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Journal of Cellular Physiology Sep 2021Pre-eclampsia (PE) is a pregnancy-related disorder that occurs after 20 weeks of gestation. It seriously affects the health of maternity and the fetus. However, the...
Pre-eclampsia (PE) is a pregnancy-related disorder that occurs after 20 weeks of gestation. It seriously affects the health of maternity and the fetus. However, the pathogenesis of PE is still unknown. Decidualization deficiency is considered a contributing factor to the development of PE. CTP synthetase (CTPS) which is the rate-limiting enzyme in the CTP de novo biosynthesis, is essential for nucleic acid synthesis and cellular energy metabolism, and often appears as cytoophidium in many cell types. Here, we found that the expression of CTPS was significantly downregulated in decidual tissues of patients with severe PE compared with healthy pregnant women. During in vitro decidualization, changes in CTPS were accompanied by opposite fluctuation of the AMPK signaling pathway. Moreover, the downregulation of CTPS by glutamine analogs or CTPS small interfering RNA inhibited the decidualization process and the AMPK signaling pathway. Investigating the underlying mechanism of action by co-immunoprecipitation coupled with mass spectrometry showed that CTPS interacted with ATP synthase (ATPS) and maintained the content of ATP on Day 3 of decidualization. However, when combined with mitochondrial stress protein STRESS-70 instead of ATPS, the concentration of ATP on Day 6 of induction was reduced. Corresponding to this, CTPS was mainly distributes in the cytoplasm on Day 3 of induction, while it appeared both in the cytoplasm and the nucleus on Day 6 in decidualized cells, which was similar to that in cells before induction. In summary, we believe that CTPS plays an important role in decidualization by participating in energy metabolism. Abnormal expression of CTPS in decidualization would lead to abnormal decidualization and consequently result in the occurrence of PE.
Topics: Adenylate Kinase; Carbon-Nitrogen Ligases; Cell Line; Cell Proliferation; Decidua; Diazooxonorleucine; Down-Regulation; Endometrium; Energy Metabolism; Female; Gene Silencing; Human Embryonic Stem Cells; Humans; Mitochondrial Proton-Translocating ATPases; Pre-Eclampsia; Pregnancy; Protein Binding; Signal Transduction; Stromal Cells
PubMed: 33576499
DOI: 10.1002/jcp.30326 -
Communications Biology 2019Glioblastoma (GBM) is an aggressive primary human brain tumour that has resisted effective therapy for decades. Although glucose and glutamine are the major fuels that...
Glioblastoma (GBM) is an aggressive primary human brain tumour that has resisted effective therapy for decades. Although glucose and glutamine are the major fuels that drive GBM growth and invasion, few studies have targeted these fuels for therapeutic management. The glutamine antagonist, 6-diazo-5-oxo-L-norleucine (DON), was administered together with a calorically restricted ketogenic diet (KD-R) to treat late-stage orthotopic growth in two syngeneic GBM mouse models: VM-M3 and CT-2A. DON targets glutaminolysis, while the KD-R reduces glucose and, simultaneously, elevates neuroprotective and non-fermentable ketone bodies. The diet/drug therapeutic strategy killed tumour cells while reversing disease symptoms, and improving overall mouse survival. The therapeutic strategy also reduces edema, hemorrhage, and inflammation. Moreover, the KD-R diet facilitated DON delivery to the brain and allowed a lower dosage to achieve therapeutic effect. The findings support the importance of glucose and glutamine in driving GBM growth and provide a therapeutic strategy for non-toxic metabolic management.
Topics: Animals; Body Weight; Brain; Brain Neoplasms; Caloric Restriction; Cell Line, Tumor; Cell Proliferation; Diazooxonorleucine; Diet, Ketogenic; Disease Models, Animal; Female; Fermentation; Glioblastoma; Glucose; Glutamine; Humans; Immunohistochemistry; Ketone Bodies; Ketones; Male; Mice; Mice, Inbred C57BL; Neoplasm Transplantation
PubMed: 31149644
DOI: 10.1038/s42003-019-0455-x -
Proceedings of the National Academy of... Dec 2018The deadliest complication of infection is cerebral malaria (CM), with a case fatality rate of 15 to 25% in African children despite effective antimalarial...
The deadliest complication of infection is cerebral malaria (CM), with a case fatality rate of 15 to 25% in African children despite effective antimalarial chemotherapy. No adjunctive treatments are yet available for this devastating disease. We previously reported that the glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON) rescued mice from experimental CM (ECM) when administered late in the infection, a time by which mice had already suffered blood-brain barrier (BBB) dysfunction, brain swelling, and hemorrhaging. Herein, we used longitudinal MR imaging to visualize brain pathology in ECM and the impact of a new DON prodrug, JHU-083, on disease progression in mice. We demonstrate in vivo the reversal of disease markers in symptomatic, infected mice following treatment, including the resolution of edema and BBB disruption, findings usually associated with a fatal outcome in children and adults with CM. Our results support the premise that JHU-083 is a potential adjunctive treatment that could rescue children and adults from fatal CM.
