RESUMO
BACKGROUND: Circular RNAs (circRNAs), which are involved in various human malignancies, have emerged as promising biomarkers. The present study aimed to investigate unique expression profiles of circRNAs in hepatocellular carcinoma (HCC) and identify novel biomarkers associated with HCC development and progression. METHODS: CircRNA expression profiles of HCC tissues were jointly analyzed to identify differentially expressed circRNAs. Overexpression plasmid and siRNA targeting candidate circRNAs were used in functional assays in vitro. CircRNA-miRNA interactions were predicted using miRNAs expressed in the miRNA-seq dataset GSE76903. To further screen downstream genes targeted by the miRNAs, survival analysis and qRT-PCR were conducted to evaluate their prognostic role in HCC and construct a ceRNA regulatory network. RESULTS: Three significantly upregulated circRNAs, hsa_circ_0002003, hsa_circ_0002454, and hsa_circ_0001394, and one significantly downregulated circRNA, hsa_circ_0003239, were identified and validated by qRT-PCR. Our in vitro data indicated that upregulation of hsa_circ_0002003 accelerated cell growth and metastasis. Mechanistically, DTYMK, DAP3, and STMN1, which were targeted by hsa-miR-1343-3p, were significantly downregulated in HCC cells when hsa_circ_0002003 was silenced and were significantly correlated with poor prognosis in patients with HCC. CONCLUSION: Hsa_circ_0002003 may play critical roles in HCC pathogenesis and serve as a potential prognostic biomarker for HCC. Targeting the hsa_circ_0002003/hsa-miR-1343-3p/STMN1 regulatory axis could be an effective therapeutic strategy in patients with HCC.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Humanos , Carcinoma Hepatocelular/patologia , RNA Circular/genética , Regulação para Cima , Neoplasias Hepáticas/patologia , MicroRNAs/metabolismo , Biomarcadores/análiseRESUMO
This study aimed to investigate the effectiveness of erbium-doped yttrium garnet (Er:YAG) laser and GLUMA desensitizer for dentin hypersensitivity in teeth affected by Molar-Incisor Hypomineralization (MIH). One hundred twenty children were randomly allocated to four groups: the control (Co) group, the desensitizer (De) group, the laser (La) group, and the laser + desensitizer (La + De) group. Outcome measures included Visual Analogue Scale (VAS) and 14-item Oral Health Impact Profile (OHIP-14) evaluation. For mean VAS scores, a significant reduction was found over time in all groups. Co and De groups, Co and La groups, Co and La + De groups, De and La + De groups, and La and La + De groups differed significantly (p < 0.05). For mean scores in all dimensions of OHIP-14 after treatment 6 months, the La + De group was significantly lower (p < 0.001). The La + De groups and the La groups as well as the La + De groups and the De groups differed significantly in total OHIP, functional limitation, physical disability, and psychological disability (p < 0.05). Physical pain between the La + De groups and the La groups and handicap between the La + De groups and De groups differed significantly (p < 0.05). The mean values of each dimension differed significantly between the group Co and the La + De group (p < 0.0001). Combination therapy of Er:YAG laser and GLUMA desensitizer had greater desensitizing effects and oral health-related quality improvement of life, which might be an effective alternative treatment in dentin hypersensitivity in MIH children.
Assuntos
Sensibilidade da Dentina , Terapia a Laser , Lasers de Estado Sólido , Hipomineralização Molar , Humanos , Criança , Lasers de Estado Sólido/uso terapêutico , Sensibilidade da Dentina/radioterapia , Sensibilidade da Dentina/tratamento farmacológico , DentinaRESUMO
Streptomyces bingchenggensis is the main industrial producer of milbemycins, which are a group of 16-membered macrocylic lactones with excellent insecticidal activities. In the past several decades, scientists have made great efforts to solve its low productivity. However, a lack of understanding of the regulatory network of milbemycin biosynthesis limited the development of high-producing strains using a regulatory rewiring strategy. SARPs (Streptomyces Antibiotic Regulatory Proteins) family regulators are widely distributed and play key roles in regulating antibiotics production in actinobacteria. In this paper, MilR3 (encoded by sbi_06842) has been screened out for significantly affecting milbemycin production from all the 19 putative SARP family regulators in S. bingchenggensis with the DNase-deactivated Cpf1-based integrative CRISPRi system. Interestingly, milR3 is about 7 Mb away from milbemycin biosynthetic gene cluster and adjacent to a putative type II PKS (the core minimal PKS encoding genes are sbi_06843, sbi_06844, sbi_06845 and sbi_06846) gene cluster, which was proved to be responsible for producing a yellow pigment. The quantitative real-time PCR analysis proved that MilR3 positively affected the transcription of specific genes within milbemycin BGC and those from the type II PKS gene cluster. Unlike previous "small" SARP family regulators that played pathway-specific roles, MilR3 was probably a unique SARP family regulator and played a pleotropic role. MilR3 was an upper level regulator in the MilR3-MilR regulatory cascade. This study first illustrated the co-regulatory role of this unique SARP regulator. This greatly enriches our understanding of SARPs and lay a solid foundation for milbemycin yield enhancement in the near future.
Assuntos
Regulação Bacteriana da Expressão Gênica , Streptomyces , Antibacterianos/metabolismo , Desoxirribonucleases/genética , Streptomyces/genética , Streptomyces/metabolismoRESUMO
BACKGROUND: The regulatory roles of circular RNAs (circRNAs) in tumorigenesis have attracted increasing attention. However, novel circRNAs with the potential to be used as serum/plasma biomarkers and their regulatory mechanism in the pathogenesis of hepatocellular carcinoma (HCC) remain explored. METHODS: CircRNA expression profiles of tumor tissues and plasma samples from HCC patients were compiled and jointly analyzed. CircRNA-miRNA-mRNA interactions were predicted by bioinformatics tools. The expression of interacting miRNAs and mRNA was verified in independent datasets. Survival analysis and pathway enrichment analysis were conducted on hub genes. RESULTS: We identified three significantly up-regulated circRNAs (hsa_circ_0009910, hsa_circ_0049783, and hsa_circ_0089172) both in HCC tissues and plasma samples. Two of them were validated to be indeed circular and could be excreted from hepatoma cells. We further revealed four miRNAs (hsa-miR-455-5p, hsa-miR-615-3p, hsa-miR-18a-3p, hsa-miR-4524a-3p) that targeting circRNAs and expressed in human HCC samples, and 95 mRNAs targeted by miRNAs and significantly up-regulated in two HCC cohorts. A protein-protein interaction network revealed 19 hub genes, 12 of them (MCM6, CCNB1, CDC20, NDC80, ZWINT, ASPM, CENPU, MCM3, MCM5, ECT2, CDC7, and DLGAP5) were associated with reduced survival in two HCC cohorts. KEGG, Reactome, and Wikipathway enrichment analysis indicated that the hub genes mainly functioned in DNA replication and cell cycle. CONCLUSIONS: Our study uncovers three novel deregulated circRNAs in tumor and plasma from HCC patients and provides an insight into the pathogenesis from the circRNA-miRNA-mRNA regulatory network.
RESUMO
Grincamycins (GCNs) are a class of angucycline glycosides isolated from actinomycete Streptomyces strains that have potent antitumor activities, but their antitumor mechanisms remain unknown. In this study, we tried to identify the cellular target of grincamycin B (GCN B), one of most dominant and active secondary metabolites, using a combined strategy. We showed that GCN B-selective-induced apoptosis of human acute promyelocytic leukemia (APL) cell line NB4 through increase of ER stress and intracellular reactive oxygen species (ROS) accumulation. Using a strategy of combining phenotype, transcriptomics and protein microarray approaches, we identified that isocitrate dehydrogenase 1(IDH1) was the putative target of GCN B, and confirmed that GCNs were a subset of selective inhibitors targeting both wild-type and mutant IDH1 in vitro. It is well-known that IDH1 converts isocitrate to 2-oxoglutarate (2-OG), maintaining intracellular 2-OG homeostasis. IDH1 and its mutant as the target of GCN B were validated in NB4 cells and zebrafish model. Knockdown of IDH1 in NB4 cells caused the similar phenotype as GCN B treatment, and supplementation of N-acetylcysteine partially rescued the apoptosis caused by IDH1 interference in NB4 cells. In zebrafish model, GCN B effectively restored myeloid abnormality caused by overexpression of mutant IDH1(R132C). Taken together, we demonstrate that IDH1 is one of the antitumor targets of GCNs, suggesting wild-type IDH1 may be a potential target for hematological malignancies intervention in the future.
