The OSMR Gene Is Involved in Hirschsprung Associated Enterocolitis Susceptibility through an Altered Downstream Signaling.

Isabella Ceccherini,Andrea Petretto,Martina Bartolucci,Francesca Lantieri,Giuseppe Santamaria,Alessio Pini Prato,Marco Di Duca,Domenico Mavilio,Stefano Avanzini,Tiziana Bachetti,Valentina Obino,Francesca Rosamilia,Serenella Sartori,Manuela Mosconi,Simona Candiani,Maria Rosaria De Filippo

doi:10.3390/ijms22083831

Abstract

Hirschsprung (HSCR) Associated Enterocolitis (HAEC) is a common life-threatening complication in HSCR. HAEC is suggested to be due to a loss of gut homeostasis caused by impairment of immune system, barrier defense, and microbiome, likely related to genetic causes. No gene has been claimed to contribute to HAEC occurrence, yet. Genetic investigation of HAEC by Whole-Exome Sequencing (WES) on 24 HSCR patients affected (HAEC) or not affected (HSCR-only) by enterocolitis and replication of results on a larger panel of patients allowed the identification of the HAEC susceptibility variant p.H187Q in the Oncostatin-M receptor (OSMR) gene (14.6% in HAEC and 5.1% in HSCR-only, p = 0.0024). Proteomic analysis on the lymphoblastoid cell lines from one HAEC patient homozygote for this variant and one HAEC patient not carrying the variant revealed two well distinct clusters of proteins significantly up or downregulated upon OSM stimulation. A marked enrichment in immune response pathways (q < 0.0001) was shown in the HAEC H187 cell line, while proteins upregulated in the HAEC Q187 lymphoblasts sustained pathways likely involved in pathogen infection and inflammation. In conclusion, OSMR p.H187Q is an HAEC susceptibility variant and perturbates the downstream signaling cascade necessary for the gut immune response and homeostasis maintenance.

Highlights

Our results show striking evidence that, after stimulation with Oncostatin M (OSM), the cell line carrying the rarer HSCR patients affected (HAEC) associated G allele was perturbated in immune pathways and enriched in several pathways likely involved in pathogen infection and inflammation
Our results demonstrate that the observed perinuclear structures do include endocytic recycling compartment (ERC) and that OSM treatment can enhance ERC functioning
We selected the HAEC patients to get sequenced by Whole-Exome Sequencing (WES) based on (i) presence of enterocolitis, (ii) complete phenotypic screening resulted in the absence of additional anomalies; (iii) Italian ancestry; (iv) sufficient and not degraded DNA

Summary

Introduction

Hirschsprung’s disease (HSCR) is a chronic constipation characterized by congenital absence of enteric ganglia [1].HSCR occurs as either familial or sporadic (up to 80%), shows high heritability, and often presents together with additional congenital anomalies [1,2].The major gene involved in HSCR is the RET proto-oncogene [3,4], several other genes and loci have been described to be involved in a minority of cases, mainly syndromic [1,5,6]. HSCR is resolved by surgery in the vast majority of cases, HirschsprungAssociated Enterocolitis (HAEC), the most serious complication in HSCR, is still lifethreatening, and occurs in around one third of patients [7]. Hirschsprung’s disease (HSCR) is a chronic constipation characterized by congenital absence of enteric ganglia [1]. HSCR occurs as either familial or sporadic (up to 80%), shows high heritability, and often presents together with additional congenital anomalies [1,2]. The major gene involved in HSCR is the RET proto-oncogene [3,4], several other genes and loci have been described to be involved in a minority of cases, mainly syndromic [1,5,6]. HSCR is resolved by surgery in the vast majority of cases, Hirschsprung. Associated Enterocolitis (HAEC), the most serious complication in HSCR, is still lifethreatening, and occurs in around one third of patients [7]. HAEC was initially believed to be caused by intestinal mechanical obstruction, but its occurrence both before and after surgery seems to claim against this hypothesis

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