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Thammasart S, Namchaiw P, Pasuwat K, Tonsomboon K, Khantachawana A. Attenuation Aβ1-42-induced neurotoxicity in neuronal cell by 660nm and 810nm LED light irradiation. PLoS One 2023; 18:e0283976. [PMID: 37478089 PMCID: PMC10361470 DOI: 10.1371/journal.pone.0283976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 03/21/2023] [Indexed: 07/23/2023] Open
Abstract
Oligomeric amyloid-β 1-42 (Aβ1-42) has a close correlation with neurodegenerative disorder especially Alzheimer's disease (AD). It induces oxidative stress and mitochondrial damage in neurons. Therefore, it is used to generate AD-like in vitro model for studying neurotoxicity and neuroprotection against amyloid-β. A low-level light therapy (LLLT) is a non-invasive method that has been used to treat several neurodegenerative disorders. In this study, the red wavelength (660nm) and near infrared wavelength (810nm) at energy densities of 1, 3, and 5 J/cm2 were used to modulate biochemical processes in the neural cells. The exposure of Aβ1-42 resulted in cell death, increased intracellular reactive oxygen species (ROS), and retracted neurite outgrowth. We showed that both of LLLT wavelengths could protect neurons form Aβ1-42-induced neurotoxicity in a biphasic manner. The treatment of LLLT at 3 J/cm2 potentially alleviated cell death and recovered neurite outgrowth. In addition, the treatment of LLLT following Aβ1-42 exposure could attenuate the intracellular ROS generation and Ca2+ influx. Interestingly, both wavelengths could induce minimal level of ROS generation. However, they did not affect cell viability. In addition, LLLT also stimulated Ca2+ influx, but not altered mitochondrial membrane potential. This finding indicated LLLT may protect neurons through the stimulation of secondary signaling messengers such as ROS and Ca2+. The increase of these secondary messengers was in a functional level and did not harmful to the cells. These results suggested the use of LLLT as a tool to modulate the neuronal toxicity following Aβ1-42 accumulation in AD's brain.
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Affiliation(s)
- Siriluk Thammasart
- Biological Engineering Program, Faculty of Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Thung Kru, Bangkok, Thailand
| | - Poommaree Namchaiw
- Biological Engineering Program, Faculty of Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Thung Kru, Bangkok, Thailand
- Neuroscience Center for Research and Innovation, Learning Institute, King Mongkut's University of Technology Thonburi (KMUTT), Thung Kru, Bangkok, Thailand
| | - Kwanchanok Pasuwat
- Biological Engineering Program, Faculty of Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Thung Kru, Bangkok, Thailand
- Department of Chemical Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Thung Kru, Bangkok, Thailand
| | - Khaow Tonsomboon
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand
| | - Anak Khantachawana
- Biological Engineering Program, Faculty of Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Thung Kru, Bangkok, Thailand
- Department of Mechanical Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Thung Kru, Bangkok, Thailand
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2
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Ray B, Maloney B, Sambamurti K, Karnati HK, Nelson PT, Greig NH, Lahiri DK. Rivastigmine modifies the α-secretase pathway and potentially early Alzheimer's disease. Transl Psychiatry 2020; 10:47. [PMID: 32066688 PMCID: PMC7026402 DOI: 10.1038/s41398-020-0709-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/25/2019] [Accepted: 12/19/2019] [Indexed: 12/12/2022] Open
Abstract
Rivastigmine (or Exelon) is a cholinesterase inhibitor, currently used as a symptomatic treatment for mild-to-moderate Alzheimer's disease (AD). Amyloid-β peptide (Aβ) generated from its precursor protein (APP) by β-secretase (or BACE1) and γ-secretase endoproteolysis. Alternative APP cleavage by α-secretase (a family of membrane-bound metalloproteases- Adamalysins) precludes the generation of toxic Aβ and yields a neuroprotective and neurotrophic secreted sAPPα fragment. Several signal transduction pathways, including protein kinase C and MAP kinase, stimulate α-secretase. We present data to suggest that rivastigmine, in addition to anticholinesterase activity, directs APP processing away from BACE1 and towards α-secretases. We treated rat neuronal PC12 cells and primary human brain (PHB) cultures with rivastigmine and the α-secretase inhibitor TAPI and assayed for levels of APP processing products and α-secretases. We subsequently treated 3×Tg (transgenic) mice with rivastigmine and harvested hippocampi to assay for levels of APP processing products. We also assayed postmortem human control, AD, and AD brains from subjects treated with rivastigmine for levels of APP metabolites. Rivastigmine dose-dependently promoted α-secretase activity by upregulating levels of ADAM-9, -10, and -17 α-secretases in PHB cultures. Co-treatment with TAPI eliminated rivastigmine-induced sAPPα elevation. Rivastigmine treatment elevated levels of sAPPα in 3×Tg mice. Consistent with these results, we also found elevated sAPPα in postmortem brain samples from AD patients treated with rivastigmine. Rivastigmine can modify the levels of several shedding proteins and directs APP processing toward the non-amyloidogenic pathway. This novel property of rivastigmine can be therapeutically exploited for disease-modifying intervention that goes beyond symptomatic treatment for AD.
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Affiliation(s)
- Balmiki Ray
- grid.257413.60000 0001 2287 3919Department of Psychiatry, Laboratory of Molecular Neurogenetics, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Bryan Maloney
- grid.257413.60000 0001 2287 3919Department of Psychiatry, Laboratory of Molecular Neurogenetics, Indiana University School of Medicine, Indianapolis, IN 46202 USA ,grid.257413.60000 0001 2287 3919Indiana Alzheimer Disease Center, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Kumar Sambamurti
- grid.259828.c0000 0001 2189 3475Department of Neurosciences, Medical University of South Carolina, Charleston, 29425 SC USA
| | - Hanuma K. Karnati
- grid.419475.a0000 0000 9372 4913National Institute on Aging, Drug Design and Development Section, Bethesda, MD 20892 USA
| | - Peter T. Nelson
- grid.266539.d0000 0004 1936 8438Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536 USA
| | - Nigel H. Greig
- grid.419475.a0000 0000 9372 4913National Institute on Aging, Drug Design and Development Section, Bethesda, MD 20892 USA
| | - Debomoy K. Lahiri
- grid.257413.60000 0001 2287 3919Department of Psychiatry, Laboratory of Molecular Neurogenetics, Indiana University School of Medicine, Indianapolis, IN 46202 USA ,grid.257413.60000 0001 2287 3919Indiana Alzheimer Disease Center, Indiana University School of Medicine, Indianapolis, IN 46202 USA ,grid.257413.60000 0001 2287 3919Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202 USA
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3
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Zhong L, Liu H, Zhang W, Liu X, Jiang B, Fei H, Sun Z. Ellagic acid ameliorates learning and memory impairment in APP/PS1 transgenic mice via inhibition of β-amyloid production and tau hyperphosphorylation. Exp Ther Med 2018; 16:4951-4958. [PMID: 30542451 PMCID: PMC6257515 DOI: 10.3892/etm.2018.6860] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 03/23/2018] [Indexed: 01/20/2023] Open
Abstract
β-amyloid (Aβ) aggregation and tau hyperphosphorylation are considered to be the primary pathological hallmarks of Alzheimer's disease (AD). Targeted inhibition of these pathological processes may provide effective treatments for AD. Accumulating evidence has demonstrated that ellagic acid (EA) exerts neuroprotective effects in several diseases. The present study investigated the effects of EA on AD-associated learning and memory deficits on APP/PS1 double transgenic mice and the underlying mechanisms. APP/PS1 mice or wild-type C57BL/6 mice were intragastrically administered EA (50 mg/kg/day) or vehicle for 60 consecutive days. The learning and memory abilities of mice were investigated using the Morris water maze test. Hippocampal regions were examined for the presence of amyloid plaques, neuronal apoptosis and tau phosphorylation. Expression levels of APP, Aβ, RAC-αserine/threonine-protein kinase and glycogen synthase kinase (GSK)3β in the hippocampus were determined by western blot analysis and ELISA. The results demonstrated that EA treatment ameliorated spatial learning and memory impairment in APP/PS1 mice and significantly reduced neuronal apoptosis and Aβ deposition in the hippocampus (P<0.05 and P<0.01). In addition, EA significantly inhibited the hyperphosphorylation of tau and significantly decreased the activity of glycogen synthase kinase (GSK)3β (P<0.01), which is involved in tau phosphorylation. Overall, these findings indicated that the beneficial effects of EA on AD-associated cognitive impairments may be attributed to the inhibition of Aβ production and tau hyperphosphorylation, and its beneficial action may be mediated in part, by the RAC-α serine/threonine-protein kinase/GSK3β signaling pathway.
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Affiliation(s)
- Lili Zhong
- Department of Pathology, The First Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150001, P.R. China.,Postdoctoral Program, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China
| | - Hong Liu
- Postdoctoral Program, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China.,Department of Pathophysiology, School of Basic Medical Sciences, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China
| | - Weijia Zhang
- Second Department of Orthopedic Surgery, Harbin First Hospital, Harbin, Heilongjiang 150010, P.R. China
| | - Xu Liu
- Experimental Center, School of Basic Medical Sciences, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China
| | - Bo Jiang
- Drug Safety Evaluation Center, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China
| | - Hongxin Fei
- Department of Pathology, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
| | - Zhongren Sun
- Key Laboratory of Acupuncture Clinical Neurobiology (Encephalopathy), Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China
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4
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Lanza V, Bellia F, Rizzarelli E. An inorganic overview of natural Aβ fragments: Copper(II) and zinc(II)-mediated pathways. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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5
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Wang Z, Huang X, Zhao P, Zhao L, Wang ZY. Catalpol Inhibits Amyloid-β Generation Through Promoting α-Cleavage of APP in Swedish Mutant APP Overexpressed N2a Cells. Front Aging Neurosci 2018; 10:66. [PMID: 29615891 PMCID: PMC5867310 DOI: 10.3389/fnagi.2018.00066] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 02/26/2018] [Indexed: 12/15/2022] Open
Abstract
Amyloid-β (Aβ) peptides play a crucial role in the pathogenesis of Alzheimer's disease (AD), due to its neurotoxicity. Thus, blocking Aβ generation and aggregation in the brain has been realized as an efficient way for the prevention of AD. The natural product catalpol, isolated from Rehmannia glutinosa, has shown neuroprotective activities through inhibiting soluble Aβ production, degrading Aβ peptide, and attenuating Aβ toxicity and neuroinflammatory responses. In the present study, we aimed to evaluate whether catalpol reduce Aβ generation associated with regulating amyloid precursor protein (APP) proteolytic processing. By using Swedish mutant APP overexpressed N2a (SweAPP N2a) cells treated with catalpol, we found that catalpol was not able to reduce the expression levels of β-secretase (BACE-1) and γ-secretase (PS1, APH-1, PEN-2 and Nicastrin). By contrast, catalpol had a significant promotion effect on the expression of α-secretase (ADAM10) and its proteolytic products, sAPPα and C83, suggesting that catalpol reduced the production of Aβ might be involved in non-amyloidogenic APP pathway. In addition, we confirmed that the extracellular signal-related kinase/cAMP-response element binding protein (ERK/CREB) signaling pathways were responsible for the up-regulation of ADAM10 in catalpol-treated SweAPP N2a cells. The present data, for the first time, have demonstrated that the effect of catalpol on the inhibiting Aβ generation might be closely related to α-cleavage of APP processing.
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Affiliation(s)
- Zhuo Wang
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Xueshi Huang
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Pu Zhao
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Limei Zhao
- Shengjing Hospital, China Medical University, Shenyang, China
| | - Zhan-You Wang
- College of Life and Health Sciences, Northeastern University, Shenyang, China.,Institute of Health Sciences, Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, China
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6
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Halawany AME, Sayed NSE, Abdallah HM, Dine RSE. Protective effects of gingerol on streptozotocin-induced sporadic Alzheimer's disease: emphasis on inhibition of β-amyloid, COX-2, alpha-, beta - secretases and APH1a. Sci Rep 2017; 7:2902. [PMID: 28588301 PMCID: PMC5460182 DOI: 10.1038/s41598-017-02961-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 04/26/2017] [Indexed: 12/27/2022] Open
Abstract
Gingerol is a major dietary compound that occurs in several plants belonging to the Zingiberaceae family. In the current study, the protective effect of gingerol on STZ-induced sporadic Alzheimer's disease (SAD) was determined. Gingerol was isolated from the seeds of Aframomum melegueta K. Schum and tested at doses of 10 and 20 mg/kgbwt for its possible effect on the SAD model in mice, using celecoxib (30 mg/kg bwt) as a reference standard. The curative effects of gingerol were assessed through measurement of β-amyloid (Aβ-42), α-, β- secretases, APH1a and COX-2 levels. In addition, improvement in the cognitive deficit in mice after treatment was confirmed using the water maze and Y-maze with intra-maze cues. Gingerol improved the cognitive and behavioral impairment and AD-like pathology in streptozotocin model mice. These beneficial effects occurred with an increase in α-secretase activity and a decrease in cerebral Aβ-42, β- secretase, APH1a activity and COX-2-linked neuro-inflammation.
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Affiliation(s)
- Ali M El Halawany
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Nesrine S El Sayed
- Department of Pharmacology &Toxicology, Faculty of pharmacy, Cairo University, 11562, Cairo, Egypt.,Department of Pharmacology &Toxicology, Faculty of pharmacy & Biotechnology, German University in Cairo, 11835, Cairo, Egypt
| | - Hossam M Abdallah
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt. .,Department of Natural Products, Faculty of Pharmacy, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
| | - Riham Salah El Dine
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
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7
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García-Ayllón MS, Lopez-Font I, Boix CP, Fortea J, Sánchez-Valle R, Lleó A, Molinuevo JL, Zetterberg H, Blennow K, Sáez-Valero J. C-terminal fragments of the amyloid precursor protein in cerebrospinal fluid as potential biomarkers for Alzheimer disease. Sci Rep 2017; 7:2477. [PMID: 28559572 PMCID: PMC5449401 DOI: 10.1038/s41598-017-02841-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/18/2017] [Indexed: 11/15/2022] Open
Abstract
This study assesses whether C-terminal fragments (CTF) of the amyloid precursor protein (APP) are present in cerebrospinal fluid (CSF) and their potential as biomarkers for Alzheimer’s disease (AD). Immunoprecipitation and simultaneous assay by Western blotting using multiplex fluorescence imaging with specific antibodies against particular domains served to characterize CTFs of APP in human CSF. We demonstrate that APP-CTFs are detectable in human CSF, being the most abundant a 25-kDa fragment, probably resulting from proteolytic processing by η-secretase. The level of the 25-kDa APP-CTF was evaluated in three independent CSF sample sets of patients and controls. The CSF level of this 25-kDa CTF is higher in subjects with autosomal dominant AD linked to PSEN1 mutations, in demented Down syndrome individuals and in sporadic AD subjects compared to age-matched controls. Our data suggest that APP-CTF could be a potential diagnostic biomarker for AD.
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Affiliation(s)
- María-Salud García-Ayllón
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550, Sant Joan d'Alacant, Alicante, España.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sant Joan d'Alacant, 03550, Alicante, España.,Unidad de Investigación, Hospital General Universitario de Elche, FISABIO, Elche, Spain
| | - Inmaculada Lopez-Font
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550, Sant Joan d'Alacant, Alicante, España.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sant Joan d'Alacant, 03550, Alicante, España
| | - Claudia P Boix
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550, Sant Joan d'Alacant, Alicante, España.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sant Joan d'Alacant, 03550, Alicante, España
| | - Juan Fortea
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sant Joan d'Alacant, 03550, Alicante, España.,Memory Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Down Medical Center, Fundació Catalana Síndrome de Down, Barcelona, Spain
| | - Raquel Sánchez-Valle
- Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, 08036, Barcelona, Spain
| | - Alberto Lleó
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sant Joan d'Alacant, 03550, Alicante, España.,Memory Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - José-Luis Molinuevo
- Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, 08036, Barcelona, Spain
| | - Henrik Zetterberg
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.,Institute of Neuroscience and Physiology, University of Gothenburg, Mölndal Campus, Sweden.,Department of Molecular Neuroscience, Institute of Neurology, University College London, London, UK
| | - Kaj Blennow
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.,Institute of Neuroscience and Physiology, University of Gothenburg, Mölndal Campus, Sweden
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550, Sant Joan d'Alacant, Alicante, España. .,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sant Joan d'Alacant, 03550, Alicante, España.
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8
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Mori T, Koyama N, Tan J, Segawa T, Maeda M, Town T. Combination therapy with octyl gallate and ferulic acid improves cognition and neurodegeneration in a transgenic mouse model of Alzheimer's disease. J Biol Chem 2017; 292:11310-11325. [PMID: 28512130 DOI: 10.1074/jbc.m116.762658] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 05/15/2017] [Indexed: 12/12/2022] Open
Abstract
To date, there is no effective Alzheimer's disease (AD)-modifying therapy. Nonetheless, combination therapy holds promise, and nutraceuticals (natural dietary compounds with therapeutic properties) and their synthetic derivatives are well-tolerated candidates. We tested whether combination therapy with octyl gallate (OG) and ferulic acid (FA) improves cognition and mitigates AD-like pathology in the presenilin-amyloid β-protein precursor (PSAPP) transgenic mouse model of cerebral amyloidosis. One-year-old mice with established β-amyloid plaques received daily doses of OG and FA alone or in combination for 3 months. PSAPP mice receiving combination therapy had statistically significant improved cognitive function versus OG or FA single treatment on some (but not all) measures. We also observed additional statistically significant reductions in brain parenchymal and cerebral vascular β-amyloid deposits as well as brain amyloid β-protein abundance in OG- plus FA-treated versus singly-treated PSAPP mice. These effects coincided with enhanced nonamyloidogenic amyloid β-protein precursor (APP) cleavage, increased α-secretase activity, and β-secretase inhibition. We detected elevated expression of nonamyloidogenic soluble APP-α and the α-secretase candidate, a disintegrin and metalloproteinase domain-containing protein 10. Correspondingly, amyloidogenic β-carboxyl-terminal APP fragment and β-site APP-cleaving enzyme 1 expression levels were reduced. In parallel, the ratio of β- to α-carboxyl-terminal APP fragment was decreased. OG and FA combination therapy strikingly attenuated neuroinflammation, oxidative stress, and synaptotoxicity. Co-treatment afforded additional statistically significant benefits on some, but not all, of these outcome measures. Taken together, these data provide preclinical proof-of-concept for AD combination therapy.
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Affiliation(s)
- Takashi Mori
- From the Departments of Biomedical Sciences and .,Pathology, Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan
| | | | - Jun Tan
- the Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center and.,the Neuroimmunology Laboratory, Department of Psychiatry and Behavioral Neurosciences, Morsoni College of Medicine, University of South Florida, Tampa, Florida 33613
| | - Tatsuya Segawa
- the Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan, and
| | - Masahiro Maeda
- the Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan, and
| | - Terrence Town
- the Zilkha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California 90089-2821
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9
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Zhang ZX, Zhao RP, Wang DS, Wang AN. Fuzhisan ameliorates Aβ production and tau phosphorylation in hippocampal of 11 month old APP/PS1 transgenic mice: A Western blot study. Exp Gerontol 2016; 84:88-95. [DOI: 10.1016/j.exger.2016.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 08/24/2016] [Accepted: 09/05/2016] [Indexed: 12/30/2022]
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10
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Zhang ZX, Zhao RP, Wang DS, Li YB. Fuzhisan Ameliorates the Memory Deficits in Aged SAMP8 Mice via Decreasing Aβ Production and Tau Hyperphosphorylation of the Hippocampus. Neurochem Res 2016; 41:3074-3082. [DOI: 10.1007/s11064-016-2028-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 07/07/2016] [Accepted: 08/02/2016] [Indexed: 01/01/2023]
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11
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Xie H, Xiao Z, Huang J. C6 Glioma-Secreted NGF and FGF2 Regulate Neuronal APP Processing Through Up-Regulation of ADAM10 and Down-Regulation of BACE1, Respectively. J Mol Neurosci 2015; 59:334-42. [PMID: 26614345 DOI: 10.1007/s12031-015-0690-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/19/2015] [Indexed: 01/05/2023]
Abstract
Excessive accumulation of amyloid-β (Aβ) caused by cleavage of amyloid precursor protein (APP) is thought to be the primary cause of Alzheimer's disease (AD). Two key enzymes ADAM10 and BACE1 are involved in the initial cleavage of APP, resulting in the onset of two pathways, the amyloidogenic pathway and the non-amyloidogenic pathway, respectively. Altering APP metabolism towards the non-amyloidogenic pathway is thought to reduce Aβ production. It has been reported that, in vivo, exogenous neurotrophic factors make APP apt to entering the non-amyloidogenic pathway. Since astrocytes secrete a battery of neurotrophic factors, we investigated the role of astrocyte-derived factors in the dynamics of Aβ generation in neural cells. Results show that C6 glioma cell-conditioned medium (GCM), obtained from cultured astrocyte-derived C6 glioma cells, inhibit Aβ1-42 production and shift APP processing towards the non-amyloidogenic pathway in APPswe-HEK293 cells. Such effect is attributed to two key APP cleavage enzymes, ADAM10 and BACE1. Two neurotrophic factors in the GCM, nerve growth factor and fibroblast growth factor 2, are responsible for the up-regulation of ADAM10 and down-regulation of BACE1, respectively. Our findings enhance our understanding of the relationship between astrocytes and Aβ generation, indicating that stimulation of astrocytic neurotrophic factors could slow AD progression.
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Affiliation(s)
- Huiping Xie
- College of Life Sciences, Wuhan University, Room 5105, Wuhan, Hubei, 430072, People's Republic of China
| | - Zhimin Xiao
- College of Life Sciences, Wuhan University, Room 5105, Wuhan, Hubei, 430072, People's Republic of China.,Sanofi, Cambridge, MA, 02142, USA
| | - Jian Huang
- College of Life Sciences, Wuhan University, Room 5105, Wuhan, Hubei, 430072, People's Republic of China.
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12
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Sun Q, Hampel H, Blennow K, Lista S, Levey A, Tang B, Li R, Shen Y. Increased plasma TACE activity in subjects with mild cognitive impairment and patients with Alzheimer's disease. J Alzheimers Dis 2015; 41:877-86. [PMID: 24685635 DOI: 10.3233/jad-140177] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Evidence suggests that the tumor necrosis factor receptor (TNFR)-signaling pathway contributes to the pathogenesis of Alzheimer's disease (AD). TNF-α converting enzyme (TACE/ADAM-17) can cleave both pro-TNF-α and TNF receptors. Recently, we have shown that TACE activity in the cerebrospinal fluid (CSF) of subjects with mild cognitive impairment (MCI) and AD patients is significantly higher than that of cognitively healthy controls (HC). To date, it is not clear whether TACE activity could be detected in the human plasma and whether TACE activity in MCI and AD patients is different from that in HC. We analyzed TACE expression and activity in a large clinical sample of 64 patients with AD, 88 subjects with MCI, and 50 age-matched HC recruited from two distinct academic centers. Plasma TACE protein levels did not differ significantly in the three study groups (AD, MCI, and HC). However, plasma TACE activity in subjects with MCI and AD patients was significantly higher than that in HC. Moreover, in MCI and AD groups, we found a significant correlation between plasma TACE activity and CSF t-tau and Aβ42 levels and CSF Aβ42/tau ratios. In AD patients, the levels of plasma TACE activity correlated significantly and negatively with cognition. These findings further support the role of the TNF-α receptor complex in AD-related neuroinflammation and propose TACE plasma activity as a promising hypothesis-driven biomarker candidate for detection, diagnosis, and prognosis of prodromal and clinical AD.
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Affiliation(s)
- Qiying Sun
- Center for Advanced Therapeutic Strategies for Brain Disorders, The Roskamp Institute, Sarasota, FL, USA Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Harald Hampel
- Department of Psychiatry and Psychotherapy, Alzheimer Memorial Center, University of Munich, Munich, Germany Université Pierre et Marie Curie, Département de Neurologie, Institut de la Mémoire et de la Maladie d'Alzheimer, Hôpital de la Salpêtrière, Paris, France
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Sahlgren's University Hospital, Mölndal, Sweden
| | - Simone Lista
- Université Pierre et Marie Curie, Département de Neurologie, Institut de la Mémoire et de la Maladie d'Alzheimer, Hôpital de la Salpêtrière, Paris, France
| | - Allan Levey
- Department of Neurology and Alzheimer's Disease Research Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Rena Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China Center for Hormone Advanced Science and Education, Roskamp Institute, Sarasota, FL, USA
| | - Yong Shen
- Center for Advanced Therapeutic Strategies for Brain Disorders, The Roskamp Institute, Sarasota, FL, USA Department of Neurology, Xiangya Hospital, Central South University, Changsha, China Department of Neurology, University of Florida College of Medicine, Gainesville, FL, USA
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13
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Baranello RJ, Bharani KL, Padmaraju V, Chopra N, Lahiri DK, Greig NH, Pappolla MA, Sambamurti K. Amyloid-beta protein clearance and degradation (ABCD) pathways and their role in Alzheimer's disease. Curr Alzheimer Res 2015; 12:32-46. [PMID: 25523424 PMCID: PMC4820400 DOI: 10.2174/1567205012666141218140953] [Citation(s) in RCA: 210] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 11/16/2014] [Accepted: 12/05/2014] [Indexed: 11/22/2022]
Abstract
Amyloid-β proteins (Aβ) of 42 (Aβ42) and 40 aa (Aβ40) accumulate as senile plaques (SP) and cerebrovascular amyloid protein deposits that are defining diagnostic features of Alzheimer's disease (AD). A number of rare mutations linked to familial AD (FAD) on the Aβ precursor protein (APP), Presenilin-1 (PS1), Presenilin- 2 (PS2), Adamalysin10, and other genetic risk factors for sporadic AD such as the ε4 allele of Apolipoprotein E (ApoE-ε4) foster the accumulation of Aβ and also induce the entire spectrum of pathology associated with the disease. Aβ accumulation is therefore a key pathological event and a prime target for the prevention and treatment of AD. APP is sequentially processed by β-site APP cleaving enzyme (BACE1) and γ-secretase, a multisubunit PS1/PS2-containing integral membrane protease, to generate Aβ. Although Aβ accumulates in all forms of AD, the only pathways known to be affected in FAD increase Aβ production by APP gene duplication or via base substitutions on APP and γ-secretase subunits PS1 and PS2 that either specifically increase the yield of the longer Aβ42 or both Aβ40 and Aβ42. However, the vast majority of AD patients accumulate Aβ without these known mutations. This led to proposals that impairment of Aβ degradation or clearance may play a key role in AD pathogenesis. Several candidate enzymes, including Insulin-degrading enzyme (IDE), Neprilysin (NEP), Endothelin-converting enzyme (ECE), Angiotensin converting enzyme (ACE), Plasmin, and Matrix metalloproteinases (MMPs) have been identified and some have even been successfully evaluated in animal models. Several studies also have demonstrated the capacity of γ-secretase inhibitors to paradoxically increase the yield of Aβ and we have recently established that the mechanism is by skirting Aβ degradation. This review outlines major cellular pathways of Aβ degradation to provide a basis for future efforts to fully characterize the panel of pathways responsible for Aβ turnover.
