Acid Aminotransferase Research Articles

Study on anti-BmNPV mechanism of branched-chain amino acid aminotransferases in silkworm

Bombyx mori nucleopolyhedrovirus (BmNPV) is the most important virus that threatens sericulture industry. At present, there is no effective treatment for BmNPV infection in silkworms, and lncRNA plays an important role in biological immune response and host-virus interaction, but there are relatively few studies in silkworms. In this study, the four midgut tissue samples of the resistance strain NB (NB) and susceptible strain 306 (306) and the NB and 306 continuously infected with BmNPV for 96 h are used for whole transcriptome sequencing to analyze the differences in the genetic background of NB and 306 and the differences after inoculation of BmNPV, and the significantly different mRNA, miRNA and lnRNA between NB and 306 after BmNPV inoculation were screened. By comparing NB and 306, 2651 significantly different mRNAs, 57 significantly different miRNAs and 198 significantly different lncRNAs were screened. By comparing NB and 306 after BmNPV inoculation, 2684 significantly different mRNAs, 39 significantly different miRNAs and 125 significantly different lncRNAs were screened. According to the significantly different mRNA, miRNA and lncRNA screened from NB and 306 and NB and 306 after virus inoculation, the mRNA-miRNA-lncRNA regulatory network was constructed before and after virus inoculation, and the BmBCAT-Bomo_chr7_8305-MSTRG.3236.2 regulatory axis was screened from them, and it was found that BmBCAT was not Bomo_chr7_8305 regulated in the genetic background, after viral infection, MSTRG.3236.2 competes for binding Bomo_chr7_8305 regulates BmBCAT. The whole transcriptome sequencing results were verified by qPCR and the time-series expression analysis was performed to prove the reliability of the regulatory network. The BmBCAT-Bomo_chr7_8305-MSTRG.3236.2 regulatory axis may play a potential role in the interaction between silkworms and BmNPV. These results provide new insights into the interaction mechanism between silkworms and BmNPV.

Management of seizures in patients with primary mitochondrial diseases: consensus statement from the InterERNs Mitochondrial Working Group.

Primary mitochondrial diseases (PMDs) are common inborn errors of energy metabolism, with an estimated prevalence of one in 4300. These disorders typically affect tissues with high energy requirements, including heart, muscle and brain. Epilepsy may be the presenting feature of PMD, can be difficult to treat and often represents a poor prognostic feature. The aim of this study was to develop guidelines and consensus recommendations on safe medication use and seizure management in mitochondrial epilepsy. A panel of 24 experts in mitochondrial medicine, pharmacology and epilepsy management of adults and/or children and two patient representatives from seven countries was established. Experts were members of five different European Reference Networks, known as the Mito InterERN Working Group. A Delphi technique was used to allow the panellists to consider draft recommendations on safe medication use and seizure management in mitochondrial epilepsy, using two rounds with predetermined levels of agreement. A high level of consensus was reached regarding the safety of 14 out of all 25 drugs reviewed, resulting in endorsement of National Institute for Health and Care Excellence guidelines for seizure management, with some modifications. Exceptions including valproic acid in POLG disease, vigabatrin in patients with γ-aminobutyric acid transaminase deficiency and topiramate in patients at risk for renal tubular acidosis were highlighted. These consensus recommendations describe our intent to improve seizure control and reduce the risk of drug-related adverse events in individuals living with PMD-related epilepsy.

The multidirectional assessment of moderate caloric restriction and metformin treatment in obese patients.

Obesity treatment is often burdensome for patients. We used the combination of moderate caloric restriction (CR) with hypoglycemic metformin to assess their multidirectional effect in obese patients. One group was treated only with moderate CR (n=21) the second was treated with moderate CR and 800 mg metformin twice daily (n=23). Serum was drawn before and after treatment. The following parameters were monitored: anthropometric, cardiovascular, inflammatory, metabolic, and markers characteristic for thyroid, liver, pancreas, and kidney functions. Both tested groups did not significantly differ in most tested parameters after the treatment. Two groups reduced anthropometric parameters (body mass, body mass index (BMI), waist circumference) and fat mass but also muscle and fat-free mass, improving systolic blood pressure, insulin and leptin concentration, insulin sensitivity, leptin to adiponectin ratio, and inflammatory markers. Unfortunately, there was little impact on improving dyslipidemia and the thyroid and liver parameters. Free triiodothyronine (fT3) and gamma glutamyl transferase (GGT) activity were decreased in both groups, but triglycerides were reduced only in patients treated with moderate CR. Metformin with CR treatment decreases uric acid and aspartate aminotransferase (AspAT) activity. Metformin treatment with moderate CR in obese patients mainly improved insulin sensitivity, resulting in a reduction of patients with glucose intolerance, improved anthropometric, cardiovascular, and inflammatory mediators, and only slightly enhanced liver and thyroid function. No changes in kidney and pancreas function were observed during the treatment. In conclusion, eight weeks of CR alone and CR with metformin in obese adults improved anthropometric and metabolic markers, reduced muscle mass, fT3, GGT, proinflammatory, and CV parameters, and displayed no changes in kidney and pancreas function. The group treated with metformin after the treatment was still more obese and had higher C-reactive protein (CRP) and homeostasis model assessment-an index of insulin resistance (HOMA-IR), but despite this, considerably reduced the number of patients with glucose intolerance.

