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The pyroptosis execution protein GSDMD is cleaved by inflammasome-activated caspase-1 and LPS-activated caspase-11/4/5. The cleavage unmasks the pore-forming domain from GSDMD-C-terminal domain. How the caspases recognize GSDMD and its connection with caspase activation are unknown. Here, we show site-specific caspase-4/11 autoprocessing, generating a p10 product, is required and sufficient for cleaving GSDMD and inducing pyroptosis. The p10-form autoprocessed caspase-4/11 binds the GSDMD-C domain with a high affinity. Structural comparison of autoprocessed and unprocessed capase-11 identifies a ß sheet induced by the autoprocessing. In caspase-4/11-GSDMD-C complex crystal structures, the ß sheet organizes a hydrophobic GSDMD-binding interface that is only possible for p10-form caspase-4/11. The binding promotes dimerization-mediated caspase activation, rendering a cleavage independently of the cleavage-site tetrapeptide sequence. Crystal structure of caspase-1-GSDMD-C complex shows a similar GSDMD-recognition mode. Our study reveals an unprecedented substrate-targeting mechanism for caspases. The hydrophobic interface suggests an additional space for developing inhibitors specific for pyroptotic caspases.
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Inflamasomas/ultraestructura , Complejos Multiproteicos/ultraestructura , Proteínas de Unión a Fosfato/ultraestructura , Piroptosis/genética , Animales , Caspasa 1/química , Caspasa 1/genética , Caspasa 1/ultraestructura , Caspasas Iniciadoras/química , Caspasas Iniciadoras/genética , Cristalografía por Rayos X , Células HEK293 , Células HeLa , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Inflamasomas/genética , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/genética , Complejos Multiproteicos/química , Complejos Multiproteicos/genética , Proteínas de Unión a Fosfato/química , Proteínas de Unión a Fosfato/genética , Conformación Proteica en Lámina beta/genética , Dominios Proteicos/genética , Procesamiento Proteico-Postraduccional/genética , ProteolisisRESUMEN
Mouse caspase-11 and human caspase-4 and caspase-5 recognize cytosolic lipopolysaccharide (LPS) to induce pyroptosis by cleaving the pore-forming protein GSDMD1-5. This non-canonical inflammasome defends against Gram-negative bacteria6,7. Shigella flexneri, which causes bacillary dysentery, lives freely within the host cytosol where these caspases reside. However, the role of caspase-11-mediated pyroptosis in S. flexneri infection is unknown. Here we show that caspase-11 did not protect mice from S. flexneri infection, in contrast to infection with another cytosolic bacterium, Burkholderia thailandensis8. S. flexneri evaded pyroptosis mediated by caspase-11 or caspase 4 (hereafter referred to as caspase-11/4) using a type III secretion system (T3SS) effector, OspC3. OspC3, but not its paralogues OspC1 and 2, covalently modified caspase-11/4; although it used the NAD+ donor, this modification was not ADP-ribosylation. Biochemical dissections uncovered an ADP-riboxanation modification on Arg314 and Arg310 in caspase-4 and caspase-11, respectively. The enzymatic activity was shared by OspC1 and 2, whose ankyrin-repeat domains, unlike that of OspC3, could not recognize caspase-11/4. ADP-riboxanation of the arginine blocked autoprocessing of caspase-4/11 as well as their recognition and cleavage of GSDMD. ADP-riboxanation of caspase-11 paralysed pyroptosis-mediated defence in Shigella-infected mice and mutation of ospC3 stimulated caspase-11- and GSDMD-dependent anti-Shigella humoral immunity, generating a vaccine-like protective effect. Our study establishes ADP-riboxanation of arginine as a bacterial virulence mechanism that prevents LPS-induced pyroptosis.
