RASL11Bgene enhances hyaluronic acid-mediated chondrogenic differentiation in human amniotic mesenchymal stem cells via the activation of Sox9/ERK/smad signals

摘要

This study aimed to elucidate the molecular mechanisms, whereby hyaluronic acid, a main extracellular matrix component of articular cartilage, promotes the chondrogenic differentiation of human amniotic mesenchymal stem cells (hAMSCs). Our previous findings indicated that hyaluronic acid combined with hAMSCs showed a marked therapeutic effect against rat osteoarthritis. In the present study, hyaluronic acid markedly enhanced the expression of chondrocyte-specific markers includingCol2 alpha 1, Acan, and Sox9 in hAMSCs, with strong synergistic effects on chondrogenic differentiation, in combination with the commonly used inducer, transforming growth factor beta 3 (TGF-beta 3). Microarray analysis showed that Ras-like protein family member 11B (RASL11B) played a pivotal role in the process of hyaluronic acid-mediated chondrogenesis of hAMSCs. This directional differentiation was significantly inhibited byRASL11Bknockdown, butRASL11Boverexpression dramatically promoted the expression of Sox9, a master chondrogenesis transcriptional factor, at the levels of transcription and translation. Increased Sox9 expression subsequently resulted in high expression levels ofCol2 alpha 1andAcanand the accumulation of cartilage-specific matrix components, such as type 2 collagen and glycosaminoglycans. Moreover, we observed thatRASL11Bactivated the signal molecules such as ERK1/2, and Smad2/3 in the presence of hyaluronic acid during TGF-beta 3-induced chondrogenesis of hAMSCs. Taken together, these findings suggest that hyaluronic acid activates theRASL11Bgene to potentiate the chondrogenic differentiation of hAMSCs via the activation of Sox9 and ERK/Smad signaling, thus providing a new strategy for cartilage defect repairing by hyaluronic acid-based stem cell therapy. Impact statement RASL11B, a member of the small GTPase superfamily, has high similarity to RAS proteins, and involves some pathophysiological processes, such as inflammation, arteriosclerosis, and cancer. However, there is no available information regarding the role ofRASL11Bin chondrogenic differentiation. We show thatRASL11Bis activated in the process of HA-mediated chondrogenesis of hAMSCs, andRASL11Bregulates the differentiation of hAMSCs into chondrocytes through the activation of Sox9 and ERK/Smad signals. The results of this study support thatRASL11Bmay be used as a target in the chondroinductive differentiation of hAMSCs in the presence of HA and even in the cartilage defect repairing by HA-based stem cell therapy.