Human Breast Milk Extracellular Vesicles Mitigate Endothelial Dysfunction

<b>Background</b>: Endothelial cell (EC) dysfunction is an early sign of compromised vascular integrity and is associated with various cardiovascular diseases (CVDs). Activation of Toll-like receptor 4 (TLR4) plays a central role in this process. Extracellular vesicles (EVs) derived from milk have known anti-inflammatory properties, particularly in suppressing TLR4 activation. This study investigates the therapeutic potential of human breast milk-derived EVs (HBM-EVs) in mitigating EC dysfunction related to CVDs. <b>Methods</b>: HBM-EVs were isolated from the breast milk of healthy nursing mothers using ultracentrifugation. HBM-EVs were applied to lipopolysaccharide (LPS)-treated human umbilical vein endothelial cells (HUVECs), and inflammatory marker expression was assessed through qPCR and Western blotting. Mitochondrial oxidative stress was measured using MitoSOX. The effects of HBM-EVs were further evaluated in ex vivo studies using mesenteric arteries from diet-induced obese mice. Additionally, the effect of HBM-EVs on angiogenesis was tested via a wound closure assay. <b>Results</b>: In HUVECs, pre-treatment with HBM-EVs inhibited LPS-induced expression of inflammatory markers, including IL-6 and VCAM-1, as well as the phosphorylation of NFκB. Additionally, HBM-EVs reduced LPS-induced mitochondrial oxidative stress. In animal studies, HBM-EV treatment restored EC-dependent vasorelaxation in mesenteric arteries from diet-induced obese mice. Furthermore, HBM-EVs enhanced EC migration, leading to improved wound closure in HUVECs. <b>Conclusion</b>: This study demonstrates the therapeutic potential of HBM-EVs in alleviating EC dysfunction, offering a promising new approach to the treatment of CVDs. Future research will focus on identifying the specific cargo of HBM-EVs and further exploring their therapeutic mechanisms in endothelial dysfunction.