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1.
J Lipid Res ; : 100125, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34571016

RESUMO

HDL-mediated cholesterol efflux capacity (CEC) may protect against cardiovascular disease. However, CEC assays are not standardized, hampering their application in large cohorts and comparison between studies. To improve standardization, we systematically investigated technical differences between existing protocols that influence assay performance that have not been previously addressed. CEC was measured in 96-well plates using J774A.1 macrophages labelled with BODIPY-cholesterol and incubated for four hours with 2% apolipoprotein B-depleted human serum. The time zero (t0) method, which calculates CEC using control wells, and the per-well method, which calculates CEC based on the actual content of BODIPY-cholesterol in each well, were compared in 506 samples. We showed that the per-well method had a considerably lower sample rejection rate (4.74% vs. 13.44%) and intra-assay (4.48% vs. 5.28%) and inter-assay coefficients of variation (two controls: 7.85%, 9.86% vs. 13.58%, 15.29%) compared to the t0 method. Correction for plate-to-plate differences using four controls on each plate also improved assay performance of both methods. Additionally, we observed the lysis reagent used had a significant effect. Compared to cholic acid, lysis with sodium hydroxide results in higher (p = 0.0082) and Triton X-100 in lower (p = .0028) CEC values. Furthermore, large cell seeding errors (30% variation) greatly biased CEC for both referencing methods (p < 0.0001) as measured by a resazurin assay. In conclusion, lysis reagents, cell numbers, and assay setup greatly impact the quality and reliability of CEC quantification and should be considered when this method is newly established in a laboratory.

2.
EBioMedicine ; 71: 103568, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34488018

RESUMO

BACKGROUND: Iron deficiency anaemia (IDA) is a major health concern. However, preventive iron supplementation in regions with high burden of infectious diseases resulted in an increase of infection related morbidity and mortality. METHODS: We fed male C57BL/6N mice with either an iron deficient or an iron adequate diet. Next, they received oral iron supplementation or placebo followed by intraperitoneal infection with Salmonella Typhimurium (S.Tm). FINDINGS: We found that mice with IDA had a poorer clinical outcome than mice on an iron adequate diet. Interestingly, iron supplementation of IDA mice resulted in higher bacterial burden in organs and shortened survival. Increased transferrin saturation and non-transferrin bound iron in the circulation together with low expression of ferroportin facilitated the access of the pathogen to iron and promoted bacterial growth. Anaemia, independent of iron supplementation, was correlated with reduced neutrophil counts and cytotoxic T cells. With iron supplementation, anaemia additionally correlated with increased splenic levels of the cytokine IL-10, which is suggestive for a weakened immune control to S.Tm infection. INTERPRETATION: Supplementing iron to anaemic mice worsens the clinical course of bacterial infection. This can be traced back to increased iron delivery to bacteria along with an impaired anti-microbial immune response. Our findings may have important implications for iron supplementation strategies in areas with high endemic burden of infections, putting those individuals, who potentially profit most from iron supplementation for anaemia, at the highest risk for infections. FUNDING: Financial support by the Christian Doppler Laboratory for Iron Metabolism and Anemia Research.

3.
Cells ; 10(7)2021 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-34359992

RESUMO

Arginase 1 (ARG1) is a cytosolic enzyme that cleaves L-arginine, the substrate of inducible nitric oxide synthase (iNOS), and thereby impairs the control of various intracellular pathogens. Herein, we investigated the role of ARG1 during infection with Salmonella enterica serovar Typhimurium (S.tm). To study the impact of ARG1 on Salmonella infections in vitro, bone marrow-derived macrophages (BMDM) from C57BL/6N wild-type, ARG1-deficient Tie2Cre+/-ARG1fl/fl and NRAMPG169 C57BL/6N mice were infected with S.tm. In wild-type BMDM, ARG1 was induced by S.tm and further upregulated by the addition of interleukin (IL)-4, whereas interferon-γ had an inhibitory effect. Deletion of ARG1 did not result in a reduction in bacterial numbers. In vivo, Arg1 mRNA was upregulated in the spleen, but not in the liver of C57BL/6N mice following intraperitoneal S.tm infection. The genetic deletion of ARG1 (Tie2Cre+/-ARG1fl/fl) or its pharmacological inhibition with CB-1158 neither affected the numbers of S.tm in spleen, liver and blood nor the expression of host response genes such as iNOS, IL-6 or tumour necrosis factor (TNF). Furthermore, ARG1 was dispensable for pathogen control irrespective of the presence or absence of the phagolysosomal natural resistance-associated macrophage protein 1 (NRAMP1). Thus, unlike the detrimental function of ARG1 seen during infections with other intraphagosomal microorganisms, ARG1 did not support bacterial survival in systemic salmonellosis, indicating differential roles of arginine metabolism for host immune response and microbe persistence depending on the type of pathogen.

