engineering, Central South University, Changsha, China
| | - Zi Chen
- Department of Endocrinology, Xiang-Ya Hospital, Central South University, Changsha, China
| | - Min-Li Qu
- Department of Endocrinology, Xiang-Ya Hospital, Central South University, Changsha, China
| | - Xin Li
- Department of Pharmaceutical Engineering, College of Chemistry and Chemical Engineering, Central South University, Changsha, China
| | - Sheng-Dan Nie
- Institute of Clinical Medicine, People's Hospital of Hunan province, The First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Duan-Fang Liao
- Division of Stem Cell Regulation and Application, School of Pharmacy, Hunan University of Traditional Chinese Medicine, Changsha, Hunan, China
| | - Jin-Jing Pei
- KI-Alzheimer's Disease Research Center, Karolinska Institutet, Novum, Stockholm, Sweden.,Department of Neurology, Xuan Wu Hospital, Capital Medical University, China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China
| | - Shan Wang
- Department of Endocrinology, Xiang-Ya Hospital, Central South University, Changsha, China.,Department of Pharmaceutical Engineering, College of Chemistry and Chemical Engineering, Central South University, Changsha, China
| |
Collapse
|
21
|
Shi X, Pi L, Zhou S, Li X, Min F, Wang S, Liu Z, Wu J. Activation of Sirtuin 1 Attenuates High Glucose-Induced Neuronal Apoptosis by Deacetylating p53. Front Endocrinol (Lausanne) 2018; 9:274. [PMID: 29892266 PMCID: PMC5985296 DOI: 10.3389/fendo.2018.00274] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Accepted: 05/09/2018] [Indexed: 12/04/2022] Open
Abstract
Diabetes mellitus (DM) has been proven to be a key risk factor for cognitive impairment. Previous studies have implicated hippocampal neuronal apoptosis in diabetes-related cognitive impairment. However, the underlying mechanism remains unknown. Sirtuin 1 (SIRT1) is a protein deacetylase depended on nicotinamide adenine dinucleotide. Furthermore, it is indispensable in normal learning and memory. Whether SIRT1 is taken part in diabetes-induced neuronal apoptosis and thus involve in the development of diabetic cognitive impairment is still not clear. To address this issue, we examined the possible role of SIRT1 in hippocampal neuronal apoptosis in streptozotocin-induced diabetic mice. Furthermore, the possible mechanism was investigated in high glucose-induced SH-SY5Y cells. We found that downregulation of the activity and expression of SIRT1 was associated with increased hippocampal neuronal apoptosis in mice. In vitro, cell apoptosis induced by high glucose which was accompanied by a downregulation of SIRT1 and an increased acetylation of p53. On the contrary, activation of SIRT1 using its agonist resveratrol ameliorated cell apoptosis via deacetylating p53. Our data suggest that high concentration of glucose can induce neuronal apoptosis through downregulation of SIRT1 and increased acetylation of p53, which likely contribute to the development of cognitive impairment in diabetes.
Collapse
Affiliation(s)
- Xiajie Shi
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, China
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Linhua Pi
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, China
| | - Shanlei Zhou
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, China
| | - Xin Li
- Department of Pharmaceutical Engineering, College of Chemistry and Chemical Engineering, Central South University, Changsha, China
| | - Fangyuan Min
- Department of Pharmaceutical Engineering, College of Chemistry and Chemical Engineering, Central South University, Changsha, China
| | - Shan Wang
- Department of Pharmaceutical Engineering, College of Chemistry and Chemical Engineering, Central South University, Changsha, China
| | - Zhenqi Liu
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, VA, United States
| | - Jing Wu
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, China
- *Correspondence: Jing Wu,
| |
Collapse
|
22
|
Luteolin, a natural flavonoid, inhibits methylglyoxal induced apoptosis via the mTOR/4E-BP1 signaling pathway. Sci Rep 2017; 7:7877. [PMID: 28801605 PMCID: PMC5554232 DOI: 10.1038/s41598-017-08204-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 07/10/2017] [Indexed: 01/28/2023] Open
Abstract
Methylglyoxal (MG) accumulation has been observed in human cerebrospinal fluid and body tissues under hyperglycaemic conditions. Recent research has demonstrated that MG-induces neuronal cell apoptosis, which promotes the development of diabetic encephalopathy. Our previous animal study has shown that luteolin, a natural flavonoid, attenuates diabetes-associated cognitive dysfunction. To further explore the neuroprotective properties of luteolin, we investigated the inhibitive effect of luteolin on MG-induced apoptosis in PC12 neuronal cells. We found that MG inhibited cell viability in a dose-dependent manner and induced apoptosis in PC12 cells. Pretreatment with Luteolin significantly elevated cell viability, reduced MG-induced apoptosis, inhibited the activation of the mTOR/4E-BP1 signaling pathway, and decreased pro-apoptotic proteins, Bax, Cytochrome C as well as caspase-3. Furthermore, we found that pretreatment with the mTOR inhibitor, rapamycin, significantly reduced the expression of the pro-apoptotic protein Bax. Therefore, these observations unambiguously suggest that the inhibitive effect of Luteolin against MG-induced apoptosis in PC12 cells is associated with inhibition of the mTOR/4E-BP1 signaling pathway.
