Rat Model Of Preeclampsia Research Articles

NAD+ depletion is central to placental dysfunction in an inflammatory subclass of preeclampsia.

Preeclampsia (PE) is a hypertensive disorder of pregnancy and a major cause of maternal/perinatal adverse health outcomes with no effective therapeutic strategies. Our group previously identified distinct subclasses of PE, one of which exhibits heightened placental inflammation (inflammation-driven PE). In non-pregnant populations, chronic inflammation is associated with decreased levels of cellular NAD+, a vitamin B3 derivative involved in energy metabolism and mitochondrial function. Interestingly, specifically in placentas from women with inflammation-driven PE, we observed the increased activity of NAD+-consuming enzymes, decreased NAD+ content, decreased expression of mitochondrial proteins, and increased oxidative damage. HTR8 human trophoblasts likewise demonstrated increased NAD+-dependent ADP-ribosyltransferase (ART) activity, coupled with decreased mitochondrial respiration rates and invasive function under inflammatory conditions. Such adverse effects were attenuated by boosting cellular NAD+ levels with nicotinamide riboside (NR). Finally, in an LPS-induced rat model of inflammation-driven PE, NR administration (200 mg/kg/day) from gestational days 1-19 prevented maternal hypertension and fetal/placental growth restriction, improved placental mitochondrial function, and reduced inflammation and oxidative stress. This study demonstrates the critical role of NAD+ in maintaining placental function and identifies NAD+ boosting as a promising preventative strategy for PE.

Protective effect of metformin on the NG-nitro-l-arginine methyl ester (l-NAME)-induced rat models of preeclampsia

Protective effect of metformin on the NG-nitro-l-arginine methyl ester (l-NAME)-induced rat models of preeclampsia

Low molecular weight heparins promote migration and invasion of trophoblast cells through regulating the PI3K/AKT signaling pathway.

Pregnant women confront a high risk of mortality due to preeclampsia (PE), which also results in severe challenges for newborns. Due to their efficient properties and minimal side effects, low molecular weight heparins (LMWHs) are extensively utilized by optimizing their molecular size. Nevertheless, there have been no reports regarding the alleviating effect of LMWHs on PE and the molecular mechanism underlying it. To examine the therapeutic impact of LMWHs on PE, we initially created a PE rat model and assessed the advantages of LMWHs on PE through Western blot, immunofluorescence, TUNEL, 24-h proteinuria determination, and other techniques. Furthermore, we examined the in vitro molecular mechanism of LMWHs therapy on PE using CCK-8, Transwell, Flow cytometry, Wound healing assay, and other techniques. LMWHs, when used in vivo, reduced the rise in blood pressure and 24-h proteinuria in rat models of PE. Additionally, they prevented trophoblast cell apoptosis in these rat models. In vitro, LMWHs demonstrated a significant ability to enhance the migration and invasion of HTR-8 and JEG-3 cells. Mechanistically, LMWHs mitigate the development of PE by activating the PI3K/AKT signaling pathway. According to our findings, the activation of the PI3K/AKT signaling pathway by LMWHs appears to provide relief for PE. Therefore, we have compelling evidence supporting the use of LMWHs as an efficient treatment for PE.

Intrauterine growth-restricted pregnant rats, from placental ischemic dams, display preeclamptic-like symptoms: A new rat model of preeclampsia.

Preeclampsia (PE) is characterized by de novo hypertension (HTN) and is often associated with intrauterine growth restriction (IUGR). Hallmarks of PE are placental ischemia, decreased nitric oxide (NO) bioavailability, oxidative stress (OS), and organ damage in the kidneys and brain. This study aims to characterize a new model of PE using pregnant IUGR rats from hypertensive placental ischemic dams. It is hypothesized that pregnant IUGR rats from hypertensive placental ischemic dams will have elevated blood pressure (BP), OS, and organ damage. In this study, pregnant rats are divided into two groups: normal pregnant (NP) and hypertensive placental ischemic dams (RUPP). Offspring from NP and RUPP dams were mated at 10 weeks of age to generate pregnant IUGR (IUGR Preg) and pregnant control (CON Preg) rats. BP and other markers of PE were evaluated during late gestation. Pregnant IUGR rats had elevated BP and systemic OS. The maternal body weight of pregnant IUGR rats and their pups' weights were decreased, while the brains were enlarged with elevated OS. In summary, pregnant IUGR rats, born from hypertensive placental ischemic dams, have HTN and increased systemic and brain OS, with larger brain sizes and smaller pups. Furthermore, this study shows that pregnant IUGR rats exhibit a preeclamptic-like phenotype, suggesting a new epigenetic model of PE.

