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1.
Redox Biol ; 59: 102581, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36565645

RESUMO

Mucus forms the first line of defence of the intestinal mucosa barrier, and mucin is its core component. Glutamine is a vital energy substance for goblet cells; it can promote mucus synthesis and alleviate damage to the intestinal mucus barrier after burn injury, but its mechanism is not fully understood. This study focused on the molecular mechanisms underlying the effects of glutamine on the synthesis and modification of mucin 2 (MUC2) by using animal and cellular models of burn sepsis. We found that anterior gradient-2 (AGR2) plays a key role in the posttranslational modification of MUC2. Oxidative stress induced by burn sepsis enhanced the S-glutathionylation of AGR2, interfered with the processing and modification of MUC2 precursors by AGR2 and blocked the synthesis of mature MUC2. Further studies revealed that NADPH, catalysed by glucose-6-phosphate dehydrogenase (G6PD), is a key molecule in inhibiting oxidative stress and regulating AGR2 activity. Glutamine promotes O-linked N-acetylglucosamine (O-GlcNAc) modification of G6PD via the hexosamine pathway, which facilitates G6PD homodimer formation and increases NADPH synthesis, thereby inhibiting AGR2 S-glutathionylation and promoting MUC2 maturation, ultimately reducing damage to the intestinal mucus barrier after burn sepsis. Overall, we have demonstrated that the central mechanisms of glutamine in promoting MUC2 maturation and maintaining the intestinal mucus barrier are the enhancement of G6PD glycosylation and inhibition of AGR2 S-glutathionylation.


Assuntos
Glucosefosfato Desidrogenase , Glutamina , Animais , Camundongos , Glucosefosfato Desidrogenase/metabolismo , Glutamina/metabolismo , Células Caliciformes/metabolismo , Muco/metabolismo , NADP/metabolismo
2.
Int J Mol Sci ; 23(24)2022 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-36555768

RESUMO

Glucose-6-phosphate dehydrogenase (G6PDH) catalyzes a metabolic hub between glycolysis and the pentose phosphate pathway (PPP), which is the oxidation of glucose-6-phosphate (G6P) to 6-phosphogluconolactone concomitantly with the production of nicotinamide adenine dinucleotide phosphate (NADPH), a reducing power. It is considered to be the rate-limiting step that governs carbon flow through the oxidative pentose phosphate pathway (OPPP). The OPPP is the main supplier of reductant (NADPH) for several "reducing" biosynthetic reactions. Although it is involved in multiple physiological processes, current knowledge on its exact role and regulation is still piecemeal. The present review provides a concise and comprehensive picture of the diversity of plant G6PDHs and their role in seed germination, nitrogen assimilation, plant branching, and plant response to abiotic stress. This work will help define future research directions to improve our knowledge of G6PDHs in plant physiology and to integrate this hidden player in plant performance.


Assuntos
Glucosefosfato Desidrogenase , Plantas , Glucosefosfato Desidrogenase/metabolismo , NADP/metabolismo , Oxirredução , Plantas/metabolismo , Fenômenos Fisiológicos Vegetais , Via de Pentose Fosfato
3.
J Neurophysiol ; 128(6): 1507-1517, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36321738

RESUMO

Heat-shock protein B (HSPB1) has a neuroprotective effect on brain injury and is a negative regulator of ferroptosis. Therefore, we infer that HSPB1 plays a protective role in hypoxic-ischemic (HI) brain damage by inhibiting ferroptosis. A neonatal rat model of hypoxic-ischemic (HI) brain damage was established. HSPB1 overexpression plasmid and the negative control were injected into the lateral ventricle of rats 48 h before HI brain damage surgery. HSPB1 and glucose-6-phosphate dehydrogenase (G6PD) levels, infarction rate, iron accumulation, apoptosis, and ferroptosis-related markers were estimated with the assistance of qRT-PCR, 2,3,5-triphenyl tetrazolium chloride (TTC) staining, Prussian blue staining, iron assay kit, TUNEL staining, and Western blot. In vitro, after transfection, HSPB1 and G6PD levels, oxygen-glucose deprivation (OGD)-mediated hippocampal neuron cell viability, apoptosis, iron content, and ferroptosis-related markers were assessed using qRT-PCR, MTT, flow cytometry, iron assay kit, and Western blot. HSPB1 and G6PD were overexpressed in the hippocampus tissues of HI rats. High expression of HSPB1 in HI rats lessened infarction rate and ferritin level, hindered iron accumulation and apoptosis, and promoted GPX4, SLC7A11, and TFR1 levels. In OGD-mediated hippocampal neuron cells, HSPB1 upregulation intensified the viability and repressed apoptosis and ferroptosis, whereas G6PD silencing reversed the effects of HSPB1 upregulation. We documented that HSPB1 overexpression unleashes neuroprotective effects via modulating G6PD expression, which offers a novel target for the prevention and treatment of HI brain damage.NEW & NOTEWORTHY HSPB1 and G6PD were overexpressed in the hippocampus tissues of HI rats. High expression of HSPB1 in HI rats mitigated infarction rate and iron accumulation. HSPB1 overexpression reduced ferritin level, attenuated apoptosis, yet augmented GPX4, SLC7A11, and TFR1 levels in the hippocampus tissues of HI rats. G6PD deletion impaired the protective role of HSPB1 overexpression against HI brain damage-induced ferroptosis.


