RESUMO
RATIONALE: Ca2+-induced Ca2+ release (CICR) in normal hearts requires close approximation of L-type calcium channels (LTCCs) within the transverse tubules (T-tubules) and RyR (ryanodine receptors) within the junctional sarcoplasmic reticulum. CICR is disrupted in cardiac hypertrophy and heart failure, which is associated with loss of T-tubules and disruption of cardiac dyads. In these conditions, LTCCs are redistributed from the T-tubules to disrupt CICR. The molecular mechanism responsible for LTCCs recruitment to and from the T-tubules is not well known. JPH (junctophilin) 2 enables close association between T-tubules and the junctional sarcoplasmic reticulum to ensure efficient CICR. JPH2 has a so-called joining region that is located near domains that interact with T-tubular plasma membrane, where LTCCs are housed. The idea that this joining region directly interacts with LTCCs and contributes to LTCC recruitment to T-tubules is unknown. OBJECTIVE: To determine if the joining region in JPH2 recruits LTCCs to T-tubules through direct molecular interaction in cardiomyocytes to enable efficient CICR. METHODS AND RESULTS: Modified abundance of JPH2 and redistribution of LTCC were studied in left ventricular hypertrophy in vivo and in cultured adult feline and rat ventricular myocytes. Protein-protein interaction studies showed that the joining region in JPH2 interacts with LTCC-α1C subunit and causes LTCCs distribution to the dyads, where they colocalize with RyRs. A JPH2 with induced mutations in the joining region (mutPG1JPH2) caused T-tubule remodeling and dyad loss, showing that an interaction between LTCC and JPH2 is crucial for T-tubule stabilization. mutPG1JPH2 caused asynchronous Ca2+-release with impaired excitation-contraction coupling after ß-adrenergic stimulation. The disturbed Ca2+ regulation in mutPG1JPH2 overexpressing myocytes caused calcium/calmodulin-dependent kinase II activation and altered myocyte bioenergetics. CONCLUSIONS: The interaction between LTCC and the joining region in JPH2 facilitates dyad assembly and maintains normal CICR in cardiomyocytes.
Assuntos
Canais de Cálcio Tipo L/metabolismo , Sinalização do Cálcio , Cálcio/metabolismo , Hipertrofia Ventricular Esquerda/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Musculares/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Canais de Cálcio Tipo L/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Gatos , Células Cultivadas , Modelos Animais de Doenças , Acoplamento Excitação-Contração , Humanos , Hipertrofia Ventricular Esquerda/patologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Cinética , Masculino , Proteínas de Membrana/genética , Mitocôndrias Cardíacas/metabolismo , Mitocôndrias Cardíacas/patologia , Proteínas Musculares/genética , Mutação , Miócitos Cardíacos/patologia , Biogênese de Organelas , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Ratos Sprague-Dawley , Canal de Liberação de Cálcio do Receptor de RianodinaRESUMO
BACKGROUND: Fibrosis and extracellular matrix remodeling are mediated by resident cardiac fibroblasts (CFs). In response to injury, fibroblasts activate, differentiating into specialized synthetic and contractile myofibroblasts producing copious extracellular matrix proteins (e.g., collagens). Myofibroblast persistence in chronic diseases, such as HF, leads to progressive cardiac dysfunction and maladaptive remodeling. We recently reported that an increase in αKG (alpha-ketoglutarate) bioavailability, which contributes to enhanced αKG-dependent lysine demethylase activity and chromatin remodeling, is required for myofibroblast formation. Therefore, we aimed to determine the substrates and metabolic pathways contributing to αKG biosynthesis and their requirement for myofibroblast formation. METHODS: Stable isotope metabolomics identified glutaminolysis as a key metabolic pathway required for αKG biosynthesis and myofibroblast formation, therefore we tested the effects of pharmacologic inhibition (CB-839) or genetic deletion of glutaminase (Gls1-/-) on myofibroblast formation in both murine and human cardiac fibroblasts. We employed immunofluorescence staining, functional gel contraction, western blotting, and bioenergetic assays to determine the myofibroblast phenotype. RESULTS: Carbon tracing indicated enhanced glutaminolysis mediating increased αKG abundance. Pharmacological and genetic inhibition of glutaminolysis prevented myofibroblast formation indicated by a reduction in αSMA+ cells, collagen gel contraction, collagen abundance, and the bioenergetic response. Inhibition of glutaminolysis also prevented TGFß-mediated histone demethylation and supplementation with cell-permeable αKG rescued the myofibroblast phenotype. Importantly, inhibition of glutaminolysis was sufficient to prevent myofibroblast formation in CFs isolated from the human failing heart. CONCLUSIONS: These results define glutaminolysis as necessary for myofibroblast formation and persistence, providing substantial rationale to evaluate several new therapeutic targets to treat cardiac fibrosis.
