bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P125: Performance of Ambulatory Blood Pressure Monitoring in Predicting Autonomic Dysfunction
Authors: Koratala Abhilash , Alquadan Kawther F , Ejaz Abutaleb A
Published: June 2021

Background:
We investigated the predictive performance of orthostatic hypotension (OH) and ambulatory blood pressure monitoring (ABP) to predict autonomic dysfunction.

Methods:
In this retrospective analysis, statistical associations among the candidate variables were investigated and comparisons of predictive performances were performed using Receiver Operating Characteristics (ROC) curves.

Results:
Ninety-four patients were included for analysis. No significant correlations could be demonstrated between OH and components of ABP (reversal of circadian pattern, postprandial hypotension and heart rate variability), nor between OH and autonomic reflex screen. Reversal of circadian pattern did not demonstrate significant correlation (r= 0.12, p=0.237) with autonomic reflex screen, but postprandial hypotension (r=0.39, p=0.003) and heart rate variability (r=0.27, p=0.009) demonstrated significant correlations. Postprandial hypotension was associated with a five-fold (OR 4.83, CI95% 1.6 - 14.4, p=0.005) increased risk and heart rate variability with a four-fold (OR 3.75, CI95% 1.3-10.6, p=0.013) increased risk for autonomic dysfunction. Per ROC curves, heart rate variability (0.671, CI
95%
0.53-0.81, p=0.025) and postprandial hypotension (0.668, CI
95%
0.52-0.72, p=0.027) were among the best predictors of autonomic dysfunction in routine clinical practice.

Conclusions:
Postprandial hypotension and heart rate variability on ambulatory blood pressure monitoring are strong predictors of autonomic dysfunction in routine clinical practice.
Abstract P129: The High Blood Pressure-Malaria Protection Hypothesis
Authors: Gallego-Delgado Julio , Walther Thomas , Rodriguez Ana
Published: June 2021

For decades, researchers have been fascinated by the idea of a causative connection between hypertension and malaria as the prevalence of hypertension is higher in populations that have been exposed to malaria for long periods. Cerebral malaria is a multi-factorial syndrome involving the interaction between
P. falciparum
-infected red blood cells (
Pf
-iRBC) and host cerebral microvascular endothelial cells. Disruption of the blood-brain-barrier (BBB), ranging from increased permeability to complete loss of inter-endothelial junctions (IEJ) and to petechial hemorrhages in the brain, is a characteristic feature of cerebral malaria. Our
in vitro
experiments show that
Pf
-iRBC induce the disruption of IEJ in human brain microvascular endothelial cells (HBMEC) mediated by the activation of β-catenin. Protection from this effect is achieved by blockade of the angiotensin II (Ang II) type 1 receptor (AT1) or stimulation of the type 2 receptor (AT2), which abrogate
Pf
-iRBC-induced activation of β-catenin and prevent the disruption HBMEC monolayers. Using a mouse model of cerebral malaria, we observed similar effects after treatment with Ang II receptors modulators, leading to protection against cerebral malaria, reduced cerebral hemorrhages (1.98 and 1.17 vs 0.63 for control, AT1 blocker and AT2 agonist respectively; p<0.05) and increased survival. While only 25% survived in controls (4 of 16 mice), 81.7% (13 of 15) and 71.4% (5 of 7) survived under AT1 blockade or AT2 agonist, respectively. In contrast, AT2-deficient mice were more susceptible to cerebral malaria (0% survival; 0 of 9). A causal association between high levels of Ang II and protection from malaria pathogenesis can provide a likely explanation for the increased prevalence in hypertension observed in populations of African and South Asian origin. Furthermore, this potential causative connection might also direct to unique approaches for the effective treatment of cerebral malaria.
Abstract P152: Aminopeptidase A in the Brain Exerts Cardiovascular Action via Degradation of Kallidin to Bradykinin
Authors: Nakamura Takuto , Yamazato Masanobu , Ohya Yusuke
Published: June 2021

Objective:
Aminopeptidase A (APA) degrades of various sympathomodulatory peptides such as angiotensin (Ang) II, cholecystkinin-8, neurokinin B and kallidin. APA activity is increased in the brain of hypertensive rats. A centrally acting APA inhibitor prodrug is currently under investigation in clinical trial for treatment of hypertension. In previous reports, a role of APA in the brain on cardiovascular regulation was researched focus on only renin-angiotensin system. We previously reported that intracerebroventricular(icv) administration of APA increased blood pressure and that this pressor response was partially blocked by angiotensin receptor blocker. In this study, we evaluated a role of APA on cardiovascular regulation focusing on peptides other than Ang II.

Method:
Eleven weeks old Wistar Kyoto rats were used. We icv administrated 800 ng/8 μL of APA after pretreatment of following drugs, i) 8μL of artificial cerebrospinal fluid (aCSF) as a control, ii) 80 nmol/8 μL of amastatin which is a non-specific aminopeptidase inhibitor, iii) 1 nmol/8 μL of HOE-140 which is a bradykinin receptor blocker to evaluate the involvement of degradation of kallidin to bradykinin by APA.

Result:
i) Icv administration of APA after pretreatment of aCSF increased blood pressure rapidly. Blood pressure reached a peak within 1 minute. The elevated blood pressure decreased gradually and reached baseline blood pressure in 10 minutes. A peak pressor response is 25.5±1.4 mmHg (n=5). ii) Icv pretreatment of amastatin or HOE-140 did not change the blood pressure. A peak pressor response induced by APA is 13.1±4.1 mmHg (n=6, p<0.05 vs aCSF). iii) Icv pretreatment of HOE-140 did not change the blood pressure. A peak pressor response induced by APA is 21.2±1.8 mmHg (n=4, p<0.05 vs aCSF).

Conclusion:
1) Icv administration of APA increased blood pressure by APA enzymatic activity. 2) Cardiovascular regulation of APA in the brain is due to not only degradation of Ang II to Ang III but also degradation of kallidin to bradykinin.

