Gestational intermittent hypoxia induces endothelial dysfunction and hypertension in pregnant rats: role of endothelin type B receptor†.

Obstructive sleep apnea is a recognized risk factor for gestational hypertension, yet the exact mechanism behind this association remains unclear. Here, we tested the hypothesis that intermittent hypoxia, a hallmark of obstructive sleep apnea, induces gestational hypertension through perturbed endothelin-1 signaling. Pregnant Sprague-Dawley rats were subjected to normoxia (control), mild intermittent hypoxia (10.5% O2), or severe intermittent hypoxia (6.5% O2) from gestational days 10-21. Blood pressure was monitored. Plasma was collected and mesenteric arteries were isolated for myograph and protein analyses. The mild and severe intermittent hypoxia groups demonstrated elevated blood pressure, reduced plasma nitrate/nitrite, and unchanged endothelin-1 levels compared to the control group. Western blot analysis revealed decreased expression of endothelin type B receptor and phosphorylated endothelial nitric oxide synthase, while the levels of endothelin type A receptor and total endothelial nitric oxide synthase remained unchanged following intermittent hypoxia exposure. The contractile responses to potassium chloride, phenylephrine, and endothelin-1 were unaffected in endothelium-denuded arteries from mild and severe intermittent hypoxia rats. However, mild and severe intermittent hypoxia rats exhibited impaired endothelium-dependent vasorelaxation responses to endothelin type B receptor agonist IRL-1620 and acetylcholine compared to controls. Endothelium denudation abolished IRL-1620-induced vasorelaxation, supporting the involvement of endothelium in endothelin type B receptor-mediated relaxation. Treatment with IRL-1620 during intermittent hypoxia exposure significantly attenuated intermittent hypoxia-induced hypertension in pregnant rats. This was associated with elevated circulating nitrate/nitrite levels, enhanced endothelin type B receptor expression, increased endothelial nitric oxide synthase activation, and improved vasodilation responses. Our data suggested that intermittent hypoxia exposure during gestation increases blood pressure in pregnant rats by suppressing endothelin type B receptor-mediated signaling, providing a molecular mechanism linking intermittent hypoxia and gestational hypertension.

Integrative Placental Multi-Omics Analysis Reveals Perturbed Pathways and Potential Prognostic Biomarkers in Gestational Hypertension.

BACKGROUND: Gestational hypertension (GH) is a severe complication that occurs after 20 weeks of pregnancy; however, its molecular mechanisms are not yet fully understood. OBJECTIVE: Through this case-control discovery phase study, we aimed to find disease-specific candidate placental microRNAs (miRNAs) and metabolite markers for differentiating GH by integrating next-generation sequencing and metabolomics multi-omics analysis of placenta. Using small RNA sequencing and metabolomics of placental tissues of healthy pregnant (HP, n = 24) and GH subjects (n = 20), the transcriptome and metabolome were characterized in both groups. RESULTS: The study identified a total of 44 downregulated placental miRNAs which includes three novel, three mature and 38 precursor miRNAs. Six miRNAs including three mature (hsa-miR-181a-5p, hsa-miR-498-5p, and hsa-miR-26b-5p) and three novel (NC_000016.10_1061, NC_000005.10_475, and NC_000001.11_53) were considered for final target prediction and functional annotation. Integrative analysis of differentially expressed miRNAs and metabolites yielded five pathways such as purine, glutathione, glycerophospholipid, inositol phosphate and ß-alanine to be significantly perturbed in GH. We present fourteen genes (LPCAT1, LPCAT2, DGKH, PISD, GPAT2, PTEN, SACM1L, PGM2, AMPD3, AK7, AK3, CNDP1, IDH2, and ODC1) and eight metabolites (xanthosine, xanthine, spermine, glycine, CDP-Choline, glyceraldehyde 3-phosphate, ß-alanine, and histidine) with potential to distinguish GH and HP. CONCLUSION: The differential expression of miRNAs, their target genes, altered metabolites and metabolic pathways in GH patients were identified for the first time in our study. Further, the altered miRNAs and metabolites were integrated to build their inter-connectivity network. The findings obtained from our study may be used as a valuable source to further unravel the molecular pathways associated with GH and also for the evaluation of prognostic markers.

Increased angiotensin II coupled with decreased Adra1a expression enhances cardiac hypertrophy in pregnancy-associated hypertensive mice.

