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1.
Cancer Res ; 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39186679

RESUMO

High-grade serous ovarian carcinoma (HGSC) remains a disease of poor prognosis that is unresponsive to current immune checkpoint inhibitors. Although PI3K pathway alterations, such as PTEN loss, are common in HGSC, attempts to target this pathway have been unsuccessful. We hypothesized that aberrant PI3K pathway activation may alter the HGSC immune microenvironment and present a targeting opportunity. Single-cell RNA sequencing identified populations of resident macrophages specific to Pten-null omental tumors in murine models, which were confirmed by flow cytometry. These macrophages derived from peritoneal fluid macrophages and had a unique gene expression program, marked by high expression of the enzyme heme oxygenase-1 (HMOX1). Targeting resident peritoneal macrophages prevented the appearance of HMOX1hi macrophages and reduced tumor growth. Furthermore, direct inhibition of HMOX1 extended survival in vivo. RNA sequencing identified IL33 in Pten-null tumor cells as a likely candidate driver leading to the appearance of HMOX1hi macrophages. Human HGSC tumors also contained HMOX1hi macrophages with a corresponding gene expression program. Moreover, the presence of these macrophages correlated with activated tumoral PI3K/mTOR signaling and poor overall survival in HGSC patients. In contrast, tumors with low numbers of HMOX1hi macrophages were marked by increased adaptive immune response gene expression. These data suggest targeting HMOX1hi macrophages as a potential therapeutic strategy for treating poor prognosis HGSC.

2.
Front Microbiol ; 15: 1392018, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39006755

RESUMO

Cationic biocides (CBs), such as quaternary ammonium compounds and biguanides, are critical for controlling the spread of bacterial pathogens like Enterococcus spp., a leading cause of multidrug-resistant healthcare-associated infections. The widespread use of CBs in recent decades has prompted concerns about the potential emergence of Enterococcus spp. populations exhibiting resistance to both biocides and antibiotics. Such concerns arise from their frequent exposure to subinhibitory concentrations of CBs in clinical, food chain and diverse environmental settings. This comprehensive narrative review aimed to explore the complexity of the Enterococcus' response to CBs and of their possible evolution toward resistance. To that end, CBs' activity against diverse Enterococcus spp. collections, the prevalence and roles of genes associated with decreased susceptibility to CBs, and the potential for co- and cross-resistance between CBs and antibiotics are reviewed. Significant methodological and knowledge gaps are identified, highlighting areas that future studies should address to enhance our comprehension of the impact of exposure to CBs on Enterococcus spp. populations' epidemiology. This knowledge is essential for developing effective One Health strategies that ensure the continued efficacy of these critical agents in safeguarding Public Health.

3.
Microbiol Spectr ; : e0232423, 2023 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37737589

RESUMO

Quaternary ammonium compounds (QACs) have been extensively used in the community, healthcare facilities, and food chain, in concentrations between 20 and 30,000 mg/L. Enterococcus faecalis and Enterococcus faecium are ubiquitous in these settings and are recognized as nosocomial pathogens worldwide, but QACs' activity against strains from diverse epidemiological and genomic backgrounds remained largely unexplored. We evaluated the role of Enterococcus isolates from different sources, years, and clonal lineages as hosts of QACs tolerance genes and their susceptibility to QACs in optimal, single-stress and cross-stress growth conditions. Only 1% of the Enterococcus isolates included in this study and 0.5% of publicly available Enterococcus genomes carried qacA/B, qacC, qacG, qacJ, qacZ, qrg, bcrABC or oqxAB genes, shared with >60 species of Bacillota, Pseudomonadota, Actinomycetota, or Spirochaetota. These genes were generally found within close proximity of antibiotics and/or metals resistance genes. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of benzalkonium chloride (BC) and didecyldimethylammonium chloride ranged between 0.5 and 4 mg/L (microdilution: 37°C/20 h/pH = 7/aerobiosis) for 210 E. faecalis and E. faecium isolates (two isolates carrying qacZ). Modified growth conditions (e.g., 22°C/pH = 5) increased MICBC/MBCBC (maximum of eightfold and MBCBC = 16 mg/L) and changed bacterial growth kinetics under BC toward later stationary phases in both species, including in isolates without QACs tolerance genes. In conclusion, Enterococcus are susceptible to in-use QACs concentrations and rarely carry QACs tolerance genes. However, their potential gene exchange with different microbiota, the decreased susceptibility to QACs under specific environmental conditions, and the presence of subinhibitory QACs concentrations in various settings may contribute to the selection of particular strains and, thus, require a One Health strategy to maintain QACs effectiveness. IMPORTANCE Despite the increasing use of quaternary ammonium compounds (QACs), the susceptibility of pathogens to these antimicrobials remains largely unknown. Enterococcus faecium and Enterococcus faecalis are susceptible to in-use QACs concentrations and are not main hosts of QACs tolerance genes but participate in gene transfer pathways with diverse bacterial taxa exposed to these biocides. Moreover, QACs tolerance genes often share the same genetic contexts with antibiotics and/or metals resistance genes, raising concerns about potential co-selection events. E. faecium and E. faecalis showed increased tolerance to benzalkonium chloride under specific environmental conditions (22°C, pH = 5), suggesting that strains might be selected in settings where they occur along with subinhibitory QACs concentrations. Transcriptomic studies investigating the cellular mechanisms of Enterococcus adaptation to QACs tolerance, along with longitudinal metadata analysis of tolerant populations dynamics under the influence of diverse environmental factors, are essential and should be prioritized within a One Health strategy.

