Search

Abstract Activating mutations in NRAS account for 15–20% of melanoma, yet effective anti-NRAS therapies are still lacking. In this study, we unveil the casein kinase 1δ (CK1δ) as an uncharacterized regulator of oncogenic NRAS mutations, specifically Q61R and Q61K, which are the most prevalent NRAS mutations in melanoma. The genetic ablation or pharmacological inhibition of CK1δ markedly destabilizes NRAS mutants and suppresses their oncogenic functions. Moreover, we identify USP46 as a bona fide deubiquitinase of NRAS mutants. Mechanistically, CK1δ directly phosphorylates USP46 and activates its deubiquitinase activity towards NRAS mutants, thus promoting oncogenic NRAS-driven melanocyte malignant transformation and melanoma progression in vitro and in vivo. Our findings underscore the significance of the CK1δ-USP46 axis in stabilizing oncogenic NRAS mutants and provide preclinical evidence that targeting this axis holds promise as a therapeutic strategy for human melanoma harboring NRAS mutations.

Abstract Chemoselective modification of specific residues within a given protein poses a significant challenge, as the microenvironment of amino acid residues in proteins is variable. Developing a universal molecular platform with tunable chemical warheads can provide powerful tools for precisely labeling specific amino acids in proteins. Cysteine and lysine are hot targets for chemoselective modification, but current cysteine/lysine‐selective warheads face challenges due to cross‐reactivity and unstable reaction products. In this study, a versatile fluorescent platform is developed for highly selective modification of cysteine/lysine under biocompatible conditions. Chloro‐ or phenoxy‐substituted NBSe derivatives effectively labeled cysteine residues in the cellular proteome with high specificity. This finding also led to the development of phenoxy‐NBSe phototheragnostic for the diagnosis and activatable photodynamic therapy of GSH‐overexpressed cancer cells. Conversely, alkoxy‐NBSe derivatives are engineered to selectively react with lysine residues in the cellular environment, exhibiting excellent anti‐interfering ability against thiols. Leveraging a proximity‐driven approach, alkoxy‐NBSe probes are successfully designed to demonstrate their utility in bioimaging of lysine deacetylase activity. This study also achieves integrating a small photosensitizer into lysine residues of proteins in a regioselective manner, achieving photoablation of cancer cells activated by overexpressed proteins.

Abstract Covalent probes coupled with chemical proteomics represent a powerful method for investigating small molecule and protein interactions. However, the creation of a reactive warhead within various ligands to form covalent probes has been a major obstacle. Herein, we report a convenient and robust process to assemble a unique electrophile, an α-acyloxyenamide, through a one-step late-stage coupling reaction. This procedure demonstrates remarkable tolerance towards other functional groups and facilitates ligand-directed labeling in proteins of interest. The reactive group has been successfully incorporated into a clinical drug targeting the EGFR L858R mutant, erlotinib, and a pan-kinase inhibitor. The resulting probes have been shown to be able to covalently engage a lysine residue proximal to the ATP-binding pocket of the EGFR L858R mutant. A series of active sites, and Mg2+, ATP-binding sites of kinases, such as K33 of CDK1, CDK2, CDK5 were detected. This is the first report of engaging these conserved catalytic lysine residues in kinases with covalent inhibition. Further application of this methodology to natural products has demonstrated its success in profiling ligandable conserved lysine residues in whole proteome. These findings offer insights for the development of new targeted covalent inhibitors (TCIs).

The solute carrier family 12 (SLC12) of cation-chloride cotransporters (CCCs) comprises potassium chloride cotransporters (KCCs, e.g. KCC1, KCC2, KCC3, and KCC4)-mediated Cl− extrusion, and sodium potassium chloride cotransporters (N[K]CCs, NKCC1, NKCC2, and NCC)-mediated Cl− loading. The CCCs play vital roles in cell volume regulation and ion homeostasis. Gain-of-function or loss-of-function of these ion transporters can cause diseases in many tissues. In recent years, there have been considerable advances in our understanding of CCCs' control mechanisms in cell volume regulations, with many techniques developed in studying the functions and activities of CCCs. Classic approaches to directly measure CCC activity involve assays that measure the transport of potassium substitutes through the CCCs. These techniques include the ammonium pulse technique, radioactive or nonradioactive rubidium ion uptake-assay, and thallium ion-uptake assay. CCCs' activity can also be indirectly observed by measuring γ-aminobutyric acid (GABA) activity with patch-clamp electrophysiology and intracellular chloride concentration with sensitive microelectrodes, radiotracer 36Cl−, and fluorescent dyes. Other techniques include directly looking at kinase regulatory sites phosphorylation, flame photometry, 22Na+ uptake assay, structural biology, molecular modeling, and high-throughput drug screening. This review summarizes the role of CCCs in genetic disorders and cell volume regulation, current methods applied in studying CCCs biology, and compounds developed that directly or indirectly target the CCCs for disease treatments.

This paper investigated the static in vitro degradation behavior of poly(L-lactic acid) (PLLA)-oriented microcellular materials. The study compared the influence of different molecular chains and internal morphological structures on water penetration into the material. Also, the relationship between thse self-accelerated degradation caused by ester bond breakage and reduced material molecular weight and mechanical properties was explored. Furthermore, the mechanism behind the static in vitro degradation of oriented microcellular PLLA materials in simulated human body fluid was explored, laying the foundation for regulating the mechanical performance decline of oriented microcellular biomimetic bone repair materials to match specific bone healing periods.

Objectives: The effectiveness of oseltamivir versus peramivir in children infected with influenza remains unclear. This study aimed to evaluate their effectiveness in young children (aged 0-5 years) infected with severe influenza A virus (IAV) or influenza B virus (IBV). Methods: We analyzed a cohort of 1662 young children with either IAV (N = 1095) or IBV (N = 567) who received oseltamivir or peramivir treatment from January 1, 2018 to March 31, 2022. Propensity score matching methods were applied to match children who were oseltamivir-treated versus peramivir-treated. Results: Children who were IAV-infected and IBV-infected shared similar features, such as influenza-associated symptoms and comorbidities at baseline. Among children infected with IAV with bacterial coinfection, the recovery rate was significantly greater in children treated with oseltamivir than in children treated with peramivir (15.6% vs 4.4%, P = 0.01). The median duration of hospitalization was also shorter in children treated with oseltamivir. Among children infected with IAV without bacterial coinfection, the recovery rate was greater in children treated with oseltamivir than in children treated with peramivir (21.1% vs 3.7%, P = 0.002). However, oseltamivir and peramivir offered similar recovery rates and duration of hospitalization (P >0.05 for both) among children infected with IBV. Conclusion: Oseltamivir and peramivir exhibit similar effectiveness in young children with severe influenza B, whereas oseltamivir demonstrated improved recovery and shorter hospitalization in the treatment of severe influenza A in hospitalized children.

Antimicrobial toxins are secreted by bacteria to kill rival species. Here the authors report the mechanism of inhibition of EsaD, a toxin secreted by some S. aureus strains to kill competitors that lack the antitoxin EsaG, showing marked mechanistic differences to other Type II toxin-antitoxin systems.

This study first prepared a layered intumescent flame retardant (IFR)-graphene oxide (GO). Then, the multi-scale polybutylene terephthalate (PBT) composites were prepared by introducing glass fiber (GF), boron nitride (BN), and nano SiO2 flame retardant synergists of different shapes and sizes. The results showed that the SiO2-containing composites displayed excellent flame resistance with a flame retardant grade of V-0 and a limiting oxygen index (LOI) of 32%. The IFR-GO, PBT, and SiO2 formed a multi-scale network structure where the three additives interacted via hydrogen bonding, catalyzing charring in situ. Finally, the composites were obtained with an excellent flame retardant grade and droplet resistance properties.

Mycobacterium tuberculosis remains a leading cause of infectious disease morbidity and mortality for which new drug combination therapies are needed. Mycobacterial bioenergetics has emerged as a promising space for the development of novel therapeutics. Further to this, unique combinations of respiratory inhibitors have been shown to have synergistic or synthetic lethal interactions, suggesting that combinations of bioenergetic inhibitors could drastically shorten treatment times. Realizing the full potential of this unique target space requires an understanding of which combinations of respiratory complexes, when inhibited, have the strongest interactions and potential in a clinical setting. In this review, we discuss (i) chemical-interaction, (ii) genetic-interaction and (iii) chemical-genetic interaction studies to explore the consequences of inhibiting multiple mycobacterial respiratory components. We provide potential mechanisms to describe the basis for the strongest interactions. Finally, whilst we place an emphasis on interactions that occur with existing bioenergetic inhibitors, by highlighting interactions that occur with alternative respiratory components we envision that this information will provide a rational to further explore alternative proteins as potential drug targets and as part of unique drug combinations.

