Advanced glycation end-product 2 and Porphyromonas gingivalis lipopolysaccharide increase sclerostin expression in mouse osteocyte-like cells
Advanced glycation end-product 2 and Porphyromonas gingivalis lipopolysaccharide increase sclerostin expression in mouse osteocyte-like cells
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晚期糖基化终产物 2 和牙龈卟啉单胞菌脂多糖增加小鼠骨细胞样细胞中硬化蛋白的表达
DOI：
10.1016/j.bone.2019.02.001
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发表时间：
2019
期刊：
影响因子：
4.1
通讯作者：
Yumoto Hiromichi
中科院分区：
文献类型：
--
作者：
Sakamoto Eijiro;Kido Jun-ichi;Takagi Ryosuke;Inagaki Yuji;Naruishi Koji;Nagata Toshihiko;Yumoto Hiromichi
硬化蛋白是一种分泌型糖蛋白，主要在骨细胞中表达，对骨形成产生负面影响，并且在糖尿病（DM）中以升高的水平存在。牙周炎是由牙周致病菌引起的感染性疾病，是糖尿病的并发症，有时伴有严重的炎症和牙槽骨吸收。晚期糖基化终产物（AGEs）是糖尿病并发症的主要病原体，对糖尿病患者的牙周炎有不良影响。本研究探讨了AGE 2和牙龈卟啉单胞菌脂多糖（P-LPS）对小鼠成骨样细胞（MLO-Y 4-A2细胞）sclerostin表达的影响及其在成骨细胞分化中的作用。AGE 2和P-LPS分别上调骨细胞AGE受体和Toll样受体2（TLR 2）的表达，并显著上调骨硬化素（sclerostin）和白细胞介素6（IL-6）的表达。AGE 2和P-LPS协同增加硬化素、RAGE和TLR 2水平。siRNA抑制AGE 2和P-LPS诱导的sclerostin表达。AGE 2通过ERK、JNK和NF-κB信号通路上调骨细胞样细胞中sclerostin的表达。另一方面，P-LPS通过TLR 2、JNK和p38以及NF-κB信号通路升高硬化素水平。当用AGE 2和P-LPS预处理的骨细胞和成骨细胞（MC 3 T3-E1）在含有硬化蛋白中和抗体的培养基中共培养时，AGE 2和P-LPS诱导的成骨细胞碱性磷酸酶活性和Runx 2表达的降低被硬化蛋白中和抗体显著抑制。提示AGE 2和P-LPS可能通过调节硬化蛋白的表达，影响骨代谢和炎症反应，从而加重糖尿病牙周炎。
Sclerostin is a secreted glycoprotein that is mainly expressed in osteocytes, exerts negative effects on bone formation, and is present at elevated levels in diabetes mellitus (DM). Periodontitis is an infectious disease caused by periodontopathic bacteria, a complication of DM, and sometimes associated with severe inflammation and alveolar bone resorption. Advanced glycation end-products (AGEs) are a major pathogen in DM complications and adversely influence periodontitis in DM patients. In the present study, the effects of AGE2 and Porphyromonas gingivalis lipopolysaccharide (P-LPS) on the expression of sclerostin in mouse osteocyte-like cells (MLO-Y4-A2 cells) and its function in osteoblast differentiation were investigated. AGE2 andP-LPS up-regulated the expressions of receptor of AGE (RAGE) and Toll-like receptor 2 (TLR2), respectively, and significantly up-regulated that of sclerostin and interleukin 6 (IL-6) in osteocytes. Sclerostin, RAGE and TLR2 levels were synergistically increased by AGE2 andP-LPS. The siRNAs of RAGE and TLR2 significantly inhibited AGE2- andP-LPS-induced sclerostin expression. AGE2 up-regulated sclerostin expression in osteocyte-like cells via the RAGE, ERK and JNK, and NF-κB signal pathways. On the other hand,P-LPS elevated sclerostin levels via the TLR2, JNK and p38, and NF-κB signal pathways. When osteocytes pre-treated with AGE2 andP-LPS and osteoblastic cells (MC3T3-E1) were co-cultured in the medium with a sclerostin-neutralizing antibody, AGE2- andP-LPS-induced decreases in alkaline phosphatase activity and Runx2 expression in osteoblastic cells were significantly inhibited by the sclerostin-neutralizing antibody. These results suggest that AGE2 andP-LPS influence bone metabolism and inflammation through the regulation of sclerostin expression, and may aggravate periodontitis with DM.