Total RNA was extracted from undifferentiated MSCs and from pellets after 3, 7, 14, or 21 days of differentiation using RNeasy kits (Qiagen, Valencia, CA, USA), according to the manufacturer's instructions. And 1,200 μL of RLT buffer supplemented with beta-mercaptoethanol (10 μL/mL) was added to the washed cells. RNA integrity was assessed by gel electrophoresis and RT-PCR and concentrations were determined by measuring absorbance at 260 nm.