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Zhou H, Zhai J, Gong H, Fang R, Zhao Y, Luo W. Novel pyrrolidine-alkylamino-substituted dicyanoisophorone derivatives as near-infrared fluorescence probe for imaging β-amyloid in vitro and in vivo. Anal Chim Acta 2024; 1317:342894. [PMID: 39030021 DOI: 10.1016/j.aca.2024.342894] [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: 02/01/2024] [Revised: 06/03/2024] [Accepted: 06/20/2024] [Indexed: 07/21/2024]
Abstract
BACKGROUND The formation of amyloid-β (Aβ) plaques is one of the key neuropathological hallmarks of Alzheimer's disease (AD). Near-infrared (NIR) probes show great potential for imaging of Aβ plaques in vivo and in vitro. Dicyanoisophorone (DCIP) based Aβ probes have attracted considerable attention due to their exceptional properties. However, DCIP probes still has some drawbacks, such as short emission wavelength (<650 nm) and low fluorescence intensity after binding to Aβ. It is clear that further modification is needed to improve their luminescence efficiency and sensitivity. RESULTS We designed and synthesize four novel pyrrolidine-alkylamino-substituted DCIP derivatives (6a-d) as imaging agents for β-amyloid (Aβ) aggregates. Compound 6c responds better to Aβ aggregates than the other three compounds (6a, 6b and 6d) and its precursor DCIP. The calculated detection limit is to be as low as 0.23 μM. Compound 6c shows no cytotoxicity in the tested concentration for SH-SY5Y and HL-7702 cells. Additionally, compound 6c is successfully applied to monitor Aβ aggregates in live SH-SY5Y cells and APP/PS1 transgenic mice. The retention time in the transgenic mice brain is much longer than that of age-matched wild-type mice. SIGNIFICANCE The results indicates that compound 6c had an excellent ability to penetrate the blood-brain barrier and it could effectively distinguish APP/PS1 transgenic mice and wide-type mice. This represents its promising applications for Aβ detection in basic and biomedical research.
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Affiliation(s)
- Hui Zhou
- Henan Key Laboratory of Natural Medicine Innovation and Transformation, Henan University, Kaifeng, 475004, China; Pharmaceutical Engineering Department, Henan Technical Institute, Kaifeng, 475004, China
| | - Jihang Zhai
- Henan Key Laboratory of Natural Medicine Innovation and Transformation, Henan University, Kaifeng, 475004, China
| | - Huiyuan Gong
- Henan Key Laboratory of Natural Medicine Innovation and Transformation, Henan University, Kaifeng, 475004, China
| | - Ru Fang
- Henan Key Laboratory of Natural Medicine Innovation and Transformation, Henan University, Kaifeng, 475004, China
| | - Yongmei Zhao
- Pharmaceutical Engineering Department, Henan Technical Institute, Kaifeng, 475004, China.
| | - Wen Luo
- Henan Key Laboratory of Natural Medicine Innovation and Transformation, Henan University, Kaifeng, 475004, China; State Key Laboratory of Antiviral Drugs, Henan University, Kaifeng 475004, China.
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2
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Zoltowska KM, Das U, Lismont S, Enzlein T, Maesako M, Houser MCQ, Franco ML, Özcan B, Gomes Moreira D, Karachentsev D, Becker A, Hopf C, Vilar M, Berezovska O, Mobley W, Chávez-Gutiérrez L. Alzheimer's disease linked Aβ42 exerts product feedback inhibition on γ-secretase impairing downstream cell signaling. eLife 2024; 12:RP90690. [PMID: 39027984 PMCID: PMC11259434 DOI: 10.7554/elife.90690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024] Open
Abstract
Amyloid β (Aβ) peptides accumulating in the brain are proposed to trigger Alzheimer's disease (AD). However, molecular cascades underlying their toxicity are poorly defined. Here, we explored a novel hypothesis for Aβ42 toxicity that arises from its proven affinity for γ-secretases. We hypothesized that the reported increases in Aβ42, particularly in the endolysosomal compartment, promote the establishment of a product feedback inhibitory mechanism on γ-secretases, and thereby impair downstream signaling events. We conducted kinetic analyses of γ-secretase activity in cell-free systems in the presence of Aβ, as well as cell-based and ex vivo assays in neuronal cell lines, neurons, and brain synaptosomes to assess the impact of Aβ on γ-secretases. We show that human Aβ42 peptides, but neither murine Aβ42 nor human Aβ17-42 (p3), inhibit γ-secretases and trigger accumulation of unprocessed substrates in neurons, including C-terminal fragments (CTFs) of APP, p75, and pan-cadherin. Moreover, Aβ42 treatment dysregulated cellular homeostasis, as shown by the induction of p75-dependent neuronal death in two distinct cellular systems. Our findings raise the possibility that pathological elevations in Aβ42 contribute to cellular toxicity via the γ-secretase inhibition, and provide a novel conceptual framework to address Aβ toxicity in the context of γ-secretase-dependent homeostatic signaling.
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Affiliation(s)
| | - Utpal Das
- Department of Neurosciences, University of California San DiegoLa JollaUnited States
| | - Sam Lismont
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
| | - Thomas Enzlein
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied SciencesMannheimGermany
| | - Masato Maesako
- Department of Neurology, Massachusetts General Hospital/Harvard Medical SchoolCharlestownUnited States
| | - Mei CQ Houser
- Department of Neurology, Massachusetts General Hospital/Harvard Medical SchoolCharlestownUnited States
| | - Maria Luisa Franco
- Molecular Basis of Neurodegeneration Unit, Instituto de Biomedicina de ValenciaValenciaSpain
| | - Burcu Özcan
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
| | | | - Dmitry Karachentsev
- Department of Neurosciences, University of California San DiegoLa JollaUnited States
| | - Ann Becker
- Department of Neurosciences, University of California San DiegoLa JollaUnited States
| | - Carsten Hopf
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied SciencesMannheimGermany
- Medical Faculty, Heidelberg UniversityHeidelbergGermany
- Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg UniversityHeidelbergGermany
| | - Marçal Vilar
- Molecular Basis of Neurodegeneration Unit, Instituto de Biomedicina de ValenciaValenciaSpain
| | - Oksana Berezovska
- Department of Neurology, Massachusetts General Hospital/Harvard Medical SchoolCharlestownUnited States
| | - William Mobley
- Department of Neurosciences, University of California San DiegoLa JollaUnited States
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3
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Volloch V, Rits-Volloch S. ACH2.0/E, the Consolidated Theory of Conventional and Unconventional Alzheimer's Disease: Origins, Progression, and Therapeutic Strategies. Int J Mol Sci 2024; 25:6036. [PMID: 38892224 PMCID: PMC11172602 DOI: 10.3390/ijms25116036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/19/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024] Open
Abstract
The centrality of amyloid-beta (Aβ) is an indisputable tenet of Alzheimer's disease (AD). It was initially indicated by the detection (1991) of a mutation within Aβ protein precursor (AβPP) segregating with the disease, which served as a basis for the long-standing Amyloid Cascade Hypothesis (ACH) theory of AD. In the intervening three decades, this notion was affirmed and substantiated by the discovery of numerous AD-causing and AD-protective mutations with all, without an exception, affecting the structure, production, and intraneuronal degradation of Aβ. The ACH postulated that the disease is caused and driven by extracellular Aβ. When it became clear that this is not the case, and the ACH was largely discredited, a new theory of AD, dubbed ACH2.0 to re-emphasize the centrality of Aβ, was formulated. In the ACH2.0, AD is caused by physiologically accumulated intraneuronal Aβ (iAβ) derived from AβPP. Upon reaching the critical threshold, it triggers activation of the autonomous AβPP-independent iAβ generation pathway; its output is retained intraneuronally and drives the AD pathology. The bridge between iAβ derived from AβPP and that generated independently of AβPP is the neuronal integrated stress response (ISR) elicited by the former. The ISR severely suppresses cellular protein synthesis; concurrently, it activates the production of a small subset of proteins, which apparently includes components necessary for operation of the AβPP-independent iAβ generation pathway that are absent under regular circumstances. The above sequence of events defines "conventional" AD, which is both caused and driven by differentially derived iAβ. Since the ISR can be elicited by a multitude of stressors, the logic of the ACH2.0 mandates that another class of AD, referred to as "unconventional", has to occur. Unconventional AD is defined as a disease where a stressor distinct from AβPP-derived iAβ elicits the neuronal ISR. Thus, the essence of both, conventional and unconventional, forms of AD is one and the same, namely autonomous, self-sustainable, AβPP-independent production of iAβ. What distinguishes them is the manner of activation of this pathway, i.e., the mode of causation of the disease. In unconventional AD, processes occurring at locations as distant from and seemingly as unrelated to the brain as, say, the knee can potentially trigger the disease. The present study asserts that these processes include traumatic brain injury (TBI), chronic traumatic encephalopathy, viral and bacterial infections, and a wide array of inflammatory conditions. It considers the pathways which are common to all these occurrences and culminate in the elicitation of the neuronal ISR, analyzes the dynamics of conventional versus unconventional AD, shows how the former can morph into the latter, explains how a single TBI can hasten the occurrence of AD and why it takes multiple TBIs to trigger the disease, and proposes the appropriate therapeutic strategies. It posits that yet another class of unconventional AD may occur where the autonomous AβPP-independent iAβ production pathway is initiated by an ISR-unrelated activator, and consolidates the above notions in a theory of AD, designated ACH2.0/E (for expanded ACH2.0), which incorporates the ACH2.0 as its special case and retains the centrality of iAβ produced independently of AβPP as the driving agent of the disease.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Sophia Rits-Volloch
- Division of Molecular Medicine, Children’s Hospital, Boston, MA 02115, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
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4
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Matveyenka M, Zhaliazka K, Kurouski D. Macrophages and Natural Killers Degrade α-Synuclein Aggregates. Mol Pharm 2024; 21:2565-2576. [PMID: 38635186 PMCID: PMC11080468 DOI: 10.1021/acs.molpharmaceut.4c00160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 04/19/2024]
Abstract
Amyloid oligomers and fibrils are protein aggregates that exert a high cell toxicity. Efficient degradation of these protein aggregates can minimize the spread and progression of neurodegeneration. In this study, we investigate the properties of natural killer (NK) cells and macrophages in the degradation of α-synuclein (α-Syn) aggregates grown in a lipid-free environment and in the presence of phosphatidylserine and cholesterol (PS/Cho), which are lipids that are directly associated with the onset and progression of Parkinson's disease. We found that both types of α-Syn aggregates were endocytosed by neurons, which caused strong damage to cell endosomes. Our results also indicated that PS/Cho vesicles drastically increased the toxicity of α-Syn fibrils formed in their presence compared to the toxicity of α-Syn aggregates grown in a lipid-free environment. Both NK cells and macrophages were able to degrade α-Syn and α-Syn/Cho monomers, oligomers, and fibrils. Quantitative analysis of protein degradation showed that macrophages demonstrated substantially more efficient internalization and degradation of amyloid aggregates in comparison to NK cells. We also found that amyloid aggregates induced the proliferation of macrophages and NK cells and significantly changed the expression of their cytokines and chemokines.
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Affiliation(s)
- Mikhail Matveyenka
- Department
of Biochemistry and Biophysics, Texas A&M
University, College
Station, Texas 77843, United States
| | - Kiryl Zhaliazka
- Department
of Biochemistry and Biophysics, Texas A&M
University, College
Station, Texas 77843, United States
| | - Dmitry Kurouski
- Department
of Biochemistry and Biophysics, Texas A&M
University, College
Station, Texas 77843, United States
- Department
of Biomedical Engineering, Texas A&M
University, College Station, Texas 77843, United States
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5
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Zhao Q, Ma L, Chen S, Huang L, She G, Sun Y, Shi W, Mu L. Tracking mitochondrial Cu(I) fluctuations through a ratiometric fluorescent probe in AD model cells: Towards understanding how AβOs induce mitochondrial Cu(I) dyshomeostasis. Talanta 2024; 271:125716. [PMID: 38301373 DOI: 10.1016/j.talanta.2024.125716] [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: 12/11/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 02/03/2024]
Abstract
Mitochondrial copper signaling pathway plays a role in Alzheimer's disease (AD), especially in relevant Amyloid-β oligomers (AβOs) neurotoxicity and mitochondrial dysfunction. Clarifying the relationship between mitochondrial copper homeostasis and both of mitochondrial dysfunction and AβOs neurotoxicity is important for understanding AD pathogenesis. Herein, we designed and synthesized a ratiometric fluorescent probe CHC-NS4 for Cu(I). CHC-NS4 possesses excellent ratiometric response, high selectivity to Cu(I) and specific ability to target mitochondria. Under mitochondrial dysfunction induced by oligomycin, mitochondrial Cu(I) levels gradually increased, which may be related to inhibition of ATP7A-mediated Cu(I) exportation and/or high expression of COX. On this basis, CHC-NS4 was further utilized to visualize the fluctuations of mitochondrial Cu(I) levels during progression of AD model cells induced by AβOs. It was found that mitochondrial Cu(I) levels were gradually elevated during the AD progression, which depended on not only AβOs concentration but also incubation time. Moreover, endocytosis maybe served as a prime pathway mode for mitochondrial Cu(I) dyshomeostasis induced by AβOs during AD progression. These results have provided a novel inspiration into mitochondrial copper biology in AD pathogenesis.
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Affiliation(s)
- Qiaowen Zhao
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liyi Ma
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Siwei Chen
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Lushan Huang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangwei She
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yongan Sun
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Wensheng Shi
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Lixuan Mu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
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6
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Zoltowska KM, Das U, Lismont S, Enzlein T, Maesako M, Houser MCQ, Franco ML, Özcan B, Moreira DG, Karachentsev D, Becker A, Hopf C, Vilar M, Berezovska O, Mobley W, Chávez-Gutiérrez L. Alzheimer's disease linked Aβ42 exerts product feedback inhibition on γ-secretase impairing downstream cell signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.02.551596. [PMID: 37577527 PMCID: PMC10418207 DOI: 10.1101/2023.08.02.551596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Amyloid β (Aβ) peptides accumulating in the brain are proposed to trigger Alzheimer's disease (AD). However, molecular cascades underlying their toxicity are poorly defined. Here, we explored a novel hypothesis for Aβ42 toxicity that arises from its proven affinity for γ-secretases. We hypothesized that the reported increases in Aβ42, particularly in the endolysosomal compartment, promote the establishment of a product feedback inhibitory mechanism on γ-secretases, and thereby impair downstream signaling events. We show that human Aβ42 peptides, but neither murine Aβ42 nor human Aβ17-42 (p3), inhibit γ-secretases and trigger accumulation of unprocessed substrates in neurons, including C-terminal fragments (CTFs) of APP, p75 and pan-cadherin. Moreover, Aβ42 treatment dysregulated cellular -homeostasis, as shown by the induction of p75-dependent neuronal death in two distinct cellular systems. Our findings raise the possibility that pathological elevations in Aβ42 contribute to cellular toxicity via the γ-secretase inhibition, and provide a novel conceptual framework to address Aβ toxicity in the context of γ-secretase-dependent homeostatic signaling.
