Aberrant IL-20 Subfamily Signaling Disturbs Epithelial Barrier Function in Eosinophilic Esophagitis

ABSTRACT: Introduction Disruption of the epithelial barrier can induce eosinophilic esophagitis (EoE), a TH2-mediated food- and aeroallergen associated chronic inflammatory disease 1, 2. The expression of IL-20 subfamily cytokines, IL-19, IL-20 and IL-24, is increased in TH2-mediated diseases, yet their function in EoE is unknown. Methods Combining RNA-sequencing (RNA-seq) and proteome analysis, we have examined the effects of the IL-20 subfamily on esophageal epithelial cells using patient-derived organoids and an experimental EoE mouse model. Results When stimulated with IL-20 subfamily cytokines patient-derived esophageal organoids showed decreased expression of Filaggrin (FLG) and Filaggrin 2 (FLG2) responsible for epithelial cornification. In agreement, EoE patients with active inflammation showed elevated IL-20 subfamily cytokines and decreased FLG and FLG2 expression. Topical corticosteroid treatment in EoE patients restored filaggrin expression, while reducing IL-20 subfamily cytokines. Abolishment of IL-20 subfamily signalling in Il20R2-/- animals attenuated experimental EoE in an OVA-induced mouse model. In the esophageal keratinocyte cell line, KYSE-180, we identified IL-20 subfamily-induced STAT3 and MAPK (ERK1/2) pathway activation. However, Stat3fl/flKrt5cre mice with an epithelium specific deletion of Stat3 developed exacerbated experimental EoE with a pronounced decrease of Flg2. In line, combined stimulation of patient-derived esophageal organoids with IL-20 subfamily cytokines and pharmacological inhibition of STAT3 resulted in aggravated decrease of FLG and FLG2. In addition, pharmacological STAT3 inhibition resulted in reduced transepithelial electrical resistance (TEER) and increased macromolecular flux in patient-derived air liquid interface (ALI) cultures. Whereas, inhibition of the MAPK (ERK1/2) pathway hampered IL-20 subfamily induced TEER reduction and paracellular flux increment. Finally, MAPK (ERK1/2) inhibitor treatment reduced infiltrating CD45+ immune cells in the esophagus and alleviated experimental EoE in mice. Conclusion We discovered a novel regulatory function of the IL-20 subfamily for epithelial barrier integrity. Aberrant IL-20 subfamily signaling disturbs the epithelial barrier function, while abrogation of IL-20 subfamily and ERK1/2 signaling restores epithelial integrity and attenuates experimental EoE. Therefore, we propose that targeting the IL-20 subfamily pathway could present a novel therapeutic strategy for EoE treatment.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Skin

SUBMITTER: Alexander Schmidt  

LAB HEAD: Alexander Schmidtq

PROVIDER: PXD031509 | Pride | 2023-05-10

REPOSITORIES: Pride