microRNAs in cardiovascular development.

Heart development requires precise temporal-spatial regulation of gene expression, in which the highly conserved modulation networks of transcription factors accurately control the signaling pathways required for normal cardiovascular development. Even slight perturbation of such programming during cardiogenesis can cause congenital heart defects and late neonatal or adult heart disease. microRNAs (miRNAs), a class of "small" non-coding RNAs, have recently drawn a lot of attention for their "big" impact on cardiovascular development and diseases. miRNAs negatively regulate the expression of their target genes in most biological organisms through post-transcriptional processes. Here, we review the roles of miRNAs in cardiovascular development and function, looking inside the molecular mechanisms by which miRNAs act as "fine tuners" and/or "safeguards" to maintain the homeostasis of cardiovascular system. We also propose new directions for therapeutic potential of these tiny molecules.