Platelet lysate induces chondrogenic differentiation of umbilical cord‐derived mesenchymal stem cells by regulating the lncRNA H19/miR‐29b‐3p/SOX9 axis

Platelet lysate (PL) has been shown to induce chondrogenic differentiation of human umbilical cord‐derived mesenchymal stem cells (hUCMSCs). However, the underlying mechanism is still not clear. The aim of this study was to investigate whether long noncoding RNA H19 is involved in this process. hUCMSCs were isolated, identified and cultured in 5% PL‐supplemented chondrogenic differentiation medium. Chondrogenic differentiation was assessed by Alcian blue staining. The expressions of H19, miR‐29b‐3p, SRY‐related high‐mobility‐group box 9 (SOX9), collagen II and aggrecan were determined by quantitative real‐time PCR and western blot. The interaction between miR‐29b‐3p and H19 or SOX9 was analyzed by luciferase reporter assay. During PL‐induced chondrogenic differentiation of hUCMSCs, expressions of H19 and SOX9 were increased, whereas miR‐29b‐3p expression was decreased. H19 overexpression promoted, whereas H19 silencing attenuated the PL‐induced chondrogenic differentiation of hUCMSCs. SOX9 was identified as a direct target of miR‐29b‐3p, and H19 was observed to act as a sponge of miR‐29b‐3p to up‐regulate SOX9 expression. The chondrogenic differentiation‐promoting effect of H19 overexpression was negated when miR‐29b‐3p expression was up‐regulated by Lenti‐miR‐29b‐3p infection. In conclusion, PL induced chondrogenic differentiation of hUCMSCs by regulating the H19/miR‐29b‐3p/SOX9 axis.