Search

Postharvest senescence of vegetables is characterized by the degradation of pigments and proteins. Protein degradation is often accompanied by the accumulation of amino acids and ammonium since the separated plant tissues cannot recycle nitrogen. Although it is known that treatments with low-intensity white- or red-light delay protein degradation during postharvest in kale, the effect of LED lighting on nitrogen metabolism is poorly studied. The objective of this work was to evaluate the effects of LED treatments on nitrogen metabolism during postharvest kale. Three treatments were performed: control, 20–25 µmol m−2 s−1 of white light or red light for 1 h. Nitrogen content remained unchanged. In the control, protein content decreased and was accompanied by the accumulation of amino acids and ammonium. In contrast, in both white and red LED light-treated leaves, protein content remained higher, and the accumulation of derivatives was delayed. Glutamine synthetase activity decreased more rapidly during storage in control than in treatments, which is related to a greater accumulation of ammonium. LED light treatments maintained a higher ascorbic acid content in kale leaves than in controls. This work demonstrates that low-intensity white or red LED treatments delay changes in postharvest nitrogen metabolism and improve the nutritional quality of kale leaves. [ABSTRACT FROM AUTHOR]

Background: The neuroretinal vascular system is comprised of three interconnected layers. The initial superficial vascular plexus formation is guided by astrocytes around birth in mice. The formation of the deep and intermediate vascular plexuses occurs in the second postnatal week and is driven by Müller-cell-derived angiogenic signaling. Previously, we reported that microglia play an important role in regulating astrocyte density during superficial vascular plexus formation. Here, we investigated the role of microglia in regulating Müller-cell-dependent inner retinal vascular development. Methodology: In this study, we depleted microglia during retinal development using Csf1R antagonist (PLX5622). We characterized the developmental progression of inner retinal vascular growth, effect of microglial depletion on inner retinal vascular growth and Müller cell marker expressions by immunostaining. Differential expressions of genes in the control and microglia depleted groups were analyzed by mRNA-seq and qPCR. Unpaired t-test was performed to determine the statistical differences between groups. Results: This study show that microglia interact with Müller cells and the growing inner retinal vasculature. Depletion of microglia resulted in reduced inner retinal vascular layers densities and decreased Vegfa isoforms transcript levels. RNA-seq analysis further revealed that microglial depletion significantly reduced specific Müller cell maturation markers including glutamine synthetase, responsible for glutamine biosynthesis, necessary for angiogenesis. Conclusions: Our study reveals an important role for microglia in facilitating inner retinal angiogenesis and Müller cell maturation. [ABSTRACT FROM AUTHOR]

A major problem for St John's wort (Hypericum perforatum) is St John's wilt, which can lead to reduced crop yields and even complete crop losses. In the past, the pathogen was referred to as Colletotrichum gloeosporioides or occasionally as Colletotrichum cf. gloeosporioides based on morphology. Although a strain from this host had been re-identified as C. cigarro in taxonomic studies, there is uncertainty about the identity of the St John's wilt pathogen, which is generally still addressed as C. gloeosporioides in applied science. In a multi-locus [internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), and glutamine synthetase (GS)] analysis of the C. gloeosporioides species complex, all isolates obtained from newly collected symptomatic H. perforatum stems and seeds from Germany and Switzerland were identified as C. cigarro. Although they belonged to the same haplotype, the morphology of the isolates was very variable. Pathogenicity tests demonstrated that only C. cigarro strains from H. perforatum cause symptoms on H. perforatum , whereas other Colletotrichum species tested only caused latent infection of H. perforatum. [ABSTRACT FROM AUTHOR]

Nitrogen metabolism, related genes, and other stress-resistance genes are poorly understood in Bosea strain. To date, most of the research work in Bosea strains has been focused on thiosulfate oxidation and arsenic reduction. This work aimed to better understand and identify genomic features that enable thiosulfate-oxidizing lichen-associated Bosea sp. PAMC26642 from the Arctic region of Svalbard, Norway, to withstand harsh environments. Comparative genomic analysis was performed using various bioinformatics tools to compare Bosea sp. PAMC26642 with other strains of the same genus, emphasizing nitrogen metabolism and stress adaptability. During genomic analysis of Bosea sp. PAMC26642, assimilatory nitrogen metabolic pathway and its associated enzymes such as nitrate reductase, NAD(P)H-nitrite reductase, ferredoxin-nitrite reductase, glutamine synthetase, glutamine synthase, and glutamate dehydrogenase were identified. In addition, carbonic anhydrase, cyanate lyase, and nitronate monooxygenase were also identified. Furthermore, the strain demonstrated nitrate reduction at two different temperatures (15°C and 25°C). Enzymes associated with various stress adaptation pathways, including oxidative stress (superoxide dismutase, catalase, and thiol peroxidase), osmotic stress (OmpR), temperature stress (Csp and Hsp), and heavy metal resistance, were also identified. The average Nucleotide Identity (ANI) value is found to be below the threshold of 94-95%, indicating this bacterium might be a potential new species. This study is very helpful in determining the diversity of thiosulfate-oxidizing nitrate-reducing bacteria, as well as their ability to adapt to extreme environments. These bacteria can be used in the future for environmental, biotechnological, and agricultural purposes, particularly in processes involving sulfur and nitrogen transformation. [ABSTRACT FROM AUTHOR]

Both elevated atmospheric CO2 concentration ([CO2]) and increased temperature exert notable influences on wheat (Triticum aestivum L.) growth and productivity when examined individually. Nevertheless, limited research comprehensively investigates the combined effects of both factors. Winter wheat was grown in environment‐controlled chambers under two concentrations of CO2 (ambient CO2 concentration and ambient CO2 concentration plus 200 µmol mol−1) and two levels of temperature (ambient temperature and ambient temperature plus 2°C). The phenology, photosynthesis, carbohydrate and nitrogen metabolism, yield and quality responses of wheat were investigated. Elevated [CO2] did not counteract warming‐induced shortening of wheat phenological period but prolonged grain filling. Even though photosynthetic adaptation occurred during the reproductive growth period, elevated [CO2] still significantly enhanced carbohydrate accumulation under warming, particularly at the grain filling stage, thereby increasing yield by 20.1% compared with the ambient control. However, elevated [CO2] inhibited nitrogen assimilation at the grain filling stage under increased temperature by downregulating the expression levels of TaNR, TaNIR, TaGS1 and TaGOGAT and reducing glutamine synthetase activity, which directly led to a significant decrease of 19.4% in grain protein content relative to the ambient control. These findings suggest that elevated [CO2] will likely increase yield but decrease grain nutritional quality for wheat under future global warming scenarios. Summary statement: Elevated CO2 concentration mitigated the negative impact of increased temperature on winter wheat yield by extending the reproductive growth period and increasing spike number, as well as enhancing carbon metabolism at grain filling stage. Whereas it decreased grain protein content by inhibiting nitrogen assimilation at the grain filling stage. [ABSTRACT FROM AUTHOR]

Light is a key factor influencing the growth and quality of crops in plant factories. To explore the optimal light quality for pakchoi production, five light formulations were applied to 'Youguan NO.3' pakchoi: white LEDs (W; CK); white/red = 4:1 (WR); white/blue = 4:1 (WB); white/red/blue = 3:1:1 (WRB); and white/green = 4:1 (WG), all with a light intensity of 250 ± 10 µmol·m−2·s−1. The results showed significant variations in growth indices, nutritional quality, enzyme activity, and other parameters under different light qualities. The best growth results were observed under the WRB treatment. Chloroplasts under WRB treatment appeared well-developed, with clear grana lamellae. The thylakoids in the chloroplast grana of the WRB plants were densely stacked, and a large number of starch grains were detected. The contents of total sugar, soluble sugar, soluble protein, and protein nitrogen were significantly higher under the WB, WRB, and WR treatments compared to the CK treatment, along with a significant reduction in nitrate content. Among all the treatments, WRB treatment resulted in the highest levels of total sugar, starch, free amino acids, soluble protein, total nitrogen, protein nitrogen, and ascorbic acid (AsA). Enzyme activity assays revealed that the activities of sucrose phosphate synthetase (SPS), nitrate reductase (NR), glutamine synthetase (GS), glutamate synthetase (GOGAT), and glutamate dehydrogenase (GDH) were highest under WRB treatment. Therefore, supplemental red-blue mixed light can effectively improve the growth and nutritional properties of pakchoi grown under white light. This supplementary lighting strategy provides a new way to enhance the nutritional value of leafy vegetables in plant factories. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is a globally significant crop with high economic and nutritional importance. Its productivity, however, relies heavily on nitrogen (N) inputs, often resulting in low nitrogen use efficiency (NUE). Enhancing NUE necessitates a comprehensive understanding of the biochemical and physiological mechanisms driving N uptake and utilization. The study evaluated the NUE heterosis of 7 inbred lines and their 12 hybrids under low and high N conditions during early vegetative growth. Significant genotypic variations across traits were analyzed using analysis of variance, principal component analysis, correlation, regression, and structural equation modeling. The key contributors to genetic variation included shoot dry weight, N accumulation, and NUE. Hybrids demonstrated enhanced root architecture, superior enzymatic activities of nitrate reductase (NR) and glutamine synthetase (GS), and improved morphological traits, photosynthetic efficiency, and N accumulation, resulting in greater biomass production, N accumulation, and NUE compared to inbred lines. Among hybrids, Zheng58 × PH4CV exhibited the highest NUE, driven by efficient N uptake, robust enzymatic activity, and substantial N accumulation. Nitrogen uptake efficiency (NUpE) correlated strongly with root traits such as activity (r = 0.80 ***), length (r = 0.73 ***), surface area (r = 0.67 ***), GS activity (r = 0.84 ***), and dry weight (r = 0.92). Similarly, nitrogen utilization efficiency (NutE) was positively correlated with shoot NR activity (r = 0.90 ***), shoot GS activity (r = 0.56 ***), leaf area (r = 0.73 ***), shoot dry weight (r = 0.82 ***), and shoot N accumulation (r = 0.55 ***), particularly under high N conditions. Based on key traits such as shoot dry weight, N accumulation, and NUE, hybrids Zheng58 × PH4CV, 444 × PH4CV, 444 × MO17, and B73 × MO17 emerged as N-efficient genotypes, confirmed by contrasting root systems, enhanced N metabolism, and superior NUE. These findings reveal the pivotal roles of root architecture and N metabolism in optimizing NUE, emphasizing the biochemical and physiological traits crucial for developing highly N-efficient maize hybrids. [ABSTRACT FROM AUTHOR]

