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The hydromechanical stress is a relevant parameter for mammalian cell cultivations, especially regarding scale-up processes. It describes the mechanical forces exerted on cells in a bioreactor. The maximum local energy dissipation rate is a suitable parameter to characterize hydromechanical stress. In literature, different studies deal with the effects of hydromechanical stress on CHO cells in stirred tank reactors. However, they often focus on lethal effects. Furthermore, systematic examinations in smaller scales like shake flasks are missing. Thus, this study systematically considers the influence of hydromechanical stress on CHO DP12 cells in shake flask cultivations. By utilizing online monitoring of the oxygen transfer rate, the study simplifies and enhances the resolution of examinations. Results indicate that while lethal effects are absent, numerous sub-lethal effects emerge with increasing hydromechanical stress: The process time is prolonged. The time of glucose and glutamine depletion, and the lactate switch correlate positively linear with the logarithmic average energy dissipation rate while the maximum specific growth rate correlates negatively. Strikingly, the final antibody concentration only declines at the highest tested average energy dissipation rate of 3.84 W kg−1 (only tested condition with a turbulent flow regime and therefore a higher maximal local energy dissipation rate) from about 250 mg L−1 to about 180 mg L−1. This study presents a straightforward method to examine the impact of hydromechanical stress in shake flasks, easily applicable to any other suspension cell line. Additionally, it offers valuable insights for scale-up processes, for example into stirred tank reactors. • CHO cells are influenced by varying hydromechanical stress levels in shake flasks. • Respiration activity online monitoring is a valuable tool for studying the influence. • Nutrient depletion is influenced by varying levels of hydromechanical stress. • The antibody titer only declines at a turbulent flow regime. [ABSTRACT FROM AUTHOR]

Epithelial-mesenchymal transition (EMT) plays an irreplaceable role in the development of silicosis. However, molecular mechanisms of EMT induced by silica exposure still remain to be addressed. Herein, metabolic profiles of human alveolar type II epithelial cells (A549 cells) exposed directly to silica were characterized using non-targeted metabolomic approaches. A total of 84 differential metabolites (DMs) were identified in silica-treated A549 cells undergoing EMT, which were mainly enriched in metabolisms of amino acids (e.g., glutamate, alanine, aspartate), purine metabolism, glycolysis, etc. The number of DMs identified in the A549 cells obviously increased with the elevated exposure concentration of silica. Remarkably, glutamine catabolism was significantly promoted in the silica-treated A549 cells, and the levels of related metabolites (e.g., succinate) and enzymes (e.g., α -ketoglutarate (α -KG) dehydrogenase) were substantially up-regulated, with a preference to α -KG pathway. Supplementation of glutamine into the cell culture could substantially enhance the expression levels of both EMT-related markers and Snail (zinc finger transcription factor). Our results suggest that the EMT of human alveolar epithelial cells directly induced by silica can be essential to the development of silicosis. [ABSTRACT FROM AUTHOR]

Increased de novo lipogenesis is a hallmark of metabolic dysfunction-associated steatotic liver disease (MASLD) in obesity, but the macronutrient carbon source for over half of hepatic fatty acid synthesis remains undetermined. Here, we discover that dietary protein, rather than carbohydrates or fat, is the primary nutritional risk factor for MASLD in humans. Consistently, ex vivo tracing studies identify amino acids as a major carbon supplier for the tricarboxylic acid (TCA) cycle and lipogenesis in isolated mouse hepatocytes. In vivo , dietary amino acids are twice as efficient as glucose in fueling hepatic fatty acid synthesis. The onset of obesity further drives amino acids into fatty acid synthesis through reductive carboxylation, while genetic and chemical interventions that divert amino acid carbon away from lipogenesis alleviate hepatic steatosis. Finally, low-protein diets (LPDs) not only prevent body weight gain in obese mice but also reduce hepatic lipid accumulation and liver damage. Together, this study uncovers the significant role of amino acids in hepatic lipogenesis and suggests a previously unappreciated nutritional intervention target for MASLD. [Display omitted] • High dietary protein intake increases the risk of MASLD/MASH • Amino acid-derived carbons readily fuel the TCA cycle and fatty acid synthesis in liver • Reducing protein intake or rerouting amino acid catabolism improves hepatic steatosis The macronutrient driver of hepatic steatosis and metabolic dysfunction-associated steatotic liver disease (MASLD) has not been fully defined. Liao et al. identify high dietary protein consumption as a significant risk factor for MASLD/MASH in the NHANES study. The authors further establish amino acids as a prime substrate fueling hepatic lipogenesis, as demonstrated through isotope tracing and a series of chemical, genetic, and dietary intervention studies. [ABSTRACT FROM AUTHOR]

This retrospective clinical study performed at a single clinical center aimed to identify the prevalence of seizures in individuals with urea cycle disorders (UCDs) with and without hyperammonemic (HA) crises. In addition, we sought to correlate the utility of biochemical markers and electroencephalography (EEG) in detecting subclinical seizures during HA. Medical records of individuals with UCDs enrolled in Urea Cycle Disorders Consortium Longitudinal Study (UCDC-LS) (NCT00237315) at Children's National Hospital between 2006 and 2022 were reviewed for evidence of clinical and subclinical seizuress during HA crises, and initial biochemical levels concurrently. Eighty-five individuals with UCD were included in the analyses. Fifty-six of the 85 patients (66%) experienced HA crises, with a total of 163 HA events. Seizures are observed in 13% of HA events. Among all HA events with concomitant EEG, subclinical seizures were identified in 27% of crises of encephalopathy without clinical seizures and 53% of crises with clinical seizures. The odds of seizures increases 2.65 (95% confidence interval [CI], 1.51 to 4.66) times for every 100 μmol/L increase in ammonia and 1.14 (95% CI, 1.04 to 1.25) times for every 100 μmol/L increase in glutamine. This study highlights the utility of EEG monitoring during crises for patients presenting with clinical seizures or encephalopathy with HA. During HA events, measurement of initial ammonia and glutamine can help determine risk for seizures and guide EEG monitoring decisions. [ABSTRACT FROM AUTHOR]

La dénutrition, un enjeu de santé publique majeur, se caractérise par un déséquilibre nutritionnel et est associée à une augmentation de la morbi-mortalité. En particulier, une augmentation du risque d'infections a été décrit chez les sujets dénutris dans de nombreuses études. Les mécanismes mis en jeu pour expliquer cette augmentation du risque infectieux sont multiples et englobent un déficit dans la réponse immunitaire, une atteinte des fonctions barrière et en particulier de la barrière intestinale. Dans cette mise au point, nous décrivons les mécanismes qui peuvent contribuer à diminuer les défenses immunitaires en nous focalisant sur les atteintes au niveau du thymus et de la rate, ainsi que le rôle des substrats énergétiques comme les acides aminés, le glucose. Le rôle des vitamines et oligoéléments est également abordé, comme le rôle de la barrière intestinale. Malnutrition, a major public health issue that characterized by an altered energetic and nutritional balance, is associated with an increase of infectious complications and mortality risk. Indeed, an increase of infectious risk has been reported in malnourished subjects in many studies. Various mechanisms are involved in the increased risk of infections and encompass an altered immune response and disrupted barrier function particularly gut barrier function. In this brief review, we focus on thymic and spleen response in malnourished conditions, as well as on the role of energetic fuels, i.e. amino acids, glucose. The contribution of vitamins and trace-elements is also discussed, as well as the role of gut barrier function. [ABSTRACT FROM AUTHOR]

Cdc14 phosphatases are related structurally and mechanistically to protein tyrosine phosphatases (PTPs) but evolved a unique specificity for phosphoSer-Pro-X-Lys/Arg sites primarily deposited by cyclin-dependent kinases. This specialization is widely conserved in eukaryotes. The evolutionary reconfiguration of the Cdc14 active site to selectively accommodate phosphoSer-Pro likely required modification to the canonical PTP catalytic cycle. While studying Saccharomyces cerevisiae Cdc14, we discovered a short sequence in the disordered C terminus, distal to the catalytic domain, which mimics an optimal substrate. Kinetic analyses demonstrated this pseudosubstrate binds the active site and strongly stimulates rate-limiting phosphoenzyme hydrolysis, and we named it “substrate-like catalytic enhancer” (SLiCE). The SLiCE motif is found in all Dikarya fungal Cdc14 orthologs and contains an invariant glutamine, which we propose is positioned via substrate-like contacts to assist orientation of the hydrolytic water, similar to a conserved active site glutamine in other PTPs that Cdc14 lacks. AlphaFold2 predictions revealed vertebrate Cdc14 orthologs contain a conserved C-terminal alpha helix bound to the active site. Although apparently unrelated to the fungal sequence, this motif also makes substratelike contacts and has an invariant glutamine in the catalytic pocket. Altering these residues in human Cdc14A and Cdc14B demonstrated that it functions by the same mechanism as the fungal motif. However, the fungal and vertebrate SLiCE motifs were not functionally interchangeable, illuminating potential active site differences during catalysis. Finally, we show that the fungal SLiCE motif is a target for phosphoregulation of Cdc14 activity. Our study uncovered evolution of an unusual stimulatory pseudosubstrate motif in Cdc14 phosphatases. [ABSTRACT FROM AUTHOR]

Glutamine metabolism, governed by enzymes including glutaminase (GLS1 and GLS2), has a pivotal role in cancer progression. The objective of this study was to determine whether GLS2 transcription levels are associated with oral squamous cell carcinoma (OSCC) when compared to matched adjacent normal tissues. Primary tumour and adjacent normal tissues were collected from 51 OSCC patients, and GLS2 mRNA expression analysis was conducted using real-time qPCR. Additionally, The Cancer Genome Atlas–Head and Neck Squamous Cell Carcinoma (TCGA-HNSCC) dataset was utilized to examine GLS2 expression in relation to clinicopathological features, the prognosis, and tumour immune cell infiltration. A significantly reduced expression of GLS2 mRNA was found in the OSCC tissues when compared to the matched adjacent normal tissue samples (P < 0.001), which aligned with the results from the TCGA-HNSCC dataset and immunohistochemistry. Moreover, GLS2 mRNA expression was associated with clinicopathological features including tumour stage, grade, and human papillomavirus status (all P < 0.05), predicted a poorer prognosis (P = 0.024), and was correlated with tumour immune cell infiltration (all P < 0.05) in head and neck squamous cell carcinoma. Functional pathway analysis indicated its involvement in cell proliferation and metabolic cycles. GLS2 dysregulation is linked to oral cancer, suggesting its potential as a predictive prognostic marker for OSCC. Furthermore, targeting glutaminases via GLS2 may represent a promising therapeutic strategy for OSCC treatment. [ABSTRACT FROM AUTHOR]

• Scirpus olneyi plants fed 5 mM (15NH 4) 2 SO 4 recorded lower 15N in stems, roots plus rhizomes, and whole plants under elevated CO 2 than ambient CO 2. • 15N concentration decreased by 51 % in stems, 63 % in roots plus rhizomes, and 74 % in whole plants exposed to elevated CO 2. • 15N uptake by S. olneyi plants was decreased by 78 % in elevated CO 2. • Under elevated CO 2 , total amino acid pool was decreased by 50 % in stems and 23 % in roots plus rhizomes of S. olneyi plants. Isotopic analysis of ambient and elevated CO 2 -treated S. olneyi plants receiving 5 mM 99 atom % excess (15NH 4) 2 SO 4 for 19 h showed significantly lower 15N in stems, roots plus rhizomes, and whole plants than ambient CO 2. The 15N concentration decreased by 51 % in stems, 63 % in roots plus rhizomes, and 74 % in whole plants of S. olneyi under elevated CO 2. 15N uptake was reduced by 78 % in elevated CO 2 , resulting in 79 % decrease in 15N content. The N concentration of the rooting medium supporting S. olneyi growth was 2.27 %, suggesting that the plants were not N-starved. The combined evidence from the 15NH 4 + assimilation data and the sediment N analysis clearly showed that the decline in N of S. olneyi under elevated CO 2 was due to inhibition of N uptake, and not low N concentration in the marsh sediment. The elevated CO 2 -induced decrease in 15N uptake and assimilation resulted in significantly reduced concentrations of amino acids in organs of S. olneyi plants. The observed decreases in stem composition of individual amino acids (e.g. serine, glycine, alanine, Gaba and lysine) ranged from 25.6 % for glycine to 65.0 % for serine. Similarly, root concentrations of aspartate, serine, glutamate, glycine, alanine, cysteine, isoleucine, and Gaba were decreased by elevated CO 2 from 2 % for Gaba up to 80 % for glutamate. Given its role as a precursor for glutamine biosynthesis via the GS/GOGAT pathway, the big decrease in glutamate concentration of roots and rhizomes under elevated CO 2 resulted in 50 % decrease in total amino acid pool of stems and 23 % in roots plus rhizomes of S. olneyi plants. The decreased NH 4 + uptake under elevated CO 2 in this study has implications for human nutrition and health in Africa, where agricultural soils are inherently low in N for production of adequate and nutritious grain, and/or development of ecotourism and animal protein from grass pastures (which have a strong preference for NH 4 + nutrition). [ABSTRACT FROM AUTHOR]

Cuproptosis, a newly discovered mechanism of inducing tumor cell death, primarily relies on the intracellular accumulation of copper ions. The utilization of Cu-based nanomaterials to induce cuproptosis holds promising prospects in future biomedical applications. However, the presence of high levels of glutathione (GSH) within tumor cells hinders the efficacy of cuproptosis. In this study, we have developed a BPTES-loaded biomimetic Cu-doped polypyrrole nanoparticles (CuP) nanosystem (PCB) for enhanced cuproptosis and immune modulation. PCB comprises an internal BPTES and CuP core and an external platelet membrane (PM) that facilitates active targeting to tumor sites following intravenous administration. Subsequently, PCB effectively suppresses glutaminase (GLS1) activity, thereby reducing GSH content. Moreover, CuP catalyze intracellular H 2 O 2 , amplifying oxidative stress while simultaneously inducing dihydrolipoyl transacetylase (DLAT) oligomerization through released Cu2+, resulting in cuproptosis. PCB not only inhibits primary tumors but also exhibits inhibitory effects on abscopal tumors. This work represents the first instance where GLS inhibition has been employed to enhance cuproptosis and immunotherapy. It also provides valuable insights into further investigations on cuproptosis. [Display omitted] [ABSTRACT FROM AUTHOR]

Neurological complications of the COVID-19 infection may be caused in part by local neurochemical and structural abnormalities that could not be detected during routine medical examinations. We examined within subject neurometabolic and structural brain alterations from pre-to post-COVID-19 in the hippocampal region of three elderly individuals (aged 63–68 years) who had a COVID-19 infection with mild symptoms. Patients were participating in an interventional study in which they were closely monitored at the time they were diagnosed with COVID-19. Patients 1 and 2 just completed 18–20 resistance training sessions prior to their diagnosis. Patient 3 was assigned to a non-training condition in the same study. Whole brain magnetic resonance imaging (MRI) images and proton magnetic resonance spectroscopy (1H-MRS) of the left hippocampus were collected before and after infection. Structural and spectroscopic imaging measures post-COVID-19 were contrasted to the pre-COVID-19 measures and were compared with values for Minimal Detectable Change at 95% (MDC 95) and 90% (MDC 90) confidence from a group of six elderly (aged 60–79 years) without COVID-19 that participated in the same study. After SARS-COV-2 infection, we observed a reduction of glutamate-glutamine (Glx) in Patients 1 and 2 (≥ 42.0%) and elevation of myo-inositol (mIns) and N -acetyl-aspartate (NAA) in Patient 3 (≥ 36.4%); all > MDC 90. MRI findings showed increased (Patients 1 and 2) or unchanged (Patient 3) hippocampal volume. Overall, findings from this exploratory study suggest that mild COVID-19 infection could be associated with development of local neuroinflammation and reduced glutamate levels in the hippocampus. Our 1H-MRS findings may have clinical value for explaining chronic neurological and psychological complaints in COVID-19 long-haulers. • 1H-MRS spectra and MRI images were collected from hippocampus of 3 COVID-19 patients. • COVID-19 disease was associated with increased myoinositol and reduced Glx levels. • Resistance trained patients showed hippocampal volume increase despite COVID-19. • COVID-19 disease was associated with increased anxiety and depression levels. • 1H-MRS may be applied to detect neurochemical abnormalities in COVID-19 long-haulers. [ABSTRACT FROM AUTHOR]

