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1.
J Immunol ; 210(10): 1564-1575, 2023 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-37042680

RESUMEN

Tuberculosis caused by Mycobacterium tuberculosis is a leading cause of death globally and a major health concern. In humans, macrophages are the first line invaded by M. tuberculosis. Upon infection, macrophages upregulate cyclooxygenase-2 (COX-2) expression and consequently elevate the formation of PGs, including PGE2 and PGD2. Although the role of proinflammatory PGE2 in M. tuberculosis infection has been reported, the roles of PGJ2 and 15-deoxy-PGJ2 (collectively named J2-PGs), the metabolites of PGD2 with anti-inflammatory features, remain elusive. In this study, we show that M. tuberculosis (H37Rv strain)-conditioned medium stimulates human monocyte-derived macrophages (MDMs) to elevate COX-2 expression along with robust generation of PGJ2, exceeding PGD2 formation, and to a minor extent also of 15-deoxy-PGJ2. Of interest, in M1-MDM phenotypes, PGJ2 and 15-deoxy-PGJ2 decreased M. tuberculosis (H37Rv strain)-conditioned medium-induced COX-2 expression and related PG formation by a negative feedback loop. Moreover, these J2-PGs downregulated the expression of the proinflammatory cytokines IL-6, IL-1ß, and IFN-γ, but elevated the anti-inflammatory cytokine IL-10 and the M2 markers arginase-1 and CD163. These anti-inflammatory effects of J2-PGs in M1-MDM correlated with impaired activation of TGF-ß-activated kinase 1/NF-κB/MAPK pathways. Finally, we found that J2-PGs regulate COX-2 expression, at least partially, via PGD2 receptor (DP1) and chemoattractant receptor homologue expressed on Th2 cells/DP2 receptors, but independent of the J2-PG receptor peroxisome proliferator-activated receptor-γ. Together, our findings reveal that M. tuberculosis induces COX-2 expression in human M1-MDMs, along with robust formation of J2-PGs that mediates anti-inflammatory effects via a negative feedback loop.


Asunto(s)
Mycobacterium tuberculosis , Prostaglandina D2 , Humanos , Prostaglandina D2/metabolismo , Mycobacterium tuberculosis/metabolismo , Ciclooxigenasa 2 , Dinoprostona , Retroalimentación , Medios de Cultivo Condicionados , Macrófagos/metabolismo , Citocinas , Antiinflamatorios
2.
Small ; : e2400083, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38501844

RESUMEN

Temperature is one of the governing factors affecting friction of solids. Undesired high friction state has been generally reported at cryogenic temperatures due to the prohibition of thermally activated processes, following conventional Arrhenius equation. This has brought huge difficulties to lubrication at extremely low temperatures in industry. Here, the study uncovers a hydrogen-correlated sub-Arrhenius friction behavior in hydrogenated amorphous carbon (a-C:H) film at cryogenic temperatures, and a stable ultralow-friction over a wide temperature range (103-348 K) is achieved. This is attributed to hydrogen-transfer-induced mild structural ordering transformation, confirmed by machine-learning-based molecular dynamics simulations. The anomalous sub-Arrhenius temperature dependence of structural ordering transformation rate is well-described by a quantum mechanical tunneling (QMT) modified Arrhenius model, which is correlated with quantum delocalization of hydrogen in tribochemical reactions. This work reveals a hydrogen-correlated friction mechanism overcoming the Arrhenius temperature dependence and provides a new pathway for achieving ultralow friction under cryogenic conditions.

3.
Nature ; 564(7734): E5, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30377311

RESUMEN

The spelling of author Qianting Yang was corrected; the affiliation of author Stephanus T. Malherbe was corrected; and graphs in Fig. 4b and c were corrected owing to reanalysis of the data into the correct timed intervals.