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Affiliation(s)
| | | | | | | | | | | | | | - Kumar Sambamurti
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, BSB 403, Charleston, SC 29425, USA.
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Mori T, Koyama N, Segawa T, Maeda M, Maruyama N, Kinoshita N, Hou H, Tan J, Town T. Methylene blue modulates β-secretase, reverses cerebral amyloidosis, and improves cognition in transgenic mice. J Biol Chem 2014; 289:30303-30317. [PMID: 25157105 DOI: 10.1074/jbc.m114.568212] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Amyloid precursor protein (APP) proteolysis is required for production of amyloid-β (Aβ) peptides that comprise β-amyloid plaques in the brains of patients with Alzheimer disease (AD). Here, we tested whether the experimental agent methylene blue (MB), used for treatment of methemoglobinemia, might improve AD-like pathology and behavioral deficits. We orally administered MB to the aged transgenic PSAPP mouse model of cerebral amyloidosis and evaluated cognitive function and cerebral amyloid pathology. Beginning at 15 months of age, animals were gavaged with MB (3 mg/kg) or vehicle once daily for 3 months. MB treatment significantly prevented transgene-associated behavioral impairment, including hyperactivity, decreased object recognition, and defective spatial working and reference memory, but it did not alter nontransgenic mouse behavior. Moreover, brain parenchymal and cerebral vascular β-amyloid deposits as well as levels of various Aβ species, including oligomers, were mitigated in MB-treated PSAPP mice. These effects occurred with inhibition of amyloidogenic APP proteolysis. Specifically, β-carboxyl-terminal APP fragment and β-site APP cleaving enzyme 1 protein expression and activity were attenuated. Additionally, treatment of Chinese hamster ovary cells overexpressing human wild-type APP with MB significantly decreased Aβ production and amyloidogenic APP proteolysis. These results underscore the potential for oral MB treatment against AD-related cerebral amyloidosis by modulating the amyloidogenic pathway.
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Affiliation(s)
- Takashi Mori
- Departments of Biomedical Sciences and Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan; Departments of Pathology, Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan,.
| | - Naoki Koyama
- Departments of Biomedical Sciences and Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan
| | - Tatsuya Segawa
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Masahiro Maeda
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Nobuhiro Maruyama
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Noriaki Kinoshita
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Huayan Hou
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center and University of South Florida, Tampa, Florida 33613
| | - Jun Tan
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center and University of South Florida, Tampa, Florida 33613; Neuroimmunology Laboratory, Department of Psychiatry and Behavioral Neurosciences, Morsoni College of Medicine, University of South Florida, Tampa, Florida 33613, and
| | - Terrence Town
- Zilkha Neurogenetic Institute, Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California 90089-2821.
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15
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Evidence of a novel mechanism for partial γ-secretase inhibition induced paradoxical increase in secreted amyloid β protein. PLoS One 2014; 9:e91531. [PMID: 24658363 PMCID: PMC3962361 DOI: 10.1371/journal.pone.0091531] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 02/12/2014] [Indexed: 02/02/2023] Open
Abstract
BACE1 (β-secretase) and α-secretase cleave the Alzheimer's amyloid β protein (Aβ) precursor (APP) to C-terminal fragments of 99 aa (CTFβ) and 83 aa (CTFα), respectively, which are further cleaved by γ-secretase to eventually secrete Aβ and Aα (a.k.a. P3) that terminate predominantly at residues 40 and 42. A number of γ-secretase inhibitors (GSIs), such as N-[N-(3,5-Difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester (DAPT), have been developed with the goal of reducing Aβ to treat Alzheimer's disease (AD). Although most studies show that DAPT inhibits Aβ in a dose-dependent manner several studies have also detected a biphasic effect with an unexpected increase at low doses of DAPT in cell cultures, animal models and clinical trials. In this article, we confirm the increase in Aβ40 and Aβ42 in SH-SY5Y human neuroblastoma cells treated with low doses of DAPT and identify one of the mechanisms for this paradox. We studied the pathway by first demonstrating that stimulation of Aβ, a product of γ-secretase, was accompanied by a parallel increase of its substrate CTFβ, thereby demonstrating that the inhibitor was not anomalously stimulating enzyme activity at low levels. Secondly, we have demonstrated that inhibition of an Aβ degrading activity, endothelin converting enzyme (ECE), yielded more Aβ, but abolished the DAPT-induced stimulation. Finally, we have demonstrated that Aα, which is generated in the secretory pathway before endocytosis, is not subject to the DAPT-mediated stimulation. We therefore conclude that impairment of γ-secretase can paradoxically increase Aβ by transiently skirting Aβ degradation in the endosome. This study adds to the growing body of literature suggesting that preserving γ-secretase activity, rather than inhibiting it, is important for prevention of neurodegeneration.
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Park H, Yoo JS, Kim JY, Hwang BY, Han JS, Yeon SW, Kang JH. Anti-amyloidogenic effects of ID1201, the ethanolic extract of the fruits of Melia toosendan, through activation of the phosphatidylinositol 3-kinase/Akt pathway. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2014; 37:513-520. [PMID: 24566006 DOI: 10.1016/j.etap.2014.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 12/27/2013] [Accepted: 01/14/2014] [Indexed: 06/03/2023]
Abstract
Amyloid beta (Aβ) peptides, which are generated from amyloid precursor protein (APP), are thought to play a major role in the pathogenesis of Alzheimer's disease (AD). This study investigated the anti-amyloidogenic effects of the ethanolic extract of Meliae Fructus (ID1201) using human embryonic kidney 293 cells with stably expressed human wild-type or Swedish mutant APP695 and β-secretase 1. ID1201 treatment enhanced the non-amyloidogenic metabolism of APP; increases in soluble APPα levels and decreases in soluble APPβ and Aβ levels resulted from the α-secretase activation through the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. In addition, ID1201-treated 5×familial AD (FAD) mice with 5 mutations in APP and presenilin 1 showed reduced levels of Aβ and amyloid plaques in the brain relative to those of 5×FAD mice with vehicle treatments. These results indicate that ID1201 possesses anti-amyloidogenic effects via the activation of the PI3K/Akt pathway, suggesting that it is a potential therapeutic agent for AD.