Cellular zinc ions (Zn2+) are crucial for signal transduction in various cell types. The transient receptor potential (TRP) ankyrin 1 (TRPA1) channel, known for its sensitivity to intracellular Zn2+ ([Zn2+]i), has been a subject of limited understanding regarding its molecular mechanism. Here, we used metal ion-affinity prediction, three-dimensional structural modeling, and mutagenesis, utilizing data from the Protein Data Bank and AlphaFold database, to elucidate the [Zn2+]i binding domain (IZD) structure composed by specific AAs residues in human (hTRPA1) and chicken TRPA1 (gTRPA1). External Zn2+ induced activation in hTRPA1, while not in gTRPA1. Moreover, external Zn2+ elevated [Zn2+]i specifically in hTRPA1. Notably, both hTRPA1 and gTRPA1 exhibited inherent sensitivity to [Zn2+]i, as evidenced by their activation upon internal Zn2+ application. The critical AAs within IZDs, specifically histidine at 983/984, lysine at 711/717, tyrosine at 714/720, and glutamate at 987/988 in IZD1, and H983/H984, tryptophan at 710/716, E854/E855, and glutamine at 979/980 in IZD2, were identified in hTRPA1/gTRPA1. Furthermore, mutations, such as the substitution of arginine at 919 (R919) to H919, abrogated the response to external Zn2+ in hTRPA1. Among single-nucleotide polymorphisms (SNPs) at Y714 and a triple SNP at R919 in hTRPA1, we revealed that the Zn2+ responses were attenuated in mutants carrying the Y714 and R919 substitution to asparagine and proline, respectively. Overall, this study unveils the intrinsic sensitivity of hTRPA1 and gTRPA1 to [Zn2+]i mediated through IZDs. Furthermore, our findings suggest that specific SNP mutations can alter the responsiveness of hTRPA1 to extracellular and intracellular Zn2+. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the neuroprotective effects of whey protein hydrolysate (WPH) containing the pentapeptide leucine-aspartate-isoleucine-glutamine-lysine (LDIQK). Whey protein hydrolysate (50, 100, and 200 µg/mL) demonstrated the ability to restore the viability of HT22 cells subjected to 300 µ M hydrogen peroxide (H 2 O 2)-induced oxidative stress. Furthermore, at a concentration of 200 µg/mL, it significantly reduced the increase in reactive oxygen species production and calcium ion (Ca2+) influx induced by H 2 O 2 by 46.1% and 46.2%, respectively. Similarly, the hydrolysate significantly decreased the levels of p-tau, a hallmark of tauopathy, and BCL2 associated X (BAX), a proapoptosis factor, while increasing the protein levels of choline acetyltransferase (ChAT), an enzyme involved in acetylcholine synthesis, brain-derived neurotrophic factor (BDNF), a nerve growth factor, and B-cell lymphoma 2 (BCL2, an antiapoptotic factor. Furthermore, it increased nuclear factor erythroid 2-related factor 2 (Nrf2)-hemoxygenase-1(HO-1) signaling, which is associated with the antioxidant response, while reducing the activation of mitogen-activated protein kinase (MAPK) signaling pathway components, namely phosphor-extracellular signal-regulated kinases (p-ERK), phosphor-c-Jun N-terminal kinases (p-JNK), and p-p38. Column chromatography and tandem mass spectrometry analysis identified LDIQK as a compound with neuroprotective effects in WPH; it inhibited Ca2+ influx and regulated the BAX/BCL2 ratio. Collectively, WPH containing LDIQK demonstrated neuroprotective effects against H 2 O 2 -induced neuronal cell damage, suggesting that WPH or its active peptide, LDIQK, may serve as a potential edible agent for improving cognitive dysfunction. [Display omitted] [ABSTRACT FROM AUTHOR]

Salinity is a global challenge to sustainable agriculture, impacting plant growth at cellular and functional levels. Nevertheless, silicon (Si), a multifunctional micro-element, plays a vital role in restoring and maintaining growth and development during unfavourable abiotic conditions such as high salinity exposure. Therefore, in the current research, two salinity levels [S1; 1 M (1000 mM) NaCl and S2; 2 M (2000 mM) NaCl] were used to assess the effects of exogenous Si (Si-1; 150 mg/L and Si-2; 250 mg/L) on key biological characteristics and especially the metabolite profiles of Panicum turgidum plants. Our findings revealed that the salt stress negatively affected the plants through high salt content (Na+ and Cl−) that further antagonized the essential nutrient balance in tissues; increased NH 4 +, but lowered NO 3 − and K+ in both roots and leaves. The excessive production of NH 4 + led to over-accumulation of methylglyoxal (MG), resulting in the hyper-accumulation of sugars and altering the concentrations of amino acids, thereby inducing diabetes-like symptoms in P. turgidum plants. Interestingly, Si application restored the growth of P. turgidum plants by reducing oxidative damage thereby modifying the nutritional status, metabolic and biochemical characteristics of the plants. Specifically, the application of Si-2 showed improvement of key biological indictors in leaves and roots under both salinity levels. The current study also demonstrated that Si substantially reduced the NH 4 +-mediated MG-induced stress by lowering the concentration of MG, up-regulating the antioxidant capacity of various enzymes glyoxalase I (Gly-I), glyoxalase II (Gly-II), glutathione (GSH), glutamine: 2-oxoglutarate aminotransferase (GOGAT), nitrate reductase (NR), glutamine synthetase (GS), glutamate dehydrogenase (GDH); with concomitant changes in the levels of sugar/carbohydrates in roots and leaves of P. turgidum. [Display omitted] • The over-accumulation of salt ions negatively affected the essential nutrients uptake and altered the metabolic profile of Panicum turgidum. • The imbalanced NH 4 + and NO 3 − ratio resulted in the hyper-accumulation of methylglyoxal (MG) and carbohydrates; concomitant lowering of the amino acids content leading to diabetes-like symptoms in Panicum turgidum. • Silicon effectively reduced the negative impacts of salinity by reducing the MG and NH 4 + content, thereby restoring the nutritional, biochemical, and metabolic profile of Panicum turgidum plants undergoing unfavorable conditions. [ABSTRACT FROM AUTHOR]

Various nutrients play a physiological role in the healing process of pressure ulcers (PUs). Nutritional interventions include the administration of enteral nutritional supplements and formulas containing arginine, glutamine, and micronutrients. The aim of this systematic review is to evaluate the effectiveness of enteral nutritional supplements and formulas containing arginine and glutamine on wound-related outcomes. These include (1) time to healing, (2) changes in wound size, (3) local wound infection, (4) PU recurrence, and (5) PU-related pain. This protocol was developed according to the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). A search will be conducted in the Cochrane Library, EMBASE, PubMed (MEDLINE), CINAHL (EBSCOhost interface) and Web of Science. In addition, a manual search will be conducted to identify relevant records. Except for systematic reviews, no restrictions will be placed on the study design, the population studied or the setting. Studies that do not address PUs, in vitro studies and studies that do not report wound-related outcomes will be excluded. Study selection, risk of bias assessment and data extraction will be performed independently by three researchers. Depending on the extent of heterogeneity of interventions, follow-up time and populations, results will be summarised either by meta-analysis or narrative synthesis. This is the first systematic review to identify, evaluate and summarise the current evidence for enteral arginine and glutamine supplementation on wound-related outcomes in PUs. The review will provide a solid basis for deriving valid and clinically relevant conclusions in this area. [ABSTRACT FROM AUTHOR]

Modulating the metabolism of cancer cells, immune cells, or both is a promising strategy to potentiate cancer immunotherapy in the nutrient-competitive tumor microenvironment. Glutamine has emerged as an ideal target as cancer cells highly rely on glutamine for replenishing the tricarboxylic acid cycle in the process of aerobic glycolysis. However, non-specific glutamine restriction may induce adverse effects in unconcerned tissues and therefore glutamine inhibitors have achieved limited success in the clinic so far. Here we report the synthesis and evaluation of a redox-responsive prodrug of 6-Diazo-5-oxo-L-norleucine (redox-DON) for tumor-targeted glutamine inhibition. When applied to treat mice bearing subcutaneous CT26 mouse colon carcinoma, redox-DON exhibited equivalent antitumor efficacy but a greatly improved safety profile, particularly, in spleen and gastrointestinal tract, as compared to the state-of-the-art DON prodrug, JHU083. Furthermore, redox-DON synergized with checkpoint blockade antibodies leading to durable cures in tumor-bearing mice. Our results suggest that redox-DON is a safe and effective therapeutic for tumor-targeted glutamine inhibition showing promise for enhanced metabolic modulatory immunotherapy. The approach of reversible chemical modification may be generalized to other metabolic modulatory drugs that suffer from overt toxicity. [Display omitted] [ABSTRACT FROM AUTHOR]

