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1.
Clin Lab ; 70(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38623677

RESUMO

BACKGROUND: The goal was to explore the aberrant human epididymal protein 4 (HE4) in chronic heart failure (CHF) patients and its association with C-reactive protein (CRP), uric acid (UA), and homocysteine (HCY). METHODS: Analysis of serum HE4 and its relevance with associated indexes in 117 CHF patients was implemented. RESULTS: Serum HE4 in CHF patients was linked with the disease's severity and CRP, UA, and HCY. An assessment value was provided for it (p < 0.05). CONCLUSIONS: HE4 is aberrant in CHF patients' serum and is associated with the disease's severity and CRP, UA, and HCY's indexes.


Assuntos
Proteína C-Reativa , Insuficiência Cardíaca , Humanos , Ácido Úrico , Homocisteína , Insuficiência Cardíaca/diagnóstico , Doença Crônica
2.
Zhonghua Gan Zang Bing Za Zhi ; 32(1): 22-28, 2024 Jan 20.
Artigo em Chinês | MEDLINE | ID: mdl-38320787

RESUMO

Objective: To observe the recurrence condition of hepatitis B in different risk groups after liver transplantation in an attempt to provide useful information on whether to discontinue hepatitis B immunoglobulin (HBIG) in the future at an early stage. Methods: The patient population was divided into high, low-risk, and special groups [especially primary hepatocellular carcinoma (HCC)] according to the guidelines for the prevention and treatment of hepatitis B recurrence after liver transplantation. The recurrence condition and risk factors in this population were observed for hepatitis B. Measurement data were analyzed using a t-test and a rank-sum test. Count data were compared using a χ(2) test between groups. Results: This study finally included 532 hepatitis B-related liver transplant cases. A total of 35 cases had HBV recurrence after liver transplantation, including 34 cases that were HBsAg positive, one case that was HBsAg negative, and 10 cases that were hepatitis B virus (HBV) DNA positive. The overall HBV recurrence rate was 6.6%. The recurrence rate of HBV was 9.2% and 4.8% in the high- and low-risk HBV DNA positive and negative groups before surgery (P = 0.057). Among the 293 cases diagnosed with HCC before liver transplantation, 30 had hepatitis B recurrence after surgery, with a recurrence rate of 10.2%. The independent related factors for the recurrence of hepatitis B in patients with HCC after liver transplantation were HCC recurrence (HR =181.92, 95%CI 15.99~2 069.96, P < 0.001), a high postoperative dose of mycophenolate mofetil dispersible tablets (MMF) ( HR =5.190, 95%CI 1.289~20.889, P = 0.020), and a high dosage of HBIG (HR = 1.012, 95%CI 1.001~1.023, P = 0.035). Among the 239 cases who were non-HCC before liver transplantation, five cases (recurrence rate of 2.1%) arouse postoperative hepatitis B recurrence. Lamivudine was used in all cases, combined with on-demand HBIG prophylaxis after surgery. There was no hepatitis B recurrence in non-HCC patients who treated with entecavir combined with HBIG after surgery. Conclusion: High-barrier-to-resistance nucleotide analogues combined with long-term HBIG have a good effect on preventing the recurrence of hepatitis B after liver transplantation. The discontinuation of HBIG may be considered at an early stage after administration of a high-barrier-to-resistance nucleotide analogue in low-risk patients. Domestically, the HBV infection rate is high, so further research is still required to explore the timing of HBIG discontinuation for high-risk patients, especially those with HCC.


Assuntos
Carcinoma Hepatocelular , Hepatite B , Neoplasias Hepáticas , Transplante de Fígado , Humanos , Transplante de Fígado/efeitos adversos , Carcinoma Hepatocelular/cirurgia , Carcinoma Hepatocelular/tratamento farmacológico , Antivirais/efeitos adversos , Antígenos de Superfície da Hepatite B , Resultado do Tratamento , Neoplasias Hepáticas/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Hepatite B/tratamento farmacológico , Vírus da Hepatite B/genética , Fatores de Risco , Imunoglobulinas/uso terapêutico , Lamivudina/uso terapêutico , Nucleotídeos/uso terapêutico , Recidiva
3.
Osteoarthritis Cartilage ; 30(8): 1130-1139, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35569801

