Surface proteins play pivotal roles in physiological processes, including cell recognition, signal transduction, substance transport, and immune responses. However, challenges persist in characterizing abnormal surface proteins in disease states and identifying therapeutic targets, due to the low abundance of these proteins within the total proteome and the frequent presence of their complex glycosylation modifications. Recent years have witnessed the vigorous development of chemical proteomics, leading to the successful creation of various chemical probes for the labeling and characterization of cell surface proteins. These techniques have subsequently been applied to the detection of disease surface proteins and the discovery of corresponding targets. Surface protein characterization techniques based on chemical proteomics are discussed herein, focusing on the principles of amino acid-targeted labeling, proximity labeling, and glycoprotein capture. The novelty, advantages, and limitations of techniques such as targeted lysine labeling, peroxidase and photocatalytic proximity labeling, and chemical glycan capture and metabolic glycan labeling are elaborated, and their applications across various biological models and disease types are described, aiming to provide some reference for target discovery and drug development targeting surface proteins.

The research and development of innovative drug have progressed remarkably, but the long development circle and high failure rate have become the bottleneck. Drug repurposing, discovering new indications of approved drugs, is a strategy to overcome these obstacles. By exploring new indications for approved drugs, rapid progress has been made in basic research and clinical translation in recent years. Rich resources of drugs, proven security, efficient development workflow and reduced cost are core advantages of this strategy, making the strategy a crucial direction of optimizing the pipeline of drug research and development. This review systematically summarizes drug repurposing cases that have received clinical approval over the past five years, and proposes core strategies for drug repurposing, including approaches based on targets, pathways, drug similarity, post-treatment phenotypes, and clinical side effects, aiming to provide some strategic guidance for drug repurposing efforts.

Immune-stimulating antibody drug conjugate (ISAC) can not only effectively solve the defects of stimulator of interferon genes (STING) agonists by coupling antibodies with STING agonists through the targeting of antibodies, but also play a synergistic role with antibodies to further improve the efficacy of STING agonists. This review first provides a concise overview of the current research landscape of ISACs and STING agonists, systematically elaborates on evolving trends in STING agonist development, and subsequently summarizes the mechanistic advances in STING ISAC research. Special emphasis is placed on representative STING ISAC candidates in preclinical/clinical development. Finally, the future directions of STING ISACs are critically discussed with perspectives and recommendations, aiming to provide theoretical insights and practical guidance for future investigations.

Histone deacetylase has proved to be a promising new antimalarial target in the development of novel antimalarial drugs. This article introduces the mechanism of action of histone deacetylase inhibitors and their antimalarial activity, with a focus on the discovery process of Plasmodium histone deacetylase inhibitors and their recent research progress both domestically and internationally. Recent research findings on hydroxamic acid-based and cyclic peptide inhibitors are reviewed and analyzed in detail according to their different structural types. Key challenges hindering drug development and approval, such as drug toxicity issues and the lag in related biological studies, are highlighted. Furthermore, future directions for drug research and development are proposed, offering insights for the further development of new antimalarial drugs.

Human lactate dehydrogenase A (LDHA) is an NADH-dependent oxidoreductase that catalyzes the conversion of pyruvate to lactate, playing a crucial role in the aerobic glycolysis of tumor cells. Additionally, LDHA is responsible for catalyzing the conversion of glyoxylate to oxalate in the liver, excessive accumulation of which leads to hyperoxaluria. Representative LDHA inhibitors reported to date include GNE-140, NCATS-SM1441, and CHK-336. In this study, NCATS-SM1441 was used as the lead compound. Based on the analysis of its cocrystal binding mode with LDH, the key carboxythiazole and aromatic pharmacophores were retained, while the original substituted pyrazole linker was replaced with urea linker moieties to simplify the structure. As a result, nine urea derivatives were designed and synthesized. Subsequently, on the basis of structure-activity relationship and molecular docking studies, nine target triazole compounds were further designed. Ultimately, triazole compound 25 was found to exhibit the most potent LDHA inhibitory activity (IC50 = 1.59 μmol/L) in vitro. Molecular dynamics simulations were employed to analyze the interactions between compound 25 and key amino acid residues. Finally, the prediction of physicochemical properties and the evaluation of cell viability were performed for compound 25. The study provides an experimental basis for future development of novel LDHA inhibitors with improved drugability.

A quantitative method for the analysis of the multi-component contents in Marsdenia tenacissimae was established, and the quality differences were evaluated by principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), factor analysis (FA) and weighted technique for order preference by similarity to ideal solution (TOPSIS) method. The contents of chlorogenic acid, cryptochlorogenic acid, sinapic acid, tenacigenoside A, tenacissoside G, tenacissoside I, tenacissoside H, drevogenin A, betulinic acid and lupeol were determined by HPLC wavelength switching method. At the same time, the contents of alcohol-soluble extract and total ash were detected. PCA, OPLS-DA and FA methods were used to identify the origin of M. tenacissimae from different producing areas. According to the OPLS-DA model, the index weight was determined to construct the weighted TOPSIS evaluation model. The qualities of M. tenacissimae from different producing areas were analyzed by model scoring results. The contents of 12 indexes in 18 batches of M. tenacissimae varied to different degrees, and the repeatability and accuracy of the test method were satisfactory. PCA analysis divided 18 batches of M. tenacissimae into three categories. OPLS-DA identified five main potential quality markers, including tenacissoside A, tenacissoside I, lupeol, tenacissoside H and chlorogenic acid. The evaluation results of FA and weighted TOPSIS method were consistent, which showed that the quality of M. tenacissimae from Yunnan and Guizhou was better. The established multi-component quantitative analysis method is accurate and reliable, the chemometrics model has strong predictive ability, and the evaluation results of FA and weighted TOPSIS method are scientific and objective. The combination of the four methods can clearly determine the qualities of M. tenacissimae from different producing areas.

The present study aimed to establish an LC-MS/MS method for the quantification of tiamulin in minipig plasma and to further conduct a pharmacokinetic comparison of different formulations. The plasma samples were extracted with acetonitrile (meloxicam as internal standard), separated on a C18 column, and quantified by multiple reaction monitoring mode (ESI+). Sanyuan minipigs were used as experimental animals. Plasma samples were collected after intravenous injection (10 mg/kg) and intragastric administration (20 mg/kg). The method showed good linearity, with intra- and inter-batch RSD of 1.00%–8.13% and RE within ±15%. The extraction recovery, matrix effect and stability of the analytical methods met the relevant requirements. Tiamulin fumarate active pharmaceutical ingredient was intravenously administered, with c0 of about (4383.73±2676.78) ng/mL, AUC0-t of about (4803.50±965.68) h·ng/mL, t1/2 of about (4.66±1.68) h, and CL of about (2.14±0.46) L/(kg·h). Three tiamulin formulations were intragastrically administered, with cmax of (552.00±328.55), (545.00±136.97) and (590.60±237.02) ng/mL, tmax of (1.47±0.68), (0.69±0.75) and (0.72±0.72) h, and F of 24.85%, 15.28% and 16.97%, respectively. The validated method meets the requirements for biological sample analysis and is applicable for the pharmacokinetic evaluation of tiamulin formulations in minipigs.

This study aimed to investigate the effects of the peptide secreted protein isthmin-1 (ISM1) on the proliferation and apoptosis of non-small cell lung cancer (NSCLC) cells. ISM1 expression in NSCLC was detected by immunohistochemistry (IHC). ISM1 was overexpressed in lung cancer cell lines by transient transfection of ISM1 plasmids, or establishing ISM1 overexpression stable cell lines, or by treating cells with recombined ISM1 (rISM1). CCK-8 was used to examine cell growth. The intracellular signal transduction pathways regulated by rISM1 were analyzed by transcriptome sequencing, and verified by qRT-PCR and Western blot. The levels of intracellular ROS and apoptosis were further detected using the kit. The results showed that the expression of ISM1 was decreased in human NSCLC tissue samples compared to normal lung tissue samples. Overexpression of ISM1 or rISM1 treatment significantly suppressed the growth of lung cancer cells. RNA sequencing revealed that rISM1 mainly regulated the FoxO signaling pathway. rISM1 treatment decreased the expression of FoxO3 and FoxO1, increased reactive oxygen species (ROS) production, and induced cell apoptosis. These results suggest that ISM1 can inhibit the growth of NSCLC by regulating the FoxO signaling pathway. These findings provide new strategies for cancer therapy.

This study employed the drug affinity responsive target stability (DARTS) technique to investigate the molecular mechanism of the antipsychotic drug penfluridol against melanoma, revealing the biological pathway to exert its effect on the HSPA6/p53/p21 signaling axis. Experiments such as the methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and cell colony formation ability assay confirmed that penfluridol could significantly downregulate the expression of cyclin D1 and cyclin-dependent kinase 4 (CDK4) in melanoma A375 and B16 cells, induce cell cycle arrest in the G1 phase, and thus inhibit the proliferation of melanoma cells. Meanwhile, the results of Western blot, Hoechst 33342 staining and Annexin V-FITC/PI double staining experiments showed that penfluridol could significantly downregulate the expression of Bcl-2 and upregulate the expression of Bax and cleaved caspase-3, inducing cell apoptosis. Further, the DARTS technique was used to identify heat shock 70 kD protein 6 (HSPA6) as the key target bound by penfluridol. Penfluridol activates the p53/p21 pathway by upregulating HSPA6. Knocking down HSPA6 reverses not only the activation of the p53/p21 pathway mediated by penfluridol but also the associated cell cycle arrest and apoptosis. Animal experiments on tumor-bearing mice also confirmed that knocking down HSPA6 could reverse the in vivo anti-tumor activity of penfluridol. This study clarified that penfluridol can inhibit the progression of melanoma by targeting HSPA6 to activate the p53/p21 signaling axis, providing a new perspective for the repositioning of antipsychotic drugs in cancer treatment.

This study aimed to investigate the mechanism of compound Agrimonia pilosula enteritis capsules (CAPEC) on ulcerative colitis (UC) in mice with dampness-heat syndrome. The mice were randomly divided into five groups: the control group, the model group, the positive drug (5-aminosalicylic acid, 5-ASA) group, the low-dose CAPEC (CAPEC-L) group and the high-dose CAPEC (CAPEC-H) group. The mice models were established by using high-fat high-sucrose diet, feeding with distilled spirit and dextran sulfate sodium (DSS). The effects of CAPEC on bile acids (BAs) metabolic profiles in bile and the FXR-SREBP-1 signaling pathway were investigated in the model of UC in mice with dampness-heat syndrome by ELISA, qRT-PCR, UHPLC-QQQ/MS, and histopathological analysis. The results showed that, compared with the model group, the CAPEC-L group and the CAPEC-H group significantly reduced the disease activity index (DAI), and proinflammatory cytokine levels (including IL-6, IL-1β, and TNF-α) in both serum and colon tissues. Additionally, CAPEC markedly ameliorated intestinal inflammation, hepatic lipid accumulation, and pathological alterations in tongue tissue. The CAPEC-H group significantly attenuated the abnormal elevation of BAs profiles in bile, and up-regulated hepatic mRNA levels of Cyp7a1, Cyp7b1, Cyp27a1, Bsep, Fxr, and Shp, while down-regulating Srebp-1 and Cyp8b1 expression. The experimental results suggest that CAPEC alleviates UC with dampness-heat syndrome by ameliorating BAs metabolic disorders, hepatic lipid accumulation, and intestinal inflammation. These findings provide mechanistic insights into CAPEC’s traditional effects of clearing heat and drying dampness, and strengthening the spleen to relieve diarrhea.