Chondroprotective Effects of Taurine in Primary Cultures of Human Articular Chondrocytes

Chondroprotective Effects of Taurine in Primary Cultures of Human Articular Chondrocytes

QIN LIU,^1,2 ZHENHUI LU,¹ HUAYU WU³ and LI ZHENG^1,2

¹The Medical and Scientific Research Center, Guangxi Medical University, Nanning, Guangxi, P.R. China
²Guangxi Key Laboratory of Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi, P.R. China
³Department of Cell Biology and Genetics, School of Premedical Sciences, Guangxi Medical University, Nanning, Guangxi, P.R. China

Articular cartilage is characterized by the lack of blood vessels and has a poor self-healing potential. Limited cell numbers and dedifferentiation of chondrocytes when expanded in vitro are the major obstacles of autologous chondrocyte implantation. Autologous chondrocyte implantation is a cell-based treatment that can be used as a second-line measure to regenerate chondral or osteochondral defects in younger, active patients. There is an urgent need to find an effective chondrogenic protection agent alleviating or inhibiting chondrocyte dedifferentiation. In this study, we explored the effect of taurine (2-aminoethane sulfonic acid) on proliferation and phenotype maintenance of human articular chondrocytes by analyzing the cell proliferation, morphology, viability, and expression of cartilage specific mRNAs and proteins. Primary chondrocytes were isolated from human articular cartilage tissues. Results showed that taurine effectively promoted chondrocyte growth and enhanced accumulation of glycosaminoglycans and collagens in the conditioned media of chondrocytes. Moreover, taurine exposure caused significant increases in the relative expression levels of mRNAs for cartilage specific markers, including aggrecan, collagen type II and SOX9. Aggrecan is a cartilage-specific proteoglycan, and SOX9 is a chondrogenic transcription factor. In contrast, the mRNA expression of collagen type I, a marker for chondrocyte dedifferentiation, was significantly decreased in cells treated with taurine, indicating that taurine inhibits the chondrocyte dedifferentiation. This study reveals that taurine is effective in proliferation promotion and phenotype maintenance of chondrocytes. Thus, taurine may be a useful pro-chondrogenic agent for autologous chondrocyte implantation in the treatment of cartilage repair.

keywords —— chondrocyte; dedifferentiation; human articular cartilage; pro-chondrogenic agent; taurine

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Tohoku J. Exp. Med., 2015, 235, 201-213

Correspondence: Li Zheng, The Medical and Scientific Research Center and Guangxi Key Laboratory of Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.

e-mail: zhengli224@163.com