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Tan S, Wu L, Liu J, Wu Z, Cheng Q, Qu Q, Zhu L, Yan Y, Wu H, Ling TJ, Liu RT, Yang S. Quercetin-3-O-glc-1-3-rham-1-6-glucoside decreases Aβ production, inhibits Aβ aggregation and neurotoxicity, and prohibits the production of inflammatory cytokines. Eur J Pharmacol 2024; 970:176491. [PMID: 38503399 DOI: 10.1016/j.ejphar.2024.176491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 01/24/2024] [Accepted: 03/11/2024] [Indexed: 03/21/2024]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease with the hallmark of aggregation of beta-amyloid (Aβ) into extracellular fibrillar deposition. Accumulating evidence suggests that soluble toxic Aβ oligomers exert diverse roles in neuronal cell death, oxidative stress, neuroinflammation, and the eventual pathogenesis of AD. Aβ is derived from the sequential cleavage of amyloid-β precursor protein (APP) by β-secretase (BACE1) and γ-secretase. The current effect of single targeting is not ideal for the treatment of AD. Therefore, developing multipotent agents with multiple properties, including anti-Aβ generation and anti-Aβ aggregation, is attracting more attention for AD treatment. Previous studies indicated that Quercetin was able to attenuate the effects of several pathogenetic factors in AD. Here, we showed that naturally synthesized Quercetin-3-O-glc-1-3-rham-1-6-glucoside (YCC31) could inhibit Aβ production by reducing β-secretase activity. Further investigations indicated that YCC31 could suppress toxic Aβ oligomer formation by directly binding to Aβ. Moreover, YCC31 could attenuate Aβ-mediated neuronal death, ROS and NO production, and pro-inflammatory cytokines release. Taken together, YCC31 targeting multiple pathogenetic factors deserves further investigation for drug development of AD.
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Affiliation(s)
- Shuo Tan
- School of Basic Medical Sciences, School of Life Sciences, Anhui Medical University, Hefei, 230032, China
| | - Linmei Wu
- School of Basic Medical Sciences, School of Life Sciences, Anhui Medical University, Hefei, 230032, China
| | - Jiayi Liu
- School of Basic Medical Sciences, School of Life Sciences, Anhui Medical University, Hefei, 230032, China
| | - Zhaoyuan Wu
- School of Basic Medical Sciences, School of Life Sciences, Anhui Medical University, Hefei, 230032, China
| | - Qiang Cheng
- School of Basic Medical Sciences, School of Life Sciences, Anhui Medical University, Hefei, 230032, China
| | - Qiuhao Qu
- School of Basic Medical Sciences, School of Life Sciences, Anhui Medical University, Hefei, 230032, China
| | - Lianghao Zhu
- School of Basic Medical Sciences, School of Life Sciences, Anhui Medical University, Hefei, 230032, China
| | - Yizhu Yan
- School of Basic Medical Sciences, School of Life Sciences, Anhui Medical University, Hefei, 230032, China
| | - Hao Wu
- School of Basic Medical Sciences, School of Life Sciences, Anhui Medical University, Hefei, 230032, China
| | - Tie-Jun Ling
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, 230036, China
| | - Rui-Tian Liu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Shigao Yang
- School of Basic Medical Sciences, School of Life Sciences, Anhui Medical University, Hefei, 230032, China.
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2
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Kim EH, Lee WS, Lee JH, Kwon DR. Microcurrent therapy as the nonpharmacological new protocol against Alzheimer's disease. Front Aging Neurosci 2024; 16:1344072. [PMID: 38304741 PMCID: PMC10833500 DOI: 10.3389/fnagi.2024.1344072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 01/09/2024] [Indexed: 02/03/2024] Open
Abstract
Introduction Alzheimer's disease (AD) poses an increasing global health challenge and is marked by gradual cognitive deterioration, memory impairment, and neuroinflammation. Innovative therapeutic approaches as non-pharmacological protocol are urgently needed with side effect risk of drugs. Microcurrent therapy, a non-invasive modality involving low-level electrical currents, has emerged as a potential solution to address AD's complex pathogenesis. This study investigates the optimal application of microcurrent therapy as a clinical protocol for AD, utilizing a comprehensive approach that integrates behavioral assessments and neuroinflammation evaluation in a mouse model of dementia. Methods and results The results reveal that microcurrent therapy holds promise in ameliorating memory impairment and reducing neuroinflammation in AD. Behavioral assessments, including the Novel Object Recognition Test (NOR) and Radial Arm Maze Test (RAM), demonstrated improved cognitive function following microcurrent therapy. Furthermore, microcurrent therapy inhibited expression of neuroinflammatory proteins, including ionized calcium binding adaptor molecule 1 (Iba1), and glial fibrillary acidic protein (GFAP) in current-treated group. Mechanistic insights suggest that microcurrent therapy may modulate neuroinflammation through the regulation of MAPK signaling pathways. Conclusion This study emphasizes the prospect of microcurrent therapy as a safe and efficacious non-pharmacological strategy for Alzheimer's disease (AD), providing optimism to the countless individuals impacted by this debilitating ailment. These results contribute to the developments of an innovative clinical protocol for AD and recovery from neurological injury, underscoring the significance of investigating unconventional therapeutic approaches for addressing this complex condition.
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Affiliation(s)
- Eun Ho Kim
- Department of Biochemistry, School of Medicine, Daegu Catholic University, Daegu, Republic of Korea
| | - Won Seok Lee
- Department of Biochemistry, School of Medicine, Daegu Catholic University, Daegu, Republic of Korea
| | - Jae Hee Lee
- Department of Rehabilitation Medicine, School of Medicine, Daegu Catholic University, Daegu, Republic of Korea
| | - Dong Rak Kwon
- Department of Rehabilitation Medicine, School of Medicine, Daegu Catholic University, Daegu, Republic of Korea
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3
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Bhatnagar D, Ladhe S, Kumar D. Discerning the Prospects of miRNAs as a Multi-Target Therapeutic and Diagnostic for Alzheimer's Disease. Mol Neurobiol 2023; 60:5954-5974. [PMID: 37386272 DOI: 10.1007/s12035-023-03446-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/14/2023] [Indexed: 07/01/2023]
Abstract
Although over the last few decades, numerous attempts have been made to halt Alzheimer's disease (AD) progression and mitigate its symptoms, only a few have been proven beneficial. Most medications available, still only cater to the symptoms of the disease rather than fixing the cause at the root level. A novel approach involving the use of miRNAs, which work on the principle of gene silencing, is being explored by scientists. Naturally present miRNAs in the biological system help to regulate various genes than may be implicated in AD-like BACE-1 and APP. One miRNA thus, holds the power to keep a check on several genes, conferring it the ability to be used as a multi-target therapeutic. With aging and the onset of diseased pathology, dysregulation of these miRNAs is observed. This flawed miRNA expression is responsible for the unusual buildup of amyloid proteins, fibrillation of tau proteins in the brain, neuronal death and other hallmarks leading to AD. The use of miRNA mimics and miRNA inhibitors provides an attractive perspective for fixing the upregulation and downregulation of miRNAs that led to abnormal cellular activities. Furthermore, the detection of miRNAs in the CSF and serum of diseased patients might be considered an earlier biomarker for the disease. While most of the therapies designed around AD have not succeeded completely, the targeting of dysregulated miRNAs in AD patients might give a new direction to scholars to develop an effective treatment for Alzheimer's disease.
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Affiliation(s)
- Devyani Bhatnagar
- Department of Pharmaceutical Chemistry, Poona College of Pharmacy, Bharati Vidyapeeth (Deemed to Be University), Erandwane, Pune, 411038, Maharashtra, India
| | - Shreya Ladhe
- Department of Pharmaceutical Chemistry, Poona College of Pharmacy, Bharati Vidyapeeth (Deemed to Be University), Erandwane, Pune, 411038, Maharashtra, India
| | - Dileep Kumar
- Department of Pharmaceutical Chemistry, Poona College of Pharmacy, Bharati Vidyapeeth (Deemed to Be University), Erandwane, Pune, 411038, Maharashtra, India.
- Department of Entomology, University of California, Davis, One Shields Ave, Davis, CA, 95616, USA.
- UC Davis Comprehensive Cancer Center, University of California, Davis, One Shields Ave, Davis, CA, 95616, USA.
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4
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Bai D, Jin G, Zhang D, Zhao L, Wang M, Zhu Q, Zhu L, Sun Y, Liu X, Chen X, Zhang L, Li W, Cui Y. Natural silibinin modulates amyloid precursor protein processing and amyloid-β protein clearance in APP/PS1 mice. J Physiol Sci 2019; 69:643-652. [PMID: 31087219 PMCID: PMC10717595 DOI: 10.1007/s12576-019-00682-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 04/29/2019] [Indexed: 11/28/2022]
Abstract
Silibinin has been shown to attenuate cognitive dysfunction and inhibit amyloid-beta (Aβ) aggregation in Alzheimer's disease (AD) models. However, the underlying mechanism by which silibinin improves cognition remains poorly understood. In this study, we investigated the effect of silibinin on β-secretase levels, Aβ enzymatic degradation, and oxidative stress in the brains of APP/PS1 mice with cognitive impairments. Oral administration of silibinin for 2 months significantly attenuated the cognitive deficits of APP/PS1 mice in the Y-maze test, novel object recognition test, and Morris water maze test. Biochemical analyses revealed that silibinin decreased Aβ deposition and the levels of soluble Aβ1-40/1-42 in the hippocampus by downregulating APP and BACE1 and upregulating NEP in APP/PS1 mice. In addition, silibinin decreased the MDA content and increased the activities of the antioxidant enzymes CAT, SOD, and NO. Based on our findings, silibinin is a potentially promising agent for preventing AD-associated Aβ pathology.
