In vitro cell viability and proliferation assays. (A) Apoptosis measured after 24 hours of incubation in either normoxic conditions or hypoxic conditions. BMMCs from control or db/db donors showed the same trend in normoxia. (B) For proliferation capacity, BMMCs were cultured for 36 hours under normoxic and hypoxic conditions and cell quantitation was performed with the MTT assay. After 36 hours, db/db BMMCs showed a significantly impaired proliferation rate as compared to control BMMCs under both normoxic conditions and hypoxic conditions. Data are expressed as percentage relative to 100% at t=0 (*P <0.05). Abbreviations: MTT assay, (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.