Clinical implication:
We think inhibition of APA in the brain may be a unique therapeutic target which affects several cardiovascular peptides in the brain.
Abstract P165: Exploration of the Mechanism in Which Saccharina Japonica Alleviates an Increase in Blood Pressure in Renovasucular Hypertensive Rats
Authors: Maruyama Saki , Segawa Yukiko , Hashimoto Hiroko , Osea Tomoko , Kurihara Nobutaka
Published: June 2021

Objective:
Saccharina japonica (SJ), one of brown algae, is a common foodstuff in Japan and neighbor countries. Some studies have shown that the intake of SJ decreases blood pressure (BP) in spontaneously hypertensive rats. As well, we previously observed it in 2-kidney, 1-clip renovascular hypertensive (2K1C) rats. However, the mechanism is still unclear. One of possible components of SJ which play an important role in decreasing BP is alginate. Since alginate is richer in the roots than in the blades in SJ, in the present study, we compared the effects in alleviating BP of intake of SJ roots with that of SJ blades in 2K1C rats. We also evaluated angiotensin II receptor type 1 (AT1R) mRNA to investigate the role of renin-angiotensin system in the mechanism.

Methods:
Male Sprague-Dawley rats (6 wks) were treated with sham operation (SHAM) or clipping the left renal artery (2K1C). After surgery, the rats started receiving a control diet (C) or a diet containing 5.0% (w/w) SJ blades (B), or SJ roots (R) for 6 weeks. The systolic BP (SBP) was measured by a tail-cuff method every week. At the end of the protocol, mean arterial pressure (MAP) was measured in each rat under anesthesia. Then, the aortas were removed for extracting mRNA. AT1R-mRNA expression was evaluated using reverse transcriptase quantitative real-time PCR.

Results:
SBP was significantly higher in 2K1C-C than SHAM-C through the experiment period (p<0.001). SBP in 2K1C-B and -R was significantly lower than in 2K1C-C (p<0.001). 2K1C-B showed a significant reduction in SBP compared with in 2K1C-R (p<0.05). At the end of the protocol, MAP showed the similar trend to SBP. AT1R mRNA expression was higher in 2K1C than in SHAM, but there were no significant differences among 2K1C-C, -B and -R.

Conclusion:
Although alginate is richer in the roots than in the blades in SJ, the effects in alleviating BP was higher in the blades than in the roots. Thus, alginate may play no major role in the mechanism. AT1R may not play an important role, neither. Therefore, we need investigate other possible mechanisms.
Abstract P170: Tonin Overexpression in Mice Diminishes Sympathetic Autonomic Modulation and Suppresses Adrenergic Response
Authors: Palomino Jara Zaira , Moraes-Silva Ivana C. , Santos Fernando , Souza Leandro E. , Irigoyen Maria Claudia , Casarini Dulce Elena
Published: June 2021

Background:
Increased blood pressure (BP) and decreased heart rate (HR) variabilities are associated with higher risk of cardiovascular morbidity. It has been reported an increase of serine- proteases of the renin-angiotensin system in cardiovascular pathophysiology, and an important serine present in the brain, heart and vasculature is the tonin enzyme.

Aim:
Evaluation of cardiovascular autonomic profile in transgenic tonin mice (TGM′(rton)) and the impact of AT1 receptor blocker, losartan.

Methods:
Male C57BL/6 (Wt) and TGM′(rton)mice were canulated for BP signals registering (Windaq, 4MHz) for 30 min in baseline and more 30 min after losartan injection (1mg/kg). BP and HR variabilities were analyzed in frequency domain by FFT method. Low frequency (LF) and high frequency (HF) components were identified for sympathetic and parasympathetic modulations analysis. Catecholamines (CA) were quantified by HPLC method.

Results:
TGM`(rton) presented higher BP ( 136 ± 3
vs
120 ± 3 mmHg, p =0.007), lower cardiac LF (33 ± 2.4
vs
66 ± 3.3 nu, p = 0.0004), higher HF(67 ± 2.4
vs
34 ± 3.4 nu, p = 0.0006), lower LF/HF (0.64 ± 0.06
vs
2.8 ± 0.11), and lower alpha index (0.35 ± 0.05
vs
1.35 ±0.13 ms/mmHg
2
) than Wt. After losartan injection, BP and LF of systolic BP were decreased in Wt mice in relation to its baseline (133 ± 3.8 vs 124 3.4 mmHg, p=0.0005; 66 ± 3.3 vs 56 ±5.8 mmHg
2
, p=0.0004; respectively). Conversely, TGM′(rton) group presented an additional decrease in cardiac LF (32.7 ±2.4
vs
8 ±0.6, p=0.0004), and increase in HF (67 ± 2.4
vs
91 ± 0.6 nu, p= 0.0009) in relation to its baseline and Wt after losartan. Additionally, losartan in TGM′(rton) mice caused a decrease in BP (140 ±2.6
vs
121 ± 1.6mmHg, p=0.0005) with no alteration in LF of systolic BP (9.9 ± 0.6
vs
9.6 ± 0.6 mmHg
2
). CA to sympathetic modulation ratio was 9x higher in TGM′(rton) than Wt at baseline. As we no response in LF of systolic BP despite CA increase after losartan in TGM′(rton), this augment in CA/LF ratio indicates that adrenergic receptors are desensitized in TGM′(rton) mice.

Conclusion:
Activation of adrenergic receptors play a key role in the sympathetic modulation to the vessels rather than to the heart in the TGM′(rton) mice, in which activation of AT1 receptors seem to be more relevant.
Abstract P172: Activation of Pgc1α by EET Stimulates Insulin Sensitivity, Normalizes Blood Pressure and Increases Mitochondrial Oxphos in Obese Mice
Authors: Singh Shailendra P , Waldman Maayan , Schragenheim Joseph , Bellner Lars , Cao Jian , Arad Michael , Hochhauser Edith , Abraham Nader
Published: June 2021

Background/Objectives:
Obesity is a risk factor in the development of type 2 diabetes mellitus (DM2), which is associated with increased morbidity and mortality, predominantly as a result of cardiovascular complications. Increased adiposity is a systemic condition characterized by increased oxidative stress (ROS), inflammation, inhibition of anti-oxidant genes such as HO-1 and increased degradation of epoxyeicosatrienoic acids (EETs).

