1
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Jaye S, Sandau US, Saugstad JA. Clathrin mediated endocytosis in Alzheimer's disease: cell type specific involvement in amyloid beta pathology. Front Aging Neurosci 2024; 16:1378576. [PMID: 38694257 PMCID: PMC11061891 DOI: 10.3389/fnagi.2024.1378576] [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: 01/29/2024] [Accepted: 04/03/2024] [Indexed: 05/04/2024] Open
Abstract
This review provides a comprehensive examination of the role of clathrin-mediated endocytosis (CME) in Alzheimer's disease (AD) pathogenesis, emphasizing its impact across various cellular contexts beyond neuronal dysfunction. In neurons, dysregulated CME contributes to synaptic dysfunction, amyloid beta (Aβ) processing, and Tau pathology, highlighting its involvement in early AD pathogenesis. Furthermore, CME alterations extend to non-neuronal cell types, including astrocytes and microglia, which play crucial roles in Aβ clearance and neuroinflammation. Dysregulated CME in these cells underscores its broader implications in AD pathophysiology. Despite significant progress, further research is needed to elucidate the precise mechanisms underlying CME dysregulation in AD and its therapeutic implications. Overall, understanding the complex interplay between CME and AD across diverse cell types holds promise for identifying novel therapeutic targets and interventions.
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Affiliation(s)
| | | | - Julie A. Saugstad
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, United States
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2
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Liu S, Wang M, Xiao H, Ye J, Cao L, Li W, Sun G. Advancements in research on the effects of panax notoginseng saponin constituents in ameliorating learning and memory disorders. Heliyon 2024; 10:e28581. [PMID: 38586351 PMCID: PMC10998096 DOI: 10.1016/j.heliyon.2024.e28581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 03/20/2024] [Accepted: 03/20/2024] [Indexed: 04/09/2024] Open
Abstract
Learning and memory disorder is a cluster of symptoms caused by neuronal aging and other diseases of the central nervous system (CNS). Panax notoginseng saponins (PNS) are a series of saponins derived from the natural active ingredients of traditional Chinese medicine (TCM) that have neuroprotective effects on the central nervous system. In this paper, we review the ameliorative effects and mechanisms of Panax notoginseng saponin-like components on learning and memory disorders to provide valuable references and insights for the development of new drugs for the treatment of learning and memory disorders. Our summary results suggest that Panax ginseng saponins have significant effects on improving learning and memory disorders, and these effects and potential mechanisms are mediated by their anti-inflammatory, anti-apoptotic, antioxidant, β-amyloid lowering, mitochondrial homeostasis in vivo, neuronal structure and function improving, neurogenesis promoting, neurotransmitter release regulating, and probiotic homeostasis in vivo activities. These findings suggest the potential of Panax notoginseng saponin-like constituents as drug candidates for improving learning and memory disorders.
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Affiliation(s)
- Shusen Liu
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China
- School of Pharmacy, Harbin University of Commerce, Harbin, 150076, China
| | - Min Wang
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China
| | - Haiyan Xiao
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China
| | - Jingxue Ye
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China
| | - Li Cao
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China
| | - Wenlan Li
- School of Pharmacy, Harbin University of Commerce, Harbin, 150076, China
| | - Guibo Sun
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China
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3
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Ban YH, Park D, Choi EK, Kim TM, Joo SS, Kim YB. Effectiveness of Combinational Treatments for Alzheimer's Disease with Human Neural Stem Cells and Microglial Cells Over-Expressing Functional Genes. Int J Mol Sci 2023; 24:ijms24119561. [PMID: 37298510 DOI: 10.3390/ijms24119561] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/23/2023] [Accepted: 05/29/2023] [Indexed: 06/12/2023] Open
Abstract
Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. In AD patients, amyloid-β (Aβ) peptide-mediated degeneration of the cholinergic system utilizing acetylcholine (ACh) for memory acquisition is observed. Since AD therapy using acetylcholinesterase (AChE) inhibitors are only palliative for memory deficits without reversing disease progress, there is a need for effective therapies, and cell-based therapeutic approaches should fulfil this requirement. We established F3.ChAT human neural stem cells (NSCs) encoding the choline acetyltransferase (ChAT) gene, an ACh-synthesizing enzyme, HMO6.NEP human microglial cells encoding the neprilysin (NEP) gene, an Aβ-degrading enzyme, and HMO6.SRA cells encoding the scavenger receptor A (SRA) gene, an Aβ-uptaking receptor. For the efficacy evaluation of the cells, first, we established an appropriate animal model based on Aβ accumulation and cognitive dysfunction. Among various AD models, intracerebroventricular (ICV) injection of ethylcholine mustard azirinium ion (AF64A) induced the most severe Aβ accumulation and memory dysfunction. Established NSCs and HMO6 cells were transplanted ICV to mice showing memory loss induced by AF64A challenge, and brain Aβ accumulation, ACh concentration and cognitive function were analyzed. All the transplanted F3.ChAT, HMO6.NEP and HMO6.SRA cells were found to survive up to 4 weeks in the mouse brain and expressed their functional genes. Combinational treatment with the NSCs (F3.ChAT) and microglial cells encoding each functional gene (HMO6.NEP or HMO6.SRA) synergistically restored the learning and memory function of AF64A-challenged mice by eliminating Aβ deposits and recovering ACh level. The cells also attenuated inflammatory astrocytic (glial fibrillary acidic protein) response by reducing Aβ accumulation. Taken together, it is expected that NSCs and microglial cells over-expressing ChAT, NEP or SRA genes could be strategies for replacement cell therapy of AD.
