Background: Hirschsprung's disease (HSCR) is caused by defective enteric neural crest cell (ENCC) migration. Exosome-transmitted microRNAs are implicated in HSCR pathogenesis, but mechanisms remain unclear.
Methods: Plasma exosomes and colon tissues were collected from HSCR patients and controls. We assessed the effects of exosomal miR-323a-3p on the proliferation and migration of immortalized ENCC-derived neural cell line (iENC) in vitro using CCK-8, EdU and Transwell assays, and its impact on ENCC migration in vivo using a zebrafish model.
Results: Exosomal miR-323a-3p was significantly upregulated in the plasma of HSCR and exhibited prospective diagnostic relevance (AUC = 0.7269, p = 0.0043). Exosomal miR-323a-3p was taken up by iENCs and suppressed their proliferation and migration. TET2 was identified as a potential miR-323a-3p target. TET2 was downregulated in HSCR aganglionic tissues, and its knockdown inhibited iENC proliferation and migration. In the zebrafish model, exosomal miR-323a-3p impaired distal ENCC colonization.
Conclusion: Exosomal miR-323a-3p is upregulated in HSCR and associated with impaired ENCC-derived cell function, potentially via TET2. These findings suggest exosome-transmitted microRNA-323a-3p participated in the occurrence of Hirschsprung's disease and exhibit promising potential as a prospective diagnostic biomarker.
Keywords: Hirschsprung’s disease; enteric nervous system; exosomes; microRNAs; neural crest cells.
Hirschsprung’s disease (HSCR) is a birth disorder caused by missing nerve cells in the gut. In this study, we discovered that small particles called exosomes carry a molecule named miR-323a-3p that is found at higher levels in the blood of HSCR patients. This molecule slows down the growth and movement of key nerve cells in the intestine. We also found that miR-323a-3p potentially does this by blocking TET2, a gene important for nerve development. Our results suggest that measuring plasma exosomal miR-323a-3p in blood could help doctors diagnose HSCR earlier and that the miR-323a-3p/TET2 pathway may be a target for future treatments.