Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.197
Filtrar
1.
Nat Commun ; 15(1): 2372, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491007

RESUMO

Tricarboxylic acid cycle (TCA cycle) plays an important role for aerobic growth of heterotrophic bacteria. Theoretically, eliminating TCA cycle would decrease carbon dissipation and facilitate chemicals biosynthesis. Here, we construct an E. coli strain without a functional TCA cycle that can serve as a versatile chassis for chemicals biosynthesis. We first use adaptive laboratory evolution to recover aerobic growth in minimal medium of TCA cycle-deficient E. coli. Inactivation of succinate dehydrogenase is a key event in the evolutionary trajectory. Supply of succinyl-CoA is identified as the growth limiting factor. By replacing endogenous succinyl-CoA dependent enzymes, we obtain an optimized TCA cycle-deficient E. coli strain. As a proof of concept, the strain is engineered for high-yield production of four separate products. This work enhances our understanding of the role of the TCA cycle in E. coli metabolism and demonstrates the advantages of using TCA cycle-deficient E. coli strain for biotechnological applications.


Assuntos
Ciclo do Ácido Cítrico , Escherichia coli , Ciclo do Ácido Cítrico/genética , Escherichia coli/metabolismo , Fermentação , Biotecnologia , Bactérias
2.
J Cell Mol Med ; 28(7): e18187, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38509725

RESUMO

Cuproptosis is a recently discovered programmed cell death pattern that affects the tricarboxylic acid (TCA) cycle by disrupting the lipoylation of pyruvate dehydrogenase (PDH) complex components. However, the role of cuproptosis in the progression of ischemic heart failure (IHF) has not been investigated. In this study, we investigated the expression of 10 cuproptosis-related genes in samples from both healthy individuals and those with IHF. Utilizing these differential gene expressions, we developed a risk prediction model that effectively distinguished healthy and IHF samples. Furthermore, we conducted a comprehensive evaluation of the association between cuproptosis and the immune microenvironment in IHF, encompassing infiltrated immunocytes, immune reaction gene-sets and human leukocyte antigen (HLA) genes. Moreover, we identified two different cuproptosis-mediated expression patterns in IHF and explored the immune characteristics associated with each pattern. In conclusion, this study elucidates the significant influence of cuproptosis on the immune microenvironment in ischemic heart failure (IHF), providing valuable insights for future mechanistic research exploring the association between cuproptosis and IHF.


Assuntos
Perfilação da Expressão Gênica , Insuficiência Cardíaca , Humanos , Insuficiência Cardíaca/genética , Apoptose , Ciclo do Ácido Cítrico , Citoplasma , Cobre , Microambiente Tumoral
3.
Mol Biol Rep ; 51(1): 389, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38446272

RESUMO

Fibrosis is characterized by abnormal deposition of the extracellular matrix (ECM), leading to organ structural remodeling and loss of function. The principal cellular effector in fibrosis is activated myofibroblasts, which serve as the main source of matrix proteins. Metabolic reprogramming, transitioning from mitochondrial oxidative phosphorylation to aerobic glycolysis, is widely observed in rapidly dividing cells such as tumor cells and activated myofibroblasts and is increasingly recognized as a fundamental pathogenic basis in organ fibrosis. Targeting metabolism represents a promising strategy to mitigate fibrosis. PKM2, a key enzyme in glycolysis, plays a pivotal role in metabolic reprogramming through allosteric regulation, impacting both metabolic and non-metabolic pathways. Therefore, metabolic reprogramming induced by PKM2 activation is involved in the occurrence and development of fibrosis in various organs. A comprehensive understanding of the role of PKM2 in fibrotic diseases is crucial for seeking new anti-fibrotic therapeutic targets. In this context, we summarize PKM2's role in glycolysis, mediating the intricate mechanisms underlying fibrosis in multiple organs, and discuss the potential value of PKM2 inhibitors and allosteric activators in future clinical treatments, aiming to identify novel therapeutic targets for proliferative fibrotic diseases.


