Cause Of Alzheimer's Disease Research Articles

Recent Studies on Heterocyclic Cholinesterase Inhibitors Against Alzheimer's Disease.

Alzheimer's disease is a progressive and neurodegenerative disease characterized by impairment in emotion, language, memory and cognitive judgment. There are many factors related to Alzheimer's disease, such as amyloid beta plaques (Aβ) due to impaired metabolism of amyloid precursor protein (APP), tau hyperphosphorylation and accumulation of neurofibrillary tangles, and disruption of the cholinergic system. Disruption of the cholinergic system responsible for cognitive function and memory processes is one of the important causes of Alzheimer's disease. Therefore, cholinesterase (acetylcholinesterase and butyrylcholinesterase) inhibitors that maintain choline (acetylcholine and butyrylcholine) levels in the synaptic gap play an important role in the symptomatic treatment of Alzheimer's disease. Numerous studies have been carried out against Alzheimer's disease involving acetylcholinesterase and butyrylcholinesterase inhibitors. However, there are very few drugs (tacrine, rivastigmine, galantamine and donepezil) approved as cholinesterase inhibitors. Therefore, cholinesterase inhibitors are needed against Alzheimer's disease. This review is focused on using heterocyclic rings that show remarkable cholinesterase inhibitory activity for Alzheimer's disease. In this review, chemical structures and structure-activity relationships of recently reported cholinesterase inhibitors are emphasized. This review will give important ideas to medicinal chemists in the discovery and development of potent cholinesterase inhibitors in their future studies.

The relationship between gut microbiota and alzheimer's disorder

The pathology of Alzheimer's disorder: neuron degeneration is the main cause of Alzheimer's disorder. Several ways will stimulate the degeneration of cells. The links between gut microbiota and Alzheimer's disorder consist of three major pathways: the vagus nerve, blood circulation, and release of chemical molecules. This paper discusses not only the pathology of Alzheimers disorder but also explores the connections between gut microbiota and Alzheimers disorder, as well as potential treatments based on gut microbiota. Probiotics are mainly discussed in this paper to present possible treatments for Alzheimer's disorder. To conclude, this paper mainly discusses the link between Alzheimers disorder and gut microbiota. Moreover, the conclusion highlights unresolved issues and unknown aspects of the interaction between Alzheimers and gut microbiota, urging further research and increased attention from scientists.

Applications of iPSC technology in Alzheimer's disease

Abstract. iPSC technology has become an invaluable tool for treating Alzheimers disease (AD). AD is a neurodegenerative disease that imposes major burden on the economy. This paper aims to summarize the hypotheses for the cause of AD, the mechanisms of iPSC technology, and the clinical applications of iPSC in AD. There are many hypotheses for the cause of AD, including Genetic mutation of genes coding for Amyloid Precursor protein (APP), presenilin 1 (PS1) and presenilin 2 (PS2), phosphorylated Tau protein, etc. There are many methods of improving the safety and efficiency of iPSC generation, including the exploration of new host cells, new transcription factors, and the incorporation of new technology like CRISPR into the generation process. iPSC modeling is a critical tool for AD treatment. iPSC is an efficient method of generating stem cells whilst also possessing less ethical concerns compared to other stem cell generation methods. iPSC modeling allows researchers to test treatment options outside of the patients body before administering the treatment method to the patient. As of current, iPSC cell therapy does not possess sufficient data for human trials. Future studies aim to develop new technologies and collect data required to launch iPSC cell therapy in clinical trials.

Study on hypothesis of amyloid beta protein being the causative factor of Alzheimers disease

Abstract. At present, people have many hypotheses about the cause of Alzheimers disease, AD is used in the following text, among which the amyloid beta protein hypothesis is one of the most famous hypotheses about the cause of AD. Therefore, to study the method of completely curing AD, amyloid beta protein, A is used in the following text, is the most important research object, and the study of drugs targeting A has become the hope of peoples treatment of AD. The research topic of this review is whether A is the cause of AD, that is, whether the amyloid beta hypothesis is valid. By reading literature and analyzing several drugs that have been developed and have effects on A, this paper proves whether A is related to AD. The results showed that the number of A had an important relationship with the severity of AD that is, the amyloid beta hypothesis was established.

