Chrysanthopoulou Akrivi, Mitroulis Ioannis, Kambas Konstantinos, Skendros Panagiotis, Kourtzelis Ioannis, Vradelis Stergios, Kolios George, Aslanidis Spyros, Doumas Michael, Ritis Konstantinos
Democritus University of Thrace, Alexandroupolis, Greece.
Arthritis Rheum. 2011 Nov;63(11):3586-97. doi: 10.1002/art.30586.
The extrinsic coagulation cascade is involved in the fibrotic process, via thrombin-dependent induction of CCN2 (connective tissue growth factor) expression. Given the previously reported activation of the coagulation system in systemic sclerosis (SSc), we undertook the present study to investigate the involvement of cross-talk between the tissue factor (TF)-thrombin axis and endothelin 1 (ET-1) signaling in the fibrotic activity of SSc.
Human colonic myofibroblasts (HCMFs) from 6 patients with SSc and gastrointestinal symptoms and from 6 control subjects were isolated and cultured under various conditions. Messenger RNA and protein levels of TF, CCN2, and endothelin receptor A (ET(A) ) were investigated. Collagen production and migratory activity of HCMFs were further assessed.
HCMFs from SSc patients demonstrated increased basal CCN2 production, collagen deposition, and migration rate, in a thrombin-dependent manner. Increased TF expression was also observed in SSc HCMFs. Subsequent activation of the extrinsic coagulation system resulted in thrombin-dependent enhancement of ET(A) expression. ET(A) overexpression led to further increases in both TF expression and fibrotic activity in HCMFs. Moreover, inhibition of ET-1 signaling by bosentan abolished the TF-mediated fibrotic capacity of HCMFs.
Tissue factor-thrombin signaling is involved in the increased fibrotic activity of HCMFs from patients with SSc. Moreover, the up-regulation of ET(A) expression by thrombin and the effect of ET-1 in the induction of TF expression indicate an amplification loop for enhanced collagen deposition. Therapeutic interventions targeting the extrinsic coagulation system or ET-1 signaling may provide clinical benefit by breaking this vicious circle.
外源性凝血级联反应通过凝血酶依赖性诱导CCN2（结缔组织生长因子）表达参与纤维化过程。鉴于先前报道系统性硬化症（SSc）中凝血系统被激活，我们开展本研究以探究组织因子（TF）-凝血酶轴与内皮素1（ET-1）信号之间的相互作用在SSc纤维化活动中的作用。
从6例有胃肠道症状的SSc患者和6例对照受试者中分离出人结肠肌成纤维细胞（HCMF），并在各种条件下进行培养。研究TF、CCN2和内皮素受体A（ET(A)）的信使核糖核酸和蛋白质水平。进一步评估HCMF的胶原蛋白产生和迁移活性。
SSc患者的HCMF以凝血酶依赖性方式表现出基础CCN2产生增加、胶原蛋白沉积增加和迁移率增加。在SSc的HCMF中也观察到TF表达增加。外源性凝血系统随后的激活导致ET(A)表达的凝血酶依赖性增强。ET(A)过表达导致HCMF中TF表达和纤维化活性进一步增加。此外，波生坦抑制ET-1信号消除了TF介导的HCMF纤维化能力。
组织因子-凝血酶信号参与SSc患者HCMF纤维化活性增加。此外，凝血酶对ET(A)表达的上调以及ET-1在诱导TF表达中的作用表明存在一个增强胶原蛋白沉积的放大环。针对外源性凝血系统或ET-1信号的治疗干预可能通过打破这个恶性循环提供临床益处。
