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Understanding how potent neutralizing antibodies (NAbs) inhibit SARS-CoV-2 is critical for effective therapeutic development. We previously described BD-368-2, a SARS-CoV-2 NAb with high potency; however, its neutralization mechanism is largely unknown. Here, we report the 3.5-Å cryo-EM structure of BD-368-2/trimeric-spike complex, revealing that BD-368-2 fully blocks ACE2 recognition by occupying all three receptor-binding domains (RBDs) simultaneously, regardless of their "up" or "down" conformations. Also, BD-368-2 treats infected adult hamsters at low dosages and at various administering windows, in contrast to placebo hamsters that manifested severe interstitial pneumonia. Moreover, BD-368-2's epitope completely avoids the common binding site of VH3-53/VH3-66 recurrent NAbs, evidenced by tripartite co-crystal structures with RBDs. Pairing BD-368-2 with a potent recurrent NAb neutralizes SARS-CoV-2 pseudovirus at pM level and rescues mutation-induced neutralization escapes. Together, our results rationalized a new RBD epitope that leads to high neutralization potency and demonstrated BD-368-2's therapeutic potential in treating COVID-19.
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Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/patologia , Pneumonia Viral/patologia , Animais , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/química , Anticorpos Antivirais/uso terapêutico , Reações Antígeno-Anticorpo , Sítios de Ligação , COVID-19 , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Cricetinae , Microscopia Crioeletrônica , Modelos Animais de Doenças , Epitopos/química , Epitopos/imunologia , Feminino , Pulmão/patologia , Masculino , Simulação de Dinâmica Molecular , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Estrutura Quaternária de Proteína , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologiaRESUMO
IFN-γ is a pleiotropic cytokine that plays a controversial role in regulatory T cell (Treg) activity. In this study, we sought to understand how IFN-γ receptor (IFN-γR) signaling affects donor Tregs following allogeneic hematopoietic cell transplant (allo-HCT), a potentially curative therapy for leukemia. We show that IFN-γR signaling inhibits Treg expansion and conversion of conventional T cells (Tcons) to peripheral Tregs in both mice and humans. Mice receiving IFN-γR-deficient allo-HCT showed markedly reduced graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effects, a trend associated with increased frequencies of Tregs, compared with recipients of wild-type allo-HCT. In mice receiving Treg-depleted allo-HCT, IFN-γR deficiency-induced peripheral Treg conversion was effective in preventing persistent GVHD while minimally affecting GVL effects. Thus, impairing IFN-γR signaling in Tcons may offer a promising strategy for achieving GVL effects without refractory GVHD. Similarly, in a human PBMC-induced xenogeneic GVHD model, significant inhibition of GVHD and an increase in donor Tregs were observed in mice cotransferred with human CD4 T cells that were deleted of IFN-γR1 by CRISPR/Cas9 technology, providing proof-of-concept support for using IFN-γR-deficient T cells in clinical allo-HCT.
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Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Leucemia , Camundongos , Humanos , Animais , Linfócitos T Reguladores , Transplante Homólogo , Leucócitos Mononucleares , Camundongos KnockoutRESUMO
Identification of the phosphatidylserine (PS) discrepancies occurring on the cellular membrane during apoptotic processes is of the utmost importance. However, monitoring the quantity of PS molecules in real-time at a single-cell level currently remains a challenging task. Here, we demonstrate this objective by leveraging the specific binding and reversible interaction exhibited by the zinc(II) dipyridinamine complex (ZnDPA) with PS. Lipoic acid-functionalized ZnDPA (LP-ZnDPA) was subsequently immobilized onto the surface of an atomic force microscopy cantilever to form a force probe, ALP-ZnDPA, enabling a PS-specific dynamic imaging and detection mode. By utilizing this technique, we can not only create a heat map of the expression level of PS with submicron resolution but also quantify the number of molecules present on a single cell's surface with a detection limit of 1.86 × 104 molecules. The feasibility of the proposed method is demonstrated through the analysis of PS expression levels in different cancer cell lines and at various stages of paclitaxel-induced apoptosis. This study represents the first application of a force probe to quantify PS molecules on the surface of individual cells, providing insight into dynamic changes in PS content during apoptosis at the molecular level and introducing a novel dimension to current detection methodologies.