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Affiliation(s)
| | - Utpal Das
- Department of Neurosciences, University of California San Diego, La Jolla, CA, United States of America
| | - Sam Lismont
- VIB-KU Leuven Center for Brain & Disease Research, VIB, Leuven, Belgium
| | - Thomas Enzlein
- VIB-KU Leuven Center for Brain & Disease Research, VIB, Leuven, Belgium
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Mannheim, Germany
| | - Masato Maesako
- Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, United States of America
| | - Mei CQ Houser
- Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, United States of America
| | - María Luisa Franco
- Molecular Basis of Neurodegeneration Unit, Institute of Biomedicine of València (IBV-CSIC), València, Spain
| | - Burcu Özcan
- VIB-KU Leuven Center for Brain & Disease Research, VIB, Leuven, Belgium
| | | | - Dmitry Karachentsev
- Department of Neurosciences, University of California San Diego, La Jolla, CA, United States of America
| | - Ann Becker
- Department of Neurosciences, University of California San Diego, La Jolla, CA, United States of America
| | - Carsten Hopf
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Mannheim, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
- Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Marçal Vilar
- Molecular Basis of Neurodegeneration Unit, Institute of Biomedicine of València (IBV-CSIC), València, Spain
| | - Oksana Berezovska
- Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, United States of America
| | - William Mobley
- Department of Neurosciences, University of California San Diego, La Jolla, CA, United States of America
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7
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Jaye S, Sandau US, Saugstad JA. Clathrin mediated endocytosis in Alzheimer's disease: cell type specific involvement in amyloid beta pathology. Front Aging Neurosci 2024; 16:1378576. [PMID: 38694257 PMCID: PMC11061891 DOI: 10.3389/fnagi.2024.1378576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 04/03/2024] [Indexed: 05/04/2024] Open
Abstract
This review provides a comprehensive examination of the role of clathrin-mediated endocytosis (CME) in Alzheimer's disease (AD) pathogenesis, emphasizing its impact across various cellular contexts beyond neuronal dysfunction. In neurons, dysregulated CME contributes to synaptic dysfunction, amyloid beta (Aβ) processing, and Tau pathology, highlighting its involvement in early AD pathogenesis. Furthermore, CME alterations extend to non-neuronal cell types, including astrocytes and microglia, which play crucial roles in Aβ clearance and neuroinflammation. Dysregulated CME in these cells underscores its broader implications in AD pathophysiology. Despite significant progress, further research is needed to elucidate the precise mechanisms underlying CME dysregulation in AD and its therapeutic implications. Overall, understanding the complex interplay between CME and AD across diverse cell types holds promise for identifying novel therapeutic targets and interventions.
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Affiliation(s)
| | | | - Julie A. Saugstad
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, United States
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8
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Volloch V, Rits-Volloch S. On the Inadequacy of the Current Transgenic Animal Models of Alzheimer's Disease: The Path Forward. Int J Mol Sci 2024; 25:2981. [PMID: 38474228 PMCID: PMC10932000 DOI: 10.3390/ijms25052981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
For at least two reasons, the current transgenic animal models of Alzheimer's disease (AD) appear to be patently inadequate. They may be useful in many respects, the AD models; however, they are not. First, they are incapable of developing the full spectrum of the AD pathology. Second, they respond spectacularly well to drugs that are completely ineffective in the treatment of symptomatic AD. These observations indicate that both the transgenic animal models and the drugs faithfully reflect the theory that guided the design and development of both, the amyloid cascade hypothesis (ACH), and that both are inadequate because their underlying theory is. This conclusion necessitated the formulation of a new, all-encompassing theory of conventional AD-the ACH2.0. The two principal attributes of the ACH2.0 are the following. One, in conventional AD, the agent that causes the disease and drives its pathology is the intraneuronal amyloid-β (iAβ) produced in two distinctly different pathways. Two, following the commencement of AD, the bulk of Aβ is generated independently of Aβ protein precursor (AβPP) and is retained inside the neuron as iAβ. Within the framework of the ACH2.0, AβPP-derived iAβ accumulates physiologically in a lifelong process. It cannot reach levels required to support the progression of AD; it does, however, cause the disease. Indeed, conventional AD occurs if and when the levels of AβPP-derived iAβ cross the critical threshold, elicit the neuronal integrated stress response (ISR), and trigger the activation of the AβPP-independent iAβ generation pathway; the disease commences only when this pathway is operational. The iAβ produced in this pathway reaches levels sufficient to drive the AD pathology; it also propagates its own production and thus sustains the activity of the pathway and perpetuates its operation. The present study analyzes the reason underlying the evident inadequacy of the current transgenic animal models of AD. It concludes that they model, in fact, not Alzheimer's disease but rather the effects of the neuronal ISR sustained by AβPP-derived iAβ, that this is due to the lack of the operational AβPP-independent iAβ production pathway, and that this mechanism must be incorporated into any successful AD model faithfully emulating the disease. The study dissects the plausible molecular mechanisms of the AβPP-independent iAβ production and the pathways leading to their activation, and introduces the concept of conventional versus unconventional Alzheimer's disease. It also proposes the path forward, posits the principles of design of productive transgenic animal models of the disease, and describes the molecular details of their construction.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Sophia Rits-Volloch
- Division of Molecular Medicine, Children’s Hospital, Boston, MA 02115, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
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9
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Rinauro DJ, Chiti F, Vendruscolo M, Limbocker R. Misfolded protein oligomers: mechanisms of formation, cytotoxic effects, and pharmacological approaches against protein misfolding diseases. Mol Neurodegener 2024; 19:20. [PMID: 38378578 PMCID: PMC10877934 DOI: 10.1186/s13024-023-00651-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 08/17/2023] [Indexed: 02/22/2024] Open
Abstract
The conversion of native peptides and proteins into amyloid aggregates is a hallmark of over 50 human disorders, including Alzheimer's and Parkinson's diseases. Increasing evidence implicates misfolded protein oligomers produced during the amyloid formation process as the primary cytotoxic agents in many of these devastating conditions. In this review, we analyze the processes by which oligomers are formed, their structures, physicochemical properties, population dynamics, and the mechanisms of their cytotoxicity. We then focus on drug discovery strategies that target the formation of oligomers and their ability to disrupt cell physiology and trigger degenerative processes.
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Affiliation(s)
- Dillon J Rinauro
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Fabrizio Chiti
- Section of Biochemistry, Department of Experimental and Clinical Biomedical Sciences, University of Florence, 50134, Florence, Italy
| | - Michele Vendruscolo
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK.
| | - Ryan Limbocker
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY, 10996, USA.
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10
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Nishikage S, Fujisawa A, Endoh H, Sakamoto H, Suzuki T, Kanzawa M, Ishii S, Okano M, Nitta E, Yakushijin K, Asakura H, Nozu K, Nitta R, Katayama Y, Sakaguchi K. Amyloid deposition through endocytosis in vascular endothelial cells. Exp Hematol 2024; 129:104129. [PMID: 37952890 DOI: 10.1016/j.exphem.2023.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/02/2023] [Accepted: 11/04/2023] [Indexed: 11/14/2023]
Abstract
No mechanistic lead is known for establishing AL amyloid deposits in organs. We here report an electron microscopic (EM) analysis in a case of intestinal AL amyloidosis before initiating treatment for amyloidosis. The dense deposits of amyloid fibrils are concentrated around the small blood vessels in the submucosal area of intestinal tissue. Surprisingly, we observed endothelial cells (ECs) of blood vessels containing plenty of endocytotic (pinocytotic) and transcytotic vesicles at the luminal side and above the basement membrane, indicating the one-way active trafficking of either the immunoglobulin (Ig) light chain or preassembled amyloid fibrils from the luminal side of ECs to the extraluminal area of ECs. Immunoelectron microscopy displayed that the immuno-gold signals were observed in the vascular cavity and the subendothelial area of amyloid deposits. However, there is no sign of an Ig light chain in pinocytotic vesicles. Therefore, the intestinal ECs may actively pump out mainly the preassembled amyloid fibrils (not light chains) from the blood stream into the subendothelial area as a physiologic function.
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Affiliation(s)
- Seiji Nishikage
- Division of General Internal Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Akira Fujisawa
- Division of General Internal Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Hiromi Endoh
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Hirotaka Sakamoto
- Department of Biology, Faculty of Environmental, Life, Natural Science and Technology, Okayama University, Kita-ku, Okayama, Japan
| | - Tomohide Suzuki
- Division of Hematology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Maki Kanzawa
- Division of Diagnostic Pathology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Shinichi Ishii
- Division of Hematology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Mitsumasa Okano
- Division of General Internal Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Eriko Nitta
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Kimikazu Yakushijin
- Division of Oncology/Hematology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Hidesaku Asakura
- Department of Hematology, Kanazawa University Hospital, Kanazawa, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Ryo Nitta
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Yoshio Katayama
- Division of Hematology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan.
| | - Kazuhiko Sakaguchi
- Division of General Internal Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan.
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11
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Volloch V, Rits-Volloch S. Next Generation Therapeutic Strategy for Treatment and Prevention of Alzheimer's Disease and Aging-Associated Cognitive Decline: Transient, Once-in-a-Lifetime-Only Depletion of Intraneuronal Aβ ( iAβ) by Its Targeted Degradation via Augmentation of Intra- iAβ-Cleaving Activities of BACE1 and/or BACE2. Int J Mol Sci 2023; 24:17586. [PMID: 38139415 PMCID: PMC10744314 DOI: 10.3390/ijms242417586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/04/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Although the long-standing Amyloid Cascade Hypothesis (ACH) has been largely discredited, its main attribute, the centrality of amyloid-beta (Aβ) in Alzheimer's disease (AD), remains the cornerstone of any potential interpretation of the disease: All known AD-causing mutations, without a single exception, affect, in one way or another, Aβ. The ACH2.0, a recently introduced theory of AD, preserves this attribute but otherwise differs fundamentally from the ACH. It posits that AD is a two-stage disorder where both stages are driven by intraneuronal (rather than extracellular) Aβ (iAβ) albeit of two distinctly different origins. The first asymptomatic stage is the decades-long accumulation of Aβ protein precursor (AβPP)-derived iAβ to the critical threshold. This triggers the activation of the self-sustaining AβPP-independent iAβ production pathway and the commencement of the second, symptomatic AD stage. Importantly, Aβ produced independently of AβPP is retained intraneuronally. It drives the AD pathology and perpetuates the operation of the pathway; continuous cycles of the iAβ-stimulated propagation of its own AβPP-independent production constitute an engine that drives AD, the AD Engine. It appears that the dynamics of AβPP-derived iAβ accumulation is the determining factor that either drives Aging-Associated Cognitive Decline (AACD) and triggers AD or confers the resistance to both. Within the ACH2.0 framework, the ACH-based drugs, designed to lower levels of extracellular Aβ, could be applicable in the prevention of AD and treatment of AACD because they reduce the rate of accumulation of AβPP-derived iAβ. The present study analyzes their utility and concludes that it is severely limited. Indeed, their short-term employment is ineffective, their long-term engagement is highly problematic, their implementation at the symptomatic stages of AD is futile, and their evaluation in conventional clinical trials for the prevention of AD is impractical at best, impossible at worst, and misleading in between. In contrast, the ACH2.0-guided Next Generation Therapeutic Strategy for the treatment and prevention of both AD and AACD, namely the depletion of iAβ via its transient, short-duration, targeted degradation by the novel ACH2.0-based drugs, has none of the shortcomings of the ACH-based drugs. It is potentially highly effective, easily evaluable in clinical trials, and opens up the possibility of once-in-a-lifetime-only therapeutic intervention for prevention and treatment of both conditions. It also identifies two plausible ACH2.0-based drugs: activators of physiologically occurring intra-iAβ-cleaving capabilities of BACE1 and/or BACE2.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Sophia Rits-Volloch
- Division of Molecular Medicine, Children’s Hospital, Boston, MA 02115, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
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12
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Wang Z, Sharda N, Omtri RS, Li L, Kandimalla KK. Amyloid-Beta Peptides 40 and 42 Employ Distinct Molecular Pathways for Cell Entry and Intracellular Transit at the Blood-Brain Barrier Endothelium. Mol Pharmacol 2023; 104:203-213. [PMID: 37541759 PMCID: PMC10586509 DOI: 10.1124/molpharm.123.000670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 06/13/2023] [Accepted: 06/16/2023] [Indexed: 08/06/2023] Open
Abstract
The blood-brain barrier (BBB) plays a critical role in maintaining the equilibrium between amyloid beta (Aβ) levels in blood and the brain by regulating Aβ transport. Our previous publications demonstrated that BBB trafficking of Aβ42 and Aβ40 is distinct and is disrupted under various pathophysiological conditions. However, the intracellular mechanisms that allow BBB endothelium to differentially handle Aβ40 and Aβ42 have not been clearly elucidated. In this study, we identified mechanisms of Aβ endocytosis in polarized human cerebral microvascular endothelial cell monolayers. Our studies demonstrated that Aβ peptides with fluorescent label (F-Aβ) were internalized by BBB endothelial cells via energy, dynamin, and actin-dependent endocytosis. Interestingly, endocytosis of F-Aβ40 but not F-Aβ42 was substantially reduced by clathrin inhibition, whereas F-Aβ42 but not F-Aβ40 endocytosis was reduced by half after inhibiting the caveolae-mediated pathway. Following endocytosis, both isoforms were sorted by the endo-lysosomal system. Although Aβ42 was shown to accumulate more in the lysosomes, which could lead to its higher degradation and/or aggregation at lower lysosomal pH, Aβ40 demonstrated robust accumulation in recycling endosomes, which may facilitate its exocytosis by the endothelial cells. These results provide a mechanistic insight into the selective ability of BBB endothelium to transport Aβ40 versus Aβ42. This knowledge contributes to the understanding of molecular pathways underlying Aβ accumulation in the BBB endothelium and associated BBB dysfunction. Moreover, it allows us to establish mechanistic rationale for altered Aβ40:Aβ42 ratios and anomalous amyloid deposition in the cerebral vasculature as well as brain parenchyma during Alzheimer's disease progression. SIGNIFICANCE STATEMENT: Differential interaction of Aβ40 and Aβ42 isoforms with the blood-brain barrier (BBB) endothelium may contribute to perturbation in Aβ42:Aβ40 ratio, which is associated with Alzheimer's disease (AD) progression and severity. The current study identified distinct molecular pathways by which Aβ40 and Aβ42 are trafficked at the BBB, which regulates equilibrium between blood and brain Aβ levels. These findings provide molecular insights into mechanisms that engender BBB dysfunction and promote Aβ accumulation in AD brain.
