Figure 1

MicroRNA-33a is elevated in osteoarthritic chondrocytes and is induced by transforming growth factor-β1. (A) Relative expression of microRNA (miR)-33a in normal and osteoarthritic (OA) chondrocytes (n = 9 for normal chondrocytes from 9 different donors, n = 14 for OA chondrocytes from 14 different donors). U6 was used for normalization of the real-time PCR data. The data are expressed as mean and standard error of the mean (SEM) of three independent experiments, each of which was run in duplicate. *P < 0.05 as measured using an unpaired Student’s t-test. (B) Relative expression of sterol regulatory element-binding protein 2 (SREBP-2) in normal and OA chondrocytes (n = 5 for normal chondrocytes from 5 different donors, n = 10 for OA chondrocytes from 10 different donors). Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used for normalization of the real-time PCR data. The data are expressed as mean and SEM of three independent experiments, each of which was run in duplicate. *P < 0.05 as measured using an unpaired Student’s t-test. (C) and (D) miR-33a expression levels in cultured normal chondrocytes (n = 4 from 4 different donors) following treatment with 10 ng/ml transforming growth factor (TGF)-β1 for 6 hours, 24 hours (C) and 48 hours (D). U6 was used for normalization of the real-time PCR data. The data are expressed as mean and SEM of two independent experiments, each of which was run in triplicate. *P < 0.05 compared with control. (E) and (F) SREBP-2 expression levels in cultured normal chondrocytes (n = 5 from 5 different donors) following treatment with 10 ng/ml TGF-β1 for 6 hours, 24 hours (E) and 48 hours (F). GAPDH was used for normalization of the real-time PCR data. The data are expressed as mean and SEM of two independent experiments, each of which was run in triplicate. *P < 0.05 compared with control.