The role of SIRT1 in BMP2-induced chondrogenic differentiation and cartilage maintenance under oxidative stress

Articular cartilage defects are common in the clinic but difficult to treat. Exploring the chondrogenic molecular mechanisms of mesenchymal stem cells (MSCs) is of great theoretical interest and industrial significance. Bone morphogenetic protein 2 (BMP2) is a key factor that induces cartilage differentiation and can induce stem cell chondrogenic differentiation. However, the oxidative stress in the microenvironment during cartilage injury and degeneration inhibits cartilage regeneration and homeostasis. Silent mating type information regulator 2 homolog-1 (SIRT1) is an important histone deacetylase that regulates proliferation, differentiation, aging, and inflammation processes; moreover, it is an essential factor for chondrogenesis. The specific mechanism of SIRT1 in cartilage differentiation and homeostasis is still unclear. First, we investigated whether SIRT1 could coordinate BMP2-induced chondrogenic differentiation. Second, we investigated the protective effect of SIRT1 on BMP2-induced MSCs under oxidative stress. The results showed that SIRT1 could promote BMP2-induced chondrogenic differentiation of MSCs, and reduce the apoptosis and decomposition of extracellular matrix under oxidative stress. In summary, these results suggested that SIRT1 plays an important coordination role in BMP2-induced chondrogenic differentiation of stem cells and cartilage maintenance under oxidative stress, establishing the experimental basis for exploring the use of SIRT1 in cartilage defect repair.