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Affiliation(s)
- Dafeng Bai
- Department of Pharmacology, The Eleventh People's Hospital of Shenyang, 103 Hai Tang Street, Sujiatun District, Shenyang, Liaoning, 110016, People's Republic of China
| | - Ge Jin
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China.
| | - Dajun Zhang
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
| | - Lini Zhao
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
| | - Mingyue Wang
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
| | - Qiwen Zhu
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
| | - Lin Zhu
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
| | - Yan Sun
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
| | - Xuan Liu
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
| | - Xueying Chen
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
| | - Liqian Zhang
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
| | - Wenbo Li
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
| | - Yan Cui
- Department of Pharmacology, Key Laboratory of Behavioral and Cognitive Neuroscience of Liaoning Province, Shenyang Medical Colleges, 146 Huanghe North Street, Yuhong District, Shenyang, Liaoning, 110034, People's Republic of China
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5
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Inhibition of endothelial nitric oxide synthase reverses the effect of exercise on improving cognitive function in hypertensive rats. Hypertens Res 2018; 41:414-425. [PMID: 29568075 DOI: 10.1038/s41440-018-0033-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 09/26/2017] [Accepted: 11/01/2017] [Indexed: 02/07/2023]
Abstract
Hypertension-induced endothelial dysfunction is associated with β-amyloid (Aβ) deposition, a typical pathology of Alzheimer's disease (AD). Endothelial nitric oxide synthase (eNOS) phosphorylation, impaired by phosphatidylinositol 3-kinase (PI3K)/protein kinase-B(Akt) pathway abnormalities in hypertensive rats, has a critical role in endothelial function. However, it is unknown whether eNOS participates in the hypertension-induced pathology of AD. In this study, we investigated the role of eNOS in Aβ deposition and cognitive function in stroke-prone spontaneously hypertensive (SHRSP) rats. Physical exercise was used as a promoter, and Nω-nitro L-arginine methyl ester (L-NAME) was used as an inhibitor of eNOS to determine the effects of eNOS on SHRSP rats. Compared with Wistar Kyoto (WKY) rats, the hypertensive challenge caused cognitive impairment, decreased eNOS levels and increased amyloid precursor protein (APP), β-secretase, and Aβ levels in the cortex and hippocampus. Sixteen weeks of exercise lowered blood pressure (BP), promoted eNOS expression, ameliorated Alzheimer's pathology, and improved cognitive function in 29-week-old SHRSP rats. Furthermore, daily treatment with L-NAME reversed the beneficial effects of exercise on SHRSP rats. Exercise also decreased the protein levels of insulin-like growth factor-1 (IGF-1), PI3K, and phospho-Akt (p-Akt, ser473). In addition, long-term exercise increased the expression levels of IGF-1, PI3K, and p-Akt (ser473) in the brains of SHRSP rats. In conclusion, eNOS downregulation contributed to hypertension-induced Alzheimer pathology and cognitive impairment. Long-term exercise initiated in rats at a young age promoted eNOS expression and attenuated vascular-related Alzheimer's pathology via the IGF-1/PI3K/p-Akt pathway in SHRSP rats.
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6
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Timmers M, Barão S, Van Broeck B, Tesseur I, Slemmon J, De Waepenaert K, Bogert J, Shaw LM, Engelborghs S, Moechars D, Mercken M, Van Nueten L, Tritsmans L, de Strooper B, Streffer JR. BACE1 Dynamics Upon Inhibition with a BACE Inhibitor and Correlation to Downstream Alzheimer's Disease Markers in Elderly Healthy Participants. J Alzheimers Dis 2018; 56:1437-1449. [PMID: 28157093 PMCID: PMC5325057 DOI: 10.3233/jad-160829] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The β-site amyloid-β protein precursor (AβPP) cleaving enzyme-1 (BACE1) is the rate limiting enzyme in the generation of amyloid-β peptide (Aβ) from AβPP, one of the major pathways in Alzheimer's disease (AD) pathology. Increased BACE1 levels and activity have been reported in the brain of patients with sporadic AD. Therefore, changes of BACE1 levels in the cerebrospinal fluid (CSF) have also been investigated as a possible biomarker of the disease. We analyzed BACE1 levels in CSF of elderly healthy participants before and after chronic treatment with a BACE inhibitor (BACEi) and evaluated the correlation between BACE1 levels and downstream AD markers. Overall, BACE1 CSF levels showed strong correlations to all downstream AD markers investigated. This is the first reported finding that shows BACE1 levels in CSF were well correlated to its end product Aβ1 - 42. As previously described, BACE1 levels were strongly correlated to total-tau and phosphorylated tau levels in CSF. Generally, chronic BACE inhibition did not influence BACE1 CSF protein levels. Follow-up studies including early-stage AD pathophysiology and prodromal AD patients will help to understand the importance of measuring BACE1 routinely in daily clinical practice and AD clinical trials.
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Affiliation(s)
- Maarten Timmers
- Janssen Research and Development, A Division of Janssen Pharmaceutica N.V., Beerse, Belgium.,Reference Center for Biological Markers of Dementia (BIODEM), Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Soraia Barão
- VIB Center for the Biology of Disease, VIB-Leuven, Belgium.,Center for Human Genetics, Universitaire ziekenhuizen and LIND, KU Leuven, Belgium
| | - Bianca Van Broeck
- Janssen Research and Development, A Division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Ina Tesseur
- Janssen Research and Development, A Division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - John Slemmon
- Janssen Research and Development LLC, La Jolla, CA, USA
| | - Katja De Waepenaert
- Janssen Research and Development, A Division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | | | - Leslie M Shaw
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sebastiaan Engelborghs
- Reference Center for Biological Markers of Dementia (BIODEM), Institute Born-Bunge, University of Antwerp, Antwerp, Belgium.,Department of Neurology and Memory Clinic, Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Antwerp, Belgium
| | - Dieder Moechars
- Janssen Research and Development, A Division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Marc Mercken
- Janssen Research and Development, A Division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Luc Van Nueten
- Janssen Research and Development, A Division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Luc Tritsmans
- Janssen Research and Development, A Division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Bart de Strooper
- VIB Center for the Biology of Disease, VIB-Leuven, Belgium.,Center for Human Genetics, Universitaire ziekenhuizen and LIND, KU Leuven, Belgium.,Institute of Neurology, University College London, UK
| | - Johannes Rolf Streffer
- Janssen Research and Development, A Division of Janssen Pharmaceutica N.V., Beerse, Belgium.,Reference Center for Biological Markers of Dementia (BIODEM), Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
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7
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Sun M, Zhang H. Par3 and aPKC regulate BACE1 endosome-to-TGN trafficking through PACS1. Neurobiol Aging 2017; 60:129-140. [PMID: 28946017 PMCID: PMC5653456 DOI: 10.1016/j.neurobiolaging.2017.08.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/11/2017] [Accepted: 08/24/2017] [Indexed: 12/29/2022]
Abstract
The cleavage of amyloid precursor protein (APP) by β-site APP cleaving enzyme 1 (BACE1) is the rate-limiting step in beta amyloid generation during Alzheimer's disease (AD) pathogenesis. In AD brains, BACE1 is abnormally accumulated in endocytic compartments, where the acidic pH is optimal for its activity. However, mechanisms regulating the endosome-to-trans-Golgi network (TGN) retrieval of BACE1 remain unclear. Here, we show that partitioning defective 3 (Par3) facilitates BACE1 retrograde trafficking from endosomes to the TGN. Par3 functions through aPKC-mediated phosphorylation of BACE1 on Ser498, which in turn promotes the interaction between BACE1 and phosphofurin acidic cluster sorting protein 1 and facilitates the retrograde trafficking of BACE1 to the TGN. In human AD brains, there is a significant decrease in Ser498 phosphorylation of BACE1 suggesting that defective phosphorylation-dependent retrograde transport of BACE1 is important in AD pathogenesis. Together, our studies provide mechanistic insight into a novel role for Par3 and aPKC in regulating the retrograde endosome-to-TGN trafficking of BACE1 and shed light on the mechanisms of AD pathogenesis.
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Affiliation(s)
- Miao Sun
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Huaye Zhang
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
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8
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Kim NY, Cho MH, Won SH, Kang HJ, Yoon SY, Kim DH. Sorting nexin-4 regulates β-amyloid production by modulating β-site-activating cleavage enzyme-1. ALZHEIMERS RESEARCH & THERAPY 2017; 9:4. [PMID: 28109317 PMCID: PMC5251330 DOI: 10.1186/s13195-016-0232-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 12/28/2016] [Indexed: 12/30/2022]
Abstract
BACKGROUND Amyloid precursor protein (APP) is cleaved by β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) to produce β-amyloid (Aβ), a critical pathogenic peptide in Alzheimer's disease (AD). Aβ generation can be affected by the intracellular trafficking of APP or its related secretases, which is thus important to understanding its pathological alterations. Although sorting nexin (SNX) family proteins regulate this trafficking, the relevance and role of sorting nexin-4 (SNX4) regarding AD has not been studied yet. METHODS In this study, human brain tissue and APP/PS1 mouse brain tissue were used to check the disease relevance of SNX4. To investigate the role of SNX4 in AD pathogenesis, several experiments were done, such as coimmunoprecipitation, Western blotting, immunohistochemistry, and gradient fractionation. RESULTS We found that SNX4 protein levels changed in the brains of patients with AD and of AD model mice. Overexpression of SNX4 significantly increased the levels of BACE1 and Aβ. Downregulation of SNX4 had the opposite effect. SNX4 interacts with BACE1 and prevents BACE1 trafficking to the lysosomal degradation system, resulting in an increased half-life of BACE1 and increased production of Aβ. CONCLUSIONS We show that SNX4 regulates BACE1 trafficking. Our findings suggest novel therapeutic implications of modulating SNX4 to regulate BACE1-mediated β-processing of APP and subsequent Aβ generation.
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Affiliation(s)
- Na-Young Kim
- Alzheimer's Disease Experts Lab (ADEL), Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.,Department of Brain Science, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, SongPa-Gu, Seoul, 05505, Korea.,Bio-Medical Institute of Technology (BMIT), University of Ulsan College of Medicine, Seoul, Korea.,Cell Dysfunction Research Center (CDRC), University of Ulsan College of Medicine, Seoul, Korea
| | - Mi-Hyang Cho
- Alzheimer's Disease Experts Lab (ADEL), Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.,Department of Brain Science, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, SongPa-Gu, Seoul, 05505, Korea.,Bio-Medical Institute of Technology (BMIT), University of Ulsan College of Medicine, Seoul, Korea.,Cell Dysfunction Research Center (CDRC), University of Ulsan College of Medicine, Seoul, Korea
| | - Se-Hoon Won
- Alzheimer's Disease Experts Lab (ADEL), Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.,Department of Brain Science, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, SongPa-Gu, Seoul, 05505, Korea.,Bio-Medical Institute of Technology (BMIT), University of Ulsan College of Medicine, Seoul, Korea.,Cell Dysfunction Research Center (CDRC), University of Ulsan College of Medicine, Seoul, Korea
| | - Hoe-Jin Kang
- Alzheimer's Disease Experts Lab (ADEL), Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.,Department of Brain Science, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, SongPa-Gu, Seoul, 05505, Korea.,Bio-Medical Institute of Technology (BMIT), University of Ulsan College of Medicine, Seoul, Korea.,Cell Dysfunction Research Center (CDRC), University of Ulsan College of Medicine, Seoul, Korea
| | - Seung-Yong Yoon
- Alzheimer's Disease Experts Lab (ADEL), Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. .,Department of Brain Science, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, SongPa-Gu, Seoul, 05505, Korea. .,Bio-Medical Institute of Technology (BMIT), University of Ulsan College of Medicine, Seoul, Korea. .,Cell Dysfunction Research Center (CDRC), University of Ulsan College of Medicine, Seoul, Korea.
| | - Dong-Hou Kim
- Alzheimer's Disease Experts Lab (ADEL), Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. .,Department of Brain Science, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, SongPa-Gu, Seoul, 05505, Korea. .,Bio-Medical Institute of Technology (BMIT), University of Ulsan College of Medicine, Seoul, Korea. .,Cell Dysfunction Research Center (CDRC), University of Ulsan College of Medicine, Seoul, Korea.
