• cystine-glutamate antiporter
• ferroptosis
• glutamate
• ischemic stroke
• neuroexcitotoxicity

Glutaminase isoenzymes GLS and GLS2 play apparently opposing roles in cancer: GLS acts as an oncoprotein, while GLS2 (GAB isoform) has context specific tumour suppressive activity. Some microRNAs (miRNAs) have been implicated in progression of tumours, including gliomas. The aim was to investigate the effect of GLS and GAB expression on both miRNAs and oxidative status in glioblastoma cells.

Microarray profiling of miRNA was performed in GLS-silenced LN229 and GAB-transfected T98G human glioblastoma cells and their wild-type counterparts. Results were validated by real-time quantitative RT-PCR. Oxidative status and antioxidant enzymes were determined by spectrophotometric or fluorescence assays in GLS-silenced LN229 and T98G, and GAB-transfected LN229 and T98G.

MiRNA-146a-5p, miRNA-140-3p, miRNA-21-5p, miRNA-1260a, and miRNA-92a-3p were downregulated, and miRNA-1246 was upregulated when GLS was knocked down. MiRNA-140-3p, miRNA-1246, miRNA-1260a, miRNA-21-5p, and miRNA-146a-5p were upregulated when GAB was overexpressed. Oxidative status (lipid peroxidation, protein carbonylation, total antioxidant capacity, and glutathione levels), as well as antioxidant enzymes (catalase, superoxide dismutase, and glutathione reductase) of silenced GLS glioblastoma cells and overexpressed GAB glioblastoma cells significantly changed versus their respective control glioblastoma cells. MiRNA-1246, miRNA-1260a, miRNA-146a-5p, and miRNA-21-5p have been characterized as strong biomarkers of glioblastoma proliferation linked to both GLS silencing and GAB overexpression. Total glutathione is a reliable biomarker of glioblastoma oxidative status steadily associated to both GLS silencing and GAB overexpression.

Glutaminase isoenzymes are related to the expression of some miRNAs and may contribute to either tumour progression or suppression through certain miRNA-mediated pathways, proving to be a key tool to switch cancer proliferation and redox status leading to a less malignant phenotype. Accordingly, GLS and GAB expression are especially involved in glutathione-dependent antioxidant defence.

• Antioxidant enzymes
• Cancer
• Glioblastoma
• Glutaminase
• Oxidative stress
• microRNA

• Cellular metabolism
• Extracellular vesicle
• Microglia
• Neuroinflammation
• Neurological disorder

• Antidepressants
• Cho
• Depression
• Glx
• Magnetic resonance spectroscopy
• NAA
• Recovery
• Recurrence
• Therapy

• Adult
• Amygdala/metabolism
• Antidepressive Agents/pharmacology
• Aspartic Acid/analogs & derivatives
• Aspartic Acid/metabolism
• Brain/metabolism
• Choline/metabolism
• Depression/drug therapy
• Humans
• Magnetic Resonance Imaging/methods
• Male
• Middle Aged
• Proton Magnetic Resonance Spectroscopy
• Recurrence

Astrocyte-to-neuron conversion is a promising avenue for neuronal replacement therapy. Neurons are particularly dependent on mitochondrial function, but how well mitochondria adapt to the new fate is unknown. Here, we determined the comprehensive mitochondrial proteome of cortical astrocytes and neurons, identifying about 150 significantly enriched mitochondrial proteins for each cell type, including transporters, metabolic enzymes, and cell-type-specific antioxidants. Monitoring their transition during reprogramming revealed late and only partial adaptation to the neuronal identity. Early dCas9-mediated activation of genes encoding mitochondrial proteins significantly improved conversion efficiency, particularly for neuron-enriched but not astrocyte-enriched antioxidant proteins. For example, Sod1 not only improves the survival of the converted neurons but also elicits a faster conversion pace, indicating that mitochondrial proteins act as enablers and drivers in this process. Transcriptional engineering of mitochondrial proteins with other functions improved reprogramming as well, demonstrating a broader role of mitochondrial proteins during fate conversion.

•

Mitochondrial proteomes of cortical astrocytes and neurons are distinct

• CRISPR-a
• antioxidant
• direct reprogramming
• metabolism
• mitochondria
• proteome

• ADAM10
• Myelin basic protein
• NGF p75 receptor
• Oleic acid
• Palmitic acid
• Pyruvate dehydrogenase

• Slc38a1
• glutamine transporter
• mTOR
• neural stem cell
• neurogenesis
• theanine

Chronic pain is a major symptom that develops in cancer patients, most commonly emerging during advanced stages of the disease. The nature of cancer-induced pain is complex, and the efficacy of current therapeutic interventions is restricted by the dose-limiting side-effects that accompany common centrally targeted analgesics.