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Affiliation(s)
- Young-Hwan Ban
- College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Chungbuk, Republic of Korea
| | - Dongsun Park
- Department of Biology Education, Korea National University of Education, Cheongju 28173, Chungbuk, Republic of Korea
| | - Ehn-Kyoung Choi
- Central Research Institute, Designed Cells Co., Ltd., Cheongju 28576, Chungbuk, Republic of Korea
| | - Tae Myoung Kim
- Central Research Institute, Designed Cells Co., Ltd., Cheongju 28576, Chungbuk, Republic of Korea
| | - Seong Soo Joo
- College of Life Science, Gangneung-Wonju National University, Gangneung 25457, Gangwon, Republic of Korea
| | - Yun-Bae Kim
- College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Chungbuk, Republic of Korea
- Department of Biology Education, Korea National University of Education, Cheongju 28173, Chungbuk, Republic of Korea
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4
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Wang Z, Zhang Z, Liu J, Guo M, Li H. Panax Ginseng in the treatment of Alzheimer's disease and vascular dementia. J Ginseng Res 2023. [DOI: 10.1016/j.jgr.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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5
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Kim S, Kim D, Um MY, Yoon M, Choi JS, Choi YH, Cho S. Marine Polyphenol Phlorotannins as a Natural Sleep Aid for Treatment of Insomnia: A Review of Sedative-Hypnotic Effects and Mechanism of Action. Mar Drugs 2022; 20:774. [PMID: 36547921 PMCID: PMC9780786 DOI: 10.3390/md20120774] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/04/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
Insomnia is a common sleep disorder. Natural sleep aids are gaining worldwide popularity as alternatives to prescription drugs for improving sleep. Recently, numerous studies have investigated the sedative-hypnotic effects of the polyphenols of terrestrial plants. The hypnotic effects of marine polyphenols have also been studied in recent years. Phlorotannins are marine polyphenols that are found only in brown algae. Phlorotannins exert sedative-hypnotic effects via the gamma-aminobutyric acid type A-benzodiazepine receptor. In addition, the brown seaweed Ecklonia cava supplement containing phlorotannins has been approved by the Ministry of Food and Drug Safety as a health-functional ingredient that helps improve sleep quality. Currently, it is meaningful to deal with the sedative-hypnotic effects of phlorotannins as natural sleep aids. The current review comprehensively presents the sedative-hypnotic effects in animal models and human clinical trials as well as their mechanism of action, extraction, purification, and safety.
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Affiliation(s)
- Seonghui Kim
- Department of Food Science and Technology, Institute of Food Science, Pukyong National University, Busan 48513, Republic of Korea
| | - Duhyeon Kim
- Department of Food Science and Technology, Institute of Food Science, Pukyong National University, Busan 48513, Republic of Korea
| | - Min Young Um
- Research Division of Food Functionality, Korea Food Research Institute, Wanju 55365, Republic of Korea
| | - Minseok Yoon
- Research Division of Food Functionality, Korea Food Research Institute, Wanju 55365, Republic of Korea
| | - Jae-Suk Choi
- Department of Seafood Science and Technology, The Institute of Marine Industry, Gyeongsang National University, 38 Cheondaegukchi-gil, Tongyeong-si 53064, Republic of Korea
| | - Yung Hyun Choi
- Department of Biochemistry, College of Korean Medicine, Dong-Eui University, Busan 47227, Republic of Korea
- Anti-Aging Research Center and Core-Facility Center for Tissue Regeneration, Dong-Eui University, Busan 47340, Republic of Korea
| | - Suengmok Cho
- Department of Food Science and Technology, Institute of Food Science, Pukyong National University, Busan 48513, Republic of Korea
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6
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Shi Z, Chen H, Zhou X, Yang W, Lin Y. Pharmacological effects of natural medicine ginsenosides against Alzheimer's disease. Front Pharmacol 2022; 13:952332. [PMID: 36467099 PMCID: PMC9708891 DOI: 10.3389/fphar.2022.952332] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/08/2022] [Indexed: 08/04/2023] Open
Abstract
Ginsenosides are the most important pharmacological active ingredient of ginseng, with multiple biological therapeutic targets, mild action and no side effects. It is having shown beneficial effects in vitro and in vivo models of AD. In this review, we analyze large literature, summarize the inhibition of ginsenosides fibrous extracellular deposition of β-amyloid (Aβ) and neurofibrillary tangles (NFTs) of possible mechanisms, and explain the effects of ginsenosides on AD neuroprotection from the aspects of antioxidant, anti-inflammatory, and anti-apoptosis, prove the potential of ginsenosides as a new class of drugs for the treatment of AD. In addition, according to the current clinical application status of natural drugs, this paper analysis the delivery route and delivery mode of ginsenosides from the perspective of pharmacokinetics, providing a deeper insight into the clinical application of ginsenosides in the treatment of AD.
