Hypertension

BackgroundHyperactivity of the orexin system has been implicated in hypertension, yet the long-term impact of orexin 1 receptor (OX1R) overexpression in the paraventricular nucleus (PVN), a key brain region involved in arterial blood pressure (ABP) regulation, remains unclear. This study examined whether chronic OX1R overexpression in the PVN alters cardiovascular, neuroendocrine, and oxidative functions. MethodsAdult male Sprague-Dawley rats received bilateral PVN injections of AAV2-OX1R or control virus AAV2-GFP. Their ABP and heart rate (HR) were monitored for eight weeks via radiotelemetry. Renal sympathetic nerve activity (RSNA) and ABP responses to PVN orexin A administration were assessed using in vivo recordings. Reactive oxygen species (ROS) were quantified using MitoProbe, and gene expression was analyzed by qPCR. Primary neuronal cultures were used to explore underlying mechanism involved in increased ROS production and neuronal activity. ResultsPVN OX1R overexpression increased mean ABP ([~]10 mmHg), water intake, and ROS levels in both the PVN and peripheral organs. In addition, orexin A evoked exaggerated RSNA (155% vs. 73%) and pressor responses (27 vs. 16 mmHg) in PVN OX1R overexpression rats compared to control rats, these effects were attenuated by the OX1R antagonist SB408124. Plasma vasopressin levels were elevated, and brain sections confirmed increased ROS in OX1R-positive neurons. In vitro experiments further demonstrated that orexin A upregulated ROS-generating enzymes, suppressed antioxidant genes, and enhanced neuronal excitability. ConclusionChronic PVN OX1R overexpression induces oxidative stress, sympathetic overactivity, and increased plasma vasopressin, contributing to hypertension development. Targeting PVN OX1R signaling may provide therapeutic benefit for hypertension.

BackgroundDeoxycorticosterone acetate (DOCA)-salt induces greater increases in blood pressure (BP) and a more pro-inflammatory T cell profile in males compared to females. T cells contribute to DOCA-salt hypertension, however, the mechanisms driving T cell activation remain unclear. The NLRP3 inflammasome has been implicated in DOCA hypertension in male mice. Little is known regarding NLRP3 in females. The goal of the current study was to test the hypothesis that NLRP3 contributes to greater increases in BP and renal inflammation with DOCA in males vs. females. MethodsRenal NLRP3 protein levels were measured in normotensive and hypertensive male and female subjects and in male and female Sprague Dawley uni-nephrectomized (UNX) control and DOCA-salt rats. Additional 11-wk-old Sprague Dawley rats were UNX and randomized to: 1) DOCA + vehicle or 2) DOCA + the NLRP3 inhibitor MCC950 (10 mg/kg/day in saline) from 11-14 wks of age. At 14-wks-of-age rats were euthanized, terminal plasma samples and remaining kidneys were collected for flow cytometric analysis of T cells. ResultsRenal NLRP3 levels were significantly greater in hypertensive males and females vs. normotensive controls. DOCA increased BP in both sexes, with greater elevations in males. MCC950 attenuated DOCA-induced increases in BP in male, but not female rats. MCC950 decreased circulating and renal CD4 and Th17 cells in both sexes, although the effect was greater in males. ConclusionDespite both males and females exhibiting an increase in NLRP3 in hypertension, NLRP3 contributes to BP elevations only in DOCA-salt males.

BackgroundAntihypertensive and cardioprotective medications are prescribed to pregnant women and include Ca2+ channel blockers (CCBs; amlodipine, nifedipine), - (doxazosin) and {beta}-(labetalol, bisoprolol, nebivolol) adrenergic receptor antagonists, and -adrenergic receptor agonists (methyldopa). These vasoactive drugs enter the fetal circulation, with unknown effects on the fetoplacental vasculature. We aimed to investigate whether cardiovascular medications modulate human fetoplacental vascular tone, which may impair or enhance placental perfusion. MethodsChorionic plate arteries (CPAs) were obtained from the placentas of women with normotensive pregnancy (N=28), with unmedicated hypertension (N=14), and those chronically medicated (N=61) with either amlodipine, nifedipine, labetalol or bisoprolol, or a combination of CCBs and labetalol. Using wire myography, ex vivo effects of amlodipine, nifedipine, labetalol, methyldopa, doxazosin, bisoprolol and nebivolol were tested in a concentration-dependent manner (10-11-10-5M) in pre-constricted CPAs isolated from the placentas of normotensive women. Differences in CPA vascular reactivity in response to chronic exposure to hypertension and/or cardiovascular medications was assessed by vasoconstriction to high potassium physiological solution (KPSS; 120mM) and to the thromboxane A2 mimetic (U46619; 10-10-2x10-6M), and relaxation to the nitric oxide donor, sodium nitroprusside (SNP; 10-10-10-5M). ResultsIn pre-constricted CPAs isolated from normotensive women, acute exposure to amlodipine, nifedipine, doxazosin and nebivolol promoted significant vasorelaxation (P<0.05). CPAs acutely exposed to labetalol, methyldopa (P<0.05) and bisoprolol (P<0.001) exhibited increased vasoconstriction compared to their respective diluent controls. CPAs from women with chronic hypertension and from those who had chronic labetalol treatment exhibited significantly reduced vasoconstriction to KPSS (P<0.05). CPAs from women with chronic hypertension and exposure to bisoprolol also had significantly attenuated vascular responses to U46619 and SNP (P<0.01 and P<0.01, respectively), compared to normal pregnancy. ConclusionsMaternal hypertension impairs vascular responses of the placenta. Cardiovascular medications prescribed during pregnancy may dysregulate placental vascular function. Further research is warranted to evaluate the relative safety of cardiovascular medications in pregnancy, as their distinct effects on fetoplacental vascular function may have important implications for maternal and fetal outcomes. Mechanistic studies alongside clinical correlations are essential to guide evidence-based prescribing.

Background: The 2017 American College of Cardiology/American Heart Association (ACC/AHA) guideline lowered diagnostic threshold for hypertension, encouraging earlier treatment initiation in the U.S. compared to UK, where the National Institute for Health and Care Excellence (NICE) guideline recommends higher thresholds. No comparative study evaluating how different hypertension guidelines and physical activity are jointly associated with mortality outcomes in two countries. Aims: This study compared hypertension prevalence, treatment uptake, blood pressure (BP) levels, and mortality between the UK Biobank (UKBB) and the U.S. National Health and Nutrition Examination Survey (NHANES). We evaluated whether moderate-to-vigorous physical activity (MVPA) modifies mortality risk among different hypertension subgroups (normotensive, medicated hypertension, and unmedicated hypertension). Methods: We harmonized demographic, biomarker, lifestyle, and accelerometer data from UKBB (n=63,452) and NHANES (n=7,397). Comprehensive weighting methods were applied in both cohorts. Accelerometry data was classified using a validated two-stage machine learning Random Forest algorithm. Associations between MVPA and all-cause mortality were examined with restricted cubic spline regression and visualized using Kaplan-Meier survival curves. Results: NHANES showed a higher proportion of treated hypertension (29.9%) and lower average blood pressure (SBP/DBP: 122.2/70.7 mmHg) compared to UKBB (11.7% treated; SBP/DBP: 136.0/81.3 mmHg). Despite lower BP levels, cardiovascular mortality was higher in UKBB (10.3 per 10,000 person-years) compared to NHANES (4.0 per 10,000 person-years). In both cohorts, greater MVPA was linked to lower mortality risk, with the strongest association observed among medicated hypertensives. Notably, NHANES participants with treated hypertension and low MVPA (<10.7 minutes/day) experienced a steeper survival decline, falling to 74% by year 8, compared to 91% in normotensives and 79% in untreated hypertensives. Conclusion: Despite higher treatment prevalence and lower average BP levels in NHANES, mortality remained higher compared with UKBB, suggesting that differences in mortality patterns may relate to broader cardiometabolic profiles and PA patterns beyond pharmacological management alone. Across both cohorts, higher levels of MVPA were associated with lower all-cause mortality, with the strongest associations were observed among individuals with medicated hypertension.

BackgroundEndothelial response to flow is key to vascular function in health and disease. Our earlier studies demonstrated that endothelial Kir2.1 is essential for flow-induced Akt1/eNOS signaling and for flow-induced vasodilation (FIV) but the mechanistic integration between Kir and other flow signaling pathways remained poorly understood. MethodsWe use a combination of electrophysiological recordings in real time of flow exposure, Ca2+ imaging, pressure myography of resistance arteries, and echocardiography. ResultsWe demonstrate that Kir2.1 is essential for flow-induced PI3K phosphorylation, whereas expression of myristoylated Akt1, which bypasses PI3K-dependent membrane recruitment, restores flow-induced Akt1/eNOS phosphorylation in Kir2.1-deficient endothelium. It also restores FIV in Kir2.1-deficient mesenteric arteries. We further demonstrate that Kir2.1 is essential for flow-induced Ca{superscript 2} influx mediated by Piezo1 and TRPV4 channels, whereas Ca{superscript 2} influx induced by pharmacological activation of these channels is Kir2.1 independent. Deficiency of Piezo1 does not affect endothelial Kir2.1 channels. We also discover that flow activation of endothelial Kir2.1 requires Syndecan1, thus creating a link between glycocalyx and downstream effects. Physiologically, we find that endothelial Kir2.1 is suppressed by infusion of Angiotensin-II and by advanced aging, resulting in significant impairment of FIV. In both cases, FIV is fully restored by endothelium-specific over-expression of Kir2.1. ConclusionsOur study reveals that Kir2.1 serves as a mechanistic linker between endothelial glycocalyx to Piezo1-mediated Ca2+ influx and downstream signaling suggesting a new integrated model of endothelial mechanotransduction. A functional loss of endothelial Kir2.1 is shown to play a significant role in FIV impairment in Angiotensin-induced hypertension and aging.

