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Zhang J, Jiang Y, Dong X, Meng Z, Ji L, Kang Y, Liu M, Zhou W, Song W. Alpha-lipoic acid alleviates cognitive deficits in transgenic APP23/PS45 mice through a mitophagy-mediated increase in ADAM10 α-secretase cleavage of APP. Alzheimers Res Ther 2024; 16:160. [PMID: 39030577 PMCID: PMC11264788 DOI: 10.1186/s13195-024-01527-3] [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: 11/28/2023] [Accepted: 07/13/2024] [Indexed: 07/21/2024]
Abstract
BACKGROUND Alpha-lipoic acid (ALA) has a neuroprotective effect on neurodegenerative diseases. In the clinic, ALA can improve cognitive impairments in patients with Alzheimer's disease (AD) and other dementias. Animal studies have confirmed the anti-amyloidosis effect of ALA, but its underlying mechanism remains unclear. In particular, the role of ALA in amyloid-β precursor protein (APP) metabolism has not been fully elucidated. OBJECTIVE To investigate whether ALA can reduce the amyloidogenic effect of APP in a transgenic mouse model of AD, and to study the mechanism underlying this effect. METHODS ALA was infused into 2-month-old APP23/PS45 transgenic mice for 4 consecutive months and their cognitive function and AD-like pathology were then evaluated. An ALA drug concentration gradient was applied to 20E2 cells in vitro to evaluate its effect on the expression of APP proteolytic enzymes and metabolites. The mechanism by which ALA affects APP processing was studied using GI254023X, an inhibitor of A Disintegrin and Metalloproteinase 10 (ADAM10), as well as the mitochondrial toxic drug carbonyl cyanide m-chlorophenylhydrazone (CCCP). RESULTS Administration of ALA ameliorated amyloid plaque neuropathology in the brain tissue of APP23/PS45 mice and reduced learning and memory impairment. ALA also increased the expression of ADAM10 in 20E2 cells and the non-amyloidogenic processing of APP to produce the 83 amino acid C-terminal fragment (C83). In addition to activating autophagy, ALA also significantly promoted mitophagy. BNIP3L-knockdown reduced the mat/pro ratio of ADAM10. By using CCCP, ALA was found to regulate BNIP3L-mediated mitophagy, thereby promoting the α-cleavage of APP. CONCLUSIONS The enhanced α-secretase cleavage of APP by ADAM10 is the primary mechanism through which ALA ameliorates the cognitive deficits in APP23/PS45 transgenic mice. BNIP3L-mediated mitophagy contributes to the anti-amyloid properties of ALA by facilitating the maturation of ADAM10. This study provides novel experimental evidence for the treatment of AD with ALA.
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Affiliation(s)
- Jie Zhang
- Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Yanshuang Jiang
- Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Xiangjun Dong
- Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Zijun Meng
- Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Liangye Ji
- Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Yu Kang
- Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Mingjing Liu
- Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Weihui Zhou
- Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.
| | - Weihong Song
- Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.
- Institute of Aging, Key Laboratory of Alzheimer's Disease of Zhejiang Province, Zhejiang Provincial Clinical Research Center for Mental Disorders, School of Mental Health and the Affiliated Wenzhou Kangning Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang, 325001, China.
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Choi HS, Kim J, Lee SB, Zhang L, Kwon D, Tran HNK, Zhang S, Huang T, Yu JS, Lee G, Yang HO. Euonymus hamiltonianus Extract Improves Amnesia in APPswe/Tau Transgenic and Scopolamine-Induced Dementia Models. Mol Neurobiol 2024:10.1007/s12035-024-04242-0. [PMID: 38801629 DOI: 10.1007/s12035-024-04242-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 05/13/2024] [Indexed: 05/29/2024]
Abstract
Dementia is a syndrome exhibiting progressive impairments on cognition and behavior beyond the normal course of aging, and Alzheimer's disease (AD) is one of the neurodegenerative diseases known to cause dementia. We investigated the effect of KGC07EH, the 30% ethanol extract of Euonymus hamiltonianus, against amyloid-β (Aβ) production and cognitive dysfunction in dementia models. KGC07EH was treated on Hela cells expressing the Swedish mutant form of amyloid precursor protein (APP), and the AD triple transgenic (3× TG) mice were given KGC07EH orally during 11-14 months of age (100 and 300 mg/kg/day). SH-SY5Y cell line was used to test KGC07EH on scopolamine-induced elevation of acetylcholinesterase (AChE) activity. ICR mice were intraperitoneally injected with scopolamine, and KGC07EH was administered orally (50, 100, and 200 mg/kg/day) for 4 weeks. KGC07EH treatment decreased Aβ, sAPPβ-sw, and sAPPβ-wt levels and APP protein expressions while sAPPα was increased in Swedish mutant-transfected HeLa cells. KGC07EH treatment also significantly reduced the accumulation of Aβ plaques and tau tangles in the brain of 3× TG mice as well as improving the cognitive function. In SH-SY5Y cells cultured with scopolamine, KGC07EH dose-dependently attenuated the increase of AChE activity. KGC07EH also improved scopolamine-induced learning and memory impairment in scopolamine-injected mice, and in their cerebral cortex and hippocampus, the expression levels of p-ERK, p-CREB, p-Akt, and BDNF were attenuated. KGC07EH inhibits APP processing and Aβ production both in vitro and in vivo, while enhancing acetylcholine signaling and cognitive dysfunction which are the major symptoms of dementia.
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Affiliation(s)
- Hyo-Sun Choi
- Department of Integrative Biological Sciences and Industry & Convergence Research Center for Natural Products, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, Republic of Korea
| | - Joonki Kim
- Natural Product Research Center, Korea Institute of Science and Technology, 679 Saimdang-ro, Gangneung, 25451, Gangwon-do, Republic of Korea
- Natural Product Applied Science, KIST School, University of Science and Technology, 679 Saimdang-ro, Gangneung, 25451, Republic of Korea
| | - Sang-Bin Lee
- Department of Integrative Biological Sciences and Industry & Convergence Research Center for Natural Products, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, Republic of Korea
| | - Lijun Zhang
- Natural Product Research Center, Korea Institute of Science and Technology, 679 Saimdang-ro, Gangneung, 25451, Gangwon-do, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology, Seoul, 02792, Republic of Korea
| | - Dowan Kwon
- Natural Product Research Center, Korea Institute of Science and Technology, 679 Saimdang-ro, Gangneung, 25451, Gangwon-do, Republic of Korea
| | - Huynh Nguyen Khanh Tran
- Natural Product Research Center, Korea Institute of Science and Technology, 679 Saimdang-ro, Gangneung, 25451, Gangwon-do, Republic of Korea
| | - Siqi Zhang
- Natural Product Research Center, Korea Institute of Science and Technology, 679 Saimdang-ro, Gangneung, 25451, Gangwon-do, Republic of Korea
- Natural Product Applied Science, KIST School, University of Science and Technology, 679 Saimdang-ro, Gangneung, 25451, Republic of Korea
| | - Tianqi Huang
- Department of Integrative Biological Sciences and Industry & Convergence Research Center for Natural Products, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology, Seoul, 02792, Republic of Korea
| | - Jae Sik Yu
- Department of Integrative Biological Sciences and Industry & Convergence Research Center for Natural Products, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, Republic of Korea
| | - Gakyung Lee
- Department of Integrative Biological Sciences and Industry & Convergence Research Center for Natural Products, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, Republic of Korea
| | - Hyun Ok Yang
- Department of Integrative Biological Sciences and Industry & Convergence Research Center for Natural Products, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, Republic of Korea.
- Natural Product Research Center, Korea Institute of Science and Technology, 679 Saimdang-ro, Gangneung, 25451, Gangwon-do, Republic of Korea.
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology, Seoul, 02792, Republic of Korea.
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Oliveira Monteiro E Pereira de Almeida MP, Valle Pedroso R, Mantellatto Grigoli M, Vicente Silva T, Manzine PR, Cominetti MR. ADAM10 as a biomarker for Alzheimer's disease: A systematic review. Rev Neurol (Paris) 2024; 180:1-11. [PMID: 37460331 DOI: 10.1016/j.neurol.2023.04.002] [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: 02/23/2022] [Revised: 01/04/2023] [Accepted: 04/18/2023] [Indexed: 02/06/2024]
Abstract
BACKGROUND Studies have shown that A Disintegrin and Metalloproteinase 10 (ADAM10) is the main α-secretase in the non-amyloidogenic cleavage of the amyloid precursor protein (APP), avoiding the production of amyloid-β peptide (Aβ), one of the pathological hallmarks of Alzheimer's disease (AD). OBJECTIVE To investigate ADAM10 from cerebrospinal fluid (CSF) and plasma/serum as a potential biomarker for AD. METHODS A systematic review was carried out in the MEDLINE/PubMed, Web of Science, Embase, and Scopus databases using the terms and Boolean operators: "Alzheimer" AND "ADAM10" AND "biomarker". Citation searching was also adopted. The inclusion criteria were original studies of ADAM10 in blood or CSF in patients with AD. The risk of bias was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. The analysis methods were registered in the PROSPERO database (#CRD42021274239). RESULTS Of the 97 records screened, 17 were included. There is strong evidence for lower levels of ADAM10 in platelets of persons with AD compared to cognitively healthy participants. On the other hand, higher levels of ADAM10 were found in plasma. Regarding CSF, controversial results were found with lower and higher levels of ADAM10 in persons with AD compared to healthy older adults. The differences may be due to diverse reasons, including different sample collection and processing and different antibodies, highlighting the importance of standardizing the experiments and choosing the appropriate antibodies for ADAM10 detection. CONCLUSION Evidence shows that ADAM10 levels are altered in platelets, plasma, serum, and CSF of individuals with AD. The alteration was evident in all stages of the disease, and therefore, the protein may represent a complementary biomarker for the disease. However, more studies must be performed to establish cut-off values for ADAM10 levels to discriminate AD participants from cognitively unimpaired older adults.
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Affiliation(s)
| | - R Valle Pedroso
- Department of Gerontology, Federal University of São Carlos. Rod. Washington Luis, km 235, 13565-905 São Carlos, SP, Brazil
| | - M Mantellatto Grigoli
- Department of Gerontology, Federal University of São Carlos. Rod. Washington Luis, km 235, 13565-905 São Carlos, SP, Brazil
| | - T Vicente Silva
- Department of Gerontology, Federal University of São Carlos. Rod. Washington Luis, km 235, 13565-905 São Carlos, SP, Brazil
| | - P R Manzine
- Department of Gerontology, Federal University of São Carlos. Rod. Washington Luis, km 235, 13565-905 São Carlos, SP, Brazil
| | - M R Cominetti
- Department of Gerontology, Federal University of São Carlos. Rod. Washington Luis, km 235, 13565-905 São Carlos, SP, Brazil; Trinity College Dublin, Dublin, Ireland; Global Brain Health Institute, Dublin, Ireland.
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Chen SY, Koch M, Chávez-Gutiérrez L, Zacharias M. How Modulator Binding at the Amyloidβ-γ-Secretase Interface Enhances Substrate Binding and Attenuates Membrane Distortion. J Med Chem 2023; 66:16772-16782. [PMID: 38059872 DOI: 10.1021/acs.jmedchem.3c01480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
Inhibition of γ-secretase, an intramembrane protease, to reduce secretion of Amyloid-β (Aβ) peptides has been considered for treating Alzheimer's disease. However, γ-secretase inhibitors suffer from severe side effects. As an alternative, γ-secretase modulators (GSM) reduce the generation of toxic peptides by enhancing the cleavage processivity without diminishing the enzyme activity. Starting from a known γ-secretase structure without substrate but in complex with an E2012 GSM, we generated a structural model that included a bound Aβ43 peptide and studied interactions among enzyme, substrate, GSM, and lipids. Our result suggests that E2012 binding at the enzyme-substrate-membrane interface attenuates the membrane distortion by shielding the substrate-membrane interaction. The model predicts that the E2012 modulation is charge-dependent and explains the preserved hydrogen acceptor and the aromatic ring observed in many imidazole-based GSM. Predicted effects of γ-secretase mutations on E2012 modulation were confirmed experimentally. We anticipate that the study will facilitate the future development of effective GSMs.