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Fosfatidilserinas , Imagem Individual de Molécula , Fosfatidilserinas/química , Apoptose , Membrana Celular/metabolismo , Microscopia de Força Atômica/métodos , Análise EspectralRESUMO
Ginger is an important cooking spice and herb worldwide, and scientific research has gradually confirmed the effect of ginger on preventing hair loss. Cedrol (CE) is a small sesquiterpene molecule in ginger and its external administration (EA) has shown hope in promoting hair growth, and alternative administration mode has become a potential treatment scheme to improve the efficacy of CE. The purpose of this study is to evaluate the effects of oral administration (OA) and EA of CE on hair regeneration of C57BL/6 alopecia areata (AA) mice induced by cyclophosphamide (CP) and to clarify the potential hair growth mechanism of CE in AA model in vitro and in vivo. The results showed that CE-OA has a shorter hair-turning black time and faster hair growth rate, and can lessen hair follicle damage induced by CP and promote hair follicle cell proliferation. Its effect is superior to CE-EA. At the same time, CE can increase the cytokines IFN-γ, IL-2, and IL-7 in the serum of mice, and decrease the expression of adhesion factors ICAM-1 and ELAM-1, thus alleviating the immunosuppression induced by CP. Mechanism research shows that CE regulates the JAK3/STAT3 signaling pathway, activates the Wnt3α/ß-catenin germinal center, and ameliorates oxidative stress induced by CP, thus promoting the proliferation of hair follicle cells and reversing AA. These results provide a theoretical basis for understanding the anti-AA mechanism of CE-OA, indicating that CE can be used as raw material for developing oral hair growth drugs.
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A novel zwitterionic polymer grafted silica stationary phase, Sil-PZIC, was prepared by bonding poly(ethylene maleic anhydride) molecules on the surface of silica via multiple binding sites, followed by ammonolysis of maleic anhydride through a nucleophilic substitution reaction with ethylenediamine. The stationary phase was characterized by solid-state 13C nuclear magnetic resonance, zeta potential, and elemental analysis and the results show the successful encapsulation of zwitterionic polymer on the surface of silica. The chromatographic performance of Sil-PZIC was investigated by using nucleosides and nucleic bases as test analytes The variation of retention and separation performance of these model compounds were investigated by varying the chromatographic conditions such as the components of mobile phase, salt concentration, and pH. The results show that the retention of the Sil-PZIC phase was dominated by a hydrophilic partitioning mechanism accompanied by secondary interactions such as electrostatic and hydrogen bonding. In addition, saccharides and Amadori compounds were also well separated on the Sil-PZIC, indicating that the Sil-PZIC column has potential application for separation of the polar compound.
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BACKGROUND AND AIMS: Although the prevalence of NAFLD has risen dramatically to 25% of the adult population worldwide, there are as yet no approved pharmacological interventions for the disease because of uncertainty about the underlying molecular mechanisms. It is known that mitochondrial dysfunction is an important factor in the development of NAFLD. Mitochondrial antiviral signaling protein (MAVS) is a critical signaling adaptor for host defenses against viral infection. However, the role of MAVS in mitochondrial metabolism during NAFLD progression remains largely unknown. APPROACH AND RESULTS: Based on expression analysis, we identified a marked down-regulation of MAVS in hepatocytes during NAFLD progression. By using MAVS global knockout and hepatocyte-specific MAVS knockout mice, we found that MAVS is protective against diet-induced NAFLD. MAVS deficiency induces extensive mitochondrial dysfunction during NAFLD pathogenesis, which was confirmed as impaired mitochondrial respiratory capacity and membrane potential. Metabolomics data also showed the extensive metabolic disorders after MAVS deletion. Mechanistically, MAVS interacts with the N-terminal stretch of voltage-dependent anion channel 2 (VDAC2), which is required for the ability of MAVS to influence mitochondrial function and hepatic steatosis. CONCLUSIONS: In hepatocytes, MAVS plays an important role in protecting against NAFLD by helping to regulate healthy mitochondrial function. These findings provide insights regarding the metabolic importance of conventional immune regulators and support the possibility that targeting MAVS may represent an avenue for treating NAFLD.