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Affiliation(s)
- Hanbyeol Park
- ILDONG Research Laboratories, ILDONG Pharmaceutical Co. Ltd., Hwaseong, Gyeonggi 445-710, Republic of Korea
| | - Jong-Su Yoo
- ILDONG Research Laboratories, ILDONG Pharmaceutical Co. Ltd., Hwaseong, Gyeonggi 445-710, Republic of Korea
| | - Ji-Young Kim
- ILDONG Research Laboratories, ILDONG Pharmaceutical Co. Ltd., Hwaseong, Gyeonggi 445-710, Republic of Korea
| | - Bang Yeon Hwang
- College of Pharmacy, Chungbuk National University, Cheongju 361-763, Republic of Korea
| | - Jung-Soo Han
- Department of Biological Sciences, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea
| | - Seung-Woo Yeon
- ILDONG Research Laboratories, ILDONG Pharmaceutical Co. Ltd., Hwaseong, Gyeonggi 445-710, Republic of Korea.
| | - Jae-Hoon Kang
- ILDONG Research Laboratories, ILDONG Pharmaceutical Co. Ltd., Hwaseong, Gyeonggi 445-710, Republic of Korea
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Dasgupta S, Bandyopadhyay M. Neuroprotective mode of action of resveratrol in central nervous system. PHARMANUTRITION 2013. [DOI: 10.1016/j.phanu.2013.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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18
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Mori T, Koyama N, Guillot-Sestier MV, Tan J, Town T. Ferulic acid is a nutraceutical β-secretase modulator that improves behavioral impairment and alzheimer-like pathology in transgenic mice. PLoS One 2013; 8:e55774. [PMID: 23409038 PMCID: PMC3568151 DOI: 10.1371/journal.pone.0055774] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 01/04/2013] [Indexed: 11/19/2022] Open
Abstract
Amyloid precursor protein (APP) proteolysis is required for production of amyloid-β (Aβ) peptides that comprise β-amyloid plaques in brains of Alzheimer's disease (AD) patients. Recent AD therapeutic interest has been directed toward a group of anti-amyloidogenic compounds extracted from plants. We orally administered the brain penetrant, small molecule phenolic compound ferulic acid (FA) to the transgenic PSAPP mouse model of cerebral amyloidosis (bearing mutant human APP and presenilin-1 transgenes) and evaluated behavioral impairment and AD-like pathology. Oral FA treatment for 6 months reversed transgene-associated behavioral deficits including defective: hyperactivity, object recognition, and spatial working and reference memory, but did not alter wild-type mouse behavior. Furthermore, brain parenchymal and cerebral vascular β-amyloid deposits as well as abundance of various Aβ species including oligomers were decreased in FA-treated PSAPP mice. These effects occurred with decreased cleavage of the β-carboxyl-terminal APP fragment, reduced β-site APP cleaving enzyme 1 protein stability and activity, attenuated neuroinflammation, and stabilized oxidative stress. As in vitro validation, we treated well-characterized mutant human APP-overexpressing murine neuron-like cells with FA and found significantly decreased Aβ production and reduced amyloidogenic APP proteolysis. Collectively, these results highlight that FA is a β-secretase modulator with therapeutic potential against AD.
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Affiliation(s)
- Takashi Mori
- Department of Biomedical Sciences, Saitama Medical Center and University, Kawagoe, Saitama, Japan
- Department of Pathology, Saitama Medical Center and University, Kawagoe, Saitama, Japan
| | - Naoki Koyama
- Department of Biomedical Sciences, Saitama Medical Center and University, Kawagoe, Saitama, Japan
| | | | - Jun Tan
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center, Department of Psychiatry and Behavioral Neurosciences, Morsoni College of Medicine, University of South Florida, Tampa, Florida, United States of America
- Neuroimmunology Laboratory, Department of Psychiatry and Behavioral Neurosciences, Morsoni College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Terrence Town
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Regenerative Medicine Institute Neural Program, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
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19
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Peters HL, Tuli A, Wang X, Liu C, Pan Z, Ouellette MM, Hollingsworth MA, Macdonald RG, Solheim JC. Relevance of amyloid precursor-like protein 2 C-terminal fragments in pancreatic cancer cells. Int J Oncol 2012; 41:1464-74. [PMID: 22797723 PMCID: PMC3482291 DOI: 10.3892/ijo.2012.1553] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 05/25/2012] [Indexed: 12/21/2022] Open
Abstract
In some cellular systems, particularly neurons, amyloid precursor-like protein 2 (APLP2), and its highly homologous family member amyloid precursor protein (APP), have been linked to cellular growth. APLP2 and APP undergo regulated intramembrane proteolysis to produce C-terminal fragments. In this study, we found comprehensive expression of APLP2 C-terminal fragments in a panel of pancreatic cancer cell lines; however, APP C-terminal fragments were notably limited to the BxPC3 cell line. Extensive glycosaminoglycan modification on APLP2 was also found in the majority of pancreatic cancer cell lines. Glycosaminoglycan-modified and -unmodified APLP2, and particularly APLP2 C-terminal fragments, also demonstrated increased expression in oncogene-transformed pancreatic ductal cells. Additionally, elevated APLP2 levels were confirmed in human pancreatic cancer tissue. Downregulation of APLP2 and APP expression, alone or in combination, caused a decrease in the growth of a pancreatic cancer cell line with representatively low APP C-terminal fragment expression, the S2-013 cell line. Furthermore, we found that treatment with β-secretase inhibitors to block formation of APLP2 C-terminal fragments decreased the growth and viability of S2-013 cells, without affecting the survival of a non-transformed pancreatic ductal cell line. In conclusion, our studies demonstrate that abundant APLP2, but not APP, C-terminal fragment expression is conserved in pancreatic cancer cell lines; however, APP and APLP2 equally regulated the growth of S2-013 pancreatic cancer cells. Chiefly, our discoveries establish a role for APLP2 in the growth of pancreatic cancer cells and show that inhibitors preventing APLP2 cleavage reduce the viability of pancreatic cancer cells.
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Affiliation(s)
- Haley L Peters
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA
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20
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Mori T, Rezai-Zadeh K, Koyama N, Arendash GW, Yamaguchi H, Kakuda N, Horikoshi-Sakuraba Y, Tan J, Town T. Tannic acid is a natural β-secretase inhibitor that prevents cognitive impairment and mitigates Alzheimer-like pathology in transgenic mice. J Biol Chem 2012; 287:6912-27. [PMID: 22219198 DOI: 10.1074/jbc.m111.294025] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Amyloid precursor protein (APP) proteolysis is essential for production of amyloid-β (Aβ) peptides that form β-amyloid plaques in brains of Alzheimer disease (AD) patients. Recent focus has been directed toward a group of naturally occurring anti-amyloidogenic polyphenols known as flavonoids. We orally administered the flavonoid tannic acid (TA) to the transgenic PSAPP mouse model of cerebral amyloidosis (bearing mutant human APP and presenilin-1 transgenes) and evaluated cognitive function and AD-like pathology. Consumption of TA for 6 months prevented transgene-associated behavioral impairment including hyperactivity, decreased object recognition, and defective spatial reference memory, but did not alter nontransgenic mouse behavior. Accordingly, brain parenchymal and cerebral vascular β-amyloid deposits and abundance of various Aβ species including oligomers were mitigated in TA-treated PSAPP mice. These effects occurred with decreased cleavage of the β-carboxyl-terminal APP fragment, lowered soluble APP-β production, reduced β-site APP cleaving enzyme 1 protein stability and activity, and attenuated neuroinflammation. As in vitro validation, we treated well characterized mutant human APP-overexpressing murine neuron-like cells with TA and found significantly reduced Aβ production associated with less amyloidogenic APP proteolysis. Taken together, these results raise the possibility that dietary supplementation with TA may be prophylactic for AD by inhibiting β-secretase activity and neuroinflammation and thereby mitigating AD pathology.
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Affiliation(s)
- Takashi Mori
- Department of Biomedical Sciences, Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan.
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21
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Marolda R, Ciotti MT, Matrone C, Possenti R, Calissano P, Cavallaro S, Severini C. Substance P activates ADAM9 mRNA expression and induces α-secretase-mediated amyloid precursor protein cleavage. Neuropharmacology 2012; 62:1954-63. [PMID: 22244942 DOI: 10.1016/j.neuropharm.2011.12.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 12/13/2011] [Accepted: 12/21/2011] [Indexed: 01/08/2023]
Abstract
Altered levels of Substance P (SP), a neuropeptide endowed with neuroprotective and anti-apoptotic properties, were found in brain areas and spinal fluid of Alzheimer's disease (AD) patients. One of the hallmarks of AD is the abnormal extracellular deposition of neurotoxic beta amyloid (Aβ) peptides, derived from the proteolytic processing of amyloid precursor protein (APP). In the present study, we confirmed, the neurotrophic action of SP in cultured rat cerebellar granule cells (CGCs) and investigated its effects on APP metabolism. Incubation with low (5 mM) potassium induced apoptotic cell death of CGCs and amyloidogenic processing of APP, whereas treatment with SP (200 nM) reverted these effects via NK1 receptors. The non-amyloidogenic effect of SP consisted of reduction of Aβ(1-42), increase of sAPPα and enhanced α-secretase activity, without a significant change in steady-state levels of cellular APP. The intracellular mechanisms whereby SP alters APP metabolism were further investigated by measuring mRNA and/or steady-state protein levels of key enzymes involved with α-, β- and γ-secretase activity. Among them, Adam9, both at the mRNA and protein level, was the only enzyme to be significantly down-regulated following the induction of apoptosis (K5) and up-regulated after SP treatment. In addition to its neuroprotective properties, this study shows that SP is able to stimulate non-amyloidogenic APP processing, thereby reducing the possibility of generation of toxic Aβ peptides in brain.
