Fig. 2. Acute exposure to FIR irradiation inhibits adipogenic differentiation and promotes osteogenic differentiation of TMSC. TMSC were exposed to FIR irradiation for 0, 30, and 60 min and further incubated in commercially available adipogenic or osteogenic differentiation medium for up to 14 days. (A) The accumulation of lipid droplets was assessed using Oil red O staining. Scale bar = 100 μm. (B) Protein levels of PPARγ and FABP4 were measured by western blot analysis. GAPDH was used as a loading control for normalization. (C) Mineralization was assessed using Alizarin red S staining. Scale bar = 200 μm. (D) Protein levels of osteocalcin and ALP were measured by western blot analysis. GAPDH was used as a loading control for normalization. The results are representative of three independent experiments, and each bar represents the mean ± S.D. Differences were statistically significant at *p<0.05, **p<0.01, and ***p<0.001.