Collapse
|
23
|
Gong FH, Ye YN, Li JM, Zhao HY, Li XK. Rapamycin-ameliorated diabetic symptoms involved in increasing adiponectin expression in diabetic mice on a high-fat diet. Kaohsiung J Med Sci 2017; 33:321-326. [DOI: 10.1016/j.kjms.2017.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 05/01/2017] [Accepted: 05/02/2017] [Indexed: 12/21/2022] Open
|
24
|
Hayashi-Park E, Ozment BN, Griffith CM, Zhang H, Patrylo PR, Rose GM. Experimentally induced diabetes worsens neuropathology, but not learning and memory, in middle aged 3xTg mice. Behav Brain Res 2017; 322:280-287. [DOI: 10.1016/j.bbr.2016.05.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 05/06/2016] [Accepted: 05/08/2016] [Indexed: 01/21/2023]
|
25
|
Palleria C, Leo A, Andreozzi F, Citraro R, Iannone M, Spiga R, Sesti G, Constanti A, De Sarro G, Arturi F, Russo E. Liraglutide prevents cognitive decline in a rat model of streptozotocin-induced diabetes independently from its peripheral metabolic effects. Behav Brain Res 2017; 321:157-169. [PMID: 28062257 DOI: 10.1016/j.bbr.2017.01.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 12/23/2016] [Accepted: 01/01/2017] [Indexed: 12/13/2022]
Abstract
Diabetes has been identified as a risk factor for cognitive dysfunctions. Glucagone like peptide 1 (GLP-1) receptor agonists have neuroprotective effects in preclinical animal models. We evaluated the effects of GLP-1 receptor agonist, liraglutide (LIR), on cognitive decline associated with diabetes. Furthermore, we studied LIR effects against hippocampal neurodegeneration induced by streptozotocin (STZ), a well-validated animal model of diabetes and neurodegeneration associated with cognitive decline. Diabetes and/or cognitive decline were induced in Wistar rats by intraperitoneal or intracerebroventricular injection of STZ and then rats were treated with LIR (300μg/kg daily subcutaneously) for 6 weeks. Rats underwent behavioral tests: Morris water maze, passive avoidance, forced swimming (FST), open field, elevated plus maze, rotarod tests. Furthermore, LIR effects on hippocampal neurodegeneration and mTOR pathway (AKT, AMPK, ERK and p70S6K) were assessed. LIR improved learning and memory only in STZ-treated animals. Anxiolytic effects were observed in all LIR-treated groups but pro-depressant effects in CTRL rats were observed. At a cellular/molecular level, intracerebroventricular STZ induced hippocampal neurodegeneration accompanied by decreased phosphorylation of AMPK, AKT, ERK and p70S6K. LIR reduced hippocampal neuronal death and prevented the decreased phosphorylation of AKT and p70S6K; AMPK was hyper-phosphorylated in comparison to CTRL group, while LIR had no effects on ERK. LIR reduced animal endurance in the rotarod test and this effect might be also linked to a reduction in locomotor activity during only the last two minutes of the FST. LIR had protective effects on cognitive functions in addition to its effects on blood glucose levels. LIR effects in the brain also comprised anxiolytic and pro-depressant actions (although influenced by reduced endurance). Finally, LIR protected from diabetes-dependent hippocampal neurodegeneration likely through an effect on mTOR pathway.
