Ursodeoxycholic acid (UDCA) is a naturally occurring, low-toxicity, and hydrophilic bile acid (BA) in the human body that is converted by intestinal flora using primary BA. Solute carrier family 7 member 11 (SLC7A11) functions to uptake extracellular cystine in exchange for glutamate, and is highly expressed in a variety of human cancers. Retroperitoneal liposarcoma (RLPS) refers to liposarcoma originating from the retroperitoneal area. Lipidomics analysis revealed that UDCA was one of the most significantly downregulated metabolites in sera of RLPS patients compared with healthy subjects. The augmentation of UDCA concentration (≥25 μg/mL) demonstrated a suppressive effect on the proliferation of liposarcoma cells. [¹⁵N₂]-cystine and [¹³C₅]-glutamine isotope tracing revealed that UDCA impairs cystine uptake and glutathione (GSH) synthesis. Mechanistically, UDCA binds to the cystine transporter SLC7A11 to inhibit cystine uptake and impair GSH de novo synthesis, leading to reactive oxygen species (ROS) accumulation and mitochondrial oxidative damage. Furthermore, UDCA can promote the anti-cancer effects of ferroptosis inducers (Erastin, RSL3), the murine double minute 2 (MDM2) inhibitors (Nutlin 3a, RG7112), cyclin dependent kinase 4 (CDK4) inhibitor (Abemaciclib), and glutaminase inhibitor (CB839). Together, UDCA functions as a cystine exchange factor that binds to SLC7A11 for antitumor activity, and SLC7A11 is not only a new transporter for BA but also a clinically applicable target for UDCA. More importantly, in combination with other antitumor chemotherapy or physiotherapy treatments, UDCA may provide effective and promising treatment strategies for RLPS or other types of tumors in a ROS-dependent manner.

The incomplete degradation of tumour cells by macrophages (Mϕ) is a contributing factor to tumour progression and metastasis, and the degradation function of Mϕ is mediated through phagosomes and lysosomes. In our preliminary experiments, we found that overactivation of NADPH oxidase 2 (NOX2) reduced the ability of Mϕ to degrade engulfed tumour cells. Above this, we screened out liquiritin from Glycyrrhiza uralensis Fisch, which can significantly inhibit NOX2 activity and inhibit tumours, to elucidate that suppressing NOX2 can enhance the ability of Mϕ to degrade tumour cells. We found that the tumour environment could activate the NOX2 activity in Mϕ phagosomes, causing Mϕ to produce excessive reactive oxygen species (ROS), thus prohibiting the formation of phagolysosomes before degradation. Conversely, inhibiting NOX2 in Mϕ by liquiritin can reduce ROS and promote phagosome-lysosome fusion, therefore improving the enzymatic degradation of tumour cells after phagocytosis, and subsequently promote T cell activity by presenting antigens. We further confirmed that liquiritin down-regulated the expression of the NOX2 specific membrane component protein gp91 phox, blocking its binding to the NOX2 cytoplasmic component proteins p67 phox and p47 phox, thereby inhibiting the activity of NOX2. This study elucidates the specific mechanism by which Mϕ cannot degrade tumour cells after phagocytosis, and indicates that liquiritin can promote the ability of Mϕ to degrade tumour cells by suppressing NOX2.

Homo- or heterodimeric compounds that affect dimeric protein function through interaction between monomeric moieties and protein subunits can serve as valuable sources of potent and selective drug candidates. Here, we screened an in-house dimeric natural product collection, and panepocyclinol A (PecA) emerged as a selective and potent STAT3 inhibitor with profound anti-tumor efficacy. Through cross-linking C712/C718 residues in separate STAT3 monomers with two distinct Michael receptors, PecA inhibits STAT3 DNA binding affinity and transcription activity. Molecular dynamics simulation reveals the key conformation changes of STAT3 dimers upon the di-covalent binding with PecA that abolishes its DNA interactions. Furthermore, PecA exhibits high efficacy against anaplastic large T cell lymphoma in vitro and in vivo, especially those with constitutively activated STAT3 or STAT3^Y640F. In summary, our study describes a distinct and effective di-covalent modification for the dimeric compound PecA to disrupt STAT3 function.

Objective:To explore the protective effect of sesquiterpene lactones of Eupatorium lindleyanum DC.(SLEL)on lipopolysac-charide(LPS)-induced acute lung injury(ALI)in rats using metabolomics.Methods:Forty-eight male SD rats were randomly divided into a blank control group(CG),a model control group(MG),low-,medium-,and high-dose SLEL groups(50,100,and 200 mg/kg),and a positive control group(dexamethasone acetate tablets,5 mg/kg).CG and MG groups were given phosphate-buffered saline.All groups received intragastric administration at a dose volume of 10 mL/kg once a day for 7 consecutive days.One hour after the last ad-ministration,LPS(5 mg/kg)was instilled into the trachea of all groups except the CG group to establish the ALI rat model.Twenty-four hours after model establishment,blood was collected from the abdominal aorta and bronchoalveolar lavage fluid(BALF)was col-lected from the left lung.The total number of inflammatory cells,neutrophils,lymphocytes,and eosinophils in BALF was counted by Wright-Giemsa staining.The levels of interleukin-18(IL-18)and interferon-γ(IFN-γ)in serum and BALF were measured by enzyme-linked immunosorbent assay.The pathological changes of lung tissue were observed using hematoxylin-eosin staining.The ex-pression levels of tight junction protein-1(ZO-1)and occludin in lung tissue were determined by Western blot.The mRNA expression levels of IL-18,IFN-γ,ZO-1,and occludin in the lung were measured by real-time fluorescence quantitative PCR.Non-targeted me-tabolomics analysis of serum and lung tissue was performed using ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry.Results:Compared with the MG group,all SLEL groups had significantly reduced wet/dry weight ratio of lung tissue,lung coefficient,and total number of inflammatory cells,neutrophils,lymphocytes,and eosinophils in BALF.SLEL signifi-cantly decreased the levels of IL-18 and IFN-γ in serum and BALF and the mRNA expression of IL-18 and IFN-γ in lung tissue,and significantly promoted the protein and mRNA expression of ZO-1 and occludin.Under light microscopy,the degree of lung tissue edema,alveolar hemorrhage,and inflammatory cell infiltration were significantly reduced,indicating a certain protective effect on ALI rats.The results of non-targeted metabolomics studies showed that there were 91 and 33 significantly different metabolites in the serum and lung tissue of rats treated with SLEL,respectively.Among them,the main differential metabolites in the serum were sphingosine,L-lactic acid,nicotinic acid,D-nucleotide,and mevalonate-5P,while the main differential metabolites in the lung tissue were tauro-cholic acid.This suggests that SLEL may mainly affect the metabolic pathways of sphingolipids,pyruvate,nicotinic acid,nicotinamide,and tryptophan in the serum and the metabolic pathways of taurine and hypotaurine in the lung tissue to improve ALI.Conclusion:SLEL has a significant protective effect on rats against LPS-induced ALI,and its mechanism of action may be related to the inhibition of inflammatory factors,improvement of lung barrier function,and regulation of related metabolic pathways.

Sarin(GB)is a typical representative of nerve agents with high toxicity,and very low amount can cause death.GB can cause water and atmospheric environment poisoning,so the detection of GB in water and air is of great significance.In this work,a colorimetric sensor array(CSA)based on GB inhibition of cholinesterase activity was constructed to detect GB with high selectivity.A 4×4 colorimetric array was constructed using acetylcholinesterase(AChE),butyryl cholinesterase(BuChE)and the corresponding substrate acetylthiocholine iodide(S-ACh),butyryl thiocholine iodide(S-BCh),acetylcholine chloride(ACh),butyryl choline chloride(BCh)and 2,6-dichloroindophenol ethyl ester(DCIE).The linear curve of the sensor was Y=131.3×lgC+271.6(R2=0.997),where Y was the array response Euclidean distance,C was the concentration of GB(mg/L),the linear range was 0.03?0.32 mg/L,and the detection limit was 27.6 μg/L.The method could effectively distinguish chemical warfare agents(CWA)such as VX,Soman(GD),mustard gas(HD),Louie reagent(L),and had high anti-interference ability,sensitivity and good repeatability.It was successfully applied to the detection of GB in simulated water and simulated air samples,and the sample recovery rate was 97.2% ?100.9%.This method would be potentially applied to the field rapid detection of nerve agents.

Objective To explore the evaluation value of serum follistatin like protein 1(FSTL1)and glu-cose regulatory protein 78(GRP78)on disease severity and readmission in elderly patients with chronic ob-structive pulmonary disease(COPD).Methods A total of 100 elderly COPD patients(COPD group)treated in this hospital from March 2020 to May 2023 were selected as COPD group,and were divided into grade Ⅰ(35 cases),grade Ⅱ(46 cases)and grade Ⅲ(19 cases)according to the severity of the disease.Another 100 elderly volunteers who underwent physical examination during the same period were selected as the control group.Serum FSTL1 and GRP78 levels were detected by enzyme-linked immunosorbent assay(ELISA).Spearman and Pearson correlation were used to analyze the correlation between serum FSTL1 and GRP78 lev-els and general data.The evaluation value of serum FSTL1 and GRP78 levels in COPD patients on disease se-verity and readmission was analyzed by receiver operating characteristics(ROC)curve.Results Compared with the control group,serum levels of FSTL1 and GRP78 in COPD group were significantly increased(P＜0.05).Serum levels of FSTL1 and GRP78 in COPD patients increased with the severity of the disease(P＜0.05).Compared with non-readmission group,the serum levels of FSTL1 and GRP78 in readmission group were significantly increased(P＜0.05).Spearman correlation analysis showed that serum FSTL1 and GRP78 levels were positively correlated with smoking history,hypertension history and disease severity(P＜0.05).Pearson correlation analysis showed that serum FSTL1 and GRP78 levels were negatively correlated with arte-rial oxygen pressure(PaO2),the ratio of forced expiratory volume in the first second to forced vital capacity(FEV1/FVC),and the percentage of forced expiratory volume in the first second to expected value(FEV1％pred),with significance(P＜0.05),while it was positively correlated with the partial pressure of carbon diox-ide(PaCO2),with significance(P＜0.05).ROC curve analysis showed that serum FSTL1,GRP78 and their combined assessment of disease severity and readmitted area under the curve(AUC)were higher in COPD pa-tients,and the combination was significantly better than the single assessment(P＜0.05).Conclusion Serum levels of FSTL1 and GRP78 are significantly increased in COPD patients,which are correlated with the severi-ty of the disease and have a high value in evaluating the severity of the disease and readmission.

Hematologic malignancies,such as lymphoma,myeloma,and myeloid neoplasms,can occur in extramedullary tissues.Traditional histopathological morphology and immunohistochemical staining have lim-itations,including time-consuming specimen processing,prolonged reporting cycles,and relatively low sensi-tivity in cases of limited cell numbers.Flow cytometry offers significant advantages in detecting tissue sam-ples,such as rapid processing,shorter reporting cycles,and high accuracy and sensitivity,making it an effective complement to histopathological and immunohistochemical methods.However,the application of flow cytome-try in tissue sample detection currently lacks standardized protocols for sample collection and preservation,single-cell suspension preparation,antibody panel design for limited samples,data analysis,and result repor-ting.To promote the standardized application of flow cytometry in detecting hematologic tumor cells in tissue samples,the Cell Analysis Professional Committee of the Chinese Society of Biotechnology organized experts to develop the Chinese Expert Consensus on Flow Cytometry for Detecting Hematologic Tumor Cells in Tis-sue Samples(hereinafter referred to as the Consensus).This Consensus elaborates on the technical aspects of flow cytometry for tissue sample detection,covering sample processing,antibody panel design,data analysis,reporting content,and quality management.It particularly emphasizes recommended antibody panels and data analysis methods for flow cytometry when tissue sample cell counts are low.This article aims to interpret the key points of the Consensus to facilitate its better application in clinical practice.

Objective To evaluate the application of flipped classroom(FC)approach in endocrine system integrated course for students from 4+4 clinical medicine pilot class at Peking Union Medical College(PUMC).Methods The study included the students of 4+4 clinical medicine pilot class grades 2019-2023 in PUMC.The students of grades 2019-2021(n=77)served as the control receiving traditional teaching method,while the students of grades 2022 and 2023(n=76)were selected as the experimental group,which were taught by FC approach.The selected teaching content is thyroid theme.The scoring rates of thyroid related questions in the final exam were as-sessed and a questionnaire survey was conducted to evaluate teaching satisfaction and effectiveness.Results The scoring rates of experimental group were significantly higher as compared to that of control group(P＜0.05).Over 90％of the students in the experimental group strongly satisfied or satisfied with the teaching content arrangement,design form,classroom atmosphere,teacher-student interaction of FC and expressed willingness to continue with this methodology.In addition,over 90％of the students strongly agreed or agreed that FC stimulated learning inter-est,improved self-learning ability,strengthened the connection between theory and clinical practice,inspired clini-cal reasoning,enhanced the abilities to analyze and solve problems,and cultivated communication and teamwork skills.Conclusions The application of FC approach in endocrine system integrated course achieved excellent teaching outcomes with high satisfaction of the students.

ObjectiveBody fluid stains left at crime scenes are frequently trace amounts, while the identification of body fluids through real time fluorogenic quantitative technique often necessitates the repeated detection within the limited sample, as multiple miRNA markers are the basis for the identification. Based on the goal of both the throughput and efficiency improvement of miRNA analysis in trace samples, a duplex real time fluorogenic quantitative PCR assay system was designed to accurately quantify two miRNAs simultaneously, and the system should be further verified by actual sample for the body fluid identification. MethodsThe duplex real time fluorogenic quantitative PCR system of miR-451a to miR-21-5p was established with specially designed primers and probes, and the concentrations of the primers and probes were both optimized. The specificity, sensitivity and reproducibility of the system were validated, while its capability for body fluid identification was assessed using the miR-451a to miR-21-5p ratio. ResultsThe optimized assay system exhibited excellent specificity and repeatability, with coefficients of variation consistently below 8% for both intra- and inter-batch variability. The amplification efficiency of miR-451a and miR-21-5p reached 71.77% and 74.81%, respectively, with high and relatively consistent results. By utilizing this duplex real time fluorogenic quantitative PCR assay system, a total of 58 body fluid samples were analyzed, exhibiting a discrimination rate of 100% between blood and non-blood samples, as well as between peripheral blood and menstrual blood samples. Moreover, the results, obtained from single real time fluorogenic quantitative PCR assay system and duplex real time fluorogenic quantitative PCR assay system, showed no statistically significant difference with randomly selected blood samples (n=20). Compared to previous single real time fluorogenic quantitative PCR assay system, the sensitivity of duplex real time fluorogenic quantitative PCR assay system exhibited remarkable improvement. A minimum input of only 0.1 ng total RNA was sufficient for accurate detection of peripheral blood and menstrual blood samples, while saliva, semen, and vaginal secretion required only 1 ng total RNA for precise identification purposes. Additionally, the duplex real time fluorogenic quantitative PCR assay system successfully differentiated between different types of body fluids in simulated samples under natural outdoor conditions. ConclusionThe duplex real time fluorogenic quantitative PCR assay system effectively reduced both the time and material costs by half compared to the single system, especially suitable for the examination of body fluid stains left at crime scenes, solving the contradiction between the trace amount and the multiple sample volumes demand of repeated real time fluorogenic quantitative PCR. The duplex real time fluorogenic quantitative PCR assay successfully distinguished blood and other body fluid, as well as peripheral blood and menstrual blood samples, which maintains an equivalent capability for body fluid identification with half sample, time and reagent consumption. This system provides an efficient tool for identifying suspicious body fluids, as well as a foundation for more multiplexed real time fluorogenic quantitative PCR assay system research.

Volume electron microscopy (vEM) imaging technology was rapidly developed in recent years. It has been the advanced technology to solve high-resolution three-dimensional structures of biological samples. Much wonderful work has revealed the fine structure and interactions of intracellular organelles, the ultrastructure of tissues, and even the three-dimensional structure of entire small biological organisms. With the continuous improvement of resolution, scale and throughput, vEM is becoming more and more widely used in medicine, life sciences, clinical diagnostics and other fields. As a result, this technology has been rated by Nature as one of the seven most noteworthy frontier technologies to watch in 2023. However, the development and application of vEM-related technologies started late in China and need to be further promoted. We write this review to introduce all related vEM technologies, covering the development history of vEM, technology classification, sample preparation, data collection, image processing, etc., which is convenient for people in various fields to understand, learn, apply and further develop this technology.