4.
Microbiol Spectr ; 10(4): e0117622, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-35862993

RESUMO

Chlorhexidine (CHX) is widely used to control the spread of pathogens (e.g., human/animal clinical settings, ambulatory care, food industry). Enterococcus faecalis, a major nosocomial pathogen, is broadly distributed in diverse hosts and environments facilitating its exposure to CHX over the years. Nevertheless, CHX activity against E. faecalis is understudied. Our goal was to assess CHX activity and the variability of ChlR-EfrEF proteins (associated with CHX tolerance) among 673 field isolates and 1,784 E. faecalis genomes from the PATRIC database from different sources, time spans, clonal lineages, and antibiotic-resistance profiles. The CHX MIC (MICCHX) and minimum bactericidal concentration (MBCCHX) against E. faecalis presented normal distributions (0.5 to 64 mg/L). However, more CHX-tolerant isolates were detected in the food chain and recent human infections, suggesting an adaptability of E. faecalis populations in settings where CHX is heavily used. Heterogeneity in ChlR-EfrEF sequences was identified, with isolates harboring incomplete ChlR-EfrEF proteins, particularly the EfrE identified in the ST40 clonal lineage, showing low MICCHX (≤1mg/L). Distinct ST40-E. faecalis subpopulations carrying truncated and nontruncated EfrE were detected, with the former being predominant in human isolates. This study provides a new insight about CHX susceptibility and ChlR-EfrEF variability within diverse E. faecalis populations. The MICCHX/MBCCHX of more tolerant E. faecalis (MICCHX = 8 mg/L; MBCCHX = 64 mg/L) remain lower than in-use concentrations of CHX (≥500 mg/L). However, increased CHX use, combined with concentration gradients occurring in diverse environments, potentially selecting multidrug-resistant strains with different CHX susceptibilities, signals the importance of monitoring the trends of E. faecalis CHX tolerance within a One Health approach. IMPORTANCE Chlorhexidine (CHX) is a disinfectant and antiseptic used since the 1950s and included in the World Health Organization's list of essential medicines. It has been widely applied in hospitals, the community, the food industry, animal husbandry and pets. CHX tolerance in Enterococcus faecalis, a ubiquitous bacterium and one of the leading causes of human hospital-acquired infections, remains underexplored. Our study provides novel and comprehensive insights about CHX susceptibility within the E. faecalis population structure context, revealing more CHX-tolerant subpopulations from the food chain and recent human infections. We further show a detailed analysis of the genetic diversity of the efrEF operon (previously associated with E. faecalis CHX tolerance) and its correlation with CHX phenotypes. The recent strains with a higher tolerance to CHX and the multiple sources where bacteria are exposed to this biocide alert us to the need for the continuous monitoring of E. faecalis adaptation toward CHX tolerance within a One Health approach.


Assuntos
Clorexidina , Desinfetantes , Animais , Antibacterianos , Clorexidina/metabolismo , Clorexidina/farmacologia , Células Clonais , Desinfetantes/metabolismo , Enterococcus faecalis/genética , Humanos , Testes de Sensibilidade Microbiana , Óperon
5.
Emerg Infect Dis ; 28(3): 730-733, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35133956

RESUMO

We conducted a prospective cohort study in a population with diverse ethnic backgrounds from Brazil to assess clinically meaningful symptoms after surviving coronavirus disease. For most of the 175 patients in the study, clinically meaningful symptoms, including fatigue, dyspnea, cough, headache, and muscle weakness, persisted for >120 days after disease onset.


