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This study established an LPS-induced RAW264.7 macrophage inflammatory injury model and an AS mouse vulnerable plaque model to observe the effect of JPHYP on macrophage inflammation, plaque formation, blood lipids, inflammation levels, intestinal flora and the influence of TLR4/MyD88/MAPK pathway, and explore the anti-AS effect and molecular mechanism of JPHYP, and detected 16S rRNA of mice intestinal microbes. The difference of intestinal flora in different groups of mice was compared to further explore the intervention effect of JPHYP and clarify the molecular biological mechanism of JPHYP in preventing and treating AS by regulating TLR4/MyD88/MAPK inflammatory signaling pathway and improving intestinal flora.
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Bitter taste receptors, particularly TAS2R14, play central roles in discerning a wide array of bitter substances, ranging from dietary components to pharmaceutical agents1,2. TAS2R14 is also widely expressed in extragustatory tissues, suggesting its extra roles in diverse physiological processes and potential therapeutic applications3. Here we present cryogenic electron microscopy structures of TAS2R14 in complex with aristolochic acid, flufenamic acid and compound 28.1, coupling with different G-protein subtypes. Uniquely, a cholesterol molecule is observed occupying what is typically an orthosteric site in class A G-protein-coupled receptors. The three potent agonists bind, individually, to the intracellular pockets, suggesting a distinct activation mechanism for this receptor. Comprehensive structural analysis, combined with mutagenesis and molecular dynamic simulation studies, elucidate the broad-spectrum ligand recognition and activation of the receptor by means of intricate multiple ligand-binding sites. Our study also uncovers the specific coupling modes of TAS2R14 with gustducin and Gi1 proteins. These findings should be instrumental in advancing knowledge of bitter taste perception and its broader implications in sensory biology and drug discovery.
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Ácidos Aristolóquicos , Colesterol , Ácido Flufenámico , Receptores Acoplados a Proteínas G , Gusto , Humanos , Ácidos Aristolóquicos/metabolismo , Ácidos Aristolóquicos/química , Ácidos Aristolóquicos/farmacología , Sitios de Unión/efectos de los fármacos , Colesterol/química , Colesterol/metabolismo , Colesterol/farmacología , Microscopía por Crioelectrón , Ácido Flufenámico/química , Ácido Flufenámico/metabolismo , Ácido Flufenámico/farmacología , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/química , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Ligandos , Modelos Moleculares , Simulación de Dinámica Molecular , Mutación , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/ultraestructura , Gusto/efectos de los fármacos , Gusto/fisiología , Transducina/química , Transducina/metabolismoRESUMEN
Nasopharyngeal carcinoma (NPC) originates in the epithelial cells of the nasopharynx and is a common malignant tumor in southern China and Southeast Asia. Metastasis of NPC remains the main cause of death for NPC patients even though the tumor is sensitive to radiotherapy and chemotherapy. Here, we found that the transmembrane protein tetraspanin1 (TSPAN1) potently inhibited the in vitro migration and invasion, as well as, the in vivo metastasis of NPC cells via interacting with the IKBB protein. In addition, TSPAN1 was essential in preventing the overactivation of the NF-kB pathway in TSPAN1 overexpressing NPC cells. Furthermore, reduced TSPAN1 expression was associated with NPC metastasis and the poor prognosis of NPC patients. These results uncovered the suppressive role of TSPAN1 against NF-kB signaling in NPC cells for preventing NPC metastasis. Its therapeutic value warrants further investigation.
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Carcinoma , Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/patología , FN-kappa B/genética , FN-kappa B/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Línea Celular Tumoral , Transducción de Señal , Movimiento Celular/genética , Regulación Neoplásica de la Expresión Génica , Tetraspaninas/genética , Tetraspaninas/metabolismoRESUMEN
The GPR139 receptor is an orphan G-protein-coupled receptor (GPCR) mainly found in the central nervous system and is a potential therapeutic target for the treatment of schizophrenia and drug addiction. Guided by the reported structure of GPR139, we conducted medicinal chemistry optimizations of TAK-041, the GPR139 agonist in clinical trials. New compounds with three different core structures were designed and synthesized, and their activity at GPR139 was evaluated. Among them, compounds 15a (EC50 = 31.4 nM) and 20a (EC50 = 24.7 nM) showed potent agonist activity at GPR139 and good pharmacokinetic properties. In murine schizophrenia models, both compounds rescued the social interaction deficits observed in BALB/c mice. Compound 20a also alleviated cognitive deficits in mice with a pharmacologically induced model of schizophrenia. These findings further demonstrated the potential of GPR139 agonists in alleviating the negative symptoms and cognitive deficits of schizophrenia. Compound 20a is worth further evaluation as an antischizophrenia drug candidate.
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Disfunción Cognitiva , Interacción Social , Ratones , Animales , Receptores Acoplados a Proteínas G/agonistas , Triazinas , Disfunción Cognitiva/tratamiento farmacológicoRESUMEN
BACKGROUND: Hepatocellular carcinoma (HCC) is difficult to diagnose with poor therapeutic effect, high recurrence rate and has a low survival rate. The survival of patients with HCC is closely related to the stage of diagnosis. At present, no specific serological indicator or method to predict HCC, early diagnosis of HCC remains a challenge, especially in China, where the situation is more severe. AIM: To identify risk factors associated with HCC and establish a risk prediction model based on clinical characteristics and liver-related indicators. METHODS: The clinical data of patients in the Affiliated Hospital of North Sichuan Medical College from 2016 to 2020 were collected, using a retrospective study method. The results of needle biopsy or surgical pathology were used as the grouping criteria for the experimental group and the control group in this study. Based on the time of admission, the cases were divided into training cohort (n = 1739) and validation cohort (n = 467). Using HCC as a dependent variable, the research indicators were incorporated into logistic univariate and multivariate analysis. An HCC risk prediction model, which was called NSMC-HCC model, was then established in training cohort and verified in validation cohort. RESULTS: Logistic univariate analysis showed that, gender, age, alpha-fetoprotein, and protein induced by vitamin K absence or antagonist-II, gamma-glutamyl transferase, aspartate aminotransferase and hepatitis B surface antigen were risk factors for HCC, alanine aminotransferase, total bilirubin and total bile acid were protective factors for HCC. When the cut-off value of the NSMC-HCC model joint prediction was 0.22, the area under receiver operating characteristic curve (AUC) of NSMC-HCC model in HCC diagnosis was 0.960, with sensitivity 94.40% and specificity 95.35% in training cohort, and AUC was 0.966, with sensitivity 90.00% and specificity 94.20% in validation cohort. In early-stage HCC diagnosis, the AUC of NSMC-HCC model was 0.946, with sensitivity 85.93% and specificity 93.62% in training cohort, and AUC was 0.947, with sensitivity 89.10% and specificity 98.49% in validation cohort. CONCLUSION: The newly NSMC-HCC model was an effective risk prediction model in HCC and early-stage HCC diagnosis.
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Distant metastasis is the primary reason for treatment failure in patients with nasopharyngeal carcinoma (NPC). In this study, we investigated the effect of ulinastatin (UTI) on NPC metastasis and its underlying mechanism. Highly-metastatic NPC cell lines S18 and 58F were treated with UTI and the effect on cell proliferation, migration, and invasion were determined by MTS and Transwell assays. S18 cells with luciferase-expressing (S18-1C3) were injected into the left hind footpad of nude mice to establish a model of spontaneous metastasis from the footpad to popliteal lymph node (LN). The luciferase messenger RNA (mRNA) was measured by quantitative polymerase chain reaction (qPCR), and the metastasis inhibition rate was calculated. Key molecular members of the UTI-related uPA, uPAR, and JAT/STAT3 signaling pathways were detected by qPCR and immunoblotting. UTI suppressed the migration and infiltration of S18 and 5-8F cells and suppressed the metastasis of S18 cells in vivo without affecting cell proliferation. uPAR expression decreased from 24 to 48 h after UTI treatment. The antimetastatic effect of UTI is partly due to the suppression of uPA and uPAR. UTI partially suppresses NPC metastasis by downregulating the expression of uPA and uPAR.
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Neoplasias Nasofaríngeas , Animales , Ratones , Humanos , Carcinoma Nasofaríngeo/tratamiento farmacológico , Carcinoma Nasofaríngeo/metabolismo , Carcinoma Nasofaríngeo/patología , Ratones Desnudos , Línea Celular Tumoral , Neoplasias Nasofaríngeas/tratamiento farmacológico , Neoplasias Nasofaríngeas/patología , Luciferasas , Movimiento Celular , Invasividad Neoplásica , Metástasis de la NeoplasiaRESUMEN
The effect of polydopamine (PDA) modification on aminated Fe3O4 nanoparticles (Fe3O4-NH2)/graphite oxide (GO)/ß-cyclodextrin polymer cross-linked by citric acid (CDP-CA) composites were studied for the removal of a cationic dye (methylene blue, MB) and an anionic dye (Congo red, CR) from waters. The micro-structural and magnetic characterizations confirmed the successful preparation of Fe3O4-NH2/GO/CDP-CA and PDA/Fe3O4-NH2/GO/CDP-CA composites. The maximum MB and CR adsorption capacities of Fe3O4-NH2/GO/CDP-CA were 75 mg/g and 104 mg/g, respectively, while the corresponding amounts for PDA/Fe3O4-NH2/GO/CDP-CA composite were 195 mg/g and 64 mg/g, respectively. The dye sorption behaviors of these two composites were explained by their corresponding surface-charged properties according to the measured zeta potential results. Moreover, the high saturation magnetizations and the stable dye removal rate in the adsorption-desorption cycles indicated the good recyclability and reusability of the fabricated composites.
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Ciclodextrinas , Grafito , Grafito/química , Ácido Cítrico , Óxidos/química , Adsorción , Fenómenos MagnéticosRESUMEN
The hydroxycarboxylic acid receptor 2 (HCA2) agonist niacin has been used as treatment for dyslipidemia for several decades albeit with skin flushing as a common side-effect in treated individuals. Extensive efforts have been made to identify HCA2 targeting lipid lowering agents with fewer adverse effects, despite little being known about the molecular basis of HCA2 mediated signalling. Here, we report the cryo-electron microscopy structure of the HCA2-Gi signalling complex with the potent agonist MK-6892, along with crystal structures of HCA2 in inactive state. These structures, together with comprehensive pharmacological analysis, reveal the ligand binding mode and activation and signalling mechanisms of HCA2. This study elucidates the structural determinants essential for HCA2 mediated signalling and provides insights into ligand discovery for HCA2 and related receptors.
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Niacina , Humanos , Niacina/farmacología , Ligandos , Microscopía por Crioelectrón , Transducción de Señal , Receptores Acoplados a Proteínas G/metabolismoRESUMEN
BACKGROUND: Metastasis is one of the main obstacles impeding the survival of nasopharyngeal carcinoma (NPC) patients, with the molecular mechanism underlying NPC metastasis still unclear. RESULTS: In this study, Cystatin A (CSTA) was found downregulated in NPC tissues with metastasis compared with those without metastasis. Shorter overall survival and distant metastasis-free survival were found in NPC patients with lower CSTA expression. Using functional assays, we found that CSTA prevented both the in vitro motility of NPC cells and their ability to metastasize in vivo. Transcriptome sequencing and western blot analysis revealed that CSTA inhibited the phosphorylation of AKT. Moreover, activating AKT using AKT agonist SG79 rescued the motility of CSTA-overexpressing NPC cells, whereas, treatment with AKT inhibitor MK2206 inhibited the motility of CSTA-knockdown NPC cells. Mechanically, immunoprecipitation coupled mass spectrometry found that CSTA interacted with the N6-adenosine-methyltransferase subunit METTL3 and promoted its ubiquitin-proteasome-mediated degradation following the upregulation of NKX3-1 and LHPP, which are negative regulators of AKT. Furthermore, knock-down of NKX3-1 and LHPP enhanced the motility of CSTA-overexpressing NPC cells. CONCLUSIONS: The inhibitory effect of CSTA upon NPC metastasis mainly depended on suppressing AKT signaling by the upregulation of NKX3-1 and LHPP expression resulting from the binding between CSTA and METLL3. Our study suggests that the CSTA-METLL3-NKX3-1/LHPP-AKT axis could be of therapeutic value for inhibiting NPC metastasis.
