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1.
Nature ; 629(8014): 1118-1125, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38778102

RESUMO

Higher plants survive terrestrial water deficiency and fluctuation by arresting cellular activities (dehydration) and resuscitating processes (rehydration). However, how plants monitor water availability during rehydration is unknown. Although increases in hypo-osmolarity-induced cytosolic Ca2+ concentration (HOSCA) have long been postulated to be the mechanism for sensing hypo-osmolarity in rehydration1,2, the molecular basis remains unknown. Because osmolarity triggers membrane tension and the osmosensing specificity of osmosensing channels can only be determined in vivo3-5, these channels have been classified as a subtype of mechanosensors. Here we identify bona fide cell surface hypo-osmosensors in Arabidopsis and find that pollen Ca2+ spiking is controlled directly by water through these hypo-osmosensors-that is, Ca2+ spiking is the second messenger for water status. We developed a functional expression screen in Escherichia coli for hypo-osmosensitive channels and identified OSCA2.1, a member of the hyperosmolarity-gated calcium-permeable channel (OSCA) family of proteins6. We screened single and high-order OSCA mutants, and observed that the osca2.1/osca2.2 double-knockout mutant was impaired in pollen germination and HOSCA. OSCA2.1 and OSCA2.2 function as hypo-osmosensitive Ca2+-permeable channels in planta and in HEK293 cells. Decreasing osmolarity of the medium enhanced pollen Ca2+ oscillations, which were mediated by OSCA2.1 and OSCA2.2 and required for germination. OSCA2.1 and OSCA2.2 convert extracellular water status into Ca2+ spiking in pollen and may serve as essential hypo-osmosensors for tracking rehydration in plants.


Assuntos
Arabidopsis , Sinalização do Cálcio , Cálcio , Germinação , Concentração Osmolar , Pólen , Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Cálcio/metabolismo , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Germinação/genética , Mutação , Pólen/genética , Pólen/metabolismo , Água/metabolismo , Células HEK293 , Humanos , Desidratação
2.
ACS Omega ; 9(1): 1535-1545, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38222553

RESUMO

Amidst the rapid advancements in flexible electronics, flexible pressure sensors have achieved widespread applications in fields such as wearable devices and motion monitoring. Nevertheless, it is still a challenge to design a sensor with high sensitivity, cost-effectiveness, and a simplified manufacturing process. This paper introduces a piezoresistive sensor built upon a composite conductive filler. The sensor incorporates a super absorbent polymer (SAP) to absorb a phosphoric acid solution and doped carbon nanotubes as the composite conductive filler. In contrast to conventional rigid conductive fillers, the elastic polymer SAP enhances the sensor's stability significantly by exhibiting superior compatibility with the polydimethylsiloxane matrix, all the while reducing its Young's modulus. This work aims to theoretically elucidate the underlying principles that enable the sensor to achieve high sensitivity. It focuses on the induction of charge carriers due to pressure, which leads to the formation of a conductive pathway and subsequent changes in resistance, thus facilitating precise pressure detection. The paper also discusses the effects of piezoresistive layers with varying thicknesses and conductive fillers on the sensor's output performance. The results highlight the sensor's high sensitivity (0.094 kPa-1), rapid response time (105 ms), and exceptional cyclic load/unload stability (>5000 cycles). Furthermore, this paper establishes a versatile sensing network by integrating a portable inductance, capacitance, and resistance instrument with a programmable logic controller module. Compared to individual sensors, this system enables multipoint measurements, offering high spatial resolution and real-time monitoring capabilities, significantly expanding its overall practicality.