Hypothesis:
We postulate that EETs increase peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) activity, which controls mitochondrial function, oxidative metabolism and may also increase antioxidants and HO-1 gene expression.

Methods:
C57/B16 mice were fed a high fat (HF) diet for 26 wks. The protocol comprised three groups: A) WT, B) HF control and C) HF-treated with EET agonist (EET-A). Renal and visceral fat tissues were harvested to measure signaling protein. Consumption was measured at 6 and 24 wks. Mice were used to assess insulin levels, insulin sensitivity, blood pressure and mitochondrial OXPHOS and mitochondrial biogenesis (Mfn1, 2 and Opa1), and oxygen consumption (VO
2
).

Results:
Animals on a HF diet exhibited increased body weight, fat content, fasting blood glucose levels, systolic blood pressure (BP) and a significant reduction in VO
2
. Administration of EET-A to HF-fed mice decreased the RQ (VCO
2
/VO
2
) ratio and normalized BP. The HF diet produced increased levels of the adipogenic markers MEST, aP2, C/EBPα and FAS. EET-A attenuated these perturbations through an increase in renal and adipose tissue PGC1α levels. The EET-mediated HO-1 induction increased mitochondrial function as measured by OXPHOS, MnSOD and thermogenic genes, TFAM, UCP1 and SIRT 1. EET-A also increased adiponectin levels, and insulin receptor phosphorylation IRP Tyr 972 and 1146 and normalized glucose levels.

Conclusion:
These data show that an EET agonist increased PGC-1α-HO-1 levels thereby providing metabolic protection and increased VO
2
consumption in HF-induced obesity in mice. This novel finding suggests that the EET-mediated PGC-1α activation is essential to increase HO-1 levels, mitochondrial biogenesis, and to decrease mitochondrial ROS and adiposity.
Abstract P175: Soluble Guanylate Cyclase Activator Attenuates Tumor Necrosis Factor- α Induced Production of Endothelin-1 from Human Glomerular Endothelial Cells
Authors: Bakrania Bhavisha , Spradley Frank T , Satchell Simon , Granger Joey P
Published: June 2021

Preeclampsia (PE) is a disorder associated with maternal hypertension, endothelial dysfunction and reductions in renal hemodynamics. Placental ischemia leads to increases in circulating maternal anti-angiogenic and pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) that induce endothelin-1 (ET-1), a potent vasoconstrictor. PE is also associated with depletion of nitric oxide, a facilitator of vasodilation, which binds to soluble guanylate cyclase (sGC), and synthesizes cGMP. In addition to promoting vasodilation, sGC activators and stimulators inhibit smooth muscle proliferation, leukocyte recruitment and platelet aggregation and are therefore, currently in clinical trials for treating cardiopulmonary disease. Although it is known that activating the nitric oxide signalling pathway induces vasodilation, its ability to inhibit TNF-α induced renal glomerular endothelial ET-1 production is unknown. We tested the hypothesis that cinaciguat, a sGC activator, attenuates ET-1 production induced by TNF-α in conditionally immortalized human glomerular endothelial cells. Cells were cultured; starved for 48 h; and treated for 12 h resulting in the following 4 groups having N=6/group: 1) Untreated, 2) 10 ng TNF-α 3) 10 μM cinaciguat + 10 ng TNF-α, and 4) 20 μM cinaciguat + 10 ng TNF-α. TNF-α (10 ng, 67.25±3.2 pg/mL) significantly increased ET-1 production compared to the untreated group (43.6±4.3 pg/mL, P<0.01). Interestingly, both cinaciguat treatment groups attenuated TNF-α induced ET-1 production, with significant reductions at a higher dose (20 μM, 57.38±1.42 pg/mL, P=0.02; 10 μM, 58.6±2.32 pg/mL, P=0.07). The results of this study demonstrate that activating sGC can attenuate ET-1 production. In conclusion, these findings suggest there is a therapeutic potential for treating preeclampsia with sGC activators.
Abstract P181: Endothelial Ciliary Muscarinic Receptors and the Pathogenesis of Hypertension in Polycystic Kidney Disease
Authors: AbouAlaiwi Wissam , Saternos Hannah C
Published: June 2021

Primary endothelial cilia are mechanosensory organelles that are projected into the lumen of blood vessels. Defects in cilia assembly or function can lead to multiple human pathologies, collectively known as ciliopathies, including hypertension. Acetylcholine, a neurotransmitter, is implicated in essential hypertension in humans and animal models. It has been demonstrated that vascular endothelia require primary cilia to sense and transmit external mechanical stimuli into internal biochemical reactions. One of these reactions includes the biosynthesis and release of nitric oxide, which is one of the most potent endogenous vasodilators. This idea has
only
been investigated in cultured endothelial cells
in
vitro
. Based on this finding, however, a very bold hypothesis is formed to test that abnormal cilia function results in vascular hypertension. Though both primary cilia and muscarinic acetylcholine receptors play important roles in vascular hypertension, their relationship has never been explored. To determine the roles of the cholinergic system and mechanosensory cilia, we studied the effects of acetylcholine on ciliary length and function in wild-type (WT) and mechano-insensitive cilia mutant endothelial cells (
Pkd1

–/–

and
Tg737

orpk/orpk

). We show for the first time that mouse vascular endothelia exhibit muscarinic receptor-type 1, 3 and 5 (AChM1, 3, and 5R), which co-localizes to primary endothelial cilia. AChM3R activation significantly increases cilia length in cells treated with AChM3R agonist compared to non-treated cells (1.63±0.01 vs.1.92±0.01). Furthermore, the chemosensory function of cilia can alter the mechanosensory function through changes in sensitivity to fluid-shear stress. We propose that activated ciliary AChM3R has a functional mechanosensory role in endothelial cells. A series of conditional mouse models are used, coupled with high-resolution microscopy techniques. We used vascular-specific mouse models of
Pkd1, Tg737
and
AChM3R
to study systolic/diastolic blood pressure. Our data corroborate our hypothesis, that cilia function knockout in the vascular system is associated with elevated blood pressure compared to wildtype controls (123±6 vs. 135±6 systolic and 79±6 vs. 89±5 diastolic).
Abstract P183: Chemokine-like Receptor 1 Mediates the Vasoconstrictor Actions of Chemerin in vitro and in vivo
Authors: Kennedy Amanda , Yang Peiran , Read Cai , Kuc Rhoda , Maguire Janet , Davenport Anthony
Published: June 2021

