Extracellular Vesicles From Women With Severe Preeclampsia Impair Vascular Endothelial Function

Abstract

BACKGROUND: Preeclampsia (PE) manifesting as hypertension and organ injury is mediated by vascular dysfunction. In biological fluids, extracellular vesicles (EVs) containing microRNA (miRNA), protein, and other cargo released from the placenta may serve as carriers to propagate injury, altering the functional phenotype of endothelial cells. PE has been consistently correlated with increased levels of placenta-derived EVs (pEVs) in maternal circulation. However, whether pEVs impaired endothelial cell function remains to be determined. In this study, we hypothesize that pEVs from pregnant women with severe PE (sPE) impair endothelial function through altered cell signaling. METHODS: We obtained plasma samples from women with sPE (n = 14) and normotensive pregnant women (n = 15) for the isolation of EVs. The total number of EV and pEV contribution was determined by quantifying immunoreactive EV-cluster of designation 63 (CD63) and placental alkaline phosphatase (PLAP) as placenta-specific markers, respectively. Vascular endothelial functional assays were determined by cell migration, electric cell-substrate impedance sensing in human aortic endothelial cells (HAECs), and wire myography in isolated blood vessels, preincubated with EVs from normotensive and sPE women. RESULTS: Plasma EV and pEV levels were increased in sPE when compared to normotensive without a significant size distribution difference in sPE (108.8 ± 30.2 nm) and normotensive-EVs (101.3 ± 20.3 nm). Impaired endothelial repair and proliferation, reduced endothelial barrier function, reduced endothelial-dependent vasorelaxation, and decreased nitrite level indicate that sPE-EVs induced vascular endothelial dysfunction. Moreover, sPE-EVs significantly downregulated endothelial nitric oxide synthase (eNOS and p-eNOS) when compared to normotensive-EV. CONCLUSIONS: EVs from sPE women impair endothelial-dependent vascular functions in vitro.

Extracellular Vesicles as Drivers of Immunoinflammation in Atherothrombosis

“…Endothelial dysfunction (ED) characterized by a proatherogenic environment is an early sign of atherosclerosis development [ 38 ]. Under pathological conditions, such as risk factors or injury, circulating EVs contribute towards a dysfunctional endothelium [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ]. Beyond the well-studied traditional cardiovascular risk factors, atherothrombosis is spearheaded by multiple risk factors such as clonal hematopoiesis and air pollution [ 51 ].…”

Extracellular Vesicles in Preeclampsia: Can Small Packages Carry a Big Punch?

“…However, it must be noted that the experimental techniques to measure, purify, and interpret EVs continue to be developed, and uncertainty remains when applying findings attributed to EVs in any disease state. 14 Indeed, in the study by Murugesan et al, 5 it cannot be definitively ruled out that contaminants from non-EV sources accounted for some of their findings. This is an important consideration given the study of O'Brien et al, 15 which suggests that placental-soluble factors and not the EVs of preeclampsia placentas impart endothelial dysfunction.…”

“…Taken together, these findings support EV cargo as an important component of the pathophysiology of preeclampsia. This form of communication from the placenta to the systemic circulation certainly requires further study, and Murugesan et al 5 are to be commended for advancing this knowledge. However, it must be noted that the experimental techniques to measure, purify, and interpret EVs continue to be developed, and uncertainty remains when applying findings attributed to EVs in any disease state.…”

“…Others have found that placenta-derived EVs are elevated as early as 11 to 14 weeks of gestation among women who subsequently develop preeclampsia. 12 Murugesan et al 5 noted that the concentration of EVs found in women who had preeclampsia was similarly elevated at the time of diagnosis compared to those who were normotensive. Identifying specific biomarkers associated with these early disease-related EVs could represent an important potential target for early diagnosis of preeclampsia; however, this potential is very far from being realized as a widely available commercial test.…”

“…When placental trophoblasts are cultured in a hypoxic environment, they secrete the solubilized receptors, thus creating the antiangiogenic environment. Murugesan et al 5 and others have demonstrated that placenta-derived EVs are able to deliver this antiangiogenic environment to cells in culture. In their experiment, human aortic endothelial cells were cultured in a monolayer on plates.…”