Fig. 6: Role of BICD1 in cP1P-induced HIF1α expression.

a UCB-MSCs were incubated with cP1P (1 μM) or S1P (1 μM) for 24 h. The protein expressions of BICD1 and β-Actin were detected by western blotting. n = 4. b, c UCB-MSCs were pretreated with rapamycin (100 nM) or PF4708671 (10 μM) for 30 min prior to cP1P (1 μM) for 24 h. BICD1 and β-Actin protein expressions were detected by western blotting. n = 3. d Interaction between HIF1α and BICD1 (HIF1α-BICD1, red) in UCB-MSCs with or without cP1P (1 μM) treatment for 24 h was assessed by PLA assay. Scale bars are 8 μm. Magnification × 1,000. n = 8. e UCB-MSCs were pretreated with cycloheximide (10 μM) for 30 min prior to cP1P (1 μM) for 24 h. Co-immunoprecipitation of HIF1α and Dynein IC with IgG and BICD1 antibodies are shown in left panel. Total protein expressions of HIF1α, Dynein IC, BICD1, and β-Actin in lysates are shown in right panel. n = 3. f–i UCB-MSCs were transfected with BICD1 or NT siRNA for 24 h prior to cP1P (1 μM) treatment for 24 h. f Total protein expressions of HIF1α, BICD1, and β-Actin were detected by western blotting. n = 3. g Nuclear and cytosolic protein expressions of HIF1α, lamin A/C, and α-Tubulin were detected by western blotting. n = 3. h UCB-MSCs were immunostained with HIF1α-specific antibody. n = 6. Scale bars are 8 μm. Magnification × 1,000 (left panel). i HIF1 activities were assessed by dual luciferase reporter assay. n = 6. All blot and immunofluorescence images are representative. Quantitative data are presented as a mean ± S.E.M with scatter plots. * indicates p < 0.05