MicroRNA-211 causes ganglion cell dysplasia in congenital intestinal atresia via down-regulation of glial-derived neurotrophic factor.

BACKGROUND: MicroRNAs (miRNAs) are known to be involved in normal brain functions and nervous system diseases. Some evidence have pointed to the dysregulation of miRNAs in congenital intestinal atresia. In this study, we investigated the differential expression of miRNAs and the posttranscriptional regulation of glial-derived neurotrophic factor (GDNF) by endogenous miRNA in congenital intestinal atresia. METHODS: Quantitative real-time PCR and a Western blot were performed to determine the regulation of miRNA and GDNF in patients with congenital intestinal atresia. The results were verified in rat model of intestinal atresia and bone marrow derived stem cell BMSCs-derived into intestinal ganglion cells. The effects of miRNA and GDNF on the cell proliferation and apoptosis of isolated intestinal ganglion cells were detected with an 3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium (MTT) assay and a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively. KEY RESULTS: Only miR-211 was greatly up-regulated in the patients with congenital intestinal atresia. The other miRNAs examined showed no change. Overexpression of miR-211 suppressed the differentiation of BMSCs into intestinal ganglion cells. In retinal ganglion cells (RGC-5 cells), miR-211 regulated the expression of GDNF. The MTT and TUNEL assays revealed that miR-211 overexpression suppressed the cell proliferation of isolated intestinal ganglion cells and that GDNF overexpression reversed the effect of pre-miR-211 on cell proliferation and apoptosis. CONCLUSIONS & INFERENCES: Our results indicate that overexpression of miR-211 suppresses the differentiation of BMSCs into intestinal ganglion cells by directly down-regulating the expression of GDNF. The findings elucidate the role of miRNA in congenital intestinal atresia.