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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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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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Pluta R, Kocki J, Bogucki J, Bogucka-Kocka A, Czuczwar SJ. LRP1 and RAGE Genes Transporting Amyloid and Tau Protein in the Hippocampal CA3 Area in an Ischemic Model of Alzheimer's Disease with 2-Year Survival. Cells 2023; 12:2763. [PMID: 38067191 PMCID: PMC10706460 DOI: 10.3390/cells12232763] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 11/21/2023] [Accepted: 12/02/2023] [Indexed: 12/18/2023] Open
Abstract
Explaining changes at the gene level that occur during neurodegeneration in the CA3 area is crucial from the point of view of memory impairment and the development of post-ischemic dementia. An ischemic model of Alzheimer's disease was used to evaluate changes in the expression of genes related to amyloid transport in the CA3 region of the hippocampus after 10 min of brain ischemia with survival of 2, 7 and 30 days and 12, 18 and 24 months. The quantitative reverse transcriptase PCR assay revealed that the expression of the LRP1 and RAGE genes involved in amyloid transport was dysregulated from 2 days to 24 months post-ischemia in the CA3 area of the hippocampus. LRP1 gene expression 2 and 7 days after ischemia was below control values. However, its expression from day 30 to 24 months, survival after an ischemic episode was above control values. RAGE gene expression 2 days after ischemia was below control values, reaching a maximum increase 7 and 30 days post-ischemia. Then, after 12, 18 and 24 months, it was again below the control values. The data indicate that in the CA3 area of the hippocampus, an episode of brain ischemia causes the increased expression of the RAGE gene for 7-30 days during the acute phase and that of LRP1 from 1 to 24 months after ischemia during the chronic stage. In other words, in the early post-ischemic stage, the expression of the gene that transport amyloid to the brain increases (7-30 days). Conversely, in the late post-ischemic stage, amyloid scavenging/cleaning gene activity increases, reducing and/or preventing further neuronal damage or facilitating the healing of damaged sites. This is how the new phenomenon of pyramidal neuronal damage in the CA3 area after ischemia is defined. In summary, post-ischemic modification of the LRP1 and RAGE genes is useful in the study of the ischemic pathways and molecular factors involved in the development of Alzheimer's disease.
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Affiliation(s)
- Ryszard Pluta
- Department of Pathophysiology, Medical University of Lublin, 20-090 Lublin, Poland;
| | - Janusz Kocki
- Department of Clinical Genetics, Medical University of Lublin, 20-080 Lublin, Poland;
| | - Jacek Bogucki
- Department of Organic Chemistry, Faculty of Pharmacy, Medical University of Lublin, 20-093 Lublin, Poland;
| | - Anna Bogucka-Kocka
- Department of Biology and Genetics, Medical University of Lublin, 20-093 Lublin, Poland;
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Piccirillo S, Preziuso A, Cerqueni G, Serfilippi T, Terenzi V, Vinciguerra A, Amoroso S, Lariccia V, Magi S. A strategic tool to improve the study of molecular determinants of Alzheimer's disease: The role of glyceraldehyde. Biochem Pharmacol 2023; 218:115869. [PMID: 37871878 DOI: 10.1016/j.bcp.2023.115869] [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: 08/20/2023] [Revised: 10/14/2023] [Accepted: 10/17/2023] [Indexed: 10/25/2023]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia and is characterized by progressive neurodegeneration leading to severe cognitive, memory, and behavioral impairments. The onset of AD involves a complex interplay among various factors, including age, genetics, chronic inflammation, and impaired energy metabolism. Despite significant efforts, there are currently no effective therapies capable of modifying the course of AD, likely owing to an excessive focus on the amyloid hypothesis and a limited consideration of other intracellular pathways. In the present review, we emphasize the emerging concept of AD as a metabolic disease, where alterations in energy metabolism play a critical role in its development and progression. Notably, glucose metabolism impairment is associated with mitochondrial dysfunction, oxidative stress, Ca2+ dyshomeostasis, and protein misfolding, forming interconnected processes that perpetuate a detrimental self-feeding loop sustaining AD progression. Advanced glycation end products (AGEs), neurotoxic compounds that accumulate in AD, are considered an important consequence of glucose metabolism disruption, and glyceraldehyde (GA), a glycolytic intermediate, is a key contributor to AGEs formation in both neurons and astrocytes. Exploring the impact of GA-induced glucose metabolism impairment opens up exciting possibilities for creating an easy-to-handle in vitro model that recapitulates the early stage of the disease. This model holds great potential for advancing the development of novel therapeutics targeting various intracellular pathways implicated in AD pathogenesis. In conclusion, looking beyond the conventional amyloid hypothesis could lead researchers to discover promising targets for intervention, offering the possibility of addressing the existing medical gaps in AD treatment.
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Affiliation(s)
- Silvia Piccirillo
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126 Ancona, Italy.
| | - Alessandra Preziuso
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126 Ancona, Italy.
| | - Giorgia Cerqueni
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126 Ancona, Italy.
| | - Tiziano Serfilippi
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126 Ancona, Italy.
| | - Valentina Terenzi
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126 Ancona, Italy.
| | - Antonio Vinciguerra
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126 Ancona, Italy.
| | - Salvatore Amoroso
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126 Ancona, Italy.
| | - Vincenzo Lariccia
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126 Ancona, Italy.
| | - Simona Magi
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126 Ancona, Italy.
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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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6
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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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Deng S, Yi P, Xu M, Yi Q, Feng J. Dysfunctional gene splicing in glucose metabolism may contribute to Alzheimer's disease. Chin Med J (Engl) 2023; 136:666-675. [PMID: 35830275 PMCID: PMC10129079 DOI: 10.1097/cm9.0000000000002214] [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: 12/14/2022] [Indexed: 11/26/2022] Open
Abstract
ABSTRACT The glucose metabolism is crucial for sustained brain activity as it provides energy and is a carbon source for multiple biomacromolecules; glucose metabolism decreases dramatically in Alzheimer's disease (AD) and may be a fundamental cause for its development. Recent studies reveal that the alternative splicing events of certain genes effectively regulate several processes in glucose metabolism including insulin receptor, insulin-degrading enzyme, pyruvate kinase M, receptor for advanced glycation endproducts, and others, thereby, influencing glucose uptake, glycolysis, and advanced glycation end-products-mediated signaling pathways. Indeed, the discovery of aberrant alternative splicing that changes the proteomic diversity and protein activity in glucose metabolism has been pivotal in our understanding of AD development. In this review, we summarize the alternative splicing events of the glucose metabolism-related genes in AD pathology and highlight the crucial regulatory roles of splicing factors in the alternative splicing process. We also discuss the emerging therapeutic approaches for targeting splicing factors for AD treatment.
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Affiliation(s)
- Shengfeng Deng
- Laboratory of Anesthesiology, Department of Anesthesiology, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Peng Yi
- Laboratory of Anesthesiology, Department of Anesthesiology, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Mingliang Xu
- Laboratory of Anesthesiology, Department of Anesthesiology, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Qian Yi
- Department of Physiology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Jianguo Feng
- Laboratory of Anesthesiology, Department of Anesthesiology, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
- Affiliated Xinhui Hospital, Southern Medical University (People's Hospital of Xinhui District), Jiangmen, Guangdong 529100, China
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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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Koerich S, Parreira GM, de Almeida DL, Vieira RP, de Oliveira ACP. Receptors for Advanced Glycation End Products (RAGE): Promising Targets Aiming at the Treatment of Neurodegenerative Conditions. Curr Neuropharmacol 2023; 21:219-234. [PMID: 36154605 PMCID: PMC10190138 DOI: 10.2174/1570159x20666220922153903] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 07/03/2022] [Accepted: 07/18/2022] [Indexed: 11/22/2022] Open
Abstract
Advanced glycation end products (AGEs) are compounds formed after the non-enzymatic addition of reducing sugars to lipids, proteins, and nucleic acids. They are associated with the development of various clinical complications observed in diabetes and cardiovascular diseases, such as retinopathy, nephropathy, diabetic neuropathy, and others. In addition, compelling evidence indicates that these molecules participate in the progression of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Multiple cellular and molecular alterations triggered by AGEs that could alter homeostasis have been identified. One of the main targets for AGE signaling is the receptor for advanced glycation end-products (RAGE). Importantly, this receptor is the target of not only AGEs, but also amyloid β peptides, HMGB1 (high-mobility group box-1), members of the S100 protein family, and glycosaminoglycans. The activation of this receptor induces intracellular signaling cascades that are involved in pathological processes and cell death. Therefore, RAGE represents a key target for pharmacological interventions in neurodegenerative diseases. This review will discuss the various effects of AGEs and RAGE activation in the pathophysiology of neurodegenerative diseases, as well as the currently available pharmacological tools and promising drug candidates.
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Affiliation(s)
- Suélyn Koerich
- Department of Pharmacology, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Gabriela Machado Parreira
- Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | | | - Rafael Pinto Vieira
- Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
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Sanaie S, Nikanfar S, Kalekhane ZY, Azizi-Zeinalhajlou A, Sadigh-Eteghad S, Araj-Khodaei M, Ayati MH, Andalib S. Saffron as a promising therapy for diabetes and Alzheimer's disease: mechanistic insights. Metab Brain Dis 2023; 38:137-162. [PMID: 35986812 DOI: 10.1007/s11011-022-01059-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 07/29/2022] [Indexed: 02/03/2023]
Abstract
The prevalence of both Alzheimer's disease (AD) and diabetes mellitus is increasing with the societies' aging and has become an essential social concern worldwide. Accumulation of amyloid plaques and neurofibrillary tangles (NFTs) of tau proteins in the brain are hallmarks of AD. Diabetes is an underlying risk factor for AD. Insulin resistance has been proposed to be involved in amyloid-beta (Aβ) aggregation in the brain. It seems that diabetic conditions can result in AD pathology by setting off a cascade of processes, including inflammation, mitochondrial dysfunction, and ROS and advanced glycation end products (AGEs) synthesis. Due to the several side effects of chemical drugs and their high cost, using herbal medicine has recently attracted attention for the treatment of diabetes and AD. Saffron and its active ingredients have been used for its anti-inflammatory, anti-oxidant, anti-diabetic, and anti-AD properties. Therefore, in the present review paper, we take account of the clinical, in vivo and in vitro evidence regarding the anti-diabetic and anti-AD effects of saffron and discuss the preventive or postponing properties of saffron or its components on AD development via its anti-diabetic effects.
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Affiliation(s)
- Sarvin Sanaie
- Research Center for Integrative Medicine in Aging, Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Saba Nikanfar
- Department of Biochemistry and Clinical Laboratories, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Zahra Yousefi Kalekhane
- Research Center of Psychiatry and Behavioral Sciences, Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Psychology, Faculty of Educational Sciences and Psychology, University of Tabriz, Tabriz, Iran
| | - Akbar Azizi-Zeinalhajlou
- Student Research Committee, Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
- Physical Medicine and Rehabilitation Research Center, Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Saeed Sadigh-Eteghad
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mostafa Araj-Khodaei
- Research Center for Integrative Medicine in Aging, Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran.
- Department of Persian Medicine, School of Traditional Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Mohammad Hossein Ayati
- Research Center for Integrative Medicine in Aging, Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran.
- Department of Traditional Medicine, School of Persian Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Sasan Andalib
- Research Unit of Clinical Physiology and Nuclear Medicine, Department of Clinical Research, Odense University Hospital, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
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Kim Y, Park H, Kim Y, Kim SH, Lee JH, Yang H, Kim SJ, Li CM, Lee H, Na DH, Moon S, Shin Y, Kam TI, Lee HW, Kim S, Song JJ, Jung YK. Pathogenic Role of RAGE in Tau Transmission and Memory Deficits. Biol Psychiatry 2022; 93:829-841. [PMID: 36759256 DOI: 10.1016/j.biopsych.2022.10.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 09/19/2022] [Accepted: 10/09/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND In tauopathies, brain regions with tau accumulation strongly correlate with clinical symptoms, and spreading of misfolded tau along neural network leads to disease progression. However, the underlying mechanisms by which tau proteins enter neurons during pathological propagation remain unclear. METHODS To identify membrane receptors responsible for neuronal propagation of tau oligomers, we established a cell-based tau uptake assay and screened complementary DNA expression library. Tau uptake and propagation were analyzed in vitro and in vivo using a microfluidic device and stereotactic injection. The cognitive function of mice was assessed using behavioral tests. RESULTS From a genome-wide cell-based functional screening, RAGE (receptor for advanced glycation end products) was isolated to stimulate the cellular uptake of tau oligomers. Rage deficiency reduced neuronal uptake of pathological tau prepared from rTg4510 mouse brains or cerebrospinal fluid from patients with Alzheimer's disease and slowed tau propagation between neurons cultured in a 3-chamber microfluidic device. RAGE levels were increased in the brains of rTg4510 mice and tau oligomer-treated neurons. Rage knockout decreased tau transmission in the brains of nontransgenic mice after injection with Alzheimer's disease patient-derived tau and ameliorated memory loss after injection with GFP-P301L-tau-AAV. Treatment of RAGE antagonist FPS-ZM1 blocked transsynaptic tau propagation and inflammatory responses and alleviated cognitive impairment in rTg4510 mice. CONCLUSIONS These results suggest that in neurons and microglia, RAGE binds to pathological tau and facilitates neuronal tau pathology progression and behavioral deficits in tauopathies.
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Affiliation(s)
- Youbin Kim
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Republic of Korea; School of the Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Hyejin Park
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Youngwon Kim
- School of the Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Seo-Hyun Kim
- School of the Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Jae Hoon Lee
- Department of Biochemistry, Yonsei University, Seoul, Republic of Korea
| | - Hanseul Yang
- School of the Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Seo Jin Kim
- School of the Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Cathena Meiling Li
- School of the Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Haneul Lee
- School of the Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Do-Hyeong Na
- School of the Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Seowon Moon
- School of the Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Yumi Shin
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Tae-In Kam
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Han-Woong Lee
- Department of Biochemistry, Yonsei University, Seoul, Republic of Korea
| | - SangYun Kim
- Department of Neurology, Seoul National University Bundang Hospital and Seoul National University College of Medicine, Gyeonggi-do, Republic of Korea
| | - Ji-Joon Song
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Yong-Keun Jung
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Republic of Korea; School of the Biological Sciences, Seoul National University, Seoul, Republic of Korea.
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12
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Contribution of hyperglycemia-induced changes in microglia to Alzheimer's disease pathology. Pharmacol Rep 2022; 74:832-846. [PMID: 36042131 DOI: 10.1007/s43440-022-00405-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 10/14/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative condition characterized by cognitive and functional impairments. The investigation of AD has focused on the formation of senile plaques, composed mainly by amyloid β (Aβ) peptide, and neurofibrillary tangles (NFTs) in the brain. Senile plaques and NFTs cause the excessive recruitment and activation of microglia, thus generating neuroinflammation and neuronal damage. Among the risk factors for the development of AD, diabetes has increasingly attracted attention. Hyperglycemia, the fundamental characteristic of diabetes, is involved in several mechanisms that give rise to microglial overactivation, resulting in neuronal damage and cognitive impairment. Indeed, various studies have identified the correlation between diabetes and AD. The aim of this review is to describe various mechanisms of the hyperglycemia-induced overactivation of microglia, which leads to neuroinflammation and neuronal damage and consequently contributes to the pathology of AD. The disruption of the regulation of microglial activity by hyperglycemia occurs through many mechanisms, including a greater production of reactive oxygen species (ROS) and glycation end products (AGEs), and a decrease in the elimination of Aβ. The future direction of research on the relation between hyperglycemia and AD is addressed, such as the importance of determining whether the hyperglycemia-induced harmful effects on microglial activity can be reversed or attenuated if blood glucose returns to a normal level.
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13
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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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14
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1,8-Cineole Ameliorates Advanced Glycation End Products-Induced Alzheimer's Disease-like Pathology In Vitro and In Vivo. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27123913. [PMID: 35745036 PMCID: PMC9229467 DOI: 10.3390/molecules27123913] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 06/12/2022] [Accepted: 06/15/2022] [Indexed: 11/25/2022]
Abstract
Advanced glycation end products (AGEs) are stable products produced by the reaction of macromolecules such as proteins, lipids or nucleic acids with glucose or other reducing monosaccharides, which can be identified by immunohistochemistry in the senile plaques and neurofibrillary tangles of Alzheimer’s disease (AD) patients. Growing evidence suggests that AGEs are important risk factors for the development and progression of AD. 1,8-cineole (CIN) is a monoterpenoid compound which exists in many plant essential oils and has been proven to have neuroprotective activity, but its specific effect and molecular mechanisms are not clear. In this study, AGEs-induced neuronal injury and intracerebroventricular-AGE animals as the possible models for AD were employed to investigate the effects of CIN on AD pathology as well as the molecular mechanisms involved both in vivo and in vitro. Our study demonstrated that CIN could ameliorate tau phosphorylation by down-regulating the activity of GSK-3β and reducing Aβ production by inhibiting the activity of BACE-1 both in vivo and in vitro. It is suggested that CIN has certain therapeutic value in the treatment of AD.
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15
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Stratification of radiosensitive brain metastases based on an actionable S100A9/RAGE resistance mechanism. Nat Med 2022; 28:752-765. [PMID: 35411077 PMCID: PMC9018424 DOI: 10.1038/s41591-022-01749-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 02/16/2022] [Indexed: 12/25/2022]
Abstract
AbstractWhole-brain radiotherapy (WBRT) is the treatment backbone for many patients with brain metastasis; however, its efficacy in preventing disease progression and the associated toxicity have questioned the clinical impact of this approach and emphasized the need for alternative treatments. Given the limited therapeutic options available for these patients and the poor understanding of the molecular mechanisms underlying the resistance of metastatic lesions to WBRT, we sought to uncover actionable targets and biomarkers that could help to refine patient selection. Through an unbiased analysis of experimental in vivo models of brain metastasis resistant to WBRT, we identified activation of the S100A9–RAGE–NF-κB–JunB pathway in brain metastases as a potential mediator of resistance in this organ. Targeting this pathway genetically or pharmacologically was sufficient to revert the WBRT resistance and increase therapeutic benefits in vivo at lower doses of radiation. In patients with primary melanoma, lung or breast adenocarcinoma developing brain metastasis, endogenous S100A9 levels in brain lesions correlated with clinical response to WBRT and underscored the potential of S100A9 levels in the blood as a noninvasive biomarker. Collectively, we provide a molecular framework to personalize WBRT and improve its efficacy through combination with a radiosensitizer that balances therapeutic benefit and toxicity.
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16
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Little K, Llorián-Salvador M, Scullion S, Hernández C, Simó-Servat O, Del Marco A, Bosma E, Vargas-Soria M, Carranza-Naval MJ, Van Bergen T, Galbiati S, Viganò I, Musi CA, Schlingemann R, Feyen J, Borsello T, Zerbini G, Klaassen I, Garcia-Alloza M, Simó R, Stitt AW. Common pathways in dementia and diabetic retinopathy: understanding the mechanisms of diabetes-related cognitive decline. Trends Endocrinol Metab 2022; 33:50-71. [PMID: 34794851 DOI: 10.1016/j.tem.2021.10.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/06/2021] [Accepted: 10/29/2021] [Indexed: 12/14/2022]
Abstract
Type 2 diabetes (T2D) is associated with multiple comorbidities, including diabetic retinopathy (DR) and cognitive decline, and T2D patients have a significantly higher risk of developing Alzheimer's disease (AD). Both DR and AD are characterized by a number of pathological mechanisms that coalesce around the neurovascular unit, including neuroinflammation and degeneration, vascular degeneration, and glial activation. Chronic hyperglycemia and insulin resistance also play a significant role, leading to activation of pathological mechanisms such as increased oxidative stress and the accumulation of advanced glycation end-products (AGEs). Understanding these common pathways and the degree to which they occur simultaneously in the brain and retina during diabetes will provide avenues to identify T2D patients at risk of cognitive decline.
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Affiliation(s)
- Karis Little
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - María Llorián-Salvador
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Sarah Scullion
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Cristina Hernández
- Vall d'Hebron Research Institute and CIBERDEM (ISCIII), Barcelona, Spain
| | - Olga Simó-Servat
- Vall d'Hebron Research Institute and CIBERDEM (ISCIII), Barcelona, Spain
| | - Angel Del Marco
- Division of Physiology, School of Medicine, Instituto de Investigacion Biomedica de Cadiz (INIBICA), Universidad de Cadiz, Cadiz, Spain
| | - Esmeralda Bosma
- Ocular Angiogenesis Group, University of Amsterdam, Amsterdam, The Netherlands
| | - Maria Vargas-Soria
- Division of Physiology, School of Medicine, Instituto de Investigacion Biomedica de Cadiz (INIBICA), Universidad de Cadiz, Cadiz, Spain
| | - Maria Jose Carranza-Naval
- Division of Physiology, School of Medicine, Instituto de Investigacion Biomedica de Cadiz (INIBICA), Universidad de Cadiz, Cadiz, Spain
| | | | - Silvia Galbiati
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Ilaria Viganò
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Clara Alice Musi
- Università Degli Studi di Milano and Istituto di Ricerche Farmacologiche Mario Negri- IRCCS, Milano, Italy
| | - Reiner Schlingemann
- Ocular Angiogenesis Group, University of Amsterdam, Amsterdam, The Netherlands; Department of Ophthalmology, University of Lausanne, Jules Gonin Eye Hospital, Lausanne, Switzerland
| | | | - Tiziana Borsello
- Università Degli Studi di Milano and Istituto di Ricerche Farmacologiche Mario Negri- IRCCS, Milano, Italy
| | - Gianpaolo Zerbini
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Ingeborg Klaassen
- Ocular Angiogenesis Group, University of Amsterdam, Amsterdam, The Netherlands
| | - Monica Garcia-Alloza
- Division of Physiology, School of Medicine, Instituto de Investigacion Biomedica de Cadiz (INIBICA), Universidad de Cadiz, Cadiz, Spain
| | - Rafael Simó
- Vall d'Hebron Research Institute and CIBERDEM (ISCIII), Barcelona, Spain.
| | - Alan W Stitt
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK.
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17
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Kinscherf NA, Pehar M. Role and Therapeutic Potential of RAGE Signaling in Neurodegeneration. Curr Drug Targets 2022; 23:1191-1209. [PMID: 35702767 PMCID: PMC9589927 DOI: 10.2174/1389450123666220610171005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/29/2022] [Accepted: 04/29/2022] [Indexed: 01/03/2023]
Abstract
Activation of the receptor for advanced glycation end products (RAGE) has been shown to play an active role in the development of multiple neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and Amyotrophic Lateral Sclerosis. Although originally identified as a receptor for advanced glycation end products, RAGE is a pattern recognition receptor able to bind multiple ligands. The final outcome of RAGE signaling is defined in a context and cell type specific manner and can exert both neurotoxic and neuroprotective functions. Contributing to the complexity of the RAGE signaling network, different RAGE isoforms with distinctive signaling capabilities have been described. Moreover, multiple RAGE ligands bind other receptors and RAGE antagonism can significantly affect their signaling. Here, we discuss the outcome of celltype specific RAGE signaling in neurodegenerative pathologies. In addition, we will review the different approaches that have been developed to target RAGE signaling and their therapeutic potential. A clear understanding of the outcome of RAGE signaling in a cell type- and disease-specific manner would contribute to advancing the development of new therapies targeting RAGE. The ability to counteract RAGE neurotoxic signaling while preserving its neuroprotective effects would be critical for the success of novel therapies targeting RAGE signaling.
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Affiliation(s)
- Noah Alexander Kinscherf
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Mariana Pehar
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.,Geriatric Research Education Clinical Center, Veterans Affairs Medical Center, Madison, WI, USA
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18
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Terzo S, Amato A, Mulè F. From obesity to Alzheimer's disease through insulin resistance. J Diabetes Complications 2021; 35:108026. [PMID: 34454830 DOI: 10.1016/j.jdiacomp.2021.108026] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/29/2021] [Accepted: 08/14/2021] [Indexed: 12/27/2022]
Abstract
Alzheimer's disease is one of the most frequent forms of dementia. It is a progressive neurodegenerative disease, characterized by presence of amyloid plaques and neurofibrillary tangles in the brain. Obesity is regarded as abnormal fat accumulation with deleterious impact on human health. There is full scientific evidence that obesity and the metabolic comorbidities (e.g., insulin resistance, hyperglycaemia, and type 2 diabetes) are related to Alzheimer's disease and likely in the causative pathway. Numerous studies have identified several overlapping neurodegenerative mechanisms, including oxidative stress, mitochondrial dysfunction, and inflammation. In this review, we present how obesity and the associated lipotoxicity as well as chronic inflammation initiate a state of insulin resistance that in turn, may have a role in causing the characteristic cerebral alterations of AD. In particular, we focus on the molecular mechanisms linking the obesity-induced impairment in insulin signalling to the upregulation of Aβ aggregation, tau hyper-phosphorylation, inflammation, oxidative stress and mitochondrial dysfunction.