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Carcinoma , Neoplasias Nasofaríngeas , Humanos , Carcinoma/patología , Cistatina A , Transición Epitelial-Mesenquimal , Metiltransferasas , Carcinoma Nasofaríngeo/genética , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/metabolismo , Neoplasias Nasofaríngeas/patología , Proteínas Proto-Oncogénicas c-akt/metabolismoRESUMEN
Cannabinoid CB2 receptor (CB2R) agonists are investigated as therapeutic agents in the clinic. However, their molecular mode-of-action is not fully understood. Here, we report the discovery of LEI-102, a CB2R agonist, used in conjunction with three other CBR ligands (APD371, HU308, and CP55,940) to investigate the selective CB2R activation by binding kinetics, site-directed mutagenesis, and cryo-EM studies. We identify key residues for CB2R activation. Highly lipophilic HU308 and the endocannabinoids, but not the more polar LEI-102, APD371, and CP55,940, reach the binding pocket through a membrane channel in TM1-TM7. Favorable physico-chemical properties of LEI-102 enable oral efficacy in a chemotherapy-induced nephropathy model. This study delineates the molecular mechanism of CB2R activation by selective agonists and highlights the role of lipophilicity in CB2R engagement. This may have implications for GPCR drug design and sheds light on their activation by endogenous ligands.
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Agonistas de Receptores de Cannabinoides , Cannabinoides , Agonistas de Receptores de Cannabinoides/farmacología , Receptores de Cannabinoides , Cannabinoides/farmacología , Receptor Cannabinoide CB1/genética , Receptor Cannabinoide CB2/genéticaRESUMEN
Wind power is a promising electricity source. Nevertheless, wind turbine blade icing can cause severe problems in turbine operation. In this study, SiO2 spherical nanoparticles (â¼90 nm), produced by RF (radio frequency) plasma spheroidization, were mixed with E51, PDMS, and ethyl acetate, and sprayed on the surface of aluminum plates and regular power windmill fan blades which were already coated with polyurethane primer. XPS and IR spectroscopies revealed the development of SiC and SiPh (Ph = phenolic ring) bonds, whose formation should be favored by the ultrasound and curing processes at 50 °C. The integrity of the coating/substrate interface, whose strength is ascribed to hydrogen bonds, was maintained after 100 icing-melting cycles. The coatings display superhydrophobic behavior and excellent anti-icing performance, along with stability in abrasion, sunlight and self-cleaning ability towards solid pollutants.
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BACKGROUND: Left ventricular non-compaction (LVNC) is a rare disease with a poor prognosis. Efforts to improve prognosis are limited by the quality and scope of the available evidence on prognostic factors. METHODS: Pubmed, Embase, China National Knowledge Infrastructure, Cochrane Library, Wanfang, and Baidu Scholar were searched and all relevant studies that examined factors related to LVNC prognosis, published before January 2021, were retrieved. Study quality evaluation and data extraction were independently completed by two authors. Statistical analyses were performed using STATA 15.0 software. RESULTS: A total of 20 cohort studies were included in this study, with a total of 1910 patients. The results of the meta-analysis are as follows: New York Heart Function Association (NYHA) class III/IV (hazard ratio [HR] = 3.93, 95% confidence interval [CI]: 1.66-9.29), (NT-proBNP) increased (HR = 1.98, 95% CI: 1.10-3.58), left ventricular ejection fraction (LVEF) decreased (HR = 1.04, 95% CI: 1.03-1.06), left ventricular end-diastolic diameter (LVEDD) increased (HR = 1.03, 95% CI: 1.01-1.06) was an independent poor prognostic factor, and body mass index (HR = 0.80, 95% CI: 0.64-0.98) was an independent protective factor. Creatinine (CR) level (HR = 1.09, 95% CI: 0.95-1.25) and late gadolinium-enhanced (LGE) imaging (HR = 3.1, 95% CI: 0.85-11.31) has no statistical significance in the prognosis of LVNC. CONCLUSION: In LVNC patients, NYHA class III/IV, elevated N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, decreased LVEF, and increased LVEDD may lead to poor prognosis, and increased body mass index may improve the prognosis of LVNC. Further clinical research with large sample sizes and long-term follow-ups should be conducted. PROSPERO REGISTRATION NUMBER: 42020152706.
