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Abdelaziz M, Mohamed AF, Zaki HF, Gad SS. Agomelatine improves memory and learning impairments in a rat model of LPS-induced neurotoxicity by modulating the ERK/SorLA/BDNF/TrkB pathway. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:1701-1714. [PMID: 37712973 PMCID: PMC10858839 DOI: 10.1007/s00210-023-02717-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 09/07/2023] [Indexed: 09/16/2023]
Abstract
The mutual interplay between neuroinflammation, synaptic plasticity, and autophagy has piqued researchers' interest, particularly when it comes to linking their impact and relationship to cognitive deficits. Being able to reduce inflammation and apoptosis, melatonin has shown to have positive neuroprotective effects; that is why we thought to check the possible role of agomelatine (AGO) as a promising candidate that could have a positive impact on cognitive deficits. In the current study, AGO (40 mg/kg/day, p.o., 7 days) successfully ameliorated the cognitive and learning disabilities caused by lipopolysaccharide (LPS) in rats (250 μg/kg/day, i.p., 7 days). This positive impact was supported by improved histopathological findings and improved spatial memory as assessed using Morris water maze. AGO showed a strong ability to control BACE1 activity and to rein in the hippocampal amyloid beta (Aβ) deposition. Also, it improved neuronal survival, neuroplasticity, and neurogenesis by boosting BDNF levels and promoting its advantageous effects and by reinforcing the pTrkB expression. In addition, it upregulated the pre- and postsynaptic neuroplasticity biomarkers resembled in synapsin I, synaptophysin, and PSD-95. Furthermore, AGO showed a modulatory action on Sortilin-related receptor with A-type repeats (SorLA) pathway and adjusted autophagy. It is noteworthy that all of these actions were abolished by administering PD98059 a MEK/ERK pathway inhibitor (0.3 mg/kg/day, i.p., 7 days). In conclusion, AGO administration significantly improves memory and learning disabilities associated with LPS administration by modulating the ERK/SorLA/BDNF/TrkB signaling pathway parallel to its capacity to adjust the autophagic process.
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Affiliation(s)
- Mahmoud Abdelaziz
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA University), Giza, Egypt
| | - Ahmed F Mohamed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Kasr El-Aini St, Cairo, 11562, Egypt.
- Faculty of Pharmacy, King Salman International University (KSIU), 46612, Ras Sedr, South Sinai, Egypt.
| | - Hala F Zaki
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Kasr El-Aini St, Cairo, 11562, Egypt
| | - Sameh S Gad
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA University), Giza, Egypt
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2
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Khalifa FN, Hussein RF, Mekawy DM, Elwi HM, Alsaeed SA, Elnawawy Y, Shaheen SH. Potential role of the lncRNA "HOTAIR"/miRNA "206"/BDNF network in the alteration in expression of synaptic plasticity gene arc and BDNF level in sera of patients with heroin use disorder through the PI3K/AKT/mTOR pathway compared to the controls. Mol Biol Rep 2024; 51:293. [PMID: 38334898 PMCID: PMC10858136 DOI: 10.1007/s11033-024-09265-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 01/17/2024] [Indexed: 02/10/2024]
Abstract
INTRODUCTION Heroin use disorder (HUD) is a seriously increasing health issue, accounting for most deaths among drug abusers. Studying non-coding ribonucleic acid gene expression among drug abusers is a promising approach, as it may be used in diagnosis and therapeutics. PARTICIPANTS AND METHODS A total of 49 male heroin-dependent patients and 49 male control participants were recruited from Kasr Al Ainy Psychiatry and Addiction outpatient clinics, Faculty of Medicine, Cairo University. Sera were gathered. qRT-PCR was utilized for the detection of gene expression of non-coding RNAs such as "HOX transcript antisense RNA" (HOTAIR), micro-RNA (miRNA-206), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), mechanistic target of rapamycin (mTOR), and Activity Regulated Cytoskeleton Associated Protein (Arc). Sera Brain-Derived Neurotrophic Factor (BDNF) levels were assessed using ELISA. Using a western blot made it possible to determine the protein expression of PI3K, AKT, and mTOR. RESULTS The study demonstrated that gene expressions of HOTAIR, AKT, PI3K, and Arc were considerably lowered between cases and controls, while gene expressions of miR-206 and mTOR1 were significantly raised. PI3K and AKT protein expressions were downregulated, while mTOR expressions were upregulated. BDNF levels were significantly decreased in some cases. CONCLUSION The results of this study suggest that decreased HOTAIR in HUD relieves miR-206 inhibition, which thus increases and affects downstream PI3K/AKT/mTOR, ARC, and BDNF expression. This may be shared in addictive and relapsing behaviors.
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Affiliation(s)
- Fatma Nada Khalifa
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Cairo University, Kasr Alainy Street, Cairo, 11562, Egypt
| | - Riham F Hussein
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Cairo University, Kasr Alainy Street, Cairo, 11562, Egypt
| | - Dina M Mekawy
- Department of Biochemistry, Faculty of Medicine, Cairo University, Kasr Alainy Street, Cairo, 11562, Egypt
| | - Heba M Elwi
- Department of Biochemistry, Faculty of Medicine, Cairo University, Kasr Alainy Street, Cairo, 11562, Egypt
| | - Shimaa Ahmed Alsaeed
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Cairo University, Kasr Alainy Street, Cairo, 11562, Egypt.
| | - Yassmin Elnawawy
- Department of Psychiatry, Faculty of Medicine, Cairo University, Kasr Alainy Street, Cairo, 11562, Egypt
| | - Somaya H Shaheen
- Department of Psychiatry, Faculty of Medicine, Cairo University, Kasr Alainy Street, Cairo, 11562, Egypt
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3
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Cozachenco D, Ribeiro FC, Ferreira ST. Defective proteostasis in Alzheimer's disease. Ageing Res Rev 2023; 85:101862. [PMID: 36693451 DOI: 10.1016/j.arr.2023.101862] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 01/11/2023] [Accepted: 01/20/2023] [Indexed: 01/22/2023]
Abstract
The homeostasis of cellular proteins, or proteostasis, is critical for neuronal function and for brain processes, including learning and memory. Increasing evidence indicates that defective proteostasis contributes to the progression of neurodegenerative disorders, including Alzheimer's disease (AD), the most prevalent form of dementia in the elderly. Proteostasis comprises a set of cellular mechanisms that control protein synthesis, folding, post-translational modification and degradation, all of which are deregulated in AD. Importantly, deregulation of proteostasis plays a key role in synapse dysfunction and in memory impairment, the major clinical manifestation of AD. Here, we discuss molecular pathways involved in protein synthesis and degradation that are altered in AD, and possible pharmacological approaches to correct these defects.
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Affiliation(s)
- Danielle Cozachenco
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Felipe C Ribeiro
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Sergio T Ferreira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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4
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Gu S, Zhou Z, Zhang S, Cai Y. Advances in Anti-Diabetic Cognitive Dysfunction Effect of Erigeron Breviscapus (Vaniot) Hand-Mazz. Pharmaceuticals (Basel) 2022; 16:ph16010050. [PMID: 36678547 PMCID: PMC9867432 DOI: 10.3390/ph16010050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/22/2022] [Accepted: 12/24/2022] [Indexed: 12/31/2022] Open
Abstract
Diabetic cognitive dysfunction (DCD) is the decline in memory, learning, and executive function caused by diabetes. Although its pathogenesis is unclear, molecular biologists have proposed various hypotheses, including insulin resistance, amyloid β hypothesis, tau protein hyperphosphorylation hypothesis, oxidative stress and neuroinflammation. DCD patients have no particular treatment options and current pharmacological regimens are suboptimal. In recent years, Chinese medicine research has shown that herbs with multi-component, multi-pathway and multi-target synergistic activities can prevent and treat DCD. Yunnan is home to the medicinal herb Erigeron breviscapus (Vant.) Hand-Mazz. (EBHM). Studies have shown that EBHM and its active components have a wide range of pharmacological effects and applications in cognitive disorders. EBHM's anti-DCD properties have been seldom reviewed. Through a literature study, we were able to evaluate the likely pathophysiology of DCD, prescribe anti-DCD medication and better grasp EBHM's therapeutic potential. EBHM's pharmacological mechanism and active components for DCD treatment were also summarized.
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Affiliation(s)
- Shanye Gu
- The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Ziyi Zhou
- The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
- Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China
- Guangdong Provincial Key Laboratory of Research on Emergency in Traditional Chinese Medicine, Guangzhou 510120, China
| | - Shijie Zhang
- The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
- Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China
- Guangdong Provincial Key Laboratory of Research on Emergency in Traditional Chinese Medicine, Guangzhou 510120, China
| | - Yefeng Cai
- The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
- Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China
- Guangdong Provincial Key Laboratory of Research on Emergency in Traditional Chinese Medicine, Guangzhou 510120, China
- Correspondence: ; Tel.: +86-136-3133-3842
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5
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Jayaraman A, Reynolds R. Diverse pathways to neuronal necroptosis in Alzheimer's disease. Eur J Neurosci 2022; 56:5428-5441. [PMID: 35377966 DOI: 10.1111/ejn.15662] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 03/21/2022] [Accepted: 03/29/2022] [Indexed: 12/14/2022]
Abstract
Necroptosis, or programmed necrosis, involves the kinase activity of receptor interacting kinases 1 and 3, the activation of the pseudokinase mixed lineage kinase domain-like and formation of a complex called the necrosome. It is one of the non-apoptotic cell death pathways that has gained interest in the recent years, especially as a neuronal cell death pathway occurring in Alzheimer's disease. In this review, we focus our discussion on the various molecular mechanisms that could trigger neuronal death through necroptosis and have been shown to play a role in Alzheimer's disease pathogenesis and neuroinflammation. We describe how each of these pathways, such as tumour necrosis factor signalling, reactive oxygen species, endosomal sorting complex, post-translational modifications and certain individual molecules, is dysregulated or activated in Alzheimer's disease, and how this dysregulation/activation could trigger necroptosis. At the cellular level, many of these molecular mechanisms and pathways may act in parallel to synergize with each other or inhibit one another, and changes in the balance between them may determine different cellular vulnerabilities at different disease stages. However, from a therapeutic standpoint, it remains unclear how best to target one or more of these pathways, given that such diverse pathways could all contribute to necroptotic cell death in Alzheimer's disease.
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Affiliation(s)
- Anusha Jayaraman
- Centre for Molecular Neuropathology, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Richard Reynolds
- Centre for Molecular Neuropathology, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,Division of Neuroscience, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
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6
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Moreira NCDS, Lima JEBDF, Fiori Marchiori M, Carvalho I, Sakamoto-Hojo ET. Neuroprotective Effects of Cholinesterase Inhibitors: Current Scenario in Therapies for Alzheimer’s Disease and Future Perspectives. J Alzheimers Dis Rep 2022; 6:177-193. [PMID: 35591949 PMCID: PMC9108627 DOI: 10.3233/adr-210061] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 03/16/2022] [Indexed: 12/12/2022] Open
Abstract
Alzheimer’s disease (AD) is a slowly progressive neurodegenerative disease conceptualized as a continuous process, ranging from mild cognitive impairment (MCI), to the mild, moderate, and severe clinical stages of AD dementia. AD is considered a complex multifactorial disease. Currently, the use of cholinesterase inhibitors (ChEI), such as tacrine, donepezil, rivastigmine, and galantamine, has been the main treatment for AD patients. Interestingly, there is evidence that ChEI also promotes neuroprotective effects, bringing some benefits to AD patients. The mechanisms by which the ChEI act have been investigated in AD. ChEI can modulate the PI3K/AKT pathway, which is an important signaling cascade that is capable of causing a significant functional impact on neurons by activating cell survival pathways to promote neuroprotective effects. However, there is still a huge challenge in the field of neuroprotection, but in the context of unravelling the details of the PI3K/AKT pathway, a new scenario has emerged for the development of more efficient drugs that act on multiple protein targets. Thus, the mechanisms by which ChEI can promote neuroprotective effects and prospects for the development of new drug candidates for the treatment of AD are discussed in this review.