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Affiliation(s)
- Zhikun Shi
- Department of Gynecology and Obstetrics, The Second Hospital of Jilin University, Changchun, China
| | - Hongyu Chen
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
| | - Xu Zhou
- Department of Gynecology and Obstetrics, The Second Hospital of Jilin University, Changchun, China
| | - Wei Yang
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
| | - Yang Lin
- Department of Gynecology and Obstetrics, The Second Hospital of Jilin University, Changchun, China
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7
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Sousa L, Guarda M, Meneses MJ, Macedo MP, Vicente Miranda H. Insulin-degrading enzyme: an ally against metabolic and neurodegenerative diseases. J Pathol 2021; 255:346-361. [PMID: 34396529 DOI: 10.1002/path.5777] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/01/2021] [Accepted: 08/09/2021] [Indexed: 11/11/2022]
Abstract
Insulin-degrading enzyme (IDE) function goes far beyond its known proteolytic role as a regulator of insulin levels. IDE has a wide substrate promiscuity, degrading several proteins such as amyloid-β peptide, glucagon, islet amyloid polypeptide (IAPP) and insulin-like growth factors, that have diverse physiological and pathophysiological functions. Importantly, IDE plays other non-proteolytical functions such as a chaperone/dead-end chaperone, an E1-ubiquitin activating enzyme, and a proteasome modulator. It also responds as a heat shock protein, regulating cellular proteostasis. Notably, amyloidogenic proteins such as IAPP, amyloid-β and α-synuclein have been reported as substrates for IDE chaperone activity. This is of utmost importance as failure of IDE may result in increased protein aggregation, a key hallmark in the pathogenesis of beta cells in type 2 diabetes mellitus and of neurons in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. In this review, we focus on the biochemical and biophysical properties of IDE and the regulation of its physiological functions. We further raise the hypothesis that IDE plays a central role in the pathological context of dysmetabolic and neurodegenerative diseases and discuss its potential as a therapeutic target. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Luís Sousa
- CEDOC, NOVA Medical School, NMS, Universidade Nova de Lisboa, 1169-056, Lisbon, Portugal
| | - Mariana Guarda
- CEDOC, NOVA Medical School, NMS, Universidade Nova de Lisboa, 1169-056, Lisbon, Portugal
| | - Maria João Meneses
- CEDOC, NOVA Medical School, NMS, Universidade Nova de Lisboa, 1169-056, Lisbon, Portugal.,APDP-Diabetes Portugal Education and Research Center (APDP-ERC), Lisbon, Portugal
| | - M Paula Macedo
- CEDOC, NOVA Medical School, NMS, Universidade Nova de Lisboa, 1169-056, Lisbon, Portugal.,APDP-Diabetes Portugal Education and Research Center (APDP-ERC), Lisbon, Portugal.,Departamento de Ciências Médicas, Instituto de Biomedicina - iBiMED, Universidade de Aveiro, Aveiro, Portugal
| | - Hugo Vicente Miranda
- CEDOC, NOVA Medical School, NMS, Universidade Nova de Lisboa, 1169-056, Lisbon, Portugal
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8
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Bandyopadhyay S. Role of Neuron and Glia in Alzheimer's Disease and Associated Vascular Dysfunction. Front Aging Neurosci 2021; 13:653334. [PMID: 34211387 PMCID: PMC8239194 DOI: 10.3389/fnagi.2021.653334] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/05/2021] [Indexed: 12/14/2022] Open
Abstract
Amyloidogenicity and vascular dysfunction are the key players in the pathogenesis of Alzheimer’s disease (AD), involving dysregulated cellular interactions. An intricate balance between neurons, astrocytes, microglia, oligodendrocytes and vascular cells sustains the normal neuronal circuits. Conversely, cerebrovascular diseases overlap neuropathologically with AD, and glial dyshomeostasis promotes AD-associated neurodegenerative cascade. While pathological hallmarks of AD primarily include amyloid-β (Aβ) plaques and neurofibrillary tangles, microvascular disorders, altered cerebral blood flow (CBF), and blood-brain barrier (BBB) permeability induce neuronal loss and synaptic atrophy. Accordingly, microglia-mediated inflammation and astrogliosis disrupt the homeostasis of the neuro-vascular unit and stimulate infiltration of circulating leukocytes into the brain. Large-scale genetic and epidemiological studies demonstrate a critical role of cellular crosstalk for altered immune response, metabolism, and vasculature in AD. The glia associated genetic risk factors include APOE, TREM2, CD33, PGRN, CR1, and NLRP3, which correlate with the deposition and altered phagocytosis of Aβ. Moreover, aging-dependent downregulation of astrocyte and microglial Aβ-degrading enzymes limits the neurotrophic and neurogenic role of glial cells and inhibits lysosomal degradation and clearance of Aβ. Microglial cells secrete IGF-1, and neurons show a reduced responsiveness to the neurotrophic IGF-1R/IRS-2/PI3K signaling pathway, generating amyloidogenic and vascular dyshomeostasis in AD. Glial signals connect to neural stem cells, and a shift in glial phenotype over the AD trajectory even affects adult neurogenesis and the neurovascular niche. Overall, the current review informs about the interaction of neuronal and glial cell types in AD pathogenesis and its critical association with cerebrovascular dysfunction.