This review focuses on how up-regulated glutamate production and export by the tumour converge at peripheral afferent nerve terminals to transmit nociceptive signals through the transient receptor cation channel, TRPV1, thereby initiating central sensitization in response to peripheral disease-mediated stimuli.

Cancer cells undergo numerous metabolic changes that include increased glutamine catabolism and over-expression of enzymes involved in glutaminolysis, including glutaminase. This mitochondrial enzyme mediates glutaminolysis, producing large pools of intracellular glutamate. Up-regulation of the plasma membrane cystine/glutamate antiporter, system xc-, promotes aberrant glutamate release from cancer cells. Increased levels of extracellular glutamate have been associated with the progression of cancer-induced pain and we discuss how this can be mediated by activation of TRPV1.

With a growing population of patients receiving inadequate treatment for intractable pain, new targets need to be considered to better address this largely unmet clinical need for improving their quality of life. A better understanding of the mechanisms that underlie the unique qualities of cancer pain will help to identify novel targets that are able to limit the initiation of pain from a peripheral source–the tumour.

• Cancer pain
• TRPV1
• glutamate
• glutaminase
• system xc

Lysophosphatidic acid (LPA) is an extracellular lipid mediator that regulates nervous system development and functions acting through G protein-coupled receptors (GPCRs). Here we explore the crosstalk between LPA₁ receptor and glutamatergic transmission by examining expression of glutaminase (GA) isoforms in different brain areas isolated from wild-type (WT) and KOLPA₁ mice. Silencing of LPA₁ receptor induced a severe down-regulation of Gls-encoded long glutaminase protein variant (KGA) (glutaminase gene encoding the kidney-type isoforms, GLS) protein expression in several brain regions, particularly in brain cortex and hippocampus. Immunohistochemical assessment of protein levels for the second type of glutaminase (GA) isoform, glutaminase gene encoding the liver-type isoforms (GLS2), did not detect substantial differences with regard to WT animals. The regional mRNA levels of GLS were determined by real time RT-PCR and did not show significant variations, except for prefrontal and motor cortex values which clearly diminished in KO mice. Total GA activity was also significantly reduced in prefrontal and motor cortex, but remained essentially unchanged in the hippocampus and rest of brain regions examined, suggesting activation of genetic compensatory mechanisms and/or post-translational modifications to compensate for KGA protein deficit. Remarkably, Golgi staining of hippocampal regions showed an altered morphology of glutamatergic pyramidal cells dendritic spines towards a less mature filopodia-like phenotype, as compared with WT littermates. This structural change correlated with a strong decrease of active matrix-metalloproteinase (MMP) 9 in cerebral cortex and hippocampus of KOLPA₁ mice. Taken together, these results demonstrate that LPA signaling through LPA¹ influence expression of the main isoenzyme of glutamate biosynthesis with strong repercussions on dendritic spines maturation, which may partially explain the cognitive and learning defects previously reported for this colony of KOLPA¹ mice.

• glutamate
• glutaminase
• lysophosphatidic acid
• matrix metalloproteinases
• rodent knockout model
• synaptic plasticity

• Astrocytes
• Glutamate
• Glutaminase-interacting proteins
• Glutamine
• Neurons

• LA
• Methylmercury
• Neurotoxicity
• Oxidative stress

• Animals
• Cerebral Cortex/drug effects
• Cerebral Cortex/metabolism
• Cerebral Cortex/pathology
• Environmental Pollutants/pharmacokinetics
• Environmental Pollutants/toxicity
• Excitatory Amino Acid Transporter 1/metabolism
• Excitatory Amino Acid Transporter 2/metabolism
• Female
• Glutamic Acid/metabolism
• Male
• Malondialdehyde/metabolism
• Methylmercury Compounds/pharmacokinetics
• Methylmercury Compounds/toxicity
• Neuroprotective Agents/pharmacology
• Neuroprotective Agents/therapeutic use
• Neurotoxicity Syndromes/drug therapy
• Neurotoxicity Syndromes/metabolism
• Neurotoxicity Syndromes/pathology
• Oxidative Stress/drug effects
• Rats, Wistar
• Reactive Oxygen Species/metabolism
• Thioctic Acid/pharmacology
• Thioctic Acid/therapeutic use

• Alzheimer type 2 astrocytosis
• Ammonia
• Brain edema
• Glutamine
• Hepatic encephalopathy
• Urea cycle enzymopathies

• Amino Acid Transport System X-AG/metabolism
• Brain Diseases/etiology
• Brain Diseases/metabolism
• Glutamates/metabolism
• Glutaminase/metabolism
• Glutamine/metabolism
• Humans
• Hyperammonemia/complications
• Mitochondria/metabolism
• Neurons/metabolism
• Syndrome

AIM: To evaluate preventative effects of glutamine in an animal model of gut ischemia/reperfusion (I/R).

