scholarly journals P. Edulis Extract Protects Against Amyloid-β Toxicity in Alzheimer’s Disease Models Through Maintenance of Mitochondrial Homeostasis via the FOXO3/DAF-16 Pathway

2021 ◽  
Author(s):  
Shu-qin Cao ◽  
Yahyah Aman ◽  
Evandro Fei Fang ◽  
Tewin Tencomnao
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mammalian Cells ◽  
Nuclear Translocation ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
C Elegans ◽  
Drug Candidates ◽  
Mitochondrial Homeostasis ◽  
Amyloid Aβ

Abstract Alzheimer’s disease (AD) is a common and devastating disease characterized by pathological aggregations of beta-amyloid (Aβ) plaques extracellularly, and Tau tangles intracellularly. While our understandings of the aetiologies of AD have greatly expanded over the decades, there is no drug available to stop disease progression. Here, we demonstrate the potential of P. edulis pericarp extract in protecting against Aβ-mediated neurotoxicity in mammalian cells and Caenorhabditis elegans models of AD. We show P. edulis pericarp protects against memory deficit, neuronal loss, and promotes longevity in the Aβ model of AD via stimulation of mitophagy, a selective cellular clearance of damaged and dysfunctional mitochondria. P. edulis pericarp also restores memory and increases neuronal resilience in a C. elegans Tau model of AD. While defective mitophagy-induced accumulation of damaged mitochondria contributes to AD progression, P. edulis pericarp improves mitochondrial homeostasis through NIX/DCT1-dependent mitophagy and SOD3-dependent mitochondrial resilience, both via increased nuclear translocation of the upstream transcriptional regulator FOXO3/DAF-16. Further studies to identify active molecules in P. edulis pericarp that could maintain neuronal mitochondrial homeostasis may enable the development of potential drug candidates for AD.

scholarly journals Ingredients in Zijuan Pu’er Tea Extract Alleviate β-Amyloid Peptide Toxicity in a Caenorhabditis elegans Model of Alzheimer’s Disease Likely through DAF-16

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 729 ◽  
Author(s):  
Fangzhou Du ◽  
Lin Zhou ◽  
Yan Jiao ◽  
Shuju Bai ◽  
Lu Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Caenorhabditis Elegans ◽  
Protective Effect ◽  
Nuclear Translocation ◽  
Amyloid Β ◽  
Amyloid Peptide ◽  
C Elegans ◽  
Β Amyloid

Amyloid-β, one of the hallmarks of Alzheimer’s disease (AD), is toxic to neurons and can also cause brain cell death. Oxidative stress is known to play an important role in AD, and there is strong evidence that oxidative stress is associated with amyloid-β. In the present study we report the protective effect of Zijuan Pu’er tea water extract (ZTWE) and the mixture of main ingredients (+)-catechins, caffeine and procyanidin (MCCP) in ZTWE on β-amyloid-induced toxicity in transgenic Caenorhabditis elegans (C. elegans) CL4176 expressing the human Aβ1–42 gene. ZTWE, (+)-catechins, caffeine, procyanidin and MCCP delayed the β-amyloid-induced paralysis to different degrees. The MCCP treatment did not affect the transcript abundance of amyloid-β transgene (amy-1); however, Thioflavin T staining showed a significant decrease in Aβ accumulation compared to untreated worms. Further research using transgenic worms found that MCCP promoted the translocation of DAF-16 from cytoplasm to nucleus and increased the expression of superoxide dismutase 3 (SOD-3). In addition, MCCP decreased the reactive oxygen species (ROS) content and increased the SOD activity in CL4176 worms. In conclusion, the results suggested that MCCP had a significant protective effect on β-amyloid-induced toxicity in C. elegans by reducing β-amyloid aggregation and inducing DAF-16 nuclear translocation that could activate the downstream signal pathway and enhance resistance to oxidative stress.

