bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P030: Dct (pro)renin Receptor Via Its Soluble Product Inhibits Ncc Activity During Regulation Of Blood Pressure And Potassium Homeostasis In Mice
Authors: Xu Chuanming , Chen Yanting , Wang Fei , Xie Shiying , Zou Changjiang , Luo Renfei , Yang Tianxin
Published: September 2020

Sodium-chloride cotransporter (NCC), uniquely located at the distal convoluted tubule (DCT), is the target of thiazide diuretics and critically involved in renal handling of both Na
+
and K
+
. However, the mechanism of how NCC activity is regulated is incompletely understood. Here we report a novel role of (pro)renin receptor (PRR) and its cleavage product soluble PRR (sPRR) via site-1 protease (S1P) as negative regulators of NCC during high-salt or high-K
+
loading. Mice with DCT-specific deletion of PRR (termed as DCT PRR KO) was generated by crossing PRR floxed mice with a transgenic mouse line expressing Cre under the control of the parvalbumin (PV) promoter. Radiotelemrty demonstrated that under basic condition, DCT PRR KO mice exhibited modest hypertension (~5 mmHg) associated with reduced urinary Na
+
(Floxed: 0.20±0.02, KO: 0.12±0.01 mmol/24h, p<0.001), K
+
(Floxed: 0.29±0.02, KO: 0.18±0.03 mmol/24h, p<0.05), and Cl
-
(Floxed: 0.30±0.03, KO: 0.21±0.02 mmol/24h, p<0.01) excretion and increased
in vivo
NCC activity as assessed by hydrochlorothiazide (HCTN)-induced natriuresis ( by 61%). Renal protein abundance of pNCC-T53 (by 51%) but not total NCC was elevated in the null mice. Following a high salt diet, DCT PRR KO mice were salt sensitive as evidenced by a ~30 mm Hg increase of mean arterial pressure (MAP) which was sensitive to HCTN (ΔMAP, Floxed+HS: -2.05±1.50, KO+HS: -12.77±2.6 mmHg, p<0.05), contrasting to salt resistance in the floxed control. The null mice also exhibited impaired kaliuresis (Floxed+HK: 3.24±0.13, KO+HK: 2.32±0.23 mmol/24h, p<0.001) and hyperkalemia (Floxed+HK: 3.75±0.05, KO+HK: 4.40±0.08 mM, p<0.001) after high K
+
intake. This phenotype was recapitulated by treatment of C57/BL6 mice with S1P inhibitor PF429242. In cultured Flp-In T-REx 293 NCC cells, S1P-derived sPRR directly dephosphorylated NCC (by 40%) via activation of angiotensin II receptor type 1 (AT1R) independently of aldosterone.

1
/
2

Taken together, the present study has demonstrated that S1P-derived sPRR via AT1R negatively regulates NCC activity in the DCT to render salt resistance and to promote K
+
excretion.

2
/
2
Abstract P033: PRESSOR, NATRIURETIC, AND RENAL RESPONSES IN ANGIOTENSIN II-INDUCED HYPERTENSION IN MALE AND FEMALE WILD-TYPE AND PROXIMAL TUBULE-SPECIFIC AT
1A
RECEPTOR KNOCKOUT MICE
Authors: Leite Ana Paula O , Li Xiao C , Casarini Dulce E , Zhuo Jia L
Published: September 2020

Dysregulation of intrarenal renin-angiotensin system is one of the key factors of human hypertension, but the mechanisms involved remain incompletely understood. To determine the roles of AT
1a
receptors in the proximal tubules of the kidney, we infused angiotensin II (Ang II) for 2 weeks (40 ng / min, i.p.) in adult male and female wild-type C57BL/6J and mutant mice with deletion of AT
1a
receptors in the proximal tubules (PT-

Agtr1a
-/-

), and treated with or without the AT
1
receptor blocker losartan (20 mg/kg/day, p.o.) (n=8 per group). The pressor response, 24 h urinary Na
+
excretion, glomerular and tubulointerstitial injury were compared between male and female wild-type and PT-

Agtr1a
-/-

mice. Basal systolic, diastolic, and mean arterial blood pressure were about 13 ± 3 mmHg lower in male and female PT-

Agtr1a
-/-

mice (
P
<0.01), but no differences were observed between male and female wild-type or PT-

Agtr1a
-/-

mice. In response to Ang II, both male and female wild-type and PT-

Agtr1a
-/-

mice developed hypertension (
P
<0.01), and the net pressor response were similar in male and female wild-type and PT-

Agtr1a
-/-

mice (n.s.). However, absolute blood pressure was about 12 ± 3 mmHg lower in male and female PT-

Agtr1a
-/-

mice (
P
<0.01 vs. wild-type). Ang II-induced hypertension increased the natriuretic response in both male and female wild-type and PT-

Agtr1a
-/-

mice (
P
<0.01), but there were no significant differences between male and female wild-type and PT-

Agtr1a
-/-

mice (n.s). Losartan did not increase the natriuretic responses further in all animals. Furthermore, Ang II-induced hypertension was associated with significant increases in glomerular and tubulointerstitial injury in male and female wild-type mice (
P
<0.01), which were attenuated in male and female PT-

Agtr1a
-/-

mice (
P
<0.01). LOS treatment attenuated Ang II-induced hypertension and decreased Ang II-induced glomerular and tubulointerstitial injury in male and female wild-type and PT-

Agtr1a
-/-

mice (
P
<0.01). Taken together, we demonstrated that intratubular AT
1
(AT
1a
) receptors in the proximal tubules of the kidney plays a key role in maintaining basal blood pressure homeostasis and overall body salt and fluid balance, and the development of Ang II-induced hypertension and kidney injury.
Abstract P034: Vasculature Remodeling In Two Models Of Reduced Renal Mass
Authors: Adam Ryan , Marks Amanda , Nasci Victoria , Kriegel Alison J
Published: September 2020

Remnant kidney models of chronic kidney disease include the 1/3 nephrectomy (1/3Nx), and 5/6 nephrectomy rats. The 1/3Nx remnant kidney spontaneously atrophies with time, and the 5/6Nx hypertrophies. This disparate remodeling must occur with commensurate vascular changes, examination of which may reveal important molecular pathways and mechanisms underlying changes in renal function. The first step toward realizing this, and the aim of this study, was to characterize the renal vasculature from 1/3Nx, 5/6Nx, and sham Nx rats.

