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Garza-Lombó C, Schroder A, Reyes-Reyes EM, Franco R. mTOR/AMPK signaling in the brain: Cell metabolism, proteostasis and survival. CURRENT OPINION IN TOXICOLOGY 2018; 8:102-110. [PMID: 30417160 PMCID: PMC6223325 DOI: 10.1016/j.cotox.2018.05.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The mechanistic (or mammalian) target of rapamycin (mTOR) and the adenosine monophosphate-activated protein kinase (AMPK) regulate cell survival and metabolism in response to diverse stimuli such as variations in amino acid content, changes in cellular bioenergetics, oxygen levels, neurotrophic factors and xenobiotics. This Opinion paper aims to discuss the current state of knowledge regarding how mTOR and AMPK regulate the metabolism and survival of brain cells and the close interrelationship between both signaling cascades. It is now clear that both mTOR and AMPK pathways regulate cellular homeostasis at multiple levels. Studies so far demonstrate that dysregulation in these two pathways is associated with neuronal injury, degeneration and neurotoxicity, but the mechanisms involved remain unclear. Most of the work so far has been focused on their antagonistic regulation of autophagy, but recent findings highlight that changes in protein synthesis, metabolism and mitochondrial function are likely to play a role in the regulatory effects of both mTOR and AMPK on neuronal health. Understanding the role and relationship between these two master regulators of cell metabolism is crucial for future therapeutic approaches to counteract alterations in cell metabolism and survival in brain injury and disease.
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Affiliation(s)
- Carla Garza-Lombó
- Redox Biology Center. University of Nebraska-Lincoln, Lincoln, NE 68588
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México 04510
| | - Annika Schroder
- Redox Biology Center. University of Nebraska-Lincoln, Lincoln, NE 68588
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583
| | - Elsa M. Reyes-Reyes
- University of Arizona College of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Tucson, AZ 85724
| | - Rodrigo Franco
- Redox Biology Center. University of Nebraska-Lincoln, Lincoln, NE 68588
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583
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152
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The Neurotoxic Role of Extracellular Tau Protein. Int J Mol Sci 2018; 19:ijms19040998. [PMID: 29584657 PMCID: PMC5979432 DOI: 10.3390/ijms19040998] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 03/21/2018] [Accepted: 03/23/2018] [Indexed: 12/31/2022] Open
Abstract
Tauopathies are a class of neurodegenerative diseases associated with the microtubule-associated protein tau, with Alzheimer’s disease (AD) being the most prevalent related disorder. Neurofibrillary tangles (NFTs) are one of the neuropathological hallmarks present in the brains of AD patients. Because NFTs are aberrant intracellular inclusions formed by hyperphosphorylated tau, it was initially proposed that phosphorylated and/or aggregated intracellular tau protein was causative of neuronal death. However, recent studies suggest a toxic role for non-phosphorylated and non-aggregated tau when it is located in the brain extracellular space. In this work, we will discuss the neurotoxic role of extracellular tau as well its involvement in the spreading of tau pathologies.
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153
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Miya Shaik M, Tamargo IA, Abubakar MB, Kamal MA, Greig NH, Gan SH. The Role of microRNAs in Alzheimer's Disease and Their Therapeutic Potentials. Genes (Basel) 2018; 9:genes9040174. [PMID: 29561798 PMCID: PMC5924516 DOI: 10.3390/genes9040174] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/05/2018] [Accepted: 03/05/2018] [Indexed: 12/19/2022] Open
Abstract
MicroRNAs (miRNAs) are short, endogenous, non-coding RNAs that post-transcriptionally regulate gene expression by base pairing with mRNA targets. Altered miRNA expression profiles have been observed in several diseases, including neurodegeneration. Multiple studies have reported altered expressions of miRNAs in the brains of individuals with Alzheimer’s disease (AD) as compared to those of healthy elderly adults. Some of the miRNAs found to be dysregulated in AD have been reported to correlate with neuropathological changes, including plaque and tangle accumulation, as well as altered expressions of species that are known to be involved in AD pathology. To examine the potentially pathogenic functions of several dysregulated miRNAs in AD, we review the current literature with a focus on the activities of ten miRNAs in biological pathways involved in AD pathogenesis. Comprehensive understandings of the expression profiles and activities of these miRNAs will illuminate their roles as potential therapeutic targets in AD brain and may lead to the discovery of breakthrough treatment strategies for AD.
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Affiliation(s)
- Munvar Miya Shaik
- School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Malaysia.
| | - Ian A Tamargo
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
| | - Murtala B Abubakar
- Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Usmanu Danfodiyo University, PMB 2254 Sokoto, Nigeria.
| | - Mohammad A Kamal
- Metabolomics and Enzymology Unit, Fundamental and Applied Biology Group, King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia.
| | - Nigel H Greig
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
| | - Siew Hua Gan
- School of Pharmacy, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia.
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154
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Amyloid-β with isomerized Asp7 cytotoxicity is coupled to protein phosphorylation. Sci Rep 2018; 8:3518. [PMID: 29476081 PMCID: PMC5824883 DOI: 10.1038/s41598-018-21815-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 01/18/2018] [Indexed: 01/08/2023] Open
Abstract
Neuronal dysfunction and loss associated with the accumulation of amyloid-β (Aβ) in the form of extracellular amyloid plaques and hyperphosphorylated tau in the form of intraneuronal neurofibrillary tangles represent key features of Alzheimer's disease (AD). Amyloid plaques found in the brains of AD patients are predominantly composed of Aβ42 and its multiple chemically or structurally modified isoforms. Recently, we demonstrated that Aβ42 with isomerised Asp7 (isoAβ42) which is one of the most abundant Aβ isoform in plaques, exhibited high neurotoxicity in human neuronal cells. Here, we show that, in SH-SY5Y neuroblastoma cells, the administration of synthetic isoAβ42 rather than intact Aβ42 resulted in a significantly higher level of protein phosphorylation, especially the phosphorylation of tau, tubulins, and matrin 3. IsoAβ42 induced a drastic reduction of tau protein levels. Our data demonstrate, for the first time, that isoAβ42, being to date the only known synthetic Aβ species to cause AD-like amyloidogenesis in an animal AD model, induced cell death by disabling structural proteins in a manner characteristic of that observed in the neurons of AD patients. The data emphasize an important role of isoAβ42 in AD progression and provide possible neurotoxicity paths for this particular isoform.
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155
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Lin TS, Tsai HJ, Lee CH, Song YQ, Huang RS, Hsieh-Li HM, Liang MC, Lin Y. An Improved Drugs Screening System Reveals that Baicalein Ameliorates the Aβ/AMPA/NMDA-Induced Depolarization of Neurons. J Alzheimers Dis 2018; 56:959-976. [PMID: 28106556 DOI: 10.3233/jad-160898] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The presence of amyloid-β (Aβ) plaque and tau protein hyperphosphorylation in brain tissue is the pathological hallmark of Alzheimer's disease (AD). At least some Aβ neurotoxicity is caused by the presence of excess glutamate that has been induced by Aβ accumulation. Memantine is currently the only NMDA receptor inhibitor approved for treating moderate-to-severe AD patients. We utilized primary cortical neurons and DiBAC4(3), a slow-response voltage sensitive fluorescence dye, to create a novel system for screening herbal medicines that allows the identification of pure compounds able to ameliorate Aβ-induced abnormal depolarization. The intensity of DiBAC4(3) fluorescence was increased when primary neurons were stimulated by Aβ; furthermore, pre-treatment with memantine abolished this change. Using this system, we identified six crude extracts made from herbal medicines that effectively alleviated this Aβ-induced abnormal depolarization. Among these herbal medicines, one pure compound, baicalein, which was known to be present in Scutellaria baricalensis and is known to improve memory using an AD mouse model, was identified by our assay. However, the compound's molecular mechanism remained unknown. We found that baicalein, in addition to inhibiting Aβ-induced depolarization, possibly functions as an antagonist of AMPA and NMDA receptors. Taken together, we have established a system/platform to identify herbal medicines that ameliorate Aβ-induced depolarization of neurons. Equally important, baicalein is a candidate drug with great potential for the treatment of AD patients.
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Affiliation(s)
- Tian-Syuan Lin
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | - Han-Jung Tsai
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | - Chih-Han Lee
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | - Yan-Qing Song
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | - Rih-Sheng Huang
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | - Hsiu-Mei Hsieh-Li
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | - Mei-Chih Liang
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan
| | - Yenshou Lin
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
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156
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Park D, Chang S. Soluble Aβ 1-42 increases the heterogeneity in synaptic vesicle pool size among synapses by suppressing intersynaptic vesicle sharing. Mol Brain 2018; 11:10. [PMID: 29463281 PMCID: PMC5819658 DOI: 10.1186/s13041-018-0353-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 02/13/2018] [Indexed: 11/10/2022] Open
Abstract
Growing evidence has indicated that prefibrillar form of soluble amyloid beta (sAβ1-42) is the major causative factor in the synaptic dysfunction associated with AD. The molecular changes leading to presynaptic dysfunction caused by sAβ1-42, however, still remains elusive. Recently, we found that sAβ1-42 inhibits chemically induced long-term potentiation-induced synaptogenesis by suppressing the intersynaptic vesicle trafficking through calcium (Ca2+) dependent hyperphosphorylation of synapsin and CaMKIV. However, it is still unclear how sAβ1-42 increases intracellular Ca2+ that induces hyperphosphorylation of CaMKIV and synapsin, and what is the functional consequences of sAβ1-42-induced defects in intersynaptic vesicle trafficking in physiological conditions. In this study, we showed that sAβ1-42elevated intracellular Ca2+ through not only extracellular Ca2+ influx but also Ca2+ release from mitochondria. Surprisingly, without Ca2+ release from mitochondria, sAβ1-42 failed to increase intracellular Ca2+ even in the presence of normal extracellular Ca2+. We further found that sAβ1-42-induced mitochondria Ca2+ release alone sufficiently increased Serine 9 phosphorylation of synapsin. By blocking synaptic vesicle reallocation, sAβ1-42 significantly increased heterogeneity of total synaptic vesicle pool size among synapses. Together, our results suggested that by disrupting the axonal vesicle trafficking, sAβ1-42 disabled neurons to adjust synaptic pool sizes among synapses, which might prevent homeostatic rescaling in synaptic strength of individual neurons.
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Affiliation(s)
- Daehun Park
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Sunghoe Chang
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea. .,Neuroscience Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, 03080, South Korea.