Hypertensive patients have significantly higher plasma concentrations of the adipokine chemerin compared with healthy controls, and levels of chemerin positively correlate with systolic and diastolic blood pressure. Chemerin activates chemokine-like receptor 1 (CMKLR1 or ChemR23) but it also activates the ‘orphan’ G protein-coupled receptor 1 (GPR1) which has been linked with hypertension. It is therefore crucial to determine whether one or both of these receptors mediate the constrictor actions of chemerin in the vasculature in order to identify a potential new therapeutic target for the treatment of hypertension. Using immunohistochemistry and molecular biology, we localized chemerin to the endothelium, smooth muscle and adventitia, and CMKLR1 and GPR1 to the smooth muscle in human conduit and resistance vessels. Chemerin activated β-arrestin via heterologously expressed receptors GPR1 (pD
2
=9.30±0.05) and CMKLR1 (pD
2
=9.23±0.03) with comparable potency. CCX832, a small molecule antagonist, was fully characterized as highly selective for CMKLR1, with no effect on GPR1 in binding or cell-based functional assays. The C-terminal fragment of chemerin, C9 (chemerin149-157) contracted human saphenous vein (pD
2
=7.30±0.31) and resistance arteries (pD
2
=6.23±0.16), and caused a significant increase in blood pressure in rats in vivo (0.2 μmol, 9.1±1.0 mmHg). These actions were blocked by CCX832, confirming for the first time that a single chemerin receptor, CMKLR1, mediates the constrictor response in humans and in vivo. Our data suggest that chemerin activation of CMKLR1 may contribute to elevated blood pressure; this in combination with the known roles of chemerin in metabolic syndrome and diabetes, could lead to increased risk of cardiovascular disease. This study provides proof of principle that the therapeutic potential of selective CMKLR1 antagonists should be explored.
Abstract P186: Proximal Tubular-Specific Overexpression of the Cyp4a12-20-Hete Synthase Promotes Hypertension
Authors: Gilani Ankit , Pandey Varunkumar , Hutcheson Rebecca , Gotlinger Katherine , Astarita Danielle , Schwartzman Michal
Published: June 2021

20-Hydroxyeicosatetraenoic acid (20-HETE) is a cytochrome P450 (CYP)-derived arachidonic acid metabolite linked to regulation of blood pressure via actions on the renal microvasculature and tubules. In renal microvessels, 20-HETE promotes vasoconstriction, vascular remodeling, and vascular injury; all of which contribute to hypertension, whereas in tubular structures 20-HETE has been linked to inhibition of sodium transport and lowering of blood pressure. Induction or global overexpression of Cyp4a12-20-HETE synthase, the primary 20-HETE producing enzyme in mice, results in hypertension. Since these mice display global overproduction of 20-HETE, it is difficult to dissect the exact contribution of vascular versus tubular 20-HETE to the hypertension. To begin addressing this issue, the current study was undertaken to define the blood pressure phenotype of novel transgenic mice with proximal tubule-specific overexpression of the Cyp4a12-20-HETE synthase (PEPCK-cyp4a12 mice). These mice generated by crossing the Cyp4a12
fl/fl
with PEPCK (phosphoenolpyruvate carboxykinase promoter)-Cre mice, showed increased Cyp4a12 mRNA expression (2.6±0.9 fold increase; p<0.05) and 20-HETE production in the renal cortex (138±32 pg/mg vs. 80±6 pg/mg). Most importantly, the systolic blood pressure was markedly elevated in the PEPCK-Cyp4a12 mice as compared to WT littermates (142±2 vs. 111±3 mmHg; p<0.05). Interestingly, the PEPCK-Cyp4a12 mice exhibited significantly higher levels of urinary 20-HETE as compared to WT littermates (205±50 vs 83±5 pg/ml; p<0.05) whereas plasma 20-HETE levels remained unchanged (231±32 vs 190±25 pg/ml). Moreover, in PEPCK-Cyp4a12 (n=4) urinary volume was lower (2.15±0.05 vs 3.17±0.20 ml/day, p=0.003) and UNaV appeared lower (181±7 vs 194±25 μmol/day, p=0.35) as compared to WT littermates. These results are in line with the possibility that 20-HETE overproduction at the level of the proximal tubule promotes rather than opposes hypertension. The exact mechanisms need to be further examined.
Abstract P189: Disruption of
Cyp2c44
Increases Sodium Chloride Cotransporter Expression and Activity in the Distal Convoluted Tubule
Authors: Su Xiao-Tong , Wang Lijun , Gao Zhongxiuzi , Lin Dao-Hong , Pandey VarunKumar , Wang Tong , Abraham Nader , Schwartzman Michal , Wang Wen-Hui
Published: June 2021

