CD36介导的脂质摄取诱导的内皮细胞僵硬导致内皮屏障破坏并促进动脉粥样硬化病变。

Endothelial Stiffening Induced by CD36-Mediated Lipid Uptake Leads to Endothelial Barrier Disruption and Contributes to Atherosclerotic Lesions.

作者信息

Aguilar Victor, Le Master Elizabeth, Paul Amit, Ahn Sang Joon, Lazarko Dana, Febbraio Maria, Mehta Dolly, Lee James C, Levitan Irena

机构信息

Departments of Medicine (V.A., E.L.M., A.P., S.J.A., D.L., I.L.), University of Illinois at Chicago.

Biomedical Engineering (V.A., J.C.L., I.L.), University of Illinois at Chicago.

出版信息

Arterioscler Thromb Vasc Biol. 2025 Jun;45(6):e201-e216. doi: 10.1161/ATVBAHA.124.322244. Epub 2025 Apr 10.

DOI:10.1161/ATVBAHA.124.322244

PMID:40207364

Abstract

BACKGROUND

Endothelial stiffening induced by Western diet was proposed to be an important factor in vascular dysfunction. In this study, we determine the role of endothelial CD36 (cluster of differentiation 36) in stiffening, disruption of aortic endothelial barrier, and atherosclerosis in mouse models of obesity and hypercholesterolemia.

METHODS

To address this goal, we generated an endothelial-specific inducible knockdown mouse model of CD36, Cdh5.CreERCD36, on C57/BL6J wild-type and LDLR genetic backgrounds. Endothelial stiffness is assessed by atomic force microscopy; endothelial barrier integrity is assessed by imaging VE (vascular endothelium)-cadherin junctions and by penetration of Evans blue dye into the aortic wall. Atherosclerotic plaques are quantified using oil red O staining.

RESULTS

Endothelial-specific downregulation of CD36 abrogates stiffening of aortic endothelium induced by Western diet in Cdh5.CreERCD36 and in Cdh5.CreERCD36LDLR mice. Prevention of Western diet-induced endothelial stiffening by downregulation of CD36 is associated with a protective effect against endothelial barrier disruption in both mouse models and with a significant decrease in the areas of atherosclerotic lesions in Cdh5.CreERCD36LDLR mice. Mechanistically, stiffening of human aortic endothelial cells in vitro is induced by saturated fatty acids, particularly palmitic acid (PA), which results in activation of RhoA. Both PA-induced endothelial stiffening and RhoA activation are abrogated by CD36 siRNA. Furthermore, PA-induced endothelial stiffening of excised aortas ex vivo is lost in aortas isolated from mice, where endothelial CD36 is downregulated. We also demonstrate that PA-induced activation of RhoA and endothelial stiffening require expressing an RhoA-inhibitory protein, Rho-GDI1 (Rho guanosine dissociation inhibitor 1). Finally, we discover that PA disrupts the colocalization of RhoA with Rho-GDI1.

CONCLUSIONS

We conclude that stiffening of the aortic endothelium by CD36-mediated uptake of fatty acids contributes significantly to Western diet-induced vascular dysfunction and atherosclerosis. We further propose that fatty acids may activate RhoA by inducing its dissociation from Rho-GDI1.

摘要

背景

西方饮食诱导的内皮细胞硬化被认为是血管功能障碍的一个重要因素。在本研究中，我们在肥胖和高胆固醇血症小鼠模型中确定内皮细胞CD36（分化簇36）在硬化、主动脉内皮屏障破坏和动脉粥样硬化中的作用。

方法

为实现这一目标，我们在C57/BL6J野生型和LDLR基因背景上构建了一种内皮细胞特异性诱导敲低CD36的小鼠模型，即Cdh5.CreERCD36。通过原子力显微镜评估内皮细胞硬度；通过成像VE（血管内皮）-钙黏蛋白连接以及伊文思蓝染料渗透到主动脉壁来评估内皮屏障完整性。使用油红O染色对动脉粥样硬化斑块进行定量分析。

结果

在Cdh5.CreERCD36和Cdh5.CreERCD36LDLR小鼠中，内皮细胞特异性下调CD36可消除西方饮食诱导的主动脉内皮硬化。在两种小鼠模型中，通过下调CD36预防西方饮食诱导的内皮细胞硬化与对内皮屏障破坏的保护作用相关，并且在Cdh5.CreERCD36LDLR小鼠中动脉粥样硬化病变面积显著减少。机制上，体外人主动脉内皮细胞的硬化由饱和脂肪酸，特别是棕榈酸（PA）诱导，这导致RhoA激活。CD36 siRNA可消除PA诱导的内皮细胞硬化和RhoA激活。此外，在从内皮细胞CD36下调的小鼠分离的主动脉中，PA诱导的离体切除主动脉的内皮细胞硬化消失。我们还证明，PA诱导的RhoA激活和内皮细胞硬化需要表达一种RhoA抑制蛋白，即Rho-GDI1（Rho鸟苷解离抑制剂1）。最后，我们发现PA破坏了RhoA与Rho-GDI1的共定位。