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157
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Rescue of Learning and Memory Deficits in the Human Nonsyndromic Intellectual Disability Cereblon Knock-Out Mouse Model by Targeting the AMP-Activated Protein Kinase-mTORC1 Translational Pathway. J Neurosci 2018; 38:2780-2795. [PMID: 29459374 DOI: 10.1523/jneurosci.0599-17.2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 01/03/2018] [Accepted: 01/27/2018] [Indexed: 01/05/2023] Open
Abstract
A homozygous nonsense mutation in the cereblon (CRBN) gene results in autosomal recessive, nonsyndromic intellectual disability that is devoid of other phenotypic features, suggesting a critical role of CRBN in mediating learning and memory. In this study, we demonstrate that adult male Crbn knock-out (CrbnKO) mice exhibit deficits in hippocampal-dependent learning and memory tasks that are recapitulated by focal knock-out of Crbn in the adult dorsal hippocampus, with no changes in social or repetitive behavior. Cellular studies identify deficits in long-term potentiation at Schaffer collateral CA1 synapses. We further show that Crbn is robustly expressed in the mouse hippocampus and CrbnKO mice exhibit hyperphosphorylated levels of AMPKα (Thr172). Examination of processes downstream of AMP-activated protein kinase (AMPK) finds that CrbnKO mice have a selective impairment in mediators of the mTORC1 translation initiation pathway in parallel with lower protein levels of postsynaptic density glutamatergic proteins and higher levels of excitatory presynaptic markers in the hippocampus with no change in markers of the unfolded protein response or autophagy pathways. Acute pharmacological inhibition of AMPK activity in adult CrbnKO mice rescues learning and memory deficits and normalizes hippocampal mTORC1 activity and postsynaptic glutamatergic proteins without altering excitatory presynaptic markers. Thus, this study identifies that loss of Crbn results in learning, memory, and synaptic defects as a consequence of exaggerated AMPK activity, inhibition of mTORC1 signaling, and decreased glutamatergic synaptic proteins. Thus, CrbnKO mice serve as an ideal model of intellectual disability to further explore molecular mechanisms of learning and memory.SIGNIFICANCE STATEMENT Intellectual disability (ID) is one of the most common neurodevelopmental disorders. The cereblon (CRBN) gene has been linked to autosomal recessive, nonsyndromic ID, characterized by an intelligence quotient between 50 and 70 but devoid of other phenotypic features, making cereblon an ideal protein for the study of the fundamental aspects of learning and memory. Here, using the cereblon knock-out mouse model, we show that cereblon deficiency disrupts learning, memory, and synaptic function via AMP-activated protein kinase hyperactivity, downregulation of mTORC1, and dysregulation of excitatory synapses, with no changes in social or repetitive behaviors, consistent with findings in the human population. This establishes the cereblon knock-out mouse as a model of pure ID without the confounding behavioral phenotypes associated with other current models of ID.
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158
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Guo X, Jiang Q, Tuccitto A, Chan D, Alqawlaq S, Won GJ, Sivak JM. The AMPK-PGC-1α signaling axis regulates the astrocyte glutathione system to protect against oxidative and metabolic injury. Neurobiol Dis 2018; 113:59-69. [PMID: 29438738 DOI: 10.1016/j.nbd.2018.02.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 01/10/2018] [Accepted: 02/08/2018] [Indexed: 02/04/2023] Open
Abstract
Neurons are highly sensitive to metabolic and oxidative injury, but endogenous astrocyte mechanisms have a critical capacity to provide protection from these stresses. We previously reported that the master regulator PGC-1α (peroxisome proliferator-activated receptor gamma coactivator-1α) is necessary for retinal astrocytes to mount effective injury responses, with particular regard to oxidative stress. Yet, this pathway has not been well studied in glia. PGC-1α is a transcriptional co-activator that is dysregulated in a variety of neurodegenerative diseases. It functions as a master regulator of cellular bioenergetics, with the ability to regulate tissue specific responses. A key inducer of PGC-1α signaling is adenosine monophosphate-activated kinase (AMPK). Thus, the AMPK-PGC-1α signaling axis coordinates metabolic and oxidative damage responses in the central nervous system (CNS). Here we report that AMPK selectively regulates expression of GCLM (glutamate cysteine ligase modulatory subunit) in astrocytes, but not neurons, through PGC-1α activation. Glutamate cysteine ligase (GCL) is the rate limiting enzyme in the biosynthesis of glutathione (GSH); a critical antioxidant and detoxifying peptide in the CNS. Through this mechanism we describe PGC-1α-dependent induction of GSH synthesis and antioxidant activity in astrocytes, and in the rodent retina in vivo. Furthermore, we demonstrate that therapeutic agonism of this pathway with the AMP mimetic, AICAR, rescues GSH levels in vivo, while reducing RGC death and astrocyte reactivity, following retinal ischemia/reperfusion injury. This mechanism presents a novel strategy for enhancing protective astrocyte antioxidant capacity in the CNS.
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Affiliation(s)
- Xiaoxin Guo
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada; Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
| | - Qi Jiang
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada; Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Alessandra Tuccitto
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada; Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Darren Chan
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada; Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
| | - Samih Alqawlaq
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada; Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Gah-Jone Won
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada; Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
| | - Jeremy M Sivak
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada; Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
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159
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McCully KS. Homocysteine, Infections, Polyamines, Oxidative Metabolism, and the Pathogenesis of Dementia and Atherosclerosis. J Alzheimers Dis 2018; 54:1283-1290. [PMID: 27567876 DOI: 10.3233/jad-160549] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hyperhomocysteinemia is a risk factor for development of dementia and Alzheimer's disease (AD), and low blood levels of folate and cobalamin are associated with hyperhomocysteinemia and AD. In elderly subjects with cognitive decline, supplementation with folate, cobalamin, and pyridoxal demonstrated reduction of cerebral atrophy in gray matter regions vulnerable to the AD process. Multiple pathogenic microbes are implicated as pathogenic factors in AD and atherosclerosis, and the deposition of amyloid-β (Aβ), phosphorylation of tau protein, neuronal injury, and apoptosis in AD are secondary to microbial infection. Glucose utilization and blood flow are reduced in AD, and these changes are accompanied by downregulation of glucose transport, Na, K-ATPase, oxidative phosphorylation, and energy consumption. Thioretinaco ozonide, the complex formed from thioretinamide, cobalamin, ozone, and oxygen is proposed to constitute the active site of oxidative phosphorylation, catalyzing synthesis of adenosine triphosphate (ATP) from nicotinamide adenine dinucleotide (NAD+) and phosphate. Pathogenic microbes cause synthesis of polyamines in host cells by increasing the transfer of aminopropyl groups from adenosyl methionine to putrescine, resulting in depletion of intracellular adenosyl methionine concentrations in host cells. Depletion of adenosyl methionine causes dysregulation of methionine metabolism, hyperhomocysteinemia, reduced biosynthesis of thioretinamide and thioretinaco ozonide, decreased oxidative phosphorylation, decreased production of nitric oxide and peroxynitrite, and impaired host response to infectious microbes, contributing to the pathogenesis of dementia and atherosclerosis.
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160
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The Stress-Induced Transcription Factor NR4A1 Adjusts Mitochondrial Function and Synapse Number in Prefrontal Cortex. J Neurosci 2018; 38:1335-1350. [PMID: 29295823 PMCID: PMC5815341 DOI: 10.1523/jneurosci.2793-17.2017] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/10/2017] [Accepted: 12/08/2017] [Indexed: 12/28/2022] Open
Abstract
The energetic costs of behavioral chronic stress are unlikely to be sustainable without neuronal plasticity. Mitochondria have the capacity to handle synaptic activity up to a limit before energetic depletion occurs. Protective mechanisms driven by the induction of neuronal genes likely evolved to buffer the consequences of chronic stress on excitatory neurons in prefrontal cortex (PFC), as this circuitry is vulnerable to excitotoxic insults. Little is known about the genes involved in mitochondrial adaptation to the buildup of chronic stress. Using combinations of genetic manipulations and stress for analyzing structural, transcriptional, mitochondrial, and behavioral outcomes, we characterized NR4A1 as a stress-inducible modifier of mitochondrial energetic competence and dendritic spine number in PFC. NR4A1 acted as a transcription factor for changing the expression of target genes previously involved in mitochondrial uncoupling, AMP-activated protein kinase activation, and synaptic growth. Maintenance of NR4A1 activity by chronic stress played a critical role in the regressive synaptic organization in PFC of mouse models of stress (male only). Knockdown, dominant-negative approach, and knockout of Nr4a1 in mice and rats (male only) protected pyramidal neurons against the adverse effects of chronic stress. In human PFC tissues of men and women, high levels of the transcriptionally active NR4A1 correlated with measures of synaptic loss and cognitive impairment. In the context of chronic stress, prolonged expression and activity of NR4A1 may lead to responses of mitochondria and synaptic connectivity that do not match environmental demand, resulting in circuit malfunction between PFC and other brain regions, constituting a pathological feature across disorders. SIGNIFICANCE STATEMENT The bioenergetic cost of chronic stress is too high to be sustainable by pyramidal prefrontal neurons. Cellular checkpoints have evolved to adjust the responses of mitochondria and synapses to the buildup of chronic stress. NR4A1 plays such a role by controlling the energetic competence of mitochondria with respect to synapse number. As an immediate-early gene, Nr4a1 promotes neuronal plasticity, but sustained expression or activity can be detrimental. NR4A1 expression and activity is sustained by chronic stress in animal models and in human studies of neuropathologies sensitive to the buildup of chronic stress. Therefore, antagonism of NR4A1 is a promising avenue for preventing the regressive synaptic reorganization in cortical systems in the context of chronic stress.
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161
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Cheng G, Li B, Sun X, Cao Z, Zhang G, Zhao Z, Zhao Y, Yu Q, Liu W. LncRNA LOC730101 promotes osteosarcoma cell survival under energy stress. Biochem Biophys Res Commun 2018; 496:1-6. [DOI: 10.1016/j.bbrc.2017.12.074] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 12/14/2017] [Indexed: 12/19/2022]
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162
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Asam K, Staniszewski A, Zhang H, Melideo SL, Mazzeo A, Voronkov M, Huber KL, Pérez E, Stock M, Stock JB, Arancio O, Nicholls RE. Eicosanoyl-5-hydroxytryptamide (EHT) prevents Alzheimer's disease-related cognitive and electrophysiological impairments in mice exposed to elevated concentrations of oligomeric beta-amyloid. PLoS One 2017; 12:e0189413. [PMID: 29253878 PMCID: PMC5734769 DOI: 10.1371/journal.pone.0189413] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 11/24/2017] [Indexed: 02/04/2023] Open
Abstract
Soluble forms of oligomeric beta-amyloid (Aβ) are thought to play a central role in Alzheimer's disease (AD). Transgenic manipulation of methylation of the serine/threonine protein phosphatase, PP2A, was recently shown to alter the sensitivity of mice to AD-related impairments resulting from acute exposure to elevated levels of Aβ. In addition, eicosanoyl-5-hydroxytryptamide (EHT), a naturally occurring component from coffee beans that modulates PP2A methylation, was shown to confer therapeutic benefits in rodent models of AD and Parkinson's disease. Here, we tested the hypothesis that EHT protects animals from the pathological effects of exposure to elevated levels of soluble oligomeric Aβ. We treated mice with EHT-containing food at two different doses and assessed the sensitivity of these animals to Aβ-induced behavioral and electrophysiological impairments. We found that EHT administration protected animals from Aβ-induced cognitive impairments in both a radial-arm water maze and contextual fear conditioning task. We also found that both chronic and acute EHT administration prevented Aβ-induced impairments in long-term potentiation. These data add to the accumulating evidence suggesting that interventions with pharmacological agents, such as EHT, that target PP2A activity may be therapeutically beneficial for AD and other neurological conditions.
