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1.
Front Chem ; 10: 950726, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35873041

RESUMO

Two new pyranone derivatives phomapyrone A (2) and phomapyrone B (3), one new coumarin 11S, 13R-(+)-phomacumarin A (1), three known pyranones (4-6), together with three known amide alkaloids fuscoatramides A-C (7-9), as well as 9S, 11R-(+)-ascosalitoxin (10) were isolated from the endophytic fungus Phoma sp. YN02-P-3, which was isolated from the healthy leaf tissue of a Paulownia tree in Yunnan Province, China. Their structures were elucidated using extensive NMR spectroscopic and HRESIMS data and by comparing the information with literature data. In addition, all compounds were tested for their cytotoxicity activity against human tumor cell lines, and the results showed that new compounds 1-3 showed moderate inhibitory activity against the HL-60 cell line with IC50 values of 31.02, 34.62, and 27.90 µM, respectively.

2.
Exp Cell Res ; 411(2): 113004, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-34990618

RESUMO

Numb regulates cell proliferation and differentiation through endocytosis and ubiquitination of signaling molecules. Besides, Numb controls the migration of epithelial cells by regulating intercellular junctions. Studies have shown that Numb promotes or inhibits tumor progression in different tumors. However, its role and mechanism in colorectal cancer remain unclear. We found that the expression level of Numb in colon tumor tissues has a great variety in different patients. Numb expression was negatively correlated with TNM stage and lymph node metastasis but positively correlated with tumor size. Elevated expression of Numb was associated with a good prognosis. Inhibiting Numb expression promoted the migration and invasion of colon cancer cells induced by TGF-ß, up-regulated the expression of EMT-related molecule Snail, and prevented the expression of E-cadherin. We also found that Numb promoted the proliferation and clones formation while inhibiting colon cancer cells' late apoptosis. In addition, Numb inhibited the RhoA activation and ROCK inhibitor Y-27632 or interfered with ROCK expression, partially inhibiting Numb-regulated cell proliferation and migration. In vivo tumorigenesis assay in nude mice also found that Numb promoted the proliferation of colon cancer cells, inhibited the expression of E-cadherin, and strengthened the expression of Snail. In conclusion, our study found that Numb plays multiple roles in the occurrence and progression of colon cancer by regulating the RhoA/ROCK signaling pathway, which provides a new theoretical molecular basis for the pathogenesis of colon cancer.


Assuntos
Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Animais , Apoptose , Movimento Celular , Proliferação de Células , Neoplasias do Colo/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HCT116 , Células HT29 , Xenoenxertos , Humanos , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Transdução de Sinais , Ensaio Tumoral de Célula-Tronco
3.
J Med Virol ; 93(8): 5173-5176, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33974278

RESUMO

Sexual transmission is currently the main mode of transmission of the human immunodeficiency virus (HIV). In this study, 181 HIV-infected female cross-border travelers entering Yunnan province were recruited between 2003 and 2012. HIV RNAs were extracted from their frozen serum and gag-pol gene sequences were obtained for phylogenetic and recombination analyses. In total, 131 gag-pol gene sequences were obtained successfully, at a rate of 72.4%. The most prevalent subtypes were CRF01_AE, followed by CRF08_BC, subtypes B and C. The other four subjects were classified as undefined subtypes and other recombinants. The subtype distribution of intravenous drug users was significantly different from that of sexually transmitted infections and unknown groups. The genetic distances of subtype B, C, and CRF01_AE strains were all close to the reference sequences from Yunnan province and Southeast Asian countries. Gene diversity and cocirculation of multiple subtypes were observed in female cross-border travelers, and CRF01_AE was the dominant epidemic subtype. The advantages of these subtype preferences for sexual transmission were obvious in HIV infection and transmission among this population. Our findings also suggest that close attention should be given to the HIV infection status of the female migrant population. In addition, a description of their epidemic characteristics is significant for the surveillance and prevention of acquired immunodeficiency syndrome in the Yunnan province.