Assuntos
Ferroptose , Glucosefosfato Desidrogenase , Proteínas de Choque Térmico HSP27 , Animais , Ratos , Ferritinas/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Hipocampo/metabolismo , Hipóxia , Infarto , Ferro/metabolismo , Isquemia , Neuroproteção , Proteínas de Choque Térmico HSP27/metabolismo
4.
Int J Mol Sci ; 23(22)2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36430836

RESUMO

Treatments to combat giardiasis have been reported to have several drawbacks, partly due to the drug resistance and toxicity of current antiparasitic agents. These constraints have prompted many researchers to investigate new drugs that act against protozoan parasites. Enzyme inhibition is an important means of regulating pathogen metabolism and has recently been identified as a significant alternative target in the search for new treatments. Glucose-6-phosphate dehydrogenase and 6-phosphogluconolactonase (G6PD::6PGL) is a bifunctional enzyme involved in the pentose phosphate pathway (PPP) in Giardia lamblia (G. lamblia). The G. lamblia enzyme is unusual since, unlike the human enzyme, it is a fused enzyme. Here, we show, through inhibition assays, that an in-house chemical library of 120 compounds and four target compounds, named CNZ-7, CNZ-8, CMC-1, and FLP-2, are potent inhibitors of the G. lamblia G6PD::6PGL fused enzyme. With a constant (k2) of 2.3, 3.2, and 2.8 M-1 s-1, respectively, they provoke alterations in the secondary and tertiary protein structure and global stability. As a novel approach, target compounds show antigiardial activity, with IC50 values of 8.7, 15.2, 15.3, and 24.1 µM in trophozoites from G. lamblia. Moreover, these compounds show selectivity against G. lamblia, since, through counter-screening in Caco-2 and HT29 human cells, they were found to have low toxicity. This finding positions these compounds as a potential and attractive starting point for new antigiardial drugs.


Assuntos
Giardia lamblia , Giardíase , Animais , Humanos , Giardíase/tratamento farmacológico , Giardíase/parasitologia , Trofozoítos/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Células CACO-2
5.
Int J Mol Sci ; 23(20)2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36293272

RESUMO

The reconfiguration of the primary metabolism is essential in plant-pathogen interactions. We compared the local metabolic responses of cucumber leaves inoculated with Pseudomonas syringae pv lachrymans (Psl) with those in non-inoculated systemic leaves, by examining the changes in the nicotinamide adenine dinucleotides pools, the concentration of soluble carbohydrates and activities/gene expression of carbohydrate metabolism-related enzymes, the expression of photosynthesis-related genes, and the tricarboxylic acid cycle-linked metabolite contents and enzyme activities. In the infected leaves, Psl induced a metabolic signature with an altered [NAD(P)H]/[NAD(P)+] ratio; decreased glucose and sucrose contents, along with a changed invertase gene expression; and increased glucose turnover and accumulation of raffinose, trehalose, and myo-inositol. The accumulation of oxaloacetic and malic acids, enhanced activities, and gene expression of fumarase and l-malate dehydrogenase, as well as the increased respiration rate in the infected leaves, indicated that Psl induced the tricarboxylic acid cycle. The changes in gene expression of ribulose-l,5-bis-phosphate carboxylase/oxygenase large unit, phosphoenolpyruvate carboxylase and chloroplast glyceraldehyde-3-phosphate dehydrogenase were compatible with a net photosynthesis decline described earlier. Psl triggered metabolic changes common to the infected and non-infected leaves, the dynamics of which differed quantitatively (e.g., malic acid content and metabolism, glucose-6-phosphate accumulation, and glucose-6-phosphate dehydrogenase activity) and those specifically related to the local or systemic response (e.g., changes in the sugar content and turnover). Therefore, metabolic changes in the systemic leaves may be part of the global effects of local infection on the whole-plant metabolism and also represent a specific acclimation response contributing to balancing growth and defense.