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Affiliation(s)
- Zengtao Wang
- Department of Pharmaceutics and Brain Barriers Research Center, University of Minnesota, College of Pharmacy, Minneapolis, Minnesota (Z.W., N.S., R.S.O., K.K.K.); and Department of Experimental and Clinical Pharmacology, University of Minnesota, College of Pharmacy, Minneapolis, Minnesota (L.L.)
| | - Nidhi Sharda
- Department of Pharmaceutics and Brain Barriers Research Center, University of Minnesota, College of Pharmacy, Minneapolis, Minnesota (Z.W., N.S., R.S.O., K.K.K.); and Department of Experimental and Clinical Pharmacology, University of Minnesota, College of Pharmacy, Minneapolis, Minnesota (L.L.)
| | - Rajesh S Omtri
- Department of Pharmaceutics and Brain Barriers Research Center, University of Minnesota, College of Pharmacy, Minneapolis, Minnesota (Z.W., N.S., R.S.O., K.K.K.); and Department of Experimental and Clinical Pharmacology, University of Minnesota, College of Pharmacy, Minneapolis, Minnesota (L.L.)
| | - Ling Li
- Department of Pharmaceutics and Brain Barriers Research Center, University of Minnesota, College of Pharmacy, Minneapolis, Minnesota (Z.W., N.S., R.S.O., K.K.K.); and Department of Experimental and Clinical Pharmacology, University of Minnesota, College of Pharmacy, Minneapolis, Minnesota (L.L.)
| | - Karunya K Kandimalla
- Department of Pharmaceutics and Brain Barriers Research Center, University of Minnesota, College of Pharmacy, Minneapolis, Minnesota (Z.W., N.S., R.S.O., K.K.K.); and Department of Experimental and Clinical Pharmacology, University of Minnesota, College of Pharmacy, Minneapolis, Minnesota (L.L.)
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13
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Hivare P, Mujmer K, Swarup G, Gupta S, Bhatia D. Endocytic pathways of pathogenic protein aggregates in neurodegenerative diseases. Traffic 2023; 24:434-452. [PMID: 37392160 DOI: 10.1111/tra.12906] [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: 09/20/2022] [Revised: 05/14/2023] [Accepted: 06/11/2023] [Indexed: 07/03/2023]
Abstract
Endocytosis is the fundamental uptake process through which cells internalize extracellular materials and species. Neurodegenerative diseases (NDs) are characterized by a progressive accumulation of intrinsically disordered protein species, leading to neuronal death. Misfolding in many proteins leads to various NDs such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and other disorders. Despite the significance of disordered protein species in neurodegeneration, their spread between cells and the cellular uptake of extracellular species is not entirely understood. This review discusses the major internalization mechanisms of the different conformer species of these proteins and their endocytic mechanisms. We briefly introduce the broad types of endocytic mechanisms found in cells and then summarize what is known about the endocytosis of monomeric, oligomeric and aggregated conformations of tau, Aβ, α-Syn, Huntingtin, Prions, SOD1, TDP-43 and other proteins associated with neurodegeneration. We also highlight the key players involved in internalizing these disordered proteins and the several techniques and approaches to identify their endocytic mechanisms. Finally, we discuss the obstacles involved in studying the endocytosis of these protein species and the need to develop better techniques to elucidate the uptake mechanisms of a particular disordered protein species.
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Affiliation(s)
- Pravin Hivare
- Biological Engineering Discipline, Indian Institute of Technology Gandhinagar, Palaj, Gujarat, India
| | - Kratika Mujmer
- Center for Brain and Cognitive Sciences, Indian Institute of Technology Gandhinagar, Palaj, Gujarat, India
| | - Gitanjali Swarup
- Biological Engineering Discipline, Indian Institute of Technology Gandhinagar, Palaj, Gujarat, India
| | - Sharad Gupta
- Biological Engineering Discipline, Indian Institute of Technology Gandhinagar, Palaj, Gujarat, India
- Center for Biomedical Engineering, Indian Institute of Technology Gandhinagar, Palaj, Gujarat, India
| | - Dhiraj Bhatia
- Biological Engineering Discipline, Indian Institute of Technology Gandhinagar, Palaj, Gujarat, India
- Center for Biomedical Engineering, Indian Institute of Technology Gandhinagar, Palaj, Gujarat, India
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14
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Volloch V, Rits-Volloch S. Principles of Design of Clinical Trials for Prevention and Treatment of Alzheimer's Disease and Aging-Associated Cognitive Decline in the ACH2.0 Perspective: Potential Outcomes, Challenges, and Solutions. J Alzheimers Dis Rep 2023; 7:921-955. [PMID: 37849639 PMCID: PMC10578334 DOI: 10.3233/adr-230037] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 07/31/2023] [Indexed: 10/19/2023] Open
Abstract
With the Amyloid Cascade Hypothesis (ACH) largely discredited, the ACH2.0 theory of Alzheimer's disease (AD) has been recently introduced. Within the framework of the ACH2.0, AD is triggered by amyloid-β protein precursor (AβPP)-derived intraneuronal Aβ (iAβ) and is driven by iAβ produced in the AβPP-independent pathway and retained intraneuronally. In this paradigm, the depletion of extracellular Aβ or suppression of Aβ production by AβPP proteolysis, the two sources of AβPP-derived iAβ, would be futile in symptomatic AD, due to its reliance on iAβ generated independently of AβPP, but effective in preventing AD and treating Aging-Associated Cognitive Decline (AACD) driven, in the ACH2.0 framework, by AβPP-derived iAβ. The observed effect of lecanemab and donanemab, interpreted in the ACH2.0 perspective, supports this notion and mandates AD-preventive clinical trials. Such trials are currently in progress. They are likely, however, to fail or to yield deceptive results if conducted conventionally. The present study considers concepts of design of clinical trials of lecanemab, donanemab, or any other drug, targeting the influx of AβPP-derived iAβ, in prevention of AD and treatment of AACD. It analyzes possible outcomes and explains why selection of high-risk asymptomatic participants seems reasonable but is not. It argues that outcomes of such AD preventive trials could be grossly misleading, discusses inevitable potential problems, and proposes feasible solutions. It advocates the initial evaluation of this type of drugs in clinical trials for treatment of AACD. Whereas AD protective trials of these drugs are potentially of an impractical length, AACD clinical trials are expected to yield unequivocal results within a relatively short duration. Moreover, success of the latter, in addition to its intrinsic value, would constitute a proof of concept for the former. Furthermore, this study introduces concepts of the active versus passive iAβ depletion, contends that targeted degradation of iAβ is the best therapeutic strategy for both prevention and treatment of AD and AACD, proposes potential iAβ-degrading drugs, and describes their feasible and unambiguous evaluation in clinical trials.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA
| | - Sophia Rits-Volloch
- Division of Molecular Medicine, Children’s Hospital, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
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15
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Volloch V, Rits-Volloch S. The Amyloid Cascade Hypothesis 2.0 for Alzheimer's Disease and Aging-Associated Cognitive Decline: From Molecular Basis to Effective Therapy. Int J Mol Sci 2023; 24:12246. [PMID: 37569624 PMCID: PMC10419172 DOI: 10.3390/ijms241512246] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/13/2023] Open
Abstract
With the long-standing amyloid cascade hypothesis (ACH) largely discredited, there is an acute need for a new all-encompassing interpretation of Alzheimer's disease (AD). Whereas such a recently proposed theory of AD is designated ACH2.0, its commonality with the ACH is limited to the recognition of the centrality of amyloid-β (Aβ) in the disease, necessitated by the observation that all AD-causing mutations affect, in one way or another, Aβ. Yet, even this narrow commonality is superficial since AD-causing Aβ of the ACH differs distinctly from that specified in the ACH2.0: Whereas in the former, the disease is caused by secreted extracellular Aβ, in the latter, it is triggered by Aβ-protein-precursor (AβPP)-derived intraneuronal Aβ (iAβ) and driven by iAβ generated independently of AβPP. The ACH2.0 envisions AD as a two-stage disorder. The first, asymptomatic stage is a decades-long accumulation of AβPP-derived iAβ, which occurs via internalization of secreted Aβ and through intracellular retention of a fraction of Aβ produced by AβPP proteolysis. When AβPP-derived iAβ reaches critical levels, it activates a self-perpetuating AβPP-independent production of iAβ that drives the second, devastating AD stage, a cascade that includes tau pathology and culminates in neuronal loss. The present study analyzes the dynamics of iAβ accumulation in health and disease and concludes that it is the prime factor driving both AD and aging-associated cognitive decline (AACD). It discusses mechanisms potentially involved in AβPP-independent generation of iAβ, provides mechanistic interpretations for all principal aspects of AD and AACD including the protective effect of the Icelandic AβPP mutation, the early onset of FAD and the sequential manifestation of AD pathology in defined regions of the affected brain, and explains why current mouse AD models are neither adequate nor suitable. It posits that while drugs affecting the accumulation of AβPP-derived iAβ can be effective only protectively for AD, the targeted degradation of iAβ is the best therapeutic strategy for both prevention and effective treatment of AD and AACD. It also proposes potential iAβ-degrading drugs.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Sophia Rits-Volloch
- Division of Molecular Medicine, Children’s Hospital, Boston, MA 02115, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
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16
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Zhaliazka K, Matveyenka M, Kurouski D. Lipids uniquely alter the secondary structure and toxicity of amyloid beta 1-42 aggregates. FEBS J 2023; 290:3203-3220. [PMID: 36705524 PMCID: PMC10389563 DOI: 10.1111/febs.16738] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/25/2022] [Accepted: 01/25/2023] [Indexed: 01/28/2023]
Abstract
Abrupt aggregation of amyloid β1-42 (Aβ) peptide is a hallmark of Alzheimer's disease (AD), a severe pathology that affects more than 44 million people worldwide. A growing body of evidence suggests that lipids can uniquely alter rates of Aβ1-42 aggregation. However, it remains unclear whether lipids only alter rates of protein aggregation or also uniquely modify the secondary structure and toxicity of Aβ1-42 oligomers and fibrils. In this study, we investigated the effect of phosphatidylcholine (PC), cardiolipin (CL), and cholesterol (Chol) on Aβ1-42 aggregation. We found that PC, CL and Chol strongly accelerated the rate of fibril formation compared to the rate of Aβ1-42 aggregation in the lipid-free environment. Furthermore, anionic CL enabled the strongest acceleration of Aβ1-42 aggregation compared to zwitterionic PC and uncharged Chol. We also found that PC, CL and Chol uniquely altered the secondary structure of early-, middle- and late-stage Aβ1-42 aggregates. Specifically, CL and Chol drastically increased the amount of parallel β-sheet in Aβ1-42 oligomers and fibrils grown in the presence of these lipids. This caused a significant increase in the toxicity of Aβ : CL and Aβ : Chol compared to the toxicity of Aβ : PC and Aβ1-42 aggregates formed in the lipid-free environment. These results demonstrate that toxicity of Aβ aggregates correlates with the amount of their β-sheet content, which, in turn, is determined by the chemical structure of lipids present at the stage of Aβ1-42 aggregation.
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Affiliation(s)
- Kiryl Zhaliazka
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Mikhail Matveyenka
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Dmitry Kurouski
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, 77843, United States
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17
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Kreutzer AG, Guaglianone G, Yoo S, Parrocha CMT, Ruttenberg SM, Malonis RJ, Tong K, Lin YF, Nguyen JT, Howitz WJ, Diab MN, Hamza IL, Lai JR, Wysocki VH, Nowick JS. Probing differences among Aβ oligomers with two triangular trimers derived from Aβ. Proc Natl Acad Sci U S A 2023; 120:e2219216120. [PMID: 37216514 PMCID: PMC10235986 DOI: 10.1073/pnas.2219216120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 04/17/2023] [Indexed: 05/24/2023] Open
Abstract
The assembly of the β-amyloid peptide (Aβ) to form oligomers and fibrils is closely associated with the pathogenesis and progression of Alzheimer's disease. Aβ is a shape-shifting peptide capable of adopting many conformations and folds within the multitude of oligomers and fibrils the peptide forms. These properties have precluded detailed structural elucidation and biological characterization of homogeneous, well-defined Aβ oligomers. In this paper, we compare the structural, biophysical, and biological characteristics of two different covalently stabilized isomorphic trimers derived from the central and C-terminal regions Aβ. X-ray crystallography reveals the structures of the trimers and shows that each trimer forms a ball-shaped dodecamer. Solution-phase and cell-based studies demonstrate that the two trimers exhibit markedly different assembly and biological properties. One trimer forms small soluble oligomers that enter cells through endocytosis and activate capase-3/7-mediated apoptosis, while the other trimer forms large insoluble aggregates that accumulate on the outer plasma membrane and elicit cellular toxicity through an apoptosis-independent mechanism. The two trimers also exhibit different effects on the aggregation, toxicity, and cellular interaction of full-length Aβ, with one trimer showing a greater propensity to interact with Aβ than the other. The studies described in this paper indicate that the two trimers share structural, biophysical, and biological characteristics with oligomers of full-length Aβ. The varying structural, assembly, and biological characteristics of the two trimers provide a working model for how different Aβ trimers can assemble and lead to different biological effects, which may help shed light on the differences among Aβ oligomers.
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Affiliation(s)
- Adam G. Kreutzer
- Department of Chemistry, University of California Irvine, Irvine, CA92697
| | | | - Stan Yoo
- Department of Chemistry, University of California Irvine, Irvine, CA92697
| | | | | | - Ryan J. Malonis
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY10461
| | - Karen Tong
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY10461
| | - Yu-Fu Lin
- Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH43210
| | - Jennifer T. Nguyen
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, CA92697
| | - William J. Howitz
- Department of Chemistry, University of California Irvine, Irvine, CA92697
| | - Michelle N. Diab
- Department of Chemistry, University of California Irvine, Irvine, CA92697
| | - Imane L. Hamza
- Department of Chemistry, University of California Irvine, Irvine, CA92697
| | - Jonathan R. Lai
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY10461
| | - Vicki H. Wysocki
- Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH43210
| | - James S. Nowick
- Department of Chemistry, University of California Irvine, Irvine, CA92697
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, CA92697
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18
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Volloch V, Rits-Volloch S. Effect of Lecanemab in Early Alzheimer's Disease: Mechanistic Interpretation in the Amyloid Cascade Hypothesis 2.0 Perspective. J Alzheimers Dis 2023:JAD230164. [PMID: 37212119 DOI: 10.3233/jad-230164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In clinical trials, lecanemab showed statistically significant yet marginal slowdown of Alzheimer's disease (AD)-associated cognitive decline. This could be due to its sub-optimal design and/or deployment; alternatively, its limited efficiency could be intrinsic. Distinguishing between the two is of great importance considering the acute need of efficient AD therapy and tremendous resources being invested in its pursuit. The present study analyzes the mode of operation of lecanemab within the framework of recently proposed Amyloid Cascade Hypothesis 2.0 and concludes that the second is correct. It suggests that substantial improvement of the efficiency of lecanemab in symptomatic AD is unlikely and proposes the alternative therapeutic strategy.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA
| | - Sophia Rits-Volloch
- Division of Molecular Medicine, Children's Hospital, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
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19
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Volloch V, Rits-Volloch S. The Amyloid Cascade Hypothesis 2.0: Generalization of the Concept. J Alzheimers Dis Rep 2023; 7:21-35. [PMID: 36777328 PMCID: PMC9912825 DOI: 10.3233/adr-220079] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/09/2022] [Indexed: 12/31/2022] Open
Abstract
Recently, we proposed the Amyloid Cascade Hypothesis 2.0 (ACH2.0), a reformulation of the ACH. In the former, in contrast to the latter, Alzheimer's disease (AD) is driven by intraneuronal amyloid-β (iAβ) and occurs in two stages. In the first, relatively benign stage, Aβ protein precursor (AβPP)-derived iAβ activates, upon reaching a critical threshold, the AβPP-independent iAβ-generating pathway, triggering a devastating second stage resulting in neuronal death. While the ACH2.0 remains aligned with the ACH premise that Aβ is toxic, the toxicity is exerted because of intra- rather than extracellular Aβ. In this framework, a once-in-a-lifetime-only iAβ depletion treatment via transient activation of BACE1 and/or BACE2 (exploiting their Aβ-cleaving activities) or by any means appears to be the best therapeutic strategy for AD. Whereas the notion of differentially derived iAβ being the principal moving force at both AD stages is both plausible and elegant, a possibility remains that the second AD stage is enabled by an AβPP-derived iAβ-activated self-sustaining mechanism producing a yet undefined deleterious "substance X" (sX) which anchors the second AD stage. The present study generalizes the ACH2.0 by incorporating this possibility and shows that, in this scenario, the iAβ depletion therapy may be ineffective at symptomatic AD stages but fully retains its preventive potential for both AD and the aging-associated cognitive decline, which is defined in the ACH2.0 framework as the extended first stage of AD.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA,Correspondence to: Vladimir Volloch, Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA. and Sophia Rits-Volloch, Division of Molecular Medicine, Children’s Hospital, Boston, MA, USA. E-mail:
| | - Sophia Rits-Volloch
- Division of Molecular Medicine, Children’s Hospital, Boston, MA, USA,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
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20
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Matveyenka M, Rizevsky S, Pellois JP, Kurouski D. Lipids uniquely alter rates of insulin aggregation and lower toxicity of amyloid aggregates. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159247. [PMID: 36272517 PMCID: PMC10401553 DOI: 10.1016/j.bbalip.2022.159247] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/14/2022] [Accepted: 10/02/2022] [Indexed: 02/25/2023]
Abstract
Amyloid formation is a hallmark of many medical diseases including diabetes type 2, Alzheimer's and Parkinson diseases. Under these pathological conditions, misfolded proteins self-assemble forming oligomers and fibrils, structurally heterogeneous aggregates that exhibit a large variety of shapes and forms. A growing body of evidence points to drastic changes in the lipid profile in organs affected by amyloidogenic diseases. In this study, we investigated the extent to which individual phospho- and sphingolipids, as well as their mixtures can impact insulin aggregation. Our results show that lipids and their mixtures uniquely alter rates of insulin aggregation simultaneously changing the secondary structure of protein aggregates that are grown in their presence. These structurally different protein-lipid aggregates impact cell viability to different extent while using distinct mechanisms of toxicity. These findings suggest that irreversible changes in lipid profiles of organs may trigger formation of toxic protein species that in turn are responsible for the onset and progression of amyloidogenic diseases.
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Affiliation(s)
- Mikhail Matveyenka
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, United States
| | - Stanislav Rizevsky
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, United States; Department of Biotechnology, Binh Duong University, Thu Dau Mot 820000, Viet Nam
| | - Jean-Philippe Pellois
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, United States
| | - Dmitry Kurouski
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, United States; Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, United States.
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21
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Molkov YI, Zaretskaia MV, Zaretsky DV. Towards the Integrative Theory of Alzheimer's Disease: Linking Molecular Mechanisms of Neurotoxicity, Beta-amyloid Biomarkers, and the Diagnosis. Curr Alzheimer Res 2023; 20:440-452. [PMID: 37605411 PMCID: PMC10790337 DOI: 10.2174/1567205020666230821141745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 06/16/2023] [Accepted: 07/14/2023] [Indexed: 08/23/2023]
Abstract
INTRODUCTION A major gap in amyloid-centric theories of Alzheimer's disease (AD) is that even though amyloid fibrils per se are not toxic in vitro, the diagnosis of AD clearly correlates with the density of beta-amyloid (Aβ) deposits. Based on our proposed amyloid degradation toxicity hypothesis, we developed a mathematical model explaining this discrepancy. It suggests that cytotoxicity depends on the cellular uptake of soluble Aβ rather than on the presence of amyloid aggregates. The dynamics of soluble beta-amyloid in the cerebrospinal fluid (CSF) and the density of Aβ deposits is described using a system of differential equations. In the model, cytotoxic damage is proportional to the cellular uptake of Aβ, while the probability of an AD diagnosis is defined by the Aβ cytotoxicity accumulated over the duration of the disease. After uptake, Aβ is concentrated intralysosomally, promoting the formation of fibrillation seeds inside cells. These seeds cannot be digested and are either accumulated intracellularly or exocytosed. Aβ starts aggregating on the extracellular seeds and, therefore, decreases in concentration in the interstitial fluid. The dependence of both Aβ toxicity and aggregation on the same process-cellular uptake of Aβ-explains the correlation between AD diagnosis and the density of amyloid aggregates in the brain. METHODS We tested the model using clinical data obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI), which included records of beta-amyloid concentration in the cerebrospinal fluid (CSF-Aβ42) and the density of beta-amyloid deposits measured using positron emission tomography (PET). The model predicts the probability of AD diagnosis as a function of CSF-Aβ42 and PET and fits the experimental data at the 95% confidence level. RESULTS Our study shows that existing clinical data allows for the inference of kinetic parameters describing beta-amyloid turnover and disease progression. Each combination of CSF-Aβ42 and PET values can be used to calculate the individual's cellular uptake rate, the effective disease duration, and the accumulated toxicity. We show that natural limitations on these parameters explain the characteristic distribution of the clinical dataset for these two biomarkers in the population. CONCLUSION The resulting mathematical model interprets the positive correlation between the density of Aβ deposits and the probability of an AD diagnosis without assuming any cytotoxicity of the aggregated beta-amyloid. To the best of our knowledge, this model is the first to mechanistically explain the negative correlation between the concentration of Aβ42 in the CSF and the probability of an AD diagnosis. Finally, based on the amyloid degradation toxicity hypothesis and the insights provided by mathematical modeling, we propose new pathophysiology-relevant biomarkers to diagnose and predict AD.
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Affiliation(s)
- Yaroslav I. Molkov
- Department of Mathematics and Statistics and Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
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22
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Vergilio J, Lockhart C, Klimov DK. De Novo Transmembrane Aggregation of Aβ10-40 Peptides in an Anionic Lipid Bilayer. J Chem Inf Model 2022; 62:6228-6241. [PMID: 36455155 DOI: 10.1021/acs.jcim.2c01192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Using the all-atom model and 10 μs serial replica-exchange molecular dynamics (SREMD), we investigated the binding of Alzheimer's Aβ10-40 peptides to the anionic dimyristoylphosphatidylcholine/dimyristoylphosphatidylglycerol (DMPC/DMPG) lipid bilayer. Our objective was to probe de novo transmembrane Aβ10-40 aggregation and to test the utility of SREMD. Our results are threefold. First, upon binding, Aβ10-40 adopts a helical structure in the C-terminus and deeply inserts into the bilayer. Binding is primarily controlled by electrostatic interactions of the peptides with water, ions, and lipids, particularly, anionic DMPG. Second, Aβ-bilayer interactions reorganize lipids in the proximity of the bound peptides, causing an influx of DMPG lipids into the Aβ binding footprint. Third and most important, computed free energy landscapes reveal that Aβ10-40 peptides partition into monomeric and dimeric species. The dimers result from transmembrane aggregation of the peptides and induce a striking lipid density void throughout both leaflets in the bilayer. There are multiple factors stabilizing transmembrane dimers, including van der Waals and steric interactions, electrostatic interactions, and hydrogen bonding, hydration, and entropic gains originating from dimer conformations and lipid disorder. We argue that helix dipole-dipole interactions underestimated in the all-atom force field must be a contributing factor to stabilizing antiparallel transmembrane dimers. We propose that transmembrane aggregates serve as mechanistic links between the populations of extra- and intracellular Aβ peptides. From the computational perspective, SREMD is found to be a viable alternative to traditional replica-exchange simulations.
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Affiliation(s)
- James Vergilio
- School of Systems Biology, George Mason University, Manassas, Virginia 20110, United States
| | - Christopher Lockhart
- School of Systems Biology, George Mason University, Manassas, Virginia 20110, United States
| | - Dmitri K Klimov
- School of Systems Biology, George Mason University, Manassas, Virginia 20110, United States
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23
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Poejo J, Orantos-Aguilera Y, Martin-Romero FJ, Mata AM, Gutierrez-Merino C. Internalized Amyloid-β (1-42) Peptide Inhibits the Store-Operated Calcium Entry in HT-22 Cells. Int J Mol Sci 2022; 23:ijms232012678. [PMID: 36293540 PMCID: PMC9604325 DOI: 10.3390/ijms232012678] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/12/2022] [Accepted: 10/17/2022] [Indexed: 01/24/2023] Open
Abstract
Dysregulation in calcium signaling pathways plays a major role in the initiation of Alzheimer's disease (AD) pathogenesis. Accumulative experimental evidence obtained with cellular and animal models, as well as with AD brain samples, points out the high cytotoxicity of soluble small oligomeric forms of amyloid-β peptides (Aβ) in AD. In recent works, we have proposed that Aβ-calmodulin (CaM) complexation may play a major role in neuronal Ca2+ signaling, mediated by CaM-binding proteins (CaMBPs). STIM1, a recognized CaMBP, plays a key role in store-operated calcium entry (SOCE), and it has been shown that the SOCE function is diminished in AD, resulting in the instability of dendric spines and enhanced amyloidogenesis. In this work, we show that 2 and 5 h of incubation with 2 μM Aβ(1-42) oligomers of the immortalized mouse hippocampal cell line HT-22 leads to the internalization of 62 ± 11 nM and 135 ± 15 nM of Aβ(1-42), respectively. Internalized Aβ(1-42) oligomers colocalize with the endoplasmic reticulum (ER) and co-immunoprecipitated with STIM1, unveiling that this protein is a novel target of Aβ. Fluorescence resonance energy transfer measurements between STIM1 tagged with a green fluorescent protein (GFP) and Aβ(1-42)-HiLyte™-Fluor555 show that STIM1 can bind nanomolar concentrations of Aβ(1-42) oligomers at a site located close to the CaM-binding site in STIM1. Internalized Aβ(1-42) produced dysregulation of the SOCE in the HT-22 cells before a sustained alteration of cytosolic Ca2+ homeostasis can be detected, and is elicited by only 2 h of incubation with 2 μM Aβ(1-42) oligomers. We conclude that Aβ(1-42)-induced SOCE dysregulation in HT-22 cells is caused by the inhibitory modulation of STIM1, and the partial activation of ER Ca2+-leak channels.
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Affiliation(s)
- Joana Poejo
- Instituto de Biomarcadores de Patologías Moleculares (IBPM), Universidad de Extremadura, 06006 Badajoz, Spain
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, 06006 Badajoz, Spain
| | - Yolanda Orantos-Aguilera
- Instituto de Biomarcadores de Patologías Moleculares (IBPM), Universidad de Extremadura, 06006 Badajoz, Spain
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, 06006 Badajoz, Spain
| | - Francisco Javier Martin-Romero
- Instituto de Biomarcadores de Patologías Moleculares (IBPM), Universidad de Extremadura, 06006 Badajoz, Spain
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, 06006 Badajoz, Spain
| | - Ana Maria Mata
- Instituto de Biomarcadores de Patologías Moleculares (IBPM), Universidad de Extremadura, 06006 Badajoz, Spain
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, 06006 Badajoz, Spain
| | - Carlos Gutierrez-Merino
- Instituto de Biomarcadores de Patologías Moleculares (IBPM), Universidad de Extremadura, 06006 Badajoz, Spain
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, 06006 Badajoz, Spain
- Correspondence:
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24
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Valappil DK, Mini NJ, Dilna A, Nath S. Membrane interaction to intercellular spread of pathology in Alzheimer’s disease. Front Neurosci 2022; 16:936897. [PMID: 36161178 PMCID: PMC9500529 DOI: 10.3389/fnins.2022.936897] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/24/2022] [Indexed: 11/22/2022] Open
Abstract
Progressive development of pathology is one of the major characteristic features of neurodegenerative diseases. Alzheimer’s disease (AD) is the most prevalent among them. Extracellular amyloid-β (Aβ) plaques and intracellular tau neurofibrillary tangles are the pathological phenotypes of AD. However, cellular and animal studies implicate tau as a secondary pathology in developing AD while Aβ aggregates is considered as a trigger point. Interaction of Aβ peptides with plasma membrane (PM) seems to be a promising site of involvement in the events that lead to AD. Aβ binding to the lipid membranes initiates formation of oligomers of Aβ species, and these oligomers are known as primary toxic agents for neuronal toxicities. Once initiated, neuropathological toxicities spread in a “prion-like” fashion probably through the mechanism of intercellular transfer of pathogenic aggregates. In the last two decades, several studies have demonstrated neuron-to-neuron transfer of neurodegenerative proteins including Aβ and tau via exosomes and tunneling nanotubes (TNTs), the two modes of long-range intercellular transfer. Emerging pieces of evidence indicate that molecular pathways related to the biogenesis of exosomes and TNTs interface with endo-lysosomal pathways and cellular signaling in connection to vesicle recycling-imposed PM and actin remodulation. In this review, we discuss interactions of Aβ aggregates at the membrane level and its implications in intercellular spread of pathogenic aggregates. Furthermore, we hypothesize how spread of pathogenic aggregates contributes to complex molecular events that could regulate pathological and synaptic changes related to AD.
