RESUMO
Significance: Autofluorescence characteristics of the reduced nicotinamide adenine dinucleotide and oxidized flavin cofactors are important for the evaluation of the metabolic status of the cells. The approaches that involve a detailed analysis of both spectral and time characteristics of the autofluorescence signals may provide additional insights into the biochemical processes in the cells and biological tissues and facilitate the transition of spectral fluorescence lifetime imaging into clinical applications. Aim: We present the experiments on multispectral fluorescence lifetime imaging with a detailed analysis of the fluorescence decays and spectral profiles of the reduced nicotinamide adenine dinucleotide and oxidized flavin under a single excitation wavelength aimed at understanding whether the use of multispectral detection is helpful for metabolic imaging of cancer cells. Approach: We use two-photon spectral fluorescence lifetime imaging microscopy. Starting from model solutions, we switched to cell cultures treated by metabolic inhibitors and then studied the metabolism of cells within tumor spheroids. Results: The use of a multispectral detector in combination with an excitation at a single wavelength of 750 nm allows the identification of fluorescence signals from three components: free and bound NAD(P)H, and flavins based on the global fitting procedure. Multispectral data make it possible to assess not only the lifetime but also the spectral shifts of emission of flavins caused by chemical perturbations. Altogether, the informative parameters of the developed approach are the ratio of free and bound NAD(P)H amplitudes, the decay time of bound NAD(P)H, the amplitude of flavin fluorescence signal, the fluorescence decay time of flavins, and the spectral shift of the emission signal of flavins. Hence, with multispectral fluorescence lifetime imaging, we get five independent parameters, of which three are related to flavins. Conclusions: The approach to probe the metabolic state of cells in culture and spheroids using excitation at a single wavelength of 750 nm and a fluorescence time-resolved spectral detection with the consequent global analysis of the data not only simplifies image acquisition protocol but also allows to disentangle the impacts of free and bound NAD(P)H, and flavin components evaluate changes in their fluorescence parameters (emission spectra and fluorescence lifetime) upon treating cells with metabolic inhibitors and sense metabolic heterogeneity within 3D tumor spheroids.
Assuntos
Flavinas , NADP , Humanos , NADP/metabolismo , Flavinas/química , Flavinas/metabolismo , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Linhagem Celular Tumoral , Esferoides Celulares/metabolismo , Microscopia de Fluorescência/métodos , NAD/metabolismo , NAD/químicaRESUMO
The Rieske non-heme iron oxygenases (Rieske oxygenases) comprise a class of metalloenzymes that are involved in the biosynthesis of complex natural products and the biodegradation of aromatic pollutants. Despite this desirable catalytic repertoire, industrial implementation of Rieske oxygenases has been hindered by the multicomponent nature of these enzymes and their requirement for expensive reducing equivalents in the form of a reduced nicotinamide adenine dinucleotide cosubstrate (NAD(P)H). Fortunately, however, some Rieske oxygenases co-occur with accessory proteins, that through a downstream reaction, recycle the needed NAD(P)H for catalysis. As these pathways and accessory proteins are attractive for bioremediation applications and enzyme engineering campaigns, herein, we describe methods for assembling Rieske oxygenase pathways in vitro. Further, using the TsaMBCD pathway as a model system, in this chapter, we provide enzymatic, spectroscopic, and crystallographic methods that can be adapted to explore both Rieske oxygenases and their co-occurring accessory proteins.
