RESUMO
BACKGROUND: To clarify the mechanisms underlying physical activity (PA)-related cardioprotection, we examined the association of PA with plasma bioactive lipids (BALs) and cardiovascular disease (CVD) events. We additionally performed genome-wide associations. METHODS: PA-bioactive lipid associations were examined in VITAL (VITamin D and OmegA-3 TriaL)-clinical translational science center (REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01169259; N=1032) and validated in JUPITER (Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin)-NC (REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT00239681; N=589), using linear models adjusted for age, sex, race, low-density lipoprotein-cholesterol, total-C, and smoking. Significant BALs were carried over to examine associations with incident CVD in 2 nested CVD case-control studies: VITAL-CVD (741 case-control pairs) and JUPITER-CVD (415 case-control pairs; validation). RESULTS: We detected 145 PA-bioactive lipid validated associations (false discovery rate <0.1). Annotations were found for 6 of these BALs: 12,13-diHOME, 9,10-diHOME, lysoPC(15:0), oxymorphone-3b-D-glucuronide, cortisone, and oleoyl-glycerol. Genetic analysis within JUPITER-NC showed associations of 32 PA-related BALs with 22 single-nucleotide polymorphisms. From PA-related BALs, 12 are associated with CVD. CONCLUSIONS: We identified a PA-related bioactive lipidome profile out of which 12 BALs also had opposite associations with incident CVD events.
Assuntos
Doenças Cardiovasculares , Exercício Físico , Inibidores de Hidroximetilglutaril-CoA Redutases , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/genética , LDL-Colesterol , Humanos , Fatores de Risco , Rosuvastatina CálcicaRESUMO
The balance between NLRP3 inflammasome activation and mitophagy is essential for homeostasis and cellular health, but this relationship remains poorly understood. Here we found that interleukin-1α (IL-1α)-deficient macrophages have reduced caspase-1 activity and diminished IL-1ß release, concurrent with reduced mitochondrial damage, suggesting a role for IL-1α in regulating this balance. LPS priming of macrophages induced pro-IL-1α translocation to mitochondria, where it directly interacted with mitochondrial cardiolipin (CL). Computational modeling revealed a likely CL binding motif in pro-IL-1α, similar to that found in LC3b. Thus, binding of pro-IL-1α to CL in activated macrophages may interrupt CL-LC3b-dependent mitophagy, leading to enhanced Nlrp3 inflammasome activation and more robust IL-1ß production. Mutation of pro-IL-1α residues predicted to be involved in CL binding resulted in reduced pro-IL-1α-CL interaction, a reduction in NLRP3 inflammasome activity, and increased mitophagy. These data identify a function for pro-IL-1α in regulating mitophagy and the potency of NLRP3 inflammasome activation.
Assuntos
Cardiolipinas/metabolismo , Interleucina-1alfa/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Autofagia , Cardiolipinas/fisiologia , Caspase 1/metabolismo , Feminino , Células HEK293 , Humanos , Inflamassomos/metabolismo , Interleucina-1alfa/fisiologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/metabolismo , Mitofagia/fisiologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/fisiologia , Ligação Proteica/fisiologia , Domínios Proteicos/fisiologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
PREMISE: Evolution of separate sexes from hermaphroditism often proceeds through gynodioecy, but genetic constraints on this process are poorly understood. Genetic (co-)variances and between-sex genetic correlations were used to predict evolutionary responses of multiple reproductive traits in a sexually dimorphic gynodioecious species, and predictions were compared with observed responses to artificial selection. METHODS: Schiedea (Caryophyllaceae) is an endemic Hawaiian lineage with hermaphroditic, gynodioecious, subdioecious, and dioecious species. We measured genetic parameters of Schiedea salicaria and used them to predict evolutionary responses of 18 traits in hermaphrodites and females in response to artificial selection for increased male (stamen) biomass in hermaphrodites or increased female (carpel, capsule) biomass in females. Observed responses over two generations were compared with predictions in replicate lines of treatments and controls. RESULTS: In only two generations, both stamen biomass in hermaphrodites and female biomass in females responded markedly to direct selection, supporting a key assumption of models for evolution of dioecy. Other biomass traits, pollen and ovule numbers, and inflorescence characters important in wind pollination evolved indirectly in response to selection on sex allocation. Responses generally followed predictions from multivariate selection models, with some responses unexpectedly large due to increased genetic correlations as selection proceeded. CONCLUSIONS: Results illustrate the power of artificial selection and utility of multivariate selection models incorporating sex differences. They further indicate that pollen and ovule numbers and inflorescence architecture could evolve in response to selection on biomass allocation to male versus female function, producing complex changes in plant phenotype as separate sexes evolve.