Objective To investigate the clinical characteristics and antibody distribution as well as evaluate the transfusion efficacy in unexpected antibody positive patients. Methods A total of 12 235 patients from January 1, 2022 to March 31, 2023 who hospitalized in our hospital and applied for blood transfusion were selected, and those with unexpected antibody were included. The clinical data, including gender, age, diagnosis, blood type, history of transfusion and pregnancy were collected for antibody distribution analysis. Patients who received transfusion were grouped according to the DAT results and the components of red blood cells transfused, and the Hb values of each group before and after transfusion were compared. Results Among12 235 patients, 118 were positive for antibody screening, with a prevalence of 0.96%. The antibodies from Rh system were the most common (27.43%, 48/175), followed by MNS system (8.57%, 15/175) and Lewis system (6.29%, 11/175), mainly anti-E (18.29%, 32/175), anti-M (8.00%, 14/175) and anti-Lea (5.71%, 10/175). In addition, 62 transfused patients were divided into group A with suspended red blood cell transfusion and group B with washed red blood cell transfusion for positive DAT, and group C for negative DAT. Hb values (g/L) pre- and post-transfusion were 59.19±15.67 vs 77.52±15.09 in group A, 56.35±14.08 vs 74.44±15.63 in group B, 56.00±12.06 vs 75.00±4.73 in group C, respectively. The Hb values of post-transfusion for three groups were all higher than those of pre-transfusion (P

Mycobacterium tuberculosis remains a leading cause of infectious disease morbidity and mortality for which new drug combination therapies are needed. Mycobacterial bioenergetics has emerged as a promising space for the development of novel therapeutics. Further to this, unique combinations of respiratory inhibitors have been shown to have synergistic or synthetic lethal interactions, suggesting that combinations of bioenergetic inhibitors could drastically shorten treatment times. Realizing the full potential of this unique target space requires an understanding of which combinations of respiratory complexes, when inhibited, have the strongest interactions and potential in a clinical setting. In this review, we discuss (i) chemical-interaction, (ii) geneticinteraction and (iii) chemical-genetic interaction studies to explore the consequences of inhibiting multiple mycobacterial respiratory components. We provide potential mechanisms to describe the basis for the strongest interactions. Finally, whilst we place an emphasis on interactions that occur with existing bioenergetic inhibitors, by highlighting interactions that occur with alternative respiratory components we envision that this information will provide a rational to further explore alternative proteins as potential drug targets and as part of unique drug combinations. [ABSTRACT FROM AUTHOR]

Objective To analyze the profile of perioperative allogenic blood transfusion for single disease in patients who underwent spinal deformity correction surgery and risk factors of the blood transfusion, in order to provide reference for clinical decision making. Methods Clinical data from medical record homepage of 292 patients who underwent elective spinal deformity correction surgery at Chengdu Third People′s Hospital from January 2015 to December 2017 were retrospectively analyzed. Statistical analysis of the transfusion profile of allogeneic blood based on the type of single disease in patients undergoing correction surgery was performed. Multiple factor linear regression analysis was used to identify the risk factors of perioperative allogenic blood transfusion in patients with spinal deformity correction surgery. Hospital length of stay and discharge status were compared between transfusion group and non-transfusion group using Mann Whitney U test and chi-square test respectively. Results The year prevalence of perioperative allogeneic blood transfusion from 2015 to 2017 were 90.38%(47/52), 93.62%(44/47) and 81.35%(157/193), respectively. The prevalence of perioperative allogeneic blood transfusion in patients with kyphotic deformity in ankylosing spondylitis, kyphosis, adolescent idiopathic scoliosis, scoliosis and spinal stenosis were 89.08%(106/119)、79.49%(62/78)、95.24%(40/42)、84.38%(27/32) and 61.90%(13/21), respectively. Multivariate linear regression analysis showed that the regression coefficients for age and osteotomy were -0.060 (P