Cytochrome-P450 (CYP) epoxygenase plays an important role in the regulation of renal sodium transport. Previous studies have demonstrated that global disruption of
Cyp2c44
, a major epoxygenase in the renal tubules, increased ENaC activity in the collecting duct. In addition, we have demonstrated that an increase in dietary Na intake significantly increased the mRNA expression of CYP2c44 in the DCT. DCT is responsible for the reabsorption of 5-9% of filter Na load and is the target for thiazide diuretic. Na absorption in the DCT is mediated by NaCl cotransporter (NCC) and also by ENaC in the late part of DCT. However, the role of epoxyeicosatrienoic acid (EET) in the regulation Na transport in the DCT is not clear. We now examine the role of CYP2c44 and EET in the regulation of NCC expression. The disruption of
Cyp2c44
increases the expression of NCC and ENaC activity in the DCT. The disruption of CYP2c44 also suppressed the renal expression of GPR75, a receptor which is activated by 20-hydroxyeicosatetraenoic acid (20-HETE). Renal Na clearance study also demonstrates that the effect of hydrochlorothiazide on Na excretion in
Cyp2c44
knockout (KO) mice was significantly higher than those of WT mice. In addition, the disruption of
Cyp2c44
significantly increased the expression of ste20-proline and alanine-rich kinase (SPAK) which is known to stimulate NCC activity by phosphorylation. Increased dietary Na intake decreases NCC expression and this effect is blunted in
Cyp2c44
KO mice. The role of EET in the regulation of NCC expression is further suggested by the finding that high fat-diet induced increase in NCC expression is inhibited by application of EET. We conclude that CYP2c44-derived EET plays an important role in inhibiting NCC and ENaC in the DCT.
Abstract P190: Alamandine Improves Cardiac Post-Ischemic Function in Isolated Hearts of TGR(mREN2)27
Authors: Almeida Jônathas F , Santos Robson A
Published: June 2021

The renin-angiotensin system (RAS) is an important regulator of cardiovascular function. Over the past years, new peptides have been described in this system. Among these new peptides, Alamandine was recently described by Santos and colleagues as an important participant in the control of cardiovascular function through its interaction with MrgD receptors. Our previous studies showed that Alamandine improved post-ischemic cardiac function in normotensive rats. Here we assessed the effects of Alamandine in a more challenging condition using hypertensive rats. TGR(mREN2)27 rats weighing between 250-300g were euthanized and their hearts were placed on Langendorff apparatus to evaluate the cardiac parameters. Hearts were submitted to 30min of stabilization, 30min of partial ischemia by occlusion of the left descending coronary artery and 30min of reperfusion. Alamandine (ALA, 22pM) was added to the perfusion setting from the beginning of the experiment until the end. 2,3,5-trypheniltetrazolium chloride were used to evaluate the extension of infarcted area. In hypertensive (mREN) animals there was an impairment in the baseline (35.57 ± 5.839 mmHg) of left ventricular systolic pressure (LVSP), and this impairment was attenuated by ALA (54.91 ± 6,304mmHg). Maximum and minimum dP/dt in mREN presented a significant reduction in the ischemic period (926.5 ± 172.3 mmHg/s and 682.7 ± 106.1 mmHg/s, respectively) compared to baseline (1761 ± 219.7 mmHg/s and 1242 ± 150.9 mmHg/s, respectively). Ischemia/reperfusion induced an arrhythmia severity index (ASI) in mREN hearts higher than in hearts treated with ALA (4,9 ± 1,26) vs (1,10 ± 0,58). ALA also reduced infarcted area compared to mREN (19,64 ± 2,61%) vs (33,85 ± 4,55%). In conclusion, our data shown that Alamandine exert cardioprotective effects in post-ischemic function in hypertensive rat isolated hearts by preventing LVSP, dP/dt max and min decrease. Furthermore, it reduced the infarcted area and I/R arrhythmias.
Abstract P191: The Origin and Fate of Renin Progenitors During Hematopoiesis
Authors: Belyea Brian C , Xu Fang , Sequeira-Lopez Maria Luisa S , Gomez R. Ariel
Published: June 2021

Our lab previously discovered the presence of novel renin-expressing progenitors within the hematopoietic system. These progenitors have cell surface markers, gene expression, and growth characteristics of B lymphocytes. Further, these cells represent a subset of total B lymphocytes, are numerous at birth, and diminish with age, suggesting renin expression may be prominent during embryonic hematopoiesis. However, it is unknown when renin progenitors first appear and what function they serve during hematopoietic development. In this study, we sought to further define the temporal appearance, identity, and evolution of renin progenitors throughout hematopoietic ontogeny. We used
in vivo
lineage-tracing techniques, flow cytometry, immunofluorescence, and polymerase chain reaction (PCR) analysis to investigate the origin and fate of renin hematopoietic progenitors. We found that renin expressing hematopoietic progenitors first appear within the yolk sac during mid gestation (E11.5 by PCR and E12.5 by flow cytometry) and peak in number at E13.5 (14.9 ± 4.8% of nucleated single cells by flow cytometry). Subsequently, renin lineage cells leave the yolk sac and colonize the fetal liver and spleen at E15.5. In the fetal liver and fetal spleen, renin lineage cells express B cell surface markers including CD19 and CD43, however they have dim B220 expression, consistent with a B-1 progenitor immunophenotype. Renin lineage cells within the bone marrow, spleen, and peripheral blood peak in number shortly after birth and then decrease with post-natal age and have a phenotype consistent with B-2 B lymphocytes (B220
+
CD19
+
CD23
+
CD11b
-
). Conversely, renin progenitors in the peritoneal cavity persist throughout adult life as B-1 B cells (B220
dim
CD19
+
CD23
-
CD11b
+
). These studies suggest that renin progenitors originate within the yolk sac during the initial wave of primitive B lymphopoiesis and then expand to the fetal liver and spleen prior to the development of definitive hematopoiesis. Renin-lineage cells persist during adult life as B-1 B cells in the peritoneal cavity and, to a lesser extent, as B-2 B cells in the bone marrow, spleen, and peripheral blood. The function of these renin progenitors is currently being investigated.
Abstract P201: Enhanced Upregulation of (Pro)renin Receptor Expression by High Salt Intake in the Kidney of Dahl Salt-sensitive Rats
Authors: Yamakoshi Seiko , Ito Osamu , Rong Rong , Ohsaki Yusuke , Muroya Yoshikazu , Mori Takefumi , Ito Sadayoshi , Takahashi Kazuhiro , Totsune Kazuhito , Kohzuki Masahiro
Published: June 2021

