Fig. 1

Irisin enhances chondrogenic differentiation of hMSCs. A Macro-images of induced-cartilage tissues were taken on Day-7 and Day-14 (Left panel). (Magnification: × 15, scale bar: 2 mm). The relative diameter of cartilage tissues in controls and r-irisin-treated group (Right panel). B The expression of integrin αVβ5 receptor in hMSCs-induced cartilage tissue. (Magnification: × 400, scale bar: 50 μm). C The mRNA expression levels of COL2A1, ACAN and SOX9 were detected by qPCR in different groups on Day-7 and Day-14. D Protein expression levels of COL2A1, ACAN and SOX9 were detected by western blot in different groups on Day-7 and Day-14. E Immunohistochemistry for COL2A1 and ACAN on Day-7 and Day-14 in different groups. (Magnification: × 200, scale bar: 100 μm). F Safranin O and Alcian Blue staining for cartilage matrix metabolism on 7 and 14 days in different groups. (Magnification: × 200, scale bar: 100 μm). The levels were determined using the ImageJ software. The concentration of irisin used in this figure was 100 ng/ml. *P < 0.05, **P < 0.01 compared with the control-group