DNA Methylation Profiling in Chondrocyte Dedifferentiation In Vitro

Authors：Duan Li; Liang Yujie; Ma Bin; Wang Daming; Liu Wei; Huang Jianghong; Xiong Jianyi; Peng Liangquan; Chen Jielin; Zhu Weimin; Wang Daping^*

Source：Journal of Cellular Physiology, 2017, 232(7): 1708-1716.

DOI：10.1002/jcp.25486

DNA methylation has emerged as a crucial regulator of chondrocyte dedifferentiation, which severely compromises the outcome of autologous chondrocyte implantation (ACI) treatment for cartilage defects. However, the full-scale DNA methylation profiling in chondrocyte dedifferentiation remains to be determined. Here, we performed a genome-wide DNA methylation profiling of dedifferentiated chondrocytes in monolayer culture and chondrocytes treated with DNA methylation inhibitor 5-azacytidine (5-AzaC). This research revealed that the general methylation level of CpG was increased while the COL-1A1 promoter methylation level was decreased during the chondrocyte dedifferentiation. 5-AzaC could reduce general methylation levels and reverse the chondrocyte dedifferentiation. Surprisingly, the DNA methylation level of COL-1A1 promoter was increased after 5-AzaC treatment. The COL-1A1 expression level was increased while that of SOX-9 was decreased during the chondrocyte dedifferentiation. 5-AzaC treatment up-regulated the SOX-9 expression while down-regulated the COL-1A1 promoter activity and gene expression. Taken together, these results suggested that differential regulation of the DNA methylation level of cartilage-specific genes might contribute to the chondrocyte dedifferentiation. Thus, the epigenetic manipulation of these genes could be a potential strategy to counteract the chondrocyte dedifferentiation accompanying in vitro propagation. J. Cell. Physiol. 232: 1708-1716, 2017.

• Institution
  海南医学院; 2; 北京大学深圳研究生院; 1; 香港中文大学; shenzhen univ; 深圳市第二人民医院