Ruminants excrete both undigested and excess consumed nitrogen (N) through feces and urine, which results in the waste of feed protein and environmental pollution. This study aims to screen bacteria to identify strains with potential to improve nitrogen utilization in the rumen. In a tube screening test, when 30 mmol/L ammonium sulfate was added as the only nitrogen source in liquid medium, among 115 bacterial strains belonging to Bacillus and lactic-acid bacteria, 10 strains with the highest growth (OD600nm level) in comparison to the other evaluated strains were identified, and of these, Ligilactobacillus agilis W70 and Limosilactobacillus fermentum M50, had the highest ammonia nitrogen utilizing capabilities of ammonium sulfate (32.09 and 40.64%, respectively). A subsequent in vitro fermentation experiment was conducted with the diet consisting of 0.5 g TMR, 50 mL buffer solution, and 25 mL fresh rumen fluid per serum bottle which was incubated at 39°C for 24 h. The experiment consisted of 3 treatments, CTL, L. agilis W70 (1 × 109 cfu/mL), and L. fermentum M50 (1 × 109 cfu/mL), each treatment had 6 replicates, repeated across 3 batches. The addition of L. agilis W70 decreased NH3N (p < 0.01), the ratio of acetate to propionate (A:P) (p < 0.01), and increased the yields of microbial protein (MCP) (p < 0.01) and enzymatic activities of glutamate dehydrogenase (GDH) (p < 0.05) and glutamine synthetase (GS) (p < 0.05). Further genome analysis revealed that the L. agilis W70 harbors the glutamate dehydrogenase and glutamine synthetase-encoding genes gdhA and glnA that play key roles in ammonia utilization. This study identified L. agilis W70 as a strain which exhibits high NH3N utilization capability and enhances ammonia assimilation in vitro. The strain was further characterized to elucidate this ammonia assimilation potential. Further studies will be conducted to develop strain L. agilis W70 as a new feed additive to improve the nitrogen utilization efficiency in ruminant animals. [ABSTRACT FROM AUTHOR]

AbstractChinese hamster ovary (CHO) cells represent the most common host system for the expression of high-quality recombinant proteins. The development of stable CHO cell lines used in industrial recombinant protein production often relies on dihydrofolate reductase (DHFR) and glutamine synthetase (GS) amplification systems. Conventional approaches to develop stable cell lines lead to heterogeneous cell populations. Consequently, it is desirable to adopt innovative strategies to increase the efficiency of clone selection to reduce the time and effort invested in the cell line development process. Attenuating the selection marker gene is an effective strategy for isolating high-producing cells. In this study, we evaluated the efficiency of an attenuated glutamine synthetase selection system for the expression of human tissue plasminogen activator (t-PA) in CHO cells. We introduced an AU-rich element (ARE) at the 3’UTR of the glutamine synthetase coding sequence and employed a weak promoter (mSV40) for the expression of this gene. Subsequently, we analyzed the effect of ARE on the GS RNA levels, and recombinant t-PA expression. Our results demonstrate that the use of ARE significantly enhances the detection of high expressing cells compared to the control. Additionally, the t-PA expression level in GS-ARE clones was approximately 900-fold greater than those without the ARE. [ABSTRACT FROM AUTHOR]

Glutamine metabolism is essential for infectious spleen and kidney necrosis virus (ISKNV) replication. Glutaminase 1 (GLS1), the key enzyme of the glutamine metabolism, and c-Myc positively regulate ISKNV infection, while c-Myc is closely correlated with GLS1. However, the regulatory mechanism among ISKNV, c-Myc and glutamine metabolism remains unclear. Here, we indicated that c-Myc increased glutamine uptake by increasing the GLS1, glutamate dehydrogenase (GDH) and isocitrate dehydrogenase (IDH2) expression of glutamine metabolism. ISKNV ORF102R, ORF093R and ORF118L co-located with c-Myc in CPB cells. Co-IP results showed that ISKNV ORF102R and ORF093R interacted with c-Myc, while ORF118L did not interact with c-Myc. The expression levels of c-Myc, GLS1 and IDH2 were increased in ISKNV ORF093R expression cells, and the mRNA and protein levels of GLS1 were upregulated in ISKNV 102R-expressing cells. These results indicated that ISKNV reconstructed glutamine metabolism to satisfy the energy and macromolecule requirements for virus proliferation by ORF093R and ORF102R interacting with c-Myc, which provides the foundation for innovative antiviral strategies. [ABSTRACT FROM AUTHOR]

Adaptation to abiotic stress is critical for the survival of perennial tree species. Salinity affects plant growth and productivity by interfering with major biosynthetic processes. Detrimental effects of salinity may vary between different plant tissues and cell types. However, spatial molecular mechanisms controlling plant responses to salinity stress are not yet thoroughly understood in perennial trees. We used laser capture microdissection in clones of Populus tremula x alba to isolate palisade and vascular cells of intermediary leaf from plants exposed to 150 mM NaCl for 10 days, followed by a recovery period. Cell‐specific changes in proteins and metabolites were determined. Salinity induced a vascular‐specific accumulation of proteins associated with photorespiration, and the accumulation of serine, 3‐phosphoglycerate and NH4+ suggesting changes in N metabolism. Accumulation of the GLUTAMINE SYNTHETASE 2 protein, and increased GS1.1 gene expression, indicated that NH4+ produced in photorespiration was assimilated to glutamine, the main amino acid translocated in Populus trees. Further analysis of total soluble proteins in stems and roots showed the accumulation of bark storage proteins induced by the salinity treatments. Collectively, our results suggest that the salt‐induced photorespiration in vascular cells mediates N‐reallocation in Populus, an essential process for the adaptation of trees to adverse conditions. Summary statement: In Populus, salinity‐induced photorespiration in the leaf vascular tissue is associated with N reallocation processes triggered by the stress‐induced reduction in C assimilation and growth at the whole plant level. [ABSTRACT FROM AUTHOR]

Weeds are among the most significant factors contributing to decreases in crop yield and quality. Glufosinate, a nonselective, broad‐spectrum herbicide, has been extensively utilized for weed control in recent decades. However, crops are usually sensitive to glufosinate. Therefore, the development of glufosinate‐resistant crops is crucial for effective weed management in agriculture. In this study, we characterized a SQUAMOSA promoter‐binding‐like (SPL) factor, OsSPL8, which acts as a negative regulator of glufosinate resistance by inhibiting the transcription of OsGS1;1 and OsGS2 and consequently reducing GS activity. Furthermore, the loss of OsSPL8 function enhanced tolerance to drought and salt stresses. Transcriptomic comparisons between the gar18‐3 mutant and wild type revealed that OsSPL8 largely downregulates stress‐responsive genes and upregulates growth‐related genes. We demonstrated that OsSPL8 directly regulates OsOMTN6 and OsNAC17, which influence drought tolerance. In addition, OsSPL8 directly represses the expression of salt stress tolerance‐related genes such as OsHKT1.1 and OsTPP1. Collectively, our results demonstrate that OsSPL8 is a negative regulator of both glufosinate resistance and abiotic stress tolerance. Summary statement: This study revealed that OsSPL8 acts as a negative regulator of glufosinate resistance in rice by directly inhibiting the transcription of GLUTAMINE SYNTHETASE 1;1 (OsGS1;1) and GLUTAMINE SYNTHETASE 2 (OsGS2). Meanwhile, loss of OsSPL8 function enhances tolerance to drought and salinity stress. [ABSTRACT FROM AUTHOR]