Assuntos
Antraquinonas/farmacologia , Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Glicosídeos/farmacologia , Isocitrato Desidrogenase/antagonistas & inibidores , Animais , Antraquinonas/metabolismo , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Inibidores Enzimáticos/metabolismo , Glicosídeos/metabolismo , Humanos , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Ácidos Cetoglutáricos/metabolismo , Simulação de Acoplamento Molecular , Mutação , Ligação Proteica , Espécies Reativas de Oxigênio/metabolismo , Peixe-ZebraRESUMO
OBJECTIVES: Development of a system for direct lactose to ethanol fermentation provides a market for the massive amounts of underutilized whey permeate made by the dairy industry. For this system, glucose and galactose metabolism were uncoupled in Saccharomyces cerevisiae by deleting two negative regulatory genes, GAL80 and MIG1, and introducing the essential lactose hydrolase LAC4 and lactose transporter LAC12, from the native but inefficient lactose fermenting yeast Kluyveromyces marxianus. RESULTS: Previously, integration of the LAC4 and LAC12 genes into the MIG1 and NTH1 loci was achieved to construct strain AY-51024M. Low rates of lactose conversion led us to generate the Δmig1Δgal80 diploid mutant strain AY-GM from AY-5, which exhibited loss of diauxic growth and glucose repression, subsequently taking up galactose for consumption at a significantly higher rate and yielding higher ethanol concentrations than strain AY-51024M. Similarly, in cheese whey permeate powder solution (CWPS) during three, repeated, batch processes in a 5L bioreactor containing either 100 g/L or 150 g/L lactose, the lactose uptake and ethanol productivity rates were both significantly greater than that of AY-51024M, while the overall fermentation times were considerably lower. CONCLUSIONS: Using the Cre-loxp system for deletion of the MIG1 and GAL80 genes to relieve glucose repression, and LAC4 and LAC12 overexpression to increase lactose uptake and conversion provides an efficient basis for yeast fermentation of whey permeate by-product into ethanol.
Assuntos
Fermentação/genética , Proteínas Fúngicas/genética , Glucose/metabolismo , Lactose , Saccharomyces cerevisiae , Reatores Biológicos/microbiologia , Etanol/metabolismo , Kluyveromyces/genética , Lactose/genética , Lactose/metabolismo , Engenharia Metabólica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Soro do Leite/metabolismoRESUMO
Peroxisomes account for ~35% of total H2O2 generation in mammalian tissues. Peroxisomal ACOX1 (acyl-CoA oxidase 1) is the first and rate-limiting enzyme in fatty acid ß-oxidation and a major producer of H2O2 ACOX1 dysfunction is linked to peroxisomal disorders and hepatocarcinogenesis. Here, we show that the deacetylase sirtuin 5 (SIRT5) is present in peroxisomes and that ACOX1 is a physiological substrate of SIRT5. Mechanistically, SIRT5-mediated desuccinylation inhibits ACOX1 activity by suppressing its active dimer formation in both cultured cells and mouse livers. Deletion of SIRT5 increases H2O2 production and oxidative DNA damage, which can be alleviated by ACOX1 knockdown. We show that SIRT5 downregulation is associated with increased succinylation and activity of ACOX1 and oxidative DNA damage response in hepatocellular carcinoma (HCC). Our study reveals a novel role of SIRT5 in inhibiting peroxisome-induced oxidative stress, in liver protection, and in suppressing HCC development.