Assuntos
Ciclo do Ácido Cítrico , Piruvato Quinase , Regulação Alostérica , Matriz Extracelular , Glicólise
4.
Artigo em Alemão | MEDLINE | ID: mdl-38354729

RESUMO

Immunometabolism is a fascinating field of research that investigates the interactions between metabolic processes and the immune response. This intricate connection plays a pivotal role in regulating inflammatory reactions and consequently exerts a significant impact on the course of sepsis. The proinflammatory response during an immune reaction is closely tied to a high energy demand in immune cells. As a result, proinflammatory immune cells rapidly require substantial amounts of energy in the form of ATP, necessitating a fundamental and swift shift in their metabolism, i.e., their means of generating energy. This entails a marked increase in glycolysis within the proinflammatory response, thereby promptly meeting the energy requirements and providing essential metabolic building blocks for the biosynthesis of macromolecules. Alongside glycolysis, there is heightened activity in the pentose phosphate pathway (PPP). The PPP significantly contributes to NADPH production within the cell, thus maintaining redox equilibrium. Elevated PPP activity consequently leads to an increased NADPH level, resulting in enhanced production of reactive oxygen species (ROS) and nitric oxide (NO). While these molecules are crucial for pathogen elimination, an excess can also induce tissue damage. Simultaneously, there are dual interruptions in the citric acid cycle. In the cellular resting state, the citric acid cycle acts as a sort of "universal processor", where metabolic byproducts of glycolysis, fatty acid breakdown, and amino acid degradation are initially transformed into NADH and FADH2, subsequently yielding ATP. While the citric acid cycle and its connected oxidative phosphorylation predominantly generate energy at rest, it becomes downregulated in the proinflammatory phase of sepsis. The two interruptions lead to an accumulation of citrate and succinate within cells, reflecting mitochondrial dysfunction. Additionally, the significantly heightened glycolysis through fermentation yields lactate, a pivotal metabolite for sepsis diagnosis and prognosis. Conversely, cells in an anti-inflammatory state revert to a metabolic profile akin to the resting state: Glycolysis is attenuated, PPP is suppressed, and the citric acid cycle is reactivated. Of particular interest is that not only does the immune reaction influence metabolic pathways, but this connection also operates in reverse. Thus, modulation of metabolic pathways also modulates the immunity of the corresponding cell and thereby the state of the immune system itself. This could potentially serve as an intriguing avenue in sepsis therapy.


Assuntos
Glicólise , Sepse , Humanos , NADP , Glicólise/fisiologia , Ciclo do Ácido Cítrico/fisiologia , Trifosfato de Adenosina
5.
Int J Mol Sci ; 25(4)2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38396952

RESUMO

Mitochondrial dysfunction and glutamate toxicity are associated with neural disorders, including brain trauma. A review of the literature suggests that toxic and transmission actions of neuronal glutamate are spatially and functionally separated. The transmission pathway utilizes synaptic GluN2A receptors, rapidly released pool of glutamate, evoked release of glutamate mediated by Synaptotagmin 1 and the amount of extracellular glutamate regulated by astrocytes. The toxic pathway utilizes extrasynaptic GluN2B receptors and a cytoplasmic pool of glutamate, which results from the spontaneous release of glutamate mediated by Synaptotagmin 7 and the neuronal 2-oxoglutarate dehydrogenase complex (OGDHC), a tricarboxylic acid (TCA) cycle enzyme. Additionally, the inhibition of OGDHC observed upon neuro-inflammation is due to an excessive release of reactive oxygen/nitrogen species by immune cells. The loss of OGDHC inhibits uptake of glutamate by mitochondria, thus facilitating its extracellular accumulation and stimulating toxic glutamate pathway without affecting transmission. High levels of extracellular glutamate lead to dysregulation of intracellular redox homeostasis and cause ferroptosis, excitotoxicity, and mitochondrial dysfunction. The latter affects the transmission pathway demanding high-energy supply and leading to cell death. Mitochondria aggravate glutamate toxicity due to impairments in the TCA cycle and become a victim of glutamate toxicity, which disrupts oxidative phosphorylation. Thus, therapies targeting the TCA cycle in neurological disorders may be more efficient than attempting to preserve mitochondrial oxidative phosphorylation.


Assuntos
Ácido Glutâmico , Doenças Mitocondriais , Humanos , Ácido Glutâmico/metabolismo , Mitocôndrias/metabolismo , Ciclo do Ácido Cítrico , Espécies Reativas de Oxigênio/metabolismo , Inflamação/metabolismo , Doenças Mitocondriais/metabolismo
6.
Biomolecules ; 14(2)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38397386

RESUMO

Feline leukemia virus C receptor 1a (FLVCR1a), initially identified as a retroviral receptor and localized on the plasma membrane, has emerged as a crucial regulator of heme homeostasis. Functioning as a positive regulator of δ-aminolevulinic acid synthase 1 (ALAS1), the rate-limiting enzyme in the heme biosynthetic pathway, FLVCR1a influences TCA cycle cataplerosis, thus impacting TCA flux and interconnected metabolic pathways. This study reveals an unexplored link between FLVCR1a, heme synthesis, and cholesterol production in endothelial cells. Using cellular models with manipulated FLVCR1a expression and inducible endothelial-specific Flvcr1a-null mice, we demonstrate that FLVCR1a-mediated control of heme synthesis regulates citrate availability for cholesterol synthesis, thereby influencing cellular cholesterol levels. Moreover, alterations in FLVCR1a expression affect membrane cholesterol content and fluidity, supporting a role for FLVCR1a in the intricate regulation of processes crucial for vascular development and endothelial function. Our results underscore FLVCR1a as a positive regulator of heme synthesis, emphasizing its integration with metabolic pathways involved in cellular energy metabolism. Furthermore, this study suggests that the dysregulation of heme metabolism may have implications for modulating lipid metabolism. We discuss these findings in the context of FLVCR1a's potential heme-independent function as a choline importer, introducing additional complexity to the interplay between heme and lipid metabolism.


Assuntos
Ciclo do Ácido Cítrico , Células Endoteliais , Camundongos , Animais , Células Endoteliais/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Membrana Celular/metabolismo , Camundongos Knockout , Heme/metabolismo
7.
J Ethnopharmacol ; 325: 117864, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38325671

RESUMO

ETHNOPHARMACOLOGY RELEVANCE: Cananga oil (CO) is derived from the flowers of the traditional medicinal plant, the ylang-ylang tree. As a traditional antidepressant, CO is commonly utilized in the treatment of various mental disorders including depression, anxiety, and autism. It is also recognized as an efficient antibacterial insecticide, and has been traditionally utilized to combat malaria and acute inflammatory responses resulting from bacterial infections both in vitro and in vivo. AIM OF THE STUDY: The objective of this study is to comprehensively investigate the anti-Salmonella activity and mechanism of CO both in vitro and in vivo, with the expectation of providing feasible strategies for exploring new antimicrobial strategies and developing novel drugs. METHODS: The in vitro antibacterial activity of CO was comprehensively analyzed by measuring MIC, MBC, growth curve, time-killing curve, surface motility, biofilm, and Live/dead bacterial staining. The analysis of the chemistry and active ingredients of CO was conducted using GC-MS. To examine the influence of CO on the membrane homeostasis of Salmonella, we conducted utilizing diverse techniques, including ANS, PI, NPN, ONPG, BCECF-AM, DiSC3(5), and scanning electron microscopy (SEM) analysis. In addition, the antibacterial mechanism of CO was analyzed and validated through metabolomics analysis. Finally, a mouse infection model of Salmonella typhimurium was established to evaluate the toxic side effects and therapeutic effects of CO. RESULTS: The antibacterial effect of CO is the result of the combined action of the main chemical components within its six (palmitic acid, α-linolenic acid, stearic acid, benzyl benzoate, benzyl acetate, and myristic acid). Furthermore, CO disrupts the balance of purine metabolism and the tricarboxylic acid cycle (TCA cycle) in Salmonella, interfering with redox processes. This leads to energy metabolic disorders and oxidative stress damage within the bacteria, resulting in bacterial shock, enhanced membrane damage, and ultimately bacterial death. It is worth emphasizing that CO exerts an effective protective influence on Salmonella infection in vivo within a non-toxic concentration range. CONCLUSION: The outcomes indicate that CO displays remarkable anti-Salmonella activity both in vitro and in vivo. It triggers bacterial death by disrupting the balance of purine metabolism and the TCA cycle, interfering with the redox process, making it a promising anti-Salmonella medication.


Assuntos
Cananga , Infecções por Salmonella , Humanos , Animais , Camundongos , Ciclo do Ácido Cítrico , Infecções por Salmonella/tratamento farmacológico , Óleos de Plantas/farmacologia , Óleos de Plantas/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias , Homeostase , Purinas/farmacologia , Testes de Sensibilidade Microbiana
8.
J Plant Physiol ; 294: 154195, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38377939

RESUMO

We discuss the role of epigenetic changes at the level of promoter methylation of the key enzymes of carbon metabolism in the regulation of respiration by light. While the direct regulation of enzymes via modulation of their activity and post-translational modifications is fast and readily reversible, the role of cytosine methylation is important for providing a prolonged response to environmental changes. In addition, adenine methylation can play a role in the regulation of transcription of genes. The mitochondrial and extramitochondrial forms of several enzymes participating in the tricarboxylic acid cycle and associated reactions are regulated via promoter methylation in opposite ways. The mitochondrial forms of citrate synthase, aconitase, fumarase, NAD-malate dehydrogenase are inhibited while the cytosolic forms of aconitase, fumarase, NAD-malate dehydrogenase, and the peroxisomal form of citrate synthase are activated. It is concluded that promoter methylation represents a universal mechanism of the regulation of activity of respiratory enzymes in plant cells by light. The role of the regulation of the mitochondrial and cytosolic forms of respiratory enzymes in the operation of malate and citrate valves and in controlling the redox state and balancing the energy level of photosynthesizing plant cells is discussed.


Assuntos
Fumarato Hidratase , Malato Desidrogenase , Malato Desidrogenase/genética , Malato Desidrogenase/metabolismo , Citrato (si)-Sintase/genética , Citrato (si)-Sintase/metabolismo , Fumarato Hidratase/genética , Ácidos Tricarboxílicos/metabolismo , Ciclo do Ácido Cítrico , Plantas/genética , Plantas/metabolismo , Aconitato Hidratase/genética , Aconitato Hidratase/metabolismo , Metilação de DNA/genética , Respiração
9.
J Pharm Biomed Anal ; 241: 116004, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38309097

RESUMO

Organic acids (OAs) play important roles in a variety of intracellular metabolic pathways, such as the tricarboxylic acid cycle, fatty acid oxidation, glycolysis. The accurate detection of OAs in fecal samples was crucial for comprehending the metabolic changes associated with various metabolic disease. However, the analytical protocol detecting OAs profiling in feces have received scant attention. In this work, an optimized protocol based on chromatography-mass spectrometry for simultaneous quantification of 23 OAs in rat feces was developed. The optimal conditions involved using a 40-mg fecal sample mixed with isopropyl alcohol, acetonitrile, and deionized water (3:2:2 vol ratio) with a total volume of 1500 µL, followed by ultrasonic extraction and a derivatization reaction with an 80 µL derivative agent. The protocol showed an acceptable linearity (R2 ≥ 0.9906), the satisfactory precision (RSD% ≤ 14.87%), the low limits of detection (0.001 to 1 µg/mL) and the limit of quantification (0.005 to 1.5 µg/mL). Moreover, the dried residues of the extracted solution showed the better stability of OAs at -20 °C, which was more suitable for a large-scale sample analysis. Finally, the developed protocol was successfully applied to compare the difference of OAs profiling in fecal samples harvested from normal and nonalcoholic fatty liver disease rats, which was beneficial to find out the metabolic change of OAs profiling and explain the related mechanism of the disease.


Assuntos
Ciclo do Ácido Cítrico , Glicólise , Ratos , Animais , Cromatografia Gasosa-Espectrometria de Massas/métodos , Fezes/química , Água/análise
10.
J Labelled Comp Radiopharm ; 67(3): 86-90, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38171549

RESUMO

[1'-13 C]Citric acid (1) was efficiently prepared from dimethyl 1,3-acetonedicarboxylate in two steps as a probe for a breath test. The synthetic method was selected because of the yield and reproducibility. Compound 1 was orally administrated to rats, and the time course of the increase of 13 CO2 /12 CO2 ratios (Δ13 CO2 ) in their breath was successfully followed, indicating the metabolism of 1. Thus, the 13 C-breath test using 1 is a promising method to evaluate tricarboxylic acid (TCA) cycle flux.


Assuntos
Ciclo do Ácido Cítrico , Ácido Cítrico , Ratos , Animais , Dióxido de Carbono , Reprodutibilidade dos Testes , Testes Respiratórios
11.
Sci Rep ; 14(1): 2333, 2024 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-38282028

RESUMO

Hepatocellular carcinoma (HCC) is the most prevalent type of liver cancer. Since the tricarboxylic acid cycle is widely involved in tumor metabolic reprogramming and cuproptosis, investigating related genes may help to identify prognostic signature of patients with HCC. Data on patients with HCC were sourced from public datasets, and were divided into train, test, and single-cell cohorts. A variety of machine learning algorithms were used to identify different molecular subtypes and determine the prognostic risk model. Our findings revealed that the risk score (TRscore), based on the genes OGDHL, CFHR4, and SPP1, showed excellent predictive performance in different datasets. Pathways related to cell cycle and immune inflammation were enriched in the high-risk group, whereas metabolism-related pathways were significantly enriched in the low-risk group. The high-risk group was associated with a greater number of mutations of detrimental biological behavior and higher levels of immune infiltration, immune checkpoint expression, and anti-cancer immunotherapy response. Low-risk patients demonstrated greater sensitivity to erlotinib and phenformin. SPP1 was mainly involved in the interaction among tumor-associated macrophages, T cells, and malignant cells via SPP1-CD44 and SPP1-(ITGA5 + ITGB1) ligand-receptor pairs. In summary, our study established a prognostic model, which may contribute to individualized treatment and clinical management of patients with HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Prognóstico , Ciclo do Ácido Cítrico/genética , Neoplasias Hepáticas/genética , Algoritmos , Microambiente Tumoral
12.
ACS Appl Mater Interfaces ; 16(5): 5486-5503, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38284176

RESUMO

Cranial bone defects remain a major clinical challenge, increasing patients' life burdens. Tricarboxylic acid (TCA) cycle metabolites play crucial roles in facilitating bone tissue regeneration. However, the development of TCA cycle metabolite-modified biomimetic grafts for skull bone regeneration still needs to be improved. The mechanism underlying the release of TCA cycle metabolites from biomaterials in regulating immune responses and mesenchymal stem cell (MSC) fate (migration and differentiation) remains unknown. Herein, this work constructs biomimetic hydrogels composed of gelatin and chitosan networks covalently cross-linked by genipin (CGG hydrogels). A series of TCA cycle metabolite-coordinated CGG hydrogels with strong mechanical and antiswelling performances are subsequently developed. Remarkably, the citrate (Na3Cit, Cit)-coordinated CGG hydrogels (CGG-Cit hydrogels) with the highest mechanical modulus and strength significantly promote skull bone regeneration in rat and murine cranial defects. Mechanistically, using a transgenic mouse model, bulk RNA sequencing, and single-cell RNA sequencing, this work demonstrates that CGG-Cit hydrogels promote Gli1+ MSC migration via neutrophil-secreted oncostatin M. Results also indicate that citrate improves osteogenesis via enhanced histone H3K9 acetylation on osteogenic master genes. Taken together, the immune microenvironment- and MSC fate-regulated CGG-Cit hydrogels represent a highly efficient and facile approach toward skull bone tissue regeneration with great potential for bench-to-bedside translation.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Humanos , Ratos , Camundongos , Animais , Histonas , Ciclo do Ácido Cítrico , Acetilação , Neutrófilos/metabolismo , Regeneração Óssea , Crânio/metabolismo , Diferenciação Celular , Hidrogéis/farmacologia , Hidrogéis/metabolismo , Citratos
13.
J Exp Clin Cancer Res ; 43(1): 22, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38238853

RESUMO

BACKGROUND: Triple-negative breast cancer is a complex breast malignancy subtype characterized by poor prognosis. The pursuit of effective therapeutic approaches for this subtype is considerably challenging. Notably, recent research has illuminated the key role of the tricarboxylic acid cycle in cancer metabolism and the complex landscape of tumor development. Concurrently, an emerging body of evidence underscores the noteworthy role that long non-coding RNAs play in the trajectory of breast cancer development. Despite this growing recognition, the exploration of whether long non-coding RNAs can influence breast cancer progression by modulating the tricarboxylic acid cycle has been limited. Moreover, the underlying mechanisms orchestrating these interactions have not been identified. METHODS: The expression levels of LINC00571 and IDH2 were determined through the analysis of the public TCGA dataset, transcriptome sequencing, qRT‒PCR, and Western blotting. The distribution of LINC00571 was assessed using RNA fluorescence in situ hybridization. Alterations in biological effects were evaluated using CCK-8, colony formation, EdU, cell cycle, and apoptosis assays and a tumor xenograft model. To elucidate the interaction between LINC00571, HNRNPK, and ILF2, RNA pull-down, mass spectrometry, coimmunoprecipitation, and RNA immunoprecipitation assays were performed. The impacts of LINC00571 and IDH2 on tricarboxylic acid cycle metabolites were investigated through measurements of the oxygen consumption rate and metabolite levels. RESULTS: This study revealed the complex interactions between a novel long non-coding RNA (LINC00571) and tricarboxylic acid cycle metabolism. We validated the tumor-promoting role of LINC00571. Mechanistically, LINC00571 facilitated the interaction between HNRNPK and ILF2, leading to reduced ubiquitination and degradation of ILF2, thereby stabilizing its expression. Furthermore, ILF2 acted as a transcription factor to enhance the expression of its downstream target gene IDH2. CONCLUSIONS: Our study revealed that the LINC00571/HNRNPK/ILF2/IDH2 axis promoted the progression of triple-negative breast cancer by regulating tricarboxylic acid cycle metabolites. This discovery provides a novel theoretical foundation and new potential targets for the clinical treatment of triple-negative breast cancer.


Assuntos
RNA Longo não Codificante , Neoplasias de Mama Triplo Negativas , Humanos , Linhagem Celular Tumoral , Neoplasias de Mama Triplo Negativas/patologia , Ciclo do Ácido Cítrico , Hibridização in Situ Fluorescente , RNA/metabolismo , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas Grupo K/metabolismo , Proteína do Fator Nuclear 45/genética , Proteína do Fator Nuclear 45/metabolismo
14.
Nat Commun ; 15(1): 846, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38287013

RESUMO

A prevalent side-reaction of succinate dehydrogenase oxidizes malate to enol-oxaloacetate (OAA), a metabolically inactive form of OAA that is a strong inhibitor of succinate dehydrogenase. We purified from cow heart mitochondria an enzyme (OAT1) with OAA tautomerase (OAT) activity that converts enol-OAA to the physiological keto-OAA form, and determined that it belongs to the highly conserved and previously uncharacterized Fumarylacetoacetate_hydrolase_domain-containing protein family. From all three domains of life, heterologously expressed proteins were shown to have strong OAT activity, and ablating the OAT1 homolog caused significant growth defects. In Escherichia coli, expression of succinate dehydrogenase was necessary for OAT1-associated growth defects to occur, and ablating OAT1 caused a significant increase in acetate and other metabolites associated with anaerobic respiration. OAT1 increased the succinate dehydrogenase reaction rate by 35% in in vitro assays with physiological concentrations of both succinate and malate. Our results suggest that OAT1 is a universal metabolite repair enzyme that is required to maximize aerobic respiration efficiency by preventing succinate dehydrogenase inhibition.


Assuntos
Malatos , Succinato Desidrogenase , Succinato Desidrogenase/genética , Succinato Desidrogenase/metabolismo , Malatos/metabolismo , Ciclo do Ácido Cítrico , Mitocôndrias Cardíacas/metabolismo , Oxaloacetatos/metabolismo , Ácido Oxaloacético/metabolismo , Malato Desidrogenase/metabolismo
15.
FASEB J ; 38(2): e23373, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38217376

RESUMO

Fatigue is a common phenomenon closely related to physical discomfort and numerous diseases, which is severely threatening the life quality and health of people. However, the exact mechanisms underlying fatigue are not fully characterized. Herein, we demonstrate that oxaloacetic acid (OAA), a crucial tricarboxylic acid cycle intermediate, modulates the muscle fatigue. The results showed that serum OAA level was positively correlated with fatigue state of mice. OAA-treated induced muscle fatigue impaired the exercise performance of mice. Mechanistically, OAA increased the c-Jun N-terminal kinase (JNK) phosphorylation and uncoupling protein 2 (UCP2) levels in skeletal muscle, which led to decreased energy substrate and enhanced glycolysis. On the other hand, OAA boosted muscle mitochondrial oxidative phosphorylation uncoupled with energy production. In addition, either UCP2 knockout or JNK inhibition totally reversed the effects of OAA on skeletal muscle. Therein, JNK mediated UCP2 activation with OAA-treated. Our studies reveal a novel role of OAA in skeletal muscle metabolism, which would shed light on the mechanism of muscle fatigue and weakness.