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Affiliation(s)
| | | | | | - Sangeeta Nath
- *Correspondence: Sangeeta Nath, ; orcid.org/0000-0003-0050-0606
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25
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Guaglianone G, Torrado B, Lin YF, Watkins MC, Wysocki VH, Gratton E, Nowick JS. Elucidating the Oligomerization and Cellular Interactions of a Trimer Derived from Aβ through Fluorescence and Mass Spectrometric Studies. ACS Chem Neurosci 2022; 13:2473-2482. [PMID: 35892278 PMCID: PMC9389591 DOI: 10.1021/acschemneuro.2c00313] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 07/15/2022] [Indexed: 01/20/2023] Open
Abstract
Aβ oligomers play a central role in the neurodegeneration observed with Alzheimer's disease. Our laboratory has developed covalently stabilized trimers derived from residues 17-36 of Aβ as model systems for studying Aβ oligomers. In the current study, we apply the emerging techniques of fluorescence lifetime imaging microscopy (FLIM) and native mass spectrometry (native MS) to better understand the assembly and interactions of the oligomer model system 2AT-L in aqueous solutions and with cells. 2AT-L and fluorescently labeled 2AT-L analogues assemble in the membrane-like environment of SDS-PAGE, showing diffuse bands of oligomers in equilibrium. Native ion mobility-mass spectrometry (native IM-MS) of 2AT-L allows for the identification of discrete oligomers in solution and shows similar patterns of oligomer formation between 2AT-L and fluorescently labeled analogues. Fluorescence microscopy with SH-SY5Y cells reveals that fluorescently labeled 2AT-L analogues colocalize within lysosomes. FLIM studies with phasor analysis further elucidate the assembly of 2AT-L within cells and establish the occurrence of FRET, indicating the presence of oligomers within cells. Collectively, these multiple complementary techniques help better understand the complex behavior of the 2AT-L model system.
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Affiliation(s)
- Gretchen Guaglianone
- Department
of Chemistry, University of California,
Irvine, Irvine, California 92697, United States
| | - Belén Torrado
- Laboratory
for Fluorescence Dynamics, Biomedical Engineering, University of California, Irvine, California 92697, United States
| | - Yu-Fu Lin
- Resource
for Native MS Guided Structural Biology, The Ohio State University, Columbus, Ohio 43210, United States
- Department
of Chemistry and Biochemistry, The Ohio
State University, Columbus, Ohio 43210, United States
| | - Matthew C. Watkins
- Department
of Chemistry, University of California,
Irvine, Irvine, California 92697, United States
| | - Vicki H. Wysocki
- Resource
for Native MS Guided Structural Biology, The Ohio State University, Columbus, Ohio 43210, United States
- Department
of Chemistry and Biochemistry, The Ohio
State University, Columbus, Ohio 43210, United States
| | - Enrico Gratton
- Laboratory
for Fluorescence Dynamics, Biomedical Engineering, University of California, Irvine, California 92697, United States
| | - James S. Nowick
- Department
of Chemistry, University of California,
Irvine, Irvine, California 92697, United States
- Department
of Pharmaceutical Sciences, University of
California, Irvine, Irvine, California 92697, United States
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26
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Volloch V, Rits-Volloch S. The Amyloid Cascade Hypothesis 2.0: On the Possibility of Once-in-a-Lifetime-Only Treatment for Prevention of Alzheimer’s Disease and for Its Potential Cure at Symptomatic Stages. J Alzheimers Dis Rep 2022; 6:369-399. [PMID: 36072366 PMCID: PMC9397896 DOI: 10.3233/adr-220031] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/08/2022] [Indexed: 11/15/2022] Open
Abstract
We posit that Alzheimer’s disease (AD) is driven by amyloid-β (Aβ) generated in the amyloid-β protein precursor (AβPP) independent pathway activated by AβPP-derived Aβ accumulated intraneuronally in a life-long process. This interpretation constitutes the Amyloid Cascade Hypothesis 2.0 (ACH2.0). It defines a tandem intraneuronal-Aβ (iAβ)-anchored cascade occurrence: intraneuronally-accumulated, AβPP-derived iAβ triggers relatively benign cascade that activates the AβPP-independent iAβ-generating pathway, which, in turn, initiates the second, devastating cascade that includes tau pathology and leads to neuronal loss. The entire output of the AβPP-independent iAβ-generating pathway is retained intraneuronally and perpetuates the pathway’s operation. This process constitutes a self-propagating, autonomous engine that drives AD and ultimately kills its host cells. Once activated, the AD Engine is self-reliant and independent from Aβ production in the AβPP proteolytic pathway; operation of the former renders the latter irrelevant to the progression of AD and brands its manipulation for therapeutic purposes, such as BACE (beta-site AβPP-cleaving enzyme) inhibition, as futile. In the proposed AD paradigm, the only valid direct therapeutic strategy is targeting the engine’s components, and the most effective feasible approach appears to be the activation of BACE1 and/or of its homolog BACE2, with the aim of exploiting their Aβ-cleaving activities. Such treatment would collapse the iAβ population and ‘reset’ its levels below those required for the operation of the AD Engine. Any sufficiently selective iAβ-depleting treatment would be equally effective. Remarkably, this approach opens the possibility of a short-duration, once-in-a-lifetime-only or very infrequent, preventive or curative therapy for AD; this therapy would be also effective for prevention and treatment of the ‘common’ pervasive aging-associated cognitive decline. The ACH2.0 clarifies all ACH-unresolved inconsistencies, explains the widespread ‘resilience to AD’ phenomenon, predicts occurrences of a category of AD-afflicted individuals without excessive Aβ plaque load and of a novel type of familial insusceptibility to AD; it also predicts the lifespan-dependent inevitability of AD in humans if untreated preventively. The article details strategy and methodology to generate an adequate AD model and validate the hypothesis; the proposed AD model may also serve as a research and drug development platform.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA
| | - Sophia Rits-Volloch
- Division of Molecular Medicine, Children’s Hospital, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
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27
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Gallego Villarejo L, Bachmann L, Marks D, Brachthäuser M, Geidies A, Müller T. Role of Intracellular Amyloid β as Pathway Modulator, Biomarker, and Therapy Target. Int J Mol Sci 2022; 23:ijms23094656. [PMID: 35563046 PMCID: PMC9103247 DOI: 10.3390/ijms23094656] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/15/2022] [Accepted: 04/19/2022] [Indexed: 02/04/2023] Open
Abstract
The β- and γ-secretase-driven cleavage of the amyloid precursor protein (APP) gives rise to the amyloid β peptide, which is believed to be the main driver of neurodegeneration in Alzheimer’s disease (AD). As it is prominently detectable in extracellular plaques in post-mortem AD brain samples, research in recent decades focused on the pathological role of extracellular amyloid β aggregation, widely neglecting the potential meaning of very early generation of amyloid β inside the cell. In the last few years, the importance of intracellular amyloid β (iAβ) as a strong player in neurodegeneration has been indicated by a rising number of studies. In this review, iAβ is highlighted as a crucial APP cleavage fragment, able to manipulate intracellular pathways and foster neurodegeneration. We demonstrate its relevance as a pathological marker and shed light on initial studies aiming to modulate iAβ through pharmacological treatment, which has been shown to have beneficial effects on cognitive properties in animal models. Finally, we display the relevance of viral infections on iAβ generation and point out future directions urgently needed to manifest the potential relevance of iAβ in Alzheimer’s disease.
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Affiliation(s)
- Lucia Gallego Villarejo
- Department of Molecular Biochemistry, Cell Signalling, Ruhr University Bochum, 44801 Bochum, Germany; (L.G.V.); (L.B.); (D.M.); (M.B.); (A.G.)
| | - Lisa Bachmann
- Department of Molecular Biochemistry, Cell Signalling, Ruhr University Bochum, 44801 Bochum, Germany; (L.G.V.); (L.B.); (D.M.); (M.B.); (A.G.)
| | - David Marks
- Department of Molecular Biochemistry, Cell Signalling, Ruhr University Bochum, 44801 Bochum, Germany; (L.G.V.); (L.B.); (D.M.); (M.B.); (A.G.)
| | - Maite Brachthäuser
- Department of Molecular Biochemistry, Cell Signalling, Ruhr University Bochum, 44801 Bochum, Germany; (L.G.V.); (L.B.); (D.M.); (M.B.); (A.G.)
| | - Alexander Geidies
- Department of Molecular Biochemistry, Cell Signalling, Ruhr University Bochum, 44801 Bochum, Germany; (L.G.V.); (L.B.); (D.M.); (M.B.); (A.G.)
| | - Thorsten Müller
- Department of Molecular Biochemistry, Cell Signalling, Ruhr University Bochum, 44801 Bochum, Germany; (L.G.V.); (L.B.); (D.M.); (M.B.); (A.G.)
- Institute of Psychiatric Phenomics and Genomics (IPPG), LMU University Hospital, LMU Munich, 80336 Munich, Germany
- Correspondence:
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28
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Albuquerque HMT, Nunes da Silva R, Pereira M, Maia A, Guieu S, Soares AR, Santos CMM, Vieira SI, Silva AMS. Steroid-Quinoline Hybrids for Disruption and Reversion of Protein Aggregation Processes. ACS Med Chem Lett 2022; 13:443-448. [PMID: 35300075 PMCID: PMC8919386 DOI: 10.1021/acsmedchemlett.1c00604] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 02/08/2022] [Indexed: 12/21/2022] Open
Abstract
Reversing protein aggregation within cells may be an important tool to fight protein-misfolding disorders such as Alzheimer's, Parkinson's, and cardiovascular diseases. Here we report the design and synthesis of a family of steroid-quinoline hybrid compounds based on the framework combination approach. This set of hybrid compounds effectively inhibited Aβ1-42 self-aggregation in vitro by delaying the exponential growth phase and/or reducing the quantity of fibrils in the steady state. Their disaggregation efficacy was further demonstrated against preaggregated Aβ1-42 peptides in cellular assays upon their endocytosis by neuroblastoma cells, as they reverted both the number and the average area of fibrils back to basal levels. The antiaggregation effect of these hybrids was further tested and demonstrated in a cellular model of general protein aggregation expressing a protein aggregation fluorescent sensor. Together, our results show that the new cholesterol-quinoline hybrids possess wide and marked disaggregation capacities and are therefore promising templates for the development of new drugs to deal with conformational disorders.
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Affiliation(s)
- Hélio M T Albuquerque
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal
| | - Raquel Nunes da Silva
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.,Department of Medical Sciences and Institute of Biomedicine, IBiMED, University of Aveiro, Agras do Crasto, 3810-193 Aveiro, Portugal
| | - Marisa Pereira
- Department of Medical Sciences and Institute of Biomedicine, IBiMED, University of Aveiro, Agras do Crasto, 3810-193 Aveiro, Portugal
| | - André Maia
- Instituto de Investigação e Inovação em Saúde (i3S) and Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4200-135 Porto, Portugal
| | - Samuel Guieu
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.,CICECO Aveiro-Institute of Materials and Department of Chemistry, University of Aveiro, 3010-193 Aveiro, Portugal
| | - Ana Raquel Soares
- Department of Medical Sciences and Institute of Biomedicine, IBiMED, University of Aveiro, Agras do Crasto, 3810-193 Aveiro, Portugal
| | - Clementina M M Santos
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.,Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, 5300-252 Bragança, Portugal
| | - Sandra I Vieira
- Department of Medical Sciences and Institute of Biomedicine, IBiMED, University of Aveiro, Agras do Crasto, 3810-193 Aveiro, Portugal
| | - Artur M S Silva
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal
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29
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Amyloids facilitate DNA transfection in vivo. Neurosci Res 2022; 180:99-107. [DOI: 10.1016/j.neures.2022.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/08/2022] [Accepted: 03/08/2022] [Indexed: 11/18/2022]
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30
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Nazere K, Takahashi T, Hara N, Muguruma K, Nakamori M, Yamazaki Y, Morino H, Maruyama H. Amyloid Beta Is Internalized via Macropinocytosis, an HSPG- and Lipid Raft-Dependent and Rac1-Mediated Process. Front Mol Neurosci 2022; 15:804702. [PMID: 36187354 PMCID: PMC9524458 DOI: 10.3389/fnmol.2022.804702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 01/17/2022] [Indexed: 12/04/2022] Open
Abstract
Intracellular amyloid β peptide (Aβ) accumulation has drawn attention in relation to the pathophysiology of Alzheimer’s disease in addition to its extracellular deposition as senile plaque. Cellular uptake of extracellular Aβ is one of the possible mechanisms by which intracellular Aβ deposits form. Given the relevance of Aβ inside cells, it is important to understand the mechanism by which it is taken up by them. In this study, we elucidated that Neuro2A and SH-SY5Y cells internalize specifically oligomerized Aβ in a time- and dose-dependent manner. The depletion of plasma membrane cholesterol with methyl-β-cyclodextrin or treatment with trypsin diminished the internalization of oAβ, suggesting that the oAβ uptake might be both a lipid raft-dependent and heparan sulfate proteoglycan-mediated process. Treatment with a macropinocytosis inhibitor (ethylisopropyl amiloride and wortmannin) also drastically reduced the uptake of oligomer-Aβ (oAβ). oAβ-treated cells exhibited an increase in Rac1 activity, indicating that macropinocytosis induced by oAβ is regulated by these small GTPases. These findings suggest that macropinocytosis is a major endocytic route through which oAβ42 enters cells.
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Affiliation(s)
- Keyoumu Nazere
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Tetsuya Takahashi
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
- Department of Rehabilitation, Faculty of Rehabilitation, Hiroshima International University, Hiroshima, Japan
- *Correspondence: Tetsuya Takahashi
| | - Naoyuki Hara
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Kazuki Muguruma
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Masahiro Nakamori
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Yu Yamazaki
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Hiroyuki Morino
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
- Department of Medical Genetics, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Hirofumi Maruyama
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
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31
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Clark GT, Yu Y, Urban CA, Fu G, Wang C, Zhang F, Linhardt RJ, Hurley JM. Circadian control of heparan sulfate levels times phagocytosis of amyloid beta aggregates. PLoS Genet 2022; 18:e1009994. [PMID: 35143487 PMCID: PMC8830681 DOI: 10.1371/journal.pgen.1009994] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 12/14/2021] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's Disease (AD) is a neuroinflammatory disease characterized partly by the inability to clear, and subsequent build-up, of amyloid-beta (Aβ). AD has a bi-directional relationship with circadian disruption (CD) with sleep disturbances starting years before disease onset. However, the molecular mechanism underlying the relationship of CD and AD has not been elucidated. Myeloid-based phagocytosis, a key component in the metabolism of Aβ, is circadianly-regulated, presenting a potential link between CD and AD. In this work, we revealed that the phagocytosis of Aβ42 undergoes a daily circadian oscillation. We found the circadian timing of global heparan sulfate proteoglycan (HSPG) biosynthesis was the molecular timer for the clock-controlled phagocytosis of Aβ and that both HSPG binding and aggregation may play a role in this oscillation. These data highlight that circadian regulation in immune cells may play a role in the intricate relationship between the circadian clock and AD.