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Affiliation(s)
- Simona Terzo
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, 90128, Italy.
| | - Antonella Amato
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, 90128, Italy.
| | - Flavia Mulè
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, 90128, Italy.
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19
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Liu J, Ye T, Zhang Y, Zhang R, Kong Y, Zhang Y, Sun J. Protective Effect of Ginkgolide B against Cognitive Impairment in Mice via Regulation of Gut Microbiota. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:12230-12240. [PMID: 34633804 DOI: 10.1021/acs.jafc.1c05038] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Ginkgolide B (GB) is one of the main bioactive components of Ginkgo biloba leaf extracts with neuroprotective activity. However, the neuroprotective mechanism link between the anti-Alzheimer's disease (AD) efficiency of GB and gut microbiota have remained elusive. Here, we elucidated the effect and possible mechanism of GB against cognitive impairment in mice. Male mice were induced with d-galactose and aluminum chloride to establish an AD animal model, and then intragastrically treated with GB. Cognitive function was assessed by an object recognition test and an open-field test. Amyloid deposition and neuropathological change were detected. The levels of receptor for advanced glycation end products (RAGE), Bcl-2, and Bax were detected. Moreover, microbial compositions were measured by 16s rRNA sequencing. Our results showed that GB significantly alleviated cognitive dysfunction, neurodegeneration, and neuropathological changes in AD model mice. Moreover, GB treatment remarkably reduced the levels of RAGE and Bax and increased the level of Bcl-2 in AD model mice. GB treatment reversed the decreased abundance of Lactobacillus and the increased abundance of Bacteroidales, Muribaculaceae, and Alloprevotella, which led to reconstruction of gut microbiota. These findings demonstrated the neuroprotective effects of GB in AD mice, which were partly mediated by modulating gut dysbiosis, indicating that GB might be a potentially active supplement to alleviate AD.
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Affiliation(s)
- Jiaming Liu
- Department of Neurology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- Department of Preventive Medicine, School of Public Health and Management, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Tao Ye
- Department of Neurology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Yuhe Zhang
- Department of Preventive Medicine, School of Public Health and Management, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Rui Zhang
- Department of Preventive Medicine, School of Public Health and Management, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yu Kong
- Department of Preventive Medicine, School of Public Health and Management, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yang Zhang
- Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China
| | - Jing Sun
- Department of Neurology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
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20
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Monterey MD, Wei H, Wu X, Wu JQ. The Many Faces of Astrocytes in Alzheimer's Disease. Front Neurol 2021; 12:619626. [PMID: 34531807 PMCID: PMC8438135 DOI: 10.3389/fneur.2021.619626] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 07/20/2021] [Indexed: 01/11/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease and is the most common cause of dementia in an aging population. The majority of research effort has focused on the role of neurons in neurodegeneration and current therapies have limited ability to slow disease progression. Recently more attention has been given to the role of astrocytes in the process of neurodegeneration. Specifically, reactive astrocytes have both advantageous and adverse effects during neurodegeneration. The ability to isolate and depict astrocyte phenotype has been challenging. However, with the recent development of single-cell sequencing technologies researchers are provided with the resource to delineate specific biomarkers associated with reactive astrocytes in AD. In this review, we will focus on the role of astrocytes in normal conditions and the pathological development of AD. We will further review recent developments in the understanding of astrocyte heterogeneity and associated biomarkers. A better understanding of astrocyte contributions and phenotypic changes in AD can ultimately lead to more effective therapeutic targets.
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Affiliation(s)
- Michael D Monterey
- The Vivian L. Smith Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Haichao Wei
- The Vivian L. Smith Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States.,Center for Stem Cell and Regenerative Medicine, UT Brown Foundation Institute of Molecular Medicine, Houston, TX, United States
| | - Xizi Wu
- The Vivian L. Smith Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States.,Center for Stem Cell and Regenerative Medicine, UT Brown Foundation Institute of Molecular Medicine, Houston, TX, United States
| | - Jia Qian Wu
- The Vivian L. Smith Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States.,Center for Stem Cell and Regenerative Medicine, UT Brown Foundation Institute of Molecular Medicine, Houston, TX, United States.,MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
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21
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Haddad M, Perrotte M, Ben Khedher MR, Madec E, Lepage A, Fülöp T, Ramassamy C. Levels of Receptor for Advanced Glycation End Products and Glyoxalase-1 in the Total Circulating Extracellular Vesicles from Mild Cognitive Impairment and Different Stages of Alzheimer's Disease Patients. J Alzheimers Dis 2021; 84:227-237. [PMID: 34487040 DOI: 10.3233/jad-210441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Growing evidence supports that receptor for advanced glycation end products (RAGE) and glyoxalase-1 (GLO-1) are implicated in the pathophysiology of Alzheimer's disease (AD). Extracellular vesicles (EVs) are nanovesicles secreted by almost all cell types, contribute to cellular communication, and are implicated in AD pathology. Recently, EVs are considered as promising tools to identify reliable biomarkers in AD. OBJECTIVE The aim of our study was to determine the levels of RAGE and GLO-1 in circulating EVs from mild cognitive impairment (MCI) and AD patients and to analyze their correlation with the clinical Mini-Mental State Examination and Montreal Cognitive Assessment scores. We have studied the possibility that neuronal cells could release and transfer GLO-1 through EVs. METHODS RAGE and GLO-1 levels were measured in circulating EVs, respectively, by Luminex assay and western blot. Released-EVs from SK-N-SH neuronal cells were isolated and GLO-1 levels were determined by western blot. RESULTS Our data showed higher levels of RAGE in EVs from late AD patients while GLO-1 levels in EVs from early AD were lower as compared to control and MCI patients. Interestingly, levels of RAGE and GLO-1 in EVs were correlated with the cognitive scores regardless of age. For the first time, we demonstrated that GLO-1 was released from neuronal cells through EVs. CONCLUSION Although more samples will be needed, our preliminary results support the use of peripheral EVs cargo as new tools for the discovery of peripheral AD biomarkers.
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Affiliation(s)
- Mohamed Haddad
- Institut National de Recherche Scientifique-Centre Armand-Frappier Santé Biotechnologie, Laval, Québec, Canada
| | - Morgane Perrotte
- Institut National de Recherche Scientifique-Centre Armand-Frappier Santé Biotechnologie, Laval, Québec, Canada.,Réseau Québécoisde Recherche sur le Vieillissement, Montréal, Québec, Canada
| | - Mohamed Raâfet Ben Khedher
- Institut National de Recherche Scientifique-Centre Armand-Frappier Santé Biotechnologie, Laval, Québec, Canada.,Réseau Québécoisde Recherche sur le Vieillissement, Montréal, Québec, Canada
| | - Elise Madec
- Institut National de Recherche Scientifique-Centre Armand-Frappier Santé Biotechnologie, Laval, Québec, Canada
| | - Aurelie Lepage
- Department of Medicine, Geriatric Division, Research Center on Aging, Sherbrooke University, Sherbrooke, Québec, Canada
| | - Tamás Fülöp
- Department of Medicine, Geriatric Division, Research Center on Aging, Sherbrooke University, Sherbrooke, Québec, Canada
| | - Charles Ramassamy
- Institut National de Recherche Scientifique-Centre Armand-Frappier Santé Biotechnologie, Laval, Québec, Canada.,Réseau Québécoisde Recherche sur le Vieillissement, Montréal, Québec, Canada
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22
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Mohamed Asik R, Suganthy N, Aarifa MA, Kumar A, Szigeti K, Mathe D, Gulyás B, Archunan G, Padmanabhan P. Alzheimer's Disease: A Molecular View of β-Amyloid Induced Morbific Events. Biomedicines 2021; 9:biomedicines9091126. [PMID: 34572312 PMCID: PMC8468668 DOI: 10.3390/biomedicines9091126] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/22/2021] [Accepted: 08/27/2021] [Indexed: 12/26/2022] Open
Abstract
Amyloid-β (Aβ) is a dynamic peptide of Alzheimer’s disease (AD) which accelerates the disease progression. At the cell membrane and cell compartments, the amyloid precursor protein (APP) undergoes amyloidogenic cleavage by β- and γ-secretases and engenders the Aβ. In addition, externally produced Aβ gets inside the cells by receptors mediated internalization. An elevated amount of Aβ yields spontaneous aggregation which causes organelles impairment. Aβ stimulates the hyperphosphorylation of tau protein via acceleration by several kinases. Aβ travels to the mitochondria and interacts with its functional complexes, which impairs the mitochondrial function leading to the activation of apoptotic signaling cascade. Aβ disrupts the Ca2+ and protein homeostasis of the endoplasmic reticulum (ER) and Golgi complex (GC) that promotes the organelle stress and inhibits its stress recovery machinery such as unfolded protein response (UPR) and ER-associated degradation (ERAD). At lysosome, Aβ precedes autophagy dysfunction upon interacting with autophagy molecules. Interestingly, Aβ act as a transcription regulator as well as inhibits telomerase activity. Both Aβ and p-tau interaction with neuronal and glial receptors elevate the inflammatory molecules and persuade inflammation. Here, we have expounded the Aβ mediated events in the cells and its cosmopolitan role on neurodegeneration, and the current clinical status of anti-amyloid therapy.
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Affiliation(s)
- Rajmohamed Mohamed Asik
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, Singapore; (R.M.A.); (B.G.)
- Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore
- Department of Animal Science, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India;
| | - Natarajan Suganthy
- Department of Nanoscience and Technology, Alagappa University, Karaikudi 630003, Tamil Nadu, India;
| | - Mohamed Asik Aarifa
- Department of Animal Science, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India;
| | - Arvind Kumar
- Centre for Cellular and Molecular Biology, Hyderabad 500007, Telangana, India;
| | - Krisztián Szigeti
- Department of Biophysics and Radiation Biology, Semmelweis University, 1094 Budapest, Hungary; (K.S.); (D.M.)
- CROmed Translational Research Centers, 1094 Budapest, Hungary
| | - Domokos Mathe
- Department of Biophysics and Radiation Biology, Semmelweis University, 1094 Budapest, Hungary; (K.S.); (D.M.)
- CROmed Translational Research Centers, 1094 Budapest, Hungary
- In Vivo Imaging Advanced Core Facility, Hungarian Center of Excellence for Molecular Medicine (HCEMM), 1094 Budapest, Hungary
| | - Balázs Gulyás
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, Singapore; (R.M.A.); (B.G.)
- Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore
- Department of Clinical Neuroscience, Karolinska Institute, 17176 Stockholm, Sweden
| | - Govindaraju Archunan
- Department of Animal Science, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India;
- Marudupandiyar College, Thanjavur 613403, Tamil Nadu, India
- Correspondence: (G.A.); (P.P.)
| | - Parasuraman Padmanabhan
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, Singapore; (R.M.A.); (B.G.)
- Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore
- Correspondence: (G.A.); (P.P.)
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23
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Loera-Valencia R, Ismail MAM, Goikolea J, Lodeiro M, Mateos L, Björkhem I, Puerta E, Romão MA, Gomes CM, Merino-Serrais P, Maioli S, Cedazo-Minguez A. Hypercholesterolemia and 27-Hydroxycholesterol Increase S100A8 and RAGE Expression in the Brain: a Link Between Cholesterol, Alarmins, and Neurodegeneration. Mol Neurobiol 2021; 58:6063-6076. [PMID: 34449045 PMCID: PMC8639576 DOI: 10.1007/s12035-021-02521-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 08/04/2021] [Indexed: 12/20/2022]
Abstract
Alterations in cholesterol metabolism in the brain have a major role in the physiology of Alzheimer's disease (AD). Oxysterols are cholesterol metabolites with multiple implications in memory functions and in neurodegeneration. Previous studies have shown detrimental effects of cholesterol metabolites in neurons, but its effect in glial cells is unknown. We used a high-fat/high-cholesterol diet in mice to study the effects of hypercholesterolemia over the alarmin S100A8 cascade in the hippocampus. Using CYP27Tg, a transgenic mouse model, we show that the hypercholesterolemia influence on the brain is mediated by the excess of 27-hydroxycholesterol (27-OH), a cholesterol metabolite. We also employed an acute model of 27-OH intraventricular injection in the brain to study RAGE and S100A8 response. We used primary cultures of neurons and astrocytes to study the effect of high levels of 27-OH over the S100A8 alarmin cascade. We report that a high-fat/high-cholesterol diet leads to an increase in S100A8 production in the brain. In CYP27Tg, we report an increase of S100A8 and its receptor RAGE in the hippocampus under elevated 27-OH in the brain. Using siRNA, we found that 27-OH upregulation of RAGE in astrocytes and neurons is mediated by the nuclear receptor RXRγ. Silencing RXRγ in neurons prevented 27-OH-mediated upregulation of RAGE. These results show that S100A8 alarmin and RAGE respond to high levels of 27-OH in the brain in both neurons and astrocytes through RXRγ. Our study supports the notion that 27-OH mediates detrimental effects of hypercholesterolemia to the brain via alarmin signaling.
