40 research outputs found
Lysozyme Fibrils Alter the Mechanism of Insulin Amyloid Aggregation.
Protein aggregation into amyloid fibrils is linked to multiple disorders. The understanding of how natively non-harmful proteins convert to these highly cytotoxic amyloid aggregates is still not sufficient, with new ideas and hypotheses being presented each year. Recently it has been shown that more than one type of protein aggregates may co-exist in the affected tissue of patients suffering from amyloid-related disorders, sparking the idea that amyloid aggregates formed by one protein may induce another protein's fibrillization. In this work, we examine the effect that lysozyme fibrils have on insulin amyloid aggregation. We show that not only do lysozyme fibrils affect insulin nucleation, but they also alter the mechanism of its aggregation
Investigation of lanthanum substitution effects in yttrium aluminium garnet: importance of solid state NMR and EPR methods
Copyright © 2020, Springer Science Business Media, LLC, part of Springer NatureIn this study, yttrium aluminium garnet (YAG) specimens in which yttrium was partially substituted by lanthanum Y3-xLaxAl5O12 (YLaAG) were prepared by an aqueous sol-gel method. YLaAG samples were analyzed by X-ray diffraction (XRD), solid state nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) methods. The presence of Ce3+ ions as an impurity originating from starting material was determined, therefore, luminescence measurements of YLaAG samples were also recorded. It was demonstrated that luminescent properties are strongly dependent on the phase composition of synthesized species. The XRD analysis results showed that only low substitution of yttrium by lanthanum is possible in Y3-xLaxAl5O12 without destroying garnet crystal structure. It was also demonstrated, that solid state NMR and EPR methods are indispensable tools for the explanation of processes and properties observed in the newly synthesized Y3-xLaxAl5O12 compounds. ---- / / / ---- This is the preprint version of the following article: Laurikenas, A., Sakalauskas, D., Marsalka, A. et al. Investigation of lanthanum substitution effects in yttrium aluminium garnet: importance of solid state NMR and EPR methods. J Sol-Gel Sci Technol (2020). https://doi.org/10.1007/s10971-020-05445-2, which has been published in final form at https://link.springer.com/article/10.1007/s10971-020-05445-2. This article may be used for non-commercial purposes in accordance with Springer Terms and Conditions for Sharing and Self-Archiving.This work was supported by a Research grant NEGEMAT (No. S-MIP-19-59) from the Research Council of Lithuania. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²
Eosinophils enhance WNT-5a and TGF-β1 genes expression in airway smooth muscle cells and promote their proliferation by increased extracellular matrix proteins production in asthma
BACKGROUND: Recent studies have suggested that eosinophils may have a direct effect on airway smooth muscle cells (ASMC), causing their proliferation in patients with asthma, but the precise mechanism of the interaction between these cells remains unknown. We propose that changes in Wnt signaling activity and extracellular matrix (ECM) production may help explain these findings. Therefore, the aim of this study was to investigate the effect of eosinophils from asthmatic and non-asthmatic subjects on Wnt-5a, transforming growth factor β1 (TGF-β1), and ECM protein (fibronectin and collagen) gene expression and ASMC proliferation. METHODS: A total of 18 subjects were involved in the study: 8 steroid-free asthma patients and 10 healthy subjects. Peripheral blood eosinophils were isolated using centrifugation and magnetic separation. An individual co-culture of eosinophils with human ASMC was prepared for each study subject. Adhesion of eosinophils to ASMC (evaluated by assaying eosinophil peroxidase activity) was determined following various incubation periods (30, 45, 60, 120, and 240 min). The expression of Wnt-5a, TGF-β1, and ECM protein genes in ASMC was measured using quantitative real-time polymerase chain reaction (PCR) after 24 h of co-culture. Proliferation of ASMC was measured using the Alamar blue method after 48 h and 72 h of co-culture with eosinophils. RESULTS: Eosinophils from asthmatic subjects demonstrated increased adhesion to ASMC compared with eosinophils from healthy subjects (p < 0.05) in vitro. The expression of Wnt-5a, TGF-β1, collagen, and fibronectin genes in ASMC was significantly higher after 24 h of co-culture with eosinophils from asthmatic subjects, while co-culture of ASMC with eosinophils from healthy subjects increased only TGF-β1 and fibronectin gene expression. ASMC proliferation was augmented after co-culture with eosinophils from asthma patients compared with co-culture with eosinophils from healthy subjects (p < 0.05). CONCLUSIONS: Eosinophils enhance Wnt-5a, TGF-β1, fibronectin, and collagen gene expression in ASMC and promote proliferation of these cells in asthma. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02648074
