Downregulation of Notch-1/Jagged-2 in human colon tissues from Hirschsprung disease patients

Abstract

Recent studies have shown that the Notch pathways play important roles in the differentiation and development of neurons. Hirschsprung disease (HSCR) is characterized by the absence of intramural ganglion cells in the nerve plexuses of the distal gut. However, putative Notch function in enteric nervous system (ENS) development and the etiology of HSCR is unknown. The aganglionosis segments of 30 HSCR patients were introduced to investigate the expression pattern of Notch-1 and Jagged-2 using immunohistochemical staining, reverse transcriptase polymerase chain reaction (RT-PCR), and Western blot analysis. Intensive Notch-1 and Jagged-2 staining was detected in the submucosal and the myenteric plexuses in normal or oligoganglionosis segments. Aganglionosis segments from HSCR patients contained no plexuses and thus not labeled with Notch-1 and Jagged-2. Western blot analysis revealed reduced Notch-1 and Jagged-2 protein levels, and RT-PCR revealed reduced Notch-1 and Jagged-2 mRNA in the aganglionosis segments of HSCR patients. This study is the first illustration of Notch-1 and Jagged-2 expression in human tissues from non-cancerous disease and sets up the base for further investigations of Notch function in ENS development and intestinal motility.