ABSTRACT
Endothelial dysfunction is a prominent feature of preeclampsia, a hypertensive disorder of pregnancy, and contributes to multiple symptoms characteristic of the syndrome. A myriad of growth factors and cytokines are dysregulated in preeclampsia as compared to normal pregnancy, however, a complete appreciation of the effect of changing concentrations of these factors on endothelial function is lacking. In this study, we evaluate the effect of a variety of growth factors and cytokines on Ca2+ signaling and monolayer integrity. We report that VEGF165, TNFα, EGF, and IL-1ß either improve or inhibit Ca2+ signaling depending on dose, whereas TNFα and IL-1ß reduce monolayer integrity and bFGF increases monolayer integrity. Additionally, to model the effects of combinations of growth factors and cytokines, we screened for Ca2+ signaling changes in response to 16 dose combinations of VEGF165 and TNFα together. This revealed an optimal combination capable of supporting pregnancy-adapted Ca2+ signaling, and that changes in either VEGF165 or TNFα dose would result in a shift toward suppressed function. This study shows in detail how growth factor or cytokine concentration effects endothelial cell function. Such data can be used to model how changing growth factor and cytokine levels in normal pregnancy may contribute to healthy endothelial function and in preeclampsia may promote endothelial dysfunction. The results of VEGF165 and TNFα combination treatments suggest that more complex growth factor and cytokine combination modeling may be important in order to more accurately understand the effects of circulating factors on the endothelial function.
Subject(s)
Calcium Signaling , Cytokines/metabolism , Endothelial Cells/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Pre-Eclampsia/metabolism , Female , Human Umbilical Vein Endothelial Cells , Humans , PregnancyABSTRACT
Sustained Ca2+ burst signaling is crucial for endothelial vasodilator production and is disrupted by growth factors and cytokines. Conjugated linoleic acid (CLA), a Src inhibitor in certain preparations, is generally regarded as safe during pregnancy by the FDA. Multiple CLA preparations; t10, c12 or c9, t11 CLA, or a 1:1 mixture of the two were administered before growth factor or cytokine treatment. Growth factors and cytokines caused a significant decrease in Ca2+ burst numbers in response to ATP stimulation. Both t10, c12 CLA and the 1:1 mixture rescued VEGF165 or TNFα inhibited Ca2+ bursts and correlated with Src-specific phosphorylation of connexin 43. VEGF165, TNFα, and IL-6 in combination at physiologic concentrations revealed IL-6 amplified the inhibitory effects of lower dose of VEGF165 and TNFα. Again, the 1:1 CLA mixture was most effective at rescue of function. Therefore, CLA formulations may be a promising treatment for endothelial dysfunction in diseases such as preeclampsia.
Subject(s)
Calcium Signaling/drug effects , Connexin 43/metabolism , Cytokines/pharmacology , Human Umbilical Vein Endothelial Cells/metabolism , Intercellular Signaling Peptides and Proteins/pharmacology , Linoleic Acids, Conjugated/pharmacology , Adenosine Triphosphate/pharmacology , Fibroblast Growth Factor 2/pharmacology , Human Umbilical Vein Endothelial Cells/drug effects , Humans , Isomerism , Phosphorylation/drug effects , Phosphotyrosine/metabolism , Regression Analysis , Tumor Necrosis Factor-alpha/pharmacology , Vascular Endothelial Growth Factor A/pharmacologyABSTRACT
Pregnancies with mean yolk sac diameter>or=5 mm on early ultrasound require monitoring and counseling about a threefold increased risk for first-trimester loss independent of maternal risk factors such as age, body mass index, polycystic ovary syndrome, smoking, and diabetes. In addition, our study shows for the first time that enlarged yolk sac diameter may be associated with an increased risk of preterm delivery.