3.
Naunyn Schmiedebergs Arch Pharmacol ; 397(2): 913-922, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37535074

RESUMO

Albuvirtide (ABT) is the first long-acting HIV fusion inhibitor developed in China, blocking the invasion of HIV-1 virus into target cells. This study aimed to compare the pharmacokinetics (PK), tolerability, and safety of ABT following a single intravenous (IV) bolus injection or intravenous drip in healthy Chinese subjects. A single-center, randomized, open-label, single-period, parallel phase I clinical trial was conducted. Thirty subjects were randomly divided into three groups in a ratio of 1:1:1. After an overnight fast, all subjects received a single dose of 320 mg ABT either by intravenous drip for 45 min (group A) or bolus injection for 0.5 min (group B), or bolus injection for 3 min (group C). ABT plasma concentrations were analyzed using a validated enzyme-linked immunosorbent assay (ELISA). Non-compartmental analysis was used to evaluate PK parameters. The median time to reach maximum concentration was 0.75 h in group A and 0.16 h in both groups B and C. Elimination half-life, mean residence time, apparent clearance, and apparent volume of distribution were similar among the three groups. The 90% confidence intervals (CI) of geometric mean ratios of PK parameters for groups B and C relative to group C were within 85-120%. All adverse events (AEs) reported in this study were mild, according to the CTCAE guidelines and the study investigator's judgement. ABT bolus injections for 0.5 min and 3 min are expected to be well tolerated and to exhibit similar PK characteristics as IV drip for 45 min, offering potential clinical benefits.


Assuntos
Maleimidas , Peptídeos , Humanos , Infusões Intravenosas , Voluntários Saudáveis , Injeções Intravenosas
4.
Plant Cell Environ ; 47(2): 682-697, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37882446

RESUMO

Quercetin is a key flavonol in tea plants (Camellia sinensis (L.) O. Kuntze) with various health benefits, and it often occurs in the form of glucosides. The roles of quercetin and its glucosylated forms in plant defense are generally not well-studied, and remain unknown in the defense of tea. Here, we found higher contents of quercetin glucosides and a decline of the aglucone upon Ectropis grisescens (E. grisescens) infestation of tea. Nine UGTs were strongly induced, among which UGT89AC1 exhibited the highest activity toward quercetin in vitro and in vivo. The mass of E. grisescens larvae that fed on plants with repressed UGT89AC1 or varieties with lower levels of UGT89AC1 was significantly lower than that of larvae fed on controls. Artificial diet supplemented with quercetin glucoside also reduced the larval growth rate, whereas artificial diet supplemented with free quercetin had no significant effect on larval growth. UGT89AC1 was located in both the cytoplasm and nucleus, and its expression was modulated by JA, JA-ILE, and MeJA. These findings demonstrate that quercetin glucosylation serves a defensive role in tea against herbivory. Our results also provide novel insights into the ecological relevance of flavonoid glycosides under biotic stress in plants.


Assuntos
Camellia sinensis , Lepidópteros , Animais , Camellia sinensis/metabolismo , Quercetina/farmacologia , Quercetina/metabolismo , Herbivoria , Larva , Chá/metabolismo , Glucosídeos/metabolismo , Proteínas de Plantas/metabolismo
5.
ACS Omega ; 8(49): 46346-46361, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38107919

RESUMO

A colorimetric sensor detects an analyte by utilizing the optical properties of the sensor unit, such as absorption or reflection, to generate a structural color that serves as the output signal to detect an analyte. Detecting the refractive index of an analyte by recording the color change of the sensor structure on its surface has several advantages, including simple operation, low cost, suitability for onsite analysis, and real-time detection. Colorimetric sensors have drawn much attention owing to their rapidity, simplicity, high sensitivity and selectivity. This Review discusses the use of colorimetric sensors in the food industry, including their applications for detecting food contaminants. The Review also provides insight into the scope of future research in this area.