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Affiliation(s)
| | | | - Marcelo Fiori Marchiori
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Ivone Carvalho
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Elza Tiemi Sakamoto-Hojo
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
- Department of Biology, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
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7
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Querfurth H, Marshall J, Parang K, Rioult-Pedotti MS, Tiwari R, Kwon B, Reisinger S, Lee HK. A PDK-1 allosteric agonist neutralizes insulin signaling derangements and beta-amyloid toxicity in neuronal cells and in vitro. PLoS One 2022; 17:e0261696. [PMID: 35061720 PMCID: PMC8782417 DOI: 10.1371/journal.pone.0261696] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 12/08/2021] [Indexed: 01/09/2023] Open
Abstract
The Alzheimer's brain is affected by multiple pathophysiological processes, which include a unique, organ-specific form of insulin resistance that begins early in its course. An additional complexity arises from the four-fold risk of Alzheimer's Disease (AD) in type 2 diabetics, however there is no definitive proof of causation. Several strategies to improve brain insulin signaling have been proposed and some have been clinically tested. We report findings on a small allosteric molecule that reverses several indices of insulin insensitivity in both cell culture and in vitro models of AD that emphasize the intracellular accumulation of β-amyloid (Aβi). PS48, a chlorophenyl pentenoic acid, is an allosteric activator of PDK-1, which is an Akt-kinase in the insulin/PI3K pathway. PS48 was active at 10 nM to 1 μM in restoring normal insulin-dependent Akt activation and in mitigating Aβi peptide toxicity. Synaptic plasticity (LTP) in prefrontal cortical slices from normal rat exposed to Aβ oligomers also benefited from PS48. During these experiments, neither overstimulation of PI3K/Akt signaling nor toxic effects on cells was observed. Another neurotoxicity model producing insulin insensitivity, utilizing palmitic acid, also responded to PS48 treatment, thus validating the target and indicating that its therapeutic potential may extend outside of β-amyloid reliance. The described in vitro and cell based-in vitro coupled enzymatic assay systems proved suitable platforms to screen a preliminary library of new analogs.
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Affiliation(s)
- Henry Querfurth
- Department of Neurology, Tufts Medical Center, Boston, MA, United States of America
| | - John Marshall
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States of America
| | - Keykavous Parang
- Center for Targeted Drug Delivery, Chapman University, School of Pharmacology, Irvine, CA United States of America
| | - Mengia S. Rioult-Pedotti
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States of America
- Department of Neurology, Clinical Neurorehabilitation, University of Zurich, Zurich, Switzerland
| | - Rakesh Tiwari
- Center for Targeted Drug Delivery, Chapman University, School of Pharmacology, Irvine, CA United States of America
| | - Bumsup Kwon
- Department of Neurology, Rhode Island Hospital, Providence, RI, United States of America
| | | | - Han-Kyu Lee
- Department of Neurology, Tufts Medical Center, Boston, MA, United States of America
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8
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Implications of Phosphoinositide 3-Kinase-Akt (PI3K-Akt) Pathway in the Pathogenesis of Alzheimer's Disease. Mol Neurobiol 2021; 59:354-385. [PMID: 34699027 DOI: 10.1007/s12035-021-02611-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/19/2021] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD) is the foremost type of dementia that afflicts considerable morbidity and mortality in aged population. Several transcription molecules, pathways, and molecular mechanisms such as oxidative stress, inflammation, autophagy, and immune system interact in a multifaceted way that disrupt physiological processes (cell growth, differentiation, survival, lipid and energy metabolism, endocytosis) leading to apoptosis, tauopathy, β-amyloidopathy, neuron, and synapse loss, which play an important role in AD pathophysiology. Despite of stupendous advancements in pathogenic mechanisms, treatment of AD is still a nightmare in the field of medicine. There is compelling urgency to find not only symptomatic but effective disease-modifying therapies. Recently, phosphoinositide 3-kinase (PI3K) and Akt are identified as a pathway triggered by diverse stimuli, including insulin, growth factors, cytokines, and cellular stress, that link amyloid-β, neurofibrillary tangles, and brain atrophy. The present review aims to explore and analyze the role of PI3K-Akt pathway in AD and agents which may modulate Akt and have therapeutic prospects in AD. The literature was researched using keywords "PI3K-Akt" and "Alzheimer's disease" from PubMed, Web of Science, Bentham, Science Direct, Springer Nature, Scopus, and Google Scholar databases including books. Articles published from 1992 to 2021 were prioritized and analyzed for their strengths and limitations, and most appropriate ones were selected for the purpose of review. PI3K-Akt pathway regulates various biological processes such as cell proliferation, motility, growth, survival, and metabolic functions, and inhibits many neurotoxic mechanisms. Furthermore, experimental data indicate that PI3K-Akt signaling might be an important therapeutic target in treatment of AD.
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9
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Querfurth H, Lee HK. Mammalian/mechanistic target of rapamycin (mTOR) complexes in neurodegeneration. Mol Neurodegener 2021; 16:44. [PMID: 34215308 PMCID: PMC8252260 DOI: 10.1186/s13024-021-00428-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Novel targets to arrest neurodegeneration in several dementing conditions involving misfolded protein accumulations may be found in the diverse signaling pathways of the Mammalian/mechanistic target of rapamycin (mTOR). As a nutrient sensor, mTOR has important homeostatic functions to regulate energy metabolism and support neuronal growth and plasticity. However, in Alzheimer's disease (AD), mTOR alternately plays important pathogenic roles by inhibiting both insulin signaling and autophagic removal of β-amyloid (Aβ) and phospho-tau (ptau) aggregates. It also plays a role in the cerebrovascular dysfunction of AD. mTOR is a serine/threonine kinase residing at the core in either of two multiprotein complexes termed mTORC1 and mTORC2. Recent data suggest that their balanced actions also have implications for Parkinson's disease (PD) and Huntington's disease (HD), Frontotemporal dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS). Beyond rapamycin; an mTOR inhibitor, there are rapalogs having greater tolerability and micro delivery modes, that hold promise in arresting these age dependent conditions.
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Affiliation(s)
- Henry Querfurth
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA.
| | - Han-Kyu Lee
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA
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10
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Zhang T, Ding H, Wang Y, Yuan Z, Zhang Y, Chen G, Xu Y, Chen L. Akt3-mTOR regulates hippocampal neurogenesis in adult mouse. J Neurochem 2021; 159:498-511. [PMID: 34077553 DOI: 10.1111/jnc.15441] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 04/16/2021] [Accepted: 05/26/2021] [Indexed: 01/19/2023]
Abstract
Akt signaling has been associated with adult neurogenesis in the hippocampal dentate gyrus (DG). We reported cognitive dysfunction in Akt3 knockout (Akt3-KO) mice with the down-regulation of mTOR activation. However, little is known about the effects of Akt3 signaling on hippocampal neurogenesis. Herein, we show that progenitor cells, neuroblasts, and mature newborn neurons in hippocampal DG expressed Akt3 protein. The Akt3 phosphorylation in hippocampal DG was increased after voluntary wheel running for 7 days in wild-type mice (running WT mice), but not in Akt3-KO mice (running Akt3-KO mice). Subsequently, we observed that the proliferation of progenitor cells was suppressed in Akt3-KO mice and the mTOR inhibitor rapamycin-treated mice, whereas enhanced in running WT mice rather than running Akt3-KO mice. Neurite growth of neuroblasts was impaired in Akt3-KO mice and rapamycin-treated mice. In contrast, neither differentiation of progenitor cells nor migrating of newly generated neurons was altered in Akt3-KO mice or running WT mice. The levels of p70S6K and 4EBP1 phosphorylation were declined in Akt3-KO mice and elevated in running WT mice depending on mTOR activation. Furthermore, telomerase activity, telomere length, and expression of telomerase reverse transcriptase (TERT) were decreased in Akt3-KO mice but increased in running WT mice rather than running Akt3-KO mice, which required the mTOR activation. The study provides in vivo evidence that Akt3-mTOR signaling plays an important role in the proliferation of progenitor cells and neurite growth through positive regulated TERT expression and activation of p70S6K and 4EBP1.
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Affiliation(s)
- Tingting Zhang
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Hong Ding
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China.,The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Ya Wang
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Zihao Yuan
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Yajie Zhang
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Guiquan Chen
- State Key Laboratory of Pharmaceutical Biotechnology, MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Yun Xu
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Ling Chen
- Department of Physiology, Nanjing Medical University, Nanjing, China
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11
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Dorandish S, Williams A, Atali S, Sendo S, Price D, Thompson C, Guthrie J, Heyl D, Evans HG. Regulation of amyloid-β levels by matrix metalloproteinase-2/9 (MMP2/9) in the media of lung cancer cells. Sci Rep 2021; 11:9708. [PMID: 33958632 PMCID: PMC8102533 DOI: 10.1038/s41598-021-88574-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 04/14/2021] [Indexed: 02/06/2023] Open
Abstract
In this study, we set out to identify regulators of intact amyloid-β40/42 (Aβ) levels in A549 (p53 wild-type) and H1299 (p53-null) lung cancer cell media. Higher Aβ levels were detected in the media of A549 than H1299 cells without or with treatment with 4-methylumbelliferone (4-MU) and/or the anti-CD44 antibody (5F12). Using inhibitors, we found that PI3K, AKT, and NFκB are likely involved in regulating Aβ levels in the media. However, increased Aβ levels that more closely resembled those found upon 4-MU co-treatment resulted from MMP2/9 inhibition, suggesting that MMP2/9 maybe the main contributors to regulation of Aβ levels in the media. Differences in Aβ levels might be accounted for, in part, by p53 since blocking p53 function in A549 cells resulted in decreased Aβ levels, increased MMP2/9 levels, increased PI3K/AKT activities and the phospho/total NFκB ratio. Using siRNA targeted against MMP2 or MMP9, we found increased Aβ levels in the media, however, MMP2 knockdown led to Aβ levels closely mimicking those detected by co-treatment with 4-MU. Cell viability or apoptosis upon treatment with either MMP2 or MMP9 siRNA along with Aβ immunodepletion, showed that MMP2 is the predominant regulator of the cytotoxic effects induced by Aβ in lung cancer cells.
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Affiliation(s)
- Sadaf Dorandish
- Chemistry Department, Eastern Michigan University, Ypsilanti, MI, 48197, USA
| | - Asana Williams
- Chemistry Department, Eastern Michigan University, Ypsilanti, MI, 48197, USA
| | - Sarah Atali
- Chemistry Department, Eastern Michigan University, Ypsilanti, MI, 48197, USA
| | - Sophia Sendo
- Chemistry Department, Eastern Michigan University, Ypsilanti, MI, 48197, USA
| | - Deanna Price
- Chemistry Department, Eastern Michigan University, Ypsilanti, MI, 48197, USA
| | - Colton Thompson
- Chemistry Department, Eastern Michigan University, Ypsilanti, MI, 48197, USA
| | - Jeffrey Guthrie
- Chemistry Department, Eastern Michigan University, Ypsilanti, MI, 48197, USA
| | - Deborah Heyl
- Chemistry Department, Eastern Michigan University, Ypsilanti, MI, 48197, USA
| | - Hedeel Guy Evans
- Chemistry Department, Eastern Michigan University, Ypsilanti, MI, 48197, USA.
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12
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Huang SH, Fang ST, Chen YC. Molecular Mechanism of Vitamin K2 Protection against Amyloid-β-Induced Cytotoxicity. Biomolecules 2021; 11:423. [PMID: 33805625 PMCID: PMC8000266 DOI: 10.3390/biom11030423] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/05/2021] [Accepted: 03/11/2021] [Indexed: 12/12/2022] Open
Abstract
The pathological role of vitamin K2 in Alzheimer's disease (AD) involves a definite link between impaired cognitive functions and decreased serum vitamin K levels. Vitamin K2 supplementation may have a protective effect on AD. However, the mechanism underlying vitamin K2 protection has not been elucidated. With the amyloid-β (Aβ) cascade hypothesis, we constructed a clone containing the C-terminal fragment of amyloid precursor protein (β-CTF/APP), transfected in astroglioma C6 cells and used this cell model (β-CTF/C6) to study the protective effect of vitamin K2 against Aβ cytotoxicity. Both cellular and biochemical assays, including cell viability and reactive oxygen species (ROS), assays assay, and Western blot and caspase activity analyses, were used to characterize and unveil the protective role and mechanism of vitamin K2 protecting against Aβ-induced cytotoxicity. Vitamin K2 treatment dose-dependently decreased the death of neural cells. The protective effect of vitamin K2 could be abolished by adding warfarin, a vitamin K2 antagonist. The addition of vitamin K2 reduced the ROS formation and inhibited the caspase-3 mediated apoptosis induced by Aβ peptides, indicating that the mechanism underlying the vitamin K2 protection is likely against Aβ-mediated apoptosis. Inhibitor assay and Western blot analyses revealed that the possible mechanism of vitamin K2 protection against Aβ-mediated apoptosis might be via regulating phosphatidylinositol 3-kinase (PI3K) associated-signaling pathway and inhibiting caspase-3-mediated apoptosis. Our study demonstrates that vitamin K2 can protect neural cells against Aβ toxicity.
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Affiliation(s)
| | | | - Yi-Cheng Chen
- Department of Medicine, MacKay Medical College, New Taipei City 252, Taiwan; (S.-H.H.); (S.-T.F.)