We recently reported that high salt (HS) intake increased the (pro)renin receptor ((P)RR) expression by 3-5 fold in several nephron segments of Sprague-Dawley rats (Peptides 63: 156-162, 2015). The preset study examined the effects of HS intake on the renal (P)RR expression in Dahl-Salt sensitive (DS) rats. Male DS rats were fed a normal salt (NS) diet (0.6%NaCl) and a HS diet (8%NaCl) for 4weeks. A part of the rats fed the HS diet were treated orally with angiotensin II type 1 receptor (AT
1
R) antagonist, candesartan (Can,3mg/kg/day) or mineralocorticoid receptor (MR) antagonist, spironolactone (Spi, 100mg/kg/day). The (P)RR expression in nephron segments was examined by immunoblot and immunohistochemical analyses. HS intake increased the blood pressure, which did not significantly affected by Can or Spi. (P)RR was expressed in the all kidney sections, glomeruli, proximal tubules (PT), medullary thick ascending limbs and inner medullary collecting ducts. HS intake increased the (P)RR expression in the cortex by 22.6 fold (p<0.001) and the PT by 4.9 fold (p<0.01), but did not change it in the other sections or segments. Can inhibited the HS intake-increased (P)RR expression in the cortex by 32% (p<0.05), Spi inhibited it by 89% (p<0.001), but neither drug did not inhibit the HS intake-increased (P)RR expression in the PT. Immunohistochemical analysis also revealed that HS intake increased the (P)RR expression in the PT and distal tubules, and that Can and Spi inhibited the HS intake-increased (P)RR expression in the distal tubules. Additionally, deoxycorticosterone acetate (DOCA, 50mg/kg/week) administered to rats fed the NS diet for 4 weeks increased the (P)RR expression in the cortex by 80% (p<0.001) and distal tubules, but not in the PT. These results indicate that HS intake-increased (P)RR expression is enhanced in the PT and distal tubules of DS rats. The mechanisms of HS intake-increased (P)RR expression may be AT
1
R and MR-dependent manner in the distal tubules, but AT
1
R or MR-independent manner in the PT.
Abstract P207: High Salt Intake desynchronizes the Molecular Clock in Rats
Authors: Speed Joshua S , Hyndman Kelly A , Roth Kaehler A , Kasztan Malgorzata , Johnston Jermaine G , Young Martin E , Pollock Jennifer S , Pollock David M
Published: June 2021

Circadian rhythms in physiologic functions are driven, at the molecular level, by a group of transcription factors that oscillate over a 24 hour period, collectively termed the molecular clock. Within the kidney, it has been shown that the molecular clock directly influences transcription of Na
+
transporters and channels, including ENaC. ENaC is regulated by endothelin-1 (ET-1), via ET
B
receptor activation, in response to high salt intake. Thus, we hypothesized that increases in dietary sodium regulate the renal molecular clock (which in turn would facilitate Na+ homeostasis) through an ET
B
dependent mechanism. To address this question, we examined the effect of high salt (HS) intake on renal clock gene (
Bmal1, Cry1, Per1, Per2
) expression. Control and ET
B
receptor deficient (ET
B
def) rats (a model of elevated renal ENaC) were placed on either HS or normal salt (NS) for two weeks and euthanized every 4 hours beginning at Zeitgeber Time 0 (Lights on). In the inner medulla, HS causes a phase delay in
Bmal1
(Fig 1A) expression in control but not ET
B
def rats (Fig 1B). In addition, HS suppressed the expression of
Cry1
, and
Per2
during the respective acrophase in both control and ET
B
def rats (Fig 1C-1F) with no significant effect on
Per1
. In contrast, no significant difference in the expression of
Bmal1, Cry1, Per2, or Per1
(Fig 1I-1P) was found in response to HS in the renal cortex of either control or ET
B
def. These data indicate that HS feeding desynchronizes the molecular clock within the kidney and provides evidence that peripheral clocks are regulated in a cell type specific manner, even within the same organ.
Abstract P213: Vascular Dysfunction and Aberrant Vascular NOTCH3 Signalling in Hypertension and Cerebral Autosomal Dominant Subcortical Infarcts and Leukoencephalopathy (CADASIL)
Authors: Harvey Adam , Moreton Fiona , Montezano Augusto C , Nguyen Dinh Cat Aurelie , Rocchiccioli Paul , Delles Christian , Muir Keith , Touyz Rhian M
Published: June 2021

Hypertension (HT) and CADASIL are clinical conditions of small vessel disease. Vascular dementia is a major feature in CADASIL, and a serious consequence of HT. CADASIL is a monogenic condition due to mutations in
NOTCH3
, which is expressed almost exclusively in VSMCs. We hypothesised that altered NOTCH3 signalling in CADASIL and HT are associated with small vessel disease. Small arteries from gluteal biopsies from CADASIL patients (n=14), HT patients (n=3) and healthy controls (n=10) were investigated. Vascular function was assessed by myography. Cultured VSMCs were used to assess signaling through NOTCH3, NO, ER stress (gene array) and Rho kinase (ELISA). CADASIL and HT patients exhibited endothelial dysfunction (Max response: CADASIL 41.7±3%, HT 54.1±2% vs Control 98.2±4%). Pre-incubation with N-acetyl-cysteine ameliorated vasorelaxation. Only CADASIL displayed impaired endothelium-independent relaxation (Max response: CADASIL 53±1.9% vs Control 93±8.9%) and contraction (Max response: CADASIL 78±1.3% vs control 102±5%) (p<0.05). AngII-induced contraction was elevated in HT (98%), yet reduced in CADASIL (28%) (vs control 64% max contraction: p<0.05), despite VSMCs from both conditions displaying increased AT
1
R mRNA expression (HT: 5.1; CADASIL: 3.8; fold vs control; p<0.05). VSMCs from CADASIL and HT have decreased expression of CAMK1, SIRT2 and VEGFA; important in NO signalling (0.5 fold; p<0.05 vs control). VSMC levels of NOTCH3 and NOTCH ligand, JAG1, were increased in CADASIL (3.5, 2.5 fold) and HT (3.0, 2.6 fold, p<0.05). Downstream targets, HEY1 and HEYL, were elevated in CADASIL (3.8, 4.2 fold) and HT (1.9, 2.6 fold) (p<0.05). CADASIL but not HT VSMCs exhibited increased expression of ER stress markers. Rho kinase activity was increased in VSMCs from CADASIL (2.5 fold) and HT (2 fold) vs control (p<0.05). These data demonstrate that in CADASIL and HT, vascular dysfunction, is associated with aberrant NOTCH3 and Rho kinase signalling. In CADASIL, but not HT, endothelium-independent relaxation and ER stress were increased. Our results demonstrate a putative role for NOTCH3 -Rho kinase in vascular dysfunction in conditions of small vessel disease and suggest that ER stress and oxidative stress may be important in vascular injury in CADASIL.
Abstract P215: Nonalcoholic Fatty Liver Disease is Associated with Coronary Artery Calcification: a Systematic Review and Meta-analysis
Authors: Jaruvongvanich Veeravich , Sanguankeo Anawin , Wirunsawanya Kamonkiat , Upala Sikarin
Published: June 2021

