scholarly journals The role of Aβ circRNA in Alzheimer’s disease: alternative mechanism of Aβ biogenesis from Aβ circRNA translation

2018 ◽  
Author(s):  
Dingding Mo ◽  
Xinping Li ◽  
Carsten A. Raabe ◽  
Timofey S. Rozhdestvensky ◽  
Boris V. Skryabin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Proteolytic Processing ◽  
Alternative Mechanism ◽  
Coding Region ◽  
Amyloid Beta Peptides ◽  
Aβ Peptides ◽  
Beta Peptides ◽  
Age Related

AbstractAlzheimer’s disease (AD) is an age-related detrimental dementia. Amyloid beta peptides (Aβ) play a crucial role in the pathology of AD. In familial AD, Aβ is generated from the full-length amyloid precursor protein (APP) via dysregulated proteolytic processing. However, Aβ biogenesis in case of sporadic AD remains so far elusive. circRNAs are a class of transcripts, which are preferentially expressed in brain. Here, we identified a circRNA (circAβ-a) derived from the Aβ-coding region of the APP gene. circAβ-a is expressed in brains of AD and nondementia controls. With the aid of our recently established approach for analysis of circRNA functions, we demonstrated that circAβ-a is efficiently translated into a novel Aβ-related Aβ175 protein in living cells. Importantly, Aβ175 was further processed to Aβ peptides, the hallmark of AD. In summary, our analysis revealed alternative route of Aβ biogenesis. circAβ-a and its corresponding protein might represent novel therapeutic targets for AD treatment.

scholarly journals Circular RNA Encoded Amyloid Beta peptides—A Novel Putative Player in Alzheimer’s Disease

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2196
Author(s):  
Dingding Mo ◽  
Xinping Li ◽  
Carsten A. Raabe ◽  
Timofey S. Rozhdestvensky ◽  
Boris V. Skryabin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Beta ◽  
Cultured Cells ◽  
Alternative Pathway ◽  
Circular Rna ◽  
Proteolytic Processing ◽  
Amyloid Beta Peptides ◽  
Beta Peptides ◽  
Age Related

Alzheimer’s disease (AD) is an age-related detrimental dementia. Amyloid beta peptides (Aβ) play a crucial role in the pathology of AD. In familial AD, Aβ are generated from the full-length amyloid beta precursor protein (APP) via dysregulated proteolytic processing; however, in the case of sporadic AD, the mechanism of Aβ biogenesis remains elusive. circRNAs are a class of transcripts preferentially expressed in brain. We identified a circRNA harboring the Aβ-coding region of the APP gene termed circAβ-a. This circular RNA was detected in the brains of AD patients and non-dementia controls. With the aid of our recently established approach for analysis of circRNA functions, we demonstrated that circAβ-a is efficiently translated into a novel Aβ-containing Aβ175 polypeptide (19.2 KDa) in both cultured cells and human brain. Furthermore, Aβ175 was shown to be processed into Aβ peptides—a hallmark of AD. In summary, our analysis revealed an alternative pathway of Aβ biogenesis. Consequently, circAβ-a and its corresponding translation product could potentially represent novel therapeutic targets for AD treatment. Importantly, our data point to yet another evolutionary route for potentially increasing proteome complexity by generating additional polypeptide variants using back-splicing of primary transcripts that yield circular RNA templates.

scholarly journals Intracellular APP Domain Regulates Serine-Palmitoyl-CoA Transferase Expression and Is Affected in Alzheimer's Disease

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Marcus O. W. Grimm ◽  
Sven Grösgen ◽  
Tatjana L. Rothhaar ◽  
Verena K. Burg ◽  
Benjamin Hundsdörfer ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
De Novo ◽  
Physiological Function ◽  
Proteolytic Processing ◽  
Sphingolipid Metabolism ◽  
Amyloid Beta Peptides ◽  
Beta Peptides ◽  
Coa Transferase ◽  
Key Enzyme

