Expression Of Dehydrogenase Research Articles

Glutathione and Xanthine Metabolic Changes in Tamoxifen Resistant Breast Cancer Cell Lines are Mediated by Down-Regulation of GSS and XDH and Correlated to Poor Prognosis.

Background: Tamoxifen is commonly used in the treatment of hormonal-positive breast cancer. However, 30%-40% of tumors treated with tamoxifen develop resistance; therefore, an important step to overcome this resistance is to understand the underlying molecular and metabolic mechanisms. In the present work, we used metabolic profiling to determine potential biomarkers of tamoxifen resistance, and gene expression levels of enzymes important to these metabolites and then correlated the expression to the survival of patients receiving tamoxifen. Methods: Tamoxifen-resistant cell lines previously developed and characterized in our laboratory were metabolically profiled with nuclear magnetic resonance spectroscopy (NMR) using cryogenic probe, and the findings were correlated with the expression of genes that encode the key enzymes of the significant metabolites. Moreover, the effect of significantly altered genes on the overall survival of patients was assessed using the Kaplan-Meier plotter web tool. Results: We observed a significant increase in the levels of glutamine, taurine, glutathione, and xanthine, and a significant decrease in the branched-chain amino acids, valine, and isoleucine, as well as glutamate and cysteine in the tamoxifen-resistant cells compared to tamoxifen sensitive cells. Moreover, xanthine dehydrogenase and glutathione synthase gene expression were downregulated, whereas glucose-6-phosphate dehydrogenase was upregulated compared to control. Additionally, increased expression of xanthine dehydrogenase was associated with a better outcome for breast cancer patients. Conclusion: Overall, this study sheds light on metabolic pathways that are dysregulated in tamoxifen-resistant cell lines and the potential role of each of these pathways in the development of resistance.

Expression of Lactate Dehydrogenase in the Black Sea Shrimp Palaemon elegans

The activity of lactate dehydrogenase enzyme was studied in the Black Sea shrimp <i>Palaemon elegans</i>. To detect the activity of lactate dehydrogenase, the electrophoretic method and the histochemical reaction of the formation of its products were used. The highest expression was found when shrimp homogenate was prepared in a phosphate buffer with pH of 7.4. Totally two forms of the enzyme have been identified. The results of determining the activity of the studied enzyme are presented.

Benfotiamine Supplementation Increases Thiamine in Muscle of Endurance-Trained Mice and Affects the Energy Metabolism.

Benfotiamine, a synthetic analog of thiamine, offers greater bioavailability compared to other thiamine salts and increases thiamine stores upon oral intake. Thiamine is essential for energy metabolism. This study aimed to evaluate the effects of oral benfotiamine supplementation on energy metabolism, particularly the Krebs cycle function, in the muscle of endurance-trained mice, and to assess its impact on endurance performance. Twenty-five mice were randomly assigned to four groups: a standard diet with sedentary behavior (Sta-Sed), a benfotiamine-supplemented diet with sedentary behavior (Ben-Sed), a standard diet with swimming training (Sta-Tr), and a benfotiamine-supplemented diet with swimming training (Ben-Tr). The trained groups underwent five weekly swimming sessions for six weeks, followed by an exhaustive test. Thiamine and its esters were measured in erythrocytes and gastrocnemius muscle. Gene expression of pyruvate dehydrogenase (PDHa) and alpha-ketoglutarate dehydrogenase (OGDH), along with levels of pyruvic, lactic, and hydroxybutyric acids in muscle, was analyzed. The benfotiamine-supplemented groups had higher thiamine levels in erythrocytes and muscles compared to the standard-diet groups. No differences were observed in PDHa and OGDH gene expression. The Ben-Tr group exhibited increased muscle lactic acid levels and a higher lactic acid to pyruvic acid ratio compared to the sedentary groups. Hydroxybutyric acid levels were also elevated in the Ben-Tr group. No significant differences in exhaustive test duration were found between the groups. Benfotiamine supplementation increases thiamine levels in erythrocytes and muscle but does not affect the gene expression of thiamine-dependent enzymes. Although it alters energy metabolism in trained muscle, it does not enhance endurance performance in mice.

