A colorimetric detection method for xanthine oxidase activity and its inhibitors(XOI)based on nitrogen-doped carbon-supported ruthenium metal atom(Ru/NC)nanozyme was developed.Through a host-guest strategy,Ru/NC nanozyme with excellent peroxidase-like activity was prepared using zeolitic imidazolate framework-8(ZIF-8)as the host molecule and ruthenium acetylacetonate(Ru(acac)3)as the guest molecule.Based on its peroxidase-like catalytic activity,the visual method for detection of hydrogen peroxide(H 2O 2)and analysis of xanthine oxidase(XO)activity were developed.Under optimized experimental conditions,the linear detection range for H 2O 2 was 10-500 μmol/L,with a detection limit of 4.8 μmol/L(3σ);for XO activity analysis,the linear range was 1-7 mU/mL,with a detection limit of 0.69 mU/mL(3σ).Furthermore,an effective method for screening XOI was developed,which had the advantages of low cost,simplicity,and visualization.

Detection of poor-water-soluble substances typically requires an organic solvent containing solution,and therefore,the biosensors that can operate in such conditions are highly promising for practical applications.However,most existing biosensors have been developed in aqueous solution and it is hard to work effectively in organic solvent systems.In this work,we uncovered that the G-quadruplex(G4)/hemin DNAzyme(G4HD)could be strongly reactivated by NH4 in organic solvents at concentration up to 30％,and the activity was significantly higher than that in aqueous solutions containing K+.Based on this discovery,a biosensing system was developed for small molecule in 40％methanol by coupling G4HD with our previously identified RNA-cleaving DNAzyme(E3).This system comprised an ATP-activated aptazyme that was made of E3 and a G4HD that was activated by the cleavage product of the aptazyme.By using a manmade pipette tip filter to separate the reaction products,the subsequent colorimetric reaction of the G4HD could be triggered.This biosensing system enabled the visualization of target molecules in organic cosolvents without any other instruments.The activable DNAzyme-cascade sensing system had potential in point-of-care detection of poor-water-soluble pollutants,thereby enhancing the practical values of functional nucleic acid-based biosensors in real-world detection conditions.

Insulin is an important protein hormone that participates in multiple metabolic pathways.Biosynthetic insulin has been widely used in the treatment of type 1 and type 2 diabetes.Currently,the number of reported cases of insulin overdose both at home and abroad is gradually increasing,and insulin homicide is no longer a means of"committing murder without leaving a trace".At present,there are no systematic protocols for the identification of insulin overdose in the field of forensic medi-cine in China.This article introduces the causes,toxicological characteristics,forensic examination,labo-ratory testing methods and indicator reference of insulin overdose.Based on the identification practice and research results and referring to relevant studies on insulin overdose at home and abroad,this pa-per aims to provide recommendations and references for the formulation of forensic identification guide-lines for insulin overdose cases.

OBJECTIVE: To investigate the susceptibility of venetoclax-resistant acute myeloid leukemia (AML) cell lines to ferroptosis and to uncover the underlying molecular mechanisms using transcriptomic and metabolomic analysis methods. METHODS: Venetoclax-resistant AML cell lines were constructed using a low-dose concentration escalation method. The sensitivity of cells to chemotherapeutic drugs was detected by CCK-8 assay. The susceptibility of drug-resistant cell lines to ferroptosis was assessed using transcriptomic and metabolomic analysis methods. The expression of cellular GPX4 and SLC7A11 protein was detected by Western blot, and cell death and lipid peroxidation levels were measured by flow cytometry. Depmap database and TCGA cohort were applied to explore the effect of ferroptosis-related genes expression on prognosis. RESULTS: Venetoclax-resistant cell lines exhibited sensitivity to ferroptosis inducers RSL3, APR246, and sorafenib. The ferroptosis inhibitor Fer-1 partially inhibited cell death induced by these inducers. Compared with the parental cells, significant changes in metabolites and gene expression levels related to ferroptosis were observed in the resistant cell lines. In particular, deregulated expression of SLC7A11 and GPX4 may play critical role in ferroptosis susceptibility. Besides, GPX4 was identified as more important for AML cell survival and higher GPX4 expression may predict shortened overall survival, NPM1 mutant and IDH1 R132 mutation positive patients may prone to possess higher GPX4 expression. CONCLUSION Venetoclax-resistant AML cell lines remain susceptible to ferroptosis, higher GPX4 expression maybe a critical marker for poor prognosis. Regulating the expression of ferroptosis-related genes and metabolites may enhance the efficacy of venetoclax and provide new treatment options for AML patients.
Humans ; Ferroptosis ; Leukemia, Myeloid, Acute/metabolism* ; Sulfonamides/pharmacology* ; Bridged Bicyclo Compounds, Heterocyclic/pharmacology* ; Drug Resistance, Neoplasm ; Metabolomics ; Cell Line, Tumor ; Phospholipid Hydroperoxide Glutathione Peroxidase ; Amino Acid Transport System y+/metabolism* ; Transcriptome

OBJECTIVE: To explore the neuroprotective effects of Xuefu Zhuyu Decoction (XFZYD) based on in vivo and metabolomics experiments. METHODS: Traumatic brain injury (TBI) was induced via a controlled cortical impact (CCI) method. Thirty rats were randomly divided into 3 groups (10 for each): sham, CCI and XFZYD groups (9 g/kg). The administration was performed by intragastric administration for 3 days. Neurological functions tests, histology staining, coagulation and haemorheology assays, and Western blot were examined. Untargeted metabolomics was employed to identify metabolites. The key metabolite was validated by enzyme-linked immunosorbent assay and immunofluorescence. RESULTS: XFZYD significantly alleviated neurological dysfunction in CCI model rats (P<0.01) but had no impact on coagulation function. As evidenced by Evans blue and IgG staining, XFZYD effectively prevented blood-brain barrier (BBB) disruption (P<0.05, P<0.01). Moreover, XFZYD not only increased the expression of collagen IV, occludin and zona occludens 1 but also decreased matrix metalloproteinase-9 (MMP-9) and cyclooxygenase-2 (COX-2), which protected BBB integrity (all P<0.05). Nine potential metabolites were identified, and all of them were reversed by XFZYD. Adenosine was the most significantly altered metabolite related to BBB repair. XFZYD significantly reduced the level of equilibrative nucleoside transporter 2 (ENT2) and increased adenosine (P<0.01), which may improve BBB integrity. CONCLUSIONS XFZYD ameliorates BBB disruption after TBI by decreasing the levels of MMP-9 and COX-2. Through further exploration via metabolomics, we found that XFZYD may exert a protective effect on BBB by regulating adenosine metabolism via ENT2.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Blood-Brain Barrier/metabolism* ; Brain Injuries, Traumatic/metabolism* ; Adenosine/metabolism* ; Male ; Rats, Sprague-Dawley ; Rats

Hepatic stellate cells (HSCs) are the primary fibrogenic cells in the liver, and their activation plays a crucial role in the development and progression of hepatic fibrosis. Here, we report that retinoid X receptor-alpha (RXRα), a unique member of the nuclear receptor superfamily, is a key modulator of HSC activation and liver fibrosis. RXRα exerts its effects by modulating calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ)-mediated activation of AMP-activated protein kinase-alpha (AMPKα). In addition, we demonstrate that K-80003, which binds RXRα by a unique mechanism, effectively suppresses HSC activation, proliferation, and migration, thereby inhibiting liver fibrosis in the CCl₄ and amylin liver NASH (AMLN) diet animal models. The effect is mediated by AMPKα activation, promoting mitophagy in HSCs. Mechanistically, K-80003 activates AMPKα by inducing RXRα to form condensates with CaMKKβ and AMPKα via a two-phase process. The formation of RXRα condensates is driven by its N-terminal intrinsic disorder region and requires phosphorylation by CaMKKβ. Our results reveal a crucial role of RXRα in liver fibrosis regulation through modulating mitochondrial activities in HSCs. Furthermore, they suggest that K-80003 and related RXRα modulators hold promise as therapeutic agents for fibrosis-related diseases.

Targeted covalent inhibitors, primarily targeting cysteine residues, have attracted great attention as potential drug candidates due to good potency and prolonged duration of action. However, their discovery is challenging. In this research, a database-assisted liquid chromatography-tandem mass spectrometry (LC-MS/MS) strategy was developed to quickly discover potential cysteine-targeting compounds. First, compounds with potential reactive groups were selected and incubated with N-acetyl-cysteine in microsomes. And the precursor ions of possible cysteine-adducts were predicted based on covalent binding mechanisms to establish in-house database. Second, substrate-independent product ions produced from N-acetyl-cysteine moiety were selected. Third, multiple reaction monitoring scan was conducted to achieve sensitive screening for cysteine-targeting compounds. This strategy showed broad applicability, and covalent compounds with diverse structures were screened out, offering structural resources for covalent inhibitors development. Moreover, the screened compounds, norketamine and hydroxynorketamine, could modify synaptic transmission-related proteins in vivo, indicating their potential as covalent inhibitors. This experimental-based screening strategy provides a quick and reliable guidance for the design and discovery of covalent inhibitors.

Targeted covalent inhibitors,primarily targeting cysteine residues,have attracted great attention as potential drug candidates due to good potency and prolonged duration of action.However,their dis-covery is challenging.In this research,a database-assisted liquid chromatography-tandem mass spec-trometry(LC-MS/MS)strategy was developed to quickly discover potential cysteine-targeting compounds.First,compounds with potential reactive groups were selected and incubated with N-acetyl-cysteine in microsomes.And the precursor ions of possible cysteine-adducts were predicted based on covalent binding mechanisms to establish in-house database.Second,substrate-independent product ions produced from N-acetyl-cysteine moiety were selected.Third,multiple reaction monitoring scan was conducted to achieve sensitive screening for cysteine-targeting compounds.This strategy showed broad applicability,and covalent compounds with diverse structures were screened out,offering structural resources for covalent inhibitors development.Moreover,the screened compounds,norket-amine and hydroxynorketamine,could modify synaptic transmission-related proteins in vivo,indicating their potential as covalent inhibitors.This experimental-based screening strategy provides a quick and reliable guidance for the design and discovery of covalent inhibitors.

This study was aimed at determining the molecular characteristics of Yersinia pestis in the natural plague foci around Qinghai Lake through single nucleotide polymorphism technology,to lay a foundation for molecular epidemiological and source-tracing analysis of Y.pestis in this area.Using the whole genome sequencing technology,we obtained the whole genome sequences of 84 representative Y.pestis strains.Using the sequences of Y.pestis and Yersinia pseudotuberculosis IP32953 from the NCBI database as references,we compared and analyzed the 2 298 SNP loci of these strains.From 1957 to 2020,84 representative strains of Y.pestis from the natural plague foci around Qinghai Lake were divided into two clades:1.IN2 and 3.ANT1.The 1.IN2 clade was the characteristic population of Y.pestis throughout all epidemic years in this area.Additionally,analysis of the SNP distribution and hosts in the region indicated that the 1.IN2 clade was located in five counties except Wulan,whereas the 3.ANT1 clade was isolated from Himalayan marmot and dog in two counties.In conclusion,the population structure of SNP of Y.pestis in the natural plague foci around Qinghai Lake is relatively simple,and SNP analysis of Y.pestis provided a scientific basis for tracing plague epidemic sources and formulating plague prevention and control measures in this area.

Alzheimer disease(AD)is a neurodegenerative disorder characterized by the abnormal deposition of amyloid β-protein(Aβ).Inflammation plays a significant role in promoting this abnormal deposition.Toll-like receptor 4(TLR4)is recognized as a"primary regulator"of the inflammatory response,facilitating the activation of microglia and interacting with various pathways,including nuclear factor-κB and nucleotide-binding oligomerization domain-like recep-tor protein 3.This interaction can lead to an inflammatory cascade that accelerates the progression of AD.Numerous pro-spective studies have demonstrated that traditional Chinese medicine can modulate the TLR4 signaling pathway,effective-ly addressing both the onset and progression of AD.However,a comprehensive review of how Chinese medicine regulates this pathway in the treatment of AD is currently lacking.Therefore,this paper aims to detail the latest findings related to TLR4 in the prevention and treatment of AD,drawing from recent literature.It will explore the mediation of traditional Chinese medicine,preserving its essence,and provide references and a basis for clinical practices aimed at preventing and treating AD.