Sox9-Increased miR-322-5p Facilitates BMP2-Induced Chondrogenic Differentiation by Targeting Smad7 in Mesenchymal Stem Cells

Figure 7

BMP2-induced chondrogenesis was enhanced, and chondrocyte hypertrophy was weakened by miR-322-5p in vivo. (a) Masses were retrieved after 4 weeks of injection. (b) Overexpressing Sox9 decreased the number of hypertrophic chondrocytes (yellow arrow), which was partly reversed by the use of the miR-322-5p antagomir ((b) i–iii); moreover, silencing Sox9 decreased the number of differentiated chondrocytes (blue arrow) and increased the number of undifferentiated MSCs (dark arrow), which was partly reversed by forced expression of the miR-322-5p agomir ((b) iii–v). (c, d) Quantitative analysis of randomized three fields in each group. (e) According to the Masson staining, increased formation of cartilage tissue promoted by Sox9 was partly reversed by adding of miR-322-5p antagomir, while decreased production of cartilage tissue caused by silencing Sox9 was partly reversed by forced expression of miR-322-5p agomir. (f, g) IHC showed that overexpression of Sox9 increased the synthesis of COL2A1 and decreased the generation of COL10A1, and both were partly reversed by use of miR-322-5p antagomir; simultaneously, silence of Sox9 decreased the production of COL2A1 and increased the formation of COL10A1, and both were partly reversed by use of miR-322-5p agomir. (h, i) Quantitative analysis of positive-stained area. Integral optical density/area (IOD/area) was calculated with Image Pro Plus software.  μm; , , and .