Assuntos
Mitocôndrias , Ácido Oxaloacético , Humanos , Camundongos , Animais , Ácido Oxaloacético/metabolismo , Ácido Oxaloacético/farmacologia , Mitocôndrias/metabolismo , Fosforilação Oxidativa , Ciclo do Ácido Cítrico , Músculo Esquelético/metabolismo , Proteína Desacopladora 2/genética , Proteína Desacopladora 2/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Proteína Desacopladora 3/metabolismo , Metabolismo Energético
16.
Biochim Biophys Acta Mol Basis Dis ; 1870(2): 166935, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37976628

RESUMO

Succinate, one of the intermediates of the tricarboxylic acid (TCA) cycle, plays an essential role in the metabolism of mitochondria and the production of energy, and is considered as a signaling molecule in metabolism as well as in initiation and progression of hepatic diseases. Of note, succinate activates a downstream signaling pathway through GPR91, and elicits a variety of intracellular responses, such as succinylation, production of reactive oxygen species (ROS), stabilization of hypoxia-inducible factor-1α (HIF-1α), and significant impact in cellular metabolism because of the pivotal role in the TCA cycle. Therefore, it is intriguing to deeply elucidate signaling mechanisms of succinate in hepatic fibrosis, metabolic reprogramming in inflammatory or immune responses, as well as carcinogenesis. This manuscript intends to review current understanding of succinate in mediating metabolism, inflammatory and immunologic reactions in liver diseases in order to establish molecular basis for the development of therapeutic strategies.


Assuntos
Succinatos , Ácido Succínico , Humanos , Ácido Succínico/metabolismo , Transdução de Sinais , Ciclo do Ácido Cítrico , Cirrose Hepática/metabolismo
17.
J Biol Chem ; 300(1): 105485, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37992808

RESUMO

EZH2 (Enhancer of Zeste Homolog 2), a subunit of Polycomb Repressive Complex 2 (PRC2), catalyzes the trimethylation of histone H3 at lysine 27 (H3K27me3), which represses expression of genes. It also has PRC2-independent functions, including transcriptional coactivation of oncogenes, and is frequently overexpressed in lung cancers. Clinically, EZH2 inhibition can be achieved with the FDA-approved drug EPZ-6438 (tazemetostat). To realize the full potential of EZH2 blockade, it is critical to understand how cell-cell/cell-matrix interactions present in 3D tissue and cell culture systems influences this blockade in terms of growth-related metabolic functions. Here, we show that EZH2 suppression reduced growth of human lung adenocarcinoma A549 cells in 2D cultures but stimulated growth in 3D cultures. To understand the metabolic underpinnings, we employed [13C6]-glucose stable isotope-resolved metabolomics to determine the effect of EZH2 suppression on metabolic networks in 2D versus 3D A549 cultures. The Krebs cycle, neoribogenesis, γ-aminobutyrate metabolism, and salvage synthesis of purine nucleotides were activated by EZH2 suppression in 3D spheroids but not in 2D cells, consistent with the growth effect. Using simultaneous 2H7-glucose + 13C5,15N2-Gln tracers and EPZ-6438 inhibition of H3 trimethylation, we delineated the effects on the Krebs cycle, γ-aminobutyrate metabolism, gluconeogenesis, and purine salvage to be PRC2-dependent. Furthermore, the growth/metabolic effects differed for mouse Matrigel versus self-produced A549 extracellular matrix. Thus, our findings highlight the importance of the presence and nature of extracellular matrix in studying the function of EZH2 and its inhibitors in cancer cells for modeling the in vivo outcomes.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste , Humanos , Linhagem Celular Tumoral , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Complexo Repressor Polycomb 2/antagonistas & inibidores , Complexo Repressor Polycomb 2/genética , Células A549 , Adenocarcinoma de Pulmão/fisiopatologia , Técnicas de Silenciamento de Genes , Glicólise/genética , Ciclo do Ácido Cítrico/genética , Via de Pentose Fosfato/genética , Nucleotídeos de Purina/genética , Regulação Neoplásica da Expressão Gênica
18.
Proteomics ; 24(1-2): e2300185, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37847886