Background:
Whether nonalcoholic fatty liver disease (NAFLD) is related to subclinical artherosclerosis is unclear. Coronary artery calcium scanning (CAC) is the robust predictor of coronary events in the asymptomatic individuals. Several recent studies have investigated the association between NAFLD and this surrogate marker. Thus, we conducted a systematic review and meta-analysis to better characterize the association between NAFLD and CAC.

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 NAFLD and CAC in adult subjects. Pooled odds ratio (OR) and 95% confidence interval (CI) from multivariate model with confounders adjustment were calculated using a random-effect, generic inverse variance method. The between-study heterogeneity of effect-size was quantified using the
Q
statistic and

I
2

.

Results:
Data were extracted from 15 studies (all cross-sectional studies) involving 35,409 subjects. NAFLD is significantly associated with CAC > 0 and CAC > 100 with pooled OR of 1.41 (95% CI 1.24-1.61, P
heterogeneity
= 0.01,

I
2

=57%) (Figure 1) and 1.24 (95% CI 1.02-1.52, P
heterogeneity
= 0.09,

I
2

=42%). The association between NAFLD and CAC > 0 was stronger in women than men (P
between sex
= 0.017).

Conclusions:
NAFLD is also associated with coronary calcification independent of traditional risk factors, obesity and metabolic syndrome in asymptomatic individuals and this association was appeared to be stronger in women.
Abstract P227: Mapping of Chromosome 2 Regions Linked to Vascular Inflammation Using Congenic Rats
Authors: Ouerd Sofiane , Idris-Khodja Noureddine , Coelho Suellen C , Caillon Antoine , Berillo Olga , Kwitek Anne E , Paradis Pierre , Schiffrin Ernesto L
Published: June 2021

Objective:
Chromosome 2 (chr2) introgression from normotensive Brown Norway rats (BN) into hypertensive Dahl salt sensitive (SS) background (consomic SS2
BN
) reduced blood pressure (BP) and vascular inflammation under a normal-salt diet. Mapping of chr2 using congenic rats revealed that the distal portion of BN chr2 (SS2
BN
a) but not the middle segment (SS2
BN
b) on the SS background under a normal-salt diet contains anti-inflammatory genes. However, the role of chr2 in the regulation of vascular inflammation under a high-salt diet (HSD) remains unknown. We hypothesized that SS2
BN
a but not SS2
BN
b rats would have reduced vascular inflammation under HSD.

Design and method:
Four-to-6 week old male SS, SS2
BN
a and SS2
BN
b rats were fed a HSD (4% NaCl) for 8 weeks or until they developed a stroke as manifested by seizures. Vascular remodeling was assessed in mesenteric arteries (MA) using pressurized myography. Reactive oxygen species (ROS) production by dihydroethidium staining, vascular cell adhesion molecule (VCAM)-1 expression and CD3
+
T cell infiltration by immunofluorescence were determined in aorta or perivascular adipose tissue (PVAT). BP was measured by telemetry after 6 weeks of HSD.

Results:
Systolic BP tended to be higher in SS2
BN
b compared to SS (185±8 vs 168±5 mmHg). The incidence of seizures was 3.9-fold higher in SS2
BN
b compared to SS (12/36 vs 3/35 rats (
P
<0.05). MA media/lumen was 1.3-fold higher in SS2
BN
a compared to SS (10.6±0.9 vs 7.9±0.4%,
P
<0.01). PVAT ROS production was 1.8-fold higher in SS2
BN
a compared to SS (5.6±0.8 vs 3.2±0.1 relative fluorescence units [RFU]/μm
2
,
P
<0.01) and tended to be lower in SS2
BN
b (2.1±0.4 vs 3.2±0.1 RFU/μm
2
). Aortic VCAM-1 was increased 2.1-fold in SS2
BN
a compared to SS (2.6±0.5 vs 1.2±0.3 RFU/μm
2
,
P
<0.05). Aortic PVAT CD3
+
T cell infiltration was 55% lower in SS2
BN
b compared to SS (17±4 vs 38±4 cells/mm
2
,
P
<0.05).

Conclusions:
Unexpectedly, SS2
BN
a rats present increased vascular injury under HSD. The absence of vascular inflammation and remodeling in SS2
BN
b rats despite slightly higher BP seems maladaptive and may explain the increased incidence of stroke.
Abstract P236: Tripartite Motif 8 Contributes to Pathological Cardiac Hypertrophy Through Enhancing TAK1-dependent Signaling Pathways
Authors: Li Hongliang , Ji Yan-Xiao , Zhang Peng
Published: June 2021