Exosomal mRNA Signatures as Predictive Biomarkers for Risk and Age of Onset in Alzheimer's Disease.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline and memory loss. While the precise causes of AD remain unclear, emerging evidence suggests that messenger RNA (mRNA) dysregulation contributes to AD pathology and risk. This study examined exosomal mRNA expression profiles of 15 individuals diagnosed with AD and 15 healthy controls from Barranquilla, Colombia. Utilizing advanced bioinformatics and machine learning (ML) techniques, we identified differentially expressed mRNAs and assessed their predictive power for AD diagnosis and AD age of onset (ADAOO). Our results showed that ENST00000331581 (CADM1) and ENST00000382258 (TNFRSF19) were significantly upregulated in AD patients. Key predictors for AD diagnosis included ENST00000311550 (GABRB3), ENST00000278765 (GGTLC1), ENST00000331581 (CADM1), ENST00000372572 (FOXJ3), and ENST00000636358 (ACY1), achieving > 90% accuracy in both training and testing datasets. For ADAOO, ENST00000340552 (LIMK2) expression correlated with a delay of ~12.6 years, while ENST00000304677 (RNASE6), ENST00000640218 (HNRNPU), ENST00000602017 (PPP5D1), ENST00000224950 (STN1), and ENST00000322088 (PPP2R1A) emerged as the most important predictors. ENST00000304677 (RNASE6) and ENST00000602017 (PPP5D1) showed promising predictive accuracy in unseen data. These findings suggest that mRNA expression profiles may serve as effective biomarkers for AD diagnosis and ADAOO, providing a cost-efficient and minimally invasive tool for early detection and monitoring. Further research is needed to validate these results in larger, diverse cohorts and explore the biological roles of the identified mRNAs in AD pathogenesis.

The case for regulatory approval of amyloid-lowering immunotherapies in Alzheimer's disease based on clearcut biomarker evidence.

Decades of research have provided evidence that Alzheimer's disease (AD) is caused in part by cerebral accumulation of amyloid beta-protein (Aβ). In 2023, the US Food and Drug Administration gave full regulatory approval to a disease-modifying Aβ antibody for early AD. Secondary prevention trials with Aβ antibodies are underway. We summarize peer-reviewed evidence for targeting Aβ and argue that regulators should consider approving new agents working by similar mechanisms (Aβantibodies and vaccines) based on robust amyloid lowering and reasonable safety. The urgent need to provide treatments to millions of mildly symptomatic patients suggests that AD should join other diseases for which standard approval is based on significant changes in mechanistically meaningful biomarkers coupled with safety. Robust amyloid lowering in secondary prevention trials of people who have amyloid plaques but are asymptomatic could also provide evidence of a change in the pathophysiological progression of AD as a basis for regulatory approval. HIGHLIGHTS: Thirteen key findings support amyloid beta as a cause of Alzheimer's disease (AD). Three immunotherapies lower amyloid and slow decline, allowing regulatory approval. New such agents could be considered for approval due to amyloid lowering and safety. Urgency suggests AD may join diseases with approval due to a key biomarker + safety.

A promising drug repurposing approach for Alzheimer's treatment: Givinostat improves cognitive behavior and pathological features in APP/PS1 mice

Alzheimer's disease (AD) is the most common neurodegenerative disease, characterized by memory loss, speech and motor defects, personality changes, and psychological disorders. The exact cause of AD remains unclear. Current treatments focus on maintaining neurotransmitter levels or targeting β-amyloid (Aβ) protein, but these only alleviate symptoms and do not reverse the disease. Developing new drugs is time-consuming, costly, and has a high failure rate. Utilizing multi-omics for drug repositioning has emerged as a new strategy. Based on transcriptomic perturbation data of over 40,000 drugs in human cells from the LINCS-L1000 database, our study employed the Jaccard index and hypergeometric distribution test for reverse transcriptional feature matching analysis, identifying Givinostat as a potential treatment for AD. Our research found that Givinostat improved cognitive behavior and brain pathology in models and enhanced hippocampal synaptic plasticity. Transcriptome sequencing revealed increased expression of mitochondrial respiratory chain complex proteins in the brains of APP/PS1 mice after Givinostat treatment. Functionally, Givinostat restored mitochondrial membrane potential, reduced reactive oxygen species, and increased ATP content in Aβ-induced HT22 cells. Additionally, it improved mitochondrial morphology and quantity in the hippocampus of APP/PS1 mice and enhanced brain glucose metabolic activity. These effects are linked to Givinostat promoting mitochondrial biogenesis and improving mitochondrial function. In summary, Givinostat offers a promising new strategy for AD treatment by targeting mitochondrial dysfunction.

