Reduction of Smad2 caused by oxidative stress leads to necrotic death of hypertrophic chondrocytes associated with an endemic osteoarthritis
Reduction of Smad2 caused by oxidative stress leads to necrotic death of hypertrophic chondrocytes associated with an endemic osteoarthritis
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DOI：
10.1093/rheumatology/keab286
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发表时间：
2022-01-01
期刊：
影响因子：
5.5
通讯作者：
Chen, Jinghong
中科院分区：
文献类型：
--
作者：
He, Ying;Fan, Lihong;Chen, Jinghong
目的大骨节病（KBD）是一种地方性骨关节炎，其发生、发展与自由基引起的氧化应激密切相关。本研究的目的是寻找大骨节病的关键信号分子或致病因子，作为潜在的治疗策略。方法采用Real-time PCR和Western blotting检测细胞和组织中mRNA和蛋白的表达水平。在大鼠模型和从儿童获得的人类样本中测定免疫组织化学染色。用流式细胞仪通过膜联蛋白V和碘化丙啶染色鉴定细胞死亡的类型。结果氧化应激可降低肥大软骨细胞Smad 2和Smad 3的表达。在大骨节病患者的软骨中，Smad 2和Smad 3蛋白的表达在中带和深带中显著降低，并且在一些样品的深带中观察到完全缺失。Smad 2蛋白减少诱导肥大软骨细胞坏死死亡，而Smad 3蛋白减少诱导凋亡。在肥大性软骨细胞坏死中，Smad 2蛋白的减少并不伴随着Smad 3蛋白的减少。此外，Smad 2的表达减少也影响了组织工程软骨的体外构建。结论氧化应激通过下调Smad 2蛋白表达导致肥大软骨细胞坏死，加重了大骨节病软骨的发病机制。Smad 2在大骨节病发病过程中的重要作用为大骨节病的治疗提供了新的潜在靶点。
Objective The occurrence and development of an endemic OA, Kashin-Beck disease (KBD), is closely related to oxidative stress induced by free radicals. The aim of the study was to find the key signalling molecules or pathogenic factors as a potential treatment strategy for KBD. Methods Real-time PCR and western blotting were performed to detect the mRNA and protein expression levels in cells and tissues. Immunohistochemical staining was assayed in rat models and human samples obtained from children. The type of cell death was identified by annexin V and propidium iodide staining with flow cytometry. Results Oxidative stress decreased levels of Smad2 and Smad3 in hypertrophic chondrocytes both in vitro and in vivo. In the cartilage of KBD patients, the expression of Smad2 and Smad3 proteins in the middle and deep zone was significantly decreased with an observed full deletion in the deep zone of some samples. Reduction of Smad2 protein induced necrotic death of hypertrophic chondrocytes, while reduction of Smad3 protein induced apoptosis. The reduction of Smad2 protein was not accompanied by Smad3 protein reduction in hypertrophic chondrocyte necrosis. Furthermore, the reduction of Smad2 also impaired the construction of tissue-engineered cartilage in vitro. Conclusion These studies reveal that oxidative stress causes necrosis of hypertrophic chondrocytes by downregulating Smad2 protein, which increases the pathogenesis of KBD cartilage. The importance of Smad2 in the development of KBD provides a new potential target for the treatment of KBD.