bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P112: Modifiable Factors Associated with Elevated Mean Arterial Pressure after Lower-Limb Loss
Authors: Stauffer Samantha , Sarlo Frank , Horne John , Sions Jaclyn
Published: October 2024

Introduction:
Adults with lower-limb loss (LLL) have increased risk of cardiovascular disease even after accounting for risk factors such as physical inactivity and comorbidity burden. Increased risk of cardiovascular mortality may be driven by structural adaptations following LLL, such as increased peripheral vascular resistance. Elevated mean arterial pressure (MAP), the steady component of blood pressure, is a clinical indicator of increased peripheral vascular resistance. Additionally, MAP >100mmHg is known to lead to cardiovascular damage. However, factors associated with elevated MAP among individuals with LLL remain unknown. We aimed to identify factors associated with elevated MAP among adults with LLL, while considering non-modifiable factors.

Hypothesis:
We hypothesized that LLL-specific non-modifiable variables (e.g., amputation level) and modifiable variables (e.g., prosthesis use) would be significantly associated with elevated MAP presence.

Methods:
From 2013 to 2023, community-dwelling adults, aged ≥18 years, with LLL and no history of a major adverse cardiac event, who attended a multidisciplinary LLL clinic, underwent standardized evaluations that included medical history review and blood pressure assessment. MAP was calculated using the equation: MAP = diastolic blood pressure + (0.466 × pulse pressure), with a MAP >100mmHg classified as elevated. Variables that were significantly different between-groups, i.e., MAP ≤ 100mmHg and MAP >100mmHg, were input in a forward stepwise logistic regression. Associations between modifiable factors and MAP status were evaluated after controlling for non-modifiable factors.

Results:
Of 206 participants (54.5±14.1 years old; 74.3% male; 72.8% Caucasian; 81.1% unilateral LLL; 59.2% transtibial; 42.2% dysvascular etiology), n=107 (51.9%) presented with elevated MAP. MAPs >100mmHg were associated with upper extremity pain [odds ratio (OR)=2.74, 95% confidence interval (CI)=1.31-5.74, p=0.008], assistive device use (OR=2.05, 95%CI=1.12-3.74, p=0.020) and elevated pulse rate (OR=1.02, CI=1.00-1.04, p=0.045).

Conclusions:
More than 50% of adults with LLL and no major adverse cardiac event history present with elevated MAP, indicating a maladaptive increase in peripheral vascular resistance. Identified factors that were significantly associated with elevated MAP may suggest subclinical cardiovascular disease and/or sympathetic overactivity, warranting closer evaluation of cardiovascular risk among adults with LLL.
Abstract P113: Hypertension Prevalence, Awareness, Treatment, and Control in Community-Dwelling Adults in Low-Resource Areas of Chicago, Illinois
Authors: Clingan Caroline , Walker James , Karthik Felix , Vanjani Nisheka , Lawande Niraj , Lloyd-Jones Donald , Shah Nilay
Published: October 2024

Background:
Hypertension (HTN) is an established risk factor for cardiovascular disease that disproportionately affects adults in low-resource communities. We examined hypertension prevalence, awareness, treatment, and control—the HTN control cascade—in low-resource neighborhoods in Chicago, Illinois.

Methods:
Using data from Keep Your Heart Healthy, a Northwestern Feinberg School of Medicine student-led community health program, we evaluated a convenience sample of adults who completed three blood pressure (BP) measurements at a community screening event between 2013 and 2019. Among adults with HTN (average systolic BP ≥140 mmHg, average diastolic BP ≥90 mmHg, or self-reported BP medication use), HTN awareness (self-reported history of HTN), HTN treatment (self-reported treatment among those who were aware), and HTN control (systolic BP <140 mmHg and diastolic BP <90 mmHg, among those who were aware and treated) rates were calculated.

Results:
Among 11,167 adults (mean age 50.9±14.8 years; 58.6% female; 63.9% Hispanic/Latino, 28.0% Black), HTN was prevalent in 45.3%. Of participants with HTN, 66.7% were aware of the diagnosis. Of those who were aware, 65.3% reported taking BP medication, of whom 48.3% achieved BP control. Overall, 21.0% of participants with HTN were aware, treated, and controlled (Figure). Additionally, 37.6% of all participants met criteria for pre-HTN (120-139 or 80-89 mmHg).

Conclusions:
In low-resource communities of Chicago, only 21.0% of participants with HTN were aware, treated, and controlled. Less than half of patients on treatment for HTN were controlled, revealing significant opportunity to improve HTN control in low-resource communities.
Abstract P115: Hypothetical Blood Pressure Lowering Interventions and Risk of Mortality in Middle-Aged and Older Chinese Adults: A Population-Based Modelling Study
Authors: Wang Man , Li Haibin
Published: October 2024

Background:
Improving hypertension control is an important global health priority. We aimed to study the effects of hypothetical interventions on systolic blood pressure (SBP) on mortality risk at the population level.

Methods:
We estimated the relationship between SBP and all-cause mortality in adults aged 45 years and older from the China Health and Retirement Longitudinal Study and compared the mortality reductions associated with lowering SBP to different hypothetical targets (120, 130, 140, 150 mm Hg). Using the parametric g-computation modeling technique, we estimated the mean blood pressure reduction required to achieve each target, the share of the population in need of management, and the number needed to treat (NNT) to avert one death under different hypothetical population-wide scale-up scenarios.

