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1.
Genes Dev ; 34(19-20): 1359-1372, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32943576

RESUMO

Transcription factor SNAI2 plays key roles during development and has also been known to promote metastasis by inducing invasive phenotype and tumor-initiating activity of cancer cells. However, the post-translational regulation of SNAI2 is less well studied. We performed a dual-luciferase-based, genome-wide E3 ligase siRNA library screen and identified ASB13 as an E3 ubiquitin ligase that targets SNAI2 for ubiquitination and degradation. ASB13 knockout in breast cancer cells promoted cell migration and decreased F-actin polymerization, while overexpression of ASB13 suppressed lung metastasis. Furthermore, ASB13 knockout decreased YAP expression, and such regulation is dependent on an increased protein level of SNAI2, which in turn represses YAP transcription. YAP suppresses tumor progression in breast cancer, as YAP knockout increases tumorsphere formation, anchorage-independent colony formation, cell migration in vitro, and lung metastasis in vivo. Clinical data analysis reveals that ASB13 expression is positively correlated with improved overall survival in breast cancer patients. These findings establish ASB13 as a suppressor of breast cancer metastasis by promoting degradation of SNAI2 and relieving its transcriptional repression of YAP.


Assuntos
Neoplasias da Mama/fisiopatologia , Regulação Neoplásica da Expressão Gênica/genética , Metástase Neoplásica/fisiopatologia , Proteólise , Proteínas Proto-Oncogênicas c-yes/genética , Fatores de Transcrição da Família Snail/metabolismo , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Feminino , Estudo de Associação Genômica Ampla , Humanos , Metástase Neoplásica/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/genética
2.
Genes Dev ; 34(19-20): 1310-1315, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32943575

RESUMO

SNAI2/SLUG, a metastasis-promoting transcription factor, is a labile protein that is degraded through the ubiquitin proteasome degradation system. Here, we conducted comprehensive gain- and loss-of-function screens using a human DUB cDNA library of 65 genes and an siRNA library of 98 genes, and identified USP20 as a deubiquitinase (DUB) that regulates SNAI2 ubiquitination and stability. Further investigation of USP20 demonstrated its function in promoting migration, invasion, and metastasis of breast cancer. USP20 positively correlates with SNAI2 protein level in breast tumor samples, and higher USP20 expression is associated with poor prognosis in ER- breast cancer patients.


Assuntos
Neoplasias da Mama/fisiopatologia , Metástase Neoplásica/genética , Fatores de Transcrição da Família Snail/metabolismo , Ubiquitina Tiolesterase/metabolismo , Neoplasias da Mama/genética , Movimento Celular/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Biblioteca Gênica , Humanos , Invasividade Neoplásica/genética , Estabilidade Proteica , Proteólise , RNA Interferente Pequeno/metabolismo , Ubiquitina Tiolesterase/genética , Ubiquitinação
3.
Genes Dev ; 33(3-4): 166-179, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30692202

RESUMO

Although changes in alternative splicing have been observed in cancer, their functional contributions still remain largely unclear. Here we report that splice isoforms of the cancer stem cell (CSC) marker CD44 exhibit strikingly opposite functions in breast cancer. Bioinformatic annotation in patient breast cancer in The Cancer Genome Atlas (TCGA) database reveals that the CD44 standard splice isoform (CD44s) positively associates with the CSC gene signatures, whereas the CD44 variant splice isoforms (CD44v) exhibit an inverse association. We show that CD44s is the predominant isoform expressed in breast CSCs. Elimination of the CD44s isoform impairs CSC traits. Conversely, manipulating the splicing regulator ESRP1 to shift alternative splicing from CD44v to CD44s leads to an induction of CSC properties. We further demonstrate that CD44s activates the PDGFRß/Stat3 cascade to promote CSC traits. These results reveal CD44 isoform specificity in CSC and non-CSC states and suggest that alternative splicing provides functional gene versatility that is essential for distinct cancer cell states and thus cancer phenotypes.


Assuntos
Processamento Alternativo , Neoplasias da Mama/genética , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/metabolismo , Células-Tronco Neoplásicas/patologia , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Isoformas de Proteínas , Transdução de Sinais/genética
4.
Mol Cell ; 72(5): 836-848.e7, 2018 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-30415952

RESUMO

Transforming members of the MYC family (MYC, MYCL1, and MYCN) encode transcription factors containing six highly conserved regions, termed MYC homology boxes (MBs). By conducting proteomic profiling of the MB interactomes, we demonstrate that half of the MYC interactors require one or more MBs for binding. Comprehensive phenotypic analyses reveal that two MBs, MB0 and MBII, are universally required for transformation. MBII mediates interactions with acetyltransferase-containing complexes, enabling histone acetylation, and is essential for MYC-dependent tumor initiation. By contrast, MB0 mediates interactions with transcription elongation factors via direct binding to the general transcription factor TFIIF. MB0 is dispensable for tumor initiation but is a major accelerator of tumor growth. Notably, the full transforming activity of MYC can be restored by co-expression of the non-transforming MB0 and MBII deletion proteins, indicating that these two regions confer separate molecular functions, both of which are required for oncogenic MYC activity.


Assuntos
Neoplasias da Mama/genética , Transformação Celular Neoplásica/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Proto-Oncogênicas c-myc/genética , Fatores de Transcrição TFII/genética , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Feminino , Perfilação da Expressão Gênica , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos NOD , Ligação Proteica , Domínios Proteicos , Mapeamento de Interação de Proteínas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução de Sinais , Análise de Sobrevida , Fatores de Transcrição TFII/metabolismo , Carga Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Nucleic Acids Res ; 51(17): 9442-9451, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37587688

RESUMO

CRISPR-Cas systems act as the adaptive immune systems of bacteria and archaea, targeting and destroying invading foreign mobile genetic elements (MGEs) such as phages. MGEs have also evolved anti-CRISPR (Acr) proteins to inactivate the CRISPR-Cas systems. Recently, AcrIIC4, identified from Haemophilus parainfluenzae phage, has been reported to inhibit the endonuclease activity of Cas9 from Neisseria meningitidis (NmeCas9), but the inhibition mechanism is not clear. Here, we biochemically and structurally investigated the anti-CRISPR activity of AcrIIC4. AcrIIC4 folds into a helix bundle composed of three helices, which associates with the REC lobe of NmeCas9 and sgRNA. The REC2 domain of NmeCas9 is locked by AcrIIC4, perturbing the conformational dynamics required for the target DNA binding and cleavage. Furthermore, mutation of the key residues in the AcrIIC4-NmeCas9 and AcrIIC4-sgRNA interfaces largely abolishes the inhibitory effects of AcrIIC4. Our study offers new insights into the mechanism of AcrIIC4-mediated suppression of NmeCas9 and provides guidelines for the design of regulatory tools for Cas9-based gene editing applications.


Assuntos
Bacteriófagos , Sistemas CRISPR-Cas , Sistemas CRISPR-Cas/genética , Proteína 9 Associada à CRISPR/metabolismo , RNA Guia de Sistemas CRISPR-Cas , Edição de Genes , Bactérias/genética , Bacteriófagos/genética
6.
Genes Dev ; 31(14): 1439-1455, 2017 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-28827399

RESUMO

Secreted proteins play crucial roles in mediating tumor-stroma interactions during metastasis of cancer to different target organs. To comprehensively profile secreted proteins involved in lung metastasis, we applied quantitative mass spectrometry-based proteomics and identified 392 breast cancer-derived and 302 melanoma-derived proteins secreted from highly lung metastatic cells. The cancer-specific lung metastasis secretome signatures (LMSSs) displayed significant prognostic value in multiple cancer clinical data sets. Moreover, we observed a significant overlap of enriched pathways between the LMSSs of breast cancer and melanoma despite an overall small overlap of specific proteins, suggesting that common biological processes are executed by different proteins to enable the two cancer types to metastasize to the lung. Among the novel candidate lung metastasis proteins, Nidogen 1 (NID1) was confirmed to promote lung metastasis of breast cancer and melanoma, and its expression is correlated with poor clinical outcomes. In vitro functional analysis further revealed multiple prometastatic functions of NID1, including enhancing cancer cell migration and invasion, promoting adhesion to the endothelium and disrupting its integrity, and improving vascular tube formation capacity. As a secreted prometastatic protein, NID1 may be developed as a new biomarker for disease progression and therapeutic target in breast cancer and melanoma.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias Pulmonares/secundário , Melanoma/metabolismo , Glicoproteínas de Membrana/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular , Feminino , Humanos , Melanoma/patologia , Glicoproteínas de Membrana/fisiologia , Prognóstico
7.
Cancer ; 130(S8): 1415-1423, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38079306

