Abstract
BACKGROUND AND OBJECTIVES: Zonulin is a human protein that regulates intercellular tight junctions and increases the permeability of the intestinal epithelium. In light of the increasing focus on zonulin's role in numerous chronic inflammatory diseases, this study aimed to investigate whether differences exist in serum zonulin levels and bronchial epithelium zonulin expression in vivo between asthma and normal groups, using a mouse model. METHODS: Sixteen mice were utilized in this study, divided evenly between the normal and asthma groups. Serum zonulin levels, the expression of zonulin antibody in the bronchial epithelium, and serum cytokine levels were evaluated in both groups. Enzyme-linked immunosorbent assay and RNA in situ hybridization were utilized for the analysis. RESULTS: The asthma group exhibited significantly higher levels of serum zonulin. High zonulin antibody expression was also observed in the bronchial epithelium of the asthma group. Given that our mouse model demonstrated a significant difference in interleukin (IL)-4 and IL-6 between the normal and asthma groups, zonulin may be associated not only with type 2 responses but also with various subtypes of asthma. Further studies are required to investigate this relationship in greater detail. CONCLUSION: Zonulin may play a role in the complex pathophysiology of asthma and could serve as a biomarker in various asthma-related situations.