地榆通过影响PPARG和SLC7A11/GPX4表达减轻溃疡性结肠炎小鼠损伤

Sanguisorbae Radix alleviates damage in ulcerative colitis model mice based on PPARG and SLC7A11/GPX4

目的基于生物信息学探究地榆(Sanguisorbae Radix,SR)改善小鼠溃疡性结肠炎的机制。方法利用R语言对高通量基因表达数据库(GEO)中GSE92415数据集进行溃疡性结肠炎(UC)差异表达基因筛选和加权基因共表达网络分析(WGCNA),并结合FerrDb数据库,获得UC相关铁死亡特征基因。对特征基因进行蛋白互作分析(PPI)和相关性分析,筛选UC铁死亡核心基因。构建葡聚糖硫酸钠(DSS)诱导的UC小鼠模型,并灌胃给予SR水提物9 d,记录疾病活动指数(DAI)和结肠长度,采用HE染色法观察结肠组织病理变化,酶联免疫吸附测定法(ELISA)检测小鼠结肠组织炎症因子肿瘤坏死因子(TNF)⁃α、白细胞介素-6(IL⁃6),生化试剂盒检测脂质过氧化因子丙二醛(MDA)、谷胱甘肽(GSH)水平,免疫荧光法检测结肠组织闭锁小带蛋白1(ZO⁃1)表达,蛋白免疫印迹法(Western blot)检测结肠组织过氧化物酶体增殖物激活受体γ(PPARG)、溶质载体家族7成员11(SLC7A11)和谷胱甘肽过氧化酶4(GPX4)蛋白表达。结果通过生物信息学筛选得到9个UC相关铁死亡特征基因,其中核心基因为PPARG。相关性分析发现PPARG与铁死亡高度相关。结合生物信息学筛选结果,探讨SR改善小鼠UC的机制,实验结果发现,SR可降低UC小鼠DAI值,缓解结肠缩短,改善肠道粘膜屏障功能,对TNF⁃α、IL⁃6、MDA、GSH水平有显著回调作用,并可提高结肠组织PPARG、SLC7A11和GPX4蛋白表达。结论铁死亡与UC密切相关,SR可通过影响PPARG和SCL7A11/GPX4蛋白,进而改善UC小鼠结肠上皮损伤和功能障碍,为UC治疗策略提供了思路与方向。

Objective To investigate the mechanism of Sanguisorbae Radix(SR)in the treatment of ulcerative colitis(UC).Methods Using the GSE92415 dataset from the Gene Expression Omnibus database,we analyzed differentially expressed genes and carried out weighted gene correlation network analysis and FerrDb analysis.Core genes were identified through protein⁃protein interaction(PPI)network and correlation analysis.UC mouse model induced by dextran sulfate sodium(DSS)was constructed and treated with SR via intragastric administration for 9 days.Disease activity index(DAI)and colon length were recorded.Pathological changes in colon tissue were observed using the HE staining.Levels of inflammatory cytokines such as tumor necrosis factor⁃α(TNF⁃α)and interleukin⁃6(IL⁃6)were detected by enzyme linked immunosorbent assay(ELISA).Lipid peroxidantion factors such as malondialdehyde(MDA)and glutathione(GSH)were detected using biochemical test kits.Protein expression levels of zonula occludens protein⁃1(ZO⁃1)tight junction protein,peroxisome proliferator⁃activated receptor gamma(PPARG),solute carrier family 7 member 11(SCL7A11),and glutathione peroxidase 4(GPX4)were examined by Western blot or immunofluorescence labeling.Results Nine differentially expressed genes associated with ferroptosis were screened and PPARG was identified as a key gene.Correlation analysis showed a strong correlation between PPARG and ferroptosis.Subsequently,the potential mechanism of SR in improving UC in mice was discussed according to the bioinformatics screening results.The experimental results demonstrated that SR significantly reduced the DAI,prevented colon shortening and improved intestinal mucosal barrier function in the colon.SR decreased TNF⁃αand IL⁃6 levels,MDA content and GSH levels in colon tissues.SR also enhanced the expression of PPARG,SLC7A11 and GPX4,which reversed the effect of DSS in mice with colitis.Conclusions Ferroptosis is closely related to UC.SR can inhibit ferroptosis by regulating PPARG and SCL7A11/GPX4 expression,thereby improving colon epithelial injury and dysfunction in UC mice.This provides ideas and directions for UC treatment strategies.