Cardiac hypertrophy is a crucial risk factor for hypertensive disorders during pregnancy, but its progression during pregnancy remains unclear. We previously showed cardiac hypertrophy in a pregnancy-associated hypertensive (PAH) mouse model, in which an increase in angiotensin II (Ang II) levels was induced by human renin and human angiotensinogen, depending on pregnancy conditions. Here, to elucidate the factors involved in the progression of cardiac hypertrophy, we performed a comprehensive analysis of changes in gene expression in the hearts of PAH mice and compared them with those in control mice. We found that alpha-1A adrenergic receptor (Adra1a) mRNA levels in the heart were significantly reduced under PAH conditions, whereas the renin-angiotensin system was upregulated. Furthermore, we found that Adra1a-deficient PAH mice exhibited more severe cardiac hypertrophy than PAH mice. Our study suggests that Adra1a levels are regulated by renin-angiotensin system and that changes in Adra1a expression are involved in progressive cardiac hypertrophy in PAH mice.

Increased urinary albumin leakage is related to injuries of glomerular glycocalyx and podocytes, and associated with tubular dysfunction in preeclampsia.

OBJECTIVE: The pathogenesis of preeclampsia (PE) is known to be endothelial cell damage; however, the existence of dysfunction in glomerular endothelial glycocalyx, podocytes and tubules remains unclear. The glomerular endothelial glycocalyx, basement membrane, podocytes, and tubules are permeability barriers against albumin excretion. This study aimed to assess the relationship between urinary albumin leakage and injuries of the glomerular endothelial glycocalyx, podocytes, and tubules in patients with PE. METHODS: A total of 81 women with uncomplicated pregnancies (control, n = 22), PE (PE, n = 36), or gestational hypertension (GH) (GH, n = 23) were enrolled. We assessed urinary albumin and serum hyaluronan for glycocalyx injuries, podocalyxin for podocytes injuries, and urinary N-acetyl-ß-d-glucosaminidase (NAG) and liver-type fatty acid-binding protein (l-FABP) for renal tubular dysfunctions. RESULTS: The serum hyaluronan and the urinary podocalyxin levels were higher in the PE and GH groups. The urinary NAG and l-FABP levels were higher in the PE group. Urinary NAG and l-FABP levels positively correlated with urinary albumin excretion. CONCLUSIONS: Our findings suggest that increased urinary albumin leakage is related to injuries of the glycocalyx and podocytes, and associated with tubular dysfunction in pregnant women with PE. The clinical trial described in this paper was registered at the UMIN Clinical Trials Registry under registration number UMIN000047875. URL of registration: https://centre6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000054437.

Conventional natural killer cells control vascular remodeling in the uterus during pregnancy by acidifying the extracellular matrix with a2V.

Vascular remodeling within the uterus immediately before and during early pregnancy increases blood flow in the fetus and prevents the development of gestational hypertension. Tissue-resident natural killer (trNK) cells secrete pro-angiogenic growth factors but are insufficient for uterine artery (UtA) remodeling in the absence of conventional natural killer (cNK) cells. Matrix metalloproteinase-9 (MMP9) is activated in acidic environments to promote UtA remodeling. We have previously shown that ATPase a2V plays a role in regulating the function of cNK cells during pregnancy. We studied the effect of a2V deletion on uterine cNK cell populations and pregnancy outcomes in VavCrea2Vfl/fl mice, where a2V is conditionally deleted in hematopoietic stem cells. Conventional NKcells were reduced but trNK cells were retained in implantation sites at gestational day 9.5, and UtA remodeling was inhibited despite no differences in concentrations of pro-angiogenic growth factors. The ratio of pro-MMP9 to total was significantly elevated in VavCrea2Vfl/fl mice, and MMP9 activity was significantly reduced. The pH of implantation sites was significantly elevated in VavCrea2Vfl/fl mice. We concluded that the role of cNK cells in the uterus is to acidify the extracellular matrix (ECM) using a2V, which activates MMP9 to degrade the ECM, release bound pro-angiogenic growth factors, and contribute to UtA remodeling. Our results are significant for the understanding of the development of gestational hypertension.

More Tools for Evaluating Decidual Artery Disease.