The global shortage of high-quality forage has significantly constrained the development of animal husbandry. Leveraging the complementary effects of forage rapeseed and hairy vetch intercropping can enhance forage yield and quality; however, the underlying mechanisms of overyielding in forage rapeseed–hairy vetch intercropping systems remain unclear. Over two years of field experiments, three cropping systems—rapeseed sole cropping, hairy vetch sole cropping, and rapeseed–hairy vetch intercropping—were investigated to assess the effects of intercropping on root and stem morphology, canopy light distribution, leaf photosynthetic physiology, and nitrogen metabolism. Our results demonstrated that intercropping increased forage biomass and crude protein yield by 14.3–20.0% and 30.7–92.8%, respectively, compared to sole cropping. Intercropping significantly enhanced root biomass, increasing lateral root biomass by 81% compared to rapeseed sole cropping. It also improved stem anatomical traits, including the cortex area (58.8–80.7%), cortex thickness (25.1–38.3%), number of vascular bundles (18.0–37.3%), vascular bundle length (17.8–18.4%), vascular bundle perimeter (6.7–18.7%), vascular bundle area (34.6–63.9%), and stem breaking strength (25.7–76.6%). Additionally, intercropping optimized vertical canopy light interception, reduced the activity of antioxidant enzymes (CAT, POD, SOD) and reactive oxygen species (ROS) accumulation, and enhanced the activities of glutamine synthetase and nitrate reductase, stomatal traits, and photosynthetic rates in the leaves of both crops. Structural equation modeling revealed that, in the intercropping system, improved population lodging resistance directly promoted nitrogen metabolism and leaf photosynthetic rates, ultimately increasing population biomass. In summary, rapeseed–hairy vetch intercropping improved canopy light distribution, strengthened rapeseed stem anatomy and root penetration, and enhanced population lodging resistance, leaf photosynthetic physiology, and nitrogen metabolism, thereby boosting forage biomass and quality. The supportive role of rapeseed in the intercropping system elucidates the overyielding mechanisms of rapeseed–hairy vetch intercropping, offering a theoretical framework for optimizing forage production systems worldwide. [ABSTRACT FROM AUTHOR]

Cancer cells undergo metabolic rewiring to support rapid proliferation and survival in challenging environments. Glutamine is a preferred resource for cancer metabolism, as it provides both carbon and nitrogen for cellular biogenesis. Recent studies suggest the potential anticancer activity of amino acid analogs. Some of these analogs disrupt cellular nucleotide synthesis, thereby inhibiting the formation of DNA and RNA in cancer cells. In the present study, we investigated the anticancer properties of Acivicin and Azaserine in the breast cancer MCF-7 cell line, comparing their effects to those on the non-tumorigenic MCF-10 epithelial cell line in vitro. Interestingly, at lower concentrations, both Acivicin and Azaserine showed potent inhibition of MCF-7 cell proliferation, as assessed by the MTT assay, without detectable toxicity to normal cells. In contrast, Sorafenib (Nexavar), a commonly used drug for solid tumors, showed harmful effects on normal cells, as indicated by increased lactate dehydrogenase (LDH) production in treated cells. Furthermore, unlike Sorafenib, treatment with Acivicin and Azaserine significantly affected apoptotic signaling in treated cells, indicating the role of both amino acid analogs in activating programmed cell death (PCD), as assessed by the Annexin-V assay, DAPI staining, and the relative expression of tumor suppressor genes PTEN and P53. ELISA analysis of MCF-7 cells revealed that both Acivicin and Azaserine treatments promoted the production of anti-inflammatory cytokines, including IL-4 and IL-10, while significantly reducing the production of tumor necrosis factor alpha (TNF-α). Mechanistically, both Acivicin and Azaserine treatment led to a significant reduction in the expression of glutamine synthetase (GS) at both the RNA and protein levels, resulting in a decrease in intracellular glutamine concentrations over time. Additionally, both treatments showed comparable effects on Raf-1 gene expression and protein phosphorylation when compared with Sorafenib, a Raf-1 inhibitor. Moreover, docking studies confirmed the strong binding affinity between Acivicin, Azaserine, and glutamine synthetase, as evidenced by their docking scores and binding interactions with the enzyme crystal. Collectively, these findings provide evidence for the anticancer activity of the two amino acid analogs Acivicin and Azaserine as antagonists of glutamine synthetase, offering novel insights into potential therapeutic strategies for breast cancer. [ABSTRACT FROM AUTHOR]

Understanding the fundamental biochemical and metabolic requirements for the replication of coronaviruses within infected cells is of notable interest for the development of broad-based therapeutic strategies, given the likelihood of the emergence of new pandemic-potential virus species, as well as future variants of SARS-CoV-2. Here we demonstrate members of the glutaminase family of enzymes (GLS and GLS2), which catalyze the hydrolysis of glutamine to glutamate (i.e., the first step in glutamine metabolism), play key roles in coronavirus replication in host cells. Using a range of human seasonal and zoonotic coronaviruses, we show three examples where GLS expression increases during coronavirus infection of host cells, and another where GLS2 is upregulated. The viruses hijack the metabolic machinery responsible for glutamine metabolism to generate the building blocks for biosynthetic processes and satisfy the bioenergetic requirements demanded by the "glutamine addiction" of virus-infected cells. We demonstrate that genetic silencing of glutaminase enzymes reduces coronavirus infection and that newer members of two classes of allosteric inhibitors targeting these enzymes, designated as SU1, a pan-GLS/GLS2 inhibitor, and UP4, a specific GLS inhibitor, block viral replication in epithelial cells. Moreover, treatment of SARS-CoV-2 infected K18-human ACE2 transgenic mice with SU1 resulted in their complete survival compared to untreated control animals, which succumbed within 10 days post-infection. Overall, these findings highlight the importance of glutamine metabolism for coronavirus replication in human cells and mice and show that glutaminase inhibitors can block coronavirus infection and thereby may represent a novel class of broad-based anti-viral drug candidates. [ABSTRACT FROM AUTHOR]

FYVE-type zinc finger-containing phosphoinositide kinase (PIKFYVE), which is essential for phosphatidylinositol 3,5-bisphosphate [PtdIns(3,5)P2] production, is an important regulator of lysosomal homeostasis. PIKFYVE dysfunction leads to cytoplasmic vacuolization; however, the underlying mechanism remains unknown. In this study, we explored the cause of vacuole enlargement upon PIKFYVE inhibition in DU145 prostate cancer cells. Enlargement of vacuoles upon PIKFYVE inhibition required glutamine and its metabolism by glutaminases. Addition of ammonia, a metabolite of glutamine, was sufficient to enlarge vacuoles via PIKFYVE inhibition. Moreover, PIKFYVE inhibition led to intracellular ammonium accumulation. Endosome-lysosome permeabilization resulted in ammonium leakage from the cells, indicating ammonium accumulation in the endosomes and lysosomes. Ammonium accumulation and vacuole expansion were suppressed by the lysosomal lumen neutralization. It is therefore assumed that PIKFYVE inhibition interferes with the efflux of NH4, which formed through protonation of NH3 in the lysosomal lumen, leading to osmotic swelling of vacuoles. Notably, glutamine or ammonium is required for PIKFYVE inhibition-induced suppression of lysosomal function and autophagic flux. In conclusion, this study shows that PIKFYVE inhibition disrupts lysosomal homeostasis via ammonium accumulation. [ABSTRACT FROM AUTHOR]

Background: Nitrogen (N) deposition has become a major driving factor affecting the balance of terrestrial ecosystems, changing the soil environment, element balance and species coexistence relationships, driving changes in biodiversity and ecosystem structure and function. Human-induced nitrogen input leads to a high NH4+/ NO3- ratio in soil. However, relatively few studies have investigated the effects of different nitrogen sources on forest plant-microbial symbionts. In this study, the effects of four nitrogen sources, N free, NH4Cl, L-glutamic acid, and Na(NO3)2 (N-, NH4+-N, Org-N, and NO3--N) on four fungal species, Suillus granulatus (Sg), Pisolithus tinctorius (Pt), Pleotrichocladium opacum (Po), and Pseudopyrenochaeta sp. (Ps), which were isolated from the roots of Pinus tabulaeformis, were studied in vitro. The effects of inoculation with the four fungi on the growth performance, nutrient uptake and nitrogen metabolism-related enzymes of Pinus tabuliformis under different nitrogen source conditions were subsequently studied. Results: The biomass and N concentration of the Sg and Po strains were the highest under the NO3--N treatment, while the biomass and N concentration of the Pt and Ps strains were significantly greater under the NH4+-N and NO3--N treatments than under the Org-N and N- treatments. All four fungi could effectively colonize the roots of P. tabuliformis and formed a symbiotic relationship with it. Under all nitrogen conditions, the inoculation of the four fungi had positive effects on the growth, root development and nutrient concentration of the P. tabuliformis seedlings. Under the Org-N and NO3--N treatments, the nitrate reductase (NR) activity of the inoculated plants was significantly greater than that of the noninoculated control (CK) plants. Under all nitrogen conditions, the glutamine synthetase (GS) activity of the inoculated plants was significantly greater than that of the CK plants. Conclusions: The four fungi can establish good symbiotic relationships with P. tabuliformis seedlings and promote their growth and development under different nitrogen source treatments. [ABSTRACT FROM AUTHOR]

The article in Acta Physiologica discusses the role of Bestrophin 1 (Best1) anion channels in maintaining chloride homeostasis in the central nervous system (CNS). Best1 channels are expressed in both neurons and astrocytes, facilitating Cl− fluxes that are crucial for balancing inhibition and excitation in neural circuits. The article highlights the importance of Cl− movement between cells and the extracellular space, emphasizing the role of Best1 in mediating inhibitory synaptic transmission. Additionally, Best1 channels are implicated in the diffusion-driven release of GABA and glutamate, contributing to sustained inhibitory neurotransmission in the CNS. [Extracted from the article]

