Glutamate Dehydrogenase Research Articles

Integrating Targeted Metabolomics and Targeted Proteomics to Study the Responses of Wheat Plants to Engineered Nanomaterials.

This manuscript presents a multiomics investigation into the metabolic and proteomic responses of wheat to molybdenum (Mo)- and copper (Cu)-based engineered nanomaterials (ENMs) exposure via root and leaf application methods. Wheat plants underwent a four-week growth period with a 16 h photoperiod (light intensity set at 150 μmol·m-2·s-1), at 22 °C and 60% humidity. Six distinct treatments were applied, including control conditions alongside exposure to Mo- and Cu-based ENMs through both root and leaf routes. The exposure dosage amounted to 6.25 mg of the respective element per plant. An additional treatment with a lower dose (0.6 mg Mo/plant) of Mo ENM exclusively through the root system was introduced upon the detection of phytotoxicity. Utilizing LC-MS/MS analysis, 82 metabolites across various classes and 24 proteins were assessed in different plant tissues (roots, stems, leaves) under diverse treatments. The investigation identified 58 responsive metabolites and 19 responsive proteins for Cu treatments, 71 responsive metabolites, and 24 responsive proteins for Mo treatments, mostly through leaf exposure for Cu and root exposure for Mo. Distinct tissue-specific preferences for metabolite accumulation were revealed, highlighting the prevalence of organic acids and fatty acids in stem or root tissues, while sugars and amino acids were abundant in leaves, mirroring their roles in energy storage and photosynthesis. Joint-pathway analysis was conducted and unveiled 23 perturbed pathways across treatments. Among these, Mo exposure via roots impacted all identified pathways, whereas exposure via leaf affected 15 pathways, underscoring the reliance on exposure route of metabolic and proteomic responses. The coordinated response observed in protein and metabolite concentrations, particularly in amino acids, highlighted a dynamic and interconnected proteomic-to-metabolic-to-proteomic relationship. Furthermore, the contrasting expression patterns observed in glutamate dehydrogenase (upregulation at 1.38 ≤ FC ≤ 1.63 with high Mo dose, and downregulation at 0.13 ≤ FC ≤ 0.54 with low Mo dose) and its consequential impact on glutamine expression (7.67 ≤ FC ≤ 39.60 with high Mo dose and 1.50 ≤ FC ≤ 1.95 with low Mo dose) following Mo root exposure highlighted dose-dependent regulatory trends influencing proteins and metabolites. These findings offer a multidimensional understanding of plant responses to ENMs exposure, guiding agricultural practices and environmental safety protocols while advancing knowledge on nanomaterial impacts on plant biology.

The activity of platelet enzymes and subpopulation composition of monocytes in schizophrenia

IntroductionThe studies on various groups of patients with schizophrenia revealed impairments in immune system, glutamatergic, and antioxidant systems contributing substantially in schizophrenia pathogenesis.Objectives To search for links between the activities of platelet enzymes involved in glutamate and glutathione metabolism and monocytes’ subpopulation compositions in patients with schizophrenia and to identify possible correlations of the biomarkers with clinical data. Research objectives: determination of subpopulation ratio of monocytes; measurement of the activity levels of glutamate dehydrogenase (GDH), phosphate-activated glutaminase (PAG), glutathione reductase (GR) and glutathione S-transferase (GST) in blood platelets; search for correlations between these parameters and the scores by psychometric scales.Methods The study included 36 women aged 16-45 years with acute schizophrenia hospitalized in the Mental Health Research Centre with their current condition assessed as depressive-delusional. The control group consisted of 17 women 18-45 years old without somatic or mental pathology. GDH, PAG, GR and GST activities were measured by spectrophotometric methods, and numbers of monocyte subpopulations - “classical”, “intermediate”, “non-classical” - by flow cytometry. The Hamilton Depression Rating Scale (HAMD-17) was used to assess depression severity. The data was processed using the Statistica 8.0 software.Results The detected changes in monocyte subpopulations’ composition towards the increase in the proportion of cells having a pro-inflammatory phenotype (CD14++CD16+ “intermediate”) indicated the activation of inflammatory reactions. Also, the activities of platelet enzymes of glutathione metabolism (GR and GST) were significantly decreased (p<0.05). Moreover, GDH and GST activities significantly correlated with the scores by HAMD-17 (r=0.40, p=0.022 and r=0.45, p=0.030, respectively). The results indicate the presence of pathological inflammatory process, the decrease in activities of glutathione antioxidant metabolism enzymes and a link to glutamate metabolism involvement (GDH) in the studied patient group.Conclusions The identified redistribution in the monocyte subpopulations’ composition and decrease in the activity of enzymes involved in glutamate metabolism and antioxidant system indicate the involvement of the immune, glutamate and antioxidant systems in the pathogenesis of schizophrenia and may reflect a functional interaction between these systems.Disclosure of InterestNone Declared

Platelet enzymatic activities in patients with late-onset schizophrenia spectrum disorders

