Objective To explore the role of E1A binding protein p300 (EP300)-mediated crotonylation (Kcr) modification of malic enzyme 1 (ME1) in ferroptosis of renal tubular epithelial cells. Methods C57BL/6 mice were divided into Sham operation group (Sham group), DMSO vehicle control + ischemia-reperfusion (IR) injury group (Vehi + IR group), and EP300 inhibitor C646 + IR injury group (C646 + IR group), with 12 mice in each group. Pathological changes in renal tissues were evaluated in each group, and indicators of renal function, ferroptosis, and fibrosis were assessed. Another 24 mice were used to establish the IR injury model to analyze changes in Kcr modification levels and EP300 expression over the 14-day course of IR injury. The in vitro HK-2 cell experimental model was established and divided into control group, hypoxia/reoxygenation (H/R) group, and C646 + H/R group. Corresponding HK-2 cells were transfected with the ME1-K337R plasmid, in which lysine 337 (K) was mutated to arginine (R) to mimic the de-Kcr modification. Small interfering RNA was used to target EP300 and transfect the cells in order to obtain EP300 knockdown cells (siEP300). The expression of ferroptosis-related proteins and fibrosis phenotypes was detected. Results At 14 d after IR injury, the protein Kcr level and EP300 expression were increased in mice. Compared with the Sham group, the Vehi+IR group showed markedly disrupted renal tissue structure, extensive red collagen deposition in the renal interstitium, decreased expression levels of glutathione, reduced nicotinamide adenine dinucleotide phosphate (NADPH), and glutathione peroxidase 4 (GPX4, P＜0.01), increased malondialdehyde and serum creatinine levels (P＜0.01), decreased ME1 enzymatic activity (P＜0.001), and increased expression of fibronectin 1 and smooth muscle actin-α (P＜0.001). Compared with the Vehi+IR group, the C646+IR group showed alleviated renal pathological injury, improved renal function, and reduced ferroptosis and fibrosis (P＜0.05). Compared with the control group, HK-2 cells subjected to H/R treatment exhibited aggravated ferroptosis and fibrosis (P＜0.05); compared with the H/R group, the C646+H/R group showed reduced ferroptosis and fibrosis (P＜0.05). Transfection with the ME1-K337R plasmid and siEP300 showed reduced ME1 Kcr, ferroptosis, and fibrosis. Conclusions EP300 contributes to ferroptosis in renal tubular epithelial cells by mediating ME1 crotonylation, and inhibition of EP300 may help alleviate the chronic progression following IR injury.

Objective To explore the key active ingredients and action characteristics of Wenxing Jingjintong Gel Patch in the treatment of rheumatoid arthritis(RA)based on the systematic pharmacology and LC-MS/MS technology.Methods The information of active ingredient from Wenxing Jingjintong Gel Patch was established through LC-MS/MS analysis and literature retrieval.The targets of the active ingredients were predicted using Swiss Target Prediction platform and then mapped with the RA-related targets obtained from GeneCards,DrugBank,and OMIM databases to identify the intersecting targets.The"active ingredients-effective targets"network was constructed through the Cytoscape software.The shared targets were imported into STRING database to construct a protein-protein interaction network.GO function and KEGG pathway enrichment analysis were performed using the Metascape database.Molecular docking studies were conducted using AutoDock software to investigate the interactions between key ingredients and target proteins.Results A total of 142 active ingredients were identified in Wenxing Jingjintong Gel Patch by wsing LC-MS/MS,which were further supplemented to 174 through literature retrieval.There were 175 shared targets between the active ingredients and RA.It was anticipated that Wenxing Jingjintong Gel Patch exerted immune regulation and anti-inflammatory and analgesic effects through the interaction between key active ingredients such as berberine,neobavaisoflavone,and palmatine chloride with key targets,including TNF,IL6,and AKT1 to regulate PI3K/Akt1,JAK/STAT,and MAPK signaling pathways.In 1 152 molecular docking validation,94%of them had binding energies less than-5.0 kcal·mol-1,while 51%of them had binding energies less than-7.0 kcal·mol-1.It was indicated that there was a good binding affinity between the potential active ingredients and core targets.Conclusion This study predicted the active ingredients and action characteristics of Wenxing Jingjintong Gel Patch in the treatment of RA,which provided a theoretical basis for further clinical application and quality control.

This study was aimed to prepare sheddable PEG modified miRNA-complexing nanoparticles and investigate in vitro cellular uptake effect and in vivo distribution profile. The sheddable PEG material was synthesized through condensation. The sheddable PEG modified miRNA-complexing nanoparticles were successfully prepared by electrostatic interaction between gene vector and miRNA, and then ibuprofen was added to deshield PEG layer. The in vitro cellular uptake effect and in vivo distribution profile of nanoparticles were investigated on 4T1 model cells. As a result, the particle size of nanoparticles was 107. 7 nm and Zeta potential was 15. 8 mV. Compared to unsheddable PEG group, the cellular uptake effect by 4T1 tumor cells as well as the concentration on tumor regions was significantly improved in the sheddable PEG group. Results showed that this systen has a great potential application in the field of tumor treatment.