Hepatic extracellular vesicle release and uptake under normolipemia and hyperlipidemia
Krisztina Németh1, Zoltán Varga2,3, Dorina Lenzinger1, Tamás Visnovitz1, Anna Koncz1,
Nikolett Hegedűs3, Ágnes Kittel4, Domokos Máthé3,5, Krisztián Szigeti3, Péter Lőrincz6,
Edit I. Buzás1,7,8*, Viola Tamási1*
1 Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest
2 Institute of Materials and Environmental Chemistry, Research Centre for Natural
Sciences, Budapest
3 Department of Biophysics and Radiation Biology, Semmelweis University, Budapest
4 Institute of Experimental Medicine, Eötvös Loránd Research Network, Budapest
5 Hungarian Centre of Excellence for Molecular Medicine, In Vivo Imaging ACF, Budapest
6 Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University,
Budapest
7 Hungarian Centre of Excellence for Molecular Medicine – Semmelweis University Extracellular
Vesicle Research Group, Budapest
8 ELKH-SE Immune-Proteogenomics Research Group, Budapest
Introduction Liver has a key role in removal of extracellular vesicles (EVs) from
the blood circulation, and it also significantly contributes to EV secretion. However,
the knowledge regarding to the involvement of the different liver cell types is scarce.
Aims Here we examined the different contribution of liver cell types in the dynamics
of EV uptake and release both in normo- and hyperlipidemia.
Methods Plasma EV profiles of C57BL/6 mice were analyzed after 20-30 weeks on high
fat diet. Furthermore, control mice were injected intravenously with 99mTc-duramycin
labelled medium (~ 330 nm) and small EVs (~ 130 nm), and an hour later, biodistribution
of EVs were determined by SPECT/CT. In vitro, different liver cell types were tested
for EV production and uptake with/without prior oleic acid/palmitic acid treatment.
Results Based on the EV marker expression, we found a significantly higher plasma
small EV concentration after 30 weeks on high fat diet. To elucidate the involvement
of primary hepatocytes, we carried out in vitro experiments. We report, that hyperlipidemic
conditions significantly increased the release of medium EVs and small EVs. When investigating
EV biodistribution, upon injection of 99mTc-duramycin labelled medium EVs and small
EVs intravenously to mice, we detected their accumulation primarily in the liver.
In vitro, we found that medium EVs were primarily taken up by Kupffer cells, while
small EV uptake was the highest in liver sinusoidal endothelial cells. Finally, we
demonstrated that in hyperlipidemia, there was a decreased EV uptake both by Kupffer
cells and liver sinusoidal endothelial cells.
Conclusions Our data suggest that hyperlipidema increases the release and reduces
the uptake of EVs by liver cells. We also provide evidence for size-dependent differential
EV uptake by the different cell types of the liver.
Funding
NVKP16-1-2016-0017, ÚNKP19-4-SE-09, János Bolyai Research Scholarship, Hungarian Scientific
Research Fund (K120237), VEKOP2.3.2-16-2017-000002, VEKOP2.3.3-15-2017-00016, H2020-MSCA-ITN-2017-722148
TRAIN EV, FIKP-Therapeutic Thematic Programme, Horizon 2020 Research and Innovation
Programme (739593)