RESUMO

OBJECTIVE: Focal lesions within the subchondral bone, termed subchondral bone cysts (SBCs), are clinically accepted radiographic markers of advanced osteoarthritis (OA), but their etiology in the hip is not well understood. DESIGN: This study used micro-computed tomography (µCT), and histological and immunocytological analysis to examine the prevalence, size, location, and morphological and cellular features of SBCs found within 34 femoral heads (14 male, 20 female; age range = 43-80 years) obtained from total hip arthroplasty procedures. RESULTS: SBCs were common-present in 91% of the femoral heads examined-and frequently commuted with the surface of the femoral head, but otherwise showed no preferred anatomical location. Few associations were found between SBC features and patient characteristics such as BMI, age and sex. SBCs were also heterogenous in composition, ranging from fibrous (most common) to predominantly fatty (least common) and often containing vasculature, nerve fibers, cartilage islands, and bony spicules. Despite this heterogeneity, focal abnormalities in bone density and cartilage thickness were consistently observed. Bone adjacent to SBCs was denser than that in the primary compressive group, and cartilage thickness in regions overlying SBCs was lower than in non-overlying regions. In contrast to these local bony changes, µCT-based finite element analyses indicated that the stiffness of the primary compressive group was only mildly affected by SBCs. CONCLUSIONS: These findings indicate that SBCs in the femoral head involve extensive perturbations in cellular activity, culminating in myriad skeletal tissue types and spatially heterogenous changes in bone and cartilage morphology that are likely to affect OA progression.


Assuntos
Cistos Ósseos , Cartilagem Articular , Osteoartrite do Quadril , Adulto , Idoso , Idoso de 80 Anos ou mais , Cistos Ósseos/diagnóstico por imagem , Cistos Ósseos/patologia , Cartilagem Articular/diagnóstico por imagem , Cartilagem Articular/patologia , Feminino , Cabeça do Fêmur/diagnóstico por imagem , Cabeça do Fêmur/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Quadril/diagnóstico por imagem , Osteoartrite do Quadril/patologia , Microtomografia por Raio-X
4.
Plant Biol (Stuttg) ; 23 Suppl 1: 80-88, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33275831

RESUMO

The enzyme 12-oxo-phytodienoic acid reductase (OPR) is important in the jasmonic acid (JA) biosynthesis pathway and thus plays a vital role in plant defence. However, systematic and comprehensive analyses of OPR genes in watermelon and their roles in defence responses are extremely limited. The physicochemical properties, phylogenetic tree, gene structure and cis-acting elements of watermelon OPR genes were analysed using bioinformatics, and qRT-PCR and RNA-Seq were applied to assay expression of OPR genes in watermelon. A total of five OPR family genes were identified in watermelon, which were unevenly distributed across the four chromosomes. Phylogenetic analysis assigned OPR members from different plant species to five subfamilies (OPRI-OPRV). The motif compositions of OPR members were relatively conserved. Expression analysis using qRT-PCR revealed that ClOPR genes, except for ClOPR5, were highly expressed in the flower and fruit. RNA-seq analysis showed that the ClOPR genes had different expression patterns during flesh and rind development. Furthermore, the ClOPR genes, particularly ClOPR2 and ClOPR4, were significantly upregulated by exogenous JA, salicylic acid (SA) and ethylene (ET) treatments. In addition, red light induced expression of ClOPR2 and ClOPR4 in leaves and roots of root-knot nematode (RKN)-infected watermelon plants, suggesting their involvement in red light-induced defence against RKN. These results provide a theoretical basis for elucidating the diverse functions of OPR family genes in watermelon.


Assuntos
Citrullus , Citrullus/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hormônios , Oxirredutases , Filogenia , Ácido Salicílico
5.
Phys Rev Lett ; 125(13): 137201, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-33034462

RESUMO

Magnetic multilayers offer diverse opportunities for the development of ultrafast functional devices through advanced interface and layer engineering. Nevertheless, a method for determining their dynamic properties as a function of depth throughout such stacks has remained elusive. By probing the ferromagnetic resonance modes with element-selective soft x-ray resonant reflectivity, we gain access to the magnetization dynamics as a function of depth. Most notably, using reflectometry ferromagnetic resonance, we find a phase lag between the coupled ferromagnetic layers in [CoFeB/MgO/Ta]_{4} multilayers that is invisible to other techniques. The use of reflectometry ferromagnetic resonance enables the time-resolved and depth-resolved probing of the complex magnetization dynamics of a wide range of functional magnetic heterostructures with absorption edges in the soft x-ray wavelength regime.