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Affiliation(s)
- Raúl Loera-Valencia
- Division of Neurogeriatrics, Department of Neurobiology Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden.
| | - Muhammad-Al-Mustafa Ismail
- Division of Neurogeriatrics, Department of Neurobiology Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Julen Goikolea
- Division of Neurogeriatrics, Department of Neurobiology Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Maria Lodeiro
- Division of Neurogeriatrics, Department of Neurobiology Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Laura Mateos
- Division of Neurogeriatrics, Department of Neurobiology Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Ingemar Björkhem
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, Huddinge, Sweden
| | - Elena Puerta
- Division of Neurogeriatrics, Department of Neurobiology Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden.,Department of Pharmacology and Toxicology, University of Navarra, Pamplona, Spain
| | - Mariana A Romão
- Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.,Departamento de Química E Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Cláudio M Gomes
- Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.,Departamento de Química E Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Paula Merino-Serrais
- Division of Neurogeriatrics, Department of Neurobiology Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden.,Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Madrid, Spain.,Departamento de Neurobiología Funcional y de Sistemas, Instituto Cajal, CSIC, Madrid, Spain
| | - Silvia Maioli
- Division of Neurogeriatrics, Department of Neurobiology Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Angel Cedazo-Minguez
- Division of Neurogeriatrics, Department of Neurobiology Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden.
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24
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Buccellato FR, D’Anca M, Fenoglio C, Scarpini E, Galimberti D. Role of Oxidative Damage in Alzheimer's Disease and Neurodegeneration: From Pathogenic Mechanisms to Biomarker Discovery. Antioxidants (Basel) 2021; 10:antiox10091353. [PMID: 34572985 PMCID: PMC8471953 DOI: 10.3390/antiox10091353] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 12/16/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder accounting for over 50% of all dementia patients and representing a leading cause of death worldwide for the global ageing population. The lack of effective treatments for overt AD urges the discovery of biomarkers for early diagnosis, i.e., in subjects with mild cognitive impairment (MCI) or prodromal AD. The brain is exposed to oxidative stress as levels of reactive oxygen species (ROS) are increased, whereas cellular antioxidant defenses are decreased. Increased ROS levels can damage cellular structures or molecules, leading to protein, lipid, DNA, or RNA oxidation. Oxidative damage is involved in the molecular mechanisms which link the accumulation of amyloid-β and neurofibrillary tangles, containing hyperphosphorylated tau, to microglia response. In this scenario, microglia are thought to play a crucial role not only in the early events of AD pathogenesis but also in the progression of the disease. This review will focus on oxidative damage products as possible peripheral biomarkers in AD and in the preclinical phases of the disease. Particular attention will be paid to biological fluids such as blood, CSF, urine, and saliva, and potential future use of molecules contained in such body fluids for early differential diagnosis and monitoring the disease course. We will also review the role of oxidative damage and microglia in the pathogenesis of AD and, more broadly, in neurodegeneration.
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Affiliation(s)
- Francesca Romana Buccellato
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, 20122 Milan, Italy; (E.S.); (D.G.)
- Correspondence: ; Tel.: +39-02 55033814
| | - Marianna D’Anca
- Fondazione IRCSS ca’ Granda, Ospedale Policlinico, 20122 Milano, Italy;
| | - Chiara Fenoglio
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy;
| | - Elio Scarpini
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, 20122 Milan, Italy; (E.S.); (D.G.)
- Fondazione IRCSS ca’ Granda, Ospedale Policlinico, 20122 Milano, Italy;
| | - Daniela Galimberti
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, 20122 Milan, Italy; (E.S.); (D.G.)
- Fondazione IRCSS ca’ Granda, Ospedale Policlinico, 20122 Milano, Italy;
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25
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Chuang Y, Van I, Zhao Y, Xu Y. Icariin ameliorate Alzheimer's disease by influencing SIRT1 and inhibiting Aβ cascade pathogenesis. J Chem Neuroanat 2021; 117:102014. [PMID: 34407393 DOI: 10.1016/j.jchemneu.2021.102014] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 08/09/2021] [Accepted: 08/09/2021] [Indexed: 12/23/2022]
Abstract
Of all types of dementia, Alzheimer's disease is the type that has the highest proportion of cases and is the cause of substantial medical and economic burden. The mechanism of Alzheimer's disease is closely associated with the aggregation of amyloid-β protein and causes neurotoxicity and extracellular accumulation in the brain and to intracellular neurofibrillary tangles caused by tau protein hyperphosphorylation in the brain tissue. Previous studies have demonstrated that sirtuin1 downregulation is involved in the pathological mechanism of Alzheimer's disease. The decrease of sirtuin1 level would cause Alzheimer's disease by means of promoting the amyloidogenic pathway to generate amyloid-β species and thereby triggering amyloid-β cascade reaction, such as tau protein hyperphosphorylation, neuron autophagy, neuroinflammation, oxidative stress, and neuron apoptosis. Currently, there is no effective treatment for Alzheimer's disease, it is necessary to develop new treatment strategies. According to the theory of traditional Chinese medicine and based on the mechanism of the disease, tonifying the kidneys is one of the principles for the treatment of Alzheimer's disease and Epimedium is a well-known Chinese medicine for tonifying kidney. Therefore, investigating the influence of the components of Epimedium on the pathological characteristics of Alzheimer's disease may provide a reference for the treatment of Alzheimer's disease in the future. In this article, we summarise the effects and mechanism of icariin, the main ingredient extracted from Epimedium, in ameliorating Alzheimer's disease by regulating sirtuin1 to inhibit amyloid-β protein and improve other amyloid-β cascade pathogenesis.
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Affiliation(s)
- Yaochen Chuang
- Faculty of Chinese Medicine, Macau University of Science and Technology, Taipa, Macao, 999078, China; Kiang Wu Nursing College of Macau, Macao, 999078, China
| | - Iatkio Van
- Kiang Wu Nursing College of Macau, Macao, 999078, China.
| | - Yonghua Zhao
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, 999078, China
| | - Youhua Xu
- Faculty of Chinese Medicine, Macau University of Science and Technology, Taipa, Macao, 999078, China; State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao, 999078, China.
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26
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Ahmad SS, Younis K, Philippe J, Aschner M, Khan H. Strategic approaches to target the enzymes using natural compounds for the management of Alzheimer's disease: A review. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2021; 21:610-620. [PMID: 34382514 DOI: 10.2174/1871527320666210811160007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 06/21/2021] [Accepted: 07/18/2021] [Indexed: 11/22/2022]
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease. It is clinically characterized by memory loss and intellectual decrease, among other neurological deficits. The etiology of AD is not completely understood but includes amyloid plaques and intracellular helical filaments as well as neurofibrillary tangles with hyperphosphorylated tau protein. AD is also associated with alterations in amyloid processing genes, such as PSEN1 or PSEN2 and APP. The modulation immune system, cholesterol metabolism, and synaptic vesicle endocytosis have all been shown to remediate AD. In this review, enzymes such as AChE, BuChE, β-secretase, γ-secretase, MAO, and RAGE are discussed as potential targets for AD treatment. The aim of this review was to addresses the molecular mechanisms as well as various genetic factors in AD etiology. The use of natural compounds against these targets might be beneficial for the management of AD.
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Affiliation(s)
- Syed Sayeed Ahmad
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 38541. Korea
| | - Kaiser Younis
- Department of Bioengineering, Faculty of Engineering, Integral University, Lucknow. India
| | - Jeandet Philippe
- Research Unit "Induced Resistance and Plant Bioprotection", EA 4707, SFR Condorcet FR CNRS 3417, Faculty of Sciences University of Reims Champagne-Ardenne, PO Box 1039, 51687 Reims Cedex 2. France
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461. United States
| | - Haroon Khan
- Department of Pharmacy, Abdul Wali Khan University Mardan 23200. Pakistan
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27
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Viejo L, Noori A, Merrill E, Das S, Hyman BT, Serrano-Pozo A. Systematic review of human post-mortem immunohistochemical studies and bioinformatics analyses unveil the complexity of astrocyte reaction in Alzheimer's disease. Neuropathol Appl Neurobiol 2021; 48:e12753. [PMID: 34297416 PMCID: PMC8766893 DOI: 10.1111/nan.12753] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/29/2021] [Accepted: 07/12/2021] [Indexed: 12/24/2022]
Abstract
AIMS Reactive astrocytes in Alzheimer's disease (AD) have traditionally been demonstrated by increased glial fibrillary acidic protein (GFAP) immunoreactivity; however, astrocyte reaction is a complex and heterogeneous phenomenon involving multiple astrocyte functions beyond cytoskeletal remodelling. To better understand astrocyte reaction in AD, we conducted a systematic review of astrocyte immunohistochemical studies in post-mortem AD brains followed by bioinformatics analyses on the extracted reactive astrocyte markers. METHODS NCBI PubMed, APA PsycInfo and WoS-SCIE databases were interrogated for original English research articles with the search terms 'Alzheimer's disease' AND 'astrocytes.' Bioinformatics analyses included protein-protein interaction network analysis, pathway enrichment, and transcription factor enrichment, as well as comparison with public human -omics datasets. RESULTS A total of 306 articles meeting eligibility criteria rendered 196 proteins, most of which were reported to be upregulated in AD vs control brains. Besides cytoskeletal remodelling (e.g., GFAP), bioinformatics analyses revealed a wide range of functional alterations including neuroinflammation (e.g., IL6, MAPK1/3/8 and TNF), oxidative stress and antioxidant defence (e.g., MT1A/2A, NFE2L2, NOS1/2/3, PRDX6 and SOD1/2), lipid metabolism (e.g., APOE, CLU and LRP1), proteostasis (e.g., cathepsins, CRYAB and HSPB1/2/6/8), extracellular matrix organisation (e.g., CD44, MMP1/3 and SERPINA3), and neurotransmission (e.g., CHRNA7, GABA, GLUL, GRM5, MAOB and SLC1A2), among others. CTCF and ESR1 emerged as potential transcription factors driving these changes. Comparison with published -omics datasets validated our results, demonstrating a significant overlap with reported transcriptomic and proteomic changes in AD brains and/or CSF. CONCLUSIONS Our systematic review of the neuropathological literature reveals the complexity of AD reactive astrogliosis. We have shared these findings as an online resource available at www.astrocyteatlas.org.
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Affiliation(s)
- Lucía Viejo
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,Departamento de Farmacología y Terapéutica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Ayush Noori
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,Harvard College, Cambridge, MA, USA.,MIND Data Science Lab, Cambridge, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Charlestown, MA, USA
| | - Emily Merrill
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,MIND Data Science Lab, Cambridge, MA, USA
| | - Sudeshna Das
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,MIND Data Science Lab, Cambridge, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Charlestown, MA, USA.,Harvard Medical School, Harvard University, Boston, MA, USA
| | - Bradley T Hyman
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Charlestown, MA, USA.,Harvard Medical School, Harvard University, Boston, MA, USA
| | - Alberto Serrano-Pozo
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Charlestown, MA, USA.,Harvard Medical School, Harvard University, Boston, MA, USA
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28
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Molecular Characteristics of RAGE and Advances in Small-Molecule Inhibitors. Int J Mol Sci 2021; 22:ijms22136904. [PMID: 34199060 PMCID: PMC8268101 DOI: 10.3390/ijms22136904] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 12/16/2022] Open
Abstract
Receptor for advanced glycation end-products (RAGE) is a member of the immunoglobulin superfamily. RAGE binds and mediates cellular responses to a range of DAMPs (damage-associated molecular pattern molecules), such as AGEs, HMGB1, and S100/calgranulins, and as an innate immune sensor, can recognize microbial PAMPs (pathogen-associated molecular pattern molecules), including bacterial LPS, bacterial DNA, and viral and parasitic proteins. RAGE and its ligands stimulate the activations of diverse pathways, such as p38MAPK, ERK1/2, Cdc42/Rac, and JNK, and trigger cascades of diverse signaling events that are involved in a wide spectrum of diseases, including diabetes mellitus, inflammatory, vascular and neurodegenerative diseases, atherothrombosis, and cancer. Thus, the targeted inhibition of RAGE or its ligands is considered an important strategy for the treatment of cancer and chronic inflammatory diseases.
