Tohoku J. Exp. Med., 2017 September, 243(1)

MicroRNA-483-5p Modulates the Expression of Cartilage-Related Genes in Human Chondrocytes through Down-Regulating TGF-β1 Expression

RONGHUA XU,^1,2 JIAYI LI,¹ BO WEI,¹ WEILING HUO² and LIMING WANG¹

¹Department of Orthopaedic Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
²Department of Orthopaedic Surgery, Xuzhou Central Hospital, Xuzhou, Jiangsu, China

Transforming growth factor-β1 (TGF-β1) has been reported to improve chondrocytes phenotype and function. The expression levels of microRNA-483-5p (miR-483-5p), a potential regulator of TGF-β signaling pathway, were elevated in chondrocytes of patients with osteoarthritis. In this study, we aimed to explore the role of miR-483-5p for the expression of cartilage-related genes in chondrocytes. Human chondrocytes were harvested from femoral condyle and tibial plateau of different donors (n = 10) following amputation due to sarcomas not involving the joint space. The expression levels of miR-483-5p and TGF-β1 mRNA were measured by qRT-PCR. Runt-related transcription factor 2 (RUNX2) is a transcription factor involved in chondrocyte differentiation, and type II collagen-degrading matrix metalloproteinase13 (MMP13) contributes to cartilage degradation. qRT-PCR was also used to measure the levels of RUNX2 and MMP-13 mRNAs, as well as type II collagen alpha 1 (COL2A1) and aggrecan mRNAs. COL2A1 and aggrecan are major cartilage extracellular matrix proteins that are essential for normal cartilage function. The expression levels of miR-483-5p were significantly increased in chondrocytes from Passage 0 to 2, whereas the expression levels of TGF-β1 mRNA were marginally decreased. Passage 1 chondrocytes were employed for following experiments. MiR-483-5p overexpression reduced TGF-β1 expression, while miR-483-5p knockdown dramatically elevated TGF-β1 expression both at mRNA and protein levels. Further, miR-483-5p overexpression significantly decreased the levels of COL2A1 and aggrecan mRNAs, and increased those of RUNX2 and MMP13 mRNAs, by down-regulating TGF-β1 expression. These findings suggest that modulating miR-483-5p expression may contribute to maintaining the cartilage tissues.

keywords —— cartilage repair; chondrocyte; miR-483-5p; osteoarthritis; TGF-β1.

© 2017 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2017, 243, 41-48

Correspondence: Liming Wang, Ph.D., Department of Orthopaedic Surgery, Nanjing First Hospital, Nanjing Medical University, No. 68 Changle Road, Nanjing, Jiangsu 210006, China.

e-mail: wang_lm@sohu.com