6.
Front Immunol ; 14: 1230772, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37818352

RESUMO

Macrophages play a critical role in the inflammatory response and tumor development. Macrophages are primarily divided into pro-inflammatory M1-like and anti-inflammatory M2-like macrophages based on their activation status and functions. In vitro macrophage models could be derived from mouse bone marrow cells stimulated with two types of differentiation factors: GM-CSF (GM-BMDMs) and M-CSF (M-BMDMs), to represent M1- and M2-like macrophages, respectively. Since macrophage differentiation requires coordinated metabolic reprogramming and transcriptional rewiring in order to fulfill their distinct roles, we combined both transcriptome and metabolome analysis, coupled with experimental validation, to gain insight into the metabolic status of GM- and M-BMDMs. The data revealed higher levels of the tricarboxylic acid cycle (TCA cycle), oxidative phosphorylation (OXPHOS), fatty acid oxidation (FAO), and urea and ornithine production from arginine in GM-BMDMs, and a preference for glycolysis, fatty acid storage, bile acid metabolism, and citrulline and nitric oxide (NO) production from arginine in M-BMDMs. Correlation analysis with the proteomic data showed high consistency in the mRNA and protein levels of metabolic genes. Similar results were also obtained when compared to RNA-seq data of human monocyte derived macrophages from the GEO database. Furthermore, canonical macrophage functions such as inflammatory response and phagocytosis were tightly associated with the representative metabolic pathways. In the current study, we identified the core metabolites, metabolic genes, and functional terms of the two distinct mouse macrophage populations. We also distinguished the metabolic influences of the differentiation factors GM-CSF and M-CSF, and wish to provide valuable information for in vitro macrophage studies.


Assuntos
Fator Estimulador de Colônias de Granulócitos e Macrófagos , Fator Estimulador de Colônias de Macrófagos , Humanos , Animais , Camundongos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Fator Estimulador de Colônias de Macrófagos/metabolismo , Transcriptoma , Proteômica , Diferenciação Celular , Macrófagos/metabolismo , Arginina/metabolismo , Ácidos Graxos/metabolismo
8.
J Med Virol ; 95(5): e28793, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37212266

RESUMO

Epstein-Barr virus (EBV) infection is prevalent in global population and associated with multiple malignancies and autoimmune diseases. During the infection, EBV-harbored or infected cell-expressing antigen could elicit a variety of antibodies with significant role in viral host response and pathogenesis. These antibodies have been extensively evaluated and found to be valuable in predicting disease diagnosis and prognosis, exploring disease mechanisms, and developing antiviral agents. In this review, we discuss the versatile roles of EBV antibodies as important biomarkers for EBV-related diseases, potential driving factors of autoimmunity, and promising therapeutic agents for viral infection and pathogenesis.


Assuntos
Doenças Autoimunes , Infecções por Vírus Epstein-Barr , Esclerose Múltipla , Humanos , Infecções por Vírus Epstein-Barr/diagnóstico , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Infecções por Vírus Epstein-Barr/complicações , Herpesvirus Humano 4 , Anticorpos Antivirais , Doenças Autoimunes/complicações , Antivirais/uso terapêutico
9.
Clin Cancer Res ; 29(15): 2869-2884, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37184976

RESUMO

PURPOSE: Radiation-induced sarcomas (RIS) have a poor prognosis and lack effective treatments. Its genome and tumor microenvironment are not well characterized and need further exploration. EXPERIMENTAL DESIGN: Here, we performed whole-exome sequencing (WES) and mRNA sequencing (mRNA-seq) on patients with RIS and primary sarcomas (WES samples 46 vs. 48, mRNA-seq samples 16 vs. 8, mainly in head and neck), investigated the antitumor effect of programmed cell death protein 1 (PD-1) blockade in RIS patient-derived xenograft models, and analyzed clinical data of patients with RIS treated with chemotherapy alone or combined with an anti-PD-1 antibody. RESULTS: Compared with primary sarcomas, RIS manifested different patterns of copy-number variations, a significantly higher number of predicted strong MHC-binding neoantigens, and significantly increased immune cell infiltration. Clinical data showed that the combinatorial use of chemotherapy and PD-1 blockade achieved a higher objective response rate (36.67% vs. 8.00%; P = 0.003), longer overall survival (31.9 months vs. 14.8 months; P = 0.014), and longer progression-free survival (4.7 months vs. 9.5 months; P = 0.032) in patients with RIS compared with single chemotherapy. CONCLUSIONS: Elevated genomic instability and higher immune cell infiltrations were found in RIS than in primary sarcomas. Moreover, higher efficacy of chemotherapy plus PD-1 blockade was observed in animal experiments and clinical practice. This evidence indicated the promising application of immune checkpoint inhibitors in the treatment of RIS.