6.
Liver Int ; 39(9): 1755-1767, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31087812

RESUMO

BACKGROUND & AIMS: Double-negative (DN) T-cell is a unique regulatory T-cell, which is essential for maintaining immune system homoeostasis. However, the role of DN T-cells in the pathogenesis of primary biliary cholangitis (PBC) is still unknown. METHODS: We investigated the number and function of DN T-cells in peripheral blood and liver biopsy specimens of PBC patients. RESULTS: The number and frequency of DN T-cells significantly decreased in peripheral blood and liver tissue of PBC patients. Furthermore, the frequency of DN T-cells in PBC was negatively correlated with disease severity and positively correlated with ursodeoxycholic acid response. In vitro assays showed that perforin expression and the suppressive capability of DN T-cells on the proliferation of CD4+ and CD8+ T-cells were impaired in PBC. Finally, lithocholic acid, the most hydrophobic acid, could downregulate the proliferation and perforin expression of DN T-cells. CONCLUSIONS: Decreased quantity and function of DN T-cells in PBC may result in the loss of immune regulations on effector CD4+ and cytotoxic CD8+ T-cells, and thereby may break the immune tolerance and promote the pathogenesis of PBC.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Cirrose Hepática Biliar/imunologia , Cirrose Hepática Biliar/patologia , Linfócitos T Reguladores/imunologia , Adulto , Idoso , Estudos de Casos e Controles , Proliferação de Células , Feminino , Humanos , Fígado/citologia , Fígado/imunologia , Fígado/patologia , Cirrose Hepática Biliar/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Ácido Ursodesoxicólico/uso terapêutico
7.
Nat Commun ; 10(1): 233, 2019 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-30651540

RESUMO

Different symmetry breaking ways determine various magnetization switching modes driven by spin-orbit torques (SOT). For instance, an applied or effective field parallel to applied current is indispensable to switch magnetization with perpendicular anisotropy by SOT. Besides of this mode, here we experimentally demonstrate a distinct field-free switching mode in a T-type magnetic system with structure of MgO/CoFeB/Ta/CoFeB/MgO where a perpendicular layer with tilted easy axis was coupled to an in-plane layer with a uniaxial easy axis. Current was applied orthogonal to both easy axes and thus also normal to an in-plane effective field experienced by the perpendicular layer. Dynamic calculation shows perpendicular layer could be switched at the same time as the in-plane layer is switched. These field-free switching modes realized in the same T-type magnetic system might expedite the birth of multi-state spin memories or spin logic devices which could be operated by all electric manners.

8.
Front Plant Sci ; 9: 1156, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30150997

RESUMO

In this study, the effects of inoculating arbuscular mycorrhizal fungi (Glomus mosseae) on the growth, chlorophyll content, photosynthetic gas exchange parameters, and chlorophyll fluorescence characteristics of Lolium perenne L. in cadmium (Cd) contaminated soil were investigated. The results showed that the root vigor of L. perenne declined, while the chlorophyll content significantly decreased with the increase of Cd content, especially the chlorophyll a content in leaves. The photosynthetic carbon assimilation capacity and PSII activity of L. perenne leaves were also significantly inhibited by Cd stress, especially the electron transfer at the receptor side of PSII, which was more sensitive to Cd stress. The infection level of G. mosseae on L. perenne roots was relatively high and inoculation with G. mosseae increased the mycorrhizal infection rate of L. perenne roots up to 50-70%. Due to the impact of the mycorrhizal infection, the Cd content in L. perenne roots was significantly increased compared to non-inoculated treatment; however, the Cd content in the aboveground part of L. perenne was not significantly different compared to the non-inoculated treatment. After inoculation with G. mosseae, the root vigor of L. perenne increased to some extent, alleviating the chlorophyll degradation in L. perenne leaves under Cd contaminated soil. Infection with G. mosseae can improve the stoma limitation of L. perenne leaves in Cd contaminated soil and increase the non-stomatal factors including the tolerance of its photosynthetic apparatus to Cd, to improve photosynthetic capacity. G. mosseae infection can improve the photosynthetic electron transport capacity of PSII in L. perenne leaves under Cd stress and promotes the activity of the oxygen-evolving complex to different degrees at the donor side of PSII and the electron transport capacity from QA to QB on the receptor side of PSII. Thus, this guarantees that L. perenne leaves inoculated with G. mosseae in Cd contaminated soil have relatively higher PSII activity. Therefore, inoculation with G. mosseae can improve the capacity of Cd tolerance of L. perenne with regard to various aspects, such as morphological characteristics and photosynthetic functions, and reduce the toxicity of Cd on L. perenne.

