Mesenteric Neural Crest Cells Are the Embryological Basis of Skip Segment Hirschsprung’s Disease

Abstract

Background & Aims Defective rostrocaudal colonization of the gut by vagal neural crest cells (vNCCs) results in Hirschsprung's disease (HSCR), which is characterized by aganglionosis in variable lengths of the distal bowel. Skip segment Hirschsprung’s disease (SSHD), referring to a ganglionated segment within an otherwise aganglionic intestine, contradicts HSCR pathogenesis and underscores a significant gap in our understanding of the development of the enteric nervous system. Here, we aimed to identify the embryonic origin of the ganglionic segments in SSHD. Methods Intestinal biopsy specimens from HSCR patients were prepared via the Swiss-roll technique to search for SSHD cases. NCC migration from the neural tube to the gut was spatiotemporally traced using targeted cell lineages and gene manipulation in mice. Results After invading the mesentery surrounding the foregut, vNCCs separated into 2 populations: mesenteric NCCs (mNCCs) proceeded to migrate along the mesentery, whereas enteric NCCs invaded the foregut to migrate along the gut. mNCCs not only produced neurons and glia within the gut mesentery, but also continuously complemented the enteric NCC pool. Two new cases of SSHD were identified from 183 HSCR patients, and Ednrb -mutant mice, but not Ret -/- mice, showed a high incidence rate of SSHD-like phenotypes. Conclusions mNCCs, a subset of vNCCs that migrate into the gut via the gut mesentery to give rise to enteric neurons, could provide an embryologic explanation for SSHD. These findings lead to novel insights into the development of the enteric nervous system and the etiology of HSCR.

Enhanced enteric neurogenesis by Schwann cell precursors in mouse models of Hirschsprung disease

“…In the colon of Ret 51(C618F)/GFP mice, delayed colonization by vagal NC-derived ENS progenitors occurred after E15.5, and robust SCP-derived neurogenesis was induced in the colonized region even in the absence of Ret. In the small intestine, proximal normally ganglionated segments contain no SCP-derived neurons, whereas SCP- (Yu et al, 2020). In the mesentery of E13.5 Ret 51(C618F)/GFP embryos, Ret (GFP)/Sox10 doublepositive cells were observed (Figure 8a).…”

Cell-autonomous retinoic acid receptor signaling has stage-specific effects on mouse enteric nervous system

“…These clusters closely resemble Schwann cell–derived ENS described by Uesaka et al, but the ENCDC we observed were restricted to small regions of fetal bowel ( 10 ). Alternatively, these cells might originate from the “mesenteric neural crest cells” recently described by Yu et al that they hypothesize contribute to human skip segment HSCR ( 8 ). Third, vagus nerves at E11.5 in Rar α DN LoxP/+ ; Wnt1Cre + mice occupied a smaller area of the stomach compared with control animals.…”

“…One concern is that we did not evaluate ENS biology in every possible control group, so we cannot exclude some effects of tamoxifen, Cre alleles, fluorescent reporters, or the Rar α DN LoxP/+ allele in isolation. For example, a recent study clearly shows that Wnt1Cre + ; R26R-TdTomato + increases the severity of the Ednrb –/– ENS phenotype ( 8 ). We also were underpowered to examine the effect of sex on ENS phenotypes, an issue that could be important for some of the milder phenotypes we examined.…”

“…These ENS cells arise primarily from vagal enteric neural crest-derived cell (ENCDC) precursors that divide rapidly and colonize the bowel in a rostral to caudal direction from E9 to E13.5 in mice ( 3 – 6 ). In addition to vagal ENCDC, ENS precursors include sacral neural crest ( 7 ), mesenteric neural crest ( 8 ), sympatho-enteric precursors ( 9 ), Schwann cells ( 10 ), and perhaps bowel epithelial cells ( 11 ). As ENCDC colonize the bowel, they differentiate into about 20 neuron types, and many types of glia that form extensive networks to control most aspects of bowel function ( 2 , 12 – 17 ).…”

Development, Diversity, and Neurogenic Capacity of Enteric Glia

“…These so called “skip segments” contain enteric neurons and glia, which were thought to arise from sacral neural crest ( Burns et al, 2000 ; O’Donnell and Puri, 2010 ). More recently, Schwann cell precursors and vagal neural crest cells migrating across the mesentery have been shown to contribute to skip segments ( Yu et al, 2020 ; Uesaka et al, 2021 ).…”