title: Effect of epigallocatechin-3-gallate on proliferation and phenotype maintenance in rabbit articular chondrocytesin vitro.
abstract: In autologous chondrocyte implantation (ACI) to restore defective cartilage, limited cell numbers and dedifferentiation of chondrocytes are the major difficulties. An alternative is the use of growth factors, but their high cost and potential for tumorigenesis are major obstacles. To ensure successful ACI therapy, it is important to find an effective substitute pro-chondrogenic agent. Epigallocatechin-3-gallate (EGCG), one of the green tea catechins, has been widely investigated in studies of interleukin-1β-induced chondrocytes. In the present study, the effects of EGCG on rabbit articular chondrocytes were investigated through the examination of cell proliferation, morphology, glycosaminoglycan synthesis and cartilage-specific gene expression. The results showed that EGCG could effectively promote chondrocyte growth and enhance the secretion and synthesis of the cartilage extracellular matrix by upregulating expression levels of aggrecan, collagen II and Sox9 genes. Expression of the collagen I gene was downregulated, which showed that EGCG effectively inhibited the dedifferentiation of chondrocytes. Hypertrophy, which may lead to chondrocyte ossification, was also undetectable in the EGCG groups. In conclusion, the recommended dose of EGCG was found to be in the range of 5 to 20 μM, with the most marked response observed with 10 μM. The present study may provide a basis for the development of a novel agent as a substitute for growth factors in the treatment of articular cartilage defects.
authors.affiliation: Graduate School, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
authors.forename: Haojia
authors.initials: H
authors.lastname: Huang
authors.affiliation: Research Center for Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China ; Medical and Scientific Research Center, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Research Center for Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Cell Biology and Genetics, School of Premedical Sciences, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
authors.forename: Huayu
authors.initials: H
authors.lastname: Wu
authors.affiliation: Research Center for Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China ; Medical and Scientific Research Center, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Zheng
keywords: chondrocyte; dedifferentiation; epigallocatechin-3-gallate; pro-chondrogenic agent; rabbit articular cartilage