Assuntos
COVID-19 , Brasil/epidemiologia , Humanos , Estudos Prospectivos , SARS-CoV-2 , Sobreviventes
6.
Int J Antimicrob Agents ; 57(1): 106227, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33207280

RESUMO

Enterococcus faecium is a significant opportunistic human pathogen with a broad host range, including humans, farm animals, pets and wildlife. Specialised subpopulations have globally evolved towards a powerful and convergent adaption to the healthcare environment by acquiring a cocktail of key antimicrobial resistance and virulence genes, enabling them to thrive in the disturbed microbiota of hospitalised patients. These populations can also be found in different community reservoirs, but the relevance of their dispersal in non-human hosts is greatly unknown and is here discussed. This review provides a brief historical overview of what we have been considering E. faecium high-risk clones worldwide alongside the advances in strain typing technologies that have revolutionised our understanding of the genetic evolution of this species over the last three decades.


Assuntos
Adaptação Biológica , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Enterococcus faecium/classificação , Enterococcus faecium/efeitos dos fármacos , Evolução Molecular , Animais , Técnicas de Tipagem Bacteriana , Enterococcus faecium/isolamento & purificação , Infecções por Bactérias Gram-Positivas/epidemiologia , Interações Hospedeiro-Patógeno , Humanos , Testes de Sensibilidade Microbiana , Virulência
7.
J Acquir Immune Defic Syndr ; 84(5): 514-521, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32692110

RESUMO

BACKGROUND: The objective was to compare the effect of HIV-1C and HIV-1B subtypes on neurofilament light (NfL) cerebrospinal fluid (CSF) levels and ratios of NfL to tau proteins. Additional comparisons were performed between people with HIV (PWH), participants with Alzheimer disease (AD), and HIV-negative controls (HIV-). We also calculated the diagnostic characteristics of CSF NfL and its ratios in HIV-associated neurocognitive disorder (HAND) diagnosis. METHODS: CSF NfL, T-tau, and P-tau181 concentrations were measured using immunoassays in a total of 108 CSF samples, including PWH (n = 68), HIV- (n = 16), and participants with AD (n = 24). These proteins were compared between HIV-1B (n = 27) and HIV-1C (n = 26) using multiple linear regression adjusted for nadir CD4 and plasma viral load suppression. Comparisons between PWH, HIV-, and participants with AD were adjusted for gender and age. RESULTS: CSF neurocytoskeleton proteins and their ratios were comparable in HIV-1B and HIV-1C. However, the HIV-1C group had a higher proportion of samples of CSF NfL above the reference value (n = 14, 53.85%) than the HIV-1B group (n = 8, 29.63%), P = 0.098. The values of CSF NfL were higher in the AD group [2578 (1864; 3500) pg/mL] than those in PWH [683 (500; 1197) pg/mL, P < 0.001] and control [660 (539; 802) pg/mL, P = 0.012] groups. The value of CSF NfL and its ratios for HAND diagnosis were poor. CONCLUSION: The effects of HIV-1B and HIV-1C on CSF NfL and tau ratios were comparable. The differences in CSF neurocytoskeleton proteins between PWH and individuals with AD suggested they might not share the same mechanisms of impairment. Further research is necessary to evaluate CSF NfL on the differential diagnoses of HAND with AD.


Assuntos
Sistema Nervoso Central/citologia , Proteínas do Citoesqueleto/líquido cefalorraquidiano , Infecções por HIV/líquido cefalorraquidiano , HIV-1/classificação , Adulto , Idoso , Doença de Alzheimer/complicações , Biomarcadores/líquido cefalorraquidiano , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
8.
Appl Environ Microbiol ; 85(23)2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31562170