Assuntos
Inibidores de Checkpoint Imunológico , Sarcoma , Animais , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Sarcoma/tratamento farmacológico , Sarcoma/genética , Genômica , RNA Mensageiro , Microambiente Tumoral
10.
Am J Transl Res ; 15(3): 1862-1870, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37056838

RESUMO

OBJECTIVE: To compare the capability of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and apparent diffusion coefficient (ADC) histogram analysis in epithelial ovarian tumor categorization. METHODS: We retrospectively recruited 52 patients with pathologically proven ovarian serous epithelial cancer from our institution. ADC histogram analysis was performed using FeAture Explorer software after outlining the whole lesion area on the ADC map. The ADC histogram parameter difference between subgroups was compared; the correlation between the quantitative parameters on MRI and Ki-67 expression was calculated for both groups. RESULTS: The repeatability of ADC measurements across the two methods was good; the area method (ADCarea) had better performance in repeatability than the ROI method (ADCroi). The ADCroi, ADCarea, Ktrans, and Kep values significantly differed between the groups (P < 0.05). The histogram parameters (percent10, entropy, minimum, range and variance) and DCE parameter (Ktrans) were strongly correlated with Ki-67 expression (P = 0.000), while the conventional ADC measurements were not significantly correlated with Ki-67 expression (P > 0.05). Overall, Ktrans had the best diagnostic performance for discriminating type I with type II ovarian cancers (AUC = 0.826). CONCLUSION: In the present study, both diffusion-weighted imaging (DWI) and DCE MRI could help classify ovarian cancer patients with high accuracy. ADC histogram analysis could accurately reflect the proliferative capability of tumor cells to some extent.

11.
Int J Mol Sci ; 24(3)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36768307

RESUMO

Super-enhancers (SEs) regulate gene expressions, which are critical for cell type-identity and tumorigenesis. Although genome wide H3K27ac profiling have revealed the presence of SE-associated genes in gastric cancer (GC), their roles remain unclear. In this study, ChIP-seq and HiChIP-seq experiments revealed mitogen-activated protein kinase 8 (MAP3K8) to be an SE-associated gene with chromosome interactions in Epstein-Barr virus-associated gastric carcinoma (EBVaGC) cells. CRISPRi mediated repression of the MAP3K8 SEs attenuated MAP3K8 expression and EBVaGC cell proliferation. The results were validated by treating EBVaGC cells with bromodomain and the extra-terminal motif (BET) inhibitor, OTX015. Further, functional analysis of MAP3K8 in EBVaGC revealed that silencing MAP3K8 could inhibit the cell proliferation, colony formation, and migration of EBVaGC cells. RNA-seq and pathway analysis indicated that knocking down MAP3K8 obstructed the notch signaling pathway and epithelial-mesenchymal transition (EMT) in EBVaGC cells. Further, analysis of the cancer genome atlas (TCGA) and GSE51575 databases exhibited augmented MAP3K8 expression in gastric cancer and it was found to be inversely correlated with the disease-free progression of GC. Moreover, Spearman's correlation revealed that MAP3K8 expression was positively correlated with the expressions of notch pathway and EMT related genes, such as, Notch1, Notch2, C-terminal binding protein 2 (CTBP2), alpha smooth muscle actin isotype 2 (ACTA2), transforming growth factor beta receptor 1 (TGFßR1), and snail family transcriptional repressors 1/2 (SNAI1/SNAI2) in GC. Taken together, we are the first to functionally interrogate the mechanism of SE-mediated regulation of MAP3K8 in EBVaGC cell lines.


