The effects of hypercholesterolaemia and atherosclerosis on circulating CD63+ extracellular vesicle levels
Brachyahu Meir Kestecher
Molecular Medicine Division
Dr. Várnai Péter
SE NET Zöld előadóterem
2025-09-02 13:00:00
Human molecular genetics and genetic diagnostics
Dr. Wiener Zoltán
Xabier Osteikoetxea
Dr. Görbe Anikó
Dr. Varga Zoltán
Dr. Szökő Éva
Dr. Vannay Ádám
Dr. Buzás Krisztina
In 2016 the discovery was made that EVs, and lipoproteins associate in blood plasma. After that initial discovery was made, many papers began flooding the field showing a co-isolation and contamination of lipoproteins in all EV preps from body fluids. The same was true for lipoprotein preparations, leading to researchers in lipoproteins taking a keen interest in the rapidly developing EV field. This prompted our hypothesis that EVs may play a crucial role in dyscholesterolaemia and ultimately in the development of atherosclerosis in CVD. Our research set out using 2 genetic mouse models (PCSK9-/- and LDLR-/-) to simulate up and down regulated LDL levels respectively. Here we measured mice cholesterol and EV levels at baseline of 11-weeks old and again after either fed them HFD for 12 weeks or let them age to 22-months. In order to see how cholesterol levels might affect CVD in mice, we also measured cardiovascular function using Doppler ultrasound and measured plaques on the aortic arch using O-Red-O staining at all three time points. We also measured EVs levels in clinical samples of angina patients admitted to an emergency clinic, all of whom were eventually determined to be non-ischemic patients. We divided the clinical samples into 2 groups, group 1 with normocholesterolaemia and group 2 were those hypercholesterolaemia. Our results show PCSK9-/- have significantly lower TC and LDL levels where as LDLR-/- have significantly elevated TC and LDL levels at all time point. Our results show for the first time that annexin V and CD63 positive EVs inversely related to cholesterol in mice, and that CD63 positive EVs are inversely related cholesterol in humans. We also highlight that in mice, during feeding, cholesterol levels are elevated compared to fasted animals, this is consistent with previous studies in mice and humans. Interesting though lEV levels were stagnant whether animals were feeding or fasting. We also observe a cardioprotective element PCSK9-/- has on younger mice with HFD and that LDLR-/- causes plaque build-up in the long run. An additional finding here, PCSK9-/- mice have consistently greater body mass than WT mice. Together these results demonstrate an involvement of EVs in cholesterol dysfunction and propose CD63 positive lEV as an additional marker for ACVD. Showing consistently that CD63 positive lEV are inversely related to cholesterol levels in disease and pre-disease states in both mice and humans. We also highlight caution to patients on PCSK9 inhibitors, as weight gain and obesity become increasingly likely.
