Induction of hypertrophic chondrocyte-like phenotypes by oxidized LDL in cultured bovine articular chondrocytes through increase in oxidative stress
Induction of hypertrophic chondrocyte-like phenotypes by oxidized LDL in cultured bovine articular chondrocytes through increase in oxidative stress
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DOI：
10.1016/j.joca.2010.05.021
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发表时间：
2010-10-01
影响因子：
7
通讯作者：
Hamanishi, C.
中科院分区：
文献类型：
--
作者：
Kishimoto, H.;Akagi, M.;Hamanishi, C.
目的：据报道，凝集素样氧化低密度脂蛋白（Ox-LDL）受体1（LOX-1）由骨关节炎（OA）软骨中的软骨细胞表达，并且Ox-LDL与LOX-1结合增加培养的牛关节软骨细胞（BAC）中的细胞内氧化应激。近年来研究表明活性氧能诱导软骨细胞向生长板肥大分化。还显示OA中活化的软骨细胞具有肥大软骨细胞样表型。本研究的目的是确定是否Ox-LDL诱导肥大的软骨细胞样表型在BACs.Design：X型胶原（COL 10）和runx相关的转录因子2（Runx 2）的mRNA表达的变化在BAC Ox-LDL刺激后，采用实时聚合酶链反应（PCR）进行了研究。Western blotting和免疫荧光细胞染色法检测蛋白质水平的变化。抗氧化剂N-乙酰半胱氨酸（NAC）用于确定氧化应激是否参与COL 10和Runx 2表达。结果：Ox-LDL可诱导LOX-1基因敲减细胞COL 10表达，并呈时间和剂量依赖性。免疫荧光染色显示Ox-LDL增加细胞外基质中COL 10的产生。用NAC和siRNA预处理可抑制Ox-LDL诱导的COL 10上调。结论：Ox-LDL与LOX-1结合可通过氧化应激诱导软骨细胞肥大样表型，提示Ox-LDL在软骨退变过程中起重要作用。(C)2010年国际骨关节炎研究学会。由爱思唯尔有限公司出版。保留所有权利。
Objective: It has been reported that the lectin-like oxidized low-density lipoprotein (Ox-LDL) receptor 1 (LOX-1) is expressed by chondrocytes in osteoarthritis (OA) cartilage and that Ox-LDL binding to LOX-1 increases intracellular oxidative stress in cultured bovine articular chondrocytes (BACs). It was recently demonstrated that reactive oxygen species (ROS) induce hypertrophic differentiation of chondrocytes in the growth plate. It has also been shown that activated chondrocytes in OA have hypertrophic chondrocyte-like phenotypes. The purpose of this study was to determine whether Ox-LDL induces hypertrophic chondrocyte-like phenotypes in BACs.Design: Changes in type X collagen (COL10) and runt-related transcription factor 2 (Runx2) mRNA expression in BACs after Ox-LDL stimulation were investigated using real-time polymerase chain reaction (PCR). Western blotting and immunofluorescent cell staining were used to investigate changes in protein level. The antioxidant N-acetyl cysteine (NAC) was used to ascertain whether oxidative stress is involved in COL10 and Runx2 expression. We induced LOX-1 knockdown cells using small interfering RNA (siRNA) to examine the receptor specificity of Ox-LDL.Results: COL10 expression was upregulated by Ox-LDL in a time- and dose-dependent manner. Immunofluorescent staining showed that Ox-LDL increased COL10 production in the extracellular matrix. Ox-LDL-induced upregulation of COL10 was suppressed by pretreatment with NAC and siRNA. Expression of Runx2 was upregulated by Ox-LDL and H2O2, and these effects were suppressed by NAC pretreatment.Conclusion: Ox-LDL binding to LOX-1 induces a hypertrophic chondrocyte-like phenotype through oxidative stress, indicating that Ox-LDL plays a role in the degeneration of cartilage. (C) 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.