RESUMO

BACKGROUND: Immune-checkpoint blockade (ICB) therapy shows promise for treating aggressive triple-negative breast cancer (TNBC). However, only some patients benefit from ICB, revealing an urgent need for identifying novel strategies for sensitizing patients to ICB. Previously, the authors demonstrated that type-I protein arginine methyltransferases (PRMTs) regulated antiviral innate-immune responses in TNBC by altering RNA splicing. This study aimed to explore the effects of targeting type-I PRMTs on the tumor microenvironment (TME) and the efficacy of ICB therapy against TNBC. METHODS: Single-cell transcriptomic analysis was performed to investigate the effects of type-I PRMT inhibition on the TME, especially T-cell subsets. Single-cell T-cell receptor sequencing was performed to analyze the diversity and dynamics of the T-cell repertoire. A syngeneic murine model of TNBC was used to evaluate the therapeutic efficacy and immune memory effect of combining a type-I PRMT inhibitor (MS023) with an anti-programmed cell death protein 1 (PD-1) antibody. RESULTS: Type-I PRMT inhibition combined with anti-PD-1 therapy reduced tumor growth. Mechanistically, type-I PRMT inhibition reshaped the TME. Increased CD8 T-cell infiltration was verified using flow cytometry. Increased clonotypes and clonal diversity were also observed after MS023 treatment, which contributed to immune memory following combination treatment. CONCLUSIONS: Targeting type-I PRMT can potentially improve immunotherapeutic efficacies in patients with TNBC. By enhancing the tumor immunogenicity and promoting a more favorable immune microenvironment, this combined approach may enable more patients with TNBC to benefit from immunotherapies.


Assuntos
Neoplasias de Mama Triplo Negativas , Humanos , Animais , Camundongos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Receptor de Morte Celular Programada 1 , Proteína-Arginina N-Metiltransferases/genética , Imunoterapia , Morte Celular , Microambiente Tumoral
8.
Cancer Immunol Immunother ; 73(3): 41, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38349474

RESUMO

BACKGROUND: The tumor microenvironment (TME) encompasses a variety of cells that influence immune responses and tumor growth, with tumor-associated macrophages (TAM) being a crucial component of the TME. TAM can guide prostate cancer in different directions in response to various external stimuli. METHODS: First, we downloaded prostate cancer single-cell sequencing data and second-generation sequencing data from multiple public databases. From these data, we identified characteristic genes associated with TAM clusters. We then employed machine learning techniques to select the most accurate TAM gene set and developed a TAM-related risk label for prostate cancer. We analyzed the tumor-relatedness of the TAM-related risk label and different risk groups within the population. Finally, we validated the accuracy of the prognostic label using single-cell sequencing data, qPCR, and WB assays, among other methods. RESULTS: In this study, the TAM_2 cell cluster has been identified as promoting the progression of prostate cancer, possibly representing M2 macrophages. The 9 TAM feature genes selected through ten machine learning methods and demonstrated their effectiveness in predicting the progression of prostate cancer patients. Additionally, we have linked these TAM feature genes to clinical pathological characteristics, allowing us to construct a nomogram. This nomogram provides clinical practitioners with a quantitative tool for assessing the prognosis of prostate cancer patients. CONCLUSION: This study has analyzed the potential relationship between TAM and PCa and established a TAM-related prognostic model. It holds promise as a valuable tool for the management and treatment of PCa patients.


Assuntos
Macrófagos , Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/genética , Macrófagos Associados a Tumor , Aprendizado de Máquina , Nomogramas , Microambiente Tumoral/genética
9.
Ann Surg Oncol ; 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824192

RESUMO

BACKGROUND: This study was designed to develop an innovative classification and guidance system for renal hilar tumors and to assess the safety and effectiveness of robot-assisted partial nephrectomy (RAPN) for managing such tumors. METHODS: A total of 179 patients undergoing RAPN for renal hilar tumors were retrospectively reviewed. A novel classification system with surgical techniques was introduced and the perioperative features, tumor characteristics, and the efficacy and safety of RAPN were compared within subgroups. RESULTS: We classified the tumors according to our novel system as follows: 131 Type I, 35 Type II, and 13 Type III. However, Type III had higher median R.E.N.A.L., PADUA, and ROADS scores compared with the others (all p < 0.001), indicating increased operative complexity and higher estimated blood loss [180.00 (115.00-215.00) ml]. Operative outcomes revealed significant disparities between Type III and the others, with longer operative times [165.00 (145.00-200.50) min], warm ischemia times [24.00 (21.50-30.50) min], tumor resection times [13.00 (12.00-15.50) min], and incision closure times [22.00 (20.00-23.50) min] (all p < 0.005). Postoperative outcomes also showed significant differences, with longer durations of drain removal (77.08 ± 18.16 h) and hospitalization for Type III [5.00 (5.00-6.00) d] (all p < 0.05). Additionally, Type I had a larger tumor diameter than the others (p = 0.009) and pT stage differed significantly between the subtypes (p = 0.020). CONCLUSIONS: The novel renal hilar tumor classification system is capable of differentiating the surgical difficulty of RAPN and further offers personalized surgical steps tailored to each specific classification. It provides a meaningful tool for clinical practice.

10.
Opt Express ; 32(9): 15882-15892, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38859228

RESUMO

To achieve a fiber strain sensor with a large detection range and high sensitivity, this paper proposes a wave structured fiber SPR strain sensor. When subjected to axial strain, the wave structured fiber is stretched axially, increasing the stretchability of the sensor and achieving a large detection range strain sensing. Meanwhile, axial strain reduces the longitudinal amplitude of the fiber wave structure, effectively changing the total reflection angle of the transmitted beam at the peak and valley (SPR incidence angle) to achieve high sensitivity SPR strain sensing. The experiment indicates that the strain detection range of the sensor can reach 0-1800µÎµ, with a maximum strain sensitivity of 36.25pm/µÎµ. The wave structured fiber SPR strain sensor designed in this article provides a new approach to improve the range and sensitivity of strain detection.

11.
Opt Express ; 32(8): 13783-13796, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38859339

RESUMO

The conical fiber SPR sensor is easy to manufacture and has been used in biochemical detection research, but it has the problem of structural fragility. This article proposes a spiral cone fiber SPR sensor, which introduces a spiral structure on the 76µm fiber coarse cone, achieving good coupling of the core mode into the cladding mode, and improving the physical strength and practicality of the cone-shaped fiber SPR sensor. By modifying the target protein on the surface of the sensor gold film, specific detection of ginsenoside Rg1, an active ingredient of traditional Chinese medicine ginseng, was achieved. The detection sensitivity was 0.138 nm/(µm/ml) and the detection limit was 0.22µm/ml. The proposed spiral cone fiber SPR sensor provides a new scheme for the specific detection of active ingredients in traditional Chinese medicine, which is structurally stable and physically strong.


Assuntos
Ginsenosídeos , Ressonância de Plasmônio de Superfície , Ginsenosídeos/análise , Ressonância de Plasmônio de Superfície/métodos , Técnicas Biossensoriais/instrumentação , Desenho de Equipamento , Tecnologia de Fibra Óptica/instrumentação , Limite de Detecção
12.
Microb Pathog ; 188: 106532, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38215861

RESUMO

Rhizopus arrhizus is a fungus that can cause central nervous system infections in animals, resulting in high morbidity and mortality, but the mechanism of injury is rarely reported. In this study, we investigated the mechanism of Rhizopus arrhizus damage to the central nervous system of mice by observing the clinical neurological symptoms and resolving the pathological changes in the ultrastructure of brain tissues, combined with the alteration of apoptosis-related genes and immunohistochemistry (IHC). The results showed that all the mice in the treated group died, the brain pyknosis of neurons, there were black mycelium aggregates around the blood vessels, and apoptotic vesicles were produced. The RT-qPCR results showed that, compared with the control group, the relative transcriptome levels of Caspase 8 and BcL-2 genes were significantly increased (P < 0.05), the relative transcriptome level of Caspase 9 gene was highly significant (P < 0.01), the relative transcriptome level of Caspase 3 and Bax gene was significantly decreased (P < 0.05), and the ratio of Bcl-2/Bax was significantly increased (P < 0.05) in the brains of the treated group. TUNEL staining showed that the rate of neuronal apoptosis in the treated group of mice was extremely significantly higher than that in the control group (P < 0.01). This study shows that Rhizopus arrhizus strain XMLO1 causes brain damage by triggering neuronal apoptosis. This study provided a theoretical basis for revealing the mechanism of Rhizopus arrhizus infection.


Assuntos
Mucormicose , Rhizopus oryzae , Rhizopus , Animais , Camundongos , Rhizopus/genética , Proteína X Associada a bcl-2/genética , Apoptose , Encéfalo
13.
J Magn Reson Imaging ; 59(4): 1394-1406, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37392060

RESUMO

BACKGROUND: Deep stromal invasion (DSI) is one of the predominant risk factors that determined the types of radical hysterectomy (RH). Thus, the accurate assessment of DSI in cervical adenocarcinoma (AC)/adenosquamous carcinoma (ASC) can facilitate optimal therapy decision. PURPOSE: To develop a nomogram to identify DSI in cervical AC/ASC. STUDY TYPE: Retrospective. POPULATION: Six hundred and fifty patients (mean age of 48.2 years) were collected from center 1 (primary cohort, 536), centers 2 and 3 (external validation cohorts 1 and 2, 62 and 52). FIELD STRENGTH/SEQUENCE: 5-T, T2-weighted imaging (T2WI, SE/FSE), diffusion-weighted imaging (DWI, EPI), and contrast-enhanced T1-weighted imaging (CE-T1WI, VIBE/LAVA). ASSESSMENT: The DSI was defined as the outer 1/3 stromal invasion on pathology. The region of interest (ROI) contained the tumor and 3 mm peritumoral area. The ROIs of T2WI, DWI, and CE-T1WI were separately imported into Resnet18 to calculate the DL scores (TDS, DDS, and CDS). The clinical characteristics were retrieved from medical records or MRI data assessment. The clinical model and nomogram were constructed by integrating clinical independent risk factors only and further combining DL scores based on primary cohort and were validated in two external validation cohorts. STATISTICAL TESTS: Student's t-test, Mann-Whitney U test, or Chi-squared test were used to compare differences in continuous or categorical variables between DSI-positive and DSI-negative groups. DeLong test was used to compare AU-ROC values of DL scores, clinical model, and nomogram. RESULTS: The nomogram integrating menopause, disruption of cervical stromal ring (DCSRMR), DDS, and TDS achieved AU-ROCs of 0.933, 0.807, and 0.817 in evaluating DSI in primary and external validation cohorts. The nomogram had superior diagnostic ability to clinical model and DL scores in primary cohort (all P < 0.0125 [0.05/4]) and CDS (P = 0.009) in external validation cohort 2. DATA CONCLUSION: The nomogram achieved good performance for evaluating DSI in cervical AC/ASC. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.


Assuntos
Adenocarcinoma , Carcinoma Adenoescamoso , Aprendizado Profundo , Neoplasias do Colo do Útero , Feminino , Humanos , Pessoa de Meia-Idade , Nomogramas , Carcinoma Adenoescamoso/diagnóstico por imagem , Carcinoma Adenoescamoso/patologia , Carcinoma Adenoescamoso/terapia , Estudos Retrospectivos , Neoplasias do Colo do Útero/patologia , Imageamento por Ressonância Magnética/métodos , Adenocarcinoma/patologia
14.
World J Urol ; 42(1): 134, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38478100

RESUMO

OBJECTIVE: To investigate the safety and feasibility of using a novel purpose-built single-port robotic system (the SHURUI Robotic Surgical System) with deformable surgical instruments to perform retroperitoneal single-port partial nephrectomy. MATERIALS AND METHODS: A prospective study was conducted to recruit patients with a single renal tumor no more than 4 cm. Robot-assisted single-port partial nephrectomy was performed by using the novel purpose-built single-port robotic system with deformable surgical instruments. Patients' demographics, tumor characteristics, and perioperative parameters were recorded and analyzed. RESULTS: Sixteen patients were recruited to the study. The median tumor size was 2.0 cm (IQR: 1.2-2.4 cm). The median R.E.N.A.L score was 6 (IQR: 4-4.5). In 3 cases, pure single-port surgery was carried out, and all the assistance was through the robotic port. Median docking time was 15.5 min (IQR: 14.25-22.25 min). Median operating time was 148.5 min (IQR: 178-238.5 min). Median console time was 107 min (IQR: 92.75-149.75 min). Median warm ischemic time was 26.5 min (IQR: 24.5-30 min). Median blood loss was 17.5 ml (IQR: 10-50 ml). CONCLUSIONS: Retroperitoneal partial nephrectomy can be safely performed with this novel purpose-built single-port robotic system (SHURUI) with deformable surgical instruments. Further studies are needed to fully evaluate the role of this new platform.


Assuntos
Neoplasias Renais , Procedimentos Cirúrgicos Robóticos , Robótica , Humanos , Estudos Prospectivos , Neoplasias Renais/cirurgia , Neoplasias Renais/patologia , Nefrectomia , Resultado do Tratamento , Estudos Retrospectivos
15.
Inorg Chem ; 63(27): 12469-12474, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38912662

RESUMO

Two Mn(II)-bridged Silverton-type {UMo12O42}-based polyoxomolybdates with different three-dimensional structures, Na6(H2O)12[Mn(UMo12O42)] (NaMn) and (NH4)2[K2Na6(µ4-O)2(H2O)1.2Mn(UMo12O42)]·4.6H2O (KMn), were hydrothermally synthesized and further characterized, demonstrating a feasible strategy for the assembly of Silverton-type polyoxomolybdates. Additionally, NaMn is demonstrated to be a good heterogeneous catalyst in the condensation cyclization reaction of hydrazines and 1,3-diketones, and a range of valuable pyrazoles were produced in up to 99% yield.

16.
Nanotechnology ; 35(15)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38176065

RESUMO

Optical nanoantennas possess broad applications in the fields of photodetection, environmental science, biosensing and nonlinear optics, owing to their remarkable ability to enhance and confine the optical field at the nanoscale. In this article, we present a theoretical investigation of surface-enhanced photoluminescence spectroscopy for single molecules confined within novel Au bowtie nanoantenna, covering a wavelength range from the visible to near-infrared spectral regions. We employ the finite element method to quantitatively study the optical enhancement properties of the plasmonic field, quantum yield, Raman scattering and fluorescence. Additionally, we systematically examine the contribution of nonlocal dielectric response in the gap mode to the quantum yield, aiming to gain a better understanding of the fluorescence enhancement mechanism. Our results demonstrate that altering the configuration of the nanoantenna has a significant impact on plasmonic sensitivity. The nonlocal dielectric response plays a crucial role in reducing the quantum yield and corresponding fluorescence intensity when the gap distance is less than 3 nm. However, a substantial excitation field can effectively overcome fluorescence quenching and enhance the fluorescence intensity. By optimizing nanoantenna configuration, the maximum enhancement of surface-enhanced Raman can be turned to 9 and 10 magnitude orders in the visible and near-infrared regions, and 3 and 4 magnitude orders for fluorescence enhancement, respectively. The maximum spatial resolutions of 0.8 nm and 1.5 nm for Raman and fluorescence are also achieved, respectively. Our calculated results not only provide theoretical guidance for the design and application of new nanoantennas, but also contribute to expanding the range of surface-enhanced Raman and fluorescence technology from the visible to the near-infrared region.

17.
Nanotechnology ; 35(36)2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38865988

RESUMO

Reactive oxygen species (ROS) play important roles in regulating various physiological functions in the human body, however, excessive ROS can cause serious damage to the human body, considering the various limitations of natural enzymes as scavengers of ROS in the body, the development of better materials for the scavenging of ROS is of great significance to the biomedical field, and nanozymes, as a kind of nanomaterials which can show the activity of natural enzymes. Have a good potential for the development in the area of ROS scavenging. Metal-organic frameworks (MOFs), which are porous crystalline materials with a periodic network structure composed of metal nodes and organic ligands, have been developed with a variety of active nanozymes including catalase-like, superoxide dismutase-like, and glutathione peroxidase-like enzymes due to the adjustability of active sites, structural diversity, excellent biocompatibility, and they have shown a wide range of applications and prospects. In the present review, we first introduce three representative natural enzymes for ROS scavenging in the human body, methods for the detection of relevant enzyme-like activities and mechanisms of enzyme-like clearance are discussed, meanwhile, we systematically summarize the progress of the research on MOF-based nanozymes, including the design strategy, mechanism of action, and medical application, etc. Finally, the current challenges of MOF-based nanozymes are summarized, and the future development direction is anticipated. We hope that this review can contribute to the research of MOF-based nanozymes in the medical field related to the scavenging of ROS.


Assuntos
Estruturas Metalorgânicas , Espécies Reativas de Oxigênio , Estruturas Metalorgânicas/química , Espécies Reativas de Oxigênio/metabolismo , Humanos , Sequestradores de Radicais Livres/química , Nanoestruturas/química , Catalase/química , Catalase/metabolismo , Animais , Superóxido Dismutase/metabolismo , Superóxido Dismutase/química
18.
Phys Chem Chem Phys ; 26(8): 6582-6589, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38329233

RESUMO

Allosteric regulation is common in protein-protein interactions and is thus promising in drug design. Previous experimental and simulation work supported the presence of allosteric regulation in the SARS-CoV-2 spike protein. Here the route of allosteric regulation in SARS-CoV-2 spike protein is examined by all-atom explicit solvent molecular dynamics simulations, contrastive machine learning, and the Ohm approach. It was found that peptide binding to the polybasic cleavage sites, especially the one at the first subunit of the trimeric spike protein, activates the fluctuation of the spike protein's backbone, which eventually propagates to the receptor-binding domain on the third subunit that binds to ACE2. Remarkably, the allosteric regulation routes starting from the polybasic cleavage sites share a high fraction (39-67%) of the critical amino acids with the routes starting from the nitrogen-terminal domains, suggesting the presence of an allosteric regulation network in the spike protein. Our study paves the way for the rational design of allosteric antibody inhibitors.


Assuntos
COVID-19 , Humanos , Glicoproteína da Espícula de Coronavírus/metabolismo , SARS-CoV-2/metabolismo , Sítios de Ligação , Ligação Proteica , Regulação Alostérica , Simulação de Dinâmica Molecular
19.
Artigo em Inglês | MEDLINE | ID: mdl-38319640

RESUMO

A 60-year-old male patient suffered from frequent episodes of atrial tachycardia (AT), after the index procedure of catheter ablation for paroxysmal atrial fibrillation. During the repeat procedure, the activation map showed that the earliest activation site was located at the roof of left atrium. Multiple ablations at the earliest activation site on the roof failed to terminate the AT; however, ablation within the pulmonary artery at an adjacent anatomical site successfully eliminated the AT, even without recording distinct near-field potential.

20.
Bioorg Chem ; 146: 107245, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38484587

RESUMO

The overuse of antibiotics has led to the enhanced resistance of many pathogenic bacteria, posing a threat to human health. Therefore, there is a need to develop green and safe alternatives to antibiotics. Beta-defensins play a crucial role in host defense against pathogens and have multifunctional properties, exerting key roles in innate and adaptive immunity, as well as non-immune processes. In this study, a 210 bp long cDNA sequence of yak DEFB114 gene was amplified and successfully expressed in a prokaryotic system. The DEFB114 protein exhibited significant inhibitory effects on the growth of Aspergillus fumigatus in vitro. When co-cultured with yak macrophages, DEFB114 protein enhanced macrophage phagocytic activity and increased nucleic acid fluorescence intensity (P < 0.05). DEFB114 protein also enhanced the activity of yak macrophages stimulated by inactivated Aspergillus fumigatus spores, increased the release of nitric oxide (NO), and promoted the expression of genes such as γ-actin, Lgals, Man2b, and Capg (P < 0.05). In mice experiments, DEFB114 protein promoted resistance against Aspergillus fumigatus infection, by regulating the NOD1/2-ATG16L1-NF-κB pathway to modulate the host immune response and exert its anti-infective effects. In summary, the yak DEFB114 protein could inhibit the growth of Aspergillus fumigatus and enhance the animal's resistance to pathogenic microorganisms, thereby having significant implications in the treatment and prevention of fungal infections.


Assuntos
Aspergilose , NF-kappa B , Animais , Camundongos , Antibacterianos , Aspergilose/tratamento farmacológico , Aspergillus fumigatus , Proteínas Relacionadas à Autofagia/metabolismo , NF-kappa B/metabolismo , Proteína Adaptadora de Sinalização NOD1/metabolismo , Transdução de Sinais
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