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13
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Desale SE, Chinnathambi S. Phosphoinositides signaling modulates microglial actin remodeling and phagocytosis in Alzheimer's disease. Cell Commun Signal 2021; 19:28. [PMID: 33627135 PMCID: PMC7905611 DOI: 10.1186/s12964-021-00715-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/26/2021] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease is one of the neurodegenerative diseases, characterized by the accumulation of abnormal protein deposits, which disrupts signal transduction in neurons and other glia cells. The pathological protein in neurodegenerative diseases, Tau and amyloid-β contribute to the disrupted microglial signaling pathways, actin cytoskeleton, and cellular receptor expression. The important secondary messenger lipids i.e., phosphatidylinositols are largely affected by protein deposits of amyloid-β in Alzheimer's disease. Phosphatidylinositols are the product of different phosphatidylinositol kinases and the state of phosphorylation at D3, D4, and D5 positions of inositol ring. Phosphatidylinositol 3,4,5-triphosphate (PI 3, 4, 5-P3) involves in phagocytic cup formation, cell polarization, whereas Phosphatidylinositol 4,5-bisphosphate (PI 4, 5-P2)-mediates the process of phagosomes formation and further its fusion with early endosome.. The necessary activation of actin-binding proteins such as Rac, WAVE complex, and ARP2/3 complex for the actin polymerization in the process of phagocytosis, migration is regulated and maintained by PI 3, 4, 5-P3 and PI 4, 5-P2. The ratio and types of fatty acid intake can influence the intracellular secondary lipid messengers along with the cellular content of phaphatidylcholine and phosphatidylethanolamine. The Amyloid-β deposits and extracellular Tau seeds disrupt phosphatidylinositides level and actin cytoskeletal network that hamper microglial-signaling pathways in AD. We hypothesize that being a lipid species intracellular levels of phosphatidylinositol would be regulated by dietary fatty acids. Further we are interested to understand phosphoinositide-based signaling cascades in phagocytosis and actin remodeling. Video Abstract.
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Affiliation(s)
- Smita Eknath Desale
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Subashchandrabose Chinnathambi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008, India.
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14
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Engin AB, Engin A. Alzheimer's Disease and Protein Kinases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1275:285-321. [PMID: 33539020 DOI: 10.1007/978-3-030-49844-3_11] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder and accounts for more than 60-80% of all cases of dementia. Loss of pyramidal neurons, extracellular amyloid beta (Abeta) accumulated senile plaques, and neurofibrillary tangles that contain hyperphosphorylated tau constitute the main pathological alterations in AD.Synaptic dysfunction and extrasynaptic N-methyl-D-aspartate receptor (NMDAR) hyperactivation contributes to excitotoxicity in patients with AD. Amyloid precursor protein (APP) and Abeta promoted neurodegeneration develop through the activation of protein kinase signaling cascade in AD. Furthermore, ultimate neuronal death in AD is under control of protein kinases-related signaling pathways. In this chapter, critical check-points within the cross-talk between neuron and protein kinases have been defined regarding the initiation and progression of AD. In this context, amyloid cascade hypothesis, neuroinflammation, oxidative stress, granulovacuolar degeneration, loss of Wnt signaling, Abeta-related synaptic alterations, prolonged calcium ions overload and NMDAR-related synaptotoxicity, damage signals hypothesis and type-3 diabetes are discussed briefly.In addition to clinical perspective of AD pathology, recommendations that might be effective in the treatment of AD patients have been reviewed.
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Affiliation(s)
- Ayse Basak Engin
- Department of Toxicology, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
| | - Atilla Engin
- Department of General Surgery, Faculty of Medicine, Gazi University, Ankara, Turkey
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15
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Wang C, Hao J, Liu X, Li C, Yuan X, Lee RJ, Bai T, Wang D. Isoforsythiaside Attenuates Alzheimer's Disease via Regulating Mitochondrial Function Through the PI3K/AKT Pathway. Int J Mol Sci 2020; 21:E5687. [PMID: 32784451 PMCID: PMC7460834 DOI: 10.3390/ijms21165687] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/01/2020] [Accepted: 08/06/2020] [Indexed: 12/28/2022] Open
Abstract
Improving mitochondrial dysfunction and inhibiting apoptosis has always been regarded as a treatment strategy for Alzheimer's disease (AD). Isoforsythiaside (IFY), a phenylethanoid glycoside isolated from the dried fruit of Forsythia suspensa, displays antioxidant activity. This study examined the neuroprotective effects of IFY and its underlying mechanisms. In the L-glutamate (L-Glu)-induced apoptosis of HT22 cells, IFY increased cell viability, inhibited mitochondrial apoptosis, and reduced the intracellular levels of reactive oxygen species (ROS), caspase-3, -8 and -9 after 3 h of pretreatment and 12-24 h of co-incubation. In the APPswe/PSEN1dE9 transgenic (APP/PS1) model, IFY reduced the anxiety of mice, improved their memory and cognitive ability, reduced the deposition of beta amyloid (Aβ) plaques in the brain, restrained the phosphorylation of the tau protein to form neurofibrillary tangles, inhibited the level of 4-hydroxynonenal in the brain, and improved phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway-related mitochondrial apoptosis. In Aβ1-42-induced U251 cells, IFY relieved the mitochondrial swelling, crest ruptures and increased their electron density after 3 h of pretreatment and 18-24 h of co-incubation. The improved cell viability and mitochondrial function after IFY incubation was blocked by the synthetic PI3K inhibitor LY294002. Taken together, these results suggest that IFY exerts a protective effect against AD by enhancing the expression levels of anti-apoptosis proteins and reducing the expression levels of pro-apoptosis proteins of B-cell lymphoma-2 (BCL-2) family members though activating the PI3K/AKT pathway.
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Affiliation(s)
- Chunyue Wang
- School of Life Sciences, Jilin University, Changchun 130012, China; (C.W.); (J.H.); (X.L.); (C.L.); (X.Y.)
| | - Jie Hao
- School of Life Sciences, Jilin University, Changchun 130012, China; (C.W.); (J.H.); (X.L.); (C.L.); (X.Y.)
| | - Xin Liu
- School of Life Sciences, Jilin University, Changchun 130012, China; (C.W.); (J.H.); (X.L.); (C.L.); (X.Y.)
| | - Chenliang Li
- School of Life Sciences, Jilin University, Changchun 130012, China; (C.W.); (J.H.); (X.L.); (C.L.); (X.Y.)
| | - Xuyang Yuan
- School of Life Sciences, Jilin University, Changchun 130012, China; (C.W.); (J.H.); (X.L.); (C.L.); (X.Y.)
| | - Robert J. Lee
- Division of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA;
| | - Tian Bai
- College of Computer Science and Technology, Jilin University, Changchun 130012, China
| | - Di Wang
- School of Life Sciences, Jilin University, Changchun 130012, China; (C.W.); (J.H.); (X.L.); (C.L.); (X.Y.)
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16
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A Curcumin Analog Exhibits Multiple Biologic Effects on the Pathogenesis of Alzheimer's Disease and Improves Behavior, Inflammation, and β-Amyloid Accumulation in a Mouse Model. Int J Mol Sci 2020; 21:ijms21155459. [PMID: 32751716 PMCID: PMC7432838 DOI: 10.3390/ijms21155459] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/06/2020] [Accepted: 07/28/2020] [Indexed: 12/19/2022] Open
Abstract
Drugs for the treatment of Alzheimer’s disease (AD) are in urgent demand due to the unmet need and the social burden associated with the disease. Curcumin has been historically considered as a beneficial product for anti-aging and AD. However, many efforts to develop curcumin for clinical use are hindered mainly due to its poor bioavailability. Recent development in drug delivery and structural design has resolved these issues. In this study, we identified a small molecule, TML-6, as a potential drug candidate for AD through screening a panel of curcumin derivatives using six biomarker platforms related to aging biology and AD pathogenesis. The structural modification of TML-6 is designed to improve the stability and metabolism of curcumin. Cell biological studies demonstrated that TML-6 could inhibit the synthesis of the β-amyloid precursor protein and β-amyloid (Aβ), upregulate Apo E, suppress NF-κB and mTOR, and increase the activity of the anti-oxidative Nrf2 gene. In the 3x-Tg AD animal model, TML-6 treatment resulted in significant improvement in learning, suppression of the microglial activation marker Iba-1, and reduction in Aβ in the brain. Although TML-6 exhibited a greater improvement in bioavailability as compared to curcumin, formulation optimization and toxicological studies are under development to assure its druggability. Taken together, TML-6 meets the current strategy to develop therapeutics for AD, targeting the combination of the Aβ cascade and aging-related biology processes.
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17
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Saha P, Sarkar S, Paidi RK, Biswas SC. TIMP-1: A key cytokine released from activated astrocytes protects neurons and ameliorates cognitive behaviours in a rodent model of Alzheimer's disease. Brain Behav Immun 2020; 87:804-819. [PMID: 32194232 DOI: 10.1016/j.bbi.2020.03.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 02/29/2020] [Accepted: 03/15/2020] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by two pathologic species, extracellular amyloid-β (Aβ) plaques and intracellular neurofibrillary tangles. Astrocytes that maintain normal homeostasis in the brain undergo a set of molecular, cellular and functional changes called reactive astrogliosis in various neurological diseases including AD. It is hypothesized that reactive astrocytes initially tend to protect neurons by reducing Aβ load and by secreting a plethora of cytokines, however, their functions have only been poorly investigated. Our studies on the kinetics of activation of cortical astrocytes following Aβ-exposure revealed significant level of activation as early as in 6 h. The astrocyte conditioned medium (ACM) from 6 h Aβ-treated astrocytes (Aβ-ACM) provided significant neuroprotection of cultured cortical neurons against Aβ insults. Analysis of the secreted proteins in Aβ-ACM revealed a marked increase of Tissue inhibitor of Metalloproteinase-1 (TIMP-1) within 6 h. Interestingly, we found that neutralization of TIMP-1 with antibody or knockdown with siRNA in astrocytes abolished most of the neuroprotective ability of the 6 h Aβ-ACM on Aβ-treated cultured neurons. Furthermore addition of exogenous rat recombinant TIMP-1 protein protects primary neurons from Aβ mediated toxicity. In a well characterized Aβ-infused rodent model of AD, intra-cerebroventricular administration of TIMP-1 revealed a reduction in Aβ load and apoptosis in hippocampal and cortical regions. Finally, we found that TIMP-1 can ameliorate Aβ-induced cognitive dysfunctions through restoration of Akt and its downstream pathway and maintenance of synaptic integrity. Thus, our results not only provide a functional clarity for TIMP-1, secreted by activated astrocytes, but also support it as a major candidate in cytokine-mediated therapy of AD especially at the early phase of disease progression.
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Affiliation(s)
- Pampa Saha
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Sukanya Sarkar
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Ramesh Kumar Paidi
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Subhas C Biswas
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India.
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18
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Park HJ, Kwon H, Lee JH, Cho E, Lee YC, Moon M, Jun M, Kim DH, Jung JW. β-Amyrin Ameliorates Alzheimer's Disease-Like Aberrant Synaptic Plasticity in the Mouse Hippocampus. Biomol Ther (Seoul) 2020; 28:74-82. [PMID: 31357749 PMCID: PMC6939697 DOI: 10.4062/biomolther.2019.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/13/2019] [Accepted: 06/17/2019] [Indexed: 01/26/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive and most frequently diagnosed neurodegenerative disorder. However, there is still no drug preventing the progress of this disorder. β-Amyrin, an ingredient of the surface wax of tomato fruit and dandelion coffee, is previously reported to ameliorate memory impairment induced by cholinergic dysfunction. Therefore, we tested whether β-amyrin can prevent AD-like pathology. β-Amyrin blocked amyloid β (Aβ)-induced long-term potentiation (LTP) impairment in the hippocampal slices. Moreover, β-amyrin improved Aβ-induced suppression of phosphatidylinositol-3-kinase (PI3K)/Akt signaling. LY294002, a PI3K inhibitor, blocked the effect of β-amyrin on Aβ-induced LTP impairment. In in vivo experiments, we observed that β-amyrin ameliorated object recognition memory deficit in Aβ-injected AD mice model. Moreover, neurogenesis impairments induced by Aβ was improved by β-amyrin treatment. Taken together, β-amyrin might be a good candidate of treatment or supplement for AD patients.