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Affiliation(s)
- R Marolda
- Institute of Cell Biology and Neurobiology, CNR, Via del Fosso di Fiorano, 65, 00143 Rome, Italy
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22
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Jiang H, Hampel H, Prvulovic D, Wallin A, Blennow K, Li R, Shen Y. Elevated CSF levels of TACE activity and soluble TNF receptors in subjects with mild cognitive impairment and patients with Alzheimer's disease. Mol Neurodegener 2011; 6:69. [PMID: 21978728 PMCID: PMC3206445 DOI: 10.1186/1750-1326-6-69] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Accepted: 10/06/2011] [Indexed: 12/28/2022] Open
Abstract
We recently reported that expression levels of tumor necrosis factor (TNF) receptors, TNFR1 and TNFR2, are significantly changed in the brains and cerebrospinal fluid (CSF) with Alzheimer's disease (AD). Moreover, we also found that, in an Alzheimer's mouse model, genetic deletion of TNF receptor (TNFR1) reduces amyloid plaques and amyloid beta peptides (Aβ) production through β-secretase (BACE1) regulation. TNF-α converting enzyme (TACE/ADAM-17) does not only cleave pro- TNF-α but also TNF receptors, however, whether the TACE activity was changed in the CSF was not clear. In this study, we examined TACE in the CSF in 32 AD patients and 27 age-matched healthy controls (HCs). Interestingly, we found that TACE activity was significantly elevated in the CSF from AD patients compared with HCs. Furthermore, we also assayed the CSF levels of TACE cleaved soluble forms of TNFR1 and TNFR2 in the same patients. We found that AD patients had higher levels of both TACE cleaved soluble TNFR1 (sTNFR1) and TNFR2 (sTNFR2) in the CSF compared to age- and gender-matched healthy controls. Levels of sTNFR1 correlated strongly with the levels of sTNFR2 (rs = 0.567-0.663, p < 0.01). The levels of both sTNFR1 and sTNFR2 significantly correlated with the TACE activity (rs = 0.491-0.557, p < 0.05). To examine if changes in TACE activity and in levels of cleaved soluble TNFRs are an early event in the course of AD, we measured these molecules in the CSF from 47 subjects with mild cognitive impairment (MCI), which is considered as a preclinical stage of AD. Unexpectedly, we found significantly higher levels of TACE activity and soluble TNFRs in the MCI group than that in AD patients. These results suggest that TACE activity and soluble TNF receptors may be potential diagnostic candidate biomarkers in AD and MCI.
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Affiliation(s)
- Hong Jiang
- Center for Advanced Therapeutic Strategies for Brain Disorders, Roskamp Institute, Sarasota, FL 34243, USA.
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23
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Bace2 is a β cell-enriched protease that regulates pancreatic β cell function and mass. Cell Metab 2011; 14:365-77. [PMID: 21907142 DOI: 10.1016/j.cmet.2011.06.018] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 05/11/2011] [Accepted: 06/22/2011] [Indexed: 11/23/2022]
Abstract
Decreased β cell mass and function are hallmarks of type 2 diabetes. Here we identified, through a siRNA screen, beta site amyloid precursor protein cleaving enzyme 2 (Bace2) as the sheddase of the proproliferative plasma membrane protein Tmem27 in murine and human β cells. Mice with functionally inactive Bace2 and insulin-resistant mice treated with a newly identified Bace2 inhibitor both display augmented β cell mass and improved control of glucose homeostasis due to increased insulin levels. These results implicate Bace2 in the control of β cell maintenance and provide a rational strategy to inhibit this protease for the expansion of functional pancreatic β cell mass.
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Sambamurti K, Greig NH, Utsuki T, Barnwell EL, Sharma E, Mazell C, Bhat NR, Kindy MS, Lahiri DK, Pappolla MA. Targets for AD treatment: conflicting messages from γ-secretase inhibitors. J Neurochem 2011; 117:359-74. [PMID: 21320126 DOI: 10.1111/j.1471-4159.2011.07213.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Current evidence suggests that Alzheimer's disease (AD) is a multi-factorial disease that starts with accumulation of multiple proteins. We have previously proposed that inhibition of γ-secretase may impair membrane recycling causing neurodegeneration starting at synapses (Sambamurti K., Suram A., Venugopal C., Prakasam A., Zhou Y., Lahiri D. K. and Greig N. H. A partial failure of membrane protein turnover may cause Alzheimer's disease: a new hypothesis. Curr. Alzheimer Res., 3, 2006, 81). We also proposed familal AD mutations increase Aβ42 by inhibiting γ-secretase. Herein, we discuss the failure of Eli Lilly's γ-secretase inhibitor, semagacestat, in clinical trials in the light of our hypothesis, which extends the problem beyond toxicity of Aβ aggregates. We elaborate that γ-secretase inhibitors lead to accumulation of amyloid precursor protein C-terminal fragments that can later be processed by γ-secretase to yields bursts of Aβ to facilitate aggregation. Although we do not exclude a role for toxic Aβ aggregates, inhibition of γ-secretase can affect numerous substrates other than amyloid precursor protein to affect multiple pathways and the combined accumulation of multiple peptides in the membrane may impair its function and turnover. Taken together, protein processing and turnover pathways play an important role in maintaining cellular homeostasis and unless we clearly see consistent disease-related increase in their levels or activity, we need to focus on preserving their function rather than inhibiting them for treatment of AD and similar diseases.
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Affiliation(s)
- Kumar Sambamurti
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
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25
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Fernandez JW, Rezai-Zadeh K, Obregon D, Tan J. EGCG functions through estrogen receptor-mediated activation of ADAM10 in the promotion of non-amyloidogenic processing of APP. FEBS Lett 2010; 584:4259-67. [PMID: 20849853 DOI: 10.1016/j.febslet.2010.09.022] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Revised: 08/29/2010] [Accepted: 09/10/2010] [Indexed: 01/21/2023]
Abstract
Estrogen depletion following menopause has been correlated with an increased risk of developing Alzheimer's disease (AD). We previously explored the beneficial effect of (-)-epigallocatechin-3-gallate (EGCG) on AD mice and found increased non-amyloidogenic processing of amyloid precursor protein (APP) through the α-secretase a disintegrin and metallopeptidase domain 10 (ADAM10). Our results in this study suggest that EGCG-mediated enhancement of non-amyloidogenic processing of APP is mediated by the maturation of ADAM10 via an estrogen receptor-α (ERα)/phosphoinositide 3-kinase/Ak-transforming dependent mechanism, independent of furin-mediated ADAM10 activation. These data support prior assertions that central selective ER modulation could be a therapeutic target for AD and support the use of EGCG as a well-tolerated alternative to estrogen therapy in the prophylaxis and treatment of this disease.
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Affiliation(s)
- Jamie Winderbaum Fernandez
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center, Tampa, FL 33613, USA.
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26
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Patil SP, Maki S, Khedkar SA, Rigby AC, Chan C. Withanolide A and asiatic acid modulate multiple targets associated with amyloid-beta precursor protein processing and amyloid-beta protein clearance. JOURNAL OF NATURAL PRODUCTS 2010; 73:1196-202. [PMID: 20553006 PMCID: PMC2917495 DOI: 10.1021/np900633j] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Alzheimer's disease (AD) is a progressive, neurodegenerative disease histochemically characterized by extracellular deposits of amyloid beta (Abeta) protein and intracellular neurofibrillary tangles of hyperphosphorylated tau protein. AD is considered to be a complex, multifactorial syndrome, with numerous causal factors contributing to its pathogenesis. Thus, for any novel therapeutic molecule to have a "disease-modifying" effect on AD, it must be able to modulate multiple, synergistic targets simultaneously. In this context, we have studied two compounds of plant origin [withanolide A (1) and asiatic acid (2)] for their potential activities against multiple targets associated with Abeta pathways (BACE1, ADAM10, IDE, and NEP). BACE1 is a rate-limiting enzyme in the production of Abeta from amyloid-beta precursor protein (AbetaPP), while ADAM10 is involved in non-amyloidogenic processing of AbetaPP. IDE and NEP are two of the prominent enzymes involved in effectively degrading Abeta. It was found that both 1 and 2 significantly down-regulated BACE1 and also up-regulated ADAM10 in primary rat cortical neurons. In addition, 1 significantly up-regulated IDE levels, which may help in degrading excess Abeta from the AD brain. On the basis of the data obtained, the two multifunctional compounds may prove valuable in developing novel, effective therapeutics for the prevention and treatment of AD-associated amyloid pathology.