4.
JCI Insight ; 6(13)2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34236052

RESUMO

Iron is an essential nutrient for mammals as well as for pathogens. Inflammation-driven changes in systemic and cellular iron homeostasis are central for host-mediated antimicrobial strategies. Here, we studied the role of the iron storage protein ferritin H (FTH) for the control of infections with the intracellular pathogen Salmonella enterica serovar Typhimurium by macrophages. Mice lacking FTH in the myeloid lineage (LysM-Cre+/+Fthfl/fl mice) displayed impaired iron storage capacities in the tissue leukocyte compartment, increased levels of labile iron in macrophages, and an accelerated macrophage-mediated iron turnover. While under steady-state conditions, LysM-Cre+/+Fth+/+ and LysM-Cre+/+Fthfl/fl animals showed comparable susceptibility to Salmonella infection, i.v. iron supplementation drastically shortened survival of LysM-Cre+/+Fthfl/fl mice. Mechanistically, these animals displayed increased bacterial burden, which contributed to uncontrolled triggering of NF-κB and inflammasome signaling and development of cytokine storm and death. Importantly, pharmacologic inhibition of the inflammasome and IL-1ß pathways reduced cytokine levels and mortality and partly restored infection control in iron-treated ferritin-deficient mice. These findings uncover incompletely characterized roles of ferritin and cellular iron turnover in myeloid cells in controlling bacterial spread and for modulating NF-κB and inflammasome-mediated cytokine activation, which may be of vital importance in iron-overloaded individuals suffering from severe infections and sepsis.

5.
Cell Syst ; 12(8): 780-794.e7, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34139154

RESUMO

COVID-19 is highly variable in its clinical presentation, ranging from asymptomatic infection to severe organ damage and death. We characterized the time-dependent progression of the disease in 139 COVID-19 inpatients by measuring 86 accredited diagnostic parameters, such as blood cell counts and enzyme activities, as well as untargeted plasma proteomes at 687 sampling points. We report an initial spike in a systemic inflammatory response, which is gradually alleviated and followed by a protein signature indicative of tissue repair, metabolic reconstitution, and immunomodulation. We identify prognostic marker signatures for devising risk-adapted treatment strategies and use machine learning to classify therapeutic needs. We show that the machine learning models based on the proteome are transferable to an independent cohort. Our study presents a map linking routinely used clinical diagnostic parameters to plasma proteomes and their dynamics in an infectious disease.


Assuntos
Biomarcadores/análise , COVID-19/patologia , Progressão da Doença , Proteoma/fisiologia , Fatores Etários , Contagem de Células Sanguíneas , Gasometria , Ativação Enzimática , Humanos , Inflamação/patologia , Aprendizado de Máquina , Prognóstico , Proteômica , SARS-CoV-2/imunologia
6.
Eur Respir J ; 57(4)2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33303539