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Adenosina Difosfato Ribosa/metabolismo , Arginina/metabolismo , Proteínas Bacterianas/metabolismo , Caspasas Iniciadoras/metabolismo , Evasión Inmune , Piroptosis , Shigella flexneri/patogenicidad , Adenosina Difosfato/metabolismo , Animales , Disentería Bacilar/inmunología , Disentería Bacilar/microbiología , Femenino , Inmunidad Humoral , Inflamasomas/metabolismo , Lipopolisacáridos/farmacología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , NAD/metabolismo , Piroptosis/efectos de los fármacos , Vacunas contra la Shigella , Shigella flexneri/inmunología , VirulenciaRESUMEN
Inflammation biomarkers can provide valuable insight into the role of inflammatory processes in many diseases and conditions. Sequencing based analyses of such biomarkers can also serve as an exemplar of the genetic architecture of quantitative traits. To evaluate the biological insight, which can be provided by a multi-ancestry, whole-genome based association study, we performed a comprehensive analysis of 21 inflammation biomarkers from up to 38 465 individuals with whole-genome sequencing from the Trans-Omics for Precision Medicine (TOPMed) program (with varying sample size by trait, where the minimum sample size was n = 737 for MMP-1). We identified 22 distinct single-variant associations across 6 traits-E-selectin, intercellular adhesion molecule 1, interleukin-6, lipoprotein-associated phospholipase A2 activity and mass, and P-selectin-that remained significant after conditioning on previously identified associations for these inflammatory biomarkers. We further expanded upon known biomarker associations by pairing the single-variant analysis with a rare variant set-based analysis that further identified 19 significant rare variant set-based associations with 5 traits. These signals were distinct from both significant single variant association signals within TOPMed and genetic signals observed in prior studies, demonstrating the complementary value of performing both single and rare variant analyses when analyzing quantitative traits. We also confirm several previously reported signals from semi-quantitative proteomics platforms. Many of these signals demonstrate the extensive allelic heterogeneity and ancestry-differentiated variant-trait associations common for inflammation biomarkers, a characteristic we hypothesize will be increasingly observed with well-powered, large-scale analyses of complex traits.
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Biomarcadores , Estudio de Asociación del Genoma Completo , Inflamación , Medicina de Precisión , Secuenciación Completa del Genoma , Humanos , Medicina de Precisión/métodos , Inflamación/genética , Estudio de Asociación del Genoma Completo/métodos , Secuenciación Completa del Genoma/métodos , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Predisposición Genética a la Enfermedad , Femenino , Interleucina-6/genéticaRESUMEN
Long non-coding RNAs (lncRNAs) are known to perform important regulatory functions in lipid metabolism. Large-scale whole-genome sequencing (WGS) studies and new statistical methods for variant set tests now provide an opportunity to assess more associations between rare variants in lncRNA genes and complex traits across the genome. In this study, we used high-coverage WGS from 66,329 participants of diverse ancestries with measurement of blood lipids and lipoproteins (LDL-C, HDL-C, TC, and TG) in the National Heart, Lung, and Blood Institute (NHLBI) Trans-Omics for Precision Medicine (TOPMed) program to investigate the role of lncRNAs in lipid variability. We aggregated rare variants for 165,375 lncRNA genes based on their genomic locations and conducted rare-variant aggregate association tests using the STAAR (variant-set test for association using annotation information) framework. We performed STAAR conditional analysis adjusting for common variants in known lipid GWAS loci and rare-coding variants in nearby protein-coding genes. Our analyses revealed 83 rare lncRNA variant sets significantly associated with blood lipid levels, all of which were located in known lipid GWAS loci (in a ±500-kb window of a Global Lipids Genetics Consortium index variant). Notably, 61 out of 83 signals (73%) were conditionally independent of common regulatory variation and rare protein-coding variation at the same loci. We replicated 34 out of 61 (56%) conditionally independent associations using the independent UK Biobank WGS data. Our results expand the genetic architecture of blood lipids to rare variants in lncRNAs.
