Conclusion
These findings indicated that miRNA-138 overexpression could protect the spinal cord development of fetal rats, and the underlying mechanisms were associated with Shh expression. The present study provides a novel strategy to promote the molecular mechanism of embryonic spinal cord development.
Methods
Two plasmid vectors including pLenti-III-mico-GFP (miRNA-138 open reading frame [ORF]) and pLenti-III-miR-Off (miRNA-138 short hairpin) were constructed and injected into the tail vein of rats on the 14th day of pregnancy. Hematoxylin-eosin (HE) staining was used to observe the cell morphology. QRT-PCR, Western blot, and immunostaining confirmed the regulatory relationship between miRNA-138 and downstream molecules sonic hedgehog (Shh).
Results
Overexpression of miRNA-138 increased neuron regeneration significantly and decreased neuronal apoptosis when compared with the control. Silencing of miRNA-138 increased neuronal apoptosis and spinal cord atrophy significantly. Furthermore, miRNA-138 ORF treatment effectively increased the expression level of miRNA-138 and also upregulated the level of Shh. Comparatively, knockdown of miRNA-138 downregulated Shh levels in myelodysplastic regions.