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Affiliation(s)
- Hye Jin Park
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan 49315, Republic of Korea
| | - Huiyoung Kwon
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan 49315, Republic of Korea
| | - Ji Hye Lee
- Division of Endocrinology, School of Medicine, Kyungpook National University, Daegu 41944, Republic of Korea
| | - Eunbi Cho
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan 49315, Republic of Korea
| | - Young Choon Lee
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan 49315, Republic of Korea.,Institute of Convergence Bio-Health, Dong-A University, Busan 49315, Republic of Korea
| | - Minho Moon
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon 35365, Republic of Korea
| | - Mira Jun
- Institute of Convergence Bio-Health, Dong-A University, Busan 49315, Republic of Korea.,Department of Food Science and Nutrition, College of Health Sciences, Dong-A University, Busan 49315, Republic of Korea
| | - Dong Hyun Kim
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan 49315, Republic of Korea.,Institute of Convergence Bio-Health, Dong-A University, Busan 49315, Republic of Korea
| | - Ji Wook Jung
- Department of Herbal Medicinal Pharmacology, College of Herbal Bio-industry, Daegu Haany University, Kyungsan 38610, Republic of Korea
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19
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Xie YC, Yao ZH, Yao XL, Pan JZ, Zhang SF, Zhang Y, Hu JC. Glucagon-Like Peptide-2 Receptor is Involved in Spatial Cognitive Dysfunction in Rats After Chronic Cerebral Hypoperfusion. J Alzheimers Dis 2019; 66:1559-1576. [PMID: 30452417 DOI: 10.3233/jad-180782] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Chronic cerebral hypoperfusion (CCH) affects the aging population and especially patients with neurodegenerative diseases, such as Alzheimer's disease or Parkinson's disease. CCH is closely related to the cognitive dysfunction in these diseases. Glucagon-like peptide-2 receptor (GLP2R) mRNA and protein are highly expressed in the gut and in hippocampal neurons. This receptor is involved in the regulation of food intake and the control of energy balance and glucose homeostasis. The present study employed behavioral techniques, electrophysiology, western blotting, immunohistochemistry, quantitative real time polymerase chain reaction (qRT-PCR), and Golgi staining to investigate whether the expression of GLP2R changes after CCH and whether GLP2R is involved in cognitive impairment caused by CCH. Our findings show that CCH significantly decreased hippocampal GLP2R mRNA and protein levels. GLP2R upregulation could prevent CCH-induced cognitive impairment. It also improved the CCH-induced impairment of long-term potentiation and long-term depression. Additionally, GLP2R modulated after CCH the AKT-mTOR-p70S6K pathway in the hippocampus. Moreover, an upregulation of the GLP2R increased the neurogenesis in the dentate gyrus, neuronal activity, and density of dendritic spines and mushroom spines in hippocampal neurons. Our findings reveal the involvement of GLP2R via a modulation of the AKT-mTOR-p70S6K pathway in the mechanisms underlying CCH-induced impairments of spatial learning and memory. We suggest that the GLP2R and the AKT-mTOR-p70S6K pathway in the hippocampus are promising targets to treat cognition deficits in CCH.
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Affiliation(s)
- Yan-Chun Xie
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhao-Hui Yao
- Department of Geriatrics, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xiao-Li Yao
- Department of Neurology, Central Hospital of Zhengzhou, Zhengzhou, China
| | - Jian-Zhen Pan
- Department of Geriatrics, Renmin Hospital of Wuhan University, Wuhan, China
| | - Shao-Feng Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yong Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Ji-Chang Hu
- Department of Pathology, Renmin Hospital of Wuhan University, Wuhan, China
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20
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Bexarotene therapy ameliorates behavioral deficits and induces functional and molecular changes in very-old Triple Transgenic Mice model of Alzheimer´s disease. PLoS One 2019; 14:e0223578. [PMID: 31596896 PMCID: PMC6785083 DOI: 10.1371/journal.pone.0223578] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 09/24/2019] [Indexed: 12/11/2022] Open
Abstract
Introduction Bexarotene, a retinoid X receptor agonist, improves cognition in murine models of Alzheimer’s disease (AD). This study evaluated the effects of bexarotene on pathological and electrophysiological changes in very old triple transgenic AD mice (3xTg-AD mice). Methods 24-month-old 3xTg-AD mice were treated with bexarotene (100 mg/kg/day for 30 days). The Morris water maze was used to evaluate spatial memory; immunofluorescence and confocal microscopy were used to evaluate pathological changes; and in vivo electrophysiological recordings were used to evaluate basal transmission and plasticity in the commissural CA3-CA1 pathway. Results In addition to cognitive improvement, bexarotene-treated 3xTg-AD mice were found to have 1) reductions of astrogliosis and reactive microglia both in cortex and hippocampus; 2) increased ApoE expression restricted to CA1; 3) increased number of cells co-labeled with ApoE and NeuN; 4) recovery of NeuN expression, suggesting neuronal protection; and, 5) recovery of basal synaptic transmission and synaptic plasticity. Discussion These results indicate that bexarotene-induced improvement in cognition is due to multiple changes that contribute to recovery of synaptic plasticity.
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21
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Chen T, Chen S, Wang D, Hung H. High‐fat diet reduces novelty‐induced expression of activity‐regulated cytoskeleton‐associated protein. J Cell Physiol 2019; 235:1065-1075. [DOI: 10.1002/jcp.29021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 06/06/2019] [Indexed: 01/08/2023]
Affiliation(s)
- Tsan‐Ju Chen
- Department of Physiology, School of Medicine, College of Medicine Kaohsiung Medical University Kaohsiung Taiwan
| | - Shun‐Sheng Chen
- Department of Neurology, Chang Gung Memorial Hospital‐Kaohsiung Medical Center, College of Medicine Chang Gung University Kaohsiung Taiwan
| | - Dean‐Chuan Wang
- Department of Sports Medicine, College of Medicine Kaohsiung Medical University Kaohsiung Taiwan
| | - Hui‐Shan Hung
- Department of Physiology, School of Medicine, College of Medicine Kaohsiung Medical University Kaohsiung Taiwan
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22
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Kucheryavykh LY, Ortiz-Rivera J, Kucheryavykh YV, Zayas-Santiago A, Diaz-Garcia A, Inyushin MY. Accumulation of Innate Amyloid Beta Peptide in Glioblastoma Tumors. Int J Mol Sci 2019; 20:ijms20102482. [PMID: 31137462 PMCID: PMC6567111 DOI: 10.3390/ijms20102482] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 04/23/2019] [Accepted: 05/15/2019] [Indexed: 12/12/2022] Open
Abstract
Immunostaining with specific antibodies has shown that innate amyloid beta (Aβ) is accumulated naturally in glioma tumors and nearby blood vessels in a mouse model of glioma. In immunofluorescence images, Aβ peptide coincides with glioma cells, and enzyme-linked immunosorbent assay (ELISA) have shown that Aβ peptide is enriched in the membrane protein fraction of tumor cells. ELISAs have also confirmed that the Aβ(1–40) peptide is enriched in glioma tumor areas relative to healthy brain areas. Thioflavin staining revealed that at least some amyloid is present in glioma tumors in aggregated forms. We may suggest that the presence of aggregated amyloid in glioma tumors together with the presence of Aβ immunofluorescence coinciding with glioma cells and the nearby vasculature imply that the source of Aβ peptides in glioma can be systemic Aβ from blood vessels, but this question remains unresolved and needs additional studies.
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Affiliation(s)
- Lilia Y Kucheryavykh
- Department of Biochemistry, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
| | - Jescelica Ortiz-Rivera
- Department of Biochemistry, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
| | - Yuriy V Kucheryavykh
- Department of Biochemistry, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
| | - Astrid Zayas-Santiago
- Department of Physiology, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
| | - Amanda Diaz-Garcia
- Department of Physiology, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
| | - Mikhail Y Inyushin
- Department of Physiology, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
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23
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Kou X, Chen D, Chen N. Physical Activity Alleviates Cognitive Dysfunction of Alzheimer's Disease through Regulating the mTOR Signaling Pathway. Int J Mol Sci 2019; 20:ijms20071591. [PMID: 30934958 PMCID: PMC6479697 DOI: 10.3390/ijms20071591] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 03/27/2019] [Accepted: 03/27/2019] [Indexed: 02/08/2023] Open
Abstract
Alzheimer's disease (AD) is one of the most common aging-related progressive neurodegenerative disorders, and can result in great suffering for a large portion of the aged population. Although the pathogenesis of AD is being elucidated, the exact mechanisms are still unclear, thereby impeding the development of effective drugs, supplements, and other interventional strategies for AD. In recent years, impaired autophagy associated with microRNA (miRNA) dysfunction has been reported to be involved in aging and aging-related neurodegenerative diseases. Therefore, miRNA-mediated regulation for the functional status of autophagy may become one of the potent interventional strategies for AD. Mounting evidence from in vivo AD models has demonstrated that physical activity can exert a neuroprotective role in AD. In addition, autophagy is strictly regulated by the mTOR signaling pathway. In this article, the regulation of the functional status of autophagy through the mTOR signaling pathway during physical activity is systematically discussed for the prevention and treatment of AD. This concept will be beneficial to developing novel and effective targets that can create a direct link between pharmacological intervention and AD in the future.
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Affiliation(s)
- Xianjuan Kou
- Tianjiu Research and Development Center for Exercise Nutrition and Foods, Hubei Key Laboratory of Exercise Training and Monitoring, College of Health Science, Wuhan Sports University, Wuhan 430079, China.
| | - Dandan Chen
- Graduate School, Wuhan Sports University, Wuhan 430079, China.
| | - Ning Chen
- Tianjiu Research and Development Center for Exercise Nutrition and Foods, Hubei Key Laboratory of Exercise Training and Monitoring, College of Health Science, Wuhan Sports University, Wuhan 430079, China.
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24
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Majd S, Power J, Majd Z. Alzheimer's Disease and Cancer: When Two Monsters Cannot Be Together. Front Neurosci 2019; 13:155. [PMID: 30881282 PMCID: PMC6407038 DOI: 10.3389/fnins.2019.00155] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 02/11/2019] [Indexed: 12/29/2022] Open
Abstract
Alzheimer's disease (AD) and cancer are among the leading causes of human death around the world. While neurodegeneration is the main feature of AD, the most important characteristic of malignant tumors is cell proliferation, placing these two diseases in opposite sides of cell division spectrum. Interestingly, AD and cancer's pathologies consist of a remarkable common feature and that is the presence of active cell cycle in both conditions. In an in vitro model of primary adult neuronal culture, we previously showed that treating cell with beta amyloid forced neurons to start a cell cycle. Instead of cell division, however, neuronal cell cycle was aborted and a massive neurodegeneration was left behind as the consequence. A high level of cell cycle entry, which is a requirement for cancer pathogenesis, was reported in clinically diagnosed cases of AD, leading to neurodegeneration. The diverse clinical manifestation of a similar etiology, have puzzled researchers for many years. In fact, the evidence showed an inverse association between AD and cancer prevalence, suggesting that switching pathogenesis toward AD protects patients against cancer and vice versa. In this mini review, we discussed the possibility of involvement of cell proliferation and survival dysregulation as the underlying mechanism of neurodegeneration in AD, and the leading event to develop both disorders' pathology. As examples, the role of phosphoinositide 3 kinase/Akt/ mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway in cell cycle re-entry and blocking autophagy are discussed as potential common intracellular components between AD and cancer pathogenesis, with diverse clinical diagnosis.
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Affiliation(s)
- Shohreh Majd
- Neuronal Injury and Repair Laboratory, Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, SA, Australia
| | - John Power
- Neuronal Injury and Repair Laboratory, Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, SA, Australia
| | - Zohreh Majd
- Psychosomatische Tagesklinik, Passau, Germany
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25
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Wang ZT, Lu MH, Zhang Y, Ji WL, Lei L, Wang W, Fang LP, Wang LW, Yu F, Wang J, Li ZY, Wang JR, Wang TH, Dou F, Wang QW, Wang XL, Li S, Ma QH, Xu RX. Disrupted-in-schizophrenia-1 protects synaptic plasticity in a transgenic mouse model of Alzheimer's disease as a mitophagy receptor. Aging Cell 2019; 18:e12860. [PMID: 30488644 PMCID: PMC6351828 DOI: 10.1111/acel.12860] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 08/09/2018] [Accepted: 09/06/2018] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial dysfunction is an early feature of Alzheimer's disease (AD). Accumulated damaged mitochondria, which are associated with impaired mitophagy, contribute to neurodegeneration in AD. We show levels of Disrupted‐in‐schizophrenia‐1 (DISC1), which is genetically associated with psychiatric disorders and AD, decrease in the brains of AD patients and transgenic model mice and in Aβ‐treated cultured cells. Disrupted‐in‐schizophrenia‐1 contains a canonical LC3‐interacting region (LIR) motif (210FSFI213), through which DISC1 directly binds to LC3‐I/II. Overexpression of DISC1 enhances mitophagy through its binding to LC3, whereas knocking‐down of DISC1 blocks Aβ‐induced mitophagy. We further observe overexpression of DISC1, but not its mutant (muFSFI) which abolishes the interaction of DISC1 with LC3, rescues Aβ‐induced mitochondrial dysfunction, loss of spines, suppressed long‐term potentiation (LTP). Overexpression of DISC1 via adeno‐associated virus (serotype 8, AAV8) in the hippocampus of 8‐month‐old APP/PS1 transgenic mice for 4 months rescues cognitive deficits, synaptic loss, and Aβ plaque accumulation, in a way dependent on the interaction of DISC1 with LC3. These results indicate that DISC1 is a novel mitophagy receptor, which protects synaptic plasticity from Aβ accumulation‐induced toxicity through promoting mitophagy.
