Barale Cristina, Tempesta Giulia, Melchionda Elena, Morotti Alessandro, Frascaroli Chiara, Danzero Alice Costanza, Femminò Saveria, Penna Claudia, Russo Isabella
Department of Clinical and Biological Sciences, Turin University, 10043 Orbassano, Italy.
San Luigi Gonzaga Hospital, 10043 Orbassano, Italy.
Int J Mol Sci. 2025 Jan 24;26(3):1003. doi: 10.3390/ijms26031003.
Beyond the regulation of cholesterol metabolism, a number of extrahepatic functions of proprotein convertase subtilisin/kexin type 9 (PCSK9) have been increasingly identified. The main purpose of this study was to verify whether PCSK9 expression in vascular smooth muscle cells (VSMC) is influenced by insulin resistance and high glucose (HG). In cultured rat aortic VSMC from lean insulin-sensitive Zucker rats (LZRs) and obese insulin-resistant Zucker rats (OZRs), a classical animal model of insulin resistance, we evaluated PCSK9 expression with or without the monoclonal antibodies against PCSK9 Alirocumab and Evolocumab or the synthetic PCSK9-binding peptide PEP 2-8. Effects and molecular mechanisms underlying altered PCSK9 expression were evaluated by proliferation and migration assay, reactive oxygen species (ROS) production, and involvement of PKC, NADPH-oxidase, MAPK/ERK-1/2 pathway activation. As a result, we found that, in comparison with LZR, VSMC from OZR showed basal PCSK9 overexpression mitigated by Alirocumab, Evolocumab, PEP 2-8, and the inhibitors of PKC, NADPH-oxidase, and MAPK. The finding of PCSK9 upregulation in VSMC from OZR paralleled with increased ROS production, proliferation, and migration. HG increased PCSK9 expression in VSMC from LZR, but not in OZR, via oxidative stress and with effects reduced by PCSK9 inhibitors. These findings suggest that a dysregulation of PCSK9 in VSMC could be involved in vascular damage in metabolic disorders, such as obesity and diabetes.
除了对胆固醇代谢的调节作用外，越来越多的研究发现了前蛋白转化酶枯草杆菌蛋白酶/kexin 9型（PCSK9）的一些肝外功能。本研究的主要目的是验证血管平滑肌细胞（VSMC）中PCSK9的表达是否受胰岛素抵抗和高糖（HG）的影响。在来自瘦素敏感的胰岛素敏感型 Zucker 大鼠（LZRs）和肥胖胰岛素抵抗型 Zucker 大鼠（OZRs）（一种经典的胰岛素抵抗动物模型）的培养大鼠主动脉 VSMC 中，我们使用抗 PCSK9 的单克隆抗体阿利西尤单抗和依洛尤单抗或合成的 PCSK9 结合肽 PEP 2-8 评估了有无PCSK9时的表达情况。通过增殖和迁移试验、活性氧（ROS）产生以及蛋白激酶C（PKC）、NADPH氧化酶、丝裂原活化蛋白激酶/细胞外信号调节激酶1/2（MAPK/ERK-1/2）通路激活情况，评估了PCSK9表达改变的影响及分子机制。结果发现，与LZRs相比，OZRs的VSMC显示基础PCSK9过表达，阿利西尤单抗、依洛尤单抗、PEP 2-8以及PKC、NADPH氧化酶和MAPK的抑制剂可减轻这种过表达。在OZRs的VSMC中PCSK9上调的发现与ROS产生增加、增殖和迁移增加相平行。HG通过氧化应激增加了LZRs的VSMC中PCSK9的表达，但在OZRs中未增加，且PCSK9抑制剂可降低其作用。这些发现表明，VSMC中PCSK9的失调可能参与肥胖和糖尿病等代谢紊乱中的血管损伤。