FOXP2 overexpression upregulates LAMA4 expression and thereby alleviates preeclampsia by regulating trophoblast behavior

Preeclampsia (PE) is a common pregnancy disorder characterized by hypertension and proteinuria. Trophoblast behavior severely affect PE progression. Transcription factor Forkhead box protein P2 (FOXP2) was involved in cell migration and invasion, but its role in PE progression remains unknown. Laminin subunit alpha 4 (LAMA4) was predicted as a downstream gene of FOXP2 and related to PE. Thus, we supposed that FOXP2 might regulate PE by regulating LAMA4. We found the decreased FOXP2 expression in patients with PE compared with healthy pregnant women. The rat model of PE was induced by L-NAME oral gavage. FOXP2 overexpression lowered systolic and diastolic blood pressure and restored pathological changes of rats with PE. Trophoblasts under the hypoxia/reoxygenation (H/R) treatment were used to mimic PE in vitro. The results revealed that FOXP2 overexpression inhibited apoptosis but promoted migration, invasion, and angiogenesis of H/R-treated trophoblasts. Dual luciferase and chromatin immunoprecipitation-polymerase chain reaction assays confirmed that FOXP2 transcriptionally upregulated the LAMA4 expression in trophoblasts. LAMA4 knockdown reversed the migration and invasion-promoting role of FOXP2 overexpression in trophoblasts with H/R treatment. Collectively, our findings suggest that the FOXP2/LAMA4 axis regulates PE by suppressing trophoblast apoptosis and promoting its migration, invasion, and angiogenesis.

1,25-Dihydroxyvitamin D3 protects against placental inflammation by suppressing NLRP3-mediated IL-1β production via Nrf2 signaling pathway in preeclampsia

BackgroundMaternal vitamin D deficiency is associated with an increased risk of preeclampsia, a potentially life-threatening multi-system disorder specific to human pregnancy. Placental trophoblast dysfunction is a key factor in the development of preeclampsia, and the activation of NOD-like receptor protein 3 (NLRP3) inflammasome may play a crucial role in this process. Previous studies have suggested that vitamin D can exert beneficial effects by suppressing inflammasome activation, but the underlying mechanism has not been fully elucidated. This study aims to explore the protective effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on the placenta and to investigate the mechanisms by which 1,25(OH)2D3 attenuates NLRP3 inflammasome activation in a rat model of preeclampsia and hypoxia-cultured placental trophoblast cells. ResultsOur findings demonstrated that supplementation of rats with 1,25(OH)2D3 mitigated placental inflammation and prevented multi-organ dysfunction associated with preeclampsia. Treatment with 1,25(OH)2D3 inhibited inflammasome-mediated inflammation in trophoblast cells via its receptor VDR by reducing the expression of NLRP3, caspase-1, and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), decreasing IL-1β production, reducing mitochondrial reactive oxygen species generation, and enhancing the expression and enzymatic activity of Cu/Zn-superoxide dismutase (SOD). Mechanistically, 1,25(OH)2D3 upregulated nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, subsequently suppressing NLRP3-mediated IL-1β overproduction in trophoblast cells. ConclusionsOur study indicates that 1,25(OH)2D3 inhibits NLRP3-mediated inflammation in trophoblast cells during preeclampsia by stimulating the Nrf2 signaling pathway and inhibiting oxidative stress.

Hypertension and Cognitive Dysfunction in a Pregnant Rat Model of PE; a Role for CD4+ T Cells.

Preeclampsia (PE) is associated with hypertension (HTN) during pregnancy and activated CD4+ T cells, inflammatory cytokines, and autoantibodies to the angiotensin II type I receptor (AT1-AA). Having had COVID-19 (CV) during pregnancy is associated with an increased incidence of a PE-like phenotype. Both PE and CV have long-lasting neurological implications and studies show that nonpregnant COVID patients produce AT1-AA. We have shown that CD4+ T cells from PE women cause a PE phenotype in nude athymic rats. In this study, we sought to examine the role of CD4+ T cells from PE with a CV History (Hx) to contribute to a PE phenotype and to determine the importance of CD4+ T cells in cognitive dysfunction during pregnancy. At delivery, blood and placentas were collected, and one million placental CD4+ T cells from each PE and each normotensive patient, with (NT) or without (NP) a CV (Hx) during pregnancy, were isolated, purified, and injected i.p. into a gestational day (GD) 12 pregnant nude athymic rat (one patient/rat). At GD19, blood pressure (MAP) and circulating factors were assessed in recipient rats. Cognitive function and memory were assessed using Novel Object Recognition and Barnes Maze tests, respectively. Placental ACE-2 activity and AT1-AA were measured from COVID Hx patients. A one- or two-way ANOVA with Bonferroni's multiple comparisons test was used for statistical analysis. Blood pressure was increased in patients with PE, with or without COVID, compared to NT patients. There were no significant changes in placental ACE activity in patients with COVID Hx with or without PE. AT1-AA was elevated in PE patients and in both PE and NT COVID Hx compared to control NP. In pregnant recipient rats, MAP increased in CV Hx PE (113±2, n=8) compared to CV Hx NT (101±5, n=6). PE and PE CV Hx CD4+ T Cell recipient rats exhibited impaired memory and cognitive dysfunction (p < 0.05), compared to control groups. Recipient rats of PE CV Hx CD4+ T cells had elevated AT1-AA compared to NT CV Hx recipients. Both COVID Hx groups and recipients of PE CD4+ T cells had elevated TNF alpha compared to NP. Our findings indicate that pregnant patients with a Hx of COVID during pregnancy produce AT1-AA, with or without PE. Recipients of CD4+ T cells from PE with or without a CV Hx during pregnancy cause HTN and elevated AT1-AA. TNF-α is elevated in PE and in CV Hx NT and PE recipients. Interestingly, recipients of T cells from PE patients with or without a Hx of CV had worse cognitive function during pregnancy, compared to recipient rats of NP CD4+ T cells. These data demonstrate the importance of CD4+ T cells in HTN and impaired neurological function during PE in the presence or absence of a prior COVID-19 infection during pregnancy.

Dysregulated Mitochondrial Calcium Causes Spiral Artery Remodeling Failure in Preeclampsia.

Calcium deficiency in women is strongly linked to an increased risk of developing preeclampsia. Mitochondrial calcium ([Ca2+]m) homeostasis is essential to regulate vascular smooth muscle cell (VSMC) function. However, the role of [Ca2+]m in preeclampsia development remains largely unknown. To investigate this, human spiral arteries obtained from normotensive and preeclamptic women were collected for vascular function, RNA sequencing, and VSMC studies. N(ω)-nitro-L-arginine methyl ester-induced preeclampsia animal experiments were established to investigate the effects of intervening in [Ca2+]m to improve the outcome for preeclamptic mothers or their infants. Our initial findings revealed compromised vessel function in spiral arteries derived from patients with preeclampsia, as evidenced by diminished vasoconstriction and vasodilation responses to angiotensin II and sodium nitroprusside, respectively. Moreover, the spiral artery VSMCs from patients with preeclampsia exhibited phenotypic transformation and proliferation associated with the disrupted regulatory mechanisms of [Ca2+]m uptake. Subsequent in vitro experiments employing gain- and loss-of-function approaches demonstrated that the mitochondrial Na+/Ca2+ exchanger played a role in promoting phenotypic switching and impaired mitochondrial functions in VSMCs. Furthermore, mtNCLX (mitochondrial Na+/Ca2+ exchanger) inhibitor CGP37157 significantly improved VSMC phenotypic changes and restored mitochondrial function in both patients with preeclampsia-derived VSMCs and the preeclampsia rat model. This study provides comprehensive evidence supporting the disrupted regulatory mechanisms of [Ca2+]m uptake in VSMCs of spiral arteries of patients with preeclampsia and further elucidates its correlation with VSMC phenotypic switching and defective spiral artery remodeling. The findings suggest that targeting mtNCLX holds promise as a novel therapeutic approach for managing preeclampsia.

GPER Stimulation Attenuates Cardiac Dysfunction in a Rat Model of Preeclampsia.