Assuntos
Caryophyllaceae , Flores , Animais , Flores/fisiologia , Melhoramento Vegetal , Polinização , Caryophyllaceae/genética , FenótipoRESUMO
In skeletal muscle fibers, mitochondria are densely packed adjacent to myofibrils because adenosine triphosphate (ATP) is needed to fuel sarcomere shortening. However, despite this close physical and biochemical relationship, the effects of mitochondrial dynamics on skeletal muscle contractility are poorly understood. In this study, we analyzed the effects of Mitochondrial Division Inhibitor 1 (mdivi-1), an inhibitor of mitochondrial fission, on the structure and function of both mitochondria and myofibrils in skeletal muscle tissues engineered on micromolded gelatin hydrogels. Treatment with mdivi-1 did not alter myotube morphology, but did increase the mitochondrial turbidity and oxidative capacity, consistent with reduced mitochondrial fission. Mdivi-1 also significantly increased basal, twitch, and tetanus stresses, as measured using the Muscular Thin Film (MTF) assay. Finally, mdivi-1 increased sarcomere length, potentially due to mdivi-1-induced changes in mitochondrial volume and compression of myofibrils. Together, these results suggest that mdivi-1 increases contractile stress generation, which may be caused by an increase in maximal respiration and/or sarcomere length due to increased volume of individual mitochondria. These data reinforce that mitochondria have both biochemical and biomechanical roles in skeletal muscle and that mitochondrial dynamics can be manipulated to alter muscle contractility.
Assuntos
Mitocôndrias Musculares/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Mioblastos Esqueléticos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Quinazolinonas/farmacologia , Animais , Linhagem Celular , Dinaminas/metabolismo , Camundongos , Mitocôndrias Musculares/metabolismo , Dinâmica Mitocondrial/fisiologia , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/fisiologia , Músculo Esquelético/citologia , Músculo Esquelético/fisiologia , Mioblastos Esqueléticos/citologia , Mioblastos Esqueléticos/metabolismo , Oxirredução/efeitos dos fármacos , Sarcômeros/efeitos dos fármacos , Sarcômeros/metabolismo , Sarcômeros/fisiologiaRESUMO
ß2 -adrenoceptor agonists improve autophagy and re-establish proteostasis in cardiac cells; therefore, suggesting autophagy as a downstream effector of ß2 -adrenoceptor signaling pathway. Here, we used the pharmacological and genetic tools to determine the autophagy effect of sustained ß2 -adrenoceptor activation in rodents with neurogenic myopathy, which display impaired skeletal muscle autophagic flux. Sustained ß2 -adrenoceptor activation using Formoterol (10 µg kg-1 day-1 ), starting at the onset of neurogenic myopathy, prevents disruption of autophagic flux in skeletal muscle 14 days after sciatic nerve constriction. These changes are followed by reduction of the cytotoxic protein levels and increased skeletal muscle cross-sectional area and contractility properties. Of interest, sustained administration of Formoterol at lower concentration (1 µg kg-1 day-1 ) induces similar improvements in skeletal muscle autophagic flux and contractility properties in neurogenic myopathy, without affecting the cross-sectional area. Sustained pharmacological inhibition of autophagy using Chloroquine (50 mg kg-1 day-1 ) abolishes the beneficial effects of ß2 -adrenoceptor activation on the skeletal muscle proteostasis and contractility properties in neurogenic myopathy. Further supporting an autophagy mechanism for ß2 -adrenoceptor activation, skeletal muscle-specific deletion of ATG7 blunts the beneficial effects of ß2 -adrenoceptor on skeletal muscle proteostasis and contractility properties in neurogenic myopathy in mice. These findings suggest autophagy as a critical downstream effector of ß2 -adrenoceptor signaling pathway in skeletal muscle.
