Proteomic analysis reveals that ACSL4 activation during reflux esophagitis contributes to ferroptosis-mediated esophageal mucosal damage

Ferroptosis has been shown to be involved in the pathological process of many diseases. However, the function and mechanism of ferroptosis in reflux esophagitis (RE), especially in the esophageal mucosal damage, remains unknown. The purpose of this study was to screen potential therapeutic target genes that mediate RE esophageal mucosal damage and regulate ferroptosis. RE rats were established by our previous protocol and proteomic analysis of esophageal mucosa was performed. In addition, the ferroptosis-related genes were retrieved from the FerrDb database and were cross analyzed with the differential proteins of proteomics to obtain potential therapeutic target genes Acyl-CoA synthetase long-chain family 4 (ACSL4), a key enzyme for ferroptosis. In the present study, we used the ACSL4 inhibitor rosiglitazone (ROSI) and the ferroptosis inhibitor ferrostatin-1 to intervene with RE rats, and evaluate the levels of protein, histological changes, lipid peroxidation levels, iron accumulation and morphological changes in esophageal tissue by HE staining, Western blot, related kit tests, and transmission electron microscope. The results showed that both ferrostatin-1 and ROSI treatment significantly reduced the levels of iron accumulation and lipid peroxidation, and protected against ferroptosis and esophageal tissue injury in RE rats. Through Immunohistochemical staining, 16SrDNA sequencing, Enzyme linked immunosorbent assay (ELISA), Western blot and other tests on the esophagus, gut, spleen and serum of RE rats, we further found that the changes of esophageal and intestinal microbiota and the increase of peripheral blood LPS were the key factors regulating ferroptosis in esophageal epithelial tissue. On the one hand, LPS could increase the expression of ACSL4 in esophageal tissue by up-regulating special protein 1 (Sp1). On the other hand, LPS could increase the secretion of serum ferritin in spleen and the accumulation of iron in esophageal tissue by activating Capase11/GSDMD pyroptosis pathway. Collectively, this study suggests that ACSL4 and ferroptosis are potential therapeutic targets for RE esophageal mucosal damage, and esophageal and gut microecology play a critical role in this process.