Assuntos
Miofibroblastos , Humanos , Camundongos , Animais , Miofibroblastos/metabolismo , Glutamina/metabolismo , Fibroblastos/metabolismo , Colágeno/metabolismo , Células CultivadasRESUMO
Cardiac fibrosis is mediated by the activation of resident cardiac fibroblasts, which differentiate into myofibroblasts in response to injury or stress. Although myofibroblast formation is a physiological response to acute injury, such as myocardial infarction, myofibroblast persistence, as occurs in heart failure, contributes to maladaptive remodeling and progressive functional decline. Although traditional pathways of activation, such as TGFß (transforming growth factor ß) and AngII (angiotensin II), have been well characterized, less understood are the alterations in mitochondrial function and cellular metabolism that are necessary to initiate and sustain myofibroblast formation and function. In this review, we highlight recent reports detailing the mitochondrial and metabolic mechanisms that contribute to myofibroblast differentiation, persistence, and function with the hope of identifying novel therapeutic targets to treat, and potentially reverse, tissue organ fibrosis.
Assuntos
Diferenciação Celular , Metabolismo Energético , Cardiopatias/metabolismo , Mitocôndrias Cardíacas/metabolismo , Miofibroblastos/metabolismo , Animais , Sinalização do Cálcio , Fibrose , Cardiopatias/patologia , Humanos , Mitocôndrias Cardíacas/patologia , Miofibroblastos/patologiaRESUMO
Metabolic pathways integrate to support tissue homeostasis and to prompt changes in cell phenotype. In particular, the heart consumes relatively large amounts of substrate not only to regenerate ATP for contraction but also to sustain biosynthetic reactions for replacement of cellular building blocks. Metabolic pathways also control intracellular redox state, and metabolic intermediates and end products provide signals that prompt changes in enzymatic activity and gene expression. Mounting evidence suggests that the changes in cardiac metabolism that occur during development, exercise, and pregnancy as well as with pathological stress (eg, myocardial infarction, pressure overload) are causative in cardiac remodeling. Metabolism-mediated changes in gene expression, metabolite signaling, and the channeling of glucose-derived carbon toward anabolic pathways seem critical for physiological growth of the heart, and metabolic inefficiency and loss of coordinated anabolic activity are emerging as proximal causes of pathological remodeling. This review integrates knowledge of different forms of cardiac remodeling to develop general models of how relationships between catabolic and anabolic glucose metabolism may fortify cardiac health or promote (mal)adaptive myocardial remodeling. Adoption of conceptual frameworks based in relational biology may enable further understanding of how metabolism regulates cardiac structure and function.
