Department of Orthopedics, The Second Xiangya Hospital Affiliated with Central South University, Changsha 410011, China.
Department of Orthopedics and Institute of Orthopedics. Clinical Medical College of Yangzhou University, Subei People's Hospital of Jiangsu Province, Yangzhou 225001, China.
Eur J Pharmacol. 2017 Sep 5;810:36-43. doi: 10.1016/j.ejphar.2017.06.006. Epub 2017 Jun 8.
Intraarticular adhesion is one of the complications when the patients suffer from operations of knee-joint. Hydroxycamptothecin (HCPT) can selectively inhibit the activity of topoisomerase I and has shown anti-proliferative effect in previous researches. The aim of our experiment was to investigate the effect of topical application of HCPT on preventing intraarticular scar adhesion by activating the PERK signal pathway. As the results showed, HCPT could prevent the intraarticular scar adhesion and the inhibitory effect was in a dose-dependent manner. Furthermore, we assumed that ER stress mediated the suppression effect of the intraarticular scar adhesion. The results of immunohistochemistry showed that the expression of GRP78 and CHOP were increased together with the tendency of HCPT. When human fibroblasts were treated with HCPT in vitro, cell viability was inhibited according to the results of CCK-8 assay and Hoechst staining, and cell apoptosis was induced according to the results of AV/PI and western blot analysis. HCPT-induced apoptosis was correlated with elevation of GRP78 and CHOP, which were hallmarks of ER stress. Proteins associated with PERK signal pathway such as p-PERK and p-eIF2α were upregulated after treated by HCPT determined by western blot analysis. Knockdown of PERK decreased the ratio of Bax/Bcl-2, GRP78 and CHOP expression, suggesting that PERK signal pathway was involved in HCPT-induced fibroblast apoptosis. Our findings indicate that topical application of HCPT can prevent intraarticular scar adhesion. ER stress plays an important role in this effect by inducing fibroblasts apoptosis that may be mediated by PERK signal pathway.
关节内粘连是膝关节手术后的并发症之一。羟基喜树碱（HCPT）可以选择性地抑制拓扑异构酶 I 的活性，并且在之前的研究中显示出抗增殖作用。我们的实验目的是通过激活 PERK 信号通路来研究局部应用 HCPT 预防关节内瘢痕粘连的效果。结果表明，HCPT 可以预防关节内瘢痕粘连，抑制作用呈剂量依赖性。此外，我们假设内质网应激介导了关节内瘢痕粘连的抑制作用。免疫组化结果表明，GRP78 和 CHOP 的表达随着 HCPT 的增加而增加。当人成纤维细胞在体外用 HCPT 处理时，根据 CCK-8 测定和 Hoechst 染色的结果，细胞活力受到抑制，根据 AV/PI 和 Western blot 分析的结果，细胞凋亡被诱导。HCPT 诱导的细胞凋亡与内质网应激标志物 GRP78 和 CHOP 的升高相关。Western blot 分析表明，HCPT 处理后 PERK 信号通路相关蛋白如 p-PERK 和 p-eIF2α 上调。PERK 敲低降低了 Bax/Bcl-2 的比值、GRP78 和 CHOP 的表达，表明 PERK 信号通路参与了 HCPT 诱导的成纤维细胞凋亡。我们的研究结果表明，局部应用 HCPT 可以预防关节内瘢痕粘连。内质网应激通过诱导成纤维细胞凋亡在这一效应中起重要作用，PERK 信号通路可能介导了这一作用。