Assuntos
Acil-CoA Oxidase/antagonistas & inibidores , Acil-CoA Oxidase/metabolismo , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Estresse Oxidativo , Sirtuínas/metabolismo , Acil-CoA Oxidase/genética , Animais , Dano ao DNA , Regulação para Baixo , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Peróxido de Hidrogênio , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Oxirredução , Peroxissomos/química , Prognóstico , Sirtuínas/genéticaRESUMO
Protein neddylation, a process of conjugating neural precursor cell expressed, developmentally downregulated 8 (NEDD8) to substrates, plays a tumor-promoting role in lung carcinogenesis. Our previous study showed MLN4924, an inhibitor of NEDD8 activating enzyme (E1), significantly inhibits the growth of multiple cancer cells. However, resistance can develop to MLN4924 by mutation. Therefore, it is important to further understand how NEDD8 acts in lung cancer. In the present study, we demonstrated NEDD8 is overactivated in lung cancers and confers a worse patient overall survival. Furthermore, we report that in lung adenocarcinoma cells, NEDD8 depletion significantly suppressed lung cancer cell growth and progression both in vitro and in vivo. Mechanistic studies revealed that NEDD8 depletion induced the accumulation of a panel of tumor-suppressive cullin-RING ubiquitin ligase substrates (e.g., p21, p27, and Wee1) via blocking their degradation, triggering cell cycle arrest at G2 phase, thus inducing apoptosis or senescence in a cell-line-dependent manner. The present study demonstrates the role of NEDD8 in regulating the malignant phenotypes of lung cancer cells and further validates NEDD8 as a potential therapeutic target in lung cancer.
Assuntos
Adenocarcinoma de Pulmão/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Proteína NEDD8/metabolismo , Adenocarcinoma de Pulmão/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ciclopentanos/farmacologia , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Ubiquitina/metabolismoRESUMO
Neddylation is a posttranslational modification that conjugates a ubiquitin-like protein NEDD8 to substrate proteins. The best-characterized substrates of neddylation are the cullin subunits of cullin-RING E3 ubiquitin ligase complexes (CRLs). CRLs as the largest family of E3 ubiquitin ligases control many important biological processes, including tumorigenesis, through promoting ubiquitylation and subsequent degradation of a variety of key regulatory proteins. The process of protein neddylation is overactivated in multiple types of human cancers, providing a sound rationale as an attractive anticancer therapeutic strategy, evidenced by the development of the NEDD8-activating enzyme (NAE) inhibitor MLN4924 (also known as pevonedistat). Recently, increasing evidence strongly indicates that neddylation inhibition by MLN4924 exerts anticancer effects mainly by triggering cell apoptosis, senescence, and autophagy and causing angiogenesis suppression, inflammatory responses, and chemo-/radiosensitization in a context-dependent manner. Here, we briefly summarize the latest progresses in this field, focusing on the preclinical studies to validate neddylation modification as a promising anticancer target.
Assuntos
Proteína NEDD8/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Ciclopentanos/farmacologia , Ciclopentanos/uso terapêutico , Humanos , Proteína NEDD8/metabolismo , Neoplasias/patologia , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/efeitos dos fármacosRESUMO
Neddylation, a post-translational modification that adds an ubiquitin-like protein NEDD8 to substrate proteins, modulates many important biological processes, including tumorigenesis. The process of protein neddylation is overactivated in multiple human cancers, providing a sound rationale for its targeting as an attractive anticancer therapeutic strategy, as evidence by the development of NEDD8-activating enzyme (NAE) inhibitor MLN4924 (also known as pevonedistat). Neddylation inhibition by MLN4924 exerts significantly anticancer effects mainly by triggering cell apoptosis, senescence and autophagy. Recently, intensive evidences reveal that inhibition of neddylation pathway, in addition to acting on tumor cells, also influences the functions of multiple important components of the tumor microenvironment (TME), including immune cells, cancer-associated fibroblasts (CAFs), cancer-associated endothelial cells (CAEs) and some factors, all of which are crucial for tumorigenesis. Here, we briefly summarize the latest progresses in this field to clarify the roles of neddylation in the TME, thus highlighting the overall anticancer efficacy of neddylaton inhibition.
