Figure 2

Effect of microRNA-33a on transforming growth factor-β1-mediated phosphoinositide 3-kinase/Akt signaling pathway in human chondrocytes. (A) Sterol regulatory element-binding protein 2 (SREBP-2) mRNA expression in human normal chondrocytes (n = 3 from 3 different donors) after treatment with 10 ng/ml transforming growth factor (TGF)-β1 with or without microRNA (miR)-33a inhibitor. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used for normalization of the real-time PCR data. The data are expressed as mean and SEM from triplicates of one representative of three experiments. *P < 0.05 versus negative control, **P < 0.01, #TGF-β1 with miR-33a inhibitor versus TGF-β1. (B) Western blot showing phosphorylated (p-Akt) and total Akt protein expression levels in normal chondrocytes treated with 10 ng/ml TGF-β1 for 0.5, 2 and 24 hours. (C) Diagram showing p-Akt protein expression normalized to total Akt using ImageJ software. The result shown represents the mean from three different blots. *P < 0.05 compared with control. (D) Western blot showing p-Akt and total Akt protein expression levels in normal chondrocytes treated with TGF-β1, TGF-β1 plus miR-33a or negative control. (E) Diagram showing p-Akt protein expression normalized to total Akt using ImageJ software. The result shown represents the mean from three different blots. *P < 0.05 compared with control. #TGF-β1 with miR-33a versus TGF-β1. (F) Western blot showing p-Akt and total Akt protein expression levels in osteoarthritis chondrocytes treated with TGF-β1 and miRNA inhibitor (anti-miR-33a), followed by treatment of TGF-β1 or negative control. (G) Diagram showing p-Akt protein expression normalized to total Akt using ImageJ software. The result shown represents the mean from three different blots. *P < 0.05 compared with control. #TGF-β1 with miR-33a inhibitor versus TGF-β1.