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Drug-drug interaction of the antiviral sofosbuvir and the antiarrhythmics amiodarone has been reported to cause fatal heartbeat slowing. Sofosbuvir and its analog, MNI-1, were reported to potentiate the inhibition of cardiomyocyte calcium handling by amiodarone, which functions as a multi-channel antagonist, and implicate its inhibitory effect on L-type Cav channels, but the molecular mechanism has remained unclear. Here we present systematic cryo-EM structural analysis of Cav1.1 and Cav1.3 treated with amiodarone or sofosbuvir alone, or sofosbuvir/MNI-1 combined with amiodarone. Whereas amiodarone alone occupies the dihydropyridine binding site, sofosbuvir is not found in the channel when applied on its own. In the presence of amiodarone, sofosbuvir/MNI-1 is anchored in the central cavity of the pore domain through specific interaction with amiodarone and directly obstructs the ion permeation path. Our study reveals the molecular basis for the physical, pharmacodynamic interaction of two drugs on the scaffold of Cav channels.
Assuntos
Amiodarona , Sofosbuvir , Sofosbuvir/efeitos adversos , Amiodarona/farmacologia , Antivirais/farmacologia , Miócitos Cardíacos/metabolismo , Sítios de Ligação , Canais de Cálcio Tipo L/metabolismo , Cálcio/metabolismoRESUMO
Although the tremendous progress has been made for mRNA delivery based on classical cationic carriers, the excess cationic charge density of lipids was necessary to compress mRNA through electrostatic interaction, and with it comes inevitably adverse events including the highly inflammatory and cytotoxic effects. How to develop the disruptive technologies to overcome cationic nature of lipids remains a major challenge for safe and efficient mRNA delivery. Here, we prepared noncationic thiourea lipids nanoparticles (NC-TNP) to compress mRNA by strong hydrogen bonds interaction between thiourea groups of NC-TNP and the phosphate groups of mRNA, abandoning the hidebound and traditional electrostatic force to construct mRNA-cationic lipids formulation. NC-TNP was a delivery system for mRNA with simple, convenient, and repeatable preparation technology and showed negligible inflammatory and cytotoxicity side effects. Furthermore, we found that NC-TNP could escape the recycling pathway to inhibit the egress of internalized nanoparticles from the intracellular compartment to the extracellular milieu which was a common fact in mRNA-LNP (lipid nanoparticles) formulation. Therefore, NC-TNP-encapsulated mRNA showed higher gene transfection efficiency in vitro and in vivo than mRNA-LNP formulation. Unexpectedly, NC-TNP showed spleen targeting delivery ability with higher accumulation ratio (spleen/liver), compared with traditional LNP. Spleen-targeting NC-TNP with mRNA exhibited high mRNA-encoded antigen expression in spleen and elicited robust immune responses. Overall, our work establishes a proof of concept for the construction of a noncationic system for mRNA delivery with good inflammatory safety profiles, high gene transfection efficiency, and spleen-targeting delivery to induce permanent and robust humoral and cell-mediated immunity for disease treatments.
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Biomimética , Nanopartículas , RNA Mensageiro/metabolismo , Lipídeos/química , Nanopartículas/química , Cátions/química , Tioureia , RNA Interferente Pequeno/genéticaRESUMO
Although biomacromolecules are promising cytosolic drugs which have attracted tremendous attention, the major obstacles were the cellular membrane hindering the entrance and the endosome entrapment inducing biomacromolecule degradation. How to avoid those limitations to realize directly cytosolic delivery was still a challenge. Here, we prepared oligoarginine modified lipid to assemble a nanovesicle for biomacromolecules delivery, including mRNA (mRNA) and proteins which could be directly delivered into the cytoplasm of dendritic cells through subendocytosis-mediated membrane fusion. We named this membrane fusion lipid nanovesicle as MF-LNV. The mRNA loaded MF-LNV as nanovaccines showed efficient antigen expression to elicit robust immuno responses for cancer therapy. What's more, the antigen protein loaded MF-LNV as nanovaccines elicits much stronger CD8+ T cell specific responses than lipid nanoparticles through normal uptake pathways. This MF-LNV represented a refreshing strategy for intracellular delivery of the biomacromolecule.