Introduction: Hypertensive disorders of pregnancy continue to pose the most important risks for adverse maternal and neonatal outcome. Among histological findings, decidual artery disease is one of the most common, one that has both good reproducibility among observers and whose abnormal vascular remodeling is the sole aspect of preeclampsia pathophysiology on which experts agree. Nevertheless, some aspects of arterial remodeling alterations are still under investigation. Methods: We selected 720 routine and consecutive placenta case studies, concordant with the Amsterdam consensus. From these studies, we collected maternal and neonatal clinical data and specific placental findings on spiral artery abnormalities. We took into account all criteria for decidual arteriopathy. Two hundred and fifteen (215) cases out of this population presented hypertensive disorders of pregnancy. Additional to expected arterial findings, we noted frequent persistent parietal trophoblast lining. Results: A large proportion of our population developed hypertensive disorders of pregnancy (30%). Among the histologic findings reported for preeclampsia, we paid particular attention to spiral artery abnormalities, and this interpretive analysis revealed high frequency of arterial remodeling abnormalities. We examined two additional aspects in our routine analysis: first, the novel one of parietal trophoblast persistence, and second, the established problem of associated acute inflammation, as a possible pitfall. Conclusion: In order to better understood, spiral maternal artery remodeling merits further study. The abnormalities in this process provide an objective tool in the study and diagnosis of important pregnancy complications; furthermore, abnormal remodeling is an expression of early pregnancy alteration, and subsequently related to preeclampsia etiology.

Serum amyloid A1 and pregnancy zone protein in pregnancy complications and correlation with markers of placental dysfunction.

BACKGROUND: Hypertensive disorders of pregnancy (preeclampsia, gestational hypertension, and chronic hypertension), diabetes mellitus, and placental dysfunction confer an increased risk of long-term maternal cardiovascular disease. Preeclampsia is also associated with acute atherosis that involves lesions of uteroplacental spiral arteries, resembling early stages of atherosclerosis. Serum amyloid A1 is involved in hypercoagulability and atherosclerosis and may aggregate into amyloid-aggregations of misfolded proteins. Pregnancy zone protein may inhibit amyloid aggregation. Amyloid is involved in Alzheimer's disease and cardiovascular disease; it has been identified in preeclampsia, but its role in preeclampsia pathophysiology is unclear. OBJECTIVE: We hypothesized that serum amyloid A1 would be increased and pregnancy zone protein decreased in hypertensive disorders of pregnancy and diabetic pregnancies and that serum amyloid A1 and pregnancy zone protein would correlate with placental dysfunction markers (fetal growth restriction and dysregulated angiogenic biomarkers) and acute atherosis. STUDY DESIGN: Serum amyloid A1 is measurable in both the serum and plasma. In our study, plasma from 549 pregnancies (normotensive, euglycemic controls: 258; early-onset preeclampsia: 71; late-onset preeclampsia: 98; gestational hypertension: 30; chronic hypertension: 9; diabetes mellitus: 83) was assayed for serum amyloid A1 and pregnancy zone protein. The serum levels of angiogenic biomarkers soluble fms-like tyrosine kinase-1 and placental growth factor were available for 547 pregnancies, and the results of acute atherosis evaluation were available for 313 pregnancies. The clinical characteristics and circulating biomarkers were compared between the pregnancy groups using the Mann-Whitney U, chi-squared, or Fisher exact test as appropriate. Spearman's rho was calculated for assessing correlations. RESULTS: In early-onset preeclampsia, serum amyloid A1 was increased compared with controls (17.1 vs 5.1 µg/mL, P<.001), whereas pregnancy zone protein was decreased (590 vs 892 µg/mL, P=.002). Pregnancy zone protein was also decreased in diabetes compared with controls (683 vs 892 µg/mL, P=.01). Serum amyloid A1 was associated with placental dysfunction (fetal growth restriction, elevated soluble fms-like tyrosine kinase-1 to placental growth factor ratio). Pregnancy zone protein correlated negatively with soluble fms-like tyrosine kinase-1 to placental growth factor ratio in all study groups. Acute atherosis was not associated with serum amyloid A1 or pregnancy zone protein. CONCLUSION: Proteins involved in atherosclerosis, hypercoagulability, and protein misfolding are dysregulated in early-onset preeclampsia and placental dysfunction, which links them and potentially contributes to future maternal cardiovascular disease.

KIR- Ligand Interactions in Hypertensive Disorders in Pregnancy.

