ELAVL1-dependent SOAT2 exacerbated the pancreatitis-like cellular injury of AR42J cells induced by hyperstimulation with caerulein

Abstract

Pancreatitis is a severe inflammatory condition characterized by damage to the pancreas. Sterol o-acyltransferase 2 (SOAT2) has been reported to aggravate acute pancreatitis, however, the underlying mechanism remains to be elucidated. Rat pancreatic exocrine cells (AR42J) were treated with caerulein to induce pancreatitis-like cellular injury. Cell viability was determined using a cell counting kit-8 (CCK-8) assay, while cell proliferation was analyzed through a 5-Ethynyl-2'-deoxyuridine assay. Cell apoptosis was measured using flow cytometry, and enzyme-linked immunosorbent assays were performed to detect levels of pro-inflammatory cytokines IL-6 and TNF-α. Additionally, Fe²⁺ levels were analyzed using a colorimetric assay kit, reactive oxygen species (ROS) levels were assessed with a Cellular ROS Assay kit, and lipid peroxidation was measured using a malondialdehyde assay kit. Glutathione levels were analyzed with a detection assay. Protein and mRNA expression were evaluated through western blotting and quantitative real-time polymerase chain reaction, respectively. Furthermore, an RNA immunoprecipitation assay was conducted to investigate the association between ELAV-like RNA binding protein 1 (ELAVL1) and SOAT2. Actinomycin D assay was performed to explore the effect of ELAVL1 depletion on the transcript stability of SOAT2 mRNA. SOAT2 and ELAVL1 expression were upregulated in caerulein-exposed AR42J cells. Caerulein treatment induced pancreatitis-like cellular apoptosis, inflammatory response, ferroptosis, and cell proliferation inhibition. Silencing of SOAT2 protected against caerulein-induced AR42J cell injury. Moreover, ELAVL1 stabilized SOAT2 mRNA expression in AR42J cells. SOAT2 overexpression attenuated the effects induced by ELAVL1 silencing in caerulein-exposed AR42J cells. Additionally, ELAVL1 knockdown activated the NRF2/HO-1 pathway by downregulating SOAT2 expression in caerulein-exposed AR42J cells. SOAT2 silencing protected AR42J cells from caerulein-induced injury by inactivating the NRF2 pathway. In conclusion, ELAVL1-dependent SOAT2 exacerbated pancreatic exocrine cell injury by inactivating the NRF2/HO-1 pathway in pancreatitis. These findings provide new insights into the molecular mechanisms underlying pancreatitis and offer potential therapeutic targets for the treatment of this condition.

Keywords: ELAVL1; NRF2/HO‐1 pathway; SOAT2; pancreatitis.