Abstract：
The study aims to explore the fluctuating expression of C/EBP Homologous Protein (CHOP) following rat carotid artery injury and its central role in vascular stenosis. Using in vivo rat carotid artery injury models and in vitro ischemia and hypoxia cell models employing human aortic endothelial cells (HAECs) and vascular smooth muscle cells (T/G HA-VSMCs), a comprehensive investigative framework was established. Histological analysis confirmed intimal hyperplasia in rat models. CHOP expression in vascular tissues was assessed using Western blot and immunohistochemical staining, and its presence in HAECs and T/G HA-VSMCs was determined through RT-PCR and Western blot. The study evaluated HAEC apoptosis, inflammatory cytokine secretion, cell proliferation, and T/G HA-VSMCs migration through Western blot, ELISA, CCK8, and Transwell migration assays. The rat carotid artery injury model revealed substantial fibrous plaque formation and vascular stenosis, resulting in an increased intimal area and plaque-to-lumen area ratio. Notably, CHOP is markedly elevated in vessels of the carotid artery injury model compared to normal vessels. Atorvastatin effectively mitigated vascular stenosis and suppresses CHOP protein expression. In HAECs, ischemia and hypoxia-induced CHOP upregulation, along with heightened TNFα, IL-6, caspase3, and caspase8 levels, while reducing cell proliferation. Atorvastatin demonstrated a dose-dependent suppression of CHOP expression in HAECs. Downregulation of CHOP or atorvastatin treatment led to reduced IL-6 and TNFα secretion, coupled with augmented cell proliferation. Similarly, ischemia and hypoxia conditions increased CHOP expression in T/G HA-VSMCs, which was concentration-dependently inhibited by atorvastatin. Furthermore, significantly increased MMP-9 and MMP-2 concentrations in the cell culture supernatant correlated with enhanced T/G HA-VSMCs migration. However, interventions targeting CHOP downregulation and atorvastatin usage curtailed MMP-9 and MMP-2 secretion and suppressed cell migration. In conclusion, CHOP plays a crucial role in endothelial injury, proliferation, and VSMCs migration during carotid artery injury, serving as a pivotal regulator in post-injury fibrous plaque formation and vascular remodeling. Statins emerge as protectors of endothelial cells, restraining VSMCs migration by modulating CHOP expression.
摘要：
本研究旨在探讨C/EBP同源蛋白(CHOP)在大鼠颈动脉损伤后的表达及其在血管狭窄中的作用。使用人主动脉内皮细胞（HAECs）和血管平滑肌细胞（T/GHA-VSMCs）的体内大鼠颈动脉损伤模型和体外缺血缺氧细胞模型，建立了一个全面的调查框架。组织学分析证实了大鼠模型中的内膜增生。使用Westernblot和免疫组织化学染色评估血管组织中的CHOP表达，通过RT-PCR和Westernblot确定其在HAECs和T/GHA-VSMCs中的存在。该研究评估了HAEC细胞凋亡，炎性细胞因子分泌，细胞增殖，通过蛋白质印迹和T/GHA-VSMCs迁移，ELISA,CCK8和Transwell迁移测定。大鼠颈动脉损伤模型显示大量纤维斑块形成和血管狭窄,导致内膜面积和斑块与管腔面积之比增加。值得注意的是,与正常血管相比,CHOP在颈动脉损伤模型的血管中显著升高。阿托伐他汀可有效缓解血管狭窄并抑制CHOP蛋白表达。在HAECs,缺血和缺氧诱导的CHOP上调，随着TNFα升高，IL-6、caspase3和caspase8水平，同时减少细胞增殖。阿托伐他汀显示了HAECs中CHOP表达的剂量依赖性抑制。下调CHOP或阿托伐他汀治疗导致IL-6和TNFα分泌减少，再加上细胞增殖增强。同样，缺血和缺氧条件增加了T/GHA-VSMCs中CHOP的表达，阿托伐他汀呈浓度依赖性抑制。此外，细胞培养上清液中MMP-9和MMP-2浓度显著增加与T/GHA-VSMCs迁移增强相关。然而,针对CHOP下调和阿托伐他汀使用的干预措施减少了MMP-9和MMP-2的分泌并抑制了细胞迁移.总之,CHOP在内皮损伤中起着至关重要的作用，扩散,和VSMC在颈动脉损伤期间的迁移，作为损伤后纤维斑块形成和血管重塑的关键调节剂。他汀类药物作为内皮细胞的保护剂出现，通过调节CHOP表达抑制VSMCs迁移。