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Lipídeos , Lipídeos/química , Animais , Humanos , Nanopartículas/química , Células Dendríticas , RNA Mensageiro/genética , RNA Mensageiro/administração & dosagem , Camundongos , Fusão de Membrana , Sistemas de Liberação de Medicamentos , Linfócitos T CD8-Positivos/imunologiaRESUMO
We proposed two physical concepts, i.e., an intramolecular relative cross section (RCS) and an intermolecular relative scattering ability (RSA), to re-understand and re-describe surface-enhanced Raman scattering (SERS) and established a general SERS quantification theory. Interestingly, RCS and RSA are intrinsic factors and are experimentally measurable to form datasheets of molecules, namely, SERS cards, with which a standard SERS quantification procedure was established. The validity of the theory and quantification procedure was confirmed by experiments. Surprisingly, RCS and RSA are also valid for complex systems being considered as virtual molecules and are experimentally measurable. This simplifies complex systems into analyte-virtual molecule binary systems. With this consideration, trace-level mitoxantrone (a typical cancer drug metabolite) in artificial urine was accurately predicted. The theory, the SERS cards, the standard quantification procedure, and the virtual molecule concept pave a way toward quantitative and standardized SERS spectroscopy in dealing with real-world problems and complex samples.
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The exploration of 2D materials has captured significant attention due to their unique performances, notably focusing on graphene and hexagonal boron nitride (h-BN). Characterized by closely resembling atomic structures arranged in a honeycomb lattice, both graphene and h-BN share comparable traits, including exceptional thermal conductivity, impressive carrier mobility, and robust pi-pi interactions with organic molecules. Notably, h-BN has been extensively examined for its exceptional electrical insulating properties, inert passivation capabilities, and provision of an ideal ultraflat surface devoid of dangling bonds. These distinct attributes, contrasting with those of h-BN, such as its conductive versus insulating behavior, active versus inert nature, and absence of dangling surface bonds versus absorbent tendencies, render it a compelling material with broad application potential. Moreover, the unity of such contradictions endows h-BN with intriguing possibilities for unique applications in specific contexts. This review aims to underscore these key attributes and elucidate the intriguing contradictions inherent in current investigations of h-BN, fostering significant insights into the understanding of material properties.
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Methylation panels, tools for investigating epigenetic changes associated with diseases like cancer, can identify DNA methylation patterns indicative of disease, providing diagnostic or prognostic insights. However, the application of methylation panels focusing on the sex-determining region Y-box 1 (SOX1) and paired box gene 1 (PAX1) genes for diagnosing cervical lesions is under-researched. This study aims to examine the diagnostic performance of PAX1/SOX1 gene methylation as a marker for cervical precancerous lesions and its potential application in triage diagnosis. From September 2022 to April 2023, 181 patients with abnormal HPV-DNA tests or cytological exam results requiring colposcopy were studied at Hubei Maternal and Child Health Hospital, China. Data were collected from colposcopy, cytology, HPV-DNA tests, and PAX1/SOX1 methylation detection. Patients were categorized as control, cervical intraepithelial neoplasia Grade 1 (CIN1), Grade 2 (CIN2), Grade 3 (CIN3), and cervical cancer (CC) groups based on histopathology. We performed HPV testing, liquid-based cytology, and PAX1/SOX1 gene methylation testing. We evaluated the diagnostic value of methylation detection in cervical cancer using DNA methylation positivity rate, sensitivity, specificity, and area under the curve (AUC), and explored its potential for triage diagnosis. PAX1/SOX1 methylation positivity rates were: control 17.1%, CIN1 22.5%, CIN2 100.0%, CIN3 90.0%, and CC 100.0%. The AUC values for PAX1 gene methylation detection in diagnosing CIN1+, CIN2+, and CIN3+ were 0.52 (95% confidence interval [CI]: 0.43-0.62), 0.88 (95% CI: 0.80-0.97), and 0.88 (95% CI: 0.75-1.00), respectively. Corresponding AUC values for SOX1 gene methylation detection were 0.47 (95% CI: 0.40-0.58), 0.80 (95% CI: 0.68-0.93), and 0.92 (95% CI: 0.811-1.00), respectively. In HPV16/18-negative patients, methylation detection showed sensitivity of 32.4% and specificity of 83.7% for CIN1+. For CIN2+ and CIN3+, sensitivity was all 100%, with specificities of 83.0% and 81.1%. Among the patients who underwent colposcopy examination, 166 cases had cytological examination results ≤ASCUS, of which 37 cases were positive for methylation, and the colposcopy referral rate was 22.29%. PAX1/SOX1 gene methylation detection exhibits strong diagnostic efficacy for cervical precancerous lesions and holds significant value in triage diagnosis.
