Identification and characterization of insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), and IGFBP proteases in human synovial fluid
Identification and characterization of insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), and IGFBP proteases in human synovial fluid
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DOI：
10.1210/jc.81.1.150
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发表时间：
1996-01-01
影响因子：
5.8
通讯作者：
Rosenfeld, RG
中科院分区：
文献类型：
--
作者：
Matsumoto, T;Gargosky, SE;Rosenfeld, RG
人体滑液中的胰岛素样生长因子（IGF）和IGF结合蛋白（IGFBP）在维持关节软骨代谢中发挥着重要作用。在本研究中，我们通过 RIA 测量了正常人滑液中 IGF-I、IGF-II 和 IGFBP-3 的浓度，并通过 Western 配体印迹 (WLB)、Western 免疫印迹和免疫沉淀来表征 IGFBP。我们还扩展了研究范围，并将正常滑液与骨关节炎 (OA) 和类风湿性关节炎 (RA) 患者的滑液进行了比较。正常滑液中IGF-I、IGF-II和IGFBP-3的浓度分别为19+/-3（平均值+/-se）、194+/-14和349+/-65ng/mL。 OA患者滑液中IGF-I水平升高，IGF-II降低，IGFBP-3水平与对照值相似。在 RA 患者中，IGF-I 和 IGFBP-3 均升高，而 IGF-II 保持不变。正常滑液的 WLB 和免疫沉淀显示 IGFBP-1 (26-29 kDa)、IGFBP-2 (32 kDa)、IGFBP-3 (42-至 39-kDa 双联体) 和 IGFBP-4 (24 kDa)； IGFBP-3 双峰非常微弱。在 RA 滑液中，所有 IGFBP 均显着增加，而 OA 滑液中几乎没有变化。针对 IGFBP-3 的蛋白质免疫印迹显示，正常成人以及 RA 和 OA 患者的滑液中存在显着的 50 kDa IGFBP-3 免疫反应片段。这与可检测到的 IGFBP-3 蛋白酶活性同时发生，IGFBP-3 蛋白酶活性属于金属蛋白酶和丝氨酸蛋白酶家族。因此，在正常滑液中，循环 IGF、IGFBP 和蛋白酶之间存在平衡，以调节 IGF 的生物活性。在病理状态下，IGF-I浓度增加伴随着滑液中IGFBP-3水平的增加。这些发现表明，病理状态下 IGF 和 IGFBP 轴的改变可能对于理解关节生长和代谢紊乱的潜在病理生理学很重要。
The insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs) in human synovial fluid play an important role in maintaining articular cartilage metabolism. In this study we measured the concentrations of IGF-I, IGF-II, and IGFBP-3 in normal human synovial fluid by RIA, and characterized the IGFBPs by Western ligand blot (WLB), Western immunoblot, and immunoprecipitation. We also extended the study and compared normal synovial fluid to synovial fluids from patients with osteoarthritis (OA) and rheumatoid arthritis (RA). The concentrations of IGF-I, IGF-II, and IGFBP-3 in normal synovial fluid were 19 +/- 3 (mean +/- se), 194 +/- 14, and 349 +/- 65 ng/mL, respectively. In synovial fluid of patients with OA, IGF-I levels were elevated, whereas IGF-II was decreased, and the IGFBP-3 level was similar to the control value. In patients with RA, both IGF-I and IGFBP-3 were elevated, whereas IGF-II remained unchanged. WLB and immunoprecipitation of normal synovial fluid revealed IGFBP-1 (26-29 kDa), IGFBP-2 (32 kDa), IGFBP-3 (42- to 39-kDa doublet), and IGFBP-4 (24 kDa); the IGFBP-3 doublet was very faint. In RA synovial fluid, all IGFBPs were dramatically increased, whereas little change was seen in the synovial fluid of OA. Western immunoblot against IGFBP-3 revealed a prominent 50-kDa immunoreactive fragment of IGFBP-3 in synovial fluids of normal adults as well as in those of RA and OA patients. This was concurrent with detectable IGFBP-3 protease activity, which was characterized to be of the metallo- and serine protease family. Thus, in normal synovial fluid, there is a balance of circulating IGF, IGFBP, and proteases to modulate the bioactivity of IGF. In pathological states, the increased IGF-I concentrations were accompanied by an increase in IGFBP-3 levels in synovial fluid. These findings suggest that alteration of the IGF and IGFBP axis in pathological states may be important for understanding the underlying pathophysiology of disordered articular growth and metabolism.