scholarly journals Thermodynamics of Homopeptide Aggregation

2020 ◽  
Author(s):  
Tam T. M. Phan ◽  
Jeremy D. Schmit
Keyword(s):  
Neurodegenerative Diseases ◽  
Disease Progression ◽  
Prion Diseases ◽  
Steric Repulsion ◽  
Polymer Micelles ◽  
Amyloid Aggregates ◽  
Exon 1 ◽  
Flanking Sequences ◽  
Precise Role

ABSTRACTAmyloid aggregates are found in many neurodegenerative diseases including Huntington’s, Alzheimer’s, and prion diseases. The precise role of the aggregates in disease progression has been difficult to elucidate due to the diversity of aggregated states they can adopt. Here we study the formation of fibrils and oligomers by exon 1 of huntingtin protein. We show that the oligomer states are consistent with polymer micelles that are limited in size by the stretching entropy of the polyglutamine region. The model shows how the sequences flanking the amyloid core modulate aggregation behavior. The N17 region promotes aggregation through weakly attractive interactions, while the C38 tail opposes aggregation via steric repulsion. We also show that the energetics of cross-β stacking by polyglutamine would produce fibrils with many alignment defects, but minor perturbations from the flanking sequences are sufficient to reduce the defects to the level observed in experiment. We conclude with a discussion of the implications of this model for other amyloid forming molecules.

scholarly journals The Role of Vesicle Trafficking Defects in the Pathogenesis of Prion and Prion-Like Disorders

2020 ◽  
Vol 21 (19) ◽  
pp. 7016
Author(s):  
Pearl Cherry ◽  
Sabine Gilch
Keyword(s):  
Neurodegenerative Diseases ◽  
Prion Diseases ◽  
Primary Component ◽  
Vesicular Trafficking ◽  
Polyglutamine Diseases ◽  
Amyloid Aggregates ◽  
The Common ◽  
Trafficking Defects ◽  
Insight Into

Prion diseases are fatal and transmissible neurodegenerative diseases in which the cellular form of the prion protein ‘PrPc’, misfolds into an infectious and aggregation prone isoform termed PrPSc, which is the primary component of prions. Many neurodegenerative diseases, like Alzheimer’s disease, Parkinson’s disease, and polyglutamine diseases, such as Huntington’s disease, are considered prion-like disorders because of the common characteristics in the propagation and spreading of misfolded proteins that they share with the prion diseases. Unlike prion diseases, these are non-infectious outside experimental settings. Many vesicular trafficking impairments, which are observed in prion and prion-like disorders, favor the accumulation of the pathogenic amyloid aggregates. In addition, many of the vesicular trafficking impairments that arise in these diseases, turn out to be further aggravating factors. This review offers an insight into the currently known vesicular trafficking defects in these neurodegenerative diseases and their implications on disease progression. These findings suggest that these impaired trafficking pathways may represent similar therapeutic targets in these classes of neurodegenerative disorders.

Role of the Structural Characteristics of Dendrimers in the Manifestation of the Antiamyloid Properties

INEOS OPEN ◽  
2020 ◽  
Vol 3 ◽  
Author(s):  
S. A. Sorokina ◽  
◽  
Yu. Yu. Stroilova ◽  
V. I. Muronets ◽  
Z. B. Shifrina ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Structural Characteristics ◽  
Short Review ◽  
External Factors ◽  
Amyloid Aggregation ◽  
Amyloid Proteins ◽  
Molecular Parameters ◽  
Amyloid Aggregates ◽  
Aggregation Processes

Among the compounds able to efficiently inhibit the amyloid aggregation of proteins and decompose the amyloid aggregates that cause neurodegenerative diseases, of particular interest are dendrimers, which represent individual macromolecules with the hypercrosslinked architectures and given molecular parameters. This short review outlines the peculiarities of the antiamyloid activity of dendrimers and discusses the effect of dendrimer structures and external factors on their antiamyloid properties. The potential of application of dendrimers in further investigations on the aggregation processes of amyloid proteins as the compounds that exhibit the remarkable antiamyloid activity is evaluated.

scholarly journals The Effect of Octapeptide Repeats on Prion Folding and Misfolding

2021 ◽  
Vol 22 (4) ◽  
pp. 1800
Author(s):  
Kun-Hua Yu ◽  
Mei-Yu Huang ◽  
Yi-Ru Lee ◽  
Yu-Kie Lin ◽  
Hau-Ren Chen ◽  
...  
Keyword(s):  
Amyloid Fibrils ◽  
Age Of Onset ◽  
Prion Diseases ◽  
Critical Role ◽  
Threshold Effect ◽  
Central Feature ◽  
Terminal Domain ◽  
Amyloid Aggregates

