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https://www.readbyqxmd.com/read/28821639/amyloid-induced-%C3%AE-cell-dysfunction-and-islet-inflammation-are-ameliorated-by-4-phenylbutyrate-pba-treatment
#1
Joel Montane, Sara de Pablo, Carlos Castaño, Júlia Rodríguez-Comas, Lisa Cadavez, Mercè Obach, Montse Visa, Gema Alcarraz-Vizán, Melchor Sanchez-Martinez, Alfons Nonell-Canals, Marcelina Parrizas, Joan-Marc Servitja, Anna Novials
Human islet amyloid polypeptide (hIAPP) aggregation is associated with β-cell dysfunction and death in type 2 diabetes (T2D). we aimed to determine whether in vivo treatment with chemical chaperone 4-phenylbutyrate (PBA) ameliorates hIAPP-induced β-cell dysfunction and islet amyloid formation. Oral administration of PBA in transgenic (Tg) mice expressing hIAPP in pancreatic β cells (hIAPP Tg) counteracted impaired glucose homeostasis and restored glucose-stimulated insulin secretion. Moreover, PBA treatment almost completely prevented the transcriptomic alterations observed in hIAPP Tg islets, including the induction of genes related to inflammation...
August 15, 2017: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
https://www.readbyqxmd.com/read/28821400/alzheimer-s-disease-as-oligomeropathy
#2
REVIEW
Kenjiro Ono
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder and is characterized by pathological aggregates of amyloid β-protein (Aβ) and tau protein. On the basis of genetic evidence, biochemical data, and animal models, Aβ has been suggested to be responsible for the pathogenesis of AD (the amyloid hypothesis). Aβ molecules tend to aggregate to form oligomers, protofibrils, and mature fibrils. Although mature fibrils in the final stage have been thought to be the cause of AD pathogenesis, recent studies using synthetic Aβ peptides, a cell culture model, Aβ precursor protein transgenic mice models, and human samples, such as cerebrospinal fluids and postmortem brains of AD patients, suggest that pre-fibrillar forms (oligomers of Aβ) are more deleterious than are extracellular fibril forms...
August 16, 2017: Neurochemistry International
https://www.readbyqxmd.com/read/28809791/imaging-collagen-in-scar-tissue-developments-in-second-harmonic-generation-microscopy-for-biomedical-applications
#3
REVIEW
Leila Mostaço-Guidolin, Nicole L Rosin, Tillie-Louise Hackett
The ability to respond to injury with tissue repair is a fundamental property of all multicellular organisms. The extracellular matrix (ECM), composed of fibrillar collagens as well as a number of other components is dis-regulated during repair in many organs. In many tissues, scaring results when the balance is lost between ECM synthesis and degradation. Investigating what disrupts this balance and what effect this can have on tissue function remains an active area of research. Recent advances in the imaging of fibrillar collagen using second harmonic generation (SHG) imaging have proven useful in enhancing our understanding of the supramolecular changes that occur during scar formation and disease progression...
August 15, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28807816/mtor-in-down-syndrome-role-in-a%C3%A3-and-tau-neuropathology-and-transition-to-alzheimer-disease-like-dementia
#4
REVIEW
Fabio Di Domenico, Antonella Tramutola, Cesira Foppoli, Elizabeth Head, Marzia Perluigi, D Allan Butterfield
The mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase involved in the regulation of protein synthesis and degradation, longevity and cytoskeletal formation. The mTOR pathway represents a key growth and survival pathway involved in several diseases such as cancer, obesity, cardiovascular disease and neurodegenerative diseases. Numerous studies linked the alterations of mTOR pathway to age-dependent cognitive decline, pathogenesis of Alzheimer disease (AD) and AD-like dementia in Down syndrome (DS)...
August 12, 2017: Free Radical Biology & Medicine
https://www.readbyqxmd.com/read/28803113/how-a-decreased-fibrillar-interconnectivity-influences-stiffness-and-swelling-properties-during-early-cartilage-degeneration
#5
Mieke Nickien, Ashvin Thambyah, Neil D Broom
OBJECTIVE: The functional coupling between the fibrillar network and the high-swelling proteoglycans largely determines the mechanical properties of the articular cartilage matrix. The objective of this new study was to show specifically how changes in fibrillar interconnectivity arising from early cartilage degeneration influence transverse stiffness and swelling properties at the tissue level. DESIGN: Radial zone transverse layers of cartilage matrix were obtained from intact and mildly degenerate bovine patellae...