RESUMO

Lactylation, as a novel posttranslational modification, is essential for studying the functions and regulation of proteins in physiological and pathological processes, as well as for gaining in-depth knowledge on the occurrence and development of many diseases, including tumors. However, few studies have examined the protein lactylation of one whole organism. Thus, we studied the lactylation of global proteins in Caenorhabditis elegans to obtain an in vivo lactylome. Using an MS-based platform, we identified 1836 Class I (localization probabilities > 0.75) lactylated sites in 487 proteins. Bioinformatics analysis showed that lactylated proteins were mainly located in the cytoplasm and involved in the tricarboxylic acid cycle (TCA cycle) and other metabolic pathways. Then, we evaluated the conservation of lactylation in different organisms. In total, 41 C. elegans proteins were lactylated and homologous to lactylated proteins in humans and rats. Moreover, lactylation on H4K80 was conserved in three species. An additional 238 lactylated proteins were identified in C. elegans for the first time. This study establishes the first lactylome database in C. elegans and provides a basis for studying the role of lactylation.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Humanos , Animais , Ratos , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Ciclo do Ácido Cítrico , Redes e Vias Metabólicas , Proteoma/metabolismo
19.
Clin Transl Oncol ; 26(2): 338-351, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37477784

RESUMO

Gastric cancer is the fifth most common malignancy worldwide having the fourth highest mortality rate. Energy metabolism is key and closely linked to tumour development. Most important in the reprogramming of cancer metabolism is the Warburg effect, which suggests that tumour cells will utilise glycolysis even with normal oxygen levels. Various molecules exert their effects by acting on enzymes in the glycolytic pathway, integral to glycolysis. Second, mitochondrial abnormalities in the reprogramming of energy metabolism, with consequences for glutamine metabolism, the tricarboxylic acid cycle and oxidative phosphorylation, abnormal fatty acid oxidation and plasma lipoprotein metabolism are important components of tumour metabolism. Third, inflammation-induced oxidative stress is a danger signal for cancer. Fourth, patterns of signalling pathways involve all aspects of metabolic transduction, and many clinical drugs exert their anticancer effects through energy metabolic signalling. This review summarises research on energy metabolism genes, enzymes and proteins and transduction pathways associated with gastric cancer, and discusses the mechanisms affecting their effects on postoperative treatment resistance and prognoses of gastric cancer. We believe that an in-depth understanding of energy metabolism reprogramming will aid the diagnosis and subsequent treatment of gastric cancer.


Assuntos
Neoplasias , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamento farmacológico , Metabolismo Energético/fisiologia , Neoplasias/patologia , Glicólise/genética , Ciclo do Ácido Cítrico , Fosforilação Oxidativa
20.
Environ Toxicol ; 39(1): 238-251, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37688782

RESUMO

Recent studies have shown that Solute Carrier Family 9 Member A2 (SLC9A2) could serve as a biomarker for cancer. However, its mechanism of action in osteosarcoma (OS) was still unclear. In this study, the data sets GSE154530 and GSE99671 were downloaded from the Gene Expression Omnibus (GEO) database, and 31 differentially expressed genes (DEGs) related to methylation were screened by bioinformatics analysis tools. Subsequently, SLC9A2 was screened as a candidate gene from DEGs, which was significantly downregulated in OS. CCK-8, transwell, western blotting and Seahorse XFe24 Cell Metabolic Analyzer assays demonstrated that overexpression of SLC9A2 could constrain OS cell proliferation, invasion, and aerobic glycolysis. Dual-luciferase reporter gene assay and chromatin immunoprecipitation (ChIP) assays indicated ETS proto-oncogene 1 (ETS1) was a transcription suppressor of SLC9A2, and overexpression of ETS1 could promote methylation levels in specific regions of the SLC9A2 promoter. ETS1 could promote the proliferation, invasion, and aerobic glycolysis ability of OS cells, as well as tumor growth in vivo by inhibiting the expression of SLC9A2. In addition, SLC9A2, suppressing by ETS1, restrains growth and invasion of OS via inhibition of aerobic glycolysis. Thus, SLC9A2 can function as a key inhibitory factor in the aerobic glycolysis to inhibit proliferation and invasion of OS. This indicated that SLC9A2 has a potential targeted therapeutic effect on OS.


Assuntos
Neoplasias Ósseas , MicroRNAs , Osteossarcoma , Humanos , Linhagem Celular Tumoral , Glicólise/genética , Proliferação de Células/genética , Ciclo do Ácido Cítrico , Osteossarcoma/metabolismo , MicroRNAs/genética , Regulação Neoplásica da Expressão Gênica , Movimento Celular/genética , Neoplasias Ósseas/patologia , Proteína Proto-Oncogênica c-ets-1/genética , Proteína Proto-Oncogênica c-ets-1/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...