Hypothesis: The activity of natural killer (NK) cells is considered an important factor for the tolerance of the fetus during pregnancy. The complications of pregnancy, such as hypertensive disorders (HDP), may be therefore associated with this immune compartment. Methods: The current study included 41 pregnant women diagnosed with HDPs (Gestational Hypertension; GH or Preeclampsia; PE) and 21 healthy women. All the patients were under continuous obstetric care during the pregnancy and labour. The number of mother-child mismatches within killer immunoglobulin-like receptors (KIRs), their ligands [MM], and missing KIR ligands [MSLs] was assessed. KIRs and their ligands were assessed with Next Generation Sequencing (NGS) and Polymerase Chain Reaction Sequence-Specific Oligonucleotide (PCR-SSO) typing. The subsets of NK cells were assessed with multicolor flow cytometry and correlated to the number of MSLs. Results: The number of MSLs was significantly higher in HDP patients when compared to healthy non-complicated pregnancy patients. Some MSLs, such as those with 2DS2 activating KIR, were present only in HDP patients. The percentage of CD56+CD16-CD94+ NK cells and CD56+CD16-CD279+ NK cells correlated with the number of MSLs with inhibiting KIRs only in healthy patients. In HDP patients, there was a correlation between the percentage of CD56-CD16+CD69+ NK cells and the number of MSLs with inhibiting and activating KIRs. As compared to the healthy group, the percentage of CD56+CD16-CD279+ NK cells and CD56-CD16+CD279+ NK cells were lower in HDP patients. HDP patients were also characterized by a higher percentage of CD56+CD16+perforin+ NK cells than their healthy counterparts. Conclusions: Patients with HDP were characterized by a higher number of MSLs within the KIRs receptors. It seemed that the number of MSLs in the healthy group was balanced by various receptors, such as CD94 or inhibitory CD279, expressed on NK cells. Conversely, in HDP patients the number of MSLs was associated with the activation detected as the increased level of CD69+ NK cells.

Oxygen extraction fraction (OEF) assesses cerebral oxygen metabolism of deep gray matter in patients with pre-eclampsia.

OBJECTIVES: The objective of this study was to compare oxygen extraction fraction (OEF) values in the deep gray matter (GM) of pre-eclampsia (PE) patients, pregnant healthy controls (PHCs), and non-pregnant healthy controls (NPHCs) to explore their brain oxygen metabolism differences in GM. METHODS: Forty-seven PE patients, forty NPHCs, and twenty-one PHCs were included. Brain OEF values were computed from quantitative susceptibility mapping (QSM) plus quantitative blood oxygen level-dependent magnitude (QSM + qBOLD = QQ)-based mapping. One-way ANOVA was used to compare mean OEF values in the three groups. The area under the curve of the mean OEF value in each region of interest was estimated using a receiver operating characteristic curve analysis. RESULTS: We found that the mean OEF values in the thalamus, putamen, caudate nucleus, pallidum, and substantia nigra were significantly different in these three groups (F = 5.867, p = 0.004; F = 5.142, p = 0007; F = 6.158, p = 0.003; F = 6.319, p = 0.003; F = 5.491, p = 0.005). The mean OEF values for these 5 regions were higher in PE patients than in NPHCs and in PHCs (p < 0.05). The AUC of these ROIs ranged from 0.673 to 0.692 (p < 0.01) and cutoff values varied from 35.1 to 36.6%, indicating that the OEF values could discriminate patients with and without PE. Stepwise multivariate analysis revealed that the OEF values correlated with hematocrit in pregnant women (r = 0.353, p = 0.003). CONCLUSION: OEF values in the brains of pregnant women can be measured in clinical practice using QQ-based OEF mapping for noninvasive assessment of hypertensive disorders. KEY POINTS: • Pre-eclampsia is a hypertensive disorder associated with abnormalities in brain oxygen extraction. • Oxygen extraction fraction (OEF) is an indicator of brain tissue viability and function. QQ-based mapping of OEF is a new MRI technique that can noninvasively quantify brain oxygen metabolism. • OEF values in the brains of pregnant women can be measured for noninvasive assessment of hypertensive disorders in clinical practice.

Expression and clinical significance of miR-204 in patients with hypertensive disorder complicating pregnancy.

OBJECTIVE: Hypertensive disorder complicating pregnancy (HDCP) is a unique and common obstetrical complication in pregnancy. The current study sought to investigate the diagnostic value of serum miR-204 in HDCP patients. METHODS: A total of 196 HDCP patients were enrolled, with 54 healthy pregnant women as controls. The expression levels of miR-204 and inflammatory factors in the serum were determined. Receiver operating characteristic (ROC) curve was used to assess the diagnostic value of miR-204 in HDCP patients. Person coefficient was introduced to analyze the correlation between miR-204 and inflammatory indexes. Kaplan-Meier method was employed to analyze the effect of miR-204 expression on the incidence of adverse pregnancy outcomes. Logistic regression was adopted to assess the risk factors for adverse pregnancy outcomes. RESULTS: miR-204 expression was upregulated in the serum of HDCP patients. The serum miR-204 level > 1.432 could assist the diagnosis of HDCP. miR-204 level in the serum was positively correlated with TNF-α, IL-6, and hs-CRP concentrations in HDCP patients. The risk of adverse outcomes was higher in pregnant women with high miR-204 expression. High miR-204 expression was associated with an increased risk of adverse pregnancy outcomes after adjusting the family history of HDCP, systolic pressure, diastolic pressure, AST, ALT, LDH, 24-h urinary protein, TNF-α, IL-6, and hs-CRP. CONCLUSION: The high expression of miR-204 assists the diagnosis of HDCP and is an independent risk factor for adverse pregnancy outcomes in HDCP patients.