Objective To retrospectively analyze the characteristics of blood transfusion compatibility detection in patients with delayed serologic transfusion reaction ( DSTR), in order to provide reference for safe and effective blood transfusion in clinical practice. Methods From April 2020 to July 2021, 6 samples of patients who applied for blood type identification, unexpected antibody screening and transfusion from the Third People′s Hospital of Chengdu or People′s Hospital of Sichuan Province were collected. Microcolumn method was used for identification of ABO and RhD blood type of patients; unexpected antibody screening, blood cross-match, antibody identification and direct anti-human globulin tests were also conducted. The sensitizing antibodies on the surface of red blood cells were identified by acid release solution, and the antigen-antibody reaction was enhanced by polyethylene glycol. The patients′ own red blood cells and input red blood cells were separated by capillary high-speed centrifugation, and the surface antigens of red blood cells were detected by serological method. Meanwhile,the characteristics of patients before and after transfusing antigen-positive red blood cells were summarized. Results Anti-E was detected in the plasma of patients 1 and 2, and anti-c,-E were detected in the red blood cell release solution, while anti-C, anti-E, anti-JKa and anti-Fyb were detected in the plasma and red blood cell release solution of patients 3, 4, 5 and 6, respectively. After capillary high-speed centrifugation, antigen-positive red blood cells were detected in the distal end of the blood samples of 6 patients. Conclusion For patients with multiple blood transfusions and a recent history of blood transfusion, when newly emerging erythrocyte antibodies with clinically significance, direct anti-human globulin test(+) or erythrocyte antibody screening(+) are detected, and the patient has no clinical symptoms of hemolysis, it should be suspected as DSTR occurrence, and the transfusion reaction investigation procedure should be initiated in time.

Transfusion-related acute lung injury (TRALI) is a severe adverse event and a leading cause of transfusion-associated death. Its poor associated prognosis is due, in large part, to the current dearth of effective therapeutic strategies. Hence, an urgent need exists for effective management strategies for the prevention and treatment of associated lung edema. Recently, various preclinical and clinical studies have advanced the current knowledge regarding TRALI pathogenesis. In fact, the application of this knowledge to patient management has successfully decreased TRALI-associated morbidity. This article reviews the most relevant data and recent progress related to TRALI pathogenesis. Based on the existing two-hit theory, a novel three-step pathogenesis model composed of a priming step, pulmonary reaction, and effector phase is postulated to explain the process of TRALI. TRALI pathogenesis stage-specific management strategies based on clinical studies and preclinical models are summarized with an explication of their models of prevention and experimental drugs. The primary aim of this review is to provide useful insights regarding the underlying pathogenesis of TRALI to inform the development of preventive or therapeutic alternatives.

Target identification of bioactive compounds within the native cellular environment is important in biomedical research and drug discovery, but it has traditionally been carried out in vitro. Information about how such molecules interact with their endogenous targets (on and off) is currently highly limited. An ideal strategy would be one that recapitulates protein–small molecule interactions in situ (e.g., in living cells) and at the same time enables enrichment of these complexes for subsequent proteome-wide target identification. Similarly, small molecule-based imaging approaches are becoming increasingly available for in situ monitoring of a variety of proteins including enzymes. Chemical proteomic strategies for simultaneous bioimaging and target identification of noncovalent bioactive compounds in live mammalian cells, however, are currently not available. This is due to a lack of photoaffinity labels that are minimally modified from their parental compounds, yet chemically tractable using copper-free bioorthogonal chemistry. We have herein developed novel minimalist linkers containing both an alkyl diazirine and a cyclopropene. We have shown chemical probes (e.g., BD-2) made from such linkers could be used for simultaneous in situ imaging and covalent labeling of endogenous BRD-4 (an important epigenetic protein) via a rapid, copper-free, tetrazine-cyclopropene ligation reaction (k2 > 5 M–1 s–1). The key features of our cyclopropenes, with their unique C-1 linkage to BRD-4-targeting moiety, are their tunable reactivity and solubility, relative stability, and synthetic accessibility. BD-2, which is a linker-modified analogue of (+)-JQ1 (a recently discovered nanomolar protein–protein-interaction inhibitor of BRD-4), was subsequently used in a cell-based proteome profiling experiment for large-scale identification of potential off-targets of (+)-JQ1. Several newly identified targets were subsequently confirmed by preliminary validation experiments. [ABSTRACT FROM AUTHOR]

