Induction of osteoblast differentiation in human adipose derived stem cells by lanthanum ions

Adipose derived stem cells represent a readily available source of adult stem cells for various biomedical applications. In this study, the proliferation and osteogenic differentiation potential of lanthanum nitrate (La³⁺) on human adipose derived mesenchymal stem cells (hADSCs) were investigated for the first time and compared with that of dexamethasone (Dex). Our results provided evidence that La³⁺ at 50 μmol/L concentration promoted proliferation of hADSCs upto 2.4 fold when treated for 21 d in DMEM medium. Treatment of hADSCs with La³⁺ containing osteogenic induction medium (α-MEM with ascorbic acid and β-glycerophosphate) for 7 d resulted in higher calcium deposition than that in the presence of Dex (0.1 μmol/L) as shown by Alizarin red S and von Kossa staining. Scanning electron micrographs also showed more extracellular matrix mineralization in the presence of La³⁺. After 7 d of treatment with La³⁺ (10 μmol/L) the expression of RunX2, osteopontin (OP) and osteocalcin (OC) increased 3.4, 5.5 and 2.7 fold respectively. Our results provided evidence that in the presence of La³⁺ osteogenic differentiation occurred earlier than that in the presence of Dex.