August 3, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28800220/the-secret-life-of-collagen-temporal-changes-in-nanoscale-fibrillar-pre-strain-and-molecular-organization-during-physiological-loading-of-cartilage
#6
Sheetal R Inamdar, David P Knight, Nicholas J Terrill, Angelo Karunaratne, Fernando Cacho-Nerin, Martin M Knight, Himadri S Gupta
Articular cartilage is a natural biomaterial whose structure at the micro- and nanoscale is critical for healthy joint function and where degeneration is associated with widespread disorders such as osteoarthritis. At the nanoscale, cartilage mechanical functionality is dependent on the collagen fibrils and hydrated proteoglycans that form the extracellular matrix. The dynamic response of these ultrastructural building blocks at the nanoscale, however, remains unclear. Here we measure time-resolved changes in collagen fibril strain, using small angle X-ray diffraction during compression of bovine and human cartilage explants...
August 11, 2017: ACS Nano
https://www.readbyqxmd.com/read/28800009/pathologic-prognostic-factors-of-pineal-parenchymal-tumor-of-intermediate-differentiation
#7
Debajyoti Chatterjee, Khushboo Lath, Navneet Singla, Narendra Kumar, Bishan D Radotra
INTRODUCTION: Pineal parenchymal tumor of intermediate differentiation (PPTID) is an uncommon tumor of the pineal gland. Although this behaves as a grade II/III tumor, the exact clinical behavior is not well known. There is no well-established pathologic factor that can predict the behavior of PPTID. AIM AND OBJECTIVE: The aim of this study was to determine the pathologic prognostic factors in PPTID. MATERIALS AND METHODS: All PPTID cases diagnosed between 2006 and 2016 were analyzed retrospectively...
August 9, 2017: Applied Immunohistochemistry & Molecular Morphology: AIMM
https://www.readbyqxmd.com/read/28798490/investigation-of-neuronal-pathfinding-and-construction-of-artificial-neuronal-networks-on-3d-arranged-porous-fibrillar-scaffolds-with-controlled-geometry
#8
Dongyoon Kim, Seong-Min Kim, Seyeong Lee, Myung-Han Yoon
Herein, we investigated the neurite pathfinding on electrospun microfibers with various fiber densities, diameters, and microbead islands, and demonstrated the development of 3D connected artificial neuronal network within a nanofiber-microbead-based porous scaffold. The primary culture of rat hippocampal embryonic neurons was deposited on geometry-controlled polystyrene (PS) fiber scaffolds while growth cone morphology, neurite outgrowth patterns, and focal adhesion protein expression were cautiously examined by microscopic imaging of immunostained and live neuronal cells derived from actin-GFP transgenic mice...
August 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28797122/cross-seeding-of-prions-by-aggregated-%C3%AE-synuclein-leads-to-transmissible-spongiform-encephalopathy
#9
Elizaveta Katorcha, Natallia Makarava, Young Jin Lee, Iris Lindberg, Mervyn J Monteiro, Gabor G Kovacs, Ilia V Baskakov
Aggregation of misfolded proteins or peptides is a common feature of neurodegenerative diseases including Alzheimer's, Parkinson's, Huntington's, prion and other diseases. Recent years have witnessed a growing number of reports of overlap in neuropathological features that were once thought to be unique to only one neurodegenerative disorder. However, the origin for the overlap remains unclear. One possibility is that diseases with mixed brain pathologies might arise from cross-seeding of one amyloidogenic protein by aggregated states of unrelated proteins...
August 10, 2017: PLoS Pathogens
https://www.readbyqxmd.com/read/28796342/elucidation-of-insulin-assembly-at-acidic-and-neutral-ph-characterization-of-low-molecular-weight-oligomers
#10
Matthew T Mawhinney, Thomas L Williams, James L Hart, Mitra L Taheri, Brigita Urbanc
Deficiency in insulin secretion and function that characterize type 2 diabetes often requires administration of extraneous insulin, leading to injection-site amyloidosis. Insulin aggregation at neutral pH is not well understood. Although oligomer formation is believed to play an important role, insulin oligomers have not been fully characterized yet. Here, we elucidate similarities and differences between in vitro insulin aggregation at acidic and neutral pH for a range of insulin concentrations (2.5-100 μM) by using kinetic thioflavin T fluorescence, circular dichroism, atomic force and electron microscopy imaging...
