Effect of zonulin inhibitor in an In Vitro model of inflammatory bowel disease
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Hacettepe Üniversitesi, Sağlık Bilimleri Enstitüsü, Kök Hücre Bilimleri A.B.D., Türkiye
Tezin Onay Tarihi: 2025
Tezin Dili: İngilizce
Öğrenci: SEMA NUR GÜR
Danışman: Fatima Susanna F. Aerts Kaya
Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
Özet:
The term inflammatory Bowel Disease (IBD) is used to collectively describe Crohn’s disease and Ulcerative Colitis, which are characterized by chronic and acute inflammation of the gastrointestinal tract. Here, we wanted to assess whether DSS, TNF-a, and IFN-g can be used to mimic IBD in vitro in intestinal enteroids, and to assess the role of the Zonulin inhibitor Larazotide Acetate (LA) to counteract the effects of these drugs. Crypts from the small intestine of healthy Balb/c mice were isolated. Organoids self-organized into small enteroids shaped in the form of buds or spheres and contained Lgr5+ intestinal stem cells, Muc2+ Goblet cells and Chromogranin A+ enteroendocrine cells. The enteroids were treated with DSS, TNF-a, and IFN-g to induce an IBD-like environment. Enteroids exposed for 48 hours to these agents showed increased intestinal permeability and loss of epithelial barrier function. Whereas DSS activated apoptotic pathways, exposure to TNF-a, and IFN-g resulted in necrotic cell death. Since DSS caused RNA degradation, it is impossible to assess its effects on gene expression in enteroids. Exposure to TNF-a and IFN-g induced an increase in Zonulin (Hp) expression, indicating loss of tight junctions. Treatment with the Zonulin inhibitor Larazotide Acetate (LA), showed that LA can counteract the effects of TNF-a, but not IFN-g and that use of LA in the absence of inflammation increases Hp expression in enteroids. In conclusion, here we generated an in vitro model that mimics IBD by exposing Balb/c-derived enteroids to TNF-a and IFN-g, resulting in a damaged epithelial barrier, increased apoptosis and increased expression of Hp. LA shows potential as a possible treatment for IBD but should be used with caution as its therapeutic effects are most obvious in a highly inflammatory environment, but maybe absent or even disadvantageous when used in a minimally inflammatory environment.