miR-146b-5p Regulates the Enteric Nervous System Development in Hirschsprung Disease via Targeting RET Pathway

The objective of the study is to investigate how miR-146b-5p might contribute to the etiology of HSCR. The study investigated the expression levels of miRNA, mRNA, and proteins in colon tissues obtained from the HSCR and control groups. The role of miR-146b-5p in cell proliferation and migration was studied in vitro. The interaction between miR-146b-5p and RET was validated through a dual-luciferase reporter experiment. To assess the impact of miR-146b-5p on the development of the enteric nervous system, zebrafish embryos were micro-injected with either miR-146b-5p mimics or negative control, followed by subsequent evaluation. Compared to the control group, miR-146b-5p expression levels in the spastic region of HSCR were significantly increased. In vitro, miR-146b-5p prevented cell migration and proliferation by targeting RET pathway. In zebrafish, miR-146b-5p negatively regulates the migration of neural crest cells through a reduction in RET expression. Overexpression of miR-146b-5p hinders the development of mature neurons by decreasing RET expression. Additionally, the aberrant phenotypes induced by miR-146b-5p were partially ameliorated when RET mRNA was co-injected. By targeting RET in HSCR patients, aberrant expression of miR-146b-5p may play a unique role in the etiology of the disease and be involved in enteric nervous system development.