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Affiliation(s)
- Shu-Yu Chen
- Center for Functional Protein Assemblies, Garching 85748, Germany
| | - Matthias Koch
- VIB/KU Leuven, VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
| | | | - Martin Zacharias
- Center for Functional Protein Assemblies, Garching 85748, Germany
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Sandoval L, Fuentealba LM, Marzolo MP. Participation of OCRL1, and APPL1, in the expression, proteolysis, phosphorylation and endosomal trafficking of megalin: Implications for Lowe Syndrome. Front Cell Dev Biol 2022; 10:911664. [PMID: 36340038 PMCID: PMC9630597 DOI: 10.3389/fcell.2022.911664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
Megalin/LRP2 is the primary multiligand receptor for the re-absorption of low molecular weight proteins in the proximal renal tubule. Its function is significantly dependent on its endosomal trafficking. Megalin recycling from endosomal compartments is altered in an X-linked disease called Lowe Syndrome (LS), caused by mutations in the gene encoding for the phosphatidylinositol 5-phosphatase OCRL1. LS patients show increased low-molecular-weight proteins with reduced levels of megalin ectodomain in the urine and accumulation of the receptor in endosomal compartments of the proximal tubule cells. To gain insight into the deregulation of megalin in the LS condition, we silenced OCRL1 in different cell lines to evaluate megalin expression finding that it is post-transcriptionally regulated. As an indication of megalin proteolysis, we detect the ectodomain of the receptor in the culture media. Remarkably, in OCRL1 silenced cells, megalin ectodomain secretion appeared significantly reduced, according to the observation in the urine of LS patients. Besides, the silencing of APPL1, a Rab5 effector associated with OCRL1 in endocytic vesicles, also reduced the presence of megalin’s ectodomain in the culture media. In both silencing conditions, megalin cell surface levels were significantly decreased. Considering that GSK3ß-mediated megalin phosphorylation reduces receptor recycling, we determined that the endosomal distribution of megalin depends on its phosphorylation status and OCRL1 function. As a physiologic regulator of GSK3ß, we focused on insulin signaling that reduces kinase activity. Accordingly, megalin phosphorylation was significantly reduced by insulin in wild-type cells. Moreover, even though in cells with low activity of OCRL1 the insulin response was reduced, the phosphorylation of megalin was significantly decreased and the receptor at the cell surface increased, suggesting a protective role of insulin in a LS cellular model.
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Affiliation(s)
- Lisette Sandoval
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Luz M. Fuentealba
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- *Correspondence: María-Paz Marzolo,
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Jang BG, Choi B, Kim S, Lee DS, Lee J, Koh YH, Jo SA, Kim JE, Kang TC, Kim MJ. 2,4-Diacetylphloroglucinol Reduces Beta-Amyloid Production and Secretion by Regulating ADAM10 and Intracellular Trafficking in Cellular and Animal Models of Alzheimer's Disease. Cells 2022; 11:cells11162585. [PMID: 36010661 PMCID: PMC9406471 DOI: 10.3390/cells11162585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/14/2022] [Accepted: 08/17/2022] [Indexed: 11/26/2022] Open
Abstract
There is currently no effective treatment against Alzheimer’s disease (AD), although many strategies have been applied to reduce beta-amyloid (Aβ) levels. Here, we investigated 2,4-diacetylphloroglucinol (DAPG) effects on Aβ levels and mechanisms of action. DAPG was the most effective phloroglucinol derivative for reducing Aβ levels, without being toxic, in various models including HEK293 cells overexpressing Swedish mutant amyloid precursor protein (APP) (293sw), primary astrocytes isolated from APPsw/PS1dE9 transgenic mice, and after intrahippocampal injection of DAPG in APPsw/PS1dE9 transgenic mice. DAPG-mediated Aβ reduction was associated with increased soluble APPα (sAPPα) levels mediated by a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) but not ADAM17. ADAM10 inhibition in DAPG-treated cells prevented the effects on sAPPα but only partly on intracellular and secreted Aβ. To identify regulators of sAPPα and Aβ secretion, various inhibitors of intracellular trafficking were administered with DAPG. Brefeldin A (BFA) reversed DAPG-mediated changes in Aβ secretion in 293sw cells, whereas golgicide A (GCA) and BFA were effective in primary astrocytes, indicating a cell type-specific regulation of the trafficking. Moreover, GCA or BFA effects on sAPPα, but not Aβ, levels in primary astrocytes resembled those of ADAM10 inhibition, indicating at least partly independent trafficking pathways for sAPPα and Aβ. In conclusion, DAPG might be a promising drug candidate against AD regulating ADAM10 and intracellular trafficking, but optimizing DAPG ability to cross the BBB will be needed.
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Affiliation(s)
- Bong-Geum Jang
- Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Boyoung Choi
- Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Suyeon Kim
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Duk-Shin Lee
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Jisun Lee
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Young Ho Koh
- Division of Brain Disease Research, Department of Chronic Disease Convergence Research, Korea National Institute of Health, Cheongju 28159, Korea
| | - Sangmee Ahn Jo
- Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan 31116, Korea
- Department of Pharmacology, College of Pharmacy, Dankook University, Cheonan 31116, Korea
| | - Ji-Eun Kim
- Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Tae-Cheon Kang
- Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Min-Ju Kim
- Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
- Correspondence: ; Tel.: +82-33-248-2523; Fax: +82-33-256-2525
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Multiple Mechanisms of NOTCH1 Activation in Chronic Lymphocytic Leukemia: NOTCH1 Mutations and Beyond. Cancers (Basel) 2022; 14:cancers14122997. [PMID: 35740661 PMCID: PMC9221163 DOI: 10.3390/cancers14122997] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/14/2022] [Accepted: 06/14/2022] [Indexed: 11/20/2022] Open
Abstract
Simple Summary Mutations of the NOTCH1 gene are a validated prognostic marker in chronic lymphocytic leukemia and a potential predictive marker for anti-CD20-based therapies. At present, the most frequent pathological alteration of the NOTCH1 gene is due to somatic genetic mutations, which have a multifaceted functional impact. However, beside NOTCH1 mutations, other factors may lead to activation of the NOTCH1 pathway, and these include mutations of FBXW7, MED12, SPEN, SF3B1 as well as other B-cell pathways. Understanding the preferential strategies though which CLL cells hijack NOTCH1 signaling may present important clues for designing targeted treatment strategies for the management of CLL. Abstract The Notch signaling pathway plays a fundamental role for the terminal differentiation of multiple cell types, including B and T lymphocytes. The Notch receptors are transmembrane proteins that, upon ligand engagement, undergo multiple processing steps that ultimately release their intracytoplasmic portion. The activated protein ultimately operates as a nuclear transcriptional co-factor, whose stability is finely regulated. The Notch pathway has gained growing attention in chronic lymphocytic leukemia (CLL) because of the high rate of somatic mutations of the NOTCH1 gene. In CLL, NOTCH1 mutations represent a validated prognostic marker and a potential predictive marker for anti-CD20-based therapies, as pathological alterations of the Notch pathway can provide significant growth and survival advantage to neoplastic clone. However, beside NOTCH1 mutation, other events have been demonstrated to perturb the Notch pathway, namely somatic mutations of upstream, or even apparently unrelated, proteins such as FBXW7, MED12, SPEN, SF3B1, as well as physiological signals from other pathways such as the B-cell receptor. Here we review these mechanisms of activation of the NOTCH1 pathway in the context of CLL; the resulting picture highlights how multiple different mechanisms, that might occur under specific genomic, phenotypic and microenvironmental contexts, ultimately result in the same search for proliferative and survival advantages (through activation of MYC), as well as immune escape and therapy evasion (from anti-CD20 biological therapies). Understanding the preferential strategies through which CLL cells hijack NOTCH1 signaling may present important clues for designing targeted treatment strategies for the management of CLL.
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Kumar R, Kumar R, Sharma N, Khurana N, Singh SK, Satija S, Mehta M, Vyas M. Pharmacological evaluation of bromelain in mouse model of Alzheimer's disease. Neurotoxicology 2022; 90:19-34. [PMID: 35219781 DOI: 10.1016/j.neuro.2022.02.009] [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: 09/11/2021] [Revised: 01/25/2022] [Accepted: 02/21/2022] [Indexed: 10/19/2022]
Abstract
The current study elucidates pharmacological evaluation of bromelain as a bioactive compound obtain from pineapple stem belongs to family Bromeliaceae in AlCl3 and D - galactose induced mice. In mice, co-administration of AlCl3 at dose 5 mg/kg b.w., via the oral route, and D - galactose at dose 60 mg/kg b.w., via intraperitoneal route for 90 days resulted in cognitive impairment, spatial learning, and memory deficits, as well as neurotoxicity. However, 30 consecutive days, treatments via an intraperitoneal route with bromelain low dose (Brm L) at dose 10 mg/kg b.w., bromelain high dose (Brm H) at dose 20 mg/kg b.w., donepezil (Dnpz) at dose 2 mg/kg b.w., and Brm L + Dnpz at doses 10, 2 mg/kg b.w. were considerably reversed the effect of AlCl3 and D - galactose induced AD mice. Consequences of behavioral parameters (Morris water maze, elevated plus maze and locomotor), biochemical estimation (MDA, GSH, SOD, CAT, Nitrite and AChE), and ELISA tests (mouse BACE, Aβ1 - 42, TNF-α, IL-6, and BDNF) confirmed significant (p < 0.05) neuroprotective effect of treatments in AlCl3 and D - galactose induced mice. Additionally, hematoxylin and eosin staining of the cerebral cortex and the hippocampus exposed eosinophilic lesions and hyperchromatic nuclei in AD mice, but these neurodegenerative effects were eliminated by Brm L, Brm H, Dnpz, and Brm L + Dnpz treatments. Thus, bromelain alone and in combination with donepezil prevent AlCl3 and D - galactose induced spatial learning and memory deficits, as well as cognitive impairment, by increasing cholinergic activity and synaptic plasticity, as well as reducing oxidative damage, neuroinflammation, Aβ 1-42 aggregations, and histopathological damage, according to our findings. The present study consequences indicate that bromelain alone and in combination with donepezil appears to have neuroprotective properties. Henceforward, this may be a promising treatment option for Alzheimer's disease.
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Affiliation(s)
- Rakesh Kumar
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India
| | - Rajan Kumar
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India
| | - Neha Sharma
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India
| | - Navneet Khurana
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India.
| | - Sachin Kumar Singh
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India
| | - Saurabh Satija
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India
| | - Meenu Mehta
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India
| | - Manish Vyas
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India
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Eggert S, Kins S, Endres K, Brigadski T. Brothers in arms: proBDNF/BDNF and sAPPα/Aβ-signaling and their common interplay with ADAM10, TrkB, p75NTR, sortilin, and sorLA in the progression of Alzheimer's disease. Biol Chem 2022; 403:43-71. [PMID: 34619027 DOI: 10.1515/hsz-2021-0330] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 09/16/2021] [Indexed: 12/22/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is an important modulator for a variety of functions in the central nervous system (CNS). A wealth of evidence, such as reduced mRNA and protein level in the brain, cerebrospinal fluid (CSF), and blood samples of Alzheimer's disease (AD) patients implicates a crucial role of BDNF in the progression of this disease. Especially, processing and subcellular localization of BDNF and its receptors TrkB and p75 are critical determinants for survival and death in neuronal cells. Similarly, the amyloid precursor protein (APP), a key player in Alzheimer's disease, and its cleavage fragments sAPPα and Aβ are known for their respective roles in neuroprotection and neuronal death. Common features of APP- and BDNF-signaling indicate a causal relationship in their mode of action. However, the interconnections of APP- and BDNF-signaling are not well understood. Therefore, we here discuss dimerization properties, localization, processing by α- and γ-secretase, relevance of the common interaction partners TrkB, p75, sorLA, and sortilin as well as shared signaling pathways of BDNF and sAPPα.
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Affiliation(s)
- Simone Eggert
- Department of Human Biology and Human Genetics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, D-67663 Kaiserslautern, Germany
| | - Stefan Kins
- Department of Human Biology and Human Genetics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, D-67663 Kaiserslautern, Germany
| | - Kristina Endres
- Department of Psychiatry and Psychotherapy, University Medical Center, Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
| | - Tanja Brigadski
- Department of Informatics and Microsystem Technology, University of Applied Sciences Kaiserslautern, D-66482 Zweibrücken, Germany
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10
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Secretases Related to Amyloid Precursor Protein Processing. MEMBRANES 2021; 11:membranes11120983. [PMID: 34940484 PMCID: PMC8706128 DOI: 10.3390/membranes11120983] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 11/24/2021] [Accepted: 12/10/2021] [Indexed: 11/29/2022]
Abstract
Alzheimer’s disease (AD) is a common neurodegenerative disease whose prevalence increases with age. An increasing number of findings suggest that abnormalities in the metabolism of amyloid precursor protein (APP), a single transmembrane aspartic protein that is cleaved by β- and γ-secretases to produce β-amyloid protein (Aβ), are a major pathological feature of AD. In recent years, a large number of studies have been conducted on the APP processing pathways and the role of secretion. This paper provides a summary of the involvement of secretases in the processing of APP and the potential drug targets that could provide new directions for AD therapy.
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11
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Role of Receptors in Relation to Plaques and Tangles in Alzheimer's Disease Pathology. Int J Mol Sci 2021; 22:ijms222312987. [PMID: 34884789 PMCID: PMC8657621 DOI: 10.3390/ijms222312987] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/26/2021] [Accepted: 11/28/2021] [Indexed: 12/23/2022] Open
Abstract
Despite the identification of Aβ plaques and NFTs as biomarkers for Alzheimer’s disease (AD) pathology, therapeutic interventions remain elusive, with neither an absolute prophylactic nor a curative medication available to impede the progression of AD presently available. Current approaches focus on symptomatic treatments to maintain AD patients’ mental stability and behavioral symptoms by decreasing neuronal degeneration; however, the complexity of AD pathology requires a wide range of therapeutic approaches for both preventive and curative treatments. In this regard, this review summarizes the role of receptors as a potential target for treating AD and focuses on the path of major receptors which are responsible for AD progression. This review gives an overall idea centering on major receptors, their agonist and antagonist and future prospects of viral mimicry in AD pathology. This article aims to provide researchers and developers a comprehensive idea about the different receptors involved in AD pathogenesis that may lead to finding a new therapeutic strategy to treat AD.
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12
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Arif N, Subhani A, Hussain W, Rasool N. In Silico Inhibition of BACE-1 by Selective Phytochemicals as Novel Potential Inhibitors: Molecular Docking and DFT Studies. Curr Drug Discov Technol 2021; 17:397-411. [PMID: 30767744 DOI: 10.2174/1570163816666190214161825] [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: 11/18/2018] [Revised: 01/16/2019] [Accepted: 01/31/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Alzheimer's Disease (AD) has become the most common age-dependent disease of dementia. The trademark pathologies of AD are the presence of amyloid aggregates in neurofibrils. Recently phytochemicals being considered as potential inhibitors against various neurodegenerative, antifungal, antibacterial and antiviral diseases in human beings. OBJECTIVE This study targets the inhibition of BACE-1 by phytochemicals using in silico drug discovery analysis. METHODS A total of 3150 phytochemicals were collected from almost 25 different plants through literature assessment. The ADMET studies, molecular docking and density functional theory (DFT) based analysis were performed to analyze the potential inhibitory properties of these phytochemicals. RESULTS The ADMET and docking results exposed seven compounds that have high potential as an inhibitory agent against BACE-1 and show binding affinity >8.0 kcal/mol against BACE-1. They show binding affinity greater than those of various previously reported inhibitors of BACE-1. Furthermore, DFT based analysis has shown high reactivity for these seven phytochemicals in the binding pocket of BACE- 1, based on ELUMO, EHOMO and Kohn-Sham energy gap. All seven phytochemicals were testified (as compared to experimental ones) as novel inhibitors against BACE-1. CONCLUSION Out of seven phytochemicals, four were obtained from plant Glycyrrhiza glabra i.e. Shinflavanone, Glabrolide, Glabrol and PrenyllicoflavoneA, one from Huperzia serrate i.e. Macleanine, one from Uncaria rhynchophylla i.e. 3a-dihydro-cadambine and another one was from VolvalerelactoneB from plant Valeriana-officinalis. It is concluded that these phytochemicals are suitable candidates for drug/inhibitor against BACE-1, and can be administered to humans after experimental validation through in vitro and in vivo trials.
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Affiliation(s)
- Nadia Arif
- Department of Life Sciences, University of Management and Technology, Lahore 54770, Pakistan
| | - Andleeb Subhani
- Department of Life Sciences, University of Management and Technology, Lahore 54770, Pakistan
| | - Waqar Hussain
- National Center of Artificial Intelligence, Punjab University College of Information Technology, University of the Punjab, Lahore, Pakistan,Center for Professional Studies, Lahore, Pakistan
| | - Nouman Rasool
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological
Sciences, University of Karachi, Karachi 75270, Pakistan,Center for Professional Studies, Lahore, Pakistan
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13
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Hounjet J, Vooijs M. The Role of Intracellular Trafficking of Notch Receptors in Ligand-Independent Notch Activation. Biomolecules 2021; 11:biom11091369. [PMID: 34572582 PMCID: PMC8466058 DOI: 10.3390/biom11091369] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 12/11/2022] Open
Abstract
Aberrant Notch signaling has been found in a broad range of human malignancies. Consequently, small molecule inhibitors and antibodies targeting Notch signaling in human cancers have been developed and tested; however, these have failed due to limited anti-tumor efficacy because of dose-limiting toxicities in normal tissues. Therefore, there is an unmet need to discover novel regulators of malignant Notch signaling, which do not affect Notch signaling in healthy tissues. This review provides a comprehensive overview of the current knowledge on the role of intracellular trafficking in ligand-independent Notch receptor activation, the possible mechanisms involved, and possible therapeutic opportunities for inhibitors of intracellular trafficking in Notch targeting.
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Peng Y, Tao H, Wang S, Xiao J, Wang Y, Su H. Dietary intervention with edible medicinal plants and derived products for prevention of Alzheimer's disease: A compendium of time-tested strategy. J Funct Foods 2021. [DOI: 10.1016/j.jff.2021.104463] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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15
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The Effect of TCM-Induced HAMP on Key Enzymes in the Hydrolysis of AD Model Cells. Neurochem Res 2021; 46:1068-1080. [PMID: 33683629 DOI: 10.1007/s11064-021-03235-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 12/31/2020] [Accepted: 01/06/2021] [Indexed: 10/22/2022]
Abstract
Alzheimer's disease (AD) process is characterized classically by two hallmark pathologies: β-amyloid (Aβ) plaque deposition and neurofibrillary tangles of hyperphosphorylated tau. Aβ peptides play an important role in AD, but despite much effort the molecular mechanisms of how Aβ contributes to AD remain unclear. The present study evaluated the effects of the active components of Epimedium, Astragalus and Radix Puerariae induced HAMP on key enzymes in the hydrolysis of APP in HT22 cells. The active components of Epimedium, Astragalus and Radix Puerariae could effectively up-regulate the expression of HAMP, alleviate the iron overload in the brain tissues of mice, significantly improve the learning and memory ability of AD, down-regulate the expression of Aβ and reduce the deposition of SP in an APPswe/PS1ΔE9 transgenic mouse model of AD. HAMP and Aβ25-35 induced HT22 cells are used as AD cell models in this study to investigate the effect of the compound consisting of the effective components of Epimedium, Astragalus and Pueraria on the key enzymes in the hydrolysis of APP. After the administration of traditional Chinese medicine (TCM), the expression levels of ADAM10 and ADAM17 were increased while the expression level of BACE1 decreased. This indicates that TCM can promote the expression level of ADAM10 and ADAM17, inhibit the expression level of BACE1, thus further inhibiting the production of amyloid protein and reducing the production of Aβ and SP. Compared with RNAi group, the expression level of ADAM10 and ADAM17 in Aβ + RNAi group was decreased while the expression level of BACE1 increased. Compared with the Aβ + RNAi group the expression level of ADAM10 and ADAM17 in the Aβ + RNAi + TCM group was increased while the expression level of BACE1 was decreased. The present study indicated the effects of the active components of Epimedium, Astragalus and Radix Puerariae may alleviate AD by up-regulating the expression of HAMP, thus reducing brain iron overload, promoting the expression of ADAM10 and ADAM17, inhibiting the expression of BACE1, and reducing the deposition of Aβ.
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16
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Harris SS, Wolf F, De Strooper B, Busche MA. Tipping the Scales: Peptide-Dependent Dysregulation of Neural Circuit Dynamics in Alzheimer’s Disease. Neuron 2020; 107:417-435. [DOI: 10.1016/j.neuron.2020.06.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/24/2020] [Accepted: 06/01/2020] [Indexed: 02/07/2023]
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17
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Paroni G, Bisceglia P, Seripa D. Understanding the Amyloid Hypothesis in Alzheimer's Disease. J Alzheimers Dis 2020; 68:493-510. [PMID: 30883346 DOI: 10.3233/jad-180802] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The amyloid hypothesis (AH) is still the most accepted model to explain the pathogenesis of inherited Alzheimer's disease (IAD). However, despite the neuropathological overlapping with the non-inherited form (NIAD), AH waver in explaining NIAD. Thus, 30 years after its first statement several questions are still open, mainly regarding the role of amyloid plaques (AP) and apolipoprotein E (APOE). Accordingly, a pathogenetic model including the role of AP and APOE unifying IAD and NIAD pathogenesis is still missing. In the present understanding of the AH, we suggested that amyloid-β (Aβ) peptides production and AP formation is a physiological aging process resulting from a systemic age-related decrease in the efficiency of the proteins catabolism/clearance machinery. In this pathogenetic model Aβ peptides act as neurotoxic molecules, but only above a critical concentration [Aβ]c. A threshold mechanism triggers IAD/NIAD onset only when [Aβ]≥[Aβ]c. In this process, APOE modifies [Aβ]c threshold in an isoform-specific way. Consequently, all factors influencing Aβ anabolism, such as amyloid beta precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2) gene mutations, and/or Aβ catabolism/clearance could contribute to exceed the threshold [Aβ]c, being characteristic of each individual. In this model, AP formation does not depend on [Aβ]c. The present interpretation of the AH, unifying the pathogenetic theories for IAD and NIAD, will explain why AP and APOE4 may be observed in healthy aging and why they are not the cause of AD. It is clear that further studies are needed to confirm our pathogenetic model. Nevertheless, our suggestion may be useful to better understand the pathogenesis of AD.
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Affiliation(s)
- Giulia Paroni
- Research Laboratory, Complex Structure of Geriatrics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
| | - Paola Bisceglia
- Research Laboratory, Complex Structure of Geriatrics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
| | - Davide Seripa
- Research Laboratory, Complex Structure of Geriatrics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
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18
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Knupp A, Mishra S, Martinez R, Braggin JE, Szabo M, Kinoshita C, Hailey DW, Small SA, Jayadev S, Young JE. Depletion of the AD Risk Gene SORL1 Selectively Impairs Neuronal Endosomal Traffic Independent of Amyloidogenic APP Processing. Cell Rep 2020; 31:107719. [PMID: 32492427 PMCID: PMC7409533 DOI: 10.1016/j.celrep.2020.107719] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/24/2020] [Accepted: 05/12/2020] [Indexed: 02/09/2023] Open
Abstract
SORL1/SORLA is a sorting receptor involved in retromer-related endosomal traffic and an Alzheimer's disease (AD) risk gene. Using CRISPR-Cas9, we deplete SORL1 in hiPSCs to ask if loss of SORL1 contributes to AD pathogenesis by endosome dysfunction. SORL1-deficient hiPSC neurons show early endosome enlargement, a hallmark cytopathology of AD. There is no effect of SORL1 depletion on endosome size in hiPSC microglia, suggesting a selective effect on neuronal endosomal trafficking. We validate defects in neuronal endosomal traffic by showing altered localization of amyloid precursor protein (APP) in early endosomes, a site of APP cleavage by the β-secretase (BACE). Inhibition of BACE does not rescue endosome enlargement in SORL1-deficient neurons, suggesting that this phenotype is independent of amyloidogenic APP processing. Our data, together with recent findings, underscore how sporadic AD pathways regulating endosomal trafficking and autosomal-dominant AD pathways regulating APP cleavage independently converge on the defining cytopathology of AD.