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9
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Li Y, Zhang T, Zhang X, Zou W, Gong X, Fu J. Cinepazide Maleate Improves Cognitive Function and Protects Hippocampal Neurons in Diabetic Rats with Chronic Cerebral Hypoperfusion. Biol Pharm Bull 2016; 40:249-255. [PMID: 27990002 DOI: 10.1248/bpb.b16-00567] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To determine the combined effect of type 2 diabetes (T2D) and chronic cerebral hypoperfusion (CCH) on learning and spatial memory, we developed a rat model of CCH by permanent occlusion of bilateral common carotid arteries (2-vessel occlusion (2VO)) in high-fat diet (HFD)-fed rats injected with low-dose streptozotocin (STZ). Furthermore, we examined the effect of cinepazide maleate (CM) on cognitive deficits and brain damage in this rat model. Rats were maintained on HFD for 6 weeks and then injected with 35 mg/kg STZ to induce T2D. Sham or 2VO surgery was performed in non-diabetic or diabetic (DM) rats to obtain four groups: blank, DM, CCH, and DM-CCH groups. Cognitive function was tested by the Morris water maze (MWM) test. To determine the effects of the vasodilator cinepazide maleate (CM) on cognitive deficits and brain damage, DM-CCH rats were administered with 10 mg/kg CM or saline daily for 14 d. Neuronal damage in DM-CCH rats was associated with increased expression of glial fibrillary acidic protein (GFAP) and β-secretase 1 (BACE1), but decreased expression of choline acetyltransferase (ChAT). Moreover, the levels of all these proteins were significantly alleviated by CM treatment. These results suggest that T2D exacerbated CCH-induced brain damage and cognitive impairment, and CM ameliorated these effects.
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Affiliation(s)
- Yumei Li
- Department of Neurology, Shanghai Jiaotong University Affiliated Sixth People's Hospital
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10
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Yan X, Hu G, Yan W, Chen T, Yang F, Zhang X, Zhao G, Liu J. Ginsenoside Rd promotes non-amyloidogenic pathway of amyloid precursor protein processing by regulating phosphorylation of estrogen receptor alpha. Life Sci 2016; 168:16-23. [PMID: 27825720 DOI: 10.1016/j.lfs.2016.11.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 10/26/2016] [Accepted: 11/02/2016] [Indexed: 11/19/2022]
Abstract
AIMS Previous study demonstrated that Ginsenoside Rd. (GS-Rd) could improve cognitive and memory function in animal model of Alzheimer's disease. This study was aimed to investigate whether GS-Rd could improve non-amyloidogenic pathway by activating estrogen receptor (ER). MAIN METHODS 10mg/kg GS-Rd in ovariectomy (OVX)+GS-Rd group and equivalent volume of saline in sham operated group and OVX group were administrated intraperitoneally for two months, respectively. The Morris Water Maze was used to examine cognitive function of rats, with sAPPα and Aβ levels in the hippocampi measured. The culture medium of HT22 hippocampal neuronal cells were incubated with GS-Rd, ER antagonist ICI182.780, MAPK inhibitor PD98059, or PI3Kinhibitor LY294002, respectively. sAPPα levels was measured, and expression of α-secretase, sAPPα, β-secretase, Aβ, phosphorylation form of AKT (p-AKT), total AKT, p-ERK, total ERK, p-ERα, total ERα, p-ERβ and total ERβ were examined by Western blot to explore the estrogenic-like activity of GS-Rd. KEY FINDINGS GS-Rd attenuate cognitive and memory impairment, increased levels of sAPPα and reduced extracellular Aβ of OVX rats. In HT22, GS-Rd could upregulate sAPPα level, which can be inhibited by inhibitor of MAPK and PI3K pathway. In addition, inhibitor of estrogen receptor prevented GS-Rd triggered release of sAPPα and activation of MAPK and PI3K pathways. GS-Rd could increase expression of α-secretase and sAPPα, while decrease expression of β-secretase and Aβ. Besides, GS-Rd promoted phosphorylation of estrogen receptor alpha at Ser118 residue. SIGNIFICANCE Our findings show that GS-Rd enhances learning and memory function of OVX rats by activating estrogen-like activity.
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Affiliation(s)
- Xiaodong Yan
- Department of Orthopaedics, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710032, China
| | - Gengyao Hu
- Department of Neurology, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China
| | - Weiming Yan
- Department of Clinical Aerospace Medicine, The Fourth Military Medical University, Xi'an 710032, China
| | - Tao Chen
- Department of Clinical Aerospace Medicine, The Fourth Military Medical University, Xi'an 710032, China; Department of Health Service, Faculty of Aerospace, The Fourth Military Medical University, Xi'an 710032, China
| | - Feng Yang
- Department of Orthopaedics, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710032, China; Diagnosis, Treatment and Rehabilitation Center of Neurological Diseases, Second Sanatorium, Qingdao 266071, China
| | - Xiao Zhang
- Department of Neurology, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China
| | - Gang Zhao
- Department of Neurology, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
| | - Juanfang Liu
- Department of Clinical Aerospace Medicine, The Fourth Military Medical University, Xi'an 710032, China.
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11
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Neuroprotective Effect of Nanodiamond in Alzheimer’s Disease Rat Model: a Pivotal Role for Modulating NF-κB and STAT3 Signaling. Mol Neurobiol 2016; 54:1906-1918. [DOI: 10.1007/s12035-016-9762-0] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 01/28/2016] [Indexed: 12/31/2022]
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12
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Hu J, Lin T, Xu J, Ding R, Wang G, Shen R, Zhang YW, Chen H. Polyphenols isolated from leaves of Vitis thunbergii var. taiwaniana regulate APP related pathway. Bioorg Med Chem Lett 2015; 26:505-511. [PMID: 26675439 DOI: 10.1016/j.bmcl.2015.11.085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/23/2015] [Accepted: 11/24/2015] [Indexed: 01/21/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain. The major component of the plaques, amyloid-β (Aβ), is generated from amyloid-β precursor protein (APP) by β- and γ-secretase-mediated cleavages. Multiple lines of evidence demonstrate that overproduction/accumulation of Aβ in vulnerable brain regions is a primary cause of the pathogenesis of AD. Among the twelve polyphenols isolated from the leaf extracts of Vitis thunbergii var. taiwaniana (VTT), stenophyllol C, stenophyllol B, ampelopsin C, vitisin A, and davidiol A were shown to significantly reduce both Aβ40 and Aβ42 levels in N2a695 cells. Further studies revealed that ampelopsin C and vitisin A reduce Aβ production through inhibiting β-secretase activity, while the effects of the other active polyphenols on reducing Aβ generation are through different mechanisms. These results suggest that VTT extracts may be beneficial for AD prevention and treatment.
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Affiliation(s)
- Jin Hu
- School of Pharmaceutical Sciences, Xiamen University, South Xiangan Road, Xiamen, Fujian 361102, China; Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, South Xiangan Road, Xiamen, Fujian 361102, China; School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Ting Lin
- School of Pharmaceutical Sciences, Xiamen University, South Xiangan Road, Xiamen, Fujian 361102, China
| | - Junyue Xu
- School of Pharmaceutical Sciences, Xiamen University, South Xiangan Road, Xiamen, Fujian 361102, China
| | - Rong Ding
- School of Pharmaceutical Sciences, Xiamen University, South Xiangan Road, Xiamen, Fujian 361102, China
| | - Guanghui Wang
- School of Pharmaceutical Sciences, Xiamen University, South Xiangan Road, Xiamen, Fujian 361102, China
| | - Ruichi Shen
- Fujian Institute of Subtropical Botany, Jiahe Road 800, Xiamen, Fujian 361006, China
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, South Xiangan Road, Xiamen, Fujian 361102, China.
| | - Haifeng Chen
- School of Pharmaceutical Sciences, Xiamen University, South Xiangan Road, Xiamen, Fujian 361102, China.
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13
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Findlay JA, Hamilton DL, Ashford MLJ. BACE1 activity impairs neuronal glucose oxidation: rescue by beta-hydroxybutyrate and lipoic acid. Front Cell Neurosci 2015; 9:382. [PMID: 26483636 PMCID: PMC4589671 DOI: 10.3389/fncel.2015.00382] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/14/2015] [Indexed: 11/13/2022] Open
Abstract
Glucose hypometabolism and impaired mitochondrial function in neurons have been suggested to play early and perhaps causative roles in Alzheimer's disease (AD) pathogenesis. Activity of the aspartic acid protease, beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), responsible for beta amyloid peptide generation, has recently been demonstrated to modify glucose metabolism. We therefore examined, using a human neuroblastoma (SH-SY5Y) cell line, whether increased BACE1 activity is responsible for a reduction in cellular glucose metabolism. Overexpression of active BACE1, but not a protease-dead mutant BACE1, protein in SH-SY5Y cells reduced glucose oxidation and the basal oxygen consumption rate, which was associated with a compensatory increase in glycolysis. Increased BACE1 activity had no effect on the mitochondrial electron transfer process but was found to diminish substrate delivery to the mitochondria by inhibition of key mitochondrial decarboxylation reaction enzymes. This BACE1 activity-dependent deficit in glucose oxidation was alleviated by the presence of beta hydroxybutyrate or α-lipoic acid. Consequently our data indicate that raised cellular BACE1 activity drives reduced glucose oxidation in a human neuronal cell line through impairments in the activity of specific tricarboxylic acid cycle enzymes. Because this bioenergetic deficit is recoverable by neutraceutical compounds we suggest that such agents, perhaps in conjunction with BACE1 inhibitors, may be an effective therapeutic strategy in the early-stage management or treatment of AD.