Preeclampsia poses a substantial clinical challenge, characterized by maternal hypertension, cardiac dysfunction, and persistent cardiovascular risks for both the mother and offspring. Despite the known roles of the estrogen receptor (GPER [G protein-coupled estrogen receptor]) in placental development, its impact on cardiovascular aspects within a preeclampsia animal model remains unexplored. We propose that G-1, a GPER agonist, could have the potential to regulate not only hypertension but also cardiac dysfunction in rats with preeclampsia. To explore the influence of G-1 on preeclampsia, we used the reduced uterine perfusion pressure (RUPP) model. RUPP rats were administered either G-1 (100 µg/kg per day) or hydralazine (25 mg/kg per day). We conducted echocardiography to probe the intricate cardiac effects of G-1. The RUPP rat model revealed signs of hypertension and cardiac dysfunction and alterations in gene and protein expression within placental and heart tissues. G-1 treatment reduced blood pressure and reversed cardiac dysfunction in rats with preeclampsia. In contrast, administration of the vasodilator hydralazine reduced blood pressure without an improvement in cardiac function. In addition, while G-1 treatment restored the levels of sFLT-1 (soluble fms-like tyrosine kinase-1) in RUPP rats, hydralazine did not normalize this antiangiogenic factor. The therapeutic intervention of G-1 significantly mitigated the cardiovascular dysfunction observed in the RUPP rat model of preeclampsia. This discovery underscores the broader significance of understanding GPER's role in the context of preeclampsia-related cardiovascular complications.

Abstract P122: Aberrant MicroRNA Expression May Underlie Cardiac Dysfunction in a rat model of Preeclampsia

Introduction: Preeclampsia (PE) patients exhibit left ventricular (LV) hypertrophy and dysfunction during pregnancy. While these clinical findings have been recapitulated in a PE animal model (reduced uterine perfusion pressure; RUPP), mechanisms underlying such adverse cardiac outcomes have not yet been explored. A few recent studies involving models of heart failure have shown that pathogenic effects of microRNAs (miRNAs) are attributed to their regulatory actions on cardiac mitochondria. Hypothesis: Inspired by this literature, we set out to test the hypothesis that cardiac dysfunction in PE is mediated by abnormal miRNA expression, and the resulting mitochondrial dysfunction within the myocardium. Methods: PE was induced in pregnant Sprague Dawley (SD) on gestational day(GD)14. After blood pressure measurements (carotid catheterization) on GD19, whole hearts were excised, weighed, and ventricular tissue was used for miRNA (Qiagen’s miRNeasy Micro Kit) and mitochondria (differential centrifugation) isolations. Small RNA sequencing(s-RNA seq) and mitochondrial experiments were performed by Illumina sequencer (NEXTFLEX Kit) and Oxygraph-2K, respectively. Differentially expression (diff-exp) analysis was conducted using DESeq2 in R (fold change=2, adj p=0.05). Results: PE phenotype in RUPP rats was confirmed by elevated MAP (116.1±1.83 vs.101.3±2.93 mmHg, p=0.0008,n=8) on GD19. Normalized heart weight was higher in RUPPs (0.0033 ±9.98e-005 vs. 0.0029±0.00014, p=0.05, n=7-8) suggesting a hypertrophied heart. S-RNA seq revealed a total of 53 (21 up and 32 down) diff-exp miRNAs in RUPP vs. control rats. The top 5 up (miR-741-5p, miR-1-5p, miR-1b, miR-30b-5p, let-7d-3p) and down (miR-871-5p, miR-2985, miR-185-3p, miR-494-3p, miR-1839-3p) regulated miRNAs included transcripts (miR-1 and miR-494-3p) shown to be implicated in cardiac remodeling. Further, complex III activity was reduced (1785±186.1 vs.2468±223.8nmol e - /min/mg, p=0.03, n=8) in RUPPs with accompanying increased trend in ROS levels (1.34±0.22 vs. 0.84±0.13nmol e - /min/mg, n=8, p=0.07) although activities of other complexes or oxygen consumption rates were unchanged. Conclusions: To the best of our knowledge, this is the first study to demonstrate abnormal expression of cardiac miRNAs in association with reduced cardiac mitochondrial function in the RUPP rat model of PE. Our ongoing work will determine whether these dysregulated miRNAs contribute to cardiac dysfunction via mitochondrial perturbations.