Collapse
Affiliation(s)
- Caterina Palleria
- Science of Health Department, School of Medicine, University "Magna Graecia" of Catanzaro, Italy
| | - Antonio Leo
- Science of Health Department, School of Medicine, University "Magna Graecia" of Catanzaro, Italy
| | - Francesco Andreozzi
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, 88100, Viale Europa, Catanzaro, Italy
| | - Rita Citraro
- Science of Health Department, School of Medicine, University "Magna Graecia" of Catanzaro, Italy
| | - Michelangelo Iannone
- CNR, Institute of Neurological Sciences, Pharmacology Section, Roccelletta di Borgia, Catanzaro, Italy
| | - Rosangela Spiga
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, 88100, Viale Europa, Catanzaro, Italy
| | - Giorgio Sesti
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, 88100, Viale Europa, Catanzaro, Italy
| | - Andrew Constanti
- Department of Pharmacology, UCL School of Pharmacy, 29/39 Brunswick Square, London, UK
| | - Giovambattista De Sarro
- Science of Health Department, School of Medicine, University "Magna Graecia" of Catanzaro, Italy
| | - Franco Arturi
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, 88100, Viale Europa, Catanzaro, Italy
| | - Emilio Russo
- Science of Health Department, School of Medicine, University "Magna Graecia" of Catanzaro, Italy.
| |
Collapse
|
26
|
l-Theanine attenuates cadmium-induced neurotoxicity through the inhibition of oxidative damage and tau hyperphosphorylation. Neurotoxicology 2016; 57:95-103. [PMID: 27649883 DOI: 10.1016/j.neuro.2016.09.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 09/15/2016] [Accepted: 09/15/2016] [Indexed: 12/11/2022]
Abstract
Cadmium (Cd) has long been known to induce neurological degenerative disorders. We studied effects of l-theanine, one of the major amino acid components in green tea, on Cd-induced brain injury in mice. Male ICR mice were intraperitoneally injected with l-theanine (100 or 200mg/kg/day) or saline and after one hour these mice were orally administrated with CdCl2 (3.75-6mg/kg). The treatment was conducted for 8 weeks. l-Theanine significantly reduced Cd level in the mouse brain and plasma. Cd-induced neuronal cell death in the mouse cortex and hippocampus were apparently inhibited by l-theanine treatment. l-Theanine also decreased the levels of malondialdehyde (MDA) and ROS, and obviously elevated the levels of glutathione (GSH) and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the mouse brain. Hyperphosphorylation of tau protein is proposed to be an early event for the evolution of tau pathology, and may play an important role in Cd-induced neurodegeneration. Our results showed that l-theanine significantly suppressed Cd-induced tau protein hyperphosphorylation at Ser199, Ser202, and Ser396. Mechanism study showed that l-theanine inhibited the activation of glycogen synthase kinase-3β (GSK-3β) which contributed to the hyperphosphorylation of tau and Cd-induced cytotoxicity. Furthermore, l-theanine reduced Cd-induced cytotoxicity possibly by interfering with the Akt/mTOR signaling pathway. In conclusion, our study indicated that l-theanine protected mice against Cd-induced neurotoxicity through reducing brain Cd level and relieved oxidative damage and tau hyperphosphorylation. Our foundings provide a novel insight into the potential use of l-theanine as prophylactic and therapeutic agents for Cd-induced neurodegenerative diseases.
