Eupatilin alleviates inflammation and epithelial-to-mesenchymal transition in chronic rhinosinusitis with nasal polyps by upregulating TFF1 and inhibiting the Wnt/ß-catenin signaling pathway.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial inflammatory disease characterized by high prevalence and morbidity. However, its pathogenesis is still obscure. This work focuses on the effects of Eupatilin (EUP) on inflammation reaction and the epithelial-to-mesenchymal transition (EMT) process in CRSwNP. METHODS: In vivo and in vitro CRSwNP models were established based on BALB/c mice and human nasal epithelial cells (hNECs) to investigate the effects of EUP on EMT and inflammation in CRSwNP. Protein levels of TFF1, EMT-related factors (E-cadherin, N-cadherin, and Vimentin), and Wnt/ß-catenin signaling-related proteins (Wnt3α and ß-catenin) were assayed via western blotting. Pro-inflammatory factors (TNF-α, IL-6, and IL-8) were assessed via ELISA assay. RESULTS: EUP treatment significantly reduced the number of polyps, epithelial thickness, and mucosal thickness in CRSwNP mice. Besides, EUP treatment also suppressed inflammation reaction and EMT events in CRSwNP mice and SEB-challenged hNECs in a dose-dependent manner. Also, EUP treatment dose-dependently upregulated TFF1 expression and inhibited Wnt/ß-catenin activation in CRSwNP mice and SEB-challenged hNECs. In addition, TFF1 inhibition or Wnt/ß-catenin activation partially abated EUP-mediated protection against SEB-induced inflammation reaction and EMT events in hNECs. CONCLUSIONS: Taken together, our findings highlighted the inhibitory role of EUP on the inflammation and EMT processes in CRSwNP in vivo and in vitro via upregulating TFF1 and inhibiting the Wnt/ß-catenin signaling, suggesting EUP could be a promising therapeutic agent for CRSwNP.

IFNγ-dependent silencing of TFF1 during Helicobacter pylori infection.

Chronic Helicobacter pylori infection is the leading cause of intestinal-type adenocarcinoma, as prolonged Helicobacter colonization triggers chronic active gastritis, which may evolve into adenocarcinoma of the intestinal type. In this environment, cytokines play a significant role in determining the evolution of the infection. In combination with other factors (genetic, environmental and nutritional), the pro-inflammatory response may trigger pro-oncogenic mechanisms that lead to the silencing of tumour-suppressor genes, such as trefoil factor 1 (TFF1). The latter is known to play a protective role by maintaining the gastric mucosa integrity and retaining H. pylori in the mucus layer, preventing the progression of infection and, consequently, the development of gastric cancer (GC). Since TFF1 expression is reduced during chronic Helicobacter infection with a loss of gastric mucosa protection, we investigated the molecular pathways involved in this reduction. Specifically, we evaluated the effect of some pro-inflammatory cytokines on TFF1 regulation in GC and primary gastric cells by RT-qPCR and luciferase reporter assay analyses and the repressor role of the transcription factor C/EBPß, overexpressed in gastric-intestinal cancer. Our results show that, among several cytokines, IFNγ stimulates C/EBPß expression, which acts as a negative regulator of TFF1 by binding its promoter at three different sites.

The TFF Peptides xP1 and xP4 Appear in Distinctive Forms in the Xenopus laevis Gastric Mucosa: Indications for Different Protective Functions.

The gastric secretory trefoil factor family (TFF) peptides xP1 and xP4 are the Xenopus laevis orthologs of mammalian TFF1 and TFF2, respectively. The aim of this study was to analyze the molecular forms of xP1 and xP4 in the X. laevis gastric mucosa by FPLC. xP1 mainly occurred in a monomeric low-molecular-mass form and only a minor subset is associated with the mucus fraction. The occurrence of monomeric xP1 is unexpected because of its odd number of cysteine residues. Probably a conserved acidic residue flanking Cys55 allows monomeric secretion. Furthermore, Cys55 is probably post-translationally modified. For the first time, we hypothesize that the free thiol of monomeric xP1-and probably also its mammalian ortholog TFF1-could have a protective scavenger function, e.g., for reactive oxygen/nitrogen species. In contrast, xP4 mainly occurs in a high-molecular-mass form and is non-covalently bound to a mucin similarly as TFF2. In vitro binding studies with radioactively labeled porcine TFF2 even showed binding to X. laevis gastric mucin. Thus, xP4 is expected to bind as a lectin to an evolutionary conserved sugar epitope of the X. laevis ortholog of mucin MUC6 creating a tight mucus barrier. Taken together, xP1 and xP4 appear to have different gastric protective functions.