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29
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Pathology, Risk Factors, and Oxidative Damage Related to Type 2 Diabetes-Mediated Alzheimer's Disease and the Rescuing Effects of the Potent Antioxidant Anthocyanin. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:4051207. [PMID: 33728019 PMCID: PMC7936905 DOI: 10.1155/2021/4051207] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 01/27/2021] [Accepted: 02/18/2021] [Indexed: 02/07/2023]
Abstract
The pathology and neurodegeneration in type 2 diabetes- (T2D-) mediated Alzheimer's disease (AD) have been reported in several studies. Despite the lack of information regarding the basic underlying mechanisms involved in the development of T2D-mediated AD, some common features of the two conditions have been reported, such as brain atrophy, reduced cerebral glucose metabolism, and insulin resistance. T2D phenotypes such as glucose dyshomeostasis, insulin resistance, impaired insulin signaling, and systemic inflammatory cytokines have been shown to be involved in the progression of AD pathology by increasing amyloid-beta accumulation, tau hyperphosphorylation, and overall neuroinflammation. Similarly, oxidative stress, mitochondrial dysfunction, and the generation of advanced glycation end products (AGEs) and their receptor (RAGE) as a result of chronic hyperglycemia may serve as critical links between diabetes and AD. The natural dietary polyflavonoid anthocyanin enhances insulin sensitivity, attenuates insulin resistance at the level of the target tissues, inhibits free fatty acid oxidation, and abrogates the release of peripheral inflammatory cytokines in obese (prediabetic) individuals, which are responsible for insulin resistance, systemic hyperglycemia, systemic inflammation, brain metabolism dyshomeostasis, amyloid-beta accumulation, and neuroinflammatory responses. In this review, we have shown that obesity may induce T2D-mediated AD and assessed the recent therapeutic advances, especially the use of anthocyanin, against T2D-mediated AD pathology. Taken together, the findings of current studies may help elucidate a new approach for the prevention and treatment of T2D-mediated AD by using the polyflavonoid anthocyanin.
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30
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Beamer E, Corrêa SAL. The p38 MAPK-MK2 Signaling Axis as a Critical Link Between Inflammation and Synaptic Transmission. Front Cell Dev Biol 2021; 9:635636. [PMID: 33585492 PMCID: PMC7876405 DOI: 10.3389/fcell.2021.635636] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/11/2021] [Indexed: 01/04/2023] Open
Abstract
p38 is a mitogen-activated protein kinase (MAPK), that responds primarily to stress stimuli. p38 has a number of targets for phosphorylation, including MAPK-activated protein kinase 2 (MK2). MK2 primarily functions as a master regulator of RNA-binding proteins, indirectly controlling gene expression at the level of translation. The role of MK2 in regulating the synthesis of pro-inflammatory cytokines downstream of inflammation and cellular stress is well-described. A significant amount of evidence, however, now points to a role for the p38MAPK-MK2 signaling axis in mediating synaptic plasticity through control of AMPA receptor trafficking and the morphology of dendritic spines. These processes are mediated through control of cytoskeletal dynamics via the activation of cofilin-1 and possibly control of the expression of Arc/Arg3.1. There is evidence that MK2 is necessary for group I metabotropic glutamate receptors long-term depression (mGluR-LTD). Disruption of this signaling may play an important role in mediating cognitive dysfunction in neurological disorders such as fragile X syndrome and Alzheimer’s disease. To date, the role of neuronal MK2 mediating synaptic plasticity in response to inflammatory stimuli has not yet been investigated. In immune cells, it is clear that MK2 is phosphorylated following activation of a broad range of cell surface receptors for cytokines and other inflammatory mediators. We propose that neuronal MK2 may be an important player in the link between inflammatory states and dysregulation of synaptic plasticity underlying cognitive functions. Finally, we discuss the potential of the p38MAPK-MK2 signaling axis as target for therapeutic intervention in a number of neurological disorders.
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Affiliation(s)
- Edward Beamer
- Faculty of Science and Engineering, Department of Life Sciences, Manchester Metropolitan University Manchester, Manchester, United Kingdom
| | - Sonia A L Corrêa
- Faculty of Science and Engineering, Department of Life Sciences, Manchester Metropolitan University Manchester, Manchester, United Kingdom
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31
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Li L, Acioglu C, Heary RF, Elkabes S. Role of astroglial toll-like receptors (TLRs) in central nervous system infections, injury and neurodegenerative diseases. Brain Behav Immun 2021; 91:740-755. [PMID: 33039660 PMCID: PMC7543714 DOI: 10.1016/j.bbi.2020.10.007] [Citation(s) in RCA: 128] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/22/2020] [Accepted: 10/06/2020] [Indexed: 02/07/2023] Open
Abstract
Central nervous system (CNS) innate immunity plays essential roles in infections, neurodegenerative diseases, and brain or spinal cord injuries. Astrocytes and microglia are the principal cells that mediate innate immunity in the CNS. Pattern recognition receptors (PRRs), expressed by astrocytes and microglia, sense pathogen-derived or endogenous ligands released by damaged cells and initiate the innate immune response. Toll-like receptors (TLRs) are a well-characterized family of PRRs. The contribution of microglial TLR signaling to CNS pathology has been extensively investigated. Even though astrocytes assume a wide variety of key functions, information about the role of astroglial TLRs in CNS disease and injuries is limited. Because astrocytes display heterogeneity and exhibit phenotypic plasticity depending on the effectors present in the local milieu, they can exert both detrimental and beneficial effects. TLRs are modulators of these paradoxical astroglial properties. The goal of the current review is to highlight the essential roles played by astroglial TLRs in CNS infections, injuries and diseases. We discuss the contribution of astroglial TLRs to host defense as well as the dissemination of viral and bacterial infections in the CNS. We examine the link between astroglial TLRs and the pathogenesis of neurodegenerative diseases and present evidence showing the pivotal influence of astroglial TLR signaling on sterile inflammation in CNS injury. Finally, we define the research questions and areas that warrant further investigations in the context of astrocytes, TLRs, and CNS dysfunction.
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Affiliation(s)
- Lun Li
- The Reynolds Family Spine Laboratory, Department of Neurosurgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States
| | - Cigdem Acioglu
- The Reynolds Family Spine Laboratory, Department of Neurosurgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States
| | - Robert F. Heary
- Department of Neurological Surgery, Hackensack Meridian School of Medicine, Nutley, NJ 07110, United States
| | - Stella Elkabes
- The Reynolds Family Spine Laboratory, Department of Neurosurgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States.
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32
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Danger-Sensing/Patten Recognition Receptors and Neuroinflammation in Alzheimer's Disease. Int J Mol Sci 2020; 21:ijms21239036. [PMID: 33261147 PMCID: PMC7731137 DOI: 10.3390/ijms21239036] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 02/06/2023] Open
Abstract
Fibrillar aggregates and soluble oligomers of both Amyloid-β peptides (Aβs) and hyperphosphorylated Tau proteins (p-Tau-es), as well as a chronic neuroinflammation are the main drivers causing progressive neuronal losses and dementia in Alzheimer’s disease (AD). However, the underlying pathogenetic mechanisms are still much disputed. Several endogenous neurotoxic ligands, including Aβs, and/or p-Tau-es activate innate immunity-related danger-sensing/pattern recognition receptors (PPRs) thereby advancing AD’s neuroinflammation and progression. The major PRR families involved include scavenger, Toll-like, NOD-like, AIM2-like, RIG-like, and CLEC-2 receptors, plus the calcium-sensing receptor (CaSR). This quite intricate picture stresses the need to identify the pathogenetically topmost Aβ-activated PRR, whose signaling would trigger AD’s three main drivers and their intra-brain spread. In theory, the candidate might belong to any PRR family. However, results of preclinical studies using in vitro nontumorigenic human cortical neurons and astrocytes and in vivo AD-model animals have started converging on the CaSR as the pathogenetically upmost PRR candidate. In fact, the CaSR binds both Ca2+ and Aβs and promotes the spread of both Ca2+ dyshomeostasis and AD’s three main drivers, causing a progressive neurons’ death. Since CaSR’s negative allosteric modulators block all these effects, CaSR’s candidacy for topmost pathogenetic PRR has assumed a growing therapeutic potential worth clinical testing.
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Drake LR, Brooks AF, Stauff J, Sherman PS, Arteaga J, Koeppe RA, Reed A, Montavon TJ, Skaddan MB, Scott PJ. Strategies for PET imaging of the receptor for advanced glycation endproducts (RAGE). J Pharm Anal 2020; 10:452-465. [PMID: 33133729 PMCID: PMC7591811 DOI: 10.1016/j.jpha.2020.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/28/2020] [Accepted: 07/30/2020] [Indexed: 02/07/2023] Open
Abstract
The implication of the receptor for advanced glycation end-products (RAGE) in numerous diseases and neurodegenerative disorders makes it interesting both as a therapeutic target and as an inflammatory biomarker. In the context of investigating RAGE as a biomarker, there is interest in developing radiotracers that will enable quantification of RAGE using positron emission tomography (PET) imaging. We have synthesized potential small molecule radiotracers for both the intracellular ([18F]InRAGER) and extracellular ([18F]RAGER) domains of RAGE. Herein we report preclinical evaluation of both using in vitro (lead panel screens) and in vivo (rodent and nonhuman primate PET imaging) methods. Both radiotracers have high affinity for RAGE and show good brain uptake, but suffer from off-target binding. The source of the off-target PET signal is not attributable to binding to melatonin receptors, but remains unexplained. We have also investigated use of lipopolysaccharide (LPS)-treated mice as a possible animal model with upregulated RAGE for evaluation of new imaging agents. Immunoreactivity of the mouse brain sections revealed increases in RAGE in the male cohorts, but no difference in the female groups. However, it proves challenging to quantify the changes in RAGE due to off-target binding of the radiotracers. Nevertheless, they are appropriate lead scaffolds for future development of 2nd generation RAGE PET radiotracers because of their high affinity for the receptor and good CNS penetration.
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Affiliation(s)
- Lindsey R. Drake
- Department of Radiology, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Allen F. Brooks
- Department of Radiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Jenelle Stauff
- Department of Radiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Phillip S. Sherman
- Department of Radiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Janna Arteaga
- Department of Radiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Robert A. Koeppe
- Department of Radiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Aimee Reed
- AbbVie Process Chemistry, North Chicago, IL, 60064, USA
| | | | | | - Peter J.H. Scott
- Department of Radiology, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
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Crosstalk between obesity, diabetes, and alzheimer's disease: Introducing quercetin as an effective triple herbal medicine. Ageing Res Rev 2020; 62:101095. [PMID: 32535272 DOI: 10.1016/j.arr.2020.101095] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 05/09/2020] [Accepted: 06/04/2020] [Indexed: 02/07/2023]
Abstract
Obesity and diabetes are the most common metabolic disorders, which are strongly related to Alzheimer's disease (AD) in aging. Diabetes and obesity can lead to the accumulation of amyloid plaques, neurofibrillary tangles (NFTs), and other symptoms of AD through several pathways, including insulin resistance, hyperglycemia, hyperinsulinemia, chronic inflammation, oxidative stress, adipokines dysregulation, and vascular impairment. Currently, the use of polyphenols has been expanded in animal models and in-vitro studies because of their comparatively negligible adverse effects. Among them, quercetin (QT) is one of the most abundant polyphenolic flavonoids, which is present in fruits and vegetables and displays many biological, health-promoting effects in a wide range of diseases. The low bioavailability and poor solubility of QT have also led researchers to make various QT-involved nanoparticles (NPs) to overcome these limitations. In this paper, we review significant molecular mechanisms induced by diabetes and obesity that increase AD pathogenesis. Then, we summarize in vitro, in vivo, and clinical evidence regarding the anti-Alzheimer, anti-diabetic and anti-obesity effects of QT. Finally, QT in pure and combination form using NPs has been suggested as a promising therapeutic agent for future studies.
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Lazarov O, Minshall RD, Bonini MG. Harnessing neurogenesis in the adult brain-A role in type 2 diabetes mellitus and Alzheimer's disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2020; 155:235-269. [PMID: 32854856 DOI: 10.1016/bs.irn.2020.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Some metabolic disorders, such as type 2 diabetes mellitus (T2DM) are risk factors for the development of cognitive deficits and Alzheimer's disease (AD). Epidemiological studies suggest that in people with T2DM, the risk of developing dementia is 2.5 times higher than that in the non-diabetic population. The signaling pathways that underlie the increased risk and facilitate cognitive deficits are not fully understood. In fact, the cause of memory deficits in AD is not fully elucidated. The dentate gyrus of the hippocampus plays an important role in memory formation. Hippocampal neurogenesis is the generation of new neurons and glia in the adult brain throughout life. New neurons incorporate in the granular cell layer of the dentate gyrus and play a role in learning and memory and hippocampal plasticity. A large body of studies suggests that hippocampal neurogenesis is impaired in mouse models of AD and T2DM. Recent evidence shows that hippocampal neurogenesis is also impaired in human patients exhibiting mild cognitive impairment or AD. This review discusses the role of hippocampal neurogenesis in the development of cognitive deficits and AD, and considers inflammatory and endothelial signaling pathways in T2DM that may compromise hippocampal neurogenesis and cognitive function, leading to AD.
