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OBJECTIVE: In response to bacterial inflammation, anorexia of acute illness is protective and is associated with the induction of fasting metabolic programs such as ketogenesis. Forced feeding during the anorectic period induced by bacterial inflammation is associated with suppressed ketogenesis and increased mortality. As ketogenesis is considered essential in fasting adaptation, we sought to determine the role of ketogenesis in illness-induced anorexia. METHODS: A mouse model of inducible hepatic specific deletion of the rate limiting enzyme for ketogenesis (HMG-CoA synthase 2, Hmgcs2) was used to investigate the role of ketogenesis in endotoxemia, a model of bacterial inflammation, and in prolonged starvation. RESULTS: Mice deficient of hepatic Hmgcs2 failed to develop ketosis during endotoxemia and during prolonged fasting. Surprisingly, hepatic HMGCS2 deficiency and the lack of ketosis did not affect survival, glycemia, or body temperature in response to endotoxemia. Mice with hepatic ketogenic deficiency also did not exhibit any defects in starvation adaptation and were able to maintain blood glucose, body temperature, and lean mass compared to littermate wild-type controls. Mice with hepatic HMGCS2 deficiency exhibited higher levels of plasma acetate levels in response to fasting. CONCLUSIONS: Circulating hepatic-derived ketones do not provide protection against endotoxemia, suggesting that alternative mechanisms drive the increased mortality from forced feeding during illness-induced anorexia. Hepatic ketones are also dispensable for surviving prolonged starvation in the absence of inflammation. Our study challenges the notion that hepatic ketogenesis is required to maintain blood glucose and preserve lean mass during starvation, raising the possibility of extrahepatic ketogenesis and use of alternative fuels as potential means of metabolic compensation.
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Hidroximetilglutaril-CoA Sintasa , Cetosis , Hígado , Inanición , Animales , Ratones , Hígado/metabolismo , Inanición/metabolismo , Hidroximetilglutaril-CoA Sintasa/metabolismo , Hidroximetilglutaril-CoA Sintasa/genética , Masculino , Cetosis/metabolismo , Endotoxemia/metabolismo , Adaptación Fisiológica , Cuerpos Cetónicos/metabolismo , Glucemia/metabolismo , Ratones Endogámicos C57BL , Ayuno/metabolismo , Ratones Noqueados , Anorexia/metabolismoRESUMEN
ECHS1 Deficiency (ECHS1D) is a rare and devastating pediatric disease that currently has no defined treatments. This disorder results from missense loss-of-function mutations in the ECHS1 gene that result in severe developmental delays, encephalopathy, hypotonia, and early death. ECHS1 enzymatic activity is necessary for the beta-oxidation of fatty acids and the oxidation of branched-chain amino acids within the inner mitochondrial matrix. The pathogenesis of disease remains unknown, however it is hypothesized that disease is driven by an accumulation of toxic metabolites from impaired valine oxidation. To expand our knowledge on disease mechanisms, a novel mouse model of ECHS1D was generated that possesses a disease-associated knock-in (KI) allele and a knock-out (KO) allele. To investigate the behavioral phenotype, a battery of testing was performed at multiple time points, which included assessments of learning, motor function, endurance, sensory responses, and anxiety. Neurological abnormalities were assessed using wireless telemetry EEG recordings, pentylenetetrazol (PTZ) seizure induction, and immunohistochemistry. Metabolic perturbations were measured within the liver, serum, and brain using mass spectrometry and magnetic resonance spectroscopy. To test disease mechanisms, mice were subjected to disease pathway stressors and then survival, body weight gain, and epilepsy were assessed. Mice containing KI/KI or KI/KO alleles were viable with normal development and survival, and the presence of KI and KO alleles resulted in a significant reduction in ECHS1 protein. ECHS1D mice displayed reduced exercise capacity and pain sensation. EEG analysis revealed increased slow wave power that was associated with perturbations in sleep. ECHS1D mice had significantly increased epileptiform EEG discharges, and were sensitive to seizure induction, which resulted in death of 60% of ECHS1D mice. Under basal conditions, brain structure was grossly normal, although histological analysis revealed increased microglial activation in aged ECHS1D mice. Increased dietary valine only affected ECHS1D mice, which significantly exacerbated seizure susceptibility and resulted in death. Lastly, acute inflammatory challenge drove regression and early lethality in ECHS1D mice. In conclusion, we developed a novel model of ECHS1D that may be used to further knowledge on disease mechanisms and to develop therapeutics. Our data suggests altered metabolic signaling and inflammation may contribute to epilepsy in ECHS1D, and these alterations may be attributed to impaired valine metabolism.