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Affiliation(s)
- Kesava Asam
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
| | - Agnieszka Staniszewski
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
| | - Hong Zhang
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
| | - Scott L. Melideo
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Adolfo Mazzeo
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
| | - Michael Voronkov
- Signum Biosciences, 133 Wall Street, Princeton, New Jersey, United States of America
| | - Kristen L. Huber
- Signum Biosciences, 133 Wall Street, Princeton, New Jersey, United States of America
| | - Eduardo Pérez
- Signum Biosciences, 133 Wall Street, Princeton, New Jersey, United States of America
| | - Maxwell Stock
- Signum Biosciences, 133 Wall Street, Princeton, New Jersey, United States of America
| | - Jeffry B. Stock
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Signum Biosciences, 133 Wall Street, Princeton, New Jersey, United States of America
| | - Ottavio Arancio
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
- Department of Medicine, Columbia University, New York, NY, United States of America
| | - Russell E. Nicholls
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
- * E-mail:
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163
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Ca 2+-CaMKKβ pathway is required for adiponectin-induced secretion in rat submandibular gland. J Mol Histol 2017; 49:99-110. [PMID: 29243095 DOI: 10.1007/s10735-017-9750-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 12/05/2017] [Indexed: 10/18/2022]
Abstract
Adiponectin functions as a promoter of saliva secretion in rat submandibular gland via activation of adenosine monophosphate-activated protein kinase (AMPK) and increased paracellular permeability. Ca2+ mobilization is the primary signal for fluid secretion in salivary acinar cells. However, whether intracellular Ca2+ mobilization is involved in adiponectin-induced salivary secretion is unknown. Here, we found that full-length adiponectin (fAd) increased intracellular Ca2+ and saliva secretion in submandibular glands. Pre-perfusion with ethylene glycol-bis (2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) combined with thapsigargin (TG), an endoplasmic reticulum Ca2+-ATPase inhibitor, abolished fAd-induced salivary secretion, AMPK phosphorylation, and enlarged tight junction (TJ) width. Furthermore, in cultured SMG-C6 cells, co-pretreatment with EGTA and TG suppressed fAd-decreased transepithelial electrical resistance and increased 4-kDa FITC-dextran flux responses. Moreover, fAd increased phosphorylation of calcium/calmodulin-dependent protein kinase (CaMKKβ), a major kinase that is activated by elevated levels of intracellular Ca2+, but not liver kinase B1 phosphorylation. Pre-perfusion of the isolated gland with STO-609, an inhibitor of CaMKKβ, abolished fAd-induced salivary secretion, AMPK activation, and enlarged TJ width. CaMKKβ shRNA suppressed, whereas CaMKKβ re-expression rescued fAd-increased paracellular permeability. Taken together, these results indicate that adiponectin induced Ca2+ modulation in rat submandibular gland acinar cells. Ca2+-CaMKKβ pathway is required for adiponectin-induced secretion through mediating AMPK activation and increase in paracellular permeability in rat submandibular glands.
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164
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Polanco JC, Li C, Bodea LG, Martinez-Marmol R, Meunier FA, Götz J. Amyloid-β and tau complexity — towards improved biomarkers and targeted therapies. Nat Rev Neurol 2017; 14:22-39. [DOI: 10.1038/nrneurol.2017.162] [Citation(s) in RCA: 235] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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165
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Cissé M, Duplan E, Lorivel T, Dunys J, Bauer C, Meckler X, Gerakis Y, Lauritzen I, Checler F. The transcription factor XBP1s restores hippocampal synaptic plasticity and memory by control of the Kalirin-7 pathway in Alzheimer model. Mol Psychiatry 2017; 22:1562-1575. [PMID: 27646263 PMCID: PMC5658671 DOI: 10.1038/mp.2016.152] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/14/2016] [Accepted: 07/18/2016] [Indexed: 12/18/2022]
Abstract
Neuronal network dysfunction and cognitive decline constitute the most prominent features of Alzheimer's disease (AD), although mechanisms causing such impairments are yet to be determined. Here we report that virus-mediated delivery of the active spliced transcription factor X-Box binding protein 1s (XBP1s) in the hippocampus rescued spine density, synaptic plasticity and memory function in a mouse model of AD. XBP1s transcriptionally activated Kalirin-7 (Kal7), a protein that controls synaptic plasticity. In addition, we found reduced levels of Kal7 in primary neurons exposed to Aβ oligomers, transgenic mouse models and human AD brains. Short hairpin RNA-mediated knockdown of Kal7 altered synaptic plasticity and memory formation in naive mice. Further, reduction of endogenous Kal7 compromised the beneficial effects of XBP1s in Alzheimer's model. Hence, our findings reveal that XBP1s is neuroprotective through a mechanism that engages Kal7 pathway with therapeutic implications in AD pathology.
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Affiliation(s)
- M Cissé
- Université de Nice-Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR7275, Sophia-Antipolis, Valbonne, France,Université de Nice-Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR7275, NEUROLOGY, IPMC/CNRS, 660 Route des Lucioles, 06560 Valbonne, France. E-mail:
| | - E Duplan
- Université de Nice-Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR7275, Sophia-Antipolis, Valbonne, France
| | - T Lorivel
- Université de Nice-Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR7275, Sophia-Antipolis, Valbonne, France
| | - J Dunys
- Université de Nice-Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR7275, Sophia-Antipolis, Valbonne, France
| | - C Bauer
- Université de Nice-Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR7275, Sophia-Antipolis, Valbonne, France
| | - X Meckler
- Université de Nice-Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR7275, Sophia-Antipolis, Valbonne, France
| | - Y Gerakis
- Université de Nice-Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR7275, Sophia-Antipolis, Valbonne, France
| | - I Lauritzen
- Université de Nice-Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR7275, Sophia-Antipolis, Valbonne, France
| | - F Checler
- Université de Nice-Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR7275, Sophia-Antipolis, Valbonne, France
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166
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Tau-based therapies in neurodegeneration: opportunities and challenges. Nat Rev Drug Discov 2017; 16:863-883. [DOI: 10.1038/nrd.2017.155] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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167
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McCully KS. Hyperhomocysteinemia, Suppressed Immunity, and Altered Oxidative Metabolism Caused by Pathogenic Microbes in Atherosclerosis and Dementia. Front Aging Neurosci 2017; 9:324. [PMID: 29056905 PMCID: PMC5635055 DOI: 10.3389/fnagi.2017.00324] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 09/20/2017] [Indexed: 12/19/2022] Open
Abstract
Many pathogenic microorganisms have been demonstrated in atherosclerotic plaques and in cerebral plaques in dementia. Hyperhomocysteinemia, which is a risk factor for atherosclerosis and dementia, is caused by dysregulation of methionine metabolism secondary to deficiency of the allosteric regulator, adenosyl methionine. Deficiency of adenosyl methionine results from increased polyamine biosynthesis by infected host cells, causing increased activity of ornithine decarboxylase, decreased nitric oxide and peroxynitrate formation and impaired immune reactions. The down-regulation of oxidative phosphorylation that is observed in aging and dementia is attributed to deficiency of thioretinaco ozonide oxygen complexed with nicotinamide adenine dinucleotide and phosphate, which catalyzes oxidative phosphorylation. Adenosyl methionine biosynthesis is dependent upon thioretinaco ozonide and adenosine triphosphate (ATP), and the deficiency of adenosyl methionine and impaired immune function in aging are attributed to depletion of thioretinaco ozonide from mitochondrial membranes. Allyl sulfides and furanonaphthoquinones protect against oxidative stress and apoptosis by increasing the endogenous production of hydrogen sulfide and by inhibiting electron transfer to the active site of oxidative phosphorylation. Diallyl trisulfide and napabucasin inhibit the signaling by the signal transducer and activator of transcription 3 (Stat3), potentially enhancing immune function by effects on T helper lymphocytes and promotion of apoptosis. Homocysteine promotes endothelial dysfunction and apoptosis by the unfolded protein response and endoplasmic reticulum stress through activation of the N-methyl D-aspartate (NMDA) receptor, causing oxidative stress, calcium influx, apoptosis and endothelial dysfunction. The prevention of atherosclerosis and dementia may be accomplished by a proposed nutritional metabolic homocysteine-lowering protocol which enhances immunity and corrects the altered oxidative metabolism in atherosclerosis and dementia.
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Affiliation(s)
- Kilmer S. McCully
- Pathology, VA Boston Healthcare System (VHA), Boston, MA, United States
- Pathology, Harvard Medical School, Boston, MA, United States
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168
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Kuan YC, Huang KW, Lin CL, Hu CJ, Kao CH. Effects of metformin exposure on neurodegenerative diseases in elderly patients with type 2 diabetes mellitus. Prog Neuropsychopharmacol Biol Psychiatry 2017; 79:77-83. [PMID: 28583443 DOI: 10.1016/j.pnpbp.2017.06.002] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 05/26/2017] [Accepted: 06/02/2017] [Indexed: 01/18/2023]
Abstract
Epidemiological evidence reveals that patients with type 2 diabetes mellitus (T2DM) have an increased risk of neurodegenerative diseases (NDs), including dementia and Parkinson's disease (PD). The effects of metformin exposure on dementia and PD risk in patients with T2DM are unknown. We evaluated the effects of metformin exposure on the risk of dementia and PD in patients with T2DM. We performed a cohort study by using Taiwan's National Health Insurance Research Database. We recruited 4651 patients in the metformin cohort and a comparable number of nonmetformin controls by using propensity score matching. Multivariate Cox proportional hazards regression was used to estimate the effects of metformin on the risk of dementia and PD after adjustment for several confounding factors. During the 12-year follow-up, the metformin cohort exhibited a higher risk of PD than the nonmetformin cohort (hazard ratio [HR]: 2.27, 95% confidence interval [CI]=1.68-3.07). The metformin cohort had an increased risk of all-cause dementia (HR: 1.66, 95% CI=1.35-2.04). Moreover, metformin exposure increased the risk of Alzheimer's disease (HR: 2.13, 95% CI=1.20-3.79) and vascular dementia (HR: 2.30, 95% CI=1.25-4.22). The effects of exposure duration and dosage on dementia and PD occurrence were also observed. Long-term metformin exposure in patients with T2DM may lead to the development of NDs, including dementia and PD. Additional large-scale, prospective controlled trials are required to confirm the observed association in patients with T2DM.
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Affiliation(s)
- Yi-Chun Kuan
- Department of Neurology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan; Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei City, Taiwan
| | - Kuang-Wei Huang
- Division of Gastroenterology, Department of Internal Medicine, Taipei Beitou Health Management Hospital, Taipei, Taiwan
| | - Cheng-Li Lin
- Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan; College of Medicine, China Medical University, Taichung, Taiwan
| | - Chaur-Jong Hu
- Department of Neurology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan
| | - Chia-Hung Kao
- Graduate Institute of Clinical Medical Science and School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan; Department of Bioinformatics and Medical Engineering, Asia University, Taichung, Taiwan.
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169
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Velazquez R, Tran A, Ishimwe E, Denner L, Dave N, Oddo S, Dineley KT. Central insulin dysregulation and energy dyshomeostasis in two mouse models of Alzheimer's disease. Neurobiol Aging 2017; 58:1-13. [PMID: 28688899 PMCID: PMC5819888 DOI: 10.1016/j.neurobiolaging.2017.06.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/23/2017] [Accepted: 06/09/2017] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder worldwide. While the causes of AD are not known, several risk factors have been identified. Among these, type two diabetes (T2D), a chronic metabolic disease, is one of the most prevalent risk factors for AD. Insulin resistance, which is associated with T2D, is defined as diminished or absent insulin signaling and is reflected by peripheral blood hyperglycemia and impaired glucose clearance. In this study, we used complementary approaches to probe for peripheral insulin resistance, central nervous system (CNS) insulin sensitivity and energy homeostasis in Tg2576 and 3xTg-AD mice, two widely used animal models of AD. We report that CNS insulin signaling abnormalities are evident months before peripheral insulin resistance. In addition, we find that brain energy metabolism is differentially altered in both mouse models, with 3xTg-AD mice showing more extensive changes. Collectively, our data suggest that early AD may reflect engagement of different signaling networks that influence CNS metabolism, which in turn may alter peripheral insulin signaling.
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Affiliation(s)
- Ramon Velazquez
- Arizona State University-Banner Neurodegenerative Disease Research Center at the Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - An Tran
- Arizona State University-Banner Neurodegenerative Disease Research Center at the Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Egide Ishimwe
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston (UTMB), Galveston, TX, USA
| | - Larry Denner
- Internal Medicine, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston (UTMB), Galveston, TX, USA
| | - Nikhil Dave
- Arizona State University-Banner Neurodegenerative Disease Research Center at the Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Salvatore Oddo
- Arizona State University-Banner Neurodegenerative Disease Research Center at the Biodesign Institute, Arizona State University, Tempe, AZ, USA; School of Life Sciences, Arizona State University, Tempe, AZ, USA.
| | - Kelly T Dineley
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston (UTMB), Galveston, TX, USA.
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170
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Zhang L, Sun C, Jin Y, Gao K, Shi X, Qiu W, Ma C, Zhang L. Dickkopf 3 (Dkk3) Improves Amyloid-β Pathology, Cognitive Dysfunction, and Cerebral Glucose Metabolism in a Transgenic Mouse Model of Alzheimer’s Disease. J Alzheimers Dis 2017; 60:733-746. [DOI: 10.3233/jad-161254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Li Zhang
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
- Neuroscience Center, Chinese Academy of Medical Sciences, Beijing, China
| | - Caixian Sun
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
| | - Yaxi Jin
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
| | - Kai Gao
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
| | - Xudong Shi
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
| | - Wenying Qiu
- Neuroscience Center, Chinese Academy of Medical Sciences, Beijing, China
- Department of Human Anatomy, Histology and Embryology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Chao Ma
- Neuroscience Center, Chinese Academy of Medical Sciences, Beijing, China
- Department of Human Anatomy, Histology and Embryology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Lianfeng Zhang
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
- Neuroscience Center, Chinese Academy of Medical Sciences, Beijing, China
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171
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Qu X, Yuan FN, Corona C, Pasini S, Pero ME, Gundersen GG, Shelanski ML, Bartolini F. Stabilization of dynamic microtubules by mDia1 drives Tau-dependent Aβ 1-42 synaptotoxicity. J Cell Biol 2017; 216:3161-3178. [PMID: 28877993 PMCID: PMC5626542 DOI: 10.1083/jcb.201701045] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 06/15/2017] [Accepted: 07/26/2017] [Indexed: 01/17/2023] Open
Abstract
Oligomeric Amyloid β1-42 (Aβ) plays a crucial synaptotoxic role in Alzheimer's disease, and hyperphosphorylated tau facilitates Aβ toxicity. The link between Aβ and tau, however, remains controversial. In this study, we find that in hippocampal neurons, Aβ acutely induces tubulin posttranslational modifications (PTMs) and stabilizes dynamic microtubules (MTs) by reducing their catastrophe frequency. Silencing or acute inhibition of the formin mDia1 suppresses these activities and corrects the synaptotoxicity and deficits of axonal transport induced by Aβ. We explored the mechanism of rescue and found that stabilization of dynamic MTs promotes tau-dependent loss of dendritic spines and tau hyperphosphorylation. Collectively, these results uncover a novel role for mDia1 in Aβ-mediated synaptotoxicity and demonstrate that inhibition of MT dynamics and accumulation of PTMs are driving factors for the induction of tau-mediated neuronal damage.
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Affiliation(s)
- Xiaoyi Qu
- Department of Pathology, Anatomy and Cell Biology, Columbia University, New York, NY
| | - Feng Ning Yuan
- Department of Pathology, Anatomy and Cell Biology, Columbia University, New York, NY
| | - Carlo Corona
- Department of Pathology, Anatomy and Cell Biology, Columbia University, New York, NY
| | - Silvia Pasini
- Department of Pathology, Anatomy and Cell Biology, Columbia University, New York, NY
| | - Maria Elena Pero
- Department of Pathology, Anatomy and Cell Biology, Columbia University, New York, NY.,Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Gregg G Gundersen
- Department of Pathology, Anatomy and Cell Biology, Columbia University, New York, NY
| | - Michael L Shelanski
- Department of Pathology, Anatomy and Cell Biology, Columbia University, New York, NY
| | - Francesca Bartolini
- Department of Pathology, Anatomy and Cell Biology, Columbia University, New York, NY
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172
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Bidirectional interactions between diabetes and Alzheimer's disease. Neurochem Int 2017; 108:296-302. [DOI: 10.1016/j.neuint.2017.04.020] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 04/24/2017] [Accepted: 04/27/2017] [Indexed: 01/21/2023]
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173
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Wu Y, Fortin DA, Cochrane VA, Chen PC, Shyng SL. NMDA receptors mediate leptin signaling and regulate potassium channel trafficking in pancreatic β-cells. J Biol Chem 2017; 292:15512-15524. [PMID: 28768770 DOI: 10.1074/jbc.m117.802249] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 08/01/2017] [Indexed: 12/25/2022] Open
Abstract
NMDA receptors (NMDARs) are Ca2+-permeant, ligand-gated ion channels activated by the excitatory neurotransmitter glutamate and have well-characterized roles in the nervous system. The expression and function of NMDARs in pancreatic β-cells, by contrast, are poorly understood. Here, we report a novel function of NMDARs in β-cells. Using a combination of biochemistry, electrophysiology, and imaging techniques, we now show that NMDARs have a key role in mediating the effect of leptin to modulate β-cell electrical activity by promoting AMP-activated protein kinase (AMPK)-dependent trafficking of KATP and Kv2.1 channels to the plasma membrane. Blocking NMDAR activity inhibited the ability of leptin to activate AMPK, induce KATP and Kv2.1 channel trafficking, and promote membrane hyperpolarization. Conversely, activation of NMDARs mimicked the effect of leptin, causing Ca2+ influx, AMPK activation, and increased trafficking of KATP and Kv2.1 channels to the plasma membrane, and triggered membrane hyperpolarization. Moreover, leptin potentiated NMDAR currents and triggered NMDAR-dependent Ca2+ influx. Importantly, NMDAR-mediated signaling was observed in rat insulinoma 832/13 cells and in human β-cells, indicating that this pathway is conserved across species. The ability of NMDARs to regulate potassium channel surface expression and thus, β-cell excitability provides mechanistic insight into the recently reported insulinotropic effects of NMDAR antagonists and therefore highlights the therapeutic potential of these drugs in managing type 2 diabetes.
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Affiliation(s)
- Yi Wu
- From the Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239 and
| | - Dale A Fortin
- From the Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239 and
| | - Veronica A Cochrane
- From the Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239 and
| | - Pei-Chun Chen
- the Department of Physiology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Show-Ling Shyng
- From the Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239 and
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174
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Carlomagno Y, Chung DEC, Yue M, Castanedes-Casey M, Madden BJ, Dunmore J, Tong J, DeTure M, Dickson DW, Petrucelli L, Cook C. An acetylation-phosphorylation switch that regulates tau aggregation propensity and function. J Biol Chem 2017; 292:15277-15286. [PMID: 28760828 PMCID: PMC5602388 DOI: 10.1074/jbc.m117.794602] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/26/2017] [Indexed: 12/26/2022] Open
Abstract
The aberrant accumulation of tau protein is a pathological hallmark of a class of neurodegenerative diseases known as tauopathies, including Alzheimer's disease and related dementias. On the basis of previous observations that tau is a direct substrate of histone deacetylase 6 (HDAC6), we sought to map all HDAC6-responsive sites in tau and determine how acetylation in a site-specific manner affects tau's biophysical properties in vitro. Our findings indicate that several acetylation sites in tau are responsive to HDAC6 and that acetylation on Lys-321 (within a KCGS motif) is both essential for acetylation-mediated inhibition of tau aggregation in vitro and a molecular tactic for preventing phosphorylation on the downstream Ser-324 residue. To determine the functional consequence of this HDAC6-regulated phosphorylation event, we examined tau's ability to promote microtubule assembly and found that phosphorylation of Ser-324 interferes with the normal microtubule-stabilizing function of tau. Tau phosphorylation of Ser-324 (pSer-324) has not previously been evaluated in the context of tauopathy, and here we observed increased deposition of pSer-324–positive tau both in mouse models of tauopathy and in patients with Alzheimer's disease. These findings uncover a novel acetylation–phosphorylation switch at Lys-321/Ser-324 that coordinately regulates tau polymerization and function. Because the disease relevance of this finding is evident, additional studies are needed to examine the role of pSer-324 in tau pathobiology and to determine whether therapeutically modulating this acetylation–phosphorylation switch affects disease progression in vivo.
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Affiliation(s)
- Yari Carlomagno
- From the Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224
| | - Dah-Eun Chloe Chung
- From the Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224.,the Neurobiology of Disease Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida 32224, and
| | - Mei Yue
- From the Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224
| | | | - Benjamin J Madden
- the Medical Genome Facility Proteomics Core, Mayo Clinic, Rochester, Minnesota 55905
| | - Judy Dunmore
- From the Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224
| | - Jimei Tong
- From the Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224
| | - Michael DeTure
- From the Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224
| | - Dennis W Dickson
- From the Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224.,the Neurobiology of Disease Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida 32224, and
| | - Leonard Petrucelli
- From the Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224, .,the Neurobiology of Disease Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida 32224, and
| | - Casey Cook
- From the Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224, .,the Neurobiology of Disease Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida 32224, and
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175
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Wei YP, Ye JW, Wang X, Zhu LP, Hu QH, Wang Q, Ke D, Tian Q, Wang JZ. Tau-Induced Ca 2+/Calmodulin-Dependent Protein Kinase-IV Activation Aggravates Nuclear Tau Hyperphosphorylation. Neurosci Bull 2017. [PMID: 28646348 DOI: 10.1007/s12264-017-0148-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Hyperphosphorylated tau is the major protein component of neurofibrillary tangles in the brains of patients with Alzheimer's disease (AD). However, the mechanism underlying tau hyperphosphorylation is not fully understood. Here, we demonstrated that exogenously expressed wild-type human tau40 was detectable in the phosphorylated form at multiple AD-associated sites in cytoplasmic and nuclear fractions from HEK293 cells. Among these sites, tau phosphorylated at Thr205 and Ser214 was almost exclusively found in the nuclear fraction at the conditions used in the present study. With the intracellular tau accumulation, the Ca2+ concentration was significantly increased in both cytoplasmic and nuclear fractions. Further studies using site-specific mutagenesis and pharmacological treatment demonstrated that phosphorylation of tau at Thr205 increased nuclear Ca2+ concentration with a simultaneous increase in the phosphorylation of Ca2+/calmodulin-dependent protein kinase IV (CaMKIV) at Ser196. On the other hand, phosphorylation of tau at Ser214 did not significantly change the nuclear Ca2+/CaMKIV signaling. Finally, expressing calmodulin-binding protein-4 that disrupts formation of the Ca2+/calmodulin complex abolished the okadaic acid-induced tau hyperphosphorylation in the nuclear fraction. We conclude that the intracellular accumulation of phosphorylated tau, as detected in the brains of AD patients, can trigger nuclear Ca2+/CaMKIV signaling, which in turn aggravates tau hyperphosphorylation. Our findings provide new insights for tauopathies: hyperphosphorylation of intracellular tau and an increased Ca2+ concentration may induce a self-perpetuating harmful loop to promote neurodegeneration.
