scholarly journals The Chick as a Model for the Study of the Cellular Mechanisms and Potential Therapies for Alzheimer's Disease

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Radmila Mileusnic ◽  
Steven Rose
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Animal Experiments ◽  
Memory Loss ◽  
Treatment Strategies ◽  
Cellular Mechanisms ◽  
Sequence Homologies ◽  
Species Specific ◽  
Close Sequence

While animal experiments have contributed much to our understanding of the mechanisms of Alzheimer's disease (AD), their value in predicting the effectiveness of treatment strategies in clinical trials has remained controversial. The disparity between the results obtained in animal models and clinical trials may in part be explained by limitations of the models and species-specific differences. We propose that one trial passive avoidance in the day-old chick is a useful system to study AD because of the close sequence homologies of chick and human amyloid precursor protein (APP). In the chick, APP is essential for memory consolidation, and disrupting its synthesis or structure results in amnesia. RER, a tripeptide sequence corresponding to part of the growth domain of APP, can restore memory loss and act as a cognitive enhancer. We suggest that RER and its homologues may form the basis for potential pharmacological protection against memory loss in AD.

scholarly journals Alzheimer’s disease: many failed trials, so where do we go from here?

2020 ◽  
Vol 68 (6) ◽  
pp. 1135-1140 ◽  
Author(s):  
Allison Bethanne Reiss ◽  
Amy D Glass ◽  
Thomas Wisniewski ◽  
Benjamin Wolozin ◽  
Irving H Gomolin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Current Knowledge ◽  
Memory Loss ◽  
Treatment Strategies ◽  
Amyloid Β ◽  
Tau Proteins ◽  
Brain Disorder ◽  
The Central Nervous System ◽  
Progressive Cognitive Impairment

Alzheimer’s disease (AD) is a neurodegenerative brain disorder associated with relentlessly progressive cognitive impairment and memory loss. AD pathology proceeds for decades before cognitive deficits become clinically apparent, opening a window for preventative therapy. Imbalance of clearance and buildup of amyloid β and phosphorylated tau proteins in the central nervous system is believed to contribute to AD pathogenesis. However, multiple clinical trials of treatments aimed at averting accumulation of these proteins have yielded little success, and there is still no disease-modifying intervention. Here, we discuss current knowledge of AD pathology and treatment with an emphasis on emerging biomarkers and treatment strategies.

scholarly journals Deep learning detection of informative features in tau PET for Alzheimer’s disease classification

2020 ◽  
Vol 21 (S21) ◽  
Author(s):  
Taeho Jo ◽  
◽  
Kwangsik Nho ◽  
Shannon L. Risacher ◽  
Andrew J. Saykin
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Deep Learning ◽  
Early Detection ◽  
Medial Temporal Lobe ◽  
Memory Loss ◽  
Disease Classification ◽  
Classification Model ◽  
Tau Pet

Abstract Background Alzheimer’s disease (AD) is the most common type of dementia, typically characterized by memory loss followed by progressive cognitive decline and functional impairment. Many clinical trials of potential therapies for AD have failed, and there is currently no approved disease-modifying treatment. Biomarkers for early detection and mechanistic understanding of disease course are critical for drug development and clinical trials. Amyloid has been the focus of most biomarker research. Here, we developed a deep learning-based framework to identify informative features for AD classification using tau positron emission tomography (PET) scans. Results The 3D convolutional neural network (CNN)-based classification model of AD from cognitively normal (CN) yielded an average accuracy of 90.8% based on five-fold cross-validation. The LRP model identified the brain regions in tau PET images that contributed most to the AD classification from CN. The top identified regions included the hippocampus, parahippocampus, thalamus, and fusiform. The layer-wise relevance propagation (LRP) results were consistent with those from the voxel-wise analysis in SPM12, showing significant focal AD associated regional tau deposition in the bilateral temporal lobes including the entorhinal cortex. The AD probability scores calculated by the classifier were correlated with brain tau deposition in the medial temporal lobe in MCI participants (r = 0.43 for early MCI and r = 0.49 for late MCI). Conclusion A deep learning framework combining 3D CNN and LRP algorithms can be used with tau PET images to identify informative features for AD classification and may have application for early detection during prodromal stages of AD.

scholarly journals Cholinergic-like neurons carrying PSEN1 E280A mutation from familial Alzheimer’s disease reveal intraneuronal Aβ42 peptide accumulation, hyperphosphorylation of TAU, oxidative stress, apoptosis and Ca2+ flux dysregulation: Therapeutic Implications