Exploring bacterial metabolites in microbe-human host dialogue and their therapeutic potential in Alzheimer's diseases.

Neurological dysfunction in association with aging, dementia, and cognitive impairment is the major cause of Alzheimer's disease (AD). Current AD therapies often yield unsatisfactory results due to their poor mechanism in treating the underlying mechanism of the disease. Recent studies suggested that metabolites from the gut microbiota facilitate brain-gut communication. A systematic network pharmacology study and the structure- and analog-based approaches are employed to investigate the metabolites produced by gut microbiota to treat AD. The microbiota metabolites available in the gutMGene database were considered in this study. Two servers, namely Swiss Target Prediction (STP) and Similarity Ensemble Approach (SEA), were used to identify the possible AD targets for the selected metabolites. Detailed KEGG pathway and Gene Ontology (GO) analysis on identified hub genes highlighted the importance of IL6, AKT1, and GSK3B in AD pathophysiology. MMTSp (Microbiota Metabolites Target Signaling pathways) network analysis elucidated that there is a strong relationship with microbiota (Paraprevotella xylaniphila YIT 11841, Bifidobacterium dentium, Paraprevotella clara YIT 11840, Enterococcus sp. 45, Bacteroides sp. 45, Bacillus sp. 46, Escherichia sp. 33, Enterococcus casseliflavus, Bacteroides uniformis, Alistipes indistinctus YIT 12060, Bacteroides ovatus, Escherichia sp. 12, and Odoribacter laneus YIT 12061) and AD pathogenesis. In addition to this, we performed molecular docking to study the metabolite interactions in the AD drug targets. The ADME/T properties of these metabolites were also calculated and the results are discussed in detail.

The structure of an amyloid precursor protein/talin complex indicates a mechanical basis of Alzheimer's disease.

Misprocessing of amyloid precursor protein (APP) is one of the major causes of Alzheimer's disease. APP comprises a large extracellular region, a single transmembrane helix and a short cytoplasmic tail containing an NPxY motif (normally referred to as the YENPTY motif). Talins are synaptic scaffold proteins that connect the cytoskeletal machinery to the plasma membrane via binding NPxY motifs in the cytoplasmic tail of integrins. Here, we report the crystal structure of an APP/talin1 complex identifying a new way to couple the cytoskeletal machinery to synaptic sites through APP. Proximity ligation assay (PLA) confirmed the close proximity of talin1 and APP in primary neurons, and talin1 depletion had a dramatic effect on APP processing in cells. Structural modelling reveals APP might form an extracellular meshwork that mechanically couples the cytoskeletons of the pre- and post-synaptic compartments. We propose APP processing represents a mechanical signalling pathway whereby under tension, the cleavage sites in APP have varying accessibility to cleavage by secretases. This leads us to propose a new hypothesis for Alzheimer's, where misregulated APP dynamics result in loss of the mechanical integrity of the synapse, corruption and loss of mechanical binary data, and excessive generation of toxic plaque-forming Aβ42 peptide.

The discovery of JAL-TA9 which cleaves amyloid-β with proteolytic activity

Amyloid-β (Aβ) 42, one of the causes of Alzheimer's disease (AD), is produced by the cleavage of amyloid precursor protein (APP) by β- or γ-secretases. Since Aβ42 oligomers exhibit strong neurotoxicity, Aβ42 is predicted to be a potentially efficient target for drug therapies. Recently, we screened peptides that activate MMP7 using our peptide library and found that the synthetic peptide JAL-TA9 (YKGSGFRMI), which is derived from the BoxA region of Tob1 protein, showed proteolytic activity. It is generally accepted that an enzyme should be a large molecular protein consisting of more than thousands of amino acids. Thus, this is the first finding that a small synthetic peptide has protease activity, and we termed Catalytide as the general name of peptides with protease activity. In this study, we demonstrate the cleavage activity of JAL-TA9 not only against the authentic soluble form of Aβ42 but also against the solid type of Aβ42 in the central region. In addition, we demonstrated the cleavage activity using brain slices of AD patients. JAL-TA9 decreased the amount of accumulated Aβ42 in the brain of Alzheimer's patients. Taken together, JAL-TA9 is an attractive seed for the development of peptide drugs with a new strategy for Alzheimer's disease.