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Affiliation(s)
- Allison Knupp
- Department of Pathology, University of Washington, Seattle, WA 98109, USA
| | - Swati Mishra
- Department of Pathology, University of Washington, Seattle, WA 98109, USA
| | - Refugio Martinez
- Department of Pathology, University of Washington, Seattle, WA 98109, USA
| | | | - Marcell Szabo
- Department of Pathology, University of Washington, Seattle, WA 98109, USA
| | - Chizuru Kinoshita
- Department of Pathology, University of Washington, Seattle, WA 98109, USA
| | - Dale W Hailey
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA
| | - Scott A Small
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Suman Jayadev
- Department of Neurology, University of Washington, Seattle, WA 98195, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA
| | - Jessica E Young
- Department of Pathology, University of Washington, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA.
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19
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Dar NJ, Glazner GW. Deciphering the neuroprotective and neurogenic potential of soluble amyloid precursor protein alpha (sAPPα). Cell Mol Life Sci 2020; 77:2315-2330. [PMID: 31960113 PMCID: PMC11105086 DOI: 10.1007/s00018-019-03404-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 11/21/2019] [Accepted: 11/28/2019] [Indexed: 12/25/2022]
Abstract
Amyloid precursor protein (APP) is a transmembrane protein expressed largely within the central nervous system. Upon cleavage, it does not produce the toxic amyloid peptide (Aβ) only, which is involved in neurodegenerative progressions but via a non-amyloidogenic pathway it is metabolized to produce a soluble fragment (sAPPα) through α-secretase. While a lot of studies are focusing on the role played by APP in the pathogenesis of Alzheimer's disease, sAPPα is reported to have numerous neuroprotective effects and it is being suggested as a candidate with possible therapeutic potential against Alzheimer's disease. However, the mechanisms through which sAPPα precisely works remain elusive. We have presented a comprehensive review of how sAPPα is regulating the neuroprotective effects in different biological models. Moreover, we have focused on the role of sAPPα during different developmental stages of the brain, neurogenic microenvironment in the brain and how this metabolite of APP is regulating the neurogenesis which is regarded as a compelling approach to ameliorate the impaired learning and memory deficits in dementia and diseases like Alzheimer's disease. sAPPα exerts beneficial physiological, biochemical and behavioral effects mitigating the detrimental effects of neurotoxic compounds. It has shown to increase the proliferation rate of numerous cell types and promised the synaptogenesis, neurite outgrowth, cell survival and cell adhesion. Taken together, we believe that further studies are warranted to investigate the exact mechanism of action so that sAPPα could be developed as a novel therapeutic target against neuronal deficits.
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Affiliation(s)
- Nawab John Dar
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
- St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, R2H 2A6, Canada
| | - Gordon W Glazner
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada.
- St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, R2H 2A6, Canada.
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20
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Assaf N, El-Shamarka ME, Salem NA, Khadrawy YA, El Sayed NS. Neuroprotective effect of PPAR alpha and gamma agonists in a mouse model of amyloidogenesis through modulation of the Wnt/beta catenin pathway via targeting alpha- and beta-secretases. Prog Neuropsychopharmacol Biol Psychiatry 2020; 97:109793. [PMID: 31669201 DOI: 10.1016/j.pnpbp.2019.109793] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 10/11/2019] [Accepted: 10/17/2019] [Indexed: 12/11/2022]
Abstract
The present study was conducted to evaluate the efficacy of fenofibrate and pioglitazone in a mouse model of amyloidogenesis induced by amyloidβ (βA) peptide. Mice were injected intracerebroventricularly with βA1-40 (400 pmol/mouse) once, followed by treatment with fenofibrate (300 mg/kg), pioglitazone (30 mg/kg),or both. After 21 days of daily treatment, memory impairment and cognitive function were evaluated by Morris water maze (MWM), Y-maze and object recognition tests. On the 22nd day, mice were sacrificed, and their hippocampi were dissected to determine the levels of α- and β-secretase, peroxisome proliferator-activated receptor (PPARα and β), Wnt and β-catenin. Significant memory impairment and cognitive dysfunction were observed in the mouse model group. This finding was associated with a significant increase in α- and β-secretase levels and a significant decrease in Wnt, β-catenin, and PPARα and β levels. Neuronal damage was also evident after histopathological examination. Treatment with fenofibrate, pioglitazone and their combination resulted in a significant improvement in the behavioural and neurochemical changes induced by βA injection. The present findings indicate that the combined administration of fenofibrate and pioglitazone was more effective than monotherapy in ameliorating the behavioural, neurochemical and histopathological changes in amyloidogenesis model mice and provide a promising therapeutic approach in the management of Alzheimer's disease complicated by diabetes and hypercholesterolemia.
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Affiliation(s)
- Naglaa Assaf
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Misr University for Science and Technology, Cairo, Egypt
| | - Marwa E El-Shamarka
- Department of Narcotics, Ergogenic Aids and Poisons, Medical Research Division, National Research Centre, Giza, Egypt
| | - Neveen A Salem
- Department of Narcotics, Ergogenic Aids and Poisons, Medical Research Division, National Research Centre, Giza, Egypt; Department of Biochemistry, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Yasser A Khadrawy
- Department of Medical Physiology, Medical Research Division, National Research Centre, Egypt
| | - Nesrine S El Sayed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Egypt.
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Ahmad SS, Khan S, Kamal MA, Wasi U. The Structure and Function of α, β and γ-Secretase as Therapeutic Target Enzymes in the Development of Alzheimer’s Disease: A Review. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2020; 18:657-667. [DOI: 10.2174/1871527318666191011145941] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 08/20/2019] [Accepted: 09/04/2019] [Indexed: 12/22/2022]
Abstract
:Alzheimer's disease is a progressive neurodegenerative disorder that affects the central nervous system. There are several factors that cause AD, like, intracellular hyperphosphorylated Tau tangles, collection of extracellular Amyloid-β42 and generation of reactive oxygen species due to mitochondrial dysfunction. This review analyses the most active target of AD and both types of AD-like early-onset AD and late-onset AD. BACE1 is a β-secretase involved in the cleavage of amyloid precursor protein and the pathogenesis of Alzheimer's disease. The presenilin proteins play a critical role in the pathogenesis of Alzheimer malady by intervening the intramembranous cleavage of amyloid precursor protein and the generation of amyloid β. The two homologous proteins PS1 and PS2 speak to the reactant subunits of particular γ-secretase edifices that intercede an assortment of cellular processes. Natural products are common molecular platforms in drug development in AD. Many natural products are being tested in various animal model systems for their role as a potential therapeutic target in AD. Presently, there are a few theories clarifying the early mechanisms of AD pathogenesis. Recently, research advancements in the field of nanotechnology, which utilize macromolecular strategies to make drugs in nanoscale measurements, offer nanotechnology-based diagnostic tools and drug carriers which are highly sensitive for effective drug targeting in the treatment of Alzheimer’s disease.
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Affiliation(s)
- Syed S. Ahmad
- Department of Bioengineering, Faculty of Engineering, Integral University, Lucknow, India
| | - Shahzad Khan
- Wuhan University, School of Medicine, Wuhan, Hubei, China
| | - Mohammad A. Kamal
- King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Umam Wasi
- Department of Biosciences, Faculty of Science, Integral University, Lucknow, India
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22
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Elevation of plasma soluble amyloid precursor protein beta in Alzheimer's disease. Arch Gerontol Geriatr 2019; 87:103995. [PMID: 31874328 DOI: 10.1016/j.archger.2019.103995] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/26/2019] [Accepted: 12/07/2019] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Beta-amyloid is considered to be a pathophysiological marker in Alzheimer's disease (AD). Soluble amyloid precursor proteins (sAPPs) -α (sAPPα) and -β (sAPPβ), which are the byproducts of non-amyloidogenic and amyloidogenic process of APP, respectively, have been repeatedly observed in the cerebrospinal fluids (CSF) of AD patients. The present study focused on the determination of sAPP levels in peripheral blood. METHODS The plasma protein levels of sAPPα and sAPPβ were measured with ELISA. Plasma from 52 AD patients, 98 amnestic mild cognitive impairment (MCI) patients, and 114 cognitively normal controls were compared. RESULTS The plasma level of sAPPβ was significantly increased in AD patients than in cognitively healthy controls. However, no significant change in plasma sAPPα was observed among the three groups. Furthermore, the plasma sAPPβ levels significantly correlated with cognitive assessment scales, such as clinical dementia rating (CDR), and mini-mental status examination (MMSE). Interestingly, sAPPα and sAPPβ had a positive correlation with each other in blood plasma, similar to previous studies on CSF sAPP. This correlation was stronger in the MCI and AD groups than in the cognitively healthy controls. CONCLUSIONS These results suggest that individuals with elevated plasma sAPPβ levels are at an increased risk of AD; elevation in these levels may reflect the progression of disease.
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23
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Czarnek M, Bereta J. Proteolytic Processing of Neuregulin 2. Mol Neurobiol 2019; 57:1799-1813. [PMID: 31838721 PMCID: PMC7118043 DOI: 10.1007/s12035-019-01846-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 11/25/2019] [Indexed: 01/17/2023]
Abstract
Neuregulin 2 (NRG2) belongs to the EGF family of growth factors. Most of this family members require proteolytic cleavage to liberate their ectodomains capable of binding and activating their cognate ErbB receptors. To date, most of the studies investigating proteolytic processing of neuregulins focused on NRG1, which was shown to undergo ectodomain shedding by several ADAM proteases and BACE1 and the remaining fragment was further cleaved by γ-secretase. Recently, NRG2 attracted more attention due to its role in the neurogenesis and modulation of behaviors associated with psychiatric disorders. In this study, we used genetic engineering methods to identify proteases involved in proteolytic processing of murine NRG2. Using non-neuronal cell lines as well as cultures of primary hippocampal neurons, we demonstrated that the major proteases responsible for releasing NRG2 ectodomain are ADAM10 and BACE2. Co-expression of NRG2 and BACE2 in neurons of certain brain structures including medulla oblongata and cerebellar deep nuclei was confirmed via immunohistochemical staining. The cleavage of NRG2 by ADAM10 or BACE2 generates a C-terminal fragment that serves as a substrate for γ-secretase. We also showed that murine NRG2 is subject to post-translational modifications, substantial glycosylation of its extracellular part, and phosphorylation of the cytoplasmic tail.
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Affiliation(s)
- Maria Czarnek
- Department of Cell Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Kraków, Gronostajowa 7, 30-387, Kraków, Poland.
| | - Joanna Bereta
- Department of Cell Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Kraków, Gronostajowa 7, 30-387, Kraków, Poland.
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Alaiyed S, Conant K. A Role for Matrix Metalloproteases in Antidepressant Efficacy. Front Mol Neurosci 2019; 12:117. [PMID: 31133801 PMCID: PMC6517485 DOI: 10.3389/fnmol.2019.00117] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 04/24/2019] [Indexed: 01/10/2023] Open
Abstract
Major depressive disorder is a debilitating condition that affects approximately 15% of the United States population. Though the neurophysiological mechanisms that underlie this disorder are not completely understood, both human and rodent studies suggest that excitatory/inhibitory (E/I) balance is reduced with the depressive phenotype. In contrast, antidepressant efficacy in responsive individuals correlates with increased excitatory neurotransmission in select brain regions, suggesting that the restoration of E/I balance may improve mood. Enhanced excitatory transmission can occur through mechanisms including increased dendritic arborization and synapse formation in pyramidal neurons. Reduced activity of inhibitory neurons may also contribute to antidepressant efficacy. Consistent with this possibility, the fast-acting antidepressant ketamine may act by selective inhibition of glutamatergic input to GABA releasing parvalbumin (PV)-expressing interneurons. Recent work has also shown that a negative allosteric modulator of the GABA-A receptor α subunit can improve depression-related behavior. PV-expressing interneurons are thought to represent critical pacemakers for synchronous network events. These neurons also represent the predominant GABAergic neuronal population that is enveloped by the perineuronal net (PNN), a lattice-like structure that is thought to stabilize glutamatergic input to this cell type. Disruption of the PNN reduces PV excitability and increases pyramidal cell excitability. Various antidepressant medications increase the expression of matrix metalloproteinases (MMPs), enzymes that can increase pyramidal cell dendritic arborization and spine formation. MMPs can also cleave PNN proteins to reduce PV neuron-mediated inhibition. The present review will focus on mechanisms that may underlie antidepressant efficacy, with a focus on monoamines as facilitators of increased matrix metalloprotease (MMP) expression and activation. Discussion will include MMP-dependent effects on pyramidal cell structure and function, as well as MMP-dependent effects on PV expressing interneurons. We conclude with discussion of antidepressant use for those at risk for Alzheimer’s disease, and we also highlight areas for further study.