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Affiliation(s)
- Sanghamitra Bandyopadhyay
- Developmental Toxicology Laboratory, Systems Toxicology & Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Lucknow, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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9
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Protein kinases A and C regulate amyloid-β degradation by modulating protein levels of neprilysin and insulin-degrading enzyme in astrocytes. Neurosci Res 2020; 166:62-72. [PMID: 32512031 DOI: 10.1016/j.neures.2020.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/02/2020] [Accepted: 05/21/2020] [Indexed: 12/24/2022]
Abstract
The pathology of sporadic Alzheimer's disease is hallmarked by altered signal transduction via the neurotransmitter receptor-G-protein-mediated protein kinase A (PKA) and protein kinase C (PKC) pathways. Because the accumulation of amyloid-β (Aβ) depends on its rates of synthesis and clearance, the metabolic pathway of Aβ in the brain and the entire body warrants exploration. The two major enzymes involved in Aβ degradation in the brain are believed to be the neprilysin and insulin-degrading enzyme (IDE). This study investigated whether PKA and PKC regulate the degradation of Aβ by modulating the protein levels of neprilysin and IDE in astrocytes. Activation of PKA induced a significant decrease in neprilysin protein levels in cultured astrocytes, whereas activation of PKC induced a significant decrease in the protein level of neprilysin and an increase in the protein level of IDE. Following activation of PKC, the reduction of neprilysin was achieved by its secretion into the culture media. Moreover, PKA-activated astrocytes significantly delayed the degradation of exogenous Aβ, whereas PKC-activated astrocytes significantly facilitated its degradation. These results suggest that PKA and PKC regulate Aβ degradation in astrocytes through a decrease in the protein level of neprilysin and an increase in neprilysin secretion and protein levels of IDE, respectively.
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10
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Ma L, Yang C, Zheng J, Chen Y, Xiao Y, Huang K. Non-polyphenolic natural inhibitors of amyloid aggregation. Eur J Med Chem 2020; 192:112197. [PMID: 32172082 DOI: 10.1016/j.ejmech.2020.112197] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/09/2020] [Accepted: 02/28/2020] [Indexed: 02/07/2023]
Abstract
Protein misfolding diseases (PMDs) are chronic and progressive, with no effective therapy so far. Aggregation and misfolding of amyloidogenic proteins are closely associated with the onset and progression of PMDs, such as amyloid-β (Aβ) in Alzheimer's disease, α-Synuclein (α-Syn) in Parkinson's disease and human islet amyloid polypeptide (hIAPP) in type 2 diabetes. Inhibiting toxic aggregation of amyloidogenic proteins is regarded as a promising therapeutic approach in PMDs. The past decade has witnessed the rapid progresses of this field, dozens of inhibitors have been screened and verified in vitro and in vivo, demonstrating inhibitory effects against the aggregation and misfolding of amyloidogenic proteins, together with beneficial effects. Natural products are major sources of small molecule amyloid inhibitors, a number of natural derived compounds have been identified with great bioactivities and translational prospects. Here, we review the non-polyphenolic natural inhibitors that potentially applicable for PMDs treatment, along with their working mechanisms. Future directions are proposed for the development and clinical applications of these inhibitors.
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Affiliation(s)
- Liang Ma
- Affiliated Wuhan Mental Health Center, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Chen Yang
- Tongji School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Jiaojiao Zheng
- Tongji School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Yuchen Chen
- Tongji School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Yushuo Xiao
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430035, China
| | - Kun Huang
- Tongji School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
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11
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Zhang Y, Yang X, Wang S, Song S. Ginsenoside Rg3 Prevents Cognitive Impairment by Improving Mitochondrial Dysfunction in the Rat Model of Alzheimer's Disease. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:10048-10058. [PMID: 31422666 DOI: 10.1021/acs.jafc.9b03793] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Ginseng, the roots and rhizomes of Panax ginseng C. A. Meyer, is used not only as a herbal medicine but also as a functional food to support body functions. Ginsenoside Rg3 (GRg3) is a major bioactive component in ginseng. In this study, the beneficial effects of GRg3 on rats with Alzheimer's disease (AD) were evaluated via the behavioral experiment and antioxidant capacity. Moreover, metabolomic analysis based on UPLC-QTOF-MS/MS and apoptosis analysis was used to obtain the change between AD and GRg3-administrated rats to assess the underlying mechanisms on improving mitochondrial dysfunction. Results showed that GRg3 could prevent the cognitive impairment of AD rats by improving the mitochondrial dysfunction. The potential mechanisms were related to regulate the abnormality of energy metabolism, electron transport chain, amino acid metabolism, purine metabolism, and antiapoptosis. These findings support the exploitation of GRg3 as an effective complementary and functional food to prevent and delay AD.