IntroductionImpairments in energy metabolism, glutamate neurotransmitter and antioxidant systems contribute substantially in development of schizophrenia spectrum disorders, especially in late-onset psychosis (LOP).ObjectivesRevealing subgroups of patients with LOP by determining activity of platelet enzymes of energy, glutamate, and glutathione metabolism.Methods62 women of 52-89 years old were studied, with late onset schizophrenia spectrum disorders (F20.0, F25, F22.0, F06.2 by ICD-10). PANSS with its subscales was used to assess the severity of psychotic symptoms. Scores by PANSS and activity levels of platelet cytochrome c-oxidase (COX), glutamate dehydrogenase (GDH), glutathione reductase (GR) and glutathione-S-transferase (GST) were evaluated twice: before and on the 28-th day of antipsychotic treatment. Activities of COX, GDH, GR, and GST were measured in 37 women of 50-84 years old comprising the control group.Results Clustering of patients by the enzymatic activities resulted in 2 clusters (C1 and C2) significantly different by COX and GST (p<0.001). In C1 (n=40), as compared with control, reduced level of GDH activity before and after treatment (p=0.049 and p=0.032, respectively) and a reduced level of GR activity before treatment (p=0.026) were revealed. In C2 (n=22), as compared with the control, COX activity was increased before and after treatment (p=0.0001), GDH activity was decreased before and after treatment (p=0.0002 and p=0.0001, respectively), and GST activity was decreased before and after treatment (p=0.029 and p=0.0029, respectively). GR activity was not significantly changed in both clusters. Significant correlations were found between enzymatic activities and scores by psychometric scales: in C1, GR activity positively correlated with the score reduction (delta) by PANSS-Pos (R=0.45, p=0.004), by PANSS-Psy (R=0.44, p=0.005), and by PANSS (R=0.47, p=0.002), and GST activity – with the score reduction by PANSS-Psy (R=0.315, p=0.048). In C2 (n=22), GDH activity negatively correlated with the score reduction by PANSS-Pos (R=-0.41, p=0.050) and by PANSS (R=-0.49, p=0.021).ConclusionsThe different correlations revealed in two separated clusters between enzymatic activity levels and clinical measures characterizing the antipsychotic treatment efficacy will allow us to approach differentiated predicting the effectiveness of pharmacotherapy using the biochemical parameters.Disclosure of InterestNone Declared

Connection of molecular and cellular components of the immune system in endogenous psychoses with depressive-delusional symptoms

IntroductionThe data of current research indicate the participation of systemic inflammation in the pathogenesis of endogenous psychoses. Changes in the level of peripheral immune markers are associated with the development of neuroinflammation and correlate with the severity of psychopathological symptoms detected in patients. However, the association between individual components of the immune system involved in the development of endogenous psychosis remains poorly understood.ObjectivesTo study the connection between molecular and cellular components of the immune system in women with endogenous psychoses with depressive-delusional symptoms.Methods32 female patients aged 23 [17; 36] years with endogenous psychoses within different nosologies (F20, F21, F31, depressive-delusional conditions) and 17 women without clinical signs of psychiatric pathology were examined. The activity of leukocyte elastase (LE), α1-proteinase inhibitor (α1-PI), the proportion of four subpopulations of monocytes (classical CD14++CD16-, intermediate CD14++CD16+, nonclassical CD14+CD16+ and transitional CD14+CD16-) in plasma, activity of cytochrome-c oxidase (COX), glutamate dehydrogenase (GDH), glutathione s-transferase (GST) and glutathione reductase (GR) in platelets and functional activity of complement system (faCS) in serum were determined. The PANSS scale was used to assess the severity of psychopathological symptoms.ResultsIncreased activity of the inflammatory markers LE (p=0.033) and α1-PI (p=0.02) was found in the plasma of the patients. Increased percentage of pro-inflammatory monocytes (intermediate and transient) in plasma (p=0.003) was confirmed by negative correlations between CD14++CD16- and CD14++CD16+ (R=-0.685, p=0.00002), CD14++CD16- and CD14+CD16- (R=-0.608, p=0.0002), CD14++CD16- and CD14+CD16+ (R=-0.424, p=0.002). A decrease in GDH activity (p=0.0079), GST activity (p=0.002) and GR activity (p=0.0006) was observed in patient platelets, which can reflect changes in the activity of intracellular metabolic pathways. A positive correlation was found between COX activity and α1-PI (R=0.51, p=0.025). A significant decrease in faCS compared to control (p=0.0003) and a negative correlation between faCS and GST activity (R=-0.496, p=0.011) were observed. faCS was positively correlated with the degree of reduction in the PANSS score (R=0.416, p=0.038).ConclusionsThe revealed connection between molecular and cellular components of the immune system in patients with endogenous psychoses reflect activation of the systemic inflammatory response accompanied by changes in the ratio of monocyte subpopulations and impaired regulation of the complement system. The data obtained can be used to develop methods of monitoring patients taking into account their immunological features.Disclosure of InterestNone Declared

Effects of mycorrhizal symbiosis and Ulva lactuca seaweed extract on growth, carbon/nitrogen metabolism, and antioxidant response in cadmium-stressed sorghum plant.

In our study on the effect of cadmium (Cd) toxicity (200µM) on the growth of Sorghum bicolor (L.) Moench plants, cultivated with arbuscular mycorrhizal fungi (AMF) (Glomus intraradices) and/or under seaweed treatment (3% Ulva lactuca extract) (U. lactuca), we found that AMF increased the tolerance of sorghum to cadmium stress, either alone or in combination with the seaweed treatment. Morphological parameters were higher in these two culture conditions, with increased chlorophyll content. AMF reduced Cd accumulation in roots and inhibited its translocation to the aerial part, while seaweed treatment alone significantly increased Cd accumulation in leaves and roots without affecting plant growth compared to stressed witnesses. Treatment with AMF and/or U. lactuca attenuated oxidative stress, measured by activation of superoxide dismutase, and resulted in a significant decrease in malondialdehyde and superoxide ions (O2-) in treated plants. Furthermore, it induced significant alterations in carbon and nitrogen metabolic pathways, with a significant increase in the activity of enzymes such as glutamine synthetase, glutamate synthase (GOGAT), glutamate dehydrogenase, phosphoenolpyruvate carboxylase, aspartate aminotransferase and isocitrate dehydrogenase in the leaves of each treated plant. These results confirm that AMF, U. lactuca algae extract and their combination can improve the biochemical parameters of sorghum under Cd stress, through modification of the antioxidant response on one hand, and improved nitrogen absorption and assimilation efficiency on the other.

Antioxidant and metabolic adjunctive treatment in late onset psychosis

IntroductionBasing on our previous findings of significant additional gain obtained from usage of adjunctive antioxidant medicine added to antipsychotic+antidepressant therapy in late-onset schizophrenia-like psychoses (LOP), the group often suffering of comorbid pathologies and experiencing substantial side-effects of drugs, we spred our approach to try “metabolic” medicines as adjunctives in LOP.ObjectivesTo reveal biochemical parameters of the blood cells which might be used for distinguishing subgroups of patients suffering with LOP for whom various adjunctive therapy (antioxidant, metabolic) would be advantageous.MethodsThe study included 59 patients 50-89 years old, with LOP (onset after 40 years), and 38 healthy peoples 51 – 84 years old. The activities of glutamate dehydrogenase (GDH), glutathione reductase (GR), and glutathione S-transferase (GST) were determined spectrophotometrically in erythrocytes and platelets. Scores by PANSS were evaluated twice: before and on the 28-th day of antipsychotic treatment.ResultsSamples from control group were used for determination of the control ranges for levels of studied enzymatic activities. Enzymatic activity levels were analyzed in three groups of patients: group Gr1 (n=16) treated without adjunctive therapy, and two other groups (Gr2 and Gr3) treated with adjunctive medicines: antioxidant 2-ethyl-6-methyl-3-hydroxypyridine succinate (Gr2, n=20), or “metabolic” medicines citicoline/cerebrolysin/cortexin/actovegin/gliatilin (Gr3, n=23).As compared with controls, activity of erythrocyte GR was decreased at baseline and after the treatment course in all patients’ groups (p<0.01); in Gr2 significant decreases in baseline platelet GDH and GST activities were observed (p=0.005). Different significant links between biochemical parameters and scores by clinical scales before treatment were observed: in Gr1, erythrocyte GST activity positively correlated with scores by PANSS-Neg (R=0.61, p=0.012), by PANSS-Psy (R=0.54, p=0.032), and by PANSS (R=0.62, p=0.010), in Gr2, erythrocyte GST activity positively correlated with scores by PANSS-Pos (R=0.53, p=0.016), by PANSS-Psy (R=0.52, p=0.015), and by PANSS (R=0.60, p=0.005), in Gr3, platelet GR activity positively correlated with PANSS-Pos (R=0.50, p=0.014).ConclusionsWe have confirmed the additional favor (decrease in side-effect severity) obtained by distinct patient groups when treated with adjunctive antioxidant or “metabolic” therapy. Moreover, correlations revealed in the patient subgroups between enzymatic activities and scores by psychometric scales enable revealing those biochemical markers measurement of which facilitate differentiating the patients for whom the adjunctive medicines to antipsychotic+antioxidant treatment can positively influence the treatment outcome.Disclosure of InterestNone Declared

Gefitinib Induces Apoptosis in NSCLC Cells by Promoting Glutaminolysis and Inhibiting the MEK/ERK Signaling Pathway.

