Division of Cardiac Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.
Division of Cardiac Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada; Division of Vascular Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada; Department of Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
J Thorac Cardiovasc Surg. 2017 Sep;154(3):978-988.e1. doi: 10.1016/j.jtcvs.2017.02.058. Epub 2017 Mar 16.
Thrombosis persists as a leading cause of morbidity and mortality. Given that endothelial cells (ECs) play a central role in regulating thrombosis, understanding the molecular endothelial cues that regulate susceptibility or resistance to thrombosis have important translational implications. Accordingly, we evaluated the role of endothelial autophagy in the development of thrombosis.
We generated mice in which the essential autophagy-related 7 (ATG7) gene was conditionally deleted from ECs (EC-ATG7 mice). Three in vivo models of thrombosis were used, and mechanistic studies were conducted with cultured human umbilical vein endothelial cells (HUVECs).
We silenced ATG7 in HUVECs and observed >60% decreases in tumor necrosis factor (TNF)-α-induced tissue factor (TF) transcript levels, protein expression, and activity. TF mRNA levels in the carotid arteries of EC-ATG7 mice subjected to the prothrombotic stimulus FeCl were lower than those in the similarly treated wild-type (WT) littermate group. Compared with WT mice, EC-ATG7 mice exhibited prolonged time to carotid (2-fold greater) and mesenteric (1.3-fold greater) artery occlusion following FeCl injury. The thrombi generated in laser-injured cremasteric arterioles were smaller in EC-ATG7 mice compared with WT mice, and took 2.3-fold longer to appear.
Taken together, these results provide definitive evidence that loss of endothelial ATG7 attenuates thrombosis and reduces the expression of TF. Our findings demonstrate that endothelial ATG7, and thus autophagy, is a critical and previously unrecognized target for modulating the susceptibility to thrombosis.
血栓仍然是发病率和死亡率的主要原因。鉴于内皮细胞（ECs）在调节血栓形成方面起着核心作用，了解调节血栓形成易感性或抗性的内皮分子线索具有重要的转化意义。因此，我们评估了内皮细胞自噬在血栓形成中的作用。
我们生成了内皮细胞中条件性缺失必需自噬相关 7（ATG7）基因的小鼠（EC-ATG7 小鼠）。使用了三种体内血栓形成模型，并在培养的人脐静脉内皮细胞（HUVEC）中进行了机制研究。
我们在 HUVEC 中沉默了 ATG7，观察到肿瘤坏死因子（TNF）-α诱导的组织因子（TF）转录本水平、蛋白表达和活性降低了>60%。在接受促血栓刺激 FeCl 的 EC-ATG7 小鼠的颈动脉中，TF mRNA 水平低于接受相同处理的野生型（WT）同窝小鼠组。与 WT 小鼠相比，EC-ATG7 小鼠在 FeCl 损伤后颈动脉（2 倍更长）和肠系膜（1.3 倍更长）动脉闭塞的时间延长。与 WT 小鼠相比，在激光损伤的附睪小动脉中生成的血栓在 EC-ATG7 小鼠中较小，且出现时间延长了 2.3 倍。
综上所述，这些结果提供了确凿的证据，证明内皮细胞 ATG7 的缺失可减轻血栓形成并降低 TF 的表达。我们的研究结果表明，内皮细胞 ATG7 以及自噬是调节血栓形成易感性的关键且以前未被认识到的靶点。