Results:
Among 12355 participants, 1203 died over 7-year follow-up. We found a weak, non-linear relationship between SBP and mortality, with larger incremental mortality benefits at higher SBP values: reducing SBP from 160 mm Hg to 120 mm Hg was associated with a relative risk of mortality of 0.75 (95% CI 0.65 to 0.86). At the population level, reducing SBP to 120 mm Hg among all those with a starting SBP of more than 120 mm Hg (120 mm Hg scenario) was associated with 13.7 deaths averted per 1000 population (95% CI -19.3 to -8.1), compared with 3.8 deaths averted per 1000 population (95% CI -6.0 to -1.6) associated with reducing SBP to 150 mm Hg among all those with a starting SBP of more than 150 mm Hg (150 mm Hg scenario). However, there were large differences between scenarios in the proportion of the population that would require treatment, ranging from 64.3% (95% CI 63.4 to 65.1) in the 120 mm Hg scenario to 16.7% (6.0 to 17.3) in the 150 mm Hg scenario. To achieve the target, the 120 mm Hg scenario required a mean shift of -14.4 mm Hg in SBP (95% CI -14.7 to -14.1) compared with a -2.9 mm Hg mean change (-3.0 to -2.7) for the 150 mm Hg scenario. Based on the ratio of number of deaths averted to the proportion requiring treatment, the 150 mm Hg scenario had the smallest NNT (n=44), followed by the 120 mm Hg scenario (n=47), the 140 mm Hg scenario (n=49), and the 130 mm Hg scenario (n=51).

Conclusions:
These findings highlight the possible substantial benefits of reducing blood pressure. We find that scaling up management based on a 150 mm Hg target is more efficient in terms of the NNT compared with strategies to reduce SBP to lower levels.
Abstract P122: Aberrant MicroRNA Expression May Underlie Cardiac Dysfunction in a rat model of Preeclampsia
Authors: Vaka Ramana , Campbell Nathan , Edwards Kristin , Hoang Ngoc , Zheng Baoying , Lamarca Babbette
Published: October 2024

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 P127: microRNA-204 protects against Angiotensin II-induced apoptosis in podocytes via Sox4
Authors: He Lishu , Liu Jing , Mishra Manoj , Guenther Maya , Therani Bhavika , Markson Ian , Pandey Rajan , Usa Kristie , Liu Pengyuan , Liu Yong , Liang Mingyu
Published: October 2024

Background:
We showed previously that global knockout (KO) of microRNA miR-204 attenuated hypertension but exacerbated renal injury including albuminuria in 14 days in C57BL/6J mice treated with uninephrectomy, angiotensin II, and a high-salt diet (Unx/AngII/salt). This suggests cell type-specific roles of miR-204. We hypothesize that miR-204 in podocytes protects against renal injury, specifically albuminuria via podocyte damage, in hypertension.

Methods:
We generated podocyte-specific miR-204 KO mice. Blood pressure and albuminuria were measured. RNA-seq in isolated miR-204 wild-type (WT) and KO mouse glomeruli, approximately 20% of which are podocytes, was performed. Human induced pluripotent stem cell-derived podocytes (iPSC-podocytes) were utilized to model and characterize podocyte injury.

Results:
Podocyte-specific miR-204 KO mice and WT littermates developed hypertension similarly following Unx/AngII/salt, but albuminuria was substantially exacerbated in miR-204 KO male mice (n=12, 8, 10 for WT, miR-204
+/-
and miR-204
-/-
, respectively; P<0.05, one-way ANOVA followed by Holm–Šidák test). RNA-seq analysis showed significant upregulation of Sox4, a target of miR-204 and a transcription factor promoting apoptotic p53, in the glomeruli of podocyte-specific miR-204 KO mice (P<0.05). A miR-204 KO iPSC line was generated by CRISPR/Cas9 and clonal expansion. Podocytes differentiated from miR-204 WT and KO iPSCs displayed arborized cell body, foot process-like structures, and significantly higher levels of podocyte markers Nphs1 and Nphs2. When apoptosis was induced via 24-hour AngII treatment, miR-204 KO iPSC-podocytes displayed upregulation of Sox4 (0.67±0.32 and 1.55±0.87, fold for WT and KO iPSC-podocytes compared to their control, n = 4, 4) and p53 (1.56±0.15 and 3.70±1.56, fold for WT and KO iPSC-podocytes compared to their control, n = 4, 4), and exacerbated AngII-induced apoptosis. Sox4 knockdown in miR-204 KO iPSC-podocytes mitigated the p53 upregulation (1.49±0.29 and 1.53±0.16, fold for WT and KO iPSC-podocytes compared to their control, n = 4, 4) and apoptosis.

Conclusions:
Our findings suggested that miR-204 in podocytes protect against AngII-induced apoptosis by suppressing Sox4, which in turn suppresses p53. Targeting the miR-204/Sox4 axis may hold therapeutic potential in attenuating podocyte injury and preserving renal function in hypertension patients.
Abstract P130: Predictive value of the MCG-based Nomogram model for the anatomical and functional evaluation of coronary artery lesions
Authors: Cui Yujie , Zhang Junyi , Jiang Yufeng , Zhou Yafeng
Published: October 2024

Objective:
Optical coherence tomography (OCT) is an intravascular imaging technology that can provide cross-sectional images of coronary arteries, which can more accurately assess the condition of coronary artery lesions and the degree of vascular stenosis. It is an important method for the anatomical evaluation of coronary artery lesions. Radionuclide myocardial perfusion imaging (MPI) is a commonly used non-invasive method for functional evaluation of myocardial ischemia in clinical practice. The clinical application of these two methods is greatly limited due to operational risk and high cost. This study aimed to explore the potential predictive value of the MCG-based Nomogram model for the anatomical and functional evaluation of coronary artery lesions.

