Identification of key genes and pathways associated with osteogenic differentiation of adipose stem cells

Adipose stem cells (ASCs) are considered a great alternative source of mesenchymal stem cells (MSCs) and have shown great promise on tissue engineering and regenerative medicine applications, including bone repair. However, the underlying mechanisms regulating the osteogenic differentiation of ASCs remain poorly known. Gene expression profiles of GSE63754 and GSE37329 were downloaded from gene expression omnibus database. R software and Bioconductor packages were used to compare and identify the differentially expressed genes (DEGs) before and after ASC osteogenic differentiation. The common significant DEGs between GSE63754 and GSE37329 were then subjected to gene ontology (GO) enrichment analysis, ingenuity pathway analysis (IPA), and protein-protein interactions (PPIs) networks analysis. One of the central node genes FOXO1 was selected for further investigation. A total of 142 up- and 69 downregulated genes were aberrantly expressed in both GSE63754 and GSE37329. GO analysis revealed that these DEGs were associated with extracellular matrix organization, proteinaceous extracellular matrix, and Wnt-protein binding. IPA analysis showed that canonical pathways, such as FXR/RXR activation, adipogenesis pathway, and LXR/RXR activation, were involved in regulating osteogenic differentiation of ASCs. A total of three subnetworks and 39 nodes were identified with PPI network and MCODE plugin. Moreover, suppression of one central node gene FOXO1 inhibited the osteogenic differentiation of ASCs. Our study provides a registry of genes and pathways that play important roles in regulating osteogenic differentiation of ASCs, which might have potential therapeutic applications in bone regeneration and bone tissue engineering.