Unveiling the role of oxidative stress in ANCA-associated glomerulonephritis through integrated machine learning and bioinformatics analyses

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic autoimmune disease often leading to rapidly progressive glomerulonephritis. Oxidative stress plays a critical role in the development and progression of ANCA-associated glomerulonephritis (AAGN), but the underlying mechanisms remain poorly understood. Targeting genes related to oxidative stress may provide novel insights and supplementary therapeutic benefits for AAGN. In the current study, we obtained differentially expressed genes from AAGN-related microarray datasets in the Gene Expression Omnibus database, and oxidative stress-related genes (OSRGs) from the GeneCards and Gene Ontology databases to identify differentially expressed OSRGs. Then, by integrating weighted gene co-expression network analysis, and machine learning algorithms, we identified four upregulated hub OSRGs (all <i>p</i> &lt; 0.01) with strong diagnostic potential (all AUC &gt; 0.9)-CD44, ITGB2, MICB, and RAC2 – in the AAGN glomerular training dataset GSE104948 and validation dataset GSE108109, along with two hub OSRGs (all <i>p</i> &lt; 0.05) with better diagnostic potential (all AUC &gt; 0.7) – upregulated gene VCAM1 and downregulated gene VEGFA-in the AAGN tubulointerstitial training dataset GSE104954 and validation dataset GSE108112. The GSEA analysis suggested that these hub genes may play a role in inflammatory and immune response processes. Moreover, we constructed regulatory networks and identified drugs that potentially target these hub genes. It’s to be noted that RAC2 and ITGB2 were associated with cyclophosphamide in the AAGN glomerular compartment, while VCAM1 and VEGFA were associated with dexamethasone in the tubulointerstitial compartment. This study offers novel insights into immune-associated OSRGs within the glomerular and tubulointerstitial compartments of AAGN which may serve as innovative targets for diagnosing and treating AAGN.

抗中性粒细胞胞浆抗体（Anti-neutrophil cytoplasmic antibody, ANCA）相关血管炎（ANCA-associated vasculitis, AAV）是一类常可引发快速进展性肾小球肾炎的全身性自身免疫性疾病。氧化应激在ANCA相关肾小球肾炎（ANCA-associated glomerulonephritis, AAGN）的发生与进展中发挥关键作用，但其具体分子机制仍未完全阐明。靶向氧化应激相关基因或可为AAGN提供全新的研究视角与辅助治疗策略。本研究从基因表达综合数据库（Gene Expression Omnibus, GEO）中获取AAGN相关微阵列数据集的差异表达基因，并从基因卡（GeneCards）与基因本体（Gene Ontology, GO）数据库中提取氧化应激相关基因（oxidative stress-related genes, OSRGs），以筛选差异表达的氧化应激相关基因。随后，通过整合加权基因共表达网络分析与机器学习算法，在AAGN肾小球训练数据集GSE104948与验证数据集GSE108109中，鉴定出4个上调的核心氧化应激相关基因（所有*p*<0.01），均具备较强的诊断价值（所有曲线下面积（area under the curve, AUC）>0.9），分别为CD44、ITGB2、MICB及RAC2；同时在AAGN肾小管间质训练数据集GSE104954与验证数据集GSE108112中，鉴定出2个核心氧化应激相关基因（所有*p*<0.05），诊断价值更优（所有AUC>0.7），即上调基因VCAM1与下调基因VEGFA。基因集富集分析（Gene Set Enrichment Analysis, GSEA）结果显示，上述核心基因可能参与炎症与免疫应答过程。此外，本研究构建了调控网络并筛选出可靶向这些核心基因的潜在药物。值得注意的是，在AAGN肾小球微环境中，RAC2与ITGB2与环磷酰胺（cyclophosphamide）存在关联；而在肾小管间质微环境中，VCAM1与VEGFA与地塞米松（dexamethasone）相关。本研究为AAGN肾小球与肾小管间质微环境中免疫相关氧化应激相关基因提供了全新的研究视角，这些基因或可成为AAGN诊断与治疗的创新性靶点。