RESUMO

Chlorhexidine (CHX) is a broad-spectrum antiseptic widely used in community and clinical contexts for many years that has recently acquired higher relevance in nosocomial infection control worldwide. Despite this, CHX tolerance among Enterococcus faecium bacteria, representing one of the leading agents causing nosocomial infections, has been poorly understood. This study provides new phenotypic and molecular data for better identification of CHX-tolerant E. faecium subpopulations in community and clinical contexts. The chlorhexidine MIC (MICCHX) distribution of 106 E. faecium isolates suggested the occurrence of tolerant subpopulations in diverse sources (human, animal, food, environment) and phylogenomic backgrounds (clades A1/A2/B), with predominance in clade A1. They carried a specific variant of the 2CS-CHXT operon, identified here. It encodes glucose and amino acid-polyamine-organocation family transporters, besides the DNA-binding response regulator ChtR, with a P102H mutation previously described only in CHX-tolerant clade A1 E. faecium, and the ChtS sensor. 2CS-CHXT seems to be associated with three regulons modulating diverse bacterial biological functions. Combined data from normal MIC distribution and 2CS-CHXT operon characterization support a tentative epidemiological cutoff (ECOFF) of 8 mg/liter to CHX, which is useful to detect tolerant E. faecium populations in future surveillance studies. The spread of tolerant E. faecium in diverse epidemiological backgrounds calls for the prudent use of CHX in multiple contexts.IMPORTANCE Chlorhexidine is one of the substances included in the World Health Organization's list of essential medicines, which comprises the safest and most effective medicines needed in global health systems. Although it has been widely applied as a disinfectant and antiseptic in health care (skin, hands, mouthwashes, eye drops) since the 1950s, its use in hospitals to prevent nosocomial infections has increased worldwide in recent years. Here, we provide a comprehensive study on chlorhexidine tolerance among strains of Enterococcus faecium, one of the leading nosocomial agents worldwide, and identify a novel 2CS-CHXT operon as a signature of tolerant strains occurring in diverse phylogenomic groups. Our data allowed for the proposal of a tentative epidemiological cutoff of 8 mg/liter, which is useful to detect tolerant E. faecium populations in surveillance studies in community and clinical contexts. The prediction of 2CS-CHXT regulons will also facilitate the design of future experimental studies to better uncover chlorhexidine tolerance among E. faecium bacteria.


Assuntos
Anti-Infecciosos Locais/farmacologia , Clorexidina/farmacologia , Farmacorresistência Bacteriana/genética , Enterococcus faecium/efeitos dos fármacos , Óperon/fisiologia , Enterococcus faecium/genética , Enterococcus faecium/fisiologia , Filogenia
9.
Food Microbiol ; 82: 99-106, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31027825

RESUMO

Alkalization is a step of cocoa processing and consists of the use of alkali and high temperature to improve the sensorial and technological qualities of cocoa. Intense food processing can select spores, which can compromise safety and quality of the final product. Thus, the aim of this study was to evaluate the fate of B. cereus and G. stearothermophilus spores during the alkalization of pre-roasted (Pr) nibs (held at 120 °C) and unroasted (Ur) nibs (held at 90 °C) using potassium carbonate (0, 2, 4 and 6% w/w). In all conditions, log-linear inactivation kinetics with a tail was observed. The inactivation rate (kmax) for B. cereus varied from 0.065 to 1.67 min-1, whereas the kmax for G. stearothermophilus varied from 0.012 to 0.063 min-1. For both microorganisms, the lowest kmax values were observed during Ur nibs alkalization. The carbonate concentration increase promoted kmax values reduction. The highest tail values were observed for G. stearothermophilus in Ur nibs alkalization, reaching 3.04 log spores/g. Tail formation and low kmax values indicated that cocoa alkalization does not cause significant reductions on bacterial spore population. Therefore, the microbiological control should be primarily ensured by the raw material quality and by avoiding recontamination in the cocoa chain.


Assuntos
Álcalis/química , Bacillus cereus/crescimento & desenvolvimento , Cacau/química , Cacau/microbiologia , Geobacillus stearothermophilus/crescimento & desenvolvimento , Viabilidade Microbiana/efeitos dos fármacos , Carbonatos/farmacologia , Manipulação de Alimentos , Microbiologia de Alimentos , Temperatura Alta , Potássio/farmacologia , Esporos Bacterianos
10.
Int J Antimicrob Agents ; 51(3): 503-507, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29175606

