scholarly journals New therapeutic strategies for Alzheimer’s disease

2021 ◽  
Vol 75 ◽  
pp. 474-490
Author(s):  
Dominika Nowak ◽  
Wojciech Słupski ◽  
Maria Rutkowska

Alzheimer’s disease (AD) described as a chronic and irreversible neurodegenerative disease remains the most common cause of dementia. Due to the aging of the population, the incurability of AD has become a growing problem of medicine in the 21stcentury. Current treatment is only symptomatic, providing minimal, temporary improvement in the patient’s cognitive function. This paper presents the latest trends in the search for effective pharmacotherapy capable of preventing or inhibiting AD progression. Since the exact pathogenesis of Alzheimer’s disease is not known, the main therapeutic strategies are based only on the following hypotheses: amyloid cascade, tau protein, oxidative stress, neuroinflammation and those associated with dysfunction of the cholinergic system as well as glutamatergic. Most of the compounds currently tested in clinical trials are targeted at pathological amyloid β (A β), which is considered the cause of neurodegeneration, according to the most widely described cascade theory. Most of the compounds currently tested in clinical trials are targeted at pathological amyloid β (Aβ), which is the main cause of neurodegeneration according to the widely described theory of the amyloid cascade. Attempts to fight the toxic Aβ are based on the following: immunotherapy (vaccines, monoclonal antibodies), compounds that inhibit its formation: γ-secretase inhibitors/modulators and β-secretase. Immunotherapy can also be us,ed to increase the clearance of hyperphosphorylated tau protein, the occurrence of which is another feature of Alzheimer’s disease. In addition to immunotherapy, anti-inflammatory, metabolic and neuroprotective compounds have been the subject of a number of studies. A range of symptomatic compounds that improve cognitive functions by compensating cholinergic, noradrenergic and glutamatergic signaling deficits have also been investigated in clinical trials.

2021 ◽  
Author(s):  
Letícia Freitas de Castro Silva ◽  
Elisa Pinheiro Weber ◽  
Gleice Silva Toledo ◽  
Josiane Fonseca Almeida

Introduction: Alzheimer’s disease (AD) is seen as the most important dementia, prevalent in the elderly over 60 years old. There is still no cure, and the pharmacological strategies are to delay the symptoms and development of the pathology. The pathophysiological mechanisms are: hyperphosphorylation of the tau protein and aggregation of amyloid-β. Update studies of the tested therapies target the main pathological mechanisms: accumulation of β amyloid (inhibitors and modulators of β-secretase and γ-secretase and active and passive anti-Aβ immunotherapies), tau protein (inhibition of abnormal hyperphosphorylation with GSK-3 inhibitors, passive and active immunotherapies and the use of intrathecal antisense oligonucleotides (ASOs) and correction of the ApoE protein (increase lipidation, correct structure, clearance of non-lipid ApoE and reduction of ApoE expression). Objectives and methodology: To develop a bibliographic review in order to address new drugs in the treatment of Alzheimer’s. Qualitative and descriptive study carried out by literary review with research on PubMed. Results: Several drugs have been tested in clinical trials, however, due to lack of effectiveness, none have been approved. Therefore, it’s important to understand the limitations of the tests developed as flaws in the methodology, insufficient understanding of the mechanisms involved and inclusion of patients in different stages of AD, so that future investigations can overcome these gaps. Conclusion: It’s important to investigate new pathophysiological mechanisms, as well as the factors that trigger AD. Diagnosis is essential, with further studies to identify new biomarkers of the disease that will also have an impact on the conduct of clinical trials.


2017 ◽  
Vol 8 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Marta Bolós ◽  
Juan Ramón Perea ◽  
Jesús Avila

AbstractAlzheimer’s disease (AD) is a neurodegenerative condition characterized by the formation of amyloid-β plaques, aggregated and hyperphosphorylated tau protein, activated microglia and neuronal cell death, ultimately leading to progressive dementia. In this short review, we focus on neuroinflammation in AD. Specifically, we describe the participation of microglia, as well as other factors that may contribute to inflammation, in neurodegeneration.


2019 ◽  
Vol 20 (3) ◽  
pp. 558 ◽  
Author(s):  
Yuan Dong ◽  
Xiaoheng Li ◽  
Jinbo Cheng ◽  
Lin Hou

Alzheimer’s disease (AD) is one of the most common causes of dementia. Its pathogenesis is characterized by the aggregation of the amyloid-β (Aβ) protein in senile plaques and the hyperphosphorylated tau protein in neurofibrillary tangles in the brain. Current medications for AD can provide temporary help with the memory symptoms and other cognitive changes of patients, however, they are not able to stop or reverse the progression of AD. New medication discovery and the development of a cure for AD is urgently in need. In this review, we summarized drugs for AD treatments and their recent updates, and discussed the potential of microglia induced neuroinflammation as a target for anti-AD drug development.


Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1261
Author(s):  
Laura D’Andrea ◽  
Ramona Stringhi ◽  
Monica Di Luca ◽  
Elena Marcello

Alzheimer’s disease (AD) is a neurodegenerative disorder representing the most common form of dementia. It is biologically characterized by the deposition of extracellular amyloid-β (Aβ) senile plaques and intracellular neurofibrillary tangles, constituted by hyperphosphorylated tau protein. The key protein in AD pathogenesis is the amyloid precursor protein (APP), which is cleaved by secretases to produce several metabolites, including Aβ and APP intracellular domain (AICD). The greatest genetic risk factor associated with AD is represented by the Apolipoprotein E ε4 (APOE ε4) allele. Importantly, all of the above-mentioned molecules that are strictly related to AD pathogenesis have also been described as playing roles in the cell nucleus. Accordingly, evidence suggests that nuclear functions are compromised in AD. Furthermore, modulation of transcription maintains cellular homeostasis, and alterations in transcriptomic profiles have been found in neurodegenerative diseases. This report reviews recent advancements in the AD players-mediated gene expression. Aβ, tau, AICD, and APOE ε4 localize in the nucleus and regulate the transcription of several genes, part of which is involved in AD pathogenesis, thus suggesting that targeting nuclear functions might provide new therapeutic tools for the disease.


2014 ◽  
Vol 56 ◽  
pp. 99-110 ◽  
Author(s):  
David Allsop ◽  
Jennifer Mayes

One of the hallmarks of AD (Alzheimer's disease) is the formation of senile plaques in the brain, which contain fibrils composed of Aβ (amyloid β-peptide). According to the ‘amyloid cascade’ hypothesis, the aggregation of Aβ initiates a sequence of events leading to the formation of neurofibrillary tangles, neurodegeneration, and on to the main symptom of dementia. However, emphasis has now shifted away from fibrillar forms of Aβ and towards smaller and more soluble ‘oligomers’ as the main culprit in AD. The present chapter commences with a brief introduction to the disease and its current treatment, and then focuses on the formation of Aβ from the APP (amyloid precursor protein), the genetics of early-onset AD, which has provided strong support for the amyloid cascade hypothesis, and then on the development of new drugs aimed at reducing the load of cerebral Aβ, which is still the main hope for providing a more effective treatment for AD in the future.


2019 ◽  
Vol 141 (3) ◽  
Author(s):  
I. A. Kuznetsov ◽  
A. V. Kuznetsov

Modeling of intracellular processes occurring during the development of Alzheimer's disease (AD) can be instrumental in understanding the disease and can potentially contribute to finding treatments for the disease. The model of intracellular processes in AD, which we previously developed, contains a large number of parameters. To distinguish between more important and less important parameters, we performed a local sensitivity analysis of this model around the values of parameters that give the best fit with published experimental results. We show that the influence of model parameters on the total concentrations of amyloid precursor protein (APP) and tubulin-associated unit (tau) protein in the axon is reciprocal to the influence of the same parameters on the average velocities of the same proteins during their transport in the axon. The results of our analysis also suggest that in the beginning of AD the aggregation of amyloid-β and misfolded tau protein have little effect on transport of APP and tau in the axon, which suggests that early damage in AD may be reversible.


2017 ◽  
Vol 05 (03) ◽  
Author(s):  
Miguel Angel Ontiveros Torres ◽  
Leonel Castellanos Aguilar ◽  
Jonathan Lennel Gutierrez Murcia ◽  
Nayeli Martinez Zuniga ◽  
Paola Flores Rodriguez ◽  
...  

2021 ◽  
Vol 14 ◽  
Author(s):  
Siva Sundara Kumar Durairajan ◽  
Karthikeyan Selvarasu ◽  
Minu Rani Bera ◽  
Kaushik Rajaram ◽  
Ashok Iyaswamy ◽  
...  

: Alzheimer’s disease (AD), a major form of dementia, has been reported to affect more than 50 million people worldwide. It is characterized by the presence of amyloid-β (Aβ) plaques and hyperphosphorylated Tau-associated neurofibrillary tangles in the brain. Apart from AD, microtubule (MT)-associated protein Tau is also involved in other neurodegenerative diseases called tauopathies, including Pick’s disease, frontotemporal lobar degeneration, progressive supranuclear palsy, and corticobasal degeneration. The recently unsuccessful phase III clinical trials related to Aβ-targeted therapeutic drugs indicated that alternative targets, such as Tau, should be studied to discover more effective and safer drugs. Recent drug discovery approaches to reduce AD-related Tau pathologies are primarily based on blocking Tau aggregation, inhibiting Tau phosphorylation, compensating impaired Tau function with MT-stabilizing agents, and targeting the degradation pathways in neuronal cells to degrade Tau protein aggregates. Owing to several limitations of the currently-available Tau-directed drugs, further studies are required to generate further effective and safer Tau-based disease-modifying drugs. Here, we review the studies that focused on medicinal plant-derived compounds capable of modulating the Tau protein, which is significantly elevated and hyperphosphorylated in AD and other tauopathies. We mainly considered the studies that focused on Tau protein as a therapeutic target. We reviewed several pertinent papers retrieved from PubMed and ScienceDirect using relevant keywords, with a primary focus on the Tau-targeting compounds from medicinal plants. These compounds include indolines, phenolics, flavonoids, coumarins, alkaloids, and iridoids, which have been scientifically proven to be Tau-targeting candidates for the treatment of AD.


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