Assuntos
Infecções por HIV/virologia , HIV/genética , Filogenia , Migrantes/estatística & dados numéricos , China/epidemiologia , Usuários de Drogas/estatística & dados numéricos , Feminino , Proteínas de Fusão gag-pol/genética , Variação Genética , Genótipo , HIV/classificação , HIV/isolamento & purificação , Infecções por HIV/epidemiologia , Humanos , Prevalência , RNA Viral/genética , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/virologia
4.
Sci Rep ; 9(1): 15744, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31673091

RESUMO

Endoscopic grading of gastroesophageal flap valve (GEFV) is simple and reproducible and offers useful information for reflux activity. To investigate the potential correlation between GEFV grading and reflux finding score (RFS) in patients with laryngopharyngeal reflux disease (LPRD), 225 consecutive Patients with suspected LPRD who underwent both routine upper gastrointestinal endoscopy and laryngoscope were enrolled in our study. Patients with a RFS of more than 7 were diagnosed with LPRD. The GEFV was graded as I through IV according to Hill's classification and was classified into two groups: normal GEFV group (grades I and II) and the abnormal GEFV group (grades III and IV). The percent of GEFV grades I to IV was 39.1%, 39.1%, 12.4%, and 9.3%, respectively. Age was significantly related to an abnormal GEFV (p = 0.002). Gender, BMI, smoke and alcohol were not related to GEFV grade. Fifty-one patients (22.67%) had positive RFS. Reflux finding scores were higher in GEFV grades III and IV than I and II (p < 0.05). Endoscopic grading of GEFV is well correlated with reflux finding score in patients with LPRD. This is a simple and useful technique that provides valuable diagnostic information of LPRD.


Assuntos
Junção Esofagogástrica/fisiopatologia , Refluxo Laringofaríngeo/patologia , Adulto , Idoso , Consumo de Bebidas Alcoólicas , Endoscopia do Sistema Digestório , Esôfago/patologia , Esôfago/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Índice de Gravidade de Doença , Fumar
5.
Am J Prev Med ; 57(2): e31-e41, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31248746

RESUMO

INTRODUCTION: This cluster RCT aimed to reduce healthcare utilization and increase the referral of patients between an academic health center and local community-based organizations (CBOs) that address social determinants of health. STUDY DESIGN: Cluster RCT. SETTINGS/PARTICIPANTS: Twenty-two CBOs located in Baltimore, Maryland, were randomly assigned to the intervention or control group, and 5,255 patients were allocated to the intervention or control group based on whether they lived closer to an intervention or control CBO. Data were collected in 2014-2016; the analysis was conducted in 2016. INTERVENTION: A multicomponent intervention included an online tool to help refer clients to community resources, meet-and-greet sessions between CBO staff and healthcare staff, and research assistants. MAIN OUTCOME MEASURES: The primary outcomes were patient emergency department visits and days spent in the hospital. Additional outcomes for CBO clients included knowledge of other CBOs, number of referrals to CBOs by the healthcare system, and number of referrals to healthcare system by CBOs. Outcomes for CBO staff included the number of referrals made to and received from the healthcare system and the number of referrals made to and received from other CBOs. RESULTS: There was no significant effect of the intervention on healthcare utilization outcomes, CBO client outcomes, or CBO staff outcomes. Ancillary analyses demonstrated a 2.9% increase in referrals by inpatient staff to intervention CBOs (p=0.051) and a 6.6% increase in referrals by outpatient staff to intervention CBOs between baseline and follow-up (p=0.027). Outpatient staff reported a significant reduction in barriers related to the lack of information about CBO services (-18.3%, p=0.004) and an increase in confidence in community resources (+14.4%, p=0.023) from baseline to follow-up. CONCLUSIONS: The intervention did not improve healthcare utilization outcomes but was associated with increased healthcare staff knowledge of, and confidence in, local CBOs. TRIAL REGISTRATION: This study is registered at www.clinicaltrials.gov NCT02222909.


Assuntos
Serviços de Saúde Comunitária/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Encaminhamento e Consulta , Características de Residência , Baltimore , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Internet , Masculino , Pessoa de Meia-Idade , Recursos Humanos em Hospital , Determinantes Sociais da Saúde , Inquéritos e Questionários
6.
Se Pu ; 36(6): 547-551, 2018 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-30136476

RESUMO

A method was established for the simultaneous determination of fipronil and its metabolites in eggs by gas chromatography-tandem mass spectrometry coupled with QuEChERS. Fipronil and its metabolites were extracted from eggs with acetonitrile, and the solution was dehydrated with 150 mg anhydrous magnesium sulfate. The extracts were purified with 50 mg N-propyl ethylenediamine (PSA) and 50 mg C18, and a capillary column pesticide Ⅱ was used. The analytes were detected in timed selected reaction monitoring (timed-SRM) mode, and were quantified using external standard method with matrix correction standard curves. A good linearity in the range of 1.0-200 µg/L with correlation coefficients (R2)>0.999 was observed. The limits of quantification (LOQs) were between 0.5 and 1.0 µg/kg. The recoveries at three spiked levels (2.0, 5.0 and 10.0 µg/kg) were in the range of 87.8% to 111.5% with RSDs between 2.0% and 9.2% (n=3). This new method satisfied the related regulations of the European Union for the determination of fipronil and its metabolites in eggs.


