Published online Apr 14, 2024. doi: 10.3748/wjg.v30.i14.2038
Peer-review started: December 8, 2023
First decision: January 4, 2024
Revised: January 19, 2024
Accepted: March 1, 2024
Article in press: March 1, 2024
Published online: April 14, 2024
Processing time: 126 Days and 14.5 Hours
Acute pancreatitis (AP) encompasses a spectrum of pancreatic inflammatory conditions, ranging from mild inflammation to severe pancreatic necrosis and multisystem organ failure. Given the challenges associated with obtaining human pancreatic samples, research on AP predominantly relies on animal models. In this study, we aimed to elucidate the fundamental molecular mechanisms underlying AP using various AP models.
To investigate the shared molecular changes underlying the development of AP across varying severity levels.
AP was induced in animal models through treatment with caerulein alone or in combination with lipopolysaccharide (LPS). Additionally, using Ptf1α to drive the specific expression of the hM3 promoter in pancreatic acinar cells transgenic C57BL/6J- hM3/Ptf1α(cre) mice were administered Clozapine N-oxide to induce AP. Subsequently, we conducted RNA sequencing of pancreatic tissues and validated the expression of significantly different genes using the Gene Expression Omnibus (GEO) database.
Caerulein-induced AP showed severe inflammation and edema, which were exacerbated when combined with LPS and accompanied by partial pancreatic tissue necrosis. Compared with the control group, RNA sequencing analysis revealed 880 significantly differentially expressed genes in the caerulein model and 885 in the caerulein combined with the LPS model. Kyoto Encyclopedia of Genes and Genomes enrichment analysis and Gene Set Enrichment Analysis indicated substantial enrichment of the TLR and NOD-like receptor signaling pathway, TLR signaling pathway, and NF-κB signaling pathway, alongside elevated levels of apoptosis-related pathways, such as apoptosis, P53 pathway, and phagosome pathway. The significantly elevated genes in the TLR and NOD-like receptor signaling pathways, as well as in the apoptosis pathway, were validated through quantitative real-time PCR experiments in animal models. Validation from the GEO database revealed that only MYD88 concurred in both mouse pancreatic tissue and human AP peripheral blood, while TLR1, TLR7, RIPK3, and OAS2 genes exhibited marked elevation in human AP. The genes TUBA1A and GADD45A played significant roles in apoptosis within human AP. The transgenic mouse model hM3/Ptf1α(cre) successfully validated significant differential genes in the TLR and NOD-like receptor signaling pathways as well as the apoptosis pathway, indicating that these pathways represent shared pathological processes in AP across different models.
The TLR and NOD receptor signaling pathways play crucial roles in the inflammatory progression of AP, notably the MYD88 gene. Apoptosis holds a central position in the necrotic processes of AP, with TUBA1A and GADD45A genes exhibiting prominence in human AP.
Core Tip: AP is a critical emergency condition with no effective targeted therapeutic interventions currently available. Therefore, RNA sequencing (RNA-seq) was employed to investigate the molecular alterations in acute pancreatitis (AP), aiming to identify novel therapeutic strategies. The RNA-seq analysis showed a significant upregulation of TLR and NOD-like signaling pathways in AP, with crucial involvement of genes such as TLR7, IRF7, and MYD88. Notably, the TUBA1A and GADD45A genes were identified as key players in the apoptosis signaling pathway. Substantial evidence was provided through comprehensive validation using Gene Expression Omnibus Series datasets from human peripheral blood and mouse pancreatic tissues, as well as transgenic mouse models to examine inflammation and apoptosis-related molecules. This study offers fresh insights for future therapeutic approaches in managing AP and establishes new directions for subsequent fundamental investigations.