Over 80% of lung cancer cases constitute non-small cell lung cancer (NSCLC), making it the most prevalent type of lung cancer globally and the leading cause of cancer-related deaths. The treatment of NSCLC patients with gefitinib has demonstrated promising initial efficacy. However, the underlying mechanism remains unclear. This study aims to investigate how gefitinib affects the mitogen-activated protein kinase kinase (MEK)/extracellular regulated protein kinases (ERK) signaling pathway-mediated growth and death of NSCLC cells. In this study, the NSCLC cell line A549 was cultured in vitro and divided into a control group and a gefitinib group. The viability of the A549 cells was assessed using the methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. Flow cytometry was employed to detect apoptosis in A549 cells, and the expression of glutamate dehydrogenase (GDH1) mRNA in these cells was determined using real-time quantitative PCR (RT-PCR). Western blotting was utilized to evaluate the protein expression levels of key components in the MEK/ERK signaling pathway, including phospho-MEK1/2, MEK1/2, phospho-ERK1/2, and ERK1/2. Additionally, intracellular glutamine content in A549 cells was measured using a colorimetric method. In contrast to the control group, the proliferation of A549 cells, the transcription level of glutamate dehydrogenase (GDH1), the intracellular glutamine content, and the protein expression levels of phospho-MEK1/2 and phospho-ERK1/2 were significantly lower in the gefitinib group. Moreover, apoptosis markedly increased. Gefitinib expedites apoptosis and diminishes proliferation in the NSCLC cell line A549 by downregulating the epidermal growth factor receptor (EGFR)/MEK/ERK signaling pathway. This effect is accomplished by fostering the expression of GDH1 to augment glutaminolysis in A549 cells.

A study to assess the prevalence and risk factors for Clostridioides difficile infection in patients with inflammatory bowel disease in a tertiary care hospital in Northern India

Objectives: The prevalence of Clostridioides difficile infection (CDI) is on rise among patients with inflammatory bowel disease (IBD). This study sought to describe the prevalence and risk factors of CDI in patients with IBD as compared to non-IBD controls. Materials and Methods: This was a prospective study conducted at a Department of Microbiology in collaboration with a Department of Gastroenterology. The patients with IBD and controls without IBD presenting with diarrhea were included in the study. The screening test for C. difficile infection was done by glutamate dehydrogenase (GDH) assay and toxin detection by enzyme-linked immunoassay (ELISA). Anaerobic culture for C. difficile was done on a selective cycloserine cefoxitin fructose agar and polymerase chain reaction (PCR) was done for Toxin A (TcdA) and Toxin B (TcdB) gene detection. C. difficile infection was confirmed if GDH and toxin ELISA or PCR were positive. Statistical Analysis: Data were analyzed with the Statistical Package for the Social Sciences version 20.0.The numerical variables were presented by means and standard deviations. Comparison of continuous variables was done using Student’s t-test. Categorical variables were analyzed by Chi square test. P<0.05 was considered to be statistically significant. Results: A total of 160 cases and 112 age- and gender-matched control were included in IBD group and nonIBD group, respectively. Only one culture was positive, 12 and six were positive for GDH ELISA and TcdA and TcdB ELISA, respectively, and 7 were positive by PCR for toxin genes. The factors found significantly associated with CDI were proton-pump inhibitors use (P = 0.001), levofloxacin (P =0.001), and azathioprine (P =0.042). Using PCR as a reference method for C. difficile toxin detection, the sensitivity, and specificity of GDH ELISA and ELISA for toxins were 100%, 96.8% and 85.7%, and 100%, respectively. Conclusions: The prevalence of CDI among patients with IBD has been found to be low, that is (only 4.4%) in this study population.

Stable Isotope Tracer Technique and Network Pharmacology to Reveal Antidepressant Targets and Active Components of Xiaoyao San.

In recent years, the research of mitochondrial dysfunction in depression has drawn the focus of researchers. Our research group previously found that Xiaoyao San (XYS) has improved the mitochondrial structure and the blocked tricarboxylic acid cycle (TCA cycle) in the hippocampal tissue of chronic unpredictable mild stress (CUMS) rats. However, the specific targets and active components of XYS remain unclear, and the potential to improve hippocampal mitochondrial TCA cycle disorder was also unexplored. In this research, a strategy to combine stable isotope-resolved metabolomics (SIRM), network pharmacology and transmission electron microscopy (TEM) was used to explore the potential, targets of action, and active components of XYS to improve hippocampal mitochondrial TCA cycle disorder of CUMS rats. The results of TEM showed that the ultrastructure of hippocampal mitochondria could be improved by XYS. A combination of SIRM and molecular docking showed that pyruvate carboxylase (PC), ATP citrate lyase (ACLK), glutamate dehydrogenase (GLDH), glutamate oxaloacetate transaminase (GOT) and pyruvate dehydrogenase (PDH) were targets of XYS to improve TCA cycle disorder. In addition, troxerutin was found to be the most potential active component of XYS to improve TCA cycle disorder. The above research results can provide new insights for the development of antidepressant drugs.

