Characterisation of cardiac health in the reduced uterine perfusion pressure model and a 3D cardiac spheroid model, of preeclampsia

Abstract

Background Preeclampsia is a dangerous cardiovascular disorder of pregnancy that leads to an increased risk of future cardiovascular and metabolic disorders. Much of the pathogenesis and mechanisms involved in cardiac health in preeclampsia are unknown. A novel anti-angiogenic protein, FKBPL, is emerging as having a potential role in both preeclampsia and cardiovascular disease (CVD). Therefore, in this study we aimed to characterise cardiac health and FKBPL regulation in the rat reduced uterine perfusion pressure (RUPP) and a 3D cardiac spheroid model of preeclampsia. Methods The RUPP model was induced in pregnant rats and histological analysis performed on the heart, kidney, liver and placenta (n ≥ 6). Picrosirius red staining was performed to quantify collagen I and III deposition in rat hearts, placentae and livers as an indicator of fibrosis. RT-qPCR was used to determine changes in Fkbpl, Icam1, Vcam1, Flt1 and Vegfa mRNA in hearts and/or placentae and ELISA to evaluate cardiac brain natriuretic peptide (BNP45) and FKBPL secretion. Immunofluorescent staining was also conducted to analyse the expression of cardiac FKBPL. Cardiac spheroids were generated using human cardiac fibroblasts and human coronary artery endothelial cells and treated with patient plasma from normotensive controls, early-onset preeclampsia (EOPE) and late-onset preeclampsia (LOPE); n = 3. FKBPL and CD31 expression was quantified by immunofluorescent labelling. Results The RUPP procedure induced significant increases in blood pressure (p < 0.001), collagen deposition (p < 0.001) and cardiac BNP45 (p < 0.05). It also induced a significant increase in cardiac FKBPL mRNA (p < 0.05) and protein expression (p < 0.01). RUPP placentae also exhibited increased collagen deposition and decreased Flt1 mRNA expression (p < 0.05). RUPP kidneys revealed an increase in average glomerular size (p < 0.05). Cardiac spheroids showed a significant increase in FKBPL expression when treated with LOPE plasma (p < 0.05) and a trend towards increased FKBPL expression following treatment with EOPE plasma (p = 0.06). Conclusions The rat RUPP model induced cardiac, renal and placental features reflective of preeclampsia. FKBPL was increased in the hearts of RUPP rats and cardiac spheroids treated with plasma from women with preeclampsia, perhaps reflective of restricted angiogenesis and inflammation in this disorder. Elucidation of these novel FKBPL mechanisms in cardiac health in preeclampsia could be key in preventing future CVD.

Impact of reduced uterine perfusion pressure model of preeclampsia on metabolism of placenta, maternal and fetal hearts

“…We have also recently shown in this model increased cardiac expression of the anti-angiogenic protein, FKBPL, and the presence of placental and cardiac fibrosis 26 . Given the significant association between preeclampsia and CVD, a more thorough investigation of cardiac health in the RUPP model is required.…”

“…Time-mated pregnant Sprague–Dawley rats were purchased from the Animal Resources Centre (ARC) and were fed a standard sterile chow diet with water access ad libitum. On gestational day (GD) 14, pregnant rats were randomised to the Sham (control; n = 8) or RUPP (n = 7) procedure as previously described 15 , 26 , 27 . Briefly, silver clips were applied to the aorta above the iliac bifurcation (0.203 mm ID) and both the right and left uterine arcades (0.100 mm ID) to reduce the blood flow to the uterus by ~ 40% in the RUPP group whereas rats in the Sham (control) group underwent a similar procedure, without clips being applied.…”

“…Maternal hearts, placentae and embryo hearts were collected, weighed and snap frozen in liquid N 2 . All clinical phenotyping, placental and embryo data for these rats were reflective of the preeclampsia phenotype as published previously 26 and reproduced here with permission (Table 1 ). For this study, five matching maternal hearts, placenta and fetal hearts were available from each group for downstream metabolomic analysis as described below.…”

“… Unpaired Student’s t-test or Mann–Whitney test were used depending on data distribution. This figure was originally published in Biology of Sex Differences and used with permission 26 ( https://doi.org/10.1186/s13293-021-00376-1 ). BP blood pressure, LV left ventricular, MABP mean arterial blood pressure, RUPP reduced uterine perfusion pressure.…”

“…This figure was originally published in Biology of Sex Differences and used with permission 26 ( https://doi.org/10.1186/s13293-021-00376-1 ).…”