Assuntos
Metilação de DNA , Fatores de Transcrição Box Pareados , Infecções por Papillomavirus , Fatores de Transcrição SOXB1 , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Adulto Jovem , Biomarcadores Tumorais/genética , China , Colposcopia , Detecção Precoce de Câncer/métodos , Fatores de Transcrição Box Pareados/genética , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/virologia , Infecções por Papillomavirus/genética , Lesões Pré-Cancerosas/diagnóstico , Lesões Pré-Cancerosas/genética , Sensibilidade e Especificidade , Fatores de Transcrição SOXB1/genética , Triagem/métodos , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/genética , Displasia do Colo do Útero/virologia , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/genéticaRESUMO
As a member of glycosyltransferases, fucosyltransferase 8 (FUT8) is essential to core fucosylation and has been considered as a potential therapeutic target for malignant tumors, including colorectal cancer (CRC). Based on the identification of key binding residues and probable conformation of FUT8, an integrated strategy that combines virtual screening and chemical optimization was carried out and compound 15 was identified as a potent FUT8 inhibitor with novel chemical structure and in vitro antitumor activity. Moreover, chemical pulldown experiments and binding assays confirmed that compound 15 selectively bound to FUT8. In vivo, compound 15 showed promising anti-CRC effects in SW480 xenografts. These data support that compound 15 is a potential FUT8 inhibitor for CRC treatment and deserve further optimization studies.
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Antineoplásicos , Neoplasias Colorretais , Descoberta de Drogas , Inibidores Enzimáticos , Fucosiltransferases , Fucosiltransferases/antagonistas & inibidores , Fucosiltransferases/metabolismo , Humanos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Animais , Relação Estrutura-Atividade , Camundongos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/síntese química , Estrutura Molecular , Ensaios de Seleção de Medicamentos Antitumorais , Relação Dose-Resposta a Droga , Proliferação de Células/efeitos dos fármacos , Camundongos Nus , Linhagem Celular Tumoral , Camundongos Endogâmicos BALB C , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Neoplasias Experimentais/metabolismo , Simulação de Acoplamento MolecularRESUMO
Nav1.5 is the primary voltage-gated Na+ (Nav) channel in the heart. Mutations of Nav1.5 are associated with various cardiac disorders exemplified by the type 3 long QT syndrome (LQT3) and Brugada syndrome (BrS). E1784K is a common mutation that has been found in both LQT3 and BrS patients. Here we present the cryo-EM structure of the human Nav1.5-E1784K variant at an overall resolution of 3.3 Å. The structure is nearly identical to that of the wild-type human Nav1.5 bound to quinidine. Structural mapping of 91- and 178-point mutations that are respectively associated with LQT3 and BrS reveals a unique distribution pattern for LQT3 mutations. Whereas the BrS mutations spread evenly on the structure, LQT3 mutations are clustered mainly to the segments in repeats III and IV that are involved in gating, voltage-sensing, and particularly inactivation. A mutational hotspot involving the fast inactivation segments is identified and can be mechanistically interpreted by our "door wedge" model for fast inactivation. The structural analysis presented here, with a focus on the impact of mutations on inactivation and late sodium current, establishes a structure-function relationship for the mechanistic understanding of Nav1.5 channelopathies.
Assuntos
Doença do Sistema de Condução Cardíaco/genética , Síndrome do QT Longo/genética , Canal de Sódio Disparado por Voltagem NAV1.5/química , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Síndrome de Brugada/genética , Microscopia Crioeletrônica , Humanos , Ativação do Canal Iônico , Modelos Moleculares , Mutação , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Conformação Proteica , Relação Estrutura-AtividadeRESUMO
Scanning near-field optical microscope (SNOM) with nanoscale spatial resolution has been a powerful tool in studying the plasmonic properties of nano materials/structures. However, the quantification of the SNOM measurement remains a major challenge in the field due to the lack of reliable methodologies. We employed the point-dipole model to describe the tip-surface interaction upon laser illumination and theoretically derived the quantitative relationship between the measured results and the actual near-field electric field strength. Thus, we can experimentally reconstruct the near-field electric field through this theoretically calculated relationship. We also developed an experimental technique together with FEM simulation to get the above relationship experimentally and reconstruct the near-field electric field from the measurement by SNOM.
