H19 siRNA inhibits the pro-chondrogenic effect seen in BMSCs seeded on the surface of E7-KGMs. (A) H19 expression of BMSCs co-cultured with EC-KGMs, E7-KGMs, and RGD-KGMs for 1, 3, and 5 days, as assessed using real-time PCR (n = 3). (B) H19 siRNA was added in the co-culture system of E7-KGMs and BMSCs, and the mRNA expressions of H19, acan, col II, and sox 9 at days 2 and 4 were assessed using real-time PCR (n = 3, * represents p < 0.05). (C) H19 siRNA was added to the co-culture system of E7-KGMs and BMSCs, and the protein expression levels of acan, col II, and sox 9 at day 4 were assessed using Western blotting (n = 3). E7 represents the E7-KGM group, si nc represents the negative/control siRNA group, and si H19 represents the H19 siRNA group. * p < 0.05.