RESUMO

This study evaluated the occurrence of enterococci resistant to clinically relevant antibiotics in long-term care facility (LTCF) residents in Porto, Portugal, a region with high rates of multidrug-resistant enterococci in infected patients and healthy carriers. Faecal samples from 48 residents in two LTCFs (2015-2016) were enriched (with/without antibiotics) and plated on Slanetz-Bartley with/without the same antibiotics (ampicillin/vancomycin/linezolid). Two colonies per morphology/sample were selected for susceptibility testing and species identification. Clonality was established by PFGE and MLST. Genes coding for vancomycin resistance (vanA/vanB), virulence and plasmids (replicases) were searched by PCR. A total of 285 isolates were obtained, comprising Enterococcus faecalis, Enterococcus faecium, Enterococcus raffinosus and Enterococcus avium colonising 83%, 77%, 27% and 10% of residents, respectively. Residents from both LTCFs were colonised with vancomycin-resistant E. faecium (VanA-VREfm) (4 residents; 8%) and/or ampicillin-resistant (AmpR) (24 residents; 50%) E. raffinosus, E. faecium and E. avium. Enterococcus faecium previously associated with major human clonal lineages (ST18/ST78) or animal clones (ST393) were identified. Some PFGE types of E. faecium, E. raffinosus and E. avium were shared by residents of both LTCFs. Recent antibiotic exposure was significantly associated with colonisation by AmpR enterococci. Residents from Portuguese LTCFs were colonised with high rates of AmpR enterococci and similar rates of VREfm compared with other EU countries. A high colonisation rate with widespread enterococcal lineages that could be selected by antibiotic consumption in LTCFs was uncovered. These findings suggest that antimicrobial stewardship is warranted in LTCFs, which constitutes a significant challenge in a home-based setting.


Assuntos
Ampicilina/farmacologia , Antibacterianos/farmacologia , Portador Sadio/epidemiologia , Infecção Hospitalar/epidemiologia , Enterococcus/isolamento & purificação , Infecções por Bactérias Gram-Positivas/epidemiologia , Resistência beta-Lactâmica , Idoso , Idoso de 80 Anos ou mais , Portador Sadio/microbiologia , Infecção Hospitalar/microbiologia , Eletroforese em Gel de Campo Pulsado , Enterococcus/classificação , Enterococcus/efeitos dos fármacos , Enterococcus/genética , Fezes/microbiologia , Feminino , Genótipo , Infecções por Bactérias Gram-Positivas/microbiologia , Instalações de Saúde , Humanos , Assistência de Longa Duração , Masculino , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Plasmídeos/análise , Reação em Cadeia da Polimerase , Portugal/epidemiologia
11.
J Cell Mol Med ; 21(11): 3087-3099, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28560754

RESUMO

Interleukin (IL)-6-type cytokines have no direct antiviral activity; nevertheless, they display immune-modulatory functions. Oncostatin M (OSM), a member of the IL-6 family, has recently been shown to induce a distinct number of classical interferon stimulated genes (ISG). Most of them are involved in antigen processing and presentation. However, induction of retinoic acid-inducible gene (RIG)-I-like receptors (RLR) has not been investigated. Here we report that OSM has the capability to induce the expression of the DExD/H-Box RNA helicases RIG-I and melanoma differentiation antigen 5 (MDA5) as well as of the transcription factors interferon regulatory factor (IRF)1, IRF7 and IRF9 in primary fibroblasts. Induction of the helicases depends on tyrosine as well as serine phosphorylation of STAT1. Moreover, we could show that the OSM-induced STAT1 phosphorylation is predominantly counter-regulated by a strong STAT3-dependent SOCS3 induction, as Stat3 as well as Socs3 knock-down results in an enhanced and prolonged helicase and IRF expression. Other factors involved in regulation of STAT1 or IRF1 activity, like protein tyrosine phosphatase, non-receptor type 2 (PTPN2), promyelocytic leukaemia protein (PML) or small ubiquitin-related modifier 1 (SUMO1), play a minor role in OSM-mediated induction of RLR. Remarkably, OSM and interferon-γ (IFN-γ) synergize to mediate transcription of RLR and pre-treatment of fibroblasts with OSM fosters the type I interferon production in response to a subsequent encounter with double-stranded RNA. Together, these findings suggest that the OSM-induced JAK/STAT1 signalling is implicated in virus protection of non-professional immune cells and may cooperate with interferons to enhance RLR expression in these cells.


Assuntos
Proteína DEAD-box 58/genética , Fibroblastos/efeitos dos fármacos , Imunidade Inata , Helicase IFIH1 Induzida por Interferon/genética , Oncostatina M/farmacologia , Fator de Transcrição STAT1/genética , Linhagem Celular Tumoral , Proteína DEAD-box 58/antagonistas & inibidores , Proteína DEAD-box 58/imunologia , Fibroblastos/citologia , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Humanos , Fator Regulador 1 de Interferon/genética , Fator Regulador 1 de Interferon/imunologia , Fator Regulador 7 de Interferon/genética , Fator Regulador 7 de Interferon/imunologia , Helicase IFIH1 Induzida por Interferon/antagonistas & inibidores , Helicase IFIH1 Induzida por Interferon/imunologia , Fator Gênico 3 Estimulado por Interferon, Subunidade gama/genética , Fator Gênico 3 Estimulado por Interferon, Subunidade gama/imunologia , Interferon gama/farmacologia , Interleucina-6/farmacologia , Fator Inibidor de Leucemia/farmacologia , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/genética , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/imunologia , Lipopolissacarídeos/farmacologia , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Cultura Primária de Células , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores Imunológicos , Fator de Transcrição STAT1/imunologia , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/imunologia , Transdução de Sinais , Pele/citologia , Pele/efeitos dos fármacos , Pele/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas/genética , Proteína 3 Supressora da Sinalização de Citocinas/imunologia
12.
Sci Signal ; 9(453): ra109, 2016 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-27919027