Methods:
We reviewed the patients who were hospitalized in the cardiovascular department of our hospital from October 2021 to July 2023 for MCG test. A total of 137 patients were included in the OCT subgroup, including 48 patients in the severe coronary artery stenosis group (inclusion criteria: OCT showed coronary artery area stenosis ≥70.0%) and 89 patients in the control group (inclusion criteria: OCT showed coronary artery area stenosis <50.0% or CCTA showed no coronary artery stenosis). A total of 46 patients were included in the MPI subgroup, including 10 patients in the severe myocardial ischemia group (inclusion criteria: MPI showed abnormal perfusion scores of at least one ventricular segment ≥3 points) and 36 patients in the control group (inclusion criteria: MPI showed abnormal perfusion scores of all ventricular segments ≤2 points). The Nomogram model was used to predict the results of patients in the two subgroups, and the results were compared with the OCT and MPI results. The sensitivity, specificity and Youden index were calculated.

Results:
The Nomogram model based on MCG had a sensitivity of 70.8%, a specificity of 85.4%, and a Youden index of 0.562 for predicting OCT results. The sensitivity, specificity and Youden index of Nomogram model for predicting MPI results were 70.0%, 72.2% and 0.422, respectively.

Conclusions:
The MCG-based Nomogram model has good prediction accuracy for the anatomical and functional evaluation of coronary artery lesions, which has potential application value.
Abstract P145: The Biological Effects of Cross-Sex Hormone Therapy in the Male Rat Does Not Enhance Renal Risk in Young Adulthood
Authors: Mallette Jordan , Crudup Breland , Willis Alex , Cockrell Kathy , Yanes Cardozo Licy , Alexander Barbara
Published: October 2024

Transgender females (
TGFs
) are born male but identify as female. Gender-affirming hormone therapy (
GAHT
) is used to treat gender dysphoria. In TGFs, GAHT includes 17β-estradiol (
E2
) combined with an anti-androgen or surgical intervention. Whether renal function is decreased in TGFs on GAHT compared to cis-gender controls is unknown. Thus, we tested the hypothesis that glomerular filtration rate (
GFR
) is reduced and that renal susceptibility to acute renal ischemia is enhanced in male rats that undergo cross-sex hormone therapy (
CSHT
) in young adulthood. Male Sprague Dawley rats were randomly assigned to Control (
CON
) or E2 [5 mg/day, silastic capsule s.c. replaced every 3 weeks] starting at 13 weeks of age (adulthood) followed by castration (
CTX
) two weeks later. At 25 weeks of age, rats in each group were randomly subdivided to undergo Sham or renal Ischemia/Reperfusion (
I/R
, 18 minute occlusion renal pedicles) (n=8-11/grp). Metabolic studies were conducted two days prior, then 1, 7, and 21 days after Sham or I/R with GFR measured (direct method of FITC-sinistrin) at end of study. Two-way ANOVA with Tukey’s post hoc analysis,
P
<0.05 considered significant. Results (
Table
): Body weight and lean mass (EchoMRI) were significantly decreased in E2+CTX vs. CONs (*
P
<0.0001). At 1-day post-surgery, proteinuria was decreased in E2+CTX vs. CONs (†
P
<0.05); yet, 3 weeks post-surgery, proteinuria was only reduced in E2+CTX I/R vs. CON Sham (†
P<
0.05). GFR did not differ but urinary creatinine, which may reflect lean mass, was decreased in both E2+CTX vs. CONs (*
P
<0.0001). These data suggest that the biological effect of CSHT in the male does not enhance renal risk in young adulthood.
Abstract P150: Epigenetic Mechanisms Linking Early-Life Stress to Hypertension Development: Implications for Prevention and Treatment
Authors: Mohyeldin Moiud , Mustafa Ahmed , Mohamed Feras
Published: October 2024

Purpose:
Adverse childhood experiences (ACEs) and early-life stress (ELS) have been identified as significant risk factors for the development of hypertension later in life. This review synthesizes current evidence on how ELS induces epigenetic modifications, particularly DNA methylation and histone modifications, that predispose individuals to hypertension and discusses the implications for prevention and treatment strategies.

Methods:
A comprehensive literature review was conducted to identify studies examining the relationship between ELS, epigenetic modifications, and hypertension development. The search included studies investigating specific genes involved in stress response, inflammation, and cardiovascular regulation, such as NR3C1, SLC6A4, BDNF, OXTR, and FKBP5.

Results:
Studies have shown that ELS exposure can lead to persistent epigenetic alterations in genes involved in stress response, inflammation, and cardiovascular regulation. These modifications may contribute to impaired stress reactivity, heightened inflammation, and dysregulation of the renin-angiotensin system and endothelial function, potentially leading to the development of hypertension. The identification of ELS-induced epigenetic signatures opens up new avenues for early detection and intervention. DNA methylation biomarkers could be used to identify individuals at increased risk for hypertension due to ELS exposure, allowing for targeted prevention strategies. Moreover, the reversibility of epigenetic modifications presents an opportunity for novel treatment approaches, such as the use of epigenetic drugs and lifestyle interventions to mitigate the adverse cardiovascular effects of ELS.