August 10, 2017: Proteins
https://www.readbyqxmd.com/read/28794461/non-uniform-self-assembly-on-the-anisotropic-architecture-of-%C3%AE-synuclein-supra-fibrillar-aggregates
#11
Slav A Semerdzhiev, Volodymyr V Shvadchak, Vinod Subramaniam, Mireille M A E Claessens
Although the function of biopolymer hydrogels in nature depends on structural anisotropy at mesoscopic length scales, the self-assembly of such anisotropic structures in vitro is challenging. Here we show that fibrils of the protein α-synuclein spontaneously self-assemble into structurally anisotropic hydrogel particles. While the fibrils in the interior of these supra-fibrillar aggregates (SFAs) are randomly oriented, the fibrils in the periphery prefer to cross neighboring fibrils at high angles. This difference in organization coincides with a significant difference in polarity of the environment in the central and peripheral parts of the SFA...
August 9, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28793213/critical-influence-of-cosolutes-and-surfaces-on-the-assembly-of-serpin-derived-amyloid-fibrils
#12
Michael W Risør, Dennis W Juhl, Morten Bjerring, Joachim Mathiesen, Jan J Enghild, Niels C Nielsen, Daniel E Otzen
Many proteins and peptides self-associate into highly ordered and structurally similar amyloid cross-β aggregates. This fibrillation is critically dependent on properties of the protein and the surrounding environment that alter kinetic and thermodynamic equilibria. Here, we report on dominating surface and solution effects on the fibrillogenic behavior and amyloid assembly of the C-36 peptide, a circulating bioactive peptide from the α1-antitrypsin serine protease inhibitor. C-36 converts from an unstructured peptide to mature amyloid twisted-ribbon fibrils over a few hours when incubated on polystyrene plates under physiological conditions through a pathway dominated by surface-enhanced nucleation...
August 8, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28783117/the-role-of-functional-amyloids-in-multicellular-growth-and-development-of-gram-positive-bacteria
#13
REVIEW
Anna Dragoš, Ákos T Kovács, Dennis Claessen
Amyloid fibrils play pivotal roles in all domains of life. In bacteria, these fibrillar structures are often part of an extracellular matrix that surrounds the producing organism and thereby provides protection to harsh environmental conditions. Here, we discuss the role of amyloid fibrils in the two distant Gram-positive bacteria, Streptomyces coelicolor and Bacillus subtilis. We describe how amyloid fibrils contribute to a multitude of developmental processes in each of these systems, including multicellular growth and community development...
August 7, 2017: Biomolecules
https://www.readbyqxmd.com/read/28782426/solvent-sensitivity-of-protein-aggregation-in-cu-zn-superoxide-dismutase-a-molecular-dynamics-simulation-study
#14
Amresh Prakash, Vijay Kumar, Preeti Pandey, Deepak R Bharti, Poonam Vishwakarma, Ruhar Singh, Md Imtaiyaz Hassan, Andrew M Lynn
Misfolding and aggregation of Cu, Zn Superoxide Dismutase (SOD1) is often found in amyotrophic lateral sclerosis (ALS) patients. The central apo SOD1 barrel was involved in protein maturation and pathological aggregation in ALS. In this work, we employed atomistic molecular dynamics (MD) simulations to study the conformational dynamics of SOD1(barrel) monomer in different concentrations of trifluoroethanol (TFE). We find concentration dependence unusual structural and dynamical features, characterized by the local unfolding of SOD1(barrel)...
August 6, 2017: Journal of Biomolecular Structure & Dynamics
https://www.readbyqxmd.com/read/28774673/can-videolaryngoscopy-be-a-first-option-in-a-patient-with-laryngeal-amyloidosis
#15
L España Fuente, G Mella Pérez, B Laserna Cocina, J L González González
Amyloidosis is a term that involves a group of diseases characterised by deposition of extracellular monoclonal light-chain fibrillar immunoglobulin aggregates in the body, including many organs, with the larynx among them. A case is presented of a 78 year-old man who was referred to our institution for strangulated umbilical hernia treatment. He suffered from progressive hoarseness and dysphagia for 5months. He had a history of primary laryngeal amyloidosis. Awake intubation was performed successful with the King Vision(®) video-laryngoscopy...
