Here, we show that four chemically divergent approved drugs reported to inhibit Ebolavirus infection, benztropine, bepridil, paroxetine and sertraline, directly interact with the Ebolavirus ...glycoprotein. Binding of these drugs destabilizes the protein, suggesting that this may be the mechanism of inhibition, as reported for the anticancer drug toremifene and the painkiller ibuprofen, which bind in the same large cavity on the glycoprotein. Crystal structures show that the position of binding and the mode of interaction within the pocket vary significantly between these compounds. The binding constants (K d) determined by thermal shift assay correlate with the protein–inhibitor interactions as well as with the antiviral activities determined by virus cell entry assays, supporting the hypothesis that these drugs inhibit viral entry by binding the glycoprotein and destabilizing the prefusion conformation. Details of the protein–inhibitor interactions of these complexes and their relation with binding affinity may facilitate the design of more potent inhibitors.
Dysregulated Krϋppel-like factor (KLF) gene expression appears in many disease-associated pathologies. In this review, we discuss physiological functions of KLFs in the kidney with a focus on ...potential pharmacological modulation/therapeutic applications of these KLF proteins. KLF2 is critical to maintaining endothelial barrier integrity and preventing gap formations and in prevention of glomerular endothelial cell and podocyte damage in diabetic mice. KLF4 is renoprotective in the setting of AKI and is a critical regulator of proteinuria in mice and humans. KLF6 expression in podocytes preserves mitochondrial function and prevents podocyte apoptosis, while KLF5 expression prevents podocyte apoptosis by blockade of ERK/p38 MAPK pathways. KLF15 is a critical regulator of podocyte differentiation and is protective against podocyte injury. Loss of KLF4 and KLF15 promotes renal fibrosis, while fibrotic kidneys have increased KLF5 and KLF6 expression. For therapeutic modulation of KLFs, continued screening of small molecules will promote drug discoveries targeting KLF proteins.
There are as yet no licensed therapeutics for the COVID-19 pandemic. The causal coronavirus (SARS-CoV-2) binds host cells via a trimeric spike whose receptor binding domain (RBD) recognizes ...angiotensin-converting enzyme 2, initiating conformational changes that drive membrane fusion. We find that the monoclonal antibody CR3022 binds the RBD tightly, neutralizing SARS-CoV-2, and report the crystal structure at 2.4 Å of the Fab/RBD complex. Some crystals are suitable for screening for entry-blocking inhibitors. The highly conserved, structure-stabilizing CR3022 epitope is inaccessible in the prefusion spike, suggesting that CR3022 binding facilitates conversion to the fusion-incompetent post-fusion state. Cryogenic electron microscopy (cryo-EM) analysis confirms that incubation of spike with CR3022 Fab leads to destruction of the prefusion trimer. Presentation of this cryptic epitope in an RBD-based vaccine might advantageously focus immune responses. Binders at this epitope could be useful therapeutically, possibly in synergy with an antibody that blocks receptor attachment.
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•CR3022 binds the RBD of SARS-CoV-2 and shows strong neutralization•Neutralization is by destroying the prefusion spike conformation•CR3022 binds a highly conserved epitope that is inaccessible in prefusion spike protein•CR3022 could have therapeutic potential alone or in synergy with a receptor blocker
Huo et al. find that the antibody CR3022 binds tightly to the receptor binding domain of the SARS-CoV-2 spike at a site different to that used by the receptor. CR3022 effectively neutralizes the virus, and cryo-EM reveals that it disrupts the spike. Such antibodies could have potential as COVID-19 therapeutics.
Infertility is a common complication in diabetic men, mainly due to the loss of germ cells by apoptotic cell death. However, effective and safe approaches to prevent diabetic induction of testicular ...apoptosis for diabetic patients have not been available. Resveratrol (RSV), a group of compounds called polyphenols from plants, has been indicated its promising used clinically for cancers and cardiovascular diseases. Therefore, the present study aimed determining whether RSV attenuates type 1 diabetes (T1D)-induced testicular apoptotic cell death in a mouse model. We found that testicular apoptosis and oxidative stress levels were significantly higher in T1D mice than control mice. In addition, the phosphorylation level of metabolism-related Akt and GSK-3β was downregulated and Akt negative regulators PTEN, PTP1B and TRB3 were upregulated in the T1D group. These effects were partially prevented by RSV treatment. Nrf2 and its downstream genes, such as NQO-1, HO-1, SOD, catalase and metallothionein were significantly upregulated by RSV treatment. In addition, RSV-induced Nrf2 activation was found due to Keap1 degradation, mainly reliant on p62 that functions as an adaptor protein during autophagy. These results indicate that the attenuation of T1D-induced testicular oxidative stress and apoptosis by RSV treatment was mainly related to Akt-mediated Nrf2 activation via p62-dependent Keap1 degradation.
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•First evidence for the resveratrol (RSV) protection from T1D-induced male germ cell apoptosis.•Nrf2 up-regulation and activation plays important role in RSV testis protection from diabetes.•RVS activation of Nrf2 may be due to p62-dependent autophagic degradation of Keap1.
