Institute of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, Hungary.
HUN-REN-SU Translational Extracellular Vesicle Research Group, Budapest, Hungary.
Cardiovasc Diabetol. 2024 Oct 17;23(1):368. doi: 10.1186/s12933-024-02459-w.
The association and co-isolation of low-density lipoproteins (LDL) and extracellular vesicles (EVs) have been shown in blood plasma. Here we explore this relationship to better understand the role of EVs in atherogenesis.
Wild type (WT), PCSK9, and LDLR C57BL/6 mice were used in this study. Eleven week-old male mice were fed high-fat diet (HFD) for 12 weeks or kept on normal diet until old age (22-months). Cardiac function was assessed by ultrasound, cholesterol was quantified with a colorimetric kit and circulating EVs were measured using flow cytometry. Plaques were analysed post-mortem using Oil-Red-O staining of the aortic arch. EVs were measured from platelet free blood plasma samples of normal and hypercholesterolaemic clinical patients. Based on annexin V and CD63 staining, we found a significant increase in EV levels in LDLR and PCSK9 mice after HFD, but CD81 showed no significant change in either group. There was no significant change in plaque formation after HFD. PCSK9 mice show a favourable cardiac function after HFD. Blood cholesterol levels progressively increased during HFD, with LDLR mice showing high levels while PCSK9 were significantly lowered compared to WT animals. In mice at old age, similar cholesterol levels were observed as in young mice. In old age, LDLR mice showed significantly increased plaques. At old age, ejection fraction was decreased in all groups of mice, as were CD63 EVs. Similarly to mice, in patients with hypercholesterolaemia, CD63 EVs were significantly depleted.
This research demonstrates an inverse relationship between circulating EVs and cholesterol, making EVs a potential marker for cardiovascular disease (CVD). HFD causes reduced cardiac function, but atherosclerotic development is slowly progressing in hypercholesterolaemic models and only observed with old animals. These results also bring further evidence for the benefit of using of PCSK9 inhibitors as therapeutic agents in CVD.
已有研究表明，在血浆中存在低密度脂蛋白（LDL）与细胞外囊泡（EVs）的关联和共分离现象。本研究旨在深入探讨这种关系，以更好地了解 EVs 在动脉粥样硬化形成中的作用。
本研究使用野生型（WT）、PCSK9 和 LDLR C57BL/6 小鼠。11 周龄雄性小鼠喂食高脂肪饮食（HFD）12 周或保持正常饮食直至老年（22 个月）。通过超声评估心功能，使用比色试剂盒定量胆固醇，使用流式细胞术测量循环 EVs。死后通过主动脉弓油红-O 染色分析斑块。从正常和高胆固醇血症临床患者的血小板游离血浆样本中测量 EVs。根据膜联蛋白 V 和 CD63 染色，我们发现 HFD 后 LDLR 和 PCSK9 小鼠的 EV 水平显著增加，但两组 CD81 均无明显变化。HFD 后斑块形成无明显变化。HFD 后 PCSK9 小鼠的心功能表现良好。HFD 期间，血液胆固醇水平逐渐升高，LDLR 小鼠的胆固醇水平较高，而 PCSK9 小鼠的胆固醇水平明显低于 WT 动物。在老年时，与年轻小鼠相比，老年小鼠的胆固醇水平相似。老年时，LDLR 小鼠的斑块明显增多。老年时，所有小鼠组的射血分数均降低，CD63 EVs 也减少。与小鼠类似，在高胆固醇血症患者中，CD63 EVs 明显减少。
本研究表明循环 EVs 与胆固醇呈负相关，这使得 EVs 成为心血管疾病（CVD）的潜在标志物。HFD 导致心功能降低，但在高胆固醇血症模型中，动脉粥样硬化的发展进展缓慢，仅在老年动物中观察到。这些结果还进一步证明了使用 PCSK9 抑制剂作为 CVD 治疗药物的益处。
