NFκB-Activated Astroglial Release of Complement C3 Compromises Neuronal Morphology and Function Associated with Alzheimer’s Disease

Mitochondrial dysfunction plays a pivotal role in the Alzheimer’s Disease (AD) pathology. Disrupted mitochondrial dynamics (i.e., fusion/fission balance), which are essential for normal mitochondria structure and function, are documented in AD. Caveolin-1 (Cav-1), a membrane/lipid raft (MLR) scaffolding protein regulates metabolic pathways in several different cell types such as hepatocytes and cancer cells. Previously, we have shown decreased expression of Cav-1 in the hippocampus of 9-month (m) old PSAPP mice, while hippocampal overexpression of neuron-targeted Cav-1 using the synapsin promoter (i.e., SynCav1) preserved cognitive function, neuronal morphology, and synaptic ultrastructure in 9 and 12 m PSAPP mice. Considering the central role of energy production in maintaining normal neuronal and synaptic function and survival, the present study reveals that PSAPP mice exhibit disrupted mitochondrial distribution, morphometry, and respiration. In contrast, SynCav1 mitigates mitochondrial damage and loss and enhances mitochondrial respiration. Furthermore, by examining mitochondrial dynamics, we found that PSAPP mice showed a significant increase in the phosphorylation of mitochondrial dynamin-related GTPase protein (DRP1), resulting in excessive mitochondria fragmentation and dysfunction. In contrast, hippocampal delivery of SynCav1 significantly decreased p-DRP1 and augmented the level of the mitochondrial fusion protein, mitofusin1 (Mfn1) in PSAPP mice, a molecular event, which may mechanistically explain for the preserved balance of mitochondria fission/fusion and metabolic resilience in 12 m PSAPP-SynCav1 mice. Our data demonstrate the critical role for Cav-1 in maintaining normal mitochondrial morphology and function through affecting mitochondrial dynamics and explain a molecular and cellular mechanism underlying the previously reported neuroprotective and cognitive preservation induced by SynCav1 in PSAPP mouse model of AD.

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Plasma Neurofilament Light and Future Declines in Cognition and Function in Alzheimer’s Disease in the FIT-AD Trial

Journal of Alzheimer s Disease Reports ◽

10.3233/adr-210302 ◽

2021 ◽

pp. 1-11

Author(s):

Danni Li ◽

Lin Zhang ◽

Nathaniel W. Nelson ◽

Michelle M. Mielke ◽

Fang Yu

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Daily Living ◽

Short Term ◽

Neurofilament Light Chain ◽

Neurofilament Light ◽

Linear Mixed Effects ◽

Future Studies ◽

Rate Of Decline ◽

And Function

Background: Utilities of blood-based biomarkers in Alzheimer’s disease (AD) clinical trials remain unknown. Objective: To evaluate the ability of plasma neurofilament light chain (NfL) to predict future declines in cognition and activities of daily living (ADL) outcomes in 26 older adults with mild-to-moderate AD dementia from the FIT-AD Trial. Methods: Plasma NfL was measured at baseline and 3 and 6 months. Cognition and ADL were assessed using the AD Assessment Scale-Cognition (ADAS-Cog) and AD Uniform Dataset Instruments and Disability Assessment for Dementia (DAD), respectively, at baseline, 3, 6, 9, and 12 months. Linear mixed effects models were used to examine the associations between baseline or change in plasma NfL and changes in outcomes. Results: Higher baseline plasma NfL was associated with greater rate of decline in ADAS-Cog from baseline to 6 months (standardized estimate of 0.00462, p = 0.02853) and in ADL from baseline to 12 months (standardized estimate of –0.00284, p = 0.03338). Greater increase in plasma NfL in short term from baseline to 3 months was associated with greater rate of decline in memory and ADL from 3 to 6 months (standardized estimate of –0.04638 [0.003], p = 0.01635; standardized estimate of –0.03818, p = 0.0435) and greater rate of decline in ADL from 3 to 12 month (standardized estimate of –0.01492, p = 0.01082). Conclusion: This study demonstrated that plasma NfL might have the potential to predict cognitive and function decline up to 12 months. However, future studies with bigger sample sizes need to confirm the findings.

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The Protective Mechanism of SIRT1 in the Regulation of Mitochondrial Biogenesis and Mitochondrial Autophagy in Alzheimer’s Disease

Journal of Alzheimer s Disease ◽

10.3233/jad-210132 ◽

2021 ◽

pp. 1-9

Author(s):

Fan Ye ◽

Anshi Wu

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Mitochondrial Biogenesis ◽

Stress Responses ◽

Histone Deacetylases ◽

Neuronal Morphology ◽

Protective Mechanism ◽

Peroxisome Proliferator ◽

Class Iii ◽

Peroxisome Proliferator Activated Receptor

Silent information-regulated transcription factor 1 (SIRT1) is the most prominent and widely studied member of the sirtuins (a family of mammalian class III histone deacetylases). It is a nuclear protein, and the deacetylation of the peroxisome proliferator-activated receptor coactivator-1 has been extensively implicated in metabolic control and mitochondrial biogenesis and is the basis for studies into its involvement in caloric restriction and its effects on lifespan. The present study discusses the potentially protective mechanism of SIRT1 in the regulation of the mitochondrial biogenesis and autophagy involved in the modulation of Alzheimer’s disease, which may be correlated with the role of SIRT1 in affecting neuronal morphology, learning, and memory during development; regulating metabolism; counteracting stress responses; and maintaining genomic stability. Drugs that activate SIRT1 may offer a promising approach to treating Alzheimer’s disease

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Microglial Function and Regulation during Development, Homeostasis and Alzheimer’s Disease

Cells ◽

10.3390/cells10040957 ◽

2021 ◽

Vol 10 (4) ◽

pp. 957

Author(s):

Brad T. Casali ◽

Erin G. Reed-Geaghan

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Immune Cells ◽

Expression Patterns ◽

Brain Parenchyma ◽

Primary Role ◽

And Function ◽

Inflammatory Milieu ◽

The Brain ◽

Homeostatic State

Microglia are the resident immune cells of the brain, deriving from yolk sac progenitors that populate the brain parenchyma during development. During development and homeostasis, microglia play critical roles in synaptogenesis and synaptic plasticity, in addition to their primary role as immune sentinels. In aging and neurodegenerative diseases generally, and Alzheimer’s disease (AD) specifically, microglial function is altered in ways that significantly diverge from their homeostatic state, inducing a more detrimental inflammatory environment. In this review, we discuss the receptors, signaling, regulation and gene expression patterns of microglia that mediate their phenotype and function contributing to the inflammatory milieu of the AD brain, as well as strategies that target microglia to ameliorate the onset, progression and symptoms of AD.

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Alterations in mitochondrial number and function in Alzheimer’s disease fibroblasts

Metabolic Brain Disease ◽

10.1007/s11011-015-9667-z ◽

2015 ◽

Vol 30 (5) ◽

pp. 1275-1278 ◽

Cited By ~ 10

Author(s):

Nora E. Gray ◽

Joseph F. Quinn

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Mitochondrial Number ◽

And Function

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Astrocytic transporters in Alzheimer's disease

Biochemical Journal ◽

10.1042/bcj20160505 ◽

2017 ◽

Vol 474 (3) ◽

pp. 333-355 ◽

Cited By ~ 7

Author(s):

Chris Ugbode ◽

Yuhan Hu ◽

Benjamin Whalley ◽

Chris Peers ◽

Marcus Rattray ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Early Stage ◽

Neurological Diseases ◽

Current Evidence ◽

Specific Targeting ◽

Disease Modifying Therapies ◽

The Central Nervous System ◽

Disease Modifying ◽

And Function

Astrocytes play a fundamental role in maintaining the health and function of the central nervous system. Increasing evidence indicates that astrocytes undergo both cellular and molecular changes at an early stage in neurological diseases, including Alzheimer's disease (AD). These changes may reflect a change from a neuroprotective to a neurotoxic phenotype. Given the lack of current disease-modifying therapies for AD, astrocytes have become an interesting and viable target for therapeutic intervention. The astrocyte transport system covers a diverse array of proteins involved in metabolic support, neurotransmission and synaptic architecture. Therefore, specific targeting of individual transporter families has the potential to suppress neurodegeneration, a characteristic hallmark of AD. A small number of the 400 transporter superfamilies are expressed in astrocytes, with evidence highlighting a fraction of these are implicated in AD. Here, we review the current evidence for six astrocytic transporter subfamilies involved in AD, as reported in both animal and human studies. This review confirms that astrocytes are indeed a viable target, highlights the complexities of studying astrocytes and provides future directives to exploit the potential of astrocytes in tackling AD.

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Microglia-Based Sex-Biased Neuropathology in Early-Stage Alzheimer’s Disease Model Mice and the Potential Pharmacologic Efficacy of Dioscin

Cells ◽

10.3390/cells10113261 ◽

2021 ◽

Vol 10 (11) ◽

pp. 3261

Author(s):

Xiao Liu ◽

Qian Zhou ◽

Jia-He Zhang ◽

Xiaoying Wang ◽

Xiumei Gao ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Early Stage ◽

Disease Model ◽

Amyloid Β ◽

Brain Lesions ◽

Synaptic Dysfunction ◽

Synaptic Loss ◽

And Function ◽

The Brain

Alzheimer’s disease (AD), the most common form of dementia, is characterized by amyloid-β (Aβ) accumulation, microglia-associated neuroinflammation, and synaptic loss. The detailed neuropathologic characteristics in early-stage AD, however, are largely unclear. We evaluated the pathologic brain alterations in young adult App knock-in model AppNL-G-F mice at 3 and 6 months of age, which corresponds to early-stage AD. At 3 months of age, microglia expression in the cortex and hippocampus was significantly decreased. By the age of 6 months, the number and function of the microglia increased, accompanied by progressive amyloid-β deposition, synaptic dysfunction, neuroinflammation, and dysregulation of β-catenin and NF-κB signaling pathways. The neuropathologic changes were more severe in female mice than in male mice. Oral administration of dioscin, a natural product, ameliorated the neuropathologic alterations in young AppNL-G-F mice. Our findings revealed microglia-based sex-differential neuropathologic changes in a mouse model of early-stage AD and therapeutic efficacy of dioscin on the brain lesions. Dioscin may represent a potential treatment for AD.

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Mesenchymal Stem Cell-Derived Extracellular Vesicle-Based Therapy for Alzheimer’s Disease: Progress and Opportunity

Membranes ◽

10.3390/membranes11100796 ◽

2021 ◽

Vol 11 (10) ◽

pp. 796

Author(s):

Yi-An Chen ◽

Cheng-Hsiu Lu ◽

Chien-Chih Ke ◽

Ren-Shyan Liu

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Neurodegenerative Disorder ◽

Therapeutic Potential ◽

Extracellular Vesicle ◽

Synaptic Loss ◽

Molecular Machinery ◽

And Function ◽

Preclinical And Clinical Studies ◽

Ad Therapy

Alzheimer’s disease (AD), as a neurodegenerative disorder, is characterized by mass neuronal and synaptic loss and, currently, there are no successful curative therapies. Extracellular vesicles (EVs) are an emerging approach to intercellular communication via transferring cellular materials such as proteins, lipids, mRNAs, and miRNAs from parental cells to recipient cells, leading to the reprogramming of the molecular machinery. Numerous studies have suggested the therapeutic potential of EVs derived from mesenchymal stem cells (MSCs) in the treatment of AD, based on the neuroprotective, regenerative and immunomodulatory effects as effective as MSCs. In this review, we focus on the biology and function of EVs, the potential of MSC-derived EVs for AD therapy in preclinical and clinical studies, as well as the potent mechanisms of MSC-derived EVs actions. Finally, we highlight the modification strategies and diagnosis utilities in order to make advance in this field.

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Tart Cherry Extract and Omega Fatty Acids Reduce Behavioral Deficits, Gliosis, and Amyloid-Beta Deposition in the 5xFAD Mouse Model of Alzheimer’s Disease

Brain Sciences ◽

10.3390/brainsci11111423 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1423

Author(s):

Zackary Bowers ◽

Panchanan Maiti ◽

Ali Bourcier ◽

Jarod Morse ◽

Kenneth Jenrow ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Fatty Acids ◽

Mouse Model ◽

Neuronal Morphology ◽

Omega Fatty Acids ◽

Tart Cherry ◽

Therapeutic Benefits ◽

Model Of Alzheimer’S Disease ◽

5Xfad Mice

Combined treatments using polyphenols and omega fatty acids provide several therapeutic benefits for a variety of age-related disorders, including Alzheimer’s disease (AD). Previously, we found a commercial product, Total Body Rhythm (TBR), consisting of tart cherry extract, a potent polyphenol, and omega fatty acids, significantly reduced memory, and neuropathological deficits in the 192 IgG-saporin mouse model of AD. The present study assessed the efficacy of TBR for treating behavioral and neuropathological deficits in the 5xFAD model of AD. Both 6- and 12-month-old 5xFAD mice and age-matched wild-type controls received TBR (60 mg/kg) or the equivalent dose of vehicle (0.5% methylcellulose) via oral administration, every other day for two months. All mice were tested in the open field (OF), novel object recognition (NOR), and the Morris water maze (MWM) tasks. In addition, neuronal morphology, neurodegeneration, Aβ plaque load, and glial activation were assessed. TBR treatment reduced memory deficits in the MWM and NOR tests and lessened anxiety levels in the OF task, mostly in the 6-month-old male mice. TBR also protected against neuron loss, reduced activation of astrocytes and microglia, primarily in 6-month-old mice, and attenuated Aβ deposition. These results suggest that the combination of tart cherry extract and omega fatty acids in TBR can reduce AD-like deficits in 5xFAD mice.

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