• Three soil inorganic amendments (SIAs) were used to produce safe rice. • SIA increased the iron plaque on rice root and decreased the transfer of Cd from rice root to grain. • SIA increased contents of total and key amino acids in brown rice. • Key amino acids (KAAs) were closely related to indigestible Cd in brown rice. • A priming effect of KAAs could stimulate to reduce Cd digestibility when Cd in rice reached a certain degree. The digestibility of cadmium (Cd) in brown rice is directly related to amino acid metabolism in rice and human health. In our field study, three kinds of alkaline calcium-rich soil inorganic amendments (SIAs) at three dosages were applied to produce safe rice and improve the quality of rice in Cd-contaminated paddy. With the increased application of SIA, Cd content in iron plaque on rice root significantly increased, the transfer of Cd from rice root to grain significantly decreased, and then Cd content in brown rice decreased synchronously. The vitro digestibility of Cd in brown rice was estimated by a physiologically based extraction test. Results showed that more than 70% of Cd in brown rice could be digested by simulated gastrointestinal juice. Based on the total and digestible Cd contents in brown rice to evaluate the health risk, the application of 2.25 ton SIA/ha could produce safe rice in acidic slightly Cd-contaminated paddy soils. The amino acids (AAs) in brown rice were determined by high-performance liquid chromatography. The contents of 5 key AAs (KAAs) that actively respond to environmental changes increased significantly with the increased application of SIA. The structural equation model indicated that KAAs could be affected by the Cd translocation capacity from rice root to grain, and consequently altered the ratio of indigestible Cd in brown rice. The formation of indigestible KAAs-Cd complexes by combining KAAs (phenylalanine, leucine, histidine, glutamine, and asparagine) with Cd in brown rice could be considered a potential mechanism for reducing the digestibility of Cd. [Display omitted] [ABSTRACT FROM AUTHOR]

The role of solute carrier family 25 member 15 (SLC25A15), a critical component of the urea cycle, in hepatocellular carcinoma (HCC) progression remains poorly understood. This study investigated the impact of SLC25A15 on HCC progression and its mechanisms. We systematically investigated the function of SLC25A15 in HCC progression using large-scale data mining and cell, animal, and organoid models. Furthermore, we analyzed its involvement in reprogramming glutamine metabolism. SLC25A15 expression was significantly decreased in HCC tissues, and patients with low SLC25A15 levels had a poorer prognosis. Hypoxia-exposed HCC cells or tissues had lower SLC25A15 expression. A positive correlation between HNF4A, a transcription factor suppressed by hypoxia, and SLC25A15 was observed in both HCC tissues and cells. Modulating HNF4A levels altered SLC25A1 5 mRNA levels. SLC25A15 upregulated SLC1A5, increasing glutamine uptake. The reactive metabolic pathway of glutamine was increased in SLC25A15-deficient HCC cells, providing energy for HCC progression through additional lipid synthesis. Ammonia accumulation due to low SLC25A15 levels suppressed the expression of OGDHL (oxoglutarate dehydrogenase L), a switch gene that mediates SLC25A15 deficiency-induced reprogramming of glutamine metabolism. SLC25A15-deficient HCC cells were more susceptible to glutamine deprivation and glutaminase inhibitors. Intervening in glutamine metabolism increased SLC25A15-deficient HCC cells' response to anti-PD-L1 treatment. SLC25A15 is hypoxia-responsive in HCC, and low SLC25A15 levels result in glutamine reprogramming through SLC1A5 and OGDHL regulation, promoting HCC progression and regulating cell sensitivity to anti-PD-L1. Interrupting the glutamine-derived energy supply is a potential therapeutic strategy for treating SLC25A15-deficient HCC. We first demonstrated the tumor suppressor role of solute carrier family 25 member 15 (SLC25A15) in hepatocellular carcinoma (HCC) and showed that its deficiency leads to reprogramming of glutamine metabolism to promote HCC development. SLC25A15 can serve as a potential biomarker to guide the development of precision therapeutic strategies aimed at targeting glutamine deprivation. Furthermore, we highlight that the use of an inhibitor of glutamine utilization can enhance the sensitivity of low SLC25A15 HCC to anti-PD-L1 therapy. [Display omitted] • SLC25A15 expression is significantly reduced in HCC tissues, and patients with low levels have a worse prognosis. • Hypoxia exposure reduces SLC25A15 expression by inhibiting HNF4A. • Low SLC25A15 levels result in glutamine reprogramming by inhibiting OGDHL, promoting HCC progression. • Low SLC25A15 reduced PD-L1 expression, thus interfering with the response to anti-PD-L1 therapy. • Interrupting the glutamine-derived energy supply may benefit patients with HCC and SLC25A15 deficiency. [ABSTRACT FROM AUTHOR]

The gut microbiota plays a pivotal role in the immunomodulatory and protumorigenic microenvironment of colorectal cancer (CRC). However, the effect of ginsenoside Rk3 (Rk3) on CRC and gut microbiota remains unclear. Therefore, the purpose of this study is to explore the potential effect of Rk3 on CRC from the perspective of gut microbiota and immune regulation. Our results reveal that treatment with Rk3 significantly suppresses the formation of colon tumors, repairs intestinal barrier damage, and regulates the gut microbiota imbalance caused by CRC, including enrichment of probiotics such as Akkermansia muciniphila and Barnesiella intestinihominis , and clearance of pathogenic Desulfovibrio. Subsequent metabolomics data demonstrate that Rk3 can modulate the metabolism of amino acids and bile acids, particularly by upregulating glutamine, which has the potential to regulate the immune response. Furthermore, we elucidate the regulatory effects of Rk3 on chemokines and inflammatory factors associated with group 3 innate lymphoid cells (ILC3s) and T helper 17 (Th17) signaling pathways, which inhibits the hyperactivation of the Janus kinase-signal transducer and activator of transcription 3 (JAK-STAT3) signaling pathway. These results indicate that Rk3 modulates gut microbiota, regulates ILC3s immune response, and inhibits the JAK-STAT3 signaling pathway to suppress the development of colon tumors. More importantly, the results of fecal microbiota transplantation suggest that the inhibitory effect of Rk3 on colon tumors and its regulation of ILC3 immune responses are mediated by the gut microbiota. In summary, these findings emphasize that Rk3 can be utilized as a regulator of the gut microbiota for the prevention and treatment of CRC. [Display omitted] • Rk3 suppresses colorectal tumorigenesis. • Rk3 modulates dysbiosis of gut microbiota. • Rk3 regulates intestinal ILC3 immune response. • The antitumor effects of Rk3 depend on gut microbiota. • Rk3-modulated gut microbiota inhibits colorectal tumorigenesis. [ABSTRACT FROM AUTHOR]