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ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , Estudio de Asociación del Genoma Completo , Medicina de Precisión , Secuenciación Completa del Genoma/métodos , Lípidos/genética , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
Attempts to identify and prioritize functional DNA elements in coding and non-coding regions, particularly through use of in silico functional annotation data, continue to increase in popularity. However, specific functional roles can vary widely from one variant to another, making it challenging to summarize different aspects of variant function with a one-dimensional rating. Here we propose multi-dimensional annotation-class integrative estimation (MACIE), an unsupervised multivariate mixed-model framework capable of integrating annotations of diverse origin to assess multi-dimensional functional roles for both coding and non-coding variants. Unlike existing one-dimensional scoring methods, MACIE views variant functionality as a composite attribute encompassing multiple characteristics and estimates the joint posterior functional probabilities of each genomic position. This estimate offers more comprehensive and interpretable information in the presence of multiple aspects of functionality. Applied to a variety of independent coding and non-coding datasets, MACIE demonstrates powerful and robust performance in discriminating between functional and non-functional variants. We also show an application of MACIE to fine-mapping and heritability enrichment analysis by using the lipids GWAS summary statistics data from the European Network for Genetic and Genomic Epidemiology Consortium.
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Genoma Humano , Estudio de Asociación del Genoma Completo , Genoma Humano/genética , Estudio de Asociación del Genoma Completo/métodos , Genómica , Humanos , Anotación de Secuencia Molecular , Polimorfismo de Nucleótido Simple/genética , ProbabilidadRESUMEN
Large-scale whole-genome sequencing studies have enabled analysis of noncoding rare-variant (RV) associations with complex human diseases and traits. Variant-set analysis is a powerful approach to study RV association. However, existing methods have limited ability in analyzing the noncoding genome. We propose a computationally efficient and robust noncoding RV association detection framework, STAARpipeline, to automatically annotate a whole-genome sequencing study and perform flexible noncoding RV association analysis, including gene-centric analysis and fixed window-based and dynamic window-based non-gene-centric analysis by incorporating variant functional annotations. In gene-centric analysis, STAARpipeline uses STAAR to group noncoding variants based on functional categories of genes and incorporate multiple functional annotations. In non-gene-centric analysis, STAARpipeline uses SCANG-STAAR to incorporate dynamic window sizes and multiple functional annotations. We apply STAARpipeline to identify noncoding RV sets associated with four lipid traits in 21,015 discovery samples from the Trans-Omics for Precision Medicine (TOPMed) program and replicate several of them in an additional 9,123 TOPMed samples. We also analyze five non-lipid TOPMed traits.
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Estudio de Asociación del Genoma Completo , Genoma , Humanos , Estudio de Asociación del Genoma Completo/métodos , Secuenciación Completa del Genoma/métodos , Fenotipo , Variación GenéticaRESUMEN
Although previous studies have reported the sex differences in behavior/cognition and the brain, the sex difference in the relationship between memory abilities and the underlying neural basis in the aging process remains unclear. In this study, we used a machine learning model to estimate the association between cortical thickness and verbal/visuospatial memory in females and males and then explored the sex difference of these associations based on a community-elderly cohort (n = 1153, age ranged from 50.42 to 86.67 years). We validated that females outperformed males in verbal memory, while males outperformed females in visuospatial memory. The key regions related to verbal memory in females include the medial temporal cortex, orbitofrontal cortex, and some regions around the insula. Further, those regions are more located in limbic, dorsal attention, and default-model networks, and are associated with face recognition and perception. The key regions related to visuospatial memory include the lateral prefrontal cortex, anterior cingulate gyrus, and some occipital regions. They overlapped more with dorsal attention, frontoparietal and visual networks, and were associated with object recognition. These findings imply the memory performance advantage of females and males might be related to the different memory processing tendencies and their associated network.