Methods:
The vasculature was examined in rats 10 weeks following surgery. To-date, these renal vasculatures have been quantified by (1) assessment of vascular density by analysis of bisected, renal vascular casts, and (2) renal blood flow doppler ultrasound. Data: Avg±SEM.

Results:
1/3Nx remnant kidney atrophied and 5/6Nx hypertrophied (cross-sectional area: sham n=9; 241±7. 5/6Nx, n=9; 247±8. 1/3Nx, n=12; 132±11: mm
2
). Despite this, kidney height (intact kidney long axis) to width (short axis) ratio was similar between the remnant models (5/6Nx; 0.8±0.04. 1/3Nx; 0.9±0.04). Sham kidney vascular density was significantly greater than that of 1/3Nx remnant kidneys, which exceeded that of 5/6Nx rats. Cortex vascular density was significantly different between all groups (sham; 95±2%. 1/3Nx; 57±9%. 5/6Nx; 25±11%). The statistical mode of the arterial blood flow distribution was not different between the groups, but mode venous flow was (sham; 100±6. 1/3Nx; 118±9. 5/6Nx; 136±8. Relative units.). Homogeneity of flow was quantified by expressing flow-direction boundaries as a percent of flow area. Sham flow was significantly more homogenous (1.8±0.2) than 1/3Nx (3.7±0.5), and 5/6Nx rats (3.9±0.3).

Conclusion:
These data demonstrate changes in vascular anatomy and function in both remnant kidney models. Interrogation of anatomical changes and molecular pathways may reveal novel treatment approaches.
Abstract P035: Prostaglandin Ep4 Receptors In Kidney Epithelial Cells Promote Resistance To Hypertension
Authors: Yang Ting , Song Chengcheng , Sparks Matthew A , Koller Beverly H , Coffman Thomas M
Published: September 2020

A role for prostanoids in blood pressure control is demonstrated by clinical studies showing that use of nonsteroidal anti-inflammatory drugs, which block all the prostanoid production, is associated with hypertension. Prostaglandin E
2
(PGE
2
) is a major prostanoid produced by the kidney and its actions are mediated by four E-prostanoid (EP) receptors: EP1-EP4. In previous studies, we found that conditional deletion of EP4R from all tissues in adult mice dramatically exaggerates Ang II-dependent hypertension, suggesting a powerful effect of EP4R to resist blood pressure elevation. We also found that elimination of EP4R from vascular smooth muscle cells did not affect severity of hypertension, indicating other cellular targets of PGE
2
must mediate this anti-hypertensive effect. Here we report studies examining actions of EP4R in two additional candidate cell lineages: macrophages and kidney epithelial cells, which have both been implicated in hypertension pathogeneses. Cell-specific deletion of EP4R was accomplished by crossing mice bearing a conditional EP4 allele (

EP4
flox

) with mouse lines carrying a

LyzM-Cre
+

transgene expressing in macrophages (MACKOs) or tetracycline-inducible

Pax8-rtTA
+
TetO-Cre
+

transgene driving expression in renal tubular epithelial cells (RTKOs). Elimination of EP4R from macrophages in MACKOs had minimal effects on baseline BP and salt sensitivity, and responses to chronic Ang II infusion were virtually identical in MACKOs and controls (138±3 vs 133±2 mm Hg; n=14/group). By contrast, absence of EP4R from kidney epithelia in RTKOs caused significant augmentation of Ang II-induced hypertension compared to Controls (average MAP: 145±4 vs. 135±3 mmHg, p=0.03; MAP increase from baseline: 31±2 vs. 20±3 mmHg, p=0.02). The increased severity of hypertension in RTKOs was associated with exaggerated cardiac hypertrophy relative to controls (heart:body weight ratio 8.6±1.5 vs. 7.3±1.2 mg/g; p=0.03). Our

findings suggest that kidney epithelial cells, but not macrophages, are critical targets of PGE
2
acting via EP4R to oppose the development of hypertension. As collecting duct is the major site of EP4R expression in renal epithelia, this may reflect actions of EP4R to modulate key sodium transporters in this nephron segment.
Abstract P044: Intensity Of Hypertensive Exposure In Young Adulthood And Myocardial Structure And Function In Middle Age
Authors: Xiong Zhenyu , Li Jiaying , Zhuang Xiaodong , Liao Xinxue
Published: September 2020

Background and aims:
To measure the association between intensity of hypertensive exposure and myocardial structure and function during a 25-year period in young adulthood.

Methods:
The Coronary Artery Risk Development in Young Adults (CARDIA) Study enrolled 5,115 healthy black and white American aged 18-30 years at baseline (March 1985 to May 2011). Intensity of hypertensive exposure was estimated based on their durations of hypertension over 25 years. Myocardial structure and function was identified by echocardiogram at year 25.

Results:
Of 2027 participants, 1315 were women (64.9%) and 906 were black (44.7%); mean (SD) age was 24.9 (3.6) at baseline. Duration of stage 1 hypertension was associated with higher left ventricular (LV) structure: LV mass (β [SE], 3.69 [1.80], P < 0.001), relative wall thickness (β [SE], 0.009 [0.003], P = 0.001), worse longitudinal strain (β [SE], 0.27 [0.008], P < 0.001), worse diastolic function: e’ (β [SE], -0.25 [0.07], P < 0.001), E/e’ (β [SE], 0.23 [0.007], P < 0.001). Duration of stage 2 hypertension was associated with higher left ventricular (LV) structure: LV mass (β [SE], 7.30 [2.23], P = 0.001), worse longitudinal strain (β [SE], 0.44 [0.13], P = 0.001), worse diastolic function: e’ (β [SE], -0.77 [0.12], P < 0.001), E/e’ (β [SE], 0.48 [0.13], P < 0.001).

Conclusions:
In early adulthood, more severe intensity of hypertensive exposure is associated with myocardial structure and diastolic dysfunction in middle age.
Key Words:
cardiac structure, cardiac dysfunction, hypertension, young adult
Abstract P046: Variable Effect Of
Gstm1
Knockout In Mice
Authors: Wang Yves T , Nehrke Keith , Brookes Paul S , Le Thu H
Published: September 2020

Glutathione S-transferase μ-1 (GSTM1) is an enzyme that has a role in the detoxification of electrophiles, including xenobiotics and products of oxidative stress. In humans, the
GSTM1(0)
null allele deletion variant is highly prevalent and is associated with both an increase in oxidative stress and an increased risk/severity of a variety of diseases, including cancers, chronic kidney disease, hypertension, and coronary artery disease.Recently, we generated a
Gstm1
knockout (

Gstm1
-/-

) mouse line on a 129S6 background. Using these animals, we demonstrated that the loss of GSTM1 resulted in increased oxidative stress and greater kidney injury with either subtotal nephrectomy-induced chronic kidney disease or angiotensin II-induced hypertension, in accordance with clinical data.Following myocardial infarction, reperfusion of the heart results in additional tissue damage that is also mediated by acute oxidative stress. Here, we used an
ex vivo
Langendorff-perfused heart model of acute cardiac ischemia-reperfusion injury (IRI). Contrary to the expectation that hearts from

Gstm1
-/-

mice would be more susceptible to IRI, we found that the loss of the antioxidant enzyme GSTM1 was protective in males compared to age-matched wild-type controls. In contrast, the

Gstm1
-/-

genotype was deleterious in female hearts as expected.To explore the hypothesis that the loss of GSTM1 causes compensatory upregulation of other GSTs and that this effect varies based on both tissue and sex, we examined mRNA expression of α, θ, κ, μ, and π classes of
Gst
genes via qPCR and corresponding protein expression via HPLC and western blot. We found significant differences between male vs. female and heart vs. kidney in several GSTs both in their expression in wild-type mice and in the change in expression between wild-type and

Gstm1
-/-

mice. These results suggest that the severity of cardiac IRI may depend on the adaptive response mediated by genes encoding GST enzymes.
Abstract P048: Hospital Readmission Of Heart Failure Patients And Its Precipitated Factors And Hypertension
Authors: Tun Han Naung , Raza Syed Haseeb
Published: September 2020

Introduction:
Hypertension is one of the most prevalent modifiable risk factor for the development of heart failure (HF). Chronic heart failure (CHF) is the most common cause of readmission for patients in worldwide. Despite this recent attention to HF readmission, we know relatively little about its actual causes despite the fact that patients are in many ways best positioned to identify the underlying factors that contribute to their readmission.

Objective:
To systematically investigate the patients' perspectives about the reasons for their hospital readmission related to hypertension after discharged of stabalized HF patients and to study how to improve our heart failure care system to reduce the number of readmission in cost effective way.

Method and Materials:
Patients were recruited for this study was admitted to national institute of cardiovascular diseases, through emergency department. Patients discharged with a primary discharge diagnosis for HF who were then readmitted for any cause in the subsequent 6 month were eligible for the study. We recruited patients over the period of 3 month form June 2019 till August 2019. Eligible patients were approached, consented, and interviewed within the next 24 hours while they were still in hospital.

Result:
For the readmission, median length of stay was 6 days. Total 500 patient included, out of which 375 (75%) were male and most important cause of heart failure is ischaemic cardiomyopathy 400 (80%). No death recorded. Common reasons for readmission are lack of counselling 200(40%), under dose 75(15%), non-compliance 60(12%), volume over load 50(10%), hypertension 50(10%), secondary infection 35(7%).

Conclusion:
We concluded that hypertension is not largely associated with heart failure hospitalization in our study. But patient compliance of medication, appropriate fluid intake, self-care and life style modification are the important elements in hospital readmission of heart failure.
Abstract P050: A QUERY OF THE DIABETES PARADOX IN TAKOTSUBO CARDIOMYOPATHY
Authors: Abe Temidayo , Olaosebikan Kikelomo , babatunde Ajibola , Abe Tolulope , Tobun Temitope
Published: September 2020

Background:
Observational studies have demonstrated a low prevalence of diabetes mellitus (DM) in patients with takotsubo cardiomyopathy (TCM) and also suggested a possible protective role due to underlying autonomic neuropathy. its impact on TCM outcomes is unclear.

Methods:
We recruited 8081 patients from 2011, 2012 National Inpatient Sample, 6325 had TCM while 1756 had TCM with DM. Our outcomes of interest were overall mortality, mechanical hemodynamic support (MHS), acute respiratory failure(ARF), cardiac arrest (SCA), cardiogenic shock (CS), and stroke. Logistic regression was used to estimate the adjusted odds ratio of the outcomes in the study compared to the control group while stratified analysis was used to adjust for sex both accounting for underlying comorbidities.

Results:
The mean age was 60.4 years. There was no difference in overall mortality (4.1% vs 3.5%; P =0.154), cardiogenic shock (6.2% vs 6.2%; P=0.905), atrial fibrillation (11.1 vs 11.8; P= 0.224), stroke (1.9% vs 2.3%; P= 0.139) and MHS (2.3% vs 2.8%; P= 0.086). The rate of acute respiratory failure was significantly higher in DM+TCM patients compared to TCM alone (20.8% vs 18.2%; P= 0.021). Table 1 reveals the adjusted odds ratio for outcomes while table 2 stratified analysis based on age and sex. Patients with TCM+ DM have higher odds for acute respiratory failure and the use of MHS. The stratified analysis revealed that compared to TCM alone, females with TCM +DM are more likely to develop acute respiratory failure, stroke, and the use of MHS, while male patients were more likely to develop atrial fibrillation.