Summary: Fibroblast heterogeneity has long been recognized in mouse and human lungs, homeostasis, and disease states. However, there is no common consensus on fibroblast subtypes, lineages, biological properties, signaling, and plasticity, which severely hampers our understanding of the mechanisms of fibrosis. To comprehensively classify fibroblast populations in the lung using an unbiased approach, single-cell RNA sequencing was performed with mesenchymal preparations from either uninjured or bleomycin-treated mouse lungs. Single-cell transcriptome analyses classified and defined six mesenchymal cell types in normal lung and seven in fibrotic lung. Furthermore, delineation of their differentiation trajectory was achieved by a machine learning method. This collection of single-cell transcriptomes and the distinct classification of fibroblast subsets provide a new resource for understanding the fibroblast landscape and the roles of fibroblasts in fibrotic diseases. : Xie et al. have analyzed mesenchymal cell subpopulations at single-cell resolution and have demonstrated known subtypes and a newly emerging subtype during pulmonary fibrosis in mouse lung. Keywords: single-cell RNA-seq, fibroblast, lung mesenchymal cells, fibrosis

A birnavirus strain, Paralichthys olivaceus birnavirus (POBV), was isolated and characterized from cultured flounder in China, and its complete genomic sequence was subsequently determined. The virus could induce cytopathic effects (CPE) in four of seven fish cell lines and was resistant to chloroform, 5-iodo-2′-deoxyuridine, acid and alkaline pH, and heat treatment. Purified virus particles had a typical icosahedral shape, with a diameter of approximately 55–60 nm. The genomic segments A and B of POBV were 3,091 and 2,780 bp in length and shared many of the features of the members of the family Birnaviridae. Segment A contained two partially overlapping ORFs encoding a polyprotein, pVP2-VP4-VP3, and a nonstructural protein, VP5, while segment B had only one ORF encoding for the VP1, a viral RNA-dependent RNA polymerase (RdRp). This is the first report about a birnavirus strain from a new non-salmonid host in China and its complete genome sequence. [ABSTRACT FROM AUTHOR]

A straightforward synthesis of indole-2-carboxylic esters was developed through a ligand-free copper-catalysed condensation/coupling/deformylation cascade process from 2-halo aryl aldehydes or ketones with ethyl isocyanoacetate. The reactions proceeded well for most of the 2-iodo-, bromo-, and chlorosubtrates under room temperature or mild conditions. [ABSTRACT FROM AUTHOR]

This article concerns the blow-up solutions of a reaction-diffusion system with nonlocal sources, subject to the homogeneous Dirichlet boundary conditions. The criteria used to identify simultaneous and non-simultaneous blow-up of solutions by using the parameters p and q in the model are proposed. Also, the uniform blow-up profiles in the interior domain are established.

Blood vessels in the tumor periphery have high pericyte coverage and are resistant to vascular disrupting agents (VDAs). VDA treatment resistance leads to a viable peripheral tumor rim that contributes to treatment failure and disease recurrence. Here, we provide evidence to support a hypothesis that shifting the target of VDAs from tumor vessel endothelial cells to pericytes disrupts tumor peripheral vessels and the viable rim, circumventing VDA treatment resistance. Through chemical engineering, we developed Z-GP-DAVLBH (from the tubulin-binding VDA desacetylvinblastine monohydrazide [DAVLBH]) as a prodrug that can be selectively activated by fibroblast activation protein α (FAPα) in tumor pericytes. Z-GP-DAVLBH selectively destroys the cytoskeleton of FAPα-expressing tumor pericytes, disrupting blood vessels both within the core and around the periphery of tumors. As a result, Z-GP-DAVLBH treatment eradicated the otherwise VDA-resistant tumor rim and led to complete regression of tumors in multiple lines of xenografts without producing the drug-related toxicity that is associated with similar doses of DAVLBH. This study demonstrates that targeting tumor pericytes with an FAPα-activated VDA prodrug represents a potential vascular disruption strategy in overcoming tumor resistance to VDA treatments. [ABSTRACT FROM AUTHOR]