2019 ◽  
Author(s):  
Viviana Soto-Mercado ◽  
Miguel Mendivil-Perez ◽  
Carlos Velez-Pardo ◽  
Francisco Lopera ◽  
Marlene Jimenez-Del-Rio
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Memory Loss ◽  
Cholinergic Neurons ◽  
Tau Phosphorylation ◽  
Cellular Mechanisms ◽  
Limited Effectiveness ◽  
Aβ42 Peptide

AbstractAlzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive memory loss and cognitive disturbance as a consequence of the loss of cholinergic neurons in the brain, neuritic plaques and hyperphosphorylation of TAU protein. Although the underlying mechanisms leading to these events are unclear, mutations in presenilin 1 (PSEN1), e.g., E280A (PSEN1 E280A), are causative factors for autosomal dominant early-onset familial AD (FAD). Despite advances in the understanding of the physiopathology of AD, there are no efficient therapies to date. Limitations in culturing brain-derived live neurons might explain the limited effectiveness of AD research. Here, we show that mesenchymal stromal (stem) cells (MSCs) can be used to model FAD, providing novel opportunities to study cellular mechanisms and to establish therapeutic strategies. Indeed, we cultured MSCs with the FAD mutation PSEN1 E280A and wild-type (WT) PSEN1 from umbilical cords and characterized the transdifferentiation of these cells into cholinergic-like neurons (ChLNs). PSEN1 E280A ChLNs but not WT PSEN1 ChLNs exhibited increased intra- and extracellular Aβ42 peptide and TAU phosphorylation (at residues Ser202/Thr205), recapitulating the molecular pathogenesis of FAD caused by mutant PSEN1. Furthermore, PSEN1 E280A ChLNs presented oxidative stress (OS) as evidenced by the oxidation of DJ-1Cys106-SH into DJ-1Cys106-SO3 and the detection of DCF-positive cells and apoptosis markers such as activated pro-apoptosis proteins p53, c-JUN, PUMA and CASPASE-3 and the concomitant loss of the mitochondrial membrane potential and DNA fragmentation. Additionally, mutant ChLNs displayed Ca2+ flux dysregulation and deficient acetylcholinesterase (AChE) activity compared to control ChLNs. Interestingly, the inhibitor JNK SP600125 almost completely blocked TAU phosphorylation. Our findings demonstrate that FAD MSC-derived cholinergic neurons with the PSEN1 E280A mutation are a valid model of AD and provide important clues for the identification of targetable pathological molecules.

scholarly journals Royal Jelly as an Intelligent Anti-Aging Agent—A Focus on Cognitive Aging and Alzheimer’s Disease: A Review

Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 937 ◽  
Author(s):  
Amira Mohammed Ali ◽  
Hiroshi Kunugi
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Performance ◽  
Cognitive Aging ◽  
Royal Jelly ◽  
Treatment Strategies ◽  
Amyloid Β ◽  
Natural Aging ◽  
Cellular Mechanisms ◽  
Age Related

The astronomical increase of the world’s aged population is associated with the increased prevalence of neurodegenerative diseases, heightened disability, and extremely high costs of care. Alzheimer’s Disease (AD) is a widespread, age-related, multifactorial neurodegenerative disease that has enormous social and financial drawbacks worldwide. The unsatisfactory outcomes of available AD pharmacotherapy necessitate the search for alternative natural resources that can target the various underlying mechanisms of AD pathology and reduce disease occurrence and/or progression. Royal jelly (RJ) is the main food of bee queens; it contributes to their fertility, long lifespan, and memory performance. It represents a potent nutraceutical with various pharmacological properties, and has been used in a number of preclinical studies to target AD and age-related cognitive deterioration. To understand the mechanisms through which RJ affects cognitive performance both in natural aging and AD, we reviewed the literature, elaborating on the metabolic, molecular, and cellular mechanisms that mediate its anti-AD effects. Preclinical findings revealed that RJ acts as a multidomain cognitive enhancer that can restore cognitive performance in aged and AD models. It promotes brain cell survival and function by targeting multiple adversities in the neuronal microenvironment such as inflammation, oxidative stress, mitochondrial alterations, impaired proteostasis, amyloid-β toxicity, Ca excitotoxicity, and bioenergetic challenges. Human trials using RJ in AD are limited in quantity and quality. Here, the limitations of RJ-based treatment strategies are discussed, and directions for future studies examining the effect of RJ in cognitively impaired subjects are noted.