Analysis of blood biochemistry and non-targeted metabolomics of endometritis in dairy cows

The incidence of bovine endometritis, which has a negative impact on the reproduction of dairy cows, has been recently increasing. In this study, the differential markers and metabolites of healthy cows and cows with endometritis were analyzed by measuring blood biochemical indicators and immune factors using biochemical and enzyme-linked immunosorbent assay kits combined with nontargeted metabolomics. The LC-QTOF platform was used to evaluate the serum metabolomics of healthy cows and cows with endometritis after 21–27 days of calving. The results showed that glucose, free fatty acid, calcium, sodium, albumin, and alanine aminotransferase levels were significantly lower in the serum of cows with endometritis than in healthy cows (P < 0.05). However, the serum potassium, interleukin-1, interleukin-6, and tumor necrosis factor levels were significantly higher in cows with endometritis (P < 0.05). In addition, the serum metabolome data analysis of the two groups showed that the expression of 468 metabolites was significantly different (P < 0.05), of which 291 were upregulated and 177 were downregulated. These metabolites were involved in 78 metabolic pathways, including amino acid, nucleotide, carbohydrate, lipid, and vitamin metabolism pathways; signal transduction pathways, and other biological pathways. Taken together, negative energy balance and immune activation, which are related to local abnormalities in amino acid, lipid, and carbohydrate metabolism, were the important causes of endometritis in dairy cows. Metabolites such as glucose, carnosine, dehydroascorbic acid, L-malic acid, tetrahydrofolic acid, and UDP-glucose may be used as key indicators in the hematological diagnosis and treatment of endometritis in dairy cows.

Possible beneficial effects of nano chitosan against doxycycline toxicity in Nile tilapia (Oreochromis niloticus)

In aquaculture, improper and illogical antibiotic use could yield negative outcomes. Therefore, this study investigates the ameliorative effects of chitosan (CS) and chitosan nanoparticles (CSNPs) against the toxicity of the antibiotic doxycycline in Nile tilapia fish. The fish were divided into four distinct categories: the first group served as the control, the second group was subjected to doxycycline (40 mg/L), the third group experienced doxycycline (40 mg/L) and CS (0.5% in fish diet), and the fourth group was exposed to doxycycline (40 mg/L) with CSNPs (0.5% in fish diet) for 15 days. Levels of creatinine, uric acid, and aspartate aminotransferase activities notably elevated (p < 0.05) in the doxycycline-treated group when compared with the control group. Meanwhile, fish in the doxycycline-exposed group demonstrated significantly lower (p < 0.05) levels of red blood cells, hemoglobin, packed cell volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and neutrophils. Conversely, mean corpuscular volume, platelets, white blood cells, and lymphocytes exhibited notably higher (p < 0.05) levels in the doxycycline group. Other hematological indicators, including monocytes and eosinophils, showed no notable variances (p > 0.05) among the studied groups. Fish treated with doxycycline exhibited notably higher (p < 0.05) interleukin-1β and interleukin-6 activity in comparison to the control group. Additionally, histopathological changes were detected in the gills, liver, and kidney tissues of doxycycline-exposed fish when contrasted with the control group. Co-exposure of CS and CSNPs significantly restored most hematological, biochemical, and immunological parameters, as well as histopathological indices, in the fish, aligning these values closer to those observed in the control group in comparison to the fish treated solely with doxycycline. In conclusion, both CS and CSNPs played an important role in moderating the negative effects of doxycycline on fish, through improving hematological indices, reductions in creatinine, uric acid, and aspartate aminotransferase activity, as well as anti-inflammatory action through reductions in interleukin-1β and interleukin-6 activity.