RESUMO

BACKGROUND: After the 2002/2003 severe acute respiratory syndrome outbreak, 30% of survivors exhibited persisting structural pulmonary abnormalities. The long-term pulmonary sequelae of coronavirus disease 2019 (COVID-19) are yet unknown, and comprehensive clinical follow-up data are lacking. METHODS: In this prospective, multicentre, observational study, we systematically evaluated the cardiopulmonary damage in subjects recovering from COVID-19 at 60 and 100 days after confirmed diagnosis. We conducted a detailed questionnaire, clinical examination, laboratory testing, lung function analysis, echocardiography and thoracic low-dose computed tomography (CT). RESULTS: Data from 145 COVID-19 patients were evaluated, and 41% of all subjects exhibited persistent symptoms 100 days after COVID-19 onset, with dyspnoea being most frequent (36%). Accordingly, patients still displayed an impaired lung function, with a reduced diffusing capacity in 21% of the cohort being the most prominent finding. Cardiac impairment, including a reduced left ventricular function or signs of pulmonary hypertension, was only present in a minority of subjects. CT scans unveiled persisting lung pathologies in 63% of patients, mainly consisting of bilateral ground-glass opacities and/or reticulation in the lower lung lobes, without radiological signs of pulmonary fibrosis. Sequential follow-up evaluations at 60 and 100 days after COVID-19 onset demonstrated a vast improvement of symptoms and CT abnormalities over time. CONCLUSION: A relevant percentage of post-COVID-19 patients presented with persisting symptoms and lung function impairment along with radiological pulmonary abnormalities >100 days after the diagnosis of COVID-19. However, our results indicate a significant improvement in symptoms and cardiopulmonary status over time.


Assuntos
COVID-19 , Fibrose Pulmonar , Humanos , Pulmão/diagnóstico por imagem , Estudos Prospectivos , SARS-CoV-2
7.
Respir Res ; 21(1): 276, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33087116

RESUMO

BACKGROUND: Severe coronavirus disease 2019 (COVID-19) is frequently associated with hyperinflammation and hyperferritinemia. The latter is related to increased mortality in COVID-19. Still, it is not clear if iron dysmetabolism is mechanistically linked to COVID-19 pathobiology. METHODS: We herein present data from the ongoing prospective, multicentre, observational CovILD cohort study (ClinicalTrials.gov number, NCT04416100), which systematically follows up patients after COVID-19. 109 participants were evaluated 60 days after onset of first COVID-19 symptoms including clinical examination, chest computed tomography and laboratory testing. RESULTS: We investigated subjects with mild to critical COVID-19, of which the majority received hospital treatment. 60 days after disease onset, 30% of subjects still presented with iron deficiency and 9% had anemia, mostly categorized as anemia of inflammation. Anemic patients had increased levels of inflammation markers such as interleukin-6 and C-reactive protein and survived a more severe course of COVID-19. Hyperferritinemia was still present in 38% of all individuals and was more frequent in subjects with preceding severe or critical COVID-19. Analysis of the mRNA expression of peripheral blood mononuclear cells demonstrated a correlation of increased ferritin and cytokine mRNA expression in these patients. Finally, persisting hyperferritinemia was significantly associated with severe lung pathologies in computed tomography scans and a decreased performance status as compared to patients without hyperferritinemia. DISCUSSION: Alterations of iron homeostasis can persist for at least two months after the onset of COVID-19 and are closely associated with non-resolving lung pathologies and impaired physical performance. Determination of serum iron parameters may thus be a easy to access measure to monitor the resolution of COVID-19. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT04416100.


Assuntos
Infecções por Coronavirus/complicações , Infecções por Coronavirus/metabolismo , Homeostase , Ferro/metabolismo , Pneumopatias/etiologia , Pneumopatias/metabolismo , Pneumonia Viral/complicações , Pneumonia Viral/metabolismo , Adulto , Idoso , Anemia/etiologia , Proteína C-Reativa/análise , COVID-19 , Estudos de Coortes , Infecções por Coronavirus/fisiopatologia , Feminino , Ferritinas/sangue , Seguimentos , Humanos , Inflamação/etiologia , Inflamação/metabolismo , Interleucina-6/sangue , Pneumopatias/fisiopatologia , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo , Pandemias , Pneumonia Viral/fisiopatologia , Estudos Prospectivos , Tomografia Computadorizada por Raios X
8.
Cell ; 181(6): 1246-1262.e22, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32442405

RESUMO

There is considerable inter-individual variability in susceptibility to weight gain despite an equally obesogenic environment in large parts of the world. Whereas many studies have focused on identifying the genetic susceptibility to obesity, we performed a GWAS on metabolically healthy thin individuals (lowest 6th percentile of the population-wide BMI spectrum) in a uniquely phenotyped Estonian cohort. We discovered anaplastic lymphoma kinase (ALK) as a candidate thinness gene. In Drosophila, RNAi mediated knockdown of Alk led to decreased triglyceride levels. In mice, genetic deletion of Alk resulted in thin animals with marked resistance to diet- and leptin-mutation-induced obesity. Mechanistically, we found that ALK expression in hypothalamic neurons controls energy expenditure via sympathetic control of adipose tissue lipolysis. Our genetic and mechanistic experiments identify ALK as a thinness gene, which is involved in the resistance to weight gain.