One of the trigger mechanisms for the development of neurodegeneration is glutamate excitotoxicity. The ATP-dependent enzyme glutamine synthetase, localized in astrocytes, regulates glutamate homeostasis by catalyzing the synthesis of glutamine from glutamate and ammonia. The purpose of the study was to identify age- and sex-specific changes in glutamine synthetase activity in a streptozotocin-induced model of Alzheimer-type neurodegeneration. The experiments were carried out on 60 old (at the age of 24 months) Wistar rats of both sexes, divided into groups: 1) control (intact) rats; 2) sham-operated rats; 3) rats with intraventricular injection of streptozotocin. using intraventricular injection of streptozotocin. In males, enzymatic activity decreased in the cortex, cerebellum, hippocampus, and hypothalamus by 40%, 33%, 36%, and 26%, respectively, compared with control rats. In females, the decrease was more pronounced, which amounted to 47% in the cortex, 39% in the cerebellum, 43% in the hippocampus, and 32% in the hypothalamus. Thus, the decrease in glutamine synthetase activity is due to age-dependent impairment of glutamate neurotransmission, reduced compensatory capabilities of neurons and altered hormonal status. [ABSTRACT FROM AUTHOR]

Abstract Choroidal neovascularization (CNV) is a leading cause of visual impairment in wet age-related macular degeneration (wAMD). Recent investigations have validated the potential of reducing glutamine synthetase (GS) to inhibit neovascularization formation, offering prospects for treating various neovascularization-related diseases. In this study, we devised a CRISPR/Cas9 delivery system employing the nucleic acid aptamer AS1411 as a targeting moiety and exosome-liposome hybrid nanoparticles as carriers (CAELN). Exploiting the binding affinity between AS1411 and nucleolin on endothelial cell surfaces, the delivery system was engineered to specifically target the glutamine synthetase gene (GLUL), thereby attenuating GS levels and continuously suppressing CNV. CAELN exhibited spherical and uniform dispersion. In vitro cellular investigations demonstrated gene editing efficiencies of CAELN ranging from 42.05 to 55.02% and its capacity to inhibit neovascularization in HUVEC cells. Moreover, in vivo pharmacodynamic studies conducted in CNV rabbits revealed efficacy of CAELN in restoring the thickness of intra- and extranuclear tissues. The findings suggest that GS is a novel target for the inhibition of pathological CNV, while the development of AS1411-modified exosome-liposome hybrid nanoparticles represents a novel delivery method for the treatment of neovascular-related diseases.

Best1 and Best2 are two members of the bestrophin family of anion channels critically involved in the prevention of retinal degeneration and maintenance of intraocular pressure, respectively. Here, we solved glutamate- and γ-aminobutyric acid (GABA)-bound Best2 structures, which delineate an intracellular glutamate binding site and an extracellular GABA binding site on Best2, respectively, identified extracellular GABA as a permeable activator of Best2, and elucidated the co-regulation of Best2 by glutamate, GABA and glutamine synthetase in vivo. We further identified multiple small molecules as activators of the bestrophin channels. Extensive analyses were carried out for a potent activator, 4-aminobenzoic acid (PABA): PABA-bound Best1 and Best2 structures are solved and illustrate the same binding site as in GABA-bound Best2; PABA treatment rescues the functional deficiency of patient-derived Best1 mutations. Together, our results demonstrate the mechanism and potential of multiple small molecule candidates as clinically applicable drugs for bestrophin-associated diseases/conditions. Bestrophin anion channels are critical for the health of eyes. Here, authors identify multiple bestrophin activators including glutamate and γ-aminobutyric acid. [ABSTRACT FROM AUTHOR]

The correction notice in the journal "Frontiers in Plant Science" addresses errors in the unit used for stomatal conductance in a study on root symbiotic fungi and nitrogen transfer in Chenopodium quinoa. The corrected figures and tables show the effects of nitrogen levels and fungal inoculation on various physiological and morphological traits in the plant. The correction also includes updates to the funding statement and reagent name used in the study. The authors acknowledge the errors and affirm that they do not impact the scientific conclusions of the article. [Extracted from the article]

Root-associated fungal endophytes may facilitate nitrogen (N) absorption in plants, leading to benefits in photosynthesis and growth. Here, we investigated whether endophytic insect pathogenic fungi (EIPF) are capable of transferring soil N to the crop species Chenopodium quinoa. We evaluated nutrient uptake, carbon allocation, and morpho-physiological performance in C. quinoa in symbiosis with two different EIPF (Beauveria and Metarhizium) under contrasting soil N supply. A controlled experiment was conducted using two plant groups: (1) plants subjected to low N level (5 mM urea) and (2) plants subjected to high N level (15 mM urea). Plants from each group were then inoculated with different EIPF strains, either Beauveria (EIPF1+), Metarhizium (EIPF2+) or without fungus (EIPF-). Differences in N and C content, amino acids, proteins, soluble sugars, starch, glutamine synthetase, glutamate dehydrogenase, and physiological (photosynthesis, stomatal conductance, transpiration), and morphological performance between plant groups under each treatment were examined. We found that both Beauveria and Metarhizium translocated N from the soil to the roots of C. quinoa , with positive effects on photosynthesis and plant growth. These effects, however, were differentially affected by fungal strain as well as by N level. Additionally, an improvement in root C and sugar content was observed in presence of EIPF, suggesting translocation of carbohydrates from leaves to roots. Whereas both strains were equally effective in N transfer to roots, Beauveria seemed to exert less demand in C. quinoa for photosynthesis-derived carbohydrates compared to Metarhizium. Our study revealed positive effects of EIPF on N transfer and morpho-physiological performance in crops, highlighting the potential of these fungi as an alternative to chemical fertilizers in agriculture systems. [ABSTRACT FROM AUTHOR]

Castration is widely used in poultry and livestock to enhance fat metabolism and improve the flavor, tenderness and juiciness of meat. However, the genetic regulatory mechanism underlying castration consequences have not been clarified. To investigate the key metabolites affecting the quality of capons and the key regulatory mechanisms, Qingyuan partridge roosters were subjected to castration. Metabolic profiling was used to detect differential metabolites in the breast muscle of both capon and control groups. Additionally, an integrative analysis of transcriptomics and proteomics was conducted to explore the genetic regulation mechanisms influencing meat quality. The results indicated that the muscle fiber density and shear force of capons was lower than that of normal chickens, and the fat percentage of capon group (CAM) was higher than control group (COM). The expression of the metabolite inostine-5'-monophosphate (IMP) was lower in capons, and lipid metabolites (PC (10:0/10:0), PC (6:0/13:1), LPC 22:6, LPC 18:2, LPE 18:1, LPE 20:4) were higher in capons. Metabolic pathways were found to be a common signaling pathway in all omics. Glutamate-ammonia ligase (GLUL), acetyl-CoA carboxylase beta (ACACB), 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2), 4-hydroxy-2-oxoglutarate aldolase 1 (HOGA1) and glutathione S-transferase alpha 2 (GSTA2) regulate the expression of citric acid, arachidonic acid, palmitic acid, isocitric acid, and betaine. These findings highlight the key mechanisms contributing to the meat quality differences between capons and normal chickens. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is one of the three major elements required for plant growth and development. It is of great significance to study the effects of different nitrogen application levels on the growth and root exudates of Phlomoides rotata, and can provide a theoretical basis for its scientific application of fertilizer to increase production. In this study, Phlomoides rotata were grown under different nitrogen conditions for two months. Soil and plant analyzer development (SPAD) values, bioaccumulation, root morphology, root exudate composition, nitrogen metabolism enzyme and antioxidant enzyme activity were evaluated. The results showed that compared with CK (no N fertilizer), N2 (CO(NH2)2 80 mg/kg) and N3 (CO(NH2)2 160 mg/kg) through significantly improved the activities of nitrogen metabolism enzyme nitrite reductase (NiR), glutamate dehydrogenase (GDH) and glutamine synthetase (GS), enhanced the nitrogen metabolism process, and increased the accumulation of plant soluble sugars (SS) and soluble protein (SP), thus improving Phlomoides rotata biomass yield. After 60 days of treatment, low nitrogen (N1, CO(NH2)2 40 mg/kg) increased root length, root volume, root surface area, average root diameter, significantly increased the diversity of organic acids in root exudates, and enhanced the activity of antioxidant enzymes to adapt the nitrogen deficiency environment. This study can provide new ideas for understanding the mechanism of nitrogen tolerance in Phlomoides rotata and developing scientific fertilization management strategies for plateau plants and medicinal plants. [ABSTRACT FROM AUTHOR]

Our previous study highlighted the therapeutic potential of glutathione (GSH), an intracellular thiol tripeptide ubiquitous in mammalian tissues, in mitigating hepatic and cerebral damage. Building on this premise, we posited the hypothesis that GSH could be a promising candidate for treating acute hepatic encephalopathy (AHE). To verify this conjecture, we systematically investigated the feasibility of GSH as a therapeutic agent for AHE through comprehensive pharmacokinetic, pharmacodynamic, and mechanistic studies using a thioacetamide-induced AHE rat model. Our pharmacodynamic data demonstrated that oral GSH could significantly improve behavioral scores and reduce hepatic damage of AHE rats by regulating intrahepatic ALT, AST, inflammatory factors, and homeostasis of amino acids. Additionally, oral GSH demonstrated neuroprotective effects by alleviating the accumulation of intracerebral glutamine, down-regulating glutamine synthetase, and reducing taurine exposure. Pharmacokinetic studies suggested that AHE modeling led to significant decrease in hepatic and cerebral exposure of GSH and cysteine. However, oral GSH greatly enhanced the intrahepatic and intracortical GSH and CYS in AHE rats. Given the pivotal roles of CYS and GSH in maintaining redox homeostasis, we investigated the interplay between oxidative stress and pathogenesis/treatment of AHE. Our data revealed that GSH administration significantly relieved oxidative stress levels caused by AHE modeling via down-regulating the expression of NADPH oxidase 4 (NOX4) and NF-κB P65. Importantly, our findings further suggested that GSH administration significantly regulated the excessive endoplasmic reticulum (ER) stress caused by AHE modeling through the iNOS/ATF4/Ddit3 pathway. In summary, our study uncovered that exogenous GSH could stabilize intracerebral GSH and CYS levels to act on brain oxidative and ER stress, which have great significance for revealing the therapeutic effect of GSH on AHE and promoting its further development and clinical application. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy, a major cause of vision loss, is characterized by neurovascular changes in the retina. The lack of effective treatments to preserve vision in diabetic patients remains a significant challenge. A previous study from our laboratory demonstrated that 12-week treatment with MDL 72527, a pharmacological inhibitor of spermine oxidase (SMOX, a critical regulator of polyamine metabolism), reduced neurodegeneration in diabetic mice. Utilizing the streptozotocin-induced diabetic mouse model and MDL 72527, the current study investigated the effectiveness of SMOX inhibition on the measures of vision impairment and neuro-glial injury following 24 weeks of diabetes. Reductions in visual acuity, contrast sensitivity, and inner retinal function in diabetic mice were improved by MDL 72527 treatment. Diabetes-induced changes in neuronal-specific class III tubulin (Tuj-1), synaptophysin, glutamine synthetase, and vimentin were attenuated in response to SMOX inhibition. In conclusion, our findings show that SMOX inhibition improved visual acuity, contrast sensitivity, and inner retinal function and mitigated diabetes-induced neuroglial damage during long-term diabetes. Targeting SMOX signaling may provide a potential strategy for reducing retinal neuronal damage and preserving vision in diabetes. [ABSTRACT FROM AUTHOR]

Ammonia nitrogen is a common environmental factor in aquaculture systems. High levels of ammonia nitrogen threaten the health of shrimp. This study aimed to investigate ammonia nitrogen stress in the hepatopancreas of Penaeus vannamei by integrating physiological, metabolome, and transcriptome analysis. The study revealed that exposure to ammonia nitrogen resulted in injury to the hepatopancreas, deformation disorder of the lumen, blurred boundaries, and increased vacuoles. After ammonia nitrogen stress, the activities of ammonia-metabolizing enzymes (glutamate dehydrogenase and glutamine synthetase) increased significantly, while the activity of transglutaminase decreased significantly. In addition, antioxidant enzymes (glutathione peroxidase, catalase, and superoxide dismutase) were significantly decreased. Additionally, the activity of energy metabolizing enzyme (hexokinase) was increased, and immune enzyme (alkaline phosphatase) activity was decreased. The accumulation of metabolites, such as d-myo-inositol, hexadecenoic acid, aspartate, and ornithine in the metabolite groups, showed significant differences under ammonia stress. Transcriptome analysis suggested that the KEGG pathways were significantly enriched in energy and primary metabolism, metabolism of cofactors and vitamins, and signaling pathways. The comprehensive analysis of metabolome and transcriptome displayed significant enrichment pathways, including TCA cycle, purine metabolism, pyrimidine metabolism, and folic acid biosynthesis under ammonia nitrogen stress. Simultaneously, six genes were found to respond to ammonia stress, including inositol oxygenase-like, histone h1-β, postembryonic, blood cell protein-glutamine-glutamyltransferase-like, receptor tyrosine protein phosphatase T-like, trichohyalin-like, and thyroxine 5-deiodinase-like. The results showed that ammonia nitrogen stress caused hepatopancreas tissue damage, changed in enzyme activities, metabolic process, and related gene expression in P. vannamei. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) pollution in arable soils and its accumulation in rice plants have become a global concern because of their harmful effects on crop yield and human health. The in-situ stabilization method which involves the application of organic amendments such as vermicompost (VC), is frequently utilized for the remediation of Cd-contaminated soils. This study investigated the effects of VC on the soil chemical properties and the physio-biochemical functions of fragrant rice, as well as nitrogen (N) metabolism and assimilatory enzyme activities, 2-acetyl-1-pyrroline (2AP) content in rice grains, and the grain yields of fragrant rice cultivars, i.e., Xiangyaxiangzhan (XGZ) and.Meixiangzhan-2 (MXZ-2) under Cd stress condition. Four doses of VC (.VC1 = 0, VC2 = 3 t. ha-1, VC3 = 4 t ha-1, and VC4 = 6 t ha-1) and two levels of Cd (0 and 25 mg Cd kg-1) were used in this study. Our results showed that VC supplementation significantly (p < 0.05) improved soil characteristics, including soil organic carbon, available N, total N, phosphorus (P), and potassium (K). Furthermore, VC enhanced plant physiological and biochemical attributes in fragrant rice, such as net photosynthetic rate (Pn), nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate oxoglutarate aminotransferase (GOGAT) enzyme activities, protein contents, amino acid, and 2-acetyl-1-pyrroline (2AP) contents under Cd stress condition. Specifically, the VC-amended treatment, Cd2 + VC3, led to an 86.75% increase in Pn and 2AP, and a 60.05% and 77.55% increase in grain yield for MXZ-2 and XGZ cultivars, respectively, compared to Cd-only treated plants (Cd2 + VC1). In addition, VC application significantly (p < 0.05) decreased the Cd uptake and accumulation in rice plants. The correlation analysis indicated that leaf physiological activity and biochemical traits are strongly correlated with soil qualitative traits, suggesting that improved soil health leads to enhanced leaf physiological activity, N metabolism, grain 2AP content, and grain yields. Among the treatments, Cd2 + VC3 showed the best performance in terms of soil fertility and rice quality and production. Consequently, our study indicates that using VC in soils may benefit rice growers by improving soil fertility and supporting sustainable rice productivity and quality in soils contaminated with Cd. [ABSTRACT FROM AUTHOR]

Background: Triple‐negative breast cancer (TNBC) is a particularly aggressive type of breast cancer, known for its lack of effective treatments and unfavorable prognosis. The G protein‐coupled estrogen receptor (GPER), a novel estrogen receptor, is linked to increased malignancy in various cancers. However, its involvement in the metabolic regulation of cancer‐associated fibroblasts (CAFs), a key component in the tumour microenvironment, remains largely unexplored. This study investigates how GPER influences the metabolic interaction between CAFs and TNBC cells, aiming to identify potential therapeutic targets. Methods: The co‐culture system is performed to examine the interaction between CAFs and TNBC cells, with a focus on GPER‐mediated glutamine production and release by CAFs and its subsequent uptake and utilization by TNBC cells. The definite roles of microenvironmental GPER/cAMP/PKA/CREB signalling in regulating the expression of glutamine synthetase (GLUL) and lactate dehydrogenase B (LDHB) are further investigated. Results: Our findings reveal that estrogen‐activated GPER in CAFs significantly upregulates the expression of GLUL and LDHB, leading to increased glutamine production. This glutamine is then secreted into the extracellular matrix and absorbed by TNBC cells, enhancing their viability, motility, and chemoresistance both in vitro and in vivo. TNBC cells further metabolize the glutamine through the glutamine transporter (ASCT2) and glutaminase (GLS1) axes, which, in turn, promote mitochondrial activity and tumour progression. Conclusions: The study identifies GPER as a critical mediator of metabolic coupling between CAFs and TNBC cells, primarily through glutamine metabolism. Targeting the estrogen/GPER/glutamine signalling axis in CAFs offers a promising therapeutic strategy to inhibit TNBC progression and improve patient outcomes. This novel insight into the tumour microenvironment highlights the potential of metabolic interventions in treating TNBC. Key points: Estrogen‐activated GPER in CAFs enhances GLUL and LDHB expression via the cAMP/PKA/CREB signalling, facilitating glutamine production and utilization.Microenvironmental GPER‐induced glutamine serves as a crucial mediator of metabolic coupling between CAFs and TNBC cells, boosting tumour progression by enhancing mitochondrial function.Targeting the glutamine metabolic coupling triggered by estrogen/GPER/GLUL signalling in CAFs is a promising therapeutic strategy for TNBC treatment. [ABSTRACT FROM AUTHOR]

Introduction: Cerebral swelling and brain injury in ischemic stroke are closely related to increased vasopressin (VP) secretion. How to alleviate ischemic brain injury by suppressing VP hypersecretion through simply available approaches remains to be established. Methods: Using a rat model of middle cerebral artery occlusion (MCAO), testing effects of the intranasal application of low concentration saline-0.09% NaCl (IAL) on brain damage, VP neuronal activity, synaptic inputs, astrocytic plasticity, and olfactory bulb (OB) activity in immunohistochemistry, patch-clamp recording, Western blotting, and co-immunoprecipitation. Results: IAL reduced MCAO-evoked neurological disorders, brain swelling, injury and loss of neurons, increase in c-Fos expression, and excitation of supraoptic VP neurons. The effects of IAL on VP neurons were associated with its suppression of MCAO-evoked increase in the frequency of excitatory synaptic inputs and decrease in the expression of glial fibrillary acidic protein (GFAP) filaments around VP neurons. MCAO and IAL also caused similar but weaker reactions in putative oxytocin neurons. In the OB, MCAO increased the firing rate of mitral cells on the MCAO side, which was reduced by IAL. A direct hypotonic challenge of OB slices increased the expression of glutamine synthetase and GFAP filaments in the glomerular bodies while reducing the firing rate of mitral cells. Blocking aquaporin 4 activity in the supraoptic and paraventricular nuclei on the MCAO side reduced MCAO-evoked VP increase and brain damage. Conclusion: IAL reduces ischemic stroke-evoked brain injury in association with suppression of VP neuronal activity through reducing excitatory synaptic inputs and astrocytic process retraction, which likely result from reducing mitral cell activation in ischemic side. Plain Language Summary: Neuroendocrine disorders during cerebral stroke are a major etiology of ischemic brain injury that occurs following the occlusion of the cerebral artery. A hypothalamic neuropeptide, antidiuretic hormone or vasopressin (VP), is a key neuroendocrine factor in ischemic brain injury. To identify the way to reduce the overly produced VP following the stroke, this study used a rat model of cerebral stroke and tested the effects of intranasal application/drops of low concentration saline-0.09% NaCl (IAL) on VP neuronal activity that determines VP secretion. The results revealed for the first time that IAL inhibition of stroke-evoked VP neuronal activation and its associated brain damage is related to IAL inhibition of ischemia-evoked astrocytic process retraction around VP neurons and increase in excitatory inputs on VP neurons from the mitral cells in the activated olfactory bulb in the ischemic side. Similar but weaker effects also occurred at oxytocin neurons that co-exist with VP neurons but exert neural protective effects. These findings highlight that IAL (or commercially available purified water?) inhibition of VP neuronal activity may provide a simply available protective strategy in the early stage of cerebral stroke after further clinical trials. [ABSTRACT FROM AUTHOR]

ve: Increasing tree productivity by genetic engineering methods is one of the main trends of forest biotechnology. A promising strategy for this is to improve the use efficiency of nitrogen, which is the main limiting factor of plant growth. For this purpose, the GS1 gene from Scots pine was transferred to downy birch (Betula pubescens) plants. This gene encodes the cytosolic form of glutamine synthetase, the main enzyme of nitrogen metabolism in plants. Methods: To assess the effects of insertion of this gene, the birch plant metabolome was analyzed using GC-MS and HPLC-MS. Results and Discussion: GC-MS analysis found 197 metabolites in birch extracts, but the metabolomes of two transgenic clones showed no statistically significant differences from the control. Using the S-plot based on the OPLS-DA model, 32 metabolite markers affecting the separation of control and transgenic birch plants were detected; 22 of them were identified. Three metabolites among them were nitrogen-containing, including γ-aminobutyric acid, the immediate precursor of which is glutamine. HPLC-MS analysis found 48 metabolites, but transgenic plants did not differ from the control. GC-MS, however, showed a decrease in the content of two phenolic compounds in transgenic plants, which is characteristic of improved nitrogen supply. Conclusions: The study shows that modification of nitrogen metabolism in birch plants does not significantly affect the biochemical composition of tree shoots. [ABSTRACT FROM AUTHOR]

The canonical arsRBC genes of the ars1 operon in Pseudomonas putida KT2440, which confer tolerance to arsenate and arsenite, are followed by a series of additional ORFs culminating in phoN1. The phoN1 gene encodes an acetyltransferase that imparts resistance to the glutamine synthetase inhibitor herbicide phosphinothricin (PPT). The co‐expression of phoN1 and ars genes in response to environmental arsenic, along with the physiological effects, was analysed through transcriptomics of cells exposed to the oxyanion and phenotypic characterization of P. putida strains deficient in different components of the bifan motif governing arsenic resistance in this bacterium. Genetic separation of arsRBC and phoN1 revealed that their associated phenotypes operate independently, indicating that their natural co‐regulation is not functionally required for simultaneous response to the same signal. The data suggest a scenario of associative evolution, akin to Pavlovian conditioning, where two unrelated but frequently co‐occurring signals result in one regulating the other's response – even if there is no functional link between the signal and the response. Such surrogate regulatory events may provide an efficient solution to complex regulatory challenges and serve as a genetic patch to address transient gaps in evolving regulatory networks. [ABSTRACT FROM AUTHOR]

Escherichia coli K12 and Lelliottia amnigena PTJIIT1005 bacteria were isolated from the polluted Yamuna River (Delhi, India) site, which can remediate nitrate from groundwater media under anaerobic conditions. BV-BRC (Bacterial and Viral Bioinformatics Resource Center) information system, RAST, and PGAP servers were used to annotate the nitrogen metabolism genes from the genome sequence of these microbes. Here we compared the strains L. amnigena PTJIIT1005 with E. coli K12 in the context of nitrogen metabolism genes. Sequence alignment, similarity percentage, and phylogenetic analysis were done to find similarities between the genes. Common nitrogen genes of these strains, like respiratory nitrate reductase, nitrite reductase, nitric oxide reductase, glutamine synthetase, and hydroxylamine reductase, have found good sequence similarity (83–94%) with each other. The PATRIC tool identified N-operons, and the nitrate reductase gene clusters were also determined as per literature survey. Protein–protein interaction network was constructed using STRING 12.0 database and Cytoscape v 3.10.0 software plug-in Network analyzer. On the basis of network topological parameters NarG, NarZ, NarY, NarH, NarI, NarV, NirB, NirD, NapA, and NapB are the key genes in network of E. coli K12 strain. Nar, NirB, NirD, NasA, NasB, NasC, NasD, NasE, and GlnA are the key genes in network of L. amnigena PTJIIT1005. Among these, NarG and NirB are the superhub genes because of having highest Betweenness centrality (BC) and node degree. The functional enrichment analysis was determined using PANTHER GENE ONTOLOGY and DAVID software exhibited their role in nitrogen metabolism pathway and nitrate assimilation. Further, SWISS-MODEL was used to predict the 3D protein structure of these enzymes, and after, these structures were validated by Ramachandran plot using the PROCHECK tool. The Real-Time Quantitative Reverse Transcription PCR (qRT-PCR) method was used to determine the N-genes expression level in both strains. This study showed that E. coli K12 and L. amnigena PTJIIT1005 have common nitrogen metabolism genes involved in the same functional role, like the denitrification pathway. Additionally, operon arrangement study and PPI network revealed that E. coli K12 has only a denitrification pathway, while L. amnigena PTJIIT1005 has both an assimilation and denitrification pathway. PCR successfully amplified selected N-metabolizing genes, and the expression level of N-genes was high in strain L. amnigena PTJIIT1005. Our previous experimental study exhibited a better nitrate remediation rate in L. amnigena PTJIIT1005 over E. coli K12. This study confirmed the presence of assimilation and denitrification process through amplified N-metabolizing genes and showed high expression of N-genes in L. amnigena PTJIIT1005, which favor the evidence of better nitrate remediation in L. amnigena PTJIIT1005 over E. coli K12. [ABSTRACT FROM AUTHOR]

The mevalonate pathway produces essential lipid metabolites such as cholesterol. Although this pathway is negatively regulated by metabolic intermediates, little is known of the metabolites that positively regulate its activity. We found that the amino acid glutamine is required to activate the mevalonate pathway. Glutamine starvation inhibited cholesterol synthesis and blocked transcription of the mevalonate pathway—even in the presence of glutamine derivatives such as ammonia and α-ketoglutarate. We pinpointed this glutamine-dependent effect to a loss in the ER-to-Golgi trafficking of SCAP that licenses the activation of SREBP2, the major transcriptional regulator of cholesterol synthesis. Both enforced Golgi-to-ER retro-translocation and the expression of a nuclear SREBP2 rescued mevalonate pathway activity during glutamine starvation. In a cell model of impaired mitochondrial respiration in which glutamine uptake is enhanced, SREBP2 activation and cellular cholesterol were increased. Thus, the mevalonate pathway senses and is activated by glutamine at a previously uncharacterized step, and the modulation of glutamine synthesis may be a strategy to regulate cholesterol levels in pathophysiological conditions. Synopsis: Whether cholesterol biosynthesis can be adjusted to the availability of input carbon sources remains unclear. This study demonstrates that glutamine is directly sensed by and required for activation of the mevalonate pathway, coupling precursor availability to cellular lipid formation. Glutamine starvation inhibits cholesterol synthesis in human cells. Glutamine, but not its derivatives nor glucose, maintains expression of the rate-limiting lipid biosynthesis enzyme HMGCR. Glutamine synthesis from ammonia and glutamate sustains HMGCR in a cell-type-specific manner. Glutamine is required for the ER-to-Golgi trafficking of the SCAP-SREBP2 complex. Chronic mitochondrial dysfunction increases glutamine uptake and cholesterol levels in murine fibroblasts. The amino acid glutamine is directly sensed by the mevalonate pathway and acts as an anabolic switch coupling precursor availability to lipid biosynthesis. [ABSTRACT FROM AUTHOR]

The specific root exudate, tripropylene glycol monomethyl ether (TPM), was significantly increased under the maize and peanut intercropping system. Exploring its effects on the growth and metabolic physiology of peanut plants could provide reference for exploring effective substances regulating the growth and development of peanut and promoting the quality and yield improvement of peanut. In this study, Qinghua No.6 peanut variety was used as experimental material, and the same volume of sterile water was added as control (CK). The dry matter accumulation, maximum photochemical efficiency, carbon and nitrogen metabolism enzyme activity and antioxidant properties of peanut plants under three tripropylene glycol monomethyl ether (TPM) adding gradient (T1:10.23μL/pot, T2:20.46μL/pot, T3: 40.92 μL/pot) were studied. The results showed that, compared with CK, T1 and T3 significantly reduced the above-ground dry matter weight of peanut plants. All TPM treatments significantly reduced the dry matter weight of underground part and maximum photochemical efficiency (Fv/Fm) of PSII. TPM supplementation significantly increased the activity of carbon and nitrogen metabolizing enzymes in peanut functional leaves, for detail, the activities of nitrate reductase (NR), sucrose synthetase (SS) and phosphate sucrose synthetase (SPS) in T1 treatment were increased by 6.49%-203.24% compared with CK, and Glutamine synthetase (GS) activity in T3 treatment was significantly increased by 39.81% compared with CK. The supplementation of TPM had stress effect on peanut plants. The content of malondialdehyde (MDA) was significantly increased by 17.32%-34.65% compared with CK. The activities of superoxide dismutase (SOD) and catalase (CAT) under T3 treatment were decreased by 75.82% and 75.74% compared with CK, respectively. The peroxidase (POD) activity under T1 treatment was significantly decreased by 30.43% compared with CK. According to the histochemical localization, T3 treatment significantly induced the accumulation of H2O2 and O2- in peanut plant functional leaves, and the content of O2- was significantly increased by 83.39% compared with CK. In conclusion, TPM can inhibit the growth of peanut plants, especially the underground part, reduce the potential maximum photosynthetic capacity (Fv/Fm) of leaves and inhibit the activities of antioxidant enzymes such as SOD, CAT and POD. However, peanut plants can reduce the damage caused by TPM by improving the activities of carbon and nitrogen metabolic enzymes such as NR, SS, SPS and GS. In this study, TPM is not suitable for peanut production. [ABSTRACT FROM AUTHOR]

Cardiac metastases are a rare site for metastatic hepatocellular carcinoma (HCC). We describe an atypical presentation of an isolated right ventricular metastasis of HCC following successful treatment with no evidence of primary disease recurrence. The case presented as gradually worsening hypertension and erythrocytosis in the setting of normal surveillance scans and alpha‐fetoprotein levels. The mass was detected on transthoracic echocardiogram and treated with surgical resection. Histopathological features of the tumor demonstrated features associated with WNT/β‐catenin mutated HCC, such as microtrabecular, acinar, and bile staining with positive glutamine synthetase expression. [ABSTRACT FROM AUTHOR]

Premium-tasty japonica rice, distinguished by its unique flavor and enriched nutritional value, has attracted significant attention across Asia. Nitrogen metabolism plays a crucial role in determining the growth, development, and quality of rice grains. This study investigates the effects of nitrogen application rates on the enzymatic activities related to nitrogen metabolism, nitrogen metabolites, and grain protein content in the premium-tasty japonica rice variety, Suxiangjing 100. Using a range of nitrogen application rates (0, 80, 160, 240, 320, and 400 kg per hectare), comprehensive analyses were conducted across various developmental stages. Results indicate that as nitrogen application increased, there were distinct patterns in the enzyme activities and metabolite concentrations related to nitrogen metabolism in the leaves of premium-tasty japonica rice. The activities of nitrate reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT) peaked at moderate nitrogen applications, while excessive nitrogen led to a decrease in their activities. The activity of Glutamate Dehydrogenase (GDH) generally increased, but showed a decline after the filling stage. With increasing nitrogen application, the concentrations of nitrate nitrogen (NO3–N), ammonium nitrogen (NH4–N), free amino acids (FAA), and soluble proteins (SP) initially rose but declined at excessive application rates. The grain protein content increased, with levels of prolamin, glutelin, and globulin peaking at nitrogen applications of 240 kg/ha and 320 kg/ha, while changes in albumin levels were minimal. This study not only provides novel insights into the role of nitrogen in shaping the growth and quality of premium-tasty japonica rice, but also suggests refined nitrogen management strategies for sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Background: Individuals with Alzheimer's disease (AD) have a heightened risk of epilepsy. However, the underlying mechanisms are not well-understood. Objective: We aimed to elucidate the role of the glutamate-glutamine cycle in this mechanism and test the effect of ceftriaxone, a glutamate transporter-1 (GLT-1) enhancer, on seizure susceptibility in the Tg2576 mouse model of AD. Methods: First, we assessed expression levels of key proteins in the glutamate-glutamine cycle in Tg2576 (n = 7) and wild-type littermates (n = 7), and subsequently in the kindling model of epilepsy (n = 6) and sham (n = 6). Then, kindling susceptibility was assessed in three groups: 200 mg/kg ceftriaxone-treated Tg2576 (Tg-Ceft, n = 9); saline-treated Tg2576 (Tg-Sal, n = 9); and saline-treated wild-type (WT-Sal, n = 15). Mice were treated for seven days before kindling, and seizure susceptibility compared between groups. Results: Protein levels of GLT-1 (p = 0.0093) and glutamine synthetase (p = 0.0016) were reduced in cortex of Tg2576 mice, compared to WT. Kindling increased GLT-1 (cortex: p < 0.0001, hippocampus: p = 0.0075), and glutaminase (cortex: p = 0.0044) protein levels, compared to sham. Both Tg-Ceft and WT-Sal displayed Class IV seizures in response to the first stimulation (p > 0.99), while Tg-Sal displayed Class V seizure (p = 0.0212 versus WT-Sal). Seizure susceptibility of Tg-Ceft was not different from Tg-Sal (p > 0.05), and kindling rates did not differ between groups. Conclusions: Disruptions to key components of the glutamate-glutamine cycle are observed in models of AD and epilepsy. However, increasing GLT-1 through ceftriaxone treatment did not influence seizure susceptibility in Tg2576 mice, suggesting this is not an effective strategy to lower seizure susceptibility in AD, or a higher dosage is needed. [ABSTRACT FROM AUTHOR]

Background and Aim: Salidroside (SA) is the main active component of Rhodiola rosea L., with potential in treating cardiovascular and cerebrovascular diseases and cerebral ischemia. However, its efficacy and mechanism in cerebral ischemia remain unclear, particularly regarding its effect on glutamate (Glu) metabolism. In this paper, we aimed to investigate the efficacy of SA in treating cerebral ischemia and its pharmacological mechanism. Experimental procedure: We studied the effects of SA on SD rats with cerebral ischemia, evaluating neurobehavior, cerebral water content, infarct size, and brain microstructure. We also assessed its impact on glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), and glutamate transporter 1 (GLT-1) proteins using immunohistochemistry and Western blot. Additionally, we used SVGp12 cells to simulate cerebral ischemia and measured Glu levels and used Western blot to observe the level of GS and GLT-1. Results: SA improved neural function, reduced infarct size, and regulated GSH and Glu levels in rats. In cell experiments, SA increased cell viability and decreased Glu concentration after ischemia induction. It also regulated the expression of GFAP, GS, and GLT-1. Conclusion: SA alleviates cerebral ischemia-induced injury by acting on astrocytes, possibly through regulating the glutamate metabolic pathway. [ABSTRACT FROM AUTHOR]

ABSTRACT Distinct target genes are modulated by microRNA members and affect various biological processes associated with abiotic stress responses in plants. In this study, we characterized a functional module comprising miRNA/target and a downstream MYB transcription factor partner, Tae‐MIR1118/TaCaM2/TaMYB44, in Triticum aestivum to mediate the plant low‐nitrogen (N) stress response. Dual luciferase (LUC) assay and expression analysis indicated that TaCaM2 is regulated by Tae‐MIR1118 through a posttranscriptional cleavage mechanism. Reporter LUC activity in N. benthamiana leaves co‐transformed with effector CaMV35S::Tae‐MIR1118 and reporter TaCaM2::LUC was significantly reduced, and the transcripts of Tae‐MIR1118 and TaCaM2 in tissues exhibited converse expression patterns under varying N levels. Specifically, the transcripts of Tae‐MIR1118 decreased, whereas those of TaCaM2 increased under low‐N stress in a temporal‐dependent manner. Yeast two‐hybrid, bimolecular fluorescence complementation (BiFC) and co‐immunoprecipitation (Co‐IP) assays indicated that TaCaM2 interacted with the MYB transcription factor TaMYB44. Transgene analysis revealed the negative roles of Tae‐MIR1118 and the positive functions of TaCaM2 and TaMYB44 in regulating plants for low‐N stress adaptation by modulating glutamine synthetase activity, N uptake capacity, and root morphology. Yeast one‐hybrid, transcriptional activation, and chromatin immunoprecipitation‐quantitative polymerase chain reaction (ChIP‐PCR) assays indicated that TaMYB44 could bind to the promoters of genes TaGS2.2, TaNRT2.1, and TaPIN4 and induce transcription of these stress‐defensive genes. Knockdown of these three genes reduced GS activity, N accumulation, and root growth traits in plants subjected to N starvation. The yield in the wheat variety panel was highly correlated with the transcripts of Tae‐MIR1118, TaCaM2, and TaMYB44 in plants cultured under N‐deprived field conditions. A major haplotype of Tae‐MIR1118, TaMIR1118‐Hap1, enhanced the low‐N stress tolerance of plants. Our findings indicate that the Tae‐MIR1118/TaCaM2/TaMYB44 pathway primarily affects the low‐N response of plants by modulating associated physiological processes. [ABSTRACT FROM AUTHOR]

The molecular mechanisms linking obstructive sleep apnea syndrome (OSA) to obesity and the development of metabolic diseases are still poorly understood. The role of hypoxia (a characteristic feature of OSA) in excessive fat accumulation has been proposed. The present study investigated the possible effects of hypoxia (4% oxygen) on de novo lipogenesis by tracking the major carbon sources in differentiating 3T3-L1 adipocytes. Gas-permeable cultuware was employed to cultivate 3T3-L1 adipocytes in hypoxia (4%) for 7 or 14 days of differentiation. We investigated the contribution of glutamine, glucose or acetate using 13C or 14C labelled carbons to the newly synthesized lipid pool, changes in intracellular lipid content after inhibiting citrate- or acetate-dependent pathways and gene expression of involved key enzymes. The results demonstrate that, in differentiating adipocytes, hypoxia decreased the synthesis of lipids from glucose (44.1 ± 8.8 to 27.5 ± 3.0 pmol/mg of protein, p < 0.01) and partially decreased the contribution of glutamine metabolized through the reverse tricarboxylic acid cycle (4.6% ± 0.2–4.2% ± 0.1%, p < 0.01). Conversely, the contribution of acetate, a citrate- and mitochondria-independent source of carbons, increased upon hypoxia (356.5 ± 71.4 to 649.8 ± 117.5 pmol/mg of protein, p < 0.01). Further, inhibiting the citrate- or acetate-dependent pathways decreased the intracellular lipid content by 58% and 73%, respectively (p < 0.01) showing the importance of de novo lipogenesis in hypoxia-exposed adipocytes. Altogether, hypoxia modified the utilization of carbon sources, leading to alterations in de novo lipogenesis in differentiating adipocytes and increased intracellular lipid content. [ABSTRACT FROM AUTHOR]

Background: A common genetic variant at the glutamate-ammonia ligase (GLUL) locus has been previously associated with an increased risk of coronary artery disease (CAD) as well as alterations of glutamic acid metabolism and the γ-glutamyl cycle in individuals with type 2 diabetes (T2D). Here we investigated whether less frequent variants in GLUL and 15 additional genes in these pathways are associated with differences in CAD risk in T2D. Methods: Coding sequences and regulatory elements of these genes were sequenced in 2,394 individuals with T2D from three CAD case/control sets. Results: Ninety-six variants with minor allele frequency [MAF]< 0.05 were identified as being nominally associated with CAD status. One of these variants (rs62447457, MAF 0.025), placed in a non-coding region flanking the γ-glutamylcyclotransferase (GGCT) gene, showed nominal evidence of replication in two other cases-control sets (n = 1,132), with summary OR of 0.54 (p = 2.5 × 10–4). Another variant (rs145322388, MAF = 0.039), flanking the dipeptidase 2 (DPEP2) gene, showed association with CAD status across discovery and replications sets (summary OR 0.61, p = 2.5 × 10–4). A third variant (rs1238275622, MAF 0.004), flanking the GLUL gene, was associated with increased risk of CAD (summary OR 1.84, p-value 2.1 × 10–3). Based on their Regulome scores (2b, 2a, and 3a, respectively), all three variants are very likely to have regulatory functions. Conclusions: In summary, we have identified low-frequency variants associated with CAD in T2D at two loci involved in glutamic acid metabolism and the γ-glutamyl cycle. These findings provide further evidence for a role of these pathways in the link between T2D and CAD. [ABSTRACT FROM AUTHOR]

Choroidal neovascularization (CNV) is a leading cause of visual impairment in wet age-related macular degeneration (wAMD). Recent investigations have validated the potential of reducing glutamine synthetase (GS) to inhibit neovascularization formation, offering prospects for treating various neovascularization-related diseases. In this study, we devised a CRISPR/Cas9 delivery system employing the nucleic acid aptamer AS1411 as a targeting moiety and exosome-liposome hybrid nanoparticles as carriers (CAELN). Exploiting the binding affinity between AS1411 and nucleolin on endothelial cell surfaces, the delivery system was engineered to specifically target the glutamine synthetase gene (GLUL), thereby attenuating GS levels and continuously suppressing CNV. CAELN exhibited spherical and uniform dispersion. In vitro cellular investigations demonstrated gene editing efficiencies of CAELN ranging from 42.05 to 55.02% and its capacity to inhibit neovascularization in HUVEC cells. Moreover, in vivo pharmacodynamic studies conducted in CNV rabbits revealed efficacy of CAELN in restoring the thickness of intra- and extranuclear tissues. The findings suggest that GS is a novel target for the inhibition of pathological CNV, while the development of AS1411-modified exosome-liposome hybrid nanoparticles represents a novel delivery method for the treatment of neovascular-related diseases. [ABSTRACT FROM AUTHOR]

Aims Methods and results Conclusions The frequency of CTNNB1 mutation, one of the most frequent genetic events in hepatocellular carcinoma (HCC), is lower in Asian countries and in hepatitis B virus (HBV)‐related HCCs. In this study, we evaluated the prevalence and types of CTNNB1‐mutation in HBV‐related HCC and correlated the molecular status with the histomorphological and immunohistochemical features.A total of 108 consecutive cases of treatment‐naïve, surgically resected HBV‐related HCCs were selected. Targeted sequencing for CTNNB1 exons 3, 7 and 8 was performed, and the results were correlated with the expression pattern of glutamine synthetase (GS), nuclear β‐catenin expression status and the histomorphological characteristics of the tumour. CTNNB1 mutations were identified in 13% of HBV‐related HCCs; of these cases, mutations were found in D32‐S37 (7%), T41 (4%) and S45 (2%) of exon 3. None of the HCCs demonstrated alterations in exons 7 and 8. CTNNB1 mutation was strongly associated with diffuse strong GS expression (P < 0.001), nuclear β‐catenin expression (P < 0.001) and the classic CTNNB1 morphology (P = 0.038). Diffuse strong GS expression was observed in 78.6% of the CTNNB1‐mutated HCCs, and nuclear β‐catenin expression was identified in 64.3% of these cases. The classic CTNNB1 morphology was observed in 57% of all CTNNB1‐mutated HCCs. Furthermore, programmed death‐ligand 1 (PD‐L1) was less frequently expressed in HCCs with classic CTNNB1 morphology.CTNNB1 mutation was observed in 13% of HBV‐related HCCs in this Korean cohort, and was associated with diffuse strong GS expression, nuclear β‐catenin expression and classic CTNNB1 morphology. [ABSTRACT FROM AUTHOR]

Improving vegetable yield and optimizing its quality through nutrient management have long been central to plant nutrition and horticultural science. Copper (Cu) is recognized as an essential trace element that promotes plant growth and development. However, the mechanisms by which Cu influences nitrogen (N) metabolism remain largely unknown, with limited studies exploring the interaction between Cu and varying nitrate-to-ammonium (nitrate/ammonium) ratios. In this study, Chinese cabbage was exposed to two Cu concentrations (0 and 0.02 mg L-1) in combination with three nitrate/ammonium ratios (10/90, 50/50, and 90/10) under hydroponic conditions. The results showed that Cu application increased plant biomass, nitrate reductase (NR) and glutamine synthetase (GS) enzyme activities, the expression of NR (NIA) and GS2 (Gln2) genes, and N content in both shoots and roots. Additionally, Cu treatment decreased nitrate and free amino acid contents, as well as the expression of nitrate transporters NRT1.1 and NRT2.1 in roots while increasing these four parameters in shoots. Additionally, these effects were significantly modulated by the nitrate/ammonium ratios. In conclusion, Cu may facilitate nitrate transportation, enhance nitrate reduction, promote ammonium assimilation, and influence the transformation of organic N compounds, highlighting its potential role in improving N metabolism in Chinese cabbage. [ABSTRACT FROM AUTHOR]

Background: The synthesis and catalysis of enzymes are inherently linked to the presence of water and drought-induced water deficit in plants can adversely impact enzyme activity. Drought severely impairs the growth and development of crops, with the extent of its impact varying according to the severity of the water scarcity. Drought also regulates the activity of carbon and nitrogen metabolizing enzymes in plants. Methods: To investigate the effects of varying degrees of drought on soybeans, this study selected HN44 (drought-resistant variety) and HN65 (drought-sensitive variety) as subjects through sand culture and assessed the changes in key enzymes involved in carbon and nitrogen metabolism within the soybean leaves in 2022. Result: The results indicated that short-term drought stress increased the activities of sucrose synthase (SUS), Sucrose Phosphate Synthase (SPS) and Glutamine Synthetase (GS), while decreasing the activity of nitrate reductase (NR). In contrast, prolonged drought reduced the activities of SUS and GS. This study provides a theoretical foundation for enhancing the drought stress resistance of soybeans. [ABSTRACT FROM AUTHOR]

The development of sensory hair cells (HCs) is closely linked to hearing loss. There are still many unidentified genes that may play a crucial role in HC development and function. Glutamine synthetase, Glul, is expressed in sensory hair cells and auditory organs. However, the role of the Glul gene family in the auditory system remains largely unexplored. This study aims to investigate the function of the Glul gene family in the auditory system. The expression patterns of the glul gene family were examined via in situ hybridization in zebrafish embryos. It was revealed that the expression of glula occurred in the otic vesicle, while glulb was expressed in the neuromast. In contrast, glulc did not exhibit any discernible signal. glula loss of function caused abnormal otolith formation and reduced hair cell number in otic vesicles, while glulb knockdown caused a decrease in HC number in both neuromasts and otic vesicles and impaired auditory function. Furthermore, we found that the knockdown of glulb induces apoptosis of hair cells. Transcriptomic analysis of zebrafish with glula and glulb knockdown revealed significant alterations in the expression of many genes associated with auditory organs. The current study sheds light on the requirement of glula and glulb in zebrafish hair cell formation and auditory function. [ABSTRACT FROM AUTHOR]