The Role of IL-6 in Experimental Post Thrombotic Syndrome

摘要 血栓后综合征(PTS)是深静脉血栓形成(DVT)最常见的后遗症， 以静脉壁纤维化、瓣膜破坏及常闭塞为特征。据估计，这种情况发生在~40%-50%之间 那些遭受深静脉血栓的人。目前还没有直接的药物疗法来治疗PTS，最近的失败凸显了这一点 分级压缩长袜，以防止PTS(SOX试验)。CaVenT的审判表明，即使是那些 接受溶栓治疗的患者在2年内仍有40%的PTS发生率。复发性深静脉血栓是一种特殊的 强烈的因素增加了PTS的风险，部分通过抗凝预防。然而，出血风险仍然存在。 即使使用新的非维生素K拮抗剂。白介素6(IL-6)是一种嗜多性炎性细胞因子， 仅与PTS和实验性静脉壁损伤有关。IL-6有两条主要的信号通路。 IL-6与膜结合的IL-6受体-α(Rα)直接结合在有限数量的细胞中，例如 肝细胞和白细胞，被称为“经典的”。更常见的是，IL-6与可溶性IL-6Rα的复合物 并与存在于大多数细胞上的辅助受体gp130结合，称为反式信号转导，并赋予最多的 炎症性和纤维化后遗症。初步和已发表的数据表明，IL-6与静脉血有很强的相关性 室壁纤维化、与内皮细胞和血管平滑肌细胞(VSMC)的共定位以及改变的纤维化 静脉血栓形成(VT)后IL-6-/-小鼠。这些观察结果表明，IL-6信号在创伤后应激过程中起核心作用。 血栓性静脉壁损伤，而且重要的是，对于这种损伤，已经有了容易翻译的抗IL-6疗法。我们的 总体假设是IL-6/sIL-6R转导信号驱动下游纤维化前静脉壁细胞改变 会导致实验性血栓后静脉壁损伤，而新的抗IL-6信号疗法可以 消除血栓形成后静脉壁损伤。我们将通过三个具体目标来解决这个假设：具体目标 1.明确早期静脉壁VT后IL-6和sIL-6R释放的早期来源和机制 细胞反应，血栓形成模型的影响。具体目标2：显示静脉壁 室性心动过速后IL-6/IL-6R、/gp130信号轴驱动内皮细胞和血管平滑肌细胞特异性促纤维化活性。 特异性目标3：应用新型直接和间接抗IL-6预防和治疗血栓形成后静脉壁损伤 作为对初发和复发实验性室速的标准护理抗凝治疗的比较。 为了实现这些目标，建立了室性心动过速的小鼠模型和体外静脉壁模型 将使用文化。组织特异性转基因小鼠研究静脉壁IL-6信号转导机制 纤维化损伤，以及新的非抗凝剂抗IL-6疗法将被测试。这里提出的实验 通过定义IL-6信号的机制和IL-6的翻译，将显著推动这一领域的发展 抑制实验性PTS，使用新的和临床可用的药物。

ABSTRACT Post-thrombotic syndrome (PTS) is the most common sequelae from deep vein thrombosis (DVT), characterized by vein wall fibrosis, valve destruction and often occlusion. It is estimated to occur in ~40 – 50% of those suffering a DVT. No direct medical therapy exists to treat PTS, highlighted by the recent failure of graded compression stockings to prevent PTS (SOX trial). The CaVenT trial suggested that even those patients treated with thrombolysis still have a ~40% incident PTS at 2 years. Recurrent DVT is a particularly strong factor increasing the risk of PTS, prevented in part by anticoagulation. However, bleeding risks remain even with the new non-vitamin-K antagonists. Interleukin-6 (IL-6) is a pleotropic inflammatory cytokine that is uniquely associated with both PTS and experimental vein wall injury. IL-6 has two primary signaling pathways. Direct IL-6 binding to membrane bound IL-6 receptor-alpha (Rα) occurs in a limited number of cells, such as hepatocytes and leukocytes, and is termed `classical'. More commonly, IL-6 complexes with soluble IL-6Rα and binds the co-receptor gp130, present on most cells, termed `trans-signaling', and confers most inflammatory and fibrotic sequelae. Preliminary and published data suggests strong correlation of IL-6 with vein wall fibrosis, co-localization with endothelial and vascular smooth muscle cells (VSMC), and altered fibrosis in IL-6-/- mice after venous thrombosis (VT). These observations suggest a central role for IL-6 signaling in post- thrombotic vein wall injury, and importantly, for which readily translatable anti-IL-6 therapies already exist. Our overall hypothesis is that IL-6/sIL-6R trans-signaling drives downstream profibrotic vein wall cellular changes that cause experimental post-thrombotic vein wall injury and that novel anti-IL-6 signaling therapies can abrogate post-thrombotic vein wall injury. We will address this hypothesis by three specific aims: Specific Aim 1: To define the early sources and mechanisms of IL-6 and sIL-6R release after VT, the early vein wall cellular responses, and the effect of thrombosis model. Specific Aim 2: To demonstrate the vein wall endothelial and VSMC specific profibrotic activities driven by IL-6/IL-6R/gp130 signaling axis after VT. Specific Aim 3: To prevent and treat post-thrombotic vein wall injury using novel direct and indirect anti-IL-6 therapies, as a comparison with standard of care anticoagulation, in primary and recurrent experimental VT. To accomplish these Aims, murine models of stasis and stenosis derived VT, as well as ex vivo vein wall culture will be used. Tissue specific transgenic mice to define the mechanisms of IL-6 signaling on vein wall fibrotic injury, and novel non anticoagulant anti-IL-6 therapies will be tested. The proposed experiments herein will significantly move the field forward by defining the mechanisms of IL-6 signaling, and the translation of IL-6 inhibition on experimental PTS, using novel and clinically available agents.