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Affiliation(s)
- John A Findlay
- Division of Cardiovascular and Diabetes Medicine, School of Medicine, Ninewells Hospital and Medical School, University of Dundee Dundee, UK
| | - David L Hamilton
- Division of Cardiovascular and Diabetes Medicine, School of Medicine, Ninewells Hospital and Medical School, University of Dundee Dundee, UK
| | - Michael L J Ashford
- Division of Cardiovascular and Diabetes Medicine, School of Medicine, Ninewells Hospital and Medical School, University of Dundee Dundee, UK
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14
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Song WJ, Son MY, Lee HW, Seo H, Kim JH, Chung SH. Enhancement of BACE1 Activity by p25/Cdk5-Mediated Phosphorylation in Alzheimer's Disease. PLoS One 2015; 10:e0136950. [PMID: 26317805 PMCID: PMC4552876 DOI: 10.1371/journal.pone.0136950] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 08/10/2015] [Indexed: 11/24/2022] Open
Abstract
The activity of beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) is elevated during aging and in sporadic Alzheimer’s disease (AD), but the underlying mechanisms of this change are not well understood. p25/Cyclin-dependent kinase 5 (Cdk5) has been implicated in the pathogenesis of several neurodegenerative diseases, including AD. Here, we describe a potential mechanism by which BACE activity is increased in AD brains. First, we show that BACE1 is phosphorylated by the p25/Cdk5 complex at Thr252 and that this phosphorylation increases BACE1 activity. Then, we demonstrate that the level of phospho-BACE1 is increased in the brains of AD patients and in mammalian cells and transgenic mice that overexpress p25. Furthermore, the fraction of p25 prepared from iodixanol gradient centrifugation was unexpectedly protected by protease digestion, suggesting that p25/Cdk5-mediated BACE1 phosphorylation may occur in the lumen. These results reveal a link between p25 and BACE1 in AD brains and suggest that upregulated Cdk5 activation by p25 accelerates AD pathogenesis by enhancing BACE1 activity via phosphorylation.
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Affiliation(s)
- Woo-Joo Song
- Department of Biochemistry and Molecular Biology, Neurodegeneration Control Research Center, School of Medicine, Kyung Hee University, Seoul, Korea
- Institute for Brain Science and Technology, Inje University, Busan, Korea
| | - Mi-Young Son
- Institute for Brain Science and Technology, Inje University, Busan, Korea
| | - Hye-Won Lee
- Institute for Brain Science and Technology, Inje University, Busan, Korea
| | - Hyemyung Seo
- Division of Molecular and Life Sciences, College of Sciences and Technology, Hanyang University, Ansan, Gyeonggi Do, Korea
| | - Jeong Hee Kim
- Department of Oral Biochemistry and Molecular Biology, School of Dentistry, Kyung Hee University, Seoul, Korea
- Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, Korea
- * E-mail: (JHK); (SHC)
| | - Sul-Hee Chung
- Department of Biochemistry and Molecular Biology, Neurodegeneration Control Research Center, School of Medicine, Kyung Hee University, Seoul, Korea
- Institute for Brain Science and Technology, Inje University, Busan, Korea
- * E-mail: (JHK); (SHC)
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15
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Dong WG, Wang F, Chen Y, Zheng XH, Xie YC, Guo WQ, Shi H. Electroacupuncture Reduces Aβ Production and BACE1 Expression in SAMP8 Mice. Front Aging Neurosci 2015; 7:148. [PMID: 26283960 PMCID: PMC4518199 DOI: 10.3389/fnagi.2015.00148] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 07/15/2015] [Indexed: 11/17/2022] Open
Abstract
Electroacupuncture (EA) has been reported to have beneficial effects on Alzheimer’s disease (AD). BACE1 (β-site amyloid precursor protein-cleaving enzyme 1) is involved in the abnormal production of amyloid-β plaque (Aβ), a hallmark of AD pathophysiology. Thus, the present study investigated the effects of EA on memory impairment, Aβ production, and BACE1 expression in senescence-accelerated mouse prone 8 (SAMP8) mice. We found that EA improved spatial learning and memory impairment of SAMP8 mice. Furthermore, EA attenuated Aβ production and repressed the expression of BACE1 in the hippocampus of SAMP8 mice. Taken together, our results suggest that EA could have a potential therapeutic application in AD and that BACE1 may be an important target of EA in the treatment of AD.
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Affiliation(s)
- Wei-Guo Dong
- Department of Integrated Traditional Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine , Fuzhou , China
| | - Feng Wang
- Department of Integrated Traditional Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine , Fuzhou , China
| | - Ye Chen
- Department of Integrated Traditional Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine , Fuzhou , China
| | - Xue-Hua Zheng
- Department of Integrated Traditional Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine , Fuzhou , China
| | - Yong-Cai Xie
- Department of Integrated Traditional Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine , Fuzhou , China
| | - Wan-Qing Guo
- The Third People's Hospital of Fujian Province , Fuzhou , China
| | - Hong Shi
- Department of Integrated Traditional Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine , Fuzhou , China
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16
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Dorresteijn B, Rotman M, Faber D, Schravesande R, Suidgeest E, van der Weerd L, van der Maarel SM, Verrips CT, El Khattabi M. Camelid heavy chain only antibody fragment domain against β-site of amyloid precursor protein cleaving enzyme 1 inhibits β-secretase activityin vitroandin vivo. FEBS J 2015; 282:3618-31. [DOI: 10.1111/febs.13367] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 06/24/2015] [Accepted: 07/01/2015] [Indexed: 02/05/2023]
Affiliation(s)
- Bram Dorresteijn
- Biomolecular Imaging Group; Division of Cell Biology; Department of Biology; Faculty of Science; Utrecht University; The Netherlands
| | - Maarten Rotman
- Department of Radiology; Leiden University Medical Center; Leiden The Netherlands
- Department of Human Genetics; Leiden University Medical Center; Leiden The Netherlands
| | - Dorien Faber
- Biomolecular Imaging Group; Division of Cell Biology; Department of Biology; Faculty of Science; Utrecht University; The Netherlands
| | - Ruud Schravesande
- Biomolecular Imaging Group; Division of Cell Biology; Department of Biology; Faculty of Science; Utrecht University; The Netherlands
| | - Ernst Suidgeest
- Department of Radiology; Leiden University Medical Center; Leiden The Netherlands
| | - Louise van der Weerd
- Department of Radiology; Leiden University Medical Center; Leiden The Netherlands
- Department of Human Genetics; Leiden University Medical Center; Leiden The Netherlands
| | | | - Cornelis T. Verrips
- Biomolecular Imaging Group; Division of Cell Biology; Department of Biology; Faculty of Science; Utrecht University; The Netherlands
- QVQ Holding BV; Utrecht The Netherlands
| | - Mohamed El Khattabi
- Biomolecular Imaging Group; Division of Cell Biology; Department of Biology; Faculty of Science; Utrecht University; The Netherlands
- QVQ Holding BV; Utrecht The Netherlands
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17
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Zhang H, Gao Y, Zhao FL, Qiao PF, Yan Y. Hydrogen sulfide-induced processing of the amyloid precursor protein in SH-SY5Y human neuroblastoma cells involves the PI3-K/Akt signaling pathway. Cell Mol Neurobiol 2014; 35:265-72. [PMID: 25293506 DOI: 10.1007/s10571-014-0121-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 09/27/2014] [Indexed: 01/08/2023]
Abstract
Hydrogen sulfide (H2S) has been recently categorized as a gasotransmitter, and it may be involved in the pathology of Alzheimer's disease. However, whether H2S induces amyloid precursor protein (APP) processing remains unknown. In the present study, we tested the ability of H2S to mediate APP processing in SH-SY5Y human neuroblastoma cells. We treated SH-SY5Y human neuroblastoma cells with a range of sodium hydrosulfide (H2S donor) concentrations. Western blot analysis showed that H2S increased the generation of C83 and decreased the production of C99. Meanwhile, H2S increased the levels of a disintegrin and metalloprotease 10 (ADAM10) mRNA and protein, but had no effect on TNF-α-converting enzyme (TACE, also known as ADAM17) mRNA and protein levels. H2S also induced a significant decrease of extracellular amyloid-β42 (Aβ42). Furthermore, SH-SY5Y human neuroblastoma cells were assayed for activation of the phosphoinositide 3-kinase (PI3-K) pathway. H2S activated the PI3-K pathway. Using specific inhibitor of PI3-K, we determined that the effects of H2S on APP processing and Aβ42 were blocked by LY 294002 (PI3-K inhibitor). These data indicate that H2S can induce APP processing, and this effect is dependent on activation of the PI3-K signaling pathway.
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Affiliation(s)
- Hua Zhang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, No. 1, Youyi Road, Chongqing, 400016, China,
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18
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Yan XX, Ma C, Gai WP, Cai H, Luo XG. Can BACE1 inhibition mitigate early axonal pathology in neurological diseases? J Alzheimers Dis 2014; 38:705-18. [PMID: 24081378 DOI: 10.3233/jad-131400] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
β-Secretase-1 (BACE1) is the rate-limiting enzyme for the genesis of amyloid-β (Aβ) peptides, the main constituents of the amyloid plaques in the brains of Alzheimer's disease (AD) patients. BACE1 is being evaluated as an anti-Aβ target for AD therapy. Recent studies indicate that BACE1 elevation is associated with axonal and presynaptic pathology during plaque development. Evidence also points to a biological role for BACE1 in axonal outgrowth and synapse formation during development. Axonal, including presynaptic, pathology exists in AD as well as many other neurological disorders such as Parkinson's disease, epilepsy, stroke, and trauma. In this review, we discuss pharmaceutical BACE1 inhibition as a therapeutic option for axonal pathogenesis, in addition to amyloid pathology. We first introduce the amyloidogenic processing of amyloid-β protein precursor and describe the normal expression pattern of the amyloidogenic proteins in the brain, with an emphasis on BACE1. We then address BACE1 elevation relative to amyloid plaque development, followed by updating recent understanding of a neurotrophic role of BACE1 in axon and synapse development. We further elaborate the occurrence of axonal pathology in some other neurological conditions. Finally, we propose pharmacological inhibition of excessive BACE1 activity as an option to mitigate early axonal pathology occurring in AD and other neurological disorders.
