microRNA-1 Regulates NCC Migration and Differentiation by Targeting sec63

Background/Aims: Neural crest cells play a vital role in craniofacial development, microRNA-1 (miR-1) is essential in development and disease of the cardiac and skeletal muscle, the objective of our study is to investigate effects of miR-1 on neural crest cell in the craniofacial development and its molecular mechanism. Methods: We knocked down miR-1 in zebrafish by miR-1 morpholino (MO) microinjection and observed phenotype of neural crest derivatives. We detected neural crest cell migration by time-lapse. Whole-mount in situ hybridization was used to monitor the expressions of genes involved in neural crest cell induction, specification, migration and differentiation. We performed a quantitative proteomics study (iTRAQ) and bioinformatics prediction to identify the targets of miR-1 and validate the relationship between miR-1 and its target gene sec63. Results: We found defects in the tissues derived from neural crest cells: a severely reduced lower jaw and delayed appearance of pigment cells. miR-1 MO injection also disrupted neural crest cell migration. At 24 hours post fertilization (hpf), reduced expression of tfap2a, dlx2, dlx3b, ngn1 and crestin indicated that miR-1 deficiency affected neural crest cell differentiation. iTRAQ and luciferase reporter assay identified SEC63 as a direct target gene of miR-1. The defects of miR-1 deficiency could be reversed, at least in part, by specific suppression of sec63 expression. Conclusion: miR-1 is involved in the regulation of neural crest cell development, and that it acts, at least partially, by targeting sec63 expression.