Assuntos
NAD , NAD/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Oxigenases/metabolismo , Oxigenases/química , Oxigenases/isolamento & purificação , Cristalografia por Raios X/métodos , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Complexo III da Cadeia de Transporte de Elétrons/química , Complexo III da Cadeia de Transporte de Elétrons/isolamento & purificação , NADP/metabolismoRESUMO
BACKGROUND: TRY-NAD metabolic network includes TRY (tryptophan), 5-HT (5-hydroxytryptamine), KYN (kynurenine), and NAD (nicotinamide adenine dinucleotide) pathway, which plays a significant role in neurological diseases and ageing. It is important to monitor these metabolites for studying the pathological anatomy of disease and treatment of responses evaluation. Although previous studies have reported quantitative methods for several metabolites in the network, the bottlenecks of simultaneously quantifying the whole metabolic network are their similar structures, diverse physico-chemical properties, and instability. Standardized protocols for the whole metabolic network are still missing, which hinders the in-depth study of TRY-NAD metabolic network in laboratory research and clinical screening. RESULTS: We developed a LC-MS/MS method for quantifying 28 metabolites in the TRY-NAD network simultaneously. Optimization was done for the mass spectral parameters, chromatographic conditions and sample pretreatment process. The developed method was fully validated in terms of standard curves, sensitivity, carryover, recovery, matrix effect, accuracy, precision, and stability. The pretreatment of 30 samples only takes 90 min, and the LC-MS/MS running time of one sample is only 13 min. With this method, we bring to light the chaos of global TRY-NAD metabolic network in sleep deprivation mice for the first time, including serum, clotted blood cells, hippocampus, cerebral cortex, and liver. NAD pathway levels in brain and blood decreased, whereas the opposite happened in the liver. The 5-HT pathway decreased and the concentration of KYN increased significantly in the brain. The concentration of many metabolites in KYN pathway (NAD+ de novo synthesis pathway) increased in the liver. SIGNIFICANCE: This method is the first time to determine the metabolites of KYN, 5-HT and NAD pathway at the same time, and it is found that TRY-NAD metabolic network will be disordered after sleep deprivation. This work clarifies the importance of the pH of the extraction solution, the time and temperature control in pretreatment in standardized protocols building, and overcoming the problems of inconsistent sample pretreatment, separation, matrix effect interference and potential metabolite degradation. This method exhibits great prospects in providing more information on metabolic disturbances caused by sleep deprivation as well as neurological diseases and ageing.
Assuntos
NAD , Privação do Sono , Espectrometria de Massas em Tandem , Triptofano , Animais , Espectrometria de Massas em Tandem/métodos , NAD/metabolismo , Camundongos , Triptofano/metabolismo , Triptofano/sangue , Triptofano/análise , Privação do Sono/metabolismo , Privação do Sono/sangue , Masculino , Redes e Vias Metabólicas , Cromatografia Líquida , Camundongos Endogâmicos C57BL , Espectrometria de Massa com Cromatografia LíquidaRESUMO
The process of skeletal regeneration initiated by stem cells following injury, especially in fractures, is significantly impaired by aging and adverse factors. Nicotinamide mononucleotide (NMN), a critical endogenous precursor of nicotinamide adenine dinucleotide (NAD), has garnered extensive attention for its multifaceted regulatory functions in living organisms and its wide-ranging therapeutic potential. However, whether NMN contributes to trauma-induced skeletal regeneration remains unclear. Methods: The transverse femoral shaft fracture model was employed to evaluate the potential advantages of NMN administration for overall repair during the initial fracture stages in male mice through micro-CT analysis, histochemistry, and biomechanical testing. The pro-proliferative function of NMN on skeletal stem cells (SSCs) was investigated through flow cytometry, qRT-PCR, NAD content measurement, and cell proliferation assay. Results: In this study, we observed that the administration of NMN during the initial phase of fracture in mice led to a larger callus and corresponding improvement in micro-CT parameters. NMN enhances the cartilaginous component of the callus by elevating the NAD content, consequently accelerating subsequent endochondral ossification and the fracture healing process. Subsequent analyses elucidated that NMN was beneficial in promoting the expansion of diverse stem cells in vivo and in vitro potentially via modulation of the Notch signaling pathway. Moreover, the depletion of macrophages profoundly obstructs the proliferation of SSCs. Conclusion: Our discoveries provide a potential strategy for enhancing fracture healing through stimulation of callus SSC proliferation at an early stage, shedding light on the translational value of NMN as an enhancer for skeletal regeneration and highlighting the pivotal role of macrophage-stem cell interactions in governing the regenerative influence of NMN on stem cells.
Assuntos
Proliferação de Células , Consolidação da Fratura , Mononucleotídeo de Nicotinamida , Animais , Camundongos , Proliferação de Células/efeitos dos fármacos , Consolidação da Fratura/efeitos dos fármacos , Mononucleotídeo de Nicotinamida/farmacologia , Masculino , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Microtomografia por Raio-X , Osteogênese/efeitos dos fármacos , Modelos Animais de Doenças , Fraturas do Fêmur/tratamento farmacológico , Fraturas do Fêmur/patologia , Camundongos Endogâmicos C57BL , Transdução de Sinais/efeitos dos fármacos , Calo Ósseo/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , NAD/metabolismoRESUMO
Aging and age-related ailments have emerged as critical challenges and great burdens within the global contemporary society. Addressing these concerns is an imperative task, with the aims of postponing the aging process and finding effective treatments for age-related degenerative diseases. Recent investigations have highlighted the significant roles of nicotinamide adenine dinucleotide (NAD+) in the realm of anti-aging. It has been empirically evidenced that supplementation with nicotinamide mononucleotide (NMN) can elevate NAD+ levels in the body, thereby ameliorating certain age-related degenerative diseases. The principal anti-aging mechanisms of NMN essentially lie in its impact on cellular energy metabolism, inhibition of cell apoptosis, modulation of immune function, and preservation of genomic stability, which collectively contribute to the deferral of the aging process. This paper critically reviews and evaluates existing research on the anti-aging mechanisms of NMN, elucidates the inherent limitations of current research, and proposes novel avenues for anti-aging investigations.
