RESUMO
Expression of mucin MUC2, a component of the colonic mucus layer, plays a crucial role in intestinal homeostasis. Here, we describe a new regulator of MUC2 expression, the deubiquitinase ZRANB1 (Trabid). A ZRANB1 mutation changing cysteine to serine in amino acid position 443, affects ubiquitination. To analyze ZRANB1 function in the intestine, we generated Zranb1 C443S mutant knock-in (Zranb1C443S/C443S) mice using the CRISPR/Cas9 system. Zranb1C443S/C443S mice exhibited decreased mRNA expression and MUC2 production. Colonic organoids from Zranb1C443S/C443S mice displayed decreased Muc2 mRNA expression following differentiation into goblet cells. Finally, we analyzed dextran sulfate sodium-induced colitis to understand ZRANB1's role in intestinal inflammation. Zranb1C443S/C443S mice with colitis exhibited significant weight loss, reduced colon length, and worsening clinical and pathological scores, indicating that ZRANB1 contributes to intestinal homeostasis. Together, these results suggest that ZRANB1 regulates MUC2 expression and intestinal inflammation, which may help elucidating the pathogenesis of inflammatory bowel disease and developing new therapeutics targeting ZRANB1.
Assuntos
Colite , Mucosa Intestinal , Proteases Específicas de Ubiquitina , Animais , Colite/induzido quimicamente , Colite/genética , Colite/metabolismo , Cisteína/metabolismo , Enzimas Desubiquitinantes/metabolismo , Sulfato de Dextrana/toxicidade , Inflamação/patologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Camundongos , Mucinas/metabolismo , Muco/metabolismo , RNA Mensageiro/genética , Serina/metabolismo , Proteases Específicas de Ubiquitina/genética , Proteases Específicas de Ubiquitina/metabolismoRESUMO
Crohn's disease is an inflammatory disease of the gut caused by a complex interplay among genetic, microbial, and environmental factors. The intestinal tract is constantly exposed to metals and other trace elements ingested as food. Synchrotron radiation-induced X-ray fluorescence spectroscopy and X-ray absorption fine structure analysis revealed the deposition of nickel particles within Crohn's disease tissue specimens. After nickel particle stimulation, THP-1 cells showed filopodia formation and autophagic vacuoles containing lipid bodies. Nickel particles precipitated colitis in mice bearing mutations of the IBD susceptibility protein A20/TNFAIP3. Nickel particles also exacerbated dextran sulfate sodium-induced colitis in mice harboring myeloid cell-specific Atg5 deficiency. These findings illustrate that nickel particle ingestion may worsen Crohn's disease by perturbing autophagic processes in the intestine, providing new insights into environmental factors in Crohn's disease pathogenesis.