Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 75
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Angew Chem Int Ed Engl ; 63(20): e202401819, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38409658

RESUMO

Density functional theory (DFT) calculations demonstrate neighboring Pt atoms can enhance the metal activity of NiCoP for hydrogen evolution reaction (HER). However, it remains a great challenge to link Pt and NiCoP. Herein, we introduced curvature of bowl-like structure to construct Pt/NiCoP interface by adding a minimal 1 ‰-molar-ratio Pt. The as-prepared sample only requires an overpotential of 26.5 and 181.6 mV to accordingly achieve the current density of 10 and 500 mA cm-2 in 1 M KOH. The water dissociation energy barrier (Ea) has a ~43 % decrease compared with NiCoP counterpart. It also shows an ultrahigh stability with a small degradation rate of 10.6 µV h-1 at harsh conditions (500 mA cm-2 and 50 °C) after 3000 hrs. X-ray photoelectron spectroscopy (XPS), soft X-ray absorption spectroscopy (sXAS), and X-ray absorption fine structure (XAFS) verify the interface electron transfer lowers the valence state of Co/Ni and activates them. DFT calculations also confirm the catalytic transition step of NiCoP can change from Heyrovsky (2.71 eV) to Tafel step (0.51 eV) in the neighborhood of Pt, in accord with the result of the improved Hads at the interface disclosed by in situ electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) tests.

2.
World J Surg Oncol ; 21(1): 188, 2023 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-37344889

RESUMO

BACKGROUND: A comprehensive understanding of the clinical characteristics and prognostic factors associated with axial chondroblastoma (ACB) is still lacking. This study aimed to understand the clinical characteristics and prognostic factors of axial chondroblastoma (ACB) and compare them with extra-axial chondroblastoma (EACB). METHODS: A retrospective review of our institution's local database was conducted, encompassing a total of 132 CB patients, of which 61 were diagnosed with ACB and 71 with EACB. Immunohistochemistry was employed to evaluate the expression levels of vimentin, S100, and cytokeratin. RESULTS: ACB and EACB shared similar characteristics, with the exception of advanced age, tumor size, elevated Vim expression, incidence of surrounding tissue invasion, and postoperative sensory or motor dysfunction. While wide resection and absence of surrounding tissue invasion consistently showed a favorable association with survival in both ACB and EACB cohorts during univariate analysis, most parameters exhibited differential prognostic significance between the two groups. Notably, the significant prognostic factors for local recurrence-free survival in the ACB cohort included the type of resection and the presence of chicken-wire calcification. In the multivariate analysis of overall survival, the type of resection emerged as a significant predictor in the ACB cohort, whereas in the EACB group, the type of resection and the occurrence of postoperative sensory or motor dysfunction were predictive of overall survival. CONCLUSION: There may exist distinct biological behaviors between ACB and EACB, thereby providing valuable insights into the prognostic characteristics of ACB patients and contributing to enhanced outcome prediction in this particular patient population.


Assuntos
Neoplasias Ósseas , Condroblastoma , Humanos , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/patologia , Condroblastoma/diagnóstico , Condroblastoma/cirurgia , Imuno-Histoquímica , Prognóstico , Estudos Retrospectivos
3.
J Sep Sci ; 45(2): 492-506, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34799974

