title: Glial cell line-derived neurotrophic factor family receptors are abnormally expressed in aganglionic bowel of a subpopulation of patients with Hirschsprung's disease.
abstract: Hirschsprung's disease (HSCR), a congenital disease, is characterized by the absence of ganglion cells in the ganglion plexuses of the caudal most gut. In the aganglionic colon, the plexus remnants are replaced by aggregates of glial cells and hypertrophied nerve fibers. Signaling of glial cell line-derived neurotrophic factor (GDNF)-GFRAs-receptor tyrosine kinase (RET) is crucial for the development and maintenance of ganglion cells. Mutations of genes such as GDNF and RET lead to the perturbation of this signaling pathway, which causes HSCR. To understand the role of GFRAs in ganglion cells and the pathogenesis of HSCR, we intended to determine the specific cell lineages in the enteric nervous system that normally express GFRAs but are affected in HSCR. We studied colon biopsy specimens from 13 patients with HSCR (aged 1 day to 38 months) and 6 age-matched patients without HSCR as normal controls. RT-PCR, in situ hybridization, and immunohistochemistry were performed to examine the expression and cellular distributions of GFRAs in resected bowel segments of normal infants and those with HSCR. In normal infants and normoganglionic colon of patients with HSCR, the expression of GFRA1 was restricted to the glial cells and neurones of the ganglion plexuses. GFRAs expression was found to be markedly reduced in the aganglionic colons of 3 infants with HSCR but was unaffected in the aganglionic colons of 10 other infants with HSCR. Residual GFRA expression was restricted to enteric glial cells in the plexus remnants of the aganglionic colons. Hypertrophied nerve fibers were not found to express GFRA1. We provide the first evidence that abnormal expression of GFRAs in the enteric nervous system may be involved in the pathogenesis of HSCR in a subpopulation of patients.
authors.affiliation: Division of Paediatric Surgery, Department of Surgery, University of Hong Kong Medical Centre, Queen Mary Hospital, Hong Kong SAR, China.
authors.forename: Vincent Chi Hang
authors.initials: VC
authors.lastname: Lui
authors.forename: Eileen Teresa
authors.initials: ET
authors.lastname: Samy
authors.forename: Mai Har
authors.initials: MH
authors.lastname: Sham
authors.forename: Lois M
authors.initials: LM
authors.lastname: Mulligan
authors.forename: Paul Kwong Hang
authors.initials: PK
authors.lastname: Tam
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002675:Child, Preschool; D003106:Colon / Q000294:innervation / Q000378:metabolism* / Q000473:pathology; D017931:DNA Primers / Q000737:chemistry; D029721:Drosophila Proteins; D005260:Female; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D006627:Hirschsprung Disease / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009197:Myenteric Plexus / Q000378:metabolism / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009457:Neuroglia / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D051096:Proto-Oncogene Proteins c-ret; D012333:RNA, Messenger / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013368:Submucous Plexus / Q000378:metabolism / Q000473:pathology
chemical_list: D015415:Biomarkers; D017931:DNA Primers; D029721:Drosophila Proteins; C494987:GFRA1 protein, human; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila