Department of Neurology, Nanjing Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
Department of Cerebrovascular Disease Treatment Center, Affiliated Nanjing Brain Hospital, Nanjing Medical University, Nanjing, China.
Neurochem Res. 2024 Nov 16;50(1):10. doi: 10.1007/s11064-024-04272-z.
Proprotein convertase substilin/kexin type 9 (PCSK9), a pivotal protein regulating lipid metabolism, has been implicated in promoting microthrombotic formation and inflammatory cascades, thereby contributing to cardiovascular ischemia/reperfusion (I/R) injury. However, its involvement in cerebral I/R injury and its potential role in microcirculation protection remain unexplored. In this investigation, we utilized a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model to simulate ischemic stroke. Different concentrations of evolocumab (1, 5, 10 mg/kg, i.v.), a PCSK9 inhibitor, were administered to assess its impact. Immunofluorescence staining was employed to analyze changes in the expression of occludin, claudin-5, thrombocyte, ICAM-1, VCAM-1, and CD45, providing insights into blood-brain barrier integrity, platelet adhesion, and immune cell infiltration. Moreover, the Morris water maze and elevated plus maze were utilized to evaluate neurological and behavioral functions in MCAO/R mice, shedding light on the effects of PCSK9 inhibition. Our findings revealed a surge in plasma PCSK9 levels post-MCAO/R, peaking at 24 h post-reperfusion. Evolocumab (10 mg/kg) treatment significantly mitigated brain infarction and neurological deficits, evidenced by enhanced locomotor function and reduced post-stroke anxiety. However, it did not ameliorate cognitive impairment following MCAO/R. Additionally, evolocumab administration led to diminished leakage of evans blue solution and upregulated expression of occludin and claudin-5. Thrombocyte, ICAM-1, VCAM-1, and CD45 levels were notably reduced in the penumbral area post-evolocumab treatment. These protective effects are speculated to be mediated through the inhibition of the ERK/NF-κB pathway. The PCSK9 inhibitor evolocumab holds promise as a therapeutic agent during the acute phase of stroke, exerting its beneficial effects by modulating the ERK/NF-κB signaling pathway.
前蛋白转化酶枯草溶菌素 9（PCSK9）是一种调节脂质代谢的关键蛋白，它被认为可以促进微血栓形成和炎症级联反应，从而导致心血管缺血/再灌注（I/R）损伤。然而，它在脑 I/R 损伤中的作用及其在微循环保护中的潜在作用仍未被探索。在本研究中，我们使用大脑中动脉闭塞/再灌注（MCAO/R）小鼠模型模拟缺血性中风。我们给予不同浓度的依洛尤单抗（1、5、10mg/kg，静脉注射），评估其对 PCSK9 的抑制作用。免疫荧光染色用于分析紧密连接蛋白 occludin、claudin-5、血小板、ICAM-1、VCAM-1 和 CD45 的表达变化，从而了解血脑屏障的完整性、血小板黏附以及免疫细胞浸润情况。此外，我们还使用 Morris 水迷宫和高架十字迷宫评估 MCAO/R 小鼠的神经和行为功能，以了解 PCSK9 抑制的效果。我们发现，MCAO/R 后血浆 PCSK9 水平升高，再灌注后 24 小时达到峰值。依洛尤单抗（10mg/kg）治疗可显著减轻脑梗死和神经功能缺损，表现为运动功能增强和卒中后焦虑减轻。然而，它并不能改善 MCAO/R 后的认知障碍。此外，依洛尤单抗治疗还可减少 Evans 蓝溶液的渗漏，并上调 occludin 和 claudin-5 的表达。依洛尤单抗治疗后，半影区血小板、ICAM-1、VCAM-1 和 CD45 水平明显降低。这些保护作用可能是通过抑制 ERK/NF-κB 通路介导的。PCSK9 抑制剂依洛尤单抗有望成为中风急性期的治疗药物，通过调节 ERK/NF-κB 信号通路发挥其有益作用。