Abstract 16: A Novel H2 Relaxin B-Chain-Only Peptide Variant B7-33 Improves The Pathophysiology Of Placental Ischemia In The Reduced Uterine Perfusion Pressure Rat Model Of Preeclampsia

Background: Preeclampsia (PE) is a hypertensive pregnancy disorder, which occurs in approximately 10% of all gestations. The literature suggests the potential therapeutic role of H2 relaxin in PE. A novel H2 relaxin B-chain-only peptide variant B7-33 (27 amino acids without any disulfide bonds) has recently been developed. Objective: The goal of this study was to test the hypothesis that a novel H2 relaxin B-chain-only peptide variant B7-33 could improve the pathophysiology of placental ischemia in the Reduced Uterine Perfusion Pressure (RUPP) rat model of PE. Methods: The efficacy of B7-33 was evaluated in the RUPP model as described previously. RUPP rats are randomly assigned to 4 groups (N=8/group): 1) vehicle, 2) B733; 3) B733-Fc; and 4) B733-HSA. Rats are dosed twice weekly (i.v.) from GD10 to GD 20. On GD 18, rats are anesthetized with isoflurane, and carotid arterial catheters are inserted into the carotid artery, tunneled under the skin, and externalized at the back of the neck. On the following day, mean arterial pressure (MAP) is monitored with a pressure transducer (Cobe III Tranducer CDX Sema) and recorded continuously for 30 min. On GD18, uterine artery resistance index (UARI) of rats is measured by Doppler sonography. The nitric oxide bioavailability, soluble fms-like tyrosine kinase-1 (sFlt-1), and TNF-α) were measured by commercially available kits. Statistical comparisons were performed using analysis of variance with Duncan’s post hoc test. Results: The RUPP rats have increased MAP (122.2 ± 8.1 mm Hg), plasma TNF-α (223 ±11.4 pg/mL), and plasma sFlt-1(863 ±18.2 pg/mL) along with decreased NO index (14±2 µM) compared to normal pregnancy: MAP (102 ± 5.2 mm Hg); plasma TNF-α (28 ± 4.1 pg/mL); plasma sFlt-1(244 ± 9.4 pg/mL) and NO index (26 ±4.1 µM). Treatment with B733 and B7-33 fusion proteins significantly (*p&lt;0.05) lowers MAP, plasma TNF-α, and plasma sFlt-1 and increased NO index back to that of normal pregnancy. The B7-33 data are consistent with earlier data with serelaxin in the RUPP model. All fusions tested ameliorate hypertension in the RUPP animals. B7-33 normalizes BP and proteinuria in the DOCA rat model of preE. Conclusion: The conclusion of the study is that both B7-33 and B7-33 fusion proteins demonstrate efficacy in attenuating the symptoms of PE including hypertension and inflammation in RUPP model. We conclude that B7-33 is an ideal candidate for development as a novel therapeutic in preE.

Abstract 65: Postpartum Alterations of Middle Cerebral Artery Reactivity and Hemodynamics in a Transgenic Rat Model of Preeclampsia

Evidence suggests that cerebrovascular disease is a leading cause of morbidity and mortality in women with preeclampsia (PE), however the mechanisms are unknown. In a transgenic rat displaying PE-like syndrome (TGA-PE: female transgenic for angiotensinogen mated to male transgenic for renin), we have shown postpartum alterations in cerebrovascular hemodynamics suggesting dysfunctional autoregulation. We hypothesize that impaired middle cerebral artery (MCA) reactivity contributes to the cerebrovascular dysfunction in this model. High frequency ultrasound was used to determine the pulsatility index (PI) of left MCA (LMCA). Vascular responses were studied in isolated segments of LMCA from SD (n= 12) and TGA-PE (n=8) two months post-delivery. Arteries were mounted on a Multi-Wire Myograph for determination of isometric force (USA-DMT). The contractile responses to K + 75 mM and endothelin-1 (ET-1, 10 -11 -10 -7 M) were measured in basal tone. Vasodilatory responses to acetylcholine (ACh, 10 -11 -10 -4 M) were determined in arteries pre-constricted with the thromboxane agonist U46619 (10 -7 M); the maximal response ( R MAX ) and sensitivity (pD 2 =-Log[EC 50 ]) were analyzed. Our data show that systolic blood pressures were elevated in TGA-PE versus SD at 2 months post-delivery (144.9±2.7 vs. 118.4±2.5, p&lt;0.05; n=10-19). However, the PI was lower in TGA-PE vs. SD (0.96±0.05 vs. 1.31±0.06; p&lt;0.05, n=8-13). No differences in basal tone of MCA segments were observed, whereas TGA-PE arteries displayed a lower optimal diameter (175±4 μm vs. 217±4 μm; p&lt;0.05) and a lower response to K + (0.85±0.11 vs. 1.29±0.1 mN/mm; p&lt;0.05) compared to SD. Vasodilatation to acetylcholine was similar (ACh MAX : 79±8 vs. 70±9%) with a lower sensitivity (pD 2 : 5.2±0.1 vs. 6.7±0.4; p&lt;0.05) in TGA-PE. The contractile response to ET-1 was increased in TGA-PE arteries (ET-1 MAX : 159±7 vs. 129±6 % K MAX ; p&lt;0.05) with no differences in sensitivity (pD 2 : 8.8±0.1 vs. 8.9±0.1). Our data demonstrate structural and functional differences in MCA from TGA-PE vs. SD at 2 months postpartum. In addition to a smaller functional diameter, a lower non-receptor dependent contraction may explain the lower resistance of MCA observed in the preeclamptic model. We conclude that attenuated vasodilatory and increased contractile responses of MCA could promote cerebrovascular dysfunction in this model, and that these adaptations may contribute to cerebrovascular pathology in postpartum preeclamptic state. Supported by NIH 1R01HL155420

Abstract P193: Adoptive transfer of placental CD4+ T Cells from preeclamptic patients with a history of COVID-19 causes hypertension and cognitive dysfunction postpartum in a pregnant rat model of preeclampsia

Preeclampsia (PE), new onset hypertension (HTN) during pregnancy, is associated with activated CD4+ T cells, impaired cognitive function, and changes in cerebral blood flow (CBF) autoregulation. Previously, PE women have been shown to develop neurovascular and cardiovascular disorders earlier in life than those that had uneventful pregnancy. COVID-19 (CV) during pregnancy is associated with an increase incidence of the PE phenotype and is also associated with chronic neurovascular and cardiovascular consequences. Previously, we showed adoptive transfer of placental CD4+ T cells from PE women into athymic nude pregnant rats causes a PE phenotype, however we don’t know the role of CD4+ T cells to cause long-term neurovascular or cardiovascular consequences in PE in the presence or absence of a history (Hx) of COVID-19 during pregnancy. Therefore, we hypothesize that CD4+ T cells from PE patients with and without a Hx of CV causes hypertension and neurovascular dysfunction compared to CD4+ T cells from normotensive patients. One million placental CD4+ T cells from Normotensive (NT), CV Hx NT, and PE patients with or without a CV Hx were isolated and injected interperitoneally (i.p.) into pregnant nude athymic rats on gestational day (GD) 12. Dams were allowed to deliver and aged 12-weeks after delivery. At 12-weeks postpartum, blood pressure (MAP) was measured; CBF autoregulation was measured by laser Doppler flowmetry. The Barnes maze and the novel object recognition behavioral assays were used to assess cognitive function 12-weeks postpartum. A two-way ANOVA was used for statistical analysis. At 12-weeks postpartum, MAP increased in CV Hx PE (153±6, n=7, p&lt;0.05) and PE (150±5 mmHg, n=5, p&lt;0.05) compared to CV Hx NT (121±6, n=6) and NT (116±6 mmHg, n=6), respectively. Behavioral analysis showed CV Hx PE and PE exhibited impaired memory and learning (P&lt;0.05) compared to either NT group. Our findings indicate that rat recipients of CD4+ T cells from PE patients in the presence or absence of CV Hx have HTN and cognitive dysfunction in the postpartum period compared to recipients of control CD4 + T cells. These data indicate the importance of CD4+ T cells in long-term consequences of PE and COVID infection during pregnancy.

Placental ischemia-upregulated angiotensin II type 1 receptor in hypothalamic paraventricular nucleus contributes to hypertension in rat.

Preeclampsia (PE) is associated with increased angiotensin II sensitivity and poor neurological outcomes marked by temporal loss of neural control of blood pressure. Yet the role of centrally expressed angiotensin II type 1 receptor (AT1R) within the paraventricular nucleus of the hypothalamus (PVN) in the PE model is not understood. In a PE rat model with reduced placental perfusion pressure (RUPP) induced on gestational day 14 (GD14), the PVN expression and cellular localization of AT1R were assessed using immunofluorescence and western blotting. The sensitivity of RUPP to acute angiotensin II infusion was assessed. AT1R was antagonized by losartan (100µg/kg/day) for 5days intracerebroventricularly (ICV). Hemodynamic data and samples were collected on GD19 for further analysis. RUPP upregulated (p < 0.05) mRNA and protein of AT1R within the PVN and lowered (p < 0.05) circulating angiotensin II in rats. RUPP increased neural and microglial activation. Cellular localization assessment revealed that AT1R was primarily expressed in neurons and slightly in microglia and astrocytes. Infusion of 100ng/kg as bolus increased the mean arterial pressure (MAP in mmHg) in both RUPP and Sham. ICV losartan infusion attenuated RUPP-increased MAP (113.6 ± 6.22 in RUPP vs. 92.16 ± 5.30 in RUPP + Los, p = 0.021) and the expression of nuclear transcription factor NF-κB, tyrosine hydroxylase (TH), NADPH oxidase 4 (NOX4) and reactive oxygen species (ROS) in the PVN. Our data suggest that centrally expressed AT1R, within the PVN, contributes to placental ischemia-induced hypertension in RUPP rats highlighting its therapeutic potential in PE.

The anti-hypertensive effects of Dombeya rotundifolia in an arginine vasopressin rat model of pre-eclampsia

The anti-hypertensive effects of Dombeya rotundifolia in an arginine vasopressin rat model of pre-eclampsia

Human amniotic epithelial cells improve uterine spiral artery remodeling to ameliorate preeclampsia in a rat model†.

Preeclampsia (PE) is a multisystem pregnancy disorder characterized by impaired remodeling of placental spiral arteries, which leads to the release of pro-inflammatory cytokines and anti-angiogenic agents. However, treatment options for PE are limited, with termination of pregnancy being the only curative option. In this work, we investigated the effects of human amniotic epithelial cells (hAECs) in PE rat model. The rats were induced with lipopolysaccharide (LPS) on gestational day 14.5 followed by injection of hAECs and human umbilical cord mesenchymal stem cells 24h later. The hAECs treatment resulted in a reduction in blood pressure and proteinuria in the PE rat model. Furthermore, hAECs treatment decreased levels of pro-inflammatory cytokines, reduced inflammatory cells aggregation, and alleviated the damage to placental spiral arteries by downregulating the expression of anti-angiogenic factor and upregulating proangiogenic factor. In vitro experiments confirmed that hAECs treatment restored the proliferation, migration, and angiogenesis of LPS-damaged human umbilical vein endothelial cells. Additionally, hAECs treatment had positive effects on fetal weight and neurological development in the PE group, with no negative effects on the physical development or fertility of offspring rats. These results suggested that hAECs transplantation may be a novel adjuvant therapeutic strategy for PE by reducing the inflammatory and enhancing placental spiral artery angiogenesis.

Therapeutic effect of E-Lip-siRNA-sFlt1 on pre-eclampsia: targeted gene silencing and improved pregnancy outcomes.

Aim: To evaluate a liposome complex conjugated with anti-epidermal growth factor receptor (EGFR) antibodies for the treatment of pre-eclampsia (PE).Methods: In in vitro experiments, the transfection rate, silencing effect and cytotoxicity were determined. In the in vivo PE model, the siRNA distribution, mean arterial pressure, 24-h urine protein concentration, serum sFlt1 concentration, number of viable fetuses and placental weight were measured.Results: The nanomedicine effectively reduced the expression of sFIt1 and had a strong ability to target placental tissues. It could significantly reduce the symptoms of pre-eclampsia and improve pregnancy outcomes in PE model rats.Conclusion: The constructed nanomedicine can improve pregnancy outcomes in a rat model of pre-eclampsia and provides a new strategy for the treatment of pre-eclampsia.

Altered Expression of BCRP Impacts Fetal Accumulation of Rosuvastatin in a Rat Model of Preeclampsia.

Expression of the breast cancer resistance protein (BCRP/ABCG2) transporter is downregulated in placentas from women with preeclampsia (PE) and in an immunological rat model of PE. While many drugs are substrates of this important efflux transporter, the impact of PE associated BCRP downregulation on maternal and fetal drug exposure has not been investigated. Using the PE rat model, we performed a pharmacokinetic study with rosuvastatin (RSV), a BCRP substrate, to investigate this impact. PE was induced in rats during gestational days (GD) 13 to 16 with daily low-dose endotoxin. On GD18, RSV (3 mg/kg) was administrated intravenously, and rats were sacrificed at time intervals between 0.5 and 6 h. As compared to controls, placental expression of Bcrp and Oatp2b1 significantly decreased in PE rats. A corresponding increase in RSV levels was seen in fetal tissues and amniotic fluid of the PE group (p < 0.05), while maternal plasma concentrations remained unchanged from the controls. An increase in Bcrp expression and decreased RSV concentration were seen in the livers of PE dams. This suggests that PE-mediated transporter dysregulation leads to significant changes in the maternal and fetal RSV disposition. Overall, our findings demonstrate that altered placental expression of transporters in PE can increase fetal accumulation of their substrates.

Effects of olive leaf extract and nifedipine, alone and in combination, on blood pressure, neutrophil gelatinase-associated lipocalin, malondialdehyde, and creatinine levels in an Nω-nitro-L-arginine methyl ester-induced rat model of preeclampsia

Preeclampsia (PE) is a significant health problem in pregnancy, affecting 6–7% of all gestations and leading to fetal growth retardation, infant morbidity and mortality, premature birth, and maternal death. Currently, effective treatment options for PE are limited. This study aimed to evaluate the therapeutic potential of olive leaf extract (OLE) and nifedipine, alone and in combination, in improving pregnancy outcomes in rats induced with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME). Rats were treated with single and combination treatments of nifedipine and OLE for four weeks, after being induced with L-NAME for six weeks. Following gestational day assessment and systolic blood pressure testing, the rats were sacrificed, and blood samples were collected for Neutrophil Gelatinase-Associated Lipocalin (NGAL), Malondialdehyde (MDA), proteinuria and Creatinine (SCr) Levels examinations. The results revealed the combination of nifedipine and OLE significantly improved the results of several biomarker analyses associated with PE, including increased NGAL levels, a significant decrease in MDA levels, decrease in proteinuria and elevated creatinine levels. The combination nifedipine and OLE treatment also exhibited a significant antihypertensive effect compared to either nifedipine or OLE monotherapy, as evidenced by the reduction in systolic and diastolic blood pressure levels. This study provides novel evidence for the potential of olive leaf extract as a nutraceutical adjunct for the prevention and treatment of PE. The significant improvements observed in several pathological features associated with PE, including antihypertensive effects, warrant further investigation. Future research should focus on elucidating the underlying mechanisms of action and exploring the clinical applicability of olive leaf extract in human populations with PE.

CD4+ T Cells from Women with Preeclampsia During Pregnancy Contribute to Hypertension, AT1-AA, and Neurovascular Dysfunction in a Pregnant Rat Model of PE

Objective: Preeclampsia (PE) is characterized by new onset hypertension (HTN) during pregnancy and is associated with activated CD4+ T cells and agonistic antibodies against the angiotensin II type 1 receptor (AT1-AA). Interestingly, having had COVID-19 during pregnancy is associated with increased incidence of a PE-like phenotype. Both PE and CV have long lasting neurological implications. We sought examine a role for CD4+ T cells from PE with or without a CV Hx to contribute to a PE phenotype and neurovascular dysfunction postpartum (PP). Methods: We utilized adoptive transfer of one million placental CD4+ T cells from PE and normotensive (NT) patients with or without a CV (Hx) during pregnancy injected i.p. into gestational day (GD) 12 nude athymic rats athymic and determined neurological consequences at 12 weeks PP. At GD19, blood pressure (MAP) and AT1-AA were measured. At 3 months PP, memory and error in navigation were assessed by Barnes maze consecutively for 5 days. CBF was measured by laser Doppler flowmetry. A two-way ANOVA was used for statistical analysis. Results: In pregnant recipient rats, MAP increased in CV Hx PE (113±2, n=8) and PE (115±2 mmHg, n=10) compared to CV Hx NT (104±4, n=7) and NT (98±2 mmHg, n=7 p&lt;0.05). AT1-AA increased in PE (8±2 ΔBPM, n=4) and CV Hx PE (4±2 ΔBPM, n=4) compared to NT (-3±2 ΔBPM, n=4, p&lt;0.05) and CV Hx NT (2±2 ΔBPM, n=2) respectively. At 3 months PP, PE and CV Hx PE had impaired CBF autoregulation compared to CV Hx NT and NT rats, and both PE groups exhibited greater mistakes and latency in maze navigation, however, the scores were worse in those receiving T cells from PE patients without a Hx of CV compared to all other groups. Conclusion: Our findings indicate that pregnant recipients of CD4+ T cells from PE with or without a CV Hx during pregnancy cause HTN and increased AT1-AA compared to recipients of NT or NT Hx CV-19 CD4 + T cells. Interestingly, recipients of T cells from PE patients without a Hx of CV had worse CBF and cognitive function at 3 months PP, demonstrating the importance of CD4+ T cells in HTN and impaired neurological function during pregnancy PP in patients with previous PE. This study was supported by NIH grants RO1HD067541 (BL), F31HD110230 (NC), P20GM121334 (BL, LMA), and American heart association (AHA) early career award 19CDA34670055 (LMA). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.