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Affiliation(s)
| | - Xiaomei Yang
- Nutritional Department , Jilin Medical University Affiliated Hospital , Jilin 132013 , P. R. China
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12
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Lue LF, Beach TG, Walker DG. Alzheimer's Disease Research Using Human Microglia. Cells 2019; 8:cells8080838. [PMID: 31387311 PMCID: PMC6721636 DOI: 10.3390/cells8080838] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/31/2019] [Accepted: 07/31/2019] [Indexed: 02/06/2023] Open
Abstract
Experimental studies of neuroinflammation in Alzheimer's disease (AD) have mostly investigated microglia, the brain-resident macrophages. This review focused on human microglia obtained at rapid autopsies. Studies employing methods to isolate and culture human brain microglia in high purity for experimental studies were discussed. These methods were employed to isolate human microglia for investigation of a number of features of neuroinflammation, including activation phenotypes, neurotoxicity, responses to abnormal aggregated proteins such as amyloid beta, phagocytosis, and the effects of aging and disease on microglia cellular properties. In recent years, interest in human microglia and neuroinflammation has been renewed due to the identification of inflammation-related AD genetic risk factors, in particular the triggering receptor expressed on myeloid cells (TREM)-2. Because of the difficulties in developing effective treatments for AD, there has been a general need for greater understanding of the functions of microglia in normal and AD brains. While most experimental studies on neuroinflammation have employed rodent microglia, this review considered the role of human microglia in experimental studies. This review focused on the development of in vitro methodology for the culture of postmortem human microglia and the key findings obtained from experimental studies with these cells.
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Affiliation(s)
- Lih-Fen Lue
- Banner Sun Health Research Institute, Sun City, AZ, 85351, USA.
- Neurodegenerative Disease Research Center and School of Life Sciences, Arizona State University, Tempe, AZ 84027, USA.
| | - Thomas G Beach
- Banner Sun Health Research Institute, Sun City, AZ, 85351, USA
| | - Douglas G Walker
- Neurodegenerative Disease Research Center and School of Life Sciences, Arizona State University, Tempe, AZ 84027, USA
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu 520, Japan
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13
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Chen NC, Partridge AT, Tuzer F, Cohen J, Nacarelli T, Navas-Martín S, Sell C, Torres C, Martín-García J. Induction of a Senescence-Like Phenotype in Cultured Human Fetal Microglia During HIV-1 Infection. J Gerontol A Biol Sci Med Sci 2018; 73:1187-1196. [PMID: 29415134 PMCID: PMC6093403 DOI: 10.1093/gerona/gly022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/31/2018] [Indexed: 12/22/2022] Open
Abstract
HIV-1 causes premature aging in chronically infected patients. Despite effective anti-retroviral therapy, around 50% of patients suffer HIV-associated neurocognitive disorders (HAND), which likely potentiate aging-associated neurocognitive decline. Microglia support productive HIV-1 infection in the brain. Elevated markers of cellular senescence, including p53 and p21, have been detected in brain tissues from patients with HAND, but the potential for microglia senescence during HIV-1 infection has not been investigated. We hypothesized that HIV-1 can induce senescence in microglia. Primary human fetal microglia were exposed to single-round infectious HIV-1 pseudotypes or controls, and examined for markers of senescence. Post-infection, microglia had significantly elevated: senescence-associated β-galactosidase activity, p21 levels, and production of cytokines such as IL-6 and IL-8, potentially indicative of a senescence-associated secretory phenotype. We also found increased detection of p53-binding protein foci in microglia nuclei post-infection. Additionally, we examined mitochondrial reactive oxygen species (ROS) and respiration, and found significantly increased mitochondrial ROS levels and decreased ATP-linked respiration during HIV-1 infection. Supernatant transfer from infected cultures to naïve microglia resulted in elevated p21 and caveolin-1 levels, and IL-8 production. Finally, nucleoside treatment reduced senescence markers induction in microglia. Overall, HIV-1 induces a senescence-like phenotype in human microglia, which could play a role in HAND.
