A bioinformatics approach for in vivo imaging of endogenous MicroRNA targets during neurogenesis

MicroRNAs (miRNAs), a class of small non-coding RNAs, have been reported to be functionally involved with cellular metabolism and a variety of diseases. The importance of miRNA expression and functional targeting has recently become a focus of intense research. However, their endogenous molecular targets have not been clearly identified despite multiple attempts in prior studies using bioinformatics. Our bioinformatics strategy and in vitro validation by the PCR, identified 16 out of 337 miR124a-predicted targets and 5 out of 299 miR9*-predicted targets were significantly and directly down-regulated by each of the miRNAs during neurogenesis. In vitro and in vivo bioluminescent imaging system was used and successfully monitored the miR9*-mediated repression of SOX2 during neuronal differentiation of the P19 cells. The results of this study demonstrate that our bioinformatics approach offers a powerful and precise method for the identification of novel miR124a and miR9* endogenous targets during neuronal differentiation. This bioinformatics approach, using microarray data available from public DBs, provides a practical means for identifying the endogenous targets of other miRNAs.