BackgroundChemokine signaling contributes to vascular inflammation and dysfunction in hypertension. CCL5 (C-C motif chemokine ligand 5) has been implicated in angiotensin II (Ang II)-induced vascular injury; however, the intracellular mechanisms linking CCL5/CCR5 (C-C chemokine receptor type 5) activation to vascular dysfunction remain unclear. We hypothesized that Ang II amplifies vascular CCL5/CCR5 signaling, leading to mitochondrial dysfunction and oxidative stress that promote vascular impairment. MethodsWild-type and CCR5-deficient mice were infused with Ang II for 14 days. Separate cohorts received recombinant CCL5 at concentrations comparable to those observed after Ang II infusion. Vascular reactivity and remodeling were assessed in the aorta and mesenteric arteries. Mitochondrial respiration, membrane potential, and reactive oxygen species (ROS) production were evaluated in vascular smooth muscle cells (VSMCs). Pharmacological inhibition of CCR5, mitochondrial ROS scavenging, and mitochondrial uncoupling were used to define underlying mechanisms. ResultsAng II increased circulating CCL5 and upregulated CCR5 expression in vascular tissues and VSMCs. CCR5 deficiency protected against Ang II-induced vascular dysfunction, remodeling, and inflammation. CCL5 infusion impaired endothelium-dependent relaxation and enhanced contractility without inducing structural remodeling. In VSMCs, CCL5 disrupted mitochondrial respiration, reduced maximal respiratory capacity, altered membrane potential, and increased mitochondrial ROS in a CCR5-dependent manner. Mitochondrial antioxidant treatment restored endothelial function but did not normalize enhanced contractility. ConclusionsAng II amplifies CCL5/CCR5 signaling, promoting CCR5-dependent mitochondrial dysfunction and oxidative stress that contribute to vascular impairment. Targeting this mitochondrial inflammatory axis may represent a therapeutic strategy in hypertension.

Preeclampsia (PE), or gestational hypertension, affects around 5% of pregnancies and leads to approximately 70,000 maternal and 500,000 fetal deaths per year worldwide, with increased cardiovascular and metabolic disease in survivors. PE is associated with elevated circulating levels of the alternative splice isoform of VEGF receptor 1 (sFlt1), defects in placental vasculature, kidney damage and, in severe disease, fetal growth restriction. Current mouse models induce PE via direct expression of sFlt1 or elevation of blood pressure, which bypass the natural risk factors for human disease, such as age, obesity, hypertension and diabetes. These risk factors have in common reduced expression of Kruppel-like factors 2 and 4 (KLF2/4), the endothelial transcription factors that protect against cardiovascular disease. We now report that inducible deletion of KLF4 in maternal endothelium (KLF4iECKO) results in gestational hypertension, elevated sFlt1, defective placental vasculature, kidney damage and fetal growth restriction. KLF4iECKO may thus serve as a mouse PE model suitable for mechanistic analysis and screening of treatments that address upstream risk factors.

BackgroundPreterm birth is one of the most significant etiologies for neonatal morbidity and mortality. Preterm delivery is classified as iatrogenic preterm delivery and spontaneous preterm delivery. The role of placental pathology is studied. Materials and methodsWe have previously collected placental pathology data with maternal pregnancy and neonatal birth data, and we investigated the role of placental pathology in preterm delivery. Preterm delivery was categorized as late preterm (34-36 weeks), moderate preterm (32 to 33 weeks), and extreme preterm (less than 32 weeks). Neonatal, maternal, placental gross and histologic features, and laboratory parameters were compared across groups using chi-square tests for categorical variables and Kruskal-Wallis tests for continuous variables using various programs in R-package. ResultsTotally 3723 singleton placentas including 3307 term (88.8%) and 416 preterm placentas (11.2%) were examined with maternal pregnancy data and neonatal birth data. There were 614 placentas from patients with preeclampsia/pregnancy induced hypertension (PRE/PIH) (16.5%). Preterm delivery showed significantly lower fetal birth weight, placental weight, and fetal-placental ratio (all p<0.01). Maternal Black race was more prevalent in preterm groups (up to 50.8% in extreme preterm vs. 33.2% in term, p<0.01). Preterm delivery was statistically associated with PRE/PIH and maternal vascular malperfusion (MVM), maternal and fetal inflammatory response (MIR and FIR), and increased pre-delivery white blood count (WBC). Extreme preterm deliveries were markedly associated with intrauterine fetal death (27.5%, p<0.01) and MIR/FIR (56.7%, p<0.01). After excluding PRE/PIH patients, preterm delivery was statistically associated with MIR/FIR and increased WBC. ConclusionsDistinct clinicopathologic profiles exist across preterm subcategories, with MVM predominating in late/moderate preterm and severe pathologic features (including fetal demise and acute inflammation) in extreme preterm. These findings highlight heterogeneous etiologies of preterm delivery.

