Leptin promotes apoptosis and inhibits autophagy of chondrocytes through upregulating lysyl oxidase-like 3 during osteoarthritis pathogenesis
Leptin promotes apoptosis and inhibits autophagy of chondrocytes through upregulating lysyl oxidase-like 3 during osteoarthritis pathogenesis
复制标题
DOI：
10.1016/j.joca.2016.02.009
复制
发表时间：
2016-07-01
影响因子：
7
通讯作者：
Tong, P.
中科院分区：
文献类型：
--
作者：
Huang, Z. M.;Du, S. H.;Tong, P.
目的：瘦素在骨关节炎中高表达。我们旨在探讨瘦素在骨关节炎发病过程中对软骨细胞凋亡和自噬的可能作用及其机制。方法：从NCBI的基因表达综合数据库（GSE57218）中下载骨性关节炎病变和保存软骨的基因表达谱。采用实时荧光定量PCR和放射免疫分析法分别测定45例骨关节炎患者和25例健康供者软骨组织中赖氨酸氧化酶样3 (LOXL3) mRNA表达和关节滑液中瘦素浓度。采用前交叉韧带横断法（ACLT）建立大鼠骨关节炎模型。Western blot检测细胞凋亡调节因子和自噬标志物的表达。CCK-8和流式细胞术分别检测细胞存活和细胞凋亡。结果：对GSE57218的再分析表明，骨关节炎影响的软骨中LOXL3 mRNA表达上调。骨关节炎患者LOXL3 mRNA表达上调，与SF瘦素浓度呈正相关。在大鼠骨关节炎模型中也得到了类似的结果。此外，ACLT手术导致cleaved caspase 3蛋白水平显著升高，Bcl-2、LC3 II/LC3 I和Beclin1蛋白水平显著降低。沉默ACLT中的LOXL3和瘦素处理的原代软骨细胞可显著抑制细胞凋亡，促进细胞增殖和自噬。此外，过表达LOXL3通过激活mTORC1显著抑制软骨细胞的自噬。结论：瘦素的下游LOXL3刺激软骨细胞凋亡，但抑制软骨细胞自噬。LOXL3是骨关节炎的潜在治疗靶点。(C) 2016国际骨关节炎研究学会。Elsevier Ltd.出版。版权所有。
Objective: Leptin has been found highly expressed in human osteoarthritis. We aimed to explore the possible effects and mechanisms of leptin on the apoptosis and autophagy of chondrocytes during osteoarthritis pathogenesis.Methods: Gene expression profile from osteoarthritis affected and preserved cartilage were downloaded from NCBI's Gene Expression Omnibus database (GSE57218). Lysyl oxidase-like 3 (LOXL3) mRNA expression in cartilage tissues and leptin concentration in joint synovial fluid (SF) was measured in samples from 45 osteoarthritis patients and 25 healthy donors by real-time PCR and radioimmunoassay, respectively. Rat osteoarthritis model was induced by anterior cruciate ligament transection (ACLT). The expression of apoptosis regulators and autophagy markers were detected by Western blot. Cell survival and cell apoptosis were identified by CCK-8 and flow cytometry, respectively.Results: Re-analysis on GSE57218 indicated that LOXL3 mRNA was upregulated in osteoarthritis affected cartilage. LOXL3 mRNA was upregulated in osteoarthritis patients, which was positively correlated with SF leptin concentration. Similar results were obtained in rat osteoarthritis model. Moreover, ACLT surgery led to a significant increase in the protein levels of cleaved caspase 3, and a notable decrease in the protein levels of Bcl-2, LC3 II/LC3 I and Beclin1. Silencing of LOXL3 in ACLT and leptin treated primary chondrocytes significantly inhibited cell apoptosis, and promoted cell proliferation and autophagy. Moreover, overexpression of LOXL3 remarkably inhibited autophagy of chondrocytes via activating mTORC1.Conclusions: LOXL3, a downstream of leptin, stimulated the apoptosis, but inhibited the autophagy of chondrocytes. LOXL3 is a potential therapy target for osteoarthritis. (C) 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.