Conrad Jobst Vascular Research Laboratories, University of Michigan Medical School, Ann Arbor, USA.
University of Michigan Health System, 1500 E. Medical Center Drive, Cardiovascular Center - 5463, Ann Arbor, MI, 48109-5867, USA.
Sci Rep. 2023 Feb 24;13(1):3253. doi: 10.1038/s41598-023-30149-2.
Deep venous thrombosis and residual thrombus burden correlates with circulating IL-6 levels in humans. To investigate the cellular source and role of IL-6 in thrombus resolution, Wild type C57BL/6J (WT), and IL-6 mice underwent induction of VT via inferior vena cava (IVC) stenosis or stasis. Vein wall (VW) and thrombus were analyzed by western blot, immunohistochemistry, and flow cytometry. Adoptive transfer of WT bone marrow derived monocytes was performed into IL6 mice to assess for rescue. Cultured BMDMs from WT and IL-6 mice underwent quantitative real time PCR and immunoblotting for fibrinolytic factors and matrix metalloproteinase activity. No differences in baseline coagulation function or platelet function were found between WT and IL-6 mice. VW and thrombus IL-6 and IL-6 leukocyte-specific receptor CD126 were elevated in a time-dependent fashion in both VT models. Ly6C Mo/MØ were the predominant leukocyte source of IL-6. IL-6 mice demonstrated larger, non-resolving stasis thrombi with less neovascularization, despite a similar number of monocytes/macrophages (Mo/MØ). Adoptive transfer of WT BMDM into IL-6 mice undergoing stasis VT resulted in phenotype rescue. Human specimens of endophlebectomized tissue showed co-staining of Monocyte and IL-6 receptor. Thrombosis matrix analysis revealed significantly increased thrombus fibronectin and collagen in IL-6 mice. MMP9 activity in vitro depended on endogenous IL-6 expression in Mo/MØ, and IL-6 mice exhibited stunted matrix metalloproteinase activity. Lack of IL-6 signaling impairs thrombus resolution potentially via dysregulation of MMP-9 leading to impaired thrombus recanalization and resolution. Restoring or augmenting monocyte-mediated IL-6 signaling in IL-6 deficient or normal subjects, respectively, may represent a non-anticoagulant target to improve thrombus resolution.
深静脉血栓形成和残余血栓负担与人类循环中的 IL-6 水平相关。为了研究 IL-6 在血栓溶解中的细胞来源和作用，野生型 C57BL/6J（WT）和 IL-6 小鼠通过下腔静脉（IVC）狭窄或停滞诱导 VT。通过 Western blot、免疫组织化学和流式细胞术分析静脉壁（VW）和血栓。将 WT 骨髓来源的单核细胞过继转移到 IL6 小鼠中以评估其拯救作用。从 WT 和 IL-6 小鼠中培养 BMDM 进行纤维蛋白溶解因子和基质金属蛋白酶活性的定量实时 PCR 和免疫印迹。WT 和 IL-6 小鼠之间在基线凝血功能或血小板功能方面没有差异。在两种 VT 模型中，VW 和血栓中的 IL-6 和白细胞特异性受体 CD126 均呈时间依赖性升高。Ly6C Mo/MØ 是 IL-6 的主要白细胞来源。尽管单核细胞/巨噬细胞（Mo/MØ）数量相似，但 IL-6 小鼠表现出更大、不可溶解的停滞血栓，新生血管化程度较低。将 WT BMDM 过继转移到发生停滞性 VT 的 IL-6 小鼠中可导致表型拯救。内切除组织的人类标本显示单核细胞和 IL-6 受体的共染色。血栓基质分析显示 IL-6 小鼠的血栓纤维连接蛋白和胶原蛋白明显增加。体外 MMP9 活性取决于 Mo/MØ 中的内源性 IL-6 表达，而 IL-6 小鼠表现出基质金属蛋白酶活性不足。缺乏 IL-6 信号会通过 MMP-9 的失调导致血栓再通和溶解受损，从而损害血栓溶解。在 IL-6 缺乏或正常受试者中分别恢复或增强单核细胞介导的 IL-6 信号，可能代表一种非抗凝靶点，以改善血栓溶解。