9.
Eur Rev Med Pharmacol Sci ; 21(10): 2316-2328, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28617560

RESUMO

OBJECTIVE: To investigate the influence of VEGF/BMP-2 on the proliferation and osteogenic differentiation of rat bone mesenchymal stem cells BMSCs) on PLGA/gelatin composite scaffold. MATERIALS AND METHODS: Randomly-oriented nanofibers with different ratios of Poly Lactic-co-Glycolic Acid (PLGA)/gelatin were produced through electrospinning. The mixture of nanofibers and BMSCs was pipetted onto the surface of the scaffolds, and BMSCs/PLGA/gelatin composite was obtained. The surface morphology, chemical structure, hydrophilicity and mechanical property of PLGA/gelatin nanofibers were revealed by scanning electron microscope. In vitro release kinetics of bone morphogenetic protein (BMP-2) and vascular endothelial growth factor (VEGF) were studied using ELISA kits. The cell adhesion, growth and proliferation of BMSCs on scaffolds were observed by scanning electron microscopy. The CCK-8 assay was used to evaluate the effects of VEGF/BMP-2 slow release system on the proliferation of BMSCs on scaffolds. RT-PCR was used to examine the activities of alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX-2), and osteocalcin (OCN). RESULTS: In each group of cells in the in-vitro experiment, through electron microscope scanning, fiber scaffolds were interconnected three-dimensional reticular structure, BMSCs firmly attached to the fiber surface and internal stent, cells experienced a long spindle, polygon change, and branch-like protrusions on the cell surface were connected. Under the electron microscope, cell proliferation curve and osteogenesis markers (ALP, RUNX-2, OCN) expression in the dual factor group on cell adhesion, proliferation and differentiation were much better than those of blank control group and single factor groups. CONCLUSIONS: In the successfully constructed gelatin/PLGA nanofiber scaffold, VEGF and BMP-2 can be sequentially released, during which VEGF and BMP-2 can promote the adhesion, proliferation, and differentiation of BMSCs.


Assuntos
Proteína Morfogenética Óssea 2/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Gelatina/química , Ácido Láctico/química , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Ácido Poliglicólico/química , Fator A de Crescimento do Endotélio Vascular/farmacologia , Animais , Adesão Celular , Liberação Controlada de Fármacos , Nanofibras/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos Sprague-Dawley , Propriedades de Superfície , Alicerces Teciduais/química
10.
Eur Psychiatry ; 39: 114-122, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28006677

RESUMO

OBJECTIVE: Although alienation toward parents is important for children (for current mental health status or later interpersonal relationships in adulthood), it is undervalued and even lacks a standardized tool of assessment. Moreover, the large number of left-behind children in China is a cause of public concern. However, their experienced alienation toward their parents remains unclear, which may be important for early detection or intervention for behavioral problems in this population. Hence, the current study aimed to develop an alienation inventory for children and then use it to investigate the experienced alienation toward parents in Chinese left-behind children. METHODS: Two studies were carried out. Study 1 was designed to develop a standard inventory of alienation toward parents (IAP). In study 2, 8361 children and adolescents (6704 of them were left-behind status) of the Chongqing area, aged between 8 and 19 years old, were recruited for investigation. All participants were surveyed with a standard sociodemographic questionnaire, children's cognitive style questionnaire, children's depression inventory, adolescent self-rating life events checklist, and newly built IAP in study 1. RESULTS: In study 1, we developed a two-component (communication and emotional distance) and 18-item (9 items for maternal or paternal form, respectively) IAP questionnaire. In study 2, exploratory factor analysis indicated an expected two-factor structure of IAP, which was confirmed by confirmatory factor analysis. The Cronbach's alpha coefficients showed a good reliability (0.887 and 0.821 for maternal and paternal form, respectively). Children with absent mother experienced the highest alienation toward parents. Boys as well as children aged 8-10 years old experienced higher alienation toward parents. Poor communication with parents (sparse or no connection), level of left-behind condition (parents divorced, been far away from parents), and psychosocial vulnerability (stressful life events, negative cognitive style) were risk factors of alienation toward parents. CONCLUSIONS: The current study develops a two-factor (communication and emotional distance) IAP, which offers a reliable tool to assess experienced alienation of affection toward parents in children aged between 8 and 19 years old. Our result is the first investigation of experienced alienation and potential influential factors in Chinese left-behind children. The findings that children with absent mother experience higher alienation toward parents, as well as three recognized risk factors for alienation of affection toward parents (poor communication with absent parents, worse left-behind condition, and psychosocial vulnerability), give valuable guidance for parents who intend to leave or who are already leaving as well as for government policymaking.