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Rhabdophane is an important permeable reactive barrier to enrich radionuclides from groundwater and has been envisaged to host radionuclides in the backend of the nuclear fuel cycle. However, understanding of how An4+ and Sr2+ precipitate into rhabdophane by wet chemistry has not been resolved. In this work, Th4+ and Sr2+ incorporation in the rhabdophane/monazite structure as La1-2xSrxThxPO4·nH2O solid solutions is successfully achieved in the acid solution at 90 °C. Some specific issues such as lattice occupation of Th4+ and Sr2+, precipitation reaction kinetics, and crystal growth affected by starting stoichiometry are discussed in detail, along with investigating the chemical stability of La1-2xSrxThxPO4·nH2O precipitations and associated La1-2xSrxThxPO4 monazite. The results reveal that the excess of Sr2+ appears to be a prevailing factor with a suggested initial Sr: Th ≥ 2 to obtain the stability domain of La1-2xSrxThxPO4·nH2O (x = 0â¼ 0.1). A rapid ion removal associated with a nucleation process has been observed within 8 h, and Th4+ can be removed more than 98% after 24 h in 0.01 mol/L solutions. From structural energetics based on density functional theory, the lattice occupation of Th4+ and Sr2+ is energetically favorable in nonhydrated lattice sites of [LaO8], although two-thirds of lattice sites are associated with [LaO8·H2O] hydrated sites. Intriguingly, the crystal transformation from rhabdophane to monazite associated with the transformation from [SrO8] to [SrO9] polyhedra can greatly improve the leaching stability of Sr2+.
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Dioscorea zingiberensis is a perennial herb famous for the production of diosgenin, which is a valuable initial material for the industrial synthesis of steroid drugs. Sterol C26-hydroxylases, such as TfCYP72A616 and PpCYP72A613, play an important role in the diosgenin biosynthesis pathway. In the present study, a novel gene, DzCYP72A12-4, was identified as C26-hydroxylase and was found to be involved in diosgenin biosynthesis, for the first time in D. zingiberensis, using comprehensive methods. Then, the diosgenin heterogenous biosynthesis pathway starting from cholesterol was created in stable transgenic tobacco (Nicotiana tabacum L.) harboring DzCYP90B71(QPZ88854), DzCYP90G6(QPZ88855) and DzCYP72A12-4. Meanwhile, diosgenin was detected in the transgenic tobacco using an ultra-performance liquid chromatography system (Vanquish UPLC 689, Thermo Fisher Scientific, Bremen, Germany) tandem MS (Q Exactive Hybrid Quadrupole-Orbitrap Mass Spectrometer, Thermo Fisher Scientific, Bremen, Germany). Further RT-qPCR analysis showed that DzCYP72A12-4 was highly expressed in both rhizomes and leaves and was upregulated under 15% polyethylene glycol (PEG) treatment, indicating that DzCYP72A12-4 may be related to drought resistance. In addition, the germination rate of the diosgenin-producing tobacco seeds was higher than that of the negative controls under 15% PEG pressure. In addition, the concentration of malonaldehyde (MDA) was lower in the diosgenin-producing tobacco seedlings than those of the control, indicating higher drought adaptability. The results of this study provide valuable information for further research on diosgenin biosynthesis in D. zingiberensis and its functions related to drought adaptability.
Assuntos
Dioscorea , Diosgenina , Animais , Diosgenina/química , Dioscorea/química , Secas , Espectrometria de Massas , Cromatografia Líquida de Alta Pressão , Animais Geneticamente Modificados , Oxigenases de Função Mista/metabolismoRESUMO
Fabricating inorganic materials with designed three-dimensional nanostructures is an exciting yet challenging area of research and industrial application. Here, we develop an approach to 3D print high-quality nanostructures of silica with sub-200 nm resolution and with the flexible capability of rare-earth element doping. The printed SiO2 can be either amorphous glass or polycrystalline cristobalite controlled by the sintering process. The 3D-printed nanostructures demonstrate attractive optical properties. For instance, the fabricated micro-toroid optical resonators can reach quality factors (Q) of over 104. Moreover, and importantly for optical applications, doping and codoping of rare-earth salts such as Er3+, Tm3+, Yb3+, Eu3+ and Nd3+ can be directly implemented in the printed SiO2 structures, showing strong photoluminescence at the desired wavelengths. This technique shows the potential for building integrated microphotonics with silica via 3D printing.
