scholarly journals Using Drosophila Models of Amyloid Toxicity to Study Autophagy in the Pathogenesis of Alzheimer’s Disease

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Louise O’Keefe ◽  
Donna Denton
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neuronal Function ◽  
Amyloid Toxicity ◽  
Cellular Pathways ◽  
Toxic Peptides ◽  
The Brain ◽  
Prevalent Form ◽  
Drosophila Models

Autophagy is a conserved catabolic pathway that involves the engulfment of cytoplasmic components such as large protein aggregates and organelles that are delivered to the lysosome for degradation. This process is important in maintaining neuronal function and raises the possibility of a role for autophagy in neurodegenerative diseases. Alzheimer’s disease (AD) is the most prevalent form of these diseases and is characterized by the accumulation of amyloid plaques in the brain which arise due to the misfolding and aggregation of toxic peptides, including amyloid beta (Aβ). There is substantial evidence from both AD patients and animal models that autophagy is dysregulated in this disease. However, it remains to be determined whether this is protective or pathogenic as there is evidence that autophagy can act to promote the degradation as well as function in the generation of toxic Aβ peptides. Understanding the molecular details of the extensive crosstalk that occurs between the autophagic and endolysosomal cellular pathways is essential for identifying the molecular details of amyloid toxicity. Drosophila models that express the toxic proteins that aggregate in AD have been generated and have been shown to recapitulate hallmarks of the disease. Here we focus on what is known about the role of autophagy in amyloid toxicity in AD from mammalian models and how Drosophila models can be used to further investigate AD pathogenesis.

scholarly journals The potential role for sphingolipids in neuropathogenesis of Alzheimer’s disease

2013 ◽  
Vol 59 (1) ◽  
pp. 25-50 ◽  
Author(s):  
A.V. Alessenko
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Functional Role ◽  
Potential Role ◽  
Early Stage ◽  
New Drugs ◽  
Neuronal Function ◽  
Sphingosine 1 Phosphate ◽  
The Brain

The review discusses the functional role of sphingolipids in the pathogenesis of Alzheimer's disease. Certain evidence exist that the imbalance of sphingolipids such as sphingomyelin, ceramide, sphingosine, sphingosine-1-phosphate and galactosylceramide in the brain of animals and humans, in the cerebrospinal fluid and blood plasma of patients with Alzheimer's disease play a crucial role in neuronal function by regulating growth, differentiation and cell death in CNS. Activation of sphingomyelinase, which leads to the accumulation of the proapoptotic agent, ceramide, can be considered as a new mechanism for AD and may be a prerequisite for the treatment of this disease by using drugs that inhibit sphingomyelinase activity. The role of sphingolipids as biomarkers for the diagnosis of the early stage of Alzheimer's disease and monitoring the effectiveness of treatment with new drugs is discussed.

Role of Nanomedicines in Delivery of Anti-Acetylcholinesterase Compounds to the Brain in Alzheimer’s Disease

2014 ◽  
Vol 13 (8) ◽  
pp. 1315-1324 ◽  
Author(s):  
Mohammad Ahmad ◽  
Javed Ahmad ◽  
Saima Amin ◽  
Mahfoozur Rahman ◽  
Mohammad Anwar ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
The Brain

scholarly journals Peptides Derived from Growth Factors to Treat Alzheimer’s Disease

2021 ◽  
Vol 22 (11) ◽  
pp. 6071
Author(s):  
Suzanne Gascon ◽  
Jessica Jann ◽  
Chloé Langlois-Blais ◽  
Mélanie Plourde ◽  
Christine Lavoie ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Growth Factors ◽  
Signaling Pathways ◽  
Brain Structures ◽  
Therapeutic Strategies ◽  
Native Proteins ◽  
Receptor Sites ◽  
The Brain

Alzheimer’s disease (AD) is a devastating neurodegenerative disease characterized by progressive neuron losses in memory-related brain structures. The classical features of AD are a dysregulation of the cholinergic system, the accumulation of amyloid plaques, and neurofibrillary tangles. Unfortunately, current treatments are unable to cure or even delay the progression of the disease. Therefore, new therapeutic strategies have emerged, such as the exogenous administration of neurotrophic factors (e.g., NGF and BDNF) that are deficient or dysregulated in AD. However, their low capacity to cross the blood–brain barrier and their exorbitant cost currently limit their use. To overcome these limitations, short peptides mimicking the binding receptor sites of these growth factors have been developed. Such peptides can target selective signaling pathways involved in neuron survival, differentiation, and/or maintenance. This review focuses on growth factors and their derived peptides as potential treatment for AD. It describes (1) the physiological functions of growth factors in the brain, their neuronal signaling pathways, and alteration in AD; (2) the strategies to develop peptides derived from growth factor and their capacity to mimic the role of native proteins; and (3) new advancements and potential in using these molecules as therapeutic treatments for AD, as well as their limitations.

scholarly journals Alzheimer’s Disease Pathogenesis: Role of Autophagy and Mitophagy Focusing in Microglia