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Gadolinio , Función Ventricular Izquierda , Creatinina , Humanos , Pronóstico , Volumen SistólicoRESUMEN
Taste sensing is a sophisticated chemosensory process, and bitter taste perception is mediated by type 2 taste receptors (TAS2Rs), or class T G protein-coupled receptors. Understanding the detailed molecular mechanisms behind taste sensation is hindered by a lack of experimental receptor structures. Here, we report the cryo-electron microscopy structures of human TAS2R46 complexed with chimeric mini-G protein gustducin, in both strychnine-bound and apo forms. Several features of TAS2R46 are disclosed, including distinct receptor structures that compare with known GPCRs, a new "toggle switch," activation-related motifs, and precoupling with mini-G protein gustducin. Furthermore, the dynamic extracellular and more-static intracellular parts of TAS2R46 suggest possible diverse ligand-recognition and activation processes. This study provides a basis for further exploration of other bitter taste receptors and their therapeutic applications.
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Neurotoxinas , Receptores Acoplados a Proteínas G , Estricnina , Gusto , Microscopía por Crioelectrón , Humanos , Ligandos , Neurotoxinas/farmacología , Conformación Proteica , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/química , Estricnina/farmacología , Gusto/efectos de los fármacosRESUMEN
G protein-coupled receptors (GPCRs) are involved in a variety of human physiological processes and are attractive targets for treating various diseases. Yet, despite the importance as therapeutic targets, only 97 unique GPCR structures have been determined to date. A key challenge in their structural biology study is to obtain adequate protein samples because GPCRs usually have the low expression in native tissues. The in vitro recombinant expression provides the possibility to obtain large quantities of high-quality proteins suitable for three-dimensional structure determination by crystallography or single particle cryo-EM methods. For GPCR protein production, eukaryotic expression systems, such as baculovirus system and mammalian system, are the most widely used. In this chapter, we provide an overview of the methodological approaches on GPCRs expression and purification optimization using insect cells and mammalian cells, which is the prerequisite conditions for structural biology studies.
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Baculoviridae , Receptores Acoplados a Proteínas G , Animales , Baculoviridae/genética , Baculoviridae/metabolismo , Cristalografía , Eucariontes/metabolismo , Humanos , Insectos/metabolismo , Mamíferos/metabolismo , Receptores Acoplados a Proteínas G/metabolismoRESUMEN
Detergents are the most frequently applied reagents in membrane protein (MP) studies. The limited diversity of one-head-one-tailed traditional detergents, however, is far from sufficient for structurally distinct MPs. Expansion of detergent repertoire has a continuous momentum. In line with the speculation that detergent pre-assembly exerts superiority, herein we report for the first time cross-conjugation of two series of monomeric detergents for constructing a two-dimensional library of dimeric detergents. Optimum detergents stood out with unique preferences in the systematic evaluation of individual MPs. Furthermore, unprecedented hybrid detergents 14M8G and 14M9G enabled high-quality EM study of transporter MsbA and NMR study of G protein-coupled receptor A2A AR, respectively. Given the abundance of cross-coupling chemistries, comprehensive diversity could be readily covered that would facilitate the finding of new detergents for the manipulation of thorny MPs and innovation of the functional and structural study in future.