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Our previous studies have revealed the important roles of the nonseed regions of microRNAs (miRNAs) in gene regulation, which provided novel insight into the development of miRNA analogs for cancer therapy. Here, we altered each nucleotide in the nonseed region of miR-34a and obtained novel synthetic miRNA analogs. Among them, AM22, with a base alteration from G to C at the 17th nucleotide of miR-34a, showed extensive antiproliferative activity against several colorectal tumor cell lines and achieved effective inhibition of core binding factor subunit ß (CBFB) expression. Subsequent investigations demonstrated that AM22 directly targeted CBFB by binding to its 3'-untranslated region (3'-UTR). Inhibition of CBFB showed obvious antiproliferative activity on HCT-116 and SW620 cells. Furthermore, the antiproliferative effects of AM22 on these cells were also measured in xenograft mouse models. In conclusion, this study identified AM22 as a potential antitumor miRNA by targeting CBFB and provided a new design approach for miRNA-based cancer treatment by changing the nonseed region of miRNA.
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Neoplasias Colorretais , MicroRNAs , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Subunidade beta de Fator de Ligação ao Core/genética , Subunidade beta de Fator de Ligação ao Core/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , NucleotídeosRESUMO
Although a number of studies have revealed the important roles of miR-34a in cancer, the regulatory roles of miR-34a in cancer immune response remain largely unknown. Our present study demonstrated a mechanism underlying miR-34a-mediated cancer immune evasion via a SIRT1/NF-κB/B7-H3/TNF-α axis. miR-34a upregulated B7-H3, an important immune checkpoint molecule, through direct inhibition of SIRT1 and consequent acetylation of NF-κB subunit p65 (a-p65), which promoted B7-H3 transcription by direct binding to its promoter. The elevated B7-H3 induced production of pro-inflammatory cytokines including TNF-α. This was further confirmed in the colon of Mir34a-deficient mice, where Sirt1 expression was boosted, and the expressions of a-p65, B7h3, and Tnf were repressed. Consequently, the in vivo inhibitory activity of miR-34a on colorectal cancer (CRC) was eradicated by the reinforced B7-H3 and TNF-α. In conclusion, our study uncovered an etiological mechanism underlying miR-34a-mediated CRC immune evasion through inhibition of SIRT1 and promotion of NF-κB/B7-H3/TNF-α axis.
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Antígenos B7/genética , Neoplasias Colorretais/genética , Tolerância Imunológica/genética , MicroRNAs/genética , NF-kappa B/genética , Sirtuína 1/genética , Fator de Necrose Tumoral alfa/genética , Animais , Células CHO , Linhagem Celular , Linhagem Celular Tumoral , Colo/patologia , Neoplasias Colorretais/patologia , Cricetulus , Citocinas/genética , Feminino , Células HCT116 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCIDRESUMO
B7-H3, an important co-inhibitor, is abnormally highly expressed in a variety of malignancies. The antibodies targeting B7-H3 have exhibited beneficial therapeutic effects in clinical trials. Therefore, discovery of the regulatory factors in B7-H3 expression may provide new strategies for tumor therapy. Here, we investigated the splicing factors involved in the splicing of B7-H3. By individual knockdown of the splicing factors in colorectal cancer (CRC) cells, we found that B7-H3 expression was markedly inhibited by SRSF3 and SRSF8, especially SRSF3. Then we found that both SRSF3 and B7-H3 were highly expressed in CRC tissues. Moreover, high-expression of either SRSF3 or B7-H3 was significantly correlated with poor prognosis of patients. The expression of B7-H3 mRNA and protein were evidently reduced by SRSF3 silence, but were enhanced by overexpression of SRSF3 in both HCT-116 and HCT-8 cells. The results from the RNA immunoprecipitation (RIP) assays demonstrated that SRSF3 protein directly binds to B7-H3 mRNA. In addition, we constructed a minigene recombinant plasmid for expressing B7-H3 exons 3-6. We found that SRSF3 contributed to the retention of B7-H3 exon 4. These findings demonstrate that SRSF3 involves in the splicing of B7-H3 by directly binding to its exon 4 and/or 6. It may provide novel insights into the regulatory mechanisms of B7-H3 expression and potential strategies for the treatment of CRC.