Anti-inflammatory response controlled by gamma wave

It is now believed that the cause of Alzheimer’s disease is the accumulation of amyloid-Bata, which is caused by a variety of factors, such as neuroinflammation. So in this study, the researchers will study the changes of microglia from M1 to M2 by changing the frequency of gamma wave. If microglia change from M1 to M2, that means it changes from pro-inflammatory to anti-inflammatory.

The Role of Non-Coding RNAs in Mitochondrial Dysfunction of Alzheimer's Disease.

Although brain amyloid-β (Aβ) peptide buildup is the main cause of Alzheimer's disease (AD), mitochondrial abnormalities can also contribute to the illness's development, as either a primary or secondary factor, as programmed cell death and efficient energy generation depend on the proper operation of mitochondria. As a result, non-coding RNAs (ncRNAs) may play a crucial role in ensuring that nuclear genes related to mitochondria and mitochondrial genes function normally. Interestingly, a significant number of recent studies have focused on the impact of ncRNAs on the expression of nucleus and mitochondrial genes. Additionally, researchers have proposed some intriguing therapeutic approaches to treat and reduce the severity of AD by adjusting the levels of these ncRNAs. The goal of this work was to consolidate the existing knowledge in this field of study by systematically investigating ncRNAs, with a particular emphasis on microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and small nucleolar RNAs (snoRNAs). Therefore, the impact and processes by which ncRNAs govern mitochondrial activity in the onset and progression of AD are thoroughly reviewed in this article. Collectively, the effects of ncRNAs on physiological and molecular mechanisms associated with mitochondrial abnormalities that exacerbate AD are thoroughly reviewed in the current research, while also emphasizing the relationship between disturbed mitophagy in AD and ncRNAs.

Impaired glymphatic clearance is an important cause of Alzheimer’s disease

Impaired glymphatic clearance is an important cause of Alzheimer’s disease

Licochalcone A Ameliorates Cognitive Dysfunction in an Alzheimer's Disease Model by Inhibiting Endoplasmic Reticulum Stress-Mediated Apoptosis.

Endoplasmic reticulum (ER) stress-induced neurodegeneration has been considered an underlying cause of Alzheimer disease (AD). Here, we investigated the beneficial effects of licochalcone A (Lico A), a valuable flavonoid of the root of the Glycyrrhiza species, against cognitive impairment in AD by regulating ER stress. The triple transgenic mouse AD models were used and were administrated 5 or 15mg/kg Lico A. Cognitive deficits, Aβ deposition, ER stress, and neuronal apoptosis were determined using Morris Water Maze test, probe trial, immunofluorescence staining, western blotting, and TUNEL staining. To investigate the mechanisms of how Lico A exerts anti-AD effects, primary hippocampal neurons were isolated from the AD model mice and treated with Lico A, salubrinal, an eIF2α phosphatase inhibitor, ML385, a Nrf2 inhibitor, or LY294002, an inhibitor of PI3K. Pharmacokinetics and toxicity of Lico A (15mg/kg) in AD mice were evaluated. We found that Lico A improved cognitive impairment, decreased Aβ plaques, inhibited ER stress, and reduced neuronal apoptosis in the hippocampus and cortex of AD mice. Treatment with Lico A in primary hippocampal neurons exerted the same effects as it did in vivo. Additionally, cotreatment with ML385 or LY294002 significantly impeded the effects of Lico A against ER stress. Moreover, 15mg/kg Lico A had a good bioavailability and low toxicity in AD mice. Our results demonstrated that Lico A ameliorates ER stress-induced neuronal apoptosis by inhibiting PERK/eIF2α/ATF4/CHOP signaling, suggesting the therapeutic potential of Lico A in AD treatment.

