Figure 2. BMSC-CM promoted collagen production in fibroblasts. (A) RT-PCR showing relative mRNA expression of collagen type I alpha 1 chain (COL1A1), collagen type I alpha 2 chain (COL1A2), collagen type III alpha 1 chain (COL3A1), matrix metalloproteinases MMP1, MMP2, and MMP3 in fibroblasts treated with different media (versus GAPDH mRNA). (B) Western blotting showing protein levels of collagen I, collagen III, MMP1, and MMP2 in the two groups of fibroblasts. (C) Relative collagen I, collagen III, MMP1 and MMP2 protein levels (versus GAPDH). Data are shown as means ± standard deviation (SD). *P < 0.05; **P < 0.01; ***P < 0.001. BMSC-CM, bone marrow stem cell-conditioned medium; con, control medium treatment group; CM, BMSC-CM treatment group.