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Affiliation(s)
- Orly Lazarov
- Department of Anatomy and Cell Biology, The University of Illinois at Chicago, Chicago, IL, United States.
| | - Richard D Minshall
- Department of Pharmacology, The University of Illinois at Chicago, Chicago, IL, United States; Department of Anesthesiology, The University of Illinois at Chicago, Chicago, IL, United States
| | - Marcelo G Bonini
- Department of Medicine (Hematology/Oncology), Feinberg School of Medicine of Northwestern University and Basic Sciences Research, Robert H. Lurie Comprehensive Cancer Centre, Chicago, IL, United States
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Safar MM, Shahin NN, Mohamed AF, Abdelkader NF. Suppression of BACE1 and amyloidogenic/RAGE axis by sitagliptin ameliorates PTZ kindling-induced cognitive deficits in rats. Chem Biol Interact 2020; 328:109144. [PMID: 32653415 DOI: 10.1016/j.cbi.2020.109144] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 05/22/2020] [Accepted: 05/27/2020] [Indexed: 12/22/2022]
Abstract
The debilitating nature of cognitive impairment in epilepsy and the potential of some traditional antiepileptics to further deteriorate cognitive function are areas of growing concern. Glucagon-like peptide-1 (GLP-1) deficiency has been linked to reduced seizure threshold as well as cognitive dysfunction. Here, we tested whether sitagliptin (SITA), by virtue of its neuroprotective properties, could alleviate both epilepsy and associated cognitive dysfunction in a rat model of kindling epilepsy. Chemical kindling was induced by subconvulsive doses of pentylenetetrazol (PTZ) (30 mg/kg; i.p). SITA (50 mg/kg; p.o) was administered 1 h before PTZ injections. SITA conceivably attenuated PTZ hippocampal histological insult, preserved neuronal integrity and amended neurotransmitter perturbations in rat hippocampi paralleled with enhanced hippocampal GLP-1 levels as well as the downstream cAMP content and protein kinase A (PKA) activity. Moreover, SITA improved cognitive functioning of rats in the Morris water maze which was coupled with hampered hippocampal p(Ser404)-tau and β-amyloid proteins. SITA replenished p(Ser9)-glycogen synthase kinase-3β (GSK-3β). It also opposed the boosted matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), and insulin-like growth factor-1 (IGF-1) levels associated with PTZ administration along with mitigation of both β-secretase-1 (BACE1) immunoreactivity and receptor for advanced glycation end products (RAGE) protein level in rat hippocampi. In conclusion, SITA subdues epileptic and cognitive upshots of PTZ kindling in rats, which might correspond to the modulation of BACE1, amyloidogenic/RAGE axis as well as GSK-3β/MMP-9/BDNF signaling cascade. SITA effects are probably mediated via boosting GLP-1 and subsequently enhancing GLP-1/GLP-1R signaling.
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Affiliation(s)
- Marwa M Safar
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt; Pharmacology and Biochemistry Department, Faculty of Pharmacy, The British University in Egypt, Cairo, Egypt
| | - Nancy N Shahin
- Biochemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Ahmed F Mohamed
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
| | - Noha F Abdelkader
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
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Yang F, Wang H, Chen H, Ran D, Tang Q, Weng P, Sun Y, Jiang W. RAGE Signaling pathway in hippocampus dentate gyrus involved in GLT-1 decrease induced by chronic unpredictable stress in rats. Brain Res Bull 2020; 163:49-56. [PMID: 32621862 DOI: 10.1016/j.brainresbull.2020.06.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/17/2020] [Accepted: 06/28/2020] [Indexed: 11/26/2022]
Abstract
A pivotal role of glutamatergic neurotransmission in the pathophysiology of major depressive disorder (MDD) has been supported in preclinical and clinical studies. Glutamate transporters are responsible for rapid uptake of glutamate to maintain glutamate homeostasis. Down-regulation of glutamate transporters has been reported in MDD patients and animal models. However, the mechanism for stress-induced modulation of glutamate transporter expression is poorly understood. Receptor for advanced glycosylation end products (RAGE), a member of immunoglobulin family, is found expressed widely in brain and play important roles in neuronal development, neurite growth, neurogenesis and neuroinflammation. Our study showed chronic unpredictable stress (CUS) induced depressive-like behaviors and reduced RAGE expression in hippocampus DG, CA1 and CA3 areas. The protein levels of GLT-1, p-CREB and p-p65 decreased in hippocampus DG as well. Knockdown of RAGE expression in hippocampus DG with RAGE shRNA lentivirus particles induced depressive-like behaviors. Meanwhile, the protein and mRNA levels of GLT-1 were significantly decreased as well as phosphorylation of CREB and p65. Neither CUS nor RAGE knockdown altered GLAST protein and mRNA levels. These findings suggested that RAGE/CREB-NF-κB signaling pathway in hippocampus DG involved in modulation of GLT-1 expression, which possibly contributed to the depressive-like behavior induced by CUS.
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Affiliation(s)
- Fang Yang
- Key Laboratory of Molecular and Biochemical Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Hong Wang
- Key Laboratory of Molecular and Biochemical Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Huali Chen
- Key Laboratory of Molecular and Biochemical Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Dongzhi Ran
- Key Laboratory of Molecular and Biochemical Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Qiang Tang
- Key Laboratory of Molecular and Biochemical Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Ping Weng
- Key Laboratory of Molecular and Biochemical Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Yuzhuo Sun
- Key Laboratory of Molecular and Biochemical Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Wengao Jiang
- Key Laboratory of Molecular and Biochemical Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, China.
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Khan MSH, Hegde V. Obesity and Diabetes Mediated Chronic Inflammation: A Potential Biomarker in Alzheimer's Disease. J Pers Med 2020; 10:jpm10020042. [PMID: 32455946 PMCID: PMC7354630 DOI: 10.3390/jpm10020042] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/16/2020] [Accepted: 05/19/2020] [Indexed: 12/15/2022] Open
Abstract
Alzheimer’s disease (AD) is the sixth leading cause of death and is correlated with obesity, which is the second leading cause of preventable diseases in the United States. Obesity, diabetes, and AD share several common features, and inflammation emerges as the central link. High-calorie intake, elevated free fatty acids, and impaired endocrine function leads to insulin resistance and systemic inflammation. Systemic inflammation triggers neuro-inflammation, which eventually hinders the metabolic and regulatory function of the brain mitochondria leading to neuronal damage and subsequent AD-related cognitive decline. As an early event in the pathogenesis of AD, chronic inflammation could be considered as a potential biomarker in the treatment strategies for AD.
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Promiscuous Roles of Autophagy and Proteasome in Neurodegenerative Proteinopathies. Int J Mol Sci 2020; 21:ijms21083028. [PMID: 32344772 PMCID: PMC7215558 DOI: 10.3390/ijms21083028] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 12/12/2022] Open
Abstract
Alterations in autophagy and the ubiquitin proteasome system (UPS) are commonly implicated in protein aggregation and toxicity which manifest in a number of neurological disorders. In fact, both UPS and autophagy alterations are bound to the aggregation, spreading and toxicity of the so-called prionoid proteins, including alpha synuclein (α-syn), amyloid-beta (Aβ), tau, huntingtin, superoxide dismutase-1 (SOD-1), TAR-DNA-binding protein of 43 kDa (TDP-43) and fused in sarcoma (FUS). Recent biochemical and morphological studies add to this scenario, focusing on the coordinated, either synergistic or compensatory, interplay that occurs between autophagy and the UPS. In fact, a number of biochemical pathways such as mammalian target of rapamycin (mTOR), transcription factor EB (TFEB), Bcl2-associated athanogene 1/3 (BAG3/1) and glycogen synthase kinase beta (GSk3β), which are widely explored as potential targets in neurodegenerative proteinopathies, operate at the crossroad between autophagy and UPS. These biochemical steps are key in orchestrating the specificity and magnitude of the two degradation systems for effective protein homeostasis, while intermingling with intracellular secretory/trafficking and inflammatory pathways. The findings discussed in the present manuscript are supposed to add novel viewpoints which may further enrich our insight on the complex interactions occurring between cell-clearing systems, protein misfolding and propagation. Discovering novel mechanisms enabling a cross-talk between the UPS and autophagy is expected to provide novel potential molecular targets in proteinopathies.
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Radiolabeling of [ 11C]FPS-ZM1, a receptor for advanced glycation end products-targeting positron emission tomography radiotracer, using a [ 11C]CO 2-to-[ 11C]CO chemical conversion. Future Med Chem 2020; 12:511-521. [PMID: 32100545 DOI: 10.4155/fmc-2019-0329] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Aim: The receptor for advanced glycation end products (RAGE) is a viable target for early Alzheimer's disease (AD) diagnosis using positron emission tomography (PET) as RAGE overexpression precedes Aβ plaque formation. The development of a carbon-11 analog of FPS-ZM1 (N-benzyl-4-chloro-N-cyclohexylbenzamide, [11C]FPS-ZM1), possessing nanomolar affinity for RAGE, may enable the imaging of RAGE for early AD detection. Methodology & results: Herein we report an optimized [11C]CO2-to-[11C]CO chemical conversion for the synthesis of [11C]FPS-ZM1 and in vitro brain autoradiography. The [11C]CO2-to-[11C]CO conversion via 11C-silanecarboxylate derivatives was achieved with a 57% yield within 30 s from end of [11C]CO2 delivery. [11C]FPS-ZM1 was obtained with a decay-corrected isolated radiochemical yield of 9.5%. Conclusion: [11C]FPS-ZM1 distribution in brain tissues of wild-type versus transgenic AD model mice showed no statistically significant difference and high nondisplaceable binding.
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Impact of HMGB1, RAGE, and TLR4 in Alzheimer's Disease (AD): From Risk Factors to Therapeutic Targeting. Cells 2020; 9:cells9020383. [PMID: 32046119 PMCID: PMC7072620 DOI: 10.3390/cells9020383] [Citation(s) in RCA: 131] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/04/2020] [Accepted: 02/04/2020] [Indexed: 12/24/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating neurodegenerative disorder and a leading cause of dementia, with accumulation of amyloid-beta (Aβ) and neurofibrillary tangles (NFTs) as defining pathological features. AD presents a serious global health concern with no cure to date, reflecting the complexity of its pathogenesis. Recent evidence indicates that neuroinflammation serves as the link between amyloid deposition, Tau pathology, and neurodegeneration. The high mobility group box 1 (HMGB1) protein, an initiator and activator of neuroinflammatory responses, has been involved in the pathogenesis of neurodegenerative diseases, including AD. HMGB1 is a typical damage-associated molecular pattern (DAMP) protein that exerts its biological activity mainly through binding to the receptor for advanced glycation end products (RAGE) and toll-like receptor 4 (TLR4). RAGE and TLR4 are key components of the innate immune system that both bind to HMGB1. Targeting of HMGB1, RAGE, and TLR4 in experimental AD models has demonstrated beneficial effects in halting AD progression by suppressing neuroinflammation, reducing Aβ load and production, improving spatial learning, and inhibiting microglial stimulation. Herein, we discuss the contribution of HMGB1 and its receptor signaling in neuroinflammation and AD pathogenesis, providing evidence of its beneficial effects upon therapeutic targeting.