Assuntos
Quinase do Linfoma Anaplásico/genética , Magreza/genética , Tecido Adiposo/metabolismo , Adulto , Animais , Linhagem Celular , Estudos de Coortes , Drosophila/genética , Estônia , Feminino , Humanos , Leptina/genética , Lipólise/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/genética , Interferência de RNA/fisiologia , Adulto Jovem
9.
Blood ; 136(9): 1080-1090, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32438400

RESUMO

Recombinant erythropoietin (EPO) and iron substitution are a standard of care for treatment of anemias associated with chronic inflammation, including anemia of chronic kidney disease. A black box warning for EPO therapy and concerns about negative side effects related to high-dose iron supplementation as well as the significant proportion of patients becoming EPO resistant over time explains the medical need to define novel strategies to ameliorate anemia of chronic disease (ACD). As hepcidin is central to the iron-restrictive phenotype in ACD, therapeutic approaches targeting hepcidin were recently developed. We herein report the therapeutic effects of a fully human anti-BMP6 antibody (KY1070) either as monotherapy or in combination with Darbepoetin alfa on iron metabolism and anemia resolution in 2 different, well-established, and clinically relevant rodent models of ACD. In addition to counteracting hepcidin-driven iron limitation for erythropoiesis, we found that the combination of KY1070 and recombinant human EPO improved the erythroid response compared with either monotherapy in a qualitative and quantitative manner. Consequently, the combination of KY1070 and Darbepoetin alfa resulted in an EPO-sparing effect. Moreover, we found that suppression of hepcidin via KY1070 modulates ferroportin expression on erythroid precursor cells, thereby lowering potentially toxic-free intracellular iron levels and by accelerating erythroid output as reflected by increased maturation of erythrocyte progenitors. In summary, we conclude that treatment of ACD, as a highly complex disease, becomes more effective by a multifactorial therapeutic approach upon mobilization of endogenous iron deposits and stimulation of erythropoiesis.


Assuntos
Anemia/terapia , Anticorpos Monoclonais/uso terapêutico , Proteína Morfogenética Óssea 6/antagonistas & inibidores , Darbepoetina alfa/uso terapêutico , Anemia/tratamento farmacológico , Anemia/etiologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Artrite/induzido quimicamente , Artrite/complicações , Medula Óssea/metabolismo , Proteína Morfogenética Óssea 6/imunologia , Proteínas de Transporte de Cátions/metabolismo , Citocinas/sangue , Darbepoetina alfa/administração & dosagem , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Eritropoetina/farmacologia , Eritropoetina/uso terapêutico , Células Hep G2 , Humanos , Ferro/metabolismo , Camundongos , Proteínas Musculares/sangue , Polissacarídeos Bacterianos/toxicidade , Distribuição Aleatória , Proteínas Recombinantes/imunologia , Insuficiência Renal Crônica/complicações
10.
Eur Heart J ; 41(40): 3949-3959, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-32227235

RESUMO

AIMS: Imbalances of iron metabolism have been linked to the development of atherosclerosis. However, subjects with hereditary haemochromatosis have a lower prevalence of cardiovascular disease. The aim of our study was to understand the underlying mechanisms by combining data from genome-wide association study analyses in humans, CRISPR/Cas9 genome editing, and loss-of-function studies in mice. METHODS AND RESULTS: Our analysis of the Global Lipids Genetics Consortium (GLGC) dataset revealed that single nucleotide polymorphisms (SNPs) in the haemochromatosis gene HFE associate with reduced low-density lipoprotein cholesterol (LDL-C) in human plasma. The LDL-C lowering effect could be phenocopied in dyslipidaemic ApoE-/- mice lacking Hfe, which translated into reduced atherosclerosis burden. Mechanistically, we identified HFE as a negative regulator of LDL receptor expression in hepatocytes. Moreover, we uncovered liver-resident Kupffer cells (KCs) as central players in cholesterol homeostasis as they were found to acquire and transfer LDL-derived cholesterol to hepatocytes in an Abca1-dependent fashion, which is controlled by iron availability. CONCLUSION: Our results disentangle novel regulatory interactions between iron metabolism, KC biology and cholesterol homeostasis which are promising targets for treating dyslipidaemia but also provide a mechanistic explanation for reduced cardiovascular morbidity in subjects with haemochromatosis.


