Paneth cells disruption and intestinal dysbiosis contribute to the development of Hirschsprung-associated enterocolitis in a benzalkonium chloride-induced Hirschsprung’s disease rat model

Background: Hirschsprung-associated enterocolitis (HAEC) is a life-threatening complication of Hirschsprung’s disease (HSCR). This study investigated the role of Paneth cells (PCs) and gut microbiota in HAEC development. Methods: Male Sprague-Dawley rats with HSCR were established by exposure of 0.1% (n = 30) benzalkonium chloride (BAC) to rectosigmoid serosa and sacrificed at 1-, 3-, 5-, 8-, and 12-weeks postintervention. The sham group was included and sacrificed on Week 12. Hematoxylin-Eosin staining was conducted to count the number of ganglionic cells and analyze the degree of enterocolitis. Intestinal barrier function was assessed for the ratio of anti-peripherin, occludin and acetylcholinesterase (AChE)/butyrylcholinesterase (BChE). PCs antimicrobial peptide (AMP) was evaluated by cryptdins, secretory Phospholipase A2, and lysozyme levels by qRT-PCR, respectively. 16S rRNA high throughput sequencing on faecal samples was used to analyze the changes in intestinal microbiota diversity in each group. Results: Compared with sham groups, 0.1% BAC group rats had fewer ganglion cells after 1-week postintervention. Occludin and peripherin were decreased, and AChE/BChE ratio was increased, respectively. Sigmoid colon tissues from BAC-treated rats showed increased a-defensins positive PCs on Week 5 postintervention. Conversely, PCs-produced AMP tended to decrease from Week 5 to Week 12. Rats in the sham group demonstrated increased Lactobacillus and decreased Bacteroides, while rats in the 0.1% BAC exhibited reciprocal changes. Enterocolitis occurred from Week 1 postintervention onwards. Conclusion: Disruption of PCs in the Week 5 postintervention and dysbiosis exacerbate the occurrence of HAEC. This research sheds new light on the cellular mechanisms of HAEC development. ### Competing Interest Statement The authors have declared no competing interest.