Pulmonary hypertension (PH) is a progressive disease with vascular remodeling as a critical structural alteration. We have previously shown that metabolic reprogramming is an early initiating mechanism in animal models of PH. This metabolic dysregulation has been linked to remodeling the mitochondrial network to favor fission. However, whether the mitochondrial fission/fusion balance underlies the metabolic reprogramming found early in PH development is unknown. Utilizing a rat early model of PH, in conjunction with cultured pulmonary endothelial cells (PECs), we utilized metabolic flux assays, Seahorse Bioassays, measurements of electron transport chain (ETC) complex activity, fluorescent microscopy, and molecular approaches to investigate the link between the disruption of mitochondrial dynamics and the early metabolic changes that occur in PH. We observed increased fusion mediators, including Mfn1, Mfn2, and Opa1, and unchanged fission mediators, including Drp1 and Fis1, in a two-week monocrotaline-induced PH animal model (early-stage PH). We were able to establish a connection between increases in fusion mediator Mfn1 and metabolic reprogramming. Using an adenoviral expression system to enhance Mfn1 levels in pulmonary endothelial cells and utilizing 13C-glucose labeled substrate, we found increased production of 13C lactate and decreased TCA cycle metabolites, revealing a Warburg phenotype. The use of a 13C 5 -glutamine substrate showed evidence that hyperfusion also induces oxidative carboxylation. The increase in glycolysis was linked to increased hypoxia-inducible factor 1α (HIF-1α) protein levels secondary to the disruption of cellular bioenergetics and higher levels of mitochondrial reactive oxygen species (mt-ROS). The elevation in mt-ROS correlated with attenuated ETC complexes I and III activities. Utilizing a mitochondrial-targeted antioxidant to suppress mt-ROS, limited HIF-1α protein levels, which reduced cellular glycolysis and reestablished mitochondrial membrane potential. Our data connects mitochondrial fusion-mediated mt-ROS to the Warburg phenotype in early-stage PH development. [Display omitted] • Fission/fusion balance disruption is critical for metabolic reprogramming in PH. • Mitofusin1 (Mfn1) overexpression produced metabolic remodeling in endothelial cells. • Mfn1 mediated metabolic remodeling disrupted bioenergetics and increased glycolysis. • Mfn1 increased mitochondrial ROS and HIF-1α, and disrupted ETC complexes I and III. • Mitochondrial targeted ROS scavenger T-SSP decreased Mfn1 mediated ROS. [ABSTRACT FROM AUTHOR]

6-Diazo-5-oxo-L-norleucine (DON) is a potent glutamine antagonist with toxic side effects; in order to reduce these effects, multiple prodrugs have been designed. However, there are currently no reports of a DON prodrug with a defined mechanism to achieve high tumor selectivity. To improve the selective toxicity of DON to tumor cells while reducing systemic toxicity, a hypoxia-activated prodrug, termed HDON, was designed. HDON achieved remarkable tumor suppression of 76.4 ± 5.2% without leading to weight loss in an H22 murine liver cancer model with high hypoxia. Moreover, to augment the therapeutic efficacy of HDON, combretastatin A4 nanoparticles were used to aggravate tumor hypoxia of MC38 murine colon cancer and 4T1 murine breast cancer, activate HDON to DON, and stimulate a robust anti-tumor immune response while selectively killing in tumor cells in vivo , achieving significantly elevated tumor suppression rates of 98.3 ± 3.4% and 98.1 ± 3.1%, with cure rates of 80.0% and 20.0%, respectively. [Display omitted] • A hypoxia-activated prodrug of 6-diazo-5-oxo-L-norleucine termed HDON was designed. • HDON exhibited stability and low toxicity under normal physiological conditions. • HDON reduced to DON in hypoxic tumors, enabling effective metabolic blockade. [ABSTRACT FROM AUTHOR]

The efficacy of supplemental enteral glutamine (GLN) in critical illness patients remains uncertainty. Based on a recently published large-scale randomized controlled trials (RCTs) as regards the use of enteral GLN, we updated a meta-analysis of RCTs for further investigating the effects of enteral GLN administration in critically ill patients. We searched RCTs reporting the impact of supplemental enteral GLN about clinical outcomes in adult critical illness patients from EMBASE, PubMed, Clinical Trials.gov , Scopus and Web of Science and subsequently registered the protocol in the PROSPERO (CRD42023399770). RCTs of combined enteral-parenteral GLN or parenteral GLN only were excluded. Hospital mortality was designated as the primary outcome. We conducted subgroup analyses of primary outcome based on specific patient populations, dosages and therapy regimens, and further performed trial sequential analysis (TSA) for clinical outcomes. Eighteen RCTs involving 2552 adult critically ill patients were identified. There were no remarkable influences on hospital mortality regardless of different subgroups (OR, 1.05; 95% CI, 0.85–1.30; p = 0.67), intensive care unit (ICU) length of stay (LOS) (MD, −0.07; 95% CI, −1.12 – 0.98; p = 0.89) and infectious complications (OR, 0.90; 95% CI, 0.75–1.10; p = 0.31) with enteral GLN supplementation. Additionally, the results of hospital mortality were confirmed by TSA. However, enteral GLN therapy was related to a reduction of hospital LOS (MD, −2.85; 95% CI, −5.27 to −0.43; p = 0.02). In this meta-analysis, it seems that enteral GLN supplementation is unlikely ameliorate clinical outcomes in critical illness patients except for the reduction of hospital LOS. Our data do not support enteral GLN supplementation used routinely in critical illness patients. This is the first meta-analysis of RCTs and trial sequential analysis to provide a comprehensive evidence of whether enteral GLN supplementation is benefit for patients with critically ill and whether there are subgroup effects of patient populations, dosages and therapy regimens. [ABSTRACT FROM AUTHOR]

• Spermidine had a positive effect on somatic embryogenesis of Lang Bian ginseng. • The fluctuations of endogenous hormones during somatic embryogenesis were recorded. • Spermidine at 0.1 mM concentration increased the activity of antioxidant enzymes. • AgNPs improved the rhizome formation rate of Lang Bian ginseng. Lang Bian ginseng (Panax vietnamensis var. langbianensis) is a rare and traditional herbal medicine with many pharmacological activities. It was first discovered by Duy et al. (2016) in Lam Dong province, Vietnam. Until now, there has been only one publication on Lang Bian ginseng micropropagation via somatic embryogenesis (Anh et al., 2022). However, this study still had limitations, including the small number of somatic embryos and the time-consuming. This study investigated the effect of spermidine, glutamine, and proline on the enhancement of somatic embryogenesis (SE) of Lang Bian ginseng using thin cell layer culture technology. The results showed that the optimal SE rate and the number of somatic embryos per explant were achieved on MS medium supplemented with 0.01 mM spermidine in leaf explants (93.32 % and 54.20 embryos, respectively) and petiole explants (96.66 % and 68.80 embryos, respectively) and higher compared to these in other treatments, including control, glutamine, and proline treatments. Besides, adding 0.01 mM spermidine to the culture medium also improved the quality of somatic embryos, mainly cotyledonary stage, through an enhanced synthesis of antioxidant enzymes [catalase (CAT) and superoxide dismutase (SOD), and ascorbate peroxidase (APX)]. In addition, the fluctuations of endogenous hormones during initiation and maturation of SE derived from 0.01 mM spermidine treatment were recorded. Endogenous CKs (ZEA, 2iP, KIN, mT), IAA, and GA 3 concentrations were the highest during the induction stage in both explants. Meanwhile, the remaining endogenous hormones (MEL, ABA, and SA) exhibited no inevitable fluctuation trends. In addition, IAA was only detected at the induction stage of SE in both explants. Moreover, cotyledonary somatic embryos derived from 0.01 mM spermidine treatment grew well in MS medium supplemented with 1.2 mg/L AgNPs. [ABSTRACT FROM AUTHOR]

Aggregation behavior provides bacteria protection from harsh environments and threats to survival. Two uncharacterized proteases, LapX and Lap, are important for Vibrio cholerae liquid-based aggregation. Here, we determined that LapX is a serine protease with a preference for cleavage after glutamate and glutamine residues in the P1 position, which processes a physiologically based peptide substrate with a catalytic efficiency of 180 ± 80 M-1s-1. The activity with a LapX substrate identified by a multiplex substrate profiling by mass spectrometry screen was 590 ± 20 M-1s-1. Lap shares high sequence identity with an aminopeptidase (termed VpAP) from Vibrio proteolyticus and contains an inhibitory bacterial prepeptidase C-terminal domain that, when eliminated, increases catalytic efficiency on leucine p-nitroanilide nearly four-fold from 5.4 ± 4.1 × 104 M-1s-1 to 20.3 ± 4.3 × 104 M-1s-1. We demonstrate that LapX processes Lap to its mature form and thus amplifies Lap activity. The increase is approximately eighteen-fold for full-length Lap (95.7 ± 5.6 × 104 M-1s-1) and six-fold for Lap lacking the prepeptidase C-terminal domain (11.3 ± 1.9 × 105 M-1s-1). In addition, substrate profiling reveals preferences for these two proteases that could inform in vivo function. Furthermore, purified LapX and Lap restore the timing of the V. cholerae aggregation program to a mutant lacking the lapX and lap genes. Both proteases must be present to restore WT timing, and thus they appear to act sequentially: LapX acts on Lap, and Lap acts on the substrate involved in aggregation. [ABSTRACT FROM AUTHOR]