Pulmonary hypertension (PH) is a progressive condition characterized by increased pulmonary arterial pressure. Endothelial cell dysfunction is one important characteristic of PH. Recently, capillary endothelial cells, including aerocytes (aCaps) and general capillary cell (gCaps), have been detected in developing lungs but their role and the regulatory mechanisms underlying PH remain poorly understood. The goal of this study was to identify changes in Caps and their effects on hypertensive pulmonary circulation. We set up a Capillary Alveoli Micro-physiological System (CAMS) incorporated with hPSCs(human pluripotent stem cells)-aCaps to show loss of Cap connection under dynamically cultured hypoxic condition. We employed single-cell RNA sequencing (scRNA-seq) and immunofluorescence to demonstrate impaired gCaps differentiation with increased expression of cell membrane receptor CD93 in PH patients and a Sugen 5416/hypoxia (SuHx) rat model. Conditional Knockdown or Lentiviral overexpression of CD93 alleviated the pathology observed in SuHx mice. We also revealed that CD93 overexpression upregulated SMAD2/3 to repress Apelin (APLN) expression by CHIP assay. Finally, supplementation with an APLNR agonist in the PH rat model promoted gCaps-to-aCaps differentiation and improved haemodynamic indices. Overall, our results highlight the potential for promoting capillary cell differentiation with G protein biased APLNR agonist as a therapeutic strategy for pulmonary vascular disease.

BackgroundHypertension affects over 30% of adults and is the leading risk factor for cardiovascular disease. It often presents without obvious symptoms, meaning that, although effective therapies exist, hypertension remains widely undiagnosed and insufficiently treated. Genomics-based prediction methods have shown only modest benefits for these disorders, but proteomic markers have demonstrated potential for greater predictive and clinical value. MethodsWe applied a novel machine-learning based patient stratification analysis pipeline to proteomics data for 7,086 hypertension patients from UK Biobanks Pharma Proteomics Project cohort (2,911 proteins). We evaluated the contribution of each protein to the output of a tree-based risk model to explore the combinations of protein expression values that naturally separate hypertension cases into clusters and assessed the prevalence of cardiovascular and renal complications within each obtained cluster. ResultsWe identified 10 clusters of hypertension patients segregated by differential expression of HAVCR1, PLAT, PTPRB, REN and RTN4R. Four of these clusters showed statistically significant enrichment for cardiovascular and renal complications, and three of them had significantly lower prevalence of complications than expected among hypertension patients. ConclusionWe hypothesize that the hypertension clusters identified may represent distinct mechanistic subtypes. With further study this could help focus studies on subgroups of hypertension patients with a shared disease etiology, identify more personalized precision medicine treatment options for each subgroup, and develop mechanism-based biomarker tests to support enriched clinical trial recruitment.

BackgroundHypertension (HTN) is a leading risk factor for mortality and disability, often as a result of heart disease or stroke, two leading causes of death. A blood pressure rise in midlife women in industrialized societies remains poorly understood. Progressively higher aldosterone levels have been associated with proportionately higher blood pressure in some populations. We examined whether aldosterone is associated with HTN in Study of Womens Health Across the Nation (SWAN). MethodsSWAN is a longitudinal cohort of women followed from midlife into late adulthood. Analyses include 999 women free of heart failure and with serum aldosterone measured during 2015-2016 (15th follow-up) study visit (V15). HTN was defined at V15 as systolic blood pressure (SBP) or diastolic blood pressure (DBP) [&ge;]140 or [&ge;]90mmHg, respectively, or use of antihypertensive medications. Utilizing the longitudinal data available in SWAN, treatment resistant hypertension (TRH) was defined as reported use of [&ge;]4 concurrent antihypertensive medications at any visit, or [&ge;]3 concurrent antihypertensive medications and SBP[&ge;]140 or DBP[&ge;]90 at two consecutive visits. Multivariable regression related aldosterone to HTN or TRH, adjusting for age, race/ethnicity, body mass index, physical activity, smoking, and low-density lipoprotein cholesterol. ResultsAt V15, women were 66{+/-}2.7 years of age, and the prevalence of HTN and TRH was 52% and 4%, respectively. Each 1 ng/dL higher aldosterone was associated with a 4% increased odds of HTN (95%CI 1.02,1.06;p<0.001); association was not significant for TRH. ConclusionsOur findings extend growing evidence that subclinical aldosterone excess is associated with greater HTN risk in postmenopausal women.

BackgroundWingless/Int-1 (Wnts) proteins are canonical Frizzled receptor ligands. Recent evidence indicates that some Wnts, including Wnt9b and Wnt5a, bind to polycystin 1 (PKD1), a transmembrane protein which can couple to polycystin 2 (PKD2) to form a non-selective cation channel. The functional significance of Wnts binding to PKD1 is unclear. Here, we tested the hypothesis that Wnts act through PKD1/PKD2 channels on endothelial cells (ECs) to regulate arterial contractility and blood pressure and investigated the cellular source and secretory regulation of vasoactive Wnt proteins. MethodsA wide variety of approaches, including inducible EC-specific PKD1 and PKD2 knockout mice, reverse-transcription polymerase chain reaction, Western blotting, immunofluorescence, pressurized artery myography, blood pressure measurements, patch-clamp electrophysiology, in vivo and in vitro Wnt and nitric oxide assays, and Wnt secretion assays. ResultsIntravascular Wnt9b or Wnt5a administration stimulates an EC PKD1/PKD2-dependent dilation in pressurized resistance-size arteries. Wnt9b and Wnt5a are present in serum and plasma and intravenous infusion rapidly stimulates a blood pressure reduction which requires EC PKD1. Wnts stimulate a PKD1-dependent non-selective cation current in ECs which through Ca2+ signaling activates endothelial nitric oxide synthase (eNOS) and small conductance Ca2+-activated K+ channels to induce vasodilation. Wnt9b acts solely via PKD1/PKD2 channels, whereas Wnt5a stimulates signaling through PKD1/PKD2, Frizzled-7 (Fzd-7), Dishevelled and c-Jun N-terminal kinase (JNK). Intravascular flow stimulates angiotensin II type 1 (AT1) receptors, which through Gq/11 and Porcupine activate Wnt9b and Wnt5a secretion in ECs. Wnts secreted in response to flow activate PKD1/PKD2 signaling in ECs and contribute to flow-mediated vasodilation. ConclusionsIntravascular flow activates AT1 receptors, which through Gq/11 and Porcupine stimulate Wnt9b and Wnt5a secretion in ECs. Wnt9b activates PKD1/PKD2 channels whereas Wnt5a stimulates both PKD1/PKD2 and Fzd-7 in ECs to induce vasodilation. Wnts contribute to flow-mediated autocrine/paracrine dilation and reduce blood pressure. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=92 SRC="FIGDIR/small/712518v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@158bad1org.highwire.dtl.DTLVardef@5113eforg.highwire.dtl.DTLVardef@f3b94eorg.highwire.dtl.DTLVardef@10ab479_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundPreeclampsia is a leading cause of maternal and perinatal morbidity and mortality, and a major contributor to low birth weight. Beta blockers (BB) and calcium channel blockers (CCB) are the most commonly recommended agents to treat hypertension in pregnancy. Yet it remains unknown whether these agents alter the risk of preeclampsia (PE), and if so, whether effects arise through maternal physiology or through direct fetal mechanisms. ObjectivesTo use drug-target Mendelian randomization (MR) to estimate the effects of genetically-proxied inhibition of beta-adrenergic and L-type calcium-channel targets on PE risk, birth weight, partitioned into maternal and fetal genetic components, and gestational age (GA). MethodsWe constructed instruments from genome-wide significant, LD-independent variants within prespecified windows around systolic blood pressure (SBP) modulating drug targets in addition to a genome-wide SBP instrument (European ancestry). Outcomes comprised of PE (16,349 cases / 595,135 controls), maternal and fetal genetic effects on birth weight (n{approx}210,267 and n{approx}298,142), and GA (n{approx}151,987). Two-sample MR estimated effects per 5mmHg decrease in SBP. Bayesian colocalization assessed shared causal variants. Multiple testing was controlled with Benjamini-Hochberg correction. ResultsGenetically lower SBP was associated with reduced PE risk and modest increases in birth weight and GA. BB (ADRB1) target inhibition showed no convincing reduction in PE risk but was associated with lower birth weight, with associations predominantly through direct fetal genetic effects and strong colocalization at ADRB1 with fetal birth-weight signals. In contrast, CCB targets collectively associated with lower PE risk without consistent evidence of fetal growth impairment; colocalization support for individual CCB loci was limited. Sensitivity analyses (heterogeneity, pleiotropy) did not materially alter these patterns where instrument counts permitted. ConclusionsDrug-target MR suggests that BB pathways are unlikely to meaningfully reduce PE and are linked to reduced fetal growth - chiefly via direct fetal mechanisms. In contrast, CCB pathways are associated with lower PE risk and largely neutral fetal growth effects. These findings support prioritizing CCBs for evaluation in comparative trials of PE prevention.

IntroductionPreterm pre-eclampsia is associated with increased risk of later cardiovascular disease. This study examines cardiometabolic health 3-6 years post-preterm pre-eclampsia and explores whether early postnatal cardiovascular phenotypes relate to later cardiovascular morbidity. MethodsPICk-UP trial participants who experienced preterm pre-eclampsia underwent assessments including anthropometry, blood pressure (BP), arteriography, echocardiography, biomarkers and cardiac magnetic resonance (CMR) imaging 3-6 years postpartum. The primary outcome was hypertension prevalence, with secondary outcomes including cardiac fibrosis, remodelling, and function, obesity, and lipid abnormalities. Associations between baseline, pregnancy and postnatal characteristics with the primary and secondary outcomes were explored. ResultsForty-five women were included; 37 underwent echocardiography and 20 had CMR. At 3-6 years, 53% had hypertension, 32% developed de novo hypertension, 30% had adverse left ventricular (LV) remodelling, 49% had diastolic dysfunction, and 27% were obese. Myocardial fibrosis was detected in 35% of CMR participants. No cardiovascular measures changed from 6 months postpartum to 3-6 years. Women who developed hypertension demonstrated higher BP and LV mass index, from 6 weeks postpartum, with distinct postnatal BP trajectories. Women with myocardial fibrosis exhibited higher sFlt and CRP concentrations from 6 weeks postpartum, with sFlt correlating with native T1 at 3-6 years. DiscussionWomen with prior preterm pre-eclampsia show significant cardiometabolic morbidity 3-6 years postpartum. Early postnatal phenotypes indicate long-term cardiovascular risk. Persistent anti-angiogenic imbalance and inflammation may contribute to myocardial fibrosis. Early BP, weight, and biomarker measurement may help identify at-risk women, warranting further studies on optimising postnatal care to mitigate cardiovascular risk after preterm pre-eclampsia.

BackgroundIn the context of increased salt intake in the world population, the understanding of the mechanisms that contribute to its correct renal excretion and therefore, avoid variation of blood volume and blood pressure is of major importance. MethodsMolecular, ex vivo microperfusion on isolated tubules, and integrative analysis, was used to identify, characterize and investigate a Na+ secretion pathway in the collecting duct. ResultsIn collecting duct of mice, salt load induced an increase of the type A intercalated cells (AIC) number, an overexpression of the H(Na),K-ATPase type 2 (HKA2) catalytic subunit Atp12a and a stimulation of the bumetanide-sensitive Na+ secretion in isolated and microperfused tubules. Surprisingly, HKA2KO mice fed a high-salt diet exhibit a strong dysregulation of their Na+ and water balance with a pronounced loss of Na+ and fluid, alkalosis, hypokalemia and low blood pressure. This Bartter-like phenotype is due to an over-inhibition of the thick ascending limb (TAL) related to an elevated PGE2 production. ConclusionOur findings establish that activation of Na+ secretion in AIC act as the fine-tuning knob in the regulation of renal Na+ excretion in response to high salt intake. Its absence is overcompensated by an inhibition of the Na+ transport system of the TAL.

BackgroundFailure of cerebrovascular reserve is a fundamental determinant of ischemic vulnerability, yet the mechanisms by which vascular smooth muscle dysfunction compromises reserve and predisposes the brain to injury remain incompletely defined. We therefore tested whether a pathogenic smooth muscle mutation produces a baseline failure of cerebrovascular reserve sufficient to render the brain vulnerable to hypoperfusion, even in the absence of fixed arterial occlusion. MethodsWe examined cerebrovascular structure, hemodynamics, and reserve in a genetically defined mouse model of ACTA2-associated multisystemic smooth muscle dysfunction syndrome with systemic or brain-restricted expression of the mutant allele. Cerebral artery morphology was assessed using magnetic resonance angiography and black ink angiography. Vascular smooth muscle phenotype was evaluated by immunohistochemistry and proliferation assays. Blood pressure reactivity and cerebral blood flow (CBF) were measured simultaneously using femoral arterial catheterization and laser speckle flowmetry during vasoactive challenges and controlled hypotension. Cerebrovascular stress responses were tested using unilateral common carotid artery occlusion. Downstream brain effects were assessed by histology, resting state functional connectivity imaging, and behavioral testing. ResultsImpaired smooth muscle contractility drove rectification and narrowing of major cerebral arteries, downregulation of contractile markers, and increased vascular cell proliferation. These structural changes produced a distinct physiological phenotype: mutant mice exhibited blunted vasoreactivity, diminished spontaneous vasodynamic activity, and a downward shift in the blood pressure-CBF relationship across a wide range of arterial pressures, consistent with loss of cerebrovascular reserve. As a result, CBF was reduced at baseline and could not be maintained during hypotension or acute vascular stress. During carotid occlusion, mutant mice showed impaired compensatory perfusion, greater physiological instability, and worse behavioral outcomes. Chronic reserve failure coincided with white matter loss, reduced neuronal density, disrupted large-scale functional connectivity, and deficits in locomotion, anxiety-related behavior, and working memory. ConclusionsPathogenic smooth muscle dysfunction caused by ACTA2 mutation produces a baseline failure of cerebrovascular reserve that renders the brain vulnerable to hypoperfusion and stress-induced ischemic injury. These findings establish cerebrovascular reserve failure as a central physiological mechanism linking vascular dysfunction to end-organ brain injury and identify reserve preservation as a critical, potentially actionable determinant of brain health in hypotension-prone vascular disease. Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABS- ACTA2 smooth muscle dysfunction produces baseline cerebrovascular reserve impairment, with reduced cerebral blood flow and a downward-shifted pressure-flow relationship in the absence of critical large-vessel occlusion. - Vascular tone dysregulation is coupled to end-organ brain injury, including white matter and neuronal loss, disrupted functional connectivity, and behavioral deficits. - The results support complementary disease mechanisms in ACTA2 vasculopathy: baseline reserve limitation and injury-provoked occlusive remodeling. Clinical Implications- Patients with ACTA2 vasculopathy may be vulnerable to ischemic brain injury during hypotension or systemic stress despite the absence of critical stenosis or occlusion on routine imaging. - Peri-procedural and acute-care management should emphasize preserving perfusion pressure and cerebrovascular reserve (e.g., during anesthesia, dehydration, or systemic illness). - More broadly, cerebrovascular reserve is a clinically relevant, potentially modifiable determinant of brain health in hypotension-prone vasculopathies and conditions characterized by impaired vascular reactivity.

BackgroundRenal sodium reabsorption occurs via both transcellular and paracellular pathways. Tight junction proteins play a key role in mediating paracellular transport. The collecting duct (CD) is critical for the fine-tuning of Na+ balance and is sensitive to changes in dietary salt intake. A low-sodium diet, which increases endogenous aldosterone secretion, stimulates transcellular sodium transport via epithelial Na+ channels (ENaC) and Na,K-ATPase. We hypothesized that a low-sodium diet also modulates paracellular Na+ permeability by regulating the expression or function of claudin-3, a major tight junction protein in the CD, in order to limit the back-leak of reabsorbed sodium and preserve sodium balance. MethodsWe used in vivo mouse models and cultured mouse CD principal cells (mCCDcl1) to assess aldosterones effects on tight junction proteins. In mCCDcl1 cells, aldosterone-induced changes in claudin-3 expression and localization were evaluated via Western blotting and immunofluorescence, and Ussing chamber assays were used to assess paracellular Na+ and Cl- permeability after modulating claudin-3 expression. Wild-type and claudin-3 knockout mice were fed low (0.01%) or normal (0.18%) sodium diets for seven days. In subsets of low sodium diet mice, spironolactone (a mineralocorticoid receptor antagonist) was administered. ResultsIn mice, a low-sodium diet upregulates renal claudin-3 expression. Concordantly, in vitro studies using mCCDcl1 cells showed that aldosterone treatment increased claudin-3 protein levels and promoted its localization to the lateral membrane. Functional analyses demonstrated that claudin-3 overexpression reduced paracellular permeability to both Na+ and Cl-, while claudin-3 silencing increased it. Claudin-3 knockout mice subjected to a low-sodium diet exhibited compensatory upregulation of the - and {gamma}-subunits of ENaC, alongside increased expression of claudin-4, claudin-8, and claudin-10. This highlights an adaptive response that maintains sodium homeostasis in the absence of claudin-3. Importantly, this compensatory mechanism persists even under spironolactone treatment, suggesting that the adaptation of claudin-3-deficient mice occurs independently of mineralocorticoid receptor activation. ConclusionsOur findings demonstrate that aldosterone enhances claudin-3 expression, reinforcing the paracellular barrier to Na+ and complementing its classical role in transcellular Na+ transport. Under low-sodium conditions, claudin-3-deficient mice adapt through complementary mechanisms aimed at increasing sodium reabsorption via ENaC activation and upregulation of claudin-4 and claudin-8, both barrier-forming claudins that restrict paracellular sodium leakage in the CD. This is associated with increased claudin-10 abundance in the thick ascending limb of Henle, a pore-forming claudin that facilitates paracellular sodium permeability. This study advances our understanding of the complex control of renal sodium handling, revealing adaptive mechanisms in response to low-salt diet and claudin-3 deficiency.

Hypertension (HTN) is the most prevalent risk factor for severe cardiovascular disease and can cause major renal damage, inflammation, and immune cell accumulation. Lymphatic endothelial cells (LECs) are involved in the removal of pro-inflammatory immune cells and cytokines and kidney-specific augmentation of lymphangiogenesis can prevent or reduce HTN. In our previous paper, we performed single-cell RNA sequencing (scRNAseq) on CD31+/podoplanin+ renal cells from mice that underwent angiotensin II-induced (A2HTN) or salt sensitive (SSHTN) models of HTN (and their respective controls) and identified populations of LECs, myeloid immune cells (MICs), and a novel multipotent population we dubbed support cells (SCs). Using NicheNet, we compared baseline signaling between these three cell types in control samples and differences in signaling between control and HTN samples in both LECs and SCs. Ligands with high regulatory potential were identified for all three cell types, with Tgfb1 having the strongest and most consistent activity across all cell types. When comparing control and HTN samples in both LECs and SCs, HTN samples consistently had a larger number of downstream targets enriched and targets that were enriched in HTN samples also corresponded to significantly increased differentially expressed genes (p<0.01) as reported previously. Significant GO terms (p<0.01) were identified from targets and showed a shift in HTN samples away from homeostatic processes and toward growth and proliferation in LECs and translation and metabolism in SCs. Validation and manipulation of the ligand-receptor-target links identified here may provide novel approaches to reduce renal inflammation and immune cell activation. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=76 SRC="FIGDIR/small/701352v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@19bd1faorg.highwire.dtl.DTLVardef@f6a105org.highwire.dtl.DTLVardef@1c56b73org.highwire.dtl.DTLVardef@11897a_HPS_FORMAT_FIGEXP M_FIG C_FIG Created with BioRender.com

BackgroundHypertension is the leading modifiable risk factor for ischemic stroke, yet the adequacy of preventative hypertension care in routine clinical practice remains suboptimal. Whether gaps in hypertension management represent missed opportunities for stroke prevention remains unclear. ObjectiveTo evaluate the association between hypertension care delivery and the risk of incident ischemic stroke. MethodsWe conducted a retrospective, matched, nested case-control study among adults with hypertension using electronic health record data from a large regional health system (2010-2024). Patients with a first-ever ischemic stroke were matched 1:2 to controls on age, sex, race and ethnicity, and calendar time. Three care metrics were assessed during follow-up: (1) outpatient visits with blood pressure (BP) measurement per year; (2) number of antihypertensive medication ingredients; and (3) medication intensification score. Conditional logistic regression estimated adjusted odds ratios (aORs). ResultsThe study included 13,476 cases and 26,952 matched controls (N = 40,428). Mean (SD) age was 64.8 (12.2) years, 54.1% were female, and mean follow-up was 2,497 (1,308) days. Cases had fewer BP visits per year (median, 2.50 vs. 3.01; p < 0.001), similar number of medication ingredients (2.00 vs 2.00), and lower treatment intensification scores (-0.211 vs - 0.125). In adjusted models, >5 BP visits per year was associated with lower stroke odds (aOR, 0.55; 95% CI, 0.51-0.59) compared with [&le;]1 visit. Use of 2-3 medication ingredients (vs 0) was also associated with reduced stroke odds (aOR, 0.80; 95% CI, 0.75-0.86), whereas >3 ingredients was not significant. The highest quartile of treatment intensification showed the strongest association (aOR, 0.47; 95% CI, 0.44-0.51). Findings were consistent across subgroup and sensitivity analyses, including strata defined by baseline SBP and follow-up SBP. ConclusionsGreater engagement in hypertension care was associated with lower odds of ischemic stroke, suggesting that gaps in routine management may represent missed opportunities for prevention.

Obesity is the most common cause of hypertension. We have previously shown that high levels of circulating leptin in diet-induced obese (DIO) mice induced hypertension by increasing expression of Transient Receptor Potential Melastatin-subfamily member 7 (TRPM7) in the carotid bodies (CB). In addition, we demonstrated in rat PC12 cells that leptin increases Trpm7 gene expression by inducing CpG site-specific demethylation within the 5 regulatory region containing a signal transducer and activator of transcription 3 (STAT3) binding site. This leptin-induced Trpm7 upregulation was prevented by inhibition of JAK-STAT3 signaling. Based on these findings, we hypothesized that reversing region-specific methylation at the Trpm7 promoter in the CB could attenuate obesity-associated hypertension. Compared with lean controls, DIO mice exhibited increased Trpm7 expression and the STAT3- binding site-specific promoter demethylation in the CB. Administration of methylated DNA oligonucleotides targeting the STAT3 binding site attenuated CpG site-specific DNA demethylation and reduced Trpm7 transcription in the CB of DIO mice. This intervention resulted in decreased carotid sinus nerve activity and reduced arterial blood pressure, especially during the light phase. Our results suggest that targeted modulation of CpG site-specific DNA methylation at the Trpm7 promoter using DNA oligonucleotide may represent a novel therapeutic strategy for obesity-induced hypertension.