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Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Mitocôndrias/metabolismo , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Animais , Células Cultivadas , Progressão da Doença , Regulação para Baixo , Técnicas de Silenciamento de Genes , Células Estreladas do Fígado , Hepatócitos , Homeostase , Humanos , Lipogênese/genética , Masculino , Metabolômica , Camundongos , Camundongos Knockout , Mitocôndrias/fisiologia , Hepatopatia Gordurosa não Alcoólica/genética , Cultura Primária de Células , Canal de Ânion 2 Dependente de Voltagem/genética , Canal de Ânion 2 Dependente de Voltagem/metabolismoRESUMO
The trans-epithelial electrical resistance (TEER) is widely used to quantitatively evaluate cellular barrier function at the organ level in vitro. The measurement of the TEER in organ-on-chips (organ chips) plays a significant role in medical and pharmacological research. However, due to the limitation of the electrical equivalent model for organ chips, the existing TEER measurements usually neglect the changes of the TEER during cell proliferation, resulting in the low accuracy of the measurements. Here, we proposed a new whole-region model of the TEER and developed a real-time TEER measurement system that contains an organ chip with a plate electrode. A whole region circuit model considering the impedance of the non-cell covered region was also established, which enables TEER measurements to be independent of the changes in the cell covered region. The impedance of the non-cell covered region is here attributed to the resistance of the porous membrane. By combining the real-time measurement system and the whole region model, subtle changes in cellular activity during the proliferation stage were measured continuously every 6 minutes and a more sensitive TEER response was obtained. Furthermore, the TEER measurement accuracy was also verified by the real-time measurement of the TEER with stimulation using the permeability enhancer ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA). The obtained results indicated that the new proposed whole region model and the real-time measurement system have higher accuracy and greater sensitivity than the traditional model.
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Células Epiteliais , Sistemas Microfisiológicos , Impedância Elétrica , Linhagem Celular , Proliferação de CélulasRESUMO
BACKGROUND: Patients with local gastric cancer experience a decline of Health-related quality of life (HRQOL) during adjuvant chemotherapy following gastrectomy. Our previous pilot study has indicated the potential of acupuncture to improve HRQOL and control cancer-related symptoms burden. This full-scale trial will focus on confirming the effect of acupuncture for patients with gastric cancer. METHODS: A multicenter, open-label, three-arm randomized controlled trial with 249 patients will be conducted in China. Patients will be randomly assigned, in a ratio of 1:1:1, to receive high-dose acupuncture (HA, 7 times each chemo-cycle for 3 cycles), low-dose acupuncture (LA, 3 times each chemo-cycle for 3 cycles), or no acupuncture. The acupoints prescription consisted of bilateral ST36, PC6, SP4, DU20, EX-HN3, and selected Back-shu points. Patients-reported Functional Assessment of Cancer Therapy-Gastric (FACT-Ga) and modified Edmonton Symptom Assessment Scale (mESAS) during the therapy will be recorded. Area under curve (AUC, 21 days/cycle × 3 cycles) and average trajectory of FACT-Ga and mESAS will be calculated. The primary outcome will be the differences in AUC of the FACT-Ga Trial Outcome Index (TOI) between HA and LA versus control groups. Secondary outcomes include AUCs and average trajectory of other FACT-Ga subscales and mESAS scores. DISCUSSION: This study aims to assess the effect of acupuncture and to compare the difference between LA and HA groups on HRQOL and symptom burden controlling in gastric cancer patients by an adequately powered trial. TRIAL REGISTRATION: This study was approved by the Ethics Committee of the Guangdong Provincial Hospital of Traditional Chinese Medicine (approval number: BF2018-118) with registration at ClinicalTrials.gov (identifier: NCT04360577).
