Department of Vascular Surgery, Fuwai Yunnan Cardiovascular Hospital, Kunming, China.
Department of Vascular Surgery, Affiliated Cardiovascular Hospital of Kunming Medical University, Kunming, China.
Vascular. 2022 Feb;30(1):120-129. doi: 10.1177/1708538121999854. Epub 2021 Mar 11.
Vein graft adaptation (VGA) is a process that vein as a vascular graft conduits in arterial reconstructive surgery; VGA can lead to postoperative vein graft stenosis (VGS) and complications after coronary artery bypass graft and other peripheral artery bypass surgeries. VGA is characterized by vein graft loss the venous features without exhibiting arterial features; furthermore, the activation of ERK inhibited the maintenance of venous properties of the vein graft. We hypothesized that ERK inhibition can affect vein VGS through regulating the expression of EphB4.
Rat vein transplantation model was established using wild-type and EphB4 Sprague-Dawley rats. Hematoxylin-eosin, Masson, Verhoeff, actin staining, and immunohistochemistry were applied to observe the structure of the vein grafts. Vascular smooth muscle cells (VSMCs) were isolated from the vein and vein grafts. Western blotting was used to determine the expression of p-ERK1/2 and EphB4, and immunofluorescence was applied to detect the expression and location of EphB4. Cell wound scratch assay and CCK8 assay were used to determine the migration and proliferation of VSMCs. Real-time polymerase chain reaction was used to determine the mRNA expression of EphB4.
Western blotting in vein sample and vein graft sample detected p-ERK1/2 and ERK1/2 expression in both EphB4 and EphB4 rats. The expression of p-ERK was increased in vein graft compared to vein. Immunofluorescence in VSMCs form EphB4 and EphB4 rats detected EphB4 expression in both cells, and the expression of EphB4 was increased in VSMCs form EphB4 rats. SCH772984 reduces the proliferation and migration of VSMCs. Inhibition of ERK suppressed the increase of vein graft wall thickness, and the expression of collagen fibers, elastic fibers, and α-actin was decreased. Vein graft from EphB4 rats reduces the expression of EphB4, and SCH772984 suppressed the decrease of EphB4 in vivo. Vein graft from EphB4 rats increased the expression of EphB4, and SCH772984 suppressed the increase of EphB4 in vivo.
The inhibition of ERK1/2 suppressed the process of VGS by decreasing the proliferation of VSMCs. The ERK-inhibitor SCH772984 suppressed the level of VGS by extending the time of EphB4 expression during the process of VGA, thus maintaining the venousization of vein graft. The mechanism may be that the inhibitor SCH772984 suppresses the level of VGS by extending the time of EphB4 expression during the process of VGA. Therefore, our research provides a new target of VGS treatment by inhibiting the expression of ERK1/2 through the process of VGA.
静脉移植物适应（VGA）是静脉作为血管移植物在动脉重建手术中的过程；VGA 可导致术后静脉移植物狭窄（VGS）和冠状动脉旁路移植术及其他外周动脉旁路手术后的并发症。VGA 的特征是静脉移植物失去静脉特征而不表现出动脉特征；此外，ERK 的激活抑制了静脉移植物静脉特性的维持。我们假设 ERK 抑制可以通过调节 EphB4 的表达来影响静脉 VGS。
使用野生型和 EphB4 Sprague-Dawley 大鼠建立大鼠静脉移植模型。应用苏木精-伊红、马松、Verhoeff、肌动蛋白染色和免疫组织化学观察静脉移植物的结构。从静脉和静脉移植物中分离血管平滑肌细胞（VSMCs）。Western blot 用于测定 p-ERK1/2 和 EphB4 的表达，免疫荧光用于检测 EphB4 的表达和位置。细胞划痕实验和 CCK8 测定用于测定 VSMCs 的迁移和增殖。实时聚合酶链反应用于测定 EphB4 的 mRNA 表达。
在 EphB4 和 EphB4 大鼠的静脉样本和静脉移植物样本中，Western blot 检测到 EphB4 和 EphB4 大鼠中 p-ERK1/2 和 ERK1/2 的表达。与静脉相比，静脉移植物中 p-ERK 的表达增加。EphB4 和 EphB4 大鼠来源的 VSMCs 中的免疫荧光检测到 EphB4 在两种细胞中的表达，EphB4 大鼠来源的 VSMCs 中 EphB4 的表达增加。SCH772984 可减少 VSMCs 的增殖和迁移。ERK 抑制降低了静脉移植物壁厚度的增加，胶原纤维、弹性纤维和α-肌动蛋白的表达减少。来自 EphB4 大鼠的静脉移植物降低 EphB4 的表达，而 SCH772984 抑制 EphB4 在体内的减少。来自 EphB4 大鼠的静脉移植物增加 EphB4 的表达，而 SCH772984 抑制 EphB4 在体内的增加。
ERK1/2 的抑制通过减少 VSMCs 的增殖来抑制 VGS 过程。ERK 抑制剂 SCH772984 通过在 VGA 过程中延长 EphB4 表达的时间来抑制 VGS 的水平，从而维持静脉移植物的静脉化。其机制可能是抑制剂 SCH772984 通过在 VGA 过程中延长 EphB4 表达的时间来抑制 VGS 的水平。因此，我们的研究通过抑制 EphB4 的表达，为 VGS 治疗提供了一个新的靶点。
