Integrating Transcriptome and Metabolome Analyses Revealed Salinity Induces Arsenobetaine Biosynthesis in Marine Medaka (Oryzias melastigma).

Marine fish exhibit elevated levels of arsenobetaine (AsB), while the impact and underlying mechanism of salinity on AsB biosynthesis remain inadequately explored. In this study, marine medaka (Oryzias melastigma), typically inhabiting 30‰ high salinity, were gradually acclimated to low salinities of 20, 10, and 0‰. Following acclimation, the fish were exposed to arsenate (As(V)) in their diet for 30 days. Results showed a significant accumulation of total arsenic (As) and AsB concentrations in the muscle and head tissues of the exposed fish, with these accumulations exhibiting a positive correlation with water salinity. Transcriptome analyses revealed that exposure to As(V) at low salinity may disrupt membrane components and induce cytoskeletal injuries, while at high salinity, it triggered oxidoreductase activity and transmembrane transport. Metabolome analyses indicated that low salinity induced osmotic stress, resulting in an increased requirement for amino acids to upload intracellular osmotic equilibrium in O. melastigma. Furthermore, the key organic osmolytes and amino acids, including taurine, l-methionine, guanidinoethyl sulfonate, and N-acetyl-l-aspartic acid, exhibited a negative correlation with the AsB concentration. These findings indicated that salinity can regulate osmotic balance by influencing amino acid synthesis under low salinity and stimulating AsB synthesis under high salinity conditions in O. melastigma. This study provides insights into the impact of high salinity on AsB biosynthesis, the underlying regulatory mechanisms, and implications for managing As(V) risk.

Development of a recombinant Lactobacillus plantarum oral vaccine expressing VP2 protein for preventing feline panleukopenia virus.

Feline panleukopenia virus (FPV) represents a significant health threat to the kittens. While traditional vaccines administered via subcutaneous or intramuscular injection are effective, they can induce stress and adverse reactions. Moreover, unvaccinated kittens visiting veterinary clinics risk exposure to FPV, increasing their susceptibility to infection. Therefore, there is an urgent need for a safer, more gentle vaccination method with streamlined administration. In this study, we developed a recombinant L. plantarum NC8/VP2 expressing the VP2 protein of the prevalent Chinese FPV strain, FPV-251. Our results show that L. plantarum NC8/VP2 effectively colonizes the feline intestinal tract and induces high levels of neutralizing antibodies through oral administration. Kittens exhibited significant protection against FPV-251 infection and associated illnesses or fatalities after 30 days of continuous dosing. These results highlight the potential of recombinant L. plantarum NC8/VP2 as a novel oral vaccine for FPV, presenting a promising approach for disease prevention in domestic cats.

Chemical aging of biochar-zero-valent iron composites in groundwater: Impact on Cd(II) and Cr(VI) co-removal.

Biochar (BC), zero-valent iron (ZVI), and their composites are promising materials for use in permeable reactive barriers, although further research is needed to understand how their properties change during long-term aging in groundwater. In this study, BC, ZVI and their composites (4BC-1ZVI) were subjected to the chemical aging tests in five media (deionized water, NaCl, NaHCO3, CaCl2 and a mixture of CaCl2 and NaHCO3 solutions) for 20 days. After treatment, the microscopic analysis and performance tests for the co-removal of Cd(II) and Cr(VI) were carried out. The results indicated that the removal of Cd(II) by aged 4BC-1ZVI followed a pseudo-second-order model, whereas the removal of Cr(VI) was better fitted with a pseudo-first order model. The aging mechanism of 4BC-1ZVI was primarily governed by iron corrosion/passivation, the reduction of soluble components, and the formation of carbonate minerals. Less Fe3O4/ γ-Fe2O3 was formed during aging in deionized water, NaCl and CaCl2 solutions. The corrosion products, Fe3O4/ γ-Fe2O3, FeCO3 and α/γ-FeOOH, were observed after aging in NaHCO3 and a mixture of NaHCO3 and CaCl2 solutions. The decrease in the soluble components of biochar led to a decrease in cation exchange, while carbonate minerals contributed to Cd(II) precipitation. This work provides insights into the aging processes of BC-ZVI composites for long-term groundwater remediation applications.

Metabolome analysis revealed the critical role of betaine for arsenobetaine biosynthesis in the marine medaka (Oryzias melastigma).

Arsenobetaine (AsB), a non-toxic arsenic (As) compound found in marine fish, structurally resembles betaine (GB), a common methyl donor in organisms. This study investigates the potential role of GB in AsB synthesis in marine medaka (Oryzias melastigma) using metabolomic analysis. Dietary exposure to arsenate (As(V)) and varying GB concentrations (0.05% and 0.1% in diets) increased total As and AsB bioaccumulation, particularly in marine medaka muscle. Metabolomic analysis revealed that GB played a crucial role in promoting up-regulation in methylthioadenosine (MTA) by modulating the methionine cycle and down-regulation in glutathione (GSH) by modulating the glutathione cycle. Methionine metabolism and GSH, potentially binding again to exogenous GB, could synchronously produce more non-toxic AsB. Combining verification experiments of differential metabolites of Escherichia coli in vitro, GB, GSH, S-adenosylmethionine (SAM), and arsenocholine (AsC) entered methionine and glutathione metabolism pathways to generate more AsB. These findings underscore the GB's crucial regulatory role in modulating the synthesis of AsB. This study provides vital insights into the interplay between the structural analogs GB and AsB, offering specific strategies to enhance the detoxification mechanisms of marine fish in As-contaminated environments.

Transformative skeletal motion analysis: optimization of exercise training and injury prevention through graph neural networks.

Introduction: Exercise is pivotal for maintaining physical health in contemporary society. However, improper postures and movements during exercise can result in sports injuries, underscoring the significance of skeletal motion analysis. This research aims to leverage advanced technologies such as Transformer, Graph Neural Networks (GNNs), and Generative Adversarial Networks (GANs) to optimize sports training and mitigate the risk of injuries. Methods: The study begins by employing a Transformer network to model skeletal motion sequences, facilitating the capture of global correlation information. Subsequently, a Graph Neural Network is utilized to delve into local motion features, enabling a deeper understanding of joint relationships. To enhance the model's robustness and adaptability, a Generative Adversarial Network is introduced, utilizing adversarial training to generate more realistic and diverse motion sequences. Results: In the experimental phase, skeletal motion datasets from various cohorts, including professional athletes and fitness enthusiasts, are utilized for validation. Comparative analysis against traditional methods demonstrates significant enhancements in specificity, accuracy, recall, and F1-score. Notably, specificity increases by ~5%, accuracy reaches around 90%, recall improves to around 91%, and the F1-score exceeds 89%. Discussion: The proposed skeletal motion analysis method, leveraging Transformer and Graph Neural Networks, proves successful in optimizing exercise training and preventing injuries. By effectively amalgamating global and local information and integrating Generative Adversarial Networks, the method excels in capturing motion features and enhancing precision and adaptability. Future research endeavors will focus on further advancing this methodology to provide more robust technological support for healthy exercise practices.

Mechanical properties of reaction mediums in permeable reactive barriers.

The mechanical properties of reaction media in permeable reactive barriers (PRB) is vital in geoenvironmental applications. Bentonite, activated carbon and zeolite, recognized for their excellent adsorption capabilities, are employed as the main reaction media in PRB for the treatment of contaminated underground water. The compaction test and the undrained and unconsolidated triaxial test were carried out to investigate the compression and shear strength of the activated carbon-zeolite mixture and activated carbon-bentonite mixture at various composition ratios. The impact of compaction degree on samples' shear strength was analyzed. The influence of different composition ratios on the mechanical properties and the permeability of each reaction medium were also evaluated. The results show that the mechanical performance of most activated carbon-zeolite (AZs) is not satisfactory compared to natural soil and activated carbon-bentonite mixtures. Activated carbon­sodium bentonite (ANBs) and activated carbon­calcium bentonite (ACBs) present similar compaction characteristics and shear properties. In ANBs and ACBs, the cohesion of mixes with a mass ratio of 1:2 (ANB2 and ACB2) was found lower than that of mixes with mass ratios of 1:1 (ANB1 and ACB1) and 1:3 (ANB3 and ACB3). And in most ANB and ACB mixes, 100 % compaction produced higher moisture content and higher friction angle, but lower cohesion, compared to 92 % compaction degree. And the shear strength behavior of ANBs is dominated by both bentonite and activated carbon. The permeability of ACB1, AZ3 and ACB1-sand are at 1.31 × 10-6 m/s, 1.37 × 10-6 m/s and 7.72 × 10-7 m/s, respectively. These results provide valuable insights into the selection and optimization of reaction media for PRBs in geoenvironmental engineering applications.

Mechanisms underlying the combination effect of arsenite and high-fat diet on aggravating liver injury in mice.

Arsenic (As) is a highly toxic metalloid that can be found in insufficiently purified drinking water and exerts adverse effects on the physiology of living organisms that can negatively affect human health after subchronic exposure, causing several diseases, such as liver damage. A high-fat diet, which is increasing in frequency worldwide, can aggravate hepatic pathology. However, the mechanisms behind liver injury caused by the combinatory effects of As exposure and a high-fat diet remain unclear. In this study, we investigated such underlying mechanisms by focusing on three different aspects: As biotransformation, pathological liver damage, and differential expression of signaling pathway components. We employed mice that were fed a regular diet or a high-fat diet and exposed them to a range of arsenite concentrations (As(III), 0.05-50 mg/L) for 12 weeks. Our results showed that a high-fat diet increased the absorption of As into the liver and enhanced liver toxicity, which became progressively more severe as the As concentration increased. Co-exposure to a high-fat diet and As(III) activated PI3K/AKT and PPAR signaling as well as fatty acid metabolism pathways. In addition, the expression of proteins related to lipid cell function, lipid metabolism, and the regulation of body weight was also affected. Our study provides insights into the mechanisms that contribute to liver injury from subchronic combinatory exposure to As and a high-fat diet and showcases the importance of a healthy lifestyle, which may be of particular benefit to people living in areas with high As(III) concentrations, as a means to reduce or prevent aggravated liver damage.

Biological Characteristics of Feline Calicivirus Epidemic Strains in China and Screening of Broad-Spectrum Protective Vaccine Strains.

Feline calicivirus (FCV) is one of the most important pathogens causing upper respiratory tract diseases in cats, posing a serious health threat to these animals. At present, FCV is mainly prevented through vaccination, but the protective efficacy of vaccines in China is limited. In this study, based on the differences in capsid proteins of isolates from different regions in China, as reported in our previous studies, seven representative FCV epidemic strains were selected and tested for their viral titers, virulence, immunogenicity, and extensive cross-protection. Subsequently, vaccine strains were selected to prepare inactivated vaccines. The whole-genome sequencing and analysis results showed that these seven representative FCV strains and 144 reference strains fell into five groups (A, B, C, D, and E). The strains isolated in China mainly fall into groups C and D, exhibiting regional characteristics. These Chinese isolates had a distant evolutionary relationship and low homology with the current FCV-255 vaccine strain. The screened FCV-HB7 and FCV-HB10 strains displayed desirable in vitro culture characteristics, with the highest virus proliferation titers (109.5 TCID50/mL) at 36 h post inoculation at a dose of 0.01 MOI. All five cats infected intranasally with FCV-HB7 or FCV-HB10 strains showed obvious clinical symptoms of FCV. The symptoms of cats infected with the FCV-HB7 strain were more severe than those infected with the FCV-HB10 strain. Both the single-strain inactivated immunization and combined bivalent inactivated vaccine immunization of FCV-HB7 and FCV-HB10 induced high neutralizing antibody titers in five cats immunized. Moreover, bivalent inactivated vaccine immunization protected cats from FCV-HB7 and FCV-HB10 strains. The cross-neutralizing antibody titer against seven representative FCV epidemic strains achieved by combined bivalent inactivated vaccine immunization was higher than that achieved by single-strain immunization, which was much higher than that achieved by commercial vaccine FCV-255 strain immunization. The above results suggest that the FCV-HB7 and FCV-HB10 strains screened in this study have great potential to become vaccine strains with broad-spectrum protective efficacy. However, their immune protective efficacy needs to be further verified by multiple methods before clinical application.

Role of microbial microbes in arsenic bioaccumulation and biotransformation in mice.

Although gut microbes can affect the accumulation and metabolism of arsenic (As), the microbes contributing to these processes remain largely unknown. Therefore, this study aimed to investigate the bioaccumulation and biotransformation of arsenate [As(V)] and arsenobetaine (AsB) in mice with a disordered gut microbiome. We used cefoperazone (Cef) to construct a mouse model of gut microbiome disruption along with 16S rRNA sequencing to elucidate the effect of gut microbiome destruction on the biotransformation and bioaccumulation of As(V) and AsB. This revealed the role of specific bacteria in As metabolism. Gut microbiome destruction increased the bioaccumulation of As(V) and AsB in various organs and reduced the excretion of As(V) and AsB in the feces. Further, gut microbiome destruction was found to be important for the biotransformation of As(V). Interference with Cef can significantly decrease Blautia and Lactobacillus while increasing Enterococcus, leading to increase As accumulation in mice and enhanced methylation. We also identified Lachnoclostridium, Erysipelatoclostridium, Blautia, Lactobacillus, and Enterococcus as biomarkers involved in As bioaccumulation and biotransformation. In conclusion, specific microbes can increase As accumulation in the host, exacerbating its potential health risks.

Significant Biotransformation of Arsenobetaine into Inorganic Arsenic in Mice.

Arsenic (As) is extremely toxic to living organisms at high concentrations. Arsenobetaine (AsB), confirmed to be a non-toxic form, is the main contributor to As in the muscle tissue of marine fish. However, few studies have investigated the biotransformation and biodegradation of AsB in mammals. In the current study, C57BL/6J mice were fed four different diets, namely, Yangjiang and Zhanjiang fish diets spiked with marine fish muscle containing AsB, and arsenite (As(III)) and arsenate (As(V)) diets spiked with As(III) and As(V), respectively, to investigate the biotransformation and bioaccumulation of AsB in mouse tissues for 42 d. Different diets exhibited different As species distributions, which contributed to varying levels of As bioaccumulation in different tissues. The intestines accumulated the highest level of As, regardless of form, which played a major part in As absorption and distribution in mice. We observed a significant biotransformation of AsB to As(V) following its diet exposure, and the liver, lungs, and spleen of AsB-treated mice showed higher As accumulation levels than those of As(III)- or As(V)-treated mice. Inorganic As showed relatively high accumulation levels in the lungs and spleen after long-term exposure to AsB. Overall, these findings provided strong evidence that AsB undergoes biotransformation to As(V) in mammals, indicating the potential health risk associated with long-term AsB intake in mammals.

Key genes for arsenobetaine synthesis in marine medaka (Oryzias melastigma) by transcriptomics.

Marine fish undergo detoxification to overcome As stress, forming non-toxic metabolites arsenobetaine (AsB). Genes associated with AsB synthesis remain unknown. Therefore, in this study, we explored the key genes involved in the synthesis of AsB by transcriptomic analysis in marine medaka (Oryzias melastigma), and then screened candidate genes related to AsB synthesis. In the liver, 40 genes were up-regulated and 23 genes were down-regulated, whereas in muscle, 83 genes were up-regulated and 331 genes were down-regulated. We revealed that bhmt, mat2aa, and gstt1a can play a significant role in the glutathione and methionine metabolic pathway. These three genes can affect the conversion of arsenocholine (AsC) to AsB by the vitro gene transformation experiments of E. coli BL21(DE3). E. coli BL21-bhmt overexpressing bhmt resulted in more oxidation of precursor AsC to AsB. Furthermore, the AsB concentration was decreased after E. coli BL21 overexpressing mat2aa and gstt1a, which were down-regulated in marine medaka. Therefore, we concluded that bhmt, mat2aa, and gstt1a are involved in AsB synthesis. Overall, this is the first report on transcriptome screening and identification of key genes for AsB synthesis in marine medaka. We provided important insights to reveal the mystery of AsB synthesis in marine fish.

Biodegradation of arsenobetaine to inorganic arsenic regulated by specific microorganisms and metabolites in mice.

Arsenobetaine (AsB) is a primary arsenic (As) compound found in marine organisms. However, in mammals, the metabolic mechanism of AsB remains indistinct. Therefore, in this study, we investigated the biotransformation and regulatory mechanism of AsB, particularly the biodegradation process, in a mouse model to assess the underlying health hazards of AsB. We studied the biotransformation process of AsB in mice through the food chain [AsB feed-marine fish (Epinephelus fuscoguttatus)-mice (Mus musculus)]. Our results showed the significant bioaccumulation of total As, AsB, and, in particular, arsenate [As(V)] through biodegradation in mice tissues. As the abundance of Staphylococcus and Blautia (phylum, Firmicutes) increased, the expression of aqp7 (absorption) and methyltransferase (as3mt) (methylation) was upregulated. In contrast, the expression of S-adenosyl methionine (sam) (methylation) was downregulated. These findings suggest that demethylation and methylation occurred simultaneously in the intestines, with demethylation capacity being greater than that of methylation. Furthermore, Firmicutes such as Staphylococcus and Blautia showed a significant inverse relationship with arachidonic acid, choline, and sphingosine. Gene, microbiome, and metabolomics analyses indicated that Staphylococcus and Blautia and arachidonic acid, choline, and sphingosine participated in the degradation of AsB to As(V) in mouse intestines. Therefore, long-term AsB ingestion through marine fish consumption could cause potential health hazards in humans.

Intestinal uptake and low transformation increase the bioaccumulation of inorganic arsenic in freshwater zebrafish.

Arsenate [As(V)] is the main form of arsenic (As) present in freshwater taken up by freshwater fish. Data on the main uptake tissue, biotransformation, and bioaccumulation in freshwater fish exposed to As(V) were limited, and the reasons for its bioaccumulation in the muscle tissue of freshwater fish remain undetermined. Accordingly, we simulated bioaccumulation and depuration in zebrafish (Danio rerio) exposed to waterborne As(V) by employing a six-compartment physiologically based pharmacokinetic model and As speciation analysis. Modeling and biotransformation suggested that intestines were the main uptake site for waterborne As(V), instead of the gills. This novel finding was evidenced by the higher As transfer constant from water to intestines (k03 = 1.52 × 10-4 L d-1) compared to gills (k02 = 5.28 × 10-5 L d-1). The low concentration and percentage of arsenobetaine (AsB) in the intestines suggested a weak ability to synthesize AsB. Our results showed a substantial proportion of inorganic As in intestines and a relatively substantial percentage in muscle tissue. Therefore, high As(V) uptake in the intestines and lack of biotransformation contributed to high bioaccumulation of inorganic As in freshwater fish. Inorganic As posed concerns due to the human health risks associated with consuming As(V)-contaminated fish and should be addressed.

Four new prenylflavonol glycosides from the leaves of Cyclocarya paliurus.

Four new prenylflavonol glycosides (1-4) along with two known analogues (5-6) were isolated from the leaves of Cyclocarya paliurus for the first time. The structures of these compounds were characterized by comprehensive analysis of 1 D, 2 D NMR, HRESIMS, UV data and enzymatic hydrolysis. In bioassays, compounds 1-4 were evaluated for inhibitory effects on xanthine oxidase (XOD) and effects on the inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS) induced RAW264.7 cells. Moreover, compounds 1 and 2 showed outstanding XOD inhibitions with IC50 values of 18.16 ± 3.91 and 37.65 ± 5.67 µM, and exhibited inhibitions against LPS-induced NO production with IC50 values of 80.50 ± 3.09 and 82.28 ± 2.87 µM.

Cyclocarioside O-Q, three novel seco-dammarane triterpenoid glycosides from the leaves of Cyclocarya paliurus.

Three previously undescribed seco-dammarane triterpenoid glycosides O-Q (1-3) along with two known compounds (4 and 5) were isolated and characterized from the leaves of Cyclocarya paliurus. Their structures were determined by comprehensive analysis of 1 D, 2 D NMR and HRESIMS data. Compounds 1-5 were evaluated for their inhibitory effects against human pancreatic tumor (ASPC-1), human gastric carcinoma (SNU5), liver hepatocellular carcinoma (HEPG-2) and human colon tumor (HCT116) cell lines. Among them cyclocarioside P (2) showed somewhat inhibitory activity towards those tumor cells.

New prenylflavonol glycosides with xanthine oxidase inhibitory activity from the leaves of Cyclocarya paliurus.

Eight new prenylflavonol glycosides (1-8), along with five known analogues (9-13) were isolated from the n-butanol extract of the dried leaves of Cyclocarya paliurus (family Juglandaceae) for the first time. The structures of these compounds were characterized by comprehensive analysis of 1D, 2D NMR, HRESIMS, UV data and acid hydrolysis. In bioassay, all these thirteen prenylflavonol glycosides exhibited inhibitory effects on xanthine oxidase (XOD) activity. Especially compounds 2 and 7, showed outstanding IC50 values of 31.81 ± 2.20 and 29.71 ± 3.69 µM, respectively.

Hypoglycemic triterpenoid glycosides from Cyclocarya paliurus (Sweet Tea Tree).

Four new rarely occurred seco-dammarane triterpenoid glycosides (1-4) and four new dammarane triterpenoid glycosides (5-8), along with four known triterpenoids (9-12), were isolated from the 70% ethanol extract of the leaves of Cyclocarya paliurus (family Juglandaceae). Their structures were elucidated by extensive spectroscopic methods, including 1D/2D NMR and HRESIMS data, together with chemical analysis and DFT GIAO 13C NMR calculation. In bioassay, compounds 5-8 significantly increased glucose consumption in 3T3-L1 adipocytes, which could be the bioactive constituents for the anti-diabetes effect of the traditional usage of C. paliurus.