2021 ◽  
Vol 22 (7) ◽  
pp. 3330
Author(s):  
Mehdi Eshraghi ◽  
Aida Adlimoghaddam ◽  
Amir Mahmoodzadeh ◽  
Farzaneh Sharifzad ◽  
Hamed Yasavoli-Sharahi ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Therapeutic Target ◽  
Neurological Disorder ◽  
Inflammatory Cells ◽  
Disease Pathogenesis ◽  
Current Review ◽  
The Brain ◽  
Comprehensive Discussion

Alzheimer’s disease (AD) is a debilitating neurological disorder, and currently, there is no cure for it. Several pathologic alterations have been described in the brain of AD patients, but the ultimate causative mechanisms of AD are still elusive. The classic hallmarks of AD, including am-yloid plaques (Aβ) and tau tangles (tau), are the most studied features of AD. Unfortunately, all the efforts targeting these pathologies have failed to show the desired efficacy in AD patients so far. Neuroinflammation and impaired autophagy are two other main known pathologies in AD. It has been reported that these pathologies exist in AD brain long before the emergence of any clinical manifestation of AD. Microglia are the main inflammatory cells in the brain and are considered by many researchers as the next hope for finding a viable therapeutic target in AD. Interestingly, it appears that the autophagy and mitophagy are also changed in these cells in AD. Inside the cells, autophagy and inflammation interact in a bidirectional manner. In the current review, we briefly discussed an overview on autophagy and mitophagy in AD and then provided a comprehensive discussion on the role of these pathways in microglia and their involvement in AD pathogenesis.

Neuroinflammatory Signaling in the Pathogenesis of Alzheimer’s Disease

2021 ◽  
Vol 19 ◽  
Author(s):  
Md. Sahab Uddin ◽  
Md. Tanvir Kabir ◽  
Maroua Jalouli ◽  
Md. Ataur Rahman ◽  
Philippe Jeandet ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Innate Immune ◽  
Misfolded Proteins ◽  
Inflammatory Signaling ◽  
Genome Wide Analysis ◽  
Genome Wide ◽  
Immunological Mechanisms ◽  
The Brain

: Alzheimer’s disease (AD) is a chronic neurodegenerative disease characterized by the formation of intracellular neurofibrillary tangles (NFTs) and extracellular amyloid plaques. Growing evidence has suggested that AD pathogenesis is not only limited to the neuronal compartment but also strongly interacts with immunological processes in the brain. On the other hand, aggregated and misfolded proteins can bind with pattern recognition receptors located on astroglia and microglia and can in turn induce an innate immune response, characterized by the release of inflammatory mediators, ultimately playing a role in both the severity and the progression of the disease. It has been reported by genome-wide analysis that several genes which elevate the risk for sporadic AD encode for factors controlling the inflammatory response and glial clearance of misfolded proteins. Obesity and systemic inflammation are examples of external factors which may interfere with the immunological mechanisms of the brain and can induce disease progression. In this review, we discussed the mechanisms and essential role of inflammatory signaling pathways in AD pathogenesis. Indeed, interfering with immune processes and modulation of risk factors may lead to future therapeutic or preventive AD approaches.

scholarly journals The Role of the Innate Immune System in Alzheimer’s Disease and Frontotemporal Lobar Degeneration: An Eye on Microglia

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Elisa Ridolfi ◽  
Cinzia Barone ◽  
Elio Scarpini ◽  
Daniela Galimberti
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Frontotemporal Lobar Degeneration ◽  
Environmental Changes ◽  
Current Evidence ◽  
Neuronal Function ◽  
Immune Effector ◽  
Effector Cells ◽  
The Central Nervous System

In the last few years, genetic and biomolecular mechanisms at the basis of Alzheimer’s disease (AD) and frontotemporal lobar degeneration (FTLD) have been unraveled. A key role is played by microglia, which represent the immune effector cells in the central nervous system (CNS). They are extremely sensitive to the environmental changes in the brain and are activated in response to several pathologic events within the CNS, including altered neuronal function, infection, injury, and inflammation. While short-term microglial activity has generally a neuroprotective role, chronic activation has been implicated in the pathogenesis of neurodegenerative disorders, including AD and FTLD. In this framework, the purpose of this review is to give an overview of clinical features, genetics, and novel discoveries on biomolecular pathogenic mechanisms at the basis of these two neurodegenerative diseases and to outline current evidence regarding the role played by activated microglia in their pathogenesis.

scholarly journals The Role of Long Noncoding RNAs in Diabetic Alzheimer’s Disease

2018 ◽  
Vol 7 (11) ◽  
pp. 461 ◽  
Author(s):  
Young-Kook Kim ◽  
Juhyun Song
Keyword(s):  
Alzheimer’S Disease ◽  
Insulin Resistance ◽  
Alzheimer's Disease ◽  
Neurodegenerative Diseases ◽  
Noncoding Rnas ◽  
Long Noncoding Rnas ◽  
Glucose Dysregulation ◽  
Near Future ◽  
The Brain