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Affiliation(s)
- Xiao-Xin Yan
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan, China
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19
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Schmidt FM, Mergl R, Stach B, Jahn I, Gertz HJ, Schönknecht P. Elevated levels of cerebrospinal fluid neuron-specific enolase (NSE) in Alzheimer's disease. Neurosci Lett 2014; 570:81-5. [DOI: 10.1016/j.neulet.2014.04.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 04/07/2014] [Indexed: 10/25/2022]
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20
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Wang L, Hu J, Zhao Y, Lu X, Zhang Q, Niu Q. Effects of aluminium on β-amyloid (1-42) and secretases (APP-cleaving enzymes) in rat brain. Neurochem Res 2014; 39:1338-45. [PMID: 24792732 DOI: 10.1007/s11064-014-1317-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 04/16/2014] [Accepted: 04/21/2014] [Indexed: 01/22/2023]
Abstract
Chronic administration of aluminium has been proposed as an environmental factor that may affect some pathological changes related to neurotoxicity and Alzheimer's disease (AD). The abnormal generation and deposition of β-amyloid (Aβ) in senile plaques are hallmark features in the brains of AD patients. Furthermore, Aβ is generated by the sequential cleavage of the amyloid precursor protein (APP) via the APP cleaving enzyme (α-secretase, or β-secretase) and γ-secretase. In the present study, we investigated the modulation of Aβ deposition and neurotoxicity in aluminium-maltolate-treated (0, 15, 30, 45 mmol/kg body weight via intraperitoneal injection) in experimental rats. We measured Aβ1-40 and Aβ1-42 in the cortex and hippocampus in rat brains using ELISA. Subtypes of α-secretase, β-secretase, and γ-secretase, including ADAM9, ADAM10, ADAM17 (TACE), BACE1, presenilin 1 (PS1) and nicastrin (NCT), were determined using western blotting analyses. These results indicated that aluminium-maltolate induced an AD-like behavioural deficit in rats at 30 and 45 mmol/kg body weight. Moreover, the Aβ1-42 content increased significantly, both in the cortex and hippocampus, although no changes were observed in Aβ1-40. Furthermore, ADAM9, ADAM10, and ADAM17 decreased significantly; in contrast, BACE1, PS1, and NCT showed significant increase. Taken together, these results suggest that the changes in secretases may correlate to the abnormal deposition of Aβ by aluminium in rat brains.
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Affiliation(s)
- Linping Wang
- School of Public Health, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
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21
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Marwarha G, Raza S, Prasanthi JRP, Ghribi O. Gadd153 and NF-κB crosstalk regulates 27-hydroxycholesterol-induced increase in BACE1 and β-amyloid production in human neuroblastoma SH-SY5Y cells. PLoS One 2013; 8:e70773. [PMID: 23951005 PMCID: PMC3739769 DOI: 10.1371/journal.pone.0070773] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 06/21/2013] [Indexed: 11/19/2022] Open
Abstract
β-amyloid (Aβ) peptide, accumulation of which is a culprit for Alzheimer's disease (AD), is derived from the initial cleavage of amyloid precursor protein by the aspartyl protease BACE1. Identification of cellular mechanisms that regulate BACE1 production is of high relevance to the search for potential disease-modifying therapies that inhibit BACE1 to reduce Aβ accumulation and AD progression. In the present study, we show that the cholesterol oxidation product 27-hydroxycholesterol (27-OHC) increases BACE1 and Aβ levels in human neuroblastoma SH-SY5Y cells. This increase in BACE1 involves a crosstalk between the two transcription factors NF-κB and the endoplasmic reticulum stress marker, the growth arrest and DNA damage induced gene-153 (gadd153, also called CHOP). We specifically show that 27-OHC induces a substantial increase in NF-κB binding to the BACE1 promoter and subsequent increase in BACE1 transcription and Aβ production. The NF-κB inhibitor, sc514, significantly attenuated the 27-OHC-induced increase in NF-κB-mediated BACE1 expression and Aβ genesis. We further show that the 27-OHC-induced NF-κB activation and increased NF-κB-mediated BACE1 expression is contingent on the increased activation of gadd153. Silencing gadd153 expression with siRNA alleviated the 27-OHC-induced increase in NF-κB activation, NF-κB binding to the BACE1 promoter, and subsequent increase in BACE1 transcription and Aβ production. We also show that increased levels of BACE1 in the triple transgenic mouse model for AD is preceded by gadd153 and NF-κB activation. In summary, our study demonstrates that gadd153 and NF-κB work in concert to regulate BACE1 expression. Agents that inhibit gadd153 activation and subsequent interaction with NF-κB might be promising targets to reduce BACE1 and Aβ overproduction and may ultimately serve as disease-modifying treatments for AD.
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Affiliation(s)
- Gurdeep Marwarha
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
| | - Shaneabbas Raza
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
| | - Jaya R. P. Prasanthi
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
| | - Othman Ghribi
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
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22
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Yang SG, Wang SW, Zhao M, Zhang R, Zhou WW, Li YN, Su YJ, Zhang H, Yu XL, Liu RT. A peptide binding to the β-site of APP improves spatial memory and attenuates Aβ burden in Alzheimer's disease transgenic mice. PLoS One 2012; 7:e48540. [PMID: 23133641 PMCID: PMC3486805 DOI: 10.1371/journal.pone.0048540] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 09/26/2012] [Indexed: 12/15/2022] Open
Abstract
Amyloid precursor protein cleaving enzyme 1 (BACE1), an aspartyl protease, initiates processing of the amyloid precursor protein (APP) into β-amyloid (Aβ); the peptide likely contributes to development of Alzheimer’s disease (AD). BACE1 is an attractive therapeutic target for AD treatment, but it exhibits other physiological activities and has many other substrates besides APP. Thus, inhibition of BACE1 function may cause adverse side effects. Here, we present a peptide, S1, isolated from a peptide library that selectively inhibits BACE1 hydrolytic activity by binding to the β-proteolytic site on APP and Aβ N-terminal. The S1 peptide significantly reduced Aβ levels in vitro and in vivo and inhibited Aβ cytotoxicity in SH-SY5Y cells. When applied to APPswe/PS1dE9 double transgenic mice by intracerebroventricular injection, S1 significantly improved the spatial memory as determined by the Morris Water Maze, and also attenuated their Aβ burden. These results indicate that the dual-functional peptide S1 may have therapeutic potential for AD by both reducing Aβ generation and inhibiting Aβ cytotoxicity.
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Affiliation(s)
- Shi-gao Yang
- Tsinghua University School of Medicine, Haidian District, Beijing, China
| | - Shao-wei Wang
- Tsinghua University School of Medicine, Haidian District, Beijing, China
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Min Zhao
- Tsinghua University School of Medicine, Haidian District, Beijing, China
| | - Ran Zhang
- Tsinghua University School of Medicine, Haidian District, Beijing, China
| | - Wei-wei Zhou
- Tsinghua University School of Medicine, Haidian District, Beijing, China
| | - Ya-nan Li
- Tsinghua University School of Medicine, Haidian District, Beijing, China
- School of Life Sciences, Ningxia University, Yinchuan, China
| | - Ya-jing Su
- Tsinghua University School of Medicine, Haidian District, Beijing, China
- School of Life Sciences, Ningxia University, Yinchuan, China
| | - He Zhang
- Tsinghua University School of Medicine, Haidian District, Beijing, China
| | - Xiao-lin Yu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- * E-mail: (RTL); (XLY)
| | - Rui-tian Liu
- Tsinghua University School of Medicine, Haidian District, Beijing, China
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- * E-mail: (RTL); (XLY)
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23
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MicroRNA-195 downregulates Alzheimer's disease amyloid-β production by targeting BACE1. Brain Res Bull 2012; 88:596-601. [DOI: 10.1016/j.brainresbull.2012.05.018] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 05/21/2012] [Accepted: 05/31/2012] [Indexed: 11/20/2022]
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Zhang X, Wang J, Xing Y, Gong L, Li H, Wu Z, Li Y, Wang J, Wang Y, Dong L, Li S. Effects of ginsenoside Rg1 or 17β-estradiol on a cognitively impaired, ovariectomized rat model of Alzheimer's disease. Neuroscience 2012; 220:191-200. [PMID: 22728092 DOI: 10.1016/j.neuroscience.2012.06.027] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 06/08/2012] [Accepted: 06/11/2012] [Indexed: 01/08/2023]
Abstract
Ginsenoside Rg1, which could improve spatial learning and memory, might be a useful agent for preventing and treating cognitive impairment in Alzheimer's disease (AD). The present study was designed to test the neuroprotective effects of ginsenoside Rg1 on an ovariectomized (OVX) and d-galactose (d-gal)-injected rat model of AD, which is characterized with progressive learning and memory deficits, AD-related molecules alteration and differentiation/apoptosis imbalance in hippocampal neurons. OVX Wistar rats received daily injections of d-gal (100mg/kg) combined with different concentrations of ginsenoside Rg1 (5, 10, 20mg/kg) or 17-β-estradiol (E2, 100 μg/kg), or normal saline (NS, 1.0 ml/kg) for 6 weeks. Ovarian steroid deprivation plus d-gal injection led to spatial learning and memory capacity impairments, as well as increased Aβ(1-42) production. Ginsenoside Rg1 and E2-treatment significantly ameliorated these deteriorations in AD rats. Seven weeks after surgery, α-secretase a disintegrin and metallopeptidase domain 10 (ADAM 10) in hippocampus of AD rats was dramatically decreased, while β-secretase β-site APP-cleaving enzyme 1 (BACE 1) increased compared with those in sham-operated ones (P<0.05). Levels of cleaved caspase 3 were increased in the hippocampus of AD rats. Ginsenoside Rg1 and E2-treatment increased ADAM 10 level while reduced BACE 1 level and apoptosis. Moreover, moderate i.e. 10mg/kg/d and high i.e. 20mg/kg/d ginsenoside Rg1 displayed more effective function than low i.e. 5mg/kg/d ginsenoside Rg1. Our findings demonstrate the neuroprotective effects of ginsenoside Rg1 and E2 on AD rats and support the potential application of ginsenoside Rg1 in the treatment of learning and memory impairments in postmenopausal women.
