bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P146: Transient Neonatal High Oxygen Exposure Accelerates Adult Cardiac Baseline and Ang Ii-induced Prooxidative and Proinflammatory Responses
Authors: Mian Muhammad Oneeb Rehman , Boudreau Fauve , Bertagnolli Mariane , Lukaszewski Marie-Amelie , LUU Thuy Mai , Nuyt Anne-Monique
Published: June 2021

Objective:
Preterm birth is associated with disequilibrated early life oxidant-antioxidant and proinflammatory conditions that can be carried into adulthood and contribute to the development of organ dysfunction. Neonatally high O
2
-exposed rats, a model of prematurity-related prooxidative conditions, exhibit adult hypertension, early cardiac dysfunction and fibrosis, and premature angiotensin (ANG) II-induced heart failure. We hypothesized that neonatal high O
2
exposure will exaggerate baseline and ANG II-induced cardiac prooxidative and proinflammatory gene expression in adult rats.

Design and Methods:
Sprague-Dawley pups were kept in 80% O
2
(H group) or room air (NNI group) from day 3-10 of life. Twelve-weeks-old H and NNI rats were infused with ANG II (100 ng.kg
-1
.min
-1
) or saline (NaCl) for 4 weeks (n = 4 per group). RNA extracted from hearts was used in arrays to assess expression of oxidative stress and inflammatory genes. Data is expressed as fold change (F.C.) compared to control NNI+NaCl.

Results:
H+NaCl exhibited increased baseline
Cd68
expression (F.C: 1.47; P<0.05 vs control), tendancy of increased
Nfkb1
and
Tnf
expression (1.52 and 1.48), and a tendancy of decreased
Il1b
and
Il18
expression (0.72 and 0.78). H+ANGII versus NNI+ANGII exhibited similar increase in
Tnf
( 2.12 vs 2.13; P<0.05 vs control), greater increase in
Cd14
,
Cd68
, and
Nfkb1
(2.5 vs 1.78, 2.13 vs 1.94, 2.0 vs 1.7; P<0.05 vs controls), and a greater tendancy of increase in
Tgfb1
,
Myd88
,
Cybb
, and
Gstp1
(2.68 vs 1.82, 2.37 vs 1.31, 1.91 vs 0.98, 2.45 vs 1.61) expression. NNI+ANGII versus H+ANGII exhibited greater increase in expression of genes involved in early inflammatory process, including
Ccl2
,
Icam1
, and
Vcam1
(2.07 vs 1.56, 1.88 vs 1.36, 2.34 vs 1.29; P<0.05 vs control).

Conclusions:
Neonatal high O
2
exposure accelerates baseline and ANG II-induced cardiac prooxidative and proinflammatory responses in adult rats, which could account for early cardiac abnormalities and premature ANG II-induced heart failure in this model.
Abstract P150: Lateral Hypothalamic Leptin and Melanocortin Signaling in the Regulation of Sympathetic Nerve Activity and Blood Pressure
Authors: Morgan Donal A , McDaniel Latisha N , Jiang Jingwei , Saito Kenji , Davis Kevin C , Lutter Michael , Rahmouni Kamal , Cui Huxing
Published: June 2021

Obesity is associated with increased sympathetic nerve activity (SNA), which contributes to the development of hypertension. Hypothalamus plays a fundamental role in both body weight homeostasis and sympathetic outflow, but the underlying neural basis of this association remains incompletely understood. Leptin and melanocortin systems in the brain are important regulators of body weight homeostasis, SNA and blood pressure. However, the neural circuits by which leptin and melanocortin regulate SNA and blood pressure remain unclear. We have previously shown that both leptin receptor (LepR) and melanocortin 4 receptor (MC4R) are co-expressed in a unique subset of GABAergic neurons in the lateral hypothalamic area (LHA). Because the LHA is a well-known site for SNA and cardiovascular function, we hypothesized that LepR and MC4R signaling in the LHA may play an important role in SNA and blood pressure. Here we show that direct microinfusion of leptin into the LHA increases renal SNA in dose-dependent manner (% changes from baseline at 4
th
hour: Vehicle -25.03 ± 7.09 %, 0.05 ug leptin 26.01 ± 9.5 %, 0.5 ug leptin 100.23 ± 26.94 %, n=5-7/group, p<0.001). Additionally, in vivo Cre/loxP system-mediated re-expression of endogenous MC4Rs in the LHA restores the blunted response of MTII-induced increase in renal SNA (Wild-type 66.67 ± 16.53 %, MC4R-null 17.65 ± 10.3 %, MC4R reactivation 48.77 ± 9.36 %, n=7-9/group, p<0.01) and elevates blood pressure in obese, but normotensive MC4R-TB mice in inactive light cycle (Wild-type 111.62 ± 4.07, MC4R-TB 115.75 ± 1.27, MC4R re-expression 125.29 ± 3014 mmHg, n=3-4/group, p<0.05) without significantly affecting body weight. Finally, optogenetic stimulation of LHA LepR-positive neurons decease blood pressure and renal SNA in conscious mice. In conclusion, our findings identify a novel brain circuit by which leptin and melanocortin signaling regulate renal SNA and blood pressure.
Abstract P151: Adam17 in the Paraventricular Nucleus Contributes to Activation of Pre-Autonomic Neurons and Maintenance of Baseline Blood Pressure
Authors: Mukerjee Snigdha , Zsombok Andrea , Lazartigues Eric
Published: June 2021

We previously reported that over-activation of the classical arm (
i.e.
ACE/Ang-II/AT1 receptor) of the brain renin-angiotensin system (RAS) up-regulates ADAM17, a disintegrin and metalloprotease. ADAM17 cleaves angiotensin converting enzyme 2 (ACE2) from the cell surface, leading to a compromised compensatory RAS axis (
i.e.
ACE2/Ang-(1-7)/Mas receptor) and neurogenic hypertension. We hypothesized that ADAM17 within the paraventricular nucleus of the hypothalamus (PVN) intrinsically regulate neuronal activity, thus contributing to sustained sympathetic drive and the development of neurogenic hypertension. To test this hypothesis, a new transgenic mouse line, named SAT, was generated to selectively knockdown ADAM17 in pre-autonomic Sim1 neurons within the PVN, using cre-loxP technology. Mean arterial pressure recorded in conscious mice (telemetry) showed a significant reduction at baseline (ΔMAP: -8 ±2 mmHg, N=3,
P
<0.05) and an increased vagal tone (Heart rate: 231 ±19 vs. 160 ±11 bpm, N=10, P<0.05) in SAT vs. control (NT) litter-mates. To address the impact of ADAM17 deletion on neuronal excitability, c-Fos immunohistochemistry was performed. SAT mice exhibited a significant reduction of c-Fos expression in the PVN compared to NT (14 ±2 vs. 124 ±8 neurons, N=3,
P
<0.001). Retrograde labeling (pseudorabies virus-eGFP) confirmed that a sub-population of these neurons projected to the kidney. In addition, mRNA expression of the GABAa receptor was higher in the hypothalamus of SAT compared to NT mice (1.3 ±0.1
vs.
1.0 ±0.1, N=7,
P
<0.05). ADAM17 knockdown from the PVN had a positive effect on the compensatory RAS, as evidenced by a rise in hypothalamic ACE2 activity compared to NT mice (82.3 ±4.2
vs.
69.7 ±3.3, N=7,
P
<0.05). Interestingly, this was also extended downstream of the PVN, with an increase in ACE2 activity (96.7 ± 3.8
vs.
82.0 ± 3.4, N=7,
P
<0.05), as well as Mas receptor gene expression (0.28 ±0.03
vs.
0.17 ± 0.01, N=6,
P
<0.01) in the brainstem of SAT compared to NT mice. Altogether, our data highlight a new role for ADAM17 in neuronal excitability and the maintenance of baseline blood pressure. Potential mechanisms opposing ADAM17-mediated neuronal excitability of PVN neurons include GABAergic pathways and the compensatory axis of the brain RAS.
Abstract P153: Downregulation of Neuronal Nitric Oxide Synthase Within the Paraventricular Nucleus in Insulin Dependent Diabetic Akita Mice
Authors: Sharma Neeru M , Mishra Paras K , Patel Kaushik P
Published: June 2021

Activation of both renin-angiotensin- system (RAS) and sympathetic system are the primary etiologic events in the development of hypertension in diabetes mellitus (DM). However, the precise mechanisms for sympathetic activation in DM have not been elucidated. Our previous studies have demonstrated that neuronal nitric oxide (nNOS) expression and nitric oxide (NO) mediated inhibition of sympathetic nerve activity (SNA) is markedly reduced in the paraventricular nucleus (PVN) of streptozotocin-induced diabetic rats. We have further demonstrated that Angiotensin II (Ang II) via Ang II type 1 receptors (AT
1
R) modulates the expression of nNOS in the PVN, which augments sympathetic outflow. Here we hypothesized that DM-linked hypertension and cardiovascular dysregulation is due to the reduction in nNOS with the PVN. To test the hypothesis, we used Ins2
+/-
Akita (a spontaneous, insulin dependent genetic diabetic murine model) which showed an increase in systolic blood pressure at the age of 14 weeks compared to corresponding C57BL/6J (WT) mice with concomitant decreased expression of nNOS (0.75±0.05 WT vs. 0.43±0.11* Akita) in the PVN. Further, Akita mice had increased expression of ACE (angiotensin converting enzyme) (WT 0.34±0.04 vs. Akita 0.58±0.05*) and AT
1
R (WT 0.29±0.09 vs. Akita 0.49±0.03*) and decreased expression of ACE2 (0.27±0.03 WT vs. 0.17±0.05* Akita) and Mas receptor (WT 0.77±0.07 vs. Akita 0.46±0.02*), suggesting an imbalance in the excitatory and protective arms of RAS. Moreover, we found increased protein levels of PIN (a protein inhibitor of nNOS, known to dissociate catalytically active nNOS dimers to monomers) (WT 0.71±0.09 vs. Akita 1.75±0.08) with 72 percent decrease in dimer/monomer ratio of nNOS (WT 0.19±0.0 vs. Akita 0.11±0.04) in the PVN of Akita mice. Taken together, our studies suggest that accumulation of PIN, mediated by activation of the excitatory arm of RAS, leads to a decrease in the active dimeric form of nNOS resulting in reduced NO causing an over-activation of the sympathetic drive, leading to hypertension in DM.

1
Abstract P157: Assessment of Vascular Endothelial Function in Postural Tachycardia Syndrome and Healthy Controls
Authors: Celedonio Jorge , Nwazue Victor , Figueroa Rocio , Paranjape Sachin , Black Bonnie , Garland Emily , Okamoto Luis , Robertson David , Diedrich Andre’ , Raj Satish , Shibao Cyndya , Biaggioni Italo , Gamboa Alfredo
Published: June 2021

Postural tachycardia syndrome (POTS) is a heterogeneous disorder characterized by an excessive rise in HR and symptoms consistent with cerebral hypoperfusion while upright. Increased sympathetic activity may contribute to this condition and may also impair nitric oxide (NO)-function. We evaluated NO function using flow-mediated dilation (FMD) and Peripheral Artery Tonometry (PAT) in POTS patients and age-matched controls. We studied 16 POTS patients (30±2 years, BMI 22.3±1 kg/m
2
) and 7 healthy control subjects (HC; 31±2 years, BMI 22.1±1 kg/m
2
). Medications affecting BP, blood volume, the immune system, and autonomic function, were withheld for ≥5 half-lives. All subjects followed the same low-monoamine, caffeine-free diet for ≥3 days before testing. Endothelial function was measured as the percentage change in FMD (%FMD) and using the reactive hyperemic index (RHI) for PAT. We also measured autonomic function, plasma levels of catecholamines, renin activity (PRA) and aldosterone. We found that POTS patients had a significantly blunted FMD (6.11±0.8 vs. 9.67±1.6 %, P=0.049, figure), compared to healthy controls. This blunted FMD response was similar as what our group has reported in obese hypertensive females (N=13, 5.7±0.9%, figure). Also, as expected they had higher upright HR (121±6 vs. 90±6 bpm, for POTS and HC, P=0.020). There were no differences in PAT (2.08±0.12, vs. 1.8±0.13 RHI, for POTS and HC, P=0.168). There were no differences in norepinephrine (765±150 vs. 545±39 pg/mL, P=0.955), renin activity (5.3±1.3 vs. 5.2±1.6 ng/mL/hr, P=0.735) or aldosterone (19.6±3.8 vs. 15.9±5.5 ng/dL, P=0.129).
Abstract P160: Non-invasive Method to Assess Human Circadian Rhythms
Authors: Chen Daian , Thomas S Justin , Calhoun David A , Pollock David M , Pollock Jennifer S
Published: June 2021