Salvianolic Acid B Alleviates Liver Injury by Regulating Lactate-Mediated Histone Lactylation in Macrophages.

Salvianolic acid B (Sal B) is the primary water-soluble bioactive constituent derived from the roots of Salvia miltiorrhiza Bunge. This research was designed to reveal the potential mechanism of Sal B anti-liver injury from the perspective of macrophages. In our lipopolysaccharide-induced M1 macrophage model, Sal B showed a clear dose-dependent gradient of inhibition of the macrophage trend of the M1 type. Moreover, Sal B downregulated the expression of lactate dehydrogenase A (LDHA), while the overexpression of LDHA impaired Sal B's effect of inhibiting the trend of macrophage M1 polarization. Additionally, this study revealed that Sal B exhibited inhibitory effects on the lactylation process of histone H3 lysine 18 (H3K18la). In a ChIP-qPCR analysis, Sal B was observed to drive a reduction in H3K18la levels in the promoter region of the LDHA, NLRP3, and IL-1β genes. Furthermore, our in vivo experiments showed that Sal B has a good effect on alleviating CCl4-induced liver injury. An examination of liver tissues and the Kupffer cells isolated from those tissues proved that Sal B affects the M1 polarization of macrophages and the level of histone lactylation. Together, our data reveal that Sal B has a potential mechanism of inhibiting the histone lactylation of macrophages by downregulating the level of LDHA in the treatment of liver injury.

Expression and purification of active shikimate dehydrogenase from Plasmodium falciparum.

Plasmodium falciparum is known to cause severe malaria, current treatment consists in artemisinin-based combination therapy, but resistance can lead to treatment failure. Knowledge concerning P. falciparum essential proteins can be used for searching new antimalarials, among these a potential candidate is shikimate dehydrogenase (SDH), an enzyme part of the shikimate pathway which is responsible for producing endogenous aromatic amino acids. SDH from P. falciparum (PfSDH) is unexplored by the scientific community, therefore, this study aims to establish the first protocol for active PfSDH expression. Putative PfSDH nucleotide sequence was used to construct an optimized expression vector pET28a+PfSDH inserted in E. coli BL21(DE3). As a result, optimal expression conditions were acquired by varying IPTG and temperature through time. Western Blot analysis was applied to verify appropriate PfSDH expression, solubilization and purification started with lysis followed by two-steps IMAC purification. Enzyme activity was measured spectrophotometrically by NADPH oxidation, optimal PfSDH expression occur at 0.1 mM IPTG for 48 hours growing at 37 °C and shaking at 200 rpm, recombinant PfSDH obtained after purification was soluble, pure and its physiological catalysis was confirmed. Thus, this study describes the first protocol for heterologous expression of PfSDH in soluble and active form.

Effects of Zinc Oxide Nanoparticles on Pyruvate Dehydrogenase and Lactate Dehydrogenase Expressions and Apoptotic Index in Breast Cancer Cells

Effects of Zinc Oxide Nanoparticles on Pyruvate Dehydrogenase and Lactate Dehydrogenase Expressions and Apoptotic Index in Breast Cancer Cells

Effect of the overexpression of external alternative NADH dehydrogenase gene in Arabidopsis on the resistance of transformed tobacco plants to negative temperatures

The study aims to confirm the functional activity and localization of the At_NDB2 transgenic protein of Arabidopsis in tobacco cells and to evaluate the effect produced by the permanent expression of external alternative NADH dehydrogenase on the resistance of a heat-loving plant to low temperatures. Proteins and mitochondria were isolated from the leaves of tobacco plants grown at 25 °С (day/night) at the 7-leaf stage. At_NDB2 protein localization in mitochondria was determined via electrophoresis and immunoblotting. The functional activity of At_NDB2 was confirmed through the polarography of isolated mitochondria and the specific mitochondrial complex I inhibitor (rotenone). It was also found that the cyanide-resistant respiration rate and the activity of an alternative oxidase enzyme were significantly higher in transgenic plants than in wild-type plants. In order to determine the resistance to low temperatures, the parent and transgenic tobacco plants were grown in soil until the 2–3 and 6–7 leaf stages, after which they were kept at 3 to -3 °С for a day in the dark and left to regrow at 25 °С for seven days. Although it was previously shown that oxidative stress is reduced in transgenic plants at low temperatures as compared to wild-type plants, it was established that the tolerance of transgenic and nontransformed plants does not differ. Thus, alternative NADH dehydrogenase activity was found to reduce oxidative stress and increase alternative oxidase activity, without enhancing the resistance of Nicotiana tabacum to negative temperatures.

Enhanced Expression of Alcohol Dehydrogenase I in Pichia pastoris Reduces the Content of Acetaldehyde in Wines.

Acetaldehyde is an important carbonyl compound commonly detected in wines. A high concentration of acetaldehyde can affect the flavor of wines and result in adverse effects on human health. Alcohol dehydrogenase I (ADH1) in Saccharomyces cerevisiae catalyzes the reduction reaction of acetaldehyde into ethanol in the presence of cofactors, showing the potential to reduce the content of acetaldehyde in wines. In this study, ADH1 was successfully expressed in Pichia pastoris GS115 based on codon optimization. Then, the expression level of ADH1 was enhanced by replacing its promoter with optimized promoters and increasing the copy number of the expression cassette, with ADH1 being purified using nickel column affinity chromatography. The enzymatic activity of purified ADH1 reached 605.44 ± 44.30 U/mg. The results of the effect of ADH1 on the content of acetaldehyde in wine revealed that the acetaldehyde content of wine samples was reduced from 168.05 ± 0.55 to 113.17 ± 6.08 mg/L with the addition of 5 mM NADH and the catalysis of ADH1, and from 135.53 ± 4.08 to 52.89 ± 2.20 mg/L through cofactor regeneration. Our study provides a novel approach to reducing the content of acetaldehyde in wines through enzymatic catalysis.

Foeniculum vulgare essential oil nanoemulsion inhibits Fusarium oxysporum causing Panax notoginseng root-rot disease

BackgroundFusarium oxysporum (F. oxysporum) is the primary pathogenic fungus that causes Panax notoginseng (P. notoginseng) root rot disease. To control the disease, safe and efficient antifungal pesticides must currently be developed. MethodsIn this study, we prepared and characterized a nanoemulsion of Foeniculum vulgare essential oil (Ne-FvEO) using ultrasonic technology and evaluated its stability. Traditional Foeniculum vulgare essential oil (T-FvEO) was prepared simultaneously with 1/1000 Tween-80 and 20/1000 dimethyl sulfoxide (DMSO). The effects and inhibitory mechanism of Ne-FvEO and T-FvEO in F. oxysporum were investigated through combined transcriptome and metabolome analyses. ResultsResults showed that the minimum inhibitory concentration (MIC) of Ne-FvEO decreased from 3.65 mg/mL to 0.35 mg/mL, and its bioavailability increased by 10-fold. The results of gas chromatography/mass spectrometry (GC/MS) showed that T-FvEO did not contain a high content of estragole compared to Foeniculum vulgare essential oil (FvEO) and Ne-FvEO. Combined metabolome and transcriptome analysis showed that both emulsions inhibited the growth and development of F. oxysporum through the synthesis of the cell wall and cell membrane, energy metabolism, and genetic information of F. oxysporum mycelium. Ne-FvEO also inhibited the expression of 2-oxoglutarate dehydrogenase and isocitrate dehydrogenase and reduced the content of 2-oxoglutarate, which inhibited the germination of spores. ConclusionOur findings suggest that Ne-FvEO effectively inhibited the growth of F. oxysporum in P. notoginseng in vivo. The findings contribute to our comprehension of the antifungal mechanism of essential oils (EOs) and lay the groundwork for the creation of plant-derived antifungal medicines.

Wild-type IDH1 maintains NSCLC stemness and chemoresistance through activation of the serine biosynthetic pathway

Tumor-initiating cells (TICs) reprogram their metabolic features to meet their bioenergetic, biosynthetic, and redox demands. Our previous study established a role for wild-type isocitrate dehydrogenase 1 (IDH1 WT ) as a potential diagnostic and prognostic biomarker for non–small cell lung cancer (NSCLC), but how IDH1 WT modulates NSCLC progression remains elusive. Here, we report that IDH1 WT activates serine biosynthesis by enhancing the expression of phosphoglycerate dehydrogenase (PHGDH) and phosphoserine aminotransferase 1 (PSAT1), the first and second enzymes of de novo serine synthetic pathway. Augmented serine synthesis leads to GSH/ROS imbalance and supports pyrimidine biosynthesis, maintaining tumor initiation capacity and enhancing gemcitabine chemoresistance. Mechanistically, we identify that IDH1 WT interacts with and stabilizes PHGDH and fragile X–related protein-1 (FXR1) by impeding their association with the E3 ubiquitin ligase parkin by coimmunoprecipitation assay and proximity ligation assay. Subsequently, stabilized FXR1 supports PSAT1 mRNA stability and translation, as determined by actinomycin D chase experiment and in vitro translation assay. Disrupting IDH1 WT -PHGDH and IDH1 WT -FXR1 interactions synergistically reduces NSCLC stemness and sensitizes NSCLC cells to gemcitabine and serine/glycine–depleted diet therapy in lung cancer xenograft models. Collectively, our findings offer insights into the role of IDH1 WT in serine metabolism, highlighting IDH1 WT as a potential therapeutic target for eradicating TICs and overcoming gemcitabine chemoresistance in NSCLC.

Calcium chloride treatment maintains quality and enhances antioxidant capacity of fresh-cut carrots through modulating DcCMLs-DcCAMTA3-mediated phenylpropanoid pathway

Whitening and microbial infection are two major reasons to induce quality deterioration in fresh-cut carrots. Calcium chloride (CaCl2) could enhance the quality attributes in fresh-cut carrots, but the molecular mechanism is still not illuminated. In this study, CaCl2 treatment suppressed the increases of whiteness index and total bacterial count as well as enhanced the antioxidant capacity of fresh-cut carrots. In addition, CaCl2 treatment promoted phenolics accumulation by upregulating the transcripts and enzyme activity of phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H) and 4-coumarate coenzyme A ligase (4CL) in phenylpropanoid pathway. However, this treatment inhibited the increase of enzyme activity and gene expression of cinnamyl alcohol dehydrogenase (CAD), thus suppressing lignin synthesis and whitening process in fresh-cut carrots. Moreover, a calmodulin-binding transcription activator (CAMTA) transcription factor DcCAMTA3, was induced in response to CaCl2 treatment. DcCAMTA3 activated the transcription of DcPAL1, DcC4H and Dc4CL1 genes and repressed the expression of DcCAD1 gene by directly targeting the CG-box. DcCML3/11, a calmodulin-like protein, interacted with DcCAMTA3, and this interaction enhanced DcCAMTA3-mediated transcriptional activation of DcPAL1, DcC4H and Dc4CL1 and repression of DcCAD1. Therefore, CaCl2 treatment is effective in maintaining quality and enhancing antioxidant capacity of fresh-cut carrots by the cooperative action of DcCMLs and DcCAMTA3 in positively regulating phenylpropanoid pathway.

Sex-Chromosome-Related Dimorphism in Steroidogenic Enzymes and Androgen Receptor in Response to Testosterone Treatment: An In Vitro Study on Human Primary Skeletal Muscle Cells.

Gender-related methodology in biomedical sciences receives considerable attention, with numerous studies highlighting biological differences between cisgender males and females. These differences influence the clinical symptoms of various diseases and impact therapeutic approaches. In this in vitro study, we investigate the potential role of sex-chromosome-related dimorphism on steroidogenic enzymes, androgen receptor (AR) expression, and cellular translocation in primary human skeletal muscle cells before and after exposure to testosterone. We analyzed 46XY and 46XX cells for 17β-hydroxysteroid dehydrogenase (17β-HSD), 5α-reductase (5α-R2), aromatase (Cyp-19), and AR gene expression. We also compared AR expression and intracellular translocation after increasing exposure to testosterone. At baseline, we observed higher mRNA expression for 5α-R2 and AR in 46XY cells and higher Cyp-19 mRNA expression in 46XX cells. Following testosterone exposure, we observed an increase in AR expression and translocation in 46XX cells, even at the lowest dose of 0.5 nM, while significant changes in 46XY cells were observed only from 10 nM. Our in vitro results demonstrate that the diverse sex chromosome assets reflect important differences in muscle steroidogenesis. They support the concept that chromosomal disparities between males and females, even in vitro, lead to pivotal variations in cellular physiology and response. This understanding represents a crucial starting point in gender medicine, ensuring a precise approach in clinical practice, sports, and exercise settings and facilitating the translation of in vitro data to in vivo applicability.

Therapeutic Nanovaccines Reshape the Metabolic and Immune Microenvironment for Enhancing Immunotherapy of Primary and Lymphatic Metastatic Tumors

AbstractThe effectiveness of anti‐metastasis therapy is hampered by the highly immunosuppressive microenvironment found in both tumor tissues and lymph nodes. In this work, a therapeutic nanovaccine, CaGlu NPs, is introduced composed of calcium carbonate nanoparticles (CaCO3 NPs) and β‐glucan. Through the synergistic effect of CaCO3 NPs and β‐glucan, CaGlu NPs can induce immunogenic cell death in tumor tissues, repolarize tumor macrophages, reverse the immunosuppressive tumor microenvironment, effectively activate antigen‐specific cytotoxic T lymphocytes, promote dendritic cells maturation, and eventually elicit an effective anti‐tumor immune response in both primary tumors and metastatic lymph nodes. Meanwhile, CaGlu NPs can remodel the metabolic microenvironment in tumors and lymph nodes by decreasing the expression of lactate dehydrogenase A and hypoxia‐inducible factor‐1α, further enhancing the anti‐tumor immune response. CaGlu NPs also inhibit tumor angiogenesis and lymphangiogenesis and induce long‐term immune memory effects. This therapeutic nanovaccine strategy, which simultaneously remodels the metabolic and immunosuppressive microenvironments in tumors and metastatic lymph nodes, showed strong anti‐metastatic effects in vivo. This study presents a promising approach to effectively treat lymph node metastatic tumors using nanomaterial‐assisted immunotherapies and underscores its broad potential for clinical applications.

Changes in carbohydrate metabolism and soil microorganisms under the stress of polyamide and polyethylene nanoplastics during rice (Oryza sativa L.) growth

Nanoplastics (NPs) presence in agricultural soils can affect plant growth and impact the quality of agricultural products. To investigate the effect of polyamide (PA) NPs and polyethylene (PE) NPs on carbohydrate metabolism and soil microorganisms during rice growth, rice seedlings were exposed to soil containing 2 g/kg of 100 nm PA or 100 nm PE powder for 33 d. The results revealed that 100 nm PE reduced shoot length and dry weight of rice by 4.14 % and 15.68 %, respectively. Analyzing the expression of hexokinase-2 (HXK), phosphofructokinase-1 (PFK), pyruvate kinase (PK) and isocitrate dehydrogenase (IDH), which are four genes related to carbohydrate metabolism, 100 nm PA decreased the expression of PFK and increased the expression of PK and IDH. 100 nm PE increased the expression of HXK, PFK, PK, and IDH. The results of soil microorganisms showed that 100 nm PA significantly effects on 3 bacterial phyla (Bacteroidota, Deinococcota, and Desulfobacterota), whereas 100 nm PE significantly effects on phylum Rozellomycota, class Umbelopsidomycetes, and an unclassified Firmicutes. Our study provides direct evidence of the negative effects of PA and PE on rice, which may be important for assessing the risk of NPs on agroecosystems.

Mechanism of Cistanche deserticola Ma in the Treatment of Myocardial Ischemia-Reperfusion (I/R) Injury Based on Network Pharmacology and in vitro Experiments

Objectives To investigate the mechanism of Cistanche deserticola Ma (CDA) in the treatment of myocardial ischemia-reperfusion (I/R) injury by network pharmacology and cell experiments. Materials and Methods The main active components of CDA were collected from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). I/R-related targets were identified from DisGeNET, OMIMD, and TTD; the I/R protein–protein interaction (PPI) network was constructed using the STRING input. The targets of CDA that inhibit I/R injury in Matescape and Microshengxin were subjected to Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Cell viability, levels of lactate dehydrogenase (LDH), superoxide dismutase (SOD), and malondialdehyde (MDA), and protein expression of phosphatidylinositol 3-kinase (PI3K) and serine/threonine kinase 1 (Akt1) were determined. Results A total of 236 targets were identified, with PI3K, Akt, epithelial growth factor receptor (EGFR), and another kinase being the major targets, and according to GO and KEGG analysis, CDA was most likely to inhibit I/R through the PI3K-Akt pathway. The optimal concentration of 10% medicated serum of CDA was determined to be the most effective concentration. The levels of LDH and MDA were significantly decreased in the CDA and BEZ23 groups, but the levels of SOD were significantly increased, thereby alleviating cell damage. In addition, the expression of PI3K, Akt, and p-AKT proteins was significantly reduced in the CDA group. Conclusion CDA alleviates I/R injury through antioxidation and inhibition of the PI3K/Akt signaling pathway.

Ajmalicine induces the pyroptosis of hepatoma cells to exert the antitumor effect.

Ajmalicine (AJM) is an alkaloid extracted from the root of Yunan Rauvolfia verticillata. At present, little research has reported the antitumor pharmacological action and mechanism of AJM. Therefore, this work aimed to conduct relevant research. The mouse hepatoma cell line H22 was intervened with a gradient concentration of AJM. Subsequently, the pyroptosis level was detected by flow cytometry. The expression of inflammatory factors and lactate dehydrogenase was measured by enzyme-linked immunosorbent assay. Reactive oxygen species (ROS) expression was detected by dichlorodihydrofluorescein diacetate probe. In addition, the tumor-bearing model mice were also treated with AJM to analyze tumor growth as well as the expression levels of tissue inflammatory factors and proteins. According to our results, AJM promoted the pyroptosis of H22 cells, increased the pyroptosis rate, and upregulated the expression of inflammatory factors tumor necrosis factor α, interleukin-1β, and interleukin-6. At the same time, it enhanced the openness of membrane pores and increased the expression of ROS. Moreover, AJM promoted the expression of Caspase-3 and N-terminal gasdermin E (GSDME). The AJM-induced pyroptosis was suppressed after N-acetylcysteine treatment to inhibit ROS, while Caspase-3 knockdown also inhibited the AJM-induced pyroptosis. In animals, AJM suppressed tumor growth. AJM can activate ROS to induce pyroptosis and exert the antitumor effect via the noncanonical Caspase-3-GSDME pyroptosis pathway.

Regulatory mechanism of the six-method massage antipyretic process on lipopolysaccharide-induced fever in juvenile rabbits: A targeted metabolomics approach

ObjectiveTo investigate the mechanism of the six-method massage antipyretic process (SMAP) and its influence on the body's metabolic state. MethodsThe random number table method was used to divide 24 New Zealand 2-month-old rabbits with qualified basal body temperature into a control group, model group and massage group (n = 8 per group). The model group and massage groups were injected with 0.5 μg/ml lipopolysaccharide (1 ml/kg) into the auricular vein, and the control group was injected with the same amount of normal saline at the same temperature. One hour after modelling, the massage group was given SMAP (opening Tianmen, pushing Kangong, rubbing Taiyang, rubbing Erhougaogu, clearing the Tianheshui and pushing the spine). The change of anal temperature 5 h after moulding was recorded to clarify the antipyretic effect. ResultsAfter modelling, the rectal temperature of the juvenile rabbits in the three groups increased. The rectal temperature of the model group was higher than that of the control group 5 h after modelling, and the rectal temperature of the massage group was lower than that of the model group (P < 0.05). The antipyretic mechanism is related to the regulation of the synthesis of phenylalanine, tyrosine and tryptophan, as well as the pentose phosphate pathway. Compared with the model group, the plasma interleukin (IL)-1, IL-6, interferon-gamma, toll-like receptor 4, nuclear factor κB, the mechanistic target of rapamycin complex 1, indoleamine 2,3-dioxygenase 1, aryl hydrocarbon receptor, liver aspartate transaminase (AST), alanine transaminase (ALT) and l-glutamate dehydrogenase (L-GLDH) expression in the massage group were significantly decreased (P < 0.05). Compared with the model group, the massage group had significantly reduced AST, ALT and L-GLDH expression in plasma (P < 0.05). ConclusionThe mechanism of SMAP therapy is related to regulating the expression of peripheral inflammatory factors and metabolic pathways.

Exploring transcriptional and post-transcriptional epigenetic regulation of crf and 11βhsd2 in rainbow trout brain during chronic social stress

Using dominance hierarchies in juvenile rainbow trout (Oncorhynchus mykiss) as a model of chronic social stress in fish, we explored whether epigenetic transcriptional and post-transcriptional mechanisms are involved in the gene expression of corticotropin-releasing factor (crf) and 11β-hydroxysteroid dehydrogenase (11βhsd2), key factors involved in the regulation of the endocrine stress axis response. In juvenile rainbow trout pairs, subordinate individuals display sustained elevation of circulating cortisol concentrations. Cortisol production is controlled by the hypothalamic-pituitary-interrenal (HPI) axis in fish and initiated by CRF release from the preoptic area (POA). Given that crf is modulated during chronic social stress, and that such stress has been implicated in the epigenetic regulation of crf in other taxa, we probed a role for epigenetic regulation of crf transcript abundance in chronically stressed rainbow trout. We also investigated the regulation of the cortisol-metabolising enzyme 11βhsd2 in the POA, which is upregulated in subordinates. The potential involvement of DNA methylation and microRNAs (miRNAs) in the regulation of crf transcript abundance was investigated during social stress in the POA of fish, as was the potential involvement of miRNAs in 11βhsd2 regulation. Although transcript abundances of crf were elevated in subordinate fish after 4 days, DNA methylation profiles within putative promoter sequences upstream of the crf gene were not significantly affected by chronic stress. An inverse relationship between crf and its predicted posttranscriptional regulator miR-103a-3p in the POA suggests that miRNAs may be involved in mediating the effects of chronic social stress on key components of the endocrine stress axis.

Nedosiran: First Approval.

Nedosiran (RIVFLOZA™), a once-monthly subcutaneous small interfering RNA (siRNA) therapy, is being developed by Dicerna Pharmaceuticals, a Novo Nordisk company, for the treatment of primary hyperoxaluria (PH). It reduces oxalate overproduction by inhibiting the expression of the hepatic lactate dehydrogenase (LDH) enzyme. Nedosiran received its first approval on 29 September 2023 in the USA to lower urinary oxalate levels in children aged ≥9 years and adults with PH type 1 (PH1) and relatively preserved kidney function [e.g. estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73m2]. This article summarizes the milestones in the development of nedosiran leading to this first approval for PH1.

Pre-optimization and one-step preparation of cascade enzymes system with broad substrates by model guidance: Application of chiral L-norvaline and L-phenylglycine biosynthesis

Cascade biocatalyst systems with catalytic promiscuity can be used for synthesis of a class of chiral chemicals but the optimization of these systems by model guidance is poorly explored. In this study, a cascade system with broad substrate spectrum was characterized and simulated by kinetic model with substrates of DL-Norvaline (DL-Nor) and DL-Phenylglycine (DL-Phg) as examples. To evaluate the optimal cascade system, maximum accumulation of intermediate products and conversion rate in the process were investigated by simultaneous solution of the rate equations for varying enzyme quantities. According to the simulation results, the cascade system was optimized by regulating the expression of D-amino acid oxidase and formate dehydrogenase and was prepared by one-step. The conversion efficiency of DL-Nor and DL-Phg have been significantly improved compared with that of before optimization. Moreover, the total of L-Nor and L-Phg were reached 498.2 mM and 79.5 mM through a gradient fed-batch conversion strategy, respectively.