4.
Nature ; 560(7720): 644-648, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30135583

RESUMEN

Most infections with Mycobacterium tuberculosis (Mtb) manifest as a clinically asymptomatic, contained state, known as latent tuberculosis infection, that affects approximately one-quarter of the global population1. Although fewer than one in ten individuals eventually progress to active disease2, tuberculosis is a leading cause of death from infectious disease worldwide3. Despite intense efforts, immune factors that influence the infection outcomes remain poorly defined. Here we used integrated analyses of multiple cohorts to identify stage-specific host responses to Mtb infection. First, using high-dimensional mass cytometry analyses and functional assays of a cohort of South African adolescents, we show that latent tuberculosis is associated with enhanced cytotoxic responses, which are mostly mediated by CD16 (also known as FcγRIIIa) and natural killer cells, and continuous inflammation coupled with immune deviations in both T and B cell compartments. Next, using cell-type deconvolution of transcriptomic data from several cohorts of different ages, genetic backgrounds, geographical locations and infection stages, we show that although deviations in peripheral B and T cell compartments generally start at latency, they are heterogeneous across cohorts. However, an increase in the abundance of circulating natural killer cells in tuberculosis latency, with a corresponding decrease during active disease and a return to baseline levels upon clinical cure are features that are common to all cohorts. Furthermore, by analysing three longitudinal cohorts, we find that changes in peripheral levels of natural killer cells can inform disease progression and treatment responses, and inversely correlate with the inflammatory state of the lungs of patients with active tuberculosis. Together, our findings offer crucial insights into the underlying pathophysiology of tuberculosis latency, and identify factors that may influence infection outcomes.


Asunto(s)
Progresión de la Enfermedad , Células Asesinas Naturales/inmunología , Linfocitos/inmunología , Tuberculosis/inmunología , Adolescente , China , Proteínas Ligadas a GPI/inmunología , Humanos , Internacionalidad , Células Asesinas Naturales/citología , Tuberculosis Latente/genética , Tuberculosis Latente/inmunología , Estudios Longitudinales , Linfocitos/citología , Neumonía/inmunología , Neumonía/patología , Receptores de IgG/inmunología , Sudáfrica , Transcriptoma , Resultado del Tratamiento , Tuberculosis/genética , Tuberculosis/patología , Tuberculosis/terapia
5.
PLoS Pathog ; 17(7): e1008911, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34320028

RESUMEN

In order to sustain a persistent infection, Mycobacterium tuberculosis (Mtb) must adapt to a changing environment that is shaped by the developing immune response. This necessity to adapt is evident in the flexibility of many aspects of Mtb metabolism, including a respiratory chain that consists of two distinct terminal cytochrome oxidase complexes. Under the conditions tested thus far, the bc1/aa3 complex appears to play a dominant role, while the alternative bd oxidase is largely redundant. However, the presence of two terminal oxidases in this obligate pathogen implies that respiratory requirements might change during infection. We report that the cytochrome bd oxidase is specifically required for resisting the adaptive immune response. While the bd oxidase was dispensable for growth in resting macrophages and the establishment of infection in mice, this complex was necessary for optimal fitness after the initiation of adaptive immunity. This requirement was dependent on lymphocyte-derived interferon gamma (IFNγ), but did not involve nitrogen and oxygen radicals that are known to inhibit respiration in other contexts. Instead, we found that ΔcydA mutants were hypersusceptible to the low pH encountered in IFNγ-activated macrophages. Unlike wild type Mtb, cytochrome bd-deficient bacteria were unable to sustain a maximal oxygen consumption rate (OCR) at low pH, indicating that the remaining cytochrome bc1/aa3 complex is preferentially inhibited under acidic conditions. Consistent with this model, the potency of the cytochrome bc1/aa3 inhibitor, Q203, is dramatically enhanced at low pH. This work identifies a critical interaction between host immunity and pathogen respiration that influences both the progression of the infection and the efficacy of potential new TB drugs.


Asunto(s)
Complejo IV de Transporte de Electrones/metabolismo , Evasión Inmune/fisiología , Mycobacterium tuberculosis/inmunología , Tuberculosis/inmunología , Adaptación Fisiológica/fisiología , Animales , Humanos , Macrófagos/inmunología , Macrófagos/metabolismo , Macrófagos/microbiología , Ratones , Mycobacterium tuberculosis/enzimología
6.
BMC Infect Dis ; 23(1): 834, 2023 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-38012543

