Figure 6
Effects of COL1A1 and/or HtrA1 siRNAs on the mRNA levels of specific and nonspecific cartilage markers. hBM-MSCs seeded onto collagen sponges were transfected with an INTERFERin®-siRNA complex (100 nM negative control (NC) siRNA, or 100 nM COL1A1 siRNA and/or 100 nM HtrA1 siRNA) at days 0 and 7 as described in Materials and Methods. hBM-MSCs were cultured in 3% O2 for 14 days with or without (−) both 50 ng/mL BMP-2 and 10 ng/mL TGF-β1 (B-T). Relative mRNA expressions of type II collagen (A), aggrecan (B), type I collagen (C), HtrA1 (D), type X collagen (G), and alkaline phosphatase (H) were obtained as described in Figs 3–4. All results were normalized to RPL13a mRNA, and are presented as the expression of each gene relative to that of untreated NC cells. We also determined the COL2A1/COL1A1 mRNA ratio (E) and the ACAN/COL1A1 mRNA ratio (F). Box plots represent the results from independent experiments performed in triplicate (n = 4). Statistically significant differences between the untreated NC cells and the different treatments were determined using the Kruskall-Wallis test (#P < 0.05). Statistically significant differences between untreated cells and BMP-2/TGF-β1-treated cells, NC siRNA-untreated cells, and other siRNA-untreated cells, and between NC siRNA BMP-2/TGF-β1-treated cells and other siRNA BMP-2/TGF-β1-treated cells were determined using the Mann-Whitney U test (*p < 0.05).