METHODS: Male Wistar rats were housed in a controlled environment and allowed access to food and water ad libitum. Twenty male Wistar rats were divided into four experimental groups: (1) control group (control) - rats underwent exploratory laparotomy; (2) control + glutamine group (control-GLU) - rats were subjected to laparotomy and treated intraperitoneally with glutamine 24 and 48 h prior to surgery; (3) I/R group - rats were subjected to occlusion of the superior mesenteric artery for 30 min followed by 15 min of reperfusion; and (4) ischemia/reperfusion + glutamine group (G + I/R) - rats were treated intraperitoneally with glutamine 24 and 48 h before I/R. Local and systemic injuries were determined by evaluating intestinal and lung segments for oxidative stress using lipid peroxidation and the activity of superoxide dismutase (SOD), interleukin-6 (IL-6) and nuclear factor kappa beta (NF-κB) after mesenteric I/R.

RESULTS: Lipid peroxidation of the membrane was increased in the animals subjected to I/R (P < 0.05). However, the group that received glutamine 24 and 48 h before the I/R procedure showed levels of lipid peroxidation similar to the control groups (P < 0.05). The activity of the antioxidant enzyme SOD was decreased in the gut of animals subjected to I/R when compared with the control group of animals not subjected to I/R (P < 0.05). However, the group that received glutamine 24 and 48 h before I/R showed similar SOD activity to both control groups not subjected to I/R (P < 0.05). The mean area of NF-κB staining for each of the control groups was similar. The I/R group showed the largest area of staining for NF-κB. The G + I/R group had the second highest amount of staining, but the mean value was much lower than that of the I/R group (P < 0.05). For IL-6, control and control-GLU groups showed similar areas of staining. The I/R group contained the largest area of IL-6 staining, followed by the G + I/R animals; however, this area was significantly lower than that of the group that underwent I/R without glutamine (P < 0.05).

CONCLUSION: These results demonstrate that pretreatment with glutamine prevents mucosal injury and improves gut and lung recovery after I/R injury in rats.

• Ischemia-reperfusion
• Glutamine
• Lipid peroxidation
• Superoxide dismutase
• Nuclear factor-kappa beta
• Interleukin 6

• Animals
• Antioxidants/pharmacology
• Biomarkers/metabolism
• Disease Models, Animal
• Glutamine/pharmacology
• Interleukin-6/metabolism
• Intestinal Mucosa/drug effects
• Intestinal Mucosa/metabolism
• Intestinal Mucosa/pathology
• Intestines/blood supply
• Intestines/drug effects
• Intestines/pathology
• Lipid Peroxidation/drug effects
• Lung/blood supply
• Lung/drug effects
• Lung/metabolism
• Lung/pathology
• Lung Injury/metabolism
• Lung Injury/pathology
• Lung Injury/prevention & control
• Male
• NF-kappa B/metabolism
• Oxidative Stress/drug effects
• Rats, Wistar
• Reperfusion Injury/metabolism
• Reperfusion Injury/pathology
• Reperfusion Injury/prevention & control
• Respiratory Mucosa/drug effects
• Respiratory Mucosa/metabolism
• Respiratory Mucosa/pathology
• Superoxide Dismutase/metabolism
• Time Factors

Liver dysfunction led hyperammonemia (HA) causes a nervous system disorder; hepatic encephalopathy (HE). In the brain, ammonia induced glutamate-excitotoxicity and oxidative stress are considered to play important roles in the pathogenesis of HE. The brain ammonia metabolism and antioxidant enzymes constitute the main components of this mechanism; however, need to be defined in a suitable animal model. This study was aimed to examine this aspect in the rats with acute liver failure (ALF).

ALF in the rats was induced by intraperitoneal administration of 300 mg thioacetamide/Kg. b.w up to 2 days. Glutamine synthetase (GS) and glutaminase (GA), the two brain ammonia metabolizing enzymes vis a vis ammonia and glutamate levels and profiles of all the antioxidant enzymes vis a vis oxidative stress markers were measured in the cerebral cortex and cerebellum of the control and the ALF rats.