Ultrasonographic (TCS) and clinical findings in overlapping phenotype of essential tremor and Parkinson’s disease (ET-PD)
BaltymĹł amiloidinÄ—s agregacijos slopinimo tyrimai
Alzheimer’s and Parkinson’s diseases are the most common forms of neurodegeneration. Despite the difference in cognitive symptoms, affected regions in the brain and the rate of disease progression, their pathophysiological hallmark is similar and considered to be linked with protein aggregation into insoluble particles that accumulate in the cerebrum. The projected steady increase in future patients has led to various drug research and clinical trials. However, the success rate of these trials showcases the need for further studies to deepen the knowledge about the potential drugs and improve drug research methods. In this thesis, polyphenolic nature molecules (epigallocatechin-3-gallate (EGCG), gallic acid and various hydroxyflavones) were investigated to understand their inhibitory potential against protein aggregation. While the portion of these molecules autoxidize at neutral or higher pH, the investigation was done with the initial and autoxidized forms. It was evident that autoxidation is a crucial process enabling their inhibitory potential against protein aggregation. In addition to that, during the study with a large number of flavones, the relationship between the structure of flavone, its autoxidation and aggregation inhibition was established. Another part of this thesis was dedicated to understanding whether cerebrospinal fluid components are critical during the in vitro anti-amyloid molecules screening procedure. Analyzing the inhibition of amyloid-beta aggregation in the reaction mixture with major CSF components showed the pronounced effect of these components not only on the inhibitory potential of benzenesulfonamide VR16-09 and oxidized EGCG but also on the amyloid beta aggregation
Officer Career in the Lithuanian Armed Forces
Dynamic and global political, social and economic environment encourages Lithuania government to seek better economic indicators, participate in EU, NATO processes, to optimize the officers and civil service management. Under current circumstances, the National Defence system must be able to adapt to the changing geopolitical environment, execute tasks ahead of nationwide and international obligations. During transformation process it is important to maintain a skilled and motivated staff which will help the organization to achieve strategic objectives. Correct career planning and management is one of the ways to optimize the entire process of organizational management, because employee qualifications, initiative, motivation and tolerance level determined by the organization and processes efficiency. In this master work Lithuanian military officer career management system has been analyzed and evaluated also identified the main career system problems. The theoretical part provides an overview of the career concept of the importance of human resources management, career process influencing internal and external factors, career development and design trends of the changing concept of a career. The exploratory part of the study presents the methodology of the legislation governing the Lithuanian Military career analysis and comparison with the provisions of modern management provisions questionnaire survey results and analysis. The design part of the action plan is intended officer career management organization and processes system of National Defence and the Lithuanian Armed Forces to improve and provide the officer career system improvement strategy, the conclusions and recommendations
Officer Career in the Lithuanian Armed Forces