July 31, 2017: Revista Española de Anestesiología y Reanimación
https://www.readbyqxmd.com/read/28774096/in-situ-soft-x-ray-spectromicroscopy-of-early-tricalcium-silicate-hydration
#16
Sungchul Bae, Manabu Kanematsu, Daniel Hernández-Cruz, Juhyuk Moon, David Kilcoyne, Paulo J M Monteiro
The understanding and control of early hydration of tricalcium silicate (C₃S) is of great importance to cement science and concrete technology. However, traditional characterization methods are incapable of providing morphological and spectroscopic information about in situ hydration at the nanoscale. Using soft X-ray spectromicroscopy, we report the changes in morphology and molecular structure of C₃S at an early stage of hydration. In situ C₃S hydration in a wet cell, beginning with induction (~1 h) and acceleration (~4 h) periods of up to ~8 h, was studied and compared with ex situ measurements in the deceleration period after 15 h of curing...
December 1, 2016: Materials
https://www.readbyqxmd.com/read/28768815/synthesis-and-self-assembly-of-cellulose-microfibrils-from-reconstituted-cellulose-synthase
#17
Sung Hyun Cho, Pallinti Purushotham, Chao Fang, Cassandra Maranas, Sara M Díaz-Moreno, Vincent Bulone, Jochen Zimmer, Manish Kumar, B Tracy Nixon
Cellulose, the major component of plant cell walls, can be converted to bioethanol and is thus highly studied. In plants, cellulose is produced by cellulose synthase, a processive family-2 glycosyltransferase. In plant cell walls, individual β-1,4-glucan chains polymerized by CesA are assembled into microfibrils that are frequently bundled into macrofibrils. An in vitro system in which cellulose is synthesized and assembled into fibrils would facilitate detailed study of this process. Here, we report the heterologous expression and partial purification of His-tagged CesA5 from Physcomitrella patens...
August 2, 2017: Plant Physiology
https://www.readbyqxmd.com/read/28768163/a-protocol-for-quantitative-analysis-of-murine-and-human-amyloid-%C3%AE-1-40-and-1-42
#18
Tomer Illouz, Ravit Madar, Kathleen Griffioen, Eitan Okun
BACKGROUND: Amyloid-β (Aβ), a hallmark of Alzheimer's disease (AD), has long been a focus of basic and translation research in AD. Quantification and dissociation of the Aβ fractions in their soluble and insoluble forms, is a key factor in numerous AD studies. NEW METHOD: Here we provide a generalized sandwich-enzyme-linked-immuno-sorbent-assay (sELISA) protocol for quantification of human and murine Aβ1-40 and Aβ1-42 and dissociation of these peptides to their soluble-oligomeric and insoluble-fibrillar forms...
July 30, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/28768117/cationic-surfactant-mediated-fibrillogenesis-in-bovine-liver-catalase-a-biophysical-approach
#19
MohsinVahid Khan, Masihuz Zaman, TajalliIlm Chandel, Mohammad Khursheed Siddiqui, Mohd Rehan Ajmal, Ali Saber Abdelhameed, RizwanHasan Khan
Protein aggregation into oligomers and mature fibrils are associated with more than 20 diseases in humans. The interactions between cationic surfactants dodecyltrimethylammonium bromide (DTAB) andtetradecyltrimethylammonium bromide (TTAB) with varying alkyl chain lengths and bovine liver catalase (BLC) were examined by various biophysical approaches. The delicate coordination of electrostatic and hydrophobic interactions with protein, play imperative role in aggregation. In this article we have reconnoitered the relation between charge, hydrophobicity and cationic surfactants DTAB and TTAB on BLC at pH 7...
August 2, 2017: Journal of Biomolecular Structure & Dynamics
https://www.readbyqxmd.com/read/28763125/small-molecule-induced-soluble-oligomers-of-%C3%AE-synuclein-with-helical-structure
#20
Luis Fonseca-Ornelas, Carla Schmidt, Aldo R Camacho-Zarco, Claudio O Fernandez, Stefan Becker, Markus Zweckstetter
Accumulation of α-synuclein (αSyn) aggregates constitutes the hallmark of synucleinopathies including Parkinson's disease. However, many steps from the innocuous, monomeric αSyn toward misfolded oligomers and fibrillar species remain unclear. Here, we show that αSyn can form in solution α-helical oligomers, which are off-pathway to fibrillization, through interaction with the tetrapyrrole phthalocyanine tetrasulfonate. Chemical cross-linking combined with mass spectrometry reveals a large number of intermolecular cross-links along the entire αSyn sequence in the phthalocyanine tetrasulfonate-stabilized αSyn oligomers...
August 1, 2017: Chemistry: a European Journal
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