Altered endothelin-3 and endothelin-B receptor mRNA expression in Hirschsprung's disease

Recently, the endothelin-3 (EDN3) and endothelin-B receptor (EDNRB) gene have been recognized as susceptibility genes for Hirschsprung's disease (HD). However, gene mutations have been observed only in limited cases, and the role of EDN3 in the pathogenesis and motility dysfunction in HD is not understood fully. To evaluate the possible implication of EDN3 and EDNRB for the development of HD, we examined the EDN3 and EDNRB mRNA level in bowel specimens of HD patients.

Entire resected specimens of colon were obtained from 14 patients with HD. Eight age-matched control patients without gastroenteric disorders also were examined. mRNA was extracted from ganglionic and aganglionic segments of the HD specimens and normal colons. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to evaluate the relative amount of EDN3 and EDNRB mRNA.

In normal colon, constant EDN3 and EDNRB mRNA expression was observed. In HD, EDN3 and EDNRB mRNA expression was observed. In HD, EDN3 and EDNRB mRNA levels were decreased both in ganglionic and aganglionic segment in 2 cases. In 6 cases, EDN3 mRNA expression was decreased in aganglionic segment and in another 2 cases, EDNRB mRNA expression was decreased in aganglionic segment. In the remaining 4 cases, EDN3 and EDNRB mRNA levels were similar to controls.

The authors' findings indicate that loss of EDN3 and EDNRB function may be involved in the maldevelopment of neural crest-derived cells causing HD in many patients.