Sports promote brain evolution: a resting-state fMRI study of volleyball athlete.

Background: Long-term skill learning can lead to structure and function changes in the brain. Different sports can trigger neuroplasticity in distinct brain regions. Volleyball, as one of the most popular team sports, heavily relies on individual abilities such as perception and prediction for high-level athletes to excel. However, the specific brain mechanisms that contribute to the superior performance of volleyball athletes compared to non-athletes remain unclear. Method: We conducted a study involving the recruitment of ten female volleyball athletes and ten regular female college students, forming the athlete and novice groups, respectively. Comprehensive behavioral assessments, including Functional Movement Screen and audio-visual reaction time tests, were administered to both groups. Additionally, resting-state magnetic resonance imaging (MRI) data were acquired for both groups. Subsequently, we conducted in-depth analyses, focusing on the amplitude of low-frequency fluctuations (ALFF), regional homogeneity (ReHo), and functional connectivity (FC) in the brain for both the athlete and novice groups. Results: No significant differences were observed in the behavioral data between the two groups. However, the athlete group exhibited noteworthy enhancements in both the ALFF and ReHo within the visual cortex compared to the novice group. Moreover, the functional connectivity between the visual cortex and key brain regions, including the left primary sensory cortex, left supplementary motor cortex, right insula, left superior temporal gyrus, and left inferior parietal lobule, was notably stronger in the athlete group than in the novice group. Conclusion: This study has unveiled the remarkable impact of volleyball athletes on various brain functions related to vision, movement, and cognition. It indicates that volleyball, as a team-based competitive activity, fosters the advancement of visual, cognitive, and motor skills. These findings lend additional support to the early cultivation of sports talents and the comprehensive development of adolescents. Furthermore, they offer fresh perspectives on preventing and treating movement-related disorders. Trial registration: Registration number: ChiCTR2400079602. Date of Registration: January 8, 2024.

The lethal K18-hACE2 knock-in mouse model mimicking the severe pneumonia of COVID-19 is practicable for antiviral development.

Animal models of COVID-19 facilitate the development of vaccines and antivirals against SARS-CoV-2. The efficacy of antivirals or vaccines may differ in different animal models with varied degrees of disease. Here, we introduce a mouse model expressing human angiotensin-converting enzyme 2 (ACE2). In this model, ACE2 with the human cytokeratin 18 promoter was knocked into the Hipp11 locus of C57BL/6J mouse by CRISPR - Cas9 (K18-hACE2 KI). Upon intranasal inoculation with high (3 × 105 PFU) or low (2.5 × 102 PFU) dose of SARS-CoV-2 wildtype (WT), Delta, Omicron BA.1, or Omicron BA.2 variants, all mice showed obvious infection symptoms, including weight loss, high viral loads in the lung, and interstitial pneumonia. 100% lethality was observed in K18-hACE2 KI mice infected by variants with a delay of endpoint for Delta and BA.1, and a significantly attenuated pathogenicity was observed for BA.2. The pneumonia of infected mice was accompanied by the infiltration of neutrophils and pulmonary fibrosis in the lung. Compared with K18-hACE2 Tg mice and HFH4-hACE2 Tg mice, K18-hACE2 KI mice are more susceptible to SARS-CoV-2. In the antivirals test, REGN10933 and Remdesivir had limited antiviral efficacies in K18-hACE2 KI mice upon the challenge of SARS-CoV-2 infections, while Nirmatrelvir, monoclonal antibody 4G4, and mRNA vaccines potently protected the mice from death. Our results suggest that the K18-hACE2 KI mouse model is lethal and stable for SARS-CoV-2 infection, and is practicable and stringent to antiviral development.

Universal cutoff for tumor mutational burden in predicting the efficacy of anti-PD-(L)1 therapy for advanced cancers.

Background: The US Food and Drug Administration (FDA)'s tumor-agnostic approval of pembrolizumab in high tumor mutational burden (TMB-high, i.e., TMB≥10 mut/Mb) cases, based on the data from KEYNOTE-158, has raised considerable concerns among the immuno-oncology community. This study aims to statistically infer the optimal universal cutoff in defining TMB-high that is predictive of the efficacy of anti-PD-(L) 1 therapy in advanced solid tumors. Methods: We integrated MSK-IMPACT TMB data from a public cohort and the objective response rate (ORR) for anti-PD-(L) 1 monotherapy across diverse cancer types in published trials. The optimal TMB cutoff was determined by varying the universal cutoff to define TMB-high across cancer types and examining the cancer-level correlation between objective response rate and the proportion of TMB-high cases. The utility of this cutoff in predicting overall survival (OS) benefits from anti-PD-(L) 1 therapy was then evaluated in a validation cohort of advanced cancers with coupled MSK-IMPACT TMB and OS data. In silico analysis of whole-exome sequencing data from The Cancer Genome Atlas was further employed to assess the generalizability of the identified cutoff among panels comprising several hundred genes. Results: The cancer type-level analysis identified 10 mut/Mb as the optimal cutoff for MSK-IMPACT in defining TMB-high, with the corresponding TMB-high (TMB≥10 mut/Mb) percentage strongly correlated with ORR for PD-(L) 1 blockade across cancer types [correlation coefficient, 0.72 (95% CI, 0.45-0.88)]. This cutoff was also the optimum in defining TMB-high (via MSK-IMPACT) when predicting OS benefits from anti-PD-(L) 1 therapy in the validation cohort. In this cohort, TMB≥10 mut/Mb was associated with significantly improved OS (hazard ratio, 0.58 [95% CI, 0.48-0.71]; p < 0.001). Moreover, in silico analyses revealed excellent agreement of TMB≥10 mut/Mb cases between MSK-IMPACT and the FDA-approved panels and between MSK-IMPACT and various randomly sampled panels. Conclusion: Our study demonstrates that 10 mut/Mb is the optimal, universal cutoff for TMB-high that guides the clinical application of anti-PD-(L) 1 therapy for advanced solid tumors. It also provides rigorous evidence beyond KEYNOTE-158 for the utility of TMB≥10 mut/Mb in predicting the efficacy of PD-(L) 1 blockade in broader settings, which could help to mitigate the challenges in embracing the tumor-agnostic approval of pembrolizumab in TMB-high cases.

Multiple mycotoxins in commonly used edible oils: Occurrence and evaluation of potential health risks.

In this study, the contamination of 51 mycotoxins in 416 edible oils were determined by UPLC-MS/MS. Totally, twenty-four mycotoxins were detected and nearly half of the samples (46.9%, n = 195) were contaminated simultaneously with six to nine kinds of mycotoxins. The predominant mycotoxins and contamination characteristics varied depending on the type of oils. More specifically, four enniatins, alternariol monomethyl ether (AME) and zearalenone were the most frequent combination. Overall, peanut and sesame oils (10.7-11.7 mycotoxins on average) were found to be the most contaminated matrices whereas camellia and sunflower seed oils (1.8-2.7 species) were the opposite. Dietary exposure risks of mycotoxins were acceptable in most cases, however, the ingestion of aflatoxins (especially aflatoxin B1) through peanut and sesame oil (margin of exposure: 239.4-386.3 < 10000) exceeded the acceptable carcinogenic risk level. Meanwhile, the risks of cumulative ingestion through the food chain should be of great concern, especially sterigmatocystin, ochratoxin A, AME and zearalenone.

Vaccination with Span, an antigen guided by SARS-CoV-2 S protein evolution, protects against challenge with viral variants in mice.

SARS-CoV-2 continues to accumulate mutations to evade immunity, leading to breakthrough infections after vaccination. How researchers can anticipate the evolutionary trajectory of the virus in advance in the design of next-generation vaccines requires investigation. Here, we performed a comprehensive study of 11,650,487 SARS-CoV-2 sequences, which revealed that the SARS-CoV-2 spike (S) protein evolved not randomly but into directional paths of either high infectivity plus low immune resistance or low infectivity plus high immune resistance. The viral infectivity and immune resistance of variants are generally incompatible, except for limited variants such as Beta and Kappa. The Omicron variant has the highest immune resistance but showed high infectivity in only one of the tested cell lines. To provide cross-clade immunity against variants that undergo diverse evolutionary pathways, we designed a new pan-vaccine antigen (Span). Span was designed by analyzing the homology of 2675 SARS-CoV-2 S protein sequences from the NCBI database before the Delta variant emerged. The refined Span protein harbors high-frequency residues at given positions that reflect cross-clade generality in sequence evolution. Compared with a prototype wild-type (Swt) vaccine, which, when administered to mice, induced serum with decreased neutralization activity against emerging variants, Span vaccination of mice elicited broad immunity to a wide range of variants, including those that emerged after our design. Moreover, vaccinating mice with a heterologous Span booster conferred complete protection against lethal infection with the Omicron variant. Our results highlight the importance and feasibility of a universal vaccine to fight against SARS-CoV-2 antigenic drift.

A Review of Traditional Chinese Medicine on Treatment of Diabetic Nephropathy and the Involved Mechanisms.

Diabetic nephropathy (DN) is a common microvascular complication of diabetes mellitus (DM), which can lead to renal failure in diabetic patients. At present, the first-line drugs for DN are mainly the renin-angiotensin system (RAS) inhibitors or angiotensin receptor blockers, and the latest approved aldosterone receptor antagonist finerenone, which delay the progression of DN to end-stage renal disease (ESRD), but the therapeutic effect is still not ideal. With a history of thousands of years, traditional Chinese medicine (TCM) has rich experience in the treatment of DN. Based on the theory of TCM, the clinical treatment of DN mainly focuses on generating fluid and nourishing blood, nourishing Qi and Yin, detoxifying and detumescent. In recently years, the therapeutic effects and mechanisms of TCM prescription, Chinese herbal medicine, and its active components on DN have received extensive attention in new drug development. This paper reviews the research progress of the mechanism of TCM on DN.

A Broad Antiviral Strategy: Inhibitors of Human DHODH Pave the Way for Host-Targeting Antivirals against Emerging and Re-Emerging Viruses.

New strategies to rapidly develop broad-spectrum antiviral therapies are urgently required for emerging and re-emerging viruses. Host-targeting antivirals (HTAs) that target the universal host factors necessary for viral replication are the most promising approach, with broad-spectrum, foresighted function, and low resistance. We and others recently identified that host dihydroorotate dehydrogenase (DHODH) is one of the universal host factors essential for the replication of many acute-infectious viruses. DHODH is a rate-limiting enzyme catalyzing the fourth step in de novo pyrimidine synthesis. Therefore, it has also been developed as a therapeutic target for many diseases relying on cellular pyrimidine resources, such as cancers, autoimmune diseases, and viral or bacterial infections. Significantly, the successful use of DHODH inhibitors (DHODHi) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection further supports the application prospects. This review focuses on the advantages of HTAs and the antiviral effects of DHODHi with clinical applications. The multiple functions of DHODHi in inhibiting viral replication, stimulating ISGs expression, and suppressing cytokine storms make DHODHi a potent strategy against viral infection.

Reprogramming of Glucose Metabolism Pathways in Triple-negative Breast Cancer Cells under Hypoxia / 中国生物化学与分子生物学报

Metabolic changes are recognized as one of the hallmarks of cancer cells. Previous studies have shown that hypoxia can change the glucose metabolism of cancer cells. However, the mechanisms still need to be studied in detail. In this study, by using RNA-Sequencing (RNA-seq) and bioinformatics analysis, we found that there is a significant change in the expression of 334 genes in BT549 cells and 215 genes in MDA-MB-231 cells induced by hypoxia at the mRNA level. Most of these genes were associated with glucose metabolism. RNA-seq data, Western blot, enzyme activity assays, and metabolite quantification experiments showed that the glucose uptake increased by elevating the expression of glucose transporter protein 1 (GLUT1) in BT549 cells and GLUT1 and GLUT3 in MDA-MB-231 cells induced by hypoxia. Hypoxia promotes glycolysis by increasing the expression of at least one isozyme or enzyme protein subunit of the enzymes that catalyze the each reaction in the glycolysis pathway, as well as the regulatory enzymes 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3) and 4 (PFKFB4) isozymes. Hypoxia increases the expression of pyruvate dehydrogenase kinase 1 (PDK1) and PDK3 and reduces the expression of isocitrate dehydrogenase 3(IDH3), succinate dehydrogenase subunit B(SDHB) and D(SDHD) to reduce the aerobic oxidation pathway. The expression of glucose-6-phosphate dehydrogenase (G6PD) and glycogen synthase was significantly increased to promote the pentose phosphate pathway and glycogen synthesis pathway. The mRNA levels of enzyme genes had no significant difference in gluconeogenesis and glycogenolysis. The breast cancer database suggests that the mRNA levels of the glucose metabolism enzymes were consistent in vivo and in vitro. Hypoxia regulates the reprogramming of glucose metabolism by altering the gene expression of isozymes or subunits of these enzymes. The study comprehensively analyzed the effects of hypoxia on the expression of all enzyme genes and major regulatory enzymes in six glucose metabolism pathways and provides an understanding of glucose metabolism in cancer cells under a hypoxia environment.

USP22 promotes IRF3 nuclear translocation and antiviral responses by deubiquitinating the importin protein KPNA2.

USP22 is a cytoplasmic and nuclear deubiquitinating enzyme, and the functions of cytoplasmic USP22 are unclear. Here, we discovered that cytoplasmic USP22 promoted nuclear translocation of IRF3 by deubiquitianting and stabilizing KPNA2 after viral infection. Viral infection induced USP22-IRF3 association in the cytoplasm in a KPNA2-depedent manner, and knockdown or knockout of USP22 or KPNA2 impaired IRF3 nuclear translocation and expression of downstream genes after viral infection. Consistently, Cre-ER Usp22fl/fl or Lyz2-Cre Usp22fl/fl mice produced decreased levels of type I IFNs after viral infection and exhibited increased susceptibility to lethal viral infection compared with the respective control littermates. Mechanistically, USP22 deubiquitinated and stabilized KPNA2 after viral infection to facilitate efficient nuclear translocation of IRF3. Reconstitution of KPNA2 into USP22 knockout cells restored virus-triggered nuclear translocation of IRF3 and cellular antiviral responses. These findings define a previously unknown function of cytoplasmic USP22 and establish a mechanistic link between USP22 and IRF3 nuclear translocation that expands potential therapeutic strategies for infectious diseases.

The role of carotid stenosis ultrasound scale in the prediction of ischemic stroke.

INTRODUCTION: To improve the accuracy of ultrasound techniques for the assessment of carotid stenosis, we designed a novel carotid artery stenosis ultrasound scale (CASUS), and evaluated its accuracy, reliability, and its value in predicting the occurrence of cardiovascular and cerebrovascular diseases in a prospective study. METHODS: A total of 750 patients with first-time ischemic stroke and hospitalized within 24 h were enrolled in the study. Using color Doppler ultrasound (CDUS), the degree of stenosis and blood flow (BF) in bilateral internal carotid arteries (ICA) and the V1-V3 segment of vertebral arteries (VA) was assessed. Cubic simulation curves for BF and global blood flow (GBF) over the stenosis score (SS), total stenosis score (TSS), and radiological imaging- total stenosis score (RI-TSS) were fitted and compared. The receiver operating characteristic (ROC) curves using TSS, RI-TSS, or GBF to predict various ischemic stroke endpoints were also analyzed and compared. RESULTS: There was a linear relationship between SS and BF both ICA and VA (R2 were 0.734 and 0.783, respectively, both P < 0.05). Both TSS and RI-TSS with GBF showed an inverse "S" curve relationship (R2 was 0.839 and 0.843, all P < 0.05). The AUC values of TSS-based and RI-TSS-based predictions of each endpoint were all greater than 0.7 (all P < 0.05), but the differences of the AUC values between TSS, RI-TSS, and GBF were not statistically significant (all P > 0.05). CONCLUSIONS: The novel CASUS can better reflect the level of cerebral reperfusion in patients with ischemic stroke and can better predict the occurrence of cardiovascular and cerebrovascular diseases.

Contamination status of bisphenol A and its analogues (bisphenol S, F and B) in foodstuffs and the implications for dietary exposure on adult residents in Zhejiang Province.

An effective method has been developed for the simultaneous determination of four bisphenols (bisphenol A, S, F and B) in various foodstuffs. The contaminants were extracted by QuEChERS-based strategy and subjected to ion-exchange solid-phase extraction for further clean-up. The critical variables were screened by Plackett-Burman design and then optimized by central composite design. Under the optimized conditions, satisfactory accuracy (recoveries 76%-116%) and precision (RSDs < 12%) were achieved. The established method was then used to assess the contamination status of 379 real samples. Bisphenol A was demonstrated to be the predominant bisphenol with highest incidence (79.7%) and average concentration (14.3 µg/kg). The positive rates (mean concentration) of bisphenol S, F and B were 37.7% (1.6 µg/kg), 26.9% (1.4 µg/kg) and 0.0% (not detected), respectively. Finally, the daily dietary intakes of ∑4bisphenolsfor adult residents were estimated (55.9-76.1 ng/kg bw/day) according to the contamination concentrations and the daily recommended intakes.

CYP3A4/5 mediates the metabolic detoxification of humantenmine, a highly toxic alkaloid from Gelsemium elegans Benth.

Gelsemium elegans Benth., a well-known toxic herbal plant, is widely used to treat rheumatic arthritis, inflammation and other diseases. Gelsemium contains humantenmine (HMT), which is an important bioactive and toxic alkaloid. Cytochrome P450 enzymes (CYPs) play important roles in the elimination and detoxification of exogenous substances. This study aimed to investigate the roles of CYPs in the metabolism and detoxification of HMT. First, metabolic studies were performed in vitro by using human liver microsomes, selective chemical inhibitors and recombinant human CYPs. Results indicated that four metabolites, including hydroxylation and oxidation metabolites, were found in human liver microsomes and identified based on their high-resolution mass spectrum. The isoform responsible for HMT metabolism was mainly CYP3A4/5. Second, the toxicity of HMT on L02 cells in the presence of the nicotinamide adenine dinucleotide phosphate system (NADPH) was significantly less than that without NADPH system. A CYP3A4/5 activity inhibition model was established by intraperitoneally injecting ketoconazole in mice and used to evaluate the role of CYP3A4/5 in HMT detoxification. In this model, the 14-day survival rate of the mice decreased to 17% after they were intragastrically treated with HMT, along with hepatic injury and increasing alanine aminotransferase (ALT) /aspartate aminotransferase (AST) levels. Overall, CYP3A4/5 mediated the metabolism and detoxification of HMT.

USP20 Promotes Cellular Antiviral Responses via Deconjugating K48-Linked Ubiquitination of MITA.

Mediator of IRF3 activation ([MITA] also known as STING) is a direct sensor of cyclic dinucleotide and critically mediates cytoplasmic DNA--triggered innate immune signaling. The activity of MITA is extensively regulated by ubiquitination and deubiquitination. In this study, we report that USP20 interacts with and removes K48-linked ubiquitin chains from MITA after HSV-1 infection, thereby stabilizing MITA and promoting cellular antiviral responses. Deletion of USP20 accelerates HSV-1-induced degradation of MITA and impairs phosphorylation of IRF3 and IκBα as well as subsequent induction of type I IFNs and proinflammatory cytokines after HSV-1 infection or cytoplasmic DNA challenge. Consistently, Usp20 -/- mice produce decreased type I IFNs and proinflammatory cytokines, exhibit increased susceptibility to lethal HSV-1 infection, and aggravated HSV-1 replication compared with Usp20 +/+ mice. In addition, complement of MITA into Usp20 -/- cells fully restores HSV-1-triggered signaling and inhibits HSV-1 infection. These findings suggest a crucial role of USP20 in maintaining the stability of MITA and promoting innate antiviral signaling.

Induction of OTUD4 by viral infection promotes antiviral responses through deubiquitinating and stabilizing MAVS.

The activity and stability of the adapter protein MAVS (also known as VISA, Cardif and IPS-1), which critically mediates cellular antiviral responses, are extensively regulated by ubiquitination. However, the process whereby MAVS is deubiquitinated is unclear. Here, we report that the ovarian tumor family deubiquitinase 4 (OTUD4) targets MAVS for deubiquitination. Viral infection leads to the IRF3/7-dependent upregulation of OTUD4 which interacts with MAVS to remove K48-linked polyubiquitin chains, thereby maintaining MAVS stability and promoting innate antiviral signaling. Knockout or knockdown of OTUD4 impairs RNA virus-triggered activation of IRF3 and NF-κB, expression of their downstream target genes, and potentiates VSV replication in vitro and in vivo. Consistently, Cre-ER Otud4fl/fl or Lyz2-Cre Otud4fl/fl mice produce decreased levels of type I interferons and proinflammatory cytokines and exhibit increased sensitivity to VSV infection compared to their control littermates. In addition, reconstitution of MAVS into OTUD4-deficient cells restores virus-induced expression of downstream genes and cellular antiviral responses. Together, our findings uncover an essential role of OTUD4 in virus-triggered signaling and contribute to the understanding of deubiquitination-mediated regulation of innate antiviral responses.

A feasibility study of producing a peanut oil matrix candidate reference material and its application to support monitoring of aflatoxins statues for public health purposes.

The first peanut oil reference materials in naturally contaminated aflatoxins was developed, because of the high consumption of this product and the potential risk associated herewith. Based on liquid chromatographic method, homogeneity, short-term of 60 °C for seven days and long-term of 25 °C for twelve months' stability studies of candidates were assessed. The obtained data and statistical results showed a successful feasibility study, without any significant trend. Nine selected expert laboratories were invited to certify the contents of candidates using distinguish quantitative liquid chromatographic method. The certified values and expanded uncertainties (k = 2) for these two batches were 6.5 ±â€¯1.6 µg/kg, 29.3 ±â€¯5.3 µg/kg for aflatoxin B1; 1.2 ±â€¯0.3 µg/kg, 5.2 ±â€¯0.9 µg/kg for aflatoxin B2; 5.0 ±â€¯0.4 µg/kg, 8.4 ±â€¯0.7 µg/kg for aflatoxin G1; and 2.1 ±â€¯0.2 µg/kg, 3.5 ±â€¯0.2 µg/kg for aflatoxin G2, respectively.

Silencing of Tctex1 impairs autophagy lysosomal degradation of α-synuclein and cell viability.

Tctex1 is an important element of the dynein motor unit in mammalian cells that helps move targets along microtubules and toward the centrosome for degradation. Here, we analyzed the role of Tctex1 in the α-synuclein autophagy-lysosome degradation pathway using Tctex1-siRNA in SH-SY5Y cells. Results showed that siRNA silencing of Tctex1 suppressed cellular viability and promoted cell apoptosis. Protein and mRNA expression of Tctex1 and dynein decreased after Tctex1 knockdown, whereas α-synuclein, LC3-II, and LAMP2 increased. Consistently, fluorescence intensity of Tctex1 was weaker in siRNA-Tctex1-transfected cells, and that of α-synuclein, LC3-II, and LAMP2 was increased. Tctex1 inhibition reduced cell viability and promoted apoptosis. These results show that Tctex1 plays an important role in α-synuclein autophagic degradation and in maintaining cellular homeostasis.

Fast and quantitative determination of saxitoxin and neosaxitoxin in urine by ultra performance liquid chromatography-triple quadrupole mass spectrometry based on the cleanup of solid phase extraction with hydrophilic interaction mechanism.

Saxitoxin (STX) and neosaxitoxin (NEO) are water-soluble toxins and their cleanup in bio-matrix is a hot topic but difficult problem. A fast and quantitative determination method for STX and NEO in urine was developed using ultra performance liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) based on the cleanup of solid phase extraction (SPE) with hydrophilic interaction (HILIC) mechanism. Acetonitrile/methanol/water mixture was used to extract the toxins in urine. Polyamide (PA) was used as HILIC SPE material to clean the toxins in sample matrix. The limits of detection were 0.2ngmL-1 for STX and 1ngmL-1 for NEO in urine. The linear ranges were 0.5ngmL-1-99.2ngmL-1 with the correlation coefficient of r=0.9992 for STX and 2.1ngmL-1-207ngmL-1 with r=0.997 for NEO in urine matrix. The recoveries at three spiking levels were 81.5%-117% with the relative standard deviations (RSDs) of 5.4%-8.5% for STX and 89.0%-118% with the RSDs of 6.7%-9.1% for NEO. STX was found in all the 6 patients' urines while NEO was only found in one sample from an intoxication case.

Optimization for quick, easy, cheap, effective, rugged and safe extraction of mycotoxins and veterinary drugs by response surface methodology for application to egg and milk.

A multiclass method was proposed for the simultaneous determination of various classes of veterinary drugs (n = 65), mycotoxins and metabolites (n = 39) in egg and milk by ultra-high performance liquid chromatography-tandem mass spectrometry. The contaminants were extracted by QuEChERS-based strategy including salt-out partitioning and dispersive solid-phase extraction for cleanup further. With the aim of maximizing throughput and extraction efficiency, Plackett-Burman design was employed initially for screening significant variables. And response surface methodology based on central composite design was conducted to achieve optimal conditions in details: 3.35% (v/v) of formic acid in acetonitrile, 1.2 g of NaCl, 0.5 g of anhydrous NaAc, 300 mg of C18 and 140 mg of primary secondary amine. Satisfactory analytical characteristics in validation, in aspects of accuracy (70%-105% for mycotoxins and quinolones, 55%-80% for sulphonamides and 40%-105% for other veterinary drugs), precision (inter-day RSDs < 14%) and sensitivity (LOQs ranged from 0.01 µg/kg to 31 µg/kg), were achieved under the optimized conditions. The matrix effects were evaluated and compensated by the use of matrix-matched calibration curves (R2 > 0.987). In practice, 45 eggs and 30 milk samples were investigated by the established method, of which positive finding aflatoxin in milk and sterigmatocystin in eggs.

Simultaneous determination of five Alternaria toxins in cereals using QuEChERS-based methodology.

Two analytical approaches, including ultra-high performance liquid chromatograph linked with photo-diode array/fluorescence detector, and ultra-high performance liquid chromatography-tandem mass spectrometry, have been proposed for simultaneous determination of five Alternaria toxins in cereals, which both based on QuEChERS strategy. After QuEChERS extraction and salting out, the collected supernatant was subjected to an extra dispersive liquid-liquid microextraction step prior to quantitative analysis. Response surface methodology based on central composite design was employed to optimize the micro-extraction conditions. During photo-diode array/fluorescence detector method validation, satisfactory analytical characteristics, in terms of selectivity, recovery (72.7%-109.1%), precision (inter-day RSDs <9.6%), sensitivity (limits of quantification ranged from 2.1µgkg-1 to 120.0µgkg-1) and linearity (R2 all higher than 0.9984), were achieved. Mass spectrometry method was employed as a certified method for accuracy. The two methodologies were successfully applied to 71 samples including three different matrices and the quantitative results were compared. As the result of non-parametric test shown, the established two analytical approach exhibited comparable quantitative accuracy to each other.

USP13 negatively regulates antiviral responses by deubiquitinating STING.

STING (also known as MITA) is critical for host defence against viruses and the activity of STING is regulated by ubiquitination. However, the deubiquitination of STING is not fully understood. Here, we show that ubiquitin-specific protease 13 (USP13) is a STING-interacting protein that catalyses deubiquitination of STING. Knockdown or knockout of USP13 potentiates activation of IRF3 and NF-κB and expression of downstream genes after HSV-1 infection or transfection of DNA ligands. USP13 deficiency results in impaired replication of HSV-1. Consistently, USP13 deficient mice are more resistant than wild-type littermates to lethal HSV-1 infection. Mechanistically, USP13 deconjugates polyubiquitin chains from STING and prevents the recruitment of TBK1 to the signalling complex, thereby negatively regulating cellular antiviral responses. Our study thus uncovers a function of USP13 in innate antiviral immunity and provides insight into the regulation of innate immunity.