RESUMO

Adenosine 5'-monophosphate-activated protein kinase (AMPK) is a pivotal regulator of metabolism at cellular and organismal levels. AMPK also suppresses inflammation. We found that pharmacological activation of AMPK rapidly inhibited the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway in various cells. In vitro kinase assays revealed that AMPK directly phosphorylated two residues (Ser515 and Ser518) within the Src homology 2 domain of JAK1. Activation of AMPK enhanced the interaction between JAK1 and 14-3-3 proteins in cultured vascular endothelial cells and fibroblasts, an effect that required the presence of Ser515 and Ser518 and was abolished in cells lacking AMPK catalytic subunits. Mutation of Ser515 and Ser518 abolished AMPK-mediated inhibition of JAK-STAT signaling stimulated by either the sIL-6Rα/IL-6 complex or the expression of a constitutively active V658F-mutant JAK1 in human fibrosarcoma cells. Clinically used AMPK activators metformin and salicylate enhanced the inhibitory phosphorylation of endogenous JAK1 and inhibited STAT3 phosphorylation in primary vascular endothelial cells. Therefore, our findings reveal a mechanism by which JAK1 function and inflammatory signaling may be suppressed in response to metabolic stress and provide a mechanistic rationale for the investigation of AMPK activators in a range of diseases associated with enhanced activation of the JAK-STAT pathway.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Células Endoteliais/metabolismo , Janus Quinase 1/metabolismo , Transdução de Sinais/fisiologia , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Substituição de Aminoácidos , Animais , Células Endoteliais/citologia , Ativação Enzimática , Janus Quinase 1/genética , Camundongos , Camundongos Knockout , Mutação de Sentido Incorreto , Fosforilação , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo
14.
Biochem Soc Trans ; 42(1): 59-62, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24450628

RESUMO

IL-6 (interleukin 6)-type cytokines are pleiotropic molecules, critical for cellular homoeostasis and with well-recognized roles in several human diseases. They all activate JAK (Janus kinase)/STAT (signal transducer and activator of transcription) signalling and, depending on the particular cytokine, cell type and cellular environment, they can also trigger the activation of MAPK (mitogen-activated protein kinase) and PI3K (phosphoinositide 3-kinase) cascades. Although it is clear that JAK/STAT and MAPK reciprocally regulate each other, how these signalling pathways are fully integrated remains to be fully understood. Not only do cells have to be able to integrate and conciliate what are often contradictory signalling cues, but they are also subject to complex regulatory mechanisms involving these pathways. More specifically, we have shown recently that ERK2 (extracellular-signal-regulated kinase 2) is required for the transcriptional regulation of gp130 (glycoprotein 130), a key receptor complex component for most IL-6-type cytokines. ERK2 not only binds to the gp130 promoter and is required for full expression of the protein, but it also regulates the stability of gp130 mRNA. This function of ERK2 is not shared by ERK1 and it probably represents an entirely novel function for this prominent kinase.


Assuntos
Interleucina-6/fisiologia , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Animais , Receptor gp130 de Citocina/genética , Receptor gp130 de Citocina/metabolismo , Regulação da Expressão Gênica , Humanos , Janus Quinases/metabolismo , Sistema de Sinalização das MAP Quinases , Fatores de Transcrição STAT/metabolismo
15.
Int J Gynaecol Obstet ; 123(3): 207-12, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24112746