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Affiliation(s)
| | | | | | | | - Christina Chan
- To whom correspondence should be addressed. Tel: 517-432-4530. Fax: 517-432-1105.
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27
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Rapamycin promotes beta-amyloid production via ADAM-10 inhibition. Biochem Biophys Res Commun 2010; 398:337-41. [PMID: 20542014 DOI: 10.1016/j.bbrc.2010.06.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Accepted: 06/04/2010] [Indexed: 11/23/2022]
Abstract
Rapamycin is a well known immunosuppressant drug for rejection prevention in organ transplantation. Numerous clinical trials using rapamycin analogs, involving both children and adults with various disorders are currently ongoing worldwide. Most recently, rapamycin gained much attention for what appears to be life-span extending properties when administered to mice. The risk for Alzheimer disease (AD) is strongly and positively correlated with advancing age and is characterized by deposition of beta-amyloid peptides (Abeta) as senile plaques in the brain. We report that rapamycin (2.5muM), significantly increases Abeta generation in murine neuron-like cells (N2a) transfected with the human "Swedish" mutant amyloid precursor protein (APP). In concert with these observations, we found rapamycin significantly decreases the neuroprotective amino-terminal APP (amyloid precursor protein) cleavage product, soluble APP-alpha (sAPP-alpha) while increasing production of the beta-carboxyl-terminal fragment of APP (beta-CTF). These cleavage events are associated with decreased activation of a disintegrin and metallopeptidase domain-10 (ADAM-10), an important candidate alpha-secretase which opposes Abeta generation. To validate these findings in vivo, we intraperitoneal (i.p.) injected Tg2576 Abeta-overproducing transgenic mice with rapamycin (3mg/kg/day) for 2weeks. We found increased Abeta levels associated with decreased sAPP-alpha at an average rapamycin plasma concentration of 169.7+/-23.5ng/mL by high performance liquid chromatography (HPLC). These data suggest that although rapamycin may increase the lifespan in some mouse models, it may not decrease the risk for age-associated neurodegenerative disorders such as AD.
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28
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Effects of TNFalpha-converting enzyme inhibition on amyloid beta production and APP processing in vitro and in vivo. J Neurosci 2009; 28:12052-61. [PMID: 19005070 DOI: 10.1523/jneurosci.2913-08.2008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Tumor necrosis factor-alpha (TNFalpha) is a proinflammatory cytokine that is elevated in Alzheimer's disease (AD) brains. Because TNFalpha is released from cell membranes by the TNFalpha-converting enzyme (TACE), inhibition of TACE has the potential to mitigate TNFalpha effects in AD brain. TACE also cleaves amyloid precursor protein (APP) and generates sAPPalpha, precluding the formation of potentially harmful amyloid beta (Abeta) peptides by beta-site APP cleaving enzymes (BACE). Hence, the anti-inflammatory benefits of TACE inhibition might be offset by an increase in Abeta. We have examined the effects of the highly selective TACE inhibitor, BMS-561392, on APP processing in vitro and in vivo. In Chinese hamster ovary cells expressing APP, BMS-561392 significantly reduced secretion of sAPPalpha without a corresponding increase in Abeta production. Conversely, a BACE inhibitor decreased sAPPbeta and Abeta peptides with no change in the secretion of sAPPalpha. These data indicate an absence of TACE and BACE competition for the APP substrate. Despite this, we observed competition for APP when TACE activity was enhanced via phorbol ester treatment or if APP was modified such that it was retained within the trans-Golgi network (TGN). These results suggest that BACE and TACE share a common TGN localization, but under normal conditions do not compete for APP. To confirm this finding in vivo, BMS-561392 was infused into the brains of Tg2576 and wild-type mice. Although decreased brain sAPPalpha levels were observed, steady-state Abeta levels were not significantly changed. Accordingly, it is possible that TACE inhibitors could reduce TNFalpha levels without increasing Abeta levels within the AD brain.
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Mei Z, Zhang F, Tao L, Zheng W, Cao Y, Wang Z, Tang S, Le K, Chen S, Pi R, Liu P. Cryptotanshinone, a compound from Salvia miltiorrhiza modulates amyloid precursor protein metabolism and attenuates beta-amyloid deposition through upregulating alpha-secretase in vivo and in vitro. Neurosci Lett 2009; 452:90-5. [PMID: 19154776 DOI: 10.1016/j.neulet.2009.01.013] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 12/29/2008] [Accepted: 01/07/2009] [Indexed: 11/19/2022]
Abstract
The amyloid precursor protein (APP) is cleaved enzymatically by non-amyloidogenic and amyloidogenic pathways. alpha-Secretase cleaves APP within beta-amyloid protein (Abeta) sequence, resulting in the release of a secreted fragment of APP (sAPPalpha) and precluding Abeta generation. Cryptotanshinone (CTS), an active component of the medicinal herb Salvia miltiorrhiza, has been shown to improve learning and memory in several pharmacological models of Alzheimer's disease (AD). However, the effects of CTS on the Abeta plaque pathology and the APP processing in AD are unclear. Here we reported that CTS strongly attenuated amyloid plaque deposition in the brain of APP/PS1 transgenic mice. In addition, CTS significantly improved spatial learning and memory in APP/PS1 mice assessed by the Morris water maze testing. To define the exact molecular mechanisms involved in the beneficial effects of CTS, we investigated the effects of the CTS on APP processing in rat cortical neuronal cells overexpressing Swedish mutant human APP695. CTS was found to decrease Abeta generation in concentration-dependent (0-10muM) manner. Interestingly, the N-terminal APP cleavage product, sAPPalpha was markedly increased by CTS. Further study showed that alpha-secretase activity was increased by CTS. Taken together, our results suggested CTS improved the cognitive ability in AD transgenic mice and promoted APP metabolism toward the non-amyloidogenic products pathway in rat cortical neuronal cells. CTS shows a promising novel way for the therapy of AD.
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Affiliation(s)
- Zhengrong Mei
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, PR China
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30
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Venugopal C, Demos CM, Rao KSJ, Pappolla MA, Sambamurti K. Beta-secretase: structure, function, and evolution. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2008; 7:278-94. [PMID: 18673212 PMCID: PMC2921875 DOI: 10.2174/187152708784936626] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The most popular current hypothesis is that Alzheimer's disease (AD) is caused by aggregates of the amyloid peptide (Abeta), which is generated by cleavage of the Abeta protein precursor (APP) by beta-secretase (BACE-1) followed by gamma-secretase. BACE-1 cleavage is limiting for the production of Abeta, making it a particularly good drug target for the generation of inhibitors that lower Abeta. A landmark discovery in AD was the identification of BACE-1 (a.k.a. Memapsin-2) as a novel class of type I transmembrane aspartic protease. Although BACE-2, a homologue of BACE-1, was quickly identified, follow up studies using knockout mice demonstrated that BACE-1 was necessary and sufficient for most neuronal Abeta generation. Despite the importance of BACE-1 as a drug target, development has been slow due to the incomplete understanding of its function and regulation and the difficulties in developing a brain penetrant drug that can specifically block its large catalytic pocket. This review summarizes the biological properties of BACE-1 and attempts to use phylogenetic perspectives to understand its function. The article also addresses the challenges in discovering a selective drug-like molecule targeting novel mechanisms of BACE-1 regulation.
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Affiliation(s)
| | | | | | | | - Kumar Sambamurti
- Medical University of South Carolina, Charleston, South Carolina
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31
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Zacchetti D, Chieregatti E, Bettegazzi B, Mihailovich M, Sousa VL, Grohovaz F, Meldolesi J. BACE1 expression and activity: relevance in Alzheimer's disease. NEURODEGENER DIS 2007; 4:117-26. [PMID: 17596706 DOI: 10.1159/000101836] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A turning point of research in Alzheimer's disease was undoubtedly the discovery of BACE1, the amyloid-beta precursor protein-cleaving enzyme that initiates the generation of amyloid-beta, the peptide strongly suspected to be responsible for neuronal malfunction and death. Several research groups started a race to identify the best inhibitor of BACE1 activity. On the other hand, basic researchers are evaluating the changes in BACE1 expression and activity with the aim to better understand the pathogenetic process of the disease. Along this second line of research, in the last few years many important results have been reported in various experimental models, as well as in Alzheimer's disease patients. As a consequence, new pathogenetic paradigms have been developed. We have reviewed these reports trying to highlight contrasting viewpoints, data awaiting final confirmation, and promising perspectives.
