Identification of a Novel Activated NK-Associated Gene Score Associated with Diagnosis and Biological Therapy Response in Ulcerative Colitis.
Natural killer (NK) cells are associated with the pathogenesis of ulcerative colitis (UC); however, their precise contributions remain unclear. The present study aimed to investigate the diagnostic value of the activated NK-associated gene (ANAG) score in UC and evaluate its predictive value in response to biological therapy.
Bulk RNA-seq and scRNA-seq datasets were obtained from the Gene Expression Omnibus (GEO) and Single Cell Portal (SCP) databases. In the bulk RNA-seq, differentially expressed genes (DEGs) were screened by the "Batch correction" and "Robust rank aggregation" (RRA) methods. The immune infiltration landscape was estimated using single-sample gene set enrichment analysis (ssGSEA) and CIBERSORT. DEGs that correlated with activated NK cells were identified as activated NK-associated genes (ANAGs). Protein-protein interaction (PPI) analysis and least absolute shrinkage and selection operator (LASSO) regression were used to screen key ANAGs and establish an ANAG score. The expression levels of the four key ANAGs were validated in human samples by real-time quantitative polymerase chain reaction (RT-qPCR) and immunofluorescence. The potential therapeutic drugs for UC were identified using the DSigDB database. Through scRNA-seq data analysis, the cell scores based on the ANAGs were calculated by "AddModuleScore" and "AUCell."
Immune infiltration analysis revealed a higher abundance of activated NK cells in noninflamed UC tissues (ssGSEA, p < 0.001; CIBERSORT, p < 0.01). Fifty-four DEGs correlated with activated NK cells were identified as ANAGs. The ANAG score was established using four key ANAGs (SELP, TIMP1, MMP7, and ABCG2). The ANAG scores were significantly higher in inflamed tissues (p < 0.001) and in biological therapy nonresponders (NR) tissues before treatment (golimumab, p < 0.05; ustekinumab, p < 0.001). The ANAG score demonstrated an excellent diagnostic value (AUC = 0.979). Patients with higher ANAG scores before treatment were more likely to experience a lack of response to golimumab or ustekinumab (golimumab, p < 0.05; ustekinumab, p < 0.001).
This study established a novel ANAG score with the ability to precisely diagnose UC and distinguish the efficacy of biological treatment.
Dong S
,Zhang Y
,Ye L
,Cao Q
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Exploring Pyroptosis-related Signature Genes and Potential Drugs in Ulcerative Colitis by Transcriptome Data and Animal Experimental Validation.
Ulcerative colitis (UC) is an idiopathic, relapsing inflammatory disorder of the colonic mucosa. Pyroptosis contributes significantly to UC. However, the molecular mechanisms of UC remain unexplained. Herein, using transcriptome data and animal experimental validation, we sought to explore pyroptosis-related molecular mechanisms, signature genes, and potential drugs in UC. Gene profiles (GSE48959, GSE59071, GSE53306, and GSE94648) were selected from the Gene Expression Omnibus (GEO) database, which contained samples derived from patients with active and inactive UC, as well as health controls. Gene Set Enrichment Analysis (GSEA), Weighted Gene Co-expression Network Analysis (WGCNA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed on microarrays to unravel the association between UC and pyroptosis. Then, differential expressed genes (DEGs) and pyroptosis-related DEGs were obtained by differential expression analyses and the public database. Subsequently, pyroptosis-related DEGs and their association with the immune infiltration landscape were analyzed using the CIBERSORT method. Besides, potential signature genes were selected by machine learning (ML) algorithms, and then validated by testing datasets which included samples of colonic mucosal tissue and peripheral blood. More importantly, the potential drug was screened based on this. And these signature genes and the drug effect were finally observed in the animal experiment. GSEA and KEGG enrichment analyses on key module genes derived from WGCNA revealed a close association between UC and pyroptosis. Then, a total of 20 pyroptosis-related DEGs of UC and 27 pyroptosis-related DEGs of active UC were screened. Next, 6 candidate genes (ZBP1, AIM2, IL1β, CASP1, TLR4, CASP11) in UC and 2 candidate genes (TLR4, CASP11) in active UC were respectively identified using the binary logistic regression (BLR), least absolute shrinkage and selection operator (LASSO), random forest (RF) analysis and artificial neural network (ANN), and these genes also showed high diagnostic specificity for UC in testing sets. Specially, TLR4 was elevated in UC and further elevated in active UC. The results of the drug screen revealed that six compounds (quercetin, cyclosporine, resveratrol, cisplatin, paclitaxel, rosiglitazone) could target TLR4, among which the effect of quercetin on intestinal pathology, pyroptosis and the expression of TLR4 in UC and active UC was further determined by the murine model. These findings demonstrated that pyroptosis may promote UC, and especially contributes to the activation of UC. Pyroptosis-related DEGs offer new ideas for the diagnosis of UC. Besides, quercetin was verified as an effective treatment for pyroptosis and intestinal inflammation. This study might enhance our comprehension on the pathogenic mechanism and diagnosis of UC and offer a treatment option for UC.
Zhao Y
,Ma Y
,Pei J
,Zhao X
,Jiang Y
,Liu Q
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Identification of Biomarkers Related to Liquid-Liquid Phase Separation for Ulcerative Colitis Based on Single-Cell and Bulk RNA Transcriptome Sequencing Data.
Liquid-Liquid Phase Separation (LLPS) is a process involved in the formation of established organelles and various condensates that lack membranes; however, the relationship between LLPS and Ulcerative Colitis (UC) remains unclear.
This study aimed to comprehensively clarify the correlation between ulcerative colitis (UC) and liquid-liquid phase separation (LLPS).
In this study, bioinformatics analyses and public databases were applied to screen and validate key genes associated with LLPS in UC. Furthermore, the roles of these key genes in UC were comprehensively analyzed.
Based on the single-cell transcriptomic data of UC obtained from the Gene Expression Omnibus (GEO) database, differences between patients with UC and their controls were compared using the limma package. The single-cell data were then filtered and normalized by the 'Seurat' package and subjected to dimension reduction by the Uniform Manifold Approximation and Projection (UMAP) algorithm. The LLPS-related genes (LLPSRGs) were searched on the Dr- LLPS website to obtain cross-correlated genes, which were scored using the ssGSEA algorithm. Next, functional enrichment, interaction network, immune landscape, and diagnostic and drug prediction of the LLPSRGs were comprehensively explored. Finally, the results were validated using external datasets and quantitative real-time PCR (qRT-PCR).
A total of eight cell types in UC were classified, namely, fibroblasts, macrophages, endothelial cells, neutrophils, NK cells, B cells, epithelial cells, and T cells. The intersection between differently expressed genes (DEGs) among the eight cell types identified 44 key genes, which were predominantly enriched in immune- and infection-related pathways. According to receiver operating characteristic (ROC) curves, PLA2G2A, GZMK, CD69, HSP90B1, and S100A11 reached an AUC value of 0.94, 0.95, 0.86, 0.89, and 0.93, respectively. Drug prediction revealed that decitabine, tetrachlorodibenzodioxin, tetradecanoylphorbol acetate, thapsigargin, and cisplatin were the potential small molecular compounds for PLA2G2A, GZMK, CD69, HSP90B1, and S100A11. Immune cell infiltration analysis demonstrated that the infiltration of CD4 memory T cell activation, macrophage M1, T macrophage M0, neutrophils, and mast cell activation was higher in the UC group than in the normal group.
The LLPSRGs play crucial roles in UC and can be used as prognostic and diagnostic markers for UC. The current findings contribute to the management of UC.
Lu J
,Lu X
,Chen B
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