Assuntos
Epigênese Genética , Infecções por Vírus Epstein-Barr , MAP Quinase Quinase Quinases , Neoplasias Gástricas , Humanos , Epigênese Genética/genética , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/patologia , Regulação Neoplásica da Expressão Gênica/genética , Herpesvirus Humano 4/genética , MAP Quinase Quinase Quinases/genética , Proteínas Proto-Oncogênicas/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Neoplasias Gástricas/virologia
12.
Front Immunol ; 13: 1049518, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36569905

RESUMO

Background: Human epidermal growth factor receptor 2 (HER2) is the most prominent therapeutic target for advanced gastric (G)/GEJ cancer. However, targeted therapy did not significantly improve survival. Currently, there are no regimens for the treatment of HER-2 amplification that exclude targeted agents. Case presentation: A 42-year-old man was diagnosed with adenocarcinoma of GEJ (stage IV) with liver metastasis and lung metastasis. The patient was enrolled in a trial that excluded patients with known HER2-positivity: AK104, a PD-1/CTLA-4 bispecific antibody, combined with chemotherapy (mXELOX) as first-line therapy for advanced gastric G/GEJ cancer (NCT03852251). After six cycles of AK104 combined with chemotherapy therapy, immune-related pulmonary toxicity was observed. We rechallenged AK104 after hormone therapy, and no further pulmonary toxicity was observed. Immune-related hepatitis occurred in the patient during immunotherapy combined with single-drug capecitabine therapy. After combining steroid therapy with mycophenolate mofetil, the patient's immune hepatitis improved. Nevertheless, the patient was excluded from the clinical study due to the long-term absence of medication. Antitumor therapy was also discontinued in view of the patient's adverse immune response. The patient did not receive subsequent immune antitumor therapy, and immune-related hepatitis still occurred intermittently, but the disease evaluation was maintained at PR. A complete response was confirmed by PET/CT and the biopsy specimen from gastroscopy on 2020-06-10. Next generation sequencing of biopsy tissue was used to guide subsequent therapy at a recent follow-up visit. The results indicated that ERBB2 mutations occurred at copy number 58.4934 (HER-2), TMB = 3.1, MSS. IHC: EBV (-), PD-L1 CPS = 3, HER-2 (3+). Conclusion: Patients with HER-2-positive advanced GEJ cancer received PD-1/CTLA-4 bispecific immunotherapy combined with chemotherapy and achieved complete remission. It offers a novel, highly specific, and highly potent therapeutic option for HER-2-positive patients. Its use should be considered as a new treatment when trastuzumab is not viable. Currently, we are working to overcome this resistance.


Assuntos
Neoplasias Esofágicas , Hepatite , Neoplasias Gástricas , Humanos , Masculino , Adulto , Receptor de Morte Celular Programada 1 , Antígeno CTLA-4 , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/patologia , Junção Esofagogástrica/patologia , Hepatite/patologia
13.
Mediators Inflamm ; 2022: 9480228, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36274973