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Affiliation(s)
- X Zhang
- Department of Traditional Chinese Integrated Western Medicine, Qi Lu Hospital, Shandong University, Jinan 250012, PR China
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Ferretti MT, Allard S, Partridge V, Ducatenzeiler A, Cuello AC. Minocycline corrects early, pre-plaque neuroinflammation and inhibits BACE-1 in a transgenic model of Alzheimer's disease-like amyloid pathology. J Neuroinflammation 2012; 9:62. [PMID: 22472085 PMCID: PMC3352127 DOI: 10.1186/1742-2094-9-62] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 04/02/2012] [Indexed: 12/20/2022] Open
Abstract
Background A growing body of evidence indicates that inflammation is one of the earliest neuropathological events in Alzheimer's disease. Accordingly, we have recently shown the occurrence of an early, pro-inflammatory reaction in the hippocampus of young, three-month-old transgenic McGill-Thy1-APP mice in the absence of amyloid plaques but associated with intracellular accumulation of amyloid beta petide oligomers. The role of such a pro-inflammatory process in the progression of the pathology remained to be elucidated. Methods and results To clarify this we administered minocycline, a tetracyclic derivative with anti-inflammatory and neuroprotective properties, to young, pre-plaque McGill-Thy1-APP mice for one month. The treatment ended at the age of three months, when the mice were still devoid of plaques. Minocycline treatment corrected the up-regulation of inducible nitric oxide synthase and cyclooxygenase-2 observed in young transgenic placebo mice. Furthermore, the down-regulation of inflammatory markers correlated with a reduction in amyloid precursor protein levels and amyloid precursor protein-related products. Beta-site amyloid precursor protein cleaving enzyme 1 activity and levels were found to be up-regulated in transgenic placebo mice, while minocycline treatment restored these levels to normality. The anti-inflammatory and beta-secretase 1 effects could be partly explained by the inhibition of the nuclear factor kappa B pathway. Conclusions Our study suggests that the pharmacological modulation of neuroinflammation might represent a promising approach for preventing or delaying the development of Alzheimer's disease neuropathology at its initial, pre-clinical stages. The results open new vistas to the interplay between inflammation and amyloid pathology.
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Affiliation(s)
- Maria Teresa Ferretti
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir-William-Osler, Montreal, QC H3G 1Y6, Canada
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Li WZ, Wu WY, Huang DK, Yin YY, Kan HW, Wang X, Yao YY, Li WP. Protective effects of astragalosides on dexamethasone and Aβ25-35 induced learning and memory impairments due to decrease amyloid precursor protein expression in 12-month male rats. Food Chem Toxicol 2012; 50:1883-90. [PMID: 22484447 DOI: 10.1016/j.fct.2012.03.064] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 02/18/2012] [Accepted: 03/21/2012] [Indexed: 11/28/2022]
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disorder of the elderly characterized by learning and memory impairment. Stress level glucocorticoids (GCs) and β-amyloid (Aβ) peptide deposition are found to be correlated with dementia progression in patients with AD. The astragalosides (AST) was extracted from traditional Chinese herb Astragalus membranaceous. In this study, 12 months male rats were treated with Aβ(25-35) (10 μg/rat, hippocampal CA1 injection) and dexamethasone (DEX, 1.5mg/kg, ig) and AST (8, 16 and 32 mg/kg, ig) or ginsenoside Rg1 (Rg1, 5 mg/kg, ig) for 14 days. We investigated the protective effect of AST against DEX+Aβ(25-35) injury in rats and its mechanisms of action. Our results indicate that DEX+Aβ(25-35) can induce learning and memory impairments and increase APP and Aβ(1-40) expression. AST (16, 32 mg/kg) or Rg1 (5mg/kg) treatment significantly improve learning and memory, down-regulate the mRNA levels of APP and β-secretase, decrease expression of APP and Aβ(1-40) in hippocampus. The results indicated that DEX might increase hippocampal vulnerability to Aβ(25-35) and highlight the potential neuronal protection of AST.
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Affiliation(s)
- Wei-Zu Li
- Department of Pharmacology, Key Laboratory of Anti-Inflammatory and Immunopharmacology, Ministry of Education, Anhui Medical University, Hefei 230032, PR China
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Dislich B, Lichtenthaler SF. The Membrane-Bound Aspartyl Protease BACE1: Molecular and Functional Properties in Alzheimer's Disease and Beyond. Front Physiol 2012; 3:8. [PMID: 22363289 PMCID: PMC3281277 DOI: 10.3389/fphys.2012.00008] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 01/11/2012] [Indexed: 12/31/2022] Open
Abstract
The β-site APP cleaving enzyme 1 (BACE1) is a transmembrane aspartyl protease involved in Alzheimer’s disease (AD) pathogenesis and in myelination. BACE1 initiates the generation of the pathogenic amyloid β-peptide, which makes BACE1 a major drug target for AD. BACE1 also cleaves and activates neuregulin 1, thereby contributing to postnatal myelination, in particular in the peripheral nervous system. Additional proteins are also cleaved by BACE1, but less is known about the physiological consequences of their cleavage. Recently, new phenotypes were described in BACE1-deficient mice. Although it remains unclear through which BACE1 substrates they are mediated, the phenotypes suggest a versatile role of this protease for diverse physiological processes. This review summarizes the enzymatic and cellular properties of BACE1 as well as its regulation by lipids, by transcriptional, and by translational mechanisms. The main focus will be on the recent progress in understanding BACE1 function and its implication for potential mechanism-based side effects upon therapeutic inhibition.
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Affiliation(s)
- Bastian Dislich
- German Center for Neurodegenerative Diseases (DZNE) Munich, Germany
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Byun CJ, Seo J, Jo SA, Park YJ, Klug M, Rehli M, Park MH, Jo I. DNA methylation of the 5'-untranslated region at +298 and +351 represses BACE1 expression in mouse BV-2 microglial cells. Biochem Biophys Res Commun 2011; 417:387-92. [PMID: 22166205 DOI: 10.1016/j.bbrc.2011.11.123] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 11/29/2011] [Indexed: 01/15/2023]
Abstract
BACE1, which cleaves the amyloid precursor protein, is the rate-limiting enzyme for β-amyloid peptide production, leading to the pathogenesis of Alzheimer's disease (AD). A high plasma level of homocysteine, acting as a potent methyltransferase inhibitor, is assumed to be a risk factor for AD onset. Using the demethylating drug 5-aza-2'-deoxycytidine (5-Aza), we tested whether and how BACE1 expression is regulated in mouse BV-2 microglial cells. 5-Aza increased both BACE1 mRNA and protein levels in a dose-dependent manner. Bisulfite-sequencing analysis revealed that two CpG sites at positions +298 and +351 in the 5'-untranslated region (5'-UTR) of the BACE1 gene were specifically demethylated in BV-2 cells treated with 5-Aza. In silico analysis showed that the +351 site is the STAT3/CTCF-binding site; the function of the +298 site has not been identified. To assess whether these two CpG sites play an important role in 5-Aza-induced transcriptional activation of BACE1, we constructed a BACE1 gene promoter including the 5'-UTR (-1136 to +500) fused to a CpG-free luciferase gene (pCpGL-BACE1) and its mutant pCpGL-BACE1-AA, which has substituted CG dinucleotides at the two CpG sites of pCpGL-BACE1 to AA. Promoter analysis showed a significant decrease (∼30%) in the activity of pCpGL-BACE1-AA compared with that of pCpGL-BACE1. Furthermore, in vitro methylation of these two reporter constructs showed a complete silencing of their promoter activities. Our data demonstrate that BACE1 gene expression is regulated by DNA methylation of at least two CpG sites at positions +298 and +351 in the 5'-UTR in BV-2 microglial cells.
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Li WZ, Li WP, Huang DK, Kan HW, Wang X, Wu WY, Yin YY, Yao YY. Dexamethasone and Aβ₂₅-₃₅ accelerate learning and memory impairments due to elevate amyloid precursor protein expression and neuronal apoptosis in 12-month male rats. Behav Brain Res 2011; 227:142-9. [PMID: 22061800 DOI: 10.1016/j.bbr.2011.10.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 10/18/2011] [Accepted: 10/23/2011] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) is an irreversible, progressive brain disorder of the elderly characterized by learning and memory impairment. Stress level glucocorticoids (GCs) and β-amyloid (Aβ) peptides deposition are found to be correlated with dementia progression in patients with AD. However, little is known about the simultaneous effects of glucocorticoids and Aβ on learning and memory impairment and its mechanism. In this study, 12-month-old male rats were chronically treated with Aβ(25-35) (10 μg/rat, hippocampal CA1 injection) and dexamethasone (DEX, 1.5mg/kg) for 14 days to investigate the effects of DEX and Aβ(25-35) treatment on learning and memory impairments, pathological changes, neuronal ultrastructure, amyloid precursor protein (APP) processing and neuronal cell apoptosis. Our results showed that DEX or Aβ(25-35) treatment alone for 14 days had caused slight damage on learning and memory impairments and hippocampal neurons, but damages were significantly increased with DEX+Aβ(25-35) treatment. And the mRNA levels of the APP, β-secretase and caspase 3 were significantly increased after DEX+Aβ(25-35) treatment. The immunohistochemistry demonstrated that APP, Aβ(1-40), caspase 3 and cytochrome c in hippocampus CA1 were significantly increased. Furthermore, Hoechst 33258 staining and Aβ(1-40) ELISA results showed that DEX+Aβ(25-35) treatment induced hippocampus CA1 neuron apoptosis and increased the level of Aβ(1-40). The results suggest that the simultaneous effects of GCs and Aβ may have important roles in the etiopathogenesis of AD, and demonstrate that stressful life events and GC therapy may increase the toxicity of Aβ and have cumulative impacts on the course of AD development and progression.