Assuntos
Ciclopentanos/uso terapêutico , Proteína NEDD8/metabolismo , Neoplasias/tratamento farmacológico , Pirimidinas/uso terapêutico , Fibroblastos Associados a Câncer/efeitos dos fármacos , Fibroblastos Associados a Câncer/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Senescência Celular , Ensaios Clínicos como Assunto , Ciclopentanos/farmacologia , Humanos , Proteína NEDD8/antagonistas & inibidores , Neoplasias/metabolismo , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacosRESUMO
The malate-aspartate shuttle is indispensable for the net transfer of cytosolic NADH into mitochondria to maintain a high rate of glycolysis and to support rapid tumor cell growth. The malate-aspartate shuttle is operated by two pairs of enzymes that localize to the mitochondria and cytoplasm, glutamate oxaloacetate transaminases (GOT), and malate dehydrogenases (MDH). Here, we show that mitochondrial GOT2 is acetylated and that deacetylation depends on mitochondrial SIRT3. We have identified that acetylation occurs at three lysine residues, K159, K185, and K404 (3K), and enhances the association between GOT2 and MDH2. The GOT2 acetylation at these three residues promotes the net transfer of cytosolic NADH into mitochondria and changes the mitochondrial NADH/NAD(+) redox state to support ATP production. Additionally, GOT2 3K acetylation stimulates NADPH production to suppress ROS and to protect cells from oxidative damage. Moreover, GOT2 3K acetylation promotes pancreatic cell proliferation and tumor growth in vivo. Finally, we show that GOT2 K159 acetylation is increased in human pancreatic tumors, which correlates with reduced SIRT3 expression. Our study uncovers a previously unknown mechanism by which GOT2 acetylation stimulates the malate-aspartate NADH shuttle activity and oxidative protection.
Assuntos
Aspartato Aminotransferase Mitocondrial/metabolismo , Ácido Aspártico/metabolismo , Carcinoma Ductal Pancreático/patologia , Malatos/metabolismo , Neoplasias Pancreáticas/patologia , Sirtuína 3/metabolismo , Acetilação , Animais , Transporte Biológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Proliferação de Células/genética , Células Cultivadas , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , NAD/metabolismo , Oxirredução , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Processamento de Proteína Pós-Traducional/fisiologia , Sirtuína 3/genéticaRESUMO
Metastasis is the leading cause of tumor-related death from lung cancer. However, limited success has been achieved in the treatment of lung cancer metastasis due to the lack of understanding of the mechanisms that underlie the metastatic process. In this study, Lewis lung carcinoma (LLC) cells which expressed green fluorescent protein in the nucleus and red fluorescent protein in the cytoplasm were used to record metastatic process in real-time via a whole-mouse imaging system. Using this system, we show the neddylation inhibitor MLN4924 inhibits multiple steps of the metastatic process, including intravascular survival, extravasation, and formation of metastatic colonies, thus finally suppressing tumor metastasis. Mechanistically, MLN4924 efficiently inhibits the expression of MMP2, MMP9, and vimentin and disrupts the actin cytoskeleton at an early stage to impair invasive potential and subsequently causes a DNA damage response, cell cycle arrest, and apoptosis upon long exposure to MLN4924. Furthermore, MMP2 and MMP9 are overexpressed in patient lung adenocarcinoma, which conferred a worse overall survival. Together, targeting the neddylation pathway via MLN4924 suppresses multiple steps of the metastatic process, highlighting the potential therapeutic value of MLN4924 for the treatment of metastatic lung cancer.
Assuntos
Neoplasias Pulmonares/metabolismo , Proteína NEDD8/metabolismo , Metástase Neoplásica/prevenção & controle , Animais , Apoptose/fisiologia , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Ciclopentanos/farmacologia , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Neoplasias Pulmonares/fisiopatologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteína NEDD8/fisiologia , Invasividade Neoplásica/fisiopatologia , Metástase Neoplásica/fisiopatologia , Processamento de Proteína Pós-Traducional/fisiologia , Pirimidinas/farmacologia , Transdução de Sinais , Enzimas Ativadoras de Ubiquitina/metabolismo , Vimentina/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Protein acetylation has emerged as a major mechanism in regulating cellular metabolism. Whereas most glycolytic steps are reversible, the reaction catalyzed by pyruvate kinase is irreversible, and the reverse reaction requires phosphoenolpyruvate carboxykinase (PEPCK1) to commit for gluconeogenesis. Here, we show that acetylation regulates the stability of the gluconeogenic rate-limiting enzyme PEPCK1, thereby modulating cellular response to glucose. High glucose destabilizes PEPCK1 by stimulating its acetylation. PEPCK1 is acetylated by the P300 acetyltransferase, and this acetylation stimulates the interaction between PEPCK1 and UBR5, a HECT domain containing E3 ubiquitin ligase, therefore promoting PEPCK1 ubiquitinylation and degradation. Conversely, SIRT2 deacetylates and stabilizes PEPCK1. These observations represent an example that acetylation targets a metabolic enzyme to a specific E3 ligase in response to metabolic condition changes. Given that increased levels of PEPCK are linked with type II diabetes, this study also identifies potential therapeutic targets for diabetes.
