Biomarkers of Maternal Cardio-vascular Dysfunction in Pregnancies Complicated by Hypertensive Disorders of Pregnancy

Profound and concomitant cardiovascular hemodynamic changes, necessary to support fetoplacental development and its increasing supply demands, occur during a physiological pregnancy characterized by an increase in cardiac output, heart rate and plasma volume, and fall in vascular resistance and blood pressure. The result of these changes is a volume overload that will lead to a compensatory transient left ventricular eccentric hypertrophy. This, together with the pro-inflammatory state typical of pregnancy, represents the pregnancy as a stress-test for the maternal cardiovascular system. Pregnancies complicated by hypertensive disorders of pregnancy (HDP), particularly those with early onset and/or complicated by intrauterine fetal growth restriction (FGR), are characterized by a cardiovascular maladaptation. Women who experienced HDP in pregnancy, especially pre-eclampsia (PE), more often develop later in life ischemic heart disease, hypertension and stroke, obesity, dyslipidemia, and end-stage renal disease.

Regardless its clinical impact, very little knowledge is available on the mechanisms by which PE could lead to cardiovascular disease (CVD), and, especially, to heart failure after pregnancy. Preliminary results suggest a cross-talk between pregnancy-induced biomarkers and cardio-vascular system. Particularly, cultures of neonatal rat cardiomyocytes and fibroblasts were used to investigate the role of the serum of women with HDP in regulating their proliferation. 5-ethynyl-2'-deoxyuridine (EdU) was administered to label DNA synthesis in proliferating cells. After 3 days of in vitro culture, EdU incorporation was analyzed upon immunofluorescence staining using specific antibodies by high content microscopy. A possible protective effect exerted by the selected sera against apoptosis was evaluated, as well, by Caspase activation. Moreover, the effect of cardiomyocytes and fibroblasts proliferation and apoptosis on maternal hemodynamic parameters was evaluated using median regression models. These data show that the serum of women with HDP triggers a net increase in the percentage of proliferating cardiomyocytes compared to controls. Moreover, there were relationship between cardiomyocytes and fibroblasts proliferation and maternal hemodynamics parameters thus, supporting the hypothesis that the serum of women with HDP may contain factors capable of stimulating cardiac cells in response to the cardiovascular stress-test