Assuntos
Aterosclerose , Proteína da Hemocromatose , Hemocromatose , Animais , Aterosclerose/genética , LDL-Colesterol , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Estudo de Associação Genômica Ampla , Hemocromatose/genética , Homeostase , Humanos , Macrófagos do Fígado , Camundongos , Receptores de LDL
12.
Nat Commun ; 11(1): 1775, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286299

RESUMO

The increased incidence of inflammatory bowel disease (IBD) has become a global phenomenon that could be related to adoption of a Western life-style. Westernization of dietary habits is partly characterized by enrichment with the ω-6 polyunsaturated fatty acid (PUFA) arachidonic acid (AA), which entails risk for developing IBD. Glutathione peroxidase 4 (GPX4) protects against lipid peroxidation (LPO) and cell death termed ferroptosis. We report that small intestinal epithelial cells (IECs) in Crohn's disease (CD) exhibit impaired GPX4 activity and signs of LPO. PUFAs and specifically AA trigger a cytokine response of IECs which is restricted by GPX4. While GPX4 does not control AA metabolism, cytokine production is governed by similar mechanisms as ferroptosis. A PUFA-enriched Western diet triggers focal granuloma-like neutrophilic enteritis in mice that lack one allele of Gpx4 in IECs. Our study identifies dietary PUFAs as a trigger of GPX4-restricted mucosal inflammation phenocopying aspects of human CD.


Assuntos
Doença de Crohn/metabolismo , Gorduras na Dieta/efeitos adversos , Enterite/metabolismo , Ácidos Graxos Insaturados/metabolismo , Inflamação/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Adulto , Animais , Morte Celular/genética , Morte Celular/fisiologia , Doença de Crohn/genética , Enterite/etiologia , Enterite/genética , Ácidos Graxos Insaturados/genética , Feminino , Glutationa Peroxidase/metabolismo , Humanos , Inflamação/genética , Peroxidação de Lipídeos/genética , Peroxidação de Lipídeos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética
13.
Microb Cell ; 6(12): 531-543, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31832425

RESUMO

Iron is an essential nutrient for immune cells and microbes, therefore the control of its homeostasis plays a decisive role for infections. Moreover, iron affects metabolic pathways by modulating the translational expression of the key tricarboxylic acid cycle (TCA) enzyme mitochondrial aconitase and the energy formation by mitochondria. Recent data provide evidence for metabolic re-programming of immune cells including macrophages during infection which is centrally controlled by mTOR. We herein studied the effects of iron perturbations on metabolic profiles in macrophages upon infection with the intracellular bacterium Salmonella enterica serovar Typhimurium and analysed for a link to the mTOR pathway. Infection of the murine macrophage cell line RAW264.7 with Salmonella resulted in the induction of mTOR activity, anaerobic glycolysis and inhibition of the TCA activity as reflected by reduced pyruvate and increased lactate levels. In contrast, iron supplementation to macrophages not only affected the mRNA expression of TCA and glycolytic enzymes but also resulted in metabolic reprogramming with increased pyruvate accumulation and reduced lactate levels apart from modulating the concentrations of several other metabolites. While mTOR slightly affected cellular iron homeostasis in infected macrophages, mTOR inhibition by rapamycin resulted in a significant growth promotion of bacteria. Importantly, iron further increased bacterial numbers in rapamycin treated macrophages, however, the metabolic profiles induced by iron in the presence or absence of mTOR activity differed in several aspects. Our data indicate, that iron not only serves as a bacterial nutrient but also acts as a metabolic modulator of the TCA cycle, partly reversing the Warburg effect and resulting in a pathogen friendly nutritional environment.