Anti-Neuroinflammatory Potential of Polyphenols by Inhibiting NF-κB to Halt Alzheimer's Disease

2020 ◽  
Vol 26 ◽  
Author(s):  
Md. Sahab Uddin ◽  
Sharifa Hasana ◽  
Jamil Ahmad ◽  
Md. Farhad Hossain ◽  
Md. Mosiqur Rahman ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Senile Plaques ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Research Area ◽  
Tau Proteins ◽  
Brain Disorder ◽  
Drug Candidates ◽  
Life Threatening

: Alzheimer's disease (AD) is an irrevocable chronic brain disorder featured by neuronal loss, microglial accumulation, and progressive cognitive impairment. The proper pathophysiology of this life-threatening disorder is not completely understood and no exact remedies are found yet. Over the last few decades, research on AD has mainly highlighted in pathomechanisms linked to a couple of the major pathological hallmarks, including extracellular senile plaques, made of amyloid-β (Aβ) peptides, and intracellular neurofibrillary tangles (NFTs), made of tau proteins. Aβ can induce apoptosis, trigger an inflammatory response, and inhibit the synaptic plasticity of the hippocampus, which ultimately contributes to reducing cognitive functions and memory impairment. Recently, a third disease hallmark, the neuroinflammatory reaction that is mediated by cerebral innate immune cells, has become a spotlight in the current research area, assured by pre-clinical, clinical, and genetic investigations. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), a cytokine producer, is significantly associated with physiological inflammatory proceedings and thus showing a promising candidate for inflammation-based AD therapy. Recent data reveal that phytochemicals mainly polyphenols compounds exhibit potential neuroprotective functions and it may be considered as a vital resource for discovering several drug candidates against AD. Interestingly, phytochemicals can easily interfere with the signaling pathway of NF-κB. This review represents the anti-neuroinflammatory potential of polyphenols as inhibitors of NF-κB to combat AD pathogenesis.

scholarly journals PPARγ-coactivator-1α gene transfer reduces neuronal loss and amyloid-β generation by reducing β-secretase in an Alzheimer’s disease model

2016 ◽  
Vol 113 (43) ◽  
pp. 12292-12297 ◽  
Author(s):  
Loukia Katsouri ◽  
Yau M. Lim ◽  
Katrin Blondrath ◽  
Ioanna Eleftheriadou ◽  
Laura Lombardero ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Pyramidal Neurons ◽  
Lentiviral Vector ◽  
Disease Model ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Peroxisome Proliferator ◽  
Neuroprotective Effects ◽  
Peroxisome Proliferator Activated Receptor

Current therapies for Alzheimer’s disease (AD) are symptomatic and do not target the underlying Aβ pathology and other important hallmarks including neuronal loss. PPARγ-coactivator-1α (PGC-1α) is a cofactor for transcription factors including the peroxisome proliferator-activated receptor-γ (PPARγ), and it is involved in the regulation of metabolic genes, oxidative phosphorylation, and mitochondrial biogenesis. We previously reported that PGC-1α also regulates the transcription of β-APP cleaving enzyme (BACE1), the main enzyme involved in Aβ generation, and its expression is decreased in AD patients. We aimed to explore the potential therapeutic effect of PGC-1α by generating a lentiviral vector to express human PGC-1α and target it by stereotaxic delivery to hippocampus and cortex of APP23 transgenic mice at the preclinical stage of the disease. Four months after injection, APP23 mice treated with hPGC-1α showed improved spatial and recognition memory concomitant with a significant reduction in Aβ deposition, associated with a decrease in BACE1 expression. hPGC-1α overexpression attenuated the levels of proinflammatory cytokines and microglial activation. This effect was accompanied by a marked preservation of pyramidal neurons in the CA3 area and increased expression of neurotrophic factors. The neuroprotective effects were secondary to a reduction in Aβ pathology and neuroinflammation, because wild-type mice receiving the same treatment were unaffected. These results suggest that the selective induction of PGC-1α gene in specific areas of the brain is effective in targeting AD-related neurodegeneration and holds potential as therapeutic intervention for this disease.

scholarly journals Early Neuronal Loss and Axonal/Presynaptic Damage is Associated with Accelerated Amyloid-β Accumulation in AβPP/PS1 Alzheimer's Disease Mice Subiculum