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Affiliation(s)
- Daniele Zacchetti
- Vita-Salute San Raffaele University and San Raffaele Scientific Institute, Milano, Italy.
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32
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Yan XX, Xiong K, Luo XG, Struble RG, Clough RW. beta-Secretase expression in normal and functionally deprived rat olfactory bulbs: inverse correlation with oxidative metabolic activity. J Comp Neurol 2007; 501:52-69. [PMID: 17206602 DOI: 10.1002/cne.21239] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Cerebral hypometabolism, mitochondrial dysfunction, and beta-amyloid peptide (Abeta) accumulation are well-characterized manifestations of Alzheimer's disease (AD). beta-Secretase (BACE) is a prerequisite for amyloidogenesis, and it is up-regulated in sporadic AD. To explore a potential in vivo mechanism by which Abeta production is modulated by neuronal activity and/or oxidative metabolism, we compared BACE expression with cytochrome c oxidase (CO) or succinic dehydrogenase (SDH) activity in normal and functionally deprived adult rat olfactory bulb. In normal bulb, BACE was expressed predominantly in the glomerular layer, but labeling intensity within individual glomeruli varied substantially. A strong negative correlation existed between BACE labeling intensity and CO or SDH activity among individual glomeruli. Unilateral naris occlusion resulted in elevated glomerular BACE labeling in the deprived bulbs relative to the nondeprived counterparts, which was correlated with decreased CO activity in the same anatomic location. Enhanced BACE labeling was confirmed by measurements of elevated protein levels, enzymatic activity, and beta-site cleavage products of amyloid precursor protein in bulb extracts. Our findings reveal a negative regulation of BACE expression by physiological neuronal activity and an intrinsic inverse correlation between BACE expression and oxidative metabolism at the first synapse on the olfactory pathway. The results point to a biological role of BACE in synapse function and plasticity as well as a potential mechanism whereby reduced neuronal activity or metabolism could lead to amyloid overproduction in synaptic terminals.
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Affiliation(s)
- Xiao-Xin Yan
- Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, Illinois 62901, USA.
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33
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Arendash GW, Schleif W, Rezai-Zadeh K, Jackson EK, Zacharia LC, Cracchiolo JR, Shippy D, Tan J. Caffeine protects Alzheimer's mice against cognitive impairment and reduces brain beta-amyloid production. Neuroscience 2006; 142:941-52. [PMID: 16938404 DOI: 10.1016/j.neuroscience.2006.07.021] [Citation(s) in RCA: 305] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Revised: 06/27/2006] [Accepted: 07/11/2006] [Indexed: 10/24/2022]
Abstract
A recent epidemiological study suggested that higher caffeine intake over decades reduces the risk of Alzheimer's disease (AD). The present study sought to determine any long-term protective effects of dietary caffeine intake in a controlled longitudinal study involving AD transgenic mice. Caffeine (an adenosine receptor antagonist) was added to the drinking water of amyloid precursor protein, Swedish mutation (APPsw) transgenic (Tg) mice between 4 and 9 months of age, with behavioral testing done during the final 6 weeks of treatment. The average daily intake of caffeine per mouse (1.5 mg) was the human equivalent of 500 mg caffeine, the amount typically found in five cups of coffee per day. Across multiple cognitive tasks of spatial learning/reference memory, working memory, and recognition/identification, Tg mice given caffeine performed significantly better than Tg control mice and similar to non-transgenic controls. In both behaviorally-tested and aged Tg mice, long-term caffeine administration resulted in lower hippocampal beta-amyloid (Abeta) levels. Expression of both Presenilin 1 (PS1) and beta-secretase (BACE) was reduced in caffeine-treated Tg mice, indicating decreased Abeta production as a likely mechanism of caffeine's cognitive protection. The ability of caffeine to reduce Abeta production was confirmed in SweAPP N2a neuronal cultures, wherein concentration-dependent decreases in both Abeta1-40 and Abeta1-42 were observed. Although adenosine A(1) or A(2A) receptor densities in cortex or hippocampus were not affected by caffeine treatment, brain adenosine levels in Tg mice were restored back to normal by dietary caffeine and could be involved in the cognitive protection provided by caffeine. Our data demonstrate that moderate daily intake of caffeine may delay or reduce the risk of AD.
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Affiliation(s)
- G W Arendash
- The Byrd Alzheimer's Center and Research Institute, Tampa, FL 33647, USA.
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34
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Obregon DF, Rezai-Zadeh K, Bai Y, Sun N, Hou H, Ehrhart J, Zeng J, Mori T, Arendash GW, Shytle D, Town T, Tan J. ADAM10 Activation Is Required for Green Tea (–)-Epigallocatechin-3-gallate-induced α-Secretase Cleavage of Amyloid Precursor Protein. J Biol Chem 2006; 281:16419-27. [PMID: 16624814 DOI: 10.1074/jbc.m600617200] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recently, we have shown that green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) exerts a beneficial role on reducing brain Abeta levels, resulting in mitigation of cerebral amyloidosis in a mouse model of Alzheimer disease. EGCG seems to accomplish this by modulating amyloid precursor protein (APP) processing, resulting in enhanced cleavage of the alpha-COOH-terminal fragment (alpha-CTF) of APP and corresponding elevation of the NH(2)-terminal APP product, soluble APP-alpha (sAPP-alpha). These beneficial effects were associated with increased alpha-secretase cleavage activity, but no significant alteration in beta-or gamma-secretase activities. To gain insight into the molecular mechanism whereby EGCG modulates APP processing, we evaluated the involvement of three candidate alpha-secretase enzymes, a-disintegrin and metalloprotease (ADAM) 9, 10, or 17, in EGCG-induced non-amyloidogenic APP metabolism. Results show that EGCG treatment of N2a cells stably transfected with "Swedish" mutant human APP (SweAPP N2a cells) leads to markedly elevated active ( approximately 60 kDa mature form) ADAM10 protein. Elevation of active ADAM10 correlates with increased alpha-CTF cleavage, and elevated sAPP-alpha. To specifically test the contribution of ADAM10 to non-amyloidogenic APP metabolism, small interfering RNA knockdown of ADAM9, -10, or -17 mRNA was employed. Results show that ADAM10 (but not ADAM9 or -17) is critical for EGCG-mediated alpha-secretase cleavage activity. In summary, ADAM10 activation is necessary for EGCG promotion of non-amyloidogenic (alpha-secretase cleavage) APP processing. Thus, ADAM10 represents an important pharmacotherapeutic target for the treatment of cerebral amyloidosis in Alzheimer disease.
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Affiliation(s)
- Demian F Obregon
- Neuroimmunology Laboratory, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, The Byrd Alzheimer's Center and Research Institute, 3515 E. Fletcher Avenue, Tampa, FL 33647, USA
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35
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Rezai-Zadeh K, Shytle D, Sun N, Mori T, Hou H, Jeanniton D, Ehrhart J, Townsend K, Zeng J, Morgan D, Hardy J, Town T, Tan J. Green tea epigallocatechin-3-gallate (EGCG) modulates amyloid precursor protein cleavage and reduces cerebral amyloidosis in Alzheimer transgenic mice. J Neurosci 2006; 25:8807-14. [PMID: 16177050 PMCID: PMC6725500 DOI: 10.1523/jneurosci.1521-05.2005] [Citation(s) in RCA: 458] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder pathologically characterized by deposition of beta-amyloid (Abeta) peptides as senile plaques in the brain. Recent studies suggest that green tea flavonoids may be used for the prevention and treatment of a variety of neurodegenerative diseases. Here, we report that (-)-epigallocatechin-3-gallate (EGCG), the main polyphenolic constituent of green tea, reduces Abeta generation in both murine neuron-like cells (N2a) transfected with the human "Swedish" mutant amyloid precursor protein (APP) and in primary neurons derived from Swedish mutant APP-overexpressing mice (Tg APPsw line 2576). In concert with these observations, we find that EGCG markedly promotes cleavage of the alpha-C-terminal fragment of APP and elevates the N-terminal APP cleavage product, soluble APP-alpha. These cleavage events are associated with elevated alpha-secretase activity and enhanced hydrolysis of tumor necrosis factor alpha-converting enzyme, a primary candidate alpha-secretase. As a validation of these findings in vivo, we treated Tg APPsw transgenic mice overproducing Abeta with EGCG and found decreased Abeta levels and plaques associated with promotion of the nonamyloidogenic alpha-secretase proteolytic pathway. These data raise the possibility that EGCG dietary supplementation may provide effective prophylaxis for AD.
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Affiliation(s)
- Kavon Rezai-Zadeh
- Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida, Tampa, Florida 33613, USA
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