Topics: Adult; Animals; Antimalarials; Biomarkers; Blood-Brain Barrier; Brain; Brain Edema; Child; Diazooxonorleucine; Disease Models, Animal; Disease Progression; Female; Glutamine; Humans; Magnetic Resonance Imaging; Malaria, Cerebral; Malaria, Falciparum; Mice; Mice, Inbred C57BL; Plasmodium falciparum
PubMed: 30514812
DOI: 10.1073/pnas.1812909115 -
Journal of Medicinal Chemistry Apr 20196-Diazo-5-oxo-l-norleucine (DON) is a glutamine antagonist with robust anticancer efficacy; however, its therapeutic potential was hampered by its biodistribution and...
6-Diazo-5-oxo-l-norleucine (DON) is a glutamine antagonist with robust anticancer efficacy; however, its therapeutic potential was hampered by its biodistribution and toxicity to normal tissues, specifically gastrointestinal (GI) tissues. To circumvent DON's toxicity, we synthesized a series of tumor-targeted DON prodrugs designed to circulate inert in plasma and preferentially activate over DON in tumor. Our best prodrug 6 (isopropyl 2-(6-acetamido-2-(adamantane-1-carboxamido)hexanamido)-6-diazo-5-oxohexanoate) showed stability in plasma, liver, and intestinal homogenates yet was readily cleaved to DON in P493B lymphoma cells, exhibiting a 55-fold enhanced tumor cell-to-plasma ratio versus that of DON and resulting in a dose-dependent inhibition of cell proliferation. Using carboxylesterase 1 knockout mice that were shown to mimic human prodrug metabolism, systemic administration of 6 delivered 11-fold higher DON exposure to tumor (target tissue; AUC = 5.1 nmol h/g) versus GI tissues (toxicity tissue; AUC = 0.45 nmol h/g). In summary, these studies describe the discovery of a glutamine antagonist prodrug that provides selective tumor exposure.
Topics: Acetylation; Animals; Antineoplastic Agents; Area Under Curve; Carboxylic Ester Hydrolases; Cell Line, Tumor; Diazooxonorleucine; Drug Delivery Systems; Humans; Lysine; Mice; Mice, Knockout; Prodrugs; Swine
PubMed: 30892035
DOI: 10.1021/acs.jmedchem.8b02009 -
British Journal of Anaesthesia Nov 2022Hypersensitivity to general anaesthetics predicts adverse postoperative outcomes in patients. Hypoxia exerts extensive pathophysiological effects on the brain; however,...
BACKGROUND
Hypersensitivity to general anaesthetics predicts adverse postoperative outcomes in patients. Hypoxia exerts extensive pathophysiological effects on the brain; however, whether hypoxia influences sevoflurane sensitivity and its underlying mechanisms remain poorly understood.
METHODS
Mice were acclimated to hypoxia (oxygen 10% for 8 h day) for 28 days and anaesthetised with sevoflurane; the effective concentrations for 50% of the animals (EC) showing loss of righting reflex (LORR) and loss of tail-pinch withdrawal response (LTWR) were determined. Positron emission tomography-computed tomography, O-glycoproteomics, seahorse analysis, carbon-13 tracing, site-specific mutagenesis, and electrophysiological techniques were performed to explore the underlying mechanisms.
RESULTS
Compared with the control group, the hypoxia-acclimated mice required higher concentrations of sevoflurane to present LORR and LTWR (EC50: 1.61 [0.03]% vs 1.46 [0.04]%, P<0.01; EC50: 2.46 [0.14]% vs 2.22 [0.06]%, P<0.01). Hypoxia-induced reduction in sevoflurane sensitivity was correlated with elevation of protein O-linked N-acetylglucosamine (O-GlcNAc) modification in brain, especially in the thalamus, and could be abolished by 6-diazo-5-oxo-l-norleucine, a glutamine fructose-6-phosphate amidotransferase inhibitor, and mimicked by thiamet-G, a selective O-GlcNAcase inhibitor. Mechanistically, O-GlcNAcylation drives de novo synthesis of glutamine from glucose in astrocytes and promotes the glutamate-glutamine cycle, partially via glycolytic flux and activation of glutamine synthetase.
CONCLUSIONS
Intermittent hypoxia exposure decreased mouse sensitivity to sevoflurane anaesthesia through enhanced O-GlcNAc-dependent modulation of the glutamate-glutamine cycle in the brain.
