PhD Scientific Days 2023

Molecular Sciences IV.

Hypercholesterolemia alters the extracellular vesicle secretion of cardiomyocytes

Text of the abstract

Introduction: Hypercholesterolemia (HC) can lead to chronic inflammation of the heart and heart failure. Extracellular vesicles (EV) play an important role in both mechanisms. However, how HC affects the EV communication of the cardiovascular system is remained unknown.
Aim: Our aim is to analyze in vitro, how HC affects the EV secretion of cardiomyocyte cells (CM).
Methods: AC16 human CMs were treated with Remembrane® HC supplement or with its vehicle (0.3% EtOH) or with FBS-free medium and then EVs were isolated using ultracentrifugation. From the isolates, particle concentration was measured using nanoparticle tracking analysis, biophysical parameters were analyzed with atomic force microscopy and protein composition was measured with liquid chromatography-tandem mass spectrometry. THP-1-ASC-GFP cells were treated with CM-EVs or with EV-free cell culture supernatant and monocyte activation was analyzed using flow cytometry to measure the inflammatory potential of CM-EVs.
Results: HC treatment significantly increased the particle concentration of CM-EV isolates, meanwhile, EV size and Young’s modulus remained unchanged. 2135 individual proteins were identified from the samples of which 92 were enriched by HC treatment, such as several ribosomal proteins, meanwhile, the presence of 41 proteins was reduced, including numerous extracellular matrix proteins. CM-EVs did not induce the activation of THP-1 monocytes, regardless of the treatmentÍ.
Conclusions: According to our data, HC modifies the EV secretion of CMs, which may have diagnostic relevance. Unravelled changes may not take part in HC-induced myocardial inflammation. To elucidate the biological roles of these changes, further investigations are needed.
Funding: CK was supported by NTP-NFTÖ-22-B-0200 and SE250+ Excellence Scholarship (EFOP-3.6.3-VEKOP-16-2017-00009), NRDI Fund (2019-1.1.1-PIACI-KFI-2019-00367)