Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo 060-8638, Japan.
Department of Advanced Clinical Glycobiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 21, Nishi 11, Kita-ku, Sapporo 001-0021, Japan.
Int J Mol Sci. 2019 Jul 19;20(14):3546. doi: 10.3390/ijms20143546.
In normal articular cartilage, chondrocytes do not readily proliferate or terminally differentiate, and exhibit a low level of metabolism. Hypertrophy-like changes of chondrocytes have been proposed to play a role in the pathogenesis of osteoarthritis by inducing protease-mediated cartilage degradation and calcification; however, the molecular mechanisms underlying these changes are unclear. Glycans are located on the outermost cell surface. Dynamic cellular differentiation can be monitored and quantitatively characterized by profiling the glycan structures of total cellular glycoproteins. This study aimed to clarify the alterations in glycans upon late differentiation of chondrocytes, during which hypertrophy-like changes occur. Primary mouse chondrocytes were differentiated using an insulin-induced chondro-osteogenic differentiation model. Comprehensive glycomics, including N-glycans, O-glycans, free oligosaccharides, glycosaminoglycan, and glycosphingolipid, were analyzed for the chondrocytes after 0-, 10- and 20-days cultivation. The comparison and clustering of the alteration of glycans upon hypertrophy-like changes of primary chondrocytes were performed. Comprehensive glycomic analyses provided complementary alterations in the levels of various glycans derived from glycoconjugates during hypertrophic differentiation. In addition, expression of genes related to glycan biosynthesis and metabolic processes was significantly correlated with glycan alterations. Our results indicate that total cellular glycan alterations are closely associated with chondrocyte hypertrophy and help to describe the glycophenotype by chondrocytes and their hypertrophic differentiation. our results will assist the identification of diagnostic and differentiation biomarkers in the future.
在正常的关节软骨中，软骨细胞不易增殖或终末分化，代谢水平较低。软骨细胞的肥大样变化被认为通过诱导蛋白酶介导的软骨降解和钙化在骨关节炎的发病机制中起作用；然而，这些变化的分子机制尚不清楚。聚糖位于细胞表面的最外层。通过分析总细胞糖蛋白的聚糖结构，可以监测和定量描述动态细胞分化。本研究旨在阐明软骨细胞晚期分化过程中发生肥大样变化时聚糖的变化。使用胰岛素诱导的软骨成骨分化模型对原代小鼠软骨细胞进行分化。分析了 0、10 和 20 天培养后软骨细胞的综合糖组学，包括 N-聚糖、O-聚糖、游离寡糖、糖胺聚糖和糖脂。对原代软骨细胞肥大样变化时聚糖的变化进行了比较和聚类分析。综合糖组学分析提供了来源于糖缀合物的各种聚糖水平变化的补充信息，这些变化与肥大分化有关。此外，与聚糖生物合成和代谢过程相关的基因的表达与聚糖变化显著相关。我们的结果表明，总细胞聚糖的变化与软骨细胞肥大密切相关，并有助于通过软骨细胞及其肥大分化来描述其糖表型。我们的结果将有助于未来识别诊断和分化的生物标志物。