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Reconocimiento Facial , Caracteres Sexuales , Anciano , Humanos , Femenino , Masculino , Persona de Mediana Edad , Anciano de 80 o más Años , Encéfalo , Cognición , CitoplasmaRESUMEN
Large biobank-scale whole genome sequencing (WGS) studies are rapidly identifying a multitude of coding and non-coding variants. They provide an unprecedented resource for illuminating the genetic basis of human diseases. Variant functional annotations play a critical role in WGS analysis, result interpretation, and prioritization of disease- or trait-associated causal variants. Existing functional annotation databases have limited scope to perform online queries and functionally annotate the genotype data of large biobank-scale WGS studies. We develop the Functional Annotation of Variants Online Resources (FAVOR) to meet these pressing needs. FAVOR provides a comprehensive multi-faceted variant functional annotation online portal that summarizes and visualizes findings of all possible nine billion single nucleotide variants (SNVs) across the genome. It allows for rapid variant-, gene- and region-level queries of variant functional annotations. FAVOR integrates variant functional information from multiple sources to describe the functional characteristics of variants and facilitates prioritizing plausible causal variants influencing human phenotypes. Furthermore, we provide a scalable annotation tool, FAVORannotator, to functionally annotate large-scale WGS studies and efficiently store the genotype and their variant functional annotation data in a single file using the annotated Genomic Data Structure (aGDS) format, making downstream analysis more convenient. FAVOR and FAVORannotator are available at https://favor.genohub.org.
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Genoma Humano , Programas Informáticos , Humanos , Anotación de Secuencia Molecular , Genómica , Genotipo , Variación GenéticaRESUMEN
Sex pheromones are pivotal for insect reproduction. However, the mechanism of sex pheromone communication remains enigmatic in hymenopteran parasitoids. Here we have identified the sex pheromone and elucidated the olfactory basis of sex pheromone communication in Campoletis chlorideae (Ichneumonidae), a solitary larval endoparasitoid of over 30 lepidopteran pests. Using coupled gas chromatography-electroantennogram detection, we identified two female-derived pheromone components, tetradecanal (14:Ald) and 2-heptadecanone (2-Hep) (1:4.6), eliciting strong antennal responses from males but weak responses from females. We observed that males but not females were attracted to both single components and the blend. The hexane-washed female cadavers failed to arouse males, and replenishing 14:Ald and 2-Hep could partially restore the sexual attraction of males. We further expressed six C. chlorideae male-biased odorant receptors in Drosophila T1 neurons and found that CchlOR18 and CchlOR47 were selectively tuned to 14:Ald and 2-Hep, respectively. To verify the biological significance of this data, we knocked down CchlOR18 and CchlOR47 individually or together in vivo and show that the attraction of C. chlorideae to their respective ligands was abolished. Moreover, the parasitoids defective in either of the receptors were less likely to court and copulate. Finally, we show that the sex pheromone and (Z)-jasmone, a potent female attractant, can synergistically affect behaviors of virgin males and virgin females and ultimately increase the parasitic efficiency of C. chlorideae. Our study provides new insights into the molecular mechanism of sex pheromone communication in C. chlorideae that may permit manipulation of parasitoid behavior for pest control.
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Receptores Odorantes , Atractivos Sexuales , Masculino , Animales , Insectos , Comunicación , Feromonas , DrosophilaRESUMEN
Accumulating evidence indicates that exosomes help to regulate bone homeostasis. The roles of bone-derived exosomes have been well-described; however, recent studies have shown that some non-bone-derived exosomes have better bone targeting ability than bone-derived exosomes and that their performance as a drug delivery vehicle for regulating bone homeostasis may be better than that of bone-derived exosomes, and the sources of non-bone-derived exosomes are more extensive and can thus be better for clinical needs. Here, we sort non-bone-derived exosomes and describe their composition and biogenesis. Their roles and specific mechanisms in bone homeostasis and bone-related diseases are also discussed. Furthermore, we reveal obstacles to current research and future challenges in the practical application of exosomes, and we provide potential strategies for more effective application of exosomes for the regulation of bone homeostasis and the treatment of bone-related diseases. Video Abstract.
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Exosomas , Vesículas Extracelulares , Huesos , Homeostasis , Sistemas de Liberación de MedicamentosRESUMEN
Contamination events in water distribution networks (WDN) pose significant threats to water supply and public health. Rapid and accurate contamination source identification (CSI) can facilitate the development of remedial measures to reduce impacts. Though many machine learning (ML) methods have been proposed for fast detection, there is a critical need for approaches capturing complex spatial dynamics in WDNs to enhance prediction accuracy. This study proposes a gated graph neural network (GGNN) for CSI in the WDN, incorporating both spatiotemporal water quality data and flow directionality between network nodes. Evaluated across various contamination scenarios, the GGNN demonstrates high prediction accuracy even with limited sensor coverage. Notably, directional connections significantly enhance the GGNN CSI accuracy, underscoring the importance of network topology and flow dynamics in ML-based WDN CSI approaches. Specifically, the method achieves a 92.27% accuracy in narrowing the contamination source to 5 points using just 2 h of sensor data. The GGNN showcases resilience under model and measurement uncertainties, reaffirming its potential for real-time implementation in practice. Moreover, our findings highlight the impact of sensor sampling frequency and measurement accuracy on CSI accuracy, offering practical insights for ML methods in water network applications.
