FIGURE 7.
TNFRSF19 transcripts 1 and 2 (TNFRSF19.1 and TNFRSF19.2) have different functions during hMSC differentiation. A, hMSC-LRP5T253 cells were transfected with siCtrl (scramble siRNA), si19.1 (TNFRSF19.1 siRNA), or si19.2 (TNFRSF19.2 siRNA) followed by osteoblastic differentiation (treated with control CM (Co-CM) or Wnt3a) or adipocyte differentiation (treated with AIM) for 7 days. ALP activity was quantitated and normalized against the cell number (left). The expression of adipogenic markers were normalized against GAPDH and the expression level in cells treated with AIM alone was set to 1 (right). Results are mean ± S.D. of 8 replicates (ALP) or 4 replicates (adipogenic markers). *, p < 0.01 comparing with siCtrl. B, proposed function of TNFRSF19 in determination of the differentiation fate of hMSC. Canonical Wnt signaling activates TNFRSF19.2 expression to drive hMSC to osteoblastic lineage. C/EBP proteins inhibit basal expression of TNFRSF19.1 to drive hMSC to adipocytic lineage.