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Affiliation(s)
- Zhao-Tao Wang
- Department of Neurosurgery; Affiliated Bayi Brain Hospital, General Army Hospital; Southern Medical University; Beijing China
| | - Mei-Hong Lu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience; Soochow University; Suzhou China
| | - Yan Zhang
- Department of Neurosurgery; Affiliated Bayi Brain Hospital, General Army Hospital; Southern Medical University; Beijing China
| | - Wen-Li Ji
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience; Soochow University; Suzhou China
| | - Lei Lei
- Department of Physiology, Liaoning Provincial Key Laboratory of Cerebral Diseases; Dalian Medical University; Dalian China
| | - Wang Wang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience; Soochow University; Suzhou China
| | - Li-Pao Fang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience; Soochow University; Suzhou China
| | - Lu-Wen Wang
- Department of Pathology; Case Western Reserve University; Cleveland Ohio
| | - Fan Yu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience; Soochow University; Suzhou China
| | - Ji Wang
- Department of Neurosurgery; Affiliated Bayi Brain Hospital, General Army Hospital; Southern Medical University; Beijing China
| | - Zhen-Yu Li
- Department of Neurosurgery; Affiliated Bayi Brain Hospital, General Army Hospital; Southern Medical University; Beijing China
| | - Jian-Rong Wang
- Hematology Center of Cyrus Tang Medical Institute, Collaborative Innovation Center of Hematology, Key Laboratory of Stem Cells and Biomedical; Materials of Jiangsu Province and Chinese Ministry of Science and Technology, State Key Laboratory of Radiation Medicine and Radioprotection; Soochow University School of Medicine; Suzhou China
| | - Ting-Hua Wang
- Institute of Neuroscience; Kunming Medical University; Kunming China
| | - Fei Dou
- College of Life Sciences; Beijing Normal University; Beijing China
| | - Qin-Wen Wang
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine; Ningbo University; Ningbo China
| | - Xing-Long Wang
- Department of Pathology; Case Western Reserve University; Cleveland Ohio
| | - Shao Li
- Department of Physiology, Liaoning Provincial Key Laboratory of Cerebral Diseases; Dalian Medical University; Dalian China
| | - Quan-Hong Ma
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience; Soochow University; Suzhou China
| | - Ru-Xiang Xu
- Department of Neurosurgery; Affiliated Bayi Brain Hospital, General Army Hospital; Southern Medical University; Beijing China
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26
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Dehghani R, Rahmani F, Rezaei N. MicroRNA in Alzheimer's disease revisited: implications for major neuropathological mechanisms. Rev Neurosci 2018; 29:161-182. [PMID: 28941357 DOI: 10.1515/revneuro-2017-0042] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 07/09/2017] [Indexed: 12/28/2022]
Abstract
Pathology of Alzheimer's disease (AD) goes far beyond neurotoxicity resulting from extracellular deposition of amyloid β (Aβ) plaques. Aberrant cleavage of amyloid precursor protein and accumulation of Aβ in the form of the plaque or neurofibrillary tangles are the known primary culprits of AD pathogenesis and target for various regulatory mechanisms. Hyper-phosphorylation of tau, a major component of neurofibrillary tangles, precipitates its aggregation and prevents its clearance. Lipid particles, apolipoproteins and lipoprotein receptors can act in favor or against Aβ and tau accumulation by altering neural membrane characteristics or dynamics of transport across the blood-brain barrier. Lipids also alter the oxidative/anti-oxidative milieu of the central nervous system (CNS). Irregular cell cycle regulation, mitochondrial stress and apoptosis, which follow both, are also implicated in AD-related neuronal loss. Dysfunction in synaptic transmission and loss of neural plasticity contribute to AD. Neuroinflammation is a final trail for many of the pathologic mechanisms while playing an active role in initiation of AD pathology. Alterations in the expression of microRNAs (miRNAs) in AD and their relevance to AD pathology have long been a focus of interest. Herein we focused on the precise pathomechanisms of AD in which miRNAs were implicated. We performed literature search through PubMed and Scopus using the search term: ('Alzheimer Disease') OR ('Alzheimer's Disease') AND ('microRNAs' OR 'miRNA' OR 'MiR') to reach for relevant articles. We show how a limited number of common dysregulated pathways and abnormal mechanisms are affected by various types of miRNAs in AD brain.
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Affiliation(s)
- Reihaneh Dehghani
- Molecular Immunology Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran 1419783151, Iran
| | - Farzaneh Rahmani
- Students Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran
| | - Nima Rezaei
- Molecular Immunology Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran 1419783151, Iran
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27
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Zhong Y, Zhu Y, He T, Li W, Li Q, Miao Y. Brain-derived neurotrophic factor inhibits hyperglycemia-induced apoptosis and downregulation of synaptic plasticity-related proteins in hippocampal neurons via the PI3K/Akt pathway. Int J Mol Med 2018; 43:294-304. [PMID: 30365051 PMCID: PMC6257855 DOI: 10.3892/ijmm.2018.3933] [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: 04/29/2018] [Accepted: 10/04/2018] [Indexed: 11/06/2022] Open
Abstract
It is not known whether brain-derived neurotrophic factor (BDNF) protects hippocampal neurons from high glucose-induced apoptosis and/or synaptic plasticity dysfunction. The present study aimed to assess whether BDNF exerted a neuroprotective effect in rat hippocampal neurons exposed to high glucose and examine the underlying mechanisms. The apoptosis of primary hippocampal neurons was assessed by Annexin V-fluorescein isothiocyanate/propidium iodide staining. The mRNA and protein expression levels were measured by reverse transcription- quantitative polymerase chain reaction and western blot experiments, respectively. Synaptic plasticity was evaluated by the immunolocalization of synaptophysin (Syn). Exposure of the hippocampal neurons to high glucose (75 mM for 72 h) resulted in cell apoptosis, decreased mRNA and protein expression levels of three synaptic plasticity-related proteins (Syn, Arc and cyclic AMP response element-binding protein), and changes in the cellular distribution of Syn, indicating loss of synaptic density. These effects of high glucose were partially or completely reversed by prior administration of BDNF (50 ng/ml for 24 h). Pre-treatment with wortmannin, a phosphatidylinositol-3-kinase (PI3K) inhibitor, suppressed the ability of BDNF to inhibit the effects of high glucose. In addition, BDNF significantly upregulated the tropomyosin-related kinase B, its cognate receptor, Akt and phosphorylated Akt at the protein levels under high glucose conditions. In conclusion, high glucose induced apoptosis and downregulated synaptic plasticity-related proteins in hippocampal neurons. These effects were reversed by BDNF via the PI3K/Akt signaling pathway.
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Affiliation(s)
- Yuan Zhong
- Department of Gerontology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
| | - Yitong Zhu
- Department of Gerontology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
| | - Ting He
- Department of Gerontology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
| | - Wei Li
- Department of Gerontology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
| | - Qinjie Li
- Department of Gerontology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
| | - Ya Miao
- Department of Gerontology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
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Gomez-Pinilla F, Yang X. System biology approach intersecting diet and cell metabolism with pathogenesis of brain disorders. Prog Neurobiol 2018; 169:76-90. [PMID: 30059718 PMCID: PMC6231047 DOI: 10.1016/j.pneurobio.2018.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 07/15/2018] [Indexed: 12/21/2022]
Abstract
The surge in meals high in calories has prompted an epidemic of metabolic disorders around the world such that the elevated incidence of obese and diabetic individuals is alarming. New research indicates that metabolic disorders pose a risk for neurological and psychiatric conditions including stroke, Alzheimer's disease, Huntington's disease, and depression, all of which have a metabolic component. These relationships are rooted to a dysfunctional interaction between molecular processes that regulate energy metabolism and synaptic plasticity. The strong adaptive force of dietary factors on shaping the brain during evolution can be manipulated to transform the interaction between cell bioenergetics and epigenome with the aptitude to promote long-lasting brain healthiness. A thorough understanding of the association between the broad action of nutrients and brain fitness requires high level data processing empowered with the capacity to integrate information from a multitude of molecular entities and pathways. Nutritional systems biology is emerging as a viable approach to elucidate the multiple molecular layers involved in information processing in cells, tissues, and organ systems in response to diet. Information about the wide range of cellular and molecular interactions elicited by foods on the brain and cognitive plasticity is crucial for the design of public health initiatives for curtailing the epidemic of metabolic and brain disorders.
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Affiliation(s)
- Fernando Gomez-Pinilla
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA; Department of Neurosurgery, UCLA Brain Injury Research Center, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| | - Xia Yang
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
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29
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Inflammation, insulin signaling and cognitive function in aged APP/PS1 mice. Brain Behav Immun 2018; 70:423-434. [PMID: 29604345 DOI: 10.1016/j.bbi.2018.03.032] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 03/17/2018] [Accepted: 03/26/2018] [Indexed: 02/06/2023] Open
Abstract
Cognitive dysfunction and neuroinflammation are typical in Alzheimer's disease (AD), but are also associated with normal aging, albeit less severely. Insulin resistance in the brain has been demonstrated in AD patients and is thought to be involved in AD pathophysiology. Using 15-18 month-old APP/PS1 mice, this study measured peripheral and central insulin signaling and sensitivity, inflammatory markers in brain and plasma and oxidative stress and synapse density in the brain. Novel object recognition, Morris water maze and reversal water maze tasks were performed to assess cognitive function in aged APP/PS1 mice and wild type littermates. Glucose tolerance and insulin sensitivity were similar in APP/PS1 mice and wild type controls, however IRS-1 pSer616 was increased in cortex and dentate gyrus of APP/PS1 mice. Recognition and spatial memory was impaired in both APP/PS1 and wild type mice, however learning impairments were apparent in APP/PS1 mice. Expression of GLP-1 receptor, ERK2, IKKβ, mTOR, PKCθ, NF-κB1 and TLR4 was similar between aged APP/PS1 mice and age-matched wild types. Compared to age-matched wild type mice, IFNγ and IL-4 were increased in brains of APP/PS1 mice. These results suggest that normal aging may be associated with enhanced neuroinflammation, oxidative stress, and cognitive decline, however distinctions are apparent in the brain of APP/PS1 mice in terms of inflammation and insulin signaling and in certain cognitive domains. Demarcation of pathological events that distinguish AD from normal aging will allow for improvements in diagnostic tools and the development of more effective therapeutics.
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30
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Prieto GA, Tong L, Smith ED, Cotman CW. TNFα and IL-1β but not IL-18 Suppresses Hippocampal Long-Term Potentiation Directly at the Synapse. Neurochem Res 2018; 44:49-60. [PMID: 29619614 DOI: 10.1007/s11064-018-2517-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/20/2018] [Accepted: 03/22/2018] [Indexed: 12/13/2022]
Abstract
CNS inflammatory responses are linked to cognitive impairment in humans. Research in animal models supports this connection by showing that inflammatory cytokines suppress long-term potentiation (LTP), the best-known cellular correlate of memory. Cytokine-induced modulation of LTP has been previously studied in vivo or in brain slices, two experimental approaches containing multiple cell populations responsive to cytokines. In their target cells, cytokines commonly increase the expression of multiple cytokines, thus increasing the complexity of brain cytokine networks even after single-cytokine challenges. Whether cytokines suppress LTP by direct effects on neurons or by indirect mechanisms is still an open question. Here, we evaluated the effect of a major set of inflammatory cytokines including tumor necrosis factor-α (TNFα), interleukin-1β (IL-1β) and interleukin-18 (IL-18) on chemically-induced LTP (cLTP) in isolated hippocampal synaptosomes of mice, using fluorescence analysis of single-synapse long-term potentiation (FASS-LTP). We found that TNFα and IL-1β suppress synaptosomal cLTP. In contrast, cLTP was not affected by IL-18, at a concentration previously shown to block LTP in hippocampal slices. We also found that IL-18 does not impair cLTP or brain-derived neurotrophic factor (BDNF) signaling in primary hippocampal neuronal cultures. Thus, using both synaptosomes and neuron cultures, our data suggest that IL-18 impairs LTP by indirect mechanisms, which may depend on non-neuronal cells, such as glia. Notably, our results demonstrate that TNFα and IL-1β directly suppress hippocampal plasticity via neuron-specific mechanisms. A better understanding of the brain's cytokine networks and their final molecular effectors is crucial to identify specific targets for intervention.