Assuntos
Proteção da Criança/psicologia , Criança Abandonada/psicologia , Depressão/psicologia , Relações Pais-Filho , Adolescente , Criança , Proteção da Criança/estatística & dados numéricos , China , Depressão/epidemiologia , Análise Fatorial , Feminino , Humanos , Acontecimentos que Mudam a Vida , Masculino , Reprodutibilidade dos Testes , Fatores de Risco , Autoimagem
11.
J AOAC Int ; 99(4): 1032-1037, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27302905

RESUMO

Consumers prefer natural and healthy food, but artificial pigments are often abused in egg products. The study aimed at differentiating the origin of pigments in eggs by applying the technique of carbon ((13)C/(12)C) and nitrogen ((15)N/(14)N) stable isotope analysis. Five hundred sixty laying hens were randomly distributed into 14 treatments, which were divided into four groups: maize, carophyll red pigment, carophyll yellow pigment, and a mixture of carophyll red and yellow pigments. Eggs were collected and pretreated to determe the values of the Roche Yolk Color Fan (RCF), δ(13)C, and δ(15)N. With increasing maize content, the RCF and δ(13)C values of yolks increased. Moreover, the RCF values in the three pigment groups were significantly influenced by the artificial colors, but δ(13)C values were not significantly different, regardless of the existence of pigment. The δ(15)N values in all treatments did not vary as regularly as the carbon stable isotope. A strong positive correlation was found between RCF and δ(13)C in the maize group, but no such correlation was be observed in the pigment groups. It is concluded that carbon stable isotope ratio analysis (δ(13)C) of the yolk can be used to differentiate the origin of the pigment added to eggs.


Assuntos
Ovos/análise , Marcação por Isótopo , Animais , Isótopos de Carbono , Galinhas , Isótopos de Nitrogênio
12.
Biochim Biophys Acta ; 1862(9): 1755-65, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27287255

RESUMO

Type IV ATPases are putative aminophospholipid translocases (APLTs), more commonly known as flippases. A pronounced induction of the flippase Atp8a1 was observed in post-mortem tissue homogenates from the hippocampus and temporal lobe of juvenile autistic subjects compared to age-matched controls. In order to simulate the human data, C57BL/6 mice were allowed to develop after intra-hippocampal injection of recombinant lentivirus expressing Atp8a1 at the early developmental stage of postnatal day 6 (P6). Transmission electron microscopy (TEM) analysis of the lentivirus-Atp8a1 treated (Atp8a1+) mice in adulthood revealed fewer and weaker excitatory synapses in the hippocampal CA1 region compared to mice injected with empty virus. Significant inhibition of the Schaffer collateral pathway was observed in the Atp8a1+ mice in paired-pulse recording (PPR) at 20-ms inter-stimulus interval. In the three-chambered sociability test, the Atp8a1+ mice displayed no preference for an encaged stranger mouse over a novel object, which is a characteristic autistic-like behavior. In sharp contrast, Atp8a1 (-/-) mice displayed a preference for a stranger mouse over the novel object, which is characteristic of neurotypical mouse behavior. However, similar to the Atp8a1+ mice, the Atp8a1 (-/-) mice harbored fewer and weaker excitatory synapses in CA1 compared to wild-type controls, and displayed inhibition at 20-ms inter-stimulus interval in PPR. These findings suggest that both elevated and diminished levels of Atp8a1 during early development are detrimental to brain connectivity, but only elevated Atp8a1 is associated with aberrant social behavior. Mice with augmented levels of Atp8a1 may therefore serve as a potential model in autism research.