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Affiliation(s)
- Yu-Ping Wei
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jin-Wang Ye
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xiong Wang
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Li-Ping Zhu
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qing-Hua Hu
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qun Wang
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Dan Ke
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qing Tian
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. .,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Jian-Zhi Wang
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. .,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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176
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Abstract
Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis are neurodegenerative disorders that are characterized by a progressive degeneration of nerve cells eventually leading to dementia. While these diseases affect different neuronal populations and present distinct clinical features, they share in common several features and signaling pathways. In particular, energy metabolism defects, oxidative stress, and excitotoxicity are commonly described and might be correlated with AMP-activated protein kinase (AMPK) deregulation. AMPK is a master energy sensor which was reported to be overactivated in the brain of patients affected by these neurodegenerative disorders. While the exact role played by AMPK in these diseases remains to be clearly established, several studies reported the implication of AMPK in various signaling pathways that are involved in these diseases' progression. In this chapter, we review the current literature regarding the involvement of AMPK in the development of these diseases and discuss the common pathways involved.
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177
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Amar F, Sherman MA, Rush T, Larson M, Boyle G, Chang L, Götz J, Buisson A, Lesné SE. The amyloid-β oligomer Aβ*56 induces specific alterations in neuronal signaling that lead to tau phosphorylation and aggregation. Sci Signal 2017; 10:10/478/eaal2021. [PMID: 28487416 DOI: 10.1126/scisignal.aal2021] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Oligomeric forms of amyloid-forming proteins are believed to be the principal initiating bioactive species in many neurodegenerative disorders, including Alzheimer's disease (AD). Amyloid-β (Aβ) oligomers are implicated in AD-associated phosphorylation and aggregation of the microtubule-associated protein tau. To investigate the specific molecular pathways activated by different assemblies, we isolated various forms of Aβ from Tg2576 mice, which are a model for AD. We found that Aβ*56, a 56-kDa oligomer that is detected before patients develop overt signs of AD, induced specific changes in neuronal signaling. In primary cortical neurons, Aβ*56 interacted with N-methyl-d-aspartate receptors (NMDARs), increased NMDAR-dependent Ca2+ influx, and consequently increased intracellular calcium concentrations and the activation of Ca2+-dependent calmodulin kinase IIα (CaMKIIα). In cultured neurons and in the brains of Tg2576 mice, activated CaMKIIα was associated with increased site-specific phosphorylation and missorting of tau, both of which are associated with AD pathology. In contrast, exposure of cultured primary cortical neurons to other oligomeric Aβ forms (dimers and trimers) did not trigger these effects. Our results indicate that distinct Aβ assemblies activate neuronal signaling pathways in a selective manner and that dissecting the molecular events caused by each oligomer may inform more effective therapeutic strategies.
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Affiliation(s)
- Fatou Amar
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA.,N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55414, USA.,Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
| | - Mathew A Sherman
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA.,N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55414, USA.,Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
| | - Travis Rush
- INSERM, U1216, Université Grenoble Alpes, Grenoble Institut des Neurosciences, BP 170, Grenoble Cedex 9, F-38042, France
| | - Megan Larson
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA.,N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55414, USA.,Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
| | - Gabriel Boyle
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA.,N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55414, USA.,Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
| | - Liu Chang
- Sydney Medical School, Brain and Mind Research Institute, University of Sydney, Camperdown, Sydney, New South Wales 2050, Australia
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Alain Buisson
- INSERM, U1216, Université Grenoble Alpes, Grenoble Institut des Neurosciences, BP 170, Grenoble Cedex 9, F-38042, France
| | - Sylvain E Lesné
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA. .,N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55414, USA.,Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
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178
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Forner S, Baglietto-Vargas D, Martini AC, Trujillo-Estrada L, LaFerla FM. Synaptic Impairment in Alzheimer's Disease: A Dysregulated Symphony. Trends Neurosci 2017; 40:347-357. [PMID: 28494972 DOI: 10.1016/j.tins.2017.04.002] [Citation(s) in RCA: 286] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/13/2017] [Accepted: 04/14/2017] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease (AD) is characterized by memory loss, cognitive decline, and devastating neurodegeneration, not only as a result of the extracellular accumulation of beta-amyloid peptide (Aβ) and intracellular accumulation of tau, but also as a consequence of the dysfunction and loss of synapses. Although significant advances have been made in our understanding of the relationship of the pathological role of Aβ and tau in synapse dysfunction, several questions remain as to how Aβ and tau interdependently cause impairments in synaptic function in AD. Overall, more insight into these questions should enable researchers in this field to develop novel therapeutic targets to mitigate or delay the cognitive deficits associated with this devastating disease.
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Affiliation(s)
- Stefania Forner
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - David Baglietto-Vargas
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Alessandra C Martini
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Laura Trujillo-Estrada
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Frank M LaFerla
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, USA.
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179
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Liu YJ, Tsai PY, Chern Y. Energy Homeostasis and Abnormal RNA Metabolism in Amyotrophic Lateral Sclerosis. Front Cell Neurosci 2017; 11:126. [PMID: 28522961 PMCID: PMC5415567 DOI: 10.3389/fncel.2017.00126] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/18/2017] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease that is clinically characterized by progressive muscle weakness and impaired voluntary movement due to the loss of motor neurons in the brain, brain stem and spinal cord. To date, no effective treatment is available. Ample evidence suggests that impaired RNA homeostasis and abnormal energy status are two major pathogenesis pathways in ALS. In the present review article, we focus on recent studies that report molecular insights of both pathways, and discuss the possibility that energy dysfunction might negatively regulate RNA homeostasis via the impairment of cytoplasmic-nuclear shuttling in motor neurons and subsequently contribute to the development of ALS.
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Affiliation(s)
- Yu-Ju Liu
- Division of Neuroscience, Institute of Biomedical Sciences, Academia SinicaTaipei, Taiwan
| | - Po-Yi Tsai
- Division of Neuroscience, Institute of Biomedical Sciences, Academia SinicaTaipei, Taiwan
| | - Yijuang Chern
- Division of Neuroscience, Institute of Biomedical Sciences, Academia SinicaTaipei, Taiwan
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180
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Nafar F, Clarke J, Mearow K. Coconut oil protects cortical neurons from amyloid beta toxicity by enhancing signaling of cell survival pathways. Neurochem Int 2017; 105:64-79. [DOI: 10.1016/j.neuint.2017.01.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 12/27/2016] [Accepted: 01/20/2017] [Indexed: 12/27/2022]
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181
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Guo T, Noble W, Hanger DP. Roles of tau protein in health and disease. Acta Neuropathol 2017; 133:665-704. [PMID: 28386764 PMCID: PMC5390006 DOI: 10.1007/s00401-017-1707-9] [Citation(s) in RCA: 565] [Impact Index Per Article: 80.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/26/2017] [Accepted: 03/26/2017] [Indexed: 01/18/2023]
Abstract
Tau is well established as a microtubule-associated protein in neurons. However, under pathological conditions, aberrant assembly of tau into insoluble aggregates is accompanied by synaptic dysfunction and neural cell death in a range of neurodegenerative disorders, collectively referred to as tauopathies. Recent advances in our understanding of the multiple functions and different locations of tau inside and outside neurons have revealed novel insights into its importance in a diverse range of molecular pathways including cell signalling, synaptic plasticity, and regulation of genomic stability. The present review describes the physiological and pathophysiological properties of tau and how these relate to its distribution and functions in neurons. We highlight the post-translational modifications of tau, which are pivotal in defining and modulating tau localisation and its roles in health and disease. We include discussion of other pathologically relevant changes in tau, including mutation and aggregation, and how these aspects impinge on the propensity of tau to propagate, and potentially drive neuronal loss, in diseased brain. Finally, we describe the cascade of pathological events that may be driven by tau dysfunction, including impaired axonal transport, alterations in synapse and mitochondrial function, activation of the unfolded protein response and defective protein degradation. It is important to fully understand the range of neuronal functions attributed to tau, since this will provide vital information on its involvement in the development and pathogenesis of disease. Such knowledge will enable determination of which critical molecular pathways should be targeted by potential therapeutic agents developed for the treatment of tauopathies.
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Affiliation(s)
- Tong Guo
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 9NU, UK
| | - Wendy Noble
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 9NU, UK
| | - Diane P Hanger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 9NU, UK.
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182
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Li J, Zhong L, Wang F, Zhu H. Dissecting the role of AMP-activated protein kinase in human diseases. Acta Pharm Sin B 2017; 7:249-259. [PMID: 28540163 PMCID: PMC5430814 DOI: 10.1016/j.apsb.2016.12.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/12/2016] [Accepted: 11/17/2016] [Indexed: 12/18/2022] Open
Abstract
AMP-activated protein kinase (AMPK), known as a sensor and a master of cellular energy balance, integrates various regulatory signals including anabolic and catabolic metabolic processes. Accompanying the application of genetic methods and a plethora of AMPK agonists, rapid progress has identified AMPK as an attractive therapeutic target for several human diseases, such as cancer, type 2 diabetes, atherosclerosis, myocardial ischemia/reperfusion injury and neurodegenerative disease. The role of AMPK in metabolic and energetic modulation both at the intracellular and whole body levels has been reviewed elsewhere. In the present review, we summarize and update the paradoxical role of AMPK implicated in the diseases mentioned above and put forward the challenge encountered. Thus it will be expected to provide important clues for exploring rational methods of intervention in human diseases.
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Affiliation(s)
- Jin Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China
| | - Liping Zhong
- Life Science College of Tarim University, Xinjiang 843300, China
| | - Fengzhong Wang
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China
- Corresponding author. Tel./fax: +86 10 62810295.
| | - Haibo Zhu
- State Key Laboratory for Bioactive Substances and Functions of Natural Medicines, Beijing 100050, China
- Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Beijing 100050, China
- Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- Corresponding author at: Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China. Tel./fax: +86 10 63188106.
