bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 575: Complement Activation in Placental Ischemia-induced Hypertension is not dependent on Angiotensin II Type 1 Receptor
Authors: Regal Jean F , Elmquist Barbara J , Peterson Jenna M , Gilbert Jeffrey S
Published: March 2022

Early onset preeclampsia is characterized by hypertension, reduced placental perfusion, intrauterine growth restriction and increased activation of complement, part of innate immunity. We reported that inhibition of complement activation attenuated reduced uterine perfusion pressure (RUPP)-induced hypertension in the pregnant rat. Although recent studies in pregnant mice indicate injection of autoantibodies to angiotensin II Type 1 receptor (AT1-AA) activate complement and increase blood pressure, the sequence of events following placental ischemia remains unknown. Thus, we hypothesized AT1-AA interaction with its antigen was responsible for complement activation critical to placental ischemia-induced hypertension. The AT1 antagonist losartan prevents AT1-AA interaction with the AT1 receptor. Thus, we determined the effect of losartan on complement activation following placental ischemia in rat. Dams received drinking water with or without 30 mg/kg/day losartan on gestation day (GD)13-19. On GD14, rats underwent Sham surgery or RUPP surgery with placement of clips on abdominal aorta and uterine arteries to decrease placental perfusion. On GD19, mean arterial pressure (MAP) via arterial catheter and serum C3a as an indicator of complement activation were measured.

As expected, RUPP surgery increased complement activation (C3a) and MAP and decreased fetal weight compared to Sham. Importantly, losartan treatment did not significantly change RUPP-induced increase in C3a. These data indicate AT1-AA interaction with the AT1 receptor does not mediate complement activation and its subsequent involvement in hypertension following placental ischemia.
Abstract 577: Increased Uterine Interimplantation Levels of Ang II, AT
1
R, and CB
1
R are Associated with Reduced Uterine Permeability at Early Pregnancy in a Transgenic Model of Preeclampsia
Authors: Brosnihan K. Bridget , Pulgar Victor M , Varagic Jasmina , Oliva Kimberly , Bader Michael , Dechend Ralf , Gallagher Patricia , Thomas Brian F , Grabenauer Megan , Yamaleyeva Liliya M
Published: March 2022

Both the renin-angiotensin (RAS) and endocannabinoid (ECS) systems are down-regulated at the early stages of normal pregnancy. The striking similarity of the pattern of distribution of the two systems and their required down-regulation in
early
events of pregnancy make a compelling argument to compare their regulation in the early events of pregnancy in an animal that has placental activation of the RAS at l
ate
gestation. Female transgenic rats with overexpression of human (h) angiotensinogen were mated with male rats with
h
renin [Preeclamptic model (PRE)]. At day 7 of gestation, normal pregnant Sprague Dawley (SD) and PRE animals were anesthetized and bovine serum albumin (BSA) conjugated to Alexa Fluor 488 was injected systemically to assess uterine permeability in the implantation (IS) and interimplantation (IIS) uterine sites. Mean blood pressures were not different between SD and PRE animals (98.8±2
vs
97±3 mmHg, p>0.05). Uterine permeability measured as the IS/IIS ratio of fluorescent BSA signal was decreased in PRE vs. SD (1.36±0.2 vs 0.68±0.1, p<0.05). The levels of Ang II and AT
1
R mRNA were increased in the IIS of PRE vs IS of PRE and IIS of SD (
FIGURE
). CB
1
R mRNA was increased in the IIS vs. IS of PRE rats, and this was associated with a significant increase in the levels of total 1+2-arachidonoylglycerol (24.9±4.1 vs 12.2±3.5 ng/mg protein, p<0.05) in IIS of PRE vs IIS of SD. These data demonstrate a synergistic up-regulation of the RAS and ECS associated with reduced uterine permeability at early pregnancy in a PRE model. These changes precede the hypertensive phenotype and are consistent with a critical role for the disrupted RAS and alterations in the ECS in early pregnancy.
Abstract 580: Apoptotic Signaling Is Augmented In Preeclampsia: An Adverse Impact On The Offspring
Authors: Co Mary A , Leonard Dean , Beeram Madhava R , Govande Vinayak P , Allen Steven R , Jones Richard O , Kuehl Thomas J , Uddin Mohammad N
Published: March 2022

Objective:
Preeclampsia (preE), a syndrome of hypertension and proteinuria in pregnancy, is thought to be initiated with alterations of placental function. Hypoxia and oxidative stress can lead to placental apoptotic signaling, which pass the placental barrier and leave persistent defect in the circulation of the offspring that may predispose to a pathological response later in life. We assessed apoptotic signaling in placentas and umbilical cords from patients with or without preE. We also evaluated the pregnancy outcomes.

Methods:
In this study, we recruited 20 normal pregnant (NP) and 20 preE consenting patients in an IRB approved prospective study from Scott & White hospital, Temple, Texas. Inclusion criteria for determination of preE patients include blood pressure >140/90 and presence of proteinuria >300 mg of protein/24h urine. Samples of placenta and umbilical cord were collected from those subjects after deliveries. Apoptotic and stress signaling proteins; pro-apoptotic Bcl-2-associated X protein (Bax), anti-apoptotic Bcl-2 protein, caspase 9 and pro-inflammatory protein cyclooxygenase-2 (Cox-2) expression were assayed both by western blot and immunohistochemistry. The p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation was evaluated by western blot. Comparisons were performed using ANOVA with Duncan’s post-hoc test.

Results:
The ratio of Bax/Bcl-2 expression (Placenta: 1.2 fold, Cord: 1.5 fold), Cox-2 (Placenta: 0.8 fold, Cord: 2.5 fold), Caspase 9 (Placenta: 1.5 fold, Cord: 1.8 fold), and p38 MAPK phosphorylation (Placenta: 1.5 fold, Cord: 1.7 fold) were up-regulated (p<0.05) in placental tissues and umbilical cords of preE compared to NP patients. We did follow up examination of the babies for both groups of patients to assess the pregnancy outcome. Average hospital stay for PreE babies were significantly longer than those of NP babies (3.4 vs 6.1). There were no complications has been reported for the NP babies. However, all of preE babies had multiple medical complications.

