Chen Yishan, Yu Yeke, Wen Ya, Chen Juan, Lin Junxin, Sheng Zixuan, Zhou Wenyan, Sun Heng, An Chengrui, Chen Jiansong, Wu Weiliang, Teng Chong, Wei Wei, Ouyang Hongwei
Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.
Department of Sports Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.
Bone Res. 2022 Apr 27;10(1):38. doi: 10.1038/s41413-022-00209-w.
Articular cartilage damage is a universal health problem. Despite recent progress, chondrocyte dedifferentiation has severely compromised the clinical outcomes of cell-based cartilage regeneration. Loss-of-function changes are frequently observed in chondrocyte expansion and other pathological conditions, but the characteristics and intermediate molecular mechanisms remain unclear. In this study, we demonstrate a time-lapse atlas of chondrocyte dedifferentiation to provide molecular details and informative biomarkers associated with clinical chondrocyte evaluation. We performed various assays, such as single-cell RNA sequencing (scRNA-seq), live-cell metabolic assays, and assays for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq), to develop a biphasic dedifferentiation model consisting of early and late dedifferentiation stages. Early-stage chondrocytes exhibited a glycolytic phenotype with increased expression of genes involved in metabolism and antioxidation, whereas late-stage chondrocytes exhibited ultrastructural changes involving mitochondrial damage and stress-associated chromatin remodeling. Using the chemical inhibitor BTB06584, we revealed that early and late dedifferentiated chondrocytes possessed distinct recovery potentials from functional phenotype loss. Notably, this two-stage transition was also validated in human chondrocytes. An image-based approach was established for clinical use to efficiently predict chondrocyte plasticity using stage-specific biomarkers. Overall, this study lays a foundation to improve the quality of chondrocytes in clinical use and provides deep insights into chondrocyte dedifferentiation.
关节软骨损伤是一个普遍存在的健康问题。尽管最近取得了进展，但软骨细胞去分化严重影响了基于细胞的软骨再生的临床效果。在软骨细胞扩增和其他病理条件下经常观察到功能丧失性变化，但其特征和中间分子机制仍不清楚。在本研究中，我们展示了软骨细胞去分化的延时图谱，以提供与临床软骨细胞评估相关的分子细节和信息丰富的生物标志物。我们进行了各种实验，如单细胞RNA测序（scRNA-seq）、活细胞代谢实验和转座酶可及染色质高通量测序实验（ATAC-seq），以建立一个由早期和晚期去分化阶段组成的双相去分化模型。早期软骨细胞表现出糖酵解表型，参与代谢和抗氧化的基因表达增加，而晚期软骨细胞表现出涉及线粒体损伤和应激相关染色质重塑的超微结构变化。使用化学抑制剂BTB06584，我们发现早期和晚期去分化的软骨细胞从功能表型丧失中恢复的潜力不同。值得注意的是，这种两阶段转变在人类软骨细胞中也得到了验证。建立了一种基于图像的方法用于临床，以使用阶段特异性生物标志物有效地预测软骨细胞可塑性。总体而言，本研究为提高临床使用中软骨细胞的质量奠定了基础，并为软骨细胞去分化提供了深入见解。
