Cholinergic innervation and ganglion cell distribution in Hirschsprung's disease

Paneth-like cells disruption and intestinal dysbiosis in the development of enterocolitis in an iatrogenic rectosigmoid hypoganglionosis rat model

Background

Hypoganglionosis resembles Hirschsprung disease (HSCR) which is characterized by severe constipation. Enterocolitis due to hypoganglionosis or Hirschsprung-associated enterocolitis (HAEC) is a life-threatening complication of both diseases. This study investigated the role of Paneth-like cells (PLCs) and gut microbiota in the development of enterocolitis in an iatrogenic rectosigmoid hypoganglionosis rat model.

Methods

The rectosigmoid serosa of male Sprague-Dawley rats were exposed to 0.1% benzalkonium chloride (BAC). The rats were then sacrificed after 1, 3, 5, 8, and 12 weeks. A sham group was sacrificed on Week 12. With hematoxylin-eosin staining, the ganglionic cells were quantified, the degree of enterocolitis was analyzed, and the PLCs was identified. Intestinal barrier function was assessed for the anti-peripherin, occludin, and acetylcholinesterase (AChE)/butyrylcholinesterase (BChE) ratio. qRT-PCR was used as reference for the evaluation of antimicrobial peptide (AMP) of PLCs using cryptdins, secretory Phospholipase A2, and lysozyme levels. 16S rRNA high-throughput sequencing on fecal samples was performed to analyze the changes in the intestinal microbiota diversity in each group.

Results

After 1 week of intervention, the ganglion cells were fewer in all sacrificial 0.1% BAC groups at varying times than those in the sham group. Occludin and peripherin were decreased, while the AChE/BChE ratio was increased. At Week 5 postintervention, the number of α-defensins-positive PLCs increased in the sigmoid colon tissues from BAC-treated rats. Conversely, PLCs-produced AMP decreased from Week 5 to Week 12. The sham group demonstrated increased Lactobacillus and decreased Bacteroides, while the 0.1% BAC group exhibited reciprocal changes, indicating dysbiosis. Enterocolitis occurred from Week 1 postintervention.

Conclusion

Application with BAC influences the disruption of PLCs in Week 5 postintervention, and dysbiosis exacerbate the occurrence of enterocolitis. Further research on Paneth cells involvement in HAEC development is warranted.

Indirubin mediates adverse intestinal reactions in guinea pigs by downregulating the expression of AchE through AhR

Indirubin is the main component of the traditional Chinese medicine Indigo naturalis (IN), a potent agonist of aryl hydrocarbon receptors (AhRs). In China, IN is used to treat psoriasis and ulcerative colitis, and indirubin is used for the treatment of chronic myelogenous leukaemia. However, IN and indirubin have adverse reactions, such as abdominal pain, diarrhoea, and intussusception, and their specific mechanism is unclear.The purpose of our research was to determine the specific mechanism underlying the adverse effects of IN and indirubin. By tracking the modifications in guinea pigs after the intragastric administration of indirubin for 28 days.The results demonstrate that indirubin could accelerate bowel movements and decrease intestinal acetylcholinesterase (AchE) expression. Experiments with NCM460 cells revealed that indirubin significantly reduced the expression of AchE, and the AchE levels were increased after the silencing of AhR and re-exposure to indirubin.This study showed that the inhibition of AchE expression by indirubin plays a key role in the occurrence of adverse reactions to indirubin and that the underlying mechanism is related to AhR-mediated AchE downregulation.

Children with Hirschsprung disease in a developing country: A cohort study of the predictors of a positive rectal biopsy result

Chronic constipation, which may be habitually or pathologically caused, is one of the most common complaints in children. One of the important pathological causes is Hirschsprung's disease (HD), which is diagnosed via multiple modalities, mainly rectal biopsy. Our aim was to compare the presentation and different predictive factors for positive rectal biopsy results in a developing country in the Middle East, such as Jordan. This cohort study was conducted at the Jordan University Hospital (JUH). All consecutive children aged <14 years who presented with refractory constipation and underwent rectal biopsies between January 2014 and December 2019 were retrospectively enrolled in the study. In the entire cohort study, 79 patients were enrolled: 45 (57%) were males and 34 (43%) were females. Regarding the biopsy results, 51 (64.6%) cases of refractory constipation without HD and 28 (35.4%) patients with refractory constipation with HD were diagnosed with open rectal biopsies. The male-to-female ratio of HD patients was 3:1. Moreover, 3 (10.7%) children who passed the meconium within the first 24 to 48 hours showed features of HD, while 17 (60.7%) children with delayed passage of the meconium showed features of HD. Abdominal distension was found to be a positive predictor of positive biopsy results (odds ratio [OR] = 4.09, P = .011), and soiling was found to be a negative predictor of positive biopsy results (OR = 0.07, P = .024). In developing countries, children presenting with HD seem to have similar symptoms and signs to those observed with traditional sampling and staining techniques.

Persistent bowel dysfunction after surgery for Hirschsprung’s disease: A neuropathological perspective

Hirschsprung’s disease (HD) is a congenital disorder, characterized by aganglionosis in the distal part of the gastrointestinal tract. Despite complete surgical resection of the aganglionic segment, both constipation and fecal incontinence persist in a considerable number of patients with limited treatment options. There is growing evidence for structural abnormalities in the ganglionic bowel proximal to the aganglionosis in both humans and animals with HD, which may play a role in persistent bowel dysfunction. These abnormalities include: (1) Histopathological abnormalities of enteric neural cells; (2) Imbalanced expression of neurotransmitters and neuroproteins; (3) Abnormal expression of enteric pacemaker cells; (4) Abnormalities of smooth muscle cells; and (5) Abnormalities within the extracellular matrix. Hence, a better understanding of these previously unrecognized neuropathological abnormalities may improve follow-up and treatment in patients with HD suffering from persistent bowel dysfunction following surgical correction. In the long term, further combination of clinical and neuropathological data will hopefully enable a translational step towards more individual treatment for HD.

Lack of Mucosal Cholinergic Innervation Is Associated With Increased Risk of Enterocolitis in Hirschsprung's Disease

BACKGROUND & AIMS

Hirschsprung's disease (HSCR) is a congenital intestinal motility disorder defined by the absence of enteric neuronal cells (ganglia) in the distal gut. The development of HSCR-associated enterocolitis remains a life-threatening complication. Absence of enteric ganglia implicates innervation of acetylcholine-secreting (cholinergic) nerve fibers. Cholinergic signals have been reported to control excessive inflammation, but the impact on HSCR-associated enterocolitis is unknown.

METHODS

We enrolled 44 HSCR patients in a prospective multicenter study and grouped them according to their degree of colonic mucosal acetylcholinesterase-positive innervation into low-fiber and high-fiber patient groups. The fiber phenotype was correlated with the tissue cytokine profile as well as immune cell frequencies using Luminex analysis and fluorescence-activated cell sorting analysis of colonic tissue and immune cells. Using confocal immunofluorescence microscopy, macrophages were identified in close proximity to nerve fibers and characterized by RNA-seq analysis. Microbial dysbiosis was analyzed in colonic tissue using 16S-rDNA gene sequencing. Finally, the fiber phenotype was correlated with postoperative enterocolitis manifestation.

RESULTS

The presence of mucosal nerve fiber innervation correlated with reduced T-helper 17 cytokines and cell frequencies. In high-fiber tissue, macrophages co-localized with nerve fibers and expressed significantly less interleukin 23 than macrophages from low-fiber tissue. HSCR patients lacking mucosal nerve fibers showed microbial dysbiosis and had a higher incidence of postoperative enterocolitis.

CONCLUSIONS

The mucosal fiber phenotype might serve as a prognostic marker for enterocolitis development in HSCR patients and may offer an approach to personalized patient care and new therapeutic options.