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Affiliation(s)
- Seham Alaiyed
- Department of Pharmacology, Georgetown University Medical Center, Washington, DC, United States
| | - Katherine Conant
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC, United States
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25
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Bazzari FH, Abdallah DM, El-Abhar HS. Pharmacological Interventions to Attenuate Alzheimer’s Disease Progression: The Story So Far. Curr Alzheimer Res 2019; 16:261-277. [DOI: 10.2174/1567205016666190301111120] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 12/15/2018] [Accepted: 01/31/2019] [Indexed: 12/23/2022]
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disease and the most common cause of dementia in the elderly. Up to date, the available pharmacological options for AD are limited to cholinesterase inhibitors and memantine that may only provide modest symptomatic management with no significance in slowing down the disease progression. Over the past three decades, the increased interest in and the understanding of AD major pathological hallmarks have provided an insight into the mechanisms mediating its pathogenesis, which in turn introduced a number of hypotheses and novel targets for the treatment of AD. Initially, targeting amyloid-beta and tau protein was considered the most promising therapeutic approach. However, further investigations have identified other major players, such as neuroinflammation, impaired insulin signalling and defective autophagy, that may contribute to the disease progression. While some promising drugs are currently being investigated in human studies, the majority of the previously developed medical agents have come to an end in clinical trials, as they have failed to illustrate any beneficial outcome. This review aims to discuss the different introduced approaches to alleviate AD progression; in addition, provides a comprehensive overview of the drugs in the development phase as well as their mode of action and an update of their status in clinical trials.
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Affiliation(s)
- Firas H. Bazzari
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Dalaal M. Abdallah
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Hanan S. El-Abhar
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
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26
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Yang XA, Zweifach A. Temperature-Dependent Expression of a CFP-YFP FRET Diacylglycerol Sensor Enables Multiple-Read Screening for Compounds That Affect C1 Domains. SLAS DISCOVERY 2019; 24:682-692. [PMID: 30802416 DOI: 10.1177/2472555219830086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Intramolecular CFP-YFP fluorescence resonance energy transfer (FRET) sensors expressed in cells are powerful research tools but have seen relatively little use in screening. We exploited the discovery that the expression of a CFP-YFP FRET diacylglycerol sensor (DAGR) increases over time when cells are incubated at room temperature to assess requirements for robust measurements using a Molecular Devices Spectramax i3x fluorescence plate reader. Expression levels resulting in YFP fluorescence >10-fold higher than untransfected cells and phorbol ester-stimulated FRET ratio changes of 60% or more were required to consistently give robust Z' > 0.5. As a means of confirming that these conditions are suitable for screening, we developed a novel multiple-read protocol to assay the NCI's Mechanistic Set III for agonists and antagonists of C1 domain activation. Sixteen compounds prevented C1 domain translocation. However, none blocked phorbol ester-stimulated protein kinase C (PKC) activity assessed using a phospho-specific antibody-six actually stimulated PKC activity. Cytometry, which produces higher Z' for a given FRET ratio change, might have been a better approach for discovering antagonists, as it would have allowed lower phorbol ester concentrations to be used. We conclude that CFP-YFP FRET measured in a Spectramax i3x plate reader can be used for screening under the conditions we defined. Our strategy of varying expression level and FRET ratio could be useful to others for determining conditions needed for robust cell-based intramolecular CFP-YFP FRET measurements on their instrumentation.
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Affiliation(s)
- Xiuyi Alexander Yang
- 1 Department of Molecular and Cell Biology, University of Connecticut at Storrs, Storrs, CT, USA
| | - Adam Zweifach
- 1 Department of Molecular and Cell Biology, University of Connecticut at Storrs, Storrs, CT, USA
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27
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The Effectiveness of Vitamin E Treatment in Alzheimer's Disease. Int J Mol Sci 2019; 20:ijms20040879. [PMID: 30781638 PMCID: PMC6412423 DOI: 10.3390/ijms20040879] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 01/31/2019] [Accepted: 02/11/2019] [Indexed: 12/21/2022] Open
Abstract
Vitamin E was proposed as treatment for Alzheimer’s disease many years ago. However, the effectiveness of the drug is not clear. Vitamin E is an antioxidant and neuroprotector and it has anti-inflammatory and hypocholesterolemic properties, driving to its importance for brain health. Moreover, the levels of vitamin E in Alzheimer’s disease patients are lower than in non-demented controls. Thus, vitamin E could be a good candidate to have beneficial effects against Alzheimer’s. However, evidence is consistent with a limited effectiveness of vitamin E in slowing progression of dementia; the information is mixed and inconclusive. The question is why does vitamin E fail to treat Alzheimer’s disease? In this paper we review the studies with and without positive results in Alzheimer’s disease and we discuss the reasons why vitamin E as treatment sometimes has positive results on cognition but at others, it does not.
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28
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Tan JZA, Gleeson PA. The trans-Golgi network is a major site for α-secretase processing of amyloid precursor protein in primary neurons. J Biol Chem 2019; 294:1618-1631. [PMID: 30545942 PMCID: PMC6364769 DOI: 10.1074/jbc.ra118.005222] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/12/2018] [Indexed: 01/09/2023] Open
Abstract
Amyloid precursor protein (APP) is processed along the amyloidogenic pathway by the β-secretase, BACE1, generating β-amyloid (Aβ), or along the nonamyloidogenic pathway by α-secretase, precluding Aβ production. The plasma membrane is considered the major site for α-secretase-mediated APP cleavage, but other cellular locations have not been rigorously investigated. Here, we report that APP is processed by endogenous α-secretase at the trans-Golgi network (TGN) of both transfected HeLa cells and mouse primary neurons. We have previously shown the adaptor protein complex, AP-4, and small G protein ADP-ribosylation factor-like GTPase 5b (Arl5b) are required for efficient post-Golgi transport of APP to endosomes. We found here that AP-4 or Arl5b depletion results in Golgi accumulation of APP and increased secretion of the soluble α-secretase cleavage product sAPPα. Moreover, inhibition of γ-secretase following APP accumulation in the TGN increases the levels of the membrane-bound C-terminal fragments of APP from both α-secretase cleavage (α-CTF, named C83 according to its band size) and BACE1 cleavage (β-CTF/C99). The level of C83 was ∼4 times higher than that of C99, indicating that α-secretase processing is the major pathway and that BACE1 processing is the minor pathway in the TGN. AP-4 silencing in mouse primary neurons also resulted in the accumulation of endogenous APP in the TGN and enhanced α-secretase processing. These findings identify the TGN as a major site for α-secretase processing in HeLa cells and primary neurons and indicate that both APP processing pathways can occur within the TGN compartment along the secretory pathway.
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Affiliation(s)
- Jing Zhi A Tan
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Paul A Gleeson
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia.
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29
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The role of membrane trafficking in the processing of amyloid precursor protein and production of amyloid peptides in Alzheimer's disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:697-712. [PMID: 30639513 DOI: 10.1016/j.bbamem.2018.11.013] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 11/25/2018] [Accepted: 11/29/2018] [Indexed: 01/18/2023]
Abstract
Alzheimer's disease (AD) is characterized by progressive accumulation of misfolded proteins, which form senile plaques and neurofibrillary tangles, and the release of inflammatory mediators by innate immune responses. β-Amyloid peptide (Aβ) is derived from sequential processing of the amyloid precursor protein (APP) by membrane-bound proteases, namely the β-secretase, BACE1, and γ-secretase. Membrane trafficking plays a key role in the regulation of APP processing as both APP and the processing secretases traffic along distinct pathways. Genome wide sequencing studies have identified several AD susceptibility genes which regulate membrane trafficking events. To understand the pathogenesis of AD it is critical that the cell biology of APP and Aβ production in neurons is well defined. This review discusses recent advances in unravelling the membrane trafficking events associated with the production of Aβ, and how AD susceptible alleles may perturb the sorting and transport of APP and BACE1. Mechanisms whereby inflammation may influence APP processing are also considered.
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30
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Wang X, Pei G. Visualization of Alzheimer's Disease Related α-/β-/γ-Secretase Ternary Complex by Bimolecular Fluorescence Complementation Based Fluorescence Resonance Energy Transfer. Front Mol Neurosci 2018; 11:431. [PMID: 30538620 PMCID: PMC6277482 DOI: 10.3389/fnmol.2018.00431] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 11/05/2018] [Indexed: 11/13/2022] Open
Abstract
The competitive ectodomain shedding of amyloid-β precursor protein (APP) by α-secretase and β-secretase, and the subsequent regulated intramembrane proteolysis by γ-secretase are the key processes in amyloid-β peptides (Aβ) generation. Previous studies indicate that secretases form binary complex and the interactions between secretases take part in substrates processing. However, whether α-, β- and γ-secretase could form ternary complex remains to be explored. Here, we adopted bimolecular fluorescence complementation in combination with fluorescence resonance energy transfer (BiFC-FRET) to visualize the formation of triple secretase complex. We show that the interaction between α-secretase ADAM10 and β-secretase BACE1 could be monitored by BiFC assay and the binding of APP to α-/β-secretase binary complex was revealed by BiFC-FRET. Further, we observed that γ-secretase interacts with α-/β-secretase binary complex, providing evidence that α-, β- and γ-secretase might form a ternary complex. Thus our study extends the interplay among Alzheimer's disease (AD) related α-/β-/γ-secretase.
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Affiliation(s)
- Xin Wang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Gang Pei
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.,School of Life Science and Technology, and The Collaborative Innovation Center for Brain Science, Tongji University, Shanghai, China
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31
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Lim SL, Tran DN, Zumkehr J, Chen C, Ghiaar S, Kieu Z, Villanueva E, Gallup V, Rodriguez-Ortiz CJ, Kitazawa M. Inhibition of hematopoietic cell kinase dysregulates microglial function and accelerates early stage Alzheimer's disease-like neuropathology. Glia 2018; 66:2700-2718. [PMID: 30277607 DOI: 10.1002/glia.23522] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 08/02/2018] [Accepted: 08/02/2018] [Indexed: 11/08/2022]
Abstract
Emerging evidence have posited that dysregulated microglia impair clearance and containment of amyloid-β (Aβ) species in the brain, resulting in aberrant buildup of Aβ and onset of Alzheimer's disease (AD). Hematopoietic cell kinase (Hck) is one of the key regulators of phagocytosis among the Src family tyrosine kinases (SFKs) in myeloid cells, and its expression is found to be significantly altered in AD brains. However, the role of Hck signaling in AD pathogenesis is unknown. We employed pharmacological inhibition and genetic ablation of Hck in BV2 microglial cells and J20 mouse model of AD, respectively, to evaluate the impact of Hck deficiency on Aβ-stimulated microglial phagocytosis, Aβ clearance, and resultant AD-like neuropathology. Our in vitro data reveal that pharmacological inhibition of SFKs/Hck in BV2 cells and genetic ablation of their downstream kinase, spleen tyrosine kinase (Syk), in primary microglia significantly attenuate Aβ oligomers-stimulated microglial phagocytosis. Whereas in Hck-deficient J20 mice, we observed exacerbated Aβ plaque burden, reduced microglial coverage, containment, and phagocytosis of Aβ plaques, and induced iNOS expression in plaque-associated microglial clusters. These multifactorial changes in microglial activities led to attenuated PSD95 levels in hippocampal DG and CA3 regions, but did not alter the postsynaptic dendritic spine morphology at the CA1 region nor cognitive function of the mice. Hck inhibition thus accelerates early stage AD-like neuropathology by dysregulating microglial function and inducing neuroinflammation. Our data implicate that Hck pathway plays a prominent role in regulating microglial neuroprotective function during the early stage of AD development.
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Affiliation(s)
- Siok Lam Lim
- Center for Occupational and Environmental Health, Department of Medicine, University of California, Irvine, California.,Molecular and Cell Biology, University of California, Merced, California
| | - Diana Nguyen Tran
- Molecular and Cell Biology, University of California, Merced, California
| | - Joannee Zumkehr
- Center for Occupational and Environmental Health, Department of Medicine, University of California, Irvine, California.,Molecular and Cell Biology, University of California, Merced, California
| | - Christine Chen
- Molecular and Cell Biology, University of California, Merced, California
| | - Sagar Ghiaar
- Molecular and Cell Biology, University of California, Merced, California
| | - Zanett Kieu
- Molecular and Cell Biology, University of California, Merced, California
| | | | - Victoria Gallup
- Molecular and Cell Biology, University of California, Merced, California
| | - Carlos J Rodriguez-Ortiz
- Center for Occupational and Environmental Health, Department of Medicine, University of California, Irvine, California.,Molecular and Cell Biology, University of California, Merced, California
| | - Masashi Kitazawa
- Center for Occupational and Environmental Health, Department of Medicine, University of California, Irvine, California.,Molecular and Cell Biology, University of California, Merced, California
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32
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Sarajärvi T, Jäntti M, Paldanius KMA, Natunen T, Wu JC, Mäkinen P, Tarvainen I, Tuominen RK, Talman V, Hiltunen M. Protein kinase C -activating isophthalate derivatives mitigate Alzheimer's disease-related cellular alterations. Neuropharmacology 2018; 141:76-88. [PMID: 30138694 DOI: 10.1016/j.neuropharm.2018.08.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 08/15/2018] [Accepted: 08/19/2018] [Indexed: 12/26/2022]
Abstract
Abnormal protein kinase C (PKC) function contributes to many pathophysiological processes relevant for Alzheimer's disease (AD), such as amyloid precursor protein (APP) processing. Phorbol esters and other PKC activators have been demonstrated to enhance the secretion of soluble APPα (sAPPα), reduce the levels of β-amyloid (Aβ), induce synaptogenesis, and promote neuroprotection. We have previously described isophthalate derivatives as a structurally simple family of PKC activators. Here, we characterised the effects of isophthalate derivatives HMI-1a3 and HMI-1b11 on neuronal viability, neuroinflammatory response, processing of APP and dendritic spine density and morphology in in vitro. HMI-1a3 increased the viability of embryonic primary cortical neurons and decreased the production of the pro-inflammatory mediator TNFα, but not that of nitric oxide, in mouse neuron-BV2 microglia co-cultures upon LPS- and IFN-γ-induced neuroinflammation. Furthermore, both HMI-1a3 and HMI-1b11 increased the levels of sAPPα relative to total sAPP and the ratio of Aβ42/Aβ40 in human SH-SY5Y neuroblastoma cells. Finally, bryostatin-1, but not HMI-1a3, increased the number of mushroom spines in proportion to total spine density in mature mouse hippocampal neuron cultures. These results suggest that the PKC activator HMI-1a3 exerts neuroprotective functions in the in vitro models relevant for AD by reducing the production of TNFα and increasing the secretion of neuroprotective sAPPα.
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Affiliation(s)
- T Sarajärvi
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - M Jäntti
- Drug Research Program and Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - K M A Paldanius
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - T Natunen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - J C Wu
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - P Mäkinen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - I Tarvainen
- Drug Research Program and Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - R K Tuominen
- Drug Research Program and Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland.
| | - V Talman
- Drug Research Program and Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - M Hiltunen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland.
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33
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Steinbuck MP, Winandy S. A Review of Notch Processing With New Insights Into Ligand-Independent Notch Signaling in T-Cells. Front Immunol 2018; 9:1230. [PMID: 29910816 PMCID: PMC5992298 DOI: 10.3389/fimmu.2018.01230] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/16/2018] [Indexed: 12/12/2022] Open
Abstract
The Notch receptor is an evolutionarily highly conserved transmembrane protein essential to a wide spectrum of cellular systems, and its deregulation has been linked to a vast number of developmental disorders and malignancies. Regulated Notch function is critical for the generation of T-cells, in which abnormal Notch signaling results in leukemia. Notch activation through trans-activation of the receptor by one of its ligands expressed on adjacent cells has been well defined. In this canonical ligand-dependent pathway, Notch receptor undergoes conformational changes upon ligand engagement, stimulated by a pulling-force on the extracellular fragment of Notch that results from endocytosis of the receptor-bound ligand into the ligand-expressing cell. These conformational changes in the receptor allow for two consecutive proteolytic cleavage events to occur, which release the intracellular region of the receptor into the cytoplasm. It can then travel to the nucleus, where it induces gene transcription. However, there is accumulating evidence that other pathways may induce Notch signaling. A ligand-independent mechanism of Notch activation has been described in which receptor processing is initiated via cell-internal signals. These signals result in the internalization of Notch into endosomal compartments, where chemical changes existing in this microenvironment result in the conformational modifications required for receptor processing. This review will present mechanisms underlying both canonical ligand-dependent and non-canonical ligand-independent Notch activation pathways and discuss the latter in the context of Notch signaling in T-cells.
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Affiliation(s)
- Martin Peter Steinbuck
- Immunology Training Program, Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Susan Winandy
- Immunology Training Program, Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, United States
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34
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Ashraf J, Ahmad J, Ali A, Ul-Haq Z. Analyzing the Behavior of Neuronal Pathways in Alzheimer's Disease Using Petri Net Modeling Approach. Front Neuroinform 2018; 12:26. [PMID: 29875647 PMCID: PMC5974338 DOI: 10.3389/fninf.2018.00026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 04/30/2018] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's Disease (AD) is the most common neuro-degenerative disorder in the elderly that leads to dementia. The hallmark of AD is senile lesions made by abnormal aggregation of amyloid beta in extracellular space of brain. One of the challenges in AD treatment is to better understand the mechanism of action of key proteins and their related pathways involved in neuronal cell death in order to identify adequate therapeutic targets. This study focuses on the phenomenon of aggregation of amyloid beta into plaques by considering the signal transduction pathways of Calpain-Calpastatin (CAST) regulation system and Amyloid Precursor Protein (APP) processing pathways along with Ca2+ channels. These pathways are modeled and analyzed individually as well as collectively through Stochastic Petri Nets for comprehensive analysis and thorough understating of AD. The model predicts that the deregulation of Calpain activity, disruption of Calcium homeostasis, inhibition of CAST and elevation of abnormal APP processing are key cytotoxic events resulting in an early AD onset and progression. Interestingly, the model also reveals that plaques accumulation start early (at the age of 40) in life but symptoms appear late. These results suggest that the process of neuro-degeneration can be slowed down or paused by slowing down the degradation rate of Calpain-CAST Complex. In the light of this study, the suggestive therapeutic strategy might be the prevention of the degradation of Calpain-CAST complexes and the inhibition of Calpain for the treatment of neurodegenerative diseases such as AD.
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Affiliation(s)
- Javaria Ashraf
- Research Center for Modeling and Simulation, National University of Sciences and Technology, Islamabad, Pakistan
| | - Jamil Ahmad
- Research Center for Modeling and Simulation, National University of Sciences and Technology, Islamabad, Pakistan
| | - Amjad Ali
- Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Zaheer Ul-Haq
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical Sciences, University of Karachi, Karachi, Pakistan
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35
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Wang X, Wang C, Pei G. α-secretase ADAM10 physically interacts with β-secretase BACE1 in neurons and regulates CHL1 proteolysis. J Mol Cell Biol 2018; 10:411-422. [DOI: 10.1093/jmcb/mjy001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 01/06/2018] [Indexed: 02/06/2023] Open
Affiliation(s)
- Xin Wang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Congcong Wang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Gang Pei
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
- Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai, China
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36
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Eggert S, Gonzalez AC, Thomas C, Schilling S, Schwarz SM, Tischer C, Adam V, Strecker P, Schmidt V, Willnow TE, Hermey G, Pietrzik CU, Koo EH, Kins S. Dimerization leads to changes in APP (amyloid precursor protein) trafficking mediated by LRP1 and SorLA. Cell Mol Life Sci 2018; 75:301-322. [PMID: 28799085 PMCID: PMC11105302 DOI: 10.1007/s00018-017-2625-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 07/17/2017] [Accepted: 08/08/2017] [Indexed: 12/22/2022]
Abstract
Proteolytic cleavage of the amyloid precursor protein (APP) by α-, β- and γ-secretases is a determining factor in Alzheimer's disease (AD). Imbalances in the activity of all three enzymes can result in alterations towards pathogenic Aβ production. Proteolysis of APP is strongly linked to its subcellular localization as the secretases involved are distributed in different cellular compartments. APP has been shown to dimerize in cis-orientation, affecting Aβ production. This might be explained by different substrate properties defined by the APP oligomerization state or alternatively by altered APP monomer/dimer localization. We investigated the latter hypothesis using two different APP dimerization systems in HeLa cells. Dimerization caused a decreased localization of APP to the Golgi and at the plasma membrane, whereas the levels in the ER and in endosomes were increased. Furthermore, we observed via live cell imaging and biochemical analyses that APP dimerization affects its interaction with LRP1 and SorLA, suggesting that APP dimerization modulates its interplay with sorting molecules and in turn its localization and processing. Thus, pharmacological approaches targeting APP oligomerization properties might open novel strategies for treatment of AD.
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Affiliation(s)
- Simone Eggert
- Department of Human Biology and Human Genetics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany.
| | - A C Gonzalez
- Department of Human Biology and Human Genetics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
- Institute for Biochemistry, Christian Albrechts University Kiel, 24118, Kiel, Germany
| | - C Thomas
- Department of Human Biology and Human Genetics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - S Schilling
- Department of Human Biology and Human Genetics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - S M Schwarz
- Department of Human Biology and Human Genetics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
- Institute for Medical Virology, University of Frankfurt, 60596, Frankfurt, Germany
| | | | - V Adam
- Department of Human Biology and Human Genetics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - P Strecker
- Department of Human Biology and Human Genetics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - V Schmidt
- Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - T E Willnow
- Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - G Hermey
- Institute for Molecular and Cellular Cognition, Center for Molecular University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - C U Pietrzik
- Institute for Pathobiochemistry, Molecular Neurodegeneration, University Medical Center of the Johannes Gutenberg-University Mainz, 55099, Mainz, Germany
| | - E H Koo
- Department of Neuroscience, University of California San Diego (UCSD), La Jolla, CA, 92093-0662, USA
| | - Stefan Kins
- Department of Human Biology and Human Genetics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany.
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37
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Trafficking in Alzheimer's Disease: Modulation of APP Transport and Processing by the Transmembrane Proteins LRP1, SorLA, SorCS1c, Sortilin, and Calsyntenin. Mol Neurobiol 2017; 55:5809-5829. [PMID: 29079999 DOI: 10.1007/s12035-017-0806-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/17/2017] [Indexed: 12/11/2022]
Abstract
The amyloid precursor protein (APP), one key player in Alzheimer's disease (AD), is extensively processed by different proteases. This leads to the generation of diverging fragments including the amyloid β (Aβ) peptide, which accumulates in brains of AD patients. Subcellular trafficking of APP is an important aspect for its proteolytic conversion, since the various secretases which cleave APP are located in different cellular compartments. As a consequence, altered subcellular targeting of APP is thought to directly affect the degree to which Aβ is generated. The mechanisms underlying intracellular APP transport are critical to understand AD pathogenesis and can serve as a target for future pharmacological interventions. In the recent years, a number of APP interacting proteins were identified which are implicated in sorting of APP, thereby influencing APP processing at different angles of the secretory or endocytic pathway. This review provides an update on the proteolytic processing of APP and the interplay of the transmembrane proteins low-density lipoprotein receptor-related protein 1, sortilin-receptor with A-type repeats, SorCS1c, sortilin, and calsyntenin. We discuss the specific interactions with APP, the capacity to modulate the intracellular itinerary and the proteolytic conversion of APP, a possible involvement in the clearance of Aβ, and the implications of these transmembrane proteins in AD and other neurodegenerative diseases.