Assuntos
Ovos/análise , Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Pirazóis/análise , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas em Tandem
8.
BMC Infect Dis ; 18(1): 211, 2018 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-29739342

RESUMO

BACKGROUND: The overall success of Human immunodeficiency virus type 1 (HIV-1) antiretroviral therapy (ART) was heavily challenged upon the occurrence of drug resistance. Dehong Prefecture witnessed not only the first report of HIV-1 infection but also the experimental adoption of antiviral treatment in China. The transmission and epidemic of HIV-1 in Dehong is impacted by cross-border activities. The characteristics of HIV-1 drug resistance among therapy-naïve Burmese entering travelers in Yunnan and their speculated origin are still not clarified. METHODS: Two hundred ninety-eight HIV-1 infected Burmese entering travelers at Dehong ports were recruited between 2003 and 2012. The partial HIV-1 pol gene fragments were amplified and sequenced for the analysis of drug-resistance mutations (DRMs). Phylogenetic analysis on gag-pol gene was conducted to elucidate phylogenetic and evolutionary characteristics of these drug resistant strains. RESULTS: It was figured out that the occurrence ratio of HIV-1 drug resistance among HIV-1 infected entering travelers from Myanmar was up to 12.8%. The resistant mutations covered several types, including one type of PI mutations (L33F), six types of NRTI mutations and seven types of NNRTI. Close genetic relationship was observed in the phylogenetic analysis on gag-pol gene among the drug resistant strains respectively from Dehong, other Yunnan areas, neighboring provinces (Guangxi) and neighboring countries (Thailand and Myanmar). CONCLUSIONS: The findings in this study revealed that HIV drug resistant locus is spreading from the population who is receiving drug-resistance treatment to the new infectors, which indicates the urgency of surveillance work on drug resistance among the migrant population with high risks of HIV infection.


Assuntos
Farmacorresistência Viral/genética , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Mutação , Adulto , Fármacos Anti-HIV/uso terapêutico , China/epidemiologia , Emigração e Imigração , Epidemias , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Mianmar , Filogenia , Prevalência , Tailândia , Viagem , Produtos do Gene pol do Vírus da Imunodeficiência Humana
9.
Surg Endosc ; 32(8): 3421-3431, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29435752

RESUMO

BACKGROUND AND AIMS: Gastric per-oral endoscopic myotomy (G-POEM) was introduced four years ago as an investigational procedure for refractory gastroparesis. The safety and efficacy were currently evaluated. With our recent studies on G-POEM, we share our experience and knowledge through the discussion of a detailed description of the procedure and review of the literature. To our knowledge, this is the first systemic review on this new therapeutic endoscopic procedure. METHODS: The indications and contraindications, various aspects of the procedure, and efficacy assessment are discussed based on our experience and current available data. RESULTS: Preoperative preparation, detailed description of the procedure, post-procedural care, and results in the literature are presented. The procedure is safe and effective. 70-80% of patients have significant improvement in overall symptoms and quality of life in short-term (6 months) follow-up, as assessed by Gastric Cardinal Symptom Index and Short Form 36. CONCLUSIONS: G-POEM is a feasible and effective procedure for refractory gastroparesis based on early and limited data. Well-designed prospective studies are expected to advance and evaluate this new procedure in the future.