The hot rolled 2024 Al alloy subjected to electropulsing was investigated in this study. The results show that the electropulsing treated sample with optimized parameter exhibits notable improvement ...of mechanical properties and greatly refined microstructure. The main grain refinement mechanism is recognized as rapid recrystallization under EPT. It is a promising method of processing techniques to optimize the mechanical behavior.
•The electropulsing was conducted on the hot rolled 2024 Al alloys.•The electropulsing remarkably improved the mechanical properties and microstructrue..•The mechanism of the grain refinement was regarded as the rapid recrystallization.
The interrelationship between ionizing radiation and the immune system is complex, multifactorial, and dependent on radiation dose/quality and immune cell type. High-dose radiation usually results in ...immune suppression. On the contrary, low-dose radiation (LDR) modulates a variety of immune responses that have exhibited the properties of immune hormesis. Although the underlying molecular mechanism is not fully understood yet, LDR has been used clinically for the treatment of autoimmune diseases and malignant tumors. These advancements in preclinical and clinical studies suggest that LDR-mediated immune modulation is a well-orchestrated phenomenon with clinical potential. We summarize recent developments in the understanding of LDR-mediated immune modulation, with an emphasis on its potential clinical applications.
Interaction of the SARS-CoV-2 Spike receptor binding domain (RBD) with the receptor ACE2 on host cells is essential for viral entry. RBD is the dominant target for neutralizing antibodies, and ...several neutralizing epitopes on RBD have been molecularly characterized. Analysis of circulating SARS-CoV-2 variants has revealed mutations arising in the RBD, N-terminal domain (NTD) and S2 subunits of Spike. To understand how these mutations affect Spike antigenicity, we isolated and characterized >100 monoclonal antibodies targeting epitopes on RBD, NTD, and S2 from SARS-CoV-2-infected individuals. Approximately 45% showed neutralizing activity, of which ∼20% were NTD specific. NTD-specific antibodies formed two distinct groups: the first was highly potent against infectious virus, whereas the second was less potent and displayed glycan-dependant neutralization activity. Mutations present in B.1.1.7 Spike frequently conferred neutralization resistance to NTD-specific antibodies. This work demonstrates that neutralizing antibodies targeting subdominant epitopes should be considered when investigating antigenic drift in emerging variants.
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•Potent nAbs were isolated from an asymptomatic donor with low plasma neutralization•RBD-specific nAbs target epitopes overlapping with known RBD antibody classes•NTD mutations in B.1.1.7 Spike confer neutralization resistance to NTD-specific nAbs•Most RBD-specific nAbs retain potent neutralization of the B.1.1.7 variant
The impact of mutations arising in SARS-CoV-2 Spike on antigenicity is still not known. Graham et al. isolate potent neutralizing monoclonal antibodies from individuals experiencing a range of COVID-19 disease severity that target RBD, NTD, and non-S1 epitopes. The B.1.1.7 variant of concern was most resistant to NTD-specific nAbs whereas RBD-specific nAbs retained potent neutralization.
High-strength low-alloy steels are widely used, but their traditional heat-treatment process is complex, energy-intensive, and makes it difficult to fully exploit the material’s potential. In this ...paper, the electropulsing processing technology was applied to the quenching and tempering process of ZG25SiMn2CrB steel. Through microstructural characterization and mechanical property testing, the influence of electropulsing on the solid-state phase transition process of annealing steel was systematically studied. The heating process of the specimen with the annealing state (initial state) is the diffusion-type transition. As the discharge time increased, the microstructure gradually transformed from ferrite/pearlitic to slate martensite. Optimal mechanical properties and fine microstructure were achieved after quenching at 500 ms. The steel subjected to rapid tempering with 160 ms electropulsing exhibited good, comprehensive mechanical properties (tensile strength 1609 MPa, yield strength 1401.27 MPa, elongation 11.63%, and hardness 48.68 HRC). These favorable mechanical properties are attributed to the coupled impact of thermal and non-thermal effects induced by high-density pulse current. Specifically, the thermal effect provides the thermodynamic conditions for phase transformation, while the non-thermal effect reduces the nucleation barrier of austenite, which increases the nucleation rate during instantaneous heating, and the following rapid cooling suppresses the growth of austenite grains. Additionally, the fine microstructure prevents the occurrence of temper brittleness.
We use NMR directly in live human cells to describe the complete post-translational maturation process of human superoxide dismutase 1 (SOD1). We follow, at atomic resolution, zinc binding, homodimer ...formation and copper uptake, and discover that copper chaperone for SOD1 oxidizes the SOD1 intrasubunit disulfide bond through both copper-dependent and copper-independent mechanisms. Our approach represents a new strategy for structural investigation of endogenously expressed proteins in a physiological (cellular) environment.
2-D metallic photonic crystals without defects, with point defects, and with a Fabry-Perot (F-P) defect are characterized by terahertz time-domain spectroscopy. The metal parallel-plate waveguide ...(PPWG) with single TEM-mode propagation is used as a tool to simulate 2-D photonic crystals in free space. The 2-D metallic photonic-crystal structures were fabricated by coating Au on an SU-8 polymer cylinder array. Wide terahertz bandgaps were observed in the photonic crystals within the PPWG. The experimental measurements have excellent agreement to 2-D photonic-crystal theory without defects. Defect modes are observed in the samples with defects and show the F-P defect has a strong localization effect
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