Endoplasmic reticulum stress-dependent ROS production mediates synovial myofibroblastic differentiation in the immobilization-induced rat knee joint contracture model
Endoplasmic reticulum stress-dependent ROS production mediates synovial myofibroblastic differentiation in the immobilization-induced rat knee joint contracture model
复制标题
在固定诱导的大鼠膝关节挛缩模型中，内质网应激依赖性ROS产生介导滑膜肌纤维母细胞分化
DOI：
10.1016/j.yexcr.2018.05.036
复制
发表时间：
2018-08-15
影响因子：
3.7
通讯作者：
Wang, Kun
中科院分区：
文献类型：
--
作者：
Jiang, Shihai;He, Ronghan;Wang, Kun
关节挛缩是关节不动患者的常见并发症，涉及关节囊中的纤维化结构改变。考虑到内质网（ER）应激在促进组织纤维化中起着重要作用，我们研究了未折叠蛋白反应（UPR）是否有助于制动诱导的膝关节挛缩的纤维化发展。使用非创伤性大鼠膝关节挛缩模型，12只雌性Sprague-Dawley大鼠接受8周的膝关节制动。我们发现，纤维化蛋白标志物（I型胶原，α-SMA）和UPR（GRP 78，ATF 6 α，XBP 1 s）标志物在大鼠原代培养的滑膜肌成纤维细胞中显著上调。在相同的细胞类型中，用ER应激抑制剂4-苯基丁酸（4-PBA）预处理，不仅废除了细胞因子TGF β 1的刺激，而且降低了UPR的蛋白水平。此外，正如预期的那样，通过流式细胞术在滑膜肌成纤维细胞中检测到高活性氧（ROS）产生。值得注意的是，通过抗氧化剂抑制ROS，TGF β 1诱导的UPR显著降低。这些数据表明，ER应激通过ROS在滑膜成纤维细胞中的过表达而充当促纤维化刺激物。有趣的是，免疫组化结果显示，在人类获得性关节挛缩囊组织和动物膝关节挛缩组织中，UPR蛋白水平均增加。总之，我们的研究结果表明，ER应激有助于关节囊纤维化的滑膜成肌纤维细胞分化，也可能作为关节挛缩的潜在治疗靶点。
Joint contracture is a common complication for people with joint immobility that involves fibrosis structural alteration in the joint capsule. Considering that endoplasmic reticulum (ER) stress plays a prominent role in the promotion of tissue fibrosis, we investigated whether the unfolded protein response (UPR) contributes to the fibrotic development in immobilization-induced knee joint contractures. Using a non-traumatic rat knee joint contracture model, twelve female Sprague-Dawley rats received knee joint immobilization for a period of 8 weeks. We found that fibrosis protein markers (type I collagen, alpha-SMA) and UPR (GRP78, ATF6 alpha, XBP1s) markers were parallelly upregulated in rat primary cultured synovial myofibroblasts. In the same cell types, pretreatment with an ER stress inhibitor, 4-phenylbutyric acid (4-PBA), not only abrogated cytokine TGF beta 1 stimulation but also reduced the protein level of UPR. Additionally, high reactive oxygen species (ROS) generation was detected in synovial myofibroblasts through flow cytometry, as expected. Notably, TGF beta 1-induced UPR was significantly reduced through the inhibition of ROS with antioxidants. These data suggest that ER stress act as a pro-fibrotic stimulus through the overexpression of ROS in synovial fibroblasts. Interestingly, immunohistochemical results showed an increase in the UPR protein levels both in human acquired joint contractures capsule tissue and in animal knee joint contracture tissue. Together, our findings suggest that ER stress contributes to synovial myofibroblastic differentiation in joint capsule fibrosis and may also serve as a potential therapeutic target in joint contractures.