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The heart alters the rate and relative oxidation of fatty acids and glucose based on availability and energetic demand. Insulin plays a crucial role in this process diminishing fatty acid and increasing glucose oxidation when glucose availability increases. Loss of insulin sensitivity and metabolic flexibility can result in cardiovascular disease. It is therefore important to identify mechanisms by which insulin regulates substrate utilization in the heart. Mitochondrial pyruvate dehydrogenase (PDH) is the key regulatory site for the oxidation of glucose for ATP production. Nevertheless, the impact of insulin on PDH activity has not been fully delineated, particularly in the heart. We sought in vivo evidence that insulin stimulates cardiac PDH and that this process is driven by the inhibition of fatty acid oxidation. Mice injected with insulin exhibited dephosphorylation and activation of cardiac PDH. This was accompanied by an increase in the content of malonyl-CoA, an inhibitor of carnitine palmitoyltransferase 1 (CPT1), and, thus, mitochondrial import of fatty acids. Administration of the CPT1 inhibitor oxfenicine was sufficient to activate PDH. Malonyl-CoA is produced by acetyl-CoA carboxylase (ACC). Pharmacologic inhibition or knockout of cardiac ACC diminished insulin-dependent production of malonyl-CoA and activation of PDH. Finally, circulating insulin and cardiac glucose utilization exhibit daily rhythms reflective of nutritional status. We demonstrate that time-of-day-dependent changes in PDH activity are mediated, in part, by ACC-dependent production of malonyl-CoA. Thus, by inhibiting fatty acid oxidation, insulin reciprocally activates PDH. These studies identify potential molecular targets to promote cardiac glucose oxidation and treat heart disease.
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Ácidos Grasos , Insulina , Miocardio , Oxidación-Reducción , Complejo Piruvato Deshidrogenasa , Animales , Insulina/metabolismo , Complejo Piruvato Deshidrogenasa/metabolismo , Ratones , Miocardio/metabolismo , Miocardio/enzimología , Ácidos Grasos/metabolismo , Acetil-CoA Carboxilasa/metabolismo , Acetil-CoA Carboxilasa/genética , Carnitina O-Palmitoiltransferasa/metabolismo , Carnitina O-Palmitoiltransferasa/genética , Malonil Coenzima A/metabolismo , Masculino , Ratones Noqueados , Glucosa/metabolismo , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: Colorectal cancer (CRC) continues to be a major global health challenge, ranking as a top cause of cancer-related mortality. Alarmingly, the five-year survival rate for CRC patients hovers around a mere 10-30 %. The disruption of fibroblast growth factor receptor (FGFRs) signaling pathways is significantly implicated in the onset and advancement of CRC, presenting a promising target for therapeutic intervention in CRC management. Further investigation is essential to comprehensively elucidate FGFR1's function in CRC and to create potent therapies that specifically target FGFR1. PURPOSE: This study aims to demonstrate the oncogenic role of FGFR1 in colorectal cancer and to explore the potential of ß,ß-dimethylacrylalkannin (ß,ß-DMAA) as a therapeutic option to inhibit FGFR1. METHODS: In this research, we employed a comprehensive suite of techniques including tissue array, kinase profiling, computational docking, knockdown assay to predict and explore the inhibitor of FGFR1. Furthermore, we utilized kinase assay, pull-down, cell proliferation tests, and Patient derived xenograft (PDX) mouse models to further investigate a novel FGFR1 inhibitor and its impact on the growth of CRC. RESULTS: In our research, we discovered that FGFR1 protein is markedly upregulated in colorectal cancer tissues, suggesting a significant role in regulating cellular proliferation, particularly in patients with colorectal cancer. Furthermore, we conducted a computational docking, kinase profiling analysis, simulation and identified that ß,ß-DMAA could directly bind with FGFR1 within ATP binding pocket domain. Cell-based assays confirmed that ß,ß-DMAA effectively inhibited the proliferation of colon cancer cells and also triggered cell cycle arrest, apoptosis, and altered FGFR1-mediated signaling pathways. Moreover, ß,ß-DMAA effectively attenuated the development of PDX tumors in mice that were FGFR1-positive, with no notable toxicity observed. In summary, our study highlights the pivotal role of FGFR1 in colorectal cancer, suggesting that inhibiting FGFR1 activity could be a promising strategy for therapeutic intervention. We present strong evidence that targeting FGFR1 with ß,ß-DMAA is a viable approach for the management of colorectal cancer. Given its low toxicity and high efficacy, ß,ß-DMAA, as an FGFR1 inhibitor, warrants further investigation in clinical settings for the treatment of FGFR1-positive tumors.
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Proliferación Celular , Neoplasias Colorrectales , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos , Animales , Femenino , Humanos , Ratones , Acrilamidas/farmacología , Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Neoplasias Colorrectales/tratamiento farmacológico , Simulación del Acoplamiento Molecular , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/metabolismo , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Novel strategies in intratumoral injection and emerging immunotherapies have heralded a new era of precise cancer treatments. The affinity of SARS-CoV-2 to ACE2 receptors, a feature which facilitates virulent human infection, is leveraged in this research. Colon cancer cells, with their high ACE2 expression, provide a potentially strategic target for using this SARS-CoV-2 feature. While the highly expression of ACE2 is observed in several cancer types, the idea of using the viral spike protein for targeting colon cancer cells offers a novel approach in cancer treatment. Intratumoral delivery of nucleic acid-based drugs is a promising alternative to overcoming the limitations of existing therapies. The increasing importance of nucleic acids in this realm, and the use of Lipid Nanoparticles (LNPs) for local delivery of nucleic acid therapeutics, are important breakthroughs. LNPs protect nucleic acid drugs from degradation and enhance cellular uptake, making them a rapidly evolving nano delivery system with high precision and adaptability. Our study leveraged a tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) combined with a receptor-binding domain from the SARS-CoV-2 spike protein, encapsulated in LNPs, to target colon cancer cells. Our results indicated that the TRAIL fusion-mRNA induced apoptosis in vitro and in vivo. Collectively, our findings highlight LNP-encapsulated TRAIL fusion-mRNA as a potential colon cancer therapy.
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Apoptosis , Neoplasias del Colon , Liposomas , Nanopartículas , ARN Mensajero , Ligando Inductor de Apoptosis Relacionado con TNF , Humanos , Apoptosis/efectos de los fármacos , Neoplasias del Colon/terapia , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Neoplasias del Colon/tratamiento farmacológico , Animales , Ligando Inductor de Apoptosis Relacionado con TNF/genética , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo , Ratones , Línea Celular Tumoral , SARS-CoV-2 , Ratones Desnudos , Enzima Convertidora de Angiotensina 2/metabolismo , Enzima Convertidora de Angiotensina 2/genéticaRESUMEN
Acetyl-CoA carboxylase (ACC) promotes prandial liver metabolism by producing malonyl-CoA, a substrate for de novo lipogenesis and an inhibitor of CPT-1-mediated fat oxidation. We report that inhibition of ACC also produces unexpected secondary effects on metabolism. Liver-specific double ACC1/2 knockout (LDKO) or pharmacologic inhibition of ACC increased anaplerosis, tricarboxylic acid (TCA) cycle intermediates, and gluconeogenesis by activating hepatic CPT-1 and pyruvate carboxylase flux in the fed state. Fasting should have marginalized the role of ACC, but LDKO mice maintained elevated TCA cycle intermediates and preserved glycemia during fasting. These effects were accompanied by a compensatory induction of proteolysis and increased amino acid supply for gluconeogenesis, which was offset by increased protein synthesis during feeding. Such adaptations may be related to Nrf2 activity, which was induced by ACC inhibition and correlated with fasting amino acids. The findings reveal unexpected roles for malonyl-CoA synthesis in liver and provide insight into the broader effects of pharmacologic ACC inhibition.
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Acetil-CoA Carboxilasa , Aminoácidos , Gluconeogénesis , Hígado , Malonil Coenzima A , Ratones Noqueados , Oxidación-Reducción , Animales , Malonil Coenzima A/metabolismo , Hígado/metabolismo , Acetil-CoA Carboxilasa/metabolismo , Ratones , Aminoácidos/metabolismo , Masculino , Piruvato Carboxilasa/metabolismo , Ciclo del Ácido Cítrico , Ácido Pirúvico/metabolismo , Ratones Endogámicos C57BL , Ayuno/metabolismo , Carnitina O-Palmitoiltransferasa/metabolismoRESUMEN
BACKGROUND: Coronary computed tomography angiography stenosis score (CCTA-SS) is a proposed diagnosis score that considers the plaque characteristics, myocardial function, and the diameter reduction rate of the lesions. This study aimed to evaluate the diagnostic performance of the CCTA-SS in seeking coronary artery disease (CAD). METHODS: The 228 patients with suspected CAD who underwent CCTA and invasive coronary angiography (ICA) procedures were under examination. The diagnostic performance was evaluated with the receiver operating curve (ROC) for CCTA-SS in detecting CAD (defined as a diameter reduction of ≥ 50%) and severe CAD (defined as a diameter reduction of ≥ 70%). RESULTS: The area under ROC (AUC) of CCTA-SS was 0.909 (95% CI: 0.864-0.943), which was significantly higher than that of CCTA (AUC: 0.826; 95% CI: 0.771-0.873; P = 0.0352) in diagnosing of CAD with a threshold of 50%. The optimal cutoff point of CCTA-SS was 51% with a sensitivity of 90.66%, specificity of 95.65%, positive predictive value of 98.80%, negative predictive value of 72.13%, and accuracy of 91.67%, whereas the optimal cutoff point of CCTA was 55%, and the corresponding values were 87.36%, 93.48%, 98.15%, 65.15%, and 88.60%, respectively. With a threshold of 70%, the performance of CCTA-SS with an AUC of 0.927 (95% CI: 0.885-0.957) was significantly higher than that of CCTA with an AUC of 0.521 (95% CI: 0.454-0.587) (P < 0.0001). CONCLUSIONS: CCTA-SS significantly improved the diagnostic accuracy of coronary stenosis, including CAD and severe CAD, compared with CCTA.
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Enfermedad de la Arteria Coronaria , Estenosis Coronaria , Humanos , Angiografía por Tomografía Computarizada/métodos , Constricción Patológica , Estenosis Coronaria/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Angiografía Coronaria/métodos , Valor Predictivo de las PruebasRESUMEN
The liver coordinates the systemic response to nutrient deprivation and availability by producing glucose from gluconeogenesis during fasting and synthesizing lipids via de novo lipogenesis (DNL) when carbohydrates are abundant. Mitochondrial pyruvate metabolism is thought to play important roles in both gluconeogenesis and DNL. We examined the effects of hepatocyte-specific mitochondrial pyruvate carrier (MPC) deletion on the fasting-refeeding response. Rates of DNL during refeeding were impaired by hepatocyte MPC deletion, but this did not reduce intrahepatic lipid content. During fasting, glycerol is converted to glucose by two pathways; a direct cytosolic pathway and an indirect mitochondrial pathway requiring the MPC. Hepatocyte MPC deletion reduced the incorporation of 13C-glycerol into TCA cycle metabolites, but not into new glucose. Furthermore, suppression of glycerol and alanine metabolism did not affect glucose concentrations in fasted hepatocyte-specific MPC-deficient mice, suggesting multiple layers of redundancy in glycemic control in mice.
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Over the past 2 decades, cancer stem cells (CSCs) have been identified as the root cause of cancer occurrence, progression, chemoradioresistance, recurrence, and metastasis. Targeting CSCs is a novel therapeutic strategy for cancer management and treatment. Liver cancer (LC) is a malignant disease that can endanger human health. Studies are increasingly suggesting that changes in the liver mechanical microenvironment are a primary driver triggering the occurrence and development of liver cancer. In this review, we summarize current understanding of the roles of the liver mechano-microenvironment and liver cancer stem cells (LCSCs) in liver cancer progression. We also discuss the relationship between the mechanical heterogeneity of liver cancer tissues and LCSC recruitment and metastasis. Finally, we highlight potential mechanosensitive molecules in LCSCs and mechanotherapy in liver cancer. Understanding the roles and regulatory mechanisms of the mechano-microenvironment and LCSCs may provide fundamental insights into liver cancer progression and aid in further development of novel therapeutic strategies.
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Neoplasias Hepáticas , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/patología , Células Madre Neoplásicas/patología , Microambiente TumoralRESUMEN
Three-dimensional (3D) extracellular matrix (ECM) microenvironment is an important regulator of the stiffness of the tumors. Cancer cells require heterogeneous metabolic phenotypes to cope with resistance in the malignant process. However, how the stiffness of the matrix affects the metabolic phenotypes of cancer cells, is lacking. In this study, the youngs modulus of the synthesized collagen-chitosan scaffolds was adjusted according to the percentage ratio of collagen to chitosan. We cultured non-small cell lung cancer (NSCLC) cells in four different microenvironments (two-dimensional (2D) plates, stiffest 0.50.5 porous collagen-chitosan scaffolds, middle stiff 0.51 porous collagen-chitosan scaffolds, and softest 0.52 porous collagen-chitosan scaffolds) to investigate the influence of the difference of 2D and 3D cultures as well as the 3D scaffolds with different stiffnesses on the metabolic dependency of NSCLC cells. The results revealed that NSCLC cells cultured in 3D collagen-chitosan scaffolds displayed higher capacity of mitochondrial metabolism and fatty acid metabolism than that cultured in 2D culture. The metabolic response of NSCLC cells is differential for 3D scaffolds with different stiffnesses. The cells cultured in middle stiff 0.51 scaffolds displayed a higher potential of mitochondrial metabolism than that of stiffer 0.50.5 scaffolds and softer 0.52 scaffolds. Furthermore, NSCLC cells culture in 3D scaffolds displayed drug resistance compared with that in 2D culture which maybe via the hyperactivation of the mTOR pathway. Moreover, the cells cultured in 0.51 scaffolds showed higher ROS levels, which were counterbalanced by an equally high expression of antioxidant enzymes when compared to the cells grown in 2D culture, which may be regulated by the increased expression of PGC-1α. Together, these results demonstrate that differences in the microenvironments of cancer cells profoundly impact their metabolic dependencies. (AU)
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Humanos , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Quitosano , Proliferación Celular , Andamios del Tejido , Microambiente TumoralRESUMEN
Three-dimensional (3D) extracellular matrix (ECM) microenvironment is an important regulator of the stiffness of the tumors. Cancer cells require heterogeneous metabolic phenotypes to cope with resistance in the malignant process. However, how the stiffness of the matrix affects the metabolic phenotypes of cancer cells, is lacking. In this study, the young's modulus of the synthesized collagen-chitosan scaffolds was adjusted according to the percentage ratio of collagen to chitosan. We cultured non-small cell lung cancer (NSCLC) cells in four different microenvironments (two-dimensional (2D) plates, stiffest 0.5-0.5 porous collagen-chitosan scaffolds, middle stiff 0.5-1 porous collagen-chitosan scaffolds, and softest 0.5-2 porous collagen-chitosan scaffolds) to investigate the influence of the difference of 2D and 3D cultures as well as the 3D scaffolds with different stiffnesses on the metabolic dependency of NSCLC cells. The results revealed that NSCLC cells cultured in 3D collagen-chitosan scaffolds displayed higher capacity of mitochondrial metabolism and fatty acid metabolism than that cultured in 2D culture. The metabolic response of NSCLC cells is differential for 3D scaffolds with different stiffnesses. The cells cultured in middle stiff 0.5-1 scaffolds displayed a higher potential of mitochondrial metabolism than that of stiffer 0.5-0.5 scaffolds and softer 0.5-2 scaffolds. Furthermore, NSCLC cells culture in 3D scaffolds displayed drug resistance compared with that in 2D culture which maybe via the hyperactivation of the mTOR pathway. Moreover, the cells cultured in 0.5-1 scaffolds showed higher ROS levels, which were counterbalanced by an equally high expression of antioxidant enzymes when compared to the cells grown in 2D culture, which may be regulated by the increased expression of PGC-1α. Together, these results demonstrate that differences in the microenvironments of cancer cells profoundly impact their metabolic dependencies.
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Carcinoma de Pulmón de Células no Pequeñas , Quitosano , Neoplasias Pulmonares , Humanos , Andamios del Tejido , Colágeno , Proliferación Celular , Microambiente TumoralRESUMEN
BACKGROUNDHepatic de novo lipogenesis (DNL) and ß-oxidation are tightly coordinated, and their dysregulation is thought to contribute to the pathogenesis of nonalcoholic fatty liver (NAFL). Fasting normally relaxes DNL-mediated inhibition of hepatic ß-oxidation, dramatically increasing ketogenesis and decreasing reliance on the TCA cycle. Thus, we tested whether aberrant oxidative metabolism in fasting NAFL subjects is related to the inability to halt fasting DNL.METHODSForty consecutive nondiabetic individuals with and without a history of NAFL were recruited for this observational study. After phenotyping, subjects fasted for 24 hours, and hepatic metabolism was interrogated using a combination of 2H2O and 13C tracers, magnetic resonance spectroscopy, and high-resolution mass spectrometry.RESULTSWithin a subset of subjects, DNL was detectable after a 24-hour fast and was more prominent in those with NAFL, though it was poorly correlated with steatosis. However, fasting DNL negatively correlated with hepatic ß-oxidation and ketogenesis and positively correlated with citrate synthesis. Subjects with NAFL but undetectable fasting DNL (25th percentile) were comparatively normal. However, those with the highest fasting DNL (75th percentile) were intransigent to the effects of fasting on the concentration of insulin, non-esterified fatty acid, and ketones. Additionally, they sustained glycogenolysis and were spared the loss of oxaloacetate to gluconeogenesis in favor of citrate synthesis, which correlated with DNL and diminished ketogenesis.CONCLUSIONMetabolic flux analysis in fasted subjects indicates that shared metabolic mechanisms link the dysregulations of hepatic DNL, ketogenesis, and the TCA cycle in NAFL.TRIAL REGISTRATIONData were obtained during the enrollment/non-intervention phase of Effect of Vitamin E on Non-Alcoholic Fatty Liver Disease, ClinicalTrials.gov NCT02690792.FUNDINGThis work was supported by the University of Texas Southwestern NORC Quantitative Metabolism Core (NIH P30DK127984), the NIH/National Institute of Diabetes and Digestive and Kidney Diseases (R01DK078184, R01DK128168, R01DK087977, R01DK132254, and K01DK133630), the NIH/National Institute on Alcohol Abuse and Alcoholism (K01AA030327), and the Robert A. Welch Foundation (I-1804).
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Enfermedad del Hígado Graso no Alcohólico , Humanos , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Lipogénesis/fisiología , Ácido Cítrico , Hígado/metabolismo , Cuerpos Cetónicos/metabolismo , Citratos/metabolismo , AyunoRESUMEN
Mitochondrial reactive oxygen species (mROS) are central to physiology. While excess mROS production has been associated with several disease states, its precise sources, regulation, and mechanism of generation in vivo remain unknown, limiting translational efforts. Here we show that in obesity, hepatic ubiquinone (Q) synthesis is impaired, which raises the QH 2 /Q ratio, driving excessive mROS production via reverse electron transport (RET) from site I Q in complex I. Using multiple complementary genetic and pharmacological models in vivo we demonstrated that RET is critical for metabolic health. In patients with steatosis, the hepatic Q biosynthetic program is also suppressed, and the QH 2 /Q ratio positively correlates with disease severity. Our data identify a highly selective mechanism for pathological mROS production in obesity, which can be targeted to protect metabolic homeostasis.
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The liver coordinates the systemic response to nutrient deprivation and availability by producing glucose from gluconeogenesis during fasting and synthesizing lipids via de novo lipogenesis (DNL) when carbohydrates are abundant. Mitochondrial pyruvate metabolism is thought to play important roles in both gluconeogenesis and DNL. We examined the effects of hepatocyte-specific mitochondrial pyruvate carrier (MPC) deletion on the fasting-refeeding response. Rates of DNL during refeeding were impaired by liver MPC deletion, but this did not reduce intrahepatic lipid content. During fasting, glycerol is converted to glucose by two pathways; a direct cytosolic pathway essentially reversing glycolysis and an indirect mitochondrial pathway requiring the MPC. MPC deletion reduced the incorporation of 13C-glycerol into TCA cycle metabolites but not into newly synthesized glucose. However, suppression of glycerol metabolism did not affect glucose concentrations in fasted hepatocyte-specific MPC-deficient mice. Thus, glucose production by kidney and intestine may compensate for MPC deficiency in hepatocytes.
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Introduction: Metabolic strategies in different microenvironments can affect cancer metabolic adaptation, ultimately influencing the therapeutic response. Understanding the metabolic alterations of cancer cells in different microenvironments is critical for therapeutic success. Methods: In this study, we cultured non-small cell lung cancer cells in three different microenvironments (two-dimensional (2D) plates, soft elastic three-dimensional (3D) porous 2 wt% scaffolds, and stiff elastic 3D porous 4 wt% scaffolds) to investigate the effects of different matrix elasticity as well as 2D and 3D culture settings on the metabolic adaptation of cancer cells. Results: The results revealed that PGC-1α expression is sensitive to the elasticity of the 3D scaffold. PGC-1α expression was markedly increased in cancer cells cultured in stiff elastic 3D porous 4 wt% scaffolds compared with cells cultured in soft elastic 3D porous 2 wt% scaffolds or 2D plates, enhancing mitochondrial biogenesis and oxidative stress resistance of non-small cell lung cancer through increased reactive oxygen species (ROS) detoxification capacity. However, phosphofructokinase-1 (PFK-1) expression, a key rate-limiting enzyme in glycolysis, did not change significantly in the three microenvironments, indicating that microenvironments may not affect the early stage of glycolysis. Conversely, monocarboxylate transporter 1 (MCT1) expression in 3D culture was significantly reduced compared to 2D culture but without significant difference between soft and stiff scaffolds, indicating that MCT1 expression is more sensitive to the shape of the different cultures of 2D and 3D microenvironment surrounding cells but is unaffected by the scaffold elasticity. Conclusions: Together, these results demonstrate that differences in the microenvironment of cancer cells profoundly impact their metabolic response.
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Colorectal cancer (CRC) is the second most common cause of cancer-related death in the world. The pro-viral integration site for Moloney murine leukemia virus 1 (PIM1) is a proto-oncogene and belongs to the serine/threonine kinase family, which are involved in cell proliferation, migration, and apoptosis. Fibroblast growth factor receptor 1 (FGFR1) is a tyrosine kinase that has been implicated in cell proliferation, differentiation and migration. Small molecule HCI-48 is a derivative of chalcone, a class of compounds known to possess anti-tumor, anti-inflammatory and antibacterial effects. However, the underlying mechanism of chalcones against colorectal cancer remains unclear. This study reports that HCI-48 mainly targets PIM1 and FGFR1 kinases, thereby eliciting antitumor effects on colorectal cancer growth in vitro and in vivo. HCI-48 inhibited the activity of both PIM1 and FGFR1 kinases in an ATP-dependent manner, as revealed by computational docking models. Cell-based assays showed that HCI-48 inhibited cell proliferation in CRC cells (HCT-15, DLD1, HCT-116 and SW620), and induced cell cycle arrest in the G2/M phase through modulation of cyclin A2. HCI-48 also induced cellular apoptosis, as evidenced by an increase in the expression of apoptosis biomarkers such as cleaved PARP, cleaved caspase 3 and cleaved caspase 7. Moreover, HCI-48 attenuated the activation of downstream components of the PIM1 and FGFR1 signaling pathways. Using patient-derived xenograft (PDX) murine tumor models, we found that treatment with HCI-48 diminished the PDX tumor growth of implanted CRC tissue expressing high protein levels of PIM1 and FGFR1. This study suggests that the inhibitory effect of HCI-48 on colorectal tumor growth is mainly mediated through the dual-targeting of PIM1 and FGFR1 kinases. This work provides a theoretical basis for the future application of HCI-48 in the treatment of clinical CRC.
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Based on Vallerand's dualistic model of passion, this study theorizes and empirically examines the temporal dynamics of two types of entrepreneurial passion in female entrepreneurs, harmonious entrepreneurial passion (HmEP) and obsessive entrepreneurial passion (ObEP), and examines the mechanisms by which entrepreneurial effort0 and fear of failure influence the temporal dynamics of entrepreneurial passion. Using data collected from a three-wave, lagged survey of female entrepreneurs, we employed Mplus to build a latent growth model for entrepreneurial passion and built a cross-lag model of the relationship between entrepreneurial passion, entrepreneurial effort, and fear of failure. We found that female entrepreneurs' HmEP and ObEP present different temporal dynamics. Furthermore, the temporal dynamics of HmEP are achieved through changes in entrepreneurial effort, whereas the temporal dynamics of ObEP are achieved through changes in current entrepreneurial effort and fear of failure in the next stage. Therefore, due to traditional gender stereotypes and varying motivations to engage in entrepreneurship, the two entrepreneurial passions have different dynamic evolution processes. Our results underscore the importance of effort and fear of failure in stimulating the dynamics of female entrepreneurial passion.
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Users' non-sustainable consumption behaviors are affecting the sustainability of access-based services (ABSs), but ABS firms can utilize messaging strategies (ex-ante reminders) to persuade users to curtail their non-sustainable consumption behaviors. Through two online scenario-based experiments in China, this study determined that: (1) Compared with rational appeal messaging, emotional appeal messaging is better able to persuade consumers to curtail non-sustainable consumption behaviors. Furthermore, loss-framed messages are more effective than gain-framed ones. (2) Message appeal and message framing have an interactive persuasive effect on reducing such consumer behaviors. Loss-framed rational appeal messages are more persuasive at reducing non-sustainable consumption behaviors than gain-framed rational appeal messages, and gain-framed emotional appeal messages persuade consumers to reduce non-sustainable consumption behaviors more than loss-framed ones. (3) Consumers' psychological ownership moderates the persuasive effect of messaging. Among consumers with a high level of psychological ownership of shared goods, only gain-framed emotional appeal messaging is effective at reducing non-sustainable consumption behaviors, whereas among consumers with low psychological ownership, the persuasive effect of loss-framed rational appeal messaging is more effective than gain-framed emotional appeal messaging. This study extends the research on non-sustainable consumption behavior management in ABSs and provides important inspiration for the management of ABSs consumer behavior.
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De novo lipogenesis (DNL) is disrupted in a wide range of human disease. Thus, quantification of DNL may provide insight into mechanisms and guide interventions if it can be performed rapidly and noninvasively. DNL flux is commonly measured by 2H incorporation into fatty acids following deuterated water (2H2O) administration. However, the sensitivity of this approach is limited by the natural abundance of 13C, which masks detection of 2H by mass spectrometry. Here we report that high-resolution Orbitrap gas-chromatography mass-spectrometry resolves 2H and 13C fatty acid mass isotopomers, allowing DNL to be quantified using lower 2H2O doses and shorter experimental periods than previously possible. Serial measurements over 24-hrs in mice detects the nocturnal activation of DNL and matches a 3H-water method in mice with genetic activation of DNL. Most importantly, DNL is detected in overnight-fasted humans in less than an hour and is responsive to feeding during a 4-h study. Thus, 2H specific MS provides the ability to study DNL in settings that are currently impractical.
Asunto(s)
Ácidos Grasos/biosíntesis , Cromatografía de Gases y Espectrometría de Masas/métodos , Lipogénesis/fisiología , Hígado/metabolismo , Triglicéridos/biosíntesis , Animales , Deuterio/química , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: Skin cancer is one of the most commonly diagnosed cancers worldwide. The 5-year survival rate of the most aggressive late-stage skin cancer ranges between 20 and 30%. Thus, the discovery and investigation of novel target therapeutic agents that can effectively treat skin cancer is of the utmost importance. The T-lymphokine-activated killer cell-originated protein kinase (TOPK), which belongs to the serine-threonine kinase class of the mitogen-activated protein kinase kinase (MAPKK) family, is highly expressed and activated in skin cancer. The present study investigates the role of 3-deoxysappanchalcone (3-DSC), a plant-derived functional TOPK inhibitor, in suppressing skin cancer cell growth. PURPOSE: In the context of skin cancer prevention and therapy, we clarify the effect and mechanism of 3-DSC on different types of skin cancer and solar-simulated light (SSL)-induced skin hyperplasia. METHODS: In an in vitro study, western blotting and in vitro kinase assays were utilized to determine the protein expression of TOPK and its activity, respectively. Pull-down assay with 3-DSC and TOPK (wild-type and T42A/N172 mutation) was performed to confirm the direct interaction between T42A/N172 amino acid sites of TOPK and 3-DSC. Cell proliferation and anchorage-independent cell growth assays were utilized to determine the effect of 3-DSC on cell growth. In an in vivo study, the thickness of skin and tumor size were measured in the acute SSL-induced inflammation mouse model or SK-MEL-2 cell-derived xenografts mouse model treated with 3-DSC. Immunohistochemistry analysis of tumors isolated from SK-MEL-2 cell-derived xenografts was performed to determine whether cell-based results observed upon 3-DSC treatment could be recapitulated in vivo. RESULTS: 3-DSC is able to inhibit cell proliferation in skin cancer cells in an anchorage-dependent and anchorage-independent manner by regulation of TOPK and its related signaling pathway in vitro. We also found that application of 3-DSC reduced acute SSL-induced murine skin hyperplasia. Additionally, we observed that 3-DSC decreased SK-MEL-2 cell-derived xenograft tumor growth through attenuating phosphorylation of TOPK and its downstream effectors including ERK, RSK, and c-Jun. CONCLUSIONS: Our results suggest that 3-DSC may function in a chemopreventive and chemotherapeutic capacity by protecting against UV-induced skin hyperplasia and inhibiting tumor cell growth by attenuating TOPK signaling, respectively.