Assuntos
Carbono-Nitrogênio Ligases , Cucumis sativus , Pseudomonas syringae/fisiologia , Cucumis sativus/genética , Cucumis sativus/metabolismo , Carbono/metabolismo , Fosfoenolpiruvato Carboxilase/genética , beta-Frutofuranosidase/metabolismo , Malato Desidrogenase/metabolismo , Rafinose/metabolismo , Trealose/metabolismo , NAD/metabolismo , Fumarato Hidratase , Glucose-6-Fosfato/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Folhas de Planta/metabolismo , Fotossíntese/fisiologia , Metabolismo dos Carboidratos , Sacarose/metabolismo , Fosfatos/metabolismo , Oxigenases/metabolismo , Inositol/metabolismo , Carbono-Nitrogênio Ligases/metabolismo , Niacinamida/metabolismo , Adenina/metabolismo , Glucose/metabolismo
6.
Planta ; 256(5): 96, 2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36217064

RESUMO

MAIN CONCLUSION: G6PDH negatively regulates viral accumulation in Nicotiana benthamiana through RBOHB-associated ROS signaling. Anti-oxidative metabolism and phytohormone-mediated immunity responses play important roles in virus infection. Glucose-6-phosphate dehydrogenase (G6PDH) is an enzyme in the pentose phosphate pathway, which plays an important role in maintaining intracellular redox homeostasis and has functions in plant growth, development and stress tolerance. However, the role of G6PDH in plants response to virus infection is poorly understood. In this study, NbG6PDH was found to be down-regulated after Chilli veinal mottle virus (ChiVMV-GFP) infection in Nicotiana benthamiana. Subcellular localization of NbG6PDH showed that it was punctate distributed in the protoplasm. Silencing of NbG6PDH reduced the sensitivity of N. benthamiana plants to ChiVMV-GFP. By contrast, transient overexpression of NbG6PDH promoted the accumulation of the virus. The results of physiological indexes showed that glutathione (GSH), catalase (CAT) and proline played an important role in maintaining plants physiological homeostasis. The results of gene expression detection showed that jasmonic acid/ethylene (JA/ET) signaling pathway was significantly correlated with the response of N. benthamiana to ChiVMV-GFP infection, and the changes of N. benthamiana respiratory burst oxidase homologues B (NbRBOHB) indicated that the NbG6PDH-dependent ROS may be regulated by NbRBOHB. Pretreatment of the inducer of reactive oxygen species (ROS) promoted virus infection, whereas inhibitor of ROS alleviated virus infection. Thus, our results indicate that the promoting effect of NbG6PDH on ChiVMV-GFP infection may be related to the NbRBOHB-regulated ROS production.


Assuntos
Potyvirus , Tabaco , Catalase/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Glutationa/metabolismo , Doenças das Plantas , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prolina/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Tabaco/metabolismo
7.
Int J Biol Sci ; 18(14): 5539-5553, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36147458

RESUMO

Overcoming energy stress is a critical step for cells in solid tumors. Under this stress microenvironment, cancer cells significantly alter their energy metabolism to maintain cell survival and even metastasis. Our previous studies have shown that thioredoxin-1 (Trx-1) expression is increased in colorectal cancer (CRC) and promotes cell proliferation. However, the exact role and mechanism of how Trx-1 is involved in energy stress are still unknown. Here, we observed that glucose deprivation of CRC cells led to cell death and promoted the migration and invasion, accompanied by upregulation of Trx-1. Increased Trx-1 supported CRC cell survival under glucose deprivation. Whereas knockdown of Trx-1 sensitized CRC cells to glucose deprivation-induced cell death and reversed glucose deprivation-induced migration, invasion, and epithelial-mesenchymal transition (EMT). Furthermore, we identified glucose-6-phosphate dehydrogenase (G6PD) interacting with Trx-1 by HuPortTM human protein chip, co-IP and co-localization. Trx-1 promoted G6PD protein expression and activity under glucose deprivation, thereby increasing nicotinamide adenine dinucleotide phosphate (NADPH) generation. Moreover, G6PD knockdown sensitized CRC cells to glucose deprivation-induced cell death and suppressed glucose deprivation-induced migration, invasion, and EMT. Inhibition of Trx-1 and G6PD, together with inhibition of glycolysis using 2-deoxy-D-glucose (2DG), resulted in significant anti-tumor effects in CRC xenografts in vivo. These findings demonstrate a novel mechanism and may represent a new effective therapeutic regimen for CRC.