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Affiliation(s)
- G Aleph Prieto
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, 92697, USA.
| | - Liqi Tong
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, 92697, USA
| | - Erica D Smith
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, 92697, USA
| | - Carl W Cotman
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, 92697, USA
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31
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Lee HK, Kwon B, Lemere CA, de la Monte S, Itamura K, Ha AY, Querfurth HW. mTORC2 (Rictor) in Alzheimer's Disease and Reversal of Amyloid-β Expression-Induced Insulin Resistance and Toxicity in Rat Primary Cortical Neurons. J Alzheimers Dis 2018; 56:1015-1036. [PMID: 28035937 DOI: 10.3233/jad-161029] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Mammalian target of rapamycin complex 1 (mTORC1), a nutrient sensor and central controller of cell growth and proliferation, is altered in various models of Alzheimer's disease (AD). Even less studied or understood in AD is mammalian target of rapamycin complex 2 (mTORC2) that influences cellular metabolism, in part through the regulations of Akt/PKB and SGK. Dysregulation of insulin/PI3K/Akt signaling is another important feature of AD pathogenesis. We found that both total mTORC1 and C2 protein levels and individual C1 and C2 enzymatic activities were decreased in human AD brain samples. In two rodent AD models, mTORC1 and C2 activities were also decreased. In a neuronal culture model of AD characterized by accumulation of cellular amyloid-β (Aβ)42, mTORC1 activity was reduced. Autophagic vesicles and markers were correspondingly increased and new protein synthesis was inhibited, consistent with mTORC1 hypofunction. Interestingly, mTORC2 activity in neural culture seemed resistant to the effects of intracellular amyloid. In various cell lines, Aβ expression provoked insulin resistance, characterized by inhibition of stimulated Akt phosphorylation, and an increase in negative mTORC1 regular, p-AMPK, itself a nutrient sensor. Rapamycin decreased phospho-mTOR and to lesser degree p-Rictor. This further suppression of mTORC1 activity protected cells from Aβ-induced toxicity and insulin resistance. More striking, Rictor over-expression fully reversed the Aβ-effects on primary neuronal cultures. Finally, using in vitro assay, Rictor protein addition completely overcame oligomeric Aβ-induced inhibition of the PDK-Akt activation step. We conclude that striking a new balance by restoring mTORC2 abundance and/or inhibition of mTORC1 has therapeutic potential in AD.
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Affiliation(s)
- Han-Kyu Lee
- Department of Neurology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Bumsup Kwon
- Department of Neurology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Cynthia A Lemere
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Suzanne de la Monte
- Department of Pathology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Kyohei Itamura
- Department of Neurology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Austin Y Ha
- Department of Neurology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Henry W Querfurth
- Department of Neurology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
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32
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Yi JH, Baek SJ, Heo S, Park HJ, Kwon H, Lee S, Jung J, Park SJ, Kim BC, Lee YC, Ryu JH, Kim DH. Direct pharmacological Akt activation rescues Alzheimer's disease like memory impairments and aberrant synaptic plasticity. Neuropharmacology 2017; 128:282-292. [PMID: 29079294 DOI: 10.1016/j.neuropharm.2017.10.028] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 09/23/2017] [Accepted: 10/21/2017] [Indexed: 12/21/2022]
Abstract
Amyloid β (Aβ) is a key mediator for synaptic dysfunction and cognitive impairment implicated in Alzheimer's disease (AD). However, the precise mechanism of the toxic effect of Aβ is still not completely understood. Moreover, there is currently no treatment for AD. Protein kinase B (PKB, also termed Akt) is known to be aberrantly regulated in the AD brain. However, its potential function as a therapeutic target for AD-associated memory impairment has not been studied. Here, we examined the role of a direct Akt activator, SC79, in hippocampus-dependent memory impairments using Aβ-injected as well as 5XFAD AD model mice. Oligomeric Aβ injections into the 3rd ventricle caused concentration-dependent and time-dependent impairments in learning/memory and synaptic plasticity. Moreover, Aβ aberrantly regulated caspase-3, GSK-3β, and Akt signaling, which interact with each other in the hippocampus. Caspase-3 and GSK-3β inhibitor ameliorated memory impairments and synaptic deficits in Aβ-injected AD model mice. We also found that pharmacological activation of Akt rescued memory impairments and aberrant synaptic plasticity in both Aβ-treated and 5XFAD mice. These results suggest that Akt could be a therapeutic target for memory impairment observed in AD.
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Affiliation(s)
- Jee Hyun Yi
- School of Clinical Sciences, Faculty of Medicine and Dentistry, University of Bristol, Bristol, UK
| | - Soo Ji Baek
- Department of Neurology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Sunghoo Heo
- Department of Neurology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Hye Jin Park
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, Republic of Korea
| | - Huiyoung Kwon
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, Republic of Korea
| | - Seungheon Lee
- Department of Aquatic Biomedical Sciences, School of Marine Biomedical Science, College of Ocean Science, Jeju National University, Jeju, Republic of Korea
| | - Jiwook Jung
- Department of Herbal Medicinal Pharmacology, College of Herbal Bio-industry, Daegu Haany University, Kyungsan, Republic of Korea
| | - Se Jin Park
- School of Natural Resources and Environmental Science, Kangwon National University, ChoonCheon, Republic of Korea
| | - Byung C Kim
- Department of Neurology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Young Choon Lee
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, Republic of Korea; Institute of Convergence Bio-Health, Dong-A University, Busan, Republic of Korea
| | - Jong Hoon Ryu
- Department of Oriental Pharmaceutical Science, College of Pharmacy, Kyung Hee University, 1 Hoeki-dong, Dongdaemoon-Gu, Seoul, Republic of Korea; Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, 1 Hoeki-dong, Dongdaemoon-Gu, Seoul, Republic of Korea.
| | - Dong Hyun Kim
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, Republic of Korea; Institute of Convergence Bio-Health, Dong-A University, Busan, Republic of Korea.
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Silva Pereira V, Elfving B, Joca SRL, Wegener G. Ketamine and aminoguanidine differentially affect Bdnf and Mtor gene expression in the prefrontal cortex of adult male rats. Eur J Pharmacol 2017; 815:304-311. [PMID: 28947331 DOI: 10.1016/j.ejphar.2017.09.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 09/15/2017] [Accepted: 09/19/2017] [Indexed: 01/23/2023]
Abstract
The rapid and sustained antidepressant properties of ketamine provide evidence of the importance of the glutamatergic system in the neurobiology of depression. The antidepressant-like effects of ketamine are dependent on brain-derived neurotrophic factor (BDNF) and mammalian target of rapamycin (mTOR) in limbic brain areas. The nitrergic system is closely related to the glutamatergic system and generates antidepressant-like effects when blocked. The aim of this study was to investigate whether the behavioural effects induced by the inhibition of nitric oxide (NO) synthesis by aminoguanidine or N-methyl-D-aspartate (NMDA) receptor blockade by ketamine would affect the gene expression of Bdnf and Mtor in the ventromedial prefrontal cortex in rats. The effects of ketamine or aminoguanidine were investigated in Sprague-Dawley (SD) rats, the Flinders Sensitive Line (FSL), a genetic rat model of depression, and their controls, the Flinders Resistant Line (FRL) rats. In the studies, the three protocols evaluated to which the animals/rats were exposed were: (1) pre-test and test sessions of forced swim test (FST), (2) pre-test session of FST alone, or (3) not exposed to the FST. Ketamine and aminoguanidine both induce antidepressant-like effects in SD and FSL rats. Quantitative real-time polymerase chain reaction analyses in SD rats demonstrated that none of the treatments can change the Bdnf or Mtor gene expression, but in FSL rats the treatment with ketamine increased only Bdnf gene expression. The data obtained strengthens the role of NMDA antagonists and NO inhibitors as potential antidepressant drugs, albeit with different effects on Bdnf gene expression.
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Affiliation(s)
- Vitor Silva Pereira
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, 8240 Risskov, Denmark; Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, Campus USP-Ribeirão Preto, Ribeirão Preto, SP 14040-904, Brazil.
| | - Betina Elfving
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, 8240 Risskov, Denmark.
| | - Sâmia R L Joca
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, 8240 Risskov, Denmark; Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, Campus USP-Ribeirão Preto, Ribeirão Preto, SP 14040-904, Brazil.
| | - Gregers Wegener
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, 8240 Risskov, Denmark; Department of Clinical Medicine, AUGUST Centre, Aarhus University, Risskov, Denmark; Centre for Pharmaceutical Excellence, School of Pharmacy, North-West University, Potchefstroom 2531, South Africa.
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34
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Arbo BD, Hoppe JB, Rodrigues K, Garcia-Segura LM, Salbego CG, Ribeiro MF. 4'-Chlorodiazepam is neuroprotective against amyloid-beta in organotypic hippocampal cultures. J Steroid Biochem Mol Biol 2017; 171:281-287. [PMID: 28442392 DOI: 10.1016/j.jsbmb.2017.04.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 02/23/2017] [Accepted: 04/19/2017] [Indexed: 01/15/2023]
Abstract
The translocator protein (TSPO) is an outer mitochondrial membrane protein involved in the transport of cholesterol into the mitochondria, which is the first step for the synthesis of steroid hormones, as well as in the regulation of mitochondrial permeability transition pore opening and apoptosis. Studies have shown that the activation of TSPO may promote neuroprotective actions in experimental models of neurodegeneration and brain injury. In a previous study, our group showed that 4'-chlorodiazepam (4'-CD), a TSPO ligand, was neuroprotective against amyloid-beta (Aβ) in SHSY-5Y neuroblastoma cells. The aim of this study was to evaluate if 4'-CD was also neuroprotective against Aβ in organotypic hippocampal cultures and to identify its mechanisms of action. Aβ decreased the cell viability of organotypic hippocampal cultures, while 4'-CD had a neuroprotective effect when administered at 100nM and 1000nM. The neuroprotective effects of 4'-CD against Aβ were associated with an increased expression of superoxide dismutase (SOD). No differences were found in the expression of catalase, glial fibrillary acidic protein, Akt and procaspase-3. In summary, our results show that 4'-CD is neuroprotective against Aβ by a mechanism involving the modulation of SOD protein expression.
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Affiliation(s)
- B D Arbo
- Laboratório de Interação Neuro-Humoral - Department of Physiology - ICBS - Universidade Federal do Rio Grande do Sul (UFRGS), Rua Sarmento Leite, 500, 90050-170, Porto Alegre, RS, Brazil.
| | - J B Hoppe
- Laboratório de Neuroproteção e Sinalização Celular - Department of Biochemistry - Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600, 90035-003, Porto Alegre, RS, Brazil
| | - K Rodrigues
- Laboratório de Neuroproteção e Sinalização Celular - Department of Biochemistry - Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600, 90035-003, Porto Alegre, RS, Brazil
| | - L M Garcia-Segura
- Instituto Cajal - CSIC, Avenida Doctor Arce, 37, 28002, Madrid, Spain
| | - C G Salbego
- Laboratório de Neuroproteção e Sinalização Celular - Department of Biochemistry - Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600, 90035-003, Porto Alegre, RS, Brazil
| | - M F Ribeiro
- Laboratório de Interação Neuro-Humoral - Department of Physiology - ICBS - Universidade Federal do Rio Grande do Sul (UFRGS), Rua Sarmento Leite, 500, 90050-170, Porto Alegre, RS, Brazil
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35
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Human neural stem/progenitor cells derived from the olfactory epithelium express the TrkB receptor and migrate in response to BDNF. Neuroscience 2017; 355:84-100. [PMID: 28499977 DOI: 10.1016/j.neuroscience.2017.04.047] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 04/27/2017] [Accepted: 04/29/2017] [Indexed: 12/31/2022]
Abstract
Neurogenesis constitutively occurs in the olfactory epithelium of mammals, including humans. The fact that new neurons in the adult olfactory epithelium derive from resident neural stem/progenitor cells suggests a potential use for these cells in studies of neural diseases, as well as in neuronal cell replacement therapies. In this regard, some studies have proposed that the human olfactory epithelium is a source of neural stem/progenitor cells for autologous transplantation. Although these potential applications are interesting, it is important to understand the cell biology and/or whether human neural stem/progenitor cells in the olfactory epithelium sense external signals, such as brain-derived neurotrophic factor (BDNF), that is also found in other pro-neurogenic microenvironments. BDNF plays a key role in several biological processes, including cell migration. Thus, we characterized human neural stem/progenitor cells derived from the olfactory epithelium (hNS/PCs-OE) and studied their in vitro migratory response to BDNF. In the present study, we determined that hNS/PCs-OE express the protein markers Nestin, Sox2, Ki67 and βIII-tubulin. Moreover, the doubling time of hNS/PCs-OE was approximately 38h. Additionally, we found that hNS/PCs-OE express the BDNF receptor TrkB, and pharmacological approaches showed that the BDNF-induced (40ng/ml) migration of differentiated hNS/PCs-OE was affected by the compound K252a, which prevents TrkB activation. This observation was accompanied by changes in the number of vinculin adhesion contacts. Our results suggest that hNS/PCs-OE exhibit a migratory response to BDNF, accompanied by the turnover of adhesion contacts.