RESUMO

Objective: The alanine aminotransferase/aspartate aminotransferase (ALT/AST) ratio is thought to be related to metabolic disorders and insulin resistance. Type 2 diabetes mellitus (T2DM) is a high-risk population for low muscle mass. This study was performed to evaluate the association between ALT/AST and muscle mass in subjects with T2DM. Method: This cross-sectional study enrolled 1068 subjects (566 males and 502 females) with T2DM. General information, medical history, and blood samples were collected. Skeletal muscle index (SMI) was detected using dual-energy X-ray absorptiometry. Logistic regression analysis was utilized to determine the correlation of ALT/AST and low muscle mass in subjects with T2DM. Multiple linear regression analysis was utilized to evaluate the association between ALT/AST, SMI and other metabolic characteristics. Result: Of all subjects, 115 men (20.3%) and 71 women (14.1%) presented low muscle mass. ALT/AST was related to an increased risk for low muscle mass in both genders. Multiple linear regression analysis displayed that SMI was negatively associated with ALT/AST, age, glycosylated hemoglobin (HbA1c), and high-density lipoprotein cholesterol (HDL) in male group. While in female group, SMI was positively associated with systolic blood pressure (SBP) and negatively associated with ALT/AST and age. Furthermore, ALT/AST was associated with age and BMI in both genders. Conclusion: ALT/AST was negatively associated with muscle mass in subjects with T2DM.


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Feminino , Masculino , Alanina Transaminase , Hemoglobinas Glicadas , Estudos Transversais , Aspartato Aminotransferases , Lipoproteínas HDL , Colesterol , Músculos
14.
Front Genet ; 13: 929049, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36035153

RESUMO

Diabetic retinopathy (DR) is a common complication and the leading cause of blindness in patients with type 2 diabetes. DR has been shown to be closely correlated with blood glucose levels and the duration of diabetes. However, the onset and progression of DR also display clinical heterogeneity. We applied whole-exome sequencing and RNA-seq approaches to study the gene mutation and transcription profiles in three groups of diabetic patients with extreme clinical phenotypes in DR onset, timing, and disease progression, aiming to identify genetic variants that may play roles in the pathogenesis of DR. We identified 23 putatively pathogenic genes, and ingenuity pathway analysis of these mutated genes reveals their functional association with glucose metabolism, diabetic complications, neural system activity, and dysregulated immune responses. In addition, ten potentially protective genes were also proposed. These findings shed light on the mechanisms underlying the pathogenesis of DR and may provide potential targets for developing new strategies to combat DR.

15.
New Phytol ; 235(4): 1665-1678, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35527515

RESUMO

Genetic mutants defective in stimulus-induced Ca2+ increases have been gradually isolated, allowing the identification of cell-surface sensors/receptors, such as the osmosensor OSCA1. However, determining the Ca2+ -signaling specificity to various stimuli in these mutants remains a challenge. For instance, less is known about the exact selectivity between osmotic and ionic stresses in the osca1 mutant. Here, we have developed a method to distinguish the osmotic and ionic effects by analyzing Ca2+ increases, and demonstrated that osca1 is impaired primarily in Ca2+ increases induced by the osmotic but not ionic stress. We recorded Ca2+ increases induced by sorbitol (osmotic effect, OE) and NaCl/CaCl2 (OE + ionic effect, IE) in Arabidopsis wild-type and osca1 seedlings. We assumed the NaCl/CaCl2 total effect (TE) = OE + IE, then developed procedures for Ca2+ imaging, image analysis and mathematic fitting/modeling, and found osca1 defects mainly in OE. The osmotic specificity of osca1 suggests that osmotic and ionic perceptions are independent. The precise estimation of these two stress effects is applicable not only to new Ca2+ -signaling mutants with distinct stimulus specificity but also the complex Ca2+ signaling crosstalk among multiple concurrent stresses that occur naturally, and will enable us to specifically fine tune multiple signal pathways to improve crop yields.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Cloreto de Cálcio/farmacologia , Pressão Osmótica , Percepção , Cloreto de Sódio/farmacologia
16.
Signal Transduct Target Ther ; 7(1): 42, 2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35136040