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Calidad del Agua , Abastecimiento de Agua , Redes Neurales de la Computación , Contaminación del Agua , IncertidumbreRESUMEN
SUMMARY: We developed the variant-Set Test for Association using Annotation infoRmation (STAAR) workflow description language (WDL) workflow to facilitate the analysis of rare variants in whole genome sequencing association studies. The open-access STAAR workflow written in the WDL allows a user to perform rare variant testing for both gene-centric and genetic region approaches, enabling genome-wide, candidate and conditional analyses. It incorporates functional annotations into the workflow as introduced in the STAAR method in order to boost the rare variant analysis power. This tool was specifically developed and optimized to be implemented on cloud-based platforms such as BioData Catalyst Powered by Terra. It provides easy-to-use functionality for rare variant analysis that can be incorporated into an exhaustive whole genome sequencing analysis pipeline. AVAILABILITY AND IMPLEMENTATION: The workflow is freely available from https://dockstore.org/workflows/github.com/sheilagaynor/STAAR_workflow. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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Nube Computacional , Programas Informáticos , Flujo de Trabajo , Genoma , Estudio de Asociación del Genoma CompletoRESUMEN
BACKGROUND: Toll-like receptor 2 (TLR2) is a crucial factor in the development of tuberculosis. However, no studies have explored the association between TLR2 polymorphisms and tuberculosis susceptibility. OBJECTIVES: This study aimed to explore the correlation between tuberculosis susceptibility and TLR2 polymorphisms (rs3804099, rs3804100, rs1898830, rs5743708, rs121917864, and (-196-174) del). METHODS: All relevant online databases including PubMed, CNKI, WANFANG DATA, and METSTR-FMRS were systematically searched. STATA17.0 (Stata Corp LP, College Station, Texas, USA) was used. RESULTS: A total of 37 studies, covering six polymorphisms and comprising 9,474 cases and 10,295 controls, were included in this analysis. rs3804099(C vs T: OR = 1.00, 95 % CI: 0.93-1.08, CC + TC vs TT: OR = 1.04, 95 % CI: 0.98-1.10), rs3804100 (C vs T: OR = 1.19, 95 % CI: 0.93-1.07, CC + TC vs TT: OR = 0.97, 95 % CI: 0.89-1.06), rs1898830(G vs A: OR = 0.90, 95 % CI: 0.81-1.00, GG + AG vs AA: OR = 0.87, 95 % CI: 0.67-1.12), (-196 â¼174) del polymorphism (Del vs Ins: OR = 0.93,95 % CI: 0.76-1.14, DD + DI vs II: OR = 0.92,95 % CI: 0.72-1.17). CONCLUSIONS: This study indicated that only the TLR2 rs5743708 polymorphism exhibited a significant association with a higher tuberculosis risk, while TLR2 rs3804099, rs3804100, rs1898830, rs121917864, and (-196-174) del polymorphisms were not associated with tuberculosis susceptibility.
