P018 Expression of annexin A1 and NLRP3 inflamassome in Chron's disease

Abstract Background Despite annexin A1 (ANXA1), an anti-inflammatory and pro-resolving protein, regulates the NLRP3 inflammasome activation in inflammatory cells, this relationship has not been explored bowel disease. Then, study evaluated expression patterns of ANXA1 Crohn's disease (CD). Methods Paraffin-embedded human intestine biopsies, obtained from CD (n=20) control (n=8) patients were processed for histological immunohistochemical analyses. The was approved by UNIFESP Ethics Committee (CEP 4.491.836/2020). GSE179285 study, which features ileum (Control - n=8, non-inflamed n=48, inflamed n=33) colon n=12, – n=74, n=14) transcriptome, selected Gene Expression Omnibus repository. Datasets analyzed using GEO2R tool to detect ANXA1, CASP1, NLRP3, PYCARD expressions. Results Bioinformatics analysis samples showed a marked increase compared controls (Fig.1A). Regarding genes associated with activation, transcriptome also revealed significant CASP1 other ones (Fig.1B,C). did show alterations between different conditions (Fig.1D). Immunohistochemical analyzes intense immunoreactivity proteins colon, especially infiltrate epithelium mucosal layer (Fig.2C,D,G,H), (Fig. 2A,B,E,F). These findings corroborate Conclusion is increased CD-inflamed intestines. High levels may contribute controlling inflammation repairing intestinal injuries. evidence dysfunction pro-inflammatory activity DC, contributing release IL-1β IL-18. Support: FAPESP (grants 20/03565-2, 21/01541-1 21/06059-3). Figure 1. Analysis performed healthy or terminal ascending/descending biopsies study. Data represent mean ± S.E.M. gene values. **p<0.01; ***p<0.001; ****p<0.0001 (Kruskal-Wallis, Dunn's post-test). 2. intestine. Representative images (A, C, E, G) (B, D, F, H) (A,B,E,F) (C,D,G,H). detected (arrows) (asterisks). Counterstaining: Carazzi's Hematoxylin. Bars: 50 µm.