Assuntos
Neoplasias Colorretais , Tiorredoxinas , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Sobrevivência Celular/genética , Neoplasias Colorretais/metabolismo , Desoxiglucose , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Glucose , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Humanos , NADP/metabolismo , Tiorredoxinas/genética , Tiorredoxinas/metabolismo , Microambiente Tumoral
8.
Cell Death Dis ; 13(9): 804, 2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-36127319

RESUMO

Circular RNAs (circRNAs) are a recently discovered kind of regulatory RNAs that have emerged as critical biomarkers of various types of cancers. Metabolic reprogramming has gradually been identified as a distinct hallmark of cancer cells. The pentose phosphate pathway (PPP) plays an indispensable role in satisfying the bioenergetic and biosynthetic demands of cancer cells. However, little is known about the role of circRNAs and PPP in colorectal cancer (CRC). The novel circ_0003215 was identified at low levels in CRC and was negatively correlated with larger tumor size, higher TNM stage, and lymph node metastasis. The decreased level of circ_0003215 was resulted from the RNA degradation by m6A writer protein YTHDF2. A series of functional assays demonstrated that circ_0003215 inhibited cell proliferation, migration, invasion, and CRC tumor metastasis in vivo and in vitro. Moreover, circ_0003215 regulated the expression of DLG4 via sponging miR-663b, thereby inducing the metabolic reprogramming in CRC. Mechanismly, DLG4 inhibited the PPP through the K48-linked ubiquitination of glucose-6-phosphate dehydrogenase (G6PD). Taken together, we have identified m6A-modified circ_0003215 as a novel regulator of metabolic glucose reprogramming that inhibited the PPP and the malignant phenotype of CRC via the miR-663b/DLG4/G6PD axis.


Assuntos
Neoplasias Colorretais , MicroRNAs , Adenosina/análogos & derivados , Adenosina/metabolismo , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Proteína 4 Homóloga a Disks-Large/genética , Regulação Neoplásica da Expressão Gênica , Glucose , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Via de Pentose Fosfato/genética , RNA Circular/genética
9.
Chemosphere ; 308(Pt 3): 136569, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36155023

RESUMO

Green turtles, Chelonia mydas, have been included in biomonitoring efforts given its status as an endangered species. Many studies, however, rely on samples from stranded animals, raising the question of how death affects important biochemical and molecular biomarkers. The goal of this study was to investigate post mortem fluctuations in the antioxidant response and metabolism of carbohydrates in the liver of C. mydas. Liver samples were obtained from six green turtles which were submitted to rehabilitation and euthanized due to the impossibility of recovery. Samples were collected immediately after death (t = 0) and at various time intervals (1, 2, 3, 4, 5, 6, 12, 18 and 24 h post mortem), frozen in liquid nitrogen and stored at -80 °C. The activities of catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PDH) were analyzed, as were the levels of lipid peroxidation, glycogen concentration, RNA integrity (RNA IQ) and transcript levels of carbonic anhydrase and pyruvate carboxylase genes. Comparison between post mortem intervals showed a temporal stability for all the biomarkers evaluated, suggesting that changes in biochemical and molecular parameters following green turtle death are not immediate, and metabolism may remain somewhat unaltered up to 24 h after death. Such stability may be associated with the overall lower metabolism of turtles, especially under an oxygen deprivation scenario such as organismal death. Overall, this study supports the use of biomarkers in sea turtles sampled within a period of 24 h post mortem for biomonitoring purposes, though it is recommended that post mortem fluctuations of particular biomarkers be evaluated prior to their application, given that proteins may show varying degrees of susceptibility to proteolysis.


Assuntos
Anidrases Carbônicas , Tartarugas , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Anidrases Carbônicas/metabolismo , Catalase/metabolismo , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glicogênio/metabolismo , Nitrogênio/metabolismo , Oxigênio/metabolismo , Piruvato Carboxilase/metabolismo , RNA/metabolismo , Tartarugas/metabolismo
10.
Phytochemistry ; 203: 113393, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35998832

RESUMO

The major aim of this study was to check the effect of one-time ozonation on selected quality parameters and antioxidant status of Actinidia arguta fruit. For this purpose, A. arguta fruit was ozonated with gas at a concentration of 10 and 100 ppm, which was carried out successively for 5, 15 and 30 min. Next, the selected quality attributes, antioxidants level as well as NADPH and mitochondrial energy metabolism in mini-kiwi fruit after ozonation were analysed. Our research has shown that ozonation reduced the level of yeast and mould without affecting the content of soluble solids or acidity. In turn, ozonation clearly influenced the antioxidant activity and the redox status of the fruit. The ozonated fruit was characterised by a lower level of ROS due to the higher level of low molecular weight antioxidants, as well as the higher activity of superoxide dismutase and catalase. In addition, improved quality and antioxidant activity of the fruit were indirectly due to improved energy metabolism and NADPH level. The ozonated fruit showed a higher level of ATP, due to both higher activity of succinate dehydrogenase and higher availability of NADH. Moreover, the increased level of NAD+ and the activity of NAD+ kinase and glucose-6-phosphate dehydrogenase contributed to higher levels of NADPH in the fruit.


Assuntos
Actinidia , Ozônio , Actinidia/química , Trifosfato de Adenosina/análise , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Catalase/metabolismo , Frutas/química , Glucosefosfato Desidrogenase/análise , Glucosefosfato Desidrogenase/metabolismo , Glucosefosfato Desidrogenase/farmacologia , NAD/metabolismo , NADP/análise , NADP/metabolismo , NADP/farmacologia , Ozônio/análise , Ozônio/metabolismo , Ozônio/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Succinato Desidrogenase/análise , Succinato Desidrogenase/metabolismo , Succinato Desidrogenase/farmacologia , Superóxido Dismutase/metabolismo
11.
Free Radic Biol Med ; 189: 91-101, 2022 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-35863688

RESUMO

More recent studies suggested that metabolic disorders could contribute to the pathogenesis of systemic lupus erythematosus (SLE) and lupus nephritis (LN). The present work aimed at identifying metabolic reprogramming in the kidney of lupus nephritis via proteomics and investigating the potential regulatory mechanism. The proteomic studies on the renal biopsies revealed that the pentose phosphate pathway (PPP) was significantly enriched in the kidneys of LN patients compared with normal controls (NCs). Immunohistochemical stanning of glucose-6-phosphate dehydrogenase (G6PD), the key rate-limiting enzyme of PPP, verify the results of proteomics. We found that G6PD was highly expressed in the kidneys of LN patients and correlated with several clinicopathological indices. The univariate Cox regression analysis (HR, 95%CI, 1.877 (1.059-3.328), P = 0.031) and Kaplan-Meier (KM) analysis (P = 0.028) suggested that high G6PD expression in the tubulointerstitial area was a risk factor for worse prognosis. Moreover, the Gene set enrichment analysis (GSEA) demonstrated that the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway ranked first in the kidneys of LN patients with high G6PD expression and G6PD was co-localized with mTORC1 activation in the tubule. Immunoglobulin G (IgG) isolated from LN patients significantly activated the mTORC1 pathway and increased G6PD expression, G6PD activity, NADPH production, NADPH oxidase 2 (NOX2) expression, reactive oxygen species (ROS) production, and cell apoptosis in tubule cells in vitro. The above phenotypes were partially rescued after the addition of rapamycin or knock-down of G6PD. Overall, our study suggested that renal G6PD expression was associated with the overall enhanced disease activity and worse renal prognosis. mTORC1 activation might be involved in IgG-LN-induced tubular damage via PPP.


Assuntos
Nefrite Lúpica , Via de Pentose Fosfato , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Humanos , Imunoglobulina G , Nefrite Lúpica/genética , Nefrite Lúpica/patologia , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteômica
12.
Sci Adv ; 8(29): eabo0404, 2022 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-35857842

RESUMO

Metastasizing cancer cells are able to withstand high levels of oxidative stress through mechanisms that are poorly understood. Here, we show that under various oxidative stress conditions, pancreatic cancer cells markedly expand NADPH and NADP+ pools. This expansion is due to up-regulation of glucose-6-phosphate dehydrogenase (G6PD), which stimulates the cytoplasmic nicotinamide adenine dinucleotide kinase (NADK1) to produce NADP+ while converting NADP+ to NADPH. G6PD is activated by the transcription factor TAp73, which is, in turn, regulated by two pathways. Nuclear factor-erythroid 2 p45-related factor-2 suppresses expression of the ubiquitin ligase PIRH2, stabilizing the TAp73 protein. Checkpoint kinases 1/2 and E2F1 induce expression of the TAp73 gene. Levels of G6PD and its upstream activators are elevated in metastatic pancreatic cancer. Knocking down G6PD impedes pancreatic cancer metastasis, whereas forced G6PD expression promotes it. These findings reveal an intracellular network that maintains redox homeostasis through G6PD-mediated increase in de novo NADP+ biosynthesis, which may be co-opted by tumor cells to enable metastasis.


