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1.
Pediatr Pulmonol ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38837645

RESUMO

OBJECTIVE: This investigation aimed to delineate the clinical manifestations associated with high-altitude pulmonary edema (HAPE) and acute mountain sickness (AMS) in pediatric populations and find the risk factors of HAPE. METHODS: We conducted a retrospective analysis of clinical data from children under 18 years diagnosed with HAPE and AMS at an average altitude of 3000 m. The clinical data between these two groups were compared. RESULTS: The study encompassed 74 pediatric patients, 27 with AMS and 47 with HAPE. HAPE presentations included classic HAPE (55.3%), reentry HAPE (27.7%), and high-altitude resident pulmonary edema (HARPE, 17.0%). Notably, 87.2% of HAPE cases were male, and 68.1% had a high body mass index (BMI). HARPE instances followed viral infections, prominently SARS-CoV-2. HAPE cases exhibited higher BMI, respiratory tract infections within 1 week preceding symptom onset, an increase in white blood cell counts (WBCs), lower peripheral arterial oxygen saturation (SpO2), and higher heart rate compared to the AMS group. Multivariate logistic regression pinpointed high BMI as an independent HAPE risk factor (odds ratio = 19.389, 95% confidence interval: 1.069-351.759, p = .045). CONCLUSION: HAPE occurs predominantly in males, with high BMI identified as a critical independent risk factor. The study underscores the need for heightened awareness and preventive strategies against HAPE in children at high altitudes.

2.
J Mol Cell Cardiol ; 193: 36-52, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38795767

RESUMO

BACKGROUND: Atherosclerosis is a chronic pathology, leading to acute coronary heart disease or stroke. MiR-127 has been found significantly upregulated in advanced atherosclerosis. But its function in atherosclerosis remains unexplored. We explored the role of miR-127-3p in regulating atherosclerosis development and its downstream mechanisms. METHODS: The expression profile of miR-127 in carotid atherosclerotic plaques of 23 patients with severe carotid stenosis was detected by RT-qPCR and in situ hybridization. Primary bone marrow-derived macrophages (BMDM) stimulated with oxidized low-density lipoprotein were used as an in vitro model. CCK-8, EdU, RT-qPCR, and flow cytometry were used to detect the proliferative capacity and polarization of BMDM, which were infected by lentivirus-carrying plasmid to upregulate or downregulate miR-127-3p expression, respectively. RNA sequencing combined with bioinformatic analysis and targeted fatty acid metabolomics approach were used to detect the transcriptome and lipid metabolites. The association between miR-127-3p and its target was verified by dual-luciferase activity reporting and Western blotting. Oxygen consumption rate of BMDM were detected using seahorse analysis. High-cholesterol-diet-fed low density lipoprotein deficient (LDLR-/-) mice, with-or-without carotid tandem-stenosis surgery, were treated with miR-127-3p agomir or antagomir to examine its effect on plaque development and stability. RESULTS: miR-127-3p, not -5p, is elevated in human advanced carotid atheroma and its expression is positively associated with macrophage accummulation in plaques. In vitro, miR-127-3p-overexpressed macrophage exhibites increased proliferation capacity and facilitates M1 polariztion whereas the contrary trend is present in miR-127-3p-inhibited macrophage. Stearoyl-CoA desaturase-1 (SCD1) is one potential target of miR-127-3p. miR-127-3p mimics decreases the activity of 3' untranslated regions of SCD-1. Furthermore, miR-127-3p downregulates SCD1 expression, and reversing the expression of SCD1 attenuates the increased proliferation induced by miR-127-3p overexpression in macrophage. miR-127-3p overexpression could also lead to decreased content of unsaturated fatty acids (UFAs), increased content of acetyl CoA and increased level of oxidative phosphorylation. In vivo, miR-127-3p agomir significantly increases atherosclerosis progression, macrophage proliferation and decreases SCD1 expression and the content of UFAs in aortic plaques of LDLR-/- mice. Conversely, miR-127-3p antagomir attenuated atherosclerosis, macrophage proliferation in LDLR-/- mice, and enhanced carotid plaque stability in mice with vulnerable plaque induced. CONCLUSION: MiR-127-3p enhances proliferation in macrophages through downregulating SCD-1 expression and decreasing the content of unsaturated fatty acid, thereby promoting atherosclerosis development and decreasing plaque stability. miR-127-3p/SCD1/UFAs might provide potential therapeutic target for anti-inflammation and atherosclerosis.