Assuntos
Gluconeogênese/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Acetilação , Linhagem Celular , Células HEK293 , Células Hep G2 , Humanos , Chaperonas Moleculares/fisiologia , Estabilidade Proteica , Sirtuína 2/fisiologia , Ubiquitina-Proteína Ligases/fisiologia , UbiquitinaçãoRESUMO
Glucose-6-phosphate dehydrogenase (G6PD) is a key enzyme in the pentose phosphate pathway (PPP) and plays an essential role in the oxidative stress response by producing NADPH, the main intracellular reductant. G6PD deficiency is the most common human enzyme defect, affecting more than 400 million people worldwide. Here, we show that G6PD is negatively regulated by acetylation on lysine 403 (K403), an evolutionarily conserved residue. The K403 acetylated G6PD is incapable of forming active dimers and displays a complete loss of activity. Knockdown of G6PD sensitizes cells to oxidative stress, and re-expression of wild-type G6PD, but not the K403 acetylation mimetic mutant, rescues cells from oxidative injury. Moreover, we show that cells sense extracellular oxidative stimuli to decrease G6PD acetylation in a SIRT2-dependent manner. The SIRT2-mediated deacetylation and activation of G6PD stimulates PPP to supply cytosolic NADPH to counteract oxidative damage and protect mouse erythrocytes. We also identified KAT9/ELP3 as a potential acetyltransferase of G6PD. Our study uncovers a previously unknown mechanism by which acetylation negatively regulates G6PD activity to maintain cellular NADPH homeostasis during oxidative stress.
Assuntos
Sobrevivência Celular/fisiologia , Glucosefosfato Desidrogenase/metabolismo , Histona Acetiltransferases/metabolismo , Homeostase/fisiologia , NADP/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Estresse Oxidativo/fisiologia , Sirtuína 2/metabolismo , Acetilação , Animais , Técnicas de Silenciamento de Genes , Glucosefosfato Desidrogenase/genética , Proteínas de Fluorescência Verde , Células HEK293 , Humanos , Camundongos , RNA Interferente Pequeno/genéticaRESUMO
Phosphoglycerate kinase 1 (PGK1) is an important enzyme in the metabolic glycolysis pathway. In this study, we observed a significant overexpression of PGK1 in liver cancer tissues and a negative correlation between PGK1 expression and liver cancer patient survival. Furthermore, depletion of PGK1 dramatically reduced cancer cell proliferation and tumorigenesis, indicating an oncogenic role of PGK1 in liver cancer progression. Moreover, we identified acetylation at the K323 site of PGK1 as an important regulatory mechanism for promoting its enzymatic activity and cancer cell metabolism. And we further characterized P300/cyclic adenosine monophosphate response element binding protein-binding protein-associated factor (PCAF) and Sirtuin 7 as the enzymes regulating K323 acetylation from both directions in liver cancer cells. CONCLUSION: These findings demonstrate a novel regulation of PGK1 as well as its important role in liver cancer progression. (Hepatology 2017;65:515-528).
Assuntos
Acetilação/efeitos dos fármacos , Carcinogênese/genética , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Fosfoglicerato Quinase/genética , Carcinoma Hepatocelular/fisiopatologia , Linhagem Celular Tumoral/metabolismo , Linhagem Celular Tumoral/patologia , Regulação Neoplásica da Expressão Gênica , Glicólise/genética , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/fisiopatologia , Modelos de Riscos Proporcionais , Técnicas de Cultura de Tecidos , Regulação para CimaRESUMO
[This corrects the article DOI: 10.1371/journal.pbio.1002243.].