Tripartite motif (TRIM) 8 functions as an E3 ligase, interacting with and ubiquitinating diverse substrates, and is implicated in various pathological processes. However, the biological function of TRIM8 in the heart remains largely uncharacterized. This study aims to explore the role of TRIM8 in the development of cardiac hypertrophy and heart failure (HF). Mice and isolated neonatal rat cardiomyocytes (NRCMs) overexpressing or lacking TRIM8 were examined in several experiment. The effect of aortic banding (AB)-induced cardiac hypertrophy were analyzed by echocardiographic, pathological and molecular analyses. Our results indicated that the TRIM8 overexpression in hearts exacerbated the pathological cardiac hypertrophy triggered by AB, promoting cardiomyocytes enlargement and fibrosis formation by about 41% and 52%. In contrast, the development of pathological cardiac hypertrophy was profoundly blocked in TRIM8-deficient hearts. Mechanistically, the present study suggests that TRIM8 may elicit cardio-detrimental effects by promoting the activation of TAK1-p38/JNK signaling pathways. Similar results were observed in cultured NRCMs treated with angiotensin II. In addition, the rescue experiments using the TAK1-specific inhibitor 5z-7-ox confirmed the requirement of TAK1 activation in pressure overload-mediated pathological cardiac hypertrophy in TRIM8-overexpressing hearts. Furthermore, a physical interaction between TRIM8 and TAK1 was identified by co-immunoprecipitation experiments. Our study demonstrated that TRIM8 plays a deleterious role in pressure overload-induced cardiac hypertrophy by accelerating the activation of TAK1-dependent signaling pathways.
Abstract P238: Effect of Zamicastat in Chronic Treatment on Right Ventricle Pressure Overload in the Rat Monocrotaline Lung Injury Model of Pulmonary Hypertension
Authors: Igreja Bruno , Pires Nuno , Moser Paul , Soares-da-Silva Patrício
Published: June 2021

Pulmonary arterial hypertension (PAH) is defined, foremost, as a plexogenic arteriopathy with subtotal luminal obliteration that increases pulmonary vascular resistance and imposes a hemodynamic stress on the right ventricle (RV) leading to RV hypertrophy and failure that contributes to premature death. There is experimental and clinical evidence that supports a relation between PAH and the sympathetic nervous system (SNS), indicating that PAH can be mediated, at least partly, by SNS hyperactivation. A strategy for the modulation of sympathetic nerve function is to reduce the biosynthesis of norepinephrine (NE) by inhibiting dopamine β-hydroxylase (DβH), the enzyme that catalyzes the conversion of dopamine (DA) to NE in sympathetic nerves. Here, we evaluated the effect of 18-day oral treatment with the DβH inhibitor zamicastat on RV pressure overload in the monocrotaline (MCT)-induced pulmonary hypertension (PH) model in the rat. MCT increased RV systolic pressure (54.7±2.9 vs 32.3±1.0 mmHg, p<0.0001), mean RV pressure (23.9±1.7 vs 16.6±1.1 mmHg, p<0.001), and decreased heart rate (240.0±5.9 vs 285.8±7.6 beats/min, p<0.0001) in vehicle-treated rats, as compared to pre-MCT values. Zamicastat treatment prevented the MCT-induced increase in mean RV pressure (change from baseline: +1.9±1.5 vs +7.4±1.8 mmHg, p<0.05). Likewise, the HR decrease was significantly attenuated in the zamicastat group as compared to the vehicle group (change from baseline: -14.3±9.7 vs -45.8±8.1 beats/min, p<0.05). Chronic zamicastat treatment decreased NE levels (480.5±43.9 vs 712.1±46.5 ng/mg protein, p<0.005) and increased DA levels (533.0±49.7 vs 12.3±2.3 ng/mg protein, p<0.0001) in adrenal gland homogenates of MCT-treated rats, as compared to vehicle group demonstrating robust inhibition of DβH. In conclusion, the DβH inhibitor zamicastat reverses heart rate and RV pressure changes, two hallmarks of PAH, in the rat MCT lung injury model.
Abstract P240: Acetylcholine Stimulation with Pyridostigmine Prevents Cardiac Arrhythmias in Conscious Myocardial Infarcted Rats and Upregulate Connexin 43, Hipoxic Inducible Factor-1α and Vascular Endothelial Grow Factor in Cardiomyocytes Culture
Authors: Santos-Almeida Fernanda M , Meschiari César A , Martins-Marques Tânia , Cury-Pavão Maria L , Salgado Helio C , Girão Henrique , Fazan Rubens
Published: June 2021

Objective:
To examine the impact on hemodynamics and electrocardiogram (ECG) of treating acutely infarcted rats with the acetylcholinesterase inhibitor pyridostigmine (PYR). We also examined the effect of PYR on connexin 43 (Cx43), an important protein for the ventricular cell to cell communication; on hypoxic inducible factor (HIF-1α), a transcriptional factor related to cell survival pathways under hypoxia, and on vascular endothelial grow factor (VEGF) in cultured cardiomyocytes subjected to ischemia-mimetic conditions.

Methods and Results:
Wistar rats, previously implanted with ECG electrodes and catheters into femoral artery and vein were subjected, under inhaled anesthesia, to coronary artery ligation to elicit MI, and after 20 min they received PYR (0.12 mg/kg iv, N=8) or saline (N=7). After 3h, the animals had their arterial pressure (AP) and ECG recorded for 60 min. Additionally, H9c2 cells were incubated with PYR (0.5 mM) during 1h before being subjected to the ischemia-mimetic solution during 1h. Mean AP was found similar between groups (94±5
vs.
90±3 mmHg) while heart rate (HR) was lower in rats treated with PYR (390±11
vs.
441±12 bpm). The number of premature ectopic beats was markedly lower in rats that received PYR, as compared to saline treated counterparts (median: 7 vs. 27, 25
th
percentile: 1.75 vs. 8.5 and 75
th
percentile: 17 vs. 166). In cultured cells incubated with PYR Cx43 was found higher (0.72±0,16
vs.
0.49±0,16), as well as HIF-1α (3.88±0.41
vs.
2.23±0.5), and mRNA for VEGF (qualitative analysis).

Conclusion:
Treatment with PYR showed positive effects, reducing the tachycardia and arrhythmias commonly seen after acute MI. Additionally, PYR affected proteins related to cell communication, cell surviving and vascular grow in cultured cardiomyocytes subjected to ischemia-mimetic conditions. The in vitro effects of PYR might be linked to its beneficial effects observed in infarcted rats. In another view, the results open a very new field of cholinergic role on cardiomyocytes to be further investigated.