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183
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Gao XJ, Yuan K, Cao L, Yan W, Luo YX, Jian M, Liu JF, Fang Q, Wang JS, Han Y, Shi J, Lu L. AMPK signaling in the nucleus accumbens core mediates cue-induced reinstatement of cocaine seeking. Sci Rep 2017; 7:1038. [PMID: 28432301 PMCID: PMC5430902 DOI: 10.1038/s41598-017-01043-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 03/22/2017] [Indexed: 12/21/2022] Open
Abstract
Relapse to drug seeking can be caused by exposure to drug-associated cues, provoking drug craving even after prolonged abstinence. Recent studies demonstrated that AMP-activated protein kinase (AMPK) regulates neuronal morphology and membrane excitability in neurons. Here, we investigated the role of AMPK activity in the nucleus accumbens (NAc) in relapse to cocaine seeking. We found that exposure to drug-related cues reinstated cocaine-seeking behavior and increased AMPK and p70s6k phosphorylation in the NAc core but not shell. Augmenting AMPK activity by intra-NAc core infusions of the AMPK activator 5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide (AICAR) or adenovirus expressing constitutively active subunits of AMPK decreased cue-induced reinstatement of cocaine seeking and inhibited the mammalian target of rapamycin complex 1 (mTORC1) and extracellular signal-regulated kinase 1/2 (ERK1/2) pathways. In contrast, inhibition of AMPK activity by intra-NAc core infusions of the AMPK inhibitor compound C or adenovirus expressing dominant-negative subunits of AMPK increased cue-induced reinstatement of cocaine seeking and enhanced mTORC1 and ERK1/2 activity. The regulation of AMPK activity in the NAc shell had no effect on cue-induced cocaine seeking. Altogether, these results indicate that AMPK activity in the NAc core is critical for the cue-induced reinstatement of cocaine seeking, which may be mediated by mTORC1 and ERK1/2 signaling.
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Affiliation(s)
- Xue-Jiao Gao
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China.,Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.,Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Kai Yuan
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China.,Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
| | - Lu Cao
- Affiliated Hospital and School of Pharmacy of Guizhou Medical University, Guiyang, China
| | - Wei Yan
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China.,Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Yi-Xiao Luo
- Department of Pharmacy, Medical College, Hunan Normal University, Changsha, China
| | - Min Jian
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China
| | - Jian-Feng Liu
- Department of Pharmacology and Toxicology, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Qin Fang
- Affiliated Hospital and School of Pharmacy of Guizhou Medical University, Guiyang, China
| | - Ji-Shi Wang
- Affiliated Hospital and School of Pharmacy of Guizhou Medical University, Guiyang, China
| | - Ying Han
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China. .,Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.
| | - Jie Shi
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China.
| | - Lin Lu
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China. .,Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China. .,Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, China.
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184
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Tau Spread, Apolipoprotein E, Inflammation, and More: Rapidly Evolving Basic Science in Alzheimer Disease. Neurol Clin 2017; 35:175-190. [PMID: 28410655 DOI: 10.1016/j.ncl.2017.01.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
To date, Alzheimer disease drug candidates have produced negative results in human trials, and progress in moving new targets out of the laboratory and into trials has been slow. However, based on 3 decades of previous work, there is reason to hope that amyloid-based and other novel therapies will move at a faster pace toward successful clinical trials. This article highlights selected preclinical research topics that are rapidly advancing in the laboratory.
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185
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Ding X, Liu S, Tian M, Zhang W, Zhu T, Li D, Wu J, Deng H, Jia Y, Xie W, Xie H, Guan JS. Activity-induced histone modifications govern Neurexin-1 mRNA splicing and memory preservation. Nat Neurosci 2017; 20:690-699. [PMID: 28346453 DOI: 10.1038/nn.4536] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 02/26/2017] [Indexed: 12/12/2022]
Abstract
Epigenetic mechanisms regulate the formation, consolidation and reconsolidation of memories. However, the signaling path from neuronal activation to epigenetic modifications within the memory-related brain circuit remains unknown. We report that learning induces long-lasting histone modifications in hippocampal memory-activated neurons to regulate memory stability. Neuronal activity triggers a late-onset shift in Nrxn1 splice isoform choice at splicing site 4 by accumulating a repressive histone marker, H3K9me3, to modulate the splicing process. Activity-dependent phosphorylation of p66α via AMP-activated protein kinase recruits HDAC2 and Suv39h1 to establish repressive histone markers and changes the connectivity of the activated neurons. Removal of Suv39h1 abolished the activity-dependent shift in Nrxn1 splice isoform choice and reduced the stability of established memories. We uncover a cell-autonomous process for memory preservation in which memory-related neurons initiate a late-onset reduction of their rewiring capacities through activity-induced histone modifications.
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Affiliation(s)
- Xinlu Ding
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research at Tsinghua University, Beijing, China.,Centre for Brain Inspired Computing Research, Tsinghua University, Beijing, China
| | - Sanxiong Liu
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research at Tsinghua University, Beijing, China.,Centre for Brain Inspired Computing Research, Tsinghua University, Beijing, China
| | - Miaomiao Tian
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research at Tsinghua University, Beijing, China.,Centre for Brain Inspired Computing Research, Tsinghua University, Beijing, China
| | - Wenhao Zhang
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Tao Zhu
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research at Tsinghua University, Beijing, China.,Centre for Brain Inspired Computing Research, Tsinghua University, Beijing, China
| | - Dongdong Li
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research at Tsinghua University, Beijing, China.,Centre for Brain Inspired Computing Research, Tsinghua University, Beijing, China
| | - Jiawei Wu
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - HaiTeng Deng
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yichang Jia
- School of Medicine, Tsinghua University, Beijing, China
| | - Wei Xie
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Hong Xie
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research at Tsinghua University, Beijing, China.,Centre for Brain Inspired Computing Research, Tsinghua University, Beijing, China.,School of Medicine, Tsinghua University, Beijing, China
| | - Ji-Song Guan
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research at Tsinghua University, Beijing, China.,Centre for Brain Inspired Computing Research, Tsinghua University, Beijing, China
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186
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Millan MJ. Linking deregulation of non-coding RNA to the core pathophysiology of Alzheimer's disease: An integrative review. Prog Neurobiol 2017; 156:1-68. [PMID: 28322921 DOI: 10.1016/j.pneurobio.2017.03.004] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 03/09/2017] [Accepted: 03/09/2017] [Indexed: 02/06/2023]
Abstract
The human genome encodes a vast repertoire of protein non-coding RNAs (ncRNA), some specific to the brain. MicroRNAs, which interfere with the translation of target mRNAs, are of particular interest since their deregulation has been implicated in neurodegenerative disorders like Alzheimer's disease (AD). However, it remains challenging to link the complex body of observations on miRNAs and AD into a coherent framework. Using extensive graphical support, this article discusses how a diverse panoply of miRNAs convergently and divergently impact (and are impacted by) core pathophysiological processes underlying AD: neuroinflammation and oxidative stress; aberrant generation of β-amyloid-42 (Aβ42); anomalies in the production, cleavage and post-translational marking of Tau; impaired clearance of Aβ42 and Tau; perturbation of axonal organisation; disruption of synaptic plasticity; endoplasmic reticulum stress and the unfolded protein response; mitochondrial dysfunction; aberrant induction of cell cycle re-entry; and apoptotic loss of neurons. Intriguingly, some classes of miRNA provoke these cellular anomalies, whereas others act in a counter-regulatory, protective mode. Moreover, changes in levels of certain species of miRNA are a consequence of the above-mentioned anomalies. In addition to miRNAs, circular RNAs, piRNAs, long non-coding RNAs and other types of ncRNA are being increasingly implicated in AD. Overall, a complex mesh of deregulated and multi-tasking ncRNAs reciprocally interacts with core pathophysiological mechanisms underlying AD. Alterations in ncRNAs can be detected in CSF and the circulation as well as the brain and are showing promise as biomarkers, with the ultimate goal clinical exploitation as targets for novel modes of symptomatic and course-altering therapy.
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Affiliation(s)
- Mark J Millan
- Centre for Therapeutic Innovation in Neuropsychiatry, institut de recherche Servier, 125 chemin de ronde, 78290 Croissy sur Seine, France.
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187
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Seixas da Silva GS, Melo HM, Lourenco MV, Lyra E Silva NM, de Carvalho MB, Alves-Leon SV, de Souza JM, Klein WL, da-Silva WS, Ferreira ST, De Felice FG. Amyloid-β oligomers transiently inhibit AMP-activated kinase and cause metabolic defects in hippocampal neurons. J Biol Chem 2017; 292:7395-7406. [PMID: 28302722 DOI: 10.1074/jbc.m116.753525] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 03/15/2017] [Indexed: 11/06/2022] Open
Abstract
AMP-activated kinase (AMPK) is a key player in energy sensing and metabolic reprogramming under cellular energy restriction. Several studies have linked impaired AMPK function to peripheral metabolic diseases such as diabetes. However, the impact of neurological disorders, such as Alzheimer disease (AD), on AMPK function and downstream effects of altered AMPK activity on neuronal metabolism have been investigated only recently. Here, we report the impact of Aβ oligomers (AβOs), synaptotoxins that accumulate in AD brains, on neuronal AMPK activity. Short-term exposure of cultured rat hippocampal neurons or ex vivo human cortical slices to AβOs transiently decreased intracellular ATP levels and AMPK activity, as evaluated by its phosphorylation at threonine residue 172 (AMPK-Thr(P)172). The AβO-dependent reduction in AMPK-Thr(P)172 levels was mediated by glutamate receptors of the N-methyl-d-aspartate (NMDA) subtype and resulted in removal of glucose transporters (GLUTs) from the surfaces of dendritic processes in hippocampal neurons. Importantly, insulin prevented the AβO-induced inhibition of AMPK. Our results establish a novel toxic impact of AβOs on neuronal metabolism and suggest that AβO-induced, NMDA receptor-mediated AMPK inhibition may play a key role in early brain metabolic defects in AD.
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Affiliation(s)
| | - Helen M Melo
- From the Institute of Medical Biochemistry Leopoldo de Meis and
| | - Mychael V Lourenco
- From the Institute of Medical Biochemistry Leopoldo de Meis and.,the Institute of Biophysics Carlos Chagas Filho
| | | | | | | | - Jorge M de Souza
- Neurosurgery, Clementino Fraga Filho Hospital, Federal University of Rio De Janeiro, Rio de Janeiro 21941-902, Brazil
| | - William L Klein
- the Department of Neurobiology, Northwestern University, Evanston, Illinois 60208-3520, and
| | | | - Sergio T Ferreira
- From the Institute of Medical Biochemistry Leopoldo de Meis and.,the Institute of Biophysics Carlos Chagas Filho
| | - Fernanda G De Felice
- From the Institute of Medical Biochemistry Leopoldo de Meis and .,the Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
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188
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St-Cyr Giguère F, Attiori Essis S, Chagniel L, Germain M, Cyr M, Massicotte G. The sphingosine-1-phosphate receptor 1 agonist SEW2871 reduces Tau-Ser262 phosphorylation in rat hippocampal slices. Brain Res 2017; 1658:51-59. [DOI: 10.1016/j.brainres.2017.01.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/10/2017] [Accepted: 01/12/2017] [Indexed: 12/13/2022]
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189
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Alzheimer's Disease: Insights from Genetic Mouse Models and Current Advances in Human IPSC-Derived Neurons. ADVANCES IN NEUROBIOLOGY 2017; 15:3-29. [PMID: 28674976 DOI: 10.1007/978-3-319-57193-5_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Alzheimer's disease was first described in 1906 and since then tremendous efforts have been made to fully understand the disease pathology and to find a cure for this neurodegenerative disease. The diagnosis of Alzheimer's is still difficult, especially in early stages of the disease. Current treatment of Alzheimer's only ameliorates the symptoms but fails to provide a therapy. Over the last decades, animal models have been proven valuable in elucidating insights of the pathology. In vitro models using patient-derived cells are currently emerging and hold great promise in understanding the disease pathophysiology. Here, we introduce the neurobiology and genetic features of Alzheimer's and describe what we have learned from studies employing mouse models and patient-derived induced pluripotent stem cells.