[Display omitted] Polypeptide consisting of ψ- N -isopropyl glutamine and glutamic acid (90 : 10, mol/mol) was synthesized by post- polymerization modification of poly(ψ-methyl glutamate). The obtained polypeptide exhibited thermoresponsive properties with the lowest critical solution temperature in the range of 41–54 °C depending on the medium and polymer concentration. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is a major pathogen, which has to defend against reactive oxygen and electrophilic species encountered during infections. Activated macrophages produce the immunometabolite itaconate as potent electrophile and antimicrobial upon pathogen infection. In this work, we used transcriptomics, metabolomics and shotgun redox proteomics to investigate the specific stress responses, metabolic changes and redox modifications caused by sublethal concentrations of itaconic acid in S. aureus. In the RNA-seq transcriptome, itaconic acid caused the induction of the GlnR, KdpDE, CidR, SigB, GraRS, PerR, CtsR and HrcA regulons and the urease-encoding operon, revealing an acid and oxidative stress response and impaired proteostasis. Neutralization using external urea as ammonium source improved the growth and decreased the expression of the glutamine synthetase-controlling GlnR regulon, indicating that S. aureus experienced ammonium starvation upon itaconic acid stress. In the extracellular metabolome, the amounts of acetate and formate were decreased, while secretion of pyruvate and the neutral product acetoin were strongly enhanced to avoid intracellular acidification. Exposure to itaconic acid affected the amino acid uptake and metabolism as revealed by the strong intracellular accumulation of lysine, threonine, histidine, aspartate, alanine, valine, leucine, isoleucine, cysteine and methionine. In the proteome, itaconic acid caused widespread S -bacillithiolation and S -itaconation of redox-sensitive antioxidant and metabolic enzymes, ribosomal proteins and translation factors in S. aureus , supporting its oxidative and electrophilic mode of action in S. aureus. In phenotype analyses, the catalase KatA, the low molecular weight thiol bacillithiol and the urease provided protection against itaconic acid-induced oxidative and acid stress in S. aureus. Altogether, our results revealed that under physiological infection conditions, such as in the acidic phagolysome, itaconic acid is a highly effective antimicrobial against multi-resistant S. aureus isolates, which acts as weak acid causing an acid, oxidative and electrophilic stress response, leading to S -bacillithiolation and itaconation. [Display omitted] • Itaconic acid causes an acid and oxidative stress response in the transcriptome of Staphylococcus aureus. • Intracellular levels of many amino acids are enhanced, while acetoin secretion is increased in the exometabolome. • Neutralization with external urea improved the growth after itaconic acid stress. • Itaconic acid leads to increased S -bacillithiolation and S -itaconation in the proteome. • KatA, bacillithiol and the urease function in the protection against itaconic acid. [ABSTRACT FROM AUTHOR]

Cisplatin (CPT) is one of the standard treatments for hepatocellular carcinoma (HCC). However, its use is limits as a monotherapy due to drug resistance, and the underlying mechanism remains unclear. To solve this problem, we tried using canagliflozin (CANA), a clinical drug for diabetes, to reduce chemoresistance to CPT, and the result showed that CANA could vigorously inhibit cell proliferation and migration independent of the original target SGLT2. Mechanistically, CANA reduced aerobic glycolysis in HCC by targeting PKM2. The downregulated PKM2 directly bound to the transcription factor c-Myc in the cytoplasm to form a complex, which upregulated the level of phosphorylated c-Myc Thr58 and promoted the ubiquitination and degradation of c-Myc. Decreased c-Myc reduced the expression of GLS1, a key enzyme in glutamine metabolism, leading to impaired glutamine utilization. Finally, intracellular glutamine starvation induced ferroptosis and sensitized HCC to CPT. In conclusion, our study showed that CANA re-sensitized HCC to CPT by inducing ferroptosis through dual effects on glycolysis and glutamine metabolism. This is a novel mechanism to increase chemosensitivity, which may provide compatible chemotherapy drugs for HCC. [Display omitted] • Canagliflozin suppresses hepatocellular carcinoma via PKM2 but not SGLT2. • Canagliflozin-triggered inhibition of aerobic glycolysis induces impaired glutamine utilization in hepatocellular carcinoma. • PKM2 was confirmed to function as a PKM2-c-Myc complex on canagliflozin treatment. • Canagliflozin combined with cisplatin has a synergistic effect on hepatocellular carcinoma and overcome cisplatin resistance. [ABSTRACT FROM AUTHOR]

Heritable renal cancer syndromes (RCS) are associated with numerous chromosomal alterations including inactivating mutations in von Hippel-Lindau (VHL) gene. Here we identify a novel aspect of the phenotype in VHL-deficient human renal cells. We call it reductive stress as it is characterised by increased NADH/NAD+ ratio that is associated with impaired cellular respiration, impaired CAC activity, upregulation of reductive carboxylation of glutamine and accumulation of lipid droplets in VHL-deficient cells. Reductive stress was mitigated by glucose depletion and supplementation with pyruvate or resazurin, a redox-reactive agent. This study demonstrates for the first time that reductive stress is a part of the phenotype associated with VHL-deficiency in renal cells and indicates that the reversal of reductive stress can augment respiratory activity and CAC activity, suggesting a strategy for altering the metabolic profile of VHL-deficient tumours. VHL-deficiency in renal cells leads to reductive stress characterazied by increased ratio of NADH/NAD+. Excess of reducing equivalents (reductive stress) alters ETC and CAC activities. A glucose depletion and supplementation with pyruvate or resazurin, a redox-reactive agent can alleviate reductive stress. [Display omitted] • Reductive stress is evidenced by increased NADH/NAD+ and reduced respiration in VHL-deficient cells. • Glucose removal and pyruvate/resazurin addition relieved symptoms of reductive stress. • Cellular respiration was monitored by real-time measurements of CO 2 and O 2 fluxes in the gas phase. [ABSTRACT FROM AUTHOR]

Cow milk is an important source of food protein for children; however, it could lead to allergy, especially for infants. α-Lactalbumin (α-LA) and β-lactoglobulin (β-LG) from whey protein make up a relatively high proportion of milk proteins and have received widespread attention as major allergens in milk. However, few studies have identified the epitopes of both proteins simultaneously. In this study, ImmunoCAP and indirect ELISA were first used for detection of sIgE to screen sera from allergic patients with high binding capacity for α-LA and β-LG. Subsequently, the mimotopes was biopanned by phage display technology and bioinformatics and 17 mimic peptide sequences were obtained. Aligned with the sequences of α-LA or β-LG, we identified one linear epitope on α-LA at AA 11–26 and 5 linear epitopes on β-LG at AA 9–29, AA 45–57, AA 77–80, AA 98–101, and AA 121–135, respectively. Meanwhile, the 8 conformational epitopes and their distributions of α-LA and β-LG were located using the Pepitope Server. Finally, glutamine and lysine were determined as common AA residues for the conformational epitopes both on α-LA and β-LG. Moreover, we found the addition of mouse anti-human IgE during the biopanning process did not significantly affect the identification of the epitopes. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] To evaluate the efficacy of preoperative glutamine infusion in reducing insulin requirements in patients with uncontrolled type 2 diabetes, defined as glycated hemoglobin (HbA1c) >7%, undergoing urgent coronary artery bypass graft (CABG) surgery. A randomized controlled trial. At Ain Shams University Hospital, Cardiothoracic Academy. Ninety-three patients (of both sexes) with uncontrolled diabetes presenting for urgent CABG were categorized into 2 groups. The dipeptiven group (n = 46) was given an infusion of dipeptiven 1.5 mL/kg body weight dissolved in normal saline (200 mL) over 3 hours before surgery. The control group (n = 47) received a normal saline infusion (200 mL). The dipeptiven group demonstrated statistically significant lower intraoperative (173.74 ± 19.97 mg/dL v 198.22 ±14.64 mg/dL) and postoperative (162.36 ±13.11 mg/dL v 176.13 ±14.86 mg/dL) mean blood glucose levels. In addition, dipeptiven infusion was found to reduce mean total insulin requirements intraoperatively by 3.64 ± 0.56 units/h and postoperatively by 37.109 ± 4.30 units/24 h in comparison to placebo (50.98 ± 16.55 units/24 h and 5.10 ± 2.28 units/h, respectively). A preoperative infusion of dipeptiven can contribute to ameliorating stress hyperglycemia in uncontrolled diabetic patients undergoing urgent CABG. [ABSTRACT FROM AUTHOR]

