scholarly journals Bioinformatics methods for identifying Hirschsprung disease genes

Author(s):  
Sudheer Menon

Hirschsprung is a birth defect of Enteric Nervous System (ENS) which is characterized by the absence of enteric neurons along the length of intestine. Hirschsprung is one of the complex diseases which has become a important topic of human genetics. In this article we have focused on RET gene mutation that is most common cause of HSCR disease. Out of seven mutations in RET gene, one mutation S339L is found to be tolerated and have no effect on protein function.

2018 ◽  
Vol 115 (18) ◽  
pp. 4696-4701 ◽  
Author(s):  
Marina Avetisyan ◽  
Julia E. Rood ◽  
Silvia Huerta Lopez ◽  
Rajarshi Sengupta ◽  
Elizabeth Wright-Jin ◽  
...  

The nervous system of the bowel regulates the inflammatory phenotype of tissue resident muscularis macrophages (MM), and in adult mice, enteric neurons are the main local source of colony stimulating factor 1 (CSF1), a protein required for MM survival. Surprisingly, we find that during development MM colonize the bowel before enteric neurons. This calls into question the requirement for neuron-derived CSF1 for MM colonization of the bowel. To determine if intestinal innervation is required for MM development, we analyzed MM of neonatal Ret−/− (Ret KO) mice that have no enteric nervous system in small bowel or colon. We found normal numbers of well-patterned MM in Ret KO bowel. Similarly, the abundance and distribution of MM in aganglionic human colon obtained from Hirschsprung disease patients was normal. We also identify endothelial cells and interstitial cells of Cajal as the main sources of CSF1 in the developing bowel. Additionally, MM from neonatal Ret KOs do not differ from controls in baseline activation status or cytokine-production in response to lipopolysaccharide. Unexpectedly, these data demonstrate that the enteric nervous system is dispensable for MM colonization and patterning in the bowel, and suggest that modulatory interactions between MM and the bowel nervous system are established postnatally.


2020 ◽  
Author(s):  
Laura Kuil ◽  
Katherine C. MacKenzie ◽  
Clara S Tang ◽  
Jonathan D. Windster ◽  
Thuy Linh Le ◽  
...  

AbstractBackgroundHirschsprung disease (HSCR) is characterized by absence of ganglia in the intestine. Approximately 18% of patients have additional anatomical malformations or neurological symptoms (HSCR-AAM). HSCR is a complex genetic disease in which the loss of enteric ganglia stems from a combination of genetic alterations: rare coding variants, predisposing haplotypes and Copy Number Variation (CNV). Pinpointing the responsible culprits within a large CNV is challenging as often many genes are affected. We investigated if we could find deleterious CNVs and if we could identify the genes responsible for the aganglionosis.ResultsDeleterious CNVs were detected in three groups of patients: HSCR-AAM, HSCR patients with a confirmed causal genetic variant and HSCR-isolated patients without a known causal variant and controls. Predisposing haplotypes were determined, confirming that every HSCR subgroup had increased contributions of predisposing haplotypes, but their contribution was highest in isolated HSCR patients without RET coding variants. CNV profiling proved that HSCR-AAM patients had larger copy number losses. Gene enrichment strategies using mouse enteric nervous system transcriptomes and constraint metrics were used to determine plausible candidate genes in Copy Number Losses. Validation in zebrafish using CRISPR/Cas9 targeting confirmed the contribution of UFD1L, TBX2, SLC8A1 and MAPK8 to ENS development. In addition, we revealed epistasis between reduced Ret and Gnl1 expression in vivo.ConclusionRare large Copy Number losses - often de novo - contribute to the disease in HSCR-AAM patients specifically. We proved the involvement of five genes in enteric nervous system development and Hirschsprung disease.


Development ◽  
2002 ◽  
Vol 129 (12) ◽  
pp. 2785-2796 ◽  
Author(s):  
Alan J. Burns ◽  
Jean-Marie M. Delalande ◽  
Nicole M. Le Douarin

The enteric nervous system (ENS) is derived from vagal and sacral neural crest cells (NCC). Within the embryonic avian gut, vagal NCC migrate in a rostrocaudal direction to form the majority of neurons and glia along the entire length of the gastrointestinal tract, whereas sacral NCC migrate in an opposing caudorostral direction, initially forming the nerve of Remak, and contribute a smaller number of ENS cells primarily to the distal hindgut. In this study, we have investigated the ability of vagal NCC, transplanted to the sacral region of the neuraxis, to colonise the chick hindgut and form the ENS in an experimentally generated hypoganglionic hindgut in ovo model. Results showed that when the vagal NC was transplanted into the sacral region of the neuraxis, vagal-derived ENS precursors immediately migrated away from the neural tube along characteristic pathways, with numerous cells colonising the gut mesenchyme by embryonic day (E) 4. By E7, the colorectum was extensively colonised by transplanted vagal NCC and the migration front had advanced caudorostrally to the level of the umbilicus. By E10, the stage at which sacral NCC begin to colonise the hindgut in large numbers, myenteric and submucosal plexuses in the hindgut almost entirely composed of transplanted vagal NCC, while the migration front had progressed into the pre-umbilical intestine, midway between the stomach and umbilicus. Immunohistochemical staining with the pan-neuronal marker, ANNA-1, revealed that the transplanted vagal NCC differentiated into enteric neurons, and whole-mount staining with NADPH-diaphorase showed that myenteric and submucosal ganglia formed interconnecting plexuses, similar to control animals. Furthermore, using an anti-RET antibody, widespread immunostaining was observed throughout the ENS, within a subpopulation of sacral NC-derived ENS precursors, and in the majority of transplanted vagal-to-sacral NCC. Our results demonstrate that: (1) a cell autonomous difference exists between the migration/signalling mechanisms used by sacral and vagal NCC, as transplanted vagal cells migrated along pathways normally followed by sacral cells, but did so in much larger numbers, earlier in development; (2) vagal NCC transplanted into the sacral neuraxis extensively colonised the hindgut, migrated in a caudorostral direction, differentiated into neuronal phenotypes, and formed enteric plexuses; (3) RET immunostaining occurred in vagal crest-derived ENS cells, the nerve of Remak and a subpopulation of sacral NCC within hindgut enteric ganglia.


2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Emilie G. Jaroy ◽  
Lourdes Acosta-Jimenez ◽  
Ryo Hotta ◽  
Allan M. Goldstein ◽  
Ragnhild Emblem ◽  
...  

Abstract Hirschsprung disease is a neurocristopathy, characterized by aganglionosis in the distal bowel. It is caused by failure of the enteric nervous system progenitors to migrate, proliferate, and differentiate in the gut. Development of an enteric nervous system is a tightly regulated process. Both the neural crest cells and the surrounding environment are regulated by different genes, signaling pathways, and morphogens. For this process to be successful, the timing of gene expression is crucial. Hence, alterations in expression of genes specific for the enteric nervous system may contribute to the pathogenesis of Hirschsprung’s disease. Several epigenetic mechanisms contribute to regulate gene expression, such as modifications of DNA and RNA, histone modifications, and microRNAs. Here, we review the current knowledge of epigenetic and epitranscriptomic regulation in the development of the enteric nervous system and its potential significance for the pathogenesis of Hirschsprung’s disease. We also discuss possible future therapies and how targeting epigenetic and epitranscriptomic mechanisms may open new avenues for novel treatment.


2019 ◽  
Vol 11 (03) ◽  
pp. 180-185 ◽  
Author(s):  
Radhika krishna OH ◽  
Mohammed Abdul Aleem ◽  
Geetha Kayla

Abstract BACKGROUND: Small bowel atresia is a congenital disorder that carves a substantial morbidity. Numerous postoperative gastrointestinal motility problems occur. The underlying cause of this motility disorder is still unclear. Interstitial cells of Cajal (ICC) play a major role in gastrointestinal motility. AIMS AND OBJECTIVES: To investigate the morphological changes of enteric nervous system and ICC in small bowel atresia. MATERIAL AND METHODS: Resected small bowel specimen from affected patients (n=15) were divided into three parts (proximal, distal, atretic). Standard histology and immunohistochemistry with anti C-KIT receptor antibody (CD117), calretinin and α-SMA was carried out. The density of myenteric ICCs in the proximal, atretic and distal parts was demonstrated by CD 117 while Calretinin was used for ganglion cells and nerve bundles, α-SMA highlighted muscle hypertrophy. RESULT AND CONCLUSION: The proximal and distal bowel revealed clear changes in the morphology and density of enteric nervous system and interstitial cells of Cajal..


2019 ◽  
Vol 316 (4) ◽  
pp. G446-G452 ◽  
Author(s):  
Simona E. Carbone ◽  
Nicholas A. Veldhuis ◽  
Arisbel B. Gondin ◽  
Daniel P. Poole

G protein-coupled receptors (GPCRs) are essential for the neurogenic control of gastrointestinal (GI) function and are important and emerging therapeutic targets in the gut. Detailed knowledge of both the distribution and functional expression of GPCRs in the enteric nervous system (ENS) is critical toward advancing our understanding of how these receptors contribute to GI function during physiological and pathophysiological states. Equally important, but less well defined, is the complex relationship between receptor expression, ligand binding, signaling, and trafficking within enteric neurons. Neuronal GPCRs are internalized following exposure to agonists and under pathological conditions, such as intestinal inflammation. However, the relationship between the intracellular distribution of GPCRs and their signaling outputs in this setting remains a “black box”. This review will briefly summarize current knowledge of agonist-evoked GPCR trafficking and location-specific signaling in the ENS and identifies key areas where future research could be focused. Greater understanding of the cellular and molecular mechanisms involved in regulating GPCR signaling in the ENS will provide new insights into GI function and may open novel avenues for therapeutic targeting of GPCRs for the treatment of digestive disorders.


Sign in / Sign up

Export Citation Format

Share Document