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Terapia por Acupuntura , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamento farmacológico , Qualidade de Vida , Projetos Piloto , Quimioterapia Adjuvante , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como AssuntoRESUMO
Circulating tumor cells (CTCs) play a vital role in the metastasis and recurrence of breast cancer. CTCs are highly heterogeneous at the stage of Epithelial-to-Mesenchymal Transition (EMT), but the phenotypic and biological characteristics in different EMT stages remain poorly defined. We conducted an orthotopic mouse (4T1) model of breast cancer to isolate CTCs and identified two phenotypes of CTCs: intermediate E/M and mesenchymal CTCs. MTT, Colony formation, Transwell migration and invasion assays were utilized to examined cell proliferation, colony forming, migration and invasion ability. Both the intermediate E/M and mesenchymal CTCs exhibited lower rates of proliferation, colony formation and invasion, as compared to primary tumor cells. The mesenchymal CTCs had a higher rate of invasion but lower rates of proliferation and colony formation than the intermediate E/M CTCs. They also exhibited lower rates of growth and metastasis than the primary tumor cells in vivo, but the mesenchymal CTCs had a higher rate of metastasis than the intermediate E/M CTCs. Fluid shear stress induced the EMT transition of CTCs. The comprehensive analysis of CTCs proteomics discovered proteins that differentially expressed in the two types of CTCs and their primary tumor cells.
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Células Neoplásicas Circulantes , Camundongos , Animais , Células Neoplásicas Circulantes/patologia , Biomarcadores Tumorais/metabolismo , Transição Epitelial-Mesenquimal/genética , Contagem de Células , Metástase NeoplásicaRESUMO
Silicosis is one of the most frequent, rapidly developing, and lethal types of pneumoconiosis. However, our understanding of the underlying mechanisms of its pathogenesis and progress remains unclear. We investigated the fundamental processes of silicosis incidence and progression using a combination of lung function testing, histopathology, 16 S rRNA, untargeted metabolomics, and cytokine chips at different exposure times (4 or 8 weeks). The results show that silica exposure damages lung tissue reduces lung function, and increases with time. Cytokines with time-specific properties were found in lung lavage fluid: IFN-γ (4 weeks; Pï¼0.05), TNF-α, M-CSF, GM-CSF (8 weeks; Pï¼0.01). In addition, silica exposure for different periods interferes to varying degrees with the metabolism of lipids. The composition of the intestinal microbiota changed with increasing exposure time and there were time-specific: Allobaculum, TuricibacterãJeotgalicoccuãCoprococcus 1 (4 weeks; Pï¼0.05), Ruminococcaceae NK4A214 groupãRuminiclostridium 5 (8 weeks; Pï¼0.05). We found strong associations between cytokines, gut microbiota changes, and metabolic disturbances at different exposure times. These results suggest that time-specific changes in crosstalk among cytokines, the gut microbiota, and metabolites may be a potential mechanism for silica-induced lung injury.
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Microbioma Gastrointestinal , Silicose , Ratos , Animais , Microbioma Gastrointestinal/genética , Citocinas/metabolismo , Ratos Wistar , Metaboloma , Silicose/metabolismo , Dióxido de Silício/toxicidade , RNA Ribossômico 16S/metabolismoRESUMO
Children are disproportionately represented among those who suffer asthma, which is a kind of chronic airway inflammation. Asthma symptoms might worsen when exposed to the air pollutant particulate matter 2.5 (PM2.5). However, it is becoming more prevalent among older adults, with more asthma-related deaths occurring in this pollution than in any other age group, and symptoms caused by asthma can reduce the quality of life of the elderly, whose asthma is underdiagnosed due to physiological factors. Therefore, in an effort to discover a therapy for older asthma during exposure to air pollution, we sought to ascertain the effects of pre-exposure (PA) and persistent exposure (PAP) to PM2.5 in aged asthma rats. In this study, we exposed aged rats to PM2.5 at different times (PA and PAP) and established an ovalbumin-mediated allergic asthma model. The basic process of elderly asthma caused by PM2.5 exposure was investigated by lung function detection, enzyme-linked immunosorbent assay (ELISA), histopathology, cytology, cytokine microarray, untargeted metabolomics, and gut microbiota analysis. Our findings demonstrated that in the PA and PAP groups, exposure to PM2.5 reduced lung function and exacerbated lung tissue damage, with varying degrees of effect on immunoglobulin levels, the findings of a cytological analysis, cytokines, and chemokines. The PA and PAP rats had higher amounts of polycyclic aromatic hydrocarbons (PAHs), such as naphthalene, 2-methylNaphthalene, 1-methylNaphthalene and flourene. Moreover, exposure to PM2.5 at different times showed different effects on plasma metabolism and gut microbiota. Bioinformatics analysis showed a strong correlation between PAHs, cytokines, and gut microbiota, and PAHs may cause metabolic disorders through the gut microbiota. These findings point to a possible mechanism for the development of asthma in older people exposure to PM2.5 that may be related to past interactions between PAHs, cytokines, gut microbiota, and plasma metabolites.