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Affiliation(s)
- Natalie C Chen
- Department of Microbiology and Immunology, Philadelphia, Pennsylvania
- MD/PhD Program, Philadelphia, Pennsylvania
- Molecular and Cell Biology and Genetics Graduate Program, Philadelphia, Pennsylvania
| | - Andrea T Partridge
- Department of Microbiology and Immunology, Philadelphia, Pennsylvania
- Microbiology and Immunology Graduate Program, Philadelphia, Pennsylvania
| | - Ferit Tuzer
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania
| | - Justin Cohen
- Molecular and Cell Biology and Genetics Graduate Program, Philadelphia, Pennsylvania
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania
| | - Timothy Nacarelli
- Molecular and Cell Biology and Genetics Graduate Program, Philadelphia, Pennsylvania
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania
| | - Sonia Navas-Martín
- Department of Microbiology and Immunology, Philadelphia, Pennsylvania
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Christian Sell
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania
| | - Claudio Torres
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania
| | - Julio Martín-García
- Department of Microbiology and Immunology, Philadelphia, Pennsylvania
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania
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14
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Umbilical Cord Mesenchymal Stem Cells Conditioned Medium Promotes Aβ25-35 phagocytosis by Modulating Autophagy and Aβ-Degrading Enzymes in BV2 Cells. J Mol Neurosci 2018; 65:222-233. [PMID: 29845511 DOI: 10.1007/s12031-018-1075-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/20/2018] [Indexed: 02/08/2023]
Abstract
Mesenchymal stem cell (MSC) therapy is a promising prospect for the treatment of Alzheimer's disease (AD); however, the underlying mechanisms by which MSCs mediate positive effects are still unclear. We speculated that MSCs mediate microglial autophagy and enhance the clearance of Aβ. To test this hypothesis, we cultured BV2 microglial cells with umbilical cord mesenchymal stem cells conditioned medium (ucMSCs-CM) in the presence or absence of Aβ25-35 oligomers. We investigated BV2 cell proliferation, cell death, and Aβ25-35 phagocytosis as well as protein expression levels of LC3, Beclin-1, p62, insulin-degrading enzyme (IDE), and neprilysin (Nep) with western blotting. The results showed that ucMSCs-CM inhibited the proliferation and decreased cell death of BV2 cells induced by Aβ25-35. ucMSCs-CM also promoted the phagocytosis of Aβ25-35 by BV2 cells and changed the expression of autophagy-related proteins LC3, Beclin-1, and p62. Treatment also upregulated the expression of Aβ-degrading enzymes IDE and Nep. Furthermore, the culture medium in BV2 cells with Aβ25-35 and ucMSCs-CM prevented neuronal cell SH-SY5Y from cell death compared to control medium without ucMSCs-CM. Altogether, these data suggested that ucMSCs-CM protect microglial and neuronal cells from Aβ25-35-induced cell death and promote Aβ phagocytosis by modulating autophagy and enhancing the expression of Aβ-degrading enzymes in microglia.
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15
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Ji XR, Cheng KC, Chen YR, Lin TY, Cheung CHA, Wu CL, Chiang HC. Dysfunction of different cellular degradation pathways contributes to specific β-amyloid42-induced pathologies. FASEB J 2018; 32:1375-1387. [PMID: 29127191 DOI: 10.1096/fj.201700199rr] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The endosomal-lysosomal system (ELS), autophagy, and ubiquitin-proteasome system (UPS) are cellular degradation pathways that each play a critical role in the removal of misfolded proteins and the prevention of the accumulation of abnormal proteins. Recent studies on Alzheimer's disease (AD) pathogenesis have suggested that accumulation of aggregated β-amyloid (Aβ) peptides in the AD brain results from a dysfunction in these cellular clearance systems. However, the specific roles of these pathways in the removal of Aβ peptides and the pathogenesis underlying AD are unclear. Our in vitro and in vivo genetic approaches revealed that ELS mainly removed monomeric β-amyloid42 (Aβ42), while autophagy and UPS clear oligomeric Aβ42. Although overproduction of phosphatidylinositol 4-phosphate-5 increased Aβ42 clearance, it reduced the life span of Aβ42 transgenic flies. Our behavioral studies further demonstrated impaired autophagy and UPS-enhanced Aβ42-induced learning and memory deficits, but there was no effect on Aβ42-induced reduction in life span. Results from genetic fluorescence imaging showed that these pathways were damaged in the following order: UPS, autophagy, and finally ELS. The results of our study demonstrate that different degradation pathways play distinct roles in the removal of Aβ42 aggregates and in disease progression. These findings also suggest that pharmacologic treatments that are designed to stimulate cellular degradation pathways in patients with AD should be used with caution.-Ji, X.-R., Cheng, K.-C., Chen, Y.-R., Lin, T.-Y., Cheung, C. H. A., Wu, C.-L., Chiang, H.-C. Dysfunction of different cellular degradation pathways contributes to specific β-amyloid42-induced pathologies.
