Objective: To investigate and validate ferroptosis genes (FRGs) in ulcerative colitis (UC) for diagnostic, subtype, and biological agent reactivity, with the goal of providing a foundation for the identification of novel therapeutic targets and the rational use of infliximab in clinical practice. Methods: UC datasets and FRGs were selected from the Gene Expression Omnibus (GEO) and FerrDb databases. WGCNA was used to identify characteristic genes of UC. LASSO and SVM models were used to discover key FRGs in UC. A nomogram was constructed for diagnosing UC using logistic regression (LR), We performed internal and external validation for the model. Furthermore, we constructed a hub-gene-signature prediction model for the effectiveness of infliximab in treating UC and deployed it on the website. Finally, the hub gene-drug interaction networks were constructed. Results: Nineteen ferroptosis-related genes associated with UC were identified through bioinformatics analysis. FTH1 and GPX4 were two of the down-regulated genes.The seventeen upregulated genes consisted of DUOX1, DUOX2, SOCS1, LPIN1, QSOX1, TRIM21, IDO1, SLC7A11, MUC1, HSPA5, SCD, ACSL3, NOS2, PARP9, PARP14, LCN2, and TRIB2. Five hub genes, including LCN2, QSOX1, MUC1, IDO1, and TRIB2, were acquried via machine learning. The mean auc of internal validation was 0.964 and 0.965 respectively, after using cross-validation and bootstrap in the training set based on the 5 hub-gene diagnostic models. In the external validation set, the AUC reached 0.976 and 0.858. RF model performs best in predicting infliximab effectiveness. In addition, we identified two ferroptosis subtypes. Cluster A mostly overlaps with the high-risk score group, with a hyperinflammatory phenotype. Conclusions: This research indicated that five hub genes related to ferroptosis might be potential markers in diagnosing and predicting infliximab sensitivity for UC.

Background: Puerarin is a flavonoid bioactive component extracted from the Chinese herb radix puerariae, which has been reported to have anti-inflammatory and neuroprotective effects and is a potential drug for the treatment of neuroinflammatory diseases. There is increasing evidence that the gut-liver-brain axis is closely related to neurological disorders. However, studies on the use of puerarin for the treatment of depression based on gut-liver-brain axis-mediated inflammatory injury have not been reported. Methods: In the present study, a 4-week chronic restraint stress (CRS) mouse depression model was established. Place the mice in 50 mL centrifuge tubes for restraint. The tubes should be perforated with 15–20 small holes to ensure adequate ventilation. The restraint period is from 9:00 a.m. to 1:00 p.m. daily, during which food and water are withheld. Based on the results of previous studies, the better antidepressant dose of puerarin, 100 mg/kg, was chosen, and fluoxetine was used as a positive control to investigate the intervention effect and potential mechanism of puerarin on depression. All of the aforementioned drugs were administered via oral gavage. Sucrose preference test (SPT), tail suspension test (TST), open field test (OFT), novelty suspended feeding test (NSFT) and forced swimming test (FST) were used to observe the behavioral changes in mice to assess the antidepressant effects. The microbial composition of the intestinal tract was analyzed using 16S rRNA gene sequencing. Histopathological changes in colon and liver were also observed by HE staining method. The levels of lipopolysaccharide (LPS) in colon, serum, liver and prefrontal cortex (PFC) and the levels of 5-hydroxytryptamine (5-HT) in prefrontal cortex were detected by enzyme-linked immunosorbent assay (ELISA). The method was developed for the detection of 5-HT in the prefrontal cortex. The serum levels of glutamate transaminase (AST) and alkaline phosphatase (ALP) were measured by microplate assay. Finally, the expression of brain-derived neurotrophic factor (BDNF), TLR4, MYD88, p-IκB-α, and p-p65 proteins were determined by immunoblotting assay (Western Blot, WB) in mice with PFC. Results: Puerarin was effective in alleviating CRS-induced depression-like behaviors measured in SPT, TST, FST and NSFT in mice. Compared with the CRS model group, puerarin increased the rate of sugar-water preference in the SPT and shortened the cumulative immobility time in the TST and FST as well as the ingestion latency in the NSFT in depressed mice. In addition, puerarin administration ameliorated CRS-induced gut microbiota dysbiosis in mice, elevating the abundance of Lactobacillaceae, Lactobacillus spp. Decreased the relative abundance of Ruminococcaceae, Ruminococcus, Desulfovibrionaceae, and Prevotella spp. Puerarin also reduced LPS, AST and ALP levels, improved damaged colon and liver tissues, inhibited neuroinflammatory damage mediated by the TLR4/MYD88/NF-κB signaling pathway, and up-regulated the levels of 5-HT and BDNF in the prefrontal cortex of the mice, thereby reversing CRS-induced depressive-like behaviors in depressed mice. Conclusion: Puerarin can improve CRS-induced depression in mice by regulating the gut-liver-brain axis and its related molecules. For example, it can regulate CRS-induced intestinal flora disorders and intestinal permeability, thereby reducing systemic LPS levels and the relative levels of AST and ALP, inhibiting the activation of the TLR4/MYD88/NF-κB signaling pathway by LPS, thereby reducing neuroinflammatory damage, and ultimately improving the depressive symptoms of CRS mice.