Figure 2.

Hypoxia affects the differentiation of bone marrow mesenchymal stem cells (BMSCs) into osteoblasts by regulating HIF-1α expression. An amount of 5% O₂ up-regulates HIF-1α; 1% O₂ downregulates HIF-1α. In the process of HIF-1α affecting BMSCs osteogenic differentiation, core binding factor α1 (Cbfα1), bone morphogenetic protein 2 (BMP2), runt-related transcription factor 2 (RUNX2), mechano growth factor (MGF), phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), MEK-extracellular regulated protein kinase 1/2 (ERK1/2), pyruvate dehydrogenase kinase 1 (PDK-1), and Wnt/β-catenin play a positive regulatory role, while Notch1, C/EBP, TWIST, and AKT/mTOR play a negative regulatory role.