RESUMO

SARS-CoV-2 variants have evolved a variety of critical mutations, leading to antigenicity changes and immune escape. The recent emerging SARS-CoV-2 Omicron variant attracted global attention due to its significant resistance to current antibody therapies and vaccines. Here, we profiled the mutations of Omicron and other various circulating SARS-CoV-2 variants in parallel by computational interface analysis and in vitro experimental assays. We identified critical mutations that lead to antigenicity changes and diminished neutralization efficiency of a panel of 14 antibodies due to diverse molecular mechanisms influencing the antigen-antibody interaction. Our study identified that Omicron exhibited extraordinary potency in immune escape compared to the other variants of concern, and explores the application of computational interface analysis in SARS-CoV-2 mutation surveillance and demonstrates its potential for the early identification of concerning variants, providing preliminary guidance for neutralizing antibody therapy.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Antígenos Virais , COVID-19 , Evasão da Resposta Imune , SARS-CoV-2 , Antígenos Virais/genética , Antígenos Virais/imunologia , COVID-19/genética , COVID-19/imunologia , Células HEK293 , Humanos , SARS-CoV-2/genética , SARS-CoV-2/imunologia
17.
Materials (Basel) ; 15(3)2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35161205

RESUMO

Waste sediment generated during tunnel construction is applied to prepare synchronous grouting material, where the influences of fly ash, slag powder, and bentonite on the rheological properties (such as consistency, fluidity, setting time, drainage rate, and stone rate) are studied. The results show that adding fly ash content increases the initial consistency, setting time, and fluidity of grouting material, but also increases its drainage rate and decreases its stone rate. The addition of slag powder results in a slight increase in the setting time and fluidity of the grouting material, yet a decrease in the initial consistency value. In contrast, with the addition of bentonite, both the initial consistency and fluidity of the grouting material decrease. Finally, the optimal mix ratio of high-performance and low-cost grouting materials is fixed to be 30% fly ash, 50% slag powder, and 10% bentonite. Therefore, the fluidity of grouting material can be 170 mm, with an initial consistency of 122 mm, setting time of 1050 min, stone rate of 96.2%, drainage rate of 1.5%, and 28-day compressive strength of 8.3 MPa.

19.
Foods ; 12(1)2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36613229

RESUMO

Selenium (Se) is a chemical element essential to human health because of its bioactive properties, including antioxidative, anticancer, and immunomodulating activities. Despite the high therapeutic potential of Se, its intrinsic properties of poor stability, a narrow therapeutic window, and low bioavailability and bioactivity have limited its clinical applications. Selenium nanoparticles (SeNPs) exhibit lower toxicity and higher bioactivity than other Se forms. Herein, we report a green method for the preparation of monodisperse SeNPs with starch microgel (SM) and epigallocatechin gallate (EGCG) through Se-O bonds and polysaccharide-polyphenol interactions (namely, SM-EGCG-SeNPs). SM-EGCG-SeNPs showed higher stability, bioactivities, and cytotoxicity than SeNPs and SM-SeNPs at the equivalent dose. SM-EGCG-SeNPs induced the apoptosis of cancer cells via the activation of several caspases and reactive oxygen species overproduction. This work proposes a facile method for the design and potentiation of structure-bioactive SeNPs via polysaccharide-polyphenol interactions.

20.
J Agric Food Chem ; 69(46): 13881-13894, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34763421

RESUMO

Colanic acid has promising applications in food, cosmetic, and healthcare fields. In this study, a recombinant WQM003/pRAU was constructed by deleting genes lon and hns and overexpressing genes rcsA and galU in E. coli MG1655Δ(L-Q). After systematic optimization of fermentation conditions, colanic acid yield in WQM003/pRAU reached 19.79 g/L, the highest yield reported so far. The colanic acid produced by WQM003/pRAU was purified and its structure and physical properties were determined. This colanic acid shows a triple-helical structure and is stable up to 102 °C, and its melting temperature is 253.9 °C. This colanic acid shows a sphere-like chain conformation in aqueous solution. The viscosity of this colanic acid solution is related to concentration, shear rate, salt, temperature, and pH. At high concentrations, this colanic acid shows both viscous and elastic behaviors. These results suggest that the colanic acid produced by WQM003/pRAU has broad application prospects.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Polissacarídeos
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