In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics. Similarities and variations of components present significant analytical challenges. A two-dimensional (2D) liquid chromatography-mass spectrometr (LC-MS) method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium (CMS). A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated. For efficient and high-accuracy screening of CMS, a targeted method based on a self-constructed high resolution (HR) mass spectrum database of CMS components was established. The database was built based on the commercial MassHunter Personal Compound Database and Library (PCDL) software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening. On this basis, the unknown peaks in the CMS chromatograms were deduced and assigned. The molecular formula, group composition, and origins of a total of 99 compounds, of which the combined area percentage accounted for more than 95% of CMS components, were deduced by this 2D-LC-MS method combined with the MassHunter PCDL. This profiling method was highly efficient and could distinguish hundreds of components within 3 h, providing reliable results for quality control of this kind of complex drugs.

BACKGROUND:Various proteins,signaling pathways,and inflammatory mediators are involved in the pathophysiological process of osteoarthritis.The development of small molecule drugs targeting these proteins,signaling pathways,and inflammatory mediators can effectively delay the progression of osteoarthritis and ameliorate its clinical manifestations. OBJECTIVE:To review the research progress of small molecule drugs in the treatment of osteoarthritis based on the pathogenesis of osteoarthritis. METHODS:PubMed,CNKI,and WanFang databases were searched with English search terms"osteoarthritis,arthritis,osteoarthrosis,degenerative,arthritides,deformans,small molecule drugs,small molecule inhibitors,small molecule agents"and Chinese search terms"osteoarthritis,small molecule drugs,small molecule inhibitors."A total of 68 articles were included for review according to the inclusion and exclusion criteria. RESULTS AND CONCLUSION:(1)Currently,studies concerning the pathogenesis of osteoarthritis remain unclear.The occurrence and development of osteoarthritis are strongly associated with proteins,cytokines,and signal transduction pathways,so its therapeutic mechanism is relatively complex.Currently,targeting proteins,cytokines,and signal transduction pathways related to osteoarthritis with small molecule drugs has become a major research focus.(2)Small molecule drugs frequently possess visible intracellular or extracellular targets and efficacy,containing enhancing cartilage repair,resisting joint degradation,attenuating inflammation,and relieving pain.Other anti-osteoarthritis small molecule drugs have shown promise in promoting stem cell chondrogenic differentiation and cartilage matrix reconstruction.(3)At present,small molecule drugs targeting the pathophysiological process of osteoarthritis to delay the progression of osteoarthritis are still in the experimental stage,but most of these small molecule drugs have shown the expected results in the experimental process,and there are no relevant studies to illustrate the efficacy of small molecule drugs in the treatment of osteoarthritis.(4)Small molecule drugs for the treatment of osteoarthritis have reached the expected experimental results in the basic experimental stage.Numerous studies have exhibited that small molecule drugs can target the suppression of specific proteins,cytokines,and signal transduction pathways that cause osteoarthritis,so as to treat osteoarthritis.Nevertheless,its safety and effectiveness still need to be identified by further basic and clinical studies.This process needs to be investigated and studied by more scholars.(5)At present,many scholars in and outside China have made contributions to the treatment of osteoarthritis.Compared with traditional treatment methods,small molecule drugs reveal better efficacy and safety in the basic experimental stage,and it is expected to become an emerging method for the treatment of osteoarthritis in the future to rid patients of pain.

Antibiotic-resistant (AR) bacterial wound infections (WIs) impose major burdens on healthcare systems, exacerbated by ineffective therapies and stalled antibiotic development. Phage therapy and phage-derived enzymes have gained traction as potent alternatives, leveraging targeted bactericidal mechanisms to combat AR pathogens. In this review, we summarised the antimicrobial mechanisms of both phage therapy and phage-derived enzymes as antimicrobial therapy, and outlined recent advances in their use for in vitro , in vivo and clinical applications for WI management. In addition, we also highlights recent advancements in their development, driven by genetic engineering, chemical modifications, and artificial intelligence. Finally, we identified the potential barriers and challenges they may encounter in clinical practice and the corresponding strategies to address these issues. The entire review gives us a comprehensive understanding of the latest advances in phages and their derivative enzyme therapies for treating WIs, in the hope that research in this field will continue to improve and innovate, accelerating the transition from the laboratory to application at the bedside and ultimately improving the efficacy of treatment for AR bacterial WIs.
Humans ; Phage Therapy/methods* ; Wound Infection/drug therapy* ; Bacteriophages/enzymology* ; Enzyme Therapy/methods* ; Animals ; Bacterial Infections/therapy*

Osteoporosis is a prevalent skeletal condition characterized by reduced bone mass and strength, leading to increased fragility. Buqi-Tongluo (BQTL) decoction, a traditional Chinese medicine (TCM) prescription, has yet to be fully evaluated for its potential in treating bone diseases such as osteoporosis. To investigate the mechanism by which BQTL decoction inhibits osteoclast differentiation in vitro and validate these findings through in vivo experiments. We employed MTS assays to assess the potential proliferative or toxic effects of BQTL on bone marrow macrophages (BMMs) at various concentrations. TRAcP experiments were conducted to examine BQTL's impact on osteoclast differentiation. RT-PCR and Western blot analyses were utilized to evaluate the relative expression levels of osteoclast-specific genes and proteins under BQTL stimulation. Finally, in vivo experiments were performed using an osteoporosis model to further validate the in vitro findings. This study revealed that BQTL suppressed receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis and osteoclast resorption activity in vitro in a dose-dependent manner without observable cytotoxicity. The inhibitory effects of BQTL on osteoclast formation and function were attributed to the downregulation of NFATc1 and c-fos activity, primarily through attenuation of the MAPK, NF-κB, and Calcineurin signaling pathways. BQTL's inhibitory capacity was further examined in vivo using an ovariectomized (OVX) rat model, demonstrating a strong protective effect against bone loss. BQTL may serve as an effective therapeutic TCM for the treatment of postmenopausal osteoporosis and the alleviation of bone loss induced by estrogen deficiency and related conditions.
Animals ; NFATC Transcription Factors/genetics* ; Drugs, Chinese Herbal/pharmacology* ; Ovariectomy ; Osteoclasts/metabolism* ; Female ; Osteogenesis/drug effects* ; Rats, Sprague-Dawley ; Rats ; NF-kappa B/genetics* ; Osteoporosis/genetics* ; Signal Transduction/drug effects* ; Bone Resorption/genetics* ; Cell Differentiation/drug effects* ; Humans ; RANK Ligand/metabolism* ; Mitogen-Activated Protein Kinases/genetics* ; Transcription Factors

Objective To identify the enhancer profile marked by histone H3K27ac modification in high-grade intraepithelial neoplasia(HGIN)in order to reveal the novel regulatory mechanism of HGIN pathogensis.Methods Gastric tissue samples were collected from Department of Gastroenterology of Army Medical Center of PLA between June 2022 and June 2023,including 14 normal gastric tissues(Nor group),31 HGIN tissues(HGIN group)and 17 gastric cancer tissues(GC group).Cleavage under targets and tagmentation(CUT&Tag)technique was employed to capture enhancer regions modified by histone H3K27ac.Multi-omics analysis was performed to identify HGIN-specific active enhancers and their potentially regulated genes.Immunohistochemical profiling was performed to assess differential expression of the gene of interest across clinically stratified specimens,combined with CRISPR-dCas9-mediated ablation of active enhancers to monitor the gene of interest transcriptional dynamics and validate enhancer-mediated regulatory mechanisms.Results Epigenomic sequencing obtained the data with excellent quality,and indicated that obvious remodeling was observed in H3K27ac enhancers in HGIN and GC groups(P<0.05),though no significant difference in the genome-wide distribution of H3K27ac modification among the 3 groups.Combining transcriptome data revealed that enhancer remodeling may up-regulate the expression of the proliferation-related target gene,CD24,in the HGIN tissue;while,inhibiting enhancer activity can notably reduce CD24 expression level(P<0.05).Immunohistochemical assay displayed a positive correlation between the expression levels of CD24 and Ki-67(P<0.001).Conclusion The remodeling of H3K27ac enhancer represents a significant epigenetic feature of the transformation from normal condition to HGIN.Remodeling of H3K27ac enhancer up-regulates CD24,which may facilitate the abnormal proliferation of gastric epithelial cells.

Objective To analyze clinical characteristics of mesenchymal-subtype gastric cancer(Mes-GC)by integrating multi-omics data and explore the characteristics of tumor cells and microenvironment associated with the risk for recurrence.Methods Gastric tumor tissue samples were collected from the patients who visited Department of Gastroenterology of Army Medical Center of PLA from January 2022 to December 2023.Transcriptome and genome sequencing were applied for these tissue samples,including 19 cases of diffuse-type gastric cancer,22 cases of intestinal-type gastric cancer,and 23 cases of mixed-type gastric cancer patients.Bioinformatics analysis was employed to investigate the differences in clinical characteristics and tumor microenvironment between Mes-GC and non-mesenchymal-subtype gastric cancer(non-Mes-GC)by integrating data resources including The Cancer Genome Atlas(TCGA),Gene Expression Omnibus(GEO),and National Genomics Data Center(NGDC).Results Compared to non-Mes-GC patients,Mes-GC ones were characterized by later clinical stages,deeper tumor infiltration,and higher rates of lymph node metastasis.Kaplan-Meier survival analysis confirmed that Mes-GC patients were associated with shorter survival time,poor prognosis as well as increased risk of cancer recurrence(P<0.05).Single-cell RNA sequencing data revealed that tumor cells in Mes-GC showed higher expression levels of the genes related to stemness,metastasis(P<0.05),and epithelial-mesenchymal transition(EMT).And in the tumor microenvironment,there were significant more myeloid cells,smooth muscle cells,endothelial cells and fibroblasts,with the most pronounced elevation in the proportion of fibroblasts(P<0.05).Moreover,the patients with larger proportion of fibroblasts were associated with poorer prognosis.Conclusion Mes-GC tumor cells exhibit higher stemness and EMT characteristics,and stromal cells such as myeloid cells,endothelial cells,and fibroblasts are enriched in the tumor microenvironment.These features may be key factors contributing to poor prognosis and high recurrence rate of Mes-GC.

Objective To identify the enhancer landscape marked by histone H3K27ac modifications in diffuse-type gastric cancer(DGC)tissues,and to elucidate the epigenetic remodeling mechanisms by which active enhancers regulate cachexia-related genes.Methods Gastric mucosal tissue samples were collected from Department of Gastroenterology of Army Medical Center of PLA during January 2022 to March 2023,including 10 normal gastric mucosa tissues(Normal group),10 DGC tissues diagnosed with cachexia(DGC group),and 10 organoids derived from DGC tissues(Organoid group).Using H3K27ac chromatin targeting cleavage and tagmentation(CUT&Tag)technology,genomic modification regions were captured to screen specific active enhancers and their potential target genes in DGC tissues.CRISPR-dCas9 gene editing technology was used to intervene with the enhancers,and the expression of target genes was detected with Western blotting and qRT-PCR.Sixteen female SPF-grade BALB/c Nude mice(6～8 weeks old,weighing 18～21 g)were utilized to establish an orthotopic xenograft tumor model using the human diffuse-type gastric cancer cell line MKN45.Cachexia-related phenotypes were evaluated in 3 groups:normal group(n=4),silencing group(n=6),and control group(n=6).Results Significant differential enhancer regions were identified between DGC and normal gastric mucosa tissues.DGC tissues exhibited a marked increase in enhancer abundance(P<0.05)and signal intensity when compared with the normal counterparts.Integrated analysis of transcriptome data revealed that some of these active enhancers up-regulated the expression of GDF15,a cachexia-associated target gene in DGC.Targeted silencing of the active enhancer of GDF15 using CRISPR/dCas9-KRAB plasmid technology resulted in a significant reduction in GDF15 expression at both mRNA levels(P<0.05)and protein.Results from orthotopic transplantation experiments of DGC demonstrated that silencing of active enhancers alleviated the cachexia phenotype in nude mice(P<0.05).Conclusion DGC exhibits enhancer remodeling,which regulates the expression of the cachexia-associated gene GDF15,and thereby contributes to the pathogenesis and progression of cancer cachexia.

The prevalence of diabetes mellitus in China has recently been increasing year by year,and spontaneous skin ulcers in diabetic patients,as one of the most serious complications,often develop on the patient's extremities represented by foot ulcers.Due to the complexity and variety of its pathogenesis,it leads to poor clinical outcomes and difficulty in healing.Thus,pa-tients often face the risk of amputation and death.Therefore,the exploration of mechanisms of the vascular pathogenesis of diabetic delayed-healing wounds and targeted screening of therapeutic agents has become a current research hotspot.Herein,in this paper,we briefly review the role of impaired angiogenesis and vascular dysfunction in diabetic skin ulcers,and the research progress of classical hypoglycemic and natural compounds against vascular lesions is preliminarily summarized to provide a theoretical basis for effective clinical treatment.

Objective To establish a method for testing isolated mitral valve in vitro and quantitatively evaluate the effect of transcatheter edge-to-edge repair technology(TEER)on functional mitral regurgitation(FMR)(non-A2-P2 regurgitation).Methods In this study,an FMR(non-A2-P2 regurgitation)model was developed by dilating the annulus orifice and displacing the papillary muscle in isolated porcine mitral valve.The hydrodynamics characteristics of 6 valves were tested by a pulsatile flow testing system under different physiological and pathological conditions before and after TEER.Results The results show that the valve regurgitation improved from moderate-severe[regurgitant fraction(60.2±17.5)％]to mild-moderate[regurgitant fraction(34.7±12.0)％]by repair(P＜0.001).The EOA[(3.8±1.6)cm2 vs.(2.2±0.5)cm2,P＜0.001]and the forward cross valve pressure difference[(1.8±1.3)mmHg vs.(3.8± 1.8)mmHg,P＜0.001],which characterize the forward flow performance of the valve,were compared before and after repair,and the differences were statistically significant.At the same time,the repair caused valve stenosis(the effective orifice area decreased by 40％and the positive differential pressure increased by 110％),but the valves was still within the normal physiological range,and no iatrogenic stenosis was caused.Conclusions It can be seen that TEER has an effect on FMR.This study provides validation and evaluation methods in vitro for expanding indications and improving TEER,and reference for developing standards of transcatheter valve repair testing in vitro.