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Antígenos B7/metabolismo , Neoplasias Colorretais/metabolismo , Fatores de Processamento de Serina-Arginina/metabolismo , Processamento Alternativo , Antígenos B7/biossíntese , Antígenos B7/genética , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Éxons , Feminino , Células HCT116 , Humanos , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Processamento de Serina-Arginina/biossíntese , Fatores de Processamento de Serina-Arginina/genética , TransfecçãoRESUMO
The families of miR-34 and miR-449 share the same seed region. However, the members showed differential effects on the expression of B7-H3 and PD-L1 in HCT-116 cells. Using miR-34a as a template, the non-seed region was modified by nucleotide alteration, yielding four synthetic microRNA (miRNA) analogs. Among those, NS-MX3, with a base alteration from G to C at the 18th locus of miR-34a, showed the most potent inhibition on both B7-H3 and PD-L1 expression. Subsequent investigations demonstrated that NS-MX3 had a broad anti-proliferation activity against several colorectal tumor cell lines and its antitumor effect was consistently reflected by tumor growth inhibition (TGI) in the HCT-116 xenograft model. In addition, NS-MX3 displayed a synergistic effect on TGI when combined with bevacizumab or regorafenib. Further analysis revealed that the superior antitumor activity of NS-MX3 was correlated to concomitant suppression of both B7-H3 and PD-L1 expression in tumor tissues. Taken together, the present study indicates that the non-seed region of miRNAs plays an important role in the regulation of checkpoint genes, thus showcasing single nucleotide alteration of the non-seed region as a promising approach to discover and develop novel immunotherapies.
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Antineoplásicos/farmacologia , Antígenos B7/antagonistas & inibidores , Neoplasias Colorretais/patologia , MicroRNAs/farmacologia , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Bevacizumab/uso terapêutico , Biomarcadores Tumorais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos SCID , Compostos de Fenilureia/uso terapêutico , Piridinas/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND & AIMS: Tropifexor (TXR) is a novel nonbile acid that acts as an agonist of farnesoid X receptor (FXR). TXR is currently in Phase 2 trials for the treatment of non-alcoholic steatohepatitis (NASH). Herein, we report the impact of TXR on in a piglet model in which cholestatic liver damage and fibrosis where induced by bile duct ligation (BDL). METHODS: The piglets received BDL and TXR for 2 wk. Hepatic, portal and colonic bile acid and amino acid profiles and gut microbiome were analysed. Portal fibroblast growth factor (FGF) 19 levels were measured using an enzyme-linked immunosorbent assay (ELISA). RESULTS: We first showed that bile acid metabolism and signalling are dysfunctional in patients with biliary atresia. Next, we observed that TXR potently suppresses BDL-induced liver injury, fibrosis and ductular reaction in piglets. Within the ileum, TXR enhances FGF19 expression and subsequently increases portal FGF19 levels. In the liver, TXR promotes the expression of small heterodimer partner (SHP) and inhibits cholesterol 7α-hydroxylase (CYP7A1). Additionally, TXR increases the abundance of bile acid-biotransforming bacteria in the distal ileum and alters the composition of amino acids in the colon. Lastly, TXR ameliorates intestinal barrier injury in piglets subjected to BDL. CONCLUSION: TXR potently ameliorated cholestatic liver injury and fibrosis by modulating the gut-liver axis in piglets. It supports the clinical evaluation of TXR as a therapeutic strategy for cholestatic liver diseases, such as biliary atresia.