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Affiliation(s)
- Wei-Zu Li
- Department of Pharmacology, Key Laboratory of Anti-inflammatory and Immunopharmacology, Ministry of Education, Key Laboratory of Chinese Medicine Research and Development, State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei 230032, PR China
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Zhang J, Zhang Y, Li J, Xing S, Li C, Li Y, Dang C, Fan Y, Yu J, Pei Z, Zeng J. Autophagosomes accumulation is associated with β-amyloid deposits and secondary damage in the thalamus after focal cortical infarction in hypertensive rats. J Neurochem 2011; 120:564-73. [PMID: 21950964 DOI: 10.1111/j.1471-4159.2011.07496.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Focal cerebral cortical infarction after distal middle cerebral artery occlusion causes β-amyloid deposition and secondary neuronal degeneration in the ipsilateral ventroposterior nucleus of the thalamus. Several studies suggest that autophagy is an active pathway for β-amyloid peptide generation. This study aimed to investigate the role of autophagy in thalamic β-amyloid deposition and neuronal degeneration after cerebral cortical infarction in hypertensive rats. At 7 and 14days after middle cerebral artery occlusion, neuronal death and β-amyloid deposits were evident in the ipsilateral ventroposterior nucleus, and the activity of β-site amyloid precursor protein (APP)-cleaving enzyme 1, required for β-amyloid peptide generation, was elevated in the thalamus. In correlation, both the number of cells showing punctate microtubule-associated protein 1A light chain 3 fluorescence and levels of light chain 3-II protein, an autophagosome marker, were markedly increased. Notably, most of the cells that over-expressed β-site APP-cleaving enzyme 1 displayed punctate light chain 3 staining. Furthermore, the inhibition of autophagy with 3-methyladenine significantly reduced the thalamic neuronal damage, β-amyloid deposits, and β-site APP-cleaving enzyme 1 activity. These results suggest that autophagosomes accumulate within thalamic cells after cerebral cortical infarction, which is associated with thalamic β-amyloid deposition and secondary neuronal degeneration via elevation of β-site APP-cleaving enzyme 1 level.
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Affiliation(s)
- Jian Zhang
- Department of Neurology and Stroke Center, First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
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31
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Regulation of alpha-secretase ADAM10 expression and activity. Exp Brain Res 2011; 217:343-52. [DOI: 10.1007/s00221-011-2885-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 09/19/2011] [Indexed: 12/20/2022]
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Cole SL, Vassar R. The Basic Biology of BACE1: A Key Therapeutic Target for Alzheimer's Disease. Curr Genomics 2011; 8:509-30. [PMID: 19415126 PMCID: PMC2647160 DOI: 10.2174/138920207783769512] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 12/27/2007] [Accepted: 12/27/2007] [Indexed: 11/22/2022] Open
Abstract
Alzheimer’s disease (AD) is an intractable, neurodegenerative disease that appears to be brought about by both genetic and non-genetic factors. The neuropathology associated with AD is complex, although amyloid plaques composed of the β-amyloid peptide (Aβ) are hallmark neuropathological lesions of AD brain. Indeed, Aβ plays an early and central role in this disease. β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) is the initiating enzyme in Aβ genesis and BACE1 levels are elevated under a variety of conditions. Given the strong correlation between Aβ and AD, and the elevation of BACE1 in this disease, this enzyme is a prime drug target for inhibiting Aβ production in AD. However, nine years on from the initial identification of BACE1, and despite intense research, a number of key questions regarding BACE1 remain unanswered. Indeed, drug discovery and development for AD continues to be challenging. While current AD therapies temporarily slow cognitive decline, treatments that address the underlying pathologic mechanisms of AD are completely lacking. Here we review the basic biology of BACE1. We pay special attention to recent research that has provided some answers to questions such as those involving the identification of novel BACE1 substrates, the potential causes of BACE1 elevation and the putative function of BACE1 in health and disease. Our increasing understanding of BACE1 biology should aid the development of compounds that interfere with BACE1 expression and activity and may lead to the generation of novel therapeutics for AD.
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Affiliation(s)
- S L Cole
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Avenue, Chicago, IL 60611, USA
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Glucocorticoids increase impairments in learning and memory due to elevated amyloid precursor protein expression and neuronal apoptosis in 12-month old mice. Eur J Pharmacol 2009; 628:108-15. [PMID: 19948164 DOI: 10.1016/j.ejphar.2009.11.045] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 10/19/2009] [Accepted: 11/03/2009] [Indexed: 11/24/2022]
Abstract
Alzheimer's disease is a chronic neurodegenerative disorder marked by a progressive loss of memory and cognitive function. Stress level glucocorticoids are correlated with dementia progression in patients with Alzheimer's disease. In this study, twelve month old male mice were chronically treated for 21 days with stress-level dexamethasone (5mg/kg). We investigated the pathological consequences of dexamethasone administration on learning and memory impairments, amyloid precursor protein processing and neuronal cell apoptosis in 12-month old male mice. Our results indicate that dexamethasone can induce learning and memory impairments, neuronal cell apoptosis, and mRNA levels of the amyloid precursor protein, beta-secretase and caspase-3 are selectively increased after dexamethasone administration. Immunohistochemistry demonstrated that amyloid precursor protein, caspase-3 and cytochrome c in the cortex and CA1, CA3 regions of the hippocampus are significantly increased in 12-month old male mice. Furthermore, dexamethasone treatment induced cortex and hippocampus neuron apoptosis as well as increasing the activity of caspase-9 and caspase-3. These findings suggest that high levels of glucocorticoids, found in Alzheimer's disease, are not merely a consequence of the disease process but rather play a central role in the development and progression of Alzheimer's disease. Stress management or pharmacological reduction of glucocorticoids warrant additional consideration of the regimen used in Alzheimer's disease therapies.
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Sun ZZ, Chen ZB, Jiang H, Li LL, Li EG, Xu Y. Alteration of Aβ metabolism-related molecules in predementia induced by AlCl3 and D-galactose. AGE (DORDRECHT, NETHERLANDS) 2009; 31:277-284. [PMID: 19468866 PMCID: PMC2813045 DOI: 10.1007/s11357-009-9099-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Accepted: 05/07/2009] [Indexed: 05/27/2023]
Abstract
The purpose of this study was to look for alterations in β-amyloid peptide (Aβ) metabolism-related molecules in predementia, the early stage of Alzheimer’s disease (AD). AlCl3 (Al) and d-galactose (D-gal) were used to induce the mouse model for predementia and AD. Protein expression of β-amyloid (Aβ), β-secretase (BACE1), neprilysin (NEP), insulin degrading enzyme (IDE) and receptor for advanced glycation end products (RAGE) in the brain was measured. The results indicated that Al + D-gal induced an AD-like behavioral deficit at 90 days. The period from 45 to 75 days showed no significant behavioral deficit, and we tentatively define this as predementia in this model. A significant increase in BACE1 and decreasing NEP characterized days 45–90 in the cortex and hippocampus. However, high Aβ occurred at day 60. IDE increased from day 60 to day 75. There was no change in RAGE. The results suggest that the observed changes in BACE1, NEP and Aβ in predementia might relate to a different stage of the AD-like pathology, which may be developed into useful biomarkers for the diagnosis of very early AD.
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Affiliation(s)
- Zong-Zheng Sun
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, 321 Zhong Shan Road, Nanjing, Jiangsu 210008 People’s Republic of China
| | - Zhi-Bin Chen
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, 321 Zhong Shan Road, Nanjing, Jiangsu 210008 People’s Republic of China
| | - Hui Jiang
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, 321 Zhong Shan Road, Nanjing, Jiangsu 210008 People’s Republic of China
| | - Ling-Ling Li
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing, School of Clinical Medicine, Southeast University, Nanjing, Jiangsu People’s Republic of China
| | - Er-Guang Li
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, 321 Zhong Shan Road, Nanjing, Jiangsu 210008 People’s Republic of China
- The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, Jiangsu 210093 People’s Republic of China
- Jiangsu Key Laboratory for Molecular Medicine, Nanjing, Jiangsu 210093 People’s Republic of China
| | - Yun Xu
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, 321 Zhong Shan Road, Nanjing, Jiangsu 210008 People’s Republic of China
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing, School of Clinical Medicine, Southeast University, Nanjing, Jiangsu People’s Republic of China
- The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, Jiangsu 210093 People’s Republic of China
- Jiangsu Key Laboratory for Molecular Medicine, Nanjing, Jiangsu 210093 People’s Republic of China
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Yamakawa H, Yagishita S, Futai E, Ishiura S. beta-Secretase inhibitor potency is decreased by aberrant beta-cleavage location of the "Swedish mutant" amyloid precursor protein. J Biol Chem 2009; 285:1634-42. [PMID: 19926793 DOI: 10.1074/jbc.m109.066753] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The amyloid-beta (Abeta) peptide, widely known as the causative molecule of Alzheimer disease (AD), is generated by the sequential cleavage of amyloid precursor protein (APP) by the aspartyl proteases BACE1/beta-secretase and presenilin/gamma-secretase. Inhibition of BACE1, therefore, is a promising strategy for preventing the progression of AD. However, beta-secretase inhibitors (BSIs) exhibit unexpectedly low potency in cells expressing "Swedish mutant" APP (APPswe) and in the transgenic mouse Tg2576, an AD model overexpressing APPswe. The Swedish mutation dramatically accelerates beta-cleavage of APP and hence the generation of Abeta; this acceleration has been assumed to underlie the poor inhibitory activity of BSI against APPswe processing. Here, we studied the mechanism by which the Swedish mutation causes this BSI potency decrease. Surprisingly, decreased BSI potency was not observed in an in vitro assay using purified BACE1 and substrates, indicating that the accelerated beta-cleavage resulting from the Swedish mutation is not its underlying cause. By focusing on differences between the cell-based and in vitro assays, we have demonstrated here that the potency decrease is caused by the aberrant subcellular localization of APPswe processing and not by accelerated beta-cleavage or the accumulation of the C-terminal fragment of beta-cleaved APP. Because most patients with sporadic AD express wild type APP, our findings suggest that the wild type mouse is superior to the Tg2576 mouse as a model for determining the effective dose of BSI for AD patients. This work provides novel insights into the potency decrease of BSI and valuable suggestions for its development as a disease-modifying agent.
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Affiliation(s)
- Hidekuni Yamakawa
- From the Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan
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36
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Cole SL, Vassar R. Linking vascular disorders and Alzheimer's disease: potential involvement of BACE1. Neurobiol Aging 2009; 30:1535-44. [PMID: 18289733 PMCID: PMC3490488 DOI: 10.1016/j.neurobiolaging.2007.12.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 11/28/2007] [Accepted: 12/14/2007] [Indexed: 01/26/2023]
Abstract
The etiology of Alzheimer's disease (AD) remains unknown. However, specific risk factors have been identified, and aging is the strongest AD risk factor. The majority of cardiovascular events occur in older people and a close relationship between vascular disorders and AD exists. Amyloid plaques, composed of the beta amyloid peptide (Abeta), are hallmark lesions in AD and evidence indicates that Abeta plays a central role in AD pathophysiology. The BACE1 enzyme is essential for Abeta generation, and BACE1 levels are elevated in AD brain. The cause(s) of this BACE1 elevation remains undetermined. Here we review the potential contribution of vascular disease to AD pathogenesis. We examine the putative vasoactive properties of Abeta and how the cellular changes associated with vascular disease may elevate BACE1 levels. Despite increasing evidence, the exact role(s) vascular disorders play in AD remains to be determined. However, given that vascular diseases can be addressed by lifestyle and pharmacologic interventions, the potential benefits of these therapies in delaying the clinical appearance and progression of AD may warrant investigation.