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38
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Jeong S. Molecular and Cellular Basis of Neurodegeneration in Alzheimer's Disease. Mol Cells 2017; 40:613-620. [PMID: 28927263 PMCID: PMC5638769 DOI: 10.14348/molcells.2017.0096] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/06/2017] [Accepted: 08/16/2017] [Indexed: 12/25/2022] Open
Abstract
The most common form of senile dementia is Alzheimer's disease (AD), which is characterized by the extracellular deposition of amyloid β-peptide (Aβ) plaques and the intracellular formation of neurofibrillary tangles (NFTs) in the cerebral cortex. Tau abnormalities are commonly observed in many neurodegenerative diseases including AD, Parkinson's disease, and Pick's disease. Interestingly, tau-mediated formation of NFTs in AD brains shows better correlation with cognitive impairment than Aβ plaque accumulation; pathological tau alone is sufficient to elicit frontotemporal dementia, but it does not cause AD. A growing amount of evidence suggests that soluble Aβ oligomers in concert with hyperphosphorylated tau (pTau) serve as the major pathogenic drivers of neurodegeneration in AD. Increased Aβ oligomers trigger neuronal dysfunction and network alternations in learning and memory circuitry prior to clinical onset of AD, leading to cognitive decline. Furthermore, accumulated damage to mitochondria in the course of aging, which is the best-known nongenetic risk factor for AD, may collaborate with soluble Aβ and pTau to induce synapse loss and cognitive impairment in AD. In this review, I summarize and discuss the current knowledge of the molecular and cellular biology of AD and also the mechanisms that underlie Aβ-mediated neurodegeneration.
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Affiliation(s)
- Sangyun Jeong
- Department of Molecular Biology, Chonbuk National University, Jeonju 54896,
Korea
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39
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Wang X, Zhou X, Li G, Zhang Y, Wu Y, Song W. Modifications and Trafficking of APP in the Pathogenesis of Alzheimer's Disease. Front Mol Neurosci 2017; 10:294. [PMID: 28966576 PMCID: PMC5605621 DOI: 10.3389/fnmol.2017.00294] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/31/2017] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease (AD), the most common neurodegenerative disorder, is the leading cause of dementia. Neuritic plaque, one of the major characteristics of AD neuropathology, mainly consists of amyloid β (Aβ) protein. Aβ is derived from amyloid precursor protein (APP) by sequential cleavages of β- and γ-secretase. Although APP upregulation can promote AD pathogenesis by facilitating Aβ production, growing evidence indicates that aberrant post-translational modifications and trafficking of APP play a pivotal role in AD pathogenesis by dysregulating APP processing and Aβ generation. In this report, we reviewed the current knowledge of APP modifications and trafficking as well as their role in APP processing. More importantly, we discussed the effect of aberrant APP modifications and trafficking on Aβ generation and the underlying mechanisms, which may provide novel strategies for drug development in AD.
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Affiliation(s)
- Xin Wang
- Department of Psychiatry, Jining Medical UniversityJining, China.,Shandong Key Laboratory of Behavioral Medicine, Jining Medical UniversityJining, China
| | - Xuan Zhou
- Department of Psychiatry, Jining Medical UniversityJining, China.,Shandong Key Laboratory of Behavioral Medicine, Jining Medical UniversityJining, China
| | - Gongying Li
- Department of Psychiatry, Jining Medical UniversityJining, China.,Shandong Key Laboratory of Behavioral Medicine, Jining Medical UniversityJining, China.,Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical UniversityJining, China
| | - Yun Zhang
- Townsend Family Laboratories, Department of Psychiatry, The University of British ColumbiaVancouver, BC, Canada
| | - Yili Wu
- Department of Psychiatry, Jining Medical UniversityJining, China.,Shandong Key Laboratory of Behavioral Medicine, Jining Medical UniversityJining, China.,Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical UniversityJining, China.,Townsend Family Laboratories, Department of Psychiatry, The University of British ColumbiaVancouver, BC, Canada
| | - Weihong Song
- Townsend Family Laboratories, Department of Psychiatry, The University of British ColumbiaVancouver, BC, Canada
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40
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Nigam SM, Xu S, Kritikou JS, Marosi K, Brodin L, Mattson MP. Exercise and BDNF reduce Aβ production by enhancing α-secretase processing of APP. J Neurochem 2017; 142:286-296. [PMID: 28382744 DOI: 10.1111/jnc.14034] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/18/2017] [Accepted: 03/20/2017] [Indexed: 12/23/2022]
Abstract
Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by aggregation of toxic forms of amyloid β peptide (Aβ). Treatment strategies have largely been focused on inhibiting the enzymes (β- and γ-secretases) that liberate Aβ from the amyloid precursor protein (APP). While evidence suggests that individuals who exercise regularly are at reduced risk for AD and studies of animal models demonstrate that running can ameliorate brain Aβ pathology and associated cognitive deficits, the underlying mechanisms are unknown. However, considerable evidence suggests that brain-derived neurotrophic factor (BDNF) mediates beneficial effects of exercise on neuroplasticity and cellular stress resistance. Here, we tested the hypothesis that BDNF promotes non-amyloidogenic APP processing. Using a transgenic mouse model of Alzheimer's disease and cultured human neural cells, we demonstrate that exercise and BDNF reduce production of toxic Aβ peptides through a mechanism involving enhanced α-secretase processing of APP. This anti-amyloidogenic APP processing involves subcellular redistribution of α-secretase and an increase in intracellular neuroprotective APP peptides capable of binding and inhibiting β-secretase. Moreover, our results suggest that BDNF's ability to promote neurite outgrowth is primarily exerted through pathways other than APP processing. Exercise and other factors that enhance BDNF signaling may therefore have both therapeutic and prophylactic value in the battle against AD. Read the Editorial Highlight for this article on page 191.
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Affiliation(s)
- Saket M Nigam
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, Maryland, USA
| | - Shaohua Xu
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Joanna S Kritikou
- Department of Microbiology Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Krisztina Marosi
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, Maryland, USA
| | - Lennart Brodin
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, Maryland, USA
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41
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Chiarini A, Armato U, Liu D, Dal Prà I. Calcium-Sensing Receptor Antagonist NPS 2143 Restores Amyloid Precursor Protein Physiological Non-Amyloidogenic Processing in Aβ-Exposed Adult Human Astrocytes. Sci Rep 2017; 7:1277. [PMID: 28455519 PMCID: PMC5430644 DOI: 10.1038/s41598-017-01215-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 03/27/2017] [Indexed: 12/11/2022] Open
Abstract
Physiological non-amyloidogenic processing (NAP) of amyloid precursor holoprotein (hAPP) by α-secretases (e.g., ADAM10) extracellularly sheds neurotrophic/neuroprotective soluble (s)APPα and precludes amyloid-β peptides (Aβs) production via β-secretase amyloidogenic processing (AP). Evidence exists that Aβs interact with calcium-sensing receptors (CaSRs) in human astrocytes and neurons, driving the overrelease of toxic Aβ42/Aβ42-os (oligomers), which is completely blocked by CaSR antagonist (calcilytic) NPS 2143. Here, we investigated the mechanisms underlying NPS 2143 beneficial effects in human astrocytes. Moreover, because Alzheimer's disease (AD) involves neuroinflammation, we examined whether NPS 2143 remained beneficial when both fibrillary (f)Aβ25-35 and a microglial cytokine mixture (CMT) were present. Thus, hAPP NAP prevailed over AP in untreated astrocytes, which extracellularly shed all synthesized sAPPα while secreting basal Aβ40/42 amounts. Conversely, fAβ25-35 alone dramatically reduced sAPPα extracellular shedding while driving Aβ42/Aβ42-os oversecretion that CMT accelerated but not increased, despite a concurring hAPP overexpression. NPS 2143 promoted hAPP and ADAM10 translocation to the plasma membrane, thereby restoring sAPPα extracellular shedding and fully suppressing any Aβ42/Aβ42-os oversecretion, but left hAPP expression unaffected. Therefore, as anti-AD therapeutics calcilytics support neuronal viability by safeguarding astrocytes neurotrophic/neuroprotective sAPPα shedding, suppressing neurons and astrocytes Aβ42/Aβ42-os build-up/secretion, and remaining effective even under AD-typical neuroinflammatory conditions.
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Affiliation(s)
- Anna Chiarini
- Human Histology & Embryology Unit, Medical School, University of Verona, Verona, Venetia, Italy.
| | - Ubaldo Armato
- Human Histology & Embryology Unit, Medical School, University of Verona, Verona, Venetia, Italy
| | - Daisong Liu
- The Third Xiangya Hospital of Central South University, Department of Plastic Surgery, Changsha, Hunan, China
| | - Ilaria Dal Prà
- Human Histology & Embryology Unit, Medical School, University of Verona, Verona, Venetia, Italy.
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42
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Toh WH, Tan JZA, Zulkefli KL, Houghton FJ, Gleeson PA. Amyloid precursor protein traffics from the Golgi directly to early endosomes in an Arl5b- and AP4-dependent pathway. Traffic 2017; 18:159-175. [DOI: 10.1111/tra.12465] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 12/13/2016] [Accepted: 12/13/2016] [Indexed: 01/14/2023]
Affiliation(s)
- Wei Hong Toh
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute; University of Melbourne; Melbourne Australia
| | - Jing Zhi A. Tan
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute; University of Melbourne; Melbourne Australia
| | - Khalisah L. Zulkefli
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute; University of Melbourne; Melbourne Australia
| | - Fiona J. Houghton
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute; University of Melbourne; Melbourne Australia
| | - Paul A. Gleeson
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute; University of Melbourne; Melbourne Australia
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43
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Gleevec shifts APP processing from a β-cleavage to a nonamyloidogenic cleavage. Proc Natl Acad Sci U S A 2017; 114:1389-1394. [PMID: 28115709 DOI: 10.1073/pnas.1620963114] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Neurotoxic amyloid-β peptides (Aβ) are major drivers of Alzheimer's disease (AD) and are formed by sequential cleavage of the amyloid precursor protein (APP) by β-secretase (BACE) and γ-secretase. Our previous study showed that the anticancer drug Gleevec lowers Aβ levels through indirect inhibition of γ-secretase activity. Here we report that Gleevec also achieves its Aβ-lowering effects through an additional cellular mechanism. It renders APP less susceptible to proteolysis by BACE without inhibiting BACE enzymatic activity or the processing of other BACE substrates. This effect closely mimics the phenotype of APP A673T, a recently discovered mutation that protects carriers against AD and age-related cognitive decline. In addition, Gleevec induces formation of a specific set of APP C-terminal fragments, also observed in cells expressing the APP protective mutation and in cells exposed to a conventional BACE inhibitor. These Gleevec phenotypes require an intracellular acidic pH and are independent of tyrosine kinase inhibition, given that a related compound lacking tyrosine kinase inhibitory activity, DV2-103, exerts similar effects on APP metabolism. In addition, DV2-103 accumulates at high concentrations in the rodent brain, where it rapidly lowers Aβ levels. This study suggests that long-term treatment with drugs that indirectly modulate BACE processing of APP but spare other BACE substrates and achieve therapeutic concentrations in the brain might be effective in preventing or delaying the onset of AD and could be safer than nonselective BACE inhibitor drugs.
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44
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Blonz ER. Alzheimer's Disease as the Product of a Progressive Energy Deficiency Syndrome in the Central Nervous System: The Neuroenergetic Hypothesis. J Alzheimers Dis 2017; 60:1223-1229. [PMID: 28946565 PMCID: PMC5676979 DOI: 10.3233/jad-170549] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2017] [Indexed: 12/25/2022]
Abstract
The decreased availability of metabolizable energy resources in the central nervous system is hypothesized to be a key factor in the pathogenesis of Alzheimer's disease. More specifically, the age-related decline in the ability of glucose to cross the blood-brain barrier creates a metabolic stress that shifts the normal, benign processing of amyloid-β protein precursor toward pathways associated with the production of amyloid-β plaques and tau-containing neurofibrillary tangles that are characteristic of the disease. The neuroenergetic hypothesis provides insight into the etiology of Alzheimer's disease and illuminates new approaches for diagnosis, monitoring, and treatment.