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Affiliation(s)
- Xuan-Ru Ji
- Department of Pharmacology, National Cheng-Kung University, Tainan, Taiwan
| | - Kuan-Chung Cheng
- Department of Pharmacology, National Cheng-Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan; and
| | - Yu-Ru Chen
- Department of Pharmacology, National Cheng-Kung University, Tainan, Taiwan
| | - Tzu-Yu Lin
- Department of Pharmacology, National Cheng-Kung University, Tainan, Taiwan
| | - Chun Hei Antonio Cheung
- Department of Pharmacology, National Cheng-Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan; and
| | - Chia-Lin Wu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Hsueh-Cheng Chiang
- Department of Pharmacology, National Cheng-Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan; and
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16
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Wang N, Jia YM, Zhang B, Xue D, Reeju M, Li Y, Huang SM, Liu XW. Neuroprotective mechanism of Kai Xin San: upregulation of hippocampal insulin-degrading enzyme protein expression and acceleration of amyloid-beta degradation. Neural Regen Res 2017; 12:654-659. [PMID: 28553348 PMCID: PMC5436366 DOI: 10.4103/1673-5374.205107] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Kai Xin San is a Chinese herbal formula composed of Radix Ginseng, Poria, Radix Polygalae and Acorus Tatarinowii Rhizome. It has been used in China for many years for treating amnesia. Kai Xin San ameliorates amyloid-β (Aβ)-induced cognitive dysfunction and is neuroprotective in vivo, but its precise mechanism remains unclear. Expression of insulin-degrading enzyme (IDE), which degrades Aβ, is strongly correlated with cognitive function. Here, we injected rats with exogenous Aβ42 (200 μM, 5 μL) into the hippocampus and subsequently administered Kai Xin San (0.54 or 1.08 g/kg/d) intragastrically for 21 consecutive days. Hematoxylin-eosin and Nissl staining revealed that Kai Xin San protected neurons against Aβ-induced damage. Furthermore, enzyme-linked immunosorbent assay, western blot and polymerase chain reaction results showed that Kai Xin San decreased Aβ42 protein levels and increased expression of IDE protein, but not mRNA, in the hippocampus. Our findings reveal that Kai Xin San facilitates hippocampal Aβ degradation and increases IDE expression, which leads, at least in part, to the alleviation of hippocampal neuron injury in rats.
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Affiliation(s)
- Na Wang
- Institute of Medicine, Qiqihar Medical University, Qiqihar, Heilongjiang Province, China
| | - Yong-Ming Jia
- Institute of Medicine, Qiqihar Medical University, Qiqihar, Heilongjiang Province, China
| | - Bo Zhang
- Department of Neuroscience, Institute of Traditional Chinese Medicine, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang Province, China
| | - Di Xue
- Institute of Medicine, Qiqihar Medical University, Qiqihar, Heilongjiang Province, China
| | - Maharjan Reeju
- Institute of Medicine, Qiqihar Medical University, Qiqihar, Heilongjiang Province, China
| | - Yan Li
- Department of Neuroscience, Institute of Traditional Chinese Medicine, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang Province, China
| | - Shu-Ming Huang
- Department of Neuroscience, Institute of Traditional Chinese Medicine, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang Province, China
| | - Xue-Wei Liu
- Institute of Medicine, Qiqihar Medical University, Qiqihar, Heilongjiang Province, China
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17
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Jha NK, Jha SK, Kumar D, Kejriwal N, Sharma R, Ambasta RK, Kumar P. Impact of Insulin Degrading Enzyme and Neprilysin in Alzheimer’s Disease Biology: Characterization of Putative Cognates for Therapeutic Applications. J Alzheimers Dis 2015; 48:891-917. [DOI: 10.3233/jad-150379] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Niraj Kumar Jha
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Saurabh Kumar Jha
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Dhiraj Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Noopur Kejriwal
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Renu Sharma
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Rashmi K. Ambasta
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
- Department of Neurology, Tufts University School of Medicine, Boston, MA, USA
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18
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Jang SK, Lee DI, Kim ST, Kim GH, Park DW, Park JY, Han D, Choi JK, Lee YB, Han NS, Kim YB, Han J, Joo SS. The anti-aging properties of a human placental hydrolysate combined with dieckol isolated from Ecklonia cava. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 15:345. [PMID: 26438076 PMCID: PMC4594884 DOI: 10.1186/s12906-015-0876-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 09/23/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUNDS In the present study, we aimed to examine the anti-aging properties of human placental hydrolysate (HPE) and dieckol (DE) from Ecklonia cava against free radical scavenging, muscle hypertrophy-related follistatin mRNA expression, amelioration of cognition-related genes and proteins, inhibition of collagenase-regulating genes, and elastinase activity. METHODS The anti-aging effects were examined in human fibroblast (CCD986sk), mouse myoblast (C2C12), and neuroblastoma (N2a) cell models, by employing various assays such as 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) scavenging, hydroxyl radical-mediated oxidation, quantitative real-time polymerase chain reaction, enzyme activity, and immunocytochemistry observation. RESULTS Our results show that HPE combined with DE (HPE:DE) strongly scavenged DPPH radicals and protected proteins against degradation by hydroxyl radical attack. HPE:DE effectively inhibited matrix metalloproteinase-1 expression, protein kinase C alpha expression, and elastinase activity. Furthermore, HPE:DE improved the expression of cognition-related genes (choline acetyltransferase and vesicular acetylcholine transporter). These events may proactively contribute to retard the aging processes and the abrupt physiological changes probably induced by mitochondrial dysfunction with aging. CONCLUSIONS Based on these findings, we conclude that the combined treatment of HPE:DE may be useful for anti-aging therapy in which the accumulation of oxidative damage is the main driving force.