Dynamic and global political, social and economic environment encourages Lithuania government to seek better economic indicators, participate in EU, NATO processes, to optimize the officers and civil service management. Under current circumstances, the National Defence system must be able to adapt to the changing geopolitical environment, execute tasks ahead of nationwide and international obligations. During transformation process it is important to maintain a skilled and motivated staff which will help the organization to achieve strategic objectives. Correct career planning and management is one of the ways to optimize the entire process of organizational management, because employee qualifications, initiative, motivation and tolerance level determined by the organization and processes efficiency. In this master work Lithuanian military officer career management system has been analyzed and evaluated also identified the main career system problems. The theoretical part provides an overview of the career concept of the importance of human resources management, career process influencing internal and external factors, career development and design trends of the changing concept of a career. The exploratory part of the study presents the methodology of the legislation governing the Lithuanian Military career analysis and comparison with the provisions of modern management provisions questionnaire survey results and analysis. The design part of the action plan is intended officer career management organization and processes system of National Defence and the Lithuanian Armed Forces to improve and provide the officer career system improvement strategy, the conclusions and recommendations
Autoxidation Enhances Anti-Amyloid Potential of Flavone Derivatives
The increasing prevalence of amyloid-related disorders, such as Alzheimer’s or Parkinson’s disease, raises the need for effective anti-amyloid drugs. It has been shown on numerous occasions that flavones, a group of naturally occurring anti-oxidants, can impact the aggregation process of several amyloidogenic proteins and peptides, including amyloid-beta. Due to flavone autoxidation at neutral pH, it is uncertain if the effective inhibitor is the initial molecule or a product of this reaction, as many anti-amyloid assays attempt to mimic physiological conditions. In this work, we examine the aggregation-inhibiting properties of flavones before and after they are oxidized. The oxidation of flavones was monitored by measuring the UV-vis absorbance spectrum change over time. The protein aggregation kinetics were followed by measuring the amyloidophilic dye thioflavin-T (ThT) fluorescence intensity change. Atomic force microscopy was employed to image the aggregates formed with the most prominent inhibitors. We demonstrate that flavones, which undergo autoxidation, have a far greater potency at inhibiting the aggregation of both the disease-related amyloid-beta, as well as a model amyloidogenic protein—insulin. Oxidized 6,2′,3′-trihydroxyflavone was the most potent inhibitor affecting both insulin (7-fold inhibition) and amyloid-beta (2-fold inhibition). We also show that this tendency to autoxidize is related to the positions of the flavone hydroxyl groups
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Lysozyme Fibrils Alter the Mechanism of Insulin Amyloid Aggregation.
Protein aggregation into amyloid fibrils is linked to multiple disorders. The understanding of how natively non-harmful proteins convert to these highly cytotoxic amyloid aggregates is still not sufficient, with new ideas and hypotheses being presented each year. Recently it has been shown that more than one type of protein aggregates may co-exist in the affected tissue of patients suffering from amyloid-related disorders, sparking the idea that amyloid aggregates formed by one protein may induce another protein's fibrillization. In this work, we examine the effect that lysozyme fibrils have on insulin amyloid aggregation. We show that not only do lysozyme fibrils affect insulin nucleation, but they also alter the mechanism of its aggregation
Identifying insulin fibril conformational differences by thioflavin-T binding characteristics
Amyloidogenic protein aggregation into highly structured fibrils is linked to more than 30 amyloidoses, including several neurodegenerative disorders. Despite significant progress in trying to understand the process of amyloid formation, there is still no cure or effective treatment available. A number of studies involving potential anti-amyloid compounds rely on the use of a fluorescent probe-thioflavin-T-to track the appearance, growth, or disassembly of these cytotoxic aggregates. Despite the wide application of this dye molecule, its interaction with amyloid fibrils is still poorly understood. Recent reports have shown it may possess distinct binding modes and fluorescence intensities based on the conformation of the examined fibrils. In this work, we generate insulin fibrils under four different conditions and attempt to identify distinct conformations using both classic methods, such as atomic force microscopy and Fourier-transform infrared spectroscopy, as well as their ThT binding ability and fluorescence quantum yield. We show that there is a significant variance of ThT fluorescence quantum yields, excitation/emission maxima positions, and binding modes between distinct insulin fibril conformations