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Affiliation(s)
- Edward R. Blonz
- Department of Clinical Pharmacy, University of California, San Francisco, CA, USA
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45
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Tam JHK, Cobb MR, Seah C, Pasternak SH. Tyrosine Binding Protein Sites Regulate the Intracellular Trafficking and Processing of Amyloid Precursor Protein through a Novel Lysosome-Directed Pathway. PLoS One 2016; 11:e0161445. [PMID: 27776132 PMCID: PMC5077117 DOI: 10.1371/journal.pone.0161445] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 08/07/2016] [Indexed: 01/18/2023] Open
Abstract
The amyloid hypothesis posits that the production of β-amyloid (Aβ) aggregates leads to neurodegeneration and cognitive decline associated with AD. Aβ is produced by sequential cleavage of the amyloid precursor protein (APP) by β- and γ-secretase. While nascent APP is well known to transit to the endosomal/ lysosomal system via the cell surface, we have recently shown that APP can also traffic to lysosomes intracellularly via its interaction with AP-3. Because AP-3 interacts with cargo protein via interaction with tyrosine motifs, we mutated the three tyrosines motif in the cytoplasmic tail of APP. Here, we show that the YTSI motif interacts with AP-3, and phosphorylation of the serine in this motif disrupts the interaction and decreases APP trafficking to lysosomes. Furthermore, we show that phosphorylation at this motif can decrease the production of neurotoxic Aβ 42. This demonstrates that reducing APP trafficking to lysosomes may be a strategy to reduce Aβ 42 in Alzheimer’s disease.
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Affiliation(s)
- Joshua H. K. Tam
- J. Allyn Taylor Centre for Cell Biology, Molecular Medicine Research Group, Robarts Research Institute, Western University, London Ontario, Canada, N6A 5B7
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada, N6A 5B7
| | - M. Rebecca Cobb
- Program in Neuroscience, Western University, London, Ontario, Canada, N6A 5B7
| | - Claudia Seah
- J. Allyn Taylor Centre for Cell Biology, Molecular Medicine Research Group, Robarts Research Institute, Western University, London Ontario, Canada, N6A 5B7
| | - Stephen H. Pasternak
- J. Allyn Taylor Centre for Cell Biology, Molecular Medicine Research Group, Robarts Research Institute, Western University, London Ontario, Canada, N6A 5B7
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada, N6A 5B7
- Program in Neuroscience, Western University, London, Ontario, Canada, N6A 5B7
- Department of Clinical Neurological Sciences, The Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada, N6A 5B7
- * E-mail:
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46
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Hartl D, Gu W, Mayhaus M, Pichler S, Schöpe J, Wagenpfeil S, Riemenschneider M. Amyloid-β Protein Precursor Cleavage Products in Postmortem Ventricular Cerebrospinal Fluid of Alzheimer's Disease Patients. J Alzheimers Dis 2016; 47:365-72. [PMID: 26401559 DOI: 10.3233/jad-150191] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Accumulation and aggregation of amyloid-β (Aβ) are considered etiologic processes in Alzheimer's disease (AD). However, the roles of other AβPP cleavage products in disease pathology remain elusive. Here, we measured levels of the major secreted AβPP processing products sAβPPα, sAβPPβ, and Aβ species in postmortem collected ventricular CSF of 196 AD patients and 74 controls. In AD we identified Aβ₄₂ to decrease continuously with progressing Braak stages, whereas Aβ₄₀ was upregulated in early stages of the disease (Braak stage 4) and down-regulated with progressing pathology. Interestingly, both sAβPPα and sAβPPβ were upregulated in AD as compared to controls (sAβPPα, p = 0.02; sAβPPβ, p = 0.01). Moreover, we observed a strong positive correlation of both alternative AβPP processing products, sAβPPα and sAβPPβ (r²= 0.781; p < 0.0001). Together, our results argue for generally enhanced AβPP processing in AD patients and emphasize the necessity of analyzing the roles of all AβPP processing products in AD pathology.
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Affiliation(s)
- Daniela Hartl
- Department of Psychiatry and Psychotherapy, Saarland University Hospital, Saarland University, Homburg, Germany.,Institute for Human Genetics and Medical Genetics, Charité University Medicine, Berlin, Germany
| | - Wei Gu
- Department of Psychiatry and Psychotherapy, Saarland University Hospital, Saarland University, Homburg, Germany.,Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Manuel Mayhaus
- Department of Psychiatry and Psychotherapy, Saarland University Hospital, Saarland University, Homburg, Germany
| | - Sabrina Pichler
- Department of Psychiatry and Psychotherapy, Saarland University Hospital, Saarland University, Homburg, Germany
| | - Jakob Schöpe
- Institute for Biometrics, Epidemiology and Medical Informatics, Saarland University Hospital, Saarland University, Homburg, Germany
| | - Stefan Wagenpfeil
- Institute for Biometrics, Epidemiology and Medical Informatics, Saarland University Hospital, Saarland University, Homburg, Germany
| | - Matthias Riemenschneider
- Department of Psychiatry and Psychotherapy, Saarland University Hospital, Saarland University, Homburg, Germany
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47
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Welt T, Kulic L, Hoey SE, McAfoose J, Späni C, Chadha AS, Fisher A, Nitsch RM. Acute Effects of Muscarinic M1 Receptor Modulation on AβPP Metabolism and Amyloid-β Levels in vivo: A Microdialysis Study. J Alzheimers Dis 2016; 46:971-82. [PMID: 25881909 DOI: 10.3233/jad-150152] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Indirect modulation of cholinergic activity by cholinesterase inhibition is currently a widely established symptomatic treatment for Alzheimer's disease (AD). Selective activation of certain muscarinic receptor subtypes has emerged as an alternative cholinergic-based amyloid-lowering strategy for AD, as selective muscarinic M1 receptor agonists can reduce amyloid-β (Aβ) production by shifting endoproteolytic amyloid-β protein precursor (AβPP) processing toward non-amyloidogenic pathways. In this study, we addressed the hypothesis that acute stimulation of muscarinic M1 receptors can inhibit Aβ production in awake and freely moving AβPP transgenic mice. By combining intracerebral microdialysis with retrodialysis, we determined hippocampal Aβ concentrations during simultaneous pharmacological modulation of brain M1 receptor function. Infusion with a M1 receptor agonist AF102B resulted in a rapid reduction of interstitial fluid (ISF) Aβ levels while treatment with the M1 antagonist dicyclomine increased ISF Aβ levels reaching significance within 120 minutes of treatment. The reduction in Aβ levels was associated with PKCα and ERK activation resulting in increased levels of the α-secretase ADAM17 and a shift in AβPP processing toward the non-amyloidogenic processing pathway. In contrast, treatment with the M1 receptor antagonist dicyclomine caused a decrease in levels of phosphorylated ERK that was independent of PKCα, and led to an elevation of β-secretase levels associated with increased amyloidogenic AβPP processing. The results of this study demonstrate rapid effects of in vivo M1 receptor modulation on the ISF pool of Aβ and suggest that intracerebral microdialysis with retrodialysis is a useful technical approach for monitoring acute treatment effects of muscarinic receptor modulators on AβPP/Aβ metabolism.
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Affiliation(s)
- Tobias Welt
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland
| | - Luka Kulic
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland.,Center for Integrative Human Physiology (ZIHP), University of Zurich, Switzerland
| | - Sarah E Hoey
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland
| | - Jordan McAfoose
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland
| | - Claudia Späni
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland
| | | | - Abraham Fisher
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Roger M Nitsch
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland
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48
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Lost region in amyloid precursor protein (APP) through TALEN-mediated genome editing alters mitochondrial morphology. Sci Rep 2016; 6:22244. [PMID: 26924205 PMCID: PMC4770288 DOI: 10.1038/srep22244] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 02/10/2016] [Indexed: 12/25/2022] Open
Abstract
Alzheimer’s disease (AD) is characterized by amyloid-β (Aβ) deposition in the brain. Aβ plaques are produced through sequential β/γ cleavage of amyloid precursor protein (APP), of which there are three main APP isoforms: APP695, APP751 and APP770. KPI-APPs (APP751 and APP770) are known to be elevated in AD, but the reason remains unclear. Transcription activator-like (TAL) effector nucleases (TALENs) induce mutations with high efficiency at specific genomic loci, and it is thus possible to knock out specific regions using TALENs. In this study, we designed and expressed TALENs specific for the C-terminus of APP in HeLa cells, in which KPI-APPs are predominantly expressed. The KPI-APP mutants lack a 12-aa region that encompasses a 5-aa trans-membrane (TM) region and 7-aa juxta-membrane (JM) region. The mutated KPI-APPs exhibited decreased mitochondrial localization. In addition, mitochondrial morphology was altered, resulting in an increase in spherical mitochondria in the mutant cells through the disruption of the balance between fission and fusion. Mitochondrial dysfunction, including decreased ATP levels, disrupted mitochondrial membrane potential, increased ROS generation and impaired mitochondrial dehydrogenase activity, was also found. These results suggest that specific regions of KPI-APPs are important for mitochondrial localization and function.
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49
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MacLeod R, Hillert EK, Cameron RT, Baillie GS. The role and therapeutic targeting of α-, β- and γ-secretase in Alzheimer's disease. Future Sci OA 2015; 1:FSO11. [PMID: 28031886 PMCID: PMC5137966 DOI: 10.4155/fso.15.9] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the elderly and its prevalence is set to increase rapidly in coming decades. However, there are as yet no available drugs that can halt or even stabilize disease progression. One of the main pathological features of AD is the presence in the brain of senile plaques mainly composed of aggregated β amyloid (Aβ), a derivative of the longer amyloid precursor protein (APP). The amyloid hypothesis proposes that the accumulation of Aβ within neural tissue is the initial event that triggers the disease. Here we review research efforts that have attempted to inhibit the generation of the Aβ peptide through modulation of the activity of the proteolytic secretases that act on APP and discuss whether this is a viable therapeutic strategy for treating AD.
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Affiliation(s)
- Ruth MacLeod
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Ellin-Kristina Hillert
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Ryan T Cameron
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - George S Baillie
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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50
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Qian M, Shen X, Wang H. The Distinct Role of ADAM17 in APP Proteolysis and Microglial Activation Related to Alzheimer's Disease. Cell Mol Neurobiol 2015; 36:471-82. [PMID: 26119306 DOI: 10.1007/s10571-015-0232-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/23/2015] [Indexed: 01/03/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease with the symptom of cognitive impairment. The deposition of amyloid β (Aβ) peptide is believed to be the primary cause to neuronal dystrophy and eventually dementia. Aβ is the proteolytic product from its precursor amyloid precursor protein (APP) by β- and γ- secretase. An optional cleavage by α-secretase happens inside the Aβ domain. ADAM17 is supposed to be the regulated α-secretase of APP. Enhanced activity of ADAM17 leads to the increasing secretion of neuroprotective soluble APP α fragment and reduction of Aβ generation, which may be benefit to the disease. ADAM17 is then considered the potential therapeutic target for AD. Microglia activation and neuroinflammation is another important event in AD pathogenesis. Interestingly, ADAM17 also participates in the cleavage of many other membrane-bound proteins, especially some inflammatory factors related to microglia activation. The facilitating role of ADAM17 in inflammation and further neuronal damage has also been illustrated. In results, the activation of ADAM17 as the solution to AD may be a tricky task. The comprehensive consideration and evaluation has to be carried out carefully before the final treatment. In the present review, the distinct role of ADAM17 in AD-related APP shedding and neuroinflammatory microglial activation will be carefully discussed.
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Affiliation(s)
- Meng Qian
- Key Lab of Inflammation and Immunoregulation, School of Medicine, Hangzhou Normal University, Xuelin Street 16, Hangzhou, 310036, China
| | - Xiaoqiang Shen
- Key Lab of Inflammation and Immunoregulation, School of Medicine, Hangzhou Normal University, Xuelin Street 16, Hangzhou, 310036, China
| | - Huanhuan Wang
- Key Lab of Inflammation and Immunoregulation, School of Medicine, Hangzhou Normal University, Xuelin Street 16, Hangzhou, 310036, China.
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