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Affiliation(s)
- Gretchen T. Clark
- Rensselaer Polytechnic Institute, Biological Sciences, Troy, New York, United States of America
| | - Yanlei Yu
- Rensselaer Polytechnic Institute, Chemistry and Chemical Biology, Troy, New York, United States of America
| | - Cooper A. Urban
- Rensselaer Polytechnic Institute, Biological Sciences, Troy, New York, United States of America
| | - Guo Fu
- Rensselaer Polytechnic Institute, Biological Sciences, Troy, New York, United States of America
- Now at the Innovation and Integration Center of New Laser Technology, Chinese Academy of Sciences, Shanghai, China
| | - Chunyu Wang
- Rensselaer Polytechnic Institute, Biological Sciences, Troy, New York, United States of America
- Rensselaer Polytechnic Institute, Chemistry and Chemical Biology, Troy, New York, United States of America
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, United States of America
| | - Fuming Zhang
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, United States of America
- Rensselaer Polytechnic Institute, Chemical and Biological Engineering, Troy, New York, United States of America
| | - Robert J. Linhardt
- Rensselaer Polytechnic Institute, Biological Sciences, Troy, New York, United States of America
- Rensselaer Polytechnic Institute, Chemistry and Chemical Biology, Troy, New York, United States of America
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, United States of America
- Rensselaer Polytechnic Institute, Chemical and Biological Engineering, Troy, New York, United States of America
| | - Jennifer M. Hurley
- Rensselaer Polytechnic Institute, Biological Sciences, Troy, New York, United States of America
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, United States of America
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32
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Zaretsky DV, Zaretskaia MV, Molkov YI. Membrane channel hypothesis of lysosomal permeabilization by beta-amyloid. Neurosci Lett 2021; 770:136338. [PMID: 34767924 DOI: 10.1016/j.neulet.2021.136338] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/29/2021] [Accepted: 11/03/2021] [Indexed: 11/16/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia affecting millions of people. Neuronal death in AD is initiated by oligomeric amyloid-β (Aβ) peptides. Recently, we proposed the amyloid degradation toxicity hypothesis, which explains multiple major observations associated with AD including autophagy failure and a decreased metabolism. According to the hypothesis, the key event in the cellular toxicity of amyloid is the formation of non-selective membrane channels in lysosomal membranes by amyloid fragments that are produced by the digestion of Aβ previously absorbed by endocytosis. Electrophysiological data suggest that amyloid-formed channels have different sizes, which can be explained by the fact that channel creating barrel-shaped amyloid aggregates can consist of different number of monomers. To estimate the ability of channels to leak molecules of various molecular weights, we modeled the channels as saline-filled cylinders in non-conductive membranes that pass spheres with a density of average globular proteins. As a basis, we used the conductance distribution taken from the previously published experimental dataset, in which single channels with electrical conductance of up to one nanosiemens were registered. Our calculations show that channels with such a giant conductance can allow for passing macromolecules such as large as lysosomal cathepsins implicated in the activation of apoptosis. The formation of giant channels is disproportionally promoted in an acidic environment. Also, amyloid fragments leaking from permeabilized lysosomes can reach the internal leaflet of the plasma membrane and permeabilize it. We conclude that while dissipation of the proton gradient by any (even smallest) amyloid channels readily explains lysosomal failure, the relatively rare events of lysosomal permeabilization to large macromolecules can be an additional mechanism of cellular death induced by exposure to Aβ.
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Affiliation(s)
| | | | - Yaroslav I Molkov
- Department of Mathematics and Statistics and Neuroscience Institute, Georgia State University, Atlanta, GA 30303, United States
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Wang Z, Sharda N, Curran GL, Li L, Lowe VJ, Kandimalla KK. Semimechanistic Population Pharmacokinetic Modeling to Investigate Amyloid Beta Trafficking and Accumulation at the BBB Endothelium. Mol Pharm 2021; 18:4148-4161. [PMID: 34664956 DOI: 10.1021/acs.molpharmaceut.1c00549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Elevated exposure to toxic amyloid beta (Aβ) peptides and consequent blood-brain barrier (BBB) dysfunction are believed to promote vasculopathy in Alzheimer's disease (AD). However, the accumulation kinetics of different Aβ isoforms within the BBB endothelium and how it drives BBB dysfunction are not clearly characterized. Using single positron emission computed tomography (SPECT)-computed tomography (CT) dynamic imaging coupled with population pharmacokinetic modeling, we investigated the accumulation kinetics of Aβ40 and Aβ42 in the BBB endothelium. Brain clearance was quantified after intracerebral administration of 125I-Aβ, and BBB-mediated transport was shown to account for 54% of 125I-Aβ40 total clearance. A brain influx study demonstrated lower values of both maximal rate (Vmax) and Michaelis constant (Km) for 125I-Aβ42 compared to 125I-Aβ40. Validated by a transcytosis study in polarized human BBB endothelial cell (hCMEC/D3) monolayers, model simulations demonstrated impaired exocytosis was responsible for inefficient permeability and enhanced accumulation of Aβ42 in the BBB endothelium. Further, both isoforms were shown to disrupt the exocytosis machinery of BBB endothelial cells so that a vicious cycle could be generated. The validated model was able to capture changes in Aβ steady-state levels in plasma as well as the brain during AD progression and allowed us to predict the kinetics of Aβ accumulation in the BBB endothelium.
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Affiliation(s)
- Zengtao Wang
- Department of Pharmaceutics and Brain Barriers Research Center, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United Sates
| | - Nidhi Sharda
- Department of Pharmaceutics and Brain Barriers Research Center, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United Sates
| | - Geoffry L Curran
- Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905, United Sates
| | - Ling Li
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United Sates
| | - Val J Lowe
- Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905, United Sates
| | - Karunya K Kandimalla
- Department of Pharmaceutics and Brain Barriers Research Center, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United Sates
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34
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Zaretsky DV, Zaretskaia MV. Intracellular ion changes induced by the exposure to beta-amyloid can be explained by the formation of channels in the lysosomal membranes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1869:119145. [PMID: 34606794 DOI: 10.1016/j.bbamcr.2021.119145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 08/29/2021] [Accepted: 09/05/2021] [Indexed: 10/20/2022]
Abstract
In this manuscript, we reassess the data on beta-amyloid-induced changes of intracellular ions concentrations published previously by Abramov et al. (2003, 2004). Their observations made using high-resolution confocal microscopy with fast temporal resolution of images formed by fluorescent ion-sensitive fluorescent probes in living cells represent an unequivocal support for the amyloid channel theory. However, closer look reveals multiple facts which cannot be explained by channel formation in plasma membrane. Recently proposed amyloid degradation toxicity hypothesis provides the interpretation to these facts by considering that channels are formed in the lysosomal membranes.
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Wen J, Zhao M, Sun W, Cheng X, Yu L, Cao D, Li P. Uptake of Aβ by OATPs might be a new pathophysiological mechanism of Alzheimer disease. BMC Neurosci 2021; 22:53. [PMID: 34521342 PMCID: PMC8439072 DOI: 10.1186/s12868-021-00658-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 09/01/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The accumulation of neurotoxic amyloid-beta (Aβ) in the brain is a characteristic of Alzheimer's disease (AD), at the same time, it is possible alterations of liver function could affect brain Aβ levels through changes in blood Aβ concentration. Over the last decade, a number of reports have shown that P-glycoprotein (encoded by ABC1B1) actively mediates the efflux transport of Aβ peptides. However, the mechanism by which Aβ peptides enter the cells is not clear. In the preliminary study, we found that the protein expression of organic anion transporting Polypeptide 1a4 (OATP1B1) in the liver tissue of mice with AD was significantly higher than that in the normal mice. In contrast, the protein expression of Oatp1a4 in the brain significantly decreased in mice with AD. OATP1B1, an important drug transporter might be related to the pathophysiology of AD. RESULTS In this study, we established an OATP1B1-GFP-HEK293T cell model to confirm the OATP1B1 mediated transport of Aβ1-42. Compared to the control group of GFP-HEK293Tcells, the uptake of Aβ1-42 protein in the OATP1B1-GFP-HEK293T group increased significantly with the increase in concentration of Aβ1-42, and also increased significantly with an increase in the duration of incubation. Similar results were observed in the flow cytometry experiment, and the uptake of Aβ1-42in HEK293T-OATP1B1 cells was almost twice that in the control group. These results indicate that OATPs may act as an important "carrier" for the transport of Aβ1-42 from the blood to the tissues, including liver and brain. CONCLUSIONS This is a novel and interesting finding and OATP1B1 can be investigated as a new treatment target for AD.
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Affiliation(s)
- Jinhua Wen
- Departmentof GCP/Psychosomatic Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.
| | - Menghua Zhao
- School of Pharmacy, Nanchang University, Nanchang, China
| | - Wenxiong Sun
- Departmentof GCP/Psychosomatic Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiaohua Cheng
- Departmentof GCP/Psychosomatic Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Luyi Yu
- Departmentof GCP/Psychosomatic Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Duanwen Cao
- Departmentof GCP/Psychosomatic Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Pu Li
- Departmentof GCP/Psychosomatic Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China
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36
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Qin H, Cui T, Liu Z, Zhou Y, Niu J, Ren J, Qu X. Engineering Amyloid Aggregation as a New Way to Eliminate Cancer Stem Cells by the Disruption of Iron Homeostasis. NANO LETTERS 2021; 21:7379-7387. [PMID: 34436904 DOI: 10.1021/acs.nanolett.1c02734] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Cancer stem cells (CSCs) play crucial roles in tumor initiation. Amyloid β (Aβ), which is associated with Alzheimer's disease (AD), has been identified to induce cytotoxicity in tumor cells besides brain cells. Herein, we find that oligomeric Aβ1-42 and Aβ1-40 (OAβ1-42 and OAβ1-40) can repress the viability of breast CSCs. Intriguingly, OAβ1-42 and OAβ1-40 preferentially induce the growth arrest of breast CSCs by contrast with the bulk cancer cells. Further studies indicate that OAβ1-42 and OAβ1-40 disturb iron homeostasis, which results in iron accumulation in lysosomes. The iron in lysosomes then induces ROS production by Fenton reaction, leading to breast CSC death. In vivo experiments show that the tumorigenesis of breast CSCs pretreated with OAβ1-42 is inhibited. These results reveal that OAβ1-42 and OAβ1-40 are multifaceted players with the ability to eliminate CSCs. Our work may provide a new clue to better understand the biological functions of amyloid oligomers.
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Affiliation(s)
- Hongshuang Qin
- Laboratory of Chemical Biology and State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Tingting Cui
- Laboratory of Chemical Biology and State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Zhenqi Liu
- Laboratory of Chemical Biology and State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Ya Zhou
- Laboratory of Chemical Biology and State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Jingsheng Niu
- Laboratory of Chemical Biology and State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Jinsong Ren
- Laboratory of Chemical Biology and State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Xiaogang Qu
- Laboratory of Chemical Biology and State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
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37
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Sheikh AM, Wada Y, Tabassum S, Inagaki S, Mitaki S, Yano S, Nagai A. Aggregation of Cystatin C Changes Its Inhibitory Functions on Protease Activities and Amyloid β Fibril Formation. Int J Mol Sci 2021; 22:ijms22189682. [PMID: 34575849 PMCID: PMC8465189 DOI: 10.3390/ijms22189682] [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: 07/29/2021] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 11/16/2022] Open
Abstract
Cystatin C (CST3) is an endogenous cysteine protease inhibitor, which is implicated in cerebral amyloid angiopathy (CAA). In CAA, CST3 is found to be aggregated. The purpose of this study is to investigate whether this aggregation could alter the activity of the protein relevant to the molecular pathology of CAA. A system of CST3 protein aggregation was established, and the aggregated protein was characterized. The results showed that CST3 aggregated both at 80 °C without agitation, and at 37 °C with agitation in a time-dependent manner. However, the levels of aggregation were high and appeared earlier at 80 °C. Dot-blot immunoassay for oligomers revealed that CST3 could make oligomeric aggregates at the 37 °C condition. Electron microscopy showed that CST3 could make short fibrillary aggregates at 37 °C. Cathepsin B activity assay demonstrated that aggregated CST3 inhibited the enzyme activity less efficiently at pH 5.5. At 7.4 pH, it lost the inhibitory properties almost completely. In addition, aggregated CST3 did not inhibit Aβ1-40 fibril formation, rather, it slightly increased it. CST3 immunocytochemistry showed that the protein was positive both in monomeric and aggregated CST3-treated neuronal culture. However, His6 immunocytochemistry revealed that the internalization of exogenous recombinant CST3 by an astrocytoma cell culture was higher when the protein was aggregated compared to its monomeric form. Finally, MTT cell viability assay showed that the aggregated form of CST3 was more toxic than the monomeric form. Thus, our results suggest that aggregation may result in a loss-of-function phenotype of CST3, which is toxic and responsible for cellular degeneration.
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Affiliation(s)
- Abdullah Md. Sheikh
- Department of Laboratory Medicine, Faculty of Medicine, Shimane University, 89-1 Enya Cho, Izumo 693-8501, Japan; (A.M.S.); (S.T.); (S.Y.)
| | - Yasuko Wada
- Department of Neurology, Faculty of Medicine, Shimane University, 89-1 Enya Cho, Izumo 693-8501, Japan; (Y.W.); (S.I.); (S.M.)
| | - Shatera Tabassum
- Department of Laboratory Medicine, Faculty of Medicine, Shimane University, 89-1 Enya Cho, Izumo 693-8501, Japan; (A.M.S.); (S.T.); (S.Y.)
| | - Satoshi Inagaki
- Department of Neurology, Faculty of Medicine, Shimane University, 89-1 Enya Cho, Izumo 693-8501, Japan; (Y.W.); (S.I.); (S.M.)
| | - Shingo Mitaki
- Department of Neurology, Faculty of Medicine, Shimane University, 89-1 Enya Cho, Izumo 693-8501, Japan; (Y.W.); (S.I.); (S.M.)
| | - Shozo Yano
- Department of Laboratory Medicine, Faculty of Medicine, Shimane University, 89-1 Enya Cho, Izumo 693-8501, Japan; (A.M.S.); (S.T.); (S.Y.)
| | - Atsushi Nagai
- Department of Laboratory Medicine, Faculty of Medicine, Shimane University, 89-1 Enya Cho, Izumo 693-8501, Japan; (A.M.S.); (S.T.); (S.Y.)