2014 ◽  
Vol 42 (2) ◽  
pp. 521-541 ◽  
Author(s):  
Laura Trujillo-Estrada ◽  
José Carlos Dávila ◽  
Elisabeth Sánchez-Mejias ◽  
Raquel Sánchez-Varo ◽  
Angela Gomez-Arboledas ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Β ◽  
Neuronal Loss

scholarly journals Increased levels of Stress-inducible phosphoprotein-1 accelerates amyloid-β deposition in a mouse model of Alzheimer’s disease

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Rachel E. Lackie ◽  
Jose Marques-Lopes ◽  
Valeriy G. Ostapchenko ◽  
Sarah Good ◽  
Wing-Yiu Choy ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Protein Quality ◽  
Amyloid Β ◽  
Amyloid Burden ◽  
C Elegans ◽  
Model Of Alzheimer’S Disease

Abstract Molecular chaperones and co-chaperones, which are part of the protein quality control machinery, have been shown to regulate distinct aspects of Alzheimer’s Disease (AD) pathology in multiple ways. Notably, the co-chaperone STI1, which presents increased levels in AD, can protect mammalian neurons from amyloid-β toxicity in vitro and reduced STI1 levels worsen Aβ toxicity in C. elegans. However, whether increased STI1 levels can protect neurons in vivo remains unknown. We determined that overexpression of STI1 and/or Hsp90 protected C. elegans expressing Aβ(3–42) against Aβ-mediated paralysis. Mammalian neurons were also protected by elevated levels of endogenous STI1 in vitro, and this effect was mainly due to extracellular STI1. Surprisingly, in the 5xFAD mouse model of AD, by overexpressing STI1, we find increased amyloid burden, which amplifies neurotoxicity and worsens spatial memory deficits in these mutants. Increased levels of STI1 disturbed the expression of Aβ-regulating enzymes (BACE1 and MMP-2), suggesting potential mechanisms by which amyloid burden is increased in mice. Notably, we observed that STI1 accumulates in dense-core AD plaques in both 5xFAD mice and human brain tissue. Our findings suggest that elevated levels of STI1 contribute to Aβ accumulation, and that STI1 is deposited in AD plaques in mice and humans. We conclude that despite the protective effects of STI1 in C. elegans and in mammalian cultured neurons, in vivo, the predominant effect of elevated STI1 is deleterious in AD.

scholarly journals GPCR19 regulates P2X7R-mediated NLRP3 inflammasomal activation of microglia by Amyloid β in Alzheimer’s diseases

2020 ◽  
Author(s):  
Jahirul Islam ◽  
Jung-Ah Cho ◽  
Ju-yong Kim ◽  
Kyung-Sun Park ◽  
Young-Jae koh ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Nlrp3 Inflammasome ◽  
Memory Function ◽  
Scavenger Receptor ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Priming Phase ◽  
5Xfad Mice ◽  
The Brain

Abstract Amyloid β (Aβ) and/or ATP activates NLRP3 inflammasome (N3I) by P2 × 7R ion channel of microglia, which is crucial in neuroinflammation shown in Alzheimer’s disease (AD). Due to polymorphisms, subtypes, and ubiquitous expression of P2 × 7R, inhibition of P2 × 7R has not been effective for AD. We first report that GPCR19 is a prerequisite for P2 × 7R-mediated N3I activation and Taurodeoxycholate (TDCA), a GPCR19 ligand, inhibited the priming phase of N3I activation, suppressed P2 × 7R expression and P2 × 7R-mediated Ca++ mobilization, and N3I oligomerization which is essential for production of IL-1β/IL-18. Further, TDCA increased expression of scavenger receptor (SR) A, enhanced phagocytosis of Aβ, and decreased Aβ plaque numbers in the brain of 5x Familial Alzheimer’s disease (5xFAD) mice. TDCA also reduced microgliosis, prevented neuronal loss, and improved memory function of 5xFAD mice. The pleiotropic roles of GPCR19 in P2 × 7-mediated N3I activation suggest that targeting GPCR19 might resolve neuroinflammation in AD patients.

scholarly journals Exploring Aβ Proteotoxicity and Therapeutic Candidates Using Drosophila melanogaster

2021 ◽  
Vol 22 (19) ◽  
pp. 10448
Author(s):  
Greta Elovsson ◽  
Liza Bergkvist ◽  
Ann-Christin Brorsson
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Drosophila Melanogaster ◽  
Model Organism ◽  
Amyloid Β ◽  
Therapeutic Strategies ◽  
Disease Genes ◽  
Amyloid Β Peptide ◽  
Drug Candidates ◽  
Human Disease Genes

Alzheimer’s disease is a widespread and devastating neurological disorder associated with proteotoxic events caused by the misfolding and aggregation of the amyloid-β peptide. To find therapeutic strategies to combat this disease, Drosophila melanogaster has proved to be an excellent model organism that is able to uncover anti-proteotoxic candidates due to its outstanding genetic toolbox and resemblance to human disease genes. In this review, we highlight the use of Drosophila melanogaster to both study the proteotoxicity of the amyloid-β peptide and to screen for drug candidates. Expanding the knowledge of how the etiology of Alzheimer’s disease is related to proteotoxicity and how drugs can be used to block disease progression will hopefully shed further light on the field in the search for disease-modifying treatments.

scholarly journals Microglia, TREM2, and Therapeutic Methods of Alzheimer’s Disease

2021 ◽  
Author(s):  
Siwei Xu ◽  
Yaya Ji ◽  
Tianle Sha ◽  
Haoming Li
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Dynamic Change ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Pathological Process ◽  
Amyloid Β Protein ◽  
Transmembrane Glycoprotein ◽  
Β Protein ◽  
The Central Nervous System

Alzheimer’s disease (AD) is one of the most common causes of dementia all around the world. It is characterized by the deposition of amyloid-β protein (Aβ) and the formation of neurofibrillary tangles (NFTs), which contribute to neuronal loss and cognitive decline. Microglia, as innate immune cells in brain, plays dual roles in the pathological process of AD. Expression in different subtypes of microglia is diverse in AD genes. Triggering receptor expressed on myeloid cells 2 (TREM2) is a transmembrane glycoprotein mainly expressed on microglia in the central nervous system (CNS). Soluble TREM2 (sTREM2), a proteolytic product of TREM2, which is abundant in the cerebrospinal fluid, shows a dynamic change in different stages and ameliorates the pathological process of AD. The interplay between the different subtypes of apolipoprotein and TREM2 is closely related to the mechanism of AD and serves as important regulatory sites. Moreover, several therapeutic strategies targeting TREM2 have shown positive outcomes during clinical trials and some novel therapies at different points are in progress. In this review, we mainly talk about the interrelationships among microglia, TREM2, and AD, and hope to give an overview of the strategies of AD.

Alzheimer’s Disease: Innovative Therapeutic Approaches Based on Peptides and Nanoparticles

2021 ◽  
pp. 107385842110164
Author(s):  
Isabela F. L. Mota ◽  
Larissa S. de Lima ◽  
Bruna de M. Santana ◽  
Giovanna de A. M. Gobbo ◽  
João V. M. L. Bicca ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Treatment Options ◽  
Pharmaceutical Research ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Acetylcholinesterase Inhibitors ◽  
Low Toxicity ◽  
New Treatments ◽  
Amyloid Cascade

Alzheimer’s disease (AD) is the main cause of dementia in the world and its etiology is not yet fully understood. The pathology of AD is primarily characterized by intracellular neurofibrillary tangles and extracellular amyloid-β plaques. Unfortunately, few treatment options are available, and most treat symptoms, as is the case of acetylcholinesterase inhibitors (IAChE) and N-methyl-d-aspartate receptor antagonists. For more than 20 years pharmaceutical research has targeted the “amyloid cascade hypothesis,” but this has not produced meaningful results, leading researchers to focus now on other characteristics of the disease and on multitarget approaches. This review aims to evaluate some new treatments that are being developed and studied. Among these are new treatments based on peptides, which have high selectivity and low toxicity; however, these compounds have a short half-life and encounter challenges when crossing the blood-brain barrier. The present review discusses up-and-coming peptides tested as treatments and explores some nanotechnological strategies to overcome the downsides. These compounds are promising, as they not only act on the symptoms but also aim to prevent progressive neuronal loss.

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