Conclusions:
Apoptotic signaling is augmented in preE which alters the intrauterine environment by modulating the pattern of hormonal signals and activating the detrimental cellular signaling that has been transported to the fetus.
Abstract 581: Protective Effects Of Bilirubin Administration On Placental Ischemia-induced Hypertension
Authors: George Eric M , Stec David E , Granger Joey P
Published: March 2022

Preeclampsia is one of the most common complications of pregnancy in humans, and is a leading cause of premature birth and fetal perinatal morbidity and mortality. The hallmark of the disorder is the manifestation of new-onset hypertension-typically after the 20th week of gestation. While the underlying cause of the disorder remains obscure, it is widely held that failure of the maternal vasculature to adequately remodel and supply the developing placenta with adequate blood flow leads to placental insufficiency and resulting ischemia. In response placental derived factors, namely the anti-angiogenic protein sFlt-1 and reactive oxygen species- are released into the maternal circulation resulting in the symptomatic phase of the. We have recently demonstrated that induction of heme oxygenase in a rodent model of placental ischemia attenuates the associated hypertension by blocking both of these pathways, presumably through byproducts carbon monoxide and bilirubin. Here, we have investigated the in vivo effects of exogenous bilirubin administration on a rodent model of placental ischemia-induced hypertension, the reduced uterine perfusion pressure (RUPP) model. RUPP animals exhibited significant increases in MAP when compared to sham animals (109 ± 3 vs 120 ± 4 mmHg, p<0.05). Exogenous administration of bilirubin (30mg/kg/q 48h, i.p.) had no significant effect on MAP in sham animals (101 ± 2 mmHg), but significantly decreased MAP in RUPP animals (107 ± 2 mmHg, p<0.05), returning pressure to sham control levels. Promisingly, bilirubin administration had no detrimental effect on fetal weight (2.5 ± 0.14 vs 2.2 ± .28 g) or incidence of fetal loss (6 ±2% shams vs 3 ± 2% treated). In RUPP animals, which have significantly increased incidence of fetal loss compared to controls (69 ± 6%, p<0.005), bilirubin tended to decrease fetal loss (43 ± 13%), however, this did not meet statistical significance. In summary, bilirubin administration attenuated the hypertension associated with placental ischemia, and moderately increased bilirubin is a potential mechanism to explain the therapeutic effects of heme oxygenase induction in this clinically relevant model for the study of preeclampsia.
Abstract 606: Soluble Guanylate Cyclase (sGC) Stimulator Reduces The Cardiac And Renal Damage In Angiotensin II (Ang II)-induced Diastolic Heart Failure
Authors: Haase Nadine , Wilck Nicola , Marko Lajos , Heuser Arnd , Brockschnieder Damian , Kretschmer Axel , Stasch Johannes-Peter , Dechend Ralf , Müller Dominik N
Published: March 2022

Diastolic heart failure (DHF) is estimated to account for approximately 40% of heart failure cases. Due to the high prevalence and high mortality rates, diastolic heart failure represents a major challenge in cardiovascular medicine. The novel therapeutic alternative with NO-independent direct stimulators of sGC has recently been approved for the treatment of pulmonary hypertension.

We analyzed the role of the sGC stimulator BAY 41-8543 in a transgenic rat model of hypertension-induced diastolic heart failure. We used 4 week-old male double transgenic rats harboring both human renin and angiotensinogen genes (dTGRs). At age 7 weeks, dTGR show striking cardiac hypertrophy with fibrosis, severe diastolic dysfunction but preserved systolic function, albuminuria, and renal failure. We compared vehicle-treated dTGR receiving 10% transcutol, 20% cremophor, 70% water, dTGR receiving 3 mg/kg/d BAY 41-8543, and vehicle-treated SD control rats (single oral dose per day for 3 weeks).

Systolic blood pressure increased progressively in vehicle-treated dTGRs compared with SD rats. BAY 41-8543 significantly reduced the blood pressure (197 ± 11 mmHg vehicle vs 133 ± 4 mmHg BAY 41-8543). Treatment with sGC stimulator ameliorated albuminuria (0.3 ± 0.06 mg/8h at week 7) compared with vehicle-treated dTGRs (12.4 ± 2.6 mg/8h at week 7). In addition BAY 41-8543 prevented fibrosis and inflammation in kidney and heart. Cardiac hypertrophy or myocyte size were not reduced by BAY 41-8543 treatment. Cardiac echocardiography and hemodynamic investigations showed that BAY 41-8543 increased ejection fraction and improved diastolic function including speckle tracking and tissue doppler imaging. Programmed electrical stimulation showed a high non-sustained and sustained ventricular tachycardia induction rate in vehicle-treated dTGRs (46%), which was significantly reduced in BAY 41-8543-treated dTGR (11%). Finally, BAY 41-8543 treatment resulted in 100% survival at week 7, whereas 76% of vehicle-treated dTGRs died.

Our data demonstrate that sGC stimulators ameliorate cardiac and renal end-organ damage including electrical remodeling in a transgenic rat model of hypertension-induced DHF. Treatment of DHF with sGC stimulators offers a novel therapeutic potential.
Abstract 607: Cardiac-specific Deletion Of ErbB4 In The Adult Mouse Increases Cardiac Cell Proliferation And Causes Physiological Cardiac Hypertrophy
Authors: Wang Zhen , Thomas Walter , Paravicini Tamara
Published: March 2022

The epidermal growth factor receptor type 4 (ErbB4) is a receptor tyrosine kinase that is activated by the growth factor neuregulin 1 (NRG1). ErbB4 is essential for cardiac development and promotes cardiomyocyte survival in culture. To investigate the physiological importance of ErbB4 in the adult heart, we generated a mouse model with conditional deletion of ErbB4 in cardiomyocytes using a tamoxifen-inducible Cre recombinase (MHC-MerCreMer). Adult MHC-MerCreMer/ErbB4
fl/fl
(ErbB4 conditional knockout, cKO, n=6) and MHC-MerCreMer/ErbB4
WT/WT
(control, n=8) animals were injected with tamoxifen (20 mg/kg/day ip for 10 days). Ten days after tamoxifen treatment, cardiac specific deletion of ErbB4 was confirmed by qPCR. At 3 months after ErbB4 deletion, echocardiography showed no differences in cardiac function (fractional shortening), however the heart weight:tibia length ratio was increased by 45% in the cKO animals (5.1±0.2 vs 7.4±0.6 mg/mm,
P
<0.05 vs controls). Cardiac-specific ErbB4 deletion did not increase expression of genes associated with pathological hypertrophy (BNP, α-MHC:β-MHC ratio), suggesting that the hypertrophy seen in the cKO animals may be physiological rather than pathological. Similarly, cardiac-specific ErbB4 deletion did not cause cardiac fibrosis (Masson’s Trichrome) or alter fibrotic gene expression (Col1A1, Col3A1 and PAI1). Cardiomyocyte cross sectional area was measured using wheat germ agglutinin staining, and showed no differences between controls and cKO. Interestingly, cardiac mRNA levels of both isoforms of the endogenous ErbB4 agonist NRG1 were strongly increased in cKO animals (fold change compared to controls: 5.3±1.7 for NRG1α; 4.3±1.2 for NRG1β,
P
<0.01) and this correlated with a significant increase in the total number of cells positive for a marker of proliferation (phosphorylated-histone H3; 1.8±0.4 vs 8.2±2.8 cells/section,
P
<0.05).

Conclusion:
Cardiac-specific deletion of ErbB4 in the adult increases heart weight without altering cardiac function, cardiomyocyte size or fibrosis. ErbB4 deletion also increases NRG1 expression, which may contribute to the maintenance of cardiac function and the development of cardiac hypertrophy via cell proliferation.
Abstract 611: Hypertension Management at United States Physician Office Visits Made by Hypertensive Adults
Authors: Myrick Kelly L , Uddin Sayeedha G
Published: March 2022

Background:
The objective was to compare the management of hypertension at ambulatory care visits by sex among previously diagnosed hypertensive patients in the United States.

Methods:
Cross-sectional data from the 2010 National Ambulatory Medical Care Survey of physician office visits was used. Visits to primary care physicians or cardiovascular disease specialists by both hypertensive males and females (non-pregnant) ≥18 years were included. Chi-square tests were used to compare visits by sex. P-value <0.05 was considered statistically significant.

Results:
There were 157 million physician office visits by hypertensive adults in 2010. Visits by patients 45-64 years represented 41% (65 of 157) of visits. Non-Hispanic Whites comprised 71% (112 of 157) of visits, Non-Hispanic Blacks 16% (25.5 of 157) and Hispanics 8% (13.3 of 157). Females represented 56% of the visits. A higher percent of current tobacco use (15%, 10 of 69) and private insurance as the expected source of payment (45%, 31 of 69) was observed in visits among males than visits among females (9%, 7.8 of 88 and 40%, 35 of 88, respectively for females). Depression screening was provided at 1% (1 of 69) of visits made by males and 2% (2 of 88, p=0.03) of visits made by females. There were no differences by sex for the following: blood pressure control (≥140/90 mmHg) (64% males, 42 of 65; 62% females, 50 of 82), smoking cessation education for current smokers (28% male smokers, 2.8 of 10; 35% female smokers) or diet/nutrition education (21% males, 14 of 69; 20% females, 18 of 88).

Conclusions:
Ambulatory visits made by hypertensive males were less likely to include depression screening than visits made by hypertensive females. Depression management is important for the management of hypertension. There were no disparities by sex in blood pressure control, diet/nutrition education or smoking cessation education for current smokers.
Abstract 617: The Consomic LH-17
LN
Rat Is A Single Chromosome Model Of Metabolic Syndrome
Authors: Ma John , Pettus Janette M , Jakoubek Jessica , Kwitek Anne E
Published: March 2022

The Lyon Hypertensive (LH) rat is an inbred model of Metabolic Syndrome, exhibiting spontaneous hypertension, high body weight, high plasma lipids, altered insulin:glucose ratio. The Lyon Normotensive (LN) control strain, selectively bred for normal blood pressure from the same Sprague Dawley (SD) colony, is genetically quite similar to the LH, but displays no features of MetS. Genetic mapping in an LHxLN cross determined that all of the MetS phenotypes mapped to rat chromosome (RNO 17). In order to identify the gene(s) causing MetS on RNO17 we generated a consomic strain (LH-17
LN
) where the LH RNO17 was replaced with that of the LN strain. Substitution of the single chromosome was sufficient to significantly lower blood pressure lower systolic blood pressure (145 + 2 vs. 161 + 2 mmHg; p<0.05), body weight (408 + 6 vs 453 + 5 g; p<0.05), and plasma cholesterol (2.5 ± 0.1 vs 2.9 ± 0.08; p<0.05) compared to the LH parental strain. To identify putative causal genes for MetS, we fine-mapped RNO17
in silico
utilizing the genome sequence of the LH and LN rat strains. The genomes of the LH and LN strains are highly similar, differing by <0.02% at the sequence level (in comparison, humans typically differ by about 1%). Moreover, we have shown that the variants cluster into <500 divergent haplotype blocks with an average length of 880 kb, which are presumed to contain the genetic variation causing the phenotypic variation between the LH and LN strains. On RNO17 there are just 14 divergent haplotypes, containing 11 genes with coding sequence differences in the LH. The combined
in vivo
and
in silico
approaches allowed for the identification of candidate causal variants for the phenotypes on RNO17 and will be studied further to determine their role(s) in MetS.
Abstract 621: Chymase-mediated Angiotensin II Formation in the Heart of Rats Overexpressing the Human Angiotensinogen Gene
Authors: Ahmad Sarfaraz , VonCannon Jessica L , Bader Michael , Varagic Jasmina , Ferrario Carlos M
Published: March 2022

The creation of a transgenic rat model harboring the human angiotensinogen gene [TGR(hAGT)L1623] allows for the identification of alternate angiotensin II (Ang II) enzymatic pathways as rat renin has little, if any, hydrolytic activity on the human angiotensinogen protein. An initial study showing that hypertension associated with cardiac hypertrophy occurs in TGR(hAGT)L1623 rats led us to characterize the cardiac expression of renin angiotensin system components in 9 male TGR(hAGT)L1623 and 11 Sprague Dawley (SD) control rats. Cardiac Ang II content was higher in TGR(hAGT)L1623 rats when compared with SD rats (37±5 fmol/mg protein vs. 9.6±0.9 fmol/mg protein, respectively;
P
< 0.001). Although content of rat angiotensin-(1-12) [Ang-(1-12)] was comparable in both transgenic and control rats, chymase activity in the heart of both groups of rats was almost 9-fold higher when compared to cardiac angiotensin-converting enzyme (ACE) activity [chymase activity: 9.6±0.8 fmol/min/mg protein vs. 1.2±0.4 fmol/min/mg protein ACE activity in TGR(hAGT)L1623]. No significant differences in plasma renin concentration (PRC) was found between TGR(hAGT)L1623 and control SD rats (1.37±0.21 fmol/mL vs. 1.47±0.31 fmol/mL, respectively). Our findings further suggest that chymase enzyme (not ACE) is primarily responsible for generating Ang II in rat heart tissue. TGR(hAGT)L1623 rats represent a novel tool to investigate the direct contribution of renin-independent Ang II formation via chymase or other Ang II forming enzymes that expressed in the rat heart possess hydrolytic activity on human angiotensinogen.
Abstract 622: Angiotensin-(1-12) Is A Better Substrate Compared To Angiotensin I To Generate Angiotensin Ii By Rat Chymase.
Authors: Ahmad Sarfaraz , Varagic Jasmina , VonCannon Jessica L , Dell'Italia Louis J , Groban Leanne , Ferrario Carlos M
Published: March 2022

Angiotensin-(1-12) [Ang-(1-12)] is metabolized by chymase to generate angiotensin II (Ang II). We investigated the affinity of rat chymase to generate Ang II from Ang-(1-12) or angiotensin I (Ang I). Plasma membranes isolated from the heart of spontaneously hypertensive rats (SHR) were incubated with radiolabeled 125I-Ang-(1-12) or 125I-Ang I substrate in the absence or in the presence of a chymase inhibitor (chymostatin, 50 μM). 125I-Ang II formation was quantified by HPLC. The rate of 125I-Ang II formation from 125I-Ang-(1-12) by chymase in cardiac plasma membranes was significantly higher (5.7±0.2 fmol/min/mg protein, P<0.001) when compared to 125I-Ang I (0.82±0.13 fmol/min/mg protein). Substrate affinity of 125I-Ang-(1-12) for rat chymase was also confirmed by using an excess amount of unlabeled Ang-(1-12) or Ang I (0-250 μM). 125I-Ang II formation was significantly decreased by unlabeled Ang-(1-12) as compared to Ang I. We also investigated angiotensin-converting enzyme (ACE) mediated hydrolysis of 125I-Ang-(1-12) and 125I-Ang I in generating Ang II in SHR cardiac plasma membranes. No significant difference in 125I-Ang II formation was detected with either substrate. Moreover, the rate of 125I-Ang II production by ACE was lower (1.8±0.4 fmol/min/mg protein for Ang-(1-12) and 2.1±1.2 fmol/min/mg protein for Ang I) as compared to chymase. These data suggest that in the rat heart, Ang II formation from Ang-(1-12) is primarily mediated by chymase rather than ACE. Overall our findings suggest in the heart of SHR that compared to Ang I, Ang-(1-12) is the better substrate for Ang II formation. In addition, we confirm our previous observation that chymase is the main hydrolyzing enzyme responsible for Ang II generation from Ang-(1-12) in the rat heart.
Abstract 624: Lower Than Expected Morbidity Of Transgenic Mice Expressing Rat Tonin After Myocardial Infarction.
Authors: Palomino Jara Zaira , Ribeiro Amanda , Ezequiel Leandro , Dos Santos Fernando , Figueroa Diego , Watanabe Ingrid , Pesquero Jorge , Irigoyen Maria Claudia , Casarini Dulce Elena
Published: March 2022

Alternative angiotensin II (AngII) formation pathways have been identified. The tonin, capable to act on angiotensinogen (Agt) to form AngII, seems to have a key role in pathophysiological processes resulting from the deleterious effects of AngII. Study with transgenic animals [TGM(rTon’)] over expressing tonin in the brain, heart, kidneys and adrenal glands showed smaller heart weight to body weight index in cardiac hypertrophy, suggesting some cardioprotective state. This unexpected result goes in disagreement with AngII effects. It was seen that other transgenic mice (ACE, renin transgenics) with anticipated increase of AngII level respond with a more severe disease state to any experimental pathophysiological stress. Thus, the aim of this study was to evaluate whether the smaller cardiac index could also mean better functional state. We assessed this question by studying the hemodynamic and neuro-humoral response of TGM(rTon’) mice to 4 months of myocardial ischemia (MI).

Before MI, TGM(rTon’) mice had similar HR and BP variability, 68% of higher sympathetic-vagal balance, 203% increased of adrenal catecholamine concentration and 77% reduced of AngII to Ang1-7 index compared to control group. After the MI, control and TGM(rTon’) animals showed similar infarction area. However, while the MI-control group reduced 62% of its HR variability and increased 27% of its BP variability, the MI-transgenic group did alter neither HR nor BP variability. Catecholamine profile showed 11% increased in the MI-control group while 41% decreased in the MI-transgenic group. The Ang II to Ang-(1-7) ratio was 40% lower in the MI-transgenic group compared to the MI-control. The TGM(rTon’) group respond to myocardial infarction with maintenance of its HR and BP variability indicating a lower prognostic index of morbidity compared to control group. Unchanged variability may be a reflection of counterbalancing processes recruitment, such as increased formation of Ang-(1-7), as seen in the heart.
Abstract 627: The Smooth Muscle-selective RhoGAP Graf3 Is A Critical Regulator Of Vascular Tone And Hypertension
Authors: Bai Xue , Stouffer George A. , Lee Craig R. , Schisler Jonathan , Patterson Cam , Lee John A. , Oni-Orisan Akinyemi , Mack Christopher P. , Taylor Joan M
Published: March 2022

Our ability to effectively treat hypertensive patients is limited by an incomplete understanding of its origin. Activation of RhoA in vascular smooth muscle cells (SMC) has been implicated in the development of vasoconstrictor-induced hypertension (HTN), but until now, the extent that RhoA contributed to basal BP was unknown and the mechanisms that limit RhoA activity in SMC were undetermined. We identified GRAF3 as a RhoA-GAP expressed specifically in SMC in mice and humans and reported that our novel global GRAF3-deficient mice exhibit significant basal HTN (+ 25 mm Hg) that was fully reversed by treatment with a Rho-kinase inhibitor (
Nature Comm. 2013;4:2910
). One objective of this new study was to test if elevated RhoA-dependent myogenic tone was causal for HTN in global GRAF3-deficient (GRAF3
gt/gt
) mice. Importantly, normal GRAF3 expression can be permanently restored by Cre recombinase-dependent excision in our model. Thus, we crossed the GRAF3
gt/gt
mice to the tamoxifen-inducible SM-specific SM MHC- CreER
T2
line and measured BP before and after tamoxifen treatment (1mg
i.p.
for 5 consecutive days). Tamoxifen induced SMC-GRAF3 re-expression and resulted in a complete reversal of MAP (from 123 mmHg to 95 mm Hg). Moreover, RhoA activity and myosin light chain phosphorylation were elevated 2-fold in GRAF3-depleted SMC in vitro and in vivo and isolated vessel segments from GRAF3-deficient mice showed a 2.5 fold increase in Rho kinase-dependent Ang II-induced contractility. Collectively, these findings provide unequivocal evidence that GRAF3 levels in SMC control basal BP homeostasis and that elevated BP in

GRAF3
gt/gt

mice is due to an enhanced, reversible, SMC contractile phenotype. A second objective was to determine whether GRAF3 variations are causally linked to cardiovascular outcomes in hypertensive patients. We found a clear and significant increase in minor allele frequency of a hypertensive GRAF3 locus in patients with HTN and coronary artery disease versus healthy volunteers (0.19 versus 0.30; p<0.05; N=920) and this association was significant regardless of race. Our studies provide a potential mechanism for the hypertensive locus identified within GRAF3 and provide the foundation for the future development of innovative HTN therapies.
Abstract 635: Achievement of Normokalemia with ZS-9 Across Subgroups in a Phase 3 Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial of Patients with Hyperkalemia
Authors: Singh Bhupinder , Rasmussen Henrik S , Lavin Philip T , Yang Alex , El-Shahawy Mohamed A
Published: March 2022

Introduction:
RAAS inhibitors (RAASi) are limited by hyperkalemia (HK; serum K
+
>5.0 mEq/L), a mortality risk factor in patients (pts) with heart failure (HF) and chronic kidney disease (CKD). Sodium zirconium cyclosilicate (ZS-9) is a nonabsorbed cation exchanger that selectively traps potassium (K
+
) in the gut. ZS-9 was well tolerated and acutely reduced and maintained K
+
in HK pts in a Phase 3 study. We report acute phase efficacy of ZS-9 vs placebo (PBO) across prespecified subgroups of baseline (BL) K
+
, eGFR, HF, CKD, diabetes mellitus (DM), and RAASi use.

Methods:
Pts (N=753) with serum K+ 5.0-6.5 mEq/L were randomized (1:1:1:1:1) to ZS-9 (1.25, 2.5, 5 or 10g) or PBO orally 3X/day for 48 hr, after which pts with K
+
≤4.9 mEq/L (n=542) were switched to ZS-9 or PBO 1x/day on Days 3-14. RAASi was kept constant. Mean serum K
+
(95% CIs) was recorded at BL and 48 hr. Differences between groups were compared by unpaired t-test.

Results:
Prevalence of subgroups were CKD 60%, HF 41% and DM 58%; 2/3 of pts were on RAASi. ZS-9 10g (n=158) vs PBO (n=143) is presented. Mean BL K
+
was 5.3 mEq/L in both groups. Mean change in K
+
at 48 hr was -0.73 mEq/L and -0.25 mEq/L in ZS-9 10g and PBO groups, respectively (p<0.001). At 48 hr, normokalaemia was achieved in the overall 10g ZS-9 group and in all subgroups (Figure).

Pts with starting K
+
>5.5 mEq/L had the largest decline in K
+
with 10g ZS-9 (-1.1 mEq/L vs -0.4 mEq/L PBO; p<0.001). Adverse events in the acute phase were similar between groups (12% ZS-9 vs 11% PBO).

Conclusions:
ZS-9 was well tolerated and achieved normokalemia in all prespecified subgroups of HK pts with CKD, HF, DM and on RAASi and may potentially permit optimal cardiorenal protection by life-saving RAASi.
Abstract 637: Effects Of A 12-Week Physical Training Program On Cardiovascular Risk Factors And Quality Of Life In Elderly Women
Authors: Conopca Severo , Silva Laércio O , Figueredo Audirene B , Marques Silas S , Baltatu Ovidiu C
Published: March 2022

Background:
Physical activity (PA) and the consequently lower cardiorespiratory fitness levels in older adults decline with age and are associated with cardiovascular disease events and mortality. In the present study we aimed at evaluating the effectiveness of a 12-week supervised physical training community-based program on cardiovascular risk factors and health-related quality of life (HRQoL) in elderly women.

METHODS:
An exercise intervention was conducted as a prospective, longitudinal and controlled study in 30 elderly participants. Intervention consisted of an individually designed group-based PA program thrice a week (aerobic exercise, resistance training and stretching exercises for 1 h each time), for a period of 12 weeks. The following cardiovascular risk data were investigated: blood pressure, triglycerides, HDL, glycaemia, body mass index (BMI) and waist circumference. HRQoL was evaluated with the Short Form-36 (SF-36).

RESULTS:
Mean age was 69 ± 0.9 years, normotensive (63% with controlled hypertension), BMI was 25 ± 0.7 kg/m2 and waist circumference was 89 ± 1.6 cm. The exercise group prevented the significant HDL decrease that occurred in the sedentary group (HDL increase: 2.5 [95%CI -4.4 to 9.4] vs HDL decrease: -9.2 [95%CI -16.2 to -2.2], p< 0.01). There was also a significant improvement in the SF-36 subscales in PA but not sedentary group: physical functioning score (increase of 24.2 [95%CI 11.8 to 36.5] vs. -9.2 [95%CI -21.5 to 3.2], p< 0.001), physical role functioning score (increase of 35.4 [95%CI 12.8 to 58.0] vs. 16.7 [95%CI -6.0 to 39.3], p< 0.01) and general health score (increase of 23.7 [95%CI 36.9 to 10.4] vs. 2.4 [95%CI -10.9 to 15.7], p< 0.001).

CONCLUSIONS:
This study shows that a 12-week physical training program may significantly improve cardiovascular risk reduction, physical capacity, physical function and general health scores.
Abstract 640: RGS2 Deficiency Impairs Renal Hemodynamics and Function
Authors: Osei-Owusu Patrick , Blumer Kendall J
Published: March 2022

Regulator of G protein signaling 2 (RGS2) regulates signaling by acting as a GTPase-activating protein for Gq/11α and Gi/oα subunits of heterotrimeric G proteins. Certain single nucleotide polymorphisms and loss-of-function mutations of RGS2 have been linked to human hypertension. RGS2 deficiency in the kidney is sufficient to cause hypertension in mice; however, the renal pathophysiological mechanisms are unknown.

Here, we assessed renal hemodynamics and function using renal blood flow (RBF) and glomerular filtration rate (GFR) measurements, and assessment of pressure natriuresis in wild type (WT) and RGS2 null (RGS2-/-) mice. GFR was measured by plasma clearance of FITC-inulin. Pressure natriuresis was determined by increasing renal perfusion pressure (RPP) stepwise by clamping the superior mesenteric and celiac arteries, and abdominal aorta, while total RBF was simultaneously recorded with flow probe.

Baseline GFR was markedly decreased in RGS2-/- mice compared to WT controls (1.8 ± 0.1 vs. 1.1 ± 0.1 ml/min/g kidney weight, p=0.004). Renal conductance was reduced (70 ± 9 vs. 51 ± 3 μl/min/g kidney weight, p=0.006) while renal vascular resistance (RVR; 14.9 ± 2.2 vs. 20.2 ± 1.3 mmHg/ml/min/g kidney weight, p=0.002) was elevated in RGS2-/- compared to WT mice. The absence of RGS2 resulted in decreased sensitivity and magnitude of change in RVR (WT: 11.17 ± 1.94 vs. RGS2-/-: 6.87 ± 0.90 mmHg/ml/min/g) and conductance (WT: -25.69 ± 3.22 vs. RGS2-/-: -13.87 ± 2.40 ml/min/mmHg/g) after a step increase in RPP. The acute pressure-natriuresis curve shifted rightward in RGS2-/- relative to WT, with no change in the slope. Fractional sodium excretion was unaffected by RGS2 deficiency.

We conclude that RGS2 deficiency impairs renal function and autoregulation by increasing renal vascular resistance and reducing effective renal blood flow. The findings provide a new line of evidence for renal vascular dysfunction as a primary cause of hypertension. Mutations or downregulation of RGS2 in the kidney may contribute to human hypertension by causing renal hypoperfusion and decreased GFR. Signaling pathways regulated by RGS2 may provide therapeutic targets in hypertension patients harboring mutations that potentially decrease expression and/or function of RGS2.
Abstract 643: Unique Cortico-medullary Topology Of D1R, AT1R And NADPH-oxidase Contributes To Hypertension And Salt-sensitivity In Aging Rats
Authors: Pokkunuri Indira , Asghar Mohammad
Published: March 2022

Aging Fisher Brown Norway (FBN) rats exhibit hypertensive phenotype due in part to increased oxidative stress and impaired dopamine D1 receptor (D1R) and angiotensin AT1 receptor (AT1R) functions in the aging kidneys. Here, we tested if these rats develop salt-sensitivity and examined its mechanisms. Adult (2- month) and aged (20- month) FBNs were treated with normal (NS, 0.4%) and high ( HS, 8%) salt for 4-weeks, conscious blood pressure (BP) measured and kidneys harvested for analyses. BP was higher in aged (120 mmHg) than in adult (113 mmHg) rats fed NS, which further increased (126 mmHg) with HS in aged rats. D1R mRNA and protein increased in cortex [NS vs HS: mRNA, 1.00 ± 0.0 vs 1. 21 ± 0.06 AU; Protein, 56.1 ± 2.01 vs 68.8 ± 3.08 DU] and medulla [NS vs HS: mRNA, 1.0 ± 0.0 vs 1.11 ± 0.12 AU; Protein, 54.2 ± 2.89 vs 70.3 ± 1.76 AU] with HS in adult rats. AT1R mRNA in cortex and medulla was higher in aged than in adult rats irrespective of salt treatment [Adult vs Old: Cortex, 1.0 ± 0.00 vs 5.04 ± 0.42; Medulla, 1.0 ± 0.00 vs 5.07 ± 0.09 AU]. However, its protein increased in medulla with HS in only aged rats [NS vs HS: 55.68 ± 4.8 vs 80.68 ± 8.3 DU]. 91phoxgp-NADPH-oxidase mRNA followed a similar pattern as of AT1 mRNA in both cortex and medulla of aged rats. However, its protein was higher in cortex of aged rats irrespective of salt intake [Adult vs Old: NS: 60.3 ± 7.2 vs 112.1 ± 8.6; HS: 61.9 ± 3.7 vs 94.25 ± 15.7 DU], but increased only with HS in medulla [Adult vs Old: 58.3 ± 6.3 vs 86.7 ± 7.2 DU] in these rats. Furthermore, NHE3 protein levels in the medulla were higher irrespective of salt treatment in aged rats [Adult vs Old: NS: 44.0 ± 5.8 vs 62.3 ± 4.6; HS: 45.4 ± 4.7 vs 65.4 ± 2.8 DU]. However, salt treatment increased the levels of Na,K-ATPase protein in the medulla of aged rats (NS vs HS: 11.8 ± 2.2 vs 18.9 ± 2.3 DU). Interestingly, renin levels in cortex were higher than in medulla irrespective of salt intake in aged rats (Cortex vs Medulla: NS: 84. 2 ± 4.5 vs 46. 32 ± 8.18; HS: 82.2 ± 1.18 vs 52.7 ± 3.51 ng/ml/hr). These data suggest that cortical renin and gp91phox-NADPH-oxidase together with medullary NHE-3 contribute to age-related hypertension, while D1R (cortical and medullary) together with medullary AT1R, gp91phox-NADPH-oxidase and Na, K-ATPase contribute to salt-sensitivity in aging FBNs.
Abstract 644: Salt Intake, Blood Pressure and Renal Function in a Black Population: A 5-Year Prospective Study
Authors: Schutte Aletta E , Van Rooyen Johannes M , Huisman Hugo W , Fourie Carla M , Wentzel-Viljoen Edelweiss , Mels Carina M , Smith Wayne , Botha Shani , Kruger Annamarie , Schutte Rudolph
Published: March 2022

Background:
The salt debate continues, also regarding the WHO recommendation to restrict salt intake below 5 g/day. Black populations exhibit a high prevalence of salt-sensitivity, but no large-scale studies in these populations have been performed to show the cardiovascular consequences of dietary salt intake.

Aim:
To determine whether estimated daily salt intake is associated with BP and renal function cross-sectionally; and prospectively over 5-years.

Methods:
We included 1589 HIV-uninfected black participants aged > 30 yrs, and followed 1174 over 5 years (of which 151 died). We collected blood and fasting morning spot urine. The Kawasaki-formula was applied to estimate 24-h urinary sodium excretion. Using ANCOVAs we compared the following salt-intake groups: <3; 3-4; 5-6; 7-8; ≥9 g/day. Group sizes ranged from 84-499 participants.

Results:
Before and after adjustments baseline SBP tended to associate with estimated daily salt intake (adjusted p-trend=0.10). At baseline, there was no association of salt intake with estimated glomerular filtration rate (eGFR; p=0.65), but a strong positive association with albumin-to-creatinine ratio (p<0.001). Baseline daily salt intake of 5-6 g/day resulted in the smallest increase in SBP/DBP of 1.49/1.25 mmHg. Low daily salt intake of <3 and 3-4 g/day resulted in greater increases in BP than intakes of 5-6 g/day, namely SBP/DBP of 5.02/5.12 mmHg for < 3 mg/day (p for trend=0.034). The highest salt intake group (≥ 9 g/day) showed increases of 4.49/3.15 mmHg, albeit not significantly different from the 5-6 g/day group (p for trend=0.24). Regarding renal function, serum creatinine decreased from 101 to 65 μmol/L over 5 years, with an increase in eGFR from 114 to 129 ml/min/1.73 m
2
(both p<0.001). %eGFR increased according to salt intake (p-trend=0.038).

Conclusion:
Estimated daily salt intake relates weakly to BP cross-sectionally, but strongly with albuminuria. Prospectively, low salt intake of less than 5 g/day predicts a significant elevation in SBP compared to 5-6 g/day. In contrast to healthy white populations indicating a decrease in GFR with age, we found an increase over 5 years, which is related to salt intake, suggesting a high prevalence of salt-sensitivity in this black population.
Abstract 645: 20-HETE and Circulating Endothelial Cells, a Unique Vascular Profile Related to CVD in Morbidly Obese Appalachian Women
Authors: Getty Morghan , O'Hanlon Kathleen , Thompson Ellen , Sodhi Komal , Maher Eamonn , Khitan Zeid , Puri Nitin , Hochhauser Edith , Abraham Nader G , Shapiro Joseph
Published: March 2022

Background:
A high BMI increases levels of metabolic syndrome biomarkers, including; Leptin in Appalachian women. Vascular dysfunction is persistent in the development of atherosclerosis and determined by the levels of inflammatory markers, circulating endothelial cells (CEC), 20-HETE (a powerful vasoconstrictor) and serum adiponectin levels. We have previously described the presence of a marked increase in CEC in both humans and mice with hypertension, obesity and diabetes. We hypothesize that a subject with high BMI would present with increased levels of CEC and 20-HETE concomitant with a marked reduction in serum adiponectin.

Methods:
Serum levels of adiponectin and 20-HETE were measured in female of Appalachian subjects. The effect of 20-HETE on 3T3 adipogenesis was also measured. Mature CEC were isolated from peripheral blood using anti-CD146-coated immunomagnetic Dynabeads™.

Results:
Subjects with a BMI between 45 to 72, had an elevated number of CECs (mean 79, range 49-116 cells/ml of peripheral blood) as compared to (mean 29, range 21-46 cells/ml peripheral blood , p<0.05) subjects with BMI of 32-46 and in non-obese subjects with BMI of 17-32, (mean 3, range 2-9). Lipidomic analysis revealed females with high BMI (50-72) displayed a significant increase in the CYP-derived 20-HETE when compared to subject with lower BMI (32-45) (p = 0.005). Treatment of 3T3 cells with 20-HETE decreased serum adiponectin levels and increased TNF
α
and adipogenesis by 38% and 76%, respectively (p<0.05). These results implicate both 20-HETE and oxidative stress as factors in the development and pathogenesis of BMI-related diseases in individuals with a high BMI.

Conclusions:
Increased BMI in Appalachian females is associated with an increase in CEC levels accompanied by an increase in 20-HETE expression and a decrease in adiponectin in peripheral blood. This represents a novel mechanism by which individuals with high BMI and controlled blood pressure remain sensitive to the development of atherogenesis and vascular dysfunction. It is the responsibility of the physician to recognize the medical problems that are endemic to the Appalachian population and to counsel the patient regarding these risks of CVD.
Abstract 007: Interleukin-6 Inhibition Attenuates Hypertension and Associated Renal Damage in Dahl Salt-sensitive (SS) Rats
Authors: Hashmat Shireen , Rudemiller Nathan , Abais Justine , Lund Hayley , Petrova Galina , Van Why Scott , Mattson David L
Published: March 2022

Data from our lab indicates that infiltration of T lymphocytes into the kidney amplifies salt-sensitive hypertension and renal damage in SS rats. Interestingly, interleukin 6 (IL-6) mRNA is >50-fold higher in T cells isolated from the kidney in comparison to circulating T cells. Experiments were performed to assess the role of IL-6 in Dahl SS rats (n=13-14/group) fed low salt chow until 9 weeks of age and subsequently treated with goat anti-rat IL-6 neutralizing antibody (anti-rIL-6; 4 μg /day, IP; R&D Systems, Minneapolis, MN) or normal goat IgG control (4 μg /day, IP) during an 11 day period of high salt intake. The MAP and urine albumin excretion rates (Ualb) were not different between the groups when fed low NaCl chow (MAP=121±1.6 mmHg versus 122±1.8 mmHg and Ualb=15±2mg/day versus 12±1.7 mg/day in the vehicle-treated versus anti-rIL-6-treated rats). Following 11 days of drug-treatment, the rats receiving anti-rIL-6 demonstrated a significant 47% reduction in IL-6 in the renal medulla compared to vehicle-treated SS. Moreover, the increase in MAP following 11 days of high NaCl intake was significantly attenuated in SS administered anti-rIL-6 (MAP=138±3 mmHg) compared with the control group (MAP=149±3 mmHg). The renal damage was also attenuated in SS administered anti-rIL-6; Ualb was significantly reduced in the treated (109±10 mg/day) compared to the control group (151±16 mg/day) and glomerular and tubular damage were also attenuated. To investigate potential mechanisms of action, a flow cytometric analysis of infiltrating immune cells in the kidney (n=4-5/group) was performed. The total number of leukocytes (CD45+) was significantly lower in the treatment vs the control group (4.8±0.5x106 vs 6.8±0.5x106 cells/kidney). Infiltrating monocytes and macrophages (CD11b/c+) were also significantly lower in the treatment vs the control group (3.7±0.3x106 vs 5.4±0.3x106 cells/kidney). The total number of infiltrating T and B lymphocytes was not different among the groups. The present studies indicate that IL-6 production may participate in the development of SS hypertension and end-organ damage by mediating the recruitment and infiltration of macrophages into the kidney.
Abstract 013: Early Life Stress Increases Susceptibility to Develop Obesity and Metabolic Syndrome in a Sex-specific Manner
Authors: Murphy Margaret , Schmuckie Lauren , Powell David , Marti Francesc , Loria Analia
Published: March 2022

Recent epidemiological studies demonstrate that women have a greater prevalence of metabolic syndrome with associated increases in fasting glucose not seen in men. Lifestyle factors including diet and physical activity contribute to the risk of developing metabolic disease; however, it has been reported that exposure to early life stress (ELS) has enduring emotional, immune, and metabolic disturbances resulting in increased risk for obesity and type II diabetes. To investigate the effects of ELS as an independent risk factor for metabolic disease, we expose C57Bl/6 mice to maternal separation (MSep), an established behavioral stress model during postnatal life. At weaning, mice were placed on a low-fat diet (LFD, n=6-10) or high-fat diet (HFD, 60% fat calories, n=10) for 16 weeks. Body weight (BW) gain was not different between MSep and control (C) mice when fed a LFD; however, only female MSep mice display higher fat mass compared to C (6.7 ± 0.5 vs. 5.2±0.5 g, p<0.05). Magnetic resonance spectroscopy revealed elevated levels of visceral fat in female MSep mice compared to C, suggesting that MSep increases central adiposity. HFD increased BW in male MSep mice vs C (54.2± 0.7 vs 51.3 ± 0.5, p<0.05); however, BW was dramatically exaggerated in female MSep mice vs. C (48.2± 1.3 vs 34.4 ±2.3 g, p<0.05). Accordingly, fat mass was increased in female MSep mice vs. C (18.2 ± 1.4 vs. 7.6 ± 0 g, p<0.05). Only female MSep exhibited significant impaired glucose tolerance (AUC: 18445±507 vs 22070± 696 AU, p<0.05), hepatomegaly, hypercholesterolemia (156±20 vs. 82 ± 2 mg/dl, p<0.05), hyperleptinemia and hyperinsulinemia (p<0.05) compared to C. Because impaired metabolic function has been linked to inflammation, we characterized splenocytes in female HFD-fed mice. We found a lower population of T-cells but no difference in B-cells in MSep mice vs. C. Functional studies of T cell differentiation demonstrated a reduced capability of naïve T cells to differentiate into anti-inflammatory T regulatory cells in MSep mice vs. C (54± 4 vs. 66± 1 % FoxP3+/CD25+ cells, p<0.05, n=3). The ability to polarize into the pro-inflammatory Th17 phenotype remained intact. These data suggest that the mechanisms by which MSep primes the metabolic responses are sex-specific. NIH R00 HL111354
Abstract 017: Ang-(1-7) Influences ET-1 Signaling Through MAS: ETBR Interactions: Implications in Pulmonary Hypertension
Authors: Hood Katie Y , Yusuf Hiba , Montezano Augusto C , Findlay Jane E , Santos Robson A , Castro Carlos H , Baillie George S , MacLean Margaret R , Touyz Rhian M
Published: March 2022

ACE2 and Ang 1-7 have been shown to protect against pulmonary hypertension (PH). Mechanisms remain unclear. Considering the important role of ET-1 in PH pathophysiology and endothelial dysfunction, we asked whether Ang 1-7 influences ET-1 signaling in endothelial cells and whether Ang 1-7 treatment influences the ET-1 system in PH. Human microvascular endothelial cells (HMEC) were stimulated with ET-1 in absence/presence of Ang 1-7 and showed that Ang 1-7 increased preproET-1 mRNA (250%), ET-1 release (125%) and ETBR protein (50%), p<0.05. ET-1 increases in e-selectin mRNA (400%), VCAM-1 protein (38%) and TNFα production (30%) were blocked by Ang 1-7, p<0.05. Pro-inflammatory effects were dependent on NO. Ang 1-7 increased NO production (257%) in a Mas and ETBR-dependent manner. Mas and ETBR interaction was observed by immunoprecipitation. To characterise physical interactions between Mas/ETBR, we utilised novel technology, employing a library of peptides scanning the MasR sequence, to define sites of ETBR binding. Substitution and truncation identified regions on MasR that confer specificity for ETBR binding. Peptide disruptors to prevent Mas/ETBR interaction were used for in vitro validation. We previously demonstrated in HMEC that Ang 1-7 stimulates Akt phosphorylation (180%), an effect inhibited by pre-incubation with peptide disruptors, p<0.05.

To investigate pathophysiological significance of our findings, we investigated whether Ang 1-7 treatment ameliorates PH and whether this is associated with altered ET-1 status. Hypoxia was used to induce PH in mice: normoxic controls (NC), hypoxic PH (HP), normoxic (NA) and hypoxic PH (HA) treated with Ang 1-7 30μg/kg/day. In HP mice, RVSP (18.7 NC vs. 47.6mmHg HP, p<0.05) RVH (0.19 NC vs. 0.28 HP, p<0.01) and ET-1 levels (0.8 NC vs 2.4pg/ml HP, p<0.05) were increased and blocked by Ang 1-7. Hypercontractility and endothelial dysfunction in pulmonary arteries of HP mice was attenuated by Ang 1-7.

These findings indicate that vasoprotective effects of Ang 1-7 may be mediated through MAS:ETBR dimerization. In vivo studies support a relationship between Ang 1-7/MAS and ET-1 systems. In conclusion we have identified a novel link between Ang 1-7 and ET-1 through physical interactions between MAS and ETBR.