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Receptor Toll-Like 2 , Tuberculosis , Humanos , Receptor Toll-Like 2/genética , Predisposición Genética a la Enfermedad , Polimorfismo Genético/genética , Tuberculosis/genética , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
INTRODUCTION: Accumulating evidence indicates that abnormalities in the composition of gastrointestinal (GI) microbiota play a vital role in stress-related disorders. Both human beings and animals perceive stressful events differently, i.e., resilience or susceptibility. However, the role of GI microbiota in stress resilience/susceptibility and the underlying mechanisms remain largely unknown. METHODS AND RESULTS: Sixty male C57BL/6J mice were exposed to 10-day chronic social defeat stress (CSDS), and 28 were found to be resilient to CSDS. We next analyzed microbiota compositions in the cecum using 16S rDNA gene sequencing, which revealed a significant increase in the relative abundance of Lactobacillus at the genus level in the resilient mice. In subsequent experiments, we found that oral administration of a strain of Lactobacillus (Lactobacillus murinus) for 2 weeks attenuated the increased levels of stress-induced corticosterone and anxiety-like behavior in stress-susceptible mice. The mRNA expression of tryptophan hydroxylase 2 (a rate-limiting enzyme in serotonin [5-HT] synthesis) was also significantly increased in the dorsal raphe nucleus (DR) of stress-susceptible mice. CONCLUSIONS: Lactobacillus contributes to stress resilience, and the DR 5-HT system may play an important role during this process. The above results suggest that certain organisms in the GI tract may play an essential role in stress response and be useful in the prevention and treatment of some stress-related psychiatric disorders, such as depression.
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Serotonina , Derrota Social , Humanos , Ratones , Masculino , Animales , Ratones Endogámicos C57BL , Estrés Psicológico/metabolismo , LactobacillusRESUMEN
Little advance has been made toward developing alternative bottom-up synthetic strategies for N-heterocyclic carbene (NHC)-stabilized gold nanoclusters, although this unique class of nanomaterials has exhibited exciting properties. We report in this work a simple and straightforward approach toward NHC-ligated gold nanoclusters by using imidazolium salts rather than free carbenes or NHC-coordinated gold complexes (NHC-Au-X, X is counterions) as precursors. Illustrated here is a one-pot and one-step preparation of an NHC-stabilized Au13Br4 cluster that features a distinct molecular formula, surface motifs, and assembling modes via chemical reduction of dpaAu, NaOMe, and FNHCBn·HBr by NaBH4 (Hdpa is dipyridylamine; FNHCBn·HBr is 1,3-dibenzyl-5,6-difluoro-1H-benzo[d]imidazole-3-ium bromide). In situ UV-vis and NMR studies have elucidated the base-assisted formation of NHCs from imidazolium salts for the protection of the metal core. This work not only reports a new NHC-ligated superatom that completes the Au13 library, thus facilitating structure-property studies, but also opens the door to explore underlying analogues in a facile and reasonable way.
RESUMEN
Barrier-to-autointegration factor (Banf1) is a small DNA-bridging protein. The binding status of Banf1 to DNA is regulated by its N-terminal phosphorylation and dephosphorylation, which plays a critical role in cell proliferation. Banf1 can be phosphorylated at Ser4 into mono-phosphorylated Banf1, which is further phosphorylated at Thr3 to form di-phosphorylated Banf1. It was observed decades ago that mono-phosphorylated Banf1 cannot bind to DNA. However, the underlying molecular- and atomic-level mechanisms remain unclear. A clear understanding of these mechanisms will aid in interfering with the cell proliferation process for better global health. Herein, we explored the detailed atomic bases of unphosphorylated Banf1-DNA binding and how mono- and di-phosphorylation of Banf1 impair these atomic bases to eliminate its DNA-binding capability, followed by exploring the DNA-binding capability of mono- and di-phosphorylation Banf1, using comprehensive and systematic molecular modelling and molecular dynamics simulations. This work presented in detail the residue-level binding energies, hydrogen bonds and water bridges between Banf1 and DNA, some of which have not been reported. Moreover, we revealed that mono-phosphorylation of Banf1 causes its N-terminal secondary structure changes, which in turn induce significant changes in Banf1's DNA binding surface, thus eliminating its DNA-binding capability. At the atomic level, we also uncovered the alterations in interactions due to the induction of mono-phosphorylation that result in the N-terminal secondary structure changes of Banf1. Additionally, our modelling showed that phosphorylated Banf1 with their dominant N-terminal secondary structures bind to DNA with a significantly lower affinity and the docked binding pose are not stable in MD simulations. These findings help future studies in predicting effect of mutations in Banf1 on its DNA-binding capability and open a novel avenue for the development of therapeutics such as cancer drugs, targeting cell proliferation by inducing conformational changes in Banf1's N-terminal domain.