RESUMO

OBJECTIVE: To determine the efficacy and safety of a titrated oral misoprostol solution compared with vaginal misoprostol tablets for labor induction. METHODS: A randomized, triple-blind, multicenter clinical trial was conducted between March 2010 and June 2011. Women with a single gestation (n=200) were randomized to receive a titrated oral misoprostol solution (initial misoprostol dose 20 µg/hour; dose increased by 20 µg/hour every 6 hours up to 80 µg/hour for a maximum of 48 doses) or vaginal misoprostol tablets (25 µg of misoprostol every 6 hours for a maximum of 8 doses). Risk ratios (RR) and 95% confidence intervals (CIs) were calculated for maternal and perinatal outcomes. RESULTS: The frequencies of vaginal delivery not achieved within 12 hours (RR 0.87; 95% CI, 0.62-1.22) and within 24 hours (RR 1.11; 95% CI, 0.83-1.49) were similar in the 2 groups. No differences were found in terms of uterine hyperstimulation, unfavorable cervix at 12 and 24 hours, oxytocin augmentation, tachysystole, epidural analgesia, adverse effects, and perinatal outcome. Approximately 70% of the women preferred the oral solution. CONCLUSION: A titrated oral misoprostol solution was as effective and safe for labor induction as vaginal misoprostol tablets. ClinicalTrial.gov: NCT00 992524.


Assuntos
Trabalho de Parto Induzido/métodos , Misoprostol/administração & dosagem , Ocitócicos/administração & dosagem , Ocitocina/administração & dosagem , Administração Intravaginal , Adolescente , Adulto , Método Duplo-Cego , Feminino , Humanos , Misoprostol/efeitos adversos , Ocitócicos/efeitos adversos , Ocitocina/efeitos adversos , Preferência do Paciente , Gravidez , Resultado da Gravidez , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
16.
Am J Cancer Res ; 1(6): 806-16, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22016828

RESUMO

Despite their long recognised pivotal roles in immunological responses, Janus kinases (JAKs) and signal transducers and activators of transcription (STATs) are now seen as important players in cancer development and progression. Indeed, mutations in the JAKs are often found in myeloproliferative disorders (MPDs) and leukaemia, and the constitutive phosphorylation of STATs is a common occurrence in many solid and blood cancer cell lines and primary tumour specimens. More recently, we have also shown that JAKs likely have additional roles in promoting drug resistance in several cancer cell types. JAKs and STATs are thus molecules that may serve as useful targets in the clinic. This review will summarise studies that support this notion.

17.
PLoS One ; 6(5): e19861, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21625473

RESUMO

The development of resistance to chemotherapy is a major cause of cancer-related death. Elucidating the mechanisms of drug resistance should thus lead to novel therapeutic strategies. Fibroblast growth factor (FGF)-2 signaling induces the assembly of a multi-protein complex that provides tumor cells with the molecular machinery necessary for drug resistance. This complex, which involves protein kinase C (PKC) ε, v-raf murine sarcoma viral oncogene homolog B1 (B-RAF) and p70 S6 kinase ß (S6K2), enhances the selective translation of anti-apoptotic proteins such as B-cell leukaemia/lymphoma-2 (BCL-2) and inhibitors of apoptosis protein (IAP) family members and these are able to protect multiple cancer cell types from chemotherapy-induced cell death. The Janus kinases (JAKs) are most noted for their critical roles in mediating cytokine signaling and immune responses. Here, we show that JAKs have novel functions that support their consideration as new targets in therapies aimed at reducing drug resistance. As an example, we show that the Janus kinase TYK2 is phosphorylated downstream of FGF-2 signaling and required for the full phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. Moreover, TYK2 is necessary for the induction of key anti-apoptotic proteins, such as BCL-2 and myeloid cell leukemia sequence (MCL) 1, and for the promotion of cell survival upon FGF-2. Silencing JAK1, JAK2 or TYK2 using RNA interference (RNAi) inhibits FGF2-mediated proliferation and results in the sensitization of tumor cells to chemotherapy-induced killing. These effects are independent of activation of signal transducer and activator of transcription (STAT) 1, STAT3 and STAT5A/B, the normal targets of JAK signaling. Instead, TYK2 associates with the other kinases previously implicated in FGF-2-mediated drug resistance. In light of these findings we hypothesize that TYK2 and other JAKs are important modulators of FGF-2-driven cell survival and that inhibitors of these kinases will likely improve the effectiveness of other cancer therapies.


