Aim: To investigate the abundance and potential diagnostic significance of neuroligin-1 and glutamate (Glu) in Hirschsprung's disease (HSCR).
Methods: Ninety children with HSCR and 50 children without HSCR matched for similar nutritional status, age and basal metabolic index were studied. The expression and localization of neuroligin-1 and Glu were assessed using double-labeling immunofluorescence staining of longitudinal muscles with adherent myenteric plexus from the surgically excised colon of children with HSCR. Western blot analysis, quantitative real-time PCR (qRT-PCR) and immunohistochemistry were performed to evaluate the abundance of neuroligin-1 and Glu in different HSCR-affected segments (ganglionic, transitional, and aganglionic segments). Enzyme-linked immunosorbent assay (ELISA) was used to detect and compare serum Glu levels in the long-segment HSCR, short-segment HSCR and non-HSCR samples.
Results: Neuroligin-1 and Glu were co-expressed highest to lowest in the ganglionic, transitional and aganglionic segments based on Western blot (neuroligin-1: 0.177 ± 0.008 vs 0.101 ± 0.006, 0.177 ± 0.008 vs 0.035 ± 0.005, and 0.101 ± 0.006 vs 0.035 ± 0.005, P < 0.005; Glu: 0.198 ± 0.006 vs 0.115 ± 0.008, 0.198 ± 0.006 vs 0.040 ± 0.003, and 0.115 ± 0.008 vs 0.040 ± 0.003, P < 0.005) and qRT-PCR (neuroligin-1: 9.58 × 10(-5) ± 9.94 × 10(-6) vs 2.49 × 10(-5) ± 1.38 × 10(-6), 9.58 × 10(-5) ± 9.94 × 10(-6) vs 7.17 × 10(-6 ±) 1.12 × 10(-6), and 2.49 × 10(-5) ± 1.38 × 10(-6) vs 7.17 × 10(-6) ± 1.12 × 10(-6), P < 0.005). Serum Glu level was the highest to lowest in the non-HSCR, short-type HSCR and long-type HSCR samples based on ELISA (in nmol/μL, 0.93 ± 0.31 vs 0.57 ± 0.25, 0.93 ± 0.31 vs 0.23 ± 0.16, and 0.57 ± 0.25 vs 0.23 ± 0.16, P < 0.005).
Conclusion: Neuroligin-1 and Glu may represent new markers of ganglion cells, whose expression may correlate with the pathogenesis, diagnosis, differential diagnosis or classification of HSCR.
Keywords: Ganglion cells; Glutamate; Hirschsprung’s disease; Neuroligin-1; Pathogenesis.