RESUMO

Black bean, in which isoflavones are the main active constituent, also contains saponins and monoterpenes. Soybean isoflavone is a secondary metabolite that is formed during the growth of soybean; it exhibits antioxidant and cardiovascular activities and traces estrogen-like effects. In this study, black bean isoflavones were extracted with n-butanol, and ultrafiltration-liquid chromatography-mass spectrometry was used to screen their activity. Subsequently, the inhibitors were isolated and purified using semipreparative liquid chromatography and stepwise flow rate countercurrent chromatography. Thereafter, five active compounds were identified using mass spectrometry and nuclear magnetic resonance experiments. Finally, the inhibition types of the xanthine oxidase inhibitors were determined using enzymatic kinetic studies. The IC50 values of daidzin, glycitein-7-O-glucoside, genistin, daidzein, and genistein were determined to be 35.08, 56.22, 30.76, 68.79, and 95.37 µg/mL, respectively. Daidzin, genistin, and daidzein exhibited reversible inhibition, whereas glycitein-7-O-glucoside and genistein presented irreversible inhibition. This novel approach, which was based on ultrafiltration-liquid chromatography-mass spectrometry and stepwise flow rate countercurrent chromatography, is a powerful method for screening and isolating xanthine oxidase inhibitors from complex matrices. The study of enzyme inhibition types is helpful for understanding the underlying inhibition mechanism. Therefore, a beneficial platform was developed for the large-scale production of bioactive and nutraceutical ingredients.


Assuntos
Distribuição Contracorrente , Isoflavonas , Xantina Oxidase , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida , Isoflavonas/química , Cinética , Phaseolus/química , Proteínas de Plantas/química , Xantina Oxidase/antagonistas & inibidores
4.
World J Surg Oncol ; 19(1): 171, 2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34118947

RESUMO

The purpose of this letter to the Editor is to report some shortcomings in the statistical analysis and variable grouping in the recent publication of the article "Clinical outcomes of chondroblastoma treated using synthetic bone substitute: risk factors for developing radiographic joint degeneration," and to further explore some of the factors that may affect the clinical prognosis of chondroblastoma patients. We also suggest future prospective controlled studies with large samples to improve the limitations encountered by Outani et al. (World J Surg Oncol. 18(1):47, 2020) due to insufficient statistical power of variables and lack of controls.


Assuntos
Neoplasias Ósseas , Substitutos Ósseos , Condroblastoma , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/cirurgia , Condroblastoma/diagnóstico por imagem , Condroblastoma/cirurgia , Humanos , Prognóstico , Fatores de Risco
5.
Microb Pathog ; 147: 104439, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32768516

RESUMO

Anaplasma phagocytophilum, the aetiologic agent of human granulocytic anaplasmosis (HGA) is an obligate intracellular Gram-negative bacterium. During intracellular replication, A. phagocytophilum interacts with many host cell components including actin cytoskeleton. However the bacterial factors contributing to the interaction between A. phagocytophilum and actin filaments remain unknown. In this study we identified a novel type IV secretion system substrate of A. phagocytophilum by employing TEM-1 ß-lactamase based protein translocation assay, and found it is an actin filament-associated protein. Here, we name this protein as an actin filament-associated Anaplasma phagocytophilumprotein (AFAP). Further analysis showed that the middle region of AFAP harboring four tandem repeats is involved in its interaction with actin filaments. The identification and characterization of an actin filament-associated A. phagocytophilum protein in this study may help understand the interaction between A. phagocytophilum and actin cytoskeleton of its host cells, facilitating the elucidation of HGA pathogenesis.


Assuntos
Anaplasma phagocytophilum , Anaplasmose , Citoesqueleto de Actina , Anaplasma phagocytophilum/genética , Animais , Proteínas de Bactérias/genética , Humanos , Sistemas de Secreção Tipo IV
6.
Gene Ther ; 25(3): 234-248, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29670247

RESUMO

Ischemia-reperfusion injury (IRI) is a major cause of cardiac damage following various pathological processes, such as free radical damage and cell apoptosis. This study aims to investigate whether microRNA-292-5p (miR-292-5p) protects against myocardial ischemia-reperfusion injury (IRI) via the peroxisome proliferator-activated receptor (PPAR)-α/-γ signaling pathway in myocardial IRI mice models. Mouse models of myocardial IRI were established. Adult male C57BL/6 mice were divided into different groups. The hemodynamic indexes, levels of related inflammatory factors and serum myocardial enzymes, and malondialdehyde (MDA) content and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were detected. The 2,3,5-triphenyltetrazolium chloride (TTC) staining was applied to determine infarct size. TUNEL staining was used to detect cardiomyocyte apoptosis. RT-qPCR and western blotting were performed to measure the related gene expressions. Compared with the model group and the T0070907 + miR-292-5p inhibitor, the miR-292-5p inhibitor group exhibited decreased incidence and duration time of ventricular tachycardia and ventricular fibrillation, serum myocardial enzymes, TNF-α, IL-6, IL-1ß, MDA, cardiomyocyte apoptosis, expressions of Bax and p53 in addition to increased SOD and GSH-Px activity, and increased expressions of Bcl-2, PPARα, PPARγ, PLIN5, AQP7, and PCK1. The T0070907 group exhibited opposite results compared to the miR-292-5p inhibitor group. The results indicate that miR-292-5p downregulation protects against myocardial IRI through activation of the PPAR-α/PPAR-γ signaling pathway.


Assuntos
MicroRNAs/fisiologia , Isquemia Miocárdica/genética , Traumatismo por Reperfusão/genética , Animais , Apoptose/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Isquemia Miocárdica/fisiopatologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio/metabolismo , PPAR alfa/genética , PPAR alfa/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Receptores Ativados por Proliferador de Peroxissomo , Traumatismo por Reperfusão/fisiopatologia , Transdução de Sinais/genética
7.
Microb Pathog ; 125: 183-188, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30217516

RESUMO

Human granulocytic anaplasmosis (HGA), an increasingly recognized febrile tick-borne illness, is caused by a gram-negative obligate intracellular bacterium Anaplasma phagocytophilum. Because of nonspecific clinical manifestations, diagnosis of HGA highly depends on laboratory tests. Identification of immunoreactive proteins is prerequisite for development of specific and sensitive immunoassays for HGA. In this study, we identified novel immunoreactive proteins of A. phagocytophilum. Previous studies indicated that secreted proteins of A. phagocytophilum and other bacteria can be immunoreactive antigens. Here we in silico screened A. phagocytophilum genome for encoding proteins which bear features of type IV secretion system substrates. Among seventy seven predicted proteins, fourteen proteins were determined for antigenicity and nine proteins were showed to be immunoreactive antigens. In addition, an APH1384 peptide harboring a B cell epitope predicted by bioinformatics was found specifically reacting with anti-A. phagocytophilum sera. Hereby, we identified novel immunoreactive proteins and delineated a specific epitope of A. phagocytophilum, which might be employed for HGA diagnosis.


Assuntos
Anaplasma phagocytophilum/imunologia , Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/imunologia , Ehrlichiose/diagnóstico , Epitopos/imunologia , Anaplasma phagocytophilum/genética , Proteínas de Bactérias/genética , Biologia Computacional , Ehrlichiose/imunologia , Epitopos/genética , Humanos , Fatores de Virulência/genética , Fatores de Virulência/imunologia
8.
J Gen Virol ; 98(6): 1163-1168, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28613141

RESUMO

G9P[8] rotavirus A (RVA) has been identified as the predominant genotype circulating in Yunnan, China. To elucidate the molecular characteristics of its genetic composition at the whole-genome level, the genomes of 12 strains isolated from paediatric patients with diarrhoea were fully sequenced and characterized. Eleven of the 12 strains were genotyped as G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1, which is closely related to the Wa-like genotype 1 constellation. In contrast, one strain was genotyped as G9-P[8]-I1-R1-C1-M1-A1-N2-T1-E1-H1, with the NSP2 gene characterized as a DS-1 like genotype. Bayesian phylogenetic analysis indicated that G9 strains had emerged in 1932 with an estimated average evolutionary rate of 1.63×10-3 substitutions/site/year. Considering the high prevalence and fast evolutionary rate of G9P[8] rotaviruses, our results suggest that G9P[8] RVA should be strictly monitored in China.