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Asma , Hidrocarbonetos Policíclicos Aromáticos , Ratos , Animais , Multiômica , Qualidade de Vida , Asma/induzido quimicamente , Citocinas , InflamaçãoRESUMO
The use of seawater as a substitute for pure water as supplemental moisture raises questions about its effect on the physicochemical properties of hydrochar. Therefore, this study aimed to investigate the feasibility of using seawater as supplemental moisture by comparing the physicochemical properties of products obtained through Co-hydrothermal carbonization of chicken manure and cornstalk under seawater and deionized water conditions. By varying the HTC temperature and blending ratios of CM and CS to investigate comprehensively the effect of seawater. Results indicated that the hydrochar yield experienced a variation from 54.54% to 57.40%, while the IC value changed from 7.69% to 8.46% as the ratio of CM:CS shifted from 3:1 to 1:3 under seawater conditions. The higher heating value of the hydrochars obtained under seawater conditions was lower than those obtained under deionized water conditions. This suggests that seawater conditions promote the hydrolysis reaction of organic solid waste. Furthermore, it was observed that when no lignin hydrolysis reaction occurred, seawater conditions had no discernible effect on the fuel quality of the hydrochar. However, at an HTC temperature of 250 °C, the fuel quality of the hydrochar obtained under seawater conditions was notably inferior to that of the hydrochar obtained under deionized water. Thus, an HTC temperature lower than 250 °C is necessary for the hydrothermal carbonization of organic solid waste under seawater conditions. Moreover, the relative content of surface -C-(C, H)/CC of the hydrochar obtained under seawater conditions was lower than that obtained under deionized water conditions, indicating that the hydrochar had a low degree of aromatization. Additionally, there was a significant increase in the immobilized Mg atoms in the hydrochar under seawater conditions, which affected the hydrochar yield and higher heating value of the hydrochar. This research presents a theoretical foundation for preparing solid fuels and materials using hydrothermal carbonization of saltwater as supplemental moisture.
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Carbono , Esterco , Animais , Galinhas , Resíduos Sólidos , Água do Mar , Água , TemperaturaRESUMO
Growing reports indicate that Sprouty (SPRY) isoforms act as inhibitors or promoters in various types of cancers. And the occurrence of different cancers may be related to the abnormal expression of one of the SPRY isoforms. The identification of SPRY isoforms thus plays a particularly important role in determining which isoform's aberrant expression inhibits or promotes cancer. But their own properties, such as similarities in the structure and molecular weight, make their identification particularly difficult. In this article, we propose a novel method to identify SPRY isoforms using atomic force microscopy (AFM) by observing differential binding of different SPRY isoforms to bovine serum albumin (BSA), which can be used to distinguish SPRY isoforms at the single-molecule level. Specific binding of SPRY1 and BSA was observed by AFM. The reduction in the number of monomeric protein molecules caused by the partial depletion of these two proteins during binding is also consistent with the weakening of the monomeric protein bands in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). At the same time, the arrangement of the two proteins in a tightly bound complex was also observed. However, the SPRY3 isoform did not interact with BSA to cause aggregation, and the diameter and height of the two proteins did not change significantly compared to those before the reaction. In this way, with the participation of BSA, the two isoforms, SPRY1 and SPRY3, can be identified and separated using atomic force microscopy. In addition, the experimental result that the formation of the SPRY1-BSA complex can selectively reduce the concentration of SPRY1 isoforms in the environment will also contribute to future research on anticancer drugs influenced by SPRY1.
