Abstract
The potential of oxidized-LDL (Ox-LDL) to elicit inflammatory responses in macrophages leading to the atherosclerosis (AS) progression is well known. Since proprotein convertase subtilisin/Kexin-9 (PCSK-9), the posttranslational regulator of LDL-receptor, is associated with elevated LDL in the circulation, the present report was aimed to uncover the ameliorative effects of Ginkgolide B, a terpenic lactone from Ginkgo biloba, against Ox-LDL-induced alterations in cholesterol metabolism in HUVECs. Consequently, our results demonstrated that incubation with Ox-LDL significantly upregulated the PCSK-9 expression in HUVECs, which was significantly downregulated, both at mRNA and protein level, after Ginkgolide B treatment via subsequent suppression of sterol element binding protein (SREBP-2) expression. Moreover, Ginkgolide B-mediated inhibition of PCSK-9 activity was also validated by in silico methods which revealed that it interferes the PSCK-9 interaction with LDL-receptor (LDL-R). Interestingly, Ox-LDL-induced LDL-R expression was further enhanced by Ginkgolide B treatment in HUVECs. Moreover, Ginkgolide B treatment lead to downregulation of lectin-like Ox-LDL receptor (LOX-1) and NADPH oxidase (NOX-4) expression which was upregulated in Ox-LDL-treated HUVECs, along with the attenuation of mitochondrial ROS generation. Furthermore, Ginkgolide B significantly inhibited the augmented expression of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) in Ox-LDL-activated HUVECs. Ginkgolide B also significantly ameliorated the inflammatory response in Ox-LDL-activated HUVECs by suppressing the expression of IL-1α, IL-1β, IL-6, CXCL-1, CXCL-2, and monocyte chemotactic protein (MCP-1), at mRNA and protein level. Our in vitro and in silico study established that Ginkgolide B alleviated the Ox-LDL-induced inflammatory cascades and altered lipid metabolism in HUVECs by suppressing the PCSK-9 and, thus, could be established as a treasured alternative therapeutic candidate in the atherosclerosis management.