15.
Nutrients ; 9(10)2017 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-28984832

RESUMO

The beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs) on cardiovascular disease have been studied extensively. However, it remains unclear to what extent n-3 PUFAs may impact Reverse Cholesterol Transport (RCT). RCT describes a mechanism by which excess cholesterol from peripheral tissues is transported to the liver for hepatobiliary excretion, thereby inhibiting foam cell formation and the development of atherosclerosis. The aim of this review is to summarize the literature and to provide an updated overview of the effects of n-3 PUFAs on key players in RCT, including apoliprotein AI (apoA-I), ATP-binding cassette transporter A1 (ABCA1), ABCG1, apoE, scavenger receptor class B type I (SR-BI), cholesteryl ester transfer protein (CETP), low-density lipoprotein receptor (LDLr), cholesterol 7 alpha-hydroxylase (CYP7A1) and ABCG5/G8. Based on current knowledge, we conclude that n-3 PUFAs may beneficially affect RCT, mainly by influencing high-density lipoprotein (HDL) remodeling and by promoting hepatobiliary sterol excretion.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Colesterol/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Células Espumosas/efeitos dos fármacos , Eliminação Hepatobiliar/efeitos dos fármacos , Fígado/efeitos dos fármacos , Animais , Transporte Biológico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/metabolismo , Células Espumosas/metabolismo , Humanos , Fígado/metabolismo , Fatores de Risco
16.
Infect Immun ; 85(12)2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28874447

RESUMO

Zinc sequestration by macrophages is considered a crucial host defense strategy against infection by the intracellular bacterium Salmonella enterica serovar Typhimurium. However, the underlying mechanisms remain elusive. In this study, we found that zinc favors pathogen survival within macrophages. Salmonella-hosting macrophages contained higher free zinc levels than did uninfected macrophages and cells that successfully eliminated bacteria, which was paralleled by the impaired production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in bacterium-harboring cells. A profound, zinc-mediated inhibition of NF-κB p65 transcriptional activity affecting the expression of the ROS- and RNS-forming enzymes phos47 and inducible nitric oxide synthase (iNOS) provided a mechanistic explanation for this phenomenon. Macrophages responded to infection by enhancing the expression of zinc-scavenging metallothioneins 1 and 2, whose genetic deletion caused increased free zinc levels, reduced ROS and RNS production, and increased the survival of Salmonella Our data suggest that Salmonella invasion of macrophages results in a bacterium-driven increase in the intracellular zinc level, which weakens antimicrobial defense and the ability of macrophages to eradicate the pathogen. Thus, limitation of cytoplasmic zinc levels may help to control infection by intracellular bacteria.


Assuntos
Macrófagos/imunologia , Salmonella typhimurium/imunologia , Fator de Transcrição RelA/antagonistas & inibidores , Zinco/metabolismo , Animais , Linhagem Celular , Citoplasma/química , Macrófagos/microbiologia , Metalotioneína/genética , Camundongos , Viabilidade Microbiana/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7 , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Salmonella typhimurium/metabolismo , Transdução de Sinais , Fator de Transcrição RelA/genética
17.
Nat Commun ; 6: 6891, 2015 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-25922916

RESUMO

Cell death on extended mitotic arrest is considered arguably most critical for the efficacy of microtubule-targeting agents (MTAs) in anticancer therapy. While the molecular machinery controlling mitotic arrest on MTA treatment, the spindle assembly checkpoint (SAC), appears well defined, the molecular components executing cell death, as well as factors connecting both networks remain poorly understood. Here we conduct a mini screen exploring systematically the contribution of individual BCL2 family proteins at single cell resolution to death on extended mitotic arrest, and demonstrate that the mitotic phosphorylation of BCL2 and BCLX represent a priming event for apoptosis that is ultimately triggered by NOXA-dependent MCL1 degradation, enabling BIM-dependent cell death. Our findings provide a comprehensive model for the initiation of apoptosis in cells stalled in mitosis and provide a molecular basis for the increased efficacy of combinatorial treatment of cancer cells using MTAs and BH3 mimetics.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose , Proteínas de Membrana/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Moduladores de Tubulina/farmacologia , Proteína 11 Semelhante a Bcl-2 , Células HeLa , Humanos , Mitocôndrias/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial , Mitose/efeitos dos fármacos
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