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Volloch V, Olsen B, Rits S. Alzheimer's Disease is Driven by Intraneuronally Retained Beta-Amyloid Produced in the AD-Specific, βAPP-Independent Pathway: Current Perspective and Experimental Models for Tomorrow. ANNALS OF INTEGRATIVE MOLECULAR MEDICINE 2020; 2:90-114. [PMID: 32617536 PMCID: PMC7331974 DOI: 10.33597/aimm.02-1007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A view of the origin and progression of Alzheimer's disease, AD, prevailing until now and formalized as the Amyloid Cascade Hypothesis theory, maintains that the disease is initiated by overproduction of beta-amyloid, Aβ, which is generated solely by the Aβ precursor protein, βAPP, proteolytic pathway and secreted from the cell. Consequent extracellular accumulation of Aβ triggers a cascade of molecular and cellular events leading to neurodegeneration that starts early in life, progresses as one prolonged process, builds up for decades, and culminates in symptomatic manifestations of the disease late in life. In this paradigm, a time window for commencement of therapeutic intervention is small and accessible only early in life. The outlook introduced in the present study is fundamentally different. It posits that the βAPP proteolytic/secretory pathway of Aβ production causes AD in humans no more than it does in either short- or long-lived non-human mammals that share this pathway with humans, accumulate beta-amyloid as they age, but do not develop the disease. Alzheimer's disease, according to this outlook, is driven by an additional powerful AD-specific pathway of Aβ production that operates in affected humans, is completely independent of the βAPP precursor, and is not available in non-human mammals. The role of the βAPP proteolytic pathway in the disease in humans is activation of this additional AD-specific Aβ production pathway. This occurs through accumulation of intracellular Aβ, primarily via ApoE-assisted cellular uptake of secreted beta-amyloid, but also through retention of a fraction of Aβ produced in the βAPP proteolytic pathway. With time, accumulated intracellular Aβ triggers mitochondrial dysfunction. In turn, cellular stresses associated with mitochondrial dysfunction, including ER stress, activate a second, AD-specific, Aβ production pathway: Asymmetric RNA-dependent βAPP mRNA amplification; animal βAPP mRNA is ineligible for this process. In this pathway, every conventionally produced βAPP mRNA molecule serves potentially as a template for production of severely 5'-truncated mRNA encoding not the βAPP but its C99 fragment (hence "asymmetric"), the immediate precursor of Aβ. Thus produced, N-terminal signal peptide-lacking C99 is processed not in the secretory pathway on the plasma membrane, but at the intracellular membrane sites, apparently in a neuron-specific manner. The resulting Aβ is, therefore, not secreted but is retained intraneuronally and accumulates rapidly within the cell. Increased levels of intracellular Aβ augment mitochondrial dysfunction, which, in turn, sustains the activity of the βAPP mRNA amplification pathway. These self-propagating mutual Aβ overproduction/mitochondrial dysfunction feedback cycles constitute a formidable two-stroke engine, an engine that drives Alzheimer's disease. The present outlook envisions Alzheimer's disorder as a two-stage disease. The first stage is a slow process of intracellular beta-amyloid accumulation. It results neither in significant neurodegenerative damage, nor in manifestation of the disease. The second stage commences with the activation of the βAPP mRNA amplification pathway shortly before symptomatic onset of the disease, sharply increases the rate of Aβ generation and the extent of its intraneuronal accumulation, produces significant damages, triggers AD symptoms, and is fast. In this paradigm, the time window of therapeutic intervention is wide open, and preventive treatment can be initiated any time, even late in life, prior to commencement of the second stage of the disease. Moreover, there are good reasons to believe that with a drug blocking the βAPP mRNA amplification pathway, it would be possible not only to preempt the disease but also to stop and to reverse it even when early AD symptoms have already manifested. There are numerous experimental models of AD, all based on a notion of the exceptionality of βAPP proteolytic/secretory pathway in Aβ production in the disease. However, with no drug even remotely effective in Alzheimer's disease, a long list of candidate drugs that succeeded remarkably in animal models, yet failed utterly in human clinical trials of potential AD drugs, attests to the inadequacy of currently employed AD models. The concept of a renewable supply of beta-amyloid, produced in the βAPP mRNA amplification pathway and retained intraneuronally in Alzheimer's disease, explains spectacular failures of both BACE inhibition and Aβ-immunotherapy in human clinical trials. This concept also forms the basis of a new generation of animal and cell-based experimental models of AD, described in the present study. These models incorporate Aβ- or C99-encoding mRNA amplification pathways of Aβ production, as well as intracellular retention of their product, and can support not only further investigation of molecular mechanisms of AD but also screening for and testing of candidate drugs aimed at therapeutic targets suggested by the present study.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, USA
| | - Bjorn Olsen
- Department of Developmental Biology, Harvard School of Dental Medicine, USA
| | - Sophia Rits
- Division of Molecular Medicine, Children’s Hospital, Boston, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, USA
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Crossing the blood-brain-barrier with nanoligand drug carriers self-assembled from a phage display peptide. Nat Commun 2019; 10:4635. [PMID: 31604928 PMCID: PMC6789111 DOI: 10.1038/s41467-019-12554-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 09/16/2019] [Indexed: 12/26/2022] Open
Abstract
The filamentous bacteriophage fd bind a cell target with exquisite specificity through its few copies of display peptides, whereas nanoparticles functionalized with hundreds to thousands of synthetically generated phage display peptides exhibit variable and often-weak target binding. We hypothesise that some phage peptides in a hierarchical structure rather than in monomeric form recognise and bind their target. Here we show hierarchial forms of a brain-specific phage-derived peptide (herein as NanoLigand Carriers, NLCs) target cerebral endothelial cells through transferrin receptor and the receptor for advanced glycation-end products, cross the blood-brain-barrier and reach neurons and microglial cells. Through intravenous delivery of NLC-β-secretase 1 (BACE1) siRNA complexes we show effective BACE1 down-regulation in the brain without toxicity and inflammation. Therefore, NLCs act as safe multifunctional nanocarriers, overcome efficacy and specificity limitations in active targeting with nanoparticles bearing phage display peptides or cell-penetrating peptides and expand the receptor repertoire of the display peptide. Bacteriophages can bind targets with only a few copies of a display peptide while most nanoparticles with thousands achieve poor binding. Here the authors form hierarchical arrangements of phage peptides to delivery siRNA across the blood brain barrier.
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Sanjari Moghaddam H, Ghazi Sherbaf F, Aarabi MH. Brain microstructural abnormalities in type 2 diabetes mellitus: A systematic review of diffusion tensor imaging studies. Front Neuroendocrinol 2019; 55:100782. [PMID: 31401292 DOI: 10.1016/j.yfrne.2019.100782] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 07/27/2019] [Accepted: 08/07/2019] [Indexed: 12/13/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is associated with deficits in the structure and function of the brain. Diffusion tensor imaging (DTI) is a highly sensitive method for characterizing cerebral tissue microstructure. Using PRISMA guidelines, we identified 29 studies which have demonstrated widespread brain microstructural impairment and topological network disorganization in patients with T2DM. Most consistently reported structures with microstructural abnormalities were frontal, temporal, and parietal lobes in the lobar cluster; corpus callosum, cingulum, uncinate fasciculus, corona radiata, and internal and external capsules in the white matter cluster; thalamus in the subcortical cluster; and cerebellum. Microstructural abnormalities were correlated with pathological derangements in the endocrine profile as well as deficits in cognitive performance in the domains of memory, information-processing speed, executive function, and attention. Altogether, the findings suggest that the detrimental effects of T2DM on cognitive functions might be due to microstructural disruptions in the central neural structures.
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Affiliation(s)
| | - Farzaneh Ghazi Sherbaf
- Neuroradiology Division, Tehran University of Medical Sciences, School of Medicine, Tehran, Iran
| | - Mohammad Hadi Aarabi
- Neuroradiology Division, Tehran University of Medical Sciences, School of Medicine, Tehran, Iran.
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AGE-RAGE stress: a changing landscape in pathology and treatment of Alzheimer's disease. Mol Cell Biochem 2019; 459:95-112. [PMID: 31079281 DOI: 10.1007/s11010-019-03553-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/04/2019] [Indexed: 12/27/2022]
Abstract
Numerous hypotheses including amyloid cascade, cholinergic, and oxidative have been proposed for pathogenesis of Alzheimer's disease (AD). The data suggest that advanced glycation end products (AGEs) and its receptor RAGE (receptor for AGE) are involved in the pathogenesis of AD. AGE-RAGE stress, defined as a balance between stressors (AGE, RAGE) and anti-stressors (sRAGE, AGE degraders) in favor of stressors, has been implicated in pathogenesis of diseases. AGE and its interaction with RAGE-mediated increase in the reactive oxygen species (ROS) damage brain because of its increased vulnerability to ROS. AGE and ROS increase the synthesis of amyloid β (Aβ) leading to deposition of Aβ and phosphorylation of tau, culminating in formation of plaques and neurofibrillary tangles. ROS increase the synthesis of Aβ, high-mobility group box 1(HMGB1), and S100 that interacts with RAGE to produce additional ROS resulting in enhancement of AD pathology. Elevation of ROS precedes the Aβ plaques formation. Because of involvement of AGE and RAGE in AD pathology, the treatment should be targeted at lowering AGE levels through reduction in consumption and formation of AGE, and lowering expression of RAGE, blocking of RAGE ligand binding, increasing levels of soluble RAGE (sRAGE), and use of antioxidants. The above treatment aspect of AD is lacking. In conclusion, AGE-RAGE stress initiates, and Aβ, HMGB1, and S100 enhance the progression of AD. Reduction of levels of AGE and RAGE, elevation of sRAGE, and antioxidants would be beneficial therapeutic modalities in the prevention, regression, and slowing of progression of AD.
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Crucial players in Alzheimer's disease and diabetes mellitus: Friends or foes? Mech Ageing Dev 2019; 181:7-21. [PMID: 31085195 DOI: 10.1016/j.mad.2019.03.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 03/02/2019] [Accepted: 03/26/2019] [Indexed: 01/21/2023]
Abstract
Alzheimer's disease (AD) and diabetes mellitus, especially type 2 (T2DM), are very common and widespread diseases in contemporary societies, and their incidence is steadily on the increase. T2DM is a multiple metabolic disorder, with several mechanisms including hyperglycaemia, insulin resistance, insulin receptor and insulin growth factor disturbances, glucose toxicity, formation of advanced glycation end products (AGEs) and the activity of their receptors. AD is the most common form of dementia, characterized by the accumulation of extracellular beta amyloid peptide aggregates and intracellular hyper-phosphorylated tau proteins, which are thought to drive and/or accelerate inflammatory and oxidative stress processes leading to neurodegeneration. The aim of this paper is to provide a comprehensive review of the evidence linking T2DM to the onset and development of AD and highlight the unknown or poorly studied "nooks and crannies" of this interesting relationship, hence providing an opportunity to stimulate new ideas for the analysis of comorbidities between AD and DM. Despite, indication of possible biomarkers of early diagnosis of T2DM and AD, this review is also an attempt to answer the question as to whether the crucial factors in the development of both conditions support the link between DM and AD.