Collapse
|
27
|
Shen W, Lu K, Wang J, Wu A, Yue Y. Activation of mTOR signaling leads to orthopedic surgery-induced cognitive decline in mice through β-amyloid accumulation and tau phosphorylation. Mol Med Rep 2016; 14:3925-34. [PMID: 27599409 DOI: 10.3892/mmr.2016.5700] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 07/13/2016] [Indexed: 11/05/2022] Open
Abstract
Postoperative cognitive dysfunction (POCD) is a serious complication following surgery, however, the mechanism of POCD remains to be elucidated. Previous evidence has revealed that POCD may be associated with the pathogenesis of neurodegenerative processes. The mammalian target of rapamycin (mTOR) signaling pathway has been reported to be crucial in the pathophysiology of neurodegenerative diseases. However, the implications of mTOR in POCD remains to be fully elucidated. In the present study, western blotting and enzyme‑linked immunosorbent assay were used to determine the expression of mTOR and any associated downstream targets; contextual fear conditioning was used to estimate the learning and memory ability of mice. Using an animal model of orthopedic surgery, it was found that surgical injury impaired hippocampal‑dependent memory and enhanced the levels of phosphorylated mTOR at Serine‑2448, phosphorylated 70‑kDa ribosomal protein S6 kinase (p70S6K) at Threonine‑389 with accumulation of β‑amyloid (Aβ) and hyperphosphorylated tau at Serine-396, compared with the control group. Pretreatment with rapamycin, an mTOR inhibitor, restored the abnormal mTOR/p70S6K signaling induced by surgery, attenuated the accumulation of Aβ and reduced the phosphorylation of tau protein. Rapamycin also reversed the surgery‑induced cognitive dysfunction. The results of the present study suggested that the surgical stimulus activated mTOR/p70S6K signaling excessively, and that the inhibition of mTOR signaling with rapamycin may prevent postoperative cognitive deficits, partly through attenuating the accumulation of Aβ and hyperphosphorylation of tau protein.
Collapse
Affiliation(s)
- Wenzhen Shen
- Department of Anesthesiology, Beijing Chao‑Yang Hospital, Capital Medical University, Beijing 100020, P.R. China
| | - Keliang Lu
- Department of Anesthesiology, Weifang Medical University, Weifang, Shandong 261031, P.R. China
| | - Jiawan Wang
- Department of Anesthesiology, Beijing Chao‑Yang Hospital, Capital Medical University, Beijing 100020, P.R. China
| | - Anshi Wu
- Department of Anesthesiology, Beijing Chao‑Yang Hospital, Capital Medical University, Beijing 100020, P.R. China
| | - Yun Yue
- Department of Anesthesiology, Beijing Chao‑Yang Hospital, Capital Medical University, Beijing 100020, P.R. China
| |
Collapse
|
28
|
Arendt T, Stieler JT, Holzer M. Tau and tauopathies. Brain Res Bull 2016; 126:238-292. [DOI: 10.1016/j.brainresbull.2016.08.018] [Citation(s) in RCA: 333] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/31/2016] [Accepted: 08/31/2016] [Indexed: 12/11/2022]
|
29
|
Regan P, Whitcomb DJ, Cho K. Physiological and Pathophysiological Implications of Synaptic Tau. Neuroscientist 2016; 23:137-151. [DOI: 10.1177/1073858416633439] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Tauopathies encompass a broad range of neurodegenerative diseases featuring extensive neuronal death and cognitive decline. However, research over the past 30 years has failed to significantly advance our understanding of how tau causes dementia, limiting the design of rational therapeutics. It has become evident that we need to expand our understanding of tau in physiology, in order to delineate how tau may contribute to pathology. This review discusses recent evidence that has uncovered a novel aspect of tau function, based on its previously uncharacterized localization to the synapse. Here, multiple streams of evidence support a critical role for synaptic tau in the regulation of synapse physiology. In particular, long-term depression, a form of synaptic weakening, is dependent on the presence of tau in hippocampal neurons. The regulation of tau by specific phosphorylation events downstream of GSK-3β activation appears to be integral to this signaling role. We also describe how the regulation of synapse physiology by tau and its phosphorylation may inform our understanding of tauopathies and comorbid diseases. This work should provide a platform for future tau biology research in addition to therapeutic design.
Collapse
Affiliation(s)
- Philip Regan
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (HW-LINE), Bristol, UK
| | - Daniel J. Whitcomb
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (HW-LINE), Bristol, UK
- Centre for Synaptic Plasticity, Faculty of Health Sciences, University of Bristol, Bristol, UK
| | - Kwangwook Cho
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (HW-LINE), Bristol, UK
- Centre for Synaptic Plasticity, Faculty of Health Sciences, University of Bristol, Bristol, UK
| |
Collapse
|
30
|
Galvan V, Hart MJ. Vascular mTOR-dependent mechanisms linking the control of aging to Alzheimer's disease. Biochim Biophys Acta Mol Basis Dis 2015; 1862:992-1007. [PMID: 26639036 DOI: 10.1016/j.bbadis.2015.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/17/2015] [Accepted: 11/18/2015] [Indexed: 02/07/2023]
Abstract
Aging is the strongest known risk factor for Alzheimer's disease (AD). With the discovery of the mechanistic target of rapamycin (mTOR) as a critical pathway controlling the rate of aging in mice, molecules at the interface between the regulation of aging and the mechanisms of specific age-associated diseases can be identified. We will review emerging evidence that mTOR-dependent brain vascular dysfunction, a universal feature of aging, may be one of the mechanisms linking the regulation of the rate of aging to the pathogenesis of Alzheimer's disease. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.