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Affiliation(s)
- Sarah L Cole
- Northwestern University, The Feinberg School of Medicine, Department of Cell and Molecular Biology, 303 E. Chicago Avenue, Chicago, IL 60611, USA.
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Neprilysin and Insulin-Degrading Enzyme Levels Are Increased in Alzheimer Disease in Relation to Disease Severity. J Neuropathol Exp Neurol 2009; 68:902-14. [DOI: 10.1097/nen.0b013e3181afe475] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Lv J, Jia H, Jiang Y, Ruan Y, Liu Z, Yue W, Beyreuther K, Tu P, Zhang D. Tenuifolin, an extract derived from tenuigenin, inhibits amyloid-beta secretion in vitro. Acta Physiol (Oxf) 2009; 196:419-25. [PMID: 19208093 DOI: 10.1111/j.1748-1716.2009.01961.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIM Previous studies have shown that tenuigenin, a crude extract of Polygala tenuifolia Willd. that is commonly used in traditional Chinese herbal medicine for memory loss, can reduce the secretion of Abeta from cultured cells. However, the mechanism underlying this effect and the active compound derived from tenuigenin is unknown. In this study, a purified component of tenuigenin, tenuifolin, was examined and revealed to be an effective compound in vitro. METHODS Abeta secretion from three sets of COS-7 cells, each carrying a plasmid expressing a different form of APP was examined following the treatment with tenuifolin. Initially, tenuifolin was determined to have no inherent toxicity to either the transfected or wild type cells at the effective concentrations. Cells were then treated with 0.5-2.0 microg mL(-1) tenuifolin for 12 h and their media were examined via an ELISA for Abeta1-40 and Abeta-42. RESULTS We found that treatment with 2.0 microg mL(-1) tenuifolin significantly decreased Abeta secretion from COS-7 cells without altering the ratio of Abeta1-40 and Abeta-42. This effect is most probably due to inhibition of the beta-site APP cleaving enzyme as Abeta secretion was not inhibited from cells expressing the C99 fragment. CONCLUSION Tenuifolin is an effective compound from tenuigenin. We believe that this finding should lead the way for future experiments to determine the exact mechanism for tenuifolin's effect on Abeta secretion.
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Affiliation(s)
- J Lv
- Institute of Mental Health, Peking University, 100083 Beijing, China
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Transcriptional regulation of beta-secretase by p25/cdk5 leads to enhanced amyloidogenic processing. Neuron 2008; 57:680-90. [PMID: 18341989 DOI: 10.1016/j.neuron.2008.02.024] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Revised: 01/10/2008] [Accepted: 02/19/2008] [Indexed: 12/22/2022]
Abstract
Cyclin-dependent kinase 5 (cdk5) has been implicated in Alzheimer's disease (AD) pathogenesis. Here, we demonstrate that overexpression of p25, an activator of cdk5, led to increased levels of BACE1 mRNA and protein in vitro and in vivo. A p25/cdk5 responsive region containing multiple sites for signal transducer and activator of transcription (STAT1/3) was identified in the BACE1 promoter. STAT3 interacts with the BACE1 promoter, and p25-overexpressing mice had elevated levels of pSTAT3 and BACE1, whereas cdk5-deficient mice had reduced levels. Furthermore, mice with a targeted mutation in the STAT3 cdk5 responsive site had lower levels of BACE1. Increased BACE levels in p25 overexpressing mice correlated with enhanced amyloidogenic processing that could be reversed by a cdk5 inhibitor. These data demonstrate a pathway by which p25/cdk5 increases the amyloidogenic processing of APP through STAT3-mediated transcriptional control of BACE1 that could have implications for AD pathogenesis.
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Cole SL, Vassar R. The Alzheimer's disease beta-secretase enzyme, BACE1. Mol Neurodegener 2007; 2:22. [PMID: 18005427 PMCID: PMC2211305 DOI: 10.1186/1750-1326-2-22] [Citation(s) in RCA: 336] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Accepted: 11/15/2007] [Indexed: 12/11/2022] Open
Abstract
The pathogenesis of Alzheimer's disease is highly complex. While several pathologies characterize this disease, amyloid plaques, composed of the β-amyloid peptide are hallmark neuropathological lesions in Alzheimer's disease brain. Indeed, a wealth of evidence suggests that β-amyloid is central to the pathophysiology of AD and is likely to play an early role in this intractable neurodegenerative disorder. The BACE1 enzyme is essential for the generation of β-amyloid. BACE1 knockout mice do not produce β-amyloid and are free from Alzheimer's associated pathologies including neuronal loss and certain memory deficits. The fact that BACE1 initiates the formation of β-amyloid, and the observation that BACE1 levels are elevated in this disease provide direct and compelling reasons to develop therapies directed at BACE1 inhibition thus reducing β-amyloid and its associated toxicities. However, new data indicates that complete abolishment of BACE1 may be associated with specific behavioral and physiological alterations. Recently a number of non-APP BACE1 substrates have been identified. It is plausible that failure to process certain BACE1 substrates may underlie some of the reported abnormalities in the BACE1-deficient mice. Here we review BACE1 biology, covering aspects ranging from the initial identification and characterization of this enzyme to recent data detailing the apparent dysregulation of BACE1 in Alzheimer's disease. We pay special attention to the putative function of BACE1 during healthy conditions and discuss in detail the relationship that exists between key risk factors for AD, such as vascular disease (and downstream cellular consequences), and the pathogenic alterations in BACE1 that are observed in the diseased state.
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Affiliation(s)
- Sarah L Cole
- Department of Cell and Molecular Biology, The Feinberg School of Medicine, Northwestern University, Chicago Avenue, Chicago, IL, USA.
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Zhao J, Fu Y, Yasvoina M, Shao P, Hitt B, O'Connor T, Logan S, Maus E, Citron M, Berry R, Binder L, Vassar R. Beta-site amyloid precursor protein cleaving enzyme 1 levels become elevated in neurons around amyloid plaques: implications for Alzheimer's disease pathogenesis. J Neurosci 2007; 27:3639-49. [PMID: 17409228 PMCID: PMC6672403 DOI: 10.1523/jneurosci.4396-06.2007] [Citation(s) in RCA: 285] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) (beta-secretase) initiates generation of beta-amyloid (Abeta), which plays an early role in Alzheimer's disease (AD). BACE1 levels are increased in postmortem AD brain, suggesting BACE1 elevation promotes Abeta production and AD. Alternatively, the BACE1 increase may be an epiphenomenon of late-stage AD. To distinguish between these possibilities, we analyzed BACE1 elevation using a highly specific BACE1 antibody, BACE-Cat1, made in BACE1-/- mice, which mount a robust anti-BACE1 immune response. Previous BACE1 immunohistochemical studies lack consistent results because typical BACE1 antibodies produce nonspecific background, but BACE-Cat1 immunolabels BACE1 only. BACE1 elevation was recapitulated in two amyloid precursor protein (APP) transgenic mouse lines. 5XFAD mice form amyloid plaques at young ages and exhibit neuron loss. In contrast, Tg2576 form plaques at a more advanced age and do not show cell death. These two mouse lines allow differentiation between early Abeta-induced events and late phenomena related to neuron death. BACE1 levels became elevated in parallel with amyloid burden in each APP transgenic, starting early in 5XFAD and late in Tg2576. The increase in BACE1 protein occurred without any change in BACE1 mRNA level, indicating a posttranscriptional mechanism. In APP transgenic and AD brains, high BACE1 levels were observed in an annulus around Abeta42-positive plaque cores and colocalized with neuronal proteins. These results demonstrate that amyloid plaques induce BACE1 in surrounding neurons at early stages of pathology before neuron death occurs. We conclude that BACE1 elevation is most likely triggered by the amyloid pathway and may drive a positive-feedback loop in AD.
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Affiliation(s)
- Jie Zhao
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
| | - Yifan Fu
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
| | - Marina Yasvoina
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
| | - Peizhen Shao
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
| | - Brian Hitt
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
| | - Tracy O'Connor
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
| | - Sreemathi Logan
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
| | - Erika Maus
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
| | | | - Robert Berry
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
| | - Lester Binder
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
| | - Robert Vassar
- Department of Cell & Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, and
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Xiong K, Cai H, Luo XG, Struble RG, Clough RW, Yan XX. Mitochondrial respiratory inhibition and oxidative stress elevate beta-secretase (BACE1) proteins and activity in vivo in the rat retina. Exp Brain Res 2007; 181:435-46. [PMID: 17429617 DOI: 10.1007/s00221-007-0943-y] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Accepted: 03/12/2007] [Indexed: 01/09/2023]
Abstract
Cerebral hypometabolism, oxidative stress and beta-amyloid peptide (Abeta) accumulation are key pathological events in Alzheimer's disease (AD). Beta-secretase (BACE, i.e., BACE1), a prerequisite for Abeta genesis, is elevated in sporadic AD. Recent studies show BACE upregulation in experimental conditions likely associated with energy insufficiency and/or oxidative stress. We investigated the effect of sublethal doses of mitochondrial respiratory inhibitors and potential endogenous oxidative substances on BACE expression in vivo using the retina as a model. Retinas were analyzed biochemically and anatomically 48 h following intraocular applications of mitochondrial complex I, II and IV inhibitors including rotenone, 3-nitropropionic acid and sodium azide, and plaque-containing oxidants including Fe(3+) and Abeta42 fibrils (Abeta42f). All agents caused elevations of BACE proteins and beta-site amyloid precursor protein (APP) cleavage product, beta-CTF, in retinal lysates in a dose-dependant manner. BACE activity and Abeta40 levels were also increased in agent-treated retinas relative to vehicle controls. BACE immunoreactivity in normal adult rat retina was present mostly in the plexiform layers, indicating a localization of the enzyme to synaptic terminals. No apparent change in laminar or cellular distribution of BACE labeling was detected in the experimental retinas. However, signs of neuronal stress including glial activation were observed in agent-treated retinas especially in high dosage groups. Our data suggest that mitochondrial respiratory inhibition and oxidative stress facilitate BACE expression in vivo. In addition, plaque constituents such as Fe(3+) and Abeta42f may participate in a self-enforcing cycle of amyloidogenesis via BACE upregulation.
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Affiliation(s)
- Kun Xiong
- Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
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