PI3K/Akt/FoxO Pathway Mediates Antagonistic Toxicity in HepG2 Cells Coexposed to Deoxynivalenol and Enniatins.

The emerging mycotoxins enniatins (ENNs) and the traditional mycotoxin deoxynivalenol (DON) often co-contaminate various grain raw materials and foods. While the liver is their common target organ, the mechanism of their combined effect remains unclear. In this study, the combined cytotoxic effects of four ENNs (ENA, ENA1, ENB, and ENB1) with DON and their mechanisms were investigated using the HepG2 cell line. Additionally, a population exposure risk assessment of these mycotoxins was performed by using in vitro experiments and computer simulations. The results showed that only ENA at 1/4 IC50 and ENB1 at 1/8 IC50 coexposed with DON showed an additive effect, while ENB showed the strongest antagonism at IC50 (CI = 3.890). Co-incubation of ENNs regulated the signaling molecule levels which were disrupted by DON. Transcriptome analysis showed that ENB (IC50) up-regulated the PI3K/Akt/FoxO signaling pathway and inhibited the expression of apoptotic genes (Bax, P53, Caspase 3, etc.) via phosphorylation of FoxO, thereby reducing the cytotoxic effects caused by DON. Both types of mycotoxins posed serious health risks, and the cumulative risk of coexposure was particularly important for emerging mycotoxins.

Double phage displayed peptides co-targeting-based biosensor with signal enhancement activity for colorimetric detection of Staphylococcus aureus.

The development of simple, fast, sensitive, and specific strategies for the detection of foodborne pathogenic bacteria is crucial for ensuring food safety and promoting human health. Currently, detection methods for Staphylococcus aureus still suffer from issues such as low specificity and low sensitivity. To address this problem, we proposed a sensitivity enhancement strategy based on double phage-displayed peptides (PDPs) co-targeting. Firstly, we screened two PDPs and analyzed their binding mechanisms through fluorescent localization, pull-down assay, and molecular docking. The two PDPs target S. aureus by binding to specific proteins on its outer membrane. Based on this phenomenon, a convenient and sensitive double PDPs colorimetric biosensor was developed. Double thiol-modified phage-displayed peptides (PDP-SH) enhance the aggregation of gold nanoparticles (AuNPs), whereas the specific interaction between the double PDPs and bacteria inhibits the aggregation of AuNPs, resulting in an increased visible color change before and after the addition of bacteria. This one-step colorimetric approach displayed a high sensitivity of 2.35 CFU/mL and a wide detection range from 10-2 × 108 CFU/mL. The combination with smartphone-based image analysis improved the portability of this method. This strategy achieves the straightforward, highly sensitive and portable detection of pathogenic bacteria.

Exploring the impact of fungal spores from agricultural environments on the mice lung microbiome and metabolic profile.

Exposure to particulate matter (PM) from agricultural environments has been extensively reported to cause respiratory health concerns in both animals and agricultural workers. Furthermore, PM from agricultural environments, containing fungal spores, has emerged as a significant threat to public health and the environment. Despite its potential toxicity, the impact of fungal spores present in PM from agricultural environments on the lung microbiome and metabolic profile is not well understood. To address this gap in knowledge, we developed a mice model of immunodeficiency using cyclophosphamide and subsequently exposed the mice to fungal spores via the trachea. By utilizing metabolomics techniques and 16 S rRNA sequencing, we conducted a comprehensive investigation into the alterations in the lung microbiome and metabolic profile of mice exposed to fungal spores. Our study uncovered significant modifications in both the lung microbiome and metabolic profile post-exposure to fungal spores. Additionally, fungal spore exposure elicited noticeable changes in α and ß diversity, with these microorganisms being closely associated with inflammatory factors. Employing non-targeted metabolomics analysis via GC-TOF-MS, a total of 215 metabolites were identified, among which 42 exhibited significant differences. These metabolites are linked to various metabolic pathways, with amino sugar and nucleotide sugar metabolism, as well as galactose metabolism, standing out as the most notable pathways. Cysteine and methionine metabolism, along with glycine, serine and threonine metabolism, emerged as particularly crucial pathways. Moreover, these metabolites demonstrated a strong correlation with inflammatory factors and exhibited significant associations with microbial production. Overall, our findings suggest that disruptions to the microbiome and metabolome may hold substantial relevance in the mechanism underlying fungal spore-induced lung damage in mice.

Rapid generation of high-quality recombinant antibodies using an Expi293F expression system for a 17 ß-estradiol immunoassay.

The rapid generation of high-quality target antibodies is essential for research employing immunoassays. The use of recombinant antibody technology that relies on genetic engineering is one such means to produce high-quality antibodies. Obtaining the gene sequence information of immunoglobulin is a prerequisite for the preparation of genetically engineered antibodies. At present, many researchers have shared their amino acid sequence data for various high-performance antibodies and their related properties. In this study, we obtained the protein sequence of a variable region of a 17 ß-estradiol (E2) antibody from the Protein Data Bank (PDB) and subsequently constructed heavy (H) and light (L) chain expression vectors through codon optimization. The transient expression, purification, and performance identification of the immunoglobulin G (IgG), antigen-binding fragment (Fab), and single-chain variable fragment (scFv) antibodies were carried out, respectively. The effects of the different expression vectors on the expression yield of the IgG antibody were further compared. Among them, the expression yield based on the pTT5 vector was the highest, reaching 27 mg/L. Based on the expressed IgG and Fab antibodies, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) standard curve of E2 was constructed, and the half-maximal inhibitory concentrations (IC50) for these two antibodies were determined to be 0.129 ng/mL and 0.188 ng/mL, respectively. In addition, an immunochromatographic assay (ICA) based on the IgG antibody was constructed with an IC50 of 3.7 ng/mL. Therefore, in featuring the advantages of simplicity, high efficiency, rapid obtainment, and high titer yield, we propose the system for the rapid generation of high-quality recombinant antibodies by reusing the published antibody information and show that it has good implementation prospects in improving upon existing immunoassay techniques.

Metabolic pathway-based self-assembled Au@MXene liver microsome electrochemical biosensor for rapid screening of aflatoxin B1.

Cytochrome P450 enzymes (CYPs) catalyze the production of aflatoxin B1 (AFB1) metabolites, which play an important role in carcinogenesis. In this study, we report a simple electrochemical liver-microsome-based biosensor using a composite of gold nanoparticles adsorbed on MXene (Au@MXene) for rapid screening of AFB1. Rat liver microsomes (RLMs) were directly adsorbed on the Au@MXene nanocomposite. The high conductivity, large specific surface area, and good biocompatibility of the Au@MXene nanocomposite enabled the direct electron transfer between the RLMs and the electrode and maintained the biological activity of the enzyme in the RLMs to a large extent. The metabolic behavior of the RLM biosensor that was developed for the electrocatalyst of AFB1 to its hydroxylation metabolite aflatoxin M1 (AFM1) was confirmed. Based on the change in the electrical signal generated by this metabolic behavior, we established the relationship between AFB1 content and amperometric (I-t) current signal. When the AFB1 concentration ranged from 0.01 µM to 50 µM, the AFB1 concentration was linearly related to the electrical signal with a limit of detection of 2.8 nM. The results of the recovery experiments for corn samples showed that the recovery and accuracy of the sensor were consistent with the UPLC-MS/MS method.

A novel cell-based electrochemical biosensor based on MnO2 catalysis for antioxidant activity evaluation of anthocyanins.

The rapid, efficient, and objective evaluation of active antioxidant components is of great significance for the basic research of natural products and food quality. In this work, a three-dimensional (3D) cell culture system-based electrochemical biosensor for H2O2 detection based on the relationship between the H2O2 extracellular level and the current signal response was developed, which could be used for evaluating the antioxidant activity of active compounds. To increase the analytical selectivity and the response specificity, an A549 cells/hydrogel@carbon nanofibers (CNFs)/manganese dioxide nanowires (MnO2NWs)/gold nanoparticles (AuNPs)-modified electrochemical biosensor was successfully prepared based on the catalytic reaction between the response of H2O2 and MnO2 to the current signal. Under the optimized modification parameters of the working electrode surface, a good linear correlation was found between the oxidation peak current (Ip) value and the H2O2 concentration induced by paraquat. The linear equation was Ip(µA) = 58.199CH2O2+5.825 (CH2O2 for H2O2 concentration) with R2 = 0.993, and the detection limit of H2O2 was 0.02 µM, which indicated high sensitivity, satisfactory reproducibility, and stability of this method. The biosensor was successfully used to evaluate and grade the antioxidant activity of 16 anthocyanins and their glycosidic derivatives, indicating the feasibility of this method for the antioxidant evaluation of natural products. This proposed method provides a new way for evaluating the in vitro efficacy of natural products based on their physiological activities and for designing a new sensing platform.

Microbial detoxification of mycotoxins in food and feed.

Mycotoxins are metabolites produced by fungi growing in food or feed, which can produce toxic effects and seriously threaten the health of humans and animals. Mycotoxins are commonly found in food and feed, and are of significant concern due to their hepatotoxicity, nephrotoxicity, carcinogenicity, mutagenicity, and ability to damage the immune and reproductive systems. Traditional physical and chemical detoxification methods to treat mycotoxins in food and feed products have limitations, such as loss of nutrients, reagent residues, and secondary pollution to the environment. Thus, there is an urgent need for new detoxification methods to effectively control mycotoxins and treat mycotoxin pollution. In recent years, microbial detoxification technology has been widely used for the degradation of mycotoxins in food and feed because this approach offers the potential for treatment with high efficiency, low toxicity, and strong specificity, without damage to nutrients. This article reviews the application of microbial detoxification technology for removal of common mycotoxins such as Aflatoxin, Ochratoxin, Zearalenone, Deoxynivalenol, and Fumonisins, and discusses the development trend of this important technology.

Efficacy of sorafenib adjuvant therapy in northwestern Chinese patients with non-metastatic renal-cell carcinoma after nephrectomy: A multicenter retrospective study.

Recent studies have confirmed the efficacy of sorafenib for patients with advanced renal cell carcinoma; however, its efficacy and safety as an adjuvant therapy in patients with non-metastatic and loco-regional renal cell carcinoma after surgery remains controversial. Thus, the aim of the present retrospective study was to evaluate the efficacy of adjuvant sorafenib therapy in such patients from 8 centers in northwestern China that were treated from August 2009 to December 2016.After surgery, the patients (n = 48) received oral sorafenib for 3 months. The control group (n = 48) comprised patients that underwent the same surgery from December 2009 to June 2016 but without adjuvant therapy who were matched 1:1 with the sorafenib group with respect to sex, age, pathological findings, disease stage and grade, operation time, and surgical procedure. The primary outcome compared between the groups was disease-free survival. Adverse events were also recorded to evaluate the safety of sorafenib. The influence of patients' characteristics and laboratory tests on recurrence was analyzed using unconditional logistic regression.Overall, the demographic characteristics of the 2 groups were similar. There was no significant difference in the rate of recurrence (8.3% for sorafenib patients and 6.2% for the matched patients, P = .66) or median disease-free survival between the 2 groups (hazard ratio = 1.561, 95% confidence interval = 0.349-6.987, P = .56). In multiple logistic regression analysis, increased blood urea nitrogen (BUN) emerged as an independent predictor of recurrence risk (P = .02).These results indicate that postoperative sorafenib adjuvant therapy did not achieve the expected beneficial effect, pointing to the need for further studies to evaluate its utility in such cases.

A novel electrochemical biosensor for antioxidant evaluation of phloretin based on cell-alginate/ʟ-cysteine/gold nanoparticle-modified glassy carbon electrode.

Antioxidant evaluation of bioactive compounds is limited, since many methods lack a real physiological environment that can be used conveniently and intuitively. In this study, a simple, label-free and effective electrochemical biosensor method has been developed to evaluate the antioxidant effect of phloretin (Ph) by 3D cell modification on a glassy carbon electrode (GCE). In response to this, A549 cells were immobilized onto a self-assembled ʟ-cysteine/gold nanoparticle (AuNPs/ʟ-Cys)-modified GCE surface by a simple drop casting after encapsulated in alginate. The electrochemical impedance spectroscopy (EIS) results showed that the impedance value (Ret) increased with the concentration of H2O2 in the range of 0-60 µmol/L with the correlation of 0.990 which acted as an oxidative stress model inducer. However, the EIS value decreased with the co-incubation of Ph ranging from 10 to 100 µmol/L, showing a dose-dependent manner and time effect, indicating that the variation of Ret was responded to the antioxidant effect. The response impedance of the biosensor is linear to Ph concentrations from 20 µmol/L to 100 µmol/L with the detection limit (LOD) as 1.96 µmol/L. A significant correlation was observed between reactive oxygen species (ROS) values and Ret values following the concentrations of Ph, thus demonstrating the good biological relevance of cell-based electrochemical method. The strategy has been used to evaluate Ph antioxidant capacity in real cells with satisfactory results, indicating the feasibility of biosensor analysis for antioxidant evaluation.