Misfolding of prion protein (PrP) into amyloid aggregates is the central feature of prion diseases. PrP has an amyloidogenic C-terminal domain with three α-helices and a flexible tail in the N-terminal domain in which multiple octapeptide repeats are present in most mammals. The role of the octapeptides in prion diseases has previously been underestimated because the octapeptides are not located in the amyloidogenic domain. Correlation between the number of octapeptide repeats and age of onset suggests the critical role of octapeptide repeats in prion diseases. In this study, we have investigated four PrP variants without any octapeptides and with 1, 5 and 8 octapeptide repeats. From the comparison of the protein structure and the thermal stability of these proteins, as well as the characterization of amyloids converted from these PrP variants, we found that octapeptide repeats affect both folding and misfolding of PrP creating amyloid fibrils with distinct structures. Deletion of octapeptides forms fewer twisted fibrils and weakens the cytotoxicity. Insertion of octapeptides enhances the formation of typical silk-like fibrils but it does not increase the cytotoxicity. There might be some threshold effect and increasing the number of peptides beyond a certain limit has no further effect on the cell viability, though the reasons are unclear at this stage. Overall, the results of this study elucidate the molecular mechanism of octapeptides at the onset of prion diseases.

scholarly journals The Golgi apparatus in neurorestoration

2019 ◽  
Vol 7 (3) ◽  
pp. 116-128
Author(s):  
Jianyang Liu ◽  
Jialin He ◽  
Yan Huang ◽  
Han Xiao ◽  
Zheng Jiang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Golgi Apparatus ◽  
Neurodegenerative Diseases ◽  
Disease Progression ◽  
Neurological Recovery ◽  
Cellular Processes ◽  
Wide Range ◽  
And Oxidative Stress

The central role of the Golgi apparatus in critical cellular processes such as the transport, processing, and sorting of proteins and lipids has placed it at the forefront of cell science. Golgi apparatus dysfunction caused by primary defects within the Golgi or pharmacological and oxidative stress has been implicated in a wide range of neurodegenerative diseases. In addition to participating in disease progression, the Golgi apparatus plays pivotal roles in angiogenesis, neurogenesis, and synaptogenesis, thereby promoting neurological recovery. In this review, we focus on the functions of the Golgi apparatus and its mediated events during neurorestoration.

Pivotal Role Of The Interaction Between Herbal Medicines And Gut Microbiota On Disease Treatment

2020 ◽  
Vol 21 ◽  
Author(s):  
Tingting Zhao ◽  
Zhe Wang ◽  
Zhilong Liu ◽  
Youhua Xu
Keyword(s):  
Cardiovascular Diseases ◽  
Gut Microbiota ◽  
Neurodegenerative Diseases ◽  
Disease Progression ◽  
Herbal Medicines ◽  
Underlying Mechanism ◽  
Disease Treatment ◽  
Endocrine Diseases ◽  
Health And Disease

: With the recognition of the important role of gut microbiota in both health and disease progression, attempts to modulate its composition as well as its co-metabolism with the organism have attracted special attention. Abundant studies have demonstrated that dysfunction or imbalance of gut microbiota is closely with disease including endocrine diseases, neurodegenerative diseases, tumors, cardiovascular diseases, et al. Herbal medicines have been applied for preventing and treating disease worldwide for hundreds of years. Although the underlying mechanism seems to be complex, one of the important one is through modulating gut microbiota. In this review, co-metabolism between herbal medicines and microbiota, as well as the potential pathways are summarized from most recent published papers.

scholarly journals De Novo designed 13 mer hairpin-peptide arrests insulin and inhibits its aggregation: role of OH–π interactions between water and hydrophobic amino acids

RSC Advances ◽  
2020 ◽  
Vol 10 (25) ◽  
pp. 14991-14999
Author(s):  
Meghomukta Mukherjee ◽  
Nilanjan Banerjee ◽  
Subhrangsu Chatterjee
Keyword(s):  
Amino Acids ◽  
Neurodegenerative Diseases ◽  
Type Ii Diabetes ◽  
De Novo ◽  
Prion Diseases ◽  
Cellular Systems ◽  
Type Ii ◽  
P Protein ◽  
Hydrophobic Amino Acids

Protein aggregation in the cellular systems can be highly fatal causing a series of diseases including neurodegenerative diseases like ALS, Alzheimer, Prion Diseases, Parkinson's and other diseases like type II diabetes.

