Dysregulation of GDNF and GFRα1 expression in multifactorial Hirschsprung disease

HSCR is caused by disruption of complex signaling pathways within the gene regulatory network (GRN) during enteric nervous system (ENS) development, including glial cell line-derived neurotrophic factor (GDNF) and GDNF family receptor alpha-1 (GFRα1). However, pathogenic variants in all GRN genes account for only ~ 80% cases; therefore, the epigenetic role remains to be elucidated. We compared GDNF and GFRα1 expression between HSCR patients and controls.

qPCR revealed an upregulated GDNF expression in both ganglionic (206.37-fold) and aganglionic (126.35-fold) HSCR compared to control colons (ΔC_T 7.65 ± 2.19 vs. 15.34 ± 1.34; p = 0.0001; and ΔC_T 8.35 ± 2.57 vs. 15.34 ± 1.34; p = 0.0001). qPCR also showed an upregulated GFRα1 expression in both ganglionic (29.66-fold) and aganglionic (18.44-fold) HSCR compared to control colons (ΔC_T 8.44 ± 1.98 vs. 13.33 ± 1.36; p = 0.0001; and ΔC_T 9.13 ± 1.46 vs. 13.33 ± 1.36; p = 0.0001). In addition, no significant differences were observed between ganglionic and aganglionic segments for either GDNF or GFRα1 (ΔC_T 7.65 ± 2.19 vs. 8.35 ± 2.57; p = 0.43; and ΔC_T 8.44 ± 1.98 vs. 9.13 ± 1.46; p = 0.29). Our study demonstrates global aberrant expression of GDNF and GFRα1 in HSCR patients. These findings underscore the complexity of HSCR as a multifactorial disorder and highlight the importance of integrated signaling networks in ENS development, providing a rationale for further mechanistic and translational studies.