Identification of Biomarkers Associated with Oxidative Stress and Immune Cells in Acute Pancreatitis

Oxidative stress promotes disease progression by stimulating the humoral and cellular immune responses. However, the molecular mechanisms underlying oxidative stress and immune responses in acute pancreatitis (AP) have not been extensively studied.

We analyzed the GSE194331 dataset and oxidative stress-related genes (OSRGs). We identified differentially expressed immune cell-associated OSRGs (DE-ICA-OSRGs) by overlapping key module genes from weighted gene co-expression network analysis, OSRGs, and DEGs between AP and normal samples. Functional enrichment analysis was performed to investigate the functions of DE-ICA-OSRGs. We then filtered diagnostic genes using receiver operating characteristic curves and investigated their molecular mechanisms using single-gene set enrichment analysis (GSEA). We also explored the correlation between diagnostic genes and differential immune cells. Finally, we constructed a transcription factor-microRNA-messenger RNA (TF-miRNA-mRNA) network of biomarkers.

In this study, three DE-ICA-OSRGs (ARG1, NME8 and VNN1) were filtered by overlapping key module genes, OSRGs and DEGs. Functional enrichment results revealed that DE-ICA-OSRGs were involved in the cellular response to reactive oxygen species and arginine biosynthesis. Latterly, a total of two diagnostic genes (ARG1 and VNN1) were derived and their expression was higher in the AP group than in the normal group. The single-gene GSEA enrichment results revealed that diagnostic genes were mainly enriched in macroautophagy and Toll-like receptor signaling pathways. Correlation analysis revealed that CD8 T cells, resting memory T CD4 cells, and resting NK cells were negatively correlated with ARG1, and neutrophils were positively correlated with ARG1, which was consistent with that of VNN1. The TF-miRNA-mRNA regulatory network included 11 miRNAs, 2 mRNAs, 10 transcription factors (TFs), and 26 pairs of regulatory relationships, like NFKB1-has-miR-2909-VNN1.

In this study, two immune cell oxidative stress-related AP diagnostic genes (ARG1 and VNN1) were screened to offer a new reference for the diagnosis of patients with AP.