RESUMO
Phosphoglycerate kinase 1 (PGK1) catalyzes the reversible transfer of a phosphoryl group from 1, 3-bisphosphoglycerate (1, 3-BPG) to ADP, producing 3-phosphoglycerate (3-PG) and ATP. PGK1 plays a key role in coordinating glycolytic energy production with one-carbon metabolism, serine biosynthesis, and cellular redox regulation. Here, we report that PGK1 is acetylated at lysine 220 (K220), which inhibits PGK1 activity by disrupting the binding with its substrate, ADP. We have identified KAT9 and HDAC3 as the potential acetyltransferase and deacetylase, respectively, for PGK1. Insulin promotes K220 deacetylation to stimulate PGK1 activity. We show that the PI3K/AKT/mTOR pathway regulates HDAC3 S424 phosphorylation, which promotes HDAC3-PGK1 interaction and PGK1 K220 deacetylation. Our study uncovers a previously unknown mechanism for the insulin and mTOR pathway in regulation of glycolytic ATP production and cellular redox potential via HDAC3-mediated PGK1 deacetylation.
Assuntos
Fosfoglicerato Quinase/metabolismo , Acetilação , Difosfato de Adenosina/metabolismo , Animais , Metabolismo dos Carboidratos , Ativação Enzimática , Glicólise , Células HEK293 , Histona Acetiltransferases/metabolismo , Histona Desacetilases/metabolismo , Humanos , Masculino , Camundongos Endogâmicos BALB C , Proteínas do Tecido Nervoso/metabolismo , Oxirredução , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismoRESUMO
Excess in mitochondrial reactive oxygen species (ROS) is considered as a major cause of cellular oxidative stress. NADPH, the main intracellular reductant, has a key role in keeping glutathione in its reduced form GSH, which scavenges ROS and thus protects the cell from oxidative damage. Here, we report that SIRT5 desuccinylates and deglutarylates isocitrate dehydrogenase 2 (IDH2) and glucose-6-phosphate dehydrogenase (G6PD), respectively, and thus activates both NADPH-producing enzymes. Moreover, we show that knockdown or knockout of SIRT5 leads to high levels of cellular ROS SIRT5 inactivation leads to the inhibition of IDH2 and G6PD, thereby decreasing NADPH production, lowering GSH, impairing the ability to scavenge ROS, and increasing cellular susceptibility to oxidative stress. Our study uncovers a SIRT5-dependent mechanism that regulates cellular NADPH homeostasis and redox potential by promoting IDH2 desuccinylation and G6PD deglutarylation.
Assuntos
Antioxidantes/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Isocitrato Desidrogenase/metabolismo , Sirtuínas/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular , Técnicas de Silenciamento de Genes , Glutationa/metabolismo , Humanos , Isocitrato Desidrogenase/química , Isocitrato Desidrogenase/genética , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Mutação , NADP/metabolismo , Oxirredução , Fosforilação Oxidativa , Estresse Oxidativo , Processamento de Proteína Pós-Traducional , Espécies Reativas de Oxigênio/metabolismo , Sirtuínas/química , Sirtuínas/genéticaRESUMO
Novel sulfur (S) anchoring materials and the corresponding mechanisms for suppressing capacity fading are urgently needed to advance the performance of Li/S batteries. Here, we designed and synthesized a graphene-like oxygenated carbon nitride (OCN) host material that contains tens of micrometer scaled two-dimensional (2D) rippled sheets, micromesopores, and oxygen heteroatoms. N content can reach as high as 20.49 wt %. A sustainable approach of one-step self-supporting solid-state pyrolysis (OSSP) was developed for the low-cost and large-scale production of OCN. The urea in solid sources not only provides self-supporting atmospheres but also produces graphitic carbon nitride (g-C3N4) working as 2D layered templates. The S/OCN cathode can deliver a high specific capacity of 1407.6 mA h g(-1) at C/20 rate with 84% S utilization and retain improved reversible capacity during long-term cycles at high current density. The increasing micropores, graphitic N, ether, and carboxylic O at the large sized OCN sheet favor S utilization and trapping for polysulfides.