Circadian rhythms are controlled by an endogenous time-keeping system oscillating approximately on a 24-h cycle under constant conditions. These rhythms depend on a network of interacting genes and proteins, including transcriptional activators such as CLOCK, NPAS2, and ARNTL (BMAL1), which induce transcription of the clock genes Period (
Per1
,
Per2
, and
Per3
) and Cryptochrome (
Cry1
and
Cry2
). Human salivary cortisol and melatonin follow a clear circadian rhythm as well. Disruption of the circadian rhythm and sleep-wake cycles are considered risk factors for a variety of health problems, especially hypertension and other cardiovascular and metabolic diseases. Here we put together practical methods for assessing circadian rhythms in adult subjects conducted by each individual. This method is non-invasive, inexpensive and provides a predictive profile of an individual’s circadian rhythm related to clock-controlled gene expression in buccal cells, salivary cortisol, salivary melatonin, and subject’s activity or sleep. Subjects are instructed on how to obtain buccal cells using swabs (Whatman OmniSwab) from the inside of their cheeks and collect saliva using salivettes (Sarstedt) every 4 hours starting at 6am, for 2 consecutive days. Subjects also wear actigraphy watches (Phillips Respironics) during the 2 days, to record their activity, light exposure and estimates of sleep times. To monitor adherence to correct time point collections, each subject is given an electronic vial called eCAP (Information Mediary Corp) that records the exact time the container is opened to place samples once collected. We demonstrate feasibility to extract up to 150ng/μl of RNA (Ambion RNAqueous-Micro Total RNA Isolation Kit) from buccal cells swabs. Salivary melatonin and cortisol are measured by radioimmunoassay (Buhlmann Lab) with melatonin peak levels ranging from 14 to 23 pg/ml and cortisol peak levels ranging from 10 to 24 ng/ml. We suggest that buccal cell expression of clock-controlled genes, salivary melatonin, salivary cortisol, and actigraphy data are valuable in providing reliable assessment of human circadian rhythm profiles under a variety of conditions.
Abstract P166: The Effect of a Muscadine Grape Extract on Angiotensin II-Induced Hypertension and Cardiac Damage
Authors: Patil Pooja , Gallagher Patricia E , Tallant E. Ann
Published: June 2021

Muscadine grapes, indigenous to the southeastern United States, are a dietary source of polyphenols, such as ellagic acid, quercetin, and resveratrol, which have both anti-inflammatory and antioxidant properties. Preclinical studies show that ground muscadine grape skins and seeds have anti-cancer effects, suggesting that supplementation with a muscadine grape extract (MGE) may serve as a chemotherapeutic or chemopreventive agent. As cancer patients often present with hypertension, diabetes, and other vascular pathologies, it is imperative to determine the effect of a muscadine grape supplement on these underlying comorbidities. The goal of this study was to determine whether MGE administered in the drinking water will exacerbate or improve hypertension and cardiac damage. Sprague-Dawley rats receiving a 4-week infusion of Ang II via subcutaneous osmotic mini-pump (24 μg/kg/h) had a significant increase in systolic blood pressure (123.1 ± 2.3 mm Hg in control vs. 213.1 ± 6.8 mm Hg in Ang II-treated; n=8; p < 0.0001). MGE supplementation had no effect on blood pressure or gross cardiac hypertrophy in either normotensive or hypertensive rats. Additionally, MGE did not alter stroke volume or cardiac output, measured by VEVO ultrasound. However, MGE ameliorated the Ang-II induced decrease in diastolic function, as measured by the E/E’ ratio (19.9 ± 0.8 in control, 28.1 ± 1.1 in Ang II-treated rats, 22.3 ± 2.0 in Ang II/MGE-treated rats; p < 0.05). Co-treatment with MGE also significantly reduced the Ang II-mediated increase in cardiomyocyte cross-sectional area (340.5 ± 12.0 μm
2
in control, 423.2 ± 17.1 μm
2
in Ang II-treated rats, and 342.6 ± 13.2 μm
2
in Ang II/MGE-treated rats, p < 0.01). MGE supplementation of Ang II-treated rats decreased interstitial cardiac fibrosis, measured by Picrosirius red staining (1.0 ± 0.1% in control, 2.0 ± 0.2% in Ang II-treated rats and 1.4 ± 0.1% in Ang II/MGE-treated rats, p < 0.05). These results demonstrate that treatment with MGE does not exacerbate hypertension or hypertension-induced cardiac damage but ameliorates cardiac hypertrophy, suggesting that MGE supplementation has an acceptable safety profile for use as an anti-cancer agent in hypertensive patients and may be used to treat cardiac hypertrophy and damage.
Abstract P173: Caloric Restriction Attenuates Diabetic Cardiomyopathy Through the Recruitment of the Antioxidant System
Authors: Waldman Maayan , Cohen Keren , Arad Michael , Abraham Nader G , Laniado-Schwartzman Michal , Gurfield Danny , Aravot Dan , Hochhauser Edith
Published: June 2021

Introduction:
Insulin resistance negatively impacts the diabetic heart in various ways, that include impaired insulin-mediated glucose uptake and a reduction in intracellular signalling. Diabetic cardiomyopathy is independent of coronary artery disease and is characterized by increased oxidative stress and extensive fibrotic changes, leading to increased myocardial stiffness and the development of diastolic dysfunction. Caloric restriction (CR) is cardioprotective mainly through its catabolic activity and increased insulin sensitivity. We examined the effect of CR on the development of diabetic cardiomyopathy and changes in oxidative stress and antioxidant genes.

Methods:
Leptin resistant (db/db) mice suffer from obesity and diabetes. Mice were treated for 4 weeks with angiotensin II (AT) to induce severe cardiomyopathy. Mice under CR were fed 90% of their normal food intake for 2 weeks and 65% for an additional 2 weeks. Each group consisted of 5-6 animals.

Results:
CR attenuated obesity and the cardiomyopathy phenotype in diabetic mice. CR reduced body weight and heart weight in diabetic mice when compared to control animals (33.7±7.9g vs.44 ±5.9g; 0.137±0.023g vs. 0.17±0.02g respectively, p<0.05); and lowered blood glucose (576±167mg/dL vs 702.5±309 mg/dL, p<0.05). Echocardiography indicated that CR attenuated the hypertrophic phenotype in the diabetic mice when compared to control animals (LV internal diameter 3.34±0.46mm vs. 4.06±0.36mm, p<0.01). Diabetic mice treated with AT suffer from oxidative stress as evident in a 110% increase in serum MDA levels (p<0.011), a reduction of 81% in adiponectin (p<0.001) and 65% in PGC-1α (p<0.0046) mRNA levels in cardiac tissue of diabetic mice compared to WT mice. The attenuation of diabetic cardiomyopathy after CR was accompanied by a reduction in serum MDA levels (p<0.028) and an increase in cardiac adiponectin, HO-1 and PGC-1α levels (p<0.05).

Conclusion:
These results indicate that a short term CR attenuated the development of AT induced diabetic cardiomyopathy through the activation of the adiponectin- PGC-1α- HO-1-axis. This appears to be a critical module in protecting the diabetic heart from the development of cardiomyopathy.
Abstract P193: Platelet-derived Growth Factor B: a Novel Determinant of Juxtaglomerular Cell Phenotypic Plasticity?
Authors: Goes Martini Alexandre , Friesema Edith C , Danser Alexander H , Reudelhuber Tim L
Published: June 2021

Renin, a key component in the regulation of blood pressure in mammals, is produced by the rare and highly specialized juxtaglomerular (JG) cells of the kidney. JG cells may be derived from vascular smooth muscle cells (VSMC) and they can reversibly differentiate in response to changes in salt, blood pressure and treatment with anti-hypertensive medications. The biochemical mechanism responsible for this phenotypic plasticity is currently unknown. Ligands involved in VSMC differentiation include platelet-derived growth factor B (PDGF-B), secreted acidic protein rich in cysteine (SPARC), type-C natriuretic peptide (NPPC), follistatin related protein (FSTL1) and lactose-binding lectin 1 (LGALS1). To test for the role of these factors in JG cell plasticity we used (pro)renin-producing As4.1 cells derived from a mouse JG cell targeted tumor. As4.1 cells were incubated for 48 hours with conditioned medium derived from human embryonic kidney (HEK) 293 cells transfected with the mouse cDNA encoding these ligands, after which both medium and cell lysate were collected. Renin and prorenin were measured using the angiotensin I generation assay. Under control conditions, the medium contained predominantly (>95%) prorenin. In contrast, the cell lysate contained renin only, at levels corresponding to <1% of the total amount of renin+prorenin in the medium (i.e., 161±61 μg angiotensin I/ml.hr, mean±SEM). Among the tested ligands, only PDGF-B affected the medium prorenin and cellular renin levels, decreasing both in parallel by 68±5% and 53±10%, respectively. In addition, PDGF-B-exposed cells changed their morphology to display a more elongated, densely packed and aligned shape with no apparent alteration in their viability. In conclusion, our data suggest that PDGF-B might be one of the factors involved in JG cell phenotypic plasticity.
Abstract P196: Effects of the Physiological Increase in Angiotensin-converting Enzyme in Acute Myocardial Infarction
Authors: Moraes Oscar A , Jensen Leonardo , Souza Leandro E , Barbosa Maikon , Scapini Kátia B , Mostarda Cristiano T , Irigoyen Maria C
Published: June 2021

The angiotensin converting enzyme (ACE) act in the production of ANG II and degradation of bradykinin. It is believed that higher levels of ACE could modulate susceptibility to coronary occlusion. To investigate this possibility we used adult males mice genetically modified to express different concentrations of ACE similar to that found in humans. Animals (1, 2 or three copies of ACE gene; n = 6 each group) were subjected to acute myocardial infarction (AMI) and evaluated 7 days after. Systolic, diastolic, and mean blood pressure (BP), heart rate, heart rate variability (HRV) were evaluated as well as cardiac function by echocardiography. Regarding hemodynamic data, AMI induced no difference in systolic, diastolic and mean BP of diferente gene copies mice (ACE1: 74.02 ± 3.0; ACE2: 108.65 ± 2.8; ACE3: 102.07 ± 4.1mmHg). Regarding heart rate it was observed a reduction in 3 copies group (ACE1: 654.51 ± 26.34; ACE2: 668.22 ± 10; ACE3: 534.11 ± 33.4 BPM). The heart rate variability evaluated by SDNN (ACE1: 5.16 ± 0.93; ACE2: 5.84 ± 1:32; ACE3: 7.69 ± 1.4 ms), RMSSD (ACE1: 5.91 ± 0.69; ACE2: 5.7 ± 1:14; ACE3: 6.78 ± 1.2ms), and the total variance (ACE1: 30 ± 12.4; ACE2: 37 ± 13.8; ACE3: 69.9 ± 25.6 ms) was higher in the ACE 3 infarcted group. Regarding the spectral analysis of HRV a higher sympathetic modulation (ACE1: 5.14 ± 3; ACE2: 7.2 ± 2.8; ACE3: 12.9 ± 4.1ms
2
) and a lower parasympathetic modulation (ACE1: 7 ± 2; ACE2: 8.6 ± 3.2; ACE3: 5.5 ± 2.8 ms
2
) were observed in ACE 3 infarcted mice. The variability of the BP (ACE1: 18.7 ± 6.2; ACE2: 14.85 ± 1.6; ACE3: 13.76 ± 4.2 mmHg
2
) and the sympathetic modulation component of the vessels were reduced in the ACE 3 AMI group (ACE1: 60.5 ± 6.2; ACE2: 54.6 ± 1.7; ACE3: 53 ± 3.3 mmHg
2
). Echocardiographic data showed diastolic dysfunction expressed by E / A ratio (ACE1: 3.40 ± 0.67; ACE2: 3:02 ± 1:36; ACE3: 2.0 ± 0.75) and increase in FAC - Fractional Area Change (ACE1: 27.9 ± 4.5; ACE2: 26.4 ± 5.7; ACE3: 33.5 ± 1.3) in the ACE 3 group after AMI. Our data suggest that increasing the number of ACE gene copies may promote autonomic imbalance evidenced by increased sympathetic modulation and the reduction of parasympathetic modulation of the cardiovascular system as well as the impairment of the diastolic function.
Abstract P197: Differences in Renin-angiotensin System Components Expression in Tumoral and Normal Cell Lines
Authors: Passos-Silva Danielle G , Oliveira Marilene L , Silva Felipe A , Oliveira Samuel F , Etelvino Gisele M , Sampaio Walkyria O , Santos Robson A
Published: June 2021

Several reports have shown the actions of ACE/ AngII/AT1 axis in the development of malignancy and also predict that RAS inhibitors could potentiate cancer therapies. On the other hand, the alternative axis of renin angiotensin system, ACE2/Ang-(1-7)/Mas, demonstrated an anti-tumoral property. This anti-tumoral effect is not clear for the recently described components of RAS, Alamandine/MrgD. The aim of this work is to characterize the expression and the enzyme activities of the RAS components in different tumoral and normal cell lines. There was a significant increase in the expression of the components (ACE and AT2) related to the formation and actions of Ang II. ACE presented 1.8 A.U. and 1.4 A.U. in A549 and MIAPACA tumoral cell lines, respectively, in comparison with 0.6 A.U. of normal cell lines (VERO) (p< 0.05). On the other hand, there was reduction in ACE2 enzyme related to the formation of Angiotensin-(1-7) and Alamandine (0.25 A.U. in MIAPACA VS 1.7 A.U. in VERO, p<0.05), which are modulatory peptides of the actions of Angiotensin II. Furthermore, there is also a significant increase in both Mas (0.18 A.U. in A549 VS 0.12 A.U. in VERO, p<0.05) and MrgD receptors (85 ±6 A.U. in A549 and 73 ±5 A.U. in MIAPACA VS 11 ±3 A.U. in VERO, p<0.001) expression in tumoral cells. Additionally, to complete the data obtained by Western Blotting, the enzymatic activity of ACE and ACE2 was evaluated in tumor cells and in Vero cells used as control. ACE enzyme activity is increased in tumor cells, while the ACE2 is reduced (950 A.U. in VERO VS 500 A.U. MIAPACA and 450 A.U. A549 p<0.01). These data suggest that RAS proliferative axis is activated in tumor cells and anti -proliferative axis is decreased compared to control cells.
Abstract P216: Association Between White-coat Hypertension and Arterial Stiffness: a Systematic Review and Meta-analysis
Authors: Upala Sikarin , Sanguankeo Anawin
Published: June 2021

Background:
Previous studies have shown inconclusive effects of target organ damage from white-coat hypertension (WCHT). Arterial stiffness is involved in the atherosclerotic processes in the setting of sustained hypertension. This meta-analysis aimed to compare arterial stiffness in subjects with diagnosis of WCHT to subjects with normotension (NT) and SHT.

Methods:
A comprehensive search of the databases of the MEDLINE and EMBASE was performed from inception through May 2016. The inclusion criterion was the observational studies’ assessment of the association between WCHT and NT or SHT in adult subjects. European Society of Hypertension practice guidelines for ambulatory blood pressure (BP) monitoring was used to define WCHT (office BP≥140/90mmHg and daytime BP <135/85mmHg), and SHT (office BP≥140/90mmHg and daytime BP≥135/85mmHg). Aortic stiffness was assessed using Carotid-femoral pulse wave velocity (PWV) measurements. Pooled mean difference (MD) of PWV and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

Results:
Data were extracted from 4 observational studies involving 2,413 subjects. PWV is not different in patients with WCHT compared with SHT (pooled MD= -0.25 m/sec; 95% CI, -0.81 to 0.30; P-value=0.37,

I
2

=74%). PWV in WCHT is also not different when compared with PWV in NT (MD= 0.86 m/sec; 95% CI, -0.30 to 2.03; P-value=0.15,

I
2

=97%).

Conclusion:
In a meta-analysis, we observe that arterial stiffness measured by pulse wave velocity is not different in patients with white-coat hypertension when compared with sustained hypertension or normotension.
Abstract P222: Ablation of Tool Like Receptor-4 Mitigates Blood Pressure Response During Hyperhomocysteinemia
Authors: Jeremic Nevena , Familtseva Anastasia , Chaturvedi Pankaj , Kunkel George H , Tyagi Suresh C
Published: June 2021

Background:
A significant number of studies have shown a positive correlation between Hcy plasma levels and hypertension. On the other hand pathogen recognition receptor, and in particular TLR-4 is a foreign antigen sensor that plays role in innate immune system activation and has recently gained a significant attention in the field of hypertension. Mitochondrial dysfunction and mitochondria-dependent apoptosis have been shown to promote endothelial cell loss leading to endothelial dysfunction that contributes to pathogenesis of hypertension. These events induce mitochondrial dysfunction characterized by excessive mitochondrial fission and mitochondrial apoptosis contributing to vascular remodeling followed by hypertension.

Objective:
The objective of this study is to define the mechanisms of homocysteine effect on aortic wall that promote vascular remodeling and hypertension and explore the role of TLR-4 mutation in alleviation of homocysteine negative effects.

Methods:
For this study we used 5 groups of mice: C57BL/6J, C3H/HEouJ, CBS+/-; C3H/HeJ, and CBS+/-/C3H. For further analysis we used isolated aorta and collected blood. Blood pressure was recorded using noninvasive tail cuff method. Effects of hyperpolarization factor and endothelial-dependent vasodilator on aorta contractility were also performed. We checked expression of mitochondrial fusion and fission proteins, antioxidant markers and expression of collagen/elastin fragments.

Results:
Data showed that there were increased values of systolic and diastolic pressure in CBS+/- mice (DP: 127.06±18.24; SP: 159.59±15.84) and C3H/HeJ mice had decreased levels of in comparing to other groups (DP: 55.43±16.19; SP: 110.04±5.90). The response to hyperpolarization factor and endothelial-dependent vasodilator were blended in CBS+/- aorta, however mitigated in CBS+/-/C3H. Fusion and fission ratio (Mfn2/DRP1) were increased in C3H/HeJ mice (1.53±0.08) and mostly decreased in CBS+/- mice (0.42±0.05) compering to other groups.

Conclusion:
These findings indicate the prevalence of mitochondrial fission over mitochondrial fusion in HHcy may explain possible endothelial cell loss and dysfunction followed by collagen accumulation that contributes to vascular remodeling.
Abstract P223: Caveolin-1 Contributes to Vascular Remodeling and Inflammation Induced by Angiotensin Ii in vivo and in vitro
Authors: Kawai Tatsuo , Forrester Steven J , Elliot Katherine J , Obama Takashi , Takayanagi Takehiko , Crawford Kevin , Eguchi Satoru , Rizzo Victor
Published: June 2021

We have recently reported that caveolin-1 (Cav1) enriched membrane microdomains in vascular smooth muscle cells (VSMC) mediate a metalloprotease ADAM17-dependent EGF receptor (EGFR) transactivation, which is linked to vascular remodeling but not contraction induced by angiotensin II (AngII). We have tested our hypothesis that Cav1, a major structural protein of caveolae, plays a critical role for development of vascular remodeling but not hypertension induced by AngII. 8 week old male Cav1-/- and the control Cav+/+ wild-type mice (WT: C57BL6) were infused with AngII (1 μg/kg/min) for 2 weeks to induce vascular remodeling and hypertension. Upon AngII infusion, histological assessments demonstrated medial hypertrophy and perivascular fibrosis of coronary and renal arteries in WT mice compared with sham-operated control mice. The AngII-infused WT mice also showed a phenotype of cardiac hypertrophy with increased heart weight/body weight (HW/BW) ratio (mg/g: 8.0±0.6 vs 5.7±0.7 p<0.01) compared with WT control. In contrast to AngII-infused WT mice, Cav1-/- mice with AngII infusion showed attenuation of vascular remodeling but not cardiac hypertrophy; HW/BW ratio (8.6±0.5 vs 6.4±0.2 p<0.05). Similar levels of AngII-induced hypertension were observed in both WT and Cav1-/- mice assessed by telemetry (mean arterial pressure: 142±9 vs 154±20 mmHg). In WT mice, Ang II enhanced ADAM17 expression and phospho-Tyr1068 EGFR staining in vasculatures of heart and kidney. These events were attenuated in vessels from Cav1-/- mice infused with AngII. In addition, immuno-histochemical analyses revealed less ER stress in heart and kidney of AngII-infused Cav1-/- mice compared with WT mice. Enhanced Cav1 and VCAM-1 expression were also observed in aorta from AngII-infused WT mice but not in Cav1-/- aorta. In rat VSMCs, adenoviral encoding Cav1 siRNA (100 moi) attenuated AngII-induced enhancements of total cell protein, cell volume and extracellular collagen content but not mitochondrial ROS generation. These data suggest that Cav1 and presumably vascular caveolae play critical roles for vascular remodeling and inflammation which likely involves the ADAM17/EGFR cascade independent from blood pressure or mitochondrial ROS regulation.
Abstract P229: Chymase-mediated Igf-1 Degradation Promotes Delayed Cell Death in Post-ischemic Hearts
Authors: Tan Lin , Tejada Thor , Torres Rebecca , Calvert John , Pejler Gunnar , Abrink Magnus , Lefer David , Husain Ahsan , Naqvi Nawazish
Published: June 2021

Heart disease is a leading cause of death in adults. Here we show that a few days after coronary artery ligation and reperfusion, the ischemia-injured heart elaborates the cardioprotective polypeptide, insulin-like growth factor-1 (IGF-1), which activates IGF-1 receptor prosurvival signaling and improves cardiac left ventricular systolic function. However, this is antagonized by the chymase, mouse mast cell protease-4 (MMCP-4), which degrades IGF-1 (Fig. 1). We found that MMCP-4 deficiency, resulted in sustained IGF-1 levels and IGF-1 receptor prosurvival signaling post-I/R. MMCP-4 deficiency markedly reduced late, but not early, infarct size (~50% reduction: n=5-7, p value= 0.001) by suppressing IGF-1 degradation and, consequently, improving cardiac function (EF: 26% greater, n=21, p value= 0.001) and adverse structural remodeling (Fig. 2). Our findings represent the first demonstration of tissue IGF-1 regulation through proteolytic degradation and suggest that chymase inhibition may be a viable therapeutic approach to enhance late cardioprotection in post-ischemic heart disease.
Abstract P230: The Influence of Calcification of Ascending Aorta on Dicrotic Notch of Thoracic Aorta
Authors: Khan Aahad , Ray Scott , Pir Syed Haris , Muhammad Mustafa Noor , Ahmad Mirza Mujadil , Hussaini Sharmeen , Ahmad Mirza Nubair , Razzaque Imaad , Syed Muhammad Nabeel , Ullah Rafath , Ammar Khawaja Afzal
Published: June 2021

Background:
Dicrotic Notch (DN) is known to dampen with age, with increasing arterial stiffness probably due to arterial calcification. Since arterial calcification has recently been shown to predominantly involve descending thoracic aorta, we hypothesized that calcification in different segments of thoracic aorta will have a different impact on DN.

Methods:
A sample of 44 patients with invasive thoracic aortic pressure tracings during cardiac catheterization was selected for this study. Non-contrast CT scans were evaluated for presence of calcification in aortic segments (ascending aorta (AA), aortic arch (arch) and descending aorta (DA)) and then quantified. DN was categorized based on aortic pressure tracings into 4 grades. Grade 1 represented normal DN; grades 2, 3 and 4 represented progressively diminishing DN, where grade 4 represented absent DN. Compliance was calculated as a change in stroke volume over aortic pulse pressure with both measurements obtained from echocardiography reports done within one year of catheterization.

Results:
The mean age of the sample population was 64.6 ± 10.5 years. Out of the 44 patients, 14 (32%) had a calcified AA, 25 (56%) had a calcified DA and n=28 (63%) had a calcified arch. Furthermore, 14 (32%) patients had only one segment calcified, whereas 10 (23%) had two and 11 (25%) had all three segments calcified. Abnormal DN was present in 16 (36%) patients. The odds of having an abnormal DN in the presence of calcified AA were more than 3 times (OR: 3.67; p=0.05). Compliance was higher in those with a normal DN versus those with an abnormal DN (1.64 ml/mmHg vs. 1.21 ml/mmHg) (p = 0.09). There was no significant association between calcification in the DA or arch of aorta.

Conclusion:
There was no association between dicrotic notch and presence of calcification in the arch of the aorta and descending aorta.
Abstract P231: Inhibition of Mir-762 Prevents and Reverses Ang II Induced Aortic Stiffening
Authors: Montaniel Kim Ramil C , Wu Jing , Bersi Matthew R , Xiao Liang , Itani Hana A , Vickers Kasey C , Humphrey Jay D , Harrison David G
Published: June 2021

We and others have shown that hypertension (HTN) is linked with striking fibrosis in the aortic adventitia. This leads to aortic stiffening, leading to organ damage. Through a screen of microRNAs (miRNAs) in the aorta, we found that miR-762 is the most upregulated miRNA in Ang II hypertensive mice. qRT-PCR confirmed that miR-762 is upregulated 6.35±1.22 (p=0.03) fold in Ang II-infused mice compared to controls. To study the role of miR-762 in HTN, we administered a locked nucleic acid inhibitor of miR-762. MiR-762 inhibition normalized stress-strain relationships and aortic systolic energy storage (ASE) (Table). Moreover, miR-762 inhibition in the last 2 weeks of Ang II infusion reversed aortic stiffness in mice treated with 4 wk of Ang II (ASE, 4 wk Ang II [51±5.18 kPa] vs 4wk Ang II + LNA-762 (last 2 wk) [20±1.76 kPa], p<0.0001). Further studies showed that miR-762 inhibition reduced mRNA for several collagens and fibronectin and upregulated collagenases MMP1a, 8 and 13 (Table). Lastly, we found that miR-762 inhibition during Ang II infusion led to a 9.11±1.92 (p=0.007) fold increase in Sprouty1 mRNA, suggesting that miR-762 targets Sprouty1 mRNA. Sprouty1 inhibits the activation of p38-MAPK which is critical in the process of aortic stiffening. Hence, miR-762 modulates aortic stiffening and fibrosis through a Sprouty1-p38-MAPK mechanism. Thus, miR-762 has a major role in modulating aortic stiffening and its inhibition dramatically inhibits pathological fibrosis, enhances matrix degradation, prevents and reverses aortic stiffness. miR-762 inhibition might represent a new approach to prevent aortic stiffening and its consequent end-organ damage.
Abstract P232: Psoriasis is Associated with Increased Arterial Stiffness: a Systematic Review and Meta-analysis
Authors: Upala Sikarin , Sanguankeo Anawin
Published: June 2021

Background:
Studies have shown that patients with psoriasis have higher risk of CVD, independent of traditional CVD risk factors. However, pathophysiology of the development of CVD in psoriasis is not well known. Arterial stiffness has been recognized as an independent predictor of cardiovascular risk. It is controversial whether psoriasis and arterial stiffness is associated. In this systematic review and meta-analysis, we sought to assess the hypothesis that patients with psoriasis have increased arterial stiffness compared with controls.

Methods:
Systematic literature search was performed using MEDLINE and EMBASE databases from inception to May 2016. We included original research publications that contained data on arterial stiffness and psoriasis. Aortic pulse wave velocity (aPWV) is the non-invasive marker for assessment of arterial stiffness. We compared aPWV between patients with psoriasis and controls and estimated the pooled mean difference (MD) and 95% confidence interval (CI) of aPWV using a random-effects model meta-analysis.

Results:
Data from five observational studies involving 438 participants (233 with psoriasis) were extracted and included in the meta-analysis. Pooled MD of aPWV was 1.17 m/sec higher in patients with psoriasis compared with controls (95% CI: 0.78-1.55, P-value<0.01, I
2
= 69%). There is no change in the direction or statistical significance of MD of aPWV after removing each study at a time in the sensitivity analysis.

Conclusion:
Psoriasis is associated with increased arterial stiffness. Assessment of arterial stiffness parameters may be important for early detection of cardiovascular deterioration in psoriasis patients.
Abstract P237: Is Ischemia/Reperfusion an Efficient Method for Producing Heart Failure in Rats?
Authors: Omoto Ana Carolina M , Gava Fábio N , de Oliveira Mauro , Silva Carlos A , Fazan Rubens , Salgado Helio C
Published: June 2021

Myocardium infarction (MI) elicited by coronary artery ligation (CAL) is commonly used to induce chronic heart failure (HF) in rats. However, CAL shows high mortality rates. Given that ischemia-reperfusion (IR) may cause the development of HF, this approach may be useful for obtaining a model of HF with low mortality rates. Therefore, it was compared the model of CAL vs. IR in rats, evaluating the mortality and cardiac morphological and functional aspects. The IR consisted of 30 minutes of cardiac ischemia. Wistar rats were assigned into three groups: CAL: n=18; IR: n=7; SHAM (fictitious IR): n=7. After four weeks of CAL, the subjects were evaluated by echocardiography and ventriculography as well. The statistical analysis consisted of ANOVA combined with Tukey’s posthoc test (p<0.05). There were no deaths in the IR and SHAM groups, whereas in the CAL group the mortality rate was 33.33% (6 out of 18). In the CAL group echocardiography showed increased left ventricular (LV) cavity during systole (8.3 ± 1mm) and diastole (10.5 ± 1mm); decreased LV free wall during systole (1.4 ± 0.5 mm); increased left atrium/aorta (2.3 ± 0.4) ratio. These changes were not significant in IR (4.8 ± 0.5mm, 7.6 ± 0.6mm, 2.6 ± 0.3 mm, 1.6 ± 0.2) and SHAM (4.6 ± 0.6 mm, 7.7 ± 0.8mm, 2.8 ± 0.4mm, 1.5 ± 0.2) groups. There was also the reduction in the ejection fraction in the CAL group (41 ± 12 %) when compared with IR (65 ± 9%) and SHAM (69 ± 7%) groups. The tissue Doppler analysis from the lateral mitral annulus showed reduction in E′ in CAL (-29 ± 8 mm/s) and IR (-31± 9 mm/s) groups when compared with the SHAM (-48 ± 11 mm/s) group. The ventriculography in the CAL group showed smaller maximum dP/dt (6519 ± 1062) and greater end-diastolic pressure (33 ± 8 mmHg) when compared with IR (8716 ± 756 mmHg/s; 9 ± 9 mmHg) and SHAM (7989 ± 1230 mmHg/s; 9 ± 7 mmHg) groups. The CAL group presented transmural infarct size of 40% of the left ventricular wall, measured under histopathological examination. In conclusion, IR for 30 minutes caused only small changes in LV diastolic function, assessed by tissue Doppler; however, the IR was not effective for promoting HF, as observed with CAL. Thus, it is possible that prolonged IR is necessary for promoting significant HF in rats.
Abstract P244: Utility or Futility of Echocardiography in Determining Cardiac Causes of CVA
Authors: Lodhi Hamza A , Shafiq Hasan , Mushtaq Asim , Khan Muhammad H , Haq Ehtesham , Shafiq Ali
Published: June 2021

Background:
Current guidelines recommend that all patients who are suspected to have a cardio-embolic cause for their cerebral vascular accident (CVA) should receive an echocardiogram. However, there are no clear risk stratification tools to help clinicians identify patients at high risk for having cardio-embolic stroke. As a result, echocardiograms appear to be over utilized and may have a low yield in routine clinical practice.

Methods:
In our single center study we included patients who were >18 years old and had been admitted from November 2015 to February 2016 to our hospital with an admission diagnosis of Cerebral Vascular Accident (CVA) using ICD-9 code 434.91. Multivariable logistic regression was used to identify factors associated with a greater likelihood of having an echocardiogram ordered as a part of the diagnostic workup.

Results:
Among 347 patients who were admitted with a diagnosis of CVA, echocardiogram was ordered in 259 (74.6%) patients. In patients who underwent echocardiography, only 3/259 (0.01%) had abnormal findings (e.g., Patent foramen ovale or intracardiac vegetations) that might suggest a cardio-embolic source for their CVA. In the adjusted analyses we found that factors like age, previous history of CVA, findings of atrial fibrillation on electrocardiogram (p-values > 0.05), were not significantly associated with the decision for ordering echocardiograms.

Conclusions:
Our study shows a low yield of echocardiography to determine an embolic cause in patients who were admitted to the hospital with diagnosis of CVA. Furthermore, no patient-level variables were associated with the likelihood of having an echocardiogram ordered. This may suggest that providers’ decisions to order echocardiograms is random rather than systematic, which itself stems from lack of clear recommendations for clinicians in when to order this test. More clear guidelines in this matter will be helpful to ensure appropriate utilization of this modality in CVA patients.
Abstract P259: Social and Biological Correlates of Elevated Blood Pressure in Afro-Caribbean Youth: Effect of Individual Risk Factors and Risk Factor Clustering
Authors: Ferguson Trevor S , Younger-Coleman Novie O , Tulloch-Reid Marshall K , Knight-Madden Jennifer M , Samms-Vaughan Maureen E , Ashley Deanna E , Wilks Rainford J
Published: June 2021

Background:
We aimed to estimate the relative risk for elevated blood pressure (BP ≥ 120/80 mmHg) for cardiovascular disease (CVD) risk factors among Afro-Caribbean youth in Jamaica and to evaluate the association between clustering of risk factors and elevated BP.

Methods:
We analysed data from 898 young adults, 18-20 years old (409 males; 489 females) from the Jamaica 1986 Birth Cohort Study. BP was measured with a mercury sphygmomanometer after the participant had been seated for 5 minutes. Anthropometric measurements were done and venous blood obtained to measure fasting glucose, lipids and insulin. Data on socioeconomic status (SES) were obtained via questionnaire. CVD risk factor status was defined using standard cut-points or the upper quintile of the distribution. Insulin resistance was estimated using the Homeostasis Model Assessment (HOMA-IR). Relative risks were computed using odds ratios (OR) from logistic regression models.

Results:
Prevalence of elevated BP was 30% among males and 13% among females (p<0.001). In multivariable logistic regression models, modifiable risk factors independently associated with elevated BP among males were: central obesity (OR 4.7, 95%CI 1.6 - 13.7), high glucose (OR 1.9, CI 1.1 - 3.1) and high HOMA-IR (OR 2.33, CI 1.1 - 5.1); among females associated factors were: high triglycerides (OR 2.2, CI 1.1 - 4.1), high HOMA-IR (OR 2.4, CI 1.1 - 5.0) and SES (OR 3.6, CI 1.03 - 12.8 [moderate vs high household possessions]; OR 1.87 CI 0.5 - 7.2 [low vs high]). Among males, having any one of central obesity, high glucose, high triglycerides or high HOMA-IR was associated with a two-fold increase in the odds of elevated BP, while having three or four factors was associated with a seven-fold increase in the odds. Among females, having any one of the four factors above was associated with two-fold higher odds, while having three or four factors was associated with a three-fold higher odds.

Conclusion:
Factors associated with elevated BP among Jamaican young adults include measures of obesity and insulin resistance, with significant differences by sex. Lower SES was associated with elevated BP among females. Clustering of risk factors was associated with markedly higher odds of elevated BP among males, but less so among females.
Abstract P311: Cardiac Sympathetic Afferents Does Not Initiate but Contributes to the Further Development of Hypertension in Spontaneous Hypertensive Rats
Authors: Wang Hanjun , Zucker Irving H.
Published: June 2021

Sympatho-excitation plays a critical role in the pathogenesis of hypertension. However, it is unclear what factors initiate and maintain sympatho-excitation in hypertension. Our past studies have confirmed a critical role of cardiac sensory nerve endings that mediate a sympatho-excitatory reflex called the “cardiac sympathetic afferent reflex” (CSAR) in the setting of heart failure. However, whether/when the CSAR is activated and contributes to the development of hypertension remains unclear. To address this issue, we chronically abolished the CSAR by epidural application of a selective afferent neurotoxin, resiniferatoxin (RTX) at the level of the T1-T4 dorsal root ganglia (DRGs) by destroying TRPV1-expressing neuronal soma in 8-week and 16-w old spontaneous hypertensive rats (SHR). Conscious blood pressure was monitored before (baseline) and during 2 months post RTX using radio telemetry. As shown in Figure 1A, in early-hypertensive (8-w old) SHR rats, there was no difference in mean arterial pressure (MAP) between vehicle and RTX groups until 3 weeks post intervention. At that time, MAP in vehicle-treated SHR rats continued to increase whereas this increase was largely abolished in the RTX-treated group. In the established (16-w old) SHR rats (Figure 1B), treatment with RTX immediately reduced MAP by ~15 mmHg, which was maintained for the 2-month recording period. These data strongly suggest that although CSAR does not initiate hypertension at the early stage in SHR, it contributes to the further development of hypertension in the mid/late stages. These data support a potential novel therapy possibly involving cardiac afferents.