SARS-CoV-2 and its emerging variants continue to pose a significant global public health threat. The SARS-CoV-2 main protease (M^pro) is a critical target for the development of antiviral agents that can inhibit viral replication and transcription. In this study, we identified chebulagic acid (CHLA), isolated from Terminalia chebula Retz., as a potent non-peptidomimetic and non-covalent M^pro inhibitor. CHLA exhibited intermolecular interactions and provided significant protection to Vero E6 cells against a range of SARS-CoV-2 variants, including the wild-type, Delta, Omicron BA.1.1, BA.2.3, BA.4, and BA.5, with EC₅₀ values below 2 μmol/L. Moreover, in vivo studies confirmed the antiviral efficacy of CHLA in K18-hACE2 mice. Notably, CHLA bound to a unique groove at the interface between M^pro domains I and II, which was revealed by the high-resolution crystal structure (1.4 Å) of the M^pro-CHLA complex, shrinking the substrate binding pocket of M^pro and inducing M^pro aggregation. CHLA was proposed to act as an allosteric inhibitor. Pharmacokinetic profiling and safety assessments underscore CHLA's potential as a promising broad-spectrum antiviral candidate. These findings report a novel binding site on M^pro and identify antiviral activity of CHLA, providing a robust framework for lead compounds discovery and elucidating the underlying molecular mechanisms of inhibition.

Objective To investigate the killing effect of the recombinant oncolytic influenza virus OvFlu-GM-CSF,constructed using reverse genetics(RG)technology,in combination with chemotherapy drug,gemcitabine(GEM),against pancreatic cancer cells.Methods The recombinant oncolytic virus OvFlu-GM-CSF was successfully rescued using RG technology in our previous study.The virus was then comprehensively characterized through chicken red blood cell hemagglutination assay,transmission electron microscopy,and viral replication assay.CCK-8 assay was utilized to determine the impact of OvFlu-GM-CSF viruses[multiplicities of infection(MOI):0,0.1,1.0,3.0]on the survival rate of pancreatic cancer cell lines(Panc02,PANC-1,SW1990,BxPC-3)and normal pancreatic ductal epithelial cells(HPDE6-C7)after treatment for 24,48 or 72 h.Using a subcutaneous tumor-bearing mouse model of pancreatic cancer,36 female C57BL/6 mice(6 weeks old)were randomly divided into PBS group,recombinant oncolytic virus group,GEM group,and the combined treatment group,with 9 mice in each group.PBS(100 μL/animal)or OvFlu-GM-CSF virus(1× 107PFU/100 μL)was given to the mice of the corresponding groups through intratumoral injection,while GEM(100 mg/kg)was injected intraperitoneally,once per 3 days,for totally 9 times.Changes in tumor volume and survival rate were monitored.Multi-immunofluorescence staining was employed to analyze T cell infiltration and proliferation in the tumor tissues.HE staining was performed to observe the pathological changes in major organs(heart,liver,lungs,kidneys and brain),and the serum levels of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)were measured to evaluate the safety of the recombinant oncolytic virus.Results The recombinant oncolytic influenza virus OvFlu-GM-CSF has a hemagglutination titer of 28,typical morphological features of influenza virus,and can selectively replicate within pancreatic cancer cells.At the cellular level,the viruses demonstrated a significant selective cytotoxic effect on Panc02,PANC-1,SW1990,and BxPC-3 cells under the conditions of 48 h post-infection and MOI=3.0,when compared to 48 h post-infection and MOI=0(P＜0.01).The cell survival rate was gradually decreased with the increase in MOI value and the extension of infection time(P＜0.01),but the viruses showed no significant effect on normal pancreatic ductal epithelial cells(HPDE6-C7).In the pancreatic cancer tumor-bearing mouse model,the combined treatment of the viruses+GEM significantly reduced the tumor volume than simple virus treatment and simple GEM treatment(P＜0.01),and enhanced the infiltration of T cells in the tumor tissues.No obvious pathological changes were observed in the above-mentioned major organs.Additionally,there were no significant differences in the serum levels of ALT and AST in the OvFlu-GM-CSF group,GEM group,and OvFlu-GM-CSF+GEM group compared to the PBS group.Conclusion RS technology-constructed recombinant oncolytic influenza virus OvFlu-GM-CSF,when combined with the chemotherapeutic agent GEM,enhances the cytotoxic efficacy against pancreatic cancer cells and effectively activates the host's anti-tumor immune response.

[Objective] To analyze factors influencing the postoperative progression-free survival (PFS) in patients with renal cell carcinoma (RCC), construct a nomogram model for predicting PFS, and compare it with other predictive models. [Methods] A retrospective analysis was conducted on the general and clinical data of 263 RCC patients who underwent surgery at the Department of Urology, the Second Affiliated Hospital of Xi'an Jiaotong University, during Apr.2014 and Nov.2021.Patients were divided into the progression group (n=34) and non-progression group (n=229). The data of the two groups were analyzed to identify prognostic variables associated with PFS, and a nomogram model was constructed.The performance of this model was compared with that of the University of California, Los Angeles Integrated Staging System (UISS) score, tumor staging, tumor size, tumor pathological grade, and tumor necrosis scoring system (SSIGN score), and Leibovich score by plotting receiver operating characteristic (ROC) curve and calculating the area under the curve (AUC). Calibration curve of the nomogram was used to validate the model's performance, and K-fold cross-validation was employed to assess its external validity. [Results] Multivariate Cox regression analysis revealed that age (HR=2.255, 95%CI: 1.032-4.926), T stage (HR=5.766, 95%CI: 2.351-14.142), pathological grade (HR=3.100, 95%CI: 1.445-6.651), and pathological necrosis (HR=2.656, 95%CI: 1.253-5.629) were independent risk factors of PFS (P<0.05). The nomogram model based on these four independent variables had AUCs (95%CI) of 0.750 (0.630-0.870), 0.803 (0.705-0.902), and 0.847 (0.757-0.937) for 1, 3, and 5 years, respectively, which were higher than those of UISS score, SSIGN score, and Leibovich score.The calibration curve of the nomogram showed good consistency between predicted and actual probabilities.In K-fold cross-validation, the average AUCs of the nomogram at 1, 3, and 5 years were 0.761, 0.808, and 0.842, indicating good external validity of the nomogram. [Conclusion] The nomogram based on age, T stage, pathological grade and pathological necrosis can accurately predict the risk of postoperative PFS in RCC patients at 1, 3, and 5 years, which can aid clinicians in the early identification of high-risk progression.

The global COVID-19 coronavirus pandemic has infected over 109 million people, leading to over 2 million deaths up to date and still lacking of effective drugs for patient treatment. Here, we screened about 1.8 million small molecules against the main protease (M^pro) and papain like protease (PL^pro), two major proteases in severe acute respiratory syndrome-coronavirus 2 genome, and identified 1851M^pro inhibitors and 205 PL^pro inhibitors with low nmol/l activity of the best hits. Among these inhibitors, eight small molecules showed dual inhibition effects on both M^pro and PL^pro, exhibiting potential as better candidates for COVID-19 treatment. The best inhibitors of each protease were tested in antiviral assay, with over 40% of M^pro inhibitors and over 20% of PL^pro inhibitors showing high potency in viral inhibition with low cytotoxicity. The X-ray crystal structure of SARS-CoV-2 M^pro in complex with its potent inhibitor 4a was determined at 1.8 Å resolution. Together with docking assays, our results provide a comprehensive resource for future research on anti-SARS-CoV-2 drug development.
Humans ; Antiviral Agents/chemistry* ; COVID-19 ; COVID-19 Drug Treatment ; High-Throughput Screening Assays ; Molecular Docking Simulation ; Protease Inhibitors/chemistry* ; SARS-CoV-2/enzymology* ; Viral Nonstructural Proteins

【Objective】 To construct an easy-to-use individual survival prognostic tool based on competing risk analyses to predict the risk of 1-, 2- and 3- year recurrence for patients with non-muscle invasive bladder cancer (NMIBC). 【Methods】 The follow-up data of 419 NMIBC patients were obtained. The patients were randomly divided into training cohort (n=293) and validation cohort (n=126). The variables included age at diagnosis, sex, history of smoking, tumor number, tumor size, histolo-gic grade, pathological stage, and bladder perfusion drug. The cumulative incidence function (CIF) of recurrence was estimated using all variables in the training cohort and potential prognostic variables were determined with Gray’s test. The Fine-Gray subdistribution proportional hazard approach was used as a multivariate competitive risk analysis to identify independent pro-gnostic variables. A competing risk nomogram was developed to predict the recurrence. The performance of the competing risk model was evaluated with the area under the receiver operating characteristic curve (AUC), calibration curve, and Brier score. 【Results】 Five independent prognostic factors including age, number of tumors, tumor size, histologic grade and pathological stage were used to construct the competing risk model. In the validation cohort, the AUC of 1-, 2- and 3- year recurrence were 0.895 (95%CI: 0.831-0.959), 0.861(95%CI: 0.774-0.948) and 0.827(95%CI: 0.721-0.934), respectively, indicating that the model had a high predictive performance. 【Conclusion】 We successfully constructed a competing risk model to predict the risk of 1-, 2- and 3-year recurrence for NMIBC patients. It may help clinicians to improve the postoperative management of patients.

Lymphocytic choriomeningitis virus/physiology* ; Allosteric Regulation ; Nucleotidyltransferases

Humans ; Severe Fever with Thrombocytopenia Syndrome ; Phlebovirus

Heme/metabolism* ; Cryoelectron Microscopy ; Membrane Transport Proteins ; Escherichia coli Proteins/metabolism*

Tongxie Yaofang， also known as Baizhu Shaoyaosan， was first recorded in Danxi's Experiential Therapy （《丹溪心法》） by ZHU Danxi in the Yuan dynasty. It is composed of Atractylodis Macrocephalae Rhizoma， Paeoniae Radix Alba， Citri Reticulatae Pericarpium， and Saposhnikoviae Radix， and serves as the representative prescription for the treatment of painful diarrhea. It has the functions of tonifying the spleen， emolliating the liver， relieving pain， and checking diarrhea， and is mainly used in the treatment of gastrointestinal diseases such as irritable bowel syndrome （IBS） and ulcerative colitis （UC）. In addition， it is effective in treating gastrointestinal disorders with mental and psychological abnormalities， as well as obstinate anorexia in children， depression syndrome， and respiratory diseases. Experimental research and clinical practice have shown that Tongxie Yaofang has multi-component， multi-pathway， and multi-target characteristics in the treatment of diseases. The mechanism of Tongxie Yaofang in treating diseases is mainly attributed to anti-inflammation， immune function regulation， intestinal hypersensitivity improvement， emotion regulation， etc. Monoterpene glycosides， flavonoids， chromones， lactones， and other components contained play an important therapeutic role. The research on the systems biology of Tongxie Yaofang， such as metabolomics， proteomics， and network pharmacology， provides a scientific basis for clarifying its mechanism of action and expanding its clinical application. However， there are still some problems to be solved， such as difficulty in combining diseases and syndromes and lack of in-depth systematic research. Through the retrieval and collation of relevant literature， this paper systematically reviewed the material basis， pharmacological effects， and systems biology research of Tongxie Yaofang， aiming to lay a foundation for in-depth research on its mechanism in treating diseases and rational application in clinical practice.

The adenosine 5'-triphosphate (ATP)-binding cassette (ABC) transporter, IrtAB, plays a vital role in the replication and viability of Mycobacterium tuberculosis (Mtb), where its function is to import iron-loaded siderophores. Unusually, it adopts the canonical type IV exporter fold. Herein, we report the structure of unliganded Mtb IrtAB and its structure in complex with ATP, ADP, or ATP analogue (AMP-PNP) at resolutions ranging from 2.8 to 3.5 Å. The structure of IrtAB bound ATP-Mg2+ shows a "head-to-tail" dimer of nucleotide-binding domains (NBDs), a closed amphipathic cavity within the transmembrane domains (TMDs), and a metal ion liganded to three histidine residues of IrtA in the cavity. Cryo-electron microscopy (Cryo-EM) structures and ATP hydrolysis assays show that the NBD of IrtA has a higher affinity for nucleotides and increased ATPase activity compared with IrtB. Moreover, the metal ion located in the TM region of IrtA is critical for the stabilization of the conformation of IrtAB during the transport cycle. This study provides a structural basis to explain the ATP-driven conformational changes that occur in IrtAB.
Siderophores/metabolism* ; Iron/metabolism* ; Mycobacterium tuberculosis/metabolism* ; Cryoelectron Microscopy ; Adenosine Triphosphate/metabolism* ; ATP-Binding Cassette Transporters