Fig. 6.

C/EBPβ downregulates the endogenous expression of Ric-8B in intact osteoblastic cells. (A) ROS17/2.8 osteoblastic cells were transfected with a specific siRNA against C/EBPβ (siC/EBPβ-1). At 48 h later, mRNA levels of Ric-8B and C/EBPβ were determined by QPCR. The bars represent the means ± the standard errors of the means of two independent experiments. Statistically significant differences were determined by the analysis of variance test. ***, P < 0.001. (B) Nuclear extracts from ROS17/2.8 cells, treated as described for panel A, were analyzed by Western blotting to determine C/EBPβ protein levels. Control, cells transfected with vehicle; siNR, cells transfected with an unrelated siRNA mix (for siRNA information, see Materials and Methods).