- Department of Neurology, Faculty of Medicine, Shimane University, 89-1 Enya Cho, Izumo 693-8501, Japan; (Y.W.); (S.I.); (S.M.)
- Correspondence: ; Tel./Fax: +81-0853-20-2198
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38
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Maguire E, Menzies GE, Phillips T, Sasner M, Williams HM, Czubala MA, Evans N, Cope EL, Sims R, Howell GR, Lloyd-Evans E, Williams J, Allen ND, Taylor PR. PIP2 depletion and altered endocytosis caused by expression of Alzheimer's disease-protective variant PLCγ2 R522. EMBO J 2021; 40:e105603. [PMID: 34254352 PMCID: PMC8408593 DOI: 10.15252/embj.2020105603] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/06/2021] [Accepted: 06/04/2021] [Indexed: 02/06/2023] Open
Abstract
Variants identified in genome-wide association studies have implicated immune pathways in the development of Alzheimer's disease (AD). Here, we investigated the mechanistic basis for protection from AD associated with PLCγ2 R522, a rare coding variant of the PLCG2 gene. We studied the variant's role in macrophages and microglia of newly generated PLCG2-R522-expressing human induced pluripotent cell lines (hiPSC) and knockin mice, which exhibit normal endogenous PLCG2 expression. In all models, cells expressing the R522 mutation show a consistent non-redundant hyperfunctionality in the context of normal expression of other PLC isoforms. This manifests as enhanced release of cellular calcium ion stores in response to physiologically relevant stimuli like Fc-receptor ligation or exposure to Aβ oligomers. Expression of the PLCγ2-R522 variant resulted in increased stimulus-dependent PIP2 depletion and reduced basal PIP2 levels in vivo. Furthermore, it was associated with impaired phagocytosis and enhanced endocytosis. PLCγ2 acts downstream of other AD-related factors, such as TREM2 and CSF1R, and alterations in its activity directly impact cell function. The inherent druggability of enzymes such as PLCγ2 raises the prospect of PLCγ2 manipulation as a future therapeutic approach in AD.
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Affiliation(s)
- Emily Maguire
- UK Dementia Research Institute at Cardiff, Cardiff, UK
| | - Georgina E Menzies
- UK Dementia Research Institute at Cardiff, Cardiff, UK.,School of Biosciences, Cardiff University, Cardiff, UK
| | | | | | | | | | - Neil Evans
- UK Dementia Research Institute at Cardiff, Cardiff, UK
| | - Emma L Cope
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Rebecca Sims
- MRC Centre for Neuropsychiatric Genetics & Genomics, Cardiff, UK
| | | | | | - Julie Williams
- UK Dementia Research Institute at Cardiff, Cardiff, UK.,MRC Centre for Neuropsychiatric Genetics & Genomics, Cardiff, UK
| | | | - Philip R Taylor
- UK Dementia Research Institute at Cardiff, Cardiff, UK.,Systems Immunity University Research Institute, Cardiff, UK
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39
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Joshi P, Riffel F, Satoh K, Enomoto M, Qamar S, Scheiblich H, Villacampa N, Kumar S, Theil S, Parhizkar S, Haass C, Heneka MT, Fraser PE, St George-Hyslop P, Walter J. Differential interaction with TREM2 modulates microglial uptake of modified Aβ species. Glia 2021; 69:2917-2932. [PMID: 34427354 DOI: 10.1002/glia.24077] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/02/2021] [Accepted: 08/06/2021] [Indexed: 12/29/2022]
Abstract
Rare coding variants of the microglial triggering receptor expressed on myeloid cells 2 (TREM2) confer an increased risk for Alzheimer's disease (AD) characterized by the progressive accumulation of aggregated forms of amyloid β peptides (Aβ). Aβ peptides are generated by proteolytic processing of the amyloid precursor protein (APP). Heterogeneity in proteolytic cleavages and additional post-translational modifications result in the production of several distinct Aβ variants that could differ in their aggregation behavior and toxic properties. Here, we sought to assess whether post-translational modifications of Aβ affect the interaction with TREM2. Biophysical and biochemical methods revealed that TREM2 preferentially interacts with oligomeric Aβ, and that phosphorylation of Aβ increases this interaction. Phosphorylation of Aβ also affected the TREM2 dependent interaction and phagocytosis by primary microglia and in APP transgenic mouse models. Thus, TREM2 function is important for sensing phosphorylated Aβ variants in distinct aggregation states and reduces the accumulation and deposition of these toxic Aβ species in preclinical models of Alzheimer's disease.
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Affiliation(s)
- Pranav Joshi
- Department of Neurology, University of Bonn, Bonn, Germany
| | - Florian Riffel
- Department of Neurology, University of Bonn, Bonn, Germany
| | - Kanayo Satoh
- Departments of Medical Biophysics and Medicine (Neurology), Tanz Centre for Research in Neurodegenerative Diseases and, Toronto, Ontario, Canada
| | - Masahiro Enomoto
- Princess Margaret Cancer Centre Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Seema Qamar
- Cambridge Institute for Medical Research, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Hannah Scheiblich
- Department of Neurodegenerative Diseases and Gerontopsychiatry, University Hospital Bonn, Bonn, Germany.,Neuroinflammation Unit, German Center for Neurodegenerative Diseases e. V. (DZNE), Bonn, Germany
| | - Nàdia Villacampa
- Department of Neurodegenerative Diseases and Gerontopsychiatry, University Hospital Bonn, Bonn, Germany.,Neuroinflammation Unit, German Center for Neurodegenerative Diseases e. V. (DZNE), Bonn, Germany
| | - Sathish Kumar
- Department of Neurology, University of Bonn, Bonn, Germany
| | - Sandra Theil
- Department of Neurology, University of Bonn, Bonn, Germany
| | - Samira Parhizkar
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Christian Haass
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Molecular Neurodegeneration Unit, German Center for Neurodegenerative Diseases e.V. (DZNE) Munich, Munich, Germany
| | - Michael T Heneka
- Department of Neurodegenerative Diseases and Gerontopsychiatry, University Hospital Bonn, Bonn, Germany.,Neuroinflammation Unit, German Center for Neurodegenerative Diseases e. V. (DZNE), Bonn, Germany
| | - Paul E Fraser
- Departments of Medical Biophysics and Medicine (Neurology), Tanz Centre for Research in Neurodegenerative Diseases and, Toronto, Ontario, Canada
| | - Peter St George-Hyslop
- Departments of Medical Biophysics and Medicine (Neurology), Tanz Centre for Research in Neurodegenerative Diseases and, Toronto, Ontario, Canada.,Cambridge Institute for Medical Research, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Jochen Walter
- Department of Neurology, University of Bonn, Bonn, Germany
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40
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Huang MY, Yu GR. Cycloastragenol inhibits Aβ 1-42-induced blood-brain barrier disruption and enhances soluble Aβ efflux in vitro. JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH 2021; 23:556-569. [PMID: 32608254 DOI: 10.1080/10286020.2020.1786372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 06/18/2020] [Indexed: 06/11/2023]
Abstract
This study aimed to evaluate the effect Cycloastragenol (CAG), a triterpenoid saponin isolated from the Radix astragali, on Aβ-induced BBB damage. An immortalized endothelial cell line (bEnd.3) was employed to mimic a BBB. The Western blot, TUNEL staining, Flow cytometric analysis and Enzyme-linked immunosorbent assay were performed. The present results showed that CAG (10, 50, 75 μM) can alleviate oligomer Aβ1-42 induced bEnd.3 cell apoptosis and increase tight junction scaffold proteins expression. The result also indicated that CAG increased soluble Aβ efflux across BBB via upregulation of the P-gp and downregulation of RAGE expression.[Formula: see text].
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Affiliation(s)
- Min-Ye Huang
- Department of Neurology, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing 210029, China
| | - Gu-Ran Yu
- Department of Neurology, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing 210029, China
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41
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Pannuzzo M. Beta-amyloid pore linked to controlled calcium influx into the cell: A new paradigm for Alzheimer's Disease. Alzheimers Dement 2021; 18:191-196. [PMID: 34051062 PMCID: PMC9290490 DOI: 10.1002/alz.12373] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/20/2021] [Accepted: 04/16/2021] [Indexed: 11/28/2022]
Abstract
Despite tremendous worldwide efforts, clinical trials assessing Alzheimer's disease (AD)‐related therapeutics have been relentlessly unsuccessful. Hence, there is an urgent need to challenge old hypotheses with novel paradigms. An emerging concept is that the amyloid‐beta (Aβ) peptide, which was until recently deemed a major player in the cause of AD, may instead modulate synaptic plasticity and protect against excitotoxicity. The link between Aβ‐mediated synaptic plasticity and Aβ trafficking is central for understanding AD pathogenesis and remains a perplexing relationship. The crossover between Aβ pathological and physiological roles is subtle and remains controversial. Based on existing literature, as a signaling molecule, Aβ is proposed to modulate its own turnover and synaptic plasticity through what is currently believed to be the cause of AD: the transient formation of pore‐like oligomers. A change of perspective regarding how Aβ pores exert a protective function will unavoidably revolutionize the entire field of anti‐amyloid drug development.
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Affiliation(s)
- Martina Pannuzzo
- Laboratory of Nanotechnology for Precision Medicine, Fondazione Istituto Italiano di Tecnologia, Genoa, Italy
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42
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Contribution of Syndecans to the Cellular Entry of SARS-CoV-2. Int J Mol Sci 2021; 22:ijms22105336. [PMID: 34069441 PMCID: PMC8159090 DOI: 10.3390/ijms22105336] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 05/14/2021] [Accepted: 05/16/2021] [Indexed: 12/13/2022] Open
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel emerging pathogen causing an unprecedented pandemic in 21st century medicine. Due to the significant health and economic burden of the current SARS-CoV-2 outbreak, there is a huge unmet medical need for novel interventions effectively blocking SARS-CoV-2 infection. Unknown details of SARS-CoV-2 cellular biology hamper the development of potent and highly specific SARS-CoV-2 therapeutics. Angiotensin-converting enzyme-2 (ACE2) has been reported to be the primary receptor for SARS-CoV-2 cellular entry. However, emerging scientific evidence suggests the involvement of additional membrane proteins, such as heparan sulfate proteoglycans, in SARS-CoV-2 internalization. Here, we report that syndecans, the evolutionarily conserved family of transmembrane proteoglycans, facilitate the cellular entry of SARS-CoV-2. Among syndecans, the lung abundant syndecan-4 was the most efficient in mediating SARS-CoV-2 uptake. The S1 subunit of the SARS-CoV-2 spike protein plays a dominant role in the virus's interactions with syndecans. Besides the polyanionic heparan sulfate chains, other parts of the syndecan ectodomain, such as the cell-binding domain, also contribute to the interaction with SARS-CoV-2. During virus internalization, syndecans colocalize with ACE2, suggesting a jointly shared internalization pathway. Both ACE2 and syndecan inhibitors exhibited significant efficacy in reducing the cellular entry of SARS-CoV-2, thus supporting the complex nature of internalization. Data obtained on syndecan specific in vitro assays present syndecans as novel cellular targets of SARS-CoV-2 and offer molecularly precise yet simple strategies to overcome the complex nature of SARS-CoV-2 infection.
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Goldwaser EL, Acharya NK, Wu H, Godsey GA, Sarkar A, DeMarshall CA, Kosciuk MC, Nagele RG. Evidence that Brain-Reactive Autoantibodies Contribute to Chronic Neuronal Internalization of Exogenous Amyloid-β1-42 and Key Cell Surface Proteins During Alzheimer's Disease Pathogenesis. J Alzheimers Dis 2021; 74:345-361. [PMID: 32039847 PMCID: PMC7175946 DOI: 10.3233/jad-190962] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Blood-brain barrier (BBB) permeability is a recognized early feature of Alzheimer’s disease (AD). In the present study, we examined consequences of increased BBB permeability on the development of AD-related pathology by tracking selected leaked plasma components and their interactions with neurons in vivo and in vitro. Histological sections of cortical regions of postmortem AD brains were immunostained to determine the distribution of amyloid-β1-42 (Aβ42), cathepsin D, IgG, GluR2/3, and alpha7 nicotinic acetylcholine receptor (α7nAChR). Results revealed that chronic IgG binding to pyramidal neurons coincided with internalization of Aβ42, IgG, GluR2/3, and α7nAChR as well as lysosomal compartment expansion in these cells in regions of AD pathology. To test possible mechanistic interrelationships of these phenomena, we exposed differentiated SH-SY5Y neuroblastoma cells to exogenous, soluble Aβ42 peptide and serum from AD and control subjects. The rate and extent of Aβ42 internalization in these cells was enhanced by serum containing neuron-binding IgG autoantibodies. This was confirmed by treating cells with individual antibodies specific for α7nAChR, purified IgG from AD or non-AD sera, and sera devoid of IgG, in the presence of 100 nM Aβ42. Initial co-localization of IgG, α7nAChR, and Aβ42 was temporally and spatially linked to early endosomes (Rab11) and later to lysosomes (LAMP-1). Aβ42 internalization was attenuated by treatment with monovalent F(ab) antibody fragments generated from purified IgG from AD serum and then rescued by coupling F(ab) fragments with divalent human anti-Fab. Overall, results suggest that cross-linking of neuron-binding autoantibodies targeting cell surface proteins can accelerate intraneuronal Aβ42 deposition in AD.
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Affiliation(s)
- Eric L Goldwaser
- University of Maryland Medical Center and Sheppard Pratt Health System, Department of Psychiatry, Baltimore, MD, USA.,Biomarker Discovery Center, New Jersey Institute for Successful Aging, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA.,Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
| | - Nimish K Acharya
- Biomarker Discovery Center, New Jersey Institute for Successful Aging, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA.,Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA.,Department of Geriatrics and Gerontology, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
| | - Hao Wu
- Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
| | - George A Godsey
- Biomarker Discovery Center, New Jersey Institute for Successful Aging, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA.,Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
| | - Abhirup Sarkar
- Biomarker Discovery Center, New Jersey Institute for Successful Aging, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA.,Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
| | - Cassandra A DeMarshall
- Biomarker Discovery Center, New Jersey Institute for Successful Aging, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA.,Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
| | - Mary C Kosciuk
- Biomarker Discovery Center, New Jersey Institute for Successful Aging, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA.,Department of Geriatrics and Gerontology, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
| | - Robert G Nagele
- Biomarker Discovery Center, New Jersey Institute for Successful Aging, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA.,Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA.,Department of Geriatrics and Gerontology, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
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44
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Vidal C, Zhang L. An Analysis of the Neurological and Molecular Alterations Underlying the Pathogenesis of Alzheimer's Disease. Cells 2021; 10:cells10030546. [PMID: 33806317 PMCID: PMC7998384 DOI: 10.3390/cells10030546] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/26/2021] [Accepted: 03/03/2021] [Indexed: 12/19/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by amyloid beta (Aβ) plaques, neurofibrillary tangles, and neuronal loss. Unfortunately, despite decades of studies being performed on these histological alterations, there is no effective treatment or cure for AD. Identifying the molecular characteristics of the disease is imperative to understanding the pathogenesis of AD. Furthermore, uncovering the key causative alterations of AD can be valuable in developing models for AD treatment. Several alterations have been implicated in driving this disease, including blood–brain barrier dysfunction, hypoxia, mitochondrial dysfunction, oxidative stress, glucose hypometabolism, and altered heme homeostasis. Although these alterations have all been associated with the progression of AD, the root cause of AD has not been identified. Intriguingly, recent studies have pinpointed dysfunctional heme metabolism as a culprit of the development of AD. Heme has been shown to be central in neuronal function, mitochondrial respiration, and oxidative stress. Therefore, dysregulation of heme homeostasis may play a pivotal role in the manifestation of AD and its various alterations. This review will discuss the most common neurological and molecular alterations associated with AD and point out the critical role heme plays in the development of this disease.
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Affiliation(s)
| | - Li Zhang
- Correspondence: ; Tel.: +1-972-883-5757
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45
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Mallach A, Gobom J, Zetterberg H, Hardy J, Piers TM, Wray S, Pocock JM. The influence of the R47H triggering receptor expressed on myeloid cells 2 variant on microglial exosome profiles. Brain Commun 2021; 3:fcab009. [PMID: 34704019 PMCID: PMC8244649 DOI: 10.1093/braincomms/fcab009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 01/08/2023] Open
Abstract
Variants in the triggering receptor expressed on myeloid cells 2 gene are linked with an increased risk of dementia, in particular the R47Hhet triggering receptor expressed on myeloid cells 2 variant is linked to late-onset Alzheimer's disease. Using human induced pluripotent stem cells-derived microglia, we assessed whether variations in the dynamics of exosome secretion, including their components, from these cells might underlie some of this risk. We found exosome size was not altered between common variant controls and R47Hhet variants, but the amount and constitution of exosomes secreted were different. Exosome quantities were rescued by incubation with an ATP donor or with lipids via a phosphatidylserine triggering receptor expressed on myeloid cells 2 ligand. Following a lipopolysaccharide or phagocytic cell stimulus, exosomes from common variant and R47Hhet microglia were found to contain cytokines, chemokines, APOE and triggering receptor expressed on myeloid cells 2. Differences were observed in the expression of CCL22, IL-1β and triggering receptor expressed on myeloid cells 2 between common variant and R47Hhet derived exosomes. Furthermore unlike common variant-derived exosomes, R47Hhet exosomes contained additional proteins linked to negative regulation of transcription and metabolic processes. Subsequent addition of exosomes to stressed neurones showed R47Hhet-derived exosomes to be less protective. These data have ramifications for the responses of microglia in Alzheimer's disease and may point to further targets for therapeutic intervention.
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Affiliation(s)
- Anna Mallach
- Department of Neuroinflammation, Queen Square Institute of Neurology, University College London, London WC1N 1PJ, UK
| | - Johan Gobom
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, S-431 80, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, S-431 80, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
- Department of Neurodegenerative Disease, University College London Queen Square Institute of Neurology, London WC1N 1PJ, UK
- Department of Neurodegenerative Disease, University College London Queen Square Institute of Neurology, London WC1N 3BG, UK
- UK Dementia Research Institute University College London, London WC1E 6BT, UK
| | - John Hardy
- Department of Neurodegenerative Disease, University College London Queen Square Institute of Neurology, London WC1N 1PJ, UK
- Department of Neurodegenerative Disease, University College London Queen Square Institute of Neurology, London WC1N 3BG, UK
- UK Dementia Research Institute University College London, London WC1E 6BT, UK
- Reta Lila Weston Institute, UCL Queen Square Institute of Neurology, London WC1N 1PJ, UK
- NIHR University College London Hospitals Biomedical Research Centre, London, UK
- Institute for Advanced Study, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Thomas M Piers
- Department of Neuroinflammation, Queen Square Institute of Neurology, University College London, London WC1N 1PJ, UK
| | - Selina Wray
- Department of Neurodegenerative Disease, University College London Queen Square Institute of Neurology, London WC1N 1PJ, UK
- Department of Neurodegenerative Disease, University College London Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Jennifer M Pocock
- Department of Neuroinflammation, Queen Square Institute of Neurology, University College London, London WC1N 1PJ, UK
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46
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Evidence for aggregation-independent, PrP C-mediated Aβ cellular internalization. Proc Natl Acad Sci U S A 2020; 117:28625-28631. [PMID: 33139554 DOI: 10.1073/pnas.2009238117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Evidence linking amyloid beta (Aβ) cellular uptake and toxicity has burgeoned, and mechanisms underlying this association are subjects of active research. Two major, interconnected questions are whether Aβ uptake is aggregation-dependent and whether it is sequence-specific. We recently reported that the neuronal uptake of Aβ depends significantly on peptide chirality, suggesting that the process is predominantly receptor-mediated. Over the past decade, the cellular prion protein (PrPC) has emerged as an important mediator of Aβ-induced toxicity and of neuronal Aβ internalization. Here, we report that the soluble, nonfibrillizing Aβ (1-30) peptide recapitulates full-length Aβ stereoselective cellular uptake, allowing us to decouple aggregation from cellular, receptor-mediated internalization. Moreover, we found that Aβ (1-30) uptake is also dependent on PrPC expression. NMR-based molecular-level characterization identified the docking site on PrPC that underlies the stereoselective binding of Aβ (1-30). Our findings therefore identify a specific sequence within Aβ that is responsible for the recognition of the peptide by PrPC, as well as PrPC-dependent cellular uptake. Further uptake stereodifferentiation in PrPC-free cells points toward additional receptor-mediated interactions as likely contributors for Aβ cellular internalization. Taken together, our results highlight the potential of targeting cellular surface receptors to inhibit Aβ cellular uptake as an alternative route for future therapeutic development for Alzheimer's disease.
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Rasgado LAV, Urbieta AT, Jiménez JMM. Affected albumin endocytosis as a new neurotoxicity mechanism of amyloid beta. AIMS Neurosci 2020; 7:344-359. [PMID: 32995492 PMCID: PMC7519963 DOI: 10.3934/neuroscience.2020021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 09/17/2020] [Indexed: 11/18/2022] Open
Abstract
Senile plaques, a hallmark of Alzheimer's disease, are composed by Amyloid-Beta (Aβ). Aβ 25-35 toxicity is caused mainly by increasing reactive oxygen species (ROS), which is reversed by albumin preventing Aβ internalization. In addition, key cellular processes and basic cell functions require of endocytosis, particularly relevant in neurons. To understand the protective effect of albumin and the toxicity mechanism of Aβ, the need of albumin uptake for neurons protection as well as the possible influence of Aβ on albumin endocytosis were investigated. With this aim the influence of lectin from soybeans (LEC), which prevents albumin endocytosis, on the effects of Aβ 25-35 on cellular morphology and viability, ROS generation and Aβ uptake with and without albumin in neurons in primary culture was investigated. Influence of Aβ on albumin endocytosis was studied using FITC-labelled albumin. LEC did not modify Aβ effects with or without albumin on neuronal morphology, but increased cell viability. LEC increased ROS generation with and without Aβ in the same magnitude. Diminished Aβ internalization observed with albumin was not affected by LEC. In presence of Aβ albumin is internalized, but endosomes did not deliver their cargo to the lysosomes for degradation. It is concluded that formation of Aβ-albumin complex does not require of albumin internalization, thus is extracellular. Aβ affects albumin endocytosis preventing late endosomes and lysosomes degradation, probably caused by changes in albumin structure or deregulation in vesicular transport. Considering the consequences such as its osmotic effects, the inability to exert its antioxidant properties, its effects on neuronal plasticity and excitability albumin affected endocytosis induced by Aβ is proposed as a new physiopathology mechanism in AD. It is hypothesized that there is critical intraneuronal level above which albumin becomes toxic.
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Affiliation(s)
- Lourdes A Vega Rasgado
- Laboratorio de Neuroquímica, Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Arantxa Tabernero Urbieta
- Instituto de Neurociencias de Castilla y León (INCYL), c/Pintor Fernando Gallego 1, 37007 Salamanca, Spain
| | - José María Medina Jiménez
- Instituto de Neurociencias de Castilla y León (INCYL), c/Pintor Fernando Gallego 1, 37007 Salamanca, Spain
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48
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Small GTPases of the Ras and Rho Families Switch on/off Signaling Pathways in Neurodegenerative Diseases. Int J Mol Sci 2020. [DOI: 10.3390/ijms21176312
expr 858053618 + 832508766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
Small guanosine triphosphatases (GTPases) of the Ras superfamily are key regulators of many key cellular events such as proliferation, differentiation, cell cycle regulation, migration, or apoptosis. To control these biological responses, GTPases activity is regulated by guanine nucleotide exchange factors (GEFs), GTPase activating proteins (GAPs), and in some small GTPases also guanine nucleotide dissociation inhibitors (GDIs). Moreover, small GTPases transduce signals by their downstream effector molecules. Many studies demonstrate that small GTPases of the Ras family are involved in neurodegeneration processes. Here, in this review, we focus on the signaling pathways controlled by these small protein superfamilies that culminate in neurodegenerative pathologies, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). Specifically, we concentrate on the two most studied families of the Ras superfamily: the Ras and Rho families. We summarize the latest findings of small GTPases of the Ras and Rho families in neurodegeneration in order to highlight these small proteins as potential therapeutic targets capable of slowing down different neurodegenerative diseases.
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Arrazola Sastre A, Luque Montoro M, Gálvez-Martín P, Lacerda HM, Lucia A, Llavero F, Zugaza JL. Small GTPases of the Ras and Rho Families Switch on/off Signaling Pathways in Neurodegenerative Diseases. Int J Mol Sci 2020; 21:E6312. [PMID: 32878220 PMCID: PMC7504559 DOI: 10.3390/ijms21176312] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 08/28/2020] [Accepted: 08/29/2020] [Indexed: 12/16/2022] Open
Abstract
Small guanosine triphosphatases (GTPases) of the Ras superfamily are key regulators of many key cellular events such as proliferation, differentiation, cell cycle regulation, migration, or apoptosis. To control these biological responses, GTPases activity is regulated by guanine nucleotide exchange factors (GEFs), GTPase activating proteins (GAPs), and in some small GTPases also guanine nucleotide dissociation inhibitors (GDIs). Moreover, small GTPases transduce signals by their downstream effector molecules. Many studies demonstrate that small GTPases of the Ras family are involved in neurodegeneration processes. Here, in this review, we focus on the signaling pathways controlled by these small protein superfamilies that culminate in neurodegenerative pathologies, such as Alzheimer's disease (AD) and Parkinson's disease (PD). Specifically, we concentrate on the two most studied families of the Ras superfamily: the Ras and Rho families. We summarize the latest findings of small GTPases of the Ras and Rho families in neurodegeneration in order to highlight these small proteins as potential therapeutic targets capable of slowing down different neurodegenerative diseases.
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Affiliation(s)
- Alazne Arrazola Sastre
- Achucarro Basque Center for Neuroscience, Science Park of the Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 48940 Leioa, Spain; (A.A.S.); (M.L.M.)
- Department of Genetics, Physical Anthropology, and Animal Physiology, Faculty of Science and Technology, UPV/EHU, 48940 Leioa, Spain
| | - Miriam Luque Montoro
- Achucarro Basque Center for Neuroscience, Science Park of the Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 48940 Leioa, Spain; (A.A.S.); (M.L.M.)
| | - Patricia Gálvez-Martín
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Granada, 180041 Granada, Spain;
- R&D Human Health, Bioibérica S.A.U., 08950 Barcelona, Spain
| | | | - Alejandro Lucia
- Faculty of Sport Science, European University of Madrid, 28670 Madrid, Spain;
- Research Institute of the Hospital 12 de Octubre (i+12), 28041 Madrid, Spain
| | - Francisco Llavero
- Achucarro Basque Center for Neuroscience, Science Park of the Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 48940 Leioa, Spain; (A.A.S.); (M.L.M.)
- Faculty of Sport Science, European University of Madrid, 28670 Madrid, Spain;
| | - José Luis Zugaza
- Achucarro Basque Center for Neuroscience, Science Park of the Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 48940 Leioa, Spain; (A.A.S.); (M.L.M.)
- Department of Genetics, Physical Anthropology, and Animal Physiology, Faculty of Science and Technology, UPV/EHU, 48940 Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
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50
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Wesén E, Lundmark R, Esbjörner EK. Role of Membrane Tension Sensitive Endocytosis and Rho GTPases in the Uptake of the Alzheimer's Disease Peptide Aβ(1-42). ACS Chem Neurosci 2020; 11:1925-1936. [PMID: 32497421 PMCID: PMC7497631 DOI: 10.1021/acschemneuro.0c00053] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Intraneuronal accumulation of amyloid-β (Aβ) is an early pathological signum of Alzheimer's disease, and compartments of the endolysosomal system have been implicated in both seeding and cell-cell propagation of Aβ aggregation. We have studied how clathrin-independent mechanisms contribute to Aβ endocytosis, exploring pathways that are sensitive to changes in membrane tension and the regulation of Rho GTPases. Using live cell confocal microscopy and flow cytometry, we show the uptake of monomeric Aβ(1-42) into endocytic vesicles and vacuole-like dilations, following relaxation of osmotic pressure-induced cell membrane tension. This indicates Aβ(1-42) uptake via clathrin independent carriers (CLICs), although overexpression of the bar-domain protein GRAF1, a key regulator of CLICs, had no apparent effect. We furthermore report reduced Aβ(1-42) uptake following overexpression of constitutively active forms of the Rho GTPases Cdc42 and RhoA, whereas modulation of Rac1, which is linked to macropinosome formation, had no effect. Our results confirm that uptake of Aβ(1-42) is clathrin- and dynamin-independent and point to the involvement of a new and distinct clathrin-independent endocytic mechanism which is similar to uptake via CLICs or macropinocytosis but that also appear to involve yet uncharacterized molecular players.
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Affiliation(s)
- Emelie Wesén
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
| | - Richard Lundmark
- Department of Integrative Medical Biology, Umeå University, Umeå 901 87, Sweden
| | - Elin K. Esbjörner
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
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