Conclusion:
Understanding the epigenetic mechanisms linking ELS to hypertension development provides valuable insights for designing targeted prevention and treatment strategies. Future research should focus on translating these findings into clinical practice and developing personalized interventions based on an individual's ELS exposure and epigenetic profile. A multidisciplinary approach integrating epigenetics, stress neurobiology, and preventive medicine is required to address the long-term cardiovascular consequences of ELS effectively.
Abstract P162: Senolytic Treatment Attenuates Palmitic Acid-Induced Microglial Activation: Therapeutic Implications for Obesity-Induced Sympathoexcitation
Authors: Plakkot Bhuvana , Turtle Chenoa , Subramanian Madhan
Published: October 2024

Objective:
Microglial dysfunction has been previously implicated in the pathogenesis of obesity-induced neuroinflammation and sympathoexcitation, both of which significantly increase the risk for cardiovascular diseases. However, the mechanisms underlying obesity-induced glial dysfunction are not clear. In the current study, we investigated the role of cellular senescence that culminates in irreversible proliferative arrest and inflammatory phenotype, in obesity-induced glial dysfunction.

Methods:
Human microglial cells (n=6 wells/group/expt) were treated with 35 μM palmitic acid (PA) for 24 hours to mimic an obese microenvironment. Subsequently, the cells were treated with senolytic drugs, Dasatinib (250 nM) and Quercetin (100 μM) (D+Q) for 48 hours after PA treatment. Real-time PCR, lipid profiling, and senescence-associated beta-galactosidase (SAβGAL) were performed to evaluate changes in microglia to PA and D+Q treatment. Immunofluorescence staining evaluated microglial activation and vesicular glutamate transporter (VGLUT1) expression.

Results:
Microglial activation was confirmed by upregulation of Iba1 and CD11b in PA-treated cells. Significant upregulation of senescence genes (p16 and p21), senescence-associated secretory phenotypes (SASPs such as TNFα, MMP3), and SAβGAL staining in the PA treatment group indicating cellular senescence. PA treatment, significantly upregulated glutamate transporters EAAT1 and EAAT2 suggesting a potential adaptive response to counteract excitotoxicity. Bodipy and Oil-Red-O (ORO) staining revealed increased lipid accumulation in PA group, indicating altered lipid metabolism. D+Q group showed a significant decrease in senescence markers (p16 and p21) and SAβGAL staining, along with a reduction in lipid markers such as perilipin 1 and 2, and decreases in activated microglial markers IBA1 and CD11b. A significant decrease in EAAT1 expression was also observed. Immunofluorescence showed a significant decrease in VGLUT1 expression in the D+Q compared to PA-treated group.

Conclusions:
The findings suggest that palmitic acid-induced changes in human microglial cells can contribute to oxidative stress, cellular senescence, and alterations in glutamate clearance pathway potentially leading to sympathetic overactivity in obesity. Senolytic treatment (D+Q) mitigated PA-induced lipid accumulation and inflammatory changes in the microglial cells indicating a promising therapeutic strategy for managing sympathoexcitation in obesity.
Abstract P173: Pivotal Role for the Kinin B1R in CB1 Receptor Mediated Neuroinflammation and Pressor Response
Authors: Theobald Drew , Abdel-Rahman Abdel , Sriramula Srinivas
Published: October 2024

The cannabinoid receptors CB1R and CB2R are involved in blood pressure (BP) regulation and CB1R is implicated in the incidence of hypertension. CB1R is highly expressed in the brain but both receptors are also expressed in the heart. Prior research has demonstrated that CB1R mediates significant cardiovascular responses, including elevated BP, heightened plasma norepinephrine levels, and increased sympathetic nerve activity. Furthermore, the activation of the kinin B1 receptor (B1R) mediates similar effects when studied independently. However, the role of B1R in CB1R-mediated BP regulation and the associated signaling mechanisms remain unknown. In this study, we tested the hypothesis that B1R plays a pivotal role in CB1R-mediated pressor response, oxidative stress and neuroinflammation. To test this, we used both
in vivo
mouse models and
in vitro
primary hypothalamic neurons. Male C57BL/6NJ wild-type (WT) and B1R knockout mice (B1RKO) underwent surgical carotid artery and jugular vein catheterization to measure BP in conscious state. Following stabilization of BP for at least 90 minutes, the CB1R agonist WIN55,212-2 (300 ug/kg; i.v., WIN) or its vehicle was administered, and recordings continued for 45 minutes. WIN increased BP in WT mice (25±7 mmHg vs baseline), but this effect was blunted in B1RKO mice (n=3, p<0.05). Moreover, administration of WIN led to an augmentation of CB1R expression in the paraventricular nucleus of WT mice, but not in B1RKO mice, thereby indicating the involvement of B1R in CB1R signaling (p<0.05, n=3 mice/group). WT, but not B1RKO, mice treated with WIN displayed a significant increase in oxidative stress levels (p<0.05, n=3 mice/group), as indicated by dihydroethidium staining. To further confirm the role of B1R blockade on CB1R signaling, we cultured primary hypothalamic neurons, as neurons express the highest levels of CB1R in the brain. Neurons were stimulated with WIN (1 uM) both with and without a B1R selective antagonist (SSR240612, 10uM). The results indicated that WIN incubation for 24 hours increased CB1R expression, inflammation, and oxidative stress compared to vehicle treated, and these responses were abrogated by prior B1R blockade (p<0.05, n=5/group), consistent with the
in vivo
observations. These data provide novel evidence that B1R is implicated in CB1R-mediated proinflammatory responses and serves as a potential therapeutic target to reduce CB1R induced effects.
Abstract P175: The Effect of TRF on Hypertension Development in Male Dahl Salt-Sensitive Rats
Authors: Yunker Lauren , Usa Kristie , Williams Adaysha , Mis Brittany , Kriegel Alison
Published: October 2024