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Detergentes , Proteínas de la Membrana , Detergentes/química , Espectroscopía de Resonancia Magnética , Proteínas de la Membrana/química , MicelasRESUMEN
BACKGROUND: Hypothermia is a common problem that is associated with increased mortality and morbidity among preterm infants, especially in China. The objective of this study was to evaluate the efficacy of a targeted quality improvement (QI) project that applied hypothermia prevention measures for very-low-birth-weight (VLBW) infants in three tertiary neonatal intensive care units (NICUs) in China. PROBLEM: Between January 2018 and December 2018, we conducted a prospective analysis and found that the incidence of AH was 88.2% among VLBW infants. METHODS: The study enrolled preterm infants born at less than 32 weeks' gestation with a VLBW of less than 1500 g who were delivered at three academic tertiary-care hospitals between January 2018 and December 2019. The primary outcome measure was the incidence of hypothermia. The outcomes of the pre-QI group (1 January-31 December 2018) were compared with those of the post-QI group (1 January-31 December 2019). INTERVENTIONS: Based on the literature, our preliminary findings and the needs of each unit, a temperature bundle that included a transport incubator, prewarmed hats, polyethylene wrap, team training and education, and temperature documentation and workflows were implemented in consecutive plan-do-study-act cycles. RESULTS: Of the 530 VLBW infants, 235 infants (36.9%) belonged to the pre-QI group, and 295 infants (46.4%) belonged to the post-QI group. The incidence of hypothermia decreased significantly, from 92.3% to 62% (p<0.001), and the mean body temperature on admission to the NICU increased significantly, from 35.5°C to 36°C±0.7°C (p<0.001). There was one case of hyperthermia during the study period. Infants in the post-QI group had a lower mortality rate (16.1% vs 8.8%, p=0.01). CONCLUSIONS: Targeted interventions can dramatically reduce admission hypothermia and improve the outcome of VLBW infants in China. TRIAL REGISTRATION NUMBER: Chi CTR 1900020861.
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Hipotermia , Humanos , Hipotermia/epidemiología , Hipotermia/prevención & control , Lactante , Recién Nacido , Recien Nacido Prematuro , Recién Nacido de muy Bajo Peso , Unidades de Cuidado Intensivo Neonatal , TemperaturaRESUMEN
Cannabinoid receptor 1 (CB1) is a G protein-coupled receptor (GPCR) that is gaining much interest for its regulating role in the central nervous system and its value as a drug target. Structures of CB1 in inactive and active states have revealed conformational change details that are not common in other GPCRs. Here, we performed molecular dynamics simulations of CB1 in different ligand binding states and with mutations to reveal its activation mechanism. The conformational change of the "twin toggle switch" residues F2003.36 and W3566.48 that correlates with ligand efficacy is identified as a key barrier step in CB1 activation. Similar conformational change of residues 3.36/6.48 is also observed in melanocortin receptor 4, showing this "twin toggle switch" residue pair is crucial for the activation of multiple GPCR members.
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Functional magnetic resonance imaging (fMRI) techniques using the blood-oxygen level-dependent (BOLD) signal have shown great potential as clinical biomarkers of disease. Thus, using these techniques in preclinical rodent models is an urgent need. Calibrated fMRI is a promising technique that can provide high-resolution mapping of cerebral oxygen metabolism (CMRO2). However, calibrated fMRI is difficult to use in rodent models for several reasons: rodents are anesthetized, stimulation-induced changes are small, and gas challenges induce noisy CMRO2 predictions. We used, in mice, a relaxometry-based calibrated fMRI method which uses cerebral blood flow (CBF) and the BOLD-sensitive magnetic relaxation component, R2', the same parameter derived in the deoxyhemoglobin-dilution model of calibrated fMRI. This method does not use any gas challenges, which we tested on mice in both awake and anesthetized states. As anesthesia induces a whole-brain change, our protocol allowed us to overcome the former limitations of rodent studies using calibrated fMRI. We revealed 1.5-2 times higher CMRO2, dependent upon brain region, in the awake state versus the anesthetized state. Our results agree with alternative measurements of whole-brain CMRO2 in the same mice and previous human anesthesia studies. The use of calibrated fMRI in rodents has much potential for preclinical fMRI.