FIG. 3.

Effects of COL1A1 and HtrA1 siRNAs on the mRNA expression of catabolic, hypertrophic, and osteogenic markers. HACs seeded onto collagen sponges were transfected with an INTERFERin-siRNA complex (5 nM NC siRNA, or 5 nM COL1A1 siRNA and/or 5 nM HtrA1 siRNA) as described in the “Materials and Methods” section. HACs were then cultured in 3% O₂ for 7 days and treated with or without BMP-2 (50 ng/mL). Relative mRNA expression of MMP-1 (A), MMP-13 (B), Aggrecanase-1 (C), Aggrecanase-2 (D), TIMP-1 (E), Cbfa1 (F), and Osterix (G) was obtained as described in Figure 1. Statistically significant differences between untreated cells and BMP-2-treated cells, NC siRNA-untreated cells, and other siRNA untreated cells, and between NC siRNA BMP-2-treated cells and other siRNA BMP-2-treated cells were determined using the Mann–Whitney U test (*p<0.05).