Study of the influence of hyperglycemia on the abundance of amino acids, fatty acids, and selected lipids in extracellular vesicles using TOF-SIMS.

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) with the Bi3+ liquid metal ion gun was used to investigate the content of lipids and amino acids (AAs) in extracellular vesicles (EVs). We induced metabolic changes in human pancreatic ß-cells by stimulation with high glucose concentrations (35 mM) and tested the hypothesis of hyperglycemia (HG) has a detrimental effect on lipids and AAs in released EV subpopulations: ectosomes and exosomes. As a result of HG treatment, selected fatty acids (FAs) such as arachidonic, myristic and palmitic acids, changed their abundance in ectosomes and exosomes. Also, intensities of the characteristic peaks for cholesterol (m/z 95.09; 147.07; 161.11; 369.45) along with the molecular ion m/z 386.37 [C27H46O+] under HG conditions, both for ectosomes and exosomes, have changed significantly. Comparative analysis of HG EVs and normoglycemic (NG) ones showed statistically significant differences in the signal intensities of four AAs: valine (m/z 72.08 and 83.05), isoleucine (m/z 86.10), phenylalanine (m/z 120.08 and 132.05) and tyrosine (m/z 107.05 and 136.09). We confirmed that ToF-SIMS is a useful technique to study selected AAs and lipid profiles in various EV subpopulations. Our study is the first demonstration of changes in FAs and AAs in exosomes and ectosomes derived from ß-cells under the influence of HG.

Radiovesicolomics-new approach in medical imaging.

This review introduce extracellular vesicles (EVs) to a molecular imaging field. The idea of modern analyses based on the use of omics studies, using high-throughput methods to characterize the molecular content of a single biological system, vesicolomics seems to be the new approach to collect molecular data about EV content, to find novel biomarkers or therapeutic targets. The use of various imaging techniques, including those based on radionuclides as positron emission tomography (PET) or single photon emission computed tomography (SPECT), combining molecular data on EVs, opens up the new space for radiovesicolomics-a new approach to be used in theranostics.

Large extracellular vesicles do not mitigate the harmful effect of hyperglycemia on endothelial cell mobility.

Extracellular vesicles, especially the larger fraction (LEVs - large extracellular vesicles), are believed to be an important means of intercellular communication. Earlier studies on LEVs have shown their healing properties, especially in the vascular cells of diabetic patients. Uptake of LEVs by endothelial cells and internalization of their cargo have also been demonstrated. Endothelial cells change their properties under hyperglycemic conditions (HGC), which reduces their activity and is the cause of endothelial dysfunction. The aim of our study was to investigate how human umbilical vein endothelial cells (HUVECs) change their biological properties: shape, mobility, cell surface stiffness, as well as describe the activation of metabolic pathways after exposure to the harmful effects of HGC and the administration of LEVs released by endothelial cells. We obtained LEVs from HUVEC cultures in HGC and normoglycemia (NGC) using the filtration and ultracentrifugation methods. We assessed the size of LEVs and the presence of biomarkers such as phosphatidylserine, CD63, beta-actin and HSP70. We analyzed the LEVs uptake efficiency by HUVECs, HUVEC shape, actin cytoskeleton remodeling, surface stiffness and finally gene expression by mRNA analysis. Under HGC conditions, HUVECs were larger and had a stiffened surface and a strengthened actin cortex compared to cells under NGC condition. HGC also altered the activation of metabolic pathways, especially those related to intracellular transport, metabolism, and organization of cellular components. The most interesting observation in our study is that LEVs did not restore cell motility disturbed by HGC. Although, LEVs were not able to reverse this deleterious effect of HGC, they activated transcription of genes involved in protein synthesis and vesicle trafficking in HUVECs.