Assuntos
Glucosefosfato Desidrogenase , Neoplasias Pancreáticas , Antioxidantes/metabolismo , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Humanos , NADP/metabolismo , Oxirredução , Neoplasias Pancreáticas/genética
13.
Cells ; 11(13)2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35805067

RESUMO

Glucose-6-phosphate dehydrogenase (G6PD) is the second rate-limiting enzyme of the pentose phosphate pathway. This enzyme is present in the cytoplasm of all mammalian cells, and its activity is essential for an adequate functioning of the antioxidant system and for the response of innate immunity. It is responsible for the production of nicotinamide adenine dinucleotide phosphate (NADPH), the first redox equivalent, in the pentose phosphate pathway. Viral infections such as SARS-CoV-2 may induce the Warburg effect with an increase in anaerobic glycolysis and production of lactate. This condition ensures the success of viral replication and production of the virion. Therefore, the activity of G6PD may be increased in COVID-19 patients raising the level of the NADPH, which is needed for the enzymatic and non-enzymatic antioxidant systems that counteract the oxidative stress caused by the cytokine storm. G6PD deficiency affects approximately 350-400 million people worldwide; therefore, it is one of the most prevalent diseases related to enzymatic deficiency worldwide. In G6PD-deficient patients exposed to SARS-CoV-2, the amount of NADPH is reduced, increasing the susceptibility for viral infection. There is loss of the redox homeostasis in them, resulting in severe pneumonia and fatal outcomes.


Assuntos
COVID-19 , Glucosefosfato Desidrogenase , Animais , Antioxidantes , Glucosefosfato Desidrogenase/metabolismo , Humanos , Mamíferos/metabolismo , NADP/metabolismo , SARS-CoV-2
14.
Plant Physiol Biochem ; 186: 207-219, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35870442

RESUMO

Embryo development is essential for seed yield and post-germination growth. Glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme in oxidative pentose phosphate pathway (OPPP), is widely involved in plant development and stress tolerance by providing nicotinamide adenine dinucleotide phosphate (NADPH). In this study, the double mutant (g6pd5/6), overexpression line (G6PD5/6OE) and complementation line (g6pd5/6Comp) of cytosolic glucose-6-phosphate dehydrogenases (Cyt-G6PD) were used to investigate Cyt-G6PD roles in embryo development of Arabidopsis. The results showed that the germination rate of g6pd5/6 seeds was delayed in comparison with that of Col-0; moreover, 11.5% of g6pd5/6 seeds did not germinate. The dysfunction of Cyt-G6PD resulted in decreased fresh weight and primary root length of g6pd5/6 seedlings. The height and silique length of g6pd5/6 plants were also decreased. Moreover, the abortion rate of siliques and seeds of g6pd5/6 plants were increased compared with those of Col-0, G6PD5/6OE and g6pd5/6Comp lines. However, the dysfunction of Cyt-G6PD did not affect pollen activity; but in g6pd5/6, the embryo development was partially delayed or inhibited. The contents of fatty acids and storage proteins, two main storage materials in Arabidopsis seeds, were decreased in g6pd5/6 seeds. Exogenous application of fatty acids (C18:2; C18:3) alleviated the delayed germination of g6pd5/6 seeds. RT-qPCR results further demonstrated that the early embryo development genes were down-regulated in g6pd5/6. Taken together, Cyt-G6PD plays a pivotal role in plant seed development by regulating the transcriptions of early embryo development genes and the accumulation of storage materials (especially fatty acids).


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação/genética , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Sementes/metabolismo
15.
Int J Mol Sci ; 23(13)2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35806424

RESUMO

Cancer cells switch their metabolism toward glucose metabolism to sustain their uncontrolled proliferation. Consequently, glycolytic intermediates are diverted into the pentose phosphate pathway (PPP) to produce macromolecules necessary for cell growth. The transcription regulator RIP140 controls glucose metabolism in tumor cells, but its role in cancer-associated reprogramming of cell metabolism remains poorly understood. Here, we show that, in human breast cancer cells and mouse embryonic fibroblasts, RIP140 inhibits the expression of the gene-encoding G6PD, the first enzyme of the PPP. RIP140 deficiency increases G6PD activity as well as the level of NADPH, a reducing cofactor essential for macromolecule synthesis. Moreover, G6PD knock-down inhibits the gain of proliferation observed when RIP140 expression is reduced. Importantly, RIP140-deficient cells are more sensitive to G6PD inhibition in cell proliferation assays and tumor growth experiments. Altogether, this study describes a novel role for RIP140 in regulating G6PD levels, which links its effect on breast cancer cell proliferation to metabolic rewiring.