Lipids play an important role as risk or protective factors in Alzheimer's disease (AD), a disease biochemically characterized by the accumulation of amyloid beta peptides (Aβ), released by proteolytic processing of the amyloid precursor protein (APP). Changes in sphingolipid metabolism have been associated to the development of AD. The key enzyme in sphingolipidde novosynthesis is serine-palmitoyl-CoA transferase (SPT). In the present study we identified a new physiological function of APP in sphingolipid synthesis. The APP intracellular domain (AICD) was found to decrease the expression of the SPT subunit SPTLC2, the catalytic subunit of the SPT heterodimer, resulting in that decreased SPT activity. AICD function was dependent on Fe65 and SPTLC2 levels are increased in APP knock-in mice missing a functional AICD domain. SPTLC2 levels are also increased in familial and sporadic ADpostmortembrains, suggesting that SPT is involved in AD pathology.

The Role of Lipids and Membranes in the Pathogenesis of Alzheimer's Disease: A Comprehensive View

2018 ◽  
Vol 15 (13) ◽  
pp. 1191-1212 ◽  
Author(s):  
Botond Penke ◽  
Gábor Paragi ◽  
János Gera ◽  
Róbert Berkecz ◽  
Zsolt Kovács ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Signaling Pathways ◽  
Membrane Lipids ◽  
Specific Protein ◽  
Dietary Factors ◽  
Lipid Signaling ◽  
Special Role ◽  
Aβ Peptides

Lipids participate in Amyloid Precursor Protein (APP) trafficking and processing - important factors in the initiation of Alzheimer’s disease (AD) pathogenesis and influence the formation of neurotoxic β-amyloid (Aβ) peptides. An important risk factor, the presence of ApoE4 protein in AD brain cells binds the lipids to AD. In addition, lipid signaling pathways have a crucial role in the cellular homeostasis and depend on specific protein-lipid interactions. The current review focuses on pathological alterations of membrane lipids (cholesterol, glycerophospholipids, sphingolipids) and lipid metabolism in AD and provides insight in the current understanding of biological membranes, their lipid structures and functions, as well as their role as potential therapeutic targets. Novel methods for studying the membrane structure and lipid composition will be reviewed in a broad sense whereas the use of lipid biomarkers for early diagnosis of AD will be shortly summarized. Interactions of Aβ peptides with the cell membrane and different subcellular organelles are reviewed. Next, the details of the most important lipid signaling pathways, including the role of the plasma membrane as stress sensor and its therapeutic applications are given. 4-hydroxy-2-nonenal may play a special role in the initiation of the pathogenesis of AD and thus the “calpain-cathepsin hypothesis” of AD is highlighted. Finally, the most important lipid dietary factors and their possible use and efficacy in the prevention of AD are discussed.

scholarly journals Inverse Correlation Between Alzheimer’s Disease and Cancer: Short Overview

2021 ◽  
Author(s):  
Agnieszka Zabłocka ◽  
Wioletta Kazana ◽  
Marta Sochocka ◽  
Bartłomiej Stańczykiewicz ◽  
Maria Janusz ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Kinase Inhibitor ◽  
Fungal Infections ◽  
Neurological Diseases ◽  
Inverse Correlation ◽  
Biological Mechanisms ◽  
Age Related ◽  
Common Risk Factors

AbstractThe negative association between Alzheimer’s disease (AD) and cancer suggests that susceptibility to one disease may protect against the other. When biological mechanisms of AD and cancer and relationship between them are understood, the unsolved problem of both diseases which still touches the growing human population could be overcome. Actual information about biological mechanisms and common risk factors such as chronic inflammation, age-related metabolic deregulation, and family history is presented here. Common signaling pathways, e.g., p53, Wnt, role of Pin1, and microRNA, are discussed as well. Much attention is also paid to the potential impact of chronic viral, bacterial, and fungal infections that are responsible for the inflammatory pathway in AD and also play a key role to cancer development. New data about common mechanisms in etiopathology of cancer and neurological diseases suggests new therapeutic strategies. Among them, the use of nilotinib, tyrosine kinase inhibitor, protein kinase C, and bexarotene is the most promising.

scholarly journals Extracellular Vesicles: A Possible Link between HIV and Alzheimer’s Disease-Like Pathology in HIV Subjects?