Long noncoding RNAs (lncRNAs) are involved in diverse physiological and pathological processes by modulating gene expression. They have been found to be dysregulated in the brain and cerebrospinal fluid of patients with neurodegenerative diseases, and are considered promising therapeutic targets for treatment. Among the various neurodegenerative diseases, diabetic Alzheimer’s disease (AD) has been recently emerging as an important issue due to several unexpected reports suggesting that metabolic issues in the brain, such as insulin resistance and glucose dysregulation, could be important risk factors for AD. To facilitate understanding of the role of lncRNAs in this field, here we review recent studies on lncRNAs in AD and diabetes, and summarize them with different categories associated with the pathogenesis of the diseases including neurogenesis, synaptic dysfunction, amyloid beta accumulation, neuroinflammation, insulin resistance, and glucose dysregulation. It is essential to understand the role of lncRNAs in the pathogenesis of diabetic AD from various perspectives for therapeutic utilization of lncRNAs in the near future.

scholarly journals Alzheimer's disease-associated TM2D genes regulate Notch signaling and neuronal function in Drosophila

2021 ◽  
Author(s):  
Jose L Salazar ◽  
Sheng-An Yang ◽  
Yong Qi Lin ◽  
David Li-Kroeger ◽  
Paul C Marcogliese ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Gene Family ◽  
Notch Signaling ◽  
Rare Variants ◽  
Neuronal Function ◽  
Evolutionarily Conserved ◽  
Cleavage Step ◽  
The Brain ◽  
Entire Gene

TM2 domain containing (TM2D) proteins are conserved in metazoans and encoded by three separate genes in each species. Rare variants in TM2D3 are associated with Alzheimer's disease (AD) and its fly ortholog almondex is required for embryonic Notch signaling. However, the functions of this gene family remain elusive. We knocked-out all three TM2D genes (almondex, CG11103/amaretto, CG10795/biscotti) in Drosophila and found that they share the same maternal-effect neurogenic defect. Triple null animals are not phenotypically worse than single nulls, suggesting these genes function together. Overexpression of the most conserved region of the TM2D proteins acts as a potent inhibitor of Notch signaling at the γ-secretase cleavage step. Lastly, Almondex is detected in the brain and its loss causes shortened lifespan accompanied by progressive electrophysiological defects. The functional links between all three TM2D genes are likely to be evolutionarily conserved, suggesting that this entire gene family may be involved in AD.

scholarly journals Sex Differences and the Influence of Sex Hormones on Cognition through Adulthood and the Aging Process

2018 ◽  
Vol 8 (9) ◽  
pp. 163 ◽  
Author(s):  
Caroline Gurvich ◽  
Kate Hoy ◽  
Natalie Thomas ◽  
Jayashri Kulkarni
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Sex Differences ◽  
Cognitive Functioning ◽  
Sex Hormones ◽  
Reproductive Function ◽  
Health And Disease ◽  
And Function ◽  
The Brain

Hormones of the hypothalamic-pituitary-gonadal (HPG) axis that regulate reproductive function have multiple effects on the development, maintenance and function of the brain. Sex differences in cognitive functioning have been reported in both health and disease, which may be partly attributed to sex hormones. The aim of the current paper was to provide a theoretical review of how sex hormones influence cognitive functioning across the lifespan as well as provide an overview of the literature on sex differences and the role of sex hormones in cognitive decline, specifically in relation to Alzheimer’s disease (AD). A summary of current hormone and sex-based interventions for enhancing cognitive functioning and/or reducing the risk of Alzheimer’s disease is also provided.

scholarly journals Genetic Variants of Lipoprotein Lipase and Regulatory Factors Associated with Alzheimer’s Disease Risk

2020 ◽  
Vol 21 (21) ◽  
pp. 8338
Author(s):  
Kimberley D. Bruce ◽  
Maoping Tang ◽  
Philip Reigan ◽  
Robert H. Eckel
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Lipoprotein Lipase ◽  
Genetic Variants ◽  
Disease Risk ◽  
Lipoprotein Metabolism ◽  
Protective Role ◽  
Direct Role ◽  
The Brain

Lipoprotein lipase (LPL) is a key enzyme in lipid and lipoprotein metabolism. The canonical role of LPL involves the hydrolysis of triglyceride-rich lipoproteins for the provision of FFAs to metabolic tissues. However, LPL may also contribute to lipoprotein uptake by acting as a molecular bridge between lipoproteins and cell surface receptors. Recent studies have shown that LPL is abundantly expressed in the brain and predominantly expressed in the macrophages and microglia of the human and murine brain. Moreover, recent findings suggest that LPL plays a direct role in microglial function, metabolism, and phagocytosis of extracellular factors such as amyloid- beta (Aβ). Although the precise function of LPL in the brain remains to be determined, several studies have implicated LPL variants in Alzheimer’s disease (AD) risk. For example, while mutations shown to have a deleterious effect on LPL function and expression (e.g., N291S, HindIII, and PvuII) have been associated with increased AD risk, a mutation associated with increased bridging function (S447X) may be protective against AD. Recent studies have also shown that genetic variants in endogenous LPL activators (ApoC-II) and inhibitors (ApoC-III) can increase and decrease AD risk, respectively, consistent with the notion that LPL may play a protective role in AD pathogenesis. Here, we review recent advances in our understanding of LPL structure and function, which largely point to a protective role of functional LPL in AD neuropathogenesis.

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