3.
Commun Biol ; 6(1): 1268, 2023 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-38097699

RESUMO

Recent developments in single-cell technology have enabled the exploration of cellular heterogeneity at an unprecedented level, providing invaluable insights into various fields, including medicine and disease research. Cell type annotation is an essential step in its omics research. The mainstream approach is to utilize well-annotated single-cell data to supervised learning for cell type annotation of new singlecell data. However, existing methods lack good generalization and robustness in cell annotation tasks, partially due to difficulties in dealing with technical differences between datasets, as well as not considering the heterogeneous associations of genes in regulatory mechanism levels. Here, we propose the scPML model, which utilizes various gene signaling pathway data to partition the genetic features of cells, thus characterizing different interaction maps between cells. Extensive experiments demonstrate that scPML performs better in cell type annotation and detection of unknown cell types from different species, platforms, and tissues.


Assuntos
Medicina , Análise da Expressão Gênica de Célula Única , Transdução de Sinais , Tecnologia
4.
PLoS One ; 18(9): e0291717, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37708155

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0181014.].

5.
Nanomicro Lett ; 15(1): 211, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37698706

RESUMO

Chirality, as the symmetric breaking of molecules, plays an essential role in physical, chemical and especially biological processes, which highlights the accurate distinction among heterochiralities as well as the precise preparation for homochirality. To this end, the well-designed structure-specific recognizer and catalysis reactor are necessitated, respectively. However, each kind of target molecules requires a custom-made chiral partner and the dynamic disorder of spatial-orientation distribution of molecules at the ensemble level leads to an inefficient protocol. In this perspective article, we developed a universal strategy capable of realizing the chirality detection and control by the external symmetry breaking based on the alignment of the molecular frame to external stimuli. Specifically, in combination with the discussion about the relationship among the chirality (molecule), spin (electron) and polarization (photon), i.e., the three natural symmetry breaking, single-molecule junctions were proposed to achieve a single-molecule/event-resolved detection and synthesis. The fixation of the molecular orientation and the CMOS-compatibility provide an efficient interface to achieve the external input of symmetry breaking. This perspective is believed to offer more efficient applications in accurate chirality detection and precise asymmetric synthesis via the close collaboration of chemists, physicists, materials scientists, and engineers.

6.
Int J Infect Dis ; 135: 118-122, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37611798

RESUMO

From December 2022 to January 2023, seven children aged ≤14 years and residing in an area at 2999 m without altitude change in the past month developed severe cough, dyspnea, cyanosis, and severe pulmonary lesions within 2-3 days after SARS-CoV-2 infection. They were diagnosed to have high-altitude resident pulmonary edema. They completely recovered following 4-7 days of treatment with oxygen inhalation, vasodilation, diuretics, and glucocorticoids.


Assuntos
COVID-19 , Edema Pulmonar , Humanos , Criança , Altitude , Edema Pulmonar/etiologia , Edema Pulmonar/diagnóstico , COVID-19/complicações , SARS-CoV-2
7.
J Am Chem Soc ; 144(45): 20797-20803, 2022 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-36274261

RESUMO

The PNP structure realized by energy band engineering is widely used in various electronic and optoelectronic devices. In this work, we succeed in constructing a PNP-type single-molecule junction and explore the intrinsic characteristics of the PNP structure at the single-molecule level. A back-to-back azulene molecule is designed with opposite ∼1.7 D dipole moments to create PNP-type single-molecule junctions. In combination with theoretical and experimental studies, it is found that the intrinsic dipole can effectively adjust single-molecule charge transport and the corresponding potential barriers. This energy band control and charge transport regulation at the single-molecule level improve deep understanding of molecular charge transport mechanisms and provide important insights into the development of high-performance functional molecular nanocircuits toward practical applications.


Assuntos
Eletrônica , Nanotecnologia
8.
Front Psychol ; 13: 960049, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35959048

RESUMO

Objectives: As the largest cohort of healthcare workers and nurses can practice as psychotherapists to integrate the psychotherapeutic interventions as part of routine care. The present study aims to evaluate the effectiveness of supportive psychotherapy (SPT) on patients who had been scheduled to undergo a fiberoptic bronchoscopy (FOB) procedure. Methods: This study retrospectively analyzed 92 patients who underwent FOB, which was divided into the SPT group and usual-care group based on whether patients were given SPT interventions or not. The Patient Health Questionnaire-9 (PHQ-9) and Hospital Anxiety and Depression Scale (HADS) were used to determine the severity of depression and anxiety, as well as the 36-Item Short-Form Health Survey questionnaire (SF-36) to evaluate the health-related quality of life (HRQoL). Moreover, the patients' satisfaction was assessed based on the Likert 5-Point Scale. Results: The baseline status of anxiety, depression, and HRQoL in patients was similar in the SPT group and the usual-care group with no significant difference. Both PHQ-9 score and HADS-D score in the SPT group after intervention were lower than that in the usual-care group, accompanied by the deceased HADS-A subscale. Moreover, the improved HRQoL was found in the patients undergoing FOB after SPT interventions as compared to those receiving conventional nursing care using the SF-36 score. Additionally, the patient satisfaction in the SPT group was higher than in the usual-care group. Conclusions: The study demonstrated that anxiety and depression, as negative emotions, can be reduced by supportive psychotherapy in patients receiving FOB with improved mental health and satisfaction with nursing care.

9.
Diagnostics (Basel) ; 12(8)2022 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-36010314

RESUMO

OBJECTIVE: To investigate the common pathogens of viral encephalitis (VE) in children, and to provide guidance for the empirical diagnosis and treatment of patients with VE. METHODS: A total of 227 cerebrospinal fluid (CSF) samples were collected from pediatric patients with VE in Zhejiang province from January 2018 to December 2019. The samples were tested using multiplex and singleplex Reverse Transcription-Polymerase Chain Reaction (RT-PCR) with primers specific to enterovirus (EV), varicella-zoster virus (VZV), mumps virus (MuV), cytomegalovirus (CMV), herpes simplex virus type 1 (HSV-1)/type 2 (HSV-2), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV-6). The data of the two analyses were compared and then verified using Sanger sequencing. RESULTS: Of the 227 CSF samples, 90 were shown to be positive for multiplex RT-PCR with a positivity rate of 39.65% and a 95% confidence interval (33.2%, 46.1%). EV was the most common cause of VE, followed by EBV, HHV-6, MuV, CMV, VZV, and HSV-1. Most included cases occurred in summer, accounting for 49.78% of all cases. For EV, EBV, and HSV-2, multiplex RT-PCR showed a positivity rate of 34.36%, which was not statistically different from that of 30.4% shown by singleplex RT-PCR. The sequences of EV, EBV, VZV, MuV, CMV, HSV-1, HHV-6, and HSV-2 were confirmed by sequencing the PCR products obtained from multiplex and singleplex PCR. CONCLUSIONS: In children, VE is more prevalent in the summer than in other seasons in Zhejiang province, and EV may be the most common causative pathogen.

10.
Diagnostics (Basel) ; 12(2)2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-35204544

RESUMO

Interferon-gamma release assays (IGRAs) are widely used in the diagnosis of Mycobacterium tuberculosis (M. tuberculosis) infection by detecting interferon-γ released by previously sensitized T-cells in-vitro. Currently, there are two assays based on either enzyme-linked immunosorbent assay (ELISA) or enzyme-linked immunospot (ELISPOT) technology, with several generations of products available. The diagnostic value of IGRAs in the immunocompromised population is significantly different from that in the immunocompetent population because their results are strongly affected by the host immune function. Both physiological and pathological factors can lead to an immunocompromised situation. We summarized the diagnostic value and clinical recommendations of IGRAs for different immunocompromised populations, including peoplewith physiological factors (pregnant and puerperal women, children, and older people), as well as people with pathological factors (solid organ transplantation recipients, combination with human immunodeficiency virus infection, diabetes mellitus, end-stage renal disease, end-stage liver disease, and chronic immune-mediated inflammatory diseases). Though the performance of IGRAs is not perfect and often requires a combination with other diagnostic strategies, it still has some value in the immunocompromised population. Hopefully, the newly developed IGRAs could better target this population.

13.
ACS Appl Mater Interfaces ; 12(38): 43250-43256, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32865960

RESUMO

Homogeneous ternary oxides of silicon-, niobium-, and molybdenum-aluminate were deposited by plasma-enhanced ALD using sequential metal precursor pulses prior to the oxidation step, to reduce interfacial defects usually observed in nanolaminate growth. The growth kinetics can be understood in terms of competitive adsorption. Trimethyl aluminum (TMA) is strongly chemisorbed to the growth surface and does not permit coadsorption of any of the other precursors; when we lead with a TMA pulse, the resulting film is always Al2O3. When we lead with the Si or Nb precursors, the growth surface is partially saturated, but open sites are available for TMA coadsorption. The Mo precursor is weakly chemisorbed and is largely displaced by a subsequent TMA dose. As compared to nanolaminate films of the constituent binary oxides, the interface state density is reduced by up to a factor of 5.

14.
J Infect Dis ; 222(6): 1008-1020, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32274497

RESUMO

BACKGROUND: Leptospirosis is a global zoonotic infectious disease caused by Leptospira interrogans. The pathogen rapidly invades into hosts and diffuses from bloodstream into internal organs and excretes from urine to cause transmission of leptospirosis. However, the mechanism of leptospiral invasiveness remains poorly understood. METHODS: Proteolytic activity of M16-type metallopeptidases (Lep-MP1/2/3) of L. interrogans was determined by spectrophotometry. Expression and secretion of Lep-MP1/2/3 during infection of cells were detected by quantitative reverse-transcription polymerase chain reaction, Western blot assay, and confocal microscopy. Deletion and complementation mutants of the genes encoding Lep-MP1/2/3 were generated to determine the roles of Lep-MP1/2/3 in invasiveness using transwell assay and virulence in hamsters. RESULTS: Leptospira interrogans but not saprophytic Leptospira biflexa strains were detectable for Lep-MP-1/2/3-encoding genes. rLep-MP1/2/3 hydrolyzed extracellular matrix proteins, but rLep-MP1/3 displayed stronger proteolysis than rLep-MP2, with 123.179/340.136 µmol/L Km and 0.154/0.159 s-1 Kcat values. Expression, secretion and translocation of Lep-MP1/2/3 during infection of cells were increased. ΔMP1/3 but not ΔMP2 mutant presented attenuated transmigration through cell monolayers, decreased leptospiral loading in the blood, lungs, liver, kidneys, and urine, and 10/13-fold decreased 50% lethal dose and milder histopathologic injury in hamsters. CONCLUSIONS: Lep-MP1 and 3 are involved in virulence of L. interrogans in invasion into hosts and diffusion in vivo, and transmission of leptospirosis.


Assuntos
Leptospira interrogans/classificação , Leptospira interrogans/genética , Leptospirose/microbiologia , Leptospirose/transmissão , Metaloproteases/genética , Animais , Carga Bacteriana , Biópsia , Cricetinae , Modelos Animais de Doenças , Ativação Enzimática , Regulação Bacteriana da Expressão Gênica , Leptospira interrogans/enzimologia , Leptospira interrogans/patogenicidade , Leptospirose/patologia , Masculino , Metaloproteases/metabolismo , Mutação , Proteólise , Coelhos , Virulência/genética , Fatores de Virulência/genética
15.
Elife ; 82019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31012847

RESUMO

Many bacterial pathogens can cause septicemia and spread from the bloodstream into internal organs. During leptospirosis, individuals are infected by contact with Leptospira-containing animal urine-contaminated water. The spirochetes invade internal organs after septicemia to cause disease aggravation, but the mechanism of leptospiral excretion and spreading remains unknown. Here, we demonstrated that Leptospira interrogans entered human/mouse endothelial and epithelial cells and fibroblasts by caveolae/integrin-ß1-PI3K/FAK-mediated microfilament-dependent endocytosis to form Leptospira (Lep)-vesicles that did not fuse with lysosomes. Lep-vesicles recruited Rab5/Rab11 and Sec/Exo-SNARE proteins in endocytic recycling and vesicular transport systems for intracellular transport and release by SNARE-complex/FAK-mediated microfilament/microtubule-dependent exocytosis. Both intracellular leptospires and infected cells maintained their viability. Leptospiral propagation was only observed in mouse fibroblasts. Our study revealed that L. interrogans utilizes endocytic recycling and vesicular transport systems for transcytosis across endothelial or epithelial barrier in blood vessels or renal tubules, which contributes to spreading in vivo and transmission of leptospirosis.


Assuntos
Células Endoteliais/microbiologia , Células Epiteliais/microbiologia , Fibroblastos/microbiologia , Interações Hospedeiro-Patógeno , Leptospira interrogans/fisiologia , Transcitose , Animais , Sobrevivência Celular , Vesículas Citoplasmáticas/microbiologia , Endocitose , Humanos , Leptospirose , Camundongos , Viabilidade Microbiana
16.
Vector Borne Zoonotic Dis ; 19(8): 604-612, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30702382

RESUMO

Leptospirosis is a worldwide zoonosis caused by spirochetes from the genus Leptospira. In the present study, a visual and rapid method for detecting Leptospira interrogans was developed based on multiple cross-displacement amplification (MCDA) and nanoparticle-based lateral flow biosensor (LFB). A set of 10 primers was specifically designed to recognize 10 regions of the lipL 41 gene of L. interrogans. The MCDA reaction was optimized at 64°C for only 40 min, and the amplification products were directly applied to the biosensor. The entire process, including DNA extraction (25 min), MCDA reaction (40 min), and result interpretation (∼2 min), could be completed within 70 min. Amplification products were detectable from as few as 10 genomic equivalents per reaction of pure L. interrogans DNA. No cross-reaction with nonpathogenic Leptospira or other bacteria was observed. The MCDA-LFB method established in the current report is suitable for the rapid screening of L. interrogans in clinical, animal, and environmental samples.


Assuntos
Técnicas Biossensoriais/métodos , Leptospira interrogans/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Animais , Primers do DNA , DNA Bacteriano , Leptospira interrogans/genética , Leptospirose/diagnóstico , Camundongos , Nanopartículas , Sensibilidade e Especificidade
17.
EBioMedicine ; 37: 428-441, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30337247

RESUMO

BACKGROUD: Leptospira interrogans is the major causative agent of leptospirosis, a worldwide zoonotic disease. Hemorrhage is a typical pathological feature of leptospirosis. Binding of von Willebrand factor (vWF) to platelet glycoprotein-Ibα (GPIbα) is a crucial step in initiation of platelet aggregation. The products of L. interrogans vwa-I and vwa-II genes contain vWF-A domains, but their ability to induce hemorrhage has not been determined. METHODS: Human (Hu)-platelet- and Hu-GPIbα-binding abilities of the recombinant proteins expressed by L. interrogans strain Lai vwa-I and vwa-II genes (rLep-vWA-I and rLep-vWA-II) were detected by flowcytometry, surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). Hu-platelet aggregation and its signaling kinases and active components were detected by lumiaggregometry, Western analysis, spectrophotometry and confocal microscopy. Hu-GPIbα-binding sites in rLep-vWA-I and rLep-vWA-II were identified by SPR/ITC measurements. FINDINGS: Both rLep-vWA-I and rLep-vWA-II were able to bind to Hu-platelets and inhibit rHu-vWF/ristocetin-induced Hu-platelet aggregation, but Hu-GPIbα-IgG, rLep-vWA-I-IgG and rLep-vWA-II-IgG blocked this binding or inhibition. SPR and ITC revealed a tight interaction between Hu-GPIbα and rLep-vWA-I/rLep-vWA-II with KD values of 3.87 × 10-7-8.65 × 10-8 M. Hu-GPIbα-binding of rL-vWA-I/rL-vWA-II neither activated the PI3K/AKT-ERK and PLC/PKC kinases nor affected the NO, cGMP, ADP, Ca2+ and TXA2 levels in Hu-platelets. G13/R36/G47 in Lep-vWA-I and G76/Q126 in Lep-vWA-II were confirmed as the Hu-GPIbα-binding sites. Injection of rLep-vWA-I or rLep-vWA-II in mice resulted in diffuse pulmonary and focal renal hemorrhage but this hemorrhage was blocked by rLep-vWA-I-IgG or rLep-vWA-II-IgG. INTERPRETATION: The products of L. interrogans vwa-I and vwa-II genes induce hemorrhage by competitive inhibition of vWF-mediated Hu-platelet aggregation.


Assuntos
Proteínas de Bactérias/metabolismo , Hemorragia/metabolismo , Leptospira interrogans/metabolismo , Leptospirose/metabolismo , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Fator de von Willebrand/metabolismo , Animais , Proteínas de Bactérias/genética , Feminino , Hemorragia/genética , Células Endoteliais da Veia Umbilical Humana , Humanos , Leptospira interrogans/genética , Leptospirose/genética , Camundongos , Complexo Glicoproteico GPIb-IX de Plaquetas/genética , Fator de von Willebrand/genética
18.
Emerg Microbes Infect ; 7(1): 135, 2018 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-30061622

RESUMO

Leptospira interrogans is the major causative agent of leptospirosis, an emerging, globally spreading zoonotic infectious disease. The pathogen induces macrophage apoptosis, but the molecular basis and mechanism remain unknown. In the present study, we found that L. interrogans caused apoptosis of phagocytosis-inhibited macrophages, and the product of the L. interrogans LB047 gene (Lep-OMP047) was the unique protein captured by mouse and human Fas proteins. The recombinant expressed Lep-OMP047 (rLep-OMP047) strongly bound mouse and human Fas proteins with equilibrium association constant (KD) values of 5.20 × 10-6 to 2.84 × 10-9 M according to surface plasmon resonance measurement and isothermal titration calorimetry. Flow-cytometric examination showed that 5 µg rLep-OMP047 or 1 µg lipopolysaccharide of L. interrogans (Lep-LPS) caused 43.70% or 21.90% early apoptosis in mouse J774A.1 macrophages and 28.41% or 15.80% for PMA-differentiated human THP-1 macrophages, respectively, but the apoptosis was blocked by Fas-antagonizing IgGs, Fas siRNAs, and caspase-8/-3 inhibitors. Moreover, Lep-OMP047 was significantly upregulated during infection of macrophages. Lep-LPS promoted the expression and cytomembrane translocation of Fas and FasL in macrophages. The JNK and p38 MAPK but not ERK signaling pathways, as well as the transcription factors c-Jun and ATF2 but not CHOP, mediated Lep-LPS-induced Fas/FasL expression and translocation. TLR2 but not TLR4 mediated Lep-LPS-induced JNK/p38 MAPK activation. Therefore, we demonstrated that a novel Fas-binding OMP and LPS of L. interrogans induce macrophage apoptosis through the Fas/FasL-caspase-8/-3 pathway.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Leptospira interrogans/metabolismo , Leptospirose/metabolismo , Macrófagos/citologia , Transdução de Sinais , Animais , Apoptose , Proteínas da Membrana Bacteriana Externa/genética , Caspase 3/genética , Caspase 3/metabolismo , Caspase 8/genética , Caspase 8/metabolismo , Proteína Ligante Fas/genética , Proteína Ligante Fas/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Leptospira interrogans/genética , Leptospirose/genética , Leptospirose/microbiologia , Leptospirose/fisiopatologia , Lipopolissacarídeos/metabolismo , Macrófagos/metabolismo , Camundongos , Receptor fas/genética , Receptor fas/metabolismo
19.
Mol Microbiol ; 2018 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-29633391