scholarly journals Exosomes: Innocent Bystanders or Critical Culprits in Neurodegenerative Diseases

2021 ◽  
Vol 9 ◽  
Author(s):  
Margarida Beatriz ◽  
Rita Vilaça ◽  
Carla Lopes
Keyword(s):  
Neurodegenerative Diseases ◽  
Intercellular Communication ◽  
Prion Diseases ◽  
Genetic Material ◽  
Cell Communication ◽  
Protein Aggregates ◽  
Potential Benefits ◽  
The Central Nervous System ◽  
Lateral Sclerosis

Extracellular vesicles (EVs) are nano-sized membrane-enclosed particles released by cells that participate in intercellular communication through the transfer of biologic material. EVs include exosomes that are small vesicles that were initially associated with the disposal of cellular garbage; however, recent findings point toward a function as natural carriers of a wide variety of genetic material and proteins. Indeed, exosomes are vesicle mediators of intercellular communication and maintenance of cellular homeostasis. The role of exosomes in health and age-associated diseases is far from being understood, but recent evidence implicates exosomes as causative players in the spread of neurodegenerative diseases. Cells from the central nervous system (CNS) use exosomes as a strategy not only to eliminate membranes, toxic proteins, and RNA species but also to mediate short and long cell-to-cell communication as carriers of important messengers and signals. The accumulation of protein aggregates is a common pathological hallmark in many neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, and prion diseases. Protein aggregates can be removed and delivered to degradation by the endo-lysosomal pathway or can be incorporated in multivesicular bodies (MVBs) that are further released to the extracellular space as exosomes. Because exosome transport damaged cellular material, this eventually contributes to the spread of pathological misfolded proteins within the brain, thus promoting the neurodegeneration process. In this review, we focus on the role of exosomes in CNS homeostasis, their possible contribution to the development of neurodegenerative diseases, the usefulness of exosome cargo as biomarkers of disease, and the potential benefits of plasma circulating CNS-derived exosomes.

Acquisition of an intracisternal A-particle element by a translocated c-myc gene in a murine plasma cell tumor

1985 ◽  
Vol 5 (12) ◽  
pp. 3625-3628
Author(s):  
R Greenberg ◽  
R Hawley ◽  
K B Marcu
Keyword(s):  
Plasma Cell ◽  
State Level ◽  
Cell Tumor ◽  
Gene Copy ◽  
Plasma Cell Tumor ◽  
Exon 1 ◽  
Myc Gene ◽  
Flanking Sequences ◽  
Intracisternal A Particle

The J558 plasma cell tumor contains two forms of a translocated c-myc gene which are distinguished by virtue of their 3' flanking sequences. The J558 alpha 4 and alpha 25 myc genes are broken by a 12;15 translocation which links c-myc exon 1 to C alpha switch sequences. Comparative restriction mapping and DNA sequence analyses demonstrated that an intracisternal A-particle (IAP) element inserted approximately 2 kilobases 3' of an alpha 4-type myc gene to generate the alpha 25 gene copy. The steady-state level of truncated myc RNAs in J558 was comparable to that in another plasma cell tumor line (MPC-11) which harbors a translocated c-myc locus without an IAP element. The significance of these observations for the putative role of IAP elements in the genesis or progression or both of plasma cell tumors is discussed.

scholarly journals POSCAbilities: The Application of the Prion Organotypic Slice Culture Assay to Neurodegenerative Disease Research

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1079
Author(s):  
Hailey Pineau ◽  
Valerie Sim
Keyword(s):  
Neurodegenerative Diseases ◽  
Prion Diseases ◽  
In Vitro Models ◽  
Slice Culture ◽  
Advantages And Disadvantages ◽  
Organotypic Slice Culture ◽  
Drug Treatments

Prion diseases are fatal, transmissible neurodegenerative disorders whose pathogenesis is driven by the misfolding, self-templating and cell-to-cell spread of the prion protein. Other neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis and Huntington’s disease, share some of these prion-like features, with different aggregation-prone proteins. Consequently, researchers have begun to apply prion-specific techniques, like the prion organotypic slice culture assay (POSCA), to these disorders. In this review we explore the ways in which the prion phenomenon has been used in organotypic cultures to study neurodegenerative diseases from the perspective of protein aggregation and spreading, strain propagation, the role of glia in pathogenesis, and efficacy of drug treatments. We also present an overview of the advantages and disadvantages of this culture system compared to in vivo and in vitro models and provide suggestions for new directions.

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