Assuntos
Envelhecimento , NAD , Mononucleotídeo de Nicotinamida , Mononucleotídeo de Nicotinamida/farmacologia , Humanos , Envelhecimento/efeitos dos fármacos , NAD/metabolismo , Animais , Apoptose/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Instabilidade Genômica/efeitos dos fármacosRESUMO
Barrett's esophagus (BE) is a common precancerous lesion that can progress to esophageal adenocarcinoma (EAC). There are significant alterations in the esophageal microbiome in the progression from healthy esophagus to BE to EAC, including an increased abundance of a variety of lactate-producing bacteria and an increase of lactate in the tumor microenvironment, as predicted by metabolic modeling. The role of bacterial lactate in EAC is unknown. Here, we utilize patient-derived organoid (PDO) models of EAC and demonstrate that lactate inhibits the growth and proliferation of EAC PDOs through alterations in the tumor NADH/NAD+ redox state. Further RNA sequencing of EAC PDOs identifies ID1 and RSAD2 as potential regulatory molecules crucial in mediating lactate's ability to suppress glycolysis and proliferation. Gene ontology analysis also identifies the activation of inflammatory and immunological pathways in addition to alterations in the metabolic pathways in EAC PDOs exposed to lactate, suggesting a multi-faceted role for lactate in the pathogenesis of EAC.
Assuntos
Adenocarcinoma , Proliferação de Células , Neoplasias Esofágicas , Ácido Láctico , NAD , Organoides , Oxirredução , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Humanos , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Organoides/metabolismo , Organoides/efeitos dos fármacos , NAD/metabolismo , Ácido Láctico/metabolismo , Proliferação de Células/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Esôfago de Barrett/metabolismo , Esôfago de Barrett/patologia , Microambiente TumoralRESUMO
Ischemic stroke (IS) is a severe condition regulated by complex molecular alterations. This study aimed to identify potential nicotinamide adenine dinucleotide (NAD+) metabolism-associated diagnostic markers of IS and explore their associations with immune dynamics. Weighted Gene Co-expression Network Analysis and single-sample gene set enrichment analysis (ssGSEA) were employed to identify key gene modules on the GEO dataset (GSE16561). LASSO regression was used to identify diagnostic genes. A diagnostic model was then developed using the training dataset, and its performance was assessed using a validation dataset (GSE22255 dataset). Associations between hub genes and immune cells, immune response genes, and human leukocyte antigen (HLA) genes were assessed by ssGSEA. A regulatory network was constructed using mirBase and TRRUST databases. A total of 20 NAD+ metabolic genes exhibited noteworthy expression variations. Within the module notably associated with NAD+ metabolism, 19 specific genes were included in the diagnostic model, which was validated on the GSE22255 dataset (AUC: 0.733). There were significant disparities in immune cell populations, immune response genes, and HLA gene expression, all of which were associated with the hub genes. A regulatory network composed of 153 edges and 103 nodes was constructed. This study advances our understanding of IS by providing insights into NAD+ metabolism and gene interactions, contributing to potential diagnostic innovations in IS.
Assuntos
Redes Reguladoras de Genes , AVC Isquêmico , Aprendizado de Máquina , NAD , Humanos , NAD/metabolismo , AVC Isquêmico/genética , AVC Isquêmico/diagnóstico , Biomarcadores/metabolismo , Bases de Dados Genéticas , Perfilação da Expressão GênicaRESUMO
Bioactive NAD+ mediated multiple biocatalytic pathways in metabolic networks. Refining the structure of NADH oxidase-like (NOX) mimics to efficiently replenish NAD+ has been promising but challenging in NAD+-dependent dehydrogenase electrochemical cascade biosensing. Herein, we discovered that PtOx structures, formed via lattice oxygen translocation from WO3 to Pt NPs at the interface, potentially activate and modulate the NOX-like functionality in Pt@WO3 nanosheets. Incorporating PtOx leads to a more positive valence of Pt species within Pt/PtOx@WO3-x, where the PtO2 species serve as preeminent reaction sites for NADH coordination, activation, and dehydrogenation. Consequently, such nanozymes display enhanced NOX-like activity towards NADH oxidation in comparison to Pt@WO3. Ultimately, the 650-Pt/PtOx@WO3-x nanozyme is employed in an electrochemical cascade biosensor for ß-hydroxybutyrate (HB) detection, achieving a calculated detection limit of 25 µM. This study offers insights into PtOx activation in Pt-based NOX mimics and supports the future development of NAD+/NADH-dependent electrochemical biosensors.
Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , NAD , Óxidos , Platina , Tungstênio , NAD/química , Tungstênio/química , Platina/química , Óxidos/química , Hidroxibutiratos/química , Oxirredução , Nanopartículas Metálicas/química , Limite de DetecçãoRESUMO
BACKGROUND: Approximately 70% of patients receiving neurotoxic chemotherapy (e.g., paclitaxel or vincristine) will develop chemotherapy-induced peripheral neuropathy. Despite the known negative effects of CIPN on physical functioning and chemotherapy dosing, little is known about how to prevent CIPN. The development of efficacious CIPN prevention interventions is hindered by the lack of knowledge surrounding CIPN mechanisms. Nicotinamide adenine dinucleotide (NAD+) and cyclic-adenosine diphosphate ribose (cADPR) are potential markers of axon degeneration following neurotoxic chemotherapy, however, such markers have been exclusively measured in preclinical models of chemotherapy-induced peripheral neuropathy (CIPN). The overall objective of this longitudinal, observational study was to determine the association between plasma NAD+, cADPR, and ADPR with CIPN severity in young adults receiving vincristine or paclitaxel. METHODS: Young adults (18-39 years old) beginning vincristine or paclitaxel were recruited from Dana-Farber Cancer Institute. Young adults completed the QLQ-CIPN20 sensory and motor subscales and provided a blood sample prior to starting chemotherapy (T1) and at increasing cumulative vincristine (T2: 3-5 mg, T3: 7-9 mg) and paclitaxel (T2: 300-500 mg/m2, T3: 700-900 mg/m2) dosages. NAD+, cADPR, and ADPR were quantified from plasma using mass spectrometry. Metabolite levels and QLQ-CIPN20 scores over time were compared using mixed-effects linear regression models and/or paired two-sample tests. RESULTS: Participants (N = 50) were mainly female (88%), white (80%), and receiving paclitaxel (78%). Sensory and motor CIPN severity increased from T1-T3 (p < 0.001). NAD+ (p = 0.28), cADPR (p = 0.62), and ADPR (p = 0.005) values decreased, while cADPR/NAD+ ratio increased from T1-T3 (p = 0.50). There were no statistically significant associations between NAD + and QLQ-CIPN20 scores over time. CONCLUSIONS: To our knowledge, this is the first study to measure plasma NAD+, cADPR, and ADPR among patients receiving neurotoxic chemotherapy. Although, no meaningful changes in NAD+, cADPR, or cADPR/NAD+ were observed among young adults receiving paclitaxel or vincristine. Future research in an adequately powered sample is needed to explore the clinical utility of biomarkers of axon degeneration among patients receiving neurotoxic chemotherapy to guide mechanistic research and novel CIPN treatments.
Assuntos
Paclitaxel , Doenças do Sistema Nervoso Periférico , Vincristina , Humanos , Vincristina/efeitos adversos , Feminino , Paclitaxel/efeitos adversos , Adulto , Masculino , Adulto Jovem , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/sangue , Adolescente , Axônios/efeitos dos fármacos , Axônios/patologia , Estudos Longitudinais , NAD/metabolismo , NAD/sangue , Biomarcadores/sangue , Antineoplásicos Fitogênicos/efeitos adversos , Degeneração Neural/induzido quimicamente , Degeneração Neural/patologia , Degeneração Neural/sangueRESUMO
Nicotinamide adenine dinucleotide (NAD+) is an essential metabolite that plays a crucial role in diverse biological processes, including energy metabolism, gene expression, DNA repair, and mitochondrial function. An aberrant NAD+ level mediates the development of cardiovascular dysfunction and diseases. Both in vivo and in vitro studies have demonstrated that nicotinamide mononucleotide (NMN), as a NAD+ precursor, alleviates the development of cardiovascular diseases such as heart failure, atherosclerosis, and myocardial ischemia/reperfusion injury. Importantly, NMN has suggested pharmacological activities mostly through its involvement in NAD+ biosynthesis. Several clinical studies have been conducted to investigate the efficacy and safety of NMN supplementation, indicating its potential role in cardiovascular protection without significant adverse effects. In this review, we systematically summarize the impact of NMN as a nutraceutical and potential therapeutic drug on cardiovascular diseases and emphasize the correlation between NMN supplementation and cardiovascular protection.