RESUMO

Leptospira spp. comprise both pathogenic and free-living saprophytic species. Little is known about the environmental adaptation and survival mechanisms of Leptospira. Alternative sigma factor, σ54 (RpoN) is known to play an important role in environmental and host adaptation in many bacteria. In this study, we constructed an rpoN mutant by allele exchange, and the complemented strain in saprophytic L. biflexa. Transcriptome analysis revealed that expression of several genes involved in nitrogen uptake and metabolism, including amtB1, glnB-amtB2, ntrX and narK, were controlled by σ54 . While wild-type L. biflexa could not grow under nitrogen-limiting conditions but was able to survive under such conditions and recover rapidly, the rpoN mutant was not. The rpoN mutant also had dramatically reduced ability to survive long-term in water. σ54 appears to regulate expression of amtB1, glnK-amtB2, ntrX and narK in an indirect manner. However, we identified a novel nitrogen-related gene, LEPBI_I1011, whose expression was directly under the control of σ54 (herein renamed as rcfA for RpoN-controlled factor A). Taken together, our data reveal that the σ54 regulatory network plays an important role in the long-term environmental survival of Leptospira spp.

20.
Microbes Infect ; 20(4): 254-260, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29432801

RESUMO

Leptospirosis is a worldwide zoonosis caused by spirochetes from the genus Leptospira. Although there is a large diversity of clinical signs and symptoms, a severe inflammatory response is common to all leptospirosis patients. The mechanism of IL-1ß secretion during Leptospira infection has been previously studied in mouse macrophages. However, the outcome of Leptospira infection is very different in human and murine macrophages, and the mechanisms responsible for IL-1ß secretion in human macrophages had not been investigated. This study therefore examines the effects of Leptospira interrogans infection on inflammasome activation and proinflammatory cytokine expression in human macrophages. Increased mRNA and protein expression of NLRP3 was observed by real time RT-PCR and flow cytometry at 1 h after co-cultivation. Enzyme-linked immunosorbent assay (ELISA) determination showed that IL-1ß and IL-18 are released in the culture supernatants at 1 h after cultivation. The inhibition assay showed that glybenclamide (a K+ efflux inhibitor that blocks NLRP3 inflammasome activation) and N-benzyloxycarbony-Val-Ala-Asp (O-methyl)-fluoromethylketone (Z-VAD-FMK; a caspase-1 inhibitor) and NLRP3 depletion with siRNAs reduced the levels of IL-1ß and IL-18 release. Moreover, the levels of IL-1ß and IL-18 production decreased in CA-074 (a cathepsin B inhibitor) and NAC (an anti-oxidant) pretreated human macrophages, compared to untreated controls. This study suggests that L. interrogans infection leads to reactive oxygen species (ROS)- and cathepsin B-dependent NLRP3 inflammasome activation, which subsequently mediates caspase-1 activation and IL-1ß and IL-18 release.


Assuntos
Inflamassomos/metabolismo , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Leptospira interrogans/metabolismo , Leptospirose/imunologia , Macrófagos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Catepsina B/antagonistas & inibidores , Humanos , Inflamassomos/antagonistas & inibidores , Macrófagos/microbiologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Interferência de RNA , Espécies Reativas de Oxigênio/antagonistas & inibidores , Células THP-1 , Regulação para Cima/genética
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