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Microscopia de Força Atômica , Eletroforese em Gel de Poliacrilamida , Peso Molecular , Isoformas de ProteínasRESUMO
OBJECTIVES: Premature ovarian insufficiency (POI) refers to the decline and cessation of ovarian functions in women under 40 years of age. Melatonin (MT) acts as a protective for the ovary. This study elucidated the role of MT in autophagy of granulosa cells (GCs) in POI via modulating the phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway. METHODS: The expression levels of microRNA (miR)-15a-5p, signal transducer and activator of transcription 3 (Stat3), and relevant hormones in the clinically collected serum samples of POI patients and healthy controls were examined. Human ovarian granulosa-like tumor cells (KGN) underwent serum starvation (SS) treatment to induce POI cell models and then received MT treatment. The expression levels of miR-15a-5p, Stat3, p-PI3K/PI3K, p-Akt/Akt, and p-mTOR/mTOR in KGN cells were tested via quantitative real-time polymerase chain reaction and Western blotting. KGN cell viability was assessed by MTT assay and the protein levels of autophagy-related markers Beclin-1, microtubule-associated protein light chain 3 II/I, and p62 were detected by Western blotting. The binding relation between miR-15a-5p and Stat3 was verified via the dual-luciferase reporter gene assay. Functional rescue experiments were performed to probe the underlying role of miR-15a-5p/Stat3/the PI3K-Akt-mTOR pathway in KGN cell autophagy. RESULTS: miR-15a-5p was increased whilst Stat3 was decreased in the serum of POI patients and SS-induced KGN cells. MT inhibited miR-15a-5p and Stat3, activated the PI3K-Akt-mTOR pathway, and repressed cell autophagy in SS-induced KGN cells. miR-15a-5p targeted and repressed Stat3 expression. Upregulation of miR-15a-5p or downregulation of Stat3 or the PI3K-Akt-mTOR pathway promoted KGN cell autophagy. CONCLUSION: MT suppressed miR-15a-5p and activated Stat3 and the PI3K-Akt-mTOR pathway, finally impeding SS-induced autophagy of GCs.
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Melatonina , Menopausa Precoce , MicroRNAs , Insuficiência Ovariana Primária , Humanos , Feminino , Proteínas Proto-Oncogênicas c-akt/metabolismo , Melatonina/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , MicroRNAs/genética , Serina-Treonina Quinases TOR/metabolismo , Células da Granulosa/metabolismo , AutofagiaRESUMO
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes severe viral pneumonia and is associated with a high fatality rate. A substantial proportion of patients infected by SARS-CoV-2 suffer from mild hyposmia to complete loss of olfactory function, resulting in anosmia. However, the pathogenesis of the olfactory dysfunction and comparative pathology of upper respiratory infections with SARS-CoV-2 are unknown. We describe the histopathological, immunohistochemical, and in situ hybridization findings from rodent models of SARS-CoV-2 infection. The main histopathological findings in the olfactory epithelia of K8-hACE2 Tg mice, hACE2 Tg mice, and hamsters were varying degrees of inflammatory lesions, including disordered arrangement, necrosis, exfoliation, and macrophage infiltration of the olfactory epithelia, and inflammatory exudation. On the basis of these observations, the nasal epithelia of these rodent models appeared to develop moderate, mild, and severe rhinitis, respectively. Correspondingly, SARS-CoV-2 viral RNA and antigen were mainly identified in the olfactory epithelia and lamina propria. Moreover, viral RNA was abundant in the cerebrum of K18-hACE2 Tg mice, including the olfactory bulb. The K8-hACE2 Tg mouse, hACE2 Tg mouse, and hamster models could be used to investigate the pathology of SARS-CoV-2 infection in the upper respiratory tract and central nervous system. These models could help to provide a better understanding of the pathogenic process of this virus and to develop effective medications and prophylactic treatments.
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COVID-19 , Doenças dos Roedores , Enzima de Conversão de Angiotensina 2 , Animais , COVID-19/veterinária , Cricetinae , Modelos Animais de Doenças , Pulmão/patologia , Melfalan , Camundongos , Camundongos Transgênicos , Mucosa Nasal , Peptidil Dipeptidase A/genética , RNA Viral , Doenças dos Roedores/patologia , SARS-CoV-2 , gama-GlobulinasRESUMO
Locust powder was converted into water-soluble fluorescent nitrogen-doped carbon dots (N-CDs) with gram-scale yield through a self-exothermic reaction between nitric acid and diethylenetriamine (DETA) within 10 min. The morphology, elemental information, and optical properties of the N-CDs were characterized using high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared, ultraviolet-visible and fluorescence spectroscopy. Spectroscopic investigation indicated that the fluorescence emission behaviour of N-CDs is excitation wavelength dependent, with the strongest emission peak at 470 nm using a 390 nm excitation wavelength. The strong absorption peak of sunset yellow (SY) at 482 nm overlaps substantially with the blue emission peak (470 nm) of N-CDs. This enables the fluorescence emission of N-CDs to be obviously quenched by SY through the inner filter effect. There was a good linear relationship between the fluorescence quenching degree and the concentrations of SY within the range 0.5-40 µM. The detection limit of developed fluorescence assay for SY is 28 nM, and the relative standard deviation is 2.3% (c = 10 µM). The N-CDs derived from locusts by the self-exothermic reaction are highly selective and sensitive fluorescent probes for SY, which were applied to the fluorescence sensing of SY in different food samples with satisfactory results.
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Gafanhotos , Pontos Quânticos , Animais , Compostos Azo , Carbono , Corantes Fluorescentes , Nitrogênio , Espectrometria de FluorescênciaRESUMO
Domestic cats, an important companion animal, can be infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This has aroused concern regarding the ability of domestic cats to spread the virus that causes coronavirus disease 2019. We systematically demonstrated the pathogenesis and transmissibility of SARS-CoV-2 in cats. Serial passaging of the virus between cats dramatically attenuated the viral transmissibility, likely owing to variations of the amino acids in the receptor-binding domain sites of angiotensin-converting enzyme 2 between humans and cats. These findings provide insight into the transmissibility of SARS-CoV-2 in cats and information for protecting the health of humans and cats.
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COVID-19/transmissão , COVID-19/veterinária , SARS-CoV-2/patogenicidade , Aminoácidos/metabolismo , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , COVID-19/metabolismo , Gatos , Linhagem Celular , Chlorocebus aethiops , Feminino , Humanos , Masculino , Células VeroRESUMO
Conformational dynamics and transitions of biologically active molecules are pivotal for understanding the physiological responses they elicit. In the case of receptor activation, there are major implications elucidating disease mechanisms and drug discovery innovation. Yet, incorporation of these factors into drug screening systems remains challenging in part due to the lack of suitable approaches to include them. Here, we present a novel strategy to probe the GPCR domain rotation by utilizing the 19fluorine signal variability of a trifluorinated keto-enol (TFKE) chemical equilibrium. The method takes advantage of the high sensitivity of the TFKE tautomerism toward microenvironmental changes resulting from receptor conformational transitions upon ligand binding. We validated the method using the adenosine A2AR receptor as a model system in which the TFKE was attached to two sites exhibiting opposing motions upon ligand binding, namely, V229C6.31 on transmembrane domain VI (TM6) and A289C7.54 on TM7. Our results demonstrated that the TFKE switch was an excellent reporter for the domain rotation and could be used to study the conformational transition and dynamics of relative domain motions. Although further studies are needed in order to establish a quantitative relationship between the rotational angle and the population distribution of different components in a particular system, the research presented here provides a foundation for its application in studying receptor domain rotation and dynamics, which could be useful in drug screening efforts.
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Flúor/química , Sondas Moleculares/química , Receptores Acoplados a Proteínas G/química , Ligantes , Conformação Proteica , Rotação , EstereoisomerismoRESUMO
BACKGROUND: Whereas there are many pharmacological interventions prescribed for patients with advanced anaplastic lymphoma kinase (ALK)- rearranged non-small cell lung cancer (NSCLC), comparative data between novel generation ALK-tyrosine kinase inhibitors (TKIs) remain scant. Here, we indirectly compared the efficacy and safety of first-line systemic therapeutic options used for the treatment of ALK-rearranged NSCLC. METHODS: We included all phase 2 and 3 randomised controlled trials (RCTs) comparing any two or three treatment options. Eligible studies reported at least one of the following outcomes: progression free survival (PFS), overall survival (OS), objective response rate (ORR), or adverse events of grade 3 or higher (Grade ≥ 3 AEs). Subgroup analysis was conducted according to central nervous system (CNS) metastases. RESULTS: A total of 9 RCTs consisting of 2484 patients with 8 treatment options were included in the systematic review. Our analysis showed that alectinib (300 mg and 600 mg), brigatinib, lorlatinib and ensartinib yielded the most favorable PFS. Whereas there was no significant OS or ORR difference among the ALK-TKIs. According to Bayesian ranking profiles, lorlatinib, alectinib 600 mg and alectinib 300 mg had the best PFS (63.7%), OS (35.9%) and ORR (37%), respectively. On the other hand, ceritinib showed the highest rate of severe adverse events (60%). CONCLUSION: Our analysis indicated that alectinib and lorlatinib might be associated with the best therapeutic efficacy in first-line treatment for major population of advanced NSCLC patients with ALK-rearrangement. However, since there is little comparative evidence on the treatment options, there is need for relative trials to fully determine the best treatment options as well as the rapidly evolving treatment landscape.
Assuntos
Quinase do Linfoma Anaplásico/genética , Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Rearranjo Gênico , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Aminopiridinas/efeitos adversos , Aminopiridinas/uso terapêutico , Antineoplásicos/efeitos adversos , Carbazóis/efeitos adversos , Carbazóis/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Humanos , Lactamas/efeitos adversos , Lactamas/uso terapêutico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Metanálise em Rede , Compostos Organofosforados/efeitos adversos , Compostos Organofosforados/uso terapêutico , Piperazinas/efeitos adversos , Piperazinas/uso terapêutico , Piperidinas/efeitos adversos , Piperidinas/uso terapêutico , Intervalo Livre de Progressão , Inibidores de Proteínas Quinases/efeitos adversos , Pirazóis/efeitos adversos , Pirazóis/uso terapêutico , Piridazinas/efeitos adversos , Piridazinas/uso terapêutico , Pirimidinas/efeitos adversos , Pirimidinas/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do TratamentoRESUMO
Tumor-derived exosomes have been recognized as potential biomarkers for cancer diagnosis because they are actively involved in cancer progression and metastasis. However, progress in practical exosome analysis is still slow due to the limitation in exosome isolation and detection. The development of microfluidic devices has provided a promising analytical platform compared with traditional methods. In this study, we develop an exosome isolation and detection method based on a microfluidic device (ExoDEP-chip), which realized microsphere mediated dielectrophoretic isolation and immunoaffinity detection. Exosomes were firstly isolated by binding to antibodies pre-immobilized on the polystyrene (PS) microsphere surface and were further detected using fluorescently labeled antibodies by fluorescence microscopy. Single microspheres were then trapped into single microwells under the DEP force in the ExoDEP-chip. A wide range from 1.4 × 103 to 1.4 × 108 exosomes per mL with a detection limit of 193 exosomes per mL was obtained. Through monitoring five proteins (CD81, CEA, EpCAM, CD147, and AFP) of exosomes from three different cell lines (A549, HEK293, and HepG2), a significant difference in marker expression levels was observed in different cell lines. Therefore, this method has good prospects in exosome-based tumor marker detection and cancer diagnosis.