Chronological Changes in MicroRNA Expression in the Developing Human Brain

OBJECTIVE MicroRNAs (miRNAs) are endogenously expressed noncoding RNA molecules that are believed to regulate multiple neurobiological processes. Expression studies have revealed distinct temporal expression patterns in the developing rodent and porcine brain, but comprehensive profiling in the developing human brain has not been previously reported. METHODS We performed microarray and TaqMan-based expression analysis of all annotated mature miRNAs (miRBase 10.0) as well as 373 novel, predicted miRNAs. Expression levels were measured in 48 post-mortem brain tissue samples, representing gestational ages 14-24 weeks, as well as early postnatal and adult time points. RESULTS Expression levels of 312 miRNAs changed significantly between at least two of the broad age categories, defined as fetal, young, and adult. CONCLUSIONS We have constructed a miRNA expression atlas of the developing human brain, and we propose a classification scheme to guide future studies of neurobiological function.