Multifunctional enzymes related to amino acid metabolism in bacteria.

In bacteria, d-amino acids are primarily synthesized from l-amino acids by amino acid racemases, but some bacteria use d-amino acid aminotransferases to synthesize d-amino acids. d-Amino acids are peptidoglycan components in the cell wall involved in several physiological processes, such as bacterial growth, biofilm dispersal, and peptidoglycan metabolism. Therefore, their metabolism and physiological roles have attracted increasing attention. Recently, we identified novel bacterial d-amino acid metabolic pathways, which involve amino acid racemases, with broad substrate specificity, as well as multifunctional enzymes with d-amino acid-metabolizing activity. Here, I review these multifunctional enzymes and their related d- and l-amino acid metabolic pathways in Escherichia coli and the hyperthermophile Thermotoga maritima.

Sucrose, cell wall, and polyamine metabolisms involve in preserving postharvest quality of ‘Zaosu’ pear fruit by L-glutamate treatment

‘Zaosu’ pear fruit is prone to yellowing of the surface and softening of the flesh after harvest. This work was performed to assess the influences of L-glutamate treatment on the quality of ‘Zaosu’ pears and elucidate the underlying mechanisms involved. Results demonstrated that L-glutamate immersion reduced ethylene release, respiratory intensity, weight loss, brightness (L*), redness (a*), yellowness (b*), and total coloration difference (ΔE); enhanced ascorbic acid, soluble solids, and soluble sugar contents; maintained chlorophyll content and flesh firmness of pears. L-glutamate also restrained the activities of neutral invertase and acid invertase, while enhancing sucrose phosphate synthetase and sucrose synthase activities to facilitate sucrose accumulation. The transcriptions of PbSGR1, PbSGR2, PbCHL, PbPPH, PbRCCR, and PbNYC were suppressed by L-glutamate, resulting in a deceleration of chlorophyll degradation. L-glutamate concurrently suppressed the transcription levels and enzymatic activities of polygalacturonases, pectin methylesterases, cellulase, and β-glucosidase. It restrained polygalacturonic acid trans-eliminase and pectin methyl-trans-eliminase activities as well as inhibited the transcription levels of PbPL and Pbβ-gal. Moreover, the gene transcriptions and enzymatic activities of arginine decarboxylase, ornithine decarboxylase, S-adenosine methionine decarboxylase, glutamate decarboxylase, γ-aminobutyric acid transaminase, glutamine synthetase along with the PbSPDS transcription was promoted by L-glutamate. L-glutamate also resulted in the down-regulation of PbPAO, PbDAO, PbSSADH, PbGDH, and PbGOGAT transcription levels, while enhancing γ-aminobutyric acid, glutamate, and pyruvate acid contents in pears. These findings suggest that L-glutamate immersion can effectively maintain the storage quality of ‘Zaosu’ pears via modulating key enzyme activities and gene transcriptions involved in sucrose, chlorophyll, cell wall, and polyamine metabolism.

Integrated single-cell and bulk characterization of branched chain amino acid metabolism-related key gene BCAT1 and association with prognosis and immunogenicity of clear cell renal cell carcinoma.

The relationship between clear cell renal cell carcinoma (ccRCC) and branched-chain amino acids (BCAA) metabolism has yet to be thoroughly explored. The BCAA metabolism-related clusters were constructed using non-negative matrix factorization (NMF). The features of BCAA metabolism in ccRCC were evaluated by building a prognostic model using least absolute shrinkage and selection operator (LASSO) regression algorithm. Real-time quantitative PCR (RT-qPCR) was employed to analyze differential expression of branched-chain amino acid transaminase 1 (BCAT1) between cancer and paracancer tissues and between different cell lines. Cell counting kit-8, wound healing and Transwell chamber assays were conducted to determine changes in proliferative and metastatic abilities of A498 and 786-O cells. Two BCAA metabolism-related clusters with distinct prognostic and immune infiltration characteristics were identified in ccRCC. The BCAA metabolic signature (BMS) was capable of distinguishing immune features, tumor mutation burden, responses to immunotherapy, and drug sensitivity among ccRCC patients. RT-qPCR revealed overexpression of BCAT1 in ccRCC tissues and cell lines. Additionally, single-gene RNA sequencing analysis demonstrated significant enrichment of BCAT1 in macrophages and tumor cells. BCAT1 played tumor-promoting role in ccRCC and was closely associated with immunosuppressive cells and checkpoints. BCAT1 promoted ccRCC cell proliferation and metastasis. The BMS played a crucial role in determining the prognosis, tumor mutation burden, responses to immunotherapy and drug sensitivity of ccRCC patients, as well as the immune cell infiltration features. BCAT1 was linked to immunosuppressive microenvironments and may offer new sights into ccRCC immunotherapeutic targets.

Identification of a novel thermostable transaminase and its application in L-phosphinothricin biosynthesis

Transaminase (TA) is a crucial biocatalyst for enantioselective production of the herbicide L-phosphinothricin (L-PPT). The use of enzymatic cascades has been shown to effectively overcome the unfavorable thermodynamic equilibrium of TA-catalyzed transamination reaction, also increasing demand for TA stability. In this work, a novel thermostable transaminase (PtTA) from Pseudomonas thermotolerans was mined and characterized. The PtTA showed a high specific activity (28.63 U/mg) towards 2‐oxo‐4‐[(hydroxy)(methyl)phosphinoyl]butyric acid (PPO), with excellent thermostability and substrate tolerance. Two cascade systems driven by PtTA were developed for L-PPT biosynthesis, including asymmetric synthesis of L-PPT from PPO and deracemization of D, L-PPT. For the asymmetric synthesis of L-PPT from PPO, a three-enzyme cascade was constructed as a recombinant Escherichia coli (E. coli G), by co-expressing PtTA, glutamate dehydrogenase (GluDH) and D-glucose dehydrogenase (GDH). Complete conversion of 400 mM PPO was achieved using only 40 mM amino donor L-glutamate. Furthermore, by coupling D-amino acid aminotransferase (Ym DAAT) from Bacillus sp. YM‐1 and PtTA, a two-transaminase cascade was developed for the one-pot deracemization of D, L-PPT. Under the highest reported substrate concentration (800 mM D, L-PPT), a 90.43% L-PPT yield was realized. The superior catalytic performance of the PtTA-driven cascade demonstrated that the thermodynamic limitation was overcome, highlighting its application prospect for L-PPT biosynthesis.Key points• A novel thermostable transaminase was mined for L-phosphinothricin biosynthesis.• The asymmetric synthesis of L-phosphinothricin was achieved via a three-enzyme cascade.• Development of a two-transaminase cascade for D, L-phosphinothricin deracemization.

Yam Gruel alone and in combination with metformin regulates hepatic lipid metabolism disorders in a diabetic rat model by activating the AMPK/ACC/CPT-1 pathway

BackgroundAs independent and correctable risk factors, disturbances in lipid metabolism are significantly associated with type 2 diabetes mellitus (T2DM). This research investigated the mechanism underlying the lipid-regulating effects of Yam Gruel in diabetic rats.MethodsFirst, rats in the control group were given a normal diet, and a diabetic rat model was established via the consumption of a diet that was rich in both fat and sugar for six weeks followed by the intraperitoneal injection of streptozotocin (STZ). After the model was established, the rats were divided into five distinct groups: the control group, model group, Yam Gruel (SYZ) group, metformin (MET) group, and combined group; each treatment was administered for six weeks. The fasting blood glucose (FBG), body and liver weights as well as liver index of the rats were determined. Total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), aspartic acid transaminase (AST), alanine aminotransferase (ALT), and nonesterified fatty acid (NEFA) levels were measured. Oil Red O staining was used to assess hepatic steatosis. In addition, the levels of Phospho-acetyl-CoA carboxylase (p-ACC), acetyl coenzyme A carboxylase (ACC), AMP-activated protein kinase (AMPK), Phospho-AMPK (p-AMPK), carnitine palmitoyl transferase I (CPT-1), and Malonyl-CoA decarboxylase (MLYCD) in liver tissues were measured by real-time PCR (q-PCR) and western blotting.ResultsAfter 6 weeks of treatment, Yam Gruel alone or in combination with metformin significantly reduced FBG level, liver weight and index. The concentrations of lipid indices (TG, TC, NEFA, and LDL-C), the levels of liver function indices (ALT and AST) and the degree of hepatic steatosis was improved in diabetic rats that were treated with Yam Gruel with or without metformin. Furthermore, Yam Gruel increased the protein levels of p-ACC/ACC, p-AMPK/AMPK, MLYCD, and CPT-1, which was consistent with the observed changes in gene expression. Additionally, the combination of these two agents was significantly more effective in upregulating the expression of AMPK pathway-related genes and proteins.ConclusionsThese results demonstrated that Yam Gruel may be a potential diet therapy for improving lipid metabolism in T2DM patients and that it may exert its effects via AMPK/ACC/CPT-1 pathway activation. In some respects, the combination of Yam Gruel and metformin exerted more benefits effects than Yam Gruel alone.

The correlation between serum total bile acid and alanine aminotransferase of pregnant women and the disorders of neonatal hyperbilirubinemia-related amino acid metabolism

BackgroundTo explore the association between liver metabolism-related indicators in maternal serum and neonatal hyperbilirubinemia (NHB), and further investigate the predictive value of these indicators in NHB-related amino acid metabolism disorders.Methods51 NHB and 182 No-NHB newborns and their mothers who treated in the Fourth Hospital of Shijiazhuang from 2018 to 2022 were participated in the study. The differences in clinical data were compared by the Mann-Whitney U test and Chi-square test. Multivariate logistic regression was used to analyze the relationship between maternal serum indicators and the occurrence of NHB. The correlation analysis and risk factor assessment of maternal serum indicators with NHB-related amino acid metabolic disorders were performed using Spearman correlation analysis and multivariate logistic regression.ResultsCompared to the non NHB group, the NHB group had higher maternal serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), ALT/AST, and total bile acid (TBA), while lower levels of serum albumin (ALB), total cholesterol (TC) and high-density lipoprotein (HDL). The levels of alanine (ALA), valine (VAL), ornithine (ORN), and proline (PRO) in the newborns were reduced in NHB group, while arginine (ARG) showed a tendency to be elevated. Multiple logistic regression analysis showed that maternal ALT, AST, ALT/AST, and TBA levels were all at higher risk with the development of NHB, whereas ALB, TC, and HDL levels were negatively associated with NHB development. Increasing maternal TBA level was associated with lower ALA (r=-0.167, p = 0.011), VAL (r=-0.214, p = 0.001), ORN (r=-0.196, p = 0.003), and PRO in the newborns (r=-0.131, p = 0.045). Maternal ALT level was negatively associated with ALA (r=-0.135, p = 0.039), VAL (r=-0.177, p = 0.007), ORN (r=-0.257, p < 0.001), while ALT/AST was positively correlated with ARG (r = 0.133, p = 0.013). After adjustment for confounding factors, maternal serum TBA and ALT were the independent risk factor for neonatal ORN metabolic disorders [(adjusted odds ratio (AOR) = 0.379, 95%CI = 0.188–0.762, p = 0.006), (AOR = 0.441, 95%CI = 0.211–0.922, p = 0.030)]. Maternal ALT level was an independent risk factor for neonatal VAL metabolic disorders (AOR = 0.454, 95%CI = 0.218–0.949, p = 0.036).ConclusionsThe levels of high TBA, ALT, AST, and low HDL, TC of maternal were associated with the risk of NHB. Maternal TBA and ALT levels were independent risk factors for NHB-related amino acid disturbances which have value as predictive makers.

Identify BCAT1 plays an oncogenic role and promotes EMT in KIRC via single cell RNA-seq and experiment.

Kidney renal clear cell carcinoma (KIRC) is a major subtype of renal cell carcinoma with poor prognosis due to its invasive and metastatic nature. Despite advances in understanding the molecular underpinnings of various cancers, the role of branched-chain amino acid transferase 1 (BCAT1) in KIRC remains underexplored. This study aims to fill this gap by investigating the oncogenic role of BCAT1 in KIRC using single-cell RNA-seq data and experimental validation. Single-cell transcriptomic data GSE159115 was utilized to investigate potential biomarkers in KIRC. After screening, we used BCAT1 as a target gene and investigated its function and mechanism in KIRC through databases such as TCGA-GTEx, using genome enrichment analysis (GSEA), genome variation analysis (GSVA), gene ontology (GO) and Kyoto Encyclopedia of the Genome (KEGG). BCAT1 expression was detected in clinical tissue samples using Western Blotting (WB) and immunohistochemical (IHC) staining techniques. We established cell lines stably overexpressing and knocking down BCAT1 and performed WB, qRT-PCR, cell scratch assay and transwell assay. BCAT1 was highly expressed in KIRC and was associated with disease prognosis and TME. Patients with mutations in the BCAT1 gene had shorter overall survival (OS) and disease-free survival (DFS). patients with high BCAT1 expression had shorter OS, progression-free interval (PFI), and disease-specific survival (DSS). GSEA showed that BCAT1 was significantly enriched in epithelial mesenchymal transition (EMT). Bioinformatics analysis and WB and IHC staining showed that BCAT1 expression was higher in KIRC than in paracancerous tissues. In vitro experiments confirmed that BCAT1 in KIRC cells may promote EMT affecting its invasion, migration. We constructed a protein interaction network (PPI) to hypothesize proteins that may interact with BCAT1. Single-sample gene set enrichment analysis (ssGSEA) revealed the immune infiltration environment of BCAT1. Furthermore, hypomethylation of the BCAT1 promoter region in KIRC may contribute to disease progression by promoting BCAT1 expression. BCAT1 promotes KIRC invasion and metastasis through EMT and has prognostic predictive value and potential as a biomarker. It may become a novel biomarker.

Inhibition of Indoleamine 2,3-Dioxygenase in the Prelimbic and Infralimbic Cortices Exerts Antidepressant Effects through Different Pathways in ICV-STZ Rats

An intracerebroventricular injection of streptozotocin (ICV-STZ) is used to simulate sporadic alzheimer’s disease (sAD) in rats. Rats exhibit depression-like behaviors at the beginning of this model. Indoleamine 2,3-dioxygenase (IDO), a rate-limiting enzyme catalyzing the conversion of tryptophan to kynurenine, is closely related to AD and depression. Present study investigated the neurophysiological mechanism of depression-like behaviors in ICV-STZ rats with a focus on IDO-related kynurenine pathways. IDO was activated in both the prelimbic cortex (PrL) and infralimbic cortex (IL), but abnormalities in downstream metabolic pathways were dramatically different and associated with separate secondary biological effects. In the PrL, the neuroprotective branch of the kynurenine pathway was attenuated, as evidenced by a decrease in kynurenic acid and kynurenine aminotransferase II accompanied by defects in astrocytes, reflected by decreases in GFAP-positive cells and glial transporters and morphological damage. In the IL, the neurotoxic branch of the kynurenine pathway was enhanced, as evidenced by an increase in 3-hydroxy-kynurenine and kynurenine 3-monooxygenase paralleled by the overactivation of microglia, reflected by an increase in Iba1-positive cells and cytokines with morphological alterations. Synaptic plasticity was attenuated in both subregions. Additionally, a microinjection of the selective IDO inhibitor 1-MT in the PrL or IL alleviated depression-like behaviors by reversing these different abnormalities in the PrL and IL. These results suggest that the antidepressant effects of IDO inhibition in the PrL and IL occur through different pathways, namely by enhancing neuroprotective effects in the PrL and attenuating neurotoxic responses in the IL.

Effects of low-temperature storage on the aroma composition and quality of Golden Empress Hami melons: A transcriptomic and metabolomic analysis

Low-temperature storage is frequently employed to prolong the shelf life of Hami melons. Nevertheless, extended low-temperature storage can hamper the synthesis of aroma compounds in these fruits. This study investigated the effects of storage at 3 °C (LT) and 21 °C (RT) on the aroma quality of Golden Empress Hami melons (GEHMs) during a shelf life of 24 d. Further, the transcription levels of genes related to aroma metabolism were also examined during this period. After 12 d, the intensity of sweet aroma (LT: 2.3, RT: 8.2) and fruit aroma (LT: 2.1, RT: 8) was significantly lower in GEHMs stored at LT than in those stored at RT. Correspondingly, between-group differences in the content of esters with sweet and fruity aromas (RT: 782.76 ± 128.41 μg/kg, LT: 53.69 ± 24.32 μg/kg) and alcohols (RT: 2252.98 ± 297.65 μg/kg, LT: 448.80 ± 106.13 μg/kg) peaked at 12 d. Furthermore, the expression levels of 52 genes related to aroma volatile biosynthesis were significantly different between GEHMs stored at RT and LT. Specifically, the expression levels of genes encoding ethanol dehydrogenase (ADH), long-chain acyl-CoA synthetase (ACSL), and branched-chain amino acid aminotransferase (ilvE) which are involved in the production of alcohols and esters— were significantly lower in GEHMs stored at LT than in those stored at RT. This study provides a deeper understanding of aroma-related biosynthetic pathways of GEHMs during postharvest storage. Additionally, it offers valuable metabolomic and transcriptomic resources for the regulation of aroma compound metabolism in postharvest GEHMs.

Lycopene modulates testicular injury oxidative stress and caspases upregulation induced by fenvalerate in male rats

Fenvalerate (FEN) is one of the widely utilized synthetic pyrethroids that may negatively impact male fertility in animals and people, while the potential mechanism is still unknown. This study aimed to assess lycopene’s potential therapeutic value in protecting male rats from testicular damage and oxidative stress caused by FEN. In our investigation, 28 male rats were randomized into four groups at random: lycopene (10 mg/kg BW), FEN (20 mg/kg BW), and lycopene plus FEN. The rats got their doses orally by gavage each day for four weeks. Animals that had consumed FEN showed high levels of hydrogen peroxide and thiobarbituric acid reactive substances, phosphatases, and aminotransferases. However, there was a considerable drop in antioxidant enzyme activity, glutathione, and protein content. Significant changes in testosterone, luteinizing and follicle-stimulating hormones, and sperm quality were also found. In addition, the expression of caspases 3 and 8 in rat testes was significantly upregulated. Biochemical, molecular, spermatological, and histological alterations have all been brought back to normal by lycopene. These findings imply that lycopene may have antioxidant and preventive properties against testicular damage brought on by FEN. Keywords: Fenvalerate; Lycopene; Apoptosis; Semen quality; Oxidative stress.

QSAR, molecular docking, and molecular designs of some anti-epilepsy compounds

Epilepsy is a non-communicable central nervous system (CNS) disease that accounts for approximately 0.8–1.2 % of the global population at any time. The hyper-activities of gamma butyric acid aminotransferase (GABAAT) enzyme have been confirmed to be largely responsible for seizure/epilepsy. Because of this special function, the GABAAT enzyme has been the main target of many anti-epilepsy drugs (AEDs). To date, many discovered AEDs have not eradicated this neurological disease. Since experimental determinations of modern drugs are usually costly and sometimes non-eco-friendly, in-silco quantitative structure–activity relationship (QSAR)-machine learning, docking and pharmacokinetics (PMK) techniques were used to design and test the oral bio-availabilities of all the designed AEDs. QSAR models were generated, and the predictive properties of R2int = 0.9827, R2ext = 0.9407, and R2adj of 0.9667 indicate the evidence that the developed model was not by chance. Six (6) new AEDs were newly designed, and they were found to have better anti-epileptic activities values of 2.146799, 2.224866, 2.31479, 2.450313, 2.301474, and 2.618303 than the standard AED, Vigabatrin (0.40672). Also, the docked new compounds shows excellent binding energies of −127.001, −129.071, −130.515, −126.881, −130.771, and −126.974 kcal/mol compared to the referenced AED (−76.9173 kcal/mol). The PMK and absorption, distribution, metabolism, excretion, and toxicity (ADMET) investigations also revealed that all the designed compounds were found to be bio-available for human administration. 'Therefore, the newly designed analogues (AEDs) could be considered as potential drug candidates for the treatment of epilepsy.

Discovery of GABA Aminotransferase Inhibitors via Molecular Docking, Molecular Dynamic Simulation, and Biological Evaluation

γ-Aminobutyric acid aminotransferase (GABA-AT) is a pyridoxal 5′-phosphate (PLP)-dependent enzyme that degrades γ-aminobutyric (GABA) in the brain. GABA is an important inhibitory neurotransmitter that plays important neurological roles in the brain. Therefore, GABA-AT is an important drug target that regulates GABA levels. Novel and potent drug development to inhibit GABA-AT is still a very challenging task. In this study, we aimed to devise novel and potent inhibitors against GABA-AT using computer-aided drug design (CADD) tools. Since the crystal structure of human GABA-AT was not yet available, we utilized a homologous structure derived from our previously published paper. To identify highly potent compounds relative to vigabatrin, an FDA-approved drug against human GABA-AT, we developed a pharmacophore analysis protocol for 530,000 Korea Chemical Bank (KCB) compounds and selected the top 50 compounds for further screening. Preliminary biological analysis was carried out for these 50 compounds and 16 compounds were further assessed. Subsequently, molecular docking, molecular dynamics (MD) simulations, and binding free energy calculations were carried out. In the results, four predicted compounds, A07, B07, D08, and H08, were found to be highly potent and were further evaluated by a biological activity assay to confirm the results of the GABA-AT activity inhibition assay.

Expanded Substrate Specificity in D-Amino Acid Transaminases: A Case Study of Transaminase from Blastococcus saxobsidens.

Enzymes with expanded substrate specificity are good starting points for the design of biocatalysts for target reactions. However, the structural basis of the expanded substrate specificity is still elusive, especially in the superfamily of pyridoxal-5'-phosphate-dependent transaminases, which are characterized by a conserved organization of both the active site and functional dimer. Here, we analyze the structure-function relationships in a non-canonical D-amino acid transaminase from Blastococcus saxobsidens, which is active towards D-amino acids and primary (R)-amines. A detailed study of the enzyme includes a kinetic analysis of its substrate scope and a structural analysis of the holoenzyme and its complex with phenylhydrazine-a reversible inhibitor and analogue of (R)-1-phenylethylamine-a benchmark substrate of (R)-selective amine transaminases. We suggest that the features of the active site of transaminase from B. saxobsidens, such as the flexibility of the R34 and R96 residues, the lack of bulky residues in the β-turn at the entrance to the active site, and the short O-pocket loop, facilitate the binding of substrates with and without α-carboxylate groups. The proposed structural determinants of the expanded substrate specificity can be used for the design of transaminases for the stereoselective amination of keto compounds.

RTID-04. GLUGLIO - A PHASE IB/II RANDOMIZED DRUG REPURPOSING TRIAL OF GLUTAMATE SIGNALING INHIBITORS IN COMBINATION WITH CHEMORADIOTHERAPY IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA (NCT05664464)

Abstract Glioblastoma synthesizes and secretes large quantities of the excitatory neurotransmitter glutamate, driving epilepsy, neuronal death, tumor growth and invasion. Several brain-penetrating drugs that have obtained clinical approval in other pathologic conditions can inhibit glutamate synthesis, secretion and signalling, respectively, including (i) the anti-seizure drug gabapentin, which inhibits the glutamate synthesis enzyme, branched chain amino acid transaminase 1, (ii) the anti-inflammatory drug sulfasalazine, which inhibits glutamate secretion by blocking the cystine-glutamate exchanger system Xc, and (iii) the cognitive enhancer memantine, which can prevent glutamate-driven, calcium-induced neuronal death and tumor cell invasion by blocking N-methyl-D-aspartate (NMDA) type glutamate receptors. The multi-centre, open-label, parallel-group, two-arm, 1:1 randomized, phase Ib/II trial GLUGLIO explores the efficacy of a triple-combination of daily oral gabapentin, sulfasalazine and memantine in combination with standard chemoradiotherapy compared to chemoradiotherapy alone. Dosing of either drug will be sought up to the maximum approved dose and will be reevaluated in an interim safety analysis after 20 patients have been randomized into the experimental arm. The primary endpoint is progression-free survival at 6 months (PFS-6). The sample size of N = 120 patients was calculated to detect an increase in PFS-6 from 50% to 70% with a power of 80% performing exploratory hypothesis testing at a one-sided significance level of 10%. Secondary endpoints include progression-free, overall and seizure-free survival, response rate, quality of life of patients and caregivers, symptom burden, cognitive functioning, tumor glutamate levels by magnetic resonance spectroscopy as well as anti-convulsant and steroid use. Surgical tissues as well as peripheral blood and electroencephalography recordings will also be sampled longitudinally for translational analyses. Recruitment is ongoing and foreseen to be completed by mid 2026. The simultaneous targeting of glutamate synthesis, secretion and signalling will clarify whether glutamate should be further explored as a clinical target in glioblastoma patients.

Research progress on branched-chain amino acid aminotransferases.

Branched-chain amino acid aminotransferases, widely present in natural organisms, catalyze bidirectional amino transfer between branched-chain amino acids and branched-chain α-ketoacids in cells. Branched-chain amino acid aminotransferases play an important role in the metabolism of branched-chain amino acids. In this paper, the interspecific evolution and biological characteristics of branched-chain amino acid aminotransferases are introduced, the related research of branched-chain amino acid aminotransferases in animals, plants, microorganisms and humans is summarized and the molecular mechanism of branched-chain amino acid aminotransferase is analyzed. It has been found that branched-chain amino acid metabolism disorders are closely related to various diseases in humans and animals and plants, such as diabetes, cardiovascular diseases, brain diseases, neurological diseases and cancer. In particular, branched-chain amino acid aminotransferases play an important role in the development of various tumors. Branched-chain amino acid aminotransferases have been used as potential targets for various cancers. This article reviews the research on branched-chain amino acid aminotransferases, aiming to provide a reference for clinical research on targeted therapy for various diseases and different cancers.