1. Apoptotic bodies from endplate chondrocytes enhance the oxidative stress‐induced mineralization by regulating PPi metabolism
- Author
-
Mingdong Zhao, Feng-Lai Yuan, Rui-Sheng Xu, Jun-Xing Ye, Xia Li, and Li-Jun Ren
- Subjects
0301 basic medicine ,Core Binding Factor Alpha 1 Subunit ,Oxidative phosphorylation ,medicine.disease_cause ,Extracellular Vesicles ,03 medical and health sciences ,Chondrocytes ,0302 clinical medicine ,medicine ,Extracellular ,Animals ,mineralization ,Growth Plate ,Pyrophosphatases ,apoptotic bodies ,Cells, Cultured ,intervertebral disc degeneration ,biology ,Phosphoric Diester Hydrolases ,Chemistry ,Calcinosis ,Phosphodiesterase ,Original Articles ,Hydrogen Peroxide ,Cell Biology ,Alkaline Phosphatase ,Oxidants ,Rats ,Cell biology ,RUNX2 ,Oxidative Stress ,030104 developmental biology ,Gene Expression Regulation ,Apoptosis ,030220 oncology & carcinogenesis ,Osteocalcin ,biology.protein ,endplate chondrocytes ,Molecular Medicine ,Alkaline phosphatase ,Original Article ,Collagen ,Oxidative stress - Abstract
This study aimed to investigate the role of apoptotic bodies (Abs) from the oxidative stressed endplate chondrocytes in regulating mineralization and potential mechanisms. Endplate chondrocytes were isolated from rats and treated with H2O2 to induce oxidative stress. The calcium deposition for matrix mineralization in the cells was examined by histological staining. The expression levels of calcification‐related genes in individual groups of cells were determined by quantitative real time‐PCR (qRT‐PCR). Subsequently, extracellular vesicles (EVs) were purified and characterized. The effect of treatment with H2O2 and/or Abs on the mineralization, extracellular PPi metabolism and related gene expression were determined. Oxidative stress significantly increased the mineralization and promoted the generation of main Abs from endplate chondrocytes. Abs were effectively endocytosed by endplate chondrocytes and co‐localized with collagen (COL)‐II in the cytoplasm, which enhanced the mineralization, alkaline phosphatase (ALP), osteocalcin (OCN), Runt‐related transcription factor 2 (RUNX2) and COL‐I expression in endplate chondrocytes. Furthermore, treatment either H2O2 or Abs significantly decreased PPi, but increased Pi production and treatment with both further enhancing the changes in endplate chondrocytes. Similarly, treatment either H2O2 or Abs significantly decreased the ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), and ankylosis protein (ANK) expression and ENPP1 promoter activity, but increased the tissue‐nonspecific alkaline phosphatase (TNAP) expression and TNAP promoter activity in endplate chondrocytes. Oxidative stress promoted the generation of Abs, which might enhance the oxidative stress‐mediated mineralization in endplate chondrocytes by regulating the PPi metabolism.
- Published
- 2019