Assuntos
Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Autofagia , Músculo Esquelético/patologia , Doenças Musculares/prevenção & controle , Proteostase , Receptores Adrenérgicos beta 2/metabolismo , Animais , Fumarato de Formoterol , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Contração Muscular , Músculo Esquelético/metabolismo , Doenças Musculares/etiologia , Doenças Musculares/metabolismo , Doenças Musculares/patologia , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos beta 2/química , Transdução de SinaisRESUMO
Cardiovascular disease is the main cause of death worldwide, making it crucial to search for new therapies to mitigate major adverse cardiac events (MACEs) after a cardiac ischemic episode. Drugs in the class of the glucagon-like peptide-1 receptor agonists (GLP1Ra) have demonstrated benefits for heart function and reduced the incidence of MACE in patients with diabetes. Previously, we demonstrated that a short-acting GLP1Ra known as DMB (2-quinoxalinamine, 6,7-dichloro-N-[1,1-dimethylethyl]-3-[methylsulfonyl]-,6,7-dichloro-2-methylsulfonyl-3-N-tert-butylaminoquinoxaline or compound 2, Sigma) also mitigates adverse postinfarction left ventricular remodeling and cardiac dysfunction in lean mice through activation of parkin-mediated mitophagy following infarction. Here, we combined proteomics with in silico analysis to characterize the range of effects of DMB in vivo throughout the course of early postinfarction remodeling. We demonstrate that the mitochondrion is a key target of DMB and mitochondrial respiration, oxidative phosphorylation and metabolic processes such as glycolysis and fatty acid beta-oxidation are the main biological processes being regulated by this compound in the heart. Moreover, the overexpression of proteins with hub properties identified by protein-protein interaction networks, such as Atp2a2, may also be important to the mechanism of action of DMB. Data are available via ProteomeXchange with identifier PXD027867.
Assuntos
Ventrículos do Coração/metabolismo , Mitocôndrias Cardíacas/metabolismo , Proteômica/métodos , Quinoxalinas/administração & dosagem , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Remodelação Ventricular/efeitos dos fármacos , Animais , Biologia Computacional , Modelos Animais de Doenças , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Glicólise , Masculino , Camundongos , Fosforilação Oxidativa , Mapas de Interação de Proteínas , Quinoxalinas/farmacologiaRESUMO
Sodium-glucose cotransporter 2 (SGLT2) inhibitors such as empagliflozin are known to reduce the risk of hospitalizations related to heart failure irrespective of diabetic state. Meanwhile, adverse cardiac remodeling remains the leading cause of heart failure and death in the USA. Thus, understanding the mechanisms that are responsible for the beneficial effects of SGLT2 inhibitors is of the utmost relevance and importance. Our previous work illustrated a connection between adverse cardiac remodeling and the regulation of mitochondrial turnover and cellular energetics using a short-acting glucagon-like peptide-1 receptor agonist (GLP1Ra). Here, we sought to determine if the mechanism of the SGLT2 inhibitor empagliflozin (EMPA) in ameliorating adverse remodeling was similar and/or to identify what differences exist, if any. To this end, we administered permanent coronary artery ligation to induce adverse remodeling in wild-type and Parkin knockout mice and examined the progression of adverse cardiac remodeling with or without EMPA treatment over time. Like GLP1Ra, we found that EMPA affords a robust attenuation of PCAL-induced adverse remodeling. Interestingly, unlike the GLP1Ra, EMPA does not require Parkin to improve/maintain mitochondria-related cellular energetics and afford its benefits against developing adverse remodeling. These findings suggests that further investigation of EMPA is warranted as a potential path for developing therapy against adverse cardiac remodeling for patients that may have Parkin and/or mitophagy-related deficiencies.
Assuntos
Compostos Benzidrílicos/uso terapêutico , Metabolismo Energético , Glucosídeos/uso terapêutico , Mitocôndrias Cardíacas/metabolismo , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/fisiopatologia , Biogênese de Organelas , Remodelação Ventricular , Animais , Compostos Benzidrílicos/farmacologia , Eletrocardiografia , Metabolismo Energético/efeitos dos fármacos , Glucosídeos/farmacologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Infarto do Miocárdio/diagnóstico por imagem , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/metabolismo , Remodelação Ventricular/efeitos dos fármacosRESUMO
Mitochondria are the major source of cellular energy (ATP), as well as critical mediators of widespread functions such as cellular redox balance, apoptosis, and metabolic flux. The organelles play an especially important role in the maintenance of cardiac homeostasis; their inability to generate ATP following impairment due to ischemic damage has been directly linked to organ failure. Methods to quantify mitochondrial content are limited to low throughput immunoassays, measurement of mitochondrial DNA, or relative quantification by untargeted mass spectrometry. Here, we present a high throughput, reproducible and quantitative mass spectrometry multiple reaction monitoring based assay of 37 proteins critical to central carbon chain metabolism and overall mitochondrial function termed 'MitoPlex'. We coupled this protein multiplex with a parallel analysis of the central carbon chain metabolites (219 metabolite assay) extracted in tandem from the same sample, be it cells or tissue. In tests of its biological applicability in cells and tissues, "MitoPlex plus metabolites" indicated profound effects of HMG-CoA Reductase inhibition (e.g., statin treatment) on mitochondria of i) differentiating C2C12 skeletal myoblasts, as well as a clear opposite trend of statins to promote mitochondrial protein expression and metabolism in heart and liver, while suppressing mitochondrial protein and ii) aspects of metabolism in the skeletal muscle obtained from C57Bl6 mice. Our results not only reveal new insights into the metabolic effect of statins in skeletal muscle, but present a new high throughput, reliable MS-based tool to study mitochondrial dynamics in both cell culture and in vivo models.