Assuntos
Adenosina Trifosfatases/metabolismo , Transtorno Autístico/metabolismo , Transtorno Autístico/psicologia , Hipocampo/metabolismo , Proteínas de Transferência de Fosfolipídeos/metabolismo , Adenosina Trifosfatases/deficiência , Adenosina Trifosfatases/genética , Animais , Transtorno Autístico/genética , Comportamento Animal , Região CA1 Hipocampal/metabolismo , Região CA1 Hipocampal/ultraestrutura , Estudos de Casos e Controles , Criança , Pré-Escolar , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Eletrônica de Transmissão , Proteínas de Transferência de Fosfolipídeos/deficiência , Proteínas de Transferência de Fosfolipídeos/genética , Comportamento Social , Sinapses/metabolismo , Sinapses/ultraestrutura , Lobo Temporal/metabolismo
13.
J Leukoc Biol ; 100(5): 1201-1211, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27354409

RESUMO

T cell dysfunction has a crucial role in establishing and maintaining viral persistence. We have previously shown a decline in miR-181a, which regulates CD4+ T cell responses via DUSP6 overexpression, in individuals with hepatitis C virus (HCV) infection. Here, we describe accelerated T cell senescence in HCV-infected individuals compared with age- and sex-matched healthy subjects. Mechanistic studies revealed that up-regulation of transcription factor ΔNp63 led to the decline of miR-181a expression, resulting in an overexpression of the antiaging protein Sirt1, in CD4+ T cells from HCV-infected individuals. Either reconstituting miR-181a or silencing ΔNp63 or Sirt1 expression in CD4+ T cells led to accelerated T cell senescence, as evidenced by an increased senescence-associated ß-galactosidase (SA-ß-gal) expression, shortened telomere length, and decreased EdU incorporation; this suggests that HCV-induced T cell senescence is counterregulated by the ΔNp63-miR-181a-Sirt1 pathway. An increase of IL-2 production was observed in these senescent CD4+ T cells and was driven by a markedly reduced frequency of Foxp3+ regulatory T (Treg) cells and increased number of Foxp3- effector T (Teff) cells upon manipulating the ΔNp63-miR-181a-Sirt1 pathway. In conclusion, these findings provide novel mechanistic insights into how HCV uses cellular senescent pathways to regulate T cell functions, revealing new targets for rejuvenating impaired T cell responses during chronic viral infection.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Hepatite C Crônica/imunologia , MicroRNAs/fisiologia , Transdução de Sinais/imunologia , Sirtuína 1/fisiologia , Fatores de Transcrição/fisiologia , Proteínas Supressoras de Tumor/fisiologia , Adulto , Idoso , Estudos de Casos e Controles , Senescência Celular , Feminino , Genes Reporter , Humanos , Interleucina-2/biossíntese , Interleucina-2/genética , Masculino , MicroRNAs/biossíntese , MicroRNAs/genética , Pessoa de Meia-Idade , Sirtuína 1/biossíntese , Sirtuína 1/genética , Encurtamento do Telômero , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Transfecção , Proteínas Supressoras de Tumor/biossíntese , Proteínas Supressoras de Tumor/genética , Regulação para Cima
14.
Immunology ; 148(4): 377-86, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27149428

RESUMO

T cells play a pivotal role in controlling viral infection; however, the precise mechanisms responsible for regulating T-cell differentiation and function during infections are incompletely understood. In this study, we demonstrated an expansion of myeloid-derived suppressor cells (MDSCs), in particular the monocytic MDSCs (M-MDSCs; CD14(+) CD33(+) CD11b(+) HLA-DR(-/low) ), in patients with chronic hepatitis C virus (HCV) infection. Notably, HCV-induced M-MDSCs express high levels of phosphorylated signal transducer and activator of transcription 3 (pSTAT3) and interleukin-10 (IL-10) compared with healthy subjects. Blocking STAT3 signalling reduced HCV-mediated M-MDSC expansion and decreased IL-10 expression. Importantly, we observed a significant increase in the numbers of CD4(+) CD25(+) Foxp3(+) regulatory T (Treg) cells following incubation of healthy peripheral blood mononuclear cells (PBMCs) with MDSCs derived from HCV-infected patients or treated with HCV core protein. In addition, depletion of MDSCs from PBMCs led to a significant reduction of Foxp3(+) Treg cells developed during chronic HCV infection. Moreover, depletion of MDSCs from PBMCs significantly increased interferon-γ production by CD4(+) T effector (Teff) cells derived from HCV patients. These results suggest that HCV-induced MDSCs promote Treg cell development and inhibit Teff cell function, suggesting a novel mechanism for T-cell regulation and a new strategy for immunotherapy against human viral diseases.


