Anthocyanins and their gut metabolites reduce the adhesion of monocyte to TNFα-activated endothelial cells at physiologically relevant concentrations

An increasing number of evidence suggests a protective role of dietary anthocyanins against cardiovascular diseases. Anthocyanins' extensive metabolism indicates that their metabolites could be responsible for the protective effects associated with consumption of anthocyanin-rich foods. The aim of this work was to investigate the effect of plasma anthocyanins and their metabolites on the adhesion of monocytes to TNFα-activated endothelial cells and on the expression of genes encoding cell adhesion molecules. Human umbilical vein endothelial cells (HUVECs) were exposed to circulating anthocyanins: cyanidin-3-arabinoside, cyanidin-3-galactoside, cyanidin-3-glucoside, delphinidin-3-glucoside, peonidin-3-glucoside, anthocyanin degradation product: 4-hydroxybenzaldehyde, or to their gut metabolites: protocatechuic, vanillic, ferulic and hippuric acid, at physiologically-relevant concentrations (0.1–2 μM) and time of exposure. Both anthocyanins and gut metabolites decreased the adhesion of monocytes to HUVECs, with a magnitude ranging from 18.1% to 47%. The mixture of anthocyanins and that of gut metabolites also reduced monocyte adhesion. However, no significant effect on the expression of genes encoding E-selectin, ICAM1 and VCAM1 was observed, suggesting that other molecular targets are involved in the observed effect. In conclusion, this study showed the potency of anthocyanins and their gut metabolites to modulate the adhesion of monocytes to endothelial cells, the initial step in atherosclerosis development, under physiologically-relevant conditions

Characterization of milk small extracellular vesicles to study adaptation to lactation in ruminants

International audienceSmall extracellular vesicles (EV) are secreted into the extracellular space by all cells. Due to the diversity of their cellular origin and the molecules they contain, small EVs have the ability to ensure extracellular communication and carry molecular signatures of their tissue of origin and its physiological state. In ruminants, early lactation is characterized by profound changes in energy balance and metabolic status. To explore physiological adaptations during early lactation, this study investigated the use of non-invasive milk EVs to identify specific indicators of inter-organ signalling. Milk samples were collected from 8 cows on weeks 2 and 7 postpartum, corresponding to negative and neutral energy balance, respectively. Small EVs were isolated by ultracentrifugation coupled with size exclusion chromatography and characterized by morphological, biophysical and biochemical criteria. Labelled-free shotgun quantitative proteomics was performed by nanoLC-MS/MS. Electron microscopy revealed cup-shaped vesicles with a diameter of about 100 nm, characteristic of small EVs. The diameter was confirmed by Tunable Resistive Pulse Sensing and the specificity of small EVs isolation by the presence of cytoplasmic (TSG101) and membrane (CD63) markers. A total of 508 proteins were identified in milk EVs at weeks 2 and 7 of lactation. Multilevel PCA analysis showed a clear separation between the 2 time points, indicating a strong effect of lactation stage on the protein composition of milk EVs. This proteomic dataset will be analysed to identify small EV molecular signatures of tissue interactions that coordinate nutrient partitioning and adaptation during early lactation