Assuntos
Espectrometria de Massas , Metabolômica/métodos , Proteínas Mitocondriais/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Cromatografia Líquida/métodos , Ciclo do Ácido Cítrico/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Ensaios de Triagem em Larga Escala , Espectrometria de Massas/métodos , Espectrometria de Massas/normas , Metabolômica/normas , Camundongos , Mitocôndrias Musculares/efeitos dos fármacos , Mitocôndrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Mioblastos/metabolismo , Reprodutibilidade dos Testes , Sinvastatina/farmacologia , Ubiquinona/farmacologiaRESUMO
The deleterious effects of statins on skeletal muscle are well known, but the mechanism associated with these effects remains unresolved. Statins are associated with mitochondrial damage, which may contribute to muscle myopathy. Here we demonstrate that simvastatin induces mitophagy in skeletal muscle cells and hypothesized that attenuating this process by silencing the mitophagy adapter p62/sequestosome-1 (SQSTM1) might mitigate myotoxicity. Surprisingly, silencing p62/SQSTM1 in differentiated C2C12 muscle cells exacerbated rather than attenuated myotoxicity. This inhibition of mitophagy in the face of statin challenge correlated with increased release of cytochrome c to the cytosol, activation of caspase-3, and lactate dehydrogenase (LDH) release. Correspondingly, targeted knockdown of Parkin, a canonical E3 ubiquitin ligase important for mitophagy, mirrored the effects of p62/SQSTM1 silencing. To corroborate these findings in vivo, we treated Parkin knockout mice with simvastatin for 2 wk. In line with our findings in vitro, these mitophagy-compromised mice displayed reduced spontaneous activity, loss of grip strength, and increased circulating levels of muscle damage marker LDH. Our findings demonstrate that mitophagy is an important mechanism to resist statin-induced skeletal muscle damage.-Ramesh, M., Campos, J. C., Lee, P., Song, Y., Hernandez, G., Sin, J., Tucker, K. C., Saadaeijahromi, H., Gurney, M., Ferreira, J. C. B., Andres, A. M. Mitophagy protects against statin-mediated skeletal muscle toxicity.
Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Mitofagia/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Proteína Sequestossoma-1/metabolismo , Sinvastatina/farmacologia , Animais , Caspase 3/metabolismo , Linhagem Celular , Citocromos c/metabolismo , L-Lactato Desidrogenase/metabolismo , Camundongos Knockout , Músculo Esquelético/citologia , Músculo Esquelético/metabolismo , Mioblastos/citologia , Mioblastos/efeitos dos fármacos , Mioblastos/metabolismo , Interferência de RNA , Proteína Sequestossoma-1/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Lower urinary tract symptoms (LUTSs) are highly prevalent among the elderly and negatively impact quality of life. Since caffeinated beverages are enjoyed worldwide and the relationship between LUTS and caffeine is still not fully understood, it would be of particular interest to examine the underlying mechanisms that drive caffeine's influence on LUTS development and progression. The aim of this study is to characterize the effects of caffeine on hTert-immortalized normal bladder epithelial cells by investigating whether exposure to caffeine can cause potential changes in the bladder proteome and/or biological pathways. In labeled LC-MS/MS proteomic analysis, 57 proteins are found as being differentially expressed in caffeine-treated bladder epithelial cells, compared to controls; this included 32 upregulated and 25 downregulated proteins. Further functional gene enrichment analysis reveals that caffeine affects major biological pathways, including those for "muscle contraction" and "chromatin assembly." These findings provide new scientific insights that may be useful in future studies investigating the role of caffeine in bladder dysfunctions.
Assuntos
Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Células Epiteliais/metabolismo , Proteoma/análise , Bexiga Urinária/metabolismo , Células Cultivadas , Cromatografia Líquida , Células Epiteliais/efeitos dos fármacos , Humanos , Espectrometria de Massas em Tandem , Bexiga Urinária/citologia , Bexiga Urinária/efeitos dos fármacosRESUMO
Mitochondria in cardiac myocytes are critical for generating ATP to meet the high metabolic demands associated with sarcomere shortening. Distinct remodeling of mitochondrial structure and function occur in cardiac myocytes in both developmental and pathological settings. However, the factors that underlie these changes are poorly understood. Because remodeling of tissue architecture and extracellular matrix (ECM) elasticity are also hallmarks of ventricular development and disease, we hypothesize that these environmental factors regulate mitochondrial function in cardiac myocytes. To test this, we developed a new procedure to transfer tunable polydimethylsiloxane disks microcontact-printed with fibronectin into cell culture microplates. We cultured Sprague-Dawley neonatal rat ventricular myocytes within the wells, which consistently formed tissues following the printed fibronectin, and measured oxygen consumption rate using a Seahorse extracellular flux analyzer. Our data indicate that parameters associated with baseline metabolism are predominantly regulated by ECM elasticity, whereas the ability of tissues to adapt to metabolic stress is regulated by both ECM elasticity and tissue alignment. Furthermore, bioenergetic health index, which reflects both the positive and negative aspects of oxygen consumption, was highest in aligned tissues on the most rigid substrate, suggesting that overall mitochondrial function is regulated by both ECM elasticity and tissue alignment. Our results demonstrate that mitochondrial function is regulated by both ECM elasticity and myofibril architecture in cardiac myocytes. This provides novel insight into how extracellular cues impact mitochondrial function in the context of cardiac development and disease.NEW & NOTEWORTHY A new methodology has been developed to measure O2 consumption rates in engineered cardiac tissues with independent control over tissue alignment and matrix elasticity. This led to the findings that matrix elasticity regulates basal mitochondrial function, whereas both matrix elasticity and tissue alignment regulate mitochondrial stress responses.
Assuntos
Matriz Extracelular/fisiologia , Coração/fisiologia , Mitocôndrias Cardíacas/fisiologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Elasticidade , Metabolismo Energético/fisiologia , Fibronectinas/metabolismo , Miócitos Cardíacos/fisiologia , Miofibrilas/fisiologia , Consumo de Oxigênio/fisiologia , Ratos , Ratos Sprague-DawleyRESUMO
Autophagy is an important physiological process in the heart, and alterations in autophagic activity can exacerbate or mitigate injury during various pathological processes. Methods to assess autophagy have changed rapidly because the field of research has expanded. As with any new field, methods and standards for data analysis and interpretation evolve as investigators acquire experience and insight. The purpose of this review is to summarize current methods to measure autophagy, selective mitochondrial autophagy (mitophagy), and autophagic flux. We will examine several published studies where confusion arose in data interpretation, to illustrate the challenges. Finally, we will discuss methods to assess autophagy in vivo and in patients.
Assuntos
Autofagia , Mitofagia , Imagem Óptica/métodos , Animais , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imunoensaio/métodos , Miócitos Cardíacos/metabolismoRESUMO
Autophagy is regulated by nutrient and energy status and plays an adaptive role during nutrient deprivation and ischemic stress. Metabolic syndrome (MetS) is a hypernutritive state characterized by obesity, dyslipidemia, elevated fasting blood glucose levels, and insulin resistance. It has also been associated with impaired autophagic flux and larger-sized infarcts. We hypothesized that diet-induced obesity (DIO) affects nutrient sensing, explaining the observed cardiac impaired autophagy. We subjected male friend virus B NIH (FVBN) mice to a high-fat diet, which resulted in increased weight gain, fat deposition, hyperglycemia, insulin resistance, and larger infarcts after myocardial ischemia-reperfusion. Autophagic flux was impaired after 4 wk on a high-fat diet. To interrogate nutrient-sensing pathways, DIO mice were subjected to overnight fasting, and hearts were processed for biochemical and proteomic analysis. Obese mice failed to upregulate LC3-II or to clear p62/SQSTM1 after fasting, although mRNA for LC3B and p62/SQSTM1 were appropriately upregulated in both groups, demonstrating an intact transcriptional response to fasting. Energy- and nutrient-sensing signal transduction pathways [AMPK and mammalian target of rapamycin (mTOR)] also responded appropriately to fasting, although mTOR was more profoundly suppressed in obese mice. Proteomic quantitative analysis of the hearts under fed and fasted conditions revealed broad changes in protein networks involved in oxidative phosphorylation, autophagy, oxidative stress, protein homeostasis, and contractile machinery. In many instances, the fasting response was quite discordant between lean and DIO mice. Network analysis implicated the peroxisome proliferator-activated receptor and mTOR regulatory nodes. Hearts of obese mice exhibited impaired autophagy, altered proteome, and discordant response to nutrient deprivation.
Assuntos
Autofagia , Jejum/metabolismo , Infarto do Miocárdio/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo , Obesidade/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Dieta Hiperlipídica , Modelos Animais de Doenças , Metabolismo Energético , Masculino , Síndrome Metabólica/etiologia , Síndrome Metabólica/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/etiologia , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/patologia , Obesidade/complicações , Obesidade/patologia , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Mapas de Interação de Proteínas , Proteólise , Proteômica/métodos , Proteína Sequestossoma-1/genética , Proteína Sequestossoma-1/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Fatores de TempoRESUMO
Balancing mitophagy and mitochondrial biogenesis is essential for maintaining a healthy population of mitochondria and cellular homeostasis. Coordinated interplay between these two forces that govern mitochondrial turnover plays an important role as an adaptive response against various cellular stresses that can compromise cell survival. Failure to maintain the critical balance between mitophagy and mitochondrial biogenesis or homeostatic turnover of mitochondria results in a population of dysfunctional mitochondria that contribute to various disease processes. In this review we outline the mechanics and relationships between mitophagy and mitochondrial biogenesis, and discuss the implications of a disrupted balance between these two forces, with an emphasis on cardiac physiology. This article is part of a Special Issue entitled "Mitochondria: From Basic Mitochondrial Biology to Cardiovascular Disease".
Assuntos
Mitocôndrias Cardíacas/metabolismo , Renovação Mitocondrial , Mitofagia , Animais , Coração/fisiopatologia , Humanos , Miocárdio/metabolismo , Miocárdio/patologiaRESUMO
Glutamine is a conditionally essential amino acid for the growth and survival of rapidly proliferating cancer cells. Many cancers are addicted to glutamine, and as a result, targeting glutamine metabolism has been explored clinically as a therapeutic approach. Glutamine-catalyzing enzymes are highly expressed in primary and metastatic head and neck squamous cell carcinoma (HNSCC). However, the nature of the glutamine-associated pathways in this aggressive cancer type has not been elucidated. Here, we explored the therapeutic potential of a broad glutamine antagonist, DRP-104 (sirpiglenastat), in HNSCC tumors and aimed at shedding light on glutamine-dependent pathways in this disease. We observed a potent antitumoral effect of sirpiglenastat in HPV- and HPV + HNSCC xenografts. We conducted a whole-genome CRISPR screen and metabolomics analyses to identify mechanisms of sensitivity and resistance to glutamine metabolism blockade. These approaches revealed that glutamine metabolism blockade results in the rapid buildup of polyunsaturated fatty acids (PUFAs) via autophagy nutrient-sensing pathways. Finally, our analysis demonstrated that GPX4 mediates the protection of HNSCC cells from accumulating toxic lipid peroxides; hence, glutamine blockade sensitizes HNSCC cells to ferroptosis cell death upon GPX4 inhibition. These findings demonstrate the therapeutic potential of sirpiglenastat in HNSCC and establish a novel link between glutamine metabolism and ferroptosis, which may be uniquely translated into targeted glutamine-ferroptosis combination therapies.
RESUMO
PREMISE OF THE STUDY: Sex allocation models assume male and female traits are measured in a common currency, allocation traits show heritability, and tradeoffs between investment in the two sexual functions occur. The potential for model predictions and genetic parameters to depend on the currency used is not well understood, despite frequent use of measures not in a common currency. ⢠METHODS: We analyzed the relationship between common currency (biomass of carpels, seeds, and stamens) measures and morphological measures (numbers of ovules, seeds, and pollen) in Schiedea salicaria (12-13% females) and S. adamantis (39% females), two closely related gynodioecious species. Additionally, we compared heritabilities and genetic correlations for male and female allocation between these two types of measures. ⢠KEY RESULTS: Ovule, seed, and pollen number show greater sexual dimorphism in S. adamantis than in S. salicaria. Most but not all morphological traits and analogous biomass traits are highly correlated with a linear relationship. Narrow-sense heritabilities based on the two methods are often similar, but higher for ovule number than carpel mass and lower for anther number than stamen mass in S. adamantis. Neither trait type shows negative genetic correlations between male and female function. ⢠CONCLUSIONS: Both trait types show greater sexual dimorphism in S. adamantis, and significant heritabilities suggest that morphological traits will continue to evolve with breeding system changes. Although most relationships between morphological and biomass traits are linear, curvilinear relationships for two traits suggest that caution is warranted if morphological and common currency traits are used interchangeably in fitness gain curves.
Assuntos
Caryophyllaceae/genética , Caryophyllaceae/fisiologia , Flores/anatomia & histologia , Evolução Biológica , Caryophyllaceae/classificação , Flores/genética , Flores/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Reprodução/genética , Reprodução/fisiologia , Especificidade da EspécieRESUMO
Heart failure is accompanied by adverse cardiac remodeling involving extracellular matrix (ECM). Cardiac ECM acts as a major reservoir for many proteins including growth factors, cytokines, collagens, and proteoglycans. Activated fibroblasts during cardiac injury can alter the composition and activity of these ECM proteins. Through unbiased analysis of a microarray dataset of human heart tissue comparing normal hearts (n = 135) to hearts with ischemic cardiomyopathy (n = 94), we identified Asporin (ASPN) as the top differentially regulated gene (DEG) in ischemic cardiomyopathy; its gene-ontology terms relate closely to fibrosis and cell death. ASPN is a Class I small leucine repeat protein member implicated in cancer, osteoarthritis, and periodontal ligament mineralization. However, its role in cardiac remodeling is still unknown. Here, we initially confirmed our big dataset analysis through cells, mice, and clinical atrial biopsy samples to demonstrate increased Aspn expression after pressure overload or cardiac ischemia/reperfusion injury. We tested the hypothesis that Aspn, being a TGFß1 inhibitor, can attenuate fibrosis in mouse models of cardiac injury. We found that Aspn is released by cardiac fibroblasts and attenuates TGFß signaling. Moreover, Aspn-/- mice displayed increased fibrosis and decreased cardiac function after pressure overload by transverse aortic constriction (TAC) in mice. In addition, Aspn protected cardiomyocytes from hypoxia/reoxygenation-induced cell death and regulated mitochondrial bioenergetics in cardiomyocytes. Increased infarct size after ischemia/reperfusion injury in Aspn-/- mice confirmed Aspn's contribution to cardiomyocyte viability. Echocardiography revealed greater reduction in left ventricular systolic function post-I/R in the Aspn-/- animals compared to wild type. Furthermore, we developed an ASPN-mimic peptide using molecular modeling and docking which when administered to mice prevented TAC-induced fibrosis and preserved heart function. The peptide also reduced infarct size after I/R in mice, demonstrating the translational potential of ASPN-based therapy. Thus, we establish the role of ASPN as a critical ECM molecule that regulates cardiac remodeling to preserve heart function.
Assuntos
Cardiomiopatias , Insuficiência Cardíaca , Traumatismo por Reperfusão , Animais , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Modelos Animais de Doenças , Matriz Extracelular/metabolismo , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Fibrose , Insuficiência Cardíaca/patologia , Infarto/metabolismo , Infarto/patologia , Isquemia , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Traumatismo por Reperfusão/patologia , Remodelação VentricularRESUMO
INTRODUCTION: Peptide markers of inflammation have been associated with the development of type 2 diabetes. The role of upstream, lipid-derived mediators of inflammation such as eicosanoids, remains less clear. The aim of this study was to examine whether eicosanoids are associated with incident type 2 diabetes. RESEARCH DESIGN & METHODS: In the FINRISK (Finnish Cardiovascular Risk Study) 2002 study, a population-based sample of Finnish men and women aged 25-74 years, we used directed, non-targeted liquid chromatography-mass spectrometry to identify 545 eicosanoids and related oxylipins in the participants' plasma samples (n=8292). We used multivariable-adjusted Cox regression to examine associations between eicosanoids and incident type 2 diabetes. The significant independent findings were replicated in the Framingham Heart Study (FHS, n=2886) and DIetary, Lifestyle and Genetic determinants of Obesity and Metabolic syndrome (DILGOM) 2007 (n=3905). Together, these three cohorts had 1070 cases of incident type 2 diabetes. RESULTS: In the FINRISK 2002 cohort, 76 eicosanoids were associated individually with incident type 2 diabetes. We identified three eicosanoids independently associated with incident type 2 diabetes using stepwise Cox regression with forward selection and a Bonferroni-corrected inclusion threshold. A three-eicosanoid risk score produced an HR of 1.56 (95% CI 1.41 to 1.72) per 1 SD increment for risk of incident diabetes. The HR for comparing the top quartile with the lowest was 2.80 (95% CI 2.53 to 3.07). In the replication analyses, the three-eicosanoid risk score was significant in FHS (HR 1.24 (95% CI 1.10 to 1.39, p<0.001)) and directionally consistent in DILGOM (HR 1.12 (95% CI 0.99 to 1.27, p=0.07)). Meta-analysis of the three cohorts yielded a pooled HR of 1.31 (95% CI 1.05 to 1.56). CONCLUSIONS: Plasma eicosanoid profiles predict incident type 2 diabetes and the clearest signals replicate in three independent cohorts. Our findings give new information on the biology underlying type 2 diabetes and suggest opportunities for early identification of people at risk.
Assuntos
Diabetes Mellitus Tipo 2 , Síndrome Metabólica , Adulto , Idoso , Diabetes Mellitus Tipo 2/complicações , Eicosanoides , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de RiscoRESUMO
Thioredoxin-interacting protein (Txnip) inhibits thioredoxin NADPH-dependent reduction of protein disulfides. Total Txnip knockout (TKO) mice adapted inappropriately to prolonged fasting by shifting fuel dependence of skeletal muscle and heart from fat and ketone bodies to glucose. TKO mice exhibited increased Akt signaling, insulin sensitivity, and glycolysis in oxidative tissues (skeletal muscle and hearts) but not in lipogenic tissues (liver and adipose tissue). The selective activation of Akt in skeletal muscle and hearts was associated with impaired mitochondrial fuel oxidation and the accumulation of oxidized (inactive) PTEN, whose activity depends on reduction of two critical cysteine residues. Whereas muscle- and heart-specific Txnip knockout mice recapitulated the metabolic phenotype exhibited by TKO mice, liver-specific Txnip knockout mice were similar to WT mice. Embryonic fibroblasts derived from knockout mice also accumulated oxidized (inactive) PTEN and had elevated Akt phosphorylation. In addition, they had faster growth rates and increased dependence on anaerobic glycolysis due to impaired mitochondrial fuel oxidation, and they were resistant to doxorubicin-facilitated respiration-dependent apoptosis. In the absence of Txnip, oxidative inactivation of PTEN and subsequent activation of Akt attenuated mitochondrial respiration, resulting in the accumulation of NADH, a competitive inhibitor of thioredoxin NADPH-reductive activation of PTEN. These findings indicate that, in nonlipogenic tissues, Txnip is required to maintain sufficient thioredoxin NADPH activity to reductively reactivate oxidized PTEN and oppose Akt downstream signaling.
Assuntos
Proteínas de Transporte/metabolismo , Dissulfetos/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Transdução de Sinais , Tiorredoxinas/metabolismo , Animais , Dieta , Embrião de Mamíferos/citologia , Embrião de Mamíferos/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Deleção de Genes , Glicólise/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Insulina/farmacologia , Resistência à Insulina , Lipídeos/administração & dosagem , Lipídeos/sangue , Lipídeos/farmacologia , Camundongos , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neoplasias/patologia , Especificidade de Órgãos/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Fenótipo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Asparagine synthetase (ASNS) is a gene on the long arm of chromosome 7 that is copy-number amplified in the majority of glioblastomas. ASNS copy-number amplification is associated with a significantly decreased survival. Using patient-derived glioma stem cells (GSC), we showed that significant metabolic alterations occur in gliomas when perturbing the expression of ASNS, which is not merely restricted to amino acid homeostasis. ASNS-high GSCs maintained a slower basal metabolic profile yet readily shifted to a greatly increased capacity for glycolysis and oxidative phosphorylation when needed. This led ASNS-high cells to a greater ability to proliferate and spread into brain tissue. Finally, we demonstrate that these changes confer resistance to cellular stress, notably oxidative stress, through adaptive redox homeostasis that led to radiotherapy resistance. Furthermore, ASNS overexpression led to modifications of the one-carbon metabolism to promote a more antioxidant tumor environment revealing a metabolic vulnerability that may be therapeutically exploited. IMPLICATIONS: This study reveals a new role for ASNS in metabolic control and redox homeostasis in glioma stem cells and proposes a new treatment strategy that attempts to exploit one vulnerable metabolic node within the larger multilayered tumor network.