The interaction of lubricin/proteoglycan 4 (PRG4) with toll-like receptors 2 and 4: an anti-inflammatory role of PRG4 in synovial fluid.
The interaction of lubricin/proteoglycan 4 (PRG4) with toll-like receptors 2 and 4: an anti-inflammatory role of PRG4 in synovial fluid.
复制标题
DOI：
10.1186/s13075-015-0877-x
复制
发表时间：
2015-12-04
影响因子：
4.9
通讯作者：
Elsaid KA
中科院分区：
文献类型：
--
作者：
Alquraini A;Garguilo S;D'Souza G;Zhang LX;Schmidt TA;Jay GD;Elsaid KA
润滑素/蛋白聚糖-4（PRG 4）是由滑膜成纤维细胞和表浅区软骨细胞分泌的粘液糖蛋白。PRG 4在关节中具有稳态多方面的作用。PRG 4关节内治疗延缓了临床前创伤后骨关节炎模型中软骨退化的进展。本研究的目的是评估重组人PRG 4（rhPRG 4）和天然人PRG 4（nhPRG 4）与toll样受体2和4（TLR 2和TLR 4）的结合，以及这种相互作用是否支持PRG 4在骨关节炎（OA）和类风湿性关节炎（RA）患者的滑液（SF）中的抗炎作用。使用直接酶联免疫吸附测定（ELISA）评估rhPRG 4和nhPRG 4与TLR 2和TLR 4的结合。用流式细胞术研究rhPRG 4与TLR 2和TLR 4过表达的人胚肾（HEK）细胞的相关性。在不存在或存在50、100和150 μg/ml的nhPRG 4的情况下，研究了激动剂Pam 3CSK 4和脂多糖（LPS）对HEK细胞上TLR 2和TLR 4的活化。评估OA SF和RA SF对TLR 2和TLR 4的活化以及nhPRG 4 SF处理对受体活化的影响。从合并的OA和RA SF中免疫沉淀PRG 4。比较了在有或没有PRG 4免疫沉淀的情况下通过合并的OA和RA SF激活TLR 2和TLR 4。rhPRG 4和nhPRG 4表现出与TLR 2和TLR 4的浓度依赖性结合。rhPRG 4以时间依赖性方式与TLR 2-和TLR 4-HEK细胞缔合。与单独的Pam 3CSK 4或LPS相比，nhPRG 4（50、100和150 μg/ml）和Pam 3CSK 4或LPS的共孵育减少了TLR 2或TLR 4活化（p <0.05）。OA SF和RA SF激活TLR 2和TLR 4，nhPRG 4处理降低SF诱导的受体激活（p <0.001）。通过免疫沉淀去除PRG 4显着增加了OA SF和RA SF对TLR 2的激活（p <0.001）。PRG 4与TLR 2和TLR 4结合，这种结合介导PRG 4的新抗炎作用。
Lubricin/proteoglycan-4 (PRG4) is a mucinous glycoprotein secreted by synovial fibroblasts and superficial zone chondrocytes. PRG4 has a homeostatic multifaceted role in the joint. PRG4 intra-articular treatment retards progression of cartilage degeneration in pre-clinical posttraumatic osteoarthritis models. The objective of this study is to evaluate the binding of recombinant human PRG4 (rhPRG4) and native human PRG4 (nhPRG4) to toll-like receptors 2 and 4 (TLR2 and TLR4) and whether this interaction underpins a PRG4 anti-inflammatory role in synovial fluid (SF) from patients with osteoarthritis (OA) and rheumatoid arthritis (RA). rhPRG4 and nhPRG4 binding to TLR2 and TLR4 was evaluated using a direct enzyme linked immunosorbent assay (ELISA). Association of rhPRG4 with TLR2 and TLR4 overexpressing human embryonic kidney (HEK) cells was studied by flow cytometry. Activation of TLR2 and TLR4 on HEK cells by agonists Pam3CSK4 and lipopolysaccharide (LPS) was studied in the absence or presence of nhPRG4 at 50, 100 and 150 μg/ml. Activation of TLR2 and TLR4 by OA SF and RA SF and the effect of nhPRG4 SF treatment on receptor activation was assessed. PRG4 was immunoprecipitated from pooled OA and RA SF. TLR2 and TLR4 activation by pooled OA and RA SF with or without PRG4 immunoprecipitation was compared. rhPRG4 and nhPRG4 exhibited concentration-dependent binding to TLR2 and TLR4. rhPRG4 associated with TLR2- and TLR4-HEK cells in a time-dependent manner. Co-incubation of nhPRG4 (50, 100 and 150 μg/ml) and Pam3CSK4 or LPS reduced TLR2 or TLR4 activation compared to Pam3CSK4 or LPS alone (p <0.05). OA SF and RA SF activated TLR2 and TLR4 and nhPRG4 treatment reduced SF-induced receptor activation (p <0.001). PRG4 depletion by immunoprecipitation significantly increased TLR2 activation by OA SF and RA SF (p <0.001). PRG4 binds to TLR2 and TLR4 and this binding mediates a novel anti-inflammatory role for PRG4.