Topics: Animals; Mice; Acetylglucosamine; Sevoflurane; Glutamine; Diazooxonorleucine; Glutamate-Ammonia Ligase; Brain; Hypoxia; Glucose; Anesthetics, General; Oxygen; Glutamates
PubMed: 36031420
DOI: 10.1016/j.bja.2022.06.041 -
Scientific Reports Aug 2017Pancreatic cancer is a lethal disease with poor prognosis. Gemcitabine has been the first line systemic treatment for pancreatic cancer. However, the rapid development...
Pancreatic cancer is a lethal disease with poor prognosis. Gemcitabine has been the first line systemic treatment for pancreatic cancer. However, the rapid development of drug resistance has been a major hurdle in gemcitabine therapy leading to unsatisfactory patient outcomes. With the recent renewed understanding of glutamine metabolism involvement in drug resistance and immuno-response, we investigated the anti-tumor effect of a glutamine analog (6-diazo-5-oxo-L-norleucine) as an adjuvant treatment to sensitize chemoresistant pancreatic cancer cells. We demonstrate that disruption of glutamine metabolic pathways improves the efficacy of gemcitabine treatment. Such a disruption induces a cascade of events which impacts glycan biosynthesis through Hexosamine Biosynthesis Pathway (HBP), as well as cellular redox homeostasis, resulting in global changes in protein glycosylation, expression and functional effects. The proteome alterations induced in the resistant cancer cells and the secreted exosomes are intricately associated with the reduction in cell proliferation and the enhancement of cancer cell chemosensitivity. Proteins associated with EGFR signaling, including downstream AKT-mTOR pathways, MAPK pathway, as well as redox enzymes were downregulated in response to disruption of glutamine metabolic pathways.
Topics: Cell Line, Tumor; Cell Proliferation; Cell Survival; Deoxycytidine; Diazooxonorleucine; Drug Resistance, Neoplasm; Drug Synergism; Glutamine; Humans; Metabolic Networks and Pathways; Oxidation-Reduction; Pancreatic Neoplasms; Proteomics; Gemcitabine
PubMed: 28801576
DOI: 10.1038/s41598-017-08436-6 -
Molecular Cancer Therapeutics Oct 2022Glutamine is a conditionally essential amino acid consumed by rapidly proliferating cancer cells, which deprives the same fuel from immune cells and contributes to tumor...
Glutamine is a conditionally essential amino acid consumed by rapidly proliferating cancer cells, which deprives the same fuel from immune cells and contributes to tumor immune evasion. As such, the broad antagonism of glutamine in tumors and the tumor microenvironment may lead to direct antitumor activity and stimulation of antitumoral immune responses. DRP-104 (sirpiglenastat) was designed as a novel prodrug of the broad-acting glutamine antagonist 6-diazo-5-oxo-L-norleucine (DON). DRP-104 is an inactive form that is preferentially converted to DON within tumors. Metabolomic profiling of tumors treated with DRP-104 revealed widespread changes indicative of the disruption of tumor anabolism and canonical cancer metabolism pathways; including altered glutamine metabolism while several immunosuppressive metabolites were decreased. Gene expression profiling revealed broad immunological modulation, confirmed by flow cytometry indicating that DRP-104 treatment resulted in substantial and broad changes in various immune cell infiltrates, such as increased TIL, T, NK, and NK T cells. Functionally, T cells became more proliferative and less exhausted; tumor-associated macrophages were polarized to the M1 phenotype; MDSCs and protumorigenic proteins were decreased in TME. Finally, DRP-104 demonstrated significant antitumor activity as a monotherapy, which was further enhanced in combination with checkpoint blockade therapies, leading to improved survival and long-term durable cures. In summary, DRP-104 broadly remodels the tumor microenvironment by inducing extensive tumor metabolism effects and enhancing the infiltration and function of multiple immune cells distinct from those obtained by checkpoint inhibitor therapy. This unique mechanism of action supports the ongoing clinical development of DRP-104 alone and in combination with checkpoint inhibitors.
Topics: Amino Acids, Essential; Cell Line, Tumor; Diazooxonorleucine; Glutamine; Humans; Immune System; Neoplasms; Prodrugs; Tumor Microenvironment
PubMed: 35930753
DOI: 10.1158/1535-7163.MCT-22-0282 -
Protein Science : a Publication of the... Jun 2017Intense efforts are underway to identify inhibitors of the enzyme gamma-glutamyl transpeptidase 1 (GGT1) which cleaves extracellular gamma-glutamyl compounds and...
Intense efforts are underway to identify inhibitors of the enzyme gamma-glutamyl transpeptidase 1 (GGT1) which cleaves extracellular gamma-glutamyl compounds and contributes to the pathology of asthma, reperfusion injury and cancer. The glutamate analog, 6-diazo-5-oxo-norleucine (DON), inhibits GGT1. DON also inhibits many essential glutamine metabolizing enzymes rendering it too toxic for use in the clinic as a GGT1 inhibitor. We investigated the molecular mechanism of human GGT1 (hGGT1) inhibition by DON to determine possible strategies for increasing its specificity for hGGT1. DON is an irreversible inhibitor of hGGT1. The second order rate constant of inactivation was 0.052 mM min and the K was 2.7 ± 0.7 mM. The crystal structure of DON-inactivated hGGT1 contained a molecule of DON without the diazo-nitrogen atoms in the active site. The overall structure of the hGGT1-DON complex resembled the structure of the apo-enzyme; however, shifts were detected in the loop forming the oxyanion hole and elements of the main chain that form the entrance to the active site. The structure of hGGT1-DON complex revealed two covalent bonds between the enzyme and inhibitor which were part of a six membered ring. The ring included the OG atom of Thr381, the reactive nucleophile of hGGT1 and the α-amine of Thr381. The structure of DON-bound hGGT1 has led to the discovery of a new mechanism of inactivation by DON that differs from its inactivation of other glutamine metabolizing enzymes, and insight into the activation of the catalytic nucleophile that initiates the hGGT1 reaction.
Topics: Catalytic Domain; Crystallography, X-Ray; Diazooxonorleucine; Enzyme Inhibitors; Humans; Protein Structure, Secondary; gamma-Glutamyltransferase
PubMed: 28378915
DOI: 10.1002/pro.3172 -
Drug Discoveries & Therapeutics Nov 2023This work describes a novel artificial intelligence-based training and monitoring system (AITMS) that was used to control and prevent nosocomial infections (NIs) by...
This work describes a novel artificial intelligence-based training and monitoring system (AITMS) that was used to control and prevent nosocomial infections (NIs) by improving the skills of donning/removing personal protective equipment (PPE). The AITMS has two working modes, namely an AI-based protective equipment surveillance mode and an AI-based training mode, that were used for routine surveillance and training, respectively. Data revealed that the accuracy rate of donning/removing PPE improved as a result of the AITMS. Interestingly, the frequency of NIs decreased with the use of the AITMS. This study suggested the key role of using PPE in controlling and preventing NIs. Data preliminarily proved that appropriate donning/removing PPE may help to reduce the risk of NIs. In addition, the newest computerized technologies, such as AI, have proven to be useful in controlling and preventing NIs. These findings should helpful to formulate a better strategy against NIs in the future.
Topics: Humans; Artificial Intelligence; Pilot Projects; Cross Infection; Diazooxonorleucine; Hospitals
PubMed: 37673650
DOI: 10.5582/ddt.2023.01068 -
International Journal of Molecular... May 2021Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) contribute to the development of atherosclerosis and restenosis. Glycolysis and...
Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) contribute to the development of atherosclerosis and restenosis. Glycolysis and glutaminolysis are increased in rapidly proliferating VSMCs to support their increased energy requirements and biomass production. Thus, it is essential to develop new pharmacological tools that regulate metabolic reprogramming in VSMCs for treatment of atherosclerosis. The effects of 6-diazo-5-oxo-L-norleucine (DON), a glutamine antagonist, have been broadly investigated in highly proliferative cells; however, it is unclear whether DON inhibits proliferation of VSMCs and neointima formation. Here, we investigated the effects of DON on neointima formation in vivo as well as proliferation and migration of VSMCs in vitro. DON simultaneously inhibited FBS- or PDGF-stimulated glycolysis and glutaminolysis as well as mammalian target of rapamycin complex I activity in growth factor-stimulated VSMCs, and thereby suppressed their proliferation and migration. Furthermore, a DON-derived prodrug, named JHU-083, significantly attenuated carotid artery ligation-induced neointima formation in mice. Our results suggest that treatment with a glutamine antagonist is a promising approach to prevent progression of atherosclerosis and restenosis.
Topics: Animals; Antimetabolites, Antineoplastic; Cell Cycle; Cell Movement; Cell Proliferation; Cells, Cultured; Diazooxonorleucine; Glutamine; Glycolysis; Immunohistochemistry; Male; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Inbred C57BL; Mitochondria; Muscle, Smooth, Vascular; Neointima; Oxidative Phosphorylation; Platelet-Derived Growth Factor; Rats; Rats, Sprague-Dawley; Serum Albumin, Bovine
PubMed: 34070527
DOI: 10.3390/ijms22115602