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Affiliation(s)
- Su Kil Jang
- Department of Marine Molecular Biotechnology, College of Life Science, Gangneung-Wonju National University, 120 Gangneung Daehangno, Gangneung, Gangwon, 210-702, Republic of Korea
| | - Do Ik Lee
- College of Pharmacy, Chung-Ang University, Heuksuk-dong, Dongjak-gu, Seoul, 156-756, Republic of Korea
| | - Seung Tae Kim
- Department of Marine Molecular Biotechnology, College of Life Science, Gangneung-Wonju National University, 120 Gangneung Daehangno, Gangneung, Gangwon, 210-702, Republic of Korea
| | - Gwang Hoon Kim
- Department of Marine Molecular Biotechnology, College of Life Science, Gangneung-Wonju National University, 120 Gangneung Daehangno, Gangneung, Gangwon, 210-702, Republic of Korea
| | - Da Woon Park
- Department of Marine Molecular Biotechnology, College of Life Science, Gangneung-Wonju National University, 120 Gangneung Daehangno, Gangneung, Gangwon, 210-702, Republic of Korea
| | - Jung Youl Park
- Industry-Academic Cooperation Foundation, Hanbat National University, Daejeon, 305-719, Republic of Korea
| | - Daehee Han
- Department of Marine Molecular Biotechnology, College of Life Science, Gangneung-Wonju National University, 120 Gangneung Daehangno, Gangneung, Gangwon, 210-702, Republic of Korea
| | - Jae Kwon Choi
- Central Research Institute, Dr. Chung's Food Co. Ltd., Chungbuk, 361-782, Republic of Korea
| | - Yoon-bok Lee
- Central Research Institute, Dr. Chung's Food Co. Ltd., Chungbuk, 361-782, Republic of Korea
| | - Nam-Soo Han
- Chungbuk National University, Chungbuk, 361-763, Republic of Korea
| | - Yun Bae Kim
- Chungbuk National University, Chungbuk, 361-763, Republic of Korea
| | - Jeongsu Han
- DF-Dr. Han Biotech., Shaoyaojubeili, Chaoyang District, Beijing, 10029, China
| | - Seong Soo Joo
- Department of Marine Molecular Biotechnology, College of Life Science, Gangneung-Wonju National University, 120 Gangneung Daehangno, Gangneung, Gangwon, 210-702, Republic of Korea.
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19
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New Insights into Epigenetic and Pharmacological Regulation of Amyloid-Degrading Enzymes. Neurochem Res 2015; 41:620-30. [PMID: 26376806 DOI: 10.1007/s11064-015-1703-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/12/2015] [Accepted: 08/18/2015] [Indexed: 10/23/2022]
Abstract
Currently, deficit of amyloid β-peptide (Aβ) clearance from the brain is considered as one of the possible causes of amyloid accumulation and neuronal death in the sporadic form of Alzheimer's disease (AD). Aβ clearance can involve either specific proteases present in the brain or Aβ-binding/transport proteins. Among amyloid-degrading enzymes the most intensively studied are neprilysin (NEP) and insulin-degrading enzyme (IDE). Since ageing and development of brain pathologies is often accompanied by a deficit in the levels of expression and activity of these enzymes in the brain, there is an urgent need to understand the mechanisms involved in their regulation. We have recently reported that NEP and also an Aβ-transport protein, transthyretin are epigenetically co-regulated by the APP intracellular domain (AICD) and this regulation depends on the cell type and APP695 isoform expression in a process that can be regulated by the tyrosine kinase inhibitor, Gleevec. We have now extended our work and shown that, unlike NEP, another amyloid-degrading enzyme, IDE, is not related to over-expression of APP695 in neuroblastoma SH-SY5Y cells but is up-regulated by APP751 and APP770 isoforms independently of AICD but correlating with reduced HDAC1 binding to its promoter. Studying the effect of the nuclear retinoid X receptor agonist, bexarotene, on NEP and IDE expression, we have found that both enzymes can be up-regulated by this compound but this mechanism is not APP-isoform specific and does not involve AICD but, on the contrary, affects HDAC1 occupancy on the NEP gene promoter. These new insights into the mechanisms of NEP and IDE regulation suggest possible pharmacological targets in developing AD therapies.
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