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 968 ◽  
Author(s):  
Sunitha Kodidela ◽  
Kelli Gerth ◽  
Sanjana Haque ◽  
Yuqing Gong ◽  
Saifudeen Ismael ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Extracellular Vesicles ◽  
Treatment Strategies ◽  
Progressive Dementia ◽  
Hiv Patients ◽  
Age Related ◽  
Infected Cells ◽  
New Treatment

The longevity of people with HIV/AIDS has been prolonged with the use of antiretroviral therapy (ART). The age-related complications, especially cognitive deficits, rise as HIV patients live longer. Deposition of beta-amyloid (Aβ), a hallmark of Alzheimer’s disease (AD), has been observed in subjects with HIV-associated neurocognitive disorders (HAND). Various mechanisms such as neuroinflammation induced by HIV proteins (e.g., Tat, gp120, Nef), excitotoxicity, oxidative stress, and the use of ART contribute to the deposition of Aβ, leading to dementia. However, progressive dementia in older subjects with HIV might be due to HAND, AD, or both. Recently, extracellular vesicles (EVs)/exosomes, have gained recognition for their importance in understanding the pathology of both HAND and AD. EVs can serve as a possible link between HIV and AD, due to their ability to package and transport the toxic proteins implicated in both AD and HIV (Aβ/tau and gp120/tat, respectively). Given that Aß is also elevated in neuron-derived exosomes isolated from the plasma of HIV patients, it is reasonable to suggest that neuron-to-neuron exosomal transport of Aβ and tau also contributes to AD-like pathology in HIV-infected subjects. Therefore, exploring exosomal contents is likely to help distinguish HAND from AD. However, future prospective clinical studies need to be conducted to compare the exosomal contents in the plasma of HIV subjects with and without HAND as well as those with and without AD. This would help to find new markers and develop new treatment strategies to treat AD in HIV-positive subjects. This review presents comprehensive literatures on the mechanisms contributing to Aβ deposition in HIV-infected cells, the role of EVs in the propagation of Aβ in AD, the possible role of EVs in HIV-induced AD-like pathology, and finally, possible therapeutic targets or molecules to treat HIV subjects with AD.

scholarly journals Zinc-mediated Neurotransmission in Alzheimer's Disease: A Potential Role of the GPR39 in Dementia

2019 ◽  
Vol 18 (1) ◽  
pp. 2-13
Author(s):  
Michal Rychlik ◽  
Katarzyna Mlyniec
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Beta ◽  
Neural Plasticity ◽  
Modern Society ◽  
Neuroprotective Drugs ◽  
Age Related ◽  
Candidate Drug ◽  
G Protein Coupled

: With more people reaching an advanced age in modern society, there is a growing need for strategies to slow down age-related neuropathology and loss of cognitive functions, which are a hallmark of Alzheimer's disease. Neuroprotective drugs and candidate drug compounds target one or more processes involved in the neurodegenerative cascade, such as excitotoxicity, oxidative stress, misfolded protein aggregation and/or ion dyshomeostasis. A growing body of research shows that a G-protein coupled zinc (Zn2+) receptor (GPR39) can modulate the abovementioned processes. : Zn2+itself has a diverse activity profile at the synapse, and by binding to numerous receptors, it plays an important role in neurotransmission. However, Zn2+ is also necessary for the formation of toxic oligomeric forms of amyloid beta, which underlie the pathology of Alzheimer’s disease. Furthermore, the binding of Zn2+ by amyloid beta causes a disruption of zincergic signaling, and recent studies point to GPR39 and its intracellular targets being affected by amyloid pathology. : In this review, we present neurobiological findings related to Zn2+ and GPR39, focusing on its signaling pathways, neural plasticity, interactions with other neurotransmission systems, as well as on the effects of pathophysiological changes observed in Alzheimer's disease on GPR39 function. : Direct targeting of the GPR39 might be a promising strategy for the pharmacotherapy of zincergic dyshomeostasis observed in Alzheimer’s disease. The information presented in this article will hopefully fuel further research into the role of GPR39 in neurodegeneration and help in identifying novel therapeutic targets for dementia.

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