Vein grafting is a frequently used surgical intervention for cardiac revascularization. However, vein grafts display regions with intraplaque (IP) angiogenesis, which promotes atherogenesis and formation of unstable plaques. Graft neovessels are mainly composed of endothelial cells (ECs) that largely depend on glycolysis for migration and proliferation. In the present study, we aimed to investigate whether loss of the glycolytic flux enzyme phosphofructokinase-2/fructose-2,6-bisphosphatase 3 (PFKFB3) in ECs inhibits IP angiogenesis and as such prevents unstable plaque formation. To this end, apolipoprotein E deficient (ApoE^−/−) mice were backcrossed to a previously generated PFKFB3^fl/fl Cdh5^iCre mouse strain. Animals were injected with either corn oil (ApoE^−/−PFKFB3^fl/fl) or tamoxifen (ApoE^−/−PFKFB3^ECKO), and were fed a western-type diet for 4 weeks prior to vein grafting. Hereafter, mice received a western diet for an additional 28 days and were then sacrificed for graft assessment. Size and thickness of vein graft lesions decreased by 35 and 32%, respectively, in ApoE^−/−PFKFB3^ECKO mice compared to controls, while stenosis diminished by 23%. Moreover, vein graft lesions in ApoE^−/−PFKFB3^ECKO mice showed a significant reduction in macrophage infiltration (29%), number of neovessels (62%), and hemorrhages (86%). EC-specific PFKFB3 deletion did not show obvious adverse effects or changes in general metabolism. Interestingly, RT-PCR showed an increased M2 macrophage signature in vein grafts from ApoE^−/−PFKFB3^ECKO mice. Altogether, EC-specific PFKFB3 gene deletion leads to a significant reduction in lesion size, IP angiogenesis, and hemorrhagic complications in vein grafts. This study demonstrates that inhibition of endothelial glycolysis is a promising therapeutic strategy to slow down plaque progression.

静脉移植是心脏血运重建常用的外科手术。然而，静脉移植物显示斑块内 (IP) 血管生成区域，这促进了动脉粥样硬化和不稳定斑块的形成。移植新血管主要由内皮细胞 (EC) 组成，内皮细胞在很大程度上依赖于糖酵解进行迁移和增殖。在本研究中，我们旨在研究 ECs 中糖酵解通量酶磷酸果糖激酶 2/果糖-2,6-双磷酸酶 3 (PFKFB3) 的缺失是否会抑制 IP 血管生成，从而防止不稳定的斑块形成。为此，将载脂蛋白 E 缺陷 (ApoE ^-/- ) 小鼠回交至先前生成的 PFKFB3 ^fl/fl Cdh5 ^iCre小鼠品系。给动物注射玉米油（ApoE^-/- PFKFB3 ^fl/fl ) 或他莫昔芬 (ApoE ^-/- PFKFB3 ECKO ⁾，并在静脉移植前喂食西方饮食 4 周。此后，小鼠再接受西方饮食 28 天，然后处死进行移植评估。^{与对照组相比，ApoE -/-} PFKFB3 ECKO^小鼠的静脉移植病变的大小和厚度分别减少了 35% 和 32%，而狭窄减少了 23%。^{此外，ApoE -/-} PFKFB3 ECKO^中的静脉移植病变小鼠的巨噬细胞浸润（29%）、新血管数量（62%）和出血（86%）显着减少。EC 特异性 PFKFB3 缺失未显示出明显的副作用或一般代谢的变化。有趣的是，RT-PCR 显示来自 ApoE ^-/- PFKFB3 ECKO^小鼠的静脉移植物中 M2 巨噬细胞特征增加。总之，EC 特异性 PFKFB3 基因缺失可显着减少静脉移植物中的病变大小、IP 血管生成和出血并发症。该研究表明，抑制内皮糖酵解是减缓斑块进展的有前景的治疗策略。