Abnormal neurotransmitter levels have been reported in individuals at high risk for schizophrenia, leading to a shift in the excitatory/inhibitory balance. However, it is unclear whether these alterations predate the onset of clinically relevant symptoms. Our aim was to explore in vivo measures of excitatory/inhibitory balance in 22q11.2 deletion carriers, a population at genetic risk for psychosis. Glx (glutamate+glutamine) and GABA+ (gamma-aminobutyric acid with macromolecules and homocarnosine) concentrations were estimated in the anterior cingulate cortex, superior temporal cortex, and hippocampus using the Mescher-Garwood point-resolved spectroscopy (MEGA-PRESS) sequence and the Gannet toolbox in 52 deletion carriers and 42 control participants. T1-weighted images were acquired longitudinally and processed with FreeSurfer version 6 to extract hippocampal volume. Subgroup analyses were conducted in deletion carriers with psychotic symptoms. While no differences were found in the anterior cingulate cortex, deletion carriers had higher levels of Glx in the hippocampus and superior temporal cortex and lower levels of GABA+ in the hippocampus than control participants. We additionally found a higher Glx concentration in the hippocampus of deletion carriers with psychotic symptoms. Finally, more pronounced hippocampal atrophy was significantly associated with increased Glx levels in deletion carriers. We provide evidence for an excitatory/inhibitory imbalance in temporal brain structures of deletion carriers, with a further hippocampal Glx increase in individuals with psychotic symptoms that was associated with hippocampal atrophy. These results are in line with theories proposing abnormally enhanced glutamate levels as a mechanistic explanation for hippocampal atrophy via excitotoxicity. Our results highlight a central role of glutamate in the hippocampus of individuals at genetic risk for schizophrenia. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance studies of many physiologically important proteins have long been impeded by the necessity to express such proteins in isotope-labeled form in higher eukaryotic cells and the concomitant high costs of providing isotopelabeled amino acids in the growth medium. Economical routes use isotope-labeled yeast or algae extracts but still require expensive isotope-labeled glutamine. Here, we have systematically quantified the effect of 15N2-glutamine on the expression and isotope labeling of different proteins in insect cells. Sufficient levels of glutamine in the medium increase the protein expression by four to five times relative to deprived conditions. 1H-15N nuclear magnetic resonance spectroscopy shows that the 15N atoms from 15N2-glutamine are scrambled with surprisingly high (60-70%) efficiency into the three amino acids alanine, aspartate, and glutamate. This phenomenon gives direct evidence that the high energy demand of insect cells during baculovirus infection and concomitant heterologous protein expression is predominantly satisfied by glutamine feeding the tricarboxylic acid cycle. To overcome the high costs of supplementing isotope-labeled glutamine, we have developed a robust method for the large-scale synthesis of 15N2-glutamine and partially deuterated 15N2-glutamine-a,ß,ß-d3 from inexpensive precursors. An application is shown for the effective large-scale expression of the isotope-labeled ß1-adrenergic receptor using the synthesized 15N2-glutamine-a,ß,ß-d3. [ABSTRACT FROM AUTHOR]

Enzyme-driven micro/nanomotors consuming in situ chemical fuels have attracted lots of attention for biomedical applications. However, motor systems composed by organism-derived organics that maximize the therapeutic efficacy of enzymatic products remain challenging. Herein, swimming proteomotors based on biocompatible urease and human serum albumin are constructed for enhanced antitumor therapy via active motion and ammonia amplification. By decomposing urea into carbon dioxide and ammonia, the designed proteomotors are endowed with self-propulsive capability, which leads to improved internalization and enhanced penetration in vitro. As a glutamine synthetase inhibitor, the loaded l -methionine sulfoximine further prevents the conversion of toxic ammonia into non-toxic glutamine in both tumor and stromal cells, resulting in local ammonia amplification. After intravesical instillation, the proteomotors achieve longer bladder retention and thus significantly inhibit the growth of orthotopic bladder tumor in vivo without adverse effects. We envision that the as-developed swimming proteomotors with amplification of the product toxicity may be a potential platform for active cancer treatment. By decomposing endogenous urea and preventing the conversion of ammonia, swimming nanomotor exhibits active motion and ammonia amplification in the urea-containing microenvironment for enhanced cancer therapy. [Display omitted] [ABSTRACT FROM AUTHOR]

p62 has been shown to be involved in many signaling pathways related to cancer cell metabolism and plays a crucial role in the regulation of cancer metabolism by participating in the activation or inhibition of these signaling pathways. p62 could regulate host metabolism through affecting the functions of tumor-infiltrating immune cells. Therapeutic intervention in cancers through the targeting of p62 is a promising cancer treatment strategy. Small-molecule compounds targeting the different domains of p62 could potentially be developed for cancer therapy. p62 is an important multifunctional adaptor protein participating in autophagy and many other activities. Many studies have revealed that p62 is highly expressed in multiple cancers and decreasing its level can effectively lower the proliferation ability of cancer cells. Moreover, much research has highlighted the significant role of the regulation of cancer cell metabolism in helping to treat tumors. Recent reports demonstrate that p62 could regulate cancer cell metabolism through various mechanisms. However, the relationship between p62 and cancer cell metabolism as well as the related mechanisms has not been fully elucidated. In this review, we describe glucose, glutamine, and fatty acid metabolism in tumor cells and some signaling pathways that can regulate cancer metabolism and are mediated by p62. [ABSTRACT FROM AUTHOR]

Follicular fluid has been found as a possible source of metabolic predictors for oocyte competence, and it is conveniently accessible during ovum pick-up (OPU). We used the OPU procedure to recover oocytes from 41 Holstein heifers for in vitro embryo production in this study. Follicular fluid was collected during OPU in order to establish a link between follicular amino acids and blastocyst formation. Each heifer's oocytes were collected, matured in vitro for 24 h and fertilized separately. The heifers were then divided into two groups based on blastocyst formation: those that produced at least one blastocyst (the blastocyst group, n = 29) and those that did not (the failed group, n = 12). The blastocyst group had higher follicular glutamine concentrations and lower aspartate levels than the failed group. Furthermore, network and Spearman correlation analyses revealed a link between blastocyst formation and aspartate (r = −0.37, p = 0.02) or glutamine (r = 0.38, p = 0.02). The receiver operator characteristic curve revealed that glutamine (AUC = 0.75) was the greatest predictor of blastocyst formation. These findings revealed that follicular amino acid levels in bovines can be used to predict blastocyst development. • Amino acids in follicular fluid are linked to blastocyst formation. • Higher follicular glutamine levels were connected to improved blastocyst formation. • In vitro embryo formation was linked to lower follicular aspartate levels. [ABSTRACT FROM AUTHOR]

Type 2 diabetes mellitus (DM) poses a major burden for the treatment and control of tuberculosis (TB). Characterization of the underlying metabolic perturbations in DM patients with TB infection would yield insights into the pathophysiology of TB-DM, thus potentially leading to improvements in TB treatment. In this study, a multimodal metabolomics and lipidomics workflow was applied to investigate plasma metabolic profiles of patients with TB and TB-DM. Significantly different biological processes and biomarkers in TB-DM vs. TB were identified using a data-driven, knowledge-based framework. Changes in metabolic and signaling pathways related to carbohydrate and amino acid metabolism were mainly captured by amide HILIC column metabolomics analysis, while perturbations in lipid metabolism were identified by the C18 metabolomics and lipidomics analysis. Compared to TB, TB-DM exhibited elevated levels of bile acids and molecules related to carbohydrate metabolism, as well as the depletion of glutamine, retinol, lysophosphatidylcholine, and phosphatidylcholine. Moreover, arachidonic acid metabolism was determined as a potentially important factor in the interaction between TB and DM pathophysiology. In a correlation network of the significantly altered molecules, among the central nodes, chenodeoxycholic acid was robustly associated with TB and DM. Fatty acid (22:4) was a component of all significant modules. In conclusion, the integration of multimodal metabolomics and lipidomics provides a thorough picture of the metabolic changes associated with TB-DM. The results obtained from this comprehensive profiling of TB patients with DM advance the current understanding of DM comorbidity in TB infection and contribute to the development of more effective treatment. • Concurrent TB-DM is associated with altered metabolome and lipidome. • Alterations of metabolic and signaling pathways linked to carbohydrates and lipids. • Glutamine and lysophosphatidylcholine were significantly depleted in TB-DM patients. • Chenodeoxycholic acid and adrenic acid were associated with TB-DM. [ABSTRACT FROM AUTHOR]