Assuntos
Cardiomegalia/metabolismo , Exercício Físico/fisiologia , Coração/crescimento & desenvolvimento , Miocárdio/metabolismo , Remodelação Ventricular/fisiologia , Adaptação Fisiológica , Trifosfato de Adenosina/biossíntese , Cardiomegalia/etiologia , Cardiomegalia Induzida por Exercícios/fisiologia , Diabetes Mellitus/metabolismo , Metabolismo Energético , Feminino , Coração Fetal/metabolismo , Expressão Gênica , Glucose/metabolismo , Insuficiência Cardíaca/metabolismo , Humanos , Gravidez , Transdução de SinaisRESUMO
BACKGROUND: Exercise promotes metabolic remodeling in the heart, which is associated with physiological cardiac growth; however, it is not known whether or how physical activity-induced changes in cardiac metabolism cause myocardial remodeling. In this study, we tested whether exercise-mediated changes in cardiomyocyte glucose metabolism are important for physiological cardiac growth. METHODS: We used radiometric, immunologic, metabolomic, and biochemical assays to measure changes in myocardial glucose metabolism in mice subjected to acute and chronic treadmill exercise. To assess the relevance of changes in glycolytic activity, we determined how cardiac-specific expression of mutant forms of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase affect cardiac structure, function, metabolism, and gene programs relevant to cardiac remodeling. Metabolomic and transcriptomic screenings were used to identify metabolic pathways and gene sets regulated by glycolytic activity in the heart. RESULTS: Exercise acutely decreased glucose utilization via glycolysis by modulating circulating substrates and reducing phosphofructokinase activity; however, in the recovered state following exercise adaptation, there was an increase in myocardial phosphofructokinase activity and glycolysis. In mice, cardiac-specific expression of a kinase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase transgene (GlycoLo mice) lowered glycolytic rate and regulated the expression of genes known to promote cardiac growth. Hearts of GlycoLo mice had larger myocytes, enhanced cardiac function, and higher capillary-to-myocyte ratios. Expression of phosphatase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase in the heart (GlycoHi mice) increased glucose utilization and promoted a more pathological form of hypertrophy devoid of transcriptional activation of the physiological cardiac growth program. Modulation of phosphofructokinase activity was sufficient to regulate the glucose-fatty acid cycle in the heart; however, metabolic inflexibility caused by invariantly low or high phosphofructokinase activity caused modest mitochondrial damage. Transcriptomic analyses showed that glycolysis regulates the expression of key genes involved in cardiac metabolism and remodeling. CONCLUSIONS: Exercise-induced decreases in glycolytic activity stimulate physiological cardiac remodeling, and metabolic flexibility is important for maintaining mitochondrial health in the heart.
Assuntos
Glucose/metabolismo , Glicólise , Coração/crescimento & desenvolvimento , Miocárdio/metabolismo , Esforço Físico , Remodelação Ventricular , Adaptação Fisiológica , Animais , Cardiomegalia Induzida por Exercícios , Tolerância ao Exercício , Ácidos Graxos/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica , Genótipo , Glicólise/genética , Preparação de Coração Isolado , Masculino , Metabolômica/métodos , Camundongos Transgênicos , Mitocôndrias Cardíacas/metabolismo , Mitocôndrias Cardíacas/ultraestrutura , Mutação , Miocárdio/ultraestrutura , Fenótipo , Fosfofrutoquinase-2/genética , Fosfofrutoquinase-2/metabolismo , Corrida , Fatores de Tempo , TranscriptomaRESUMO
Although ancillary pathways of glucose metabolism are critical for synthesizing cellular building blocks and modulating stress responses, how they are regulated remains unclear. In the present study, we used radiometric glycolysis assays, [13C6]-glucose isotope tracing, and extracellular flux analysis to understand how phosphofructokinase (PFK)-mediated changes in glycolysis regulate glucose carbon partitioning into catabolic and anabolic pathways. Expression of kinase-deficient or phosphatase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase in rat neonatal cardiomyocytes co-ordinately regulated glycolytic rate and lactate production. Nevertheless, in all groups, >40% of glucose consumed by the cells was unaccounted for via catabolism to pyruvate, which suggests entry of glucose carbons into ancillary pathways branching from metabolites formed in the preparatory phase of glycolysis. Analysis of 13C fractional enrichment patterns suggests that PFK activity regulates glucose carbon incorporation directly into the ribose and the glycerol moieties of purines and phospholipids, respectively. Pyrimidines, UDP-N-acetylhexosamine, and the fatty acyl chains of phosphatidylinositol and triglycerides showed lower 13C incorporation under conditions of high PFK activity; the isotopologue 13C enrichment pattern of each metabolite indicated limitations in mitochondria-engendered aspartate, acetyl CoA and fatty acids. Consistent with this notion, high glycolytic rate diminished mitochondrial activity and the coupling of glycolysis to glucose oxidation. These findings suggest that a major portion of intracellular glucose in cardiac myocytes is apportioned for ancillary biosynthetic reactions and that PFK co-ordinates the activities of the pentose phosphate, hexosamine biosynthetic, and glycerolipid synthesis pathways by directly modulating glycolytic intermediate entry into auxiliary glucose metabolism pathways and by indirectly regulating mitochondrial cataplerosis.
Assuntos
Glucose/metabolismo , Glicólise , Mitocôndrias Musculares/metabolismo , Miócitos Cardíacos/metabolismo , Via de Pentose Fosfato , Fosfofrutoquinase-1 Hepática/metabolismo , Substituição de Aminoácidos , Animais , Animais Recém-Nascidos , Isótopos de Carbono , Células Cultivadas , Meios de Cultura Livres de Soro , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Hexosaminas/metabolismo , Ácido Láctico/metabolismo , Mitocôndrias Musculares/enzimologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/enzimologia , Oligopeptídeos/genética , Oligopeptídeos/metabolismo , Fosfofrutoquinase-1 Hepática/genética , Mutação Puntual , Pirimidinas/metabolismo , Ácido Pirúvico/metabolismo , Ratos Sprague-Dawley , Proteínas Recombinantes de Fusão/metabolismo , Difosfato de Uridina/análogos & derivados , Difosfato de Uridina/metabolismoRESUMO
Type 2 diabetes is associated with increased mortality and progression to heart failure. Recent studies suggest that diabetes also impairs reparative responses after cell therapy. In this study, we examined potential mechanisms by which diabetes affects cardiac progenitor cells (CPCs). CPCs isolated from the diabetic heart showed diminished proliferation, a propensity for cell death, and a pro-adipogenic phenotype. The diabetic CPCs were insulin-resistant, and they showed higher energetic reliance on glycolysis, which was associated with up-regulation of the pro-glycolytic enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3). In WT CPCs, expression of a mutant form of PFKFB, which mimics PFKFB3 activity and increases glycolytic rate, was sufficient to phenocopy the mitochondrial and proliferative deficiencies found in diabetic cells. Consistent with activation of phosphofructokinase in diabetic cells, stable isotope carbon tracing in diabetic CPCs showed dysregulation of the pentose phosphate and glycero(phospho)lipid synthesis pathways. We describe diabetes-induced dysregulation of carbon partitioning using stable isotope metabolomics-based coupling quotients, which relate relative flux values between metabolic pathways. These findings suggest that diabetes causes an imbalance in glucose carbon allocation by uncoupling biosynthetic pathway activity, which could diminish the efficacy of CPCs for myocardial repair.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Glicólise , Mioblastos Cardíacos/metabolismo , Fosfofrutoquinase-2/biossíntese , Animais , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patologia , Regulação Enzimológica da Expressão Gênica , Glucose/genética , Masculino , Camundongos , Mioblastos Cardíacos/patologia , Fosfofrutoquinase-2/genética , Regulação para CimaRESUMO
We report a concise, enantio- and diastereoselective route to novel nonsymmetrically substituted N-protected ß,ß-diaryl-α-amino acids and esters, through the asymmetric hydrogenation of tetrasubstituted olefins, some of the most challenging examples in the field. Stereoselective generation of an E- or Z-enol tosylate, when combined with stereoretentive Suzuki-Miyaura cross-coupling and enantioselective hydrogenation catalyzed by (NBD)2RhBF4 and a Josiphos ligand, allows for full control over the two vicinal stereogenic centers. High yields and excellent enantioselectivities (up to 99% ee) were obtained for a variety of N-acetyl, N-methoxycarbonyl, and N-Boc ß,ß-diaryldehydroamino acids, containing a diverse and previously unreported series of heterocyclic and aryl substituted groups (24 examples) and allowing access to all four stereoisomers of these valuable building blocks.
Assuntos
Aminoácidos/química , Aminoácidos/síntese química , Catálise , Técnicas de Química Sintética , Hidrogenação , Modelos Moleculares , Conformação Molecular , Estereoisomerismo , Especificidade por SubstratoRESUMO
Adipose tissue metabolism is a critical regulator of adiposity and whole body energy expenditure; however, metabolic changes that occur in white adipose tissue (WAT) with obesity remain unclear. The purpose of this study was to understand the metabolic and bioenergetic changes occurring in WAT with obesity. Wild-type (C57BL/6J) mice fed a high-fat diet (HFD) showed significant increases in whole body adiposity, had significantly lower VÌ(O2), VÌ(CO2), and respiratory exchange ratios, and demonstrated worsened glucose and insulin tolerance compared with low-fat-fed mice. Metabolomic analysis of WAT showed marked changes in lipid, amino acid, carbohydrate, nucleotide, and energy metabolism. Tissue levels of succinate and malate were elevated, and metabolites that could enter the Krebs cycle via anaplerosis were mostly diminished in high-fat-fed mice, suggesting altered mitochondrial metabolism. Despite no change in basal oxygen consumption or mitochondrial DNA abundance, citrate synthase activity was decreased by more than 50%, and responses to FCCP were increased in WAT from mice fed a high-fat diet. Moreover, Pgc1a was downregulated and Cox7a1 upregulated after 6 wk of HFD. After 12 wk of high-fat diet, the abundance of several proteins in the mitochondrial respiratory chain or matrix was diminished. These changes were accompanied by increased Parkin and Pink1, decreased p62 and LC3-I, and ultrastructural changes suggestive of autophagy and mitochondrial remodeling. These studies demonstrate coordinated restructuring of metabolism and autophagy that could contribute to the hypertrophy and whitening of adipose tissue in obesity.
Assuntos
Gordura Abdominal/metabolismo , Adiposidade , Autofagia , Metabolismo Energético , Regulação Enzimológica da Expressão Gênica , Dinâmica Mitocondrial , Obesidade/metabolismo , Gordura Abdominal/patologia , Gordura Abdominal/ultraestrutura , Animais , Tamanho Celular , Citrato (si)-Sintase/metabolismo , Ciclo do Ácido Cítrico , Dieta Hiperlipídica/efeitos adversos , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Hipertrofia , Metabolismo dos Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/etiologia , Obesidade/patologia , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
IMPORTANCE: The yeast C. albicans exhibits metabolic flexibility for adaptability to host niches with varying availability of nutrients including essential metals like iron. For example, blood is iron deplete, while the oral cavity and the intestinal lumen are considered iron replete. We show here that C. albicans can tolerate very high levels of environmental iron, despite an increase in high iron-induced reactive oxygen species (ROS) that it mitigates with the help of a unique oxidase, known as alternative oxidase (AOX). High iron induces AOX1/2 that limits mitochondrial accumulation of ROS. Genetic elimination of AOX1/2 resulted in diminished virulence during oropharyngeal candidiasis in high iron mice. Since human mitochondria lack AOX protein, it represents a unique target for treatment of fungal infections.
Assuntos
Candida albicans , Oxirredutases , Humanos , Animais , Camundongos , Candida albicans/genética , Candida albicans/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Ferro/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismoRESUMO
Mitochondrial supercomplexes are observed in mammalian tissues with high energy demand and may influence metabolism and redox signaling. Nevertheless, the mechanisms that regulate supercomplex abundance remain unclear. In this study, we examined the composition of supercomplexes derived from murine cardiac mitochondria and determined how their abundance changes with substrate provision or by genetically induced changes to the cardiac glucose-fatty acid cycle. Protein complexes from digitonin-solubilized cardiac mitochondria were resolved by blue-native polyacrylamide gel electrophoresis and were identified by mass spectrometry and immunoblotting to contain constituents of Complexes I, III, IV, and V as well as accessory proteins involved in supercomplex assembly and stability, cristae architecture, carbohydrate and fat oxidation, and oxidant detoxification. Respiratory analysis of high molecular mass supercomplexes confirmed the presence of intact respirasomes, capable of transferring electrons from NADH to O2. Provision of respiratory substrates to isolated mitochondria augmented supercomplex abundance, with fatty acyl substrate (octanoylcarnitine) promoting higher supercomplex abundance than carbohydrate-derived substrate (pyruvate). Mitochondria isolated from transgenic hearts that express kinase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (GlycoLo), which decreases glucose utilization and increases reliance on fatty acid oxidation for energy, had higher mitochondrial supercomplex abundance and activity compared with mitochondria from wild-type or phosphatase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-expressing hearts (GlycoHi), the latter of which encourages reliance on glucose catabolism for energy. These findings indicate that high energetic reliance on fatty acid catabolism bolsters levels of mitochondrial supercomplexes, supporting the idea that the energetic state of the heart is regulatory factor in supercomplex assembly or stability.
Assuntos
Coração , Fosfofrutoquinase-2 , Camundongos , Animais , Fosfofrutoquinase-2/metabolismo , Mitocôndrias Cardíacas/metabolismo , Glucose/metabolismo , Ácidos Graxos/metabolismo , Mamíferos/metabolismoRESUMO
Rationale: Cardiovascular disease accounts for one-third of deaths in patients with chronic obstructive pulmonary disease (COPD). Better control of cardiovascular risk factors in primary care could improve outcomes. Objectives: To define the prevalence, monitoring, treatment, and control of risk factors in patients with COPD. Methods: Repeated cross-sectional analysis of primary care electronic medical records for all patients with COPD in the Canadian Primary Care Sentinel Surveillance Network from 2013 to 2018 (n = 32,695 in 2018). A control group was matched 1:1 for age, sex, and rural residence (n = 32,638 in 2018). Five risk factors were defined using validated definitions including laboratory results: hypertension, dyslipidemia, diabetes, obesity, and smoking. Results: All risk factors were more common in patients with COPD compared with matched control subjects, including hypertension (52.3% vs. 44.9%), dyslipidemia (62.0% vs. 57.8%), diabetes (25.0% vs. 20.2%), obesity (40.8% vs. 36.8%), and smoking (40.9% vs. 11.4%), respectively. The mean Framingham risk score was 20.6% versus 18.6%, with 53.8% of patients with COPD being high risk (⩾20%). Monitoring of risk factors within the last year in patients with COPD in 2018 was suboptimal: 71.8% hypertension, 39.4% dyslipidemia, 74.5% diabetes, 52.3% obesity. Smoking status was infrequently recorded in the electronic record. In those monitored, guideline recommended targets were achieved in 60.8%, 46.6%, 57.4%, 10.6% and 12.0% for each risk factor. Cardiovascular therapies including angiotensin-converting enzyme inhibitors (69%), statins (69%), and smoking cessation therapies (27%) were underused. Conclusions: In patients with COPD, major cardiovascular risk factors are common, yet inadequately monitored, undertreated, and poorly controlled. Strategies are needed to improve comprehensive risk factor management proven to reduce cardiovascular morbidity and mortality.
Assuntos
Doenças Cardiovasculares , Dislipidemias , Hipertensão , Doença Pulmonar Obstrutiva Crônica , Canadá/epidemiologia , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Estudos Transversais , Fatores de Risco de Doenças Cardíacas , Humanos , Hipertensão/epidemiologia , Obesidade/complicações , Obesidade/epidemiologia , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Fatores de RiscoRESUMO
BACKGROUND: Heart failure (HF) poses a substantial global health burden, particularly in patients with chronic obstructive pulmonary disease (COPD). The objective of this study was to validate an electronic medical record-based definition of HF in patients with COPD in primary care practices in the province of British Columbia, Canada. METHODS: We conducted a cross-sectional retrospective chart review from Sept. 1, 2018, to Dec. 31, 2018, for a cohort of patients from primary care practices in BC whose physicians were recruited through the BC node of the Canadian Primary Care Sentinel Surveillance Network. Heart failure case definitions were developed by combining diagnostic codes, medication information and laboratory values available in primary care electronic medical records. These were compared with HF diagnoses identified through detailed chart review as the gold standard. Sensitivity, specificity, negative (NPV) and positive predictive values (PPV) were calculated for each definition. RESULTS: Charts of 311 patients with COPD were reviewed, of whom 72 (23.2%) had HF. Five categories of definitions were constructed, all of which had appropriate sensitivity, specificity and NPV. The optimal case definition consisted of 1 HF billing code or a specific combination of medications for HF. This definition had an excellent specificity (93.3%, 95% confidence interval [CI] 89.4%-96.1%), sensitivity (90.3%, 95% CI 81.0%-96.0%), PPV (80.2%, 95% CI 69.9%-88.3%) and NPV (97.0%, 95% CI 93.8%-98.8%). INTERPRETATION: This comprehensive case definition improves upon previous primary care HF definitions to include medication codes and laboratory data, along with previously used billing codes. A case definition for HF was derived and validated and can be used with data from electronic medical records to identify HF in patients with COPD in primary care accurately.
Assuntos
Insuficiência Cardíaca , Atenção Primária à Saúde , Doença Pulmonar Obstrutiva Crônica , Colúmbia Britânica/epidemiologia , Sistemas de Informação em Laboratório Clínico/estatística & dados numéricos , Estudos Transversais , Bases de Dados de Produtos Farmacêuticos/estatística & dados numéricos , Registros Eletrônicos de Saúde/estatística & dados numéricos , Feminino , Sistemas de Informação em Saúde/organização & administração , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Humanos , Classificação Internacional de Doenças , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Atenção Primária à Saúde/métodos , Atenção Primária à Saúde/organização & administração , Atenção Primária à Saúde/normas , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/terapia , Melhoria de Qualidade , Estudos Retrospectivos , Sensibilidade e Especificidade , Vigilância de Evento SentinelaRESUMO
In this study the authors used systems biology to define progressive changes in metabolism and transcription in a large animal model of heart failure with preserved ejection fraction (HFpEF). Transcriptomic analysis of cardiac tissue, 1-month post-banding, revealed loss of electron transport chain components, and this was supported by changes in metabolism and mitochondrial function, altogether signifying alterations in oxidative metabolism. Established HFpEF, 4 months post-banding, resulted in changes in intermediary metabolism with normalized mitochondrial function. Mitochondrial dysfunction and energetic deficiencies were noted in skeletal muscle at early and late phases of disease, suggesting cardiac-derived signaling contributes to peripheral tissue maladaptation in HFpEF. Collectively, these results provide insights into the cellular biology underlying HFpEF progression.
RESUMO
Macrophages have been linked to tumor initiation, progression, metastasis, and treatment resistance. However, the transcriptional regulation of macrophages driving the protumor function remains elusive. Here, we demonstrate that the transcription factor c-Maf is a critical controller for immunosuppressive macrophage polarization and function in cancer. c-Maf controls many M2-related genes and has direct binding sites within a conserved noncoding sequence of the Csf-1r gene and promotes M2-like macrophage-mediated T cell suppression and tumor progression. c-Maf also serves as a metabolic checkpoint regulating the TCA cycle and UDP-GlcNAc biosynthesis, thus promoting M2-like macrophage polarization and activation. Additionally, c-Maf is highly expressed in tumor-associated macrophages (TAMs) and regulates TAM immunosuppressive function. Deletion of c-Maf specifically in myeloid cells results in reduced tumor burden with enhanced antitumor T cell immunity. Inhibition of c-Maf partly overcomes resistance to anti-PD-1 therapy in a subcutaneous LLC tumor model. Similarly, c-Maf is expressed in human M2 and tumor-infiltrating macrophages/monocytes as well as circulating monocytes of human non-small cell lung carcinoma (NSCLC) patients and critically regulates their immunosuppressive activity. The natural compound ß-glucan downregulates c-Maf expression on macrophages, leading to enhanced antitumor immunity in mice. These findings establish a paradigm for immunosuppressive macrophage polarization and transcriptional regulation by c-Maf and suggest that c-Maf is a potential target for effective tumor immunotherapy.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/imunologia , Imunidade Celular , Neoplasias Pulmonares/imunologia , Ativação de Macrófagos , Macrófagos/imunologia , Neoplasias Experimentais/imunologia , Proteínas Proto-Oncogênicas c-maf/imunologia , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Macrófagos/patologia , Masculino , Camundongos , Camundongos Knockout , Monócitos/imunologia , Monócitos/patologia , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapia , Proteínas Proto-Oncogênicas c-maf/genética , Linfócitos T/imunologia , Linfócitos T/patologiaRESUMO
PCR amplification of tetrameric short tandem repeats (STRs) can lead to Taq enzyme slippage and artefact products typically one repeat unit less in size than the parent STR. These back stutter or n-4 amplification products are low-level relative to the amplification of the parent STR but are widely seen in the forensic community where tetrameric STRs are employed in the generation of DNA profiles. To aid the interpretation of DNA mixtures where minor contributor(s) might be present in comparable amounts to the back stutter products, the typical amounts of back stutter generated have been well characterised and guidelines for interpretation are in place. However, further artefacts thought to be Taq enzyme slippage leading to products with one repeat unit greater than the parent sequence (n+4 or forward stutter) or two repeats less (n-8 or double back stutter) also occur, but these have not been well characterised despite their potential influence in mixture interpretations. Here we present findings with respect to these additional artefacts from a study of 10,000 alleles and include guidelines for interpretation.
Assuntos
Impressões Digitais de DNA , Reação em Cadeia da Polimerase/instrumentação , Sequências de Repetição em Tandem , Alelos , Artefatos , HumanosRESUMO
Individuals with the rs671 SNP in the gene encoding aldehyde dehydrogenase 2 (ALDH2) are at increased risk of cardiovascular disease (CVD); however, it has been unclear if this mutation contributes to CVD development. In this issue of the JCI, Zhong et al. perform an elegant set of experiments that reveal a pathway wherein the ALDH2 rs671 mutant is phosphorylated by AMPK and translocates to the nucleus where it represses the transcription of a lysosomal H+ pump subunit that is critical for lipid degradation and foam cell formation, as occurs in atherosclerosis. The discovery of this pathway may explain how subjects harboring ALDH2 rs671 are at a greater risk for numerous other disease states and thereby provide new targets for therapeutic intervention.
Assuntos
Aterosclerose , Polimorfismo de Nucleotídeo Único , Proteínas Quinases Ativadas por AMP , Aldeído-Desidrogenase Mitocondrial , Aldeído Oxirredutases , Células Espumosas , HumanosRESUMO
Stable isotope-resolved metabolomics (SIRM) provides information regarding the relative activity of numerous metabolic pathways and the contribution of nutrients to specific metabolite pools; however, SIRM experiments can be difficult to execute, and data interpretation is challenging. Furthermore, standardization of analytical procedures and workflows remain significant obstacles for widespread reproducibility. Here, we demonstrate the workflow of a typical SIRM experiment and suggest experimental controls and measures of cross-validation that improve data interpretation. Inhibitors of glycolysis and oxidative phosphorylation as well as mitochondrial uncouplers serve as pharmacological controls, which help define metabolic flux configurations that occur under well-controlled metabolic states. We demonstrate how such controls and time course labeling experiments improve confidence in metabolite assignments as well as delineate metabolic pathway relationships. Moreover, we demonstrate how radiolabeled tracers and extracellular flux analyses integrate with SIRM to improve data interpretation. Collectively, these results show how integration of flux methodologies and use of pharmacological controls increase confidence in SIRM data and provide new biological insights.