*2.2. Isolation of Primary MSCs*

Mouse primary MSCs were obtained from bone aspirates of DBA mice. Both femurs and tibias from each leg were used. The cell suspension was homogenized and centrifuged at 2000 g for 10 min. Cell pellets were resuspended in high glucose Dulbecco's Modified Eagle Medium (DMEM) containing 10% fetal calf serum (FCS) (Invitrogen, Waltham, MA, USA), 10 μg/mL insulin, 5.5 μg/mL transferrin, 6.7 ng/mL sodium selenite, 10 ng/mL basic fibroblast growth factor, 2 mM L-glutamine, and 50 μg/mL gentamicin. The cells were seeded in culture flasks (Costar, New York, NY, USA) at a concentration of 2 <sup>×</sup> 10<sup>6</sup> cells/mL. The next day, as well as every subsequent 3-4 days, the culture medium was replaced. The resulting adhesive cell population was reseeded using a 0.25% trypsin solution. MSCs were cultured at 37◦C in a 5% CO2 atmosphere. Unless otherwise specified, culture media and other reagents were purchased from PanEco, Russia (Moscow, Russia).
