The role of the α7nAChR-mediated cholinergic anti-inflammatory pathway in Hirschsprung associated enterocolitis

Abstract Background To investigate the role and the underlying mechanism of the α7nAChR-mediated cholinergic anti-inflammatory pathway in the pathogenesis of Hirschsprung(HSCR) associated enterocolitis（HAEC）. Methods Experimental group:twenty-one-day-old Ednrb-/- mice were selected (n=10), with comparable-age wild type(Ednrb+/+) mice controls (n=10). Intestinal samples were collected. The experimental colons were divided into narrow and dilated segments according to morphology changes. The control colons were divided into distal and proximal segments.Colon HE staining was used to judge HAEC.Acetylcholine levels in colon was measured using enzyme-linked immunosorbent assays. Detected phosphorylated Jak2 (p-Jak2), Jak2, phosphorylated Stat3 (p-Stat3), Stat3, phosphorylated IκBα (p-IκBα) and IκBα were studied by Western blotting; mRNA levels of Jak2, Stat3, and IκBα were detected by RT-qPCR. Results Colon HE staining indicated that HAEC mainly occured in the dilated segments of HSCR mice (Ednrb-/- mice) (EDNRB-P).Acetylcholine content in EDNRB-P was significantly lower than that in the narrow segments (EDNRB-D) (P<0.05). Western blotting showed that the Jak2, p-Jak2, Stat3 and p-Stat3 levels in EDNRB-D were significantly higher than those in EDNRB-P (P<0.05). The p-IκBα and IκBα levels in EDNRB-P were significantly higher than those in EDNRB-D(P<0.05). The mRNA levels of Jak2 and Stat3 in EDNRB-D were higher than those in EDNRB-P, but the IκBα mRNA level was significantly lower than that in EDNRB-P (P<0.05). Conclusions During HAEC, the inflammation in the dilated segment was more severe ,while in the narrow segment there was no obvious inflammatory reaction and the content of acetylcholine was higher, which was associated with the α7nAChR-mediated cholinergic anti-inflammatory pathway.