Nasal lymphatic obstruction of CSF drainage as a possible cause of Alzheimer's disease and dementia.

Alzheimer's disease, the most common form of dementia among older adults, slowly destroys memory and thinking skills. In recent years, scientists have made tremendous progress in understanding Alzheimer's disease, still, they do not yet fully understand what causes the disease. This article proposes a novel etiology for Alzheimer's disease. Our hypothesis developed from a review of nuclear medicine scans, in which the authors observed a significant increase in nasal turbinate vasodilation and blood pooling in patients with hypertension, sleep apnea, diabetes and/or obesity, all risk factors for Alzheimer's disease. The authors propose that nasal turbinate vasodilation and resultant blood pooling lead to the obstruction of normal nasal lymphatic clearance of cerebrospinal fluid and its waste products from the brain. The nasal turbinate vasodilation, due to increased parasympathetic activity, occurs alongside the well-established increased sympathetic activity of the cardiovascular system as seen in patients with hypertension. The increased parasympathetic activity is likely due to an autonomic imbalance secondary to the increase in worldwide consumption of highly processed food associated with dysregulation of the glucose regulatory system. The authors' hypothesis offers a novel mechanism and a new paradigm for the etiology of Alzheimer's disease and helps explain the rapid worldwide rise in the disease and other dementias which are expected to double in the next 20 years. This new paradigm provides compelling evidence for the modulation of the parasympathetic nervous system as a novel treatment strategy for Alzheimer's disease and other degenerative brain diseases, specifically targeting nasal turbinate lymphatic flow.

Application of CRISPR/Cas9 gene-editing technology in Alzheimers disease

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder. It triggers metabolic disorders within the body due to genetic mutations, thus leading to irreversible damage to one's memory and brain. The primary pathogenic features of AD are intracellular neurofibrillary tangles caused by hyperphosphorylated Tau and extracellular amyloid plaques created by the buildup of -amyloid -protein (A). However, up to now, there has been no effective treatment program for Alzheimer's disease. And after a long time of development, many gene editing technologies have been perfected and utilized in practice. Among them, CRISPR-Cas9 technology is the most efficient and practical. As a result, an increasing number of scientists have examined and debated the potential use of CRISPR-Cas9 technology in the management of Alzheimer's disease. This review addresses the use of the CRISPR/Cas9 system to treat Alzheimer's disease and presents the disease's pathophysiology, including the establishment of AD models, genetic screening for the cause of AD, and targeted therapy for AD.

The gut microbiota as a link between Alzheimer's disease and obesity.

Alzheimer's disease (AD) is a degenerative disease that causes a progressive decline in memory and thinking skills. Over the past few years, diverse studies have shown that there is no single cause of AD; instead, it has been reported that factors such as genetics, lifestyle, and environment contribute to the pathogenesis of the disease. In this sense, it has been shown that obesity during middle age is one of the most prominent modifiable risk factors for AD. Of the multiple potential mechanisms linking obesity and AD, the gut microbiota (GM) has gained increasing attention in recent years. However, the underlying mechanisms that connect the GM with the process of neurodegeneration remain unclear. Through this narrative review, we present a comprehensive understanding of how alterations in the GM of people with obesity may result in systemic inflammation and affect pathways related to the pathogenesis of AD. We conclude with an analysis of the relationship between GM and insulin resistance, a risk factor for AD that is highly prevalent in people with obesity. Understanding the crosstalk between obesity, GM, and the pathogenesis of AD will help to design new strategies aimed at preventing neurodegeneration.