The ALF rats showed significantly increased levels of ammonia in the blood (HA) but little changes in the cortex and cerebellum. This was consistent with the activation of the GS-GA cycle and static levels of glutamate in these brain regions. However, significantly increased levels of lipid peroxidation and protein carbonyl contents were consistent with the reduced levels of all the antioxidant enzymes in both the brain regions of these ALF rats.

ALF activates the GS-GA cycle to metabolize excess ammonia and thereby, maintains static levels of ammonia and glutamate in the cerebral cortex and cerebellum. Moreover, ALF induces oxidative stress by reducing the levels of all the antioxidant enzymes which is likely to play important role, independent of glutamate levels, in the pathogenesis of acute HE.

• Animals
• Catalase/metabolism
• Cerebellum/enzymology
• Cerebral Cortex/enzymology
• Glutamic Acid/metabolism
• Glutamine/metabolism
• Glutathione/metabolism
• Glutathione Peroxidase/metabolism
• Glutathione Reductase/metabolism
• Liver Failure, Acute/enzymology
• Liver Failure, Acute/metabolism
• Male
• Metabolic Networks and Pathways
• Organ Specificity
• Oxidative Stress
• Protein Carbonylation
• Rats
• Superoxide Dismutase/metabolism

• GABA
• cotransmission
• dopamine
• glutamate
• vesicular

• Animals
• Dopaminergic Neurons/metabolism
• Glutamic Acid/metabolism
• Humans
• Neurotransmitter Agents/metabolism
• Synaptic Transmission/physiology
• gamma-Aminobutyric Acid/metabolism

• K01 DA026504 NIDA NIH HHS
• P50 MH086404 NIMH NIH HHS
• MOP-106556 Medical Research Council
• R01 DA017978 NIDA NIH HHS
• R01 DA007418 NIDA NIH HHS

Tumour cells thrive in environments that would be hostile to their normal cell counterparts. Survival depends on the selection of cell lines that harbour modifications of both, gene regulation that shifts the balance between the cell cycle and apoptosis and those that involve the plasticity of the metabolic machinery. With regards to metabolism, the selected phenotypes usually display enhanced anaerobic glycolysis even in the presence of oxygen, the so-called Warburg effect, and anabolic pathways that provide precursors for the synthesis of lipids, proteins and DNA. The review will discuss the original ideas of Otto Warburg and how they initially led to the notion that mitochondria of tumour cells were dysfunctional. Data will be presented to show that not only the organelles are viable and respiring, but that they are key players in tumorigenesis and metastasis. Likewise, interconnecting pathways that stand out in the tumour phenotype and that require intact mitochondria such as glutaminolysis will be addressed. Furthermore, comments will be made as to how the peculiarities of the biochemistry of tumour cells renders them amenable to new forms of treatment by highlighting possible targets for inhibitors. In this respect, a case study describing the effect of a metabolite analogue, the alkylating agent 3BP (3-bromopyruvate), on glycolytic enzyme targets will be presented.

• A8
• A9
• VGluT2
• VTA
• dopamine
• midbrain glutamatergic neurons

• Ammonia/metabolism
• Animals
• Astrocytes/cytology
• Astrocytes/metabolism
• Cells, Cultured
• Culture Media
• Gene Expression Profiling
• Glutamic Acid/metabolism
• Glutamine/metabolism
• Humans

• R01 DK063311 NIDDK NIH HHS
• DK063311 NIDDK NIH HHS

• mrs
• j-resolved
• megapress
• neurotransmission

• Cerebral Cortex/metabolism
• Chromosomes, Human, Pair 2/genetics
• Databases, Factual
• Female
• Genotype
• Glutamic Acid/metabolism
• Glutaminase/genetics
• Glutamine/metabolism
• Humans
• Magnetic Resonance Imaging
• Magnetic Resonance Spectroscopy/methods
• Male
• Polymorphism, Single Nucleotide/genetics
• Protons

• R01MH079799 NIMH NIH HHS
• K23MH079982 NIMH NIH HHS
• K24 DA015116 NIDA NIH HHS
• K24DA015116 NIDA NIH HHS
• K05 DA031247 NIDA NIH HHS
• R01 MH079799 NIMH NIH HHS
• K23 MH079982 NIMH NIH HHS

• Glutamate
• paracrine
• receptor
• synaptic