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The Neuroprotective Effects of Brazilian Green Propolis on Neurodegenerative Damage in Human Neuronal SH-SY5Y Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:7984327. [PMID: 28265338 PMCID: PMC5317132 DOI: 10.1155/2017/7984327] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 12/19/2016] [Accepted: 12/28/2016] [Indexed: 12/31/2022]
Abstract
Oxidative stress and synapse dysfunction are the major neurodegenerative damage correlated to cognitive impairment in Alzheimer's disease (AD). We have found that Brazilian green propolis (propolis) improves the cognitive functions of mild cognitive impairment patients living at high altitude; however, mechanism underlying the effects of propolis is unknown. In the present study, we investigated the effects of propolis on oxidative stress, expression of brain-derived neurotrophic factor (BDNF), and activity-regulated cytoskeleton-associated protein (Arc), the critical factors of synapse efficacy, using human neuroblastoma SH-SY5Y cells. Pretreatment with propolis significantly ameliorated the hydrogen peroxide- (H2O2-) induced cytotoxicity in SH-SY5Y cells. Furthermore, propolis significantly reduced the H2O2-generated reactive oxygen species (ROS) derived from mitochondria and 8-oxo-2'-deoxyguanosine (8-oxo-dG, the DNA oxidative damage marker) but significantly reversed the fibrillar β-amyloid and IL-1β-impaired BDNF-induced Arc expression in SH-SY5Y cells. Furthermore, propolis significantly upregulated BDNF mRNA expression in time- and dose-dependent manners. In addition, propolis induced Arc mRNA and protein expression via phosphoinositide-3 kinase (PI3K). These observations strongly suggest that propolis protects from the neurodegenerative damage in neurons through the properties of various antioxidants. The present study provides a potential molecular mechanism of Brazilian green propolis in prevention of cognitive impairment in AD as well as aging.
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Saleem S, Biswas SC. Tribbles Pseudokinase 3 Induces Both Apoptosis and Autophagy in Amyloid-β-induced Neuronal Death. J Biol Chem 2016; 292:2571-2585. [PMID: 28011637 DOI: 10.1074/jbc.m116.744730] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 12/22/2016] [Indexed: 11/06/2022] Open
Abstract
Amyloid-β (Aβ)-induced neuron death is considered central to the pathogenesis of Alzheimer's disease (AD). Among several death modalities, autophagy and apoptosis play important roles in Aβ-induced neuron death suggesting that there may be regulatory mechanisms that initiate both cell death pathways. However, molecules that govern both pathways have not been identified. Here, we report that, upon Aβ treatment, tribbles pseudokinase 3 (Trib3, an ortholog of Drosophila Tribbles) is up-regulated in neurons both in vivo and in vitro Increased Trib3 levels inhibited the activity of the kinase Akt by interacting with it. As a result, forkhead box O1 (FoxO1), a transcription factor that is negatively regulated by Akt, was activated, translocated to the nucleus, and induced the pro-apoptotic gene BCL2-like 11 (Bim). Conversely, FoxO1 responded to Aβ insult by binding to the Trib3 gene promoter, enhancing its expression. Our investigations further revealed that Trib3 also induces autophagy. We found that Trib3 indirectly activates unc-51-like autophagy-activating kinase1 (Ulk1) by impeding phosphorylation of, and thus inactivating, a negative regulator of Ulk1, mechanistic target of rapamycin. Ulk1 activation augmented autophagosome formation and reduced autophagy flux. Thus, Trib3 was required for formation of autophagosomes, which accumulated in neurons as autophagic flux was thwarted. Most importantly, silencing endogenous Trib3 strongly protected neurons from Aβ insult. Our results suggest that a self-amplifying feed-forward loop among Trib3, Akt, and FoxO1 in Aβ-treated neurons induces both apoptosis and autophagy, culminating in neuron death. Thus, Trib3 may serve as a potential therapeutic target for AD.
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Affiliation(s)
- Suraiya Saleem
- From the Cell Biology and Physiology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, India
| | - Subhas Chandra Biswas
- From the Cell Biology and Physiology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, India
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Jiang Q, Chen S, Hu C, Huang P, Shen H, Zhao W. Neuregulin-1 (Nrg1) signaling has a preventive role and is altered in the frontal cortex under the pathological conditions of Alzheimer's disease. Mol Med Rep 2016; 14:2614-24. [PMID: 27486021 PMCID: PMC4991731 DOI: 10.3892/mmr.2016.5542] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 07/14/2016] [Indexed: 02/05/2023] Open
Abstract
Alzheimer's disease (AD), one of the neurodegenerative disorders that may develop in the elderly, is characterized by the deposition of β‑amyloid protein (Aβ) and extensive neuronal cell death in the brain. Neuregulin‑1 (Nrg1)‑mediated intercellular and intracellular communication via binding to ErbB receptors regulates a diverse set of biological processes involved in the development of the nervous system. In the present study, a linear correlation was identified between Nrg1 and phosphorylated ErbB (pNeu and pErbB4) receptors in a human cortical tissue microarray. In addition, increased expression levels of Nrg1, but reduced pErbB receptor levels, were detected in the frontal lobe of a patient with AD. Western blotting and immunofluorescence staining were subsequently performed to uncover the potential preventive role of Nrg1 in cortical neurons affected by the neurodegenerative processes of AD. It was observed that the expression of Nrg1 increased as the culture time of the cortical neurons progressed. In addition, H2O2 and Aβ1‑42, two inducers of oxidative stress and neuronal damage, led to a dose‑dependent decrease in Nrg1 expression. Recombinant Nrg1β, however, was revealed to exert a pivotal role in preventing oxidative stress and neuronal damage from occurring in the mouse cortical neurons. Taken together, these results suggest that changes in Nrg1 signaling may influence the pathological development of AD, and exogenous Nrg1 may serve as a potential candidate for the prevention and treatment of AD.
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Affiliation(s)
| | | | | | | | | | - Weijiang Zhao
- Correspondence to: Professor Weijiang Zhao, Center for Neuroscience, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, P.R. China, E-mail:
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Najafi A, Amidi F, Sedighi Gilani MA, Moawad AR, Asadi E, Khanlarkhni N, Fallah P, Rezaiian Z, Sobhani A. Effect of brain-derived neurotrophic factor on sperm function, oxidative stress and membrane integrity in human. Andrologia 2016; 49. [DOI: 10.1111/and.12601] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/08/2016] [Indexed: 01/08/2023] Open
Affiliation(s)
- A. Najafi
- Department of Anatomy; School of Medicine; Tehran University of Medical Sciences; Tehran Iran
| | - F. Amidi
- Department of Anatomy; School of Medicine; Tehran University of Medical Sciences; Tehran Iran
| | - M. A. Sedighi Gilani
- Department of Urology; Shariati Hospital; Tehran University of Medical Sciences; Tehran Iran
| | - A. R. Moawad
- Departments of Obstetrics and Gynecology; Surgery; McGill University; Montreal QC Canada
- Department of Theriogenology; Faculty of Veterinary Medicine; Cairo University; Giza Egypt
| | - E. Asadi
- Department of Anatomy; School of Medicine; Tehran University of Medical Sciences; Tehran Iran
| | - N. Khanlarkhni
- Department of Anatomy; School of Medicine; Tehran University of Medical Sciences; Tehran Iran
| | - P. Fallah
- Infertility Center; Shariati Hospital; Tehran University of Medical Sciences; Tehran Iran
| | - Z. Rezaiian
- Infertility Center; Shariati Hospital; Tehran University of Medical Sciences; Tehran Iran
| | - A. Sobhani
- Department of Anatomy; School of Medicine; Tehran University of Medical Sciences; Tehran Iran
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Agrawal R, Noble E, Vergnes L, Ying Z, Reue K, Gomez-Pinilla F. Dietary fructose aggravates the pathobiology of traumatic brain injury by influencing energy homeostasis and plasticity. J Cereb Blood Flow Metab 2016; 36:941-53. [PMID: 26661172 PMCID: PMC4853835 DOI: 10.1177/0271678x15606719] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 07/19/2015] [Indexed: 12/23/2022]
Abstract
Fructose consumption has been on the rise for the last two decades and is starting to be recognized as being responsible for metabolic diseases. Metabolic disorders pose a particular threat for brain conditions characterized by energy dysfunction, such as traumatic brain injury. Traumatic brain injury patients experience sudden abnormalities in the control of brain metabolism and cognitive function, which may worsen the prospect of brain plasticity and function. The mechanisms involved are poorly understood. Here we report that fructose consumption disrupts hippocampal energy homeostasis as evidenced by a decline in functional mitochondria bioenergetics (oxygen consumption rate and cytochrome C oxidase activity) and an aggravation of the effects of traumatic brain injury on molecular systems engaged in cell energy homeostasis (sirtuin 1, peroxisome proliferator-activated receptor gamma coactivator-1alpha) and synaptic plasticity (brain-derived neurotrophic factor, tropomyosin receptor kinase B, cyclic adenosine monophosphate response element binding, synaptophysin signaling). Fructose also worsened the effects of traumatic brain injury on spatial memory, which disruption was associated with a decrease in hippocampal insulin receptor signaling. Additionally, fructose consumption and traumatic brain injury promoted plasma membrane lipid peroxidation, measured by elevated protein and phenotypic expression of 4-hydroxynonenal. These data imply that high fructose consumption exacerbates the pathology of brain trauma by further disrupting energy metabolism and brain plasticity, highlighting the impact of diet on the resilience to neurological disorders.
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Affiliation(s)
- Rahul Agrawal
- Department of Integrative Biology & Physiology, UCLA, Los Angeles, USA
| | - Emily Noble
- Department of Integrative Biology & Physiology, UCLA, Los Angeles, USA
| | - Laurent Vergnes
- Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, USA
| | - Zhe Ying
- Department of Integrative Biology & Physiology, UCLA, Los Angeles, USA
| | - Karen Reue
- Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, USA
| | - Fernando Gomez-Pinilla
- Department of Integrative Biology & Physiology, UCLA, Los Angeles, USA Department of Neurosurgery, UCLA Brain Injury Research Center, Los Angeles, USA
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Chen TJ, Chen SS, Wang DC, Hung HS. The Cholinergic Signaling Responsible for the Expression of a Memory-Related Protein in Primary Rat Cortical Neurons. J Cell Physiol 2016; 231:2428-38. [PMID: 26895748 DOI: 10.1002/jcp.25347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 02/17/2016] [Indexed: 01/09/2023]
Abstract
Cholinergic dysfunction in the brain is closely related to cognitive impairment including memory loss. In addition to the degeneration of basal forebrain cholinergic neurons, deficits in the cholinergic receptor signaling may also play an important role. In the present study, to examine the cholinergic signaling pathways responsible for the induction of a memory-related postsynaptic protein, a cholinergic agonist carbachol was used to induce the expression of activity-regulated cytoskeleton associated protein (Arc) in primary rat cortical neurons. After pretreating neurons with various antagonists or inhibitors, the levels of carbachol-induced Arc protein expression were detected by Western blot analysis. The results show that carbachol induces Arc protein expression mainly through activating M1 acetylcholine receptors and the downstream phospholipase C pathway, which may lead to the activation of the MAPK/ERK signaling pathway. Importantly, carbachol-mediated M2 receptor activation exerts negative effects on Arc protein expression and thus counteracts the enhanced effects of M1 activation. Furthermore, it is suggested for the first time that M1-mediated enhancement of N-methyl-D-aspartate receptor (NMDAR) responses, leading to Ca(2+) entry through NMDARs, contributes to carbachol-induced Arc protein expression. These findings reveal a more complete cholinergic signaling that is responsible for carbachol-induced Arc protein expression, and thus provide more information for developing treatments that can modulate cholinergic signaling and consequently alleviate cognitive impairment. J. Cell. Physiol. 231: 2428-2438, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Tsan-Ju Chen
- Department of Physiology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shun-Sheng Chen
- Department of Neurology, Chang Gung Memorial Hospital, Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Dean-Chuan Wang
- Department of Sports Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hui-Shan Hung
- Department of Physiology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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Mitochondrial FOXO3a is involved in amyloid β peptide-induced mitochondrial dysfunction. J Bioenerg Biomembr 2016; 48:189-96. [PMID: 26782277 DOI: 10.1007/s10863-016-9645-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 01/13/2016] [Indexed: 01/23/2023]
Abstract
Mitochondrial dysfunction is a hallmark of amyloid β peptide (Aβ)-induced neuronal toxicity in Alzheimer's disease (AD). However, the precise mechanism(s) of Aβ-induced mitochondrial dysfunction has not been fully understood. There is evidence that Forkhead box O3a (FOXO3a) is normally present in neuronal mitochondria. Using HT22 murine hippocampal neuronal cells and primary hippocampal neurons, the present study investigated whether mitochondrial FOXO3a was involved in mitochondrial dysfunction induced by Aβ. It was found that Aβ induced dephosphorylation and mitochondrial translocation of FOXO3a. In addition, Aβ enhanced association of FOXO3a with mitochondrial DNA (mtDNA), causing a decrease in the expression of cytochrome c oxidase subunit 1 (COX1) and the activity of COX. In addition, Aβ-induced mitochondrial dysfunction, indicated by the decrease in 3- (4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) conversion, mitochondrial adenosine triphosphate (ATP) production and COX activity, could be suppressed by knockdown of FOXO3a (FOXO3a-KD). These results provide new insights into the mechanism underlying Aβ-induced neurotoxicity and open up new therapeutic perspectives for AD.