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Majd S, Power JHT, Koblar SA, Grantham HJM. The impact of tau hyperphosphorylation at Ser 262 on memory and learning after global brain ischaemia in a rat model of reversible cardiac arrest. IBRO Rep 2016; 2:1-13. [PMID: 30135928 PMCID: PMC6084925 DOI: 10.1016/j.ibror.2016.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 12/12/2016] [Accepted: 12/21/2016] [Indexed: 01/12/2023] Open
Abstract
An increase in phosphorylated tau (p-tau) is associated with Alzheimer's disease (AD), and brain hypoxia. Investigation of the association of residue-specific tau hyperphosphorylation and changes in cognition, leads to greater understanding of its potential role in the pathology of memory impairment. The aims of this study are to investigate the involvement of the main metabolic kinases, Liver Kinase B1 (LKB1) and Adenosine Monophosphate Kinase Protein Kinase (AMPK), in tau phosphorylation-derived memory impairment, and to study the potential contribution of the other tau kinases and phosphatases including Glycogen Synthase Kinase (GSK-3β), Protein kinase A (PKA) and Protein Phosphatase 2A (PP2A). Spatial memory and learning were tested in a rat global brain ischemic model of reversible cardiac arrest (CA). The phosphorylation levels of LKB1, AMPK, GSK-3β, PP2A, PKA and tau-specific phosphorylation were assessed in rats, subjected to ischaemia/reperfusion and in clinically diagnosed AD and normal human brains. LKB1 and AMPK phosphorylation increased 4 weeks after CA as did AMPK related p-tau (Ser262). The animals showed unchanged levels of GSK-3β specific p-tau (Ser202/Thr205), phospho-PP2A (Tyr307), total GSK-3β, PP2A, phospho-cAMP response element-binding protein (CREB) which is an indicator of PKA activity, and no memory deficits. AD brains had hyperphosphorylated tau in all the residues of Ser262, Ser202 and Thr205, with increased phosphorylation of both AMPK (Thr172) and GSK-3β (Ser9), and reduced PP2A levels. Our data suggests a crucial role for a combined activation of tau kinases and phosphatases in adversely affecting memory and that hyperphosphorylation of tau in more than one specific site may be required to create memory deficits. Short-term brain ischaemia causes AMPK activation and tau phosphorylation at its AMPK-sensitive site (Ser262). Activation of GSK-3β, PP2A and PKA are remained unchanged in short-term brain ischaemia/reperfusion. In clinical cases of AD, activation of AMPK, GSK-3β, PP2A and multiple site hyperphosphorylation of tau are observed. Hyperphosphorylation of tau (Ser262) alone without involving the other tau kinases/phosphatase does not affect memory.
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Affiliation(s)
- Shohreh Majd
- Neuronal Injury and Repair Laboratory, Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, Australia
| | - John H T Power
- Department of Human Physiology, School of Medicine, Flinders University, Adelaide, Australia
| | - Simon A Koblar
- School of Medicine, The Queen Elizabeth Hospital (TQEH) Campus, University of Adelaide, Australia
| | - Hugh J M Grantham
- Neuronal Injury and Repair Laboratory, Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, Australia
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191
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Narne P, Pandey V, Simhadri PK, Phanithi PB. Poly(ADP-ribose)polymerase-1 hyperactivation in neurodegenerative diseases: The death knell tolls for neurons. Semin Cell Dev Biol 2016; 63:154-166. [PMID: 27867042 DOI: 10.1016/j.semcdb.2016.11.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/31/2016] [Accepted: 11/15/2016] [Indexed: 12/21/2022]
Abstract
Neurodegeneration is a salient feature of chronic refractory brain disorders like Alzheimer's, Parkinson's, Huntington's, amyotropic lateral sclerosis and acute conditions like cerebral ischemia/reperfusion etc. The pathological protein aggregates, mitochondrial mutations or ischemic insults typifying these disease conditions collude with and intensify existing oxidative stress and attendant mitochondrial dysfunction. Interlocking these mechanisms is poly(ADP-ribose) polymerase (PARP-1) hyperactivation that invokes a distinct form of neuronal cell death viz., 'parthanatos'. PARP-1, a typical 'moonlighting protein' by virtue of its ability to poly(ADP-ribosyl)ate a plethora of cellular proteins exerts diverse functions that impinge significantly on cellular processes. In addition, its interactions with various nuclear proteins like transcription factors and chromatin modifiers elicit varied transcriptional outcomes that wield pathological cellular responses. Further, emerging leitmotifs like mitochondrial and nucleolar PARPs and the novel aspects of gene expression regulation by PARP-1 and poly(ADP-ribosyl)ation can provide a holistic view of PARP-1's influence on cell vitality. In this review, we discuss the pathological underpinnings of PARP-1, with a special emphasis on mitochondrial dysfunction and cell death subroutines, in the realm of neurodegeneration. This would provide a deeper insight into the functions of PARP-1 in neurodegenerative conditions that would enable the development of more effective therapeutic strategies.
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Affiliation(s)
- Parimala Narne
- Laboratory of Neuroscience, Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Vimal Pandey
- Laboratory of Neuroscience, Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Praveen Kumar Simhadri
- Laboratory of Neuroscience, Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Prakash Babu Phanithi
- Laboratory of Neuroscience, Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
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192
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Kam TI, Park H, Gwon Y, Song S, Kim SH, Moon SW, Jo DG, Jung YK. FcγRIIb-SHIP2 axis links Aβ to tau pathology by disrupting phosphoinositide metabolism in Alzheimer's disease model. eLife 2016; 5. [PMID: 27834631 PMCID: PMC5106215 DOI: 10.7554/elife.18691] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 10/17/2016] [Indexed: 02/02/2023] Open
Abstract
Amyloid-β (Aβ)-containing extracellular plaques and hyperphosphorylated tau-loaded intracellular neurofibrillary tangles are neuropathological hallmarks of Alzheimer's disease (AD). Although Aβ exerts neuropathogenic activity through tau, the mechanistic link between Aβ and tau pathology remains unknown. Here, we showed that the FcγRIIb-SHIP2 axis is critical in Aβ1-42-induced tau pathology. Fcgr2b knockout or antagonistic FcγRIIb antibody inhibited Aβ1-42-induced tau hyperphosphorylation and rescued memory impairments in AD mouse models. FcγRIIb phosphorylation at Tyr273 was found in AD brains, in neuronal cells exposed to Aβ1-42, and recruited SHIP2 to form a protein complex. Consequently, treatment with Aβ1-42 increased PtdIns(3,4)P2 levels from PtdIns(3,4,5)P3 to mediate tau hyperphosphorylation. Further, we found that targeting SHIP2 expression by lentiviral siRNA in 3xTg-AD mice or pharmacological inhibition of SHIP2 potently rescued tau hyperphosphorylation and memory impairments. Thus, we concluded that the FcγRIIb-SHIP2 axis links Aβ neurotoxicity to tau pathology by dysregulating PtdIns(3,4)P2 metabolism, providing insight into therapeutic potential against AD.
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Affiliation(s)
- Tae-In Kam
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea.,Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Baltimore, United States.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Hyejin Park
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea.,Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Baltimore, United States.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Youngdae Gwon
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Sungmin Song
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Seo-Hyun Kim
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Seo Won Moon
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon, Korea
| | - Yong-Keun Jung
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea
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193
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Jang S, Kim H, Jeong J, Lee SK, Kim EW, Park M, Kim CH, Lee JE, Namkoong K, Kim E. Blunted response of hippocampal AMPK associated with reduced neurogenesis in older versus younger mice. Prog Neuropsychopharmacol Biol Psychiatry 2016; 71:57-65. [PMID: 27343360 DOI: 10.1016/j.pnpbp.2016.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/16/2016] [Accepted: 06/21/2016] [Indexed: 01/17/2023]
Abstract
The rate of hippocampal neurogenesis declines with aging. This is partly explained by decreased neural responsiveness to various cues stimulating metabolism. AMP-activated protein kinase (AMPK), a pivotal enzyme regulating energy homeostasis in response to metabolic demands, showed the diminished sensitivity in peripheral tissues during aging. AMPK is also known to be involved in neurogenesis. We aimed to see whether AMPK reactivity is also blunted in the aged hippocampus, and thus is associated with aging-related change in neurogenesis. Following subchronic (7days) intraperitoneal and acute intracerebroventricular (i.c.v.) administration of either 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR; AMPK activator) or saline (sham) to young (16-week-old) and old (72-week-old) mice, we measured changes in AMPK activity, brain-derived neurotrophic factor (BDNF) expression or neurogenesis in the hippocampus. AICAR-induced changes in AMPK activity were observed in the hippocampus of young mice after acute i.c.v. injection. However, neither subchronic nor acute treatment induced significant changes in AMPK activity in old mice. Intriguingly, directions of AICAR-induced changes in AMPK activity were opposite between the hippocampus (decrease) and skeletal muscle (increase). ATP levels were inversely correlated with hippocampal AMPK activity, suggesting that the higher energy levels achieved by AICAR treatment might deactivate neuronal AMPK in young mice. The blunted response of AMPK to AICAR in old age was also indicated by the observations that the levels of neurogenesis and BDNF expression were significantly changed only in young mice upon AICAR treatment. Our findings suggest that the blunted response of neuronal AMPK in old age might be responsible for aging-associated decline in neurogenesis. Therefore, in addition to activation of AMPK, recovering its sensitivity may be necessary to enhance hippocampal neurogenesis in old age.
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Affiliation(s)
- Sooah Jang
- Department of Psychiatry, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
| | - Hyunjeong Kim
- Department of Psychiatry, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
| | - Jihyeon Jeong
- Department of Psychiatry, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
| | - Su Kyoung Lee
- Department of Psychiatry, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
| | - Eun Woo Kim
- Department of Psychiatry, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
| | - Minsun Park
- Department of Psychiatry, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
| | - Chul Hoon Kim
- Department of Psychiatry, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Department of Pharmacology,Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
| | - Jong Eun Lee
- Department of Anatomy,Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
| | - Kee Namkoong
- Department of Psychiatry, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
| | - Eosu Kim
- Department of Psychiatry, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
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194
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Su KH, Dai C. Metabolic control of the proteotoxic stress response: implications in diabetes mellitus and neurodegenerative disorders. Cell Mol Life Sci 2016; 73:4231-4248. [PMID: 27289378 PMCID: PMC5599143 DOI: 10.1007/s00018-016-2291-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 05/13/2016] [Accepted: 06/07/2016] [Indexed: 12/12/2022]
Abstract
Proteome homeostasis, or proteostasis, is essential to maintain cellular fitness and its disturbance is associated with a broad range of human health conditions and diseases. Cells are constantly challenged by various extrinsic and intrinsic insults, which perturb cellular proteostasis and provoke proteotoxic stress. To counter proteomic perturbations and preserve proteostasis, cells mobilize the proteotoxic stress response (PSR), an evolutionarily conserved transcriptional program mediated by heat shock factor 1 (HSF1). The HSF1-mediated PSR guards the proteome against misfolding and aggregation. In addition to proteotoxic stress, emerging studies reveal that this proteostatic mechanism also responds to cellular energy state. This regulation is mediated by the key cellular metabolic sensor AMP-activated protein kinase (AMPK). In this review, we present an overview of the maintenance of proteostasis by HSF1, the metabolic regulation of the PSR, particularly focusing on AMPK, and their implications in the two major age-related diseases-diabetes mellitus and neurodegenerative disorders.