Assuntos
Hepacivirus/imunologia , Hepatite C/imunologia , Células Supressoras Mieloides/fisiologia , Fator de Transcrição STAT3/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Proliferação de Células , Células Cultivadas , Doença Crônica , Fatores de Transcrição Forkhead/metabolismo , Antígenos da Hepatite C/imunologia , Humanos , Interferon gama/metabolismo , Interleucina-10/metabolismo , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Células Supressoras Mieloides/virologia , Linfócitos T Auxiliares-Indutores/virologia , Linfócitos T Reguladores/virologia , Proteínas do Core Viral/imunologia
15.
Bull World Health Organ ; 93(11): 750-8, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26549902

RESUMO

OBJECTIVE: To investigate if the first national insecticide-treated bed-net campaign in Burkina Faso, done in 2010, was followed by a decrease in childhood malaria in a district with high baseline transmission of the disease. METHODS: We obtained data on the prevalence of Plasmodium falciparum parasitaemia in children aged 2 weeks to 36 months from malaria surveys in 2009 and 2011. We assessed morbidity in children younger than 5 years by comparing data from the Nouna health district's health management information system before and after the campaign in 2010. We analysed mortality data from 2008 to 2012 from Nouna's health and demographic surveillance system. FINDINGS: The bed-net campaign was associated with an increase in the reported use of insecticide-treated nets. In 2009, 73% (630/869) of children reportedly slept under nets. In 2011, 92% (449/487) did. The campaign had no effect on the proportion of young children with P. falciparum parasitaemia after the rainy season; 52% (442/858) in 2009 and 53% (263/499) in 2011. Cases of malaria increased markedly after the campaign, as did the number of children presenting with other diseases. The campaign was not associated with any changes in child mortality. CONCLUSION: The 2010 insecticide-treated net campaign in Burkina Faso was not associated with a decrease in care-seeking for malaria or all-cause mortality in children younger than 5 years. The most likely explanation is the high coverage of nets in the study area before the campaign which could have had an effect on mosquito vectors, limiting the campaign's impact.


Assuntos
Mosquiteiros Tratados com Inseticida , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Controle de Mosquitos/métodos , Burkina Faso/epidemiologia , Pré-Escolar , Estudos Transversais , Feminino , Promoção da Saúde/métodos , Humanos , Lactente , Recém-Nascido , Inseticidas/uso terapêutico , Masculino , Plasmodium falciparum/efeitos dos fármacos , Prevalência
17.
Immunology ; 145(4): 485-97, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25772938

RESUMO

Host immune responses must be tightly regulated by an intricate balance between positive and negative signals while fighting pathogens; persistent pathogens may usurp these regulatory mechanisms to dampen host immunity to facilitate survival in vivo. Here we report that Tim-3, a negative signalling molecule expressed on monocytes and T cells, is up-regulated on natural killer (NK) cells in individuals chronically infected with hepatitis C virus (HCV). Additionally, the transcription factor T-bet was also found to be up-regulated and associated with Tim-3 expression in NK cells during chronic HCV infection. MicroRNA-155 (miR-155), an miRNA that inhibits signalling proteins involved in immune responses, was down-regulated in NK cells by HCV infection. This Tim-3/T-bet over-expression and miR-155 inhibition were recapitulated in vitro by incubating primary NK cells or NK92 cell line with Huh-7 hepatocytes expressing HCV. Reconstitution of miR-155 in NK cells from HCV-infected patients led to a decrease in T-bet/Tim-3 expression and an increase in interferon-γ production. Blocking Tim-3 signalling also enhanced interferon-γ production in NK cells by improving signal transducer and activator of transcription-5 phosphorylation. These data indicate that HCV-induced, miR-155-regulated Tim-3 expression regulates NK cell function, suggesting a novel mechanism for balancing immune clearance and immune injury during chronic viral infection.


Assuntos
Hepatite C Crônica/imunologia , Interferon gama/imunologia , Células Matadoras Naturais/imunologia , Proteínas de Membrana/imunologia , MicroRNAs/imunologia , Transdução de Sinais/imunologia , Regulação para Cima/imunologia , Adulto , Idoso , Linhagem Celular , Feminino , Receptor Celular 2 do Vírus da Hepatite A , Hepatite C Crônica/patologia , Hepatócitos/imunologia , Hepatócitos/patologia , Humanos , Células Matadoras Naturais/patologia , Masculino , Pessoa de Meia-Idade , Proteínas com Domínio T/imunologia
18.
J Innate Immun ; 7(2): 116-26, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25401944