Assuntos
Neoplasias , Via de Pentose Fosfato , Animais , Proliferação de Células/genética , Fibroblastos/metabolismo , Glucose/metabolismo , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Camundongos
16.
Int J Mol Sci ; 23(13)2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35806430

RESUMO

Glucose 6-P dehydrogenase (G6PD) is the first rate-limiting enzyme in pentose phosphate pathway (PPP), and it is proverbial that G6PD is absent in skeletal muscle. However, how and why G6PD is down-regulated during skeletal muscle development is unclear. In this study, we confirmed the expression of G6PD was down-regulated during myogenesis in vitro and in vivo. G6PD was absolutely silent in adult skeletal muscle. Histone H3 acetylation and DNA methylation act together on the expression of G6PD. Neither knock-down of G6PD nor over-expression of G6PD affects myogenic differentiation. Knock-down of G6PD significantly promotes the sensitivity and response of skeletal muscle cells to insulin; over-expression of G6PD significantly injures the sensitivity and response of skeletal muscle cells to insulin. High-fat diet treatment impairs insulin signaling by up-regulating G6PD, and knock-down of G6PD rescues the impaired insulin signaling and glucose uptake caused by high-fat diet treatment. Taken together, this study explored the importance of G6PD deficiency during myogenic differentiation, which provides new sight to treat insulin resistance and type-2 diabetes.


Assuntos
Deficiência de Glucosefosfato Desidrogenase , Glucosefosfato Desidrogenase , Insulina , Músculo Esquelético , Adulto , Glucose/metabolismo , Glucose 1-Desidrogenase/metabolismo , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Deficiência de Glucosefosfato Desidrogenase/genética , Deficiência de Glucosefosfato Desidrogenase/metabolismo , Humanos , Insulina/metabolismo , Músculo Esquelético/enzimologia , Músculo Esquelético/metabolismo
17.
J Pharm Biomed Anal ; 219: 114901, 2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-35780529

RESUMO

Reduced nicotinamide adenine dinucleotide phosphate (NADPH) participates in several anabolic and catabolic pathways, being essential in numerous biochemical reactions involving energy release. Most of these reactions require a high amount of NADPH, which can be expensive from an industry point of view. Thus, biotechnology industries developed a great interest in NADPH production. Currently, there are different ways to obtain NADPH in situ, however, the most common is by enzymatic reactions, known as generator systems. Although this approach can be beneficial in terms of cost, the major drawback is the impossibility of reusing the enzyme. To overcome this, enzyme immobilization is a proven alternative. Herein, we report the use of glucose-6-phosphate dehydrogenase immobilized onto magnetic beads (G6PDH-Mb) through glutaraldehyde coupling to produce high amounts of NADPH. The G6PDH-Mbs were kinetically characterized showing a sigmoidal curve. Besides, the stability was evaluated, and their reuse was demonstrated for a period superior to 40 days. The G6PDH-Mb was used to in situ production of the NADPH metabolism experiments, using human liver microsome solutions and either albendazole or fiscalin B as model targets. The production of in vitro metabolites from albendazole and fiscalin B was evaluated by comparing the use of NADPH generated in situ with those obtained by commercial NADPH. Moreover, the activity of the G6PDH-Mb was monitored after using it for five consecutive albendazole metabolism reactions, with only a minor decrease in the enzyme activity (3.58 ± 1.67%) after the fifth time of use. The higher concentration obtained when using the designed G6PDH-Mb generator system demonstrated proof of the concept and its applicability.