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Affiliation(s)
- Kuo-Hui Su
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Chengkai Dai
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA.
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195
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CaMKK2 Suppresses Muscle Regeneration through the Inhibition of Myoblast Proliferation and Differentiation. Int J Mol Sci 2016; 17:ijms17101695. [PMID: 27783047 PMCID: PMC5085727 DOI: 10.3390/ijms17101695] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/27/2016] [Accepted: 09/29/2016] [Indexed: 12/15/2022] Open
Abstract
Skeletal muscle has a major role in locomotion and muscle disorders are associated with poor regenerative efficiency. Therefore, a deeper understanding of muscle regeneration is needed to provide a new insight for new therapies. CaMKK2 plays a role in the calcium/calmodulin-dependent kinase cascade; however, its role in skeletal muscle remains unknown. Here, we found that CaMKK2 expression levels were altered under physiological and pathological conditions including postnatal myogensis, freeze or cardiotoxin-induced muscle regeneration, and Duchenne muscular dystrophy. Overexpression of CaMKK2 suppressed C2C12 myoblast proliferation and differentiation, while inhibition of CaMKK2 had opposite effect. We also found that CaMKK2 is able to activate AMPK in C2C12 myocytes. Inhibition of AMPK could attenuate the effect of CaMKK2 overexpression, while AMPK agonist could abrogate the effect of CaMKK2 knockdown on C2C12 cell differentiation and proliferation. These results suggest that CaMKK2 functions as an AMPK kinase in muscle cells and AMPK mediates the effect of CaMKK2 on myoblast proliferation and differentiation. Our data also indicate that CaMKK2 might inhibit myoblast proliferation through AMPK-mediated cell cycle arrest by inducing cdc2-Tyr15 phosphorylation and repress differentiation through affecting PGC1α transcription. Lastly, we show that overexpressing CaMKK2 in the muscle of mice via electroporation impaired the muscle regeneration during freeze-induced injury, indicating that CaMKK2 could serve as a potential target to treat patients with muscle injury or myopathies. Together, our study reveals a new role for CaMKK2 as a negative regulator of myoblast differentiation and proliferation and sheds new light on the molecular regulation of muscle regeneration.
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196
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Reduction of Nuak1 Decreases Tau and Reverses Phenotypes in a Tauopathy Mouse Model. Neuron 2016; 92:407-418. [PMID: 27720485 DOI: 10.1016/j.neuron.2016.09.022] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 08/05/2016] [Accepted: 09/09/2016] [Indexed: 11/22/2022]
Abstract
Many neurodegenerative proteinopathies share a common pathogenic mechanism: the abnormal accumulation of disease-related proteins. As growing evidence indicates that reducing the steady-state levels of disease-causing proteins mitigates neurodegeneration in animal models, we developed a strategy to screen for genes that decrease the levels of tau, whose accumulation contributes to the pathology of both Alzheimer disease (AD) and progressive supranuclear palsy (PSP). Integrating parallel cell-based and Drosophila genetic screens, we discovered that tau levels are regulated by Nuak1, an AMPK-related kinase. Nuak1 stabilizes tau by phosphorylation specifically at Ser356. Inhibition of Nuak1 in fruit flies suppressed neurodegeneration in tau-expressing Drosophila, and Nuak1 haploinsufficiency rescued the phenotypes of a tauopathy mouse model. These results demonstrate that decreasing total tau levels is a valid strategy for mitigating tau-related neurodegeneration and reveal Nuak1 to be a novel therapeutic entry point for tauopathies.
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197
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Athauda D, Foltynie T. Insulin resistance and Parkinson's disease: A new target for disease modification? Prog Neurobiol 2016; 145-146:98-120. [PMID: 27713036 DOI: 10.1016/j.pneurobio.2016.10.001] [Citation(s) in RCA: 202] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 09/28/2016] [Accepted: 10/02/2016] [Indexed: 12/12/2022]
Abstract
There is growing evidence that patients with Type 2 diabetes have an increased risk of developing Parkinson's disease and share similar dysregulated pathways suggesting common underlying pathological mechanisms. Historically insulin was thought solely to be a peripherally acting hormone responsible for glucose homeostasis and energy metabolism. However accumulating evidence indicates insulin can cross the blood-brain-barrier and influence a multitude of processes in the brain including regulating neuronal survival and growth, dopaminergic transmission, maintenance of synapses and pathways involved in cognition. In conjunction, there is growing evidence that a process analogous to peripheral insulin resistance occurs in the brains of Parkinson's disease patients, even in those without diabetes. This raises the possibility that defective insulin signalling pathways may contribute to the development of the pathological features of Parkinson's disease, and thereby suggests that the insulin signalling pathway may potentially be a novel target for disease modification. Given these growing links between PD and Type 2 diabetes it is perhaps not unsurprising that drugs used the treatment of T2DM are amongst the most promising treatments currently being prioritised for repositioning as possible novel treatments for PD and several clinical trials are under way. In this review, we will examine the underlying cellular links between insulin resistance and the pathogenesis of PD and then we will assess current and future pharmacological strategies being developed to restore neuronal insulin signalling as a potential strategy for slowing neurodegeneration in Parkinson's disease.
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Affiliation(s)
- D Athauda
- Sobell Department of Motor Neuroscience, UCL Institute of Neurology & The National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, United Kingdom.
| | - T Foltynie
- Sobell Department of Motor Neuroscience, UCL Institute of Neurology & The National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, United Kingdom.
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198
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Ahmad W, Ebert PR. Metformin Attenuates Aβ Pathology Mediated Through Levamisole Sensitive Nicotinic Acetylcholine Receptors in a C. elegans Model of Alzheimer's Disease. Mol Neurobiol 2016; 54:5427-5439. [PMID: 27596506 DOI: 10.1007/s12035-016-0085-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/24/2016] [Indexed: 12/22/2022]
Abstract
The metabolic disease, type 2 diabetes mellitus (T2DM), is a major risk factor for Alzheimer's disease (AD). This suggests that drugs such as metformin that are used to treat T2DM may also be therapeutic toward AD and indicates an interaction between AD and energy metabolism. In this study, we have investigated the effects of metformin and another T2DM drug, 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) in C. elegans expressing human Aβ42. We found that Aβ expressed in muscle inhibited levamisole sensitive nicotinic acetylcholine receptors and that metformin delayed Aβ-linked paralysis and improved acetylcholine neurotransmission in these animals. Metformin also moderated the effect of neuronal expression of Aβ: decreasing hypersensitivity to serotonin, restoring normal chemotaxis, and improving fecundity. Metformin was unable to overcome the small effect of neuronal Aβ on egg viability. The protective effects of metformin were associated with a decrease in the amount of toxic, oligomeric Aβ. AICAR has a similar protective effect against Aβ toxicity. This work supports the notion that anti-diabetes drugs and metabolic modulators may be effective against AD and that the worm model can be used to identify the specific interactions between Aβ and cellular proteins.
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Affiliation(s)
- Waqar Ahmad
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia
| | - Paul R Ebert
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia.
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199
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Tau phosphorylation at Alzheimer's disease-related Ser356 contributes to tau stabilization when PAR-1/MARK activity is elevated. Biochem Biophys Res Commun 2016; 478:929-34. [PMID: 27520376 DOI: 10.1016/j.bbrc.2016.08.053] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 08/08/2016] [Indexed: 02/08/2023]
Abstract
Abnormal phosphorylation of the microtubule-associated protein tau is observed in many neurodegenerative diseases, including Alzheimer's disease (AD). AD-related phosphorylation of two tau residues, Ser262 and Ser356, by PAR-1/MARK stabilizes tau in the initial phase of mismetabolism, leading to subsequent phosphorylation events, accumulation, and toxicity. However, the relative contribution of phosphorylation at each of these sites to tau stabilization has not yet been elucidated. In a Drosophila model of human tau toxicity, we found that tau was phosphorylated at Ser262, but not at Ser356, and that blocking Ser262 phosphorylation decreased total tau levels. By contrast, when PAR-1 was co-overexpressed with tau, tau was hyperphosphorylated at both Ser262 and Ser356. Under these conditions, the protein levels of tau were significantly elevated, and prevention of tau phosphorylation at both residues was necessary to completely suppress this elevation. These results suggest that tau phosphorylation at Ser262 plays the predominant role in tau stabilization when PAR-1/MARK activity is normal, whereas Ser356 phosphorylation begins to contribute to this process when PAR-1/MARK activity is abnormally elevated, as in diseased brains.
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200
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Thomas MH, Pelleieux S, Vitale N, Olivier JL. Dietary arachidonic acid as a risk factor for age-associated neurodegenerative diseases: Potential mechanisms. Biochimie 2016; 130:168-177. [PMID: 27473185 DOI: 10.1016/j.biochi.2016.07.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 07/24/2016] [Indexed: 11/28/2022]
Abstract
Alzheimer's disease and associated diseases constitute a major public health concern worldwide. Nutrition-based, preventive strategies could possibly be effective in delaying the occurrence of these diseases and lower their prevalence. Arachidonic acid is the second major polyunsaturated fatty acid (PUFA) and several studies support its involvement in Alzheimer's disease. The objective of this review is to examine how dietary arachidonic acid contributes to Alzheimer's disease mechanisms and therefore to its prevention. First, we explore the sources of neuronal arachidonic acid that could potentially originate from either the conversion of linoleic acid, or from dietary sources and transfer across the blood-brain-barrier. In a second part, a brief overview of the role of the two main agents of Alzheimer's disease, tau protein and Aβ peptide is given, followed by the examination of the relationship between arachidonic acid and the disease. Third, the putative mechanisms by which arachidonic acid could influence Alzheimer's disease occurrence and evolution are presented. The conclusion is devoted to what remains to be determined before integrating arachidonic acid in the design of preventive strategies against Alzheimer's disease and other neurodegenerative diseases.
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Affiliation(s)
- Mélanie H Thomas
- Unité de Recherche Aliment et Fonctionnalité des Produits Animaux (URAFPA), INRA USC 0340, Université de Lorraine, Nancy, France
| | - Sandra Pelleieux
- Unité de Recherche Aliment et Fonctionnalité des Produits Animaux (URAFPA), INRA USC 0340, Université de Lorraine, Nancy, France
| | - Nicolas Vitale
- Institut des Neurosciences Cellulaires et Intégratives (INCI), UPR CNRS 3212, Université de Strasbourg, Strasbourg, France
| | - Jean Luc Olivier
- Unité de Recherche Aliment et Fonctionnalité des Produits Animaux (URAFPA), INRA USC 0340, Université de Lorraine, Nancy, France.
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