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Simulación de Dinámica Molecular , Fosforilación , Conformación Molecular , Proliferación Celular , Enlace de HidrógenoRESUMEN
Nicotinic acetylcholine receptors (nAChRs) are widespread throughout the central nervous system. Signaling through nAChRs contributes to numerous higher-order functions, including memory and cognition, as well as abnormalities such as nicotine addiction and neurodegenerative disorders. Although recent studies indicate that the PDZ-containing proteins comprising PSD-95 family co-localize with nicotinic acetylcholine receptors and mediate downstream signaling in the neurons, the mechanisms by which α7nAChRs are regulated remain unclear. Here, we show that the PDZ-LIM domain family protein PDLIM5 binds to α7nAChRs and plays a role in nicotine-induced α7nAChRs upregulation and surface expression. We find that chronic exposure to 1 µM nicotine upregulated α7, ß2-contained nAChRs and PDLIM5 in cultured hippocampal neurons, and the upregulation of α7nAChRs and PDLIM5 is increased more on the cell membrane than the cytoplasm. Interestingly, in primary hippocampal neurons, α7nAChRs and ß2nAChRs display distinct patterns of expression, with α7nAChRs colocalized more with PDLIM5. Furthermore, PDLIM5 interacts with α7nAChRs, but not ß2nAChRs in native brain neurons. Knocking down of PDLIM5 in SH-SY5Y abolishes nicotine-induced upregulation of α7nAChRs. In primary hippocampal neurons, using shRNA against PDLIM5 decreased both surface clustering of α7nAChRs and α7nAChRs-mediated currents. Proteomics analysis and isothermal titration calorimetry (ITC) results show that PDLIM5 interacts with α7nAChRs through the PDZ domain, and the interaction between PDLIM5 and α7nAChRs can be promoted by nicotine. Collectively, our data suggest a novel cellular role of PDLIM5 in the regulation of α7nAChRs, which may be relevant to plastic changes in the nervous system.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Hipocampo/metabolismo , Proteínas con Dominio LIM/metabolismo , Nicotina/farmacología , Receptor Nicotínico de Acetilcolina alfa 7/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Conducta Adictiva/fisiopatología , Línea Celular Tumoral , Membrana Celular/metabolismo , Células HEK293 , Hipocampo/citología , Humanos , Proteínas con Dominio LIM/genética , Neuronas/metabolismo , Dominios Proteicos/fisiología , Interferencia de ARN , ARN Interferente Pequeño/genética , Ratas , Ratas Sprague-Dawley , Transducción de Señal/fisiología , Fumar , Regulación hacia Arriba , Receptor Nicotínico de Acetilcolina alfa 7/biosíntesisRESUMEN
The incidence of heart failure mainly resulting from cardiac hypertrophy and fibrosis increases sharply in post-menopausal women compared with men at the same age, which indicates a cardioprotective role of estrogen. Previous studies in our group have shown that the novel estrogen receptor G Protein Coupled Receptor 30 (GPR30) could attenuate myocardial fibrosis caused by ischemic heart disease. However, the role of GPR30 in myocardial hypertrophy in ovariectomized mice has not been investigated yet. In this study, female mice with bilateral ovariectomy or sham surgery underwent transverse aortic constriction (TAC) surgery. After 8 weeks, mice in the OVX + TAC group exhibited more severe myocardial hypertrophy and fibrosis than mice in the TAC group. G1, the specific agonist of GPR30, could attenuate myocardial hypertrophy and fibrosis of mice in the OVX + TAC group. Furthermore, the expression of LC3II was significantly higher in the OVX + TAC group than in the OVX + TAC + G1 group, which indicates that autophagy might play an important role in this process. An in vitro study showed that G1 alleviated AngiotensionII (AngII)-induced hypertrophy and reduced the autophagy level of H9c2 cells, as revealed by LC3II expression and tandem mRFP-GFP-LC3 fluorescence analysis. Additionally, Western blot results showed that the AKT/mTOR pathway was inhibited in the AngII group, whereas it was restored in the AngII + G1 group. To further verify the mechanism, PI3K inhibitor LY294002 or autophagy activator rapamycin was added in the AngII + G1 group, and the antihypertrophy effect of G1 on H9c2 cells was blocked by LY294002 or rapamycin. In summary, our results demonstrate that G1 can attenuate cardiac hypertrophy and fibrosis and improve the cardiac function of mice in the OVX + TAC group through AKT/mTOR mediated inhibition of autophagy. Thus, this study demonstrates a potential option for the drug treatment of pressure overload-induced cardiac hypertrophy in postmenopausal women.