Correlation between N-terminal pro-atrial natriuretic peptide, corin, and target organ damage in hypertensive disorders of pregnancy.

The objective was to evaluate the correlation between N-terminal pro-atrial natriuretic peptide (NT-proANP), corin and the severity of target organ injury in hypertensive disorders of pregnancy. A total of 78 women with hypertensive disorders of pregnancy and 49 normotensive pregnancies were enrolled. The clinical characteristics, laboratory index and echocardiogram results were collected. NT-proANP, corin, sFlt-1 and PlGF levels were measured. A receiver's operating characteristics (ROC) curve was performed to evaluate the efficacy of predicting target organ injury in the HDP group. The NT-proANP, corin, and sFlt-1/PlGF ratio were increased in the HDP group (p < .05). The area under the curve (AUC) predicted by NT-proANP and corin were larger than sFlt-1/PlGF ratio (0.779, 0.867, and 0.766, respectively). The creatinine and urine protein were significantly increased, while the estimated glomerular filtration rate (eGFR) was dramatically decreased in the HDP group (p < .05 each). The left atrial diameter (LAD), left atrial volume index (LAVI), left ventricular posterior wall thickness (LVPWT), and left ventricular septal thickness (LVST) were larger in the HDP group (p < .001 each). The NT-proANP/corin levels were positively correlated with LAD, creatinine, and urine protein, and negatively correlated with eGFR in HDP group (p < .05 each). Multiple regressions demonstrated that NT-proANP was an independent risk factor of LAD and urine protein, and corin was an independent risk factor of creatinine and eGFR in HDP group. NT-proANP and corin may be reliable biomarkers for evaluating the severity of target organ damage in the hypertensive disorders of pregnant patients.

Association between serum placental growth factor and vascular endothelial function in hyprtensive disorders complicating pregnancy.

Hypertensive disorders complicating pregnancy (HDCP) is a systemic disease among pregnant women. Therefore, the prevention and prediction of hypertension during pregnancy are critical. This study aimed to clarify whether the vascular endothelial function of women with gestational hypertension was linked to placental growth factor. A total of 200 pregnant women were enrolled in our study and subsequently divided into two groups: the HDCP group and the normal pregnancy controls. The levels of serum placental growth factor, as well as plasma endothelin-1 and nitric oxide, between the two groups were measured. In addition, the endothelial function indexes, including pressure-strain elasticity coefficient (EP), the common carotid stiffness index (ß), arterial compliance, single-point pulsed-wave velocity, and augment index (AI) of bilateral common carotid arteries, were compared between the HDCP and control groups using the echo tracking technique. In our study, the level of placental growth factor in the HDCP group was significantly lower than the control group. Furthermore, our results clarified that endothelin-1 increased while nitric oxide decreased in the HDCP group compared with the control group. On the other hand, we found that EP, ß, pulsed-wave velocity and augment index values were significantly higher in the HDCP group than in the control group (P < 0.001). However, the value of arterial compliance was significantly decreased in patients of the HDCP group compared with the control group (P < 0.001). In conclusion, the association between serum placental growth factor and vascular endothelial function in HDCP could serve as a more accurate predictive factor of pregnant hypertension.

First trimester placental growth factor in maternal blood and placenta related disorders.