Effects of dietary pectin on the growth performance, intestinal barrier, and antioxidant status of juvenile rainbow trout (Oncorhynchus mykiss)

To evaluate the effects of dietary pectin on growth performance, intestinal barrier, and antioxidant status of juvenile rainbow trout (Oncorhynchus mykiss), 10-week feeding trial was conducted. Five isoproteic and isoenergetic diets were formulated to contain 0% (P0), 4% (P4), 8% (P8), and 16% (P16) pectin as well as 0.02% pectinase (PE) at the expense of wheat starch, respectively. Dietary inclusion of 416% pectin linearly promoted the feed intake and growth performance but depressed the feed efficiency, but significant differences were only observed between the P16 and P0 groups. Similarly, dietary inclusion of 816% pectin significantly increased the foregut trypsin and amylase activities but decreased the foregut and midgut sucrase activity. The midgut muc2 gene expression level was significantly down-regulated by the inclusion of 16% pectin. Dietary inclusion of 2% pectin increased the abundance of Proteobacteria and Stenotrophomonas but reduced the abundance of Actinobacteria, Bacteroides and Helicobacter; while the lowest values of observed species, Chao1 and ACE indices of intestinal flora were found in the P8 group. Fish fed with the P8 diet exhibited the lowest plasma catalase and midgut glutathione S-transferase activities as well as malondialdehyde content, but the highest midgut malondialdehyde content. Dietary inclusion of 816% pectin significantly depressed the plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1) and mechanistic target of rapamycin contents as well as alanine aminotransferase activity, the hepatic adenosine monophosphate deaminase and glutamate dehydrogenase (GDH) activities. Dietary treatment with 0.02% pectinase did not affect the growth performance, but depressed the foregut sucrase activity, the midgut amylase and sucrase activities, increased the plasma GH and IGF-1 contents as well as hepatic GDH and aspartate aminotransferase activities. In conclusion, high-dose of dietary pectin (816%) may promote the feed intake and intestinal digestive enzyme activities and thereby improve the growth performance of rainbow trout.

Cytokeratin-18 is a sensitive biomarker of alanine transaminase increase in a placebo-controlled, randomized, crossover trial of therapeutic paracetamol dosing (PATH-BP biomarker substudy).

Drug-induced liver injury (DILI) is a challenge in clinical medicine and drug development. Highly sensitive novel biomarkers have been identified for detecting DILI following a paracetamol overdose. The study objective was to evaluate biomarker performance in a 14-day trial of therapeutic dose paracetamol. The PATH-BP trial was a double-blind, placebo-controlled, crossover study. Individuals (n = 110) were randomized to receive 1 g paracetamol 4× daily or matched placebo for 2 weeks followed by a 2-week washout before crossing over to the alternate treatment. Blood was collected on days 0 (baseline), 4, 7, and 14 in both arms. Alanine transaminase (ALT) activity was measured in all patients. MicroRNA-122 (miR-122), cytokeratin-18 (K18), and glutamate dehydrogenase (GLDH) were measured in patients who had an elevated ALT on paracetamol treatment (≥50% from baseline). ALT increased in 49 individuals (45%). All 3 biomarkers were increased at the time of peak ALT (K18 paracetamol arm: 18.9 ± 9.7 ng/ml, placebo arm: 11.1 ± 5.4 ng/ml, ROC-AUC = 0.80, 95% CI 0.71-0.89; miR-122: 15.1 ± 12.9fM V 4.9 ± 4.7fM, ROC-AUC = 0.83, 0.75-0.91; and GLDH: 24.6 ± 31.1U/l V 12.0 ± 11.8U/l, ROC-AUC = 0.66, 0.49-0.83). All biomarkers were correlated with ALT (K18 r = 0.68, miR-122 r = 0.67, GLDH r = 0.60). To assess sensitivity, biomarker performance was analyzed on the visit preceding peak ALT (mean 3 days earlier). K18 identified the subsequent ALT increase (K18 ROC-AUC = 0.70, 0.59-0.80; miR-122 ROC-AUC = 0.60, 0.49-0.72, ALT ROC-AUC = 0.59, 0.48-0.70; GLDH ROC-AUC = 0.70, 0.50-0.90). Variability was lowest for ALT and K18. In conclusion, K18 was more sensitive than ALT, miR-122, or GLDH and has potential significant utility in the early identification of DILI in trials and clinical practice.

Blood-based assessment of oxidative stress, inflammation, endocrine and metabolic adaptations in eventing horses accounting for plasma volume shift after exercise.

After submaximal exercise, blood values of eventing horses show physiological reactions. This prospective longitudinal study investigated blood parameters in 20 elite eventing horses before and after two-four-star cross-country rides. Using a mixed model adjusting for plasma volume shift, we assessed exercise-dependent parameters and compared blood values with reference ranges for healthy horses at rest. Following exercise, cortisol, triiodothyronine (T3) and thyroxine (T4) showed short-term increases, and superoxide-dismutase showed a small short-term increase. Hepatic values showed short-term (haemoglobin [HGB], globulins) or sustained increases (bilirubin, glutamate dehydrogenase, alanine aminotransferase). Digestion-related parameters showed small short-term increases (α-amylase, triglycerides) or decreases (cholesterol, DGGR-lipase), apparent through plasma shift adjustment. Zinc decreased in the short term, and iron showed a delayed decrease. White blood cell count increased persistently after training, whereas serum amyloid A remained unchanged. Exercised eventing horses had consistently elevated HGB and cortisol levels 10 and 30min after submaximal exercise, exceeding the reference ranges for healthy horses at rest. Exercise activates the hypothalamic-pituitary-adrenocortical and hypothalamic-pituitary-thyroid axes. Antioxidant activity was observed. Increased energy requirements led to the mobilization of energy reserves, and a sustained increase in liver enzymes indicated hepatocellular injury. Mild haemolysis suggested increased muscle metabolism, whereas signs of inflammation were subtle. Further research is needed to identify which horses deviate from mean values.

Toxic Trio: Zinc, Copper, and Mercury's Effects on Earthworm Enzymes

The impact of heavy metal exposure on earthworm enzyme activities, specifically lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), xanthine oxidase (XOD), lipid peroxidation, superoxide dismutase (SOD), catalase, and glutathione-S-transferase (GST), was investigated in Perionyx excavatus. In control earthworms, LDH activities were 0.120 µmoles/mg protein/hour in the skin, 0.087 µmoles/mg protein/hour in the ovary, 0.062 µmoles/mg protein/hour in the testis, and 0.096 µmoles/mg protein/hour in the intestine. Exposure to mercuric chloride, copper sulfate, and zinc sulfate resulted in significant decreases in LDH activities by 10% to 19.35%, 4.16% to 22.58%, and 5.74% to 15%, respectively. Similarly, SDH activities declined by 10% to 23% with mercuric chloride, 6.89% to 17.91% with copper sulfate, and 4.13% to 16.66% with zinc sulfate treatments. MDH activities also decreased dramatically across all organs, with statistically significant reductions. GDH activities showed varied responses, while XOD activities uniformly decreased. Lipid peroxidation increased significantly after heavy metal exposure. SOD activities increased with mercuric chloride and copper sulfate, while catalase activities decreased with all three treatments. GST activities were significantly reduced by all treatments, particularly by mercuric chloride and copper sulfate. These findings underscore the substantial impact of heavy metal exposure on earthworm enzyme activities, suggesting potential cellular stress and metabolic disturbances.

Ammoniagenic Action of Valproate without Signs of Hepatic Dysfunction in Rats: Possible Causes and Supporting Evidence.

(1) Background: Valproic acid (VPA) is one of the frequently prescribed antiepileptic drugs and is generally considered well tolerated. However, VPA neurologic adverse effects in the absence of liver failure are fairly common, suggesting that in the mechanism for the development of VPA-induced encephalopathy, much more is involved than merely the exposure to hyperammonemia (HA) caused by liver insufficiency to perform detoxification. Taking into account the importance of the relationship between an impaired brain energy metabolism and elevated ammonia production, and based on the ability of VPA to interfere with neuronal oxidative pathways, the current study intended to investigate a potential regional ammoniagenic effect of VPA on rats' brains by determining activities of the enzymes responsible for ammonia production and neutralization. (2) Methods: Rats received a single intraperitoneal injection of VPA (50, 100, 250, 500 mg/kg). Plasma, the neocortex, the cerebellum, and the hippocampus were collected at 30 min after injection. The levels of ammonia, urea, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were measured in blood plasma. The activities of glutaminase and glutamate dehydrogenase (GDH) in mitochondria and the activities of AMP deaminase (AMPD), adenosine deaminase (ADA), and glutamine synthetase (GS) in cytosolic fractions isolated from rat brain regions were measured. Ammonia, ALT, and AST values were determined in the mitochondrial and cytosolic fractions. (3) Results: Multi-dose VPA treatment did not significantly affect the plasma levels of ammonia and urea or the ALT and AST liver enzymes. Significant dose-independent increases in the accumulation of ammonia were found only in the cytosol from the cerebellum and there was a strong correlation between the ammonia level and the ADA activity in this brain structure. A significant decrease in the AMPD and AST activities was observed, while the ALT activity was unaffected. Only the highest VPA dose (500 mg/kg) was associated with significantly less activity of GS compared to the control in all studied brain structures. In the mitochondria of all studied brain structures, VPA caused a dose-independent increases in ammonia levels, a high concentration of which was strongly and positively correlated with the increased GDH and ALT activity, while glutaminase activity remained unchanged, and AST activity significantly decreased compared to the control in all studied brain structures. (4) Conclusions: This study highlights the rat brain region-specific ammoniagenic effects of VPA, which may manifest themselves in the absence of hyperammonemia. Further research should analyze how the responsiveness of the different brain regions may vary in VPA-treated animals that exhibit compromised energy metabolism, leading to increased ammoniagenesis.