Assuntos
Doenças Cardiovasculares , Mononucleotídeo de Nicotinamida , Humanos , Mononucleotídeo de Nicotinamida/uso terapêutico , Mononucleotídeo de Nicotinamida/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/tratamento farmacológico , Animais , Suplementos Nutricionais , NAD/metabolismoRESUMO
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting both upper and lower motor neurons. While there have been many potential factors implicated for ALS development, such as oxidative stress and mitochondrial dysfunction, no exact mechanism has been determined at this time. Nicotinamide adenine dinucleotide (NAD+) is one of the most abundant metabolites in mammalian cells and is crucial for a broad range of cellular functions from DNA repair to energy homeostasis. NAD+ can be synthesized from three different intracellular pathways, but it is the NAD+ salvage pathway that generates the largest proportion of NAD+. Impaired NAD+ homeostasis has been connected to aging and neurodegenerative disease-related dysfunctions. In ALS mice, NAD+ homeostasis is potentially disrupted prior to the appearance of physical symptoms and is significantly reduced in the nervous system at the end stage. Treatments targeting NAD+ metabolism, either by administering NAD+ precursor metabolites or small molecules that alter NAD+-dependent enzyme activity, have shown strong beneficial effects in ALS disease models. Here, we review the therapeutic interventions targeting NAD+ metabolism for ALS and their effects on the most prominent pathological aspects of ALS in animal and cell models.
Assuntos
Esclerose Lateral Amiotrófica , NAD , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/tratamento farmacológico , NAD/metabolismo , Humanos , Animais , Modelos Animais de DoençasRESUMO
Cellular NAD+ is continuously degraded and synthesized under resting conditions. In mammals, NAD+ synthesis is primarily initiated from nicotinamide (Nam) by Nam phosphoribosyltransferase, whereas poly(ADP-ribose) polymerase 1 (PARP1) and 2 (PARP2), sirtuin1 (SIRT1), CD38, and sterile alpha and TIR motif containing 1 (SARM1) are involved in NAD+ breakdown. Using flux analysis with 2H-labeled Nam, we found that when mammalian cells were cultured in the absence of Nam, cellular NAD+ levels were maintained and NAD+ breakdown was completely suppressed. In the presence of Nam, the rate of NAD+ breakdown (RB) did not significantly change upon PARP1, PARP2, SIRT1, or SARM1 deletion, whereas stable expression of CD38 did not increase RB. However, RB in PARP1-deleted cells was much higher compared with that in wild-type cells, in which PARP1 activity was blocked with a selective inhibitor. In contrast, RB in CD38-overexpressing cells in the presence of a specific CD38 inhibitor was much lower compared with that in control cells. The results indicate that PARP1 deletion upregulates the activity of other NADases, whereas CD38 expression downregulates the activity of endogenous NADases, including PARP1 and PARP2. The rate of cellular NAD+ breakdown and the resulting NAD+ concentration may be maintained at a constant level, despite changes in the NAD+-degrading enzyme expression, through the compensatory regulation of NADase activity.
Assuntos
ADP-Ribosil Ciclase 1 , NAD , Poli(ADP-Ribose) Polimerase-1 , Sirtuína 1 , NAD/metabolismo , ADP-Ribosil Ciclase 1/metabolismo , ADP-Ribosil Ciclase 1/genética , Animais , Poli(ADP-Ribose) Polimerase-1/metabolismo , Sirtuína 1/metabolismo , Sirtuína 1/genética , Niacinamida/farmacologia , Niacinamida/metabolismo , Camundongos , Poli(ADP-Ribose) Polimerases/metabolismo , Humanos , Nicotinamida Fosforribosiltransferase/metabolismo , Nicotinamida Fosforribosiltransferase/genética , Deleção de GenesRESUMO
Environmental conditions significantly impact the metabolism of Saccharomyces cerevisiae, a Crabtree-positive yeast that maintains a fermentative metabolism in high-sugar environments even in the presence of oxygen. Although the introduction of oxygen has been reported to induce alterations in yeast metabolism, knowledge of the mechanisms behind these metabolic adaptations in relation to redox cofactor metabolism and their implications in the context of wine fermentation remains limited. This study aimed to compare the intracellular redox cofactor levels, the cofactor ratios, and primary metabolite production in S. cerevisiae under aerobic and anaerobic conditions in synthetic grape juice. The molecular mechanisms underlying these metabolic differences were explored using a transcriptomic approach. Aerobic conditions resulted in an enhanced fermentation rate and biomass yield. Total NADP(H) levels were threefold higher during aerobiosis, while a decline in the total levels of NAD(H) was observed. However, there were stark differences in the ratio of NAD+/NADH between the treatments. Despite few changes in the differential expression of genes involved in redox cofactor metabolism, anaerobiosis resulted in an increased expression of genes involved in lipid biosynthesis pathways, while the presence of oxygen increased the expression of genes associated with thiamine, methionine, and sulfur metabolism. The production of fermentation by-products was linked with differences in the redox metabolism in each treatment. This study provides valuable insights that may help steer the production of metabolites of industrial interest during alcoholic fermentation (including winemaking) by using oxygen as a lever of redox metabolism.