Metabolic and endocrine pathways are central to the body's compensatory response to trauma. They drive mobilization of energy substrates, volume conservation and haemostasis via activation of the hypothalamic pituitary adrenal axis, the sympathetic nervous system and an inflammatory response. As clinicians, we can intervene in these pathways, however optimal management of anaesthesia, fluids, transfusion, nutrition and the use of steroids remains controversial and to be determined. [ABSTRACT FROM AUTHOR]

To test the hypothesis that intraperitoneal instillation of a single bolus dose of l -alanyl- l -glutamine (AG) will reduce the incidence, extent and/or severity of adhesions following myomectomy and establish preliminary safety and tolerability of AG in humans. Phase 1,2 Randomized, double-blind, placebo-controlled study (DBRCT). Tertiary care gynecology surgical centre. Thirty-eight women who underwent myomectomies by laparoscopy (N = 38; AG-19 vs Placebo-19) or laparotomy (N = 10; AG-5 vs Placebo-5) with a scheduled second-look laparoscopy (SLL) 6–8 weeks later. Thirty-two patients in the laparoscopy arm completed SLL. Bolus dose of AG or normal saline solution control (0.9% NaCl) administered intraperitoneally immediately prior to suture closure of the laparoscopic ports. The average dose was 170 mL of AG or control based on a dosing scheme of 1 g/kg bodyweight. Digital recordings obtained for all procedures. The primary endpoint was reduction in the incidence, severity and extent of post-operative adhesions analyzed by intention-to-treat (ITT) approach. Three independent, blinded reviewers evaluated all operative video recordings to assess presence of adhesions. Post-hoc analysis assessed presence or absence of adhesions in the peritoneal cavity. Secondary endpoints assessed safety and tolerability of AG. Administration of AG reduced the incidence, severity and/or extent of post-operative adhesions (p = 0.046). The presence of adhesions in the AG group was lower than in the Control group (p = 0.041). Adhesion improvement was achieved in 15 of 15 (100%) in the AG group versus 5 of 17 (29.6%) in the placebo group. No serious adverse events were reported. No differences in safety parameters were observed. Intraperitoneal l -alanyl- l -glutamine reduced adhesion formation in all patients following laparoscopic myomectomy. Complete absence of adhesions was achieved at all abdominal sites in 93% of patients. Results confirm AG's known effects on cellular mechanisms of adhesiogenesis and lay the foundation for new adhesion prophylaxis research and treatment. [ABSTRACT FROM AUTHOR]

Immune checkpoint blockade (ICB) has shown significant clinical success, yet its responses can vary due to immunosuppressive tumor microenvironments. To enhance antitumor immunity, combining ICB therapy with tumor metabolism reprogramming may be a promising strategy. In this study, we developed a photodynamic immunostimulant called BVC aiming to boost immune recognition and prevent immune escape for metastatic tumor eradication by reprogramming glutamine metabolism. BVC, a carrier free self-assembled nanoparticle, comprises a photosensitizer (chlorin e6), an ASCT2 inhibitor (V9302) and a PD1/PDL1 blocker (BMS-1), offering favorable stability and enhanced drug delivery efficiency. The potent photodynamic therapy (PDT) capability of BVC is attributed to its regulation of glutamine metabolism, which influences the redox microenvironment within tumor tissues. By targeting ASCT2-mediated glutamine metabolism, BVC inhibits glutamine transport and GSH synthesis, leading to the upregulation of Fas and PDL1. Additionally, BVC-mediated PDT induces immunogenic cell death, triggering a cascade of immune responses. Consequently, BVC not only enhances immune recognition between CD8+ T cells and Fas-overexpressing tumor cells but also reduces tumor cell immune escape through PD1/PDL1 blockade, significantly benefiting metastatic tumor eradication. This study paves a novel approach for multi-synergistic tumor treatment. Photodynamic immunostimulant (BVC) is developed through the self-assembly of photosensitizer (Ce6), ASCT2 inhibitor (V9302) and PD1/PDL1 blocker (BMS). Tumor metabolism reprogramming capacity of BVC can inhibit alanine-serine-cysteine transporter 2 (ASCT2) to transport glutamine and synthesize glutathione, contributing to improving the immune recognition by T cells and blocking the immune escape of tumor cells for metastatic tumor eradication. [Display omitted] [ABSTRACT FROM AUTHOR]

Polynucleotide kinase 30-phosphatase (PNKP), an essential DNA end-processing enzyme in mammals with 30-phosphatase and 50-kinase activities, plays a pivotal role in multiple DNA repair pathways. Its functional deficiency has been etiologically linked to various neurological disorders. Recent reports have shown that mutation at a conserved glutamine (Gln) in PNKP leads to late-onset ataxia with oculomotor apraxia type 4 (AOA4) in humans and embryonic lethality in pigs. However, the molecular mechanism underlying such phenotypes remains elusive. Here, we report that the enzymatic activities of the mutant versus WT PNKP are comparable; however, cells expressing mutant PNKP and peripheral blood mononuclear cells (PBMCs) of AOA4 patients showed a significant amount of DNA double-strand break accumulation and consequent activation of the DNA damage response. Further investigation revealed that the nuclear localization of mutant PNKP is severely abrogated, and the mutant proteins remain primarily in the cytoplasm. Western blot analysis of AOA4 patientderived PBMCs also revealed the presence of mutated PNKP predominantly in the cytoplasm. To understand the molecular determinants, we identified that mutation at a conserved Gln residue impedes the interaction of PNKP with importin alpha but not with importin beta, two highly conserved proteins that mediate the import of proteins from the cytoplasm into the nucleus. Collectively, our data suggest that the absence of PNKP in the nucleus leads to constant activation of the DNA damage response due to persistent accumulation of doublestrand breaks in the mutant cells, triggering death of vulnerable brain cells--a potential cause of neurodegeneration in AOA4 patients. [ABSTRACT FROM AUTHOR]

Successful in-vitro production of bovine embryos relies on meiotic maturation of oocytes in vitro (IVM) before they can be fertilised. High levels of IVM are currently achieved using a complex medium that contains all 20 common amino acids, namely TCM199, but can also be achieved using a simple inorganic salt solution containing non-essential amino acids, proline, and glutamine. Further simplification of the amino acid content of medium used for IVM could lead to a more defined medium that provides reproducible IVM. The aim of this study was, therefore, to determine the minimal amino acid requirements for bovine oocyte nuclear maturation, as measured by progression to metaphase II (MII) of meiosis. Supplementation of a simple medium composed of inorganic salts (M1 medium) with multiple amino-acid combinations showed that M1 containing glutamine, proline, and isoleucine resulted in nuclear maturation comparable to that of TCM199 (57.4 ± 3.4% vs 67% ± 1.7%, respectively) but was reduced when cystine (Cys2) to that seen with M1 alone (38.0 ± 2.2%). Viability of oocytes matured in this simplified medium was equal to those matured in TCM199 since the same proportion of zygotes with 2 pronuclei were observed following fertilisation in medium containing no amino acids (33.9 ± 6.5% vs 33.3 ± 3.6%, respectively). Addition of glutamine, proline and isoleucine to fertilisation medium also increased the proportion of zygotes but did not increase blastocyst development rates. Thus, a defined medium containing only glutamine, proline and isoleucine is sufficient for oocyte maturation and successful fertilisation. • A specific combination of amino acids is sufficient for maturation of bovine oocytes. • Gln, Pro and Ile support in vitro nuclear maturation of bovine oocytes. • The combination of Gln, Pro and Ile increases the fertilisation rate of oocytes. • Blastocyst development rates is not increased in oocytes matured in Gln, Pro and Ile. [ABSTRACT FROM AUTHOR]