Assuntos
Albendazol , Glucosefosfato Desidrogenase , Glucosefosfato Desidrogenase/metabolismo , Humanos , Fenômenos Magnéticos , NADP/metabolismo
18.
Biochem Biophys Res Commun ; 620: 92-97, 2022 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-35780586

RESUMO

Excess nutrients are stored as triglycerides, mostly as lipid droplets found in adipose tissue. Previous studies have characterized a group of splicing factors called serine/arginine rich (SR) proteins that function to identify intron/exon borders in regulating metabolic homeostasis in the Drosophila fat body. Decreasing the function of one SR protein, 9G8, causes an increase in triglyceride storage; however, the full complement of genes regulated by 9G8 to control metabolism is unknown. To address this question, we performed RNA sequencing on Drosophila fat bodies with 9G8 levels reduced by RNAi. Differential expression and differential exon usage analyses revealed several genes involved in the immune response, xenobiotic biology, protein translation, sleep, and lipid and carbohydrate metabolism whose expression or splicing is altered in 9G8-RNAi fat bodies. One gene that was both downregulated and had altered splicing in 9G8-RNAi fat bodies was Zwischenferment (Zw), the Drosophila homolog of human glucose 6-phosphate dehydrogenase (G6PD). G6PD regulates flux of glucose 6-phosphate (G6P) into the pentose phosphate pathway, which generates NADPH, a coenzyme for lipid synthesis. Interestingly, the other NADPH-producing enzyme genes in Drosophila (phosphogluconate dehydrogenase, isocitrate dehydrogenase and malic enzyme) were also decreased in 9G8-RNAi flies. Together, these findings suggest that 9G8 regulates several classes of genes and may regulate NADPH-producing enzyme genes to maintain metabolic homeostasis.


Assuntos
Drosophila , Lipídeos , Fatores de Processamento de Serina-Arginina/metabolismo , Animais , Drosophila/metabolismo , Glucose , Glucosefosfato Desidrogenase/metabolismo , Humanos , NADP/metabolismo , Fosfatos/metabolismo , Fatores de Processamento de RNA/metabolismo
19.
Biochem Biophys Res Commun ; 617(Pt 2): 62-68, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-35689843

RESUMO

Ovarian cancer is the eminent gynecological malignancy and chemoresistance remains a major reason for poor in ovarian cancer patients. Taxol has been proved as the most effective chemotherapeutic agent against ovarian cancer. However development of Taxol resistance remains a major problem. Here, we report that STAT3, directly activates pentose-phosphate pathway to exert pro-oncogenic effects on Taxol resistance of ovarian cancer. In addition, we found that STAT3, p-STAT3 and glucose-6-phosphate dehydrogenase (G6PD) protein levels are upregulated in Taxol resistant cell lines compared with Taxol sensitive cell lines. Furthermore, inhibition of STAT3 decreased G6PD mRNA expression level and enhanced the sensitivity of Taxol resistant cell to Taxol. Finally, we found that STAT3 directly binds to the G6PD promoter region and promotes the expression of G6PD at transcriptional level. Taken together, our data indicate that activation of STAT3 promotes ovarian cancer cell proliferation, colony formation, and Taxol resistance via augmenting G6PD expression and pentose-phosphate metabolism flux, which provides a potential therapeutic target that may improve prognosis by decreasing G6PD expression and enhancing Taxol-sensitivity.


Assuntos
Neoplasias Ovarianas , Paclitaxel , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Fator de Transcrição STAT3/metabolismo
20.
Biosci Rep ; 42(6)2022 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-35712981

RESUMO

Hepatocellular carcinoma (HCC) is a common malignant tumour with high rates of morbidity and mortality worldwide. Therefore, it is of great significance to find new molecular markers for HCC diagnosis and treatment. G6PD is known to be dysregulated in a variety of tumours. In addition, the ceRNA network plays a crucial role in the occurrence and development of HCC. However, the mechanism by which the ceRNA network regulates G6PD in HCC remains unclear. We used TCGA-LIHC data to analyse the possibility of using G6PD as an independent prognostic marker. Univariate Cox proportional hazards regression, multivariate Cox proportional hazards regression, and receiver operating characteristic curve analysis were used to analyse the influence of G6PD overexpression on the prognosis of HCC patients. We also analysed the biological function of G6PD, its effect on the immune microenvironment, and drug sensitivity. Finally, we constructed a ceRNA network of lncRNAs/miR-122-5p/G6PD to explore the regulatory mechanism of G6PD. G6PD was highly expressed in HCC, was related to pathological stage and poor prognosis, and could be used as an independent prognostic indicator of HCC. The expression of G6PD was closely related to the immune microenvironment of HCC. In addition, the expression of G6PD in HCC could be regulated by the ceRNA network. Therefore, G6PD can be used as an immunotherapy target to improve the survival and prognosis of HCC patients, and the ceRNA regulatory network of G6PD has potential diagnostic and therapeutic value for HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Carcinoma Hepatocelular/patologia , Regulação Neoplásica da Expressão Gênica , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Humanos , Neoplasias Hepáticas/patologia , MicroRNAs/genética , Microambiente Tumoral/genética
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