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Volloch V, Rits-Volloch S. News from Mars: Two-Tier Paradox, Intracellular PCR, Chimeric Junction Shift, Dark Matter mRNA and Other Remarkable Features of Mammalian RNA-Dependent mRNA Amplification. Implications for Alzheimer's Disease, RNA-Based Vaccines and mRNA Therapeutics. ACTA ACUST UNITED AC 2019; 2:131-173. [PMID: 33942036 DOI: 10.33597/aimm.02-1009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Molecular Biology, a branch of science established to examine the flow of information from "letters" encrypted into DNA structure to functional proteins, was initially defined by a concept of DNA-to-RNA-to-Protein information movement, a notion termed the Central Dogma of Molecular Biology. RNA-dependent mRNA amplification, a novel mode of eukaryotic protein-encoding RNA-to-RNA-to-Protein genomic information transfer, constitutes the extension of the Central Dogma in the context of mammalian cells. It was shown to occur in cellular circumstances requiring exceptionally high levels of production of specific polypeptides, e.g. globin chains during erythroid differentiation or defined secreted proteins in the context of extracellular matrix deposition. Its potency is reflected in the observed cellular levels of the resulting amplified mRNA product: At the peak of the erythroid differentiation, for example, the amount of globin mRNA produced in the amplification pathway is about 1500-fold higher than the amount of its conventionally generated counterpart in the same cells. The cellular enzymatic machinery at the core of this process, RNA-dependent RNA polymerase activity (RdRp), albeit in a non-conventional form, was shown to be constitutively and ubiquitously present, and RNA-dependent RNA synthesis (RdRs) appeared to regularly occur, in mammalian cells. Under most circumstances, the mammalian RdRp activity produces only short antisense RNA transcripts. Generation of complete antisense RNA transcripts and amplification of mRNA molecules require the activation of inducible components of the mammalian RdRp complex. The mechanism of such activation is not clear. The present article suggests that it is triggered by a variety of cellular stresses and occurs in the context of stress responses in general and within the framework of the integrated stress response (ISR) in particular. In this process, various cellular stresses activate, in a stress type-specific manner, defined members of the mammalian translation initiation factor 2α, eIF2α, kinase family: PKR, GCN2, PERK and HRI. Any of these kinases, in an activated form, phosphorylates eIF2α. This results in suppression of global cellular protein synthesis but also in activation of expression of select group of transcription factors including ATF4, ATF5 and CHOP. These transcription factors either function as inducible components of the RdRp complex or enable their expression. The assembly of the competent RdRp complex activates mammalian RNA-dependent mRNA amplification, which appears to be a two-tier process. Tier One is a "chimeric" pathway, named so because it results in an amplified chimeric mRNA molecule containing a fragment of the antisense RNA strand at its 5' terminus. Tier Two further amplifies one of the two RNA end products of the chimeric pathway and constitutes the physiologically occurring intracellular polymerase chain reaction, iPCR. Depending on the structure of the initial mRNA amplification progenitor, the chimeric pathway, Tier One, may result in multiple outcomes including chimeric mRNA that produces either a polypeptide identical to the original, conventional mRNA progenitor-encoded protein or only its C-terminal fragment, CTF. The chimeric RNA end product of Tier One may also produce a polypeptide that is non-contiguously encoded in the genome, activate translation from an open reading frame, which is "silent" in a conventionally transcribed mRNA, or initiate an abortive translation. In sharp contrast, regardless of the outcome of Tier One, the mRNA end product of Tier Two of mammalian mRNA amplification, the iPCR pathway, always produces a polypeptide identical to a conventional mRNA progenitor-encoded protein. This discordance is referred to as the Two-Tier Paradox and discussed in detail in the present article. On the other hand, both Tiers are similar in that they result in heavily modified mRNA molecules resistant to reverse transcription, undetectable by reverse transcription-based methods of sequencing and therefore constituting a proverbial "Dark Matter" mRNA, despite being highly ubiquitous. It appears that in addition to their other functions, the modifications of the amplified mRNA render it compatible, unlike the bulk of cellular mRNA, with phosphorylated eIF2α in translation, implying that in addition to being extraordinarily abundant due to the method of its generation, amplified mRNA is also preferentially translated under the ISR conditions, thus augmenting the efficiency of the amplification process. The vital importance of powerful mechanisms of amplification of protein-encoding genomic information in normal physiology is self-evident. Their malfunctions or misuse appear to be associated with two types of abnormalities, the deficiency of a protein normally produced by these mechanisms and the mRNA amplification-mediated overproduction of a protein normally not generated by such a process. Certain classes of beta-thalassemia exemplify the first type, whereas the second type is represented by overproduction of beta-amyloid in Alzheimer's disease. Moreover, the proposed mechanism of Alzheimer's disease allows a crucial and verifiable prediction, namely that the disease-causing intraneuronally retained variant of beta-amyloid differs from that produced conventionally by βAPP proteolysis in that it contains the additional methionine or acetylated methionine at its N-terminus. Because of its extraordinary evidential value as a natural reporter of the mRNA amplification pathway, this feature, if proven, would, arguably, constitute the proverbial Holy Grail not only for Alzheimer's disease but also for the mammalian RNA-dependent mRNA amplification field in general. Both examples are discussed in detail in the present article, which summarizes and systematizes our current understanding of the field and describes two categories of reporter constructs, one for the chimeric Tier of mRNA amplification, another for the iPCR pathway; both reporter types are essential for elucidating underlying molecular mechanisms. It also suggests, in light of the recently demonstrated feasibility of RNA-based vaccines, that the targeted intracellular amplification of exogenously introduced amplification-eligible antigen-encoding mRNAs via the induced or naturally occurring RNA-dependent mRNA amplification pathway could be of substantial benefit in triggering a fast and potent immune response and instrumental in the development of future vaccines. Similar approaches can also be effective in achieving efficient and sustained expression of exogenous mRNA in mRNA therapeutics.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, USA
| | - Sophia Rits-Volloch
- Division of Molecular Medicine, Children's Hospital, USA.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, USA
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Volloch V, Olsen B, Rits S. Alzheimer's Disease Prevention and Treatment: Case for Optimism. ACTA ACUST UNITED AC 2019; 2:115-130. [PMID: 33043322 DOI: 10.33597/aimm.02-1008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A paradigm shift is under way in the Alzheimer's field. A view of Alzheimer's disease, AD, prevailing until now, the old paradigm, maintains that it is initiated and driven by the overproduction and extracellular accumulation of beta-amyloid, Aβ; a peptide assumed to be derived, both in health and disease, solely by proteolysis of its large precursor, βAPP. In AD, according to this view, Aβ overproduction-associated neurodegeneration begins early, accumulates throughout the lifespan, and manifests symptomatically late in life. A number of drugs, designed within the framework of exceptionality of the βAPP proteolytic/secretory pathway in Aβ production in Alzheimer's disease, achieved spectacular successes in treatment, even the reversal, of AD symptoms in animal models. Without exception, they all exhibited equally spectacular failures in human clinical trials. This paradigm provides few causes for optimism with regard to prevention and treatment of AD. In its context, the disease is considered untreatable in the symptomatic phase; even prodromal cases are assumed too advanced for treatment because Aβ-triggered damages have been accumulating for preceding decades, presumably starting in the early twenties and, to be effective, this is when therapeutic intervention should commence and continue for life. The new paradigm does not dispute the seminal role of Aβ in AD but posits that beta-amyloid produced in the βAPP proteolytic/secretory pathway causes AD in humans no more than it does in non-human mammals that share this pathway with humans, accumulate Aβ as they age, but do not develop the disease. Alzheimer's disease, according to this outlook, is driven by the AD-specific pathway of Aβ production, independent of βAPP and absent in animals. Its activation, late in life, occurs through accumulation, via both cellular uptake of secreted Aβ and neuronal retention of a fraction of beta-amyloid produced in the βAPP proteolytic pathway, of intraneuronal Aβ, which triggers mitochondrial dysfunction. Cellular stresses associated with mitochondrial dysfunction, or, probably, the integrated stress response, ISR, elicited by it, activate an AD-specific Aβ production pathway. In it, every conventionally produced βAPP mRNA molecule potentially serves repeatedly as a template for production of severely 5'-truncated mRNA encoding C99 fragment of βAPP, the immediate precursor of Aβ that is processed in a non-secretory pathway, apparently in a neuron-specific manner. The resulting intraneuronally retained Aβ augments mitochondrial dysfunction, which, in turn, sustains the activity of the βAPP mRNA amplification pathway. These self-propagating Aβ overproduction/mitochondrial dysfunction mutual feedback cycles constitute the engine that drives AD and ultimately triggers neuronal death. In this paradigm, preventive treatment can be initiated any time prior to commencement of βAPP mRNA amplification. Moreover, there are good reasons to believe that with a drug blocking the amplification pathway, it would be possible not only to preempt the disease but also stop and reverse it even when early AD symptoms are already manifested. Thus, the new paradigm introduces a novel theory of Alzheimer's disease. It explains the observed discordances, determines defined therapeutic targets, provides blueprints for a new generation of conceptually distinct AD models and specifies design of a reporter for the mRNA amplification pathway. Most importantly, it offers detailed guidance and tangible hope for prevention of the disease and its treatment at the early symptomatic stages.
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Affiliation(s)
- Vladimir Volloch
- Department of Developmental Biology, Harvard School of Dental Medicine, USA
| | - Bjorn Olsen
- Department of Developmental Biology, Harvard School of Dental Medicine, USA
| | - Sophia Rits
- Division of Molecular Medicine, Children's Hospital, Boston, USA.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, USA
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Dong Y, Wang Q, Yao H, Xiao Y, Wei J, Xie P, Hu J, Chen W, Tang Y, Zhou H, Liu J. A promising structural magnetic resonance imaging assessment in patients with preclinical cognitive decline and diabetes mellitus. J Cell Physiol 2019; 234:16838-16846. [PMID: 30786010 DOI: 10.1002/jcp.28359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/30/2019] [Accepted: 02/01/2019] [Indexed: 01/18/2023]
Abstract
Subjective cognitive decline (SCD) is frequently reported in diabetic patients. Diabetes mellitus (DM) is associated with changes in the microstructure of the brain arise in diabetic patients, including changes in gray matter volume (GMV). However, the underlying mechanisms of changes in GMV in DM patients with cognitive impairment remain uncertain. Here, we present an overview of amyloid-β-dependent cognitive impairment in DM patients with SCD. Moreover, we review the evolving insights from studies on the GMV changes in GMV and cognitive dysfunction to which provide the mechanisms of cognitive impairment in T2DM. Ultimately, the novel structural magnetic resonance imaging (MRI) protocol was used for detecting neuroimaging biomarkers that can predict the clinical outcomes in diabetic patients with SCD. A reliable MRI protocol would be helpful to detect neurobiomarkers, and to understand the pathological mechanisms of preclinical cognitive impairment in diabetic patients.
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Affiliation(s)
- Yulan Dong
- Department of Radiology, the First Affiliated Hospital of University of South China, Hengyang, China
| | - Qi Wang
- Department of Radiology, the Hunan Province Hospital, Changsha, China
| | - Hailun Yao
- Institute of Pharmacy and Medical Technology, Hunan Polytechnic of Environment and Biology, Hengyang, Hunan, China
| | - Yawen Xiao
- Department of Radiology, the First Affiliated Hospital of University of South China, Hengyang, China
| | - Jiaohong Wei
- Department of Radiology, the First Affiliated Hospital of University of South China, Hengyang, China
| | - Peihan Xie
- Department of Radiology, the First Affiliated Hospital of University of South China, Hengyang, China
| | - Jun Hu
- Department of Radiology, the First Affiliated Hospital of University of South China, Hengyang, China
| | - Wen Chen
- Department of Radiology, the First Affiliated Hospital of University of South China, Hengyang, China
| | - Yan Tang
- Department of Ultrasound, the First Affiliated Hospital of University of South China, Hengyang, China
| | - Hong Zhou
- Department of Radiology, the First Affiliated Hospital of University of South China, Hengyang, China.,Hengyang Medical College, University of South China, Hengyang, China
| | - Jincai Liu
- Department of Radiology, the First Affiliated Hospital of University of South China, Hengyang, China
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Fang F, Yu Q, Arancio O, Chen D, Gore SS, Yan SS, Yan SF. RAGE mediates Aβ accumulation in a mouse model of Alzheimer's disease via modulation of β- and γ-secretase activity. Hum Mol Genet 2019; 27:1002-1014. [PMID: 29329433 DOI: 10.1093/hmg/ddy017] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/03/2018] [Indexed: 12/18/2022] Open
Abstract
Receptor for Advanced Glycation End products (RAGE) has been implicated in amyloid β-peptide (Aβ)-induced perturbation relevant to the pathogenesis of Alzheimer's disease (AD). However, whether and how RAGE regulates Aβ metabolism remains largely unknown. Aβ formation arises from aberrant cleavage of amyloid pre-cursor protein (APP) by β- and γ-secretase. To investigate whether RAGE modulates β- and γ-secretase activity potentiating Aβ formation, we generated mAPP mice with genetic deletion of RAGE (mAPP/RO). These mice displayed reduced cerebral amyloid pathology, inhibited aberrant APP-Aβ metabolism by reducing β- and γ-secretases activity, and attenuated impairment of learning and memory compared with mAPP mice. Similarly, RAGE signal transduction deficient mAPP mice (mAPP/DN-RAGE) exhibited the reduction in Aβ40 and Aβ42 production and decreased β-and γ-secretase activity compared with mAPP mice. Furthermore, RAGE-deficient mAPP brain revealed suppression of activation of p38 MAP kinase and glycogen synthase kinase 3β (GSK3β). Finally, RAGE siRNA-mediated gene silencing or DN-RAGE-mediated signaling deficiency in the enriched human APP neuronal cells demonstrated suppression of activation of GSK3β, accompanied with reduction in Aβ levels and decrease in β- and γ-secretases activity. Our findings highlight that RAGE-dependent signaling pathway regulates β- and γ-secretase cleavage of APP to generate Aβ, at least in part through activation of GSK3β and p38 MAP kinase. RAGE is a potential therapeutic target to limit aberrant APP-Aβ metabolism in halting progression of AD.
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Affiliation(s)
- Fang Fang
- Department of Pharmacology and Toxicology, and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS 66047, USA
| | - Qing Yu
- Department of Pharmacology and Toxicology, and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS 66047, USA
| | - Ottavio Arancio
- Department of Pathology and Taub Institute for Research on Aging and Alzheimer's Disease, Physicians & Surgeons College of Columbia University, New York, NY 10032, USA
| | - Doris Chen
- Department of Pharmacology and Toxicology, and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS 66047, USA
| | - Smruti S Gore
- Department of Pharmacology and Toxicology, and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS 66047, USA
| | - Shirley ShiDu Yan
- Department of Pharmacology and Toxicology, and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS 66047, USA
| | - Shi Fang Yan
- Department of Pharmacology and Toxicology, and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS 66047, USA
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