Roles of microRNAs in prenatal chondrogenesis, postnatal chondrogenesis and cartilage-related diseases.

Cartilage has limited repair and regeneration capacity, thus damage of cartilage often results in its dysfunction and even chronic diseases like osteoarthritis (OA). Chondrogenesis induced by tissue-engineering methods is essential to treating cartilage-related diseases. MicroRNAs (miRNAs) are a class of small non-coding single-stranded RNAs which exert their biological effects by binding to the target messenger RNAs (mRNAs), resulting in decay or translation suppression of target mRNAs. There are emerging evidence indicating that miRNAs may play important roles in regulating both prenatal and postnatal chondrogenesis. During embryonic skeletal development, prenatal chondrogenesis is thought to be a precondition for formation of cartilage in developing limbs. Plenty of studies on different types of stem cells have undoubtedly proven their capacity of differentiating into chondrocytes. MiRNAs are found to comprehensively modulate these processes by establishing an interaction network with target genes, transcription factors and cytokines et al. In addition, translational application of miRNA technology has also been explored. In this review, we focus on the up-dated progress on regulatory mechanisms of miRNAs in prenatal and postnatal chondrogenesis. In addition, several miRNA target genes and roles of miRNAs in cartilage-related diseases are also discussed. This will contribute to studies of chondrogenesis mechanisms and development of new treating methods.