bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 208: Action of Multifaceted Microglia on Blood Pressure Control
Authors: Li You , Li Liang , Shan Zhiying , Bernstein Kenneth E , Shen Xiao , Shi Peng
Published: July 2021

Microglia are the resident surveillance cells in the CNS, and are involved in shaping neuronal plasticity. Previous studies show that hypertension is associated with neuroinflammation. Interference of neuroinflammation by targeting microglia can inhibit or attenuate hypertension. To investigate the phenotypic changes of microglia during hypertension, we compared the profiles of microglia dissociated from normotensive and Ang II-induced hypertensive mice by flow cytometry. We found significant increases in the expression of CD89 (76%), CCR7 (52%), IFNγR (150%), MHC II (85%), CCR2 (51%), IL-4R (164%), mannose receptor (61%) and CD36 (60%) in Ang II microglia compared to the controls. To understand whether the microglial activation has a direct effect on blood pressure, we utilized microglia adoptive transfer strategy via intracerebroventricular (ICV) injection and then examined the blood pressure responses. Mouse microglial cell line, N9, was stimulated in groups as follows: 1) medium control, 2) 10 ng/ml LPS, 3)10 ng/ml LPS + 100 μM minocycline. After 6 hr treatment, half a million N9 cells were transferred into mice via ICV injection. Twenty-four hr later, the recipient mice were anesthetized, cannulated and positioned on the stereotaxic frame. The baseline blood pressure and heart rates were similar among groups (82±2 mmHg, 328±12.8 bpm). However, when we injected Ang II (50 ng in 1μl, ICV), there was a significant prolonged response in the recipient mice transferred with LPS-primed microglia compared to the ones receiving naïve controls (LPS 817±170 sec vs. control 475±70 sec; P<0.05 by unpaired T-test). This increase was fully abolished by co-incubation with minocycline, an inhibitor for microglial activation (LPS+minocycline 507±33 sec). There were no differences observed in pressure magnitude to ICV Ang II across the groups (11±2 mmHg). These data suggest that activated microglia alter neuronal plasticity and potentiate the neuronal responses to Ang II challenge. Taken together, microglial cells are activated, manifested by up-regulation of myeloid cell differentiation markers during hypertension, and then participate in the modulation of blood pressure.
Abstract 221: Lost Adiponectin-induced Renal Sodium Excretion in Hypertension
Authors: Huang hefei , Han Yu , Wang Zhen , Zeng chunyu
Published: July 2021

Obesity related hypertensive patients are often with impaired sodium excretion. However,the mechanisms are not clear. Adipocytes secrete numerous hormones, among which adiponectin is an important one. Adiponectin KO mice developed hypertension when maintained on a high-salt diet. In hypertensive patients, the plasma adiponectin levels are lower; there is relationship between lower serum adiponectin and new-onset hypertension.We hypothesize that adiponectin induces natriuresis and diuresis, the impaired adiponectin-induced sodium excretion might be involved in hypertension. Our present study found the expressions of both adiponectin (AdipoR1 and AdipoR2) receptor in kidney from Wistar-Kyoto rats. Infusion of adiponectin via supra-renal artery induces natriuresis and diuresis in Wistar-Kyoto rats. Treatment with adiponectin inhibited Na
+
-K
+
-ATPase activity in renal proximal tubule cells of Wistar-Kyoto rats. The inhibitory effect was mainly via AdipoR2 receptor, because the siRNA of AdipoR2, not AdipoR1,completely blocked the effect of adiponectin. In the presence of inhibitor for AMPK (compound C) or eNOS (L-NAME), the inhibitory effect of adiponectin on Na+-K+-ATPase activity was blocked, indicating AMPK-NO pathway is involved in the signaling pathway. In spontaneous hypertension rats, adiponectin-induced natriuresis and diuresis were lost;similarly, the inhibitory effect on Na+-K+-ATPase activity was also lost in renal proximal tubule cells of spontaneously hypertension rats. The impaired adiponectin effect might be ascribed to lower AdipoR2 expression in renal proximal tubule cells od spontaneously hypertension rats, because transfected with AdipoR2 reversed the inhibitory effect on Na+-K+-ATPase activity. These datas suggested that adiponection, via AdipoR2,induces natriuresis and diuresis; the impaired adiponectin function might be involved in the pathogenesis of hypertension.
Abstract 223: Zinc-finger Nuclease Knockout Of Dual-specificity Protein Phosphatase-5 Enhances Myogenic Response In Autoregulation Of Cerebral Blood Flow In Fhh.1bn Rats
Authors: Fan Fan , Geurts Aron M , Pabbidi Mallikarjuna R , Harder David R , Jacob Howard , Roman Richard J
Published: July 2021