Collapse
Affiliation(s)
- Veronica Galvan
- Department of Physiology and the Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio.
| | - Matthew J Hart
- Department of Biochemistry, University of Texas Health Science Center at San Antonio
| |
Collapse
|
31
|
PI3K/AKT/mTOR/p70S6K Pathway Is Involved in Aβ25-35-Induced Autophagy. BIOMED RESEARCH INTERNATIONAL 2015; 2015:161020. [PMID: 26583091 PMCID: PMC4637023 DOI: 10.1155/2015/161020] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 07/17/2015] [Accepted: 08/04/2015] [Indexed: 02/06/2023]
Abstract
Disruption or deregulation of the autophagy system has been implicated in neurodegenerative disorders such as Alzheimer's disease (AD). Aβ plays an important role in this autophagic system. In many cases, autophagy is regulated by the phosphatidylinositol 3-phosphate kinase/AKT/mammalian target of rapamycin/p70 ribosomal protein S6 kinase (PI3K/AKT/mTOR/p70S6K) signaling pathway. However, whether this signaling pathway is involved in Aβ-induced autophagy in neuronal cells is not known. Here, we studied whether Aβ25-35 induces autophagy in HT22 cells and C57 mice and investigated whether PI3K is involved in the autophagy induction. We found that Aβ25-35 inhibited HT22 cell viability in a dose- and time-dependent manner. Aβ25-35 induced autophagosome formation, the conversion of microtubule-associated protein light chain 3 (LC3), and the suppression of the mTOR pathway both in vitro and in vivo. Furthermore, Aβ25-35 impaired the learning abilities of C57 mice. Our study suggests that Aβ25-35 induces autophagy and the PI3K/AKT/mTOR/p70S6K pathway is involved in the process, which improves our understanding of the pathogenesis of AD and provides an additional model for AD research.
Collapse
|
32
|
Nine-month follow-up of the insulin receptor signalling cascade in the brain of streptozotocin rat model of sporadic Alzheimer's disease. J Neural Transm (Vienna) 2014; 122:565-76. [PMID: 25503661 DOI: 10.1007/s00702-014-1323-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 10/01/2014] [Indexed: 12/21/2022]
Abstract
Sporadic Alzheimer disease (sAD) is associated with impairment of insulin receptor (IR) signalling in the brain. Rats used to model sAD develop insulin-resistant brain state following intracerebroventricular treatment with a betacytotoxic drug streptozotocin (STZ-icv). Brain IR signalling has been explored usually at only one time point in periods ≤3 months after the STZ-icv administration. We have investigated insulin signalling in the rat hippocampus at five time points in periods ≤9 months after STZ-icv treatment. Male Wistar rats were given vehicle (control)- or STZ (3 mg/kg)-icv injection and killed 0.5, 1, 3, 6 and 9 months afterwards. Insulin-1 (Ins-1), IR, phospho- and total (p/t)-glycogen synthase kinase 3-β (GSK-3β), p/t-tau and insulin degrading enzyme (IDE) mRNA and/or protein were measured. Acute upregulation of tau and IR mRNA (p < 0.05) was followed by a pronounced downregulation of Ins-1, IR and IDE mRNA (p < 0.05) in the course of time. Acute decrement in p/t-tau and p/t-GSK-3β ratios (p < 0.05) was followed by increment in both ratios (3-6 months, p < 0.05) after which p/t-tau ratio demonstrated a steep rise and p/t-GSK-3β ratio a steep fall up to 9 months (p < 0.05). Acute decline in IDE and IR expression (p < 0.05) was followed by a slow progression of the former and a slow recovery of the latter in 3-9 months. Results indicate a biphasic pattern in time dependency of onset and progression of changes in brain insulin signalling of STZ-icv model (partly reversible acute toxicity and chronic AD-like changes) which should be considered when using this model as a tool in translational sAD research.
Collapse
|