Time restricted feeding (TRF), or food consumption restricted to <10 hrs/day, has been shown to improve blood pressure in various cardiometabolic diseases, yet there is limited data on the effect in SS hypertension. The goal of this study was to examine the effect of TRF on disease development in the Dahl SS rat. We hypothesized that implementing TRF during a critical timepoint in disease progression would reduce mean arterial blood pressure (MAP). To study this, femoral catheters were surgically implanted in male Dahl SS rats at 9±0.5 weeks of age (n=5-7/group), allowing for urine and arterial blood sample collection from conscious rats during continual blood pressure recording. After 1 week of recovery, rats either continued a low salt (LS;0.4% NaCl) diet or were switched to a high salt diet (HS;4% NaCl) with ad libitum (ad lib) access for 1 week. At the start of week 2, a subset of rats began TRF, in which food was provided for 8 hrs (10PM-6AM) during their active period for an additional week. Rats meeting the following criteria were included in analysis: pulse pressure > 10 mmHg, baseline MAP of 115-130 mmHg, and a 10-20 mmHg increase in MAP after 1 week on HS. Differences in MAP were analyzed by 2-way ANOVA with Tukey multiple comparisons and data are reported as mean ± SEM. By the end of week 2, HS TRF rats trended toward lower average MAP compared to HS ad lib rats (141.51±3.41 vs 149.49±1.65 mmHg; p=0.07). However, we found that the HS TRF rats had reduced MAP during their active period (6PM-6AM), compared to the HS ad lib rats (142.60±2.99 vs 151.65±1.862 mmHg; p<0.05), but no difference during the inactive period (6AM-6PM). At the end of the study, average MAP was calculated every 4 hrs to identify the timing at which TRF reduced MAP. We found that the HS TRF rats had lower MAP from 6PM to 10PM (134.61±2.34 vs 146.75±1.21 mmHg; p<0.05) and 10PM to 2AM (144.58±2.79 vs 154.70±2.18 mmHg; p<0.05) when compared to the HS ad lib rats. The LS TRF group also had lower pressure from 6PM-10PM compared to the LS ad lib group (124.93±1.19 vs 130.56±0.73 mmHg; p<0.05), suggesting that this time-specific reduction in MAP may be due to fasting, as there were no other differences in MAP within the LS groups. This suggests that TRF may slow progression of hypertension development in the Dahl SS rat, primarily by affecting MAP during the active period. Future studies will examine how TRF affects Na
+
handling to further understand these time-dependent effects.
Abstract P176: Elevated Circulating T Cell-Monocyte Complexes in Long COVID-19 Tachycardia Syndrome: Implications of Immune Dysregulation, Inflammation, and Disease Progression
Authors: Abd-Eldayem Marwa , Golchha Meenakshi , Vance Yuliya , Ding Tan , Mwesigwa Naome , Chen Wei , Shibao Cyndya , Harrison David
Published: October 2024

Background:
Postural orthostatic tachycardia syndrome (POTS) is a common complication in Long-COVID. Long-COVID POTS (LCP) is characterized by abnormal orthostatic tachycardia, symptoms of orthostatic intolerance, and persistent inflammation.

Hypothesis:
Novel parameters of immune activation exist in and likely contribute to the pathogenesis of LCP.

Methods:
We enrolled 15 LCP patients and 5 subjects who recovered from COVID-19 infection without lingering effects as controls. Hemodynamic parameters were measured at baseline and during a 10-minute 75° head-up tilt. Flow cytometry was used to detect circulating T cells, monocyte subsets, and their cytokines. Immune synapse formation between T cells and monocytes was detected using Forster Resonance Energy Transfer (FRET) between T cell receptors (TCR) and human leukocyte antigens (HLAs). Intracellular staining was used to detect the cytokines IL-17A, IFN-γ and IL-6.

Results:
Subjects with LCP exhibited a greater increase in heart rate (HR) during 10-min upright tilt compared with controls (50.23± 4.6 vs. 20.33 ± 3.17 bpm,
p<0.01,
Figure). Circulating monocyte/T cell complexes were increased in LCP vs controls and these exhibited high TCR/HLA FRET (
p<0.005
), suggesting immune synapse formation. Importantly, complexed T cells demonstrated higher levels of IL-17A and IFN-γ, compared to non-complexed T cells and a profound increase in intracellular IL-6 compared to non-complexed monocytes (
p<0.005
). Notably, the percent of IFN-γ
+
and IL-17A
+
T cells in the monocyte/T cell complexes of LCP subjects positively correlated with their increase in HR (ΔHR) in 10 min active standing test (Figure).

Conclusion:
Circulating T cell-monocyte complexes are markedly increased in humans with LPC, and exhibit evidence of functional and dynamic cellular interactions. We propose that these contribute to persistent inflammation and the pathogenesis of autonomic dysfunction in these subjects.
Abstract P181: Class 1 human leukocyte antigens exhibit marked variability in capacity to present isolevuglandin adducts
Authors: Hunter Kuniko , Bloodworth Nathaniel , Abd-Eldayem Marwa , Chen Wei , Mallal Simon , Phillips Elizabeth , Harrison David
Published: October 2024

Introduction:
Isolevuglandins (isoLGs) are lipid peroxidation products that covalently modify lysine residues on self-proteins. These modified self-proteins are processed to peptides that are presented in the context of class I major histocompatibility complexes (MHC-I). In hypertension, this modification enhances CD8
+
T cell activation, contributing to inflammation and elevated blood pressure. In mice we found that IsoLG-adduct presentation is highly dependent on class I MHC structure. We sought to determine if human class I MHC (HLAs) exhibit similar variability in their ability to present these adducts by screening alleles representing 90% of the population.

Hypothesis:
We hypothesize that HLA subtypes exhibit variable capacity for isoLG presentation.

Methods:
HLA alleles representing 90% demographic frequency were identified from the US National Merit Donor Program Allele Frequency Database. HLA-null human K562 cells were transduced with these alleles, expanded, and enriched for HLA expression by flow cytometry to produce single HLA allele lines. To induce isoLG adduct presentation, cells were treated with 1mM tert-Butyl hydroperoxide (tBHP). After 24 hours, we employed Forster resonance energy transfer (FRET) between HLAs and isoLG-adducts using antibodies specific for both, which we have shown is indicative of IsoLG-adduct presentation (Fig 1A-C).

Results:
Substantial variability for isoLG-adduct presentation was observed between HLA subtypes A, B and C (Figure 1A-1C). Scikit-learn’s KMeans clustering revealed four patterns of isoLG-adduct presentation among HLAs: Low baseline/low activation, low baseline/high activation, intermediate baseline/intermediate activation, and high baseline/high activation alleles (Fig 1D).

Conclusions:
These findings identify specific HLA alleles as high isoLG presenters, potentially associated with increased immune activation risk. Combining these findings, HLA alleles, and diagnosis code databases could aid in identifying high-risk haplotypes for immune activation in human hypertension.
Abstract P182: Antigen Presenting Cell-specific Keap1-Nrf2 pathway Mediates Salt-Sensitive Hypertension in Humans
Authors: Khan Mohd , Saleem Mohammad , Ahmad Taseer , Mutchler Ashley , Haynes Alexandria , Kirabo Annet
Published: October 2024

Background:
Hypertension remains the leading cause of mortality worldwide and is a primary risk factor for cardiovascular disease. Of the 1.3 billion people globally affected by hypertension, over 50% exhibit salt-sensitivity of blood pressure (SSBP), which leads to higher rates of mortality, morbidity, and kidney damage compared to those with salt-resistant hypertension. Previously our research has shown that high salt intake activates antigen-presenting cells (APCs), causing inflammation and hypertension. This pro-inflammatory response is partly driven by the epithelial sodium channel (ENaC), which facilitates sodium ion transport into APCs. While the Keap1-Nrf2 pathway is known for its role in antioxidant defense and inflammatory responses, its contribution to salt-sensitive hypertension remains unclear. We hypothesize that ENaC-dependent sodium entry triggers inflammation and activates the Sp1-MALAT1-Keap1-Nrf2 signaling axis in APCs, thereby contributing to SSBP.

Method:
We utilized a well-established inpatient protocol to phenotype participants for salt sensitivity of blood pressure. Additionally, we conducted RNA sequencing (RNAseq) on human monocytes exposed to elevated sodium levels in vitro and performed Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) analysis on peripheral blood mononuclear cells (PBMCs).

Results:
We found that whereas high salt did not significantly increases expression of Sp1 (5380.63 ± 359.77 vs 7414.54 ± 434.19, q=0.829), MALAT1 (86888.54 ±12200.12 vs 219429.90 ± 109994.16, q=0.717), Keap1 (1586.54 ± 132.94 vs 2203.72 ± 177.48, q=0.884), it significantly increased Nrf2 expression (5080.36 ± 416.64 vs 5443.54 ± 432.78, q=0.019) in RNAseq analysis of human high salt compared to normal salt treated monocyte. Furthermore, the results of the CITE-seq experiment indicated that changes in the expression of the Sp1 correlate with SSBP (r=0.5205, p=0.038).

Conclusion:
These preliminary findings reveal a physiological link between inflammation and salt-sensitive hypertension through the Sp1-MALAT1-Keap1-Nrf2 signaling axis in APCs. The activation of APCs mediated by Sp1 could potentially serve as a diagnostic marker for salt sensitivity in blood pressure.
Abstract P195: Vascular MAPK/ERK Activation in sFTL-1-Induced Preeclampsia
In Vivo
Authors: Kumar Nitin , Hunker Kristina , Ganesh Santhi
Published: October 2024

Vascular endothelial growth factor (VEGF) inhibition is linked to the development of hypertension and proteinuria in preeclampsia. This occurs as anti-angiogenic factors from the placenta contribute to pregnancy-related hypertension disorder. Soluble VEGF receptor fms-like tyrosine kinase-1 (sFLT-1) is an anti-angiogenic factor that counteracts VEGF. Levels of sFLT-1 are three times higher in preeclamptic placentas compared to those from normotensive pregnancies, and plasma sFLT-1 levels increase with the severity of preeclampsia. Infusing sFLT-1 in rodents induces hypertension, proteinuria, and glomerular endotheliosis, resembling the human condition of preeclampsia. Currently, there is no effective pharmacological treatment of preeclampsia, and in severe cases, early delivery is often the only effective treatment. In this study, we aim to determine how sFLT-1 exposure affects the activation of the vascular MAPK/ERK pathway and the contractility of the aorta
ex-vivo
using wire myography, to assess if the MAPK/ERK pathway can be a therapeutic target in preeclampsia. To this end, we treated pregnant female C57BL/6 mice from embryonic day E7.5 to E18.5 with either sFLT-1 (3.7mg/kg/day) or vehicle (phosphate-buffered saline) delivered by osmotic minipumps (intraperitoneal) and carried out non-invasive tail-cuff blood pressure measurements. After sacrifice, we isolated descending thoracic aorta for isometric tension measurements in a wire myograph. Infusion of sFLT-1 resulted in marked systolic blood pressure (SBP) elevation (D increase of 14 mmHg, P=0.0003) and augmented aortic phosphorylated-ERK activation (2-fold increase, P=0.040) by western blot and displayed impaired acetylcholine-induced endothelial relaxation in thoracic aortic segments (P<0.05), providing
in vivo
evidence of increased vascular p-ERK activation, accompanied by higher SBP and endothelial dysfunction in sFLT-1
-
indued mouse model of preeclampsia. Future experiments are aimed to test the effect of pharmacological ERK inhibition in sFLT-1 infusion
in vivo
. We hypothesize that sFLT-1-induced rise in SBP and vascular p-ERK could be prevented
in vivo
by treatment with the pharmacological ERK inhibitor.
Abstract P201: Macula Densa (Pro)Renin Receptor Contributes to 2-Kidney, 1-Clip-Induced Renovascular Hypertension but not Ischemic Nephropathy in Mice
Authors: Fu Ziwei , Kaewsaro Kannaree , Lee Matias , Liu Ruisheng , Yang Tianxin
Published: October 2024

Our previous presentation at this meeting showed that collecting duct (CD)-specific deletion of (pro)renin receptor (PRR) or renin attenuated hypertension and kidney damage induced by the 2-kidney, 1 clip (2K1C) procedure, highlighting an essential role of the intrarenal renin-angiotensin system (RAS) in the pathogenesis of renovascular hypertension and ischemic nephropathy. Besides the CD, PRR is also expressed in the macula densa (MD), mediating renin release from the juxtaglomerular (JG) cells. Here we examined the phenotype of NKCC2-Cre-mediated MD/TAL-specific deletion of PRR (MD/TAL PRR KO) following the 2K1C procedure. Clipping-induced hypertension was partially attenuated in MD/TAL PRR KO mice compared to floxed controls (MAP on day 24: Floxed/2K1C 148.3±1.8 mm Hg vs. MD/TAL PRR KO/2K1C 138.8±2.9 mm Hg, n=6, p < 0.05), to a similar degree in mice lacking PRR or renin in the CD. However, MD/TAL PRR KO mice did not exhibit protective effects against ischemic nephropathy compared to floxed controls following the 2K1C procedure (urinary albumin/creatinine: Floxed/2K1C 65.9 ± 4.6 mg/g vs. MD/TAL PRR KO/2K1C 59.5 ± 2.7 mg/g, n=6). Furthermore, there were no significant differences in clipping-induced protein abundance of renal fibronectin, α-SMA, or proinflammatory markers such as IL-1β, TNF-α, MCP-1. The protective phenotype against hypertension observed in KO mice was paralleled with suppressed plasma renin activity, active renin content, and total prorenin/renin levels. Additionally, while clipping upregulated renin mRNA expression in both renal cortex and medulla of floxed mice, only cortical renin expression was reduced by 39% in MD/TAL PRR KO mice. The 2K1C-induced increase in circulating sPRR was attenuated by 31% in MD/TAL PRR KO mice. Overall, our results suggest that renovascular hypertension in the 2K1C model is jointly determined by the systemic and intrarenal RAS whereas ischemic nephropathy in this model solely depends on the intrarenal RAS.
Abstract P206: Renal hemodynamic and transcriptomic changes in response to salt in Dahl salt-sensitive rats
Authors: Shimada Satoshi , Yang Chun , Dash Ranjan , Cowley Allen
Published: October 2024

Introduction:
Continuous measurements (24/7) of arterial pressure (AP) and renal blood flow (RBF), along with intermittent sampling of arterial and renal venous blood and urine in freely moving rats, have enabled the determination of sequential changes in global substrate metabolism and their association with physiological responses in the kidney. It was found that salt loading in Sprague-Dawley (SD) rats resulted in an increase in RBF and renal O
2
consumption with minimal changes in AP. At the same time, TCA cycle pathway was downregulated with reduced metabolism of free fatty acids and amino acids, while glycolysis was upregulated, in the kidney cortex (Cx). In contrast, no significant changes were observed in metabolism-related pathways in the outer medulla (OM). (PMID: 37575482). Here, we report transcriptomic responses of Dahl salt-sensitive (SS) rats to the HS diet as compared to the salt-resistant SD rats.

Method:
Male SS rats were fed a 0.4% NaCl (LS) diet. At 8 weeks of age, the rats were implanted with an RBF probe together with an arterial and a renal venous catheter. RBF and AP were measured continuously, and arterial and renal venous blood and urine were sampled when rats were fed the LS and on days 7, 14, and 21 after switching to the 4.0% NaCl (HS) diet. From separate groups of rats subjected to the same protocol, Cx and OM were removed for mRNAseq analysis (Novogene, Inc).

Results:
When switching to the HS diet, mean AP of SS rats rose from 122 ± 2 to 164 ± 5 mmHg by HS21. RBF (mL/min/g kidney weight) fell significantly over the 3 weeks of the HS diet averaging 7.2 ± 0.6 (LS) to 4.6 ± 0.7 (HS21). The gene set enrichment analysis (GSEA) of the mRNAseq data revealed that only a few metabolic pathways were enriched in HS7 in Cx such as glycosphingolipid biosynthesis, while metabolic pathways such as linolenic acid and arachidonic acid metabolism and glycosphingolipid biosynthesis were enriched in OM. Downregulation of the lysine degradation and glutathione metabolic pathways was observed in both Cx and OM in HS21. In general, fewer metabolic pathways responded to HS in SS rats compared to SD in Cx (22 in SD vs 7 in SS).

Conclusion:
The Cx of SS rats appear less capable of adjusting to the increased metabolic needs imposed by a HS diet compared to SD rats in contrast to the OM. The functional implications of this are being examined and the metabolomic analysis of blood, tissue and urine samples is currently in progress at the JAX lab.
Abstract P209: The novel angiotensin Alamandine-(1-5) is increased in plasma of pediatric patients with primary nephrotic syndrome
Authors: Silva Ana Cristina , Alves Soares Vaz de Castro Pedro , Silva Filipe , Ribeiro Lucas , Verano-Braga Thiago , Santos Robson
Published: October 2024

Background and Aim:
The Renin Angiotensin System (RAS) has an important role in the pathophysiology of primary nephrotic syndrome (NS). It was previously found that urinary levels of angiotensin converting enzyme 2 (ACE2) are reduced in patients with NS in comparison to health controls. The aim of this study was to measure the novel angiotensin peptide, Alamandine-(1-5), in plasma samples of patients with primary NS and to compare with sex and age-matched controls.

Methods:
Blood samples of pediatric patients with primary NS (n=11) and of sex and age-matched health controls (n=11) were collected in sterile tubes with 7.5% (w/v) EDTA. After plasma separation and purification by solid phase extraction, the circulating levels of Alamandine and of Alamandine-(1-5) were measured by Mass Spectrometry using multiple reaction monitoring on an ACQUITY I-Class UPLC system coupled to electrospray ionization (ESI) tandem mass spectrometry (LC-ESI-MS/MS Xevo TQ-S). Data were compared between patients and controls and associated with laboratory findings. Continuous variables were presented as mean ± standard error of the mean.

Results:
A total of 11 patients (7 males) with NS with mean age of 10.65±3.66 were compared to 11 controls (6 males) and with 10.86±4.35 years. In terms of disease response, 5 patients were in partial remission, 5 patients in total remission and only 1 patient was in disease relapse. All patients have normal renal function. Plasma levels of Alamandine-(1-5) were significantly higher in patients when compared to controls (28.03±7.54 vs. 10.68±3.02 pg.mL-1 in controls). Despite a mild decrease in patients, plasma levels of Alamandine did not differ between groups (19.54±6.33 vs 26.09±6.12 pg.mL-1 in controls). No correlations were found between RAS molecules and proteinuria and with the medications in use. However, Alamandine-(1-5) negatively correlated with plasma levels of albumin (r= -0.695; p=0.038). In addition, Alamandine negatively correlated with total cholesterol (r=-0.700; p = 0.036), LDL (r=-0.800; p=0.004), and HDL (r = -0.762; p = 0.038).

Conclusion:
The novel RAS peptide Alamandine-(1-5) is significantly increased in primary NS and inversely correlated with plasma albumin levels. These findings suggest a potential role of Alamandine-(1-5) in NS
Abstract P211: Angiotensin-(2-7): A novel antihypertensive peptide of the renin-angiotensin-system
Authors: Barros Carolina , Ferraz Kamylle , Chaves Sthefanie , Bessa Amanda , Vieira-Machado Uri , Feng Isadora , Itaborahy Matheus , Monteiro Adelson , Silva Filipe , Nakaie Clovis , Silva Rogerio , Bersanetti Patricia , Carmona Adriana , Leite M. Fatima , Santos Robson
Published: October 2024

Recently, it has been described that acetyl-angiotensin (2-7)-amide (Ac-Ang-(2-7)-NH2) is a potent ACE inhibitor. In addition, the putative endogenous peptide angiotensin-(2-7) was also reported to be an ACE inhibitor. Here we tested the effect of Ang-(2-7) in blood pressure (BP) and isolated aortic rings of Wistar and SHR. In addition, we evaluated whether this hexapeptide stimulates receptors from the alternative renin-angiotensin system (RAS), including Mas, MrgD, and AT2R using CHO-transfected cells. To record BP and administer drugs, the femoral arterial and vein were cannulated. In the baseline period, BP was recorded for 1 hour. In bolus intravenous injection of Ang-(2-7) was performed at doses of 30, 6, and 2.4 μg/kg, in a volume of 0,1 ml/100g. After the injection BP and heart rate (HR) were recorded for six hours. Additionally, we evaluated the effect of Ang-(2-7) in isolated aortic rings from SHR and Wistar rats, pre-constricted with phenylephrine (10
-7
mol.L
-1
). The peptide effect was tested in the range of 10
-12
to 10
-6
molar. The effect of the peptide was also evaluated in endothelium-denuded rings. Furthermore, the effect of Ang-(2-7) was tested in rings pre-treated with the Mas/MrgD antagonist D-Pro
7
-Ang-(1-7) (10-6 μmol.L
-1
). Finally, we used NO intracellular measurements to test for the Ang-(2-7) activation of Mas, MrgD, or AT2 receptors using transfected-CHO cells. To confirm the effectiveness of Ang-(2-7) for NO production we used 4,5-diaminofluorescein-diacetate (DAF-FM diacetate) and the human umbilical vein cell line EA.hy926. Our data showed a progressive and marked reduction in BP reaching -40 mmHg (123±12mmHg;n=3) with 6 hours after 30ug/kg administration of injection of Ang-(2-7). There was no significant effect on Blood pressure in Wistar rats after injection. The aortic rings had a vasorelaxing effect of the Ang-(2-7) in both Wistar and SHR, which was abolished after endothelium was removed. The vasorelaxant effect of Ang-(2-7) was abolished by pre-treatment with D-Pro
7
-Ang-(1-7). Accordingly, Ang-(2-7) induced NO production in EA.hy926 and MrgD-transfected CHO cells. A slight effect on NO production was also observed in AT2-transfected cells. In conclusion, we have identified a new biologically active component of the RAS with a potent antihypertensive effect in SHR. Our results suggest an important contribution of MrgD/NO to the Ang-(2-7) cardiovascular effects.