We recently reported that the pressure-induced myogenic responses of afferent arteries (Af-Art) and middle cerebral arteries (MCAs) were impaired in the fawn hooded hypertensive (FHH) rats and were restored in FHH.1BN congenic strain in which chromosome 1 from the Brown Norway (BN) rats containing 11 genes including dual-specificity protein phosphatase-5 (Dusp5) was transferred into FHH genetic background. There are 4 single nucleotide polymorphisms (SNP) in Dusp5 in FHH as compared with BN rats, one of which causes G155R mutation. To determine whether Dusp5 contributes to the impaired vascular myogenic response in FHH rats, we created a Dusp5 knockout (KO) rats in the FHH.1BN genetic background using zinc-finger nuclease (ZFN) that introduced a premature stop codon at amino acid (AA) 121. The expression of Dusp5 in KO rats were significantly decreased and the level of phosphorylated ERK2 (p-ERK2) was significantly increased in multiple organs including liver, spleen and white blood cells (WBCs). The luminal diameter of the MCAs in FHH.1BN rats (n=12) decreased 20 ± 2 % when the perfusion pressure was increased from 40 to 140 mmHg, whereas it decreased 34 ± 7 % in Dusp5 KO rats (n=6) and increased 10 ± 4% in FHH strain (n=8). Autoregulation was markedly impaired and CBF increased by 54 ± 6% in FHH rats when MAP was increased from 100 to 160 mmHg. CBF was better autoregulated in FHH.1BN strain and Dusp5 KO rats increased by only 26 ± 3% and 12 ± 3% when MAP was increased over the same range. However, the range of autoregulation of CBF was extended in the FHH rats (n=7) in that CBF rose to 107 ± 6% in FHH.1BN rats (n=7) when pressure was increased to 190 mmHg versus 33 ± 4% in the Dusp5 KO animals (n=6). These results suggest that Dusp5 plays an important role in modulating of myogenic tone in the cerebral circulation. Unless the G155R mutation activates Dusp5 in FHH rats, it is unlikely that Dusp5 is responsible for the impaired myogenic response in FHH rats.
Abstract 230: Angiotensin-Converting Enzyme Inhibition Increases ADMA Concentration in Patients on Hemodialysis
Authors: Gamboa Jorge L , Pretorius Mias , Ikizler Talat A , Brown Nancy J
Published: July 2021

Endothelial dysfunction occurs commonly in patients with end-stage renal disease (ESRD) and is associated with increased cardiovascular morbidity and mortality. Asymmetric dimethylarginine (ADMA), an inhibitor of nitric oxidase synthase, is elevated in patients with chronic kidney disease and contributes to endothelial dysfunction in ESRD. In the general population, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) decrease ADMA levels, but no study has compared the effect of these drugs in patients with ESRD on hemodialysis. We therefore evaluated the effect of one-week treatment with ramipril (5 mg/d), valsartan (160 mg/d) and placebo on ADMA levels in fifteen patients on hemodialysis in a previously published double-blind, placebo-controlled, 3X3 cross-over study. We found that ADMA levels were increased at baseline and throughout the dialysis session during ramipril treatment (Figure 1, p<0.001 compared to both placebo and valsartan). Ramipril did not increase ADMA levels in a study of patients without ESRD, suggesting that factors related to ESRD or hemodialysis contribute to the ACE inhibitor-induced increase in ADMA levels. We have previously shown that ACE inhibition increases bradykinin (BK) levels during hemodialysis. Therefore, we evaluated the effect of BK on ADMA production in A549 cells; incubation with BK increased intracellular ADMA concentration through bradykinin B2- receptor (B2R) stimulation (Figure 2). In conclusion, ACE inhibition increases ADMA in patients on hemodialysis. Studies in vitro suggest that this could occur through a bradykinin-mediated increase in ADMA production.
Abstract 235: Chronic Endothelin Type A Receptor Blockade Abolishes Age-dependent Hypertension In Female Intrauterine Growth Restricted Rat Offspring.
Authors: Intapad Suttira , Backstrom Miles A , Carter Anthony J , Dasinger John H , Alexander Barbara T
Published: July 2021

Birth weight is inversely associated with blood pressure. Placental insufficiency in the rat induces low birth weight indicative of intrauterine growth restriction (IUGR) associated with sex-dependent hypertension in IUGR offspring in young adulthood. However, placental insufficiency programs the development of age-dependent hypertension in the female IUGR rat by 12 months of age. Blood pressure increases with age and the prevalence of hypertension is significantly increased in low birth weight women at 60 relative to 50 years of age. Yet, the exact mechanisms that mediate age-dependent hypertension following a developmental insult are unknown. We previously noted that endothelin mediated via its endothelin type A receptor (ET
A
R) plays a significant role in blood pressure regulation in hypertensive male IUGR but not in normotensive female IUGR rats in young adulthood. Thus, we hypothesized that endothelin mediated via its ET
A
R would play a contributory role in the development of age-dependent hypertension in the female IUGR rat. Mean arterial pressure (MAP) was measured via arterial catheter in conscious female control and female IUGR offspring at approximately 12 and 18 months of age in animals that received vehicle or an ET
A
R antagonist (ABT-627, 5 mg/kg BW, Abbott) in the drinking water for 4 days prior to measure of MAP. MAP was significantly increased in IUGR (135±2 mmHg;
P
<0.05,) relative to control (121±2 mmHg) at 12 months of age (N=9 per group). MAP was remained significantly elevated in IUGR (149±5 mmHg,
P
<0.05) relative to control (135±5 mmHg) at 18 months of age (N=5 per group) despite age-dependent increases in MAP in IUGR and control rats. Chronic ET
A
R blockade significantly decreased MAP in treated IUGR (113±2 mmHg;
P
<0.05 vs. untreated IUGR, N=6) but blockade of the ET
A
R had no impact on blood pressure in treated control (134±9 mmHg; N=5) at 18 months of age. Thus, these findings indicate that age augments the importance of endothelin via its ET
A
R in the etiology of hypertension programmed by IUGR but does not contribute to the age-dependent increase in blood pressure in the female control. Furthermore, this study highlights the need for sex- and age-specific considerations in the management of hypertension following a developmental insult.
Abstract 265: Validation of a novel Brachial Pulse Wave Analysis-Based Method for Estimating Central Blood Pressure among Japanese Cardiovascular Patients
Authors: Shoji Toshihiro , Okada Sho , Nakagomi Atsushi , Kobayashi Yoshio
Published: July 2021

Background:
Hypertension is a significant predictive factor for future cardiovascular(CV) events. Historically its assessment has been made at the brachial arm, and this method is still cardinal for hypertension treatment.

Blood pressure measured at the root of the aorta, named ‘central’ blood pressure (cBP), shows actual load on the heart and proximal large arteries. It has been recognized as more accurate predictor for CV events than ‘brachial’ one. Despite this, invasive maneuvers on cBP measurement have long limited its widespread clinical use.

Recently several non-invasive methods were developed for cBP measurement. ARC Solver algorithm, which calculates cBP from brachial BP using novel pulse wave analysis-based method, enabled us to assess ambulatory cBP values. Though it was already validated among western countries, its accuracy nor optimal conditions still remains unknown among us Japanese.

Object:
To validate ARC Solver algorithm-based cBP measurement among Japanese CV patients.

Method:
For 89 patients who underwent elective coronary angiography in our hospital, we simultaneously measured invasive cBP (cBPinv) and calculated cBP with ARC Solver algorithm (cBPcalc) . We used systolic and diastolic BP (Calc1) or mean and diastolic BP(Calc2) for calibration. Then we evaluated the error and correlation of the data with Bland-Altman analysis and Pearson correlation analysis, respectively. After excluding the perturbing factors such as arrhythmia and valvular heart disease, we performed the same analyses.

Results:
cBPinv and cBPcalc showