Figure 5.

The viperin secretome and CXCL10. At day 5 in ATDC5 chondrogenic differentiation, viperin expression was reduced by either transfection of a viperin-specific siRNA duplex (Viperin siRNA) or a scrambled control siRNA duplex (Scrambled siRNA); or viperin expression was further induced by transfection of a p3xFLAG-viperin plasmid (FLAG-Viperin) or the empty p3xFLAG plasmid (FLAG-empty). The cells were then further differentiated until day 7, and viperin expression levels were determined (A and B). Immunoblots are shown for two independent representative examples. Culture supernatants from these day 7 cultures were collected, and the protein secretome was determined by label-free LC-MS/MS. Differentially secreted extracellular protein species (control versus condition) with p < 0.05 are shown (C). FC, fold change. In culture supernatants analyzed with LC-MS/MS, secreted CXCL10 levels were determined (D). In ATDC5 culture supernatants from Fig. 2, secreted CXCL10 levels were determined (E). The p values are indicated, and error bars indicate means ± S.E.