1 Department of Orthopedic Surgery, Tainan Hospital , Department of Health, Executive Yuan, Tainan 70043, Taiwan .
Hum Gene Ther. 2013 Oct;24(10):871-82. doi: 10.1089/hum.2012.189.
Immune cells are involved in the pathogenesis of osteoarthritis (OA). CD4(+) T cells were activated during the onset of OA and induced macrophage inflammatory protein (MIP)-1γ expression and subsequent osteoclast formation. We evaluated the effects of local knockdown of MIP-1γ in a mouse OA model induced by anterior cruciate ligament transection. The mouse macrophage cell lines and osteoclast-like cells generated from immature hematopoietic monocyte/macrophage progenitors of murine bone marrow were cocultured with either receptor activator of NFκB ligand (RANKL) or CD4(+) T cells. The levels of MIP-1γ and RANKL in cells and mice were examined by enzyme-linked immunosorbent assay (ELISA). The osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase and cathepsin K staining. OA was induced in one hind-leg knee joint of B6 mice. Lentiviral vector encoding MIP-1γ small hairpin RNA (shRNA) and control vector were individually injected intra-articularly into the knee joints, which were histologically assessed for manifestations of OA. The expression of MIP-1γ and matrix metalloproteinase (MMP)-13 and the infiltration of CD4(+) T cells, macrophages, and osteoclastogenesis in tissues were examined using immunohistochemistry. CD4(+) T cells were involved in OA by inducing MIP-1γ expression in osteoclast progenitors and the subsequent osteoclast formation. Neutralizing MIP-1γ with a specific antibody abolishes RANKL-stimulated and CD4(+) T-cell-stimulated osteoclast formation. MIP-1γ levels were significantly higher in synovium and the chondro-osseous junction of joints 90 days postsurgery. The number of infiltrated CD4(+) T cells and macrophages and IL-1β expression were reduced in the synovial tissues of mice treated with MIP-1γ shRNA. Histopathological examinations revealed that mice treated with MIP-1γ shRNA had less severe OA than control mice had, as well as decreased osteoclast formation and MMP-13 expression. Locally inhibiting MIP-1γ expression may ameliorate disease progression and provide a new OA therapy.
免疫细胞参与骨关节炎 (OA) 的发病机制。在 OA 发病时，CD4(+) T 细胞被激活，并诱导巨噬细胞炎性蛋白 (MIP)-1γ 的表达和随后的破骨细胞形成。我们评估了局部敲低 MIP-1γ 在由前交叉韧带切断引起的小鼠 OA 模型中的作用。将小鼠巨噬细胞系和由骨髓未成熟造血单核/巨噬细胞祖细胞生成的破骨细胞样细胞与核因子-κB 配体 (RANKL) 或 CD4(+) T 细胞共培养。通过酶联免疫吸附试验 (ELISA) 检测细胞和小鼠中 MIP-1γ 和 RANKL 的水平。通过抗酒石酸酸性磷酸酶和组织蛋白酶 K 染色评估破骨细胞生成。在 B6 小鼠的一条后腿膝关节中诱导 OA。单独将编码 MIP-1γ 短发夹 RNA (shRNA) 的慢病毒载体和对照载体注射到膝关节内，通过组织学评估 OA 的表现。使用免疫组织化学检测组织中 MIP-1γ、基质金属蛋白酶 (MMP)-13 的表达以及 CD4(+) T 细胞、巨噬细胞的浸润和破骨细胞生成。CD4(+) T 细胞通过诱导破骨细胞前体中 MIP-1γ 的表达和随后的破骨细胞形成参与 OA。用特异性抗体中和 MIP-1γ 可消除 RANKL 刺激和 CD4(+) T 细胞刺激的破骨细胞形成。术后 90 天，滑膜和关节软骨 - 骨交界处的 MIP-1γ 水平明显升高。用 MIP-1γ shRNA 处理的小鼠滑膜组织中浸润的 CD4(+) T 细胞和巨噬细胞数量减少，IL-1β 表达减少。组织病理学检查显示，用 MIP-1γ shRNA 治疗的小鼠的 OA 比对照组的小鼠更严重，破骨细胞形成和 MMP-13 表达减少。局部抑制 MIP-1γ 的表达可能改善疾病进展并为 OA 提供新的治疗方法。