OBJECTIVE: To describe and compare the placental growth factor levels at first trimester in patients that developed preeclampsia, gestational hypertension, IUGR and in those patients without impaired placentation diseases. METHODS: Observational study based on a prospective cohort of 422 pregnant women. PlGF values were compared between the different groups (preeclampsia, intrauterine growth restriction (IUGR), gestational hypertension or normal group-patients without impaired placentation diseases). RESULTS: The 85.3% (n = 360, 95% CI = 81.9-88.7) had a normal pregnancy, 7.6% (n = 32, 95% CI = 5.1-10.1) had preeclampsia, 3.8% (n = 16, 95% CI = 2.0-5.6) had IUGR and 3.3% (n = 14, 95% CI = 1.6-5.0) had gestational hypertension. The median level of PlGF for preeclampsia (0.76) and IUGR (0.75) were lower than gestational hypertension (0.82) and normal group (1.02). The groups of preeclampsia >34 weeks (0.76), preeclampsia <37 weeks (0.73), and preeclampsia ≥37 weeks (0.77), were significantly lower than the normal group. The sensitivity and specificity of PlGF for impaired placentation diseases is 65% and 64.9%, respectively. CONCLUSION: It was found in this study that PlGF has significantly lower levels in gestational hypertension than normal pregnancies, in concordance with the other impaired placentation diseases. Additionally, a better comparison of the PlGF values was obtained when separating early onset of preeclampsia <37 weeks and late-onset of preeclampsia 37≥ weeks of gestations.

HSPA8 Is Identified as a Novel Regulator of Hypertensive Disorders in Pregnancy by Modulating the ß-Arrestin1/A1AR Axis.

Heat shock protein alpha 8 (HSPA8) was found to be downregulated in the placentas of patients with hypertensive disorders in pregnancy (HDP). We aim to explore the underlying role and mechanism of HSPA8 in HDP progression. Herein, HSPA8 mRNA expression in placentas and peripheral blood of patients with HDP and normal pregnant controls was measured with RT-qPCR. We found that HSPA8 expression was downregulated in placentas and peripheral blood of patients with HDP. HTR8/SVneo human trophoblast cells were transfected with pcDNA-HSPA8 or si-HSPA8. HSPA8 overexpression promoted cell proliferation, migration, and MMP-2 and MMP-9 protein levels, and inhibited apoptosis, while HSPA8 silencing showed the opposite results. Co-immunoprecipitation assay validated the binding between HSPA8 and ß-arrestin1, as well as ß-arrestin1 and A1AR proteins. HSPA8 bound with ß-arrestin1 protein and promoted ß-arrestin1 expression. ß-arrestin1 bound with A1AR protein and inhibited A1AR expression. Then, HTR8/SVneo cells were transfected with pcDNA-HSPA8 alone or together with si-ß-arrestin1, as well as transfected with pcDNA-ß-arrestin1 alone or together with pcDNA-A1AR. ß-arrestin1 silencing reversed the effects of HSPA8 overexpression on HTR8/SVneo cell functions. ß-arrestin1 overexpression promoted cell proliferation migration, and MMP-2 and MMP-9 protein levels, and inhibited apoptosis, while these effects were reversed by A1AR overexpression. Lentivirus HSPA8 overexpression vector (Lv-HSPA8) was injected into a preeclampsia (PE) rat model, which attenuated blood pressure and fetal detrimental changes in PE rats. In conclusion, HSPA8 promoted proliferation and migration and inhibited apoptosis in trophoblast cells, and attenuated the symptoms of PE rats by modulating the ß-arrestin1/A1AR axis. Our study provided a novel theoretical evidence and potential strategy for HDP treatment.

Macula Densa NOS1ß Modulates Renal Hemodynamics and Blood Pressure during Pregnancy: Role in Gestational Hypertension.

BACKGROUND: Regulation of renal hemodynamics and BP via tubuloglomerular feedback (TGF) may be an important adaptive mechanism during pregnancy. Because the ß-splice variant of nitric oxide synthase 1 (NOS1ß) in the macula densa is a primary modulator of TGF, we evaluated its role in normal pregnancy and gestational hypertension in a mouse model. We hypothesized that pregnancy upregulates NOS1ß in the macula densa, thus blunting TGF, allowing the GFR to increase and BP to decrease. METHODS: We used sophisticated techniques, including microperfusion of juxtaglomerular apparatus in vitro, micropuncture of renal tubules in vivo, clearance kinetics of plasma FITC-sinistrin, and radiotelemetry BP monitoring, to determine the effects of normal pregnancy or reduced uterine perfusion pressure (RUPP) on macula densa NOS1ß/NO levels, TGF responsiveness, GFR, and BP in wild-type and macula densa-specific NOS1 knockout (MD-NOS1KO) mice. RESULTS: Macula densa NOS1ß was upregulated during pregnancy, resulting in blunted TGF, increased GFR, and decreased BP. These pregnancy-induced changes in TGF and GFR were largely diminished, with a significant rise in BP, in MD-NOS1KO mice. In addition, RUPP resulted in a downregulation in macula densa NOS1ß, enhanced TGF, decreased GFR, and hypertension. The superimposition of RUPP into MD-NOS1KO mice only caused a modest further alteration in TGF and its associated changes in GFR and BP. Finally, in African green monkeys, renal cortical NOS1ß expression increased in normotensive pregnancies, but decreased in spontaneous gestational hypertensive pregnancies. CONCLUSIONS: Macula densa NOS1ß plays a critical role in the control of renal hemodynamics and BP during pregnancy.

Baicalin enhances the proliferation and invasion of trophoblasts and suppresses vascular endothelial damage by modulating long non-coding RNA NEAT1/miRNA-205-5p in hypertensive disorder complicating pregnancy.

AIM: Trophoblastic and vascular endothelial injuries were closely associated with the pathogenesis of hypertensive disorder complicating pregnancy (HDCP). The present study was designed to determine the functional role of baicalin in the proliferation and invasion of trophoblasts and vascular endothelial injury. METHODS: Ang II was adopted to stimulate HTR-8/SVneo and human umbilical vein endothelial cells (HUVECs). Cell viability was examined by CCK-8 assay. Flow cytometry and TUNEL staining determined cell apoptosis. Invasive ability of HTR-8/SVneo cells was measured by transwell assay. In vitro angiogenesis of HUVECs was assessed by Tube formation assay. In addition, the production of reactive oxygen species (ROS) was determined by DCFH-DA staining. Furthermore, long non-coding RNA (lncRNA) NEAT1 and miRNA-205-5p levels were detected using real-time quantitative polymerase chain reaction and the binding relationship between lncRNA NEAT1 and miRNA-205-5p was verified by dual-luciferase reporter assay. Moreover, interactions among lncRNA NEAT1, miRNA-205-5p, and MMP9 or vascular endothelial growth factor (VEGF) were confirmed by RNA immunoprecipitation assay. RESULTS: Baicalin visibly improved cell viability, reduced the apoptosis of Ang II-stimulated HTR-8/SVneo and HUVEC cells, and repressed overproduction of ROS. Additionally, baicalin promoted the invasion of Ang II-stimulated HTR-8/SVneo cells and induced a stronger in vitro angiogenesis of Ang II-stimulated HUVECs. What's more, baicalin upregulated lncRNA NEAT1 expression and downregulated miR-205-5p expression. LncRNA NEAT1 sponged miR-205-5p and inhibited the combination of miR-205-5p and MMP9 or VEGF. CONCLUSIONS: Baicalin can facilitate the proliferation and invasion of trophoblasts and alleviate vascular endothelial damage by upregulating lncRNA NEAT1 to impede the interaction between miR-205-5p and MMP9 or VEGF.

Preexisting hypertension and pregnancy-induced hypertension reveal molecular differences in placental proteome in rodents.

Preexisting or new onset of hypertension affects pregnancy and is one of the leading causes of maternal and fetal morbidity and mortality. In certain cases, it also leads to long-term maternal cardiovascular complications. The placenta is a key player in the pathogenesis of complicated hypertensive pregnancies, however the pathomechanisms leading to an abnormal placenta are poorly understood. In this study, we compared the placental proteome of two pregnant hypertensive models with their corresponding normotensive controls: a preexisting hypertension pregnancy model (stroke-prone spontaneously hypertensive rats; SHRSP) versus Wistar-Kyoto and the transgenic RAS activated gestational hypertension model (transgenic for human angiotensinogen Sprague-Dawley rats; SD-PE) versus Sprague-Dawley rats, respectively. Label-free proteomics using nano LC-MS/MS was performed for identification and quantification of proteins. Between the two models, we found widespread differences in the expression of placental proteins including those related to hypertension, inflammation, and trophoblast invasion, whereas pathways such as regulation of serine endopeptidase activity, tissue injury response, coagulation, and complement activation were enriched in both models. We present for the first time the placental proteome of SHRSP and SD-PE and provide insight into the molecular make-up of models of hypertensive pregnancy. Our study informs future research into specific preeclampsia and chronic hypertension pregnancy mechanisms and translation of rodent data to the clinic.

Maternal systemic vascular dysfunction in a primate model of defective uterine spiral artery remodeling.

Uterine spiral artery remodeling (UAR) is essential for placental perfusion and fetal development. A defect in UAR underpins placental ischemia disorders, e.g., preeclampsia, that result in maternal systemic vascular endothelial dysfunction and hypertension. We have established a model of impaired UAR by prematurely elevating maternal serum estradiol levels during the first trimester of baboon pregnancy. However, it is unknown whether this experimental paradigm is associated with maternal vascular endothelial dysfunction. Therefore, in the present study baboons were administered estradiol on days 25-59 of gestation to suppress UAR and maternal vascular function determined on day 165 (term = 184 days) peripherally and in skeletal muscle, which accounts for over 40% of body mass and 25% of resting systemic vascular resistance. Maternal serum sFlt-1 levels were 2.5-fold higher (P < 0.05), and skeletal muscle arteriolar endothelial nitric oxide synthase (eNOS) protein expression and luminal area, and skeletal muscle capillary density were 30-50% lower (P < 0.05) in UAR suppressed baboons. Coinciding with these changes in eNOS expression, luminal area, and capillary density, maternal brachial artery flow-mediated dilation and volume flow were 70% and 55% lower (P < 0.05), respectively, and mean arterial blood pressure 29% higher (P < 0.01) in UAR defective baboons. In summary, maternal vascular function was disrupted in a baboon model of impaired UAR. These results highlight the translational impact of this primate model and relevance to adverse conditions of human pregnancy underpinned by improper uterine artery transformation.NEW & NOTEWORTHY Maternal vascular dysfunction is a hallmark of abnormal human pregnancy, particularly early-onset preeclampsia, elicited by impaired UAR. The present study makes the novel discovery that maternal systemic vascular dysfunction was induced in a baboon experimental model of impaired UAR. This study highlights the translational relevance of this nonhuman primate model to adverse conditions of human pregnancy underpinned by defective UAR.

Untargeted analysis of first trimester serum to reveal biomarkers of pregnancy complications: a case-control discovery phase study.

Understanding of causal biology and predictive biomarkers are lacking for hypertensive disorders of pregnancy (HDP) and preterm birth (PTB). First-trimester serum specimens from 51 cases of HDP, including 18 cases of pre-eclampsia (PE) and 33 cases of gestational hypertension (GH); 53 cases of PTB; and 109 controls were obtained from the Global Alliance to Prevent Prematurity and Stillbirth repository. Metabotyping was conducted using liquid chromatography high resolution mass spectroscopy and nuclear magnetic resonance spectroscopy. Multivariable logistic regression was used to identify signals that differed between groups after controlling for confounders. Signals important to predicting HDP and PTB were matched to an in-house physical standards library and public databases. Pathway analysis was conducted using GeneGo MetaCore. Over 400 signals for endogenous and exogenous metabolites that differentiated cases and controls were identified or annotated, and models that included these signals produced substantial improvements in predictive power beyond models that only included known risk factors. Perturbations of the aminoacyl-tRNA biosynthesis, L-threonine, and renal secretion of organic electrolytes pathways were associated with both HDP and PTB, while pathways related to cholesterol transport and metabolism were associated with HDP. This untargeted metabolomics analysis identified signals and common pathways associated with pregnancy complications.

Sulforaphane Bioavailability and Effects on Blood Pressure in Women with Pregnancy Hypertension.

Sulforaphane, an isothiocyanate found in cruciferous vegetables such as broccoli, shows promise as an adjuvant therapy for preeclampsia. To inform future clinical trials, we set out to determine the bioavailability of sulforaphane in non-pregnant and preeclamptic women. In six healthy female volunteers, we performed a crossover trial to compare the bioavailability of sulforaphane and metabolites afforded by an activated and non-activated broccoli extract preparation. We then undertook a dose escalation study of the activated broccoli extract in 12 women with pregnancy hypertension. In non-pregnant women, an equivalent dose of activated broccoli extract gave higher levels of sulforaphane and metabolites than a non-activated extract (p < 0.0001) and greater area under the curve (AUC) (3559 nM vs. 2172 nM, p = 0.03). Compared to non-pregnant women, in women with preeclampsia, the same dose of activated extract gave lower levels of total metabolites (p < 0.000) and AUC (3559 nM vs. 1653 nM, p = 0.007). Doubling the dose of the activated extract in women with preeclampsia doubled levels of sulforaphane and metabolites (p = 0.02) and AUC (1653 nM vs. 3333 nM, p = 0.02). In women with preeclampsia, activated broccoli extract was associated with modest decreases in diastolic blood pressure (p = 0.05) and circulating levels of sFlt-1 (p = 0.0002). A myrosinase-activated sulforaphane formulation affords better sulforaphane bioavailability than a non-activated formulation. Higher doses of sulforaphane are required to achieve likely effective doses in pregnant women than in non-pregnant women. Sulforaphane may improve endothelial function and blood pressure in women with pregnancy hypertension.