Therapeutic research for osteoporosis with rheumatoid arthritis

目标。关节周围骨质疏松和关节破坏是类风湿关节炎(RA)的主要并发症，由破骨细胞介导的骨吸收引起。然而，单核细胞/破骨细胞成熟的机制以及RA内皮细胞(RAECs)在控制破骨细胞生成中的作用尚不清楚。本研究旨在确定RAEC产生的众多因素中影响单核细胞聚集和破骨细胞形成的最重要因素。我们利用寡核苷酸芯片分析了不同器官(RA滑膜、脐静脉、皮肤、肝窦、肾小球和脑)内皮细胞中各种基因的表达谱。具体来说，通过实时定量聚合酶链式反应、酶联免疫吸附试验和RA滑膜免疫染色来评估RAECs上调的基因。用EZ-TAXIScanTM趋化小室检测单核细胞的迁移。镜下可见抗酒石酸酸性磷酸酶(TRAP)阳性的多核细胞形成。在多种上皮细胞表达因子中，巨噬细胞集落刺激因子(M-CSF)基因在RAECs中大量特异表达。成纤维细胞生长因子-2、白介素6和护骨素基因在血管内皮细胞上也有高表达。M-CSF中和抗体可抑制RAEC培养上清液促进的单核细胞迁移和破骨细胞形成。巨噬细胞来源的巨噬细胞集落刺激因子参与了单核细胞的破骨细胞分化、迁移和TRAP阳性单核细胞的形成。

Objective. Periarticular osteoporosis and joint destruction are major complications in rheumatoid arthritis (RA), caused by osteoclast-mediated bone resorption. However, the mechanisms of monocyte/osteoclast maturation and 'role of RA endothelial cells (RAECs) in the control of osteoclastogenesis remain unclear. The present study was designed to determine the most important factors that influence monocyte accumulation and osteoclast formation among the many factors produced by RAEC.Methods. We analyzed the expression profiles of various genes in human endothelial cells from various organs (RA synovium, umbilical vein, skin, liver sinusoid, renal glomerulus and brain) using oligonucleotide microarrays. Specifically, up-regulated gene in RAECs was assessed by real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and immunostaining of RA synovia. Migration of monocytes was assessed by the chemotactic chamber EZ-TAXIScanTM. Tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell formation was observed by microscopy.Results. Among many epithelial-expressed factors, macrophage-colony stimulating factor (M-CSF) gene was abundantly expressed specifically in RAECs. Genes of fibroblast growth factor-2, interleukin-6 and osteoprotegerin were also overexpressed on RAECs. Migration of monocytes and osteoclast formation in co-cultures promoted by culture supernatants of RAEC were inhibited by M-CSF neutralizing antibody.Conclusion. M-CSF produced by RAECs is involved in osteoclastogenesis from monocytes, migration and TRAP-positive MNC formation.