Histological Study of the Protective Effect of CoQ10 on Aluminium Chloride-Induced Alzheimer's Disease in Adult Male Albino Rats' Hippocampus

Abstract Background Alzheimer’s disease (AD) is a neurodegenerative disorder that leads to cognitive decline associated with memory loss and dementia. Oxidative stress has a role as a cause of AD. Coenzyme Q10 (Q10) is a powerful antioxidant that buffers the potential adverse consequences of free radicals. Aim of the Work to detect the protective effect of CoQ10 on aluminium chloride-induced Alzheimer’s disease in albino rats’ hippocampus histologically. Materials and Methods Thirty-six adult male albino rats weighing 200-250 g were divided into four groups. Group I (control group) included 15 rats. Group II included 7 rats that were given CoQ10 dissolved in corn oil, at a dose of (200 mg/kg/day, by oral gavage) for 6 weeks. Group III included 7 rats that were received AlCl3 dissolved in distilled water, at a dose of (100 mg/kg/day, intraperitoneal) for 6 weeks. Group IV included 7 rats that were given AlCl3 along with CoQ10 for 6 weeks. At the end of the experiment, brains were excised and processed for light microscopic examination. Morphometrical measurements and statistical analysis were performed. Results Group III revealed many structural changes, such as disarrangement of the pyramidal cell layer in areas of the Cornu Ammonis of the hippocampus proper, which also exhibited deeply stained nuclei and vacuolated cytoplasm that were the same for granule cells in the dentate gyrus (DG). CoQ10 administration ameliorated these histological alterations. Conclusion CoQ10 has a protective effect on AD induced by AlCl3 in rats.

Pathophysiologic abnormalities in transgenic mice carrying the Alzheimer disease PSEN1 Δ440 mutation.

Mutations in PSEN1 were first discovered as a cause of Alzheimer's disease (AD) in 1995, yet the mechanism(s) by which the mutations cause disease still remains unknown. The generation of novel mouse models assessing the effects of different mutations could aid in this endeavor. Here we report on transgenic mouse lines made with the Δ440 PSEN1 mutation that causes AD with parkinsonism:- two expressing the un-tagged human protein and two expressing a HA-tagged version. Detailed characterization of these lines showed that Line 305 in particular, which expresses the untagged protein, develops age-dependent memory deficits and pathologic features, many of which are consistent with features found in AD. Key behavioral and physiological alterations found in the novel 305 line included an age-dependent deficit in spontaneous alternations in the Y-maze, a decrease in exploration of the center of an open field box, a decrease in the latency to fall on a rotarod, a reduction in synaptic strength and pair-pulse facilitation by electrophysiology, and profound alterations to cerebral blood flow regulation. The pathologic alterations found in the line included, significant neuronal loss in the hippocampus and cortex, astrogliosis, and changes in several proteins involved in synaptic and mitochondrial function, Ca2+ regulation, and autophagy. Taken together, these findings suggest that the transgenic lines will be useful for the investigation of AD pathogenesis.

Investigation of amyloid‑β peptide production and clearance pathways in different stages of Alzheimer's disease.

Alzheimer's disease (AD) is an age‑related, progressive decline in cognitive ability. Accumulation and deposition of amyloid‑β (Aβ) is still the best‑known cause of AD that worsens over time. It is unclear whether the increase in Aβ production or the inefficiency of the degradation system causes the accumulation of β‑fibrils during AD development. This research investigated Aβ‑producing and clearance pathways in different stages of AD. For this purpose, patients were categorized into four experimental groups: patients with mild cognitive impairment, patients with moderate cognitive decline, patients with very severe cognitive decline, and healthy patients as control. Levels of Aβ‑40, soluble amyloid precursor protein beta (sAPPβ), matrix metalloproteinase‑9 (MMP‑9), matrix metalloproteinase‑3 (MMP‑3), neprilysin (NEP), angiotensin‑converting enzyme (ACE), and insulin‑degrading enzyme (IDE) were determined by ELISA kits and immunoblotting in serum samples. According to the results, the levels of Aβ‑40 and sAPPβ increased in AD patients from an early stage, and levels were maintained in progressive AD stages. MMP‑9 also increased in the early stage, but its content decreased with disease development. MMP‑3 was significantly higher in the three stages of AD compared to the control patients. However, IDE, NEP, and ACE enzymes as clearing systems decreased in all studied AD samples, with their reductions more remarkable in the middle and late stages. The results showed that multiple Aβ‑degrading enzymes such as NEP and IDE in AD patients decline as AD progresses, while Aβ‑40 and sAPPβ increased from the early stage of the disease. Therefore, it could be concluded that detection of the dementia phase is a critical step for therapeutic strategies.