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Estenosis de la Válvula Aórtica , Proteínas Proto-Oncogénicas c-akt , Ratones , Femenino , Animales , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores de Estrógenos/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Cardiomegalia/tratamiento farmacológico , Cardiomegalia/etiología , Cardiomegalia/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Estenosis de la Válvula Aórtica/patología , Autofagia , Fibrosis , Sirolimus/farmacología , Sirolimus/uso terapéutico , Ratones Endogámicos C57BL , Miocitos Cardíacos/metabolismo , Miocardio/metabolismoRESUMEN
Galectin-10 (Gal-10) forms Charcot-Leyden crystals (CLCs), which play a key role in the symptoms of asthma and allergies and some other diseases. Gal-10 has a carbohydrate-binding site; however, neither the Gal-10 dimer nor the CLCs can bind sugars. To investigate the monomer-dimer equilibrium of Gal-10, high-performance size-exclusion chromatography (SEC) was employed to separate serial dilutions of Gal-10 with and without carbohydrates. We found that both the dimerization and crystallization of Gal-10 were promoted by lactose/galactose binding. A peak position shift for the monomer was observed after treatment with either lactose or galactose, implying that the polarity of the monomer was reduced by lactose/galactose binding. Further experiments indicated that alkaline conditions of pH 8.8 mimicked the lactose/galactose-binding environment, and the time interval between monomers and dimers in the chromatogram decreased from 0.8 min to 0.4 min. Subsequently, the electrostatic potential of the Gal-10 monomers was computed. After lactose/galactose binding, the top side of the monomer shifted from negatively charged to electrically neutral, allowing it to interact with the carbohydrate-binding site of the opposing subunit during dimerization. Since lactose/galactose promotes the crystallization of Gal-10, our findings implied that dairy-free diets (free of lactose/galactose) might be beneficial to patients with CLC-related diseases.
Asunto(s)
Galactosa , Lactosa , Humanos , Lactosa/química , Galactosa/metabolismo , Cristalización , Galectinas/química , Sitios de UniónRESUMEN
Clinical trial results have recently demonstrated that inhibiting inflammation by targeting the interleukin-1ß pathway can offer a significant reduction in lung cancer incidence and mortality, highlighting a pressing and unmet need to understand the benefits of inflammation-focused lung cancer therapies at the genetic level. While numerous genome-wide association studies (GWAS) have explored the genetic etiology of lung cancer, there remains a large gap between the type of information that may be gleaned from an association study and the depth of understanding necessary to explain and drive translational findings. Thus, in this study we jointly model and integrate extensive multiomics data sources, utilizing a total of 40 genome-wide functional annotations that augment previously published results from the International Lung Cancer Consortium (ILCCO) GWAS, to prioritize and characterize single nucleotide polymorphisms (SNPs) that increase risk of squamous cell lung cancer through the inflammatory and immune responses. Our work bridges the gap between correlative analysis and translational follow-up research, refining GWAS association measures in an interpretable and systematic manner. In particular, reanalysis of the ILCCO data highlights the impact of highly associated SNPs from nuclear factor-κB signaling pathway genes as well as major histocompatibility complex mediated variation in immune responses. One consequence of prioritizing likely functional SNPs is the pruning of variants that might be selected for follow-up work by over an order of magnitude, from potentially tens of thousands to hundreds. The strategies we introduce provide informative and interpretable approaches for incorporating extensive genome-wide annotation data in analysis of genetic association studies.