Conclusion:
Underlying DM is associated with an increased risk for poor outcomes in patients with TCM.
Abstract P051: Application Of Artificial Intelligence In Transcriptome-based Diagnosis Of Cardiomyopathies
Authors: Cheng Xi , Alimadadi Ahmad , Manandhar Ishan , Aryal Sachin , Munroe Patricia B , Joe Bina
Published: September 2020

Dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) are predisposing conditions for increased risk of cardiovascular diseases including heart failure, valve disease and arrhythmias. An accurate diagnostic strategy of differentially classifying different types of cardiomyopathies could contribute to precision medicine in routine clinical care. We hypothesized that artificial intelligence (AI) could be trained with cardiac transcriptomic data for diagnostic classifications of clinical cardiomyopathies. To test this hypothesis, various supervised machine learning (ML) models, such as support vector machine with radial kernel (svmRadial), neural networks with principal component analysis (pcaNNet), decision tree (DT), elastic net (ENet) and random forest (RF), were used to analyze RNA-seq data of human left ventricle tissues collected from 41 DCM patients, 47 ICM patients and 49 non-failure controls (NF). Initial ML classifications achieved an AUC of ~0.96 (ENet, pcaNNet and svmRadial) for NF vs DCM, an AUC of ~0.89 (RF) for NF vs ICM, and an AUC of ~0.90 (svmRadial) for DCM vs ICM. Next, 50 highly contributing genes (HCGs) for classifying NF and DCM, 68 HCGs for classifying NF and ICM, and 59 HCGs for classifying DCM and ICM were selected for re-training ML models. The re-trained models achieved an AUC of ~0.96 (RF) for NF vs DCM, an AUC of ~0.97 (pcaNNet) for NF vs ICM, and an AUC of ~0.94 (RF) for DCM vs ICM. Pathway analyses of the selected HCGs further demonstrated their pathophysiological roles in cardiovascular dysfunctions including cardiomyopathies. Overall, our study demonstrates the promising potential of using AI via ML models as a novel approach to achieve a greater level of precision in diagnosing different types of clinical cardiomyopathies.
Abstract P053: Enhanced Exercise Capacity By Muscadine Grape Extract Treatment Is Only Evident In Older Hypertensive Female Rats And Is Independent Of Blood Pressure
Authors: Cruz Diaz Nildris , Duncan A'ja V , Graham Wayne , Westwood Brian , Gallagher Patricia E. , Tallant E. Ann , Chappell Mark C. , Yamaleyeva Liliya M. , Diz Debra I.
Published: September 2020

Physical performance and systolic blood pressure (SBP) during aging in normotensive female Sprague-Dawley (SD) and hypertensive (mRen2)27 transgenic rats were assessed following long-term treatment with a Muscadine Grape Extract (MGE, Piedmont Research and Development Corp). MGE was administered at a dose of 0.2 mg/mL in the drinking water starting at 14 weeks (wks) of age with an endpoint at 70 wks of age (total time of treatment of 56 wks). At 20-, 40- and 70-wks of age, physical performance (exercise capacity in seconds and workload in grams - meters) was determined using a treadmill at a velocity of 17 cm/second with a 5% incline. SBP was determined by tail-cuff plethysmography in trained rats. There were no significant differences in physical performance between SD and (mRen2)27 female rats at any age despite the higher SBP in the (mRen2)27 rats at all ages. Long-term treatment with MGE had no significant effect on physical performance or SBP in SD rats at any age. In contrast, MGE treatment markedly increased exercise capacity (40 wks: 1615 ± 166 vs 4943 ± 442 seconds, p<0.01, n = 4-9; 70 wks: 2520 ± 374 vs 4117 ± 245 seconds, p<0.01, n = 4-8) and workload (40 wks: 4579 ± 490 vs 14730 ± 1353 grams - meters, p<0.01, n = 4-9; 70 wks: 8338 ± 1340 vs 13659 ± 933 grams - meters, p<0.01, n = 4-8) at the later ages in female (mRen2)27 rats, while there was no effect on SBP (20 wks: 167 ± 4 vs 173 ± 4 mm Hg, n = 4-6; 40 wks: 177 ± 8 vs 170 ± 7 mm Hg, n = 6-7; 70 wks:154 ± 6 vs 172 ± 6 mm Hg, n = 5) at any age. These data suggest that MGE treatment is effective in improving physical performance only in hypertensive female rats and may be independent of changes in blood pressure. The benefit of MGE in the older hypertensive female may reflect reductions in vascular stiffness and oxidative stress. Support: Chronic Disease Research Fund, Hypertension & Vascular Research Center
Abstract P056: Voltage-gated Chloride Channel 6 Regulates Intracellular Calcium Signaling In Vascular Smooth Muscle Cells And Prevents Arterial Stiffening
Authors: Klemens Christine A , Wu Jing , Khan Md Abdul Hye , Levchenko Vladislav , Imig John D , Sigmund Curt D , Palygin Oleg , Staruschenko Alexander
Published: September 2020

Hypertension is a global health problem that increases the risk of stroke, heart failure, and kidney disease. GWAS have linked the
CLCN6
gene to blood pressure regulation.
CLCN6
encodes the voltage-sensitive chloride channel 6 (ClC-6), an intracellular protein of little-known function. Due to its high expression in vascular smooth muscle cells (VSMCs) and its localization in the Golgi, we hypothesized that ClC-6 is involved in Ca
2+
uptake in the Golgi and that reducing Golgi Ca
2+
levels changes VSMC function and therefore blood pressure, potentially by altering protein trafficking or cell proliferation. Using a knock-out of
Clcn6
on the Dahl salt-sensitive rat background, we determined that KO rats have impaired vasodilation in response to 10 μM acetylcholine in mesenteric arteries (82 ± 6% vs 41 ± 13%, N=6 rats, n ≥ 9 vessels, p<0.01). Two-Photon microscopy in mesenteric arteries determined that KO VSMCs continue to release intracellular Ca
2+
in response to acetylcholine at a greater frequency than WT. Additionally, arterial stiffness, determined by pulse-wave velocity (PWV) measurements, was greater in KO rats at baseline (4.5 ± 0.3 vs. 3.6 ± 0.2 mm/msec, N≥6 rats, p<0.05); however, after 3 weeks on a 4% NaCl diet to develop hypertension, the WT rat PWVs increased significantly (4.6 ± 0.1 vs. 3.6 ± 0.2 mm/sec, N=6, p<0.05) whereas the KO rat PWVs did not change (4.6 ± 0.1 vs. 4.5 ± 0.3 mm/msec, N=6, p=0.91). To assess the effect of ClC-6 on Golgi Ca
2+
, confocal microscopy with an organelle-specific Ca
2+
dye and pharmacological agents was used to measure Ca
2+
. SR Ca
2+
stores were depleted with thapsigargin + ATP, followed by release of Golgi Ca
2+
stores by emetine. Total Golgi calcium levels were determined by area under the curve measurements of recorded fluorescence changes. Emetine-sensitive Golgi Ca
2+
stores were significantly reduced in KO rat VSMCs compared to WT. In conclusion, these results suggest that ClC-6 regulates Golgi Ca
2+
levels, and alteration to these stores results in cellular changes that slow or prevent arterial stiffness during the development of hypertension. Future studies will assess vessel fibrosis, cell proliferation, and apoptosis to elucidate the underlying molecular mechanisms impacting vessel stiffness and Ca
2+
signaling.
Abstract P058: Female Rats Artificially Selected For Low Vs. High Intrinsic Aerobic Capacity Display Divergent Mechanisms In Vascular Inflammation
Authors: Aradhyula Vaishnavi , McCarthy Cam , Bearss Nicole , Joe Bina , Koch Lauren G , Wenceslau Camilla F
Published: September 2020

