Priam Sabrina, Bougault Carole, Houard Xavier, Gosset Marjolaine, Salvat Colette, Berenbaum Francis, Jacques Claire
University Pierre and Marie Curie Paris VI, Paris, France.
Arthritis Rheum. 2013 Jul;65(7):1831-42. doi: 10.1002/art.37951.
Mechanical stress plays an important role in cartilage degradation and subchondral bone remodeling in osteoarthritis (OA). The remodeling of the subchondral bone could initiate cartilage loss in OA through the interplay of bone and cartilage. The aim of this study was to identify soluble mediators released by loaded osteoblasts/osteocytes that could induce the release of catabolic factors by chondrocytes.
Murine osteoblasts/osteocytes were subjected to cyclic compression, and then conditioned medium from either compressed (CCM) or uncompressed (UCM) cells was used to stimulate mouse chondrocytes. Chondrocyte expression of matrix metalloproteinase 3 (MMP-3), MMP-13, type II collagen, and aggrecan was assessed by reverse transcription-polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay. Soluble mediators released by compressed osteoblasts/osteocytes were identified using iTRAQ (isobaric tags for relative and absolute quantification), a differential secretome analysis. Subchondral bone and cartilage samples were isolated from OA patients, and culture medium conditioned with OA subchondral bone or cartilage was used to stimulate human chondrocytes.
Stimulation of mouse chondrocytes with CCM strongly induced the messenger RNA (mRNA) expression and protein release of MMP-3 and MMP-13 and inhibited the mRNA expression of type II collagen and aggrecan. Differential secretome analysis revealed that 10 proteins were up-regulated in compressed osteoblasts/osteocytes. Among them, soluble 14-3-3∊ (s14-3-3∊) dose-dependently induced the release of catabolic factors by chondrocytes, mimicking the effects of cell compression. Addition of a 14-3-3∊ blocking antibody greatly attenuated the CCM-mediated induction of MMP-3 and MMP-13 expression. Furthermore, in human OA subchondral bone, s14-3-3∊ was strongly released, and in cultures of human OA chondrocytes, s14-3-3∊ stimulated MMP-3 expression.
The results of this study identify s14-3-3∊ as a novel soluble mediator critical in the communication between subchondral bone and cartilage in OA. Thus, s14-3-3∊ may be a potential target for future therapeutic or prognostic applications in OA.
机械应力在骨关节炎（OA）的软骨降解和软骨下骨重塑中起重要作用。软骨下骨的重塑可通过骨与软骨的相互作用引发OA中的软骨丢失。本研究的目的是鉴定加载的成骨细胞/骨细胞释放的可溶性介质，这些介质可诱导软骨细胞释放分解代谢因子。
对小鼠成骨细胞/骨细胞进行循环压缩，然后用来自压缩（CCM）或未压缩（UCM）细胞的条件培养基刺激小鼠软骨细胞。通过逆转录-聚合酶链反应、蛋白质印迹和酶联免疫吸附测定评估软骨细胞中基质金属蛋白酶3（MMP-3）、MMP-13、II型胶原蛋白和聚集蛋白聚糖的表达。使用iTRAQ（相对和绝对定量的等压标签），一种差异分泌组分析，鉴定压缩的成骨细胞/骨细胞释放的可溶性介质。从OA患者中分离软骨下骨和软骨样本，并用OA软骨下骨或软骨条件培养基刺激人软骨细胞。
用CCM刺激小鼠软骨细胞强烈诱导MMP-3和MMP-13的信使核糖核酸（mRNA）表达和蛋白质释放，并抑制II型胶原蛋白和聚集蛋白聚糖的mRNA表达。差异分泌组分析显示，10种蛋白质在压缩的成骨细胞/骨细胞中上调。其中，可溶性14-3-3ε（s14-3-3ε）剂量依赖性地诱导软骨细胞释放分解代谢因子，模拟细胞压缩的作用。添加14-3-3ε阻断抗体大大减弱了CCM介导的MMP-3和MMP-13表达诱导。此外，在人OA软骨下骨中，s14-3-3ε大量释放，并且在人OA软骨细胞培养物中，s14-3-3ε刺激MMP-3表达。
本研究结果确定s14-3-3ε是OA中软骨下骨与软骨之间通讯中的一种新型关键可溶性介质。因此，s14-3-3ε可能是OA未来治疗或预后应用的潜在靶点。