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Fígado , Hepatopatia Gordurosa não Alcoólica , Animais , Benzotiazóis , Ácidos e Sais Biliares , Fibrose , Humanos , Isoxazóis , Fígado/patologia , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/patologia , Cirrose Hepática/prevenção & controle , Hepatopatia Gordurosa não Alcoólica/patologia , SuínosRESUMO
B-site Os-doped quadruple perovskite oxides LaCu3Fe4-xOsxO12 (x = 1 and 2) were prepared under high-pressure and high-temperature conditions. Although parent compound LaCu3Fe4O12 experiences Cu-Fe intermetallic charge transfer that changes the Cu3+/Fe3+ charge combination to Cu2+/Fe3.75+ at 393 K, in the Os-doped samples, the Cu and Fe charge states are found to be constant 2+ and 3+, respectively, indicating the complete suppression of charge transfer. Correspondingly, Os6+ and mixed Os4.5+ valence states are determined by X-ray absorption spectroscopy for x = 1 and x = 2 compositions, respectively. The x = 1 sample crystallizes in an Fe/Os disordered structure with the Im3Ì space group. It experiences a spin-glass transition around 480 K. With further Os substitution up to x = 2, the crystal symmetry changes to Pn3Ì , where Fe and Os are orderly distributed in a rocksalt-type fashion at the B site. Moreover, this composition shows a long-range Cu2+(↑)Fe3+(↑)Os4.5+(↓) ferrimagnetic ordering near 520 K. This work provides a rare example for 5d substitution-suppressed intermetallic charge transfer as well as induced structural and magnetic phase transitions with high spin ordering temperature.
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OBJECTIVES: Intestinal failure-associated liver disease (IFALD) is a life-threatening complication for patients with intestinal failure who receive long-term parenteral nutrition (PN). We evaluated the effects of the farnesoid X receptor agonist tropifexor on a neonatal piglet model of IFALD fed with PN. METHODS: The piglets received PN and tropifexor for 14âdays, then levels of liver enzymes, bile acid metabolism, inflammation, and intestinal barrier markers were assessed using quantitative real-time PCR. Fibroblast growth factor (FGF) 19 serum levels were determined using enzyme-linked immunosorbent assays. Bile acids were determined in liver, serum, and intestinal contents, and the microbiome was sequenced in different intestinal segments. RESULTS: The PN model was established in newborn piglets. The levels of serum liver enzymes, pro-inflammatory factors, and oxidative stress increased in the livers of piglets fed with PN, but not in those fed with PN and tropifexor. Tropifexor stimulated FGF19 expression in ileal epithelial cells, increased portal FGF19 levels, then inhibited cholesterol 7α-hydroxylase expression in the liver. Tropifexor increased the relative abundance of bacteria associated with bile salt hydrolase and 7α-dehydrogenation in the contents of ileum and altered the composition of bile acids in serum, liver, and intestinal contents. Tropifexor also inhibited intestinal inflammation, alleviated intestinal mucosal atrophy, and improved the intestinal barrier. CONCLUSIONS: Tropifexor might prevent liver damage in neonatal piglets receiving PN by altering the composition of intestinal microbiota and bile acids. Tropifexor also alleviates intestinal inflammation and preserves the intestinal barrier.
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Hepatopatias , Animais , Benzotiazóis , Humanos , Isoxazóis , Fígado , Nutrição Parenteral , SuínosRESUMO
Knowledge about the impact of altitude and ethnicity on human oral microbiota is currently limited. To obtain the baseline of normal salivary microbiota, we analyzed the bacteria and fungi composition in Tibetan (HY group) and Han population (CD group) living at different altitudes by using next-generation sequencing (NGS) technology combined with PICRUSt and FUNGuild analyses. There were significant differences in oral microbiota composition between the two groups at phylum and genus levels. At the phylum level, the HY group had higher relative abundances of Firmicutes and Ascomycota, whereas the Bacteroidetes and Basidiomycota in the CD group were richer. These changes at the phylum level reflected different dominant genus compositions. Compared with the Han population, Candida, Fusarium, Zopfiella, Streptococcus, Veillonella and Rothia in Tibetan were higher. Surprisingly, the Zopfiella was found almost exclusively in the Tibetan. The PICRUSt and FUNGuild analysis also indicated that the function of the bacterial and fungal communities was altered between the two groups. In conclusion, our results suggest that there are significant differences in oral microbial structure and metabolic characteristics and trophic modes among Tibetan and Han population living at different altitudes. We first established the oral microbiota framework and represented a critical step for determining the diversity of oral microbiota in the Tibetan and Han population.