Hypertension is an important clinical symptom of metabolic syndrome (MetS). Rats selectively bred for low intrinsic aerobic capacity (LCR) are animal models for MetS, and present with increased blood pressure and vascular dysfunction. In contrast, rats selected for high intrinsic aerobic capacity (HCR) display reduced vascular inflammation and no metabolic abnormalities. Two important enzymes for vascular inflammation and the resolution of inflammation are cyclooxygenase (COX) and lipoxygenase (LOX), respectively; however, it is unknown whether COX and LOX play a role in the vascular function of LCR and HCR. We hypothesized that mesenteric resistance arteries (MRA) from untrained LCR present increased COX activity, while arteries from HCR show decreased COX and increased LOX activity.

Female (18-38 weeks old) LCR, HCR, and high response trained (HRT) rats, control, were used. HRT rats present higher intrinsic aerobic capacity than LCR, but lower than HCR. MRA were mounted onto a wire myograph. One-way ANOVA: p<0.05: *vs. control (HRT);
#
vs. HCR;
&
vs. absence of indomethacin (INDO), a COX inhibitor. LCR rats showed increased periovarian fat pad [HRT: 0.95±0.1 (n=7) vs. LCR: 1.80±0.1*
#
(n=7) vs. HCR: 1.18±0.1 (n=7) (g)]. No significant differences were observed in the KCl (120 mM), acetylcholine, and sodium-nitroprusside-induced responses. However, LCR presented a decrease in phenylephrine (PE)-induced contraction [PE: E
max
%: HRT: 103±3 (n=8); LCR: 74±9*
#
(n=11); HCR: 112±5 (n=9)]. Inhibiting COX [INDO, 10 μM] decreased contraction in HRT arteries, but had little effect on HCR arteries. Contrarily, INDO abolished contraction in MRA from LCR [PE+INDO: E
max
%: HRT: 31±18
&
(n=7); LCR: 2±0.9
&
(n=8); HCR: 77±9 (n=8)]. Lipoxin (LXA4), a LOX-derived mediator for resolution of inflammation, induced contraction in MRA from HCR, but relaxation in LCR and HRT arteries [LXA4: E
max
%: HRT: -69±19 (n=4); LCR: -18±9 (n=3); HCR: 11±5 (n=4)*]. Thus, HCR are unresponsive to COX inhibition, suggesting a change from a normal inflammatory state to a higher resolution state. LCR display low-grade chronic inflammation via increased COX activity. These data reveal novel, inherited mechanisms for vascular physiology in high vs. low intrinsic aerobic capacity.
Abstract P060: High Salt Induces An Endothelial HDAC1-stimulating Circulating Factor Leading To Disrupted Renal Microvascular Nitric Oxide Signaling
Authors: Dunaway Luke S , Cook Anthony K , Inscho Edward W , Pollock Jennifer
Published: September 2020

High salt diet (HS) decreases endothelial nitric oxide (NO) signaling as described in human and rodent studies. We have previously shown that inhibition of HDAC1 restores NO signaling in the afferent arteriole of HS fed rats. It remains unknown, however, how HS initiates endothelial dysfunction and activates HDAC1. We first investigated if HS induced endothelial dysfunction is acutely regulated by a circulating factor. To test this, male Sprague Dawley rats were fed normal salt diet (NS; 0.49% NaCl) or 2 weeks of HS (4.0% NaCl). Afferent arteriole vasoconstrictor responses to the NOS inhibitor, L-NAME, were monitored using the in vitro, blood perfused juxtamedullary nephron preparation. Perfusing arterioles from NS fed rats with HS blood blunted constriction to L-NAME (88 ± 1% of Con) compared to perfusing with NS blood (76 ± 2% of Con; P=0.0003), but not completely as seen in arterioles from HS fed rats perfused with HS blood (96 ± 2% of Con; P=0.0095). HS arterioles perfused with NS blood had similar L-NAME-induced constriction (75 ± 2% of Con) compared to arterioles from NS fed rats perfused with NS blood (P=0.9107). These results suggest HS induces endothelial function through an acute-acting circulating factor. This was not due to increased plasma arginase activity (NS: 7.96 ± 3.73 U/L vs HS: 5.42 ± 1.83 U/L P=0.5813) which competes with NO synthase 3 for arginine, nor was it due to decreased superoxide scavenging capacity of the plasma (NS: 7.96 ± 3.73 U/L vs HS: 5.42 ± 1.83 U/L P=0.5813) as measured by a cytochrome c reduction based assay. We then investigated if HS increased endothelial HDAC1 activity. Renal endothelial cells were isolated via magnetic activated cell sorting from NS and HS fed rats and incubated in plasma from the same rat. HDAC1 activity was monitored as the MS-275 (HDAC1 specific inhibitor) inhibitable portion of total HDAC activity. We found HS significantly increased renal endothelium HDAC1 activity (NS: 0.38 ± 0.03 pmol/min vs HS:0.94 ± 0.19 pmol/min, P=0.01). We conclude that HS disruption of renal microvascular NO signaling is initiated by a circulating factor(s) that is dependent upon increased endothelial HDAC1 activity.
Abstract P061: Identification Of Piezo1 Channels In Perivascular Adipose Tissue (pvat) And Their Potential Role In Vascular Function
Authors: Miron Taylor , Flood Emma D , Negron Marie , Thompson Janice , Watts Stephanie W
Published: September 2020

The vasculature constantly experiences distension/pressure exerted by the blood and responds accordingly to maintain homeostasis. Perivascular adipose tissue (PVAT) is gaining support as a formal blood vessel layer and also experiences these changes. We hypothesized that activation of the mechanotransducer Piezo1 directly increases vascular contraction in a way that might be modified by PVAT. The presence of Piezo1 was investigated at the mRNA level via PCR; protein via immunohistochemistry; and contractility via isolated tissue bath. Rat superior and mesenteric arteries, thoracic aortae, human mesenteric vessels and their PVATs were studied. Piezo1 mRNA (beta2 microglobulin calibrator) was expressed in the aortic vessel (2
-ΔC
T
=0.011); aortic PVAT (2
-ΔC
T
=0.0172); mesenteric vessel (2
-ΔC
T
=.00302), and mesenteric PVAT (2
-ΔC
T
=0.0219). Both adipocytes (2
-ΔC
T
=0.0249) and stromal vascular fraction (2
-ΔC
T
=0.0159) of mesenteric PVAT expressed Piezo1 mRNA. Piezo1 mRNA expression was greater in magnitude (one-way ANOVA) than that of the mechanotransducers Piezo2, TRPV4, TMEM16, and Panx1. Piezo1 protein was present in rat aortic PVAT, rat mesenteric (mes) artery, vein, and PVAT, as well as in human artery, vein, and PVAT. The Piezo1 agonists Yoda and Jedi (1 nM - 10 μM) did not stimulate rat aortic contraction [max <10% phenylephrine (PE) 10 μM contraction] or relaxation independent from vehicle in tissues + or - PVAT (relaxation as % of half maximal PE contraction was: Veh-PVAT=45.3±7.0; Yoda-PVAT=46.7±25.6; Jedi-PVAT= 40.4±10.3; Veh+PVAT= 71.8±19.7; Jedi+PVAT=39.1±13.2; Yoda +PVAT=21.6±10.9). Slightly K+ depolarizing the aorta did not unmask contraction to Yoda. Finally, the Piezo1 antagonist Dooku [10 μM] did not shift the PE curve (-log EC50 values [M]: Veh-PVAT= 7.96±0.12; Dooku-PVAT=7.26±0.22, Veh+PVAT=7.29±0.08; Dooku+PVAT=6.96±0.07). Surprisingly, Dooku [10 μM] directly caused aortic contraction in the absence of PVAT (Dooku 27.2±11.7 vs vehicle 13.5±11.2 %PE contraction), but not in the presence of PVAT vs vehicle (Dooku 2.9±1.9 vs Vehicle 7.3±5.2% PE contraction). Thus, Piezo1 is present and functional in the isolated aorta, important knowledge given that this molecule may serve as a translator of vascular pressure.
Abstract P064: The Activity Of Antioxidant Enzymes In Patients With Arterial Hypertension, Depending On The Environmental Comfort Of Life
Authors: Glova Svetlana , Shlyk Sergey
Published: September 2020

Oxidative stress is known as one of the mechanisms for the development of endothelial dysfunction. Prooxidants and antioxidants are usually produced in humans, and there is a balance between production and disposal. When the balance between oxidizing agents and antioxidants is disturbed, oxidative stress occurs.

Purpose:
assessment of the activity of antioxidant enzymes in patients with arterial hypertension, depending on the environmental comfort of life.

Materials and methods:
Fifty-six patients from a random stratified sample of city residents by age and gender were examined. To determine the relationship between hypertension and environmental comfort, all subjects, depending on the ecological comfort of life, were divided into groups that were formed based on the “Map of the ecological comfort of life in the city of Rostov-on-Don”, developed by V.V. Privalenko. The age of the subjects ranged from 25 to 64 years, with an average value of 46.79 ± 0.63 years: group Ia - 14 healthy subjects and group IIa - 12 patients with hypertension living in ecologically clean areas; group Ib - 16 healthy subjects and group IIb - 14 patients with hypertension living in ecologically unfavorable regions. First-line protective antioxidants: superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) were evaluated in patients' blood plasma. Statistical data processing is carried out using the program Statistica 6.0.

Results:
The maximum activity of GPX (347.04 ± 11.39) was recorded in healthy people living in areas with an ecologically unfavorable environment. CAT levels were also higher in healthy people living in areas with an unfavorable environment (p<0.05). Minimal GPX activity was found in patients with arterial hypertension (265.85 ± 12.46) who also live in ecologically unfavorable areas (p<0.05). Differences in GPX activity in healthy people and hypertensive patients living in ecologically polluted areas were statistically significant (p<0.05).

Results:
The activity of antioxidant enzymes in healthy people living in environmentally disadvantaged areas is increasing. With the development of arterial hypertension, we observed an insufficient antioxidant response, which reflects the depletion of the antioxidant system's capabilities.
Abstract P066: Purinergic Receptor Function In The Middle Cerebral Artery From Clopidogrel-treated Rabbits
Authors: Kuszynski Dawn , Christian Barbara , Dorrance Anne M , Lauver Dale A
Published: September 2020

Arterial thrombosis is the leading cause of death in the developed world and hypertensive patients are at an increased risk. Dual antiplatelet therapy, consisting of low-dose aspirin in combination with a P2Y
12
antagonist, is the most common preventative treatment for arterial thrombosis. Clopidogrel, a P2Y
12
antagonist, is associated with cerebral microbleeds and intracerebral hemorrhages. We have previously reported in rabbits that clopidogrel (3mg/kg) induces bleeding at lower doses than required to inhibit platelet aggregation, making it unlikely that the clopidogrel-mediated bleeding events are the result of platelet inhibition. I hypothesized that clopidogrel was acting on other purinergic receptors to impair artery function due to the structural similarity of the metabolites of clopidogrel.

Purinergic receptors, P2Y
1
, P2Y
2
, P2Y
4
and P2Y
6
, are expressed in the endothelium of cerebral vessels.

The purpose of this study was to determine the effects of clopidogrel on vascular function in response to activation of P2Y
1
, P2Y
2
, P2Y
4
and P2Y
6
. The middle cerebral artery (MCA) was used as it is the site most common for cerebrovascular events. New Zealand white rabbits (n=3) were treated for 3 days with vehicle or clopidogrel (3mg/kg/day) prior to MCA isolation. Myogenic tone was allowed to develop before assessing the response of the MCA to increasing concentrations (10
-9
-10
-5
M) of specific purinergic receptor agonists P2Y
1
: MRS 2365; P2Y
2
: MRS 2768; P2Y
4
: MRS 4062; P2Y
6
: MRS 2693. If myogenic tone was not generated the MCA was preconstricted with 10
-6
M serotonin. Response was analyzed by two-way ANOVA and compared to vehicle using Dunnett’s post-test. In all cases,
p
< 0.05 denote statistical significance. Constriction was calculated as a percent change from baseline. Stimulation with the P2Y
4
agonist resulted in a mean maximal constriction of 28.95% (28.95 of 100) for vehicle and 52.72% (52.72 of 100) for 3mg/kg clopidogrel. There was no significant difference upon stimulation with the P2Y
1
, P2Y
2
, or P2Y
6
agonists compared to vehicle. These data suggest that clopidogrel has vascular effects on the P2Y
4
receptor expressed in the MCA and may explain the cerebral bleeding side effects observed.
Abstract P072: Hypertensive Emergency Presenting With Intraventricular Hemorrhage
Authors: Kaplan Jason G , Kanwal Arjun , Bykowski Adam , Berquist John , Mirocke Andrew , Dickey John Q
Published: September 2020

A 34-year-old African American female with a past medical history of hypertension and medical noncompliance presented to the emergency department after being found down and unresponsive by her son. On presentation, the patient's blood pressure was found to be 298/194 with a Glasgow coma score of 4, with decerebrate posturing. The computed tomography of the head showed large acute intraventricular hemorrhage in the right lateral ventricle extending along the frontal horn into the left lateral ventricle, third and fourth ventricles, causing a 4 mm leftward shift. The patient was managed with a Nicardipine drip and underwent a bilateral ventriculostomy placement, which improved the patient's neurologic status. Following a 24 day hospital stay, the patient was alert and oriented without any significant neurologic deficits and discharged to a subacute rehab facility.

Hypertension is one of the most common medical conditions affecting 50 million people in the United States and approximately 1 billion people worldwide. Approximately 1% of patients with hypertension will have a hypertensive emergency at some point in their life. The clinical manifestations of hypertensive emergencies are seen with organ dysfunction, which typically require diastolic blood pressures greater than 130mmHg, in nonpregnant adults. A severe outcome of hypertensive emergency is an intracerebral hemorrhage. In these patients, when the bleed extends into the ventricles, the mortality ranges from 50-80%.

One study examined medical compliance in hypertensive patients, which showed approximately 40% of patients discontinued treatment one year after initiation of their antihypertensive medication and 4% never initiated therapy. This case illustrates the importance of compliance in hypertensive patients, as well as the dramatic ramifications that can occur with uncontrolled hypertension leading to hypertensive emergency.
Abstract P073: Arterial Stiffness In Severely Obese Patients: Early Changes After Bariatric Surgery And Pathophysiological Mechanisms
Authors: Oliveras Anna , Riera Marta , Alvarez Sara , Goday Albert , Vazquez Susana , Vera Maria , Galceran Isabel , Outon Sara , Sans-Atxer Laia , Pascual Julio
Published: September 2020

Objective:
to analyze AS before and 1 month (m) after bariatric surgery (BS), and search for pathophysiological mechanisms of changes (Δ).

Methods:
Forty-seven MO (72% women, 43% hypertensives, age 42.7±9.4 yr, BMI 42.2±5.4 Kg/m
2
, waist circumference 132.4±11.7 cm) were evaluated before and 1m after BS, with AS assessed by pulse-wave velocity (PWV), augmentation index at 75 beats/minute (AIx@75) and pulse pressure (PP) using a Mobile-O-Graph® device. 24h-ambulatory blood pressure (BP), RAAS components and several adipokines and inflammatory markers were also analyzed.

Results:
at 1m body weight (-13.6±4.32 Kg) and waist circumference (-9.2±5.3 cm) decreased (p<0.001). There were also significant Δ in BP, RAAS components and adipokines and inflammatory biomarkers (Table). Correlations were also explored. There was no correlation between Δ of any marker of AS and anthropometric changes nor with Δ of adipokines or inflammatory markers. Δ 24h-PP correlated with Δ 24h-systolic BP (coef. P. = 0.749; p <0.001) and with Δ of plasma renin activity (rho = -0.299; p = 0.049). Δ 24h-PWV correlated with Δ 24h-SBP (coef. P. = 0.587; p <0.001), with Δ 24h-DBP (coef. P. = 0.503; p <0.001) and with Δ ACE/ACE2 (coef. P. = -0.474; p =0.002). Δ AIx@75 correlated with Δ ACE (coef. P. = 0.316; p = 0.041).

Conclusions:
there is a decrease in AS one month after BS in obese patients. These changes correlated with Δ in both BP and the renin-angiotensin aldosterone system.

(
*
) Data shown as median [interquartile range]
Abstract P075: Angiotensin II Induces Endothelial Dysfunction And Vascular Remodeling Dependent Of Nlrp3 Inflammasome
Authors: Cau Stefany B , da Silva Marcondes , Ferreira Nathanne d , Tostes Rita C , Bruder-Nascimento Thiago
Published: September 2020

The NLRP3 inflammasome is a multimeric protein complex constituted by NLRP3, Asc and Capase-1 (Casp1). It triggers an inflammatory response by releasing the pro-inflammatory cytokines IL-1β and IL-18. NLRP3 inflammasome is expressed in different cells and its activation has been associated with several diseases including atherosclerosis and hypertension. Herein we tested the hypothesis that angiotensin II (AngII) induces vascular damage by activating the NLPR3 inflammasome in the vasculature. C57BL/6J male mice (Ctrl) and Casp-1 deficient mice (Casp1-/-) were treated with AngII (490 ng/min/kg/14 days by osmotic mini pump). In Ctrl mice, AngII treatment impaired the vascular relaxation to acetylcholine in mesenteric arteries, increased aorta media thickness [Ctrl: 49.4 ± 2.5 vs AngII: 62.3 ± 2.3* (μm), *P<0.05] and cross-sectional area [Ctrl: 0.11 ± 0.1 vs AngII: 0.15 ± 0.2* (mm), *P<0.05] and triggered NLRP3 inflammasome activation in aorta and mesenteric arteries, analyzed by caspase-1 cleavage and IL-1B maturation via western blot and casp1 activity - FAM-FLICA assay. Fascinatingly, Casp1-/- mice were protected from AngII-induced endothelial dysfunction and vascular remodeling. Furthermore, AngII (0.1uM) incubation, combined or not with lipopolysaccharide (500 ng.ml
–1
ultrapure) or Nigericin (20 μM), elevated Casp1 cleavage and IL-1B maturation in Rat Aortic Smooth Muscle Cells (RASMC). Moreover, AngII elevated PCNA (~2.5-fold) and CyclinD1 (~2.1-fold) protein expression and induced vascular migration and proliferation measured by scratch assay and cell counting kit-8 (CCK-8) assay respectively. Interestingly NLRP3 antagonist incubation (MCC950, 1uM) abolished PCNA expression and attenuated the vascular migration and proliferation produced by AngII incubation. Our data suggest that AngII induces vascular damage by activating NLPR3 inflammasome directly in the vasculature. We place this innate immune receptor as a master regulator of the vascular phenotype and as a target for therapeutic strategies for vascular diseases. Future studies will be helpful providing a better understanding into the molecular mechanism of NLRP3 inflammasome activation and regulation in the control of vascular diseases.
Abstract P080: Mutation Of Lysine 68 To Arginine Mimics Deacetylation Of Mitochondrial Superoxide Dismutase, Protects From Vascular Oxidative Stress And Attenuates Angiotensin II-Induced Hypertension
Authors: Dikalova Anna , Tkachuk Liliya , Lopez Marcos G , Billings Frederic T , Dikalov Sergey I
Published: September 2020

By recent guidelines, almost one-half of adults have hypertension, and blood pressure is poorly controlled in a third of patients despite use of multiple drugs, likely due to mechanisms contributing to blood pressure elevation that are not affected by current treatments. Hypertension is linked to oxidative stress; however, common antioxidants are ineffective. We found that hypertension is associated with inactivation of key mitochondrial antioxidant, superoxide dismutase 2 (SOD2), due to acetylation of lysine residues at the catalytic center. The role of specific SOD2 lysine residues in hypertension, however, has not been defined. We proposed that inactivation of key intrinsic antioxidant, SOD2, in hypertension is linked to acetylation of Lysine 68, and mutation of K68 to Arginine mimics SOD2 deacetylation, inhibits vascular oxidative stress and attenuates angiotensin II-induced hypertension. To test this hypothesis, we have investigated SOD2 acetylation in arterioles from patients with essential hypertension and developed a new deacetylation mimic SOD2 mutant K68R mice (SOD2-K68R). Western blot analysis of arterioles isolated from human mediastinal fat showed 3-fold increase in SOD2 acetylation in hypertensive patients compared with normotensive subjects while SOD2 levels were not affected. To define the functional significance of K68 acetylation we performed studies in vivo in SOD2-K68R mice using angiotensin II model of vascular dysfunction and hypertension. Angiotensin II infusion in wild-type C57Bl/6J mice induced vascular inflammation and oxidative stress, and increased blood pressure to 160 mm Hg. Mutation of Lysine 68 to Arginine in SOD2-K68R mice completely prevented the increase in mitochondrial superoxide and significantly attenuated the angiotensin II induced hypertension (135 mm Hg). Angiotensin II and TNFα co-operatively induce SOD2 acetylation and hypertension. Treatment of wild-type aortas with angiotensin II and TNFα in organoid culture increased mitochondrial superoxide by 2-fold which was completely prevented in aortas isolated from SOD2-K68R mice. These data support an important role of SOD2-K68 acetylation in hypertension, and strategies to reduce mitochondrial acetylation may have therapeutic potential.
Abstract P081: Expression Of Micro-rnas And Transfer Of Lipids To HDL
In Vitro
In Stroke Due To Hypertensive Emergency
Authors: Oliveira-Andrade Days , Freitas Fatima , Aguiar Franciana , Mansor Ana Luiza , Maranhao Raul , Vilela-Martin Jose F
Published: September 2020

Objective:
This study evaluates the association of expression of microRNAs (miRNAs) 221/222 and lipid transfer in ischemic stroke (IS) patients due to hypertensive emergency (HE).

Methods:
Thirty and one patients with IS due to hypertensive emergency (IS-HE), 33 individuals with IS without HE (IS), 31 controlled hypertensive (CHT) and 33 normotensive (NT) individuals were studied. The expression of miRNAs was performed by RT-q PCR (real-time quantitative polymerase chain reaction). The lipid transfer to high density lipoprotein cholesterol (HDLc) was evaluated after incubation of the plasma with an artificial nanoparticle used as a donor of esterified and non-esterified cholesterol, radiolabelled. Cholesterol transfer was measured in the HDLc fraction, after chemical precipitation of lipoproteins containing apolipoprotein B.

Results:
Systolic and diastolic blood pressure were significantly higher in the IS-HE compared to IS, CT and NT groups (162/99 mmHg vs 140/87, 128/69 and 129/82 mmHg, respectively; p<0.05). The miRNA-221 expression was higher in the IS-HE group compared to the IS, CHT and NT groups (4.23 vs 2.44, 1.35 and 1.05, respectively; p<0.003). MiRNA-222 showed overexpression in the IS-HE and IS groups compared to the CHT group (1.26 and 1.27 vs 0.24, respectively; p<0.0001). The esterified cholesterol transfer was reduced in the IS-HE and IS groups in relation to the CHT and NT groups (4.19 and 3.76 vs 4.5 and 4.75, respectively; p<0.05). Non-esterified cholesterol transfer was decreased in the IS-HE and IS groups compared to CHT and NT groups (4.57 and 4.06 vs 5.47 and 5.71, respectively; p<0.05). There was a negative correlation between miRNA-221 and esterified cholesterol transfer and also with free cholesterol.

Conclusions:
This study provides evidence of the miRNAs participation in IS-HE, suggesting that the increased expression of miRNAs-221/222 can be a biomarker in cases of IS, mainly associated to HE. In addition, lipid transfer to HDLc is decreased in patients with stroke and hypertensive emergency. This reduction was previously associated with coronary heart disease, but no with stroke. Therefore, HDLc functions can be reduced in ischemic stroke by hypertensive emergency, which can also contribute to atherogenic process.