Assuntos
Gastroparesia/cirurgia , Piloromiotomia/métodos , Seguimentos , Gastroparesia/diagnóstico , Humanos , Qualidade de Vida , Resultado do Tratamento
10.
Mol Med Rep ; 17(2): 2313-2320, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29207065

RESUMO

Microgravity can affect many aspects of intestinal homeostasis, leading to an increased risk of colitis. Estrogen, the most frequently affected hormone when under simulated microgravity, regulates the permeability of the colonic mucosa barrier. The associations between alterations in intestinal microbiota and increased susceptibility under microgravity have not been thoroughly elucidated. The aim of the present study was to evaluate the changes in intestinal microbiota under simulated microgravity and to investigate the protective effect of estrogen against those changes. The hindlimb unweighting (HU) model was used to simulate microgravity in rats. Estrogen was administered via intramuscular injection. Amplicons of the V3 variable regions of bacterial 16S rDNA were analyzed using denaturing gradient gel electrophoresis (DGGE), cloning and sequencing. Several specific bacterial groups were assayed using quantitative­polymerase chain reaction. Bacterial translocation was evaluated by detecting serum lipopolysaccharide (LPS) and LPS binding protein (LBP) levels. DGGE profiles generated by universal primers revealed minor, though specific, changes in bacterial communities under simulated microgravity, particularly the band matching the sequence of Escherichia coli (E. coli). The quantification of 16S RNA revealed increased numbers of Bacteroides fragilis, E. coli and Fusobacterium nucleatum; however, Bifidobacteria longum significantly decreased under microgravity. Estrogen inhibited the overgrowth of E. coli, and decreased the levels of LBS and LBP under simulated microgravity. These results demonstrated that simulated microgravity alters the intestinal microflora and may contribute to bacterial translocation in the gut mucosa. The data also suggested that further investigations evaluating the administration of estrogen to protect against microgravity­associated diseases may be required.


Assuntos
Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Estrogênios/farmacologia , Mucosa Intestinal/microbiologia , Ausência de Peso , Animais , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Biodiversidade , Fezes/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Masculino , Ratos
12.
J Clin Gastroenterol ; 51(4): 300-311, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28267052

RESUMO

The present study conducted a meta-analysis and systematic review of current evidence to assess the efficacy of probiotics in preventing or treating small intestinal bacterial overgrowth (SIBO). Relevant studies from PubMed, Embase, and the Cochrane Central Register of Controlled Trials, until May 2016, were assimilated. The prevention efficacy was assessed by the incidence of SIBO in the probiotic group, and the treatment efficacy by the SIBO decontamination rate, reduction in H2 concentration, and symptom improvement. The relative risk (RR) and weighted mean difference (WMD) were used as effect measures and the random-effects model used for meta-analysis. A total of 14 full-text articles and 8 abstracts were included for the systematic review, and 18 studies were eligible for data synthesis. Patients on probiotic usage showed an insignificant trend toward low SIBO incidence [RR=0.54; 95% confidence intervals (CI), 0.19-1.52; P=0.24]. The pooled SIBO decontamination rate was 62.8% (51.5% to 72.8%). The probiotics group showed a significantly higher SIBO decontamination rate than the nonprobiotic group (RR=1.61; 95% CI, 1.19-2.17; P<0.05). Also, the H2 concentration was significantly reduced among probiotic users (WMD=-36.35 ppm; 95% CI, -44.23 to -28.47 ppm; P<0.05). Although probiotics produced a marked decrease in the abdominal pain scores (WMD=-1.17; 95% CI, -2.30 to -0.04; P<0.05), it did not significantly reduce the daily stool frequency (WMD=-0.09; 95% CI, -0.47 to 0.29). Therefore, the present findings indicated that probiotics supplementation could effectively decontaminate SIBO, decrease H2 concentration, and relieve abdominal pain, but were ineffective in preventing SIBO.


Assuntos
Infecções Bacterianas/prevenção & controle , Doenças do Jejuno/prevenção & controle , Probióticos/uso terapêutico , Infecções Bacterianas/microbiologia , Humanos , Probióticos/administração & dosagem , Ensaios Clínicos Controlados Aleatórios como Assunto
14.
Sci Rep ; 6: 22978, 2016 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-26960914

RESUMO

Endoscopic ultrasound-guided fine needle core biopsy (EUS-FNB) has been used as an effective method of diagnosing pancreatic malignant lesions. It has the advantage of providing well preserved tissue for histologic grading and subsequent molecular biological analysis. In order to estimate the diagnostic accuracy of EUS-FNB for pancreatic malignant lesions, studies assessing EUS-FNB to diagnose solid pancreatic masses were selected via Medline. Sixteen articles published between 2005 and 2015, covering 828 patients, met the inclusion criteria. The summary estimates for EUS-FNB differentiating malignant from benign solid pancreatic masses were: sensitivity 0.84 (95% confidence interval (CI), 0.82-0.87); specificity 0.98 (95% CI, 0.93-1.00); positive likelihood ratio 8.0 (95% CI 4.5-14.4); negative likelihood ratio 0.17 (95% CI 0.10-0.26); and DOR 64 (95% CI 30.4-134.8). The area under the sROC curve was 0.96. Subgroup analysis did not identify other factors that could substantially affect the diagnostic accuracy, such as the study design, location of study, number of centers, location of lesion, whether or not a cytopathologist was present, and so on. EUS-FNB is a reliable diagnostic tool for solid pancreatic masses and should be especially considered for pathology where histologic morphology is preferred for diagnosis.


Assuntos
Biópsia por Agulha Fina , Endossonografia , Neoplasias Pancreáticas/diagnóstico , Humanos , Neoplasias Pancreáticas/patologia
15.
Medicine (Baltimore) ; 94(49): e2077, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26656333

RESUMO

Early diagnosis and prompt treatment of spontaneous bacterial peritonitis (SBP) due to end-stage liver disease is vital to shorten hospital stays and reduce mortality. Many studies have explored the potential usefulness of serum procalcitonin (PCT) in predicting SBP. The aim of this study is to evaluate the overall diagnostic accuracy of PCT levels for identifying SBP due to end-stage liver disease.After performing a systematic search of the Medline, Embase, and Cochrane databases for studies that evaluated the diagnostic role of PCT for SBP, sensitivity, specificity, and other measures of accuracy of PCT concentrations in serum for SBP diagnosis were pooled using random-effects models. A summary receiver operating characteristic curve was used to summarize overall test performance.Seven publications met the inclusion criteria covering 742 episodes of suspected SBP along with 339 confirmed cases. The summary estimates for serum PCT in the diagnosis of SBP attributable to end-stage liver disease were: sensitivity 0.82 (95% CI 0.79-0.87), specificity 0.86 (95% CI 0.82-0.89), positive likelihood ratio 4.94 (95% CI 2.28-10.70), negative likelihood ratio 0.22 (95% CI 0.10-0.52), and diagnostic OR 22.55 (95% CI 7.01-108.30). The area under the curve was 0.92. There was evidence of significant heterogeneity but no evidence of publication bias.Serum PCT is a relatively sensitive and specific test for the identification of SBP. However, due to the limited high-quality studies available, medical decisions should be carefully made in the context of both PCT test results and other clinical findings.


Assuntos
Infecções Bacterianas/diagnóstico , Biomarcadores/sangue , Calcitonina/sangue , Cirrose Hepática/complicações , Peritonite/diagnóstico , Precursores de Proteínas/sangue , Infecções Bacterianas/sangue , Infecções Bacterianas/etiologia , Peptídeo Relacionado com Gene de Calcitonina , Bases de Dados Factuais , Humanos , Peritonite/sangue , Peritonite/etiologia , Valor Preditivo dos Testes , Curva ROC
16.
Immunology ; 141(2): 203-10, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24400795

RESUMO

Increasing evidence suggests that gut flora play an important role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Our previous studies show that hepatic natural killer T (NKT) cells play a significant role in the pathogenesis of NAFLD. In this study, we explore the mechanism by which modification of gut flora leads to the alteration of hepatic NKT cells and improvement of steatosis. Mice were fed a high-fat (HF) diet to induce NAFLD. Some of them also received different doses of mixed-strain probiotics (VSL#3); single-strain probiotic (Bifidobacterium infantis) or antibiotics. Animal weight, glucose tolerance, liver steatosis and hepatic NKT cells were assessed. Lipid extracts from probiotics were tested for their ability to activate NKT cells. Toll-like receptor 4 (TLR4) knockout mice were also evaluated for their responses to HF diet. High-dose VSL#3 was more effective than low-dose VSL#3 and B. infantis for the improvement of hepatic NKT cell depletion and steatosis. The lipids extracted from VSL#3 stimulated NKT cells both in vivo and in vitro. In contrast, lipids from B. infantis decreased α-GalCer-mediated NKT cell activation in vitro, but were able to stimulate NKT cells. TLR4 knockout mice have a similar response to HF-diet-induced NKT cell depletion and obesity. These results suggest that alterations in the gut flora have profound effects on hepatic NKT cells and steatosis, which are both strain-specific and dose-dependent, but not through TLR4 signalling. Furthermore, these data suggest that probiotics may contain bacterial glycolipid antigens that directly modulate the effector functions of hepatic NKT cells.


Assuntos
Fígado Gorduroso/etiologia , Fígado/efeitos dos fármacos , Células T Matadoras Naturais/efeitos dos fármacos , Probióticos/farmacologia , Animais , Dieta Hiperlipídica , Fígado Gorduroso/tratamento farmacológico , Fígado/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células T Matadoras Naturais/imunologia , Hepatopatia Gordurosa não Alcoólica , Obesidade/etiologia , Receptor 4 Toll-Like/fisiologia
17.
J Immunol ; 190(4): 1788-96, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23296703

RESUMO

T cell Ig and mucin domain (Tim)-3 is well known to interact with its natural ligand, Galectin-9 (Gal-9), to regulate T cell function. However, little is known about the function of Tim-3/Gal-9 signaling in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) mediated by hepatic NKT cells that also express Tim-3. In the current study, we define the role and the mechanism of Tim-3/Gal-9 signaling in hepatic NKT cell regulation in a mouse model of diet-induced NAFLD. Adult male wild-type or CD1d knockout C57BL/6 mice were fed a high-fat diet to induce steatosis. Some of the mice also received one or a combination of Gal-9, anti-IL-15R/IL-15 mAb, rIL-15, α-galactosylceramide, and multilamellar liposomes containing Cl(2)MDP. The expression of Tim-3 and various markers reflecting cell proliferation, activation, cytokine production, and apoptosis was analyzed. Liver histology, steatosis grade, and hepatic triglyceride content were also evaluated. In the liver, Tim-3(+) NKT cells are in an activated state, and Gal-9 directly induces Tim-3(+) NKT cell apoptosis and contributes to the depletion of NKT cells in diet-induced steatosis. However, Gal-9 also interacts with Tim-3-expressing Kupffer cells to induce secretion of IL-15, thus promoting NKT cell proliferation. Exogenous administration of Gal-9 significantly ameliorates diet-induced steatosis by modulating hepatic NKT cell function. In summary, the Tim-3/Gal-9-signaling pathway plays a critical role in the homeostasis of hepatic NKT cells through activation-induced apoptosis and secondary proliferation and, thus, contributes to the pathogenesis of NAFLD.


Assuntos
Fígado Gorduroso/imunologia , Fígado Gorduroso/metabolismo , Galectinas/fisiologia , Homeostase/imunologia , Células T Matadoras Naturais/imunologia , Receptores Virais/fisiologia , Animais , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Fígado Gorduroso/patologia , Receptor Celular 2 do Vírus da Hepatite A , Interleucina-15/metabolismo , Células de Kupffer/imunologia , Células de Kupffer/metabolismo , Depleção Linfocítica/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células T Matadoras Naturais/patologia , Hepatopatia Gordurosa não Alcoólica , Transdução de Sinais/imunologia
18.
PLoS One ; 6(11): e27038, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22073248

RESUMO

BACKGROUND/AIMS: Regulatory T cells (Tregs) and natural killer T (NKT) cells are two distinct lymphocyte subsets that independently regulate hepatic adaptive and innate immunity, respectively. In the current study, we examine the interaction between Tregs and NKT cells to understand the mechanisms of cross immune regulation by these cells. METHODS: The frequency and function of Tregs were evaluated in wild type and NKT cell deficient (CD1dko) mice. In vitro lymphocyte proliferation and apoptosis assays were performed with NKT cells co-cultured with Tregs. The ability of Tregs to inhibit NKT cells in vivo was examined by adoptive transfer of Tregs in a model of NKT cell mediated hepatitis. RESULTS: CD1dko mice have a significant reduction in hepatic Tregs. Although, the Tregs from CD1dko mice remain functional and can suppress conventional T cells, their ability to suppress activation induced NKT cell proliferation and to promote NKT cell apoptosis is greatly diminished. These effects are CD1d dependent and require cell to cell contact. Adoptive transfer of Tregs inhibits NKT cell-mediated liver injury. CONCLUSIONS: NKT cells promote Tregs, and Tregs inhibit NKT cells in a CD1d dependent manner requiring cell to cell contact. These cross-talk immune regulations provide a linkage between innate and adaptive immunity.


Assuntos
Adaptação Fisiológica/imunologia , Antígenos CD1d/imunologia , Imunidade Inata , Células Matadoras Naturais/imunologia , Fígado/citologia , Linfócitos T Reguladores/imunologia , Animais , Apoptose , Ensaio de Imunoadsorção Enzimática , Fígado/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
19.
Gastrointest Endosc ; 74(3): 637-44, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21872714

RESUMO

BACKGROUND: Increased visceral adiposity is a key feature of obesity and metabolic syndrome. Previous studies have generated controversial results regarding visceral fat (VF) removal as a therapy for obesity and metabolic syndrome. OBJECTIVE: To study the effect of surgical VF removal on metabolic profiles in a mouse model of diet-induced obesity and metabolic syndrome and to evaluate for the first time the feasibility of endoscopic omentectomy using natural orifice transluminal endoscopic surgery (NOTES) technique as treatment for obesity and metabolic syndrome in a feline model. SETTING: The Johns Hopkins Hospital. DESIGN: Sham-controlled study in a mouse model of metabolic syndrome and then pilot endoscopic sham-controlled study in cats. INTERVENTIONS: Partial or total surgical VF removal was performed in a high-fat diet-induced mouse model of obesity and metabolic syndrome, followed by measurements of metabolic profiles, and endoscopic omentectomy was performed in a feline model using the NOTES approach. MAIN OUTCOME MEASUREMENTS: Weight loss and metabolic profiles. RESULTS: In a mouse model of obesity, total but not partial VF removal significantly improved obesity and metabolic syndrome, including insulin resistance and hepatic steatosis (all P < .05 vs sham surgery). The improved metabolic syndrome was associated with significantly decreased inflammatory cytokines. In a feline model, endoscopic omentectomy was feasible and safe and resulted in a net weight loss compared with sham surgery (-387 ± 437 g vs 233 ± 351 g, P = .1, respectively). LIMITATIONS: Animal experiments. CONCLUSIONS: Endoscopic omentectomy is safe and feasible and has the potential to treat obesity and metabolic syndrome. Near-total VF removal is required to achieve net weight loss and improvement of metabolic syndrome.


Assuntos
Tecido Adiposo/cirurgia , Síndrome Metabólica/cirurgia , Cirurgia Endoscópica por Orifício Natural , Obesidade/cirurgia , Omento/cirurgia , Vísceras/cirurgia , Animais , Gatos , Fígado Gorduroso/fisiopatologia , Masculino , Síndrome Metabólica/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/fisiopatologia , Projetos Piloto , Redução de Peso
20.
PLoS One ; 6(4): e18909, 2011 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-21526159

RESUMO

T helper cells that produce IL-17 (Th17 cells) have recently been identified as the third distinct subset of effector T cells. Emerging data suggests that Th17 cells play an important role in the pathogenesis of many liver diseases by regulating innate immunity, adaptive immunity, and autoimmunity. In this study, we examine the role and mechanism of Th17 cells in the pathogenesis of autoimmune hepatitis (AIH). The serum levels of IL-17 and IL-23, as well as the frequency of IL-17+ cells in the liver, were significantly elevated in patients with AIH, compared to other chronic hepatitis and healthy controls. The hepatic expressions of IL-17, IL-23, ROR-γt, IL-6 and IL-1ß in patients with AIH were also significantly increased and were associated with increased inflammation and fibrosis. IL-17 induces IL-6 expression via the MAPK signaling pathway in hepatocytes, which, in turn, may further stimulate Th17 cells and forms a positive feedback loop. In conclusion, Th17 cells are key effector T cells that regulate the pathogenesis of AIH, via induction of MAPK dependent hepatic IL-6 expression. Blocking the signaling pathway and interrupting the positive feedback loop are potential therapeutic targets for autoimmune hepatitis.


Assuntos
Hepatite Autoimune/etiologia , Hepatite Autoimune/imunologia , Interleucina-17/metabolismo , Interleucina-6/metabolismo , Fígado/metabolismo , Adolescente , Adulto , Biópsia , Estudos de Casos e Controles , Feminino , Células Hep G2 , Hepatite B Crônica/sangue , Hepatite B Crônica/patologia , Hepatite Autoimune/sangue , Humanos , Interleucina-17/sangue , Interleucina-17/farmacologia , Interleucina-23/sangue , Fígado/enzimologia , Fígado/imunologia , Fígado/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Células Th17/efeitos dos fármacos , Células Th17/metabolismo , Adulto Jovem
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