RESUMEN

INTRODUCTION: The urgent need for new treatments for multidrug-resistant tuberculosis (MDR-TB) and pre-extensively drug-resistant tuberculosis (pre-XDR-TB) is evident. However, the classic randomized controlled trial (RCT) approach faces ethical and practical constraints, making alternative research designs and treatment strategies necessary, such as single-arm trials and host-directed therapies (HDTs). METHODS: Our study adopts a randomized withdrawal trial design for MDR-TB to maximize resource allocation and better mimic real-world conditions. Patients' treatment regimens are initially based on drug resistance profiles and patient's preference, and later, treatment-responsive cases are randomized to different treatment durations. Alongside, a single-arm trial is being conducted to evaluate the potential of sulfasalazine (SASP) as an HDT for pre-XDR-TB, as well as another short-course regimen without HDT for pre-XDR-TB. Both approaches account for the limitations in second-line anti-TB drug resistance testing in various regions. DISCUSSION: Although our study designs may lack the internal validity commonly associated with RCTs, they offer advantages in external validity, feasibility, and ethical appropriateness. These designs align with real-world clinical settings and also open doors for exploring alternative treatments like SASP for tackling drug-resistant TB forms. Ultimately, our research aims to strike a balance between scientific rigor and practical utility, offering valuable insights into treating MDR-TB and pre-XDR-TB in a challenging global health landscape. In summary, our study employs innovative trial designs and treatment strategies to address the complexities of treating drug-resistant TB, fulfilling a critical gap between ideal clinical trials and the reality of constrained resources and ethical considerations. TRAIL REGISTRATION: Chictr.org.cn, ChiCTR2100045930. Registered on April 29, 2021.


Asunto(s)
Tuberculosis Extensivamente Resistente a Drogas , Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Humanos , Antituberculosos/efectos adversos , Tuberculosis Extensivamente Resistente a Drogas/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Protocolos Clínicos , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Multicéntricos como Asunto
7.
Clin Chem Lab Med ; 61(3): 473-484, 2023 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-36542027

RESUMEN

OBJECTIVES: Due to lack of effective biomarkers for non-small cell lung cancer (NSCLC), many patients are diagnosed at an advanced stage, which leads to poor prognosis. Dysregulation of N6-methyladenosine (m6A) RNA contributes significantly to tumorigenesis and tumor progression. However, the diagnostic value of m6A RNA status in peripheral blood to screen NSCLC remains unclear. METHODS: Peripheral blood samples from 152 NSCLC patients and 64 normal controls (NCs) were applied to assess the m6A RNA levels. Bioinformatics and qRT-PCR analysis were performed to identify the specific immune cells in peripheral blood cells and investigate the mechanism of the alteration of m6A RNA levels. RESULTS: Robust elevation of m6A RNA levels of peripheral blood cells was exhibited in the NSCLC group. Moreover, the m6A levels increased as NSCLC progressed, and reduced after treatment. The m6A levels contained area under the curve (AUC) was 0.912, which was remarkably greater than the AUCs for CEA (0.740), CA125 (0.743), SCC (0.654), and Cyfra21-1 (0.730). Furthermore, the combination of these traditional biomarkers with m6A levels elevated the AUC to 0.970. Further analysis established that the expression of m6A erasers FTO and ALKBH5 were both markedly reduced and negatively correlated with m6A levels in peripheral blood of NSCLC. Additionally, GEO database and flow cytometry analysis implied that FTO and ALKBH5 attributes to peripheral CD4+ T cells proportion and activated the immune functions of T cells. CONCLUSIONS: These findings unraveled that m6A RNA of peripheral blood immune cells was a prospective biomarker for the diagnosis of NSCLC.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/genética , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , ARN/genética , Biomarcadores de Tumor , Pronóstico , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato/análisis
8.
J Infect Dis ; 225(5): 825-835, 2022 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-32939551

RESUMEN

Previous studies demonstrated that transforming growth factor (TGT) ß1 plays an immunosuppressive role in clinical tuberculosis. However, the contribution of TGF-ß1 gene polymorphisms to human tuberculosis susceptibility remains undetermined. In this study, we showed that single-nucleotide polymorphisms (SNPs) in TGF-ß1 gene were associated with increased susceptibility to tuberculosis in the discovery cohort (1533 case patients and 1445 controls) and the validation cohort (832 case patients and 1084 controls), and 2 SNPs located in the promoter region (rs2317130 and rs4803457) are in strong linkage disequilibrium. The SNP rs2317130 was associated with the severity of tuberculosis. Further investigation demonstrated that rs2317130 CC genotype is associated with higher TGF-ß1 and interleukin 17A production. The mechanistic study showed that rs2317130 C allele affected TGF-ß1 promoter activity by regulating binding activity to nuclear extracts. These findings provide insights into the pathogenic role of TGF-ß1 in human tuberculosis and reveal a function for the TGF-ß1 promoter SNPs in regulating immune responses during Mycobacterium tuberculosis infection.