RESUMO

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature suppressor cells that are generated due to aberrant myelopoiesis under pathological conditions. Although MDSCs have been recognized for more than 20 years under the guise of different monikers, these particular populations of myeloid cells gained more attention recently due to their immunosuppressive properties, which halt host immune responses to growing cancers or overwhelming infections. While MDSCs may contribute to immune homeostasis after infection or tissue injury by limiting excessive inflammatory processes, their expansion may be at the expense of pathogen elimination and thus may lead to disease persistence. Therefore, MDSCs may be either damaging or obliging to the host by attenuating, for example, antitumor or anti-infectious immune responses. In this review, we recapitulate the biological and immunological aspects of MDSCs, including their generation, distribution, trafficking and the factors involved in their activation, expansion, suppressive functions, and interplay between MDSCs and regulatory T cells, with a focus on the perspectives of infection and inflammation.


Assuntos
Infecções/imunologia , Células Mieloides/imunologia , Linfócitos T Reguladores/imunologia , Animais , Comunicação Celular , Homeostase , Humanos , Tolerância Imunológica , Imunidade , Mielopoese
19.
Hepatology ; 61(4): 1163-73, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25477247

RESUMO

UNLABELLED: T cells play a crucial role in viral clearance or persistence; however, the precise mechanisms that control their responses during viral infection remain incompletely understood. MicroRNA (miR) has been implicated as a key regulator controlling diverse biological processes through posttranscriptional repression. Here, we demonstrate that hepatitis C virus (HCV)-mediated decline of miR-181a expression impairs CD4(+) T-cell responses through overexpression of dual specific phosphatase 6 (DUSP6). Specifically, a significant decline of miR-181a expression along with overexpression of DUSP6 was observed in CD4(+) T cells from chronically HCV-infected individuals compared to healthy subjects, and the levels of miR-181a loss were found to be negatively associated with the levels of DUSP6 overexpression in these cells. Importantly, reconstitution of miR-181a or blockade of DUSP6 expression in CD4(+) T cells led to improved T-cell responses including enhanced CD25 and CD69 expression, increased interleukin-2 expression, and improved proliferation of CD4(+) T cells derived from chronically HCV-infected individuals. CONCLUSION: Since a decline of miR-181a concomitant with DUSP6 overexpression is the signature marker for age-associated T-cell senescence, these findings provide novel mechanistic insights into HCV-mediated premature T-cell aging through miR-181a-regulated DUSP6 signaling and reveal new targets for therapeutic rejuvenation of impaired T-cell responses during chronic viral infection.


Assuntos
Linfócitos T CD4-Positivos/fisiologia , Fosfatase 6 de Especificidade Dupla/biossíntese , Hepacivirus/fisiologia , MicroRNAs/fisiologia , Células Cultivadas , Humanos
20.
PLoS One ; 9(1): e87821, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24498204

RESUMO

In this study, we engineered Listeria monocytogens (Lm) by deleting the LmΔactA/ΔinlB virulence determinants and inserting HCV-NS5B consensus antigens to develop a therapeutic vaccine against hepatitis C virus (HCV) infection. We tested this recombinant Lm-HCV vaccine in triggering of innate and adaptive immune responses in vitro using immune cells from HCV-infected and uninfected individuals. This live-attenuated Lm-HCV vaccine could naturally infect human dendritic cells (DC), thereby driving DC maturation and antigen presentation, producing Th1 cytokines, and triggering CTL responses in uninfected individuals. However, vaccine responses were diminished when using DC and T cells derived from chronically HCV-infected individuals, who express higher levels of inhibitory molecule Tim-3 on immune cells. Notably, blocking Tim-3 signaling significantly improved the innate and adaptive immune responses in chronically HCV-infected patients, indicating that novel strategies to enhance the potential of antigen presentation and cellular responses are essential for developing an effective therapeutic vaccine against HCV infection.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Hepacivirus/imunologia , Listeria monocytogenes/imunologia , Listeriose/imunologia , Proteínas de Membrana/imunologia , Vacinas contra Hepatite Viral/imunologia , Feminino , Hepacivirus/genética , Receptor Celular 2 do Vírus da Hepatite A , Hepatite C Crônica/genética , Hepatite C Crônica/imunologia , Hepatite C Crônica/prevenção & controle , Humanos , Listeria monocytogenes/genética , Listeriose/genética , Masculino , Transdução de Sinais/imunologia , Células Th1/imunologia , Vacinas contra Hepatite Viral/genética
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