Assuntos
Neoplasias Ósseas/metabolismo , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos , Fator 2 de Crescimento de Fibroblastos/metabolismo , Janus Quinases/metabolismo , Osteossarcoma/metabolismo , Transdução de Sinais/efeitos dos fármacos , Antineoplásicos/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Sobrevivência Celular/efeitos dos fármacos , Fator 2 de Crescimento de Fibroblastos/antagonistas & inibidores , Fator 2 de Crescimento de Fibroblastos/genética , Humanos , Imunoprecipitação , Osteossarcoma/tratamento farmacológico , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Interferente Pequeno/genética , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT5/metabolismo , TYK2 Quinase/metabolismo , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor/metabolismo
18.
Biochim Biophys Acta ; 1816(1): 38-49, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21447371

RESUMO

Signal transducers and activators of transcription (STATs) are, as the name indicates, both signal transducers and transcription factors. STATs are activated by cytokines and some growth factors and thus control important biological processes. These include cell growth, cell differentiation, apoptosis and immune responses. Dysregulation of STATs, either due to constitutive activation or function impairment, can have, therefore, deleterious biological consequences. This review places particular emphasis on their structural organization, biological activities and regulatory mechanisms most commonly utilized by cells to control STAT-mediated signalling. STATs also play important roles in cancer and immune deficiencies and are thus being exploited as therapeutic targets.


Assuntos
Citocinas/fisiologia , Neoplasias/etiologia , Fatores de Transcrição STAT/fisiologia , Transdução de Sinais/fisiologia , Animais , Humanos , Fosforilação , Isoformas de Proteínas , Fatores de Transcrição STAT/química , Ubiquitinação
19.
Cancer Cell ; 18(5): 524-35, 2010 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-21074499

RESUMO

The JAK2V617F mutation is associated with distinct myeloproliferative neoplasms, including polycythemia vera (PV) and essential thrombocythemia (ET), but it remains unclear how it generates disparate disorders. By comparing clonally-derived mutant and wild-type cells from individual patients, we demonstrate that the transcriptional consequences of JAK2V617F are subtle, and that JAK2V617F-heterozygous erythroid cells from ET and PV patients exhibit differential interferon signaling and STAT1 phosphorylation. Increased STAT1 activity in normal CD34-positive progenitors produces an ET-like phenotype, whereas downregulation of STAT1 activity in JAK2V617F-heterozygous ET progenitors produces a PV-like phenotype. Our results illustrate the power of clonal analysis, indicate that the consequences of JAK2V617F reflect a balance between STAT5 and STAT1 activation and are relevant for other neoplasms associated with signaling pathway mutations.


Assuntos
Janus Quinase 2/genética , Transtornos Mieloproliferativos/genética , Policitemia Vera/genética , Fator de Transcrição STAT1/metabolismo , Trombocitemia Essencial/genética , Substituição de Aminoácidos , Técnicas de Cultura de Células , Diferenciação Celular/genética , Células Cultivadas , Análise por Conglomerados , Regulação para Baixo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Heterozigoto , Humanos , Interferons/metabolismo , Megacariócitos/patologia , Fenótipo , Fosforilação , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT5/genética , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais , Ativação Transcricional
20.
Mem Inst Oswaldo Cruz ; 105(4): 555-62, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20721508

RESUMO

Praziquantel chemotherapy has been the focus of the Schistosomiasis Control Program in Brazil for the past two decades. Nevertheless, information on the impact of selective chemotherapy against Schistosoma mansoni infection under the conditions confronted by the health teams in endemic municipalities remains scarce. This paper compares the spatial pattern of infection before and after treatment with either a 40 mg/kg or 60 mg/kg dose of praziquantel by determining the intensity of spatial cluster among patients at 180 and 360 days after treatment. The spatial-temporal distribution of egg-positive patients was analysed in a Geographic Information System using the kernel smoothing technique. While all patients became egg-negative after 21 days, 17.9% and 30.9% reverted to an egg-positive condition after 180 and 360 days, respectively. Both the prevalence and intensity of infection after treatment were significantly lower in the 60 mg/kg than in the 40 mg/kg treatment group. The higher intensity of the kernel in the 40 mg/kg group compared to the 60 mg/kg group, at both 180 and 360 days, reflects the higher number of reverted cases in the lower dose group. Auxiliary, preventive measures to control transmission should be integrated with chemotherapy to achieve a more enduring impact.


Assuntos
Sistemas de Informação Geográfica , Praziquantel/administração & dosagem , Esquistossomose mansoni/tratamento farmacológico , Esquistossomicidas/administração & dosagem , Adolescente , Brasil/epidemiologia , Criança , Análise por Conglomerados , Fezes/parasitologia , Feminino , Humanos , Masculino , Contagem de Ovos de Parasitas , Prevalência , Esquistossomose mansoni/epidemiologia , Adulto Jovem
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