人骨性关节炎软骨细胞中基质金属蛋白酶-13 的抑制作用因 IFN-γ受体水平降低而受 IFN-γ损害。

Human osteoarthritic chondrocytes are impaired in matrix metalloproteinase-13 inhibition by IFN-gamma due to reduced IFN-gamma receptor levels.

机构信息

Département de Médecine, Université de Montréal, Centre de recherche du CHUM Hôpital Notre-Dame, Montreal, Quebec H2L 4M1, Canada.

出版信息

Osteoarthritis Cartilage. 2009 Aug;17(8):1049-55. doi: 10.1016/j.joca.2009.02.008. Epub 2009 Mar 3.

DOI:10.1016/j.joca.2009.02.008

PMID:19285161

Abstract

OBJECTIVE

Human osteoarthritic (OA) cartilage type-II collagen is preferentially cleaved by the proinflammatory cytokine-induced matrix metalloproteinases-13 (MMP-13). Interferon-gamma (IFN-gamma) potently inhibits interleukin-1 (IL-1)-induced MMP-13 expression in healthy chondrocytes. Our goal was to study the previously unknown impact of IFN-gamma on MMP-13 in OA and compare the levels and functional activity of IFN-gamma receptor (IFN-gammaR1) in healthy and OA chondrocytes.

METHODS

Chondrocytes were obtained from OA patients and non-arthritic control subjects and treated with IL-1+ or- IFN-gamma. MMP-13 mRNA and protein expression were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. IFN-gammaR1 expression was assessed by flow cytometry, immunoprecipitation and immunohistochemistry with fluorescein-labeled antibody. IFN-gammaR1 was neutralized with its antibody and signal transducer and activator of transcription 1 (STAT1) phosphorylation analyzed by Western blotting. OA chondrocytes were also transfected with control and IFN-gammaR1 expression vectors.

RESULTS

OA chondrocytes displayed a drastically impaired MMP-13 suppression by IFN-gamma compared to control cells. IFN-gammaR1 levels were significantly decreased in OA chondrocytes as assessed by flow cytometry, immunoprecipitation and immunohistochemistry. Consequently, IFN-gamma-stimulated STAT1 phosphorylation mediated by IFN-gammaR1 was also considerably reduced in OA patient chondrocytes. IFN-gammaR1 overexpression in OA cells restored MMP-13 suppression by IFN-gamma.

CONCLUSIONS

Ability of IFN-gamma to suppress IL-1-induced MMP-13 expression is diminished in OA chondrocytes due to decreased IFN-gammaR1 levels, activity and impaired downstream signal transduction. Therefore, IFN-gammaR1 modulation and weakened endogenous IFN-gamma response may be important mechanisms in OA pathogenesis and cartilage degradation.

摘要

目的

人骨性关节炎（OA）Ⅱ型胶原易被炎症细胞因子诱导的基质金属蛋白酶-13（MMP-13）切割。干扰素-γ（IFN-γ）能强烈抑制健康软骨细胞中白细胞介素-1（IL-1）诱导的 MMP-13 表达。我们的目标是研究 IFN-γ对 OA 中 MMP-13 的未知影响，并比较健康和 OA 软骨细胞中 IFN-γ受体（IFN-γR1）的水平和功能活性。

方法

从 OA 患者和非关节炎对照者中获取软骨细胞，并分别用 IL-1+或-IFN-γ处理。通过逆转录-聚合酶链反应（RT-PCR）和 Western blot 测定 MMP-13 mRNA 和蛋白表达。用流式细胞术、免疫沉淀和用荧光标记抗体的免疫组织化学评估 IFN-γR1 表达。用其抗体中和 IFN-γR1，并通过 Western blot 分析信号转导和转录激活因子 1（STAT1）磷酸化。还转染 OA 软骨细胞对照和 IFN-γR1 表达载体。

结果

与对照细胞相比，OA 软骨细胞中 IFN-γ对 MMP-13 的抑制作用明显受损。通过流式细胞术、免疫沉淀和免疫组织化学评估，IFN-γR1 水平在 OA 软骨细胞中显著降低。因此，OA 患者软骨细胞中 IFN-γ刺激的 IFN-γR1 介导的 STAT1 磷酸化也明显减少。OA 细胞中 IFN-γR1 的过表达恢复了 IFN-γ对 MMP-13 的抑制作用。