Zinc Imidazole Framework‐8 Nanoparticles Disperse MRSA Biofilm by Inhibiting Arginine Biosynthesis and Down‐Regulating Adhesion‐Related Proteins

AbstractNanomaterials, including ZIF‐8 nanoparticles (NPs), are shown to be effective antimicrobial agents against Methicillin‐resistant Staphylococcus aureus(MRSA). However, the antibiofilm properties and mechanisms of ZIF‐8 NPs remain uncertain. In this study, ZIF‐8 NPs are prepared using the room temperature solution reaction method and characterized. Biofilm formation inhibition test and biofilm eradication test are performed and the results show that ZIF‐8 NPs can inhibit the formation of MRSA biofilm as well as disperse established MRSA biofilm. Proteomics and real‐time fluorescence quantitative polymerase chain reaction (PCR) are conducted to prove that ZIF‐8 NPs reduce the expression of adhesion‐related proteins, namely the fibronectin‐binding proteins A and B (fnbA/fnbB), fibrinogen binding protein caking factors A and B (clfA/clfB), elastin binding protein (ebps), and fibrin binding protein (eno). ZIF‐8 NPs also inhibit the arginine biosynthesis pathway by affecting the activities of argininosuccinate lyase, ornithine carbamyl transferase, Glutamate dehydrogenase, carbamate kinase, and arginine deiminase. A conclusion can be drawn from the above results that ZIF‐8 NPs can inhibit bacterial adhesion and kill bacteria directly, ultimately destroying MRSA biofilm. This study provides a molecular basis for the treatment of MRSA biofilm with ZIF‐8 NPs.

SIRT4 as a novel interactor and candidate suppressor of C-RAF kinase in MAPK signaling.

Cellular responses leading to development, proliferation, and differentiation depend on RAF/MEK/ERK signaling, which integrates and amplifies signals from various stimuli for downstream cellular responses. C-RAF activation has been reported in many types of tumor cell proliferation and developmental disorders, necessitating the discovery of potential C-RAF protein regulators. Here, we identify a novel and specific protein interaction between C-RAF among the RAF kinase paralogs, and SIRT4 among the mitochondrial sirtuin family members SIRT3, SIRT4, and SIRT5. Structurally, C-RAF binds to SIRT4 through the N-terminal cysteine-rich domain, whereas SIRT4 predominantly requires the C-terminus for full interaction with C-RAF. Interestingly, SIRT4 specifically interacts with C-RAF in a pre-signaling inactive (serine 259-phosphorylated) state. Consistent with this finding, the expression of SIRT4 in HEK293 cells results in an up-regulation of pS259-C-RAF levels and a concomitant reduction in MAPK signaling as evidenced by strongly decreased phospho-ERK signals. Thus, we propose an additional extra-mitochondrial function of SIRT4 as a cytosolic tumor suppressor of C-RAF-MAPK signaling, besides its metabolic tumor suppressor role of glutamate dehydrogenase and glutamate levels in mitochondria.

Mulberry leaf and konjac flour compound dietary fiber improves digestion and metabolism in elderly mice with high-fish-protein diet by regulating gut microbiota structure and intestinal tissue repair

Ensuring sufficient protein intake, efficient digestion, and optimal absorption are crucial for the elderly. This study aims to investigate the potential of a compound dietary fiber, consisting of mulberry leaf and konjac flour (CMK), to enhance the digestion and absorption of a high-fish-protein diet in elderly mice. Results showed that CMK effectively reduced the number of unique peptide segments, generated short-chain fatty acids (SCFA) in feces, improved the content of glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), amino acid, and urea nitrogen in serum, activated the contents of pepsin, trypsin, and erepsin, and enhanced the expression of glutamate dehydrogenase (GDH), peptide transporter 1 (PepT1), and aminopeptidase N (APN). Furthermore, CMK demonstrated its ability to decrease the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-10 (IL-10), lipopolysaccharide (LPS), and lipopolysaccharide binding protein (LBP), while increase the abundance of beneficial bacteria, such as Lactobacillus and Blautia. In conclusion, CMK proved effective in enhancing the digestion and metabolism of protein in elderly mice through the regulation of gut microbiota structure and intestinal tissue repair.

Neuroprotective effects of platinum nanoparticle-based microreactors in bicuculline-induced seizures

Epilepsy designates a group of chronic brain disorders, characterized by the recurrence of hypersynchronous, repetitive activity, of neuronal clusters. Epileptic seizures are the hallmark of epilepsy. The primary goal of epilepsy treatment is to eliminate seizures with minimal side effects. Nevertheless, approximately 30% of patients do not respond to the available drugs. An imbalance between excitatory/inhibitory neurotransmission, that leads to excitotoxicity, seizures, and cell death, has been proposed as an important mechanism regarding epileptogenesis. Recently, it has been shown that microreactors composed of platinum nanoparticles (Pt-NP) and glutamate dehydrogenase possess in vitro and in vivo activity against excitotoxicity. This study investigates the in vivo effects of these microreactors in an animal model of epilepsy induced by the administration of the GABAergic antagonist bicuculline. Male Wistar rats were administered intracerebroventricularly (i.c.v.) with the microreactors or saline and, five days later, injected with bicuculline or saline. Seizure severity was evaluated in an open field. Thirty min after behavioral measurements, animals were euthanized, and their brains processed for neurodegeneration evaluation and for neurogenesis. Treatment with the microreactors significantly increased the time taken for the onset of seizures and for the first tonic-clonic seizure, when compared to the bicuculline group that did not receive the microreactor. The administration of the microreactors also increased the time spent in total exploration and grooming. Treatment with the microreactors decreased bicuculline-induced neurodegeneration and increased neurogenesis in the dorsal and ventral hippocampus. These observations suggest that treatment with Pt-NP-based microreactors attenuates the behavioral and neurobiological consequences of epileptiform seizure activity.

Synergistic regulation of hydrogen sulfide and nitric oxide on biochemical components, exopolysaccharides, and nitrogen metabolism in nickel stressed rice field cyanobacteria.

The present study examined the regulatory mechanism of hydrogen sulfide (H2S) and nitric oxide (NO) in nickel (Ni) stressed cyanobacteria viz., Nostoc muscorum and Anabaena sp. by analyzing growth, photosynthetic pigments, biochemical components (protein and carbohydrate), exopolysaccharides (EPS), inorganic nitrogen content, and activity of enzymes comprised in nitrogen metabolism and Ni accumulation. The 1µM Ni substantially diminished growth by 18% and 22% in N. muscorum and Anabaena sp. respectively, along with declining the pigment contents (Chl a/Car ratio and phycobiliproteins), and biochemical components. It also exerted negative impacts on inorganic uptake of nitrate and nitrite contents; nitrate reductase and nitrite reductase; and ammonium assimilating enzymes (glutamine synthetase, glutamate synthase, and glutamate dehydrogenase exhibited a reverse trend) activities. Nonetheless, the adverse impact of Ni can be mitigated through the exogenous supplementation of NaHS [sodium hydrosulfide (8µM); H2S donor] and SNP [sodium nitroprusside (10µM); NO donor] which showed substantial improvement on growth, pigments, nitrogen metabolism, and EPS layer and noticeably occurred as a consequence of a substantial reduction in Ni accumulation content which minimized the toxicity effects. The accumulation of Ni on both the cyanobacterial cell surface (EPS layer) are confirmed by the SEM-EDX analysis. Further, the addition of NO scavenger (PTIO; 20µM) and inhibitor of NO (L-NAME; 100µM); and H2S scavenger (HT; 20µM) and H2S inhibitor (PAG; 50µM) reversed the positive responses of H2S and NO and damages were more prominent under Ni stress thereby, suggesting the downstream signaling of H2S on NO-mediated alleviation. Thus, this study concludes the crosstalk mechanism of H2S and NO in the mitigation of Ni-induced toxicity in rice field cyanobacteria.

First report of Giardia duodenalis in dairy cattle and beef cattle in Shanxi, China.

Giardia duodenalis is an important intestinal parasitic protozoan that infects several vertebrates, including humans. Cattle are considered the major source of giardiasis outbreak in humans. This study aimed to investigate the prevalence and multilocus genotype (MLG) of G. duodenalis in Shanxi, and lay the foundation for the prevention and control of Giardiosis. DNA extraction, nested polymerase chain reaction, sequence analysis, MLG analysis, and statistical analysis were performed using 858 bovine fecal samples from Shanxi based on three gene loci: β-giardin (bg), glutamate dehydrogenase (gdh), and triosephosphate isomerase (tpi). The overall prevalence of G. duodenalis was 28.3%, while its prevalence in Yingxian and Lingqiu was 28.1% and 28.5%, respectively. The overall prevalence of G. duodenalis in dairy cattle and beef cattle was 28.0% and 28.5%, respectively. G. duodenalis infection was detected in all age groups evaluated in this study. The overall prevalence of G. duodenalis in diarrhea and nondiarrhea samples was 32.4% and 27.5%, respectively, whereas that in intensively farmed and free-range cattle was 35.0% and 19.9%, respectively. We obtained 83, 53, and 59 sequences of bg, gdh, and tpi in G. duodenalis, respectively. Moreover, assemblage A (n = 2) and assemblage E (n = 81) by bg, assemblage A (n = 1) and assemblage E (n = 52) by gdh, and assemblage A (n = 2) and assemblage E (n = 57) by tpi were identified. Multilocus genotyping yielded 29 assemblage E MLGs, which formed 10 subgroups. To the best of our knowledge, this is the first study to report cattle infected with G. duodenalis in Shanxi, China. Livestock-specific G. duodenalis assemblage E was the dominant assemblage genotype, and zoonotic sub-assemblage AI was also detected in this region.