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Zhong Y, Zhu Y, He T, Li W, Yan H, Miao Y. Rolipram-induced improvement of cognitive function correlates with changes in hippocampal CREB phosphorylation, BDNF and Arc protein levels. Neurosci Lett 2016; 610:171-6. [DOI: 10.1016/j.neulet.2015.09.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 09/09/2015] [Accepted: 09/21/2015] [Indexed: 12/18/2022]
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Sandoval-Hernández AG, Buitrago L, Moreno H, Cardona-Gómez GP, Arboleda G. Role of Liver X Receptor in AD Pathophysiology. PLoS One 2015; 10:e0145467. [PMID: 26720273 PMCID: PMC4697813 DOI: 10.1371/journal.pone.0145467] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 12/03/2015] [Indexed: 12/01/2022] Open
Abstract
Alzheimer's disease (AD) is the major cause of dementia worldwide. The pharmacological activation of nuclear receptors (Liver X receptors: LXRs or Retinoid X receptors: RXR) has been shown to induce overexpression of the ATP-Binding Cassette A1 (ABCA1) and Apolipoprotein E (ApoE), changes that are associated with improvement in cognition and reduction of amyloid beta pathology in amyloidogenic AD mouse models (i.e. APP, PS1: 2tg-AD). Here we investigated whether treatment with a specific LXR agonist has a measurable impact on the cognitive impairment in an amyloid and Tau AD mouse model (3xTg-AD: 12-months-old; three months treatment). The data suggests that the LXR agonist GW3965 is associated with increased expression of ApoE and ABCA1 in the hippocampus and cerebral cortex without a detectable reduction of the amyloid load. We also report that most cells overexpressing ApoE (86±12%) are neurons localized in the granular cell layer of the hippocampus and entorhinal cortex. In the GW3965 treated 3xTg-AD mice we also observed reduction in astrogliosis and increased number of stem and proliferating cells in the subgranular zone of the dentate gyrus. Additionally, we show that GW3965 rescued hippocampus long term synaptic plasticity, which had been disrupted by oligomeric amyloid beta peptides. The effect of GW3965 on synaptic function was protein synthesis dependent. Our findings identify alternative functional/molecular mechanisms by which LXR agonists may exert their potential benefits as a therapeutic strategy against AD.
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Affiliation(s)
| | - Luna Buitrago
- Departments of Neurology and Physiology/Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, New York, United States of America
| | - Herman Moreno
- Departments of Neurology and Physiology/Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, New York, United States of America
| | - Gloria Patricia Cardona-Gómez
- Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Calle 70, No. 52–21, Medellín, Colombia
| | - Gonzalo Arboleda
- Grupo de Muerte Celular, Instituto de Genética Universidad Nacional de Colombia, Bogotá, Colombia
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Maiese K. Targeting molecules to medicine with mTOR, autophagy and neurodegenerative disorders. Br J Clin Pharmacol 2015; 82:1245-1266. [PMID: 26469771 DOI: 10.1111/bcp.12804] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 10/11/2015] [Accepted: 10/13/2015] [Indexed: 12/14/2022] Open
Abstract
Neurodegenerative disorders are significantly increasing in incidence as the age of the global population continues to climb with improved life expectancy. At present, more than 30 million individuals throughout the world are impacted by acute and chronic neurodegenerative disorders with limited treatment strategies. The mechanistic target of rapamycin (mTOR), also known as the mammalian target of rapamycin, is a 289 kDa serine/threonine protein kinase that offers exciting possibilities for novel treatment strategies for a host of neurodegenerative diseases that include Alzheimer's disease, Parkinson's disease, Huntington's disease, epilepsy, stroke and trauma. mTOR governs the programmed cell death pathways of apoptosis and autophagy that can determine neuronal stem cell development, precursor cell differentiation, cell senescence, cell survival and ultimate cell fate. Coupled to the cellular biology of mTOR are a number of considerations for the development of novel treatments involving the fine control of mTOR signalling, tumourigenesis, complexity of the apoptosis and autophagy relationship, functional outcome in the nervous system, and the intimately linked pathways of growth factors, phosphoinositide 3-kinase (PI 3-K), protein kinase B (Akt), AMP activated protein kinase (AMPK), silent mating type information regulation two homologue one (Saccharomyces cerevisiae) (SIRT1) and others. Effective clinical translation of the cellular signalling mechanisms of mTOR offers provocative avenues for new drug development in the nervous system tempered only by the need to elucidate further the intricacies of the mTOR pathway.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, New Jersey, 07101, USA.
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46
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Simvastatin prevents β-amyloid25–35-impaired neurogenesis in hippocampal dentate gyrus through α7nAChR-dependent cascading PI3K-Akt and increasing BDNF via reduction of farnesyl pyrophosphate. Neuropharmacology 2015; 97:122-32. [DOI: 10.1016/j.neuropharm.2015.05.020] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 05/17/2015] [Accepted: 05/19/2015] [Indexed: 02/06/2023]
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47
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Zeng Y, Zhang J, Zhu Y, Zhang J, Shen H, Lu J, Pan X, Lin N, Dai X, Zhou M, Chen X. Tripchlorolide improves cognitive deficits by reducing amyloid β and upregulating synapse-related proteins in a transgenic model of Alzheimer's Disease. J Neurochem 2015; 133:38-52. [DOI: 10.1111/jnc.13056] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 01/21/2015] [Accepted: 01/22/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Yuqi Zeng
- Department of Neurology and Geriatrics; Fujian Institute of Geriatrics; Fujian Medical University Union Hospital; Fuzhou China
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
| | - Jian Zhang
- Department of Neurology and Geriatrics; Fujian Institute of Geriatrics; Fujian Medical University Union Hospital; Fuzhou China
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
| | - Yuangui Zhu
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
| | - Jing Zhang
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
| | - Hui Shen
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
| | - Jianping Lu
- Department of Neurology and Geriatrics; Fujian Institute of Geriatrics; Fujian Medical University Union Hospital; Fuzhou China
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
| | - Xiaodong Pan
- Department of Neurology and Geriatrics; Fujian Institute of Geriatrics; Fujian Medical University Union Hospital; Fuzhou China
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
| | - Nan Lin
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
| | - Xiaoman Dai
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
| | - Meng Zhou
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
| | - Xiaochun Chen
- Department of Neurology and Geriatrics; Fujian Institute of Geriatrics; Fujian Medical University Union Hospital; Fuzhou China
- Key Laboratory of Brain Aging and Neurodegenerative Disease; Fujian Key Laboratory of Molecular Neurology; Fujian Medical University; Fuzhou China
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Abstract
Alzheimer's disease (AD) is characterized by cognitive impairment in clinical presentation, and by β-amyloid (Aβ) production and the hyper-phosphorylation of tau in basic research. More highlights demonstrate that the activation of the mammalian target of rapamycin (mTOR) enhances Aβ generation and deposition by modulating amyloid precursor protein (APP) metabolism and upregulating β- and γ-secretases. mTOR, an inhibitor of autophagy, decreases Aβ clearance by scissoring autophagy function. mTOR regulates Aβ generation or Aβ clearance by regulating several key signaling pathways, including phosphoinositide 3-kinase (PI3-K)/protein kinase B (Akt), glycogen synthase kinase 3 [GSK-3], AMP-activated protein kinase (AMPK), and insulin/insulin-like growth factor 1 (IGF-1). The activation of mTOR is also a contributor to aberrant hyperphosphorylated tau. Rapamycin, the inhibitor of mTOR, may mitigate cognitive impairment and inhibit the pathologies associated with amyloid plaques and neurofibrillary tangles by promoting autophagy. Furthermore, the upstream and downstream components of mTOR signaling are involved in the pathogenesis and progression of AD. Hence, inhibiting the activation of mTOR may be an important therapeutic target for AD.
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Affiliation(s)
- Zhiyou Cai
- Department of Neurology, Renmin Hospital, Hubei University of Medicine, Shiyan Renmin Hospital, Shiyan, Hubei Province, People's Republic of China
| | - Guanghui Chen
- Department of Neurology, Renmin Hospital, Hubei University of Medicine, Shiyan Renmin Hospital, Shiyan, Hubei Province, People's Republic of China
| | - Wenbo He
- Department of Neurology, Renmin Hospital, Hubei University of Medicine, Shiyan Renmin Hospital, Shiyan, Hubei Province, People's Republic of China
| | - Ming Xiao
- Department of Anatomy, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Liang-Jun Yan
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA
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In vivo AAV1 transduction with hRheb(S16H) protects hippocampal neurons by BDNF production. Mol Ther 2014; 23:445-55. [PMID: 25502903 DOI: 10.1038/mt.2014.241] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 12/06/2014] [Indexed: 01/08/2023] Open
Abstract
Recent evidence has shown that Ras homolog enriched in brain (Rheb) is dysregulated in Alzheimer's disease (AD) brains. However, it is still unclear whether Rheb activation contributes to the survival and protection of hippocampal neurons in the adult brain. To assess the effects of active Rheb in hippocampal neurons in vivo, we transfected neurons in the cornu ammonis 1 (CA1) region in normal adult rats with an adeno-associated virus containing the constitutively active human Rheb (hRheb(S16H)) and evaluated the effects on thrombin-induced neurotoxicity. Transduction with hRheb(S16H) significantly induced neurotrophic effects in hippocampal neurons through activation of mammalian target of rapamycin complex 1 (mTORC1) without side effects such as long-term potentiation impairment and seizures from the alteration of cytoarchitecture, and the expression of hRheb(S16H) prevented thrombin-induced neurodegeneration in vivo, an effect that was diminished by treatment with specific neutralizing antibodies against brain-derived neurotrophic factor (BDNF). In addition, our results showed that the basal mTORC1 activity might be insufficient to mediate the level of BDNF expression, but hRheb(S16H)-activated mTORC1 stimulated BDNF production in hippocampal neurons. These results suggest that viral vector transduction with hRheb(S16H) may have therapeutic value in the treatment of neurodegenerative diseases such as AD.
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BDNF prevents amyloid-dependent impairment of LTP in the entorhinal cortex by attenuating p38 MAPK phosphorylation. Neurobiol Aging 2014; 36:1303-9. [PMID: 25554494 DOI: 10.1016/j.neurobiolaging.2014.11.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 10/24/2014] [Accepted: 11/25/2014] [Indexed: 12/18/2022]
Abstract
The oligomeric form of the amyloid peptide Aβ(1-42) is capable of perturbing synaptic plasticity in different brain areas. Here, we evaluated the protective role of brain-derived neurotrophic factor (BDNF) in beta amyloid (Aβ)-dependent impairment of long-term potentiation in entorhinal cortex (EC) slices. We found that BDNF (1 ng/mL) supplied by perfusion was able to rescue long-term potentiation in Aβ(1-42)-treated slices; BDNF protection was mediated by TrkB receptor as assessed by using the tyrosine kinase inhibitor K252a (200 nM). We also investigated the function of endogenous BDNF using a soluble form of TrkB receptor (TrkB IgG). Incubation of slices with TrkB IgG (1 μg/mL) increased the EC vulnerability to Aβ. Finally, we investigated the effect of BDNF on the cell stress-kinase p38 mitogen-activated protein kinase (MAPK) in primary cortical cell cultures exposed to Aβ(1-42). We found that Aβ induces p38 MAPK phosphorylation, although pretreatment with BDNF prevented Aβ-dependent p38 MAPK phosphorylation. This result was confirmed by an immunoassay in tissue extracts from EC slices collected after electrophysiology.
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