Involvement of Toll-Like Receptor 2 and Pro-Apoptotic Signaling Pathways in Bone Remodeling in Osteomyelitis
Involvement of Toll-Like Receptor 2 and Pro-Apoptotic Signaling Pathways in Bone Remodeling in Osteomyelitis
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DOI：
10.1159/000366387
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发表时间：
2014-01-01
影响因子：
--
通讯作者：
Xu, Jianzhong
中科院分区：
文献类型：
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作者：
Chen, Qianbo;Hou, Tianyong;Xu, Jianzhong
背景和目的：骨髓炎是侵袭性金黄色葡萄球菌感染的常见表现，以骨丢失和破坏为特征。我们研究了Toll样受体2（TLR 2）在细菌识别和清除中的作用，以响应骨髓炎分离株S。金黄色。方法：采用Annexin V-FITC/PI双染法和流式细胞仪检测成骨细胞系MC 3 T3-E1的凋亡情况。通过qRT-PCR和蛋白质印迹法评估TLR 2和凋亡相关和丝裂原活化蛋白激酶途径蛋白的表达。采用碱性磷酸酶（ALP）活性测定和茜素红染色法检测细胞内钙沉积和ALP活性。结果：S.金黄色葡萄球菌诱导细胞凋亡，上调TLR 2表达，并以时间依赖性方式激活丝裂原活化蛋白激酶途径。抑制c-Jun N-末端激酶（JNK）通路下调TLR 2，抑制S.金黄色葡萄球菌诱导促凋亡途径的活化。短发夹RNA介导的TLR 2沉默逆转了S.金黄色葡萄球菌可诱导细胞凋亡，降低ALP活性和钙沉积，抑制JNK也有类似的作用。结论：我们发现，成骨细胞凋亡和成骨细胞分化的细菌入侵是依赖于TLR 2的表达和JNK激活，这表明新的潜在的治疗骨髓炎的治疗靶点。版权所有（C）2014 S. Karger AG，巴塞尔
Background and Aims: Osteomyelitis is a common manifestation of invasive Staphylococcus aureus infection characterized by bone loss and destruction. We investigated the role of toll-like receptor 2 (TLR2) in bacterial recognition and clearance in response to infection with an osteomyelitis isolate of S. aureus. Methods: Apoptosis was assessed in the osteoblastic cell line MC3T3-E1 by annexin V-FITC/PI staining and flow cytometry. The expression of TLR2 and apoptosis-related and mitogen-activated protein kinase pathway proteins was assessed by qRT-PCR and western blotting. Alkaline phosphatase (ALP) activity and calcium deposition were assessed by ALP activity assay and Alizarin red staining. Results: S. aureus induced apoptosis, upregulated TLR2 expression, and activated mitogen-activated protein kinase pathways in a time dependent manner. Inhibition of the c-Jun N-terminal kinase (JNK) pathway downregulated TLR2 and suppressed the S. aureus induced activation of pro-apoptotic pathways. Short-hairpin RNA mediated silencing of TLR2 reversed S. aureus induced apoptosis and decrease in ALP activity and calcium deposition, and inhibition of JNK had a similar effect. Conclusion: We showed that osteoblast apoptosis and osteogenic differentiation in response to bacterial invasion are dependent on TLR2 expression and JNK activation, suggesting novel potential therapeutic targets for the treatment of osteomyelitis. Copyright (C) 2014 S. Karger AG, Basel