Identification of genes associated with the differentiation potential of adipose-derived stem cells to osteocytes or myocytes.

Adipose-derived stem cells (ADSCs) have been considered as the optimal cells for regenerative medicine because ADSCs have the potential of multi-directional differentiation. To study the mechanisms of ADSCs differentiation, we analyzed microarray of GSE37329. GSE37329 was downloaded from Gene Expression Omnibus including 3 ADSCs, 2 ADSCs-derived osteocytes, and 2 ADSCs-derived myocytes samples. The differentially expressed genes (DEGs) were screened using limma package. Their underlying functions were predicted by gene ontology and pathway enrichment analyses. Besides, the interaction relationships of the proteins encoded by DEGs were obtained from STRING database, and protein-protein interaction (PPI) network was constructed using Cytoscape. Furthermore, modules analysis of PPI network was performed using MCODE in Cytoscape. We screened 662 and 484 DEG separately for the ADSCs-derived osteocytes and myocytes compared with ADSCs. There were 205 common up-regulated and 128 common down-regulated DEGs between the two groups. Function enrichment indicated that these common DEGs, especially, VEGFA, FGF2, and EGR1 may be related to cell differentiation. PPI network for common DEGs also suggested that VEGFA (degree = 29), FGF2 (degree = 17), and EGR1 (degree = 12) might be more important because they had higher connectivity degrees, and they might be involved in cell differentiation by interacting with other genes in module A (e.g., EGR1-NGF and EGR1-LEP), and B (e.g., VEGFA-PDGFD). Additionally, the IGF1 and BTG1 may be, respectively, specific for osteocytes and myocytes differentiation. VEGFA, PDGFD, FGF2, EGR1, NGF, LEP, IGF1, and BTG1 might serve as target genes in regulating ADSCs differentiation.