Asunto(s)
Factor de Crecimiento Transformador beta1 , Tuberculosis , Humanos , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Polimorfismo de Nucleótido Simple , Factor de Crecimiento Transformador beta , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismo , Tuberculosis/genética
9.
Gut ; 71(2): 333-344, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-33692094

RESUMEN

OBJECTIVE: Solid tumours respond poorly to immune checkpoint inhibitor (ICI) therapies. One major therapeutic obstacle is the immunosuppressive tumour microenvironment (TME). Cancer-associated fibroblasts (CAFs) are a key component of the TME and negatively regulate antitumour T-cell response. Here, we aimed to uncover the mechanism underlying CAFs-mediated tumour immune evasion and to develop novel therapeutic strategies targeting CAFs for enhancing ICI efficacy in oesophageal squamous cell carcinoma (OSCC) and colorectal cancer (CRC). DESIGN: Anti-WNT2 monoclonal antibody (mAb) was used to treat immunocompetent C57BL/6 mice bearing subcutaneously grafted mEC25 or CMT93 alone or combined with anti-programmed cell death protein 1 (PD-1), and the antitumour efficiency and immune response were assessed. CAFs-induced suppression of dendritic cell (DC)-differentiation and DC-mediated antitumour immunity were analysed by interfering with CAFs-derived WNT2, either by anti-WNT2 mAb or with short hairpin RNA-mediated knockdown. The molecular mechanism underlying CAFs-induced DC suppression was further explored by RNA-sequencing and western blot analyses. RESULTS: A negative correlation between WNT2+ CAFs and active CD8+ T cells was detected in primary OSCC tumours. Anti-WNT2 mAb significantly restored antitumour T-cell responses within tumours and enhanced the efficacy of anti-PD-1 by increasing active DC in both mouse OSCC and CRC syngeneic tumour models. Directly interfering with CAFs-derived WNT2 restored DC differentiation and DC-mediated antitumour T-cell responses. Mechanistic analyses further demonstrated that CAFs-secreted WNT2 suppresses the DC-mediated antitumour T-cell response via the SOCS3/p-JAK2/p-STAT3 signalling cascades. CONCLUSIONS: CAFs could suppress antitumour immunity through WNT2 secretion. Targeting WNT2 might enhance the ICI efficacy and represent a new anticancer immunotherapy.


Asunto(s)
Fibroblastos Asociados al Cáncer/metabolismo , Carcinoma de Células Escamosas/metabolismo , Neoplasias Colorrectales/metabolismo , Neoplasias Esofágicas/metabolismo , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Proteína wnt2/metabolismo , Animales , Linfocitos T CD8-positivos , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/patología , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/patología , Células Dendríticas/fisiología , Modelos Animales de Enfermedad , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/patología , Femenino , Ratones , Ratones Endogámicos C57BL , Microambiente Tumoral
10.
Cancer Cell Int ; 22(1): 116, 2022 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-35279146

RESUMEN

BACKGROUND: Breast cancer is the most commonly diagnosed cancer in women. Triple negative breast cancer (TNBC) is the most difficult subtype of breast cancer to treat due to the deficiency in drug-targetable receptors. LRP11-AS1, a newly identified oncogenic long noncoding RNA (lncRNA) was found to be significantly overexpressed in TNBC cells. The aim of this study is to investigate the malignant roles and the oncogenic mechanisms of LRP11-AS1 in TNBC. METHODS: CCK-8, colony formation, transwell migration and transwell invasion assays were performed to study the functions of LRP11-AS1. Quantitative PCR and western blot were used to determine the gene expression. Bioinformatics analysis and dual-luciferase reporter assay were conducted to study lncRNA and miRNA interactions. RESULTS: LRP11-AS1 was found to be significantly overexpressed in TNBC cells compared to the non-TNBC cells and normal mammary epithelial cells. Knockdown of LRP11-AS1 could inhibit the growth and metastasis of TNBC cells and regulate cell cycle. Mechanistically, LRP11-AS1 was found to act as a competing endogenous RNA (ceRNA) to sponge miR-149-3p. Silencing of LRP11-AS1 increased the expression of miR-149-3p and overexpression of miR-149-3p suppressed the expression of LRP11-AS1. Inhibition of miR-149-3p could reverse the anticancer effect of LRP11-AS1 deficiency in TNBC cells. Moreover, Neuropilin-2 (NRP2) was found to be the target of miR-149-3p. Rescue experiments revealed that NRP2 overexpression could rescue the anticancer effect of LRP11-AS1 deficiency in TNBC cells. CONCLUSION: LRP11-AS1 overexpressed in TNBC showed the oncogenic effects possibly by sponging miR-149-3p and regulating the miR-149-3p/NRP2 axis, which indicated LRP11-AS1 as a potential diagnostic biomarker and therapeutic target in TNBC.

11.
J Immunol ; 204(9): 2331-2336, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-32229539

RESUMEN

Tissue-resident memory T cells (TRMs) have a key role in mediating the host defense against tuberculosis (TB) in mice, but their human counterparts have not been well characterized. In this article, we recruited patients with TB and determined TRM frequency, trafficking, activation marker expression, and cytokine production by flow or mass cytometry at different infection sites, including peripheral blood, pleural fluid, bronchoalveolar lavage fluid, and lung. We found a high frequency of TRMs at all infection sites apart from the peripheral blood. These TRMs exhibited a memory phenotype, were highly activated (based on CD38 and HLA-DR expression), and expressed high levels of trafficking (CCR5 and CXCR6) and exhaustion (PD-1) markers. When stimulated with Mycobacterium tuberculosis, TRMs secreted cytokines, including IFN-γ, TNF-α, and IL-2, and exhibited a multifunctional phenotype. TRMs limited intracellular M. tuberculosis replication in macrophages. These data inform our current understanding of immunosurveillance at different infection sites in patients with TB.


Asunto(s)
Memoria Inmunológica/inmunología , Linfocitos T/inmunología , Tuberculosis/inmunología , Adulto , Biomarcadores/sangre , Líquido del Lavado Bronquioalveolar/inmunología , Células Cultivadas , Femenino , Humanos , Interferón gamma/inmunología , Interleucina-2/inmunología , Pulmón/inmunología , Pulmón/microbiología , Macrófagos/inmunología , Macrófagos/microbiología , Masculino , Mycobacterium tuberculosis/inmunología , Fenotipo , Linfocitos T/microbiología , Tuberculosis/sangre , Tuberculosis/microbiología , Factor de Necrosis Tumoral alfa/inmunología
12.
Clin Lab ; 68(5)2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35536079

RESUMEN

BACKGROUND: Corona virus disease 2019 (COVID-19) is a severe acute respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Different pooling testing strategies have been applied for the detection of SARS-CoV-2. However, the discrepancies among different pooling strategies are still to be explored. METHODS: The aim of this study was to evaluate the two pooling strategies of collecting respiratory specimens for the detection of SARS-CoV-2 RNA. Two groups of five-sample pools were prepared to evaluate the impact of sample pooling and pooled sampling on test sensitivity, respectively. Viral RNA of coronavirus was extracted with the automation system. The N and ORF1ab genes of SARS-CoV-2 RNA were detected with real-time reverse-transcription PCR. The turnaround time of SARS-CoV-2 testing was analyzed before and after the implement of pooled sampling. RESULTS: The pooled sampling displayed advantages in assay sensitivity over the sample pooling. The implementation of pooled sampling significantly shortened the turnaround time of SARS-CoV-2 testing. CONCLUSIONS: The pooled sampling is an efficient and economical strategy for SARS-CoV-2 detection during the periods of high screening demand in low-prevalence areas.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , COVID-19/epidemiología , Prueba de COVID-19 , Humanos , Prevalencia , ARN Viral/genética , Sensibilidad y Especificidad , Manejo de Especímenes
13.
Mycoses ; 65(12): 1159-1169, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35899426

RESUMEN

BACKGROUND: Scedosporium species have drawn significant interest as inhabitants of polluted soil and water and as cause of high mortality in near-drowning patients. So far, most cases have been reported from Europe and Australia, while knowledge on their prevalence and genotypic diversity from Asia is scant. OBJECTIVES: To increase the knowledge of the genetic diversity and in vitro antifungal susceptibility of Scedosporium species involved in human infections from China. METHODS: Here, we applied the ISHAM-MLST consensus scheme for molecular typing of Scedosporium species and revealed both high species diversity and high genotypic diversity among 45 Chinese clinical Scedosporium isolates. RESULTS: Among the five species, Scedosporium boydii (n = 22) was the most common, followed by S. apiospermum (n = 18), S. aurantiacum (n = 4) and S. dehoogii (n = 1). S. aurantiacum was reported for the first time from clinical samples in China. The predominant sequence types (STs) were ST17 in S. apiospermum, ST4 in S. boydii and ST92 in S. aurantiacum, including four novel STs (ST40, ST41, ST42 and ST43) in S. apiospermum. Based on the CLSI-M38 A2 criterion, voriconazole was the only antifungal compound with low MIC values (MIC90 ≤ 1 µg/ml) for all Scedosporium isolates in our study. CONCLUSIONS: The genetic diversity of clinical isolates of Scedosporium species from China is extremely high, with S. boydii being predominant and S. aurantiacum being firstly reported here. VOR was the only antifungal compound with low MIC values for all Scedosporium isolates in our study, which should be recommended as the firstline antifungal treatment against scedosporiosis in China.


Asunto(s)
Scedosporium , Humanos , Scedosporium/genética , Antifúngicos/farmacología , Tipificación de Secuencias Multilocus , Voriconazol/farmacología , Australia
14.
Nano Lett ; 21(24): 10165-10171, 2021 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-34889617

RESUMEN

A fundamental cryogenic study in tribology from 20 to 300 K revealed that a kind of disulfide film could exhibit a superlubricity state. Inspired by this, we designed a more delicate experiment and reported an extremely low friction coefficient for a multilayered MoS2-Ag film in a cryogenic environment against a bare steel ball under a high load. The results showed that the multilayered MoS2-Ag film could undergo a pressure exceeding 2 GPa to maintain a superlow friction coefficient of below 0.001 at 170 K. The film material was transferred to the sliding contacts to form an antifriction tribofilm. The superlubricity mechanism was attributed to the formation of MoS2-wrapped Ag nanoparticles accumulated at the sliding interface through nanoparticle movement and layered-structure sliding. This new kind of multilayered MoS2-Ag film provides a novel design for a solid lubricant and broadens the application of solid lubrication films under harsh working conditions for mechanical engineering.


Asunto(s)
Nanopartículas del Metal , Molibdeno , Fricción , Lubrificación , Plata
15.
Rev Invest Clin ; 74(5): 276-268, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36328028

RESUMEN

Background: While sarcopenia is an important clinical finding in individuals diagnosed with chronic heart failure (CHF), efforts to identify a reliable biomarker capable of predicting the overall muscular and functional decline in CHF patients have been unsuccessful to date. Objectives: The objectives of this study were to study the diagnostic utility of MicroRNA (miRNA)-1-3p as a predictor of sarcopenia status in individuals diagnosed with CHF. Methods: In total, 80 individuals with heart failure exhibiting a left ventricular ejection fraction < 50% were enrolled in this study. All patients were analyzed to assess miR-1-3p expression levels, with body composition being evaluated through dual-energy X-ray absorptiometry and sarcopenia being defined based on the sum of appendicular lean muscle mass (ALM) divided by height in meters squared and handgrip strength (HGS). In addition, the activation of the Akt/mTOR signaling pathway was evaluated in these individuals. Results: In total, 40 of the enrolled patients (50%) exhibited sarcopenia. Sarcopenic patients presented with increased miR-1-3p expression levels as compared to non-sarcopenic individuals (1.69 ± 0.132 vs. 1.22 ± 0.106; p < 0.05). With respect to sarcopenic indices, appendicular skeletal mass index was most strongly correlated with miR-1-3p expression, which was also strongly correlated with HGS. High levels of Akt/mTOR signaling pathway components were expressed in sarcopenic individuals, highlighting a significant relationship between miR-1-3p activity and signaling through this pathway. Moreover, miR-1-3p was identified as a specific marker for sarcopenia in individuals with CHF. Conclusions: These results suggest that circulating miR-1-3p levels are related to Akt/mTOR pathway activation and can offer valuable insight into the overall physical capacity and muscular integrity of CHF patients as a predictor of sarcopenia. (Rev Invest Clin. 2022;74(5):276-83).


Asunto(s)
MicroARN Circulante , Insuficiencia Cardíaca , Sarcopenia , Humanos , Sarcopenia/diagnóstico , Fuerza de la Mano/fisiología , Volumen Sistólico , Proteínas Proto-Oncogénicas c-akt , Función Ventricular Izquierda , Biomarcadores , Serina-Treonina Quinasas TOR
16.
Infect Immun ; 89(11): e0030621, 2021 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-34370506

RESUMEN

A mitochondrion, as a highly dynamic organelle, continuously changes morphology and position during its life cycle. Mitochondrial dynamics, including fission and fusion, play a critical role in maintaining functional mitochondria for ATP production, which is directly linked to host defense against Mycobacterium tuberculosis infection. However, how macrophages regulate mitochondrial dynamics during M. tuberculosis infection remains elusive. In this study, we found that M. tuberculosis infection induced mitochondrial fusion by enhancing the expression of mitofusin 1 (MFN1), which resulted in increased ATP production. Silencing of MFN1 inhibited mitochondrial fusion and subsequently reduced ATP production, which, in turn, severely impaired macrophages' mycobactericidal activity by inhibiting autophagy. Impairment of mycobactericidal activity and autophagy was replicated using oligomycin, an inhibitor of ATP synthase. In summary, our study revealed that MFN1-mediated mitochondrial fusion is essential for macrophages' mycobactericidal activity through the regulation of ATP-dependent autophagy. The MFN1-mediated metabolism pathway might be a target for the development of a host direct therapy (HDT) strategy against tuberculosis.


Asunto(s)
Autofagia/fisiología , GTP Fosfohidrolasas/fisiología , Macrófagos/inmunología , Dinámicas Mitocondriales/fisiología , Proteínas de Transporte de Membrana Mitocondrial/fisiología , Tuberculosis/inmunología , Adenosina Trifosfato/biosíntesis , Humanos , Células THP-1 , Tuberculosis/tratamiento farmacológico
17.
Small ; 17(1): e2005607, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33284504

RESUMEN

Diamond-like carbon (DLC) films are capable of achieving superlubricity at sliding interfaces by a rapid running-in process. However, fundamental mechanisms governing the friction evolution during this running-in processes remain elusive especially at the nanoscale, which hinders strategic tailoring of tribosystems for minimizing friction and wear. Here, it is revealed that the running-in governing superlubricity of DLC demonstrates two sub-stages in single-asperity nanocontacts. The first stage, mechanical removal of a thin oxide layer, is described quantitatively by a stress-activated Arrhenius model. In the second stage, a large friction decrease occurs due to a structural ordering transformation, with the kinetics well described by the Johnson-Mehl-Avrami-Kolmogorov model with a modified load dependence of the activation energy. The direct observation of a graphitic-layered transfer film formation together with the measured Avrami exponent reveal the primary mechanism of the ordering transformation. The findings provide fundamental insights into friction evolution mechanisms, and design criteria for superlubricity.

18.
IUBMB Life ; 73(8): 1073-1083, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34048129

RESUMEN

Tuberculosis (TB) is caused by Mycobacterium tuberculosis and is one of the primary causes of death worldwide. Rapid and accurate diagnosis of TB is one of the most direct means to reduce the incidence of TB. In this study, urinary proteomic profiling of TB patients and non-TB individual controls (HCs) was performed, and differentially expressed urinary proteins between TB and HCs were compared and exclusively expressed proteins in TB patients were selected to establish a clinically useful disease marker panel. In total, these top 11 targeted proteins with 265 peptides were scheduled for multiple reaction monitoring validation analysis by using urine samples from 52 TB patients and 52 HCs. The result demonstrated that a three-protein combination out of the five-protein panel (namely P22352, Q9P121, P15151, Q13291, and Q8NDA2) exhibited sensitivity rate of 82.7% in the diagnosis of TB. Furthermore, the three-protein combination could differentiate TB from the latent tuberculosis (LTB) effectively, which exhibited specificity rate of 92.3% for the diagnosis of TB from the LTB category. Although more numbers of clinical samples are required for further verification, the results provided preliminary evidence that this "three-protein combination" out of the five-protein panel could probably be a novel TB diagnostic biomarker in clinical application.


Asunto(s)
Biomarcadores/orina , Proteinuria/diagnóstico , Tuberculosis/orina , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Tuberculosis Latente/diagnóstico , Tuberculosis Latente/orina , Masculino , Peso Molecular , Proteínas/química , Proteínas/metabolismo , Proteómica/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espectrometría de Masas en Tándem , Tuberculosis/diagnóstico , Urinálisis/métodos
19.
Arch Biochem Biophys ; 704: 108876, 2021 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-33864753

RESUMEN

Tuberculosis (TB) is a serious infectious disease with high infection and mortality rates. 5%-10% of the latent tuberculosis infections (LTBI) are likely to develop into active TB, and there are currently no clinical biomarkers that can distinguish between LTBI, active TB and other non-tuberculosis populations. Therefore, it is necessary to develop rapid diagnostic methods for active TB and LTBI. In this study, urinary metabolome of 30 active TB samples and the same number of LTBI and non-TB control samples were identified and analyzed by UPLC-Q Exactive MS. In total, 3744 metabolite components were obtained in ESI- mode and 4086 in ESI + mode. Orthogonal partial least square discriminant analysis (OPLS-DA) and hierarchical cluster analysis (HCA) showed that there were significant differences among LTBI, active TB and non-TB. Six differential metabolites were screened in positive and negative mode, 3-hexenoic acid, glutathione (GSH), glycochenodeoxycholate-3-sulfate, N-[4'-hydroxy-(E)-cinnamoyl]-l-aspartic acid, deoxyribose 5-phosphate and histamine. The overlapping pathways differential metabolites involved were mainly related to immune regulation and urea cycle. The results showed that the urine metabolism of TB patients was disordered and many metabolic pathways changed. Multivariate statistical analysis revealed that GSH and histamine were selected as potential molecular markers, with area under curve of receiver operating characteristic curve over 0.75. Among the multiple differential metabolites, GSH and histamine changed to varying degrees in active TB, LTBI and the non-TB control group. The levels of GSH and histamine in 48 urinary samples were measured by ELISA in validation phase, and the result in our study provided the potential for non-invasive biomarkers of TB.


Asunto(s)
Glutatión/orina , Histamina/orina , Tuberculosis Latente/diagnóstico , Tuberculosis Latente/orina , Metabolómica , Adulto , Biomarcadores/orina , Femenino , Humanos , Masculino , Persona de Mediana Edad
20.
Pharmacol Res ; 167: 105556, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33812006

RESUMEN

The pentacyclic triterpenoid quinone methide celastrol (CS) from Tripterygium wilfordii Hook. F. effectively ameliorates inflammation with potential as therapeutics for inflammatory diseases. However, the molecular mechanisms underlying the anti-inflammatory and inflammation-resolving features of CS are incompletely understood. Here we demonstrate that CS potently inhibits the activity of human 5-lipoxygenase (5-LOX), the key enzyme in pro-inflammatory leukotriene (LT) formation, in cell-free assays with IC50 = 0.19-0.49 µM. Employing metabololipidomics using ultra-performance liquid chromatography coupled to tandem mass spectrometry in activated human polymorphonuclear leukocytes or M1 macrophages we found that CS (1 µM) potently suppresses 5-LOX-derived products without impairing the formation of lipid mediators (LM) formed by 12-/15-LOXs as well as fatty acid substrate release. Intriguingly, CS induced the generation of 12-/15-LOX-derived LM including the specialized pro-resolving mediator (SPM) resolvin D5 in human M2 macrophages. Finally, intraperitoneal pre-treatment of mice with 10 mg/kg CS strongly impaired zymosan-induced LT formation and simultaneously elevated the levels of SPM and related 12-/15-LOX-derived LM in peritoneal exudates, spleen and plasma in vivo. Conclusively, CS promotes a switch from LT biosynthesis to formation of SPM which may underlie the anti-inflammatory and inflammation-resolving effects of CS, representing an interesting pharmacological strategy for intervention with inflammatory disorders.


Asunto(s)
Antiinflamatorios/farmacología , Leucotrienos/metabolismo , Metabolismo de los Lípidos/efectos de los fármacos , Inhibidores de la Lipooxigenasa/farmacología , Triterpenos Pentacíclicos/farmacología , Animales , Antiinflamatorios/química , Araquidonato 5-Lipooxigenasa/metabolismo , Vías Biosintéticas/efectos de los fármacos , Células Cultivadas , Humanos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Inhibidores de la Lipooxigenasa/química , Masculino , Ratones , Simulación del Acoplamiento Molecular , Triterpenos Pentacíclicos/química , Tripterygium/química
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