Assuntos
Evolução Molecular , Variação Genética , Genótipo , Infecções por Rotavirus/virologia , Rotavirus/classificação , Rotavirus/genética , China , Análise por Conglomerados , Diarreia/virologia , Genoma Viral , Técnicas de Genotipagem , Humanos , Filogenia , Análise de Sequência de DNA , Homologia de Sequência
9.
Arch Virol ; 162(1): 281-285, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27718075

RESUMO

The aim of this study was to determine the prevalence of rotavirus A (RVA) infections in children from Kunming, China, and the RVA genotypes present. A total of 16,311 children with acute gastroenteritis were recruited for the study, and 33.1 % (5,394/16,311) were RVA positive. Children under 24 months of age were more susceptible to RVA infection, with an infection rate of 87.4 % (4,712/5,394). The most prevalent genotype was G9P[8] (85/107, 79.4 %), which showed high sequence similarity to G9P[8] strains from other regions of China and neighbouring countries, but not to the licensed vaccine strain LLR. These findings should be useful for the prevention of RVA infections.


Assuntos
Gastroenterite/epidemiologia , Genótipo , Infecções por Rotavirus/epidemiologia , Rotavirus/classificação , Rotavirus/genética , Adolescente , Fatores Etários , Criança , Pré-Escolar , China/epidemiologia , Feminino , Gastroenterite/virologia , Humanos , Lactente , Recém-Nascido , Masculino , Epidemiologia Molecular , Prevalência , Rotavirus/isolamento & purificação , Infecções por Rotavirus/virologia
10.
Fish Shellfish Immunol ; 49: 252-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26723267

RESUMO

Salmonella enterica serovar typhimurium (S. typhimurium) is a facultative intracellular pathogen that can cause gastroenteritis and systemic infection in a wide range of hosts. Salmonella plasmid virulence gene spvB is closely related to bacterial virulence in different cells and animal models, and the encoded protein acts as an intracellular toxin required for ADP-ribosyl transferase activity. However, until now there is no report about the pathogenecity of spvB gene on zebrafish. Due to the outstanding advantages of zebrafish in analyzing bacteria-host interactions, a S. typhimurium infected zebrafish model was set up here to study the effect of spvB on autophagy and intestinal pathogenesis in vivo. We found that spvB gene could decrease the LD50 of S. typhimurium, and the strain carrying spvB promoted bacterial proliferation and aggravated the intestinal damage manifested by the narrowed intestines, fallen microvilli, blurred epithelium cell structure and infiltration of inflammatory cells. Results demonstrated the enhanced virulence induced by spvB in zebrafish. In spvB-mutant strain infected zebrafish, the levels of Lc3 turnover and Beclin1 expression increased, and the double-membraned autophagosome structures were observed, suggesting that spvB can inhibit autophagy activity. In summary, our results indicate that S. typhimurium strain containing spvB displays more virulence, triggering an increase in bacterial survival and intestine injuries by suppressing autophagy for the first time. This model provides novel insights into the role of Salmonella plasmid virulence gene in bacterial pathogenesis, and can help to further elucidate the relationship between bacteria and host immune response.


Assuntos
ADP Ribose Transferases/genética , ADP Ribose Transferases/metabolismo , Autofagia/genética , Infecções por Salmonella/microbiologia , Salmonella typhimurium/genética , Salmonella typhimurium/patogenicidade , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Infecções por Salmonella/fisiopatologia , Virulência/genética , Peixe-Zebra
11.
Med Sci Monit ; 22: 2392-403, 2016 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-27393911

RESUMO

BACKGROUND Syncytin-1, a cell membrane-localizing fusogen, is abnormally expressed in several cancers, including endometrial cancer, breast cancer, and leukemia. Although abnormal syncytin-1 expression has been detected in two-thirds of leukemia blood samples, its expression profile in acute leukemia patients has not yet been analyzed. MATERIAL AND METHODS Bone marrow samples from 50 acute myelogenous leukemia (AML) cases and 14 B-cell acute lymphocytic leukemia (B-cell ALL) patients were subjected to flow cytometry to assess leukocyte type distributions and leukocytic syncytin-1 surface expression. RT-PCR was applied to assess leukocytic syncytin-1 mRNA expression. Statistical analysis was applied to compare syncytin-1 expression between AML and B-cell ALL patients across blasts, granulocytes, lymphocytes, and monocytes as well as to determine clinical factors statistically associated with changes in syncytin-1 expression. RESULTS The leukocyte type distributions of the AML and B-cell ALL cohorts highly overlapped, with an observable difference in blast distribution between the 2 cohorts. The AML cohort displayed significantly greater syncytin-1 surface and mRNA expression (p<0.05). Syncytin-1 surface and mRNA expression was significantly increased across all 4 leukocyte types (p<0.05). The percentage of syncytin-1-expressing blasts was significantly greater in AML patients (p<0.05), with blasts showing the largest fold-change in syncytin-1 expression (p<0.05). M5, M5a, and M5b AML patients displayed significantly higher syncytin-1 surface expression relative to all other AML French-American-British (FAB) classifications (p<0.05). CONCLUSIONS These findings suggest leukocytic syncytin-1 expression may play a role in the development and/or maintenance of the AML phenotype and the acute monocytic leukemia phenotype in particular.


Assuntos
Produtos do Gene env/biossíntese , Leucemia Mieloide Aguda/sangue , Leucemia-Linfoma Linfoblástico de Células Precursoras B/sangue , Proteínas da Gravidez/biossíntese , Adolescente , Adulto , Idoso , Linfócitos B/metabolismo , Medula Óssea/metabolismo , Medula Óssea/patologia , Criança , Pré-Escolar , Feminino , Produtos do Gene env/genética , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Contagem de Leucócitos , Leucócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Proteínas da Gravidez/genética , Transcriptoma , Regulação para Cima
12.
Echocardiography ; 33(5): 764-70, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26711003

RESUMO

BACKGROUND: The long-term prognosis of patients with Kawasaki disease (KD) complicated by coronary artery aneurysm (CAA) is unclear. The aim of this study was to evaluate the complications of KD with CAAs. METHOD: We retrospectively analyzed the clinical data and complications of 38 KD patients with CAAs who were treated and underwent regular follow-up with echocardiography between January 1989 and May 2013. RESULTS: During a period of 29 days to 19 years after disease onset, complications seen included coronary stenosis and occlusion (six patients), thrombosis (17 patients), myocardial infarction (six patients), and calcification of CAAs (seven patients). Rupture of giant CAAs occurred in two patients and caused sudden death in one of these patients at 29 days and in the other patient at 5 months after disease onset. A total of seven deaths occurred, with five deaths caused by myocardial infarction. Three of these had undiagnosed incomplete KD or had not received regular treatment, while two experienced sudden death after several asymptomatic myocardial infarctions. CONCLUSION: Cardiac complications of KD with CAAs include thrombosis, coronary stenosis, myocardial infarction, sudden death, and calcification. Although rare, rupture of giant CAAs is fatal and might occur earlier after the onset of disease. Mortality occurred primarily in the earlier cases when anticoagulant therapy was insufficient and in patients who did not receive regular treatment. Echocardiography can provide reliable information for assessing the progression and prognosis of this condition.


Assuntos
Doenças Cardiovasculares/mortalidade , Aneurisma Coronário/mortalidade , Síndrome de Linfonodos Mucocutâneos/mortalidade , Adolescente , Causalidade , Criança , Pré-Escolar , China/epidemiologia , Comorbidade , Aneurisma Coronário/diagnóstico por imagem , Ecocardiografia/estatística & dados numéricos , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Síndrome de Linfonodos Mucocutâneos/diagnóstico por imagem , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Taxa de Sobrevida , Adulto Jovem
14.
Cytokine ; 72(1): 31-5, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25569374

RESUMO

BACKGROUND AND AIMS: It is suggested that regulatory immune cells play a critical role in cancer cell growth by facilitating cancer cells to escape from the immune surveillance. The generation of the immune regulatory cells in cancer has not been fully understood yet. This study aims to investigate the role of the hepatoma-derived growth factor (HDGF) in the generation of regulatory T cells (Treg). METHODS: CCL-9.1 cells (A mouse hepatoma cell line), were cultured. The expression of HDGF in CCL-9.1 cells was assessed by quantitative RT-PCR and Western blotting. The generation of Foxp3(+) T cells was assessed by cell culture and flow cytometry. The immune suppressor function of the Foxp3(+) T cells on CD8(+) T cell activities was assessed by the carboxyfluorescein succinimidyl ester (CFSE)-dilution assay and enzyme-linked immunosorbent assay. RESULTS: The results showed that exposure to PolyIC markedly increased the expression of HDGF in CCL-9.1 cells. Coculture of CCL-9.1 cells and CD4(+) CD25(-) T cells in the presence of PolyIC generated the Forkhead box protein (Foxp)3(+) T cells. The exposure to HDGF increased the expression of Foxp3 and decreased the expression of GATA3 in CD4(+) T cells. After activation, the Foxp3(+) T cells suppressed the CD8(+) T cell proliferation and the release of the cytotoxic cytokines. CONCLUSIONS: Liver cancer cell-derived HDGF can induce Foxp3(+) T cells; the latter has the immune suppressor functions on CD8(+) T cell activities.


Assuntos
Carcinoma Hepatocelular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Western Blotting , Linhagem Celular Tumoral , Técnicas de Cocultura , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Fatores de Transcrição Forkhead/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/isolamento & purificação , Neoplasias Hepáticas/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Poli I-C/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Linfócitos T Reguladores/fisiologia
15.
Proc Natl Acad Sci U S A ; 109(51): 20800-7, 2012 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-23197835

RESUMO

Autophagy, a cytoplasmic catabolic process, plays a critical role in defense against intracellular infection. In turn, evasion or inhibition of autophagy has emerged as an important virulence factor for intracellular pathogens. However, Anaplasma phagocytophilum, the obligatory intracellular bacterium that causes human granulocytic anaplasmosis, replicates in the membrane-bound compartment resembling early autophagosome. Here, we found that Anaplasma translocated substrate 1 (Ats-1), a type IV secretion effector, binds Beclin 1, a subunit of the class III PI3K and Atg14L, and it nucleates autophagosomes with markers of omegasomes, double FYVE-containing protein 1, Atg14L, and LC3. Ats-1 autophagy induction did not activate the starvation signaling pathway of mammalian target of rapamycin. These autophagy proteins were also localized to the Anaplasma inclusion. Ectopically expressed Ats-1 targeted the Anaplasma inclusions and enhanced infection, whereas host cytoplasmic delivery of anti-Ats-1 or Beclin 1 depletion by siRNA suppressed the infection; beclin 1 heterozygous-deficient mice were resistant to Anaplasma infection. Furthermore, Anaplasma growth arrest by the class III PI3K inhibitor 3-methyladenine was alleviated by essential amino acid supplementation. Thus, Anaplasma actively induces autophagy by secreting Ats-1 that hijacks the Beclin 1-Atg14L autophagy initiation pathway likely to acquire host nutrients for its growth.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/química , Proteínas Reguladoras de Apoptose/química , Autofagia , Proteínas de Membrana/química , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Anaplasma phagocytophilum/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Relacionadas à Autofagia , Proteína Beclina-1 , Linhagem Celular , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Retículo Endoplasmático/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Células HL-60 , Humanos , Proteínas de Membrana/metabolismo , Microscopia de Fluorescência/métodos , Mitocôndrias/metabolismo , Modelos Biológicos , Ligação Proteica , RNA Interferente Pequeno/metabolismo , Serina-Treonina Quinases TOR/metabolismo
16.
J Immunother Cancer ; 12(6)2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38908855

RESUMO

BACKGROUND: Chordoma, a rare bone tumor, presents limited treatment options and patients typically exhibit poor survival outcomes. While immunotherapy has shown promising results in treating various tumors, research on the immune microenvironment of chordomas is still in its early stages. Therefore, understanding how the immune microenvironment of chordomas influences the outcomes of immunotherapy is crucial. METHODS: We employed single-cell RNA sequencing (scRNA-seq), bulk RNA-seq, CellChat, gene set variation analysis, as well as calculation of immune features to further dissect the complex immune microenvironment of chordoma. RESULTS: Previous research by van Oost et al argued that compared with other sarcomas, chordomas typically exhibit an immunologically "hot" microenvironment, a conclusion with which we concur based on their research findings. Additionally, the authors suggest that T cell-mediated immunotherapy is feasible for the majority of chordomas. However, we are inclined to categorize them as an immune-excluded phenotype according to the latest classification methods, rather than persisting with the concepts of "cold" and "hot". Unlike them, we explored immune infiltration scores (IS), T lymphocyte scoring (TLS), and human leucocyte antigen class I (HLA-I) using Bulk RNA-seq data from 126 chordoma patients and found that higher IS, TLS, and higher HLA-I expression were associated with poorer patient prognosis. Additionally, CellChat analysis of scRNA-seq results from six chordoma patients revealed no direct interaction between T cells and tumor cells. CONCLUSIONS: These findings suggested that the efficacy of T cell-based immunotherapy may be limited or even ineffective for patients with chordoma.


Assuntos
Cordoma , Microambiente Tumoral , Humanos , Cordoma/imunologia , Cordoma/genética , Cordoma/terapia , Microambiente Tumoral/imunologia , Masculino , Feminino , Pessoa de Meia-Idade , Imunoterapia/métodos
17.
Cell Microbiol ; 14(7): 1037-50, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22348527

RESUMO

Ehrlichia chaffeensis infects monocytes/macrophages and causes human monocytic ehrlichiosis. To determine the role of type IV secretion (T4S) system in infection, candidates for T4S effectors were identified by bacterial two-hybrid screening of E. chaffeensis hypothetical proteins with positively charged C-terminus using E. chaffeensis VirD4 as bait. Of three potential T4S effectors, ECH0825 was highly upregulated early during exponential growth in a human monocytic cell line. ECH0825 was translocated from the bacterium into the host-cell cytoplasm and localized to mitochondria. Delivery of anti-ECH0825 into infected host cells significantly reduced bacterial infection. Ectopically expressed ECH0825 also localized to mitochondria and inhibited apoptosis of transfected cells in response to etoposide treatment. In double transformed yeast, ECH0825 localized to mitochondria and inhibited human Bax-induced apoptosis. Mitochondrial manganese superoxide dismutase (MnSOD) was increased over ninefold in E. chaffeensis-infected cells, and the amount of reactive oxygen species (ROS) in infected cells was significantly lower than that in uninfected cells. Similarly, MnSOD was upregulated and the ROS level was reduced in ECH0825-transfected cells. These data suggest that, by upregulating MnSOD, ECH0825 prevents ROS-induced cellular damage and apoptosis to allow intracellular infection. This is the first example of host ROS levels linked to a bacterial T4S effector.


Assuntos
Apoptose , Sistemas de Secreção Bacterianos , Ehrlichia chaffeensis/patogenicidade , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Virulência/metabolismo , Proteínas de Bactérias/metabolismo , Linhagem Celular , Humanos , Mitocôndrias/enzimologia , Monócitos/metabolismo , Monócitos/microbiologia , Transporte Proteico , Técnicas do Sistema de Duplo-Híbrido
18.
Front Psychol ; 14: 1124588, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37138990

RESUMO

Background: Recently, identifying the psychological mechanism of college students' loneliness has attracted wide attention because the maladjustment caused by college students' loneliness is increasingly common. This study explored the relationship and potential mechanism between college students' neuroticism and loneliness in a large sample. Methods: A total of 4,600 college students completed the Big Five Personality Scale, Loneliness Scale, Self-efficacy Scale and Social Avoidance and Distress Scale. Results: By examining the chain mediating roles of self-efficacy, social avoidance and distress (SAD) in the relation between neuroticism and loneliness, the present study found that college students' neuroticism was positively associated with loneliness via self-efficacy and SAD, respectively, and sequentially. Conclusions: The results suggest a significant positive association between neuroticism and loneliness, which is influenced by the mediating effects of both self-efficacy and social avoidance and distress (SAD), as well as the chained mediating effects of self-efficacy and SAD.

19.
J Pers Med ; 13(2)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36836536

RESUMO

Anaplasma phagocytophilum, the aetiologic agent of human granulocytic anaplasmosis (HGA), is an obligate intracellular Gram-negative bacterium. During infection, A. phagocytophilum enhances the adhesion of neutrophils to the infected endothelial cells. However, the bacterial factors contributing to this phenomenon remain unknown. In this study, we characterized a type IV secretion system substrate of A. phagocytophilum, AFAP (an actin filament-associated Anaplasma phagocytophilum protein) and found that it dynamically changed its pattern and subcellular location in cells and enhanced cell adhesion. Tandem affinity purification combined with mass spectrometry identified host nucleolin as an AFAP-interacting protein. Further study showed the disruption of nucleolin by RNA interference, and the treatment of a nucleolin-binding DNA aptamer AS1411 attenuated AFAP-mediated cell adhesion, indicating that AFAP enhanced cell adhesion in a nucleolin-dependent manner. The characterization of cell adhesion-enhancing AFAP and the identification of host nucleolin as its interaction partner may help understand the mechanism underlying A. phagocytophilum-promoting cell adhesion, facilitating the elucidation of HGA pathogenesis.

20.
Neurosurgery ; 92(3): 524-537, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36409294

RESUMO

BACKGROUND: Currently, little is known about the prognostic value of tumor growth rate (TGR) in spinal giant cell tumors of bone (GCTB). OBJECTIVE: To investigate the correlation of TGR with clinicopathological features, immune microenvironment, prognosis, and response to denosumab treatment of spinal GCTB. METHODS: A total of 128 patients with spinal GCTB treated at 5 centers from 2011 to 2021 were included. TGR was assessed by 2 independent neuroradiologists using at least 2 preoperative thin-section magnetic resonance imaging scans at a minimum interval of 2 months. Immunohistochemistry was used to assess tumor-infiltrating lymphocyte subtypes for CD3, CD4, CD8, CD20, PD-1, PD-L1, and Foxp3. Then, these parameters were analyzed for their associations with patient outcomes (progression-free survival and overall survival), clinicopathological features, and denosumab treatment responsiveness. RESULTS: High TGR predicted both poor progression-free survival and overall survival (both P < .001). In addition, TGR was associated with postoperative neurological dysfunction ( P < .001), Enneking staging ( P = .016), denosumab treatment responsiveness ( P = .035), and the number of CD3 + ( P < .001), PD-1 + ( P = .009), PD-L1 + ( P < .001), and FoxP3 + tumor-infiltrating lymphocyte ( P = .02). Importantly, TGR outperformed the traditional Enneking, Campanacci, and American Joint Committee on Cancer staging systems in predicting the clinical outcomes of spinal GCTB. CONCLUSION: These data support the use of TGR as a reliable predictive tool for clinically relevant outcomes and response to denosumab therapy of spinal GCTB, which may be helpful in guiding prognostic risk stratification and therapeutic optimization of patients.


Assuntos
Conservadores da Densidade Óssea , Neoplasias Ósseas , Tumor de Células Gigantes do Osso , Humanos , Denosumab/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Antígeno B7-H1 , Conservadores da Densidade Óssea/uso terapêutico , Receptor de Morte Celular Programada 1 , Tumor de Células Gigantes do Osso/diagnóstico por imagem , Tumor de Células Gigantes do Osso/tratamento farmacológico , Tumor de Células Gigantes do Osso/patologia , Fatores de Transcrição Forkhead/uso terapêutico , Microambiente Tumoral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA