Department of Precision Medicine, the University of Campania "Luigi Vanvitelli" Italy.
IRCCS MultiMedica, Via Fantoli 16/15, 20138, Milan, Italy.
Theranostics. 2023 Jan 1;13(2):531-542. doi: 10.7150/thno.80289. eCollection 2023.
: Proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors (i) are a class of lipid-lowering drugs suggested to hold a plethora of beneficial effects independent of their LDL cholesterol-lowering properties. However, the mechanism underlying such observations is debated. : Human aortic endothelial cells (TeloHAEC) were pre-treated with 100 µg/mL of the PCSK9i evolocumab and then exposed to 20 ng/mL of IL-6, a major driver of cardiovascular diseases (CVD), in both naïve state and after siRNA-mediated suppression of the NAD-dependent deacetylase sirtuin-3 (SIRT3). Inflammation, autophagy, and oxidative stress were assessed through Western Blots, ELISAs, and/or immunofluorescence coupled by flow cytometry. To explore the human relevance of the findings, we also evaluated the expression of IL-6, SIRT3, IL-1β, the ratio LC3B II/I, and PCSK9 within the plaques of patients undergoing carotid endarterectomy (n=277), testing possible correlations between these proteins. : PCSK9i improved a range of phenotypes including the activation of inflammatory pathways, oxidative stress, and autophagy. Indeed, treatment with PCSK9i was able to counteract the IL-6 induced increase in inflammasome activation, the accrual of autophagic cells, and mitochondrial ROS accumulation. Of note, silencing of SIRT3 reverted the beneficial effects observed with PCSK9i treatment on all these phenomena. In atheroma specimens, the expression of PCSK9 was inversely related to that of SIRT3 while positively correlating with IL-6, IL-1β, and the ratio LC3B II/I. : Overall, these data suggest that PCSK9i bear intrinsic anti-inflammatory, anti-autophagic, and antioxidant properties in endothelial cells, and that these pleiotropic effects might be mediated, at least in part, by SIRT3. These results provide an additional mechanism supporting the emerging knowledge relative to the benefit of PCSK9i on CVD beyond LDL-lowering and uncover SIRT3 as a putative mediator of such pleiotropy.
: 前蛋白转化酶枯草溶菌素 9（PCSK9）抑制剂（i）是一类降脂药物，被认为具有许多独立于降低 LDL 胆固醇作用的有益作用。然而，这种观察结果的机制仍存在争议。: 人主动脉内皮细胞（TeloHAEC）先用 100μg/ml 的 PCSK9i 依洛尤单抗预处理，然后在未用 siRNA 抑制 NAD 依赖性去乙酰化酶 SIRT3 和用 siRNA 抑制 SIRT3 的情况下，分别用 20ng/ml 的白细胞介素-6（IL-6）处理，IL-6 是心血管疾病（CVD）的主要驱动因素。通过 Western Blot、ELISA 和/或流式细胞术耦联的免疫荧光来评估炎症、自噬和氧化应激。为了探索这些发现的人类相关性，我们还评估了接受颈动脉内膜切除术（n=277）的患者斑块中 IL-6、SIRT3、IL-1β、LC3B II/I 比值和 PCSK9 的表达，检验这些蛋白之间可能存在的相关性。: PCSK9i 改善了一系列表型，包括炎症途径的激活、氧化应激和自噬。事实上，PCSK9i 的治疗能够抵消 IL-6 诱导的炎症小体激活、自噬细胞积累和线粒体 ROS 积累的增加。值得注意的是，沉默 SIRT3 逆转了 PCSK9i 治疗对所有这些现象的有益作用。在动脉粥样硬化标本中，PCSK9 的表达与 SIRT3 呈负相关，而与 IL-6、IL-1β 和 LC3B II/I 比值呈正相关。: 综上所述，这些数据表明，PCSK9i 在血管内皮细胞中具有内在的抗炎、抗自噬和抗氧化特性，这些多效性作用可能至少部分通过 SIRT3 介导。这些结果提供了一个额外的机制，支持了 PCSK9i 在降低 LDL 之外对 CVD 的益处的新认识，并揭示了 SIRT3 作为这种多效性的潜在介质。