Assuntos
Fermentação , Oxirredução , Oxigênio , Saccharomyces cerevisiae , Vinho , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Oxigênio/metabolismo , Vinho/microbiologia , Vinho/análise , Anaerobiose , Vitis/microbiologia , Vitis/metabolismo , NAD/metabolismo , Etanol/metabolismo , NADP/metabolismo , Aerobiose , Regulação Fúngica da Expressão Gênica , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Coenzimas/metabolismoRESUMO
Glioblastoma multiforme (GBM) is the most aggressive type of cancer in the brain and has an inferior prognosis because of the lack of suitable medicine, largely due to its tremendous invasion. GBM has selfish metabolic pathways to promote migration, invasion, and proliferation compared to normal cells. Among various metabolic pathways, NAD (nicotinamide adenine dinucleotide) is essential in generating ATP and is used as a resource for cancer cells. LbNOX (Lactobacillus brevis NADH oxidase) is an enzyme that can directly manipulate the NAD+/NADH ratio. In this study, we found that an increased NAD+/NADH ratio by LbNOX or mitoLbNOX reduced intracellular glutamate and calcium responses and reduced invasion capacity in GBM. However, the invasion was not affected in GBM by rotenone, an ETC (Electron Transport Chain) complex I inhibitor, or nicotinamide riboside, a NAD+ precursor, suggesting that the crucial factor is the NAD+/NADH ratio rather than the absolute quantity of ATP or NAD+ for the invasion of GBM. To develop a more accurate and effective GBM treatment, our findings highlight the importance of developing a new medicine that targets the regulation of the NAD+/NADH ratio, given the current lack of effective treatment options for this brain cancer.
Assuntos
Glioblastoma , Metaboloma , NAD , Glioblastoma/metabolismo , Glioblastoma/patologia , NAD/metabolismo , Humanos , Linhagem Celular Tumoral , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Complexos Multienzimáticos/metabolismo , Levilactobacillus brevis/metabolismo , Invasividade Neoplásica , Cálcio/metabolismo , Ácido Glutâmico/metabolismo , Movimento Celular , Trifosfato de Adenosina/metabolismo , NADH NADPH OxirredutasesRESUMO
Experiments now support theoretical suggestions that coenzymes mediated key metabolic reactions before the emergence of enzymes. Three coenzymes believed essential to the core metabolism of the last universal common ancestor to extant life (pyridoxal phosphate, adenosine diphosphate, and nicotinamide adenine dinucleotide) were recently found to be active in their corresponding metabolic reactions in the absence of enzymes. These findings suggest an earlier contribution of coenzymes to abiogenesis, ultimately yielding insights into the prebiotic origins of metabolism.
Assuntos
Coenzimas , Coenzimas/metabolismo , Enzimas/metabolismo , NAD/metabolismo , Origem da Vida , Difosfato de Adenosina/metabolismo , Fosfato de Piridoxal/metabolismoRESUMO
Myopathy is a common manifestation in mitochondrial disorders, but the pathomechanisms are still insufficiently studied in children. Here, we report a severe, progressive mitochondrial myopathy in a four-year-old child, who died at eight years. He developed progressive loss of muscle strength with nocturnal hypoventilation and dilated cardiomyopathy. Skeletal muscle showed ragged red fibers and severe combined respiratory chain deficiency. Mitochondrial DNA sequencing revealed a novel m.5670A>G mutation in mitochondrial tRNAAsn (MTTN) with 88 % heteroplasmy in muscle. The proband also had systemic NAD+ deficiency but rescuing this with the NAD+ precursor niacin did not stop disease progression. Targeted metabolomics revealed an overall shift of metabolism towards controls after niacin supplementation, with normalized tryptophan metabolites and lipid-metabolic markers, but most amino acids did not respond to niacin therapy. To conclude, we report a new MTTN mutation, secondary NAD+ deficiency in childhood-onset mitochondrial myopathy with metabolic but meager clinical response to niacin supplementation.
Assuntos
Miopatias Mitocondriais , NAD , Niacina , Humanos , Masculino , Miopatias Mitocondriais/genética , Miopatias Mitocondriais/tratamento farmacológico , NAD/metabolismo , Pré-Escolar , Músculo Esquelético/patologia , Músculo Esquelético/efeitos dos fármacos , Mutação , Suplementos Nutricionais , DNA Mitocondrial/genética , CriançaRESUMO
BACKGROUND: Fever is one of the main pathophysiological reactions that occurs during the acute phase of various diseases. Excessive body temperature can lead to various adverse consequences such as brain tissue damage and abnormal immune responses. Phillyrin (Phr) is the main active ingredient in Forsythia suspensa (Thunb.) Vahl (Lian Qiao) and has antipyretic effects; however, its antipyretic mechanism of action remains unclear. PURPOSE: This study aimed to explore the antipyretic mechanisms of Phr and provide a new treatment plan for fever. METHODS: The antipyretic effects of Phr were evaluated using a mouse model of pneumonia fever. The main metabolites of Phr involved in its antipyretic function were identified using a mitochondrial temperature-sensitive probe. Further synthesis of the main metabolite, phillygenin (Phg), an alkynylated probe, was performed, and chemical proteomics was used to capture and analyze its direct target for antipyretic effects. The mechanism of action of Phg and its antipyretic targets was explored using metabolomics and various molecular biology methods. RESULTS: Phr showed significant antipyretic and anti-inflammatory effects in a mouse model of lipopolysaccharide-induced fever. Phg reversibly targeted the nicotinamide adenine dinucleotide (NAD+) binding domain of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), malate dehydrogenase 2 (MDH2), and isocitrate dehydrogenase 2 (IDH2) to inhibit their enzymatic activity. In-depth analysis of cellular metabolomics and mitochondrial stress testing indicated that inhibition of GAPDH, MDH2, and IDH2 enzyme activity by Phg led to a decrease in cellular energy supply and heat production regulated by glycolysis, tricarboxylic acid cycle, and oxidative phosphorylation signaling pathways. Phg specifically targeted macrophages and inhibited LPS-induced macrophage activation by downregulating GAPDH enzyme activity, thereby exerting anti-inflammatory effects. In vivo experiments also confirmed that the antipyretic effect of Phr in LPS-induced fever model mice was related to its main metabolites, Phg and Phg-sulfonate (Phg-S), which directly targeted the NAD+ binding domain of GAPDH, IDH2, and MDH2, inhibiting the activity of these enzymes, thereby reducing energy supply and regulating febrile-related inflammatory factors. CONCLUSION: This study reported for the first time that the antipyretic effect of Phr is produced by targeting GAPDH, IDH2, and MDH2 to regulate energy supply and febrile-related inflammatory factors through its main metabolites Phg and Phg-S. This study not only provides potential drugs for fever treatment but also provides new ideas for improving clinical fever treatment plans.
Assuntos
Antipiréticos , Febre , Isocitrato Desidrogenase , Animais , Antipiréticos/farmacologia , Febre/tratamento farmacológico , Isocitrato Desidrogenase/metabolismo , Camundongos , Masculino , Malato Desidrogenase/metabolismo , Modelos Animais de Doenças , NAD/metabolismo , Lipopolissacarídeos , Anti-Inflamatórios/farmacologia , Células RAW 264.7 , Pneumonia/tratamento farmacológico , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , GlucosídeosRESUMO
Lactate dehydrogenase (Ldh, EC 1.1.1.27), an oxidoreductase enzyme catalyses the interconversion of pyruvate to L-lactate and vice-versa with concomitant oxidation and reduction of NADH and NAD+. The enzyme functions as a ROS sensor and mitigates stress response by maintaining NAD+/NADH homeostasis. In this study, we delineated the role of the Ldh enzyme in imparting cadmium stress tolerance in rice. Previously, we identified a putatively active Ldh in rice (OsLdh7) through insilico modelling. Biochemical characterization of the OsLdh7 enzyme revealed it to be optimally active at pH 6.6 in the forward direction and pH 9 in the reverse direction. Overexpression of OsLdh7 in rice cv. IR64, increased tolerance of the transgenic lines to cadmium stress compared to the wild type (WT) at both seedling and reproductive stages. The transgenic lines showed increased enzyme activity in the reverse direction under cadmium stress, attributed to elevated cytosolic pH resulting from increased calcium concentration. This increased NADH content is highly essential for functioning of the ROS scavenging enzymes, RbohD and MPK6. qPCR analysis revealed that the overexpression lines had increased transcript abundance of these genes indicating an effective ROS scavenging mechanism. Additionally, the overexpression lines showed an efficient cadmium sequestration mechanism compared to the WT by increasing the transcript levels of the vacuolar transporters of cadmium as well as total phytochelatin content. Thus, our findings indicated OsLdh7 imparts cadmium stress tolerance in rice through a two-pronged approach by mitigating ROS and sequestering cadmium ions, highlighting its potential for crop improvement programs.
Assuntos
Cádmio , NAD , Oryza , Proteínas de Plantas , Estresse Fisiológico , Oryza/genética , Oryza/metabolismo , Oryza/enzimologia , Oryza/efeitos dos fármacos , Cádmio/metabolismo , Cádmio/toxicidade , NAD/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Estresse Fisiológico/genética , Plantas Geneticamente Modificadas , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , L-Lactato Desidrogenase/metabolismo , L-Lactato Desidrogenase/genéticaRESUMO
Most kidney cancers are metabolically dysfunctional1-4, but how this dysfunction affects cancer progression in humans is unknown. We infused 13C-labelled nutrients in over 80 patients with kidney cancer during surgical tumour resection. Labelling from [U-13C]glucose varies across subtypes, indicating that the kidney environment alone cannot account for all tumour metabolic reprogramming. Compared with the adjacent kidney, clear cell renal cell carcinomas (ccRCCs) display suppressed labelling of tricarboxylic acid (TCA) cycle intermediates in vivo and in ex vivo organotypic cultures, indicating that suppressed labelling is tissue intrinsic. [1,2-13C]acetate and [U-13C]glutamine infusions in patients, coupled with measurements of respiration in isolated human kidney and tumour mitochondria, reveal lower electron transport chain activity in ccRCCs that contributes to decreased oxidative and enhanced reductive TCA cycle labelling. However, ccRCC metastases unexpectedly have enhanced TCA cycle labelling compared with that of primary ccRCCs, indicating a divergent metabolic program during metastasis in patients. In mice, stimulating respiration or NADH recycling in kidney cancer cells is sufficient to promote metastasis, whereas inhibiting electron transport chain complex I decreases metastasis. These findings in humans and mice indicate that metabolic properties and liabilities evolve during kidney cancer progression, and that mitochondrial function is limiting for metastasis but not growth at the original site.
Assuntos
Carcinoma de Células Renais , Ciclo do Ácido Cítrico , Complexo I de Transporte de Elétrons , Neoplasias Renais , Mitocôndrias , Metástase Neoplásica , Neoplasias Renais/patologia , Neoplasias Renais/metabolismo , Humanos , Animais , Complexo I de Transporte de Elétrons/metabolismo , Camundongos , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/metabolismo , Mitocôndrias/metabolismo , Masculino , Feminino , Glutamina/metabolismo , NAD/metabolismo , Glucose/metabolismo , Isótopos de Carbono/metabolismo , Respiração Celular , Acetatos/metabolismo , Acetatos/farmacologia , OxirreduçãoRESUMO
Liver fibrosis progressing to cirrhosis is a major risk factor for liver cancer, impacting surgical treatment and survival. Our study focuses on the role of extracellular nicotinamide adenine dinucleotide (eNAD+) in liver fibrosis, analyzing liver disease patients undergoing surgery. Additionally, we explore NAD+'s therapeutic potential in a mouse model of extended liver resection and in vitro using 3D hepatocyte spheroids. eNAD+ correlated with aspartate transaminase (AST) and bilirubin after liver resection (AST: r = 0.2828, p = 0.0087; Bilirubin: r = 0.2584, p = 0.0176). Concordantly, post-hepatectomy liver failure (PHLF) was associated with higher eNAD+ peaks (n = 10; p = 0.0063). Post-operative eNAD+ levels decreased significantly (p < 0.05), but in advanced stages of liver fibrosis or cirrhosis, this decline not only diminished but actually showed a trend towards an increase. The expression of NAD+ biosynthesis rate-limiting enzymes, nicotinamide phosphoribosyltransferase (NAMPT) and nicotinamide mononucleotide adenylyltransferase 3 (NMNAT3), were upregulated significantly in the liver tissue of patients with higher liver fibrosis stages (p < 0.0001). Finally, the administration of NAD+ in a 3D hepatocyte spheroid model rescued hepatocytes from TNFalpha-induced cell death and improved viability (p < 0.0001). In a mouse model of extended liver resection, NAD+ treatment significantly improved survival (p = 0.0158) and liver regeneration (p = 0.0186). Our findings reveal that eNAD+ was upregulated in PHLF, and rate-limiting enzymes of NAD+ biosynthesis demonstrated higher expressions under liver fibrosis. Further, eNAD+ administration improved survival after extended liver resection in mice and enhanced hepatocyte viability in vitro. These insights may offer a potential target for future therapies.