Stem Cell-based Therapeutic and Diagnostic Approaches in Alzheimer's Disease

2021 ◽  
Vol 20 ◽  
Author(s):  
Sadaf Abdi ◽  
Nima Javanmehr ◽  
Maryam Ghasemi-Kasman ◽  
Hanie Yavarpour Bali ◽  
Marzieh Pirzadeh
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Stem Cells ◽  
Clinical Trials ◽  
Stem Cell ◽  
Memory Loss ◽  
Stem Cell Therapies ◽  
Cell Therapies ◽  
Advantages And Disadvantages ◽  
Diagnostic Approaches

Background: Alzheimer’s disease (AD) is a neurodegenerative impairment mainly recognized by memory loss and cognitive deficits. However, the current therapies against AD are mostly limited to palliative medications, prompting researchers to investigate more efficient therapeutic approaches for AD, such as stem cell therapy. Recent evidence has proposed that extensive neuronal and synaptic loss and altered adult neurogenesis, which is perceived pivotal in terms of plasticity and network maintenance, occurs early in the course of AD, which exacerbates neuronal vulnerability to AD. Thus, regeneration and replenishing the depleted neuronal networks by strengthening the endogenous repair mechanisms or exogenous stem cells and their cargoes is a rational therapeutic approach. Currently, several stem cell-based therapies as well as stem cell products like exosomes, have shown promising results in the early diagnosis of AD. Objective: This review begins with a comparison between AD and normal aging pathophysiology and a discussion on open questions in the field. Next, summarizing the current stem cell-based therapeutic and diagnostic approaches, we declare the advantages and disadvantages of each method. Also, we comprehensively evaluate the human clinical trials of stem cell therapies for AD. Methodology: Peer-reviewed reports were extracted through Embase, PubMed, and Google Scholar until 2021. Results: With several ongoing clinical trials, stem cells and their derivatives (e.g., exosomes) are an emerging and encouraging field in diagnosing and treating neurodegenerative diseases. Although stem cell therapies have been successful in animal models, numerous clinical trials in AD patients have yielded unpromising results, which we will further discuss.

THE PATIENT IN YOUR ALZHEIMER’S DISEASE STUDY MAY BE IN ANOTHER: DUPLICATION AND DECEPTION IN CLINICAL TRIALS OF ALZHEIMER’S DISEASE

2020 ◽  
pp. 1-4
Author(s):  
T. Shiovitz ◽  
B. Steinmiller ◽  
C. Steinmetz ◽  
S. Perez ◽  
R. Oseas
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Active Treatment ◽  
Memory Loss ◽  
Mechanisms Of Action ◽  
Efficacy And Safety ◽  
Significant Issue ◽  
Disease Study ◽  
Safety Signals

Duplicate and deceptive subjects, a significant issue in CNS studies, are not often considered in Alzheimer’s Disease (AD) clinical trials. However, AD patients and their study partners may be motivated to take advantage of different mechanisms of action, increase odds of receiving active treatment, and/or obtain financial compensation, which may lead them to participate in multiple studies. CTSdatabase reviewed memory loss subjects (n=1087) from January 2017 through May 2019 to determine how many attempted to screen at multiple sites. 117 subjects (10.8%) visited more than one site within two years. When these potential AD subjects went to additional sites, it was predominantly for non-memory indications (often MDD or schizophrenia). For those that participated in studies, the rate of duplication approached 4% of screened AD subjects. This data indicates that significant numbers of AD subjects attempt to enroll at multiple sites, which confounds efficacy and safety signals in clinical trials.

scholarly journals Pharmacological Treatment of Alzheimer’s Disease: Insights from Drosophila melanogaster

2020 ◽  
Vol 21 (13) ◽  
pp. 4621
Author(s):  
Xingyi Cheng ◽  
Chaochun Song ◽  
Yanjiao Du ◽  
Uma Gaur ◽  
Mingyao Yang
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Drosophila Melanogaster ◽  
Rational Design ◽  
Clinical Symptoms ◽  
Memory Loss ◽  
Treatment Strategies ◽  
Mechanistic Study ◽  
Pathophysiological Mechanism ◽  
Age Related

Aging is an ineluctable law of life. During the process of aging, the occurrence of neurodegenerative disorders is prevalent in the elderly population and the predominant type of dementia is Alzheimer’s disease (AD). The clinical symptoms of AD include progressive memory loss and impairment of cognitive functions that interfere with daily life activities. The predominant neuropathological features in AD are extracellular β-amyloid (Aβ) plaque deposition and intracellular neurofibrillary tangles (NFTs) of hyperphosphorylated Tau. Because of its complex pathobiology, some tangible treatment can only ameliorate the symptoms, but not prevent the disease altogether. Numerous drugs during pre-clinical or clinical studies have shown no positive effect on the disease outcome. Therefore, understanding the basic pathophysiological mechanism of AD is imperative for the rational design of drugs that can be used to prevent this disease. Drosophila melanogaster has emerged as a highly efficient model system to explore the pathogenesis and treatment of AD. In this review we have summarized recent advancements in the pharmacological research on AD using Drosophila as a model species, discussed feasible treatment strategies and provided further reference for the mechanistic study and treatment of age-related AD.

scholarly journals Reversal of Calcium Dysregulation as Potential Approach for Treating Alzheimer's Disease

2020 ◽  
Vol 17 (4) ◽  
pp. 344-354 ◽  
Author(s):  
Elena Popugaeva ◽  
Daria Chernyuk ◽  
Ilya Bezprozvanny
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Memory Loss ◽  
Preclinical Models ◽  
Calcium Dysregulation ◽  
Novel Drugs ◽  
Alternative Approaches ◽  
Disease Modifying ◽  
Disease Modifying Treatment

Despite decades of research and effort, there is still no effective disease-modifying treatment for Alzheimer’s Disease (AD). Most of the recent AD clinical trials were targeting amyloid pathway, but all these trials failed. Although amyloid pathology is a hallmark and defining feature of AD, targeting the amyloid pathway has been very challenging due to low efficacy and serious side effects. Alternative approaches or mechanisms for our understanding of the major cause of memory loss in AD need to be considered as potential therapeutic targets. Increasing studies suggest that Ca2+ dysregulation in AD plays an important role in AD pathology and is associated with other AD abnormalities, such as excessive inflammation, increased ROS, impaired autophagy, neurodegeneration, synapse, and cognitive dysfunction. Ca2+ dysregulation in cytosolic space, Endoplasmic Reticulum (ER) and mitochondria have been reported in the context of various AD models. Drugs or strategies, to correct the Ca2+ dysregulation in AD, have been demonstrated to be promising as an approach for the treatment of AD in preclinical models. This review will discuss the mechanisms of Ca2+ dysregulation in AD and associated pathology and discuss potential approaches or strategies to develop novel drugs for the treatment of AD by targeting Ca2+ dysregulation.

scholarly journals Current Perspectives regarding Stem Cell-Based Therapy for Alzheimer’s Disease

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Kyeong-Ah Kwak ◽  
Seung-Pyo Lee ◽  
Jin-Young Yang ◽  
Young-Seok Park
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Stem Cell ◽  
Small Molecules ◽  
Neurodegenerative Disorder ◽  
Memory Loss ◽  
Cell Based Therapy ◽  
Synaptic Failure ◽  
Excessive Accumulation

Alzheimer’s disease (AD), a progressive neurodegenerative disorder featuring memory loss and cognitive impairment, is caused by synaptic failure and the excessive accumulation of misfolded proteins. Many unsuccessful attempts have been made to develop new small molecules or antibodies to intervene in the disease’s pathogenesis. Stem cell-based therapies cast a new hope for AD treatment as a replacement or regeneration strategy. The results from recent preclinical studies regarding stem cell-based therapies are promising. Human clinical trials are now underway. However, a number of questions remain to be answered prior to safe and effective clinical translation. This review explores the pathophysiology of AD and summarizes the relevant stem cell research according to cell type. We also briefly summarize related clinical trials. Finally, future perspectives are discussed with regard to their clinical applications.

The Therapeutic Potential of Purinergic Receptors in Alzheimer’s Disease and Promising Therapeutic Modulators

2020 ◽  
Vol 20 ◽  
Author(s):  
Lili Pan ◽  
Yu Ma ◽  
Yunchun Li ◽  
Haoxing Wu ◽  
Rui Huang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Purinergic Receptors ◽  
Therapeutic Potential ◽  
Purinergic Signaling ◽  
Memory Loss ◽  
Related Research ◽  
Central Nervous System Disorders ◽  
G Protein Coupled

Abstract:: Recent studies have proven that the purinergic signaling pathway plays a key role in neurotransmission and neuromodulation, and is involved in various neurodegenerative diseases and psychiatric disorders. With the characterization of the subtypes of receptors in purinergic signaling, i.e. the P1 (adenosine), P2X (ion channel) and P2Y (G protein-coupled), more attentions were paid to the pathophysiology and therapeutic potential of purinergic signaling in central nervous system disorders. Alzheimer’s disease (AD) is a progressive and deadly neurodegenerative disease that is characterized by memory loss, cognitive impairment and dementia. However, as drug development aimed to prevent or control AD follows a series of failures in recent years, more researchers focused on the neuroprotection-related mechanisms such as purinergic signaling in AD patients to find a potential cure. This article reviews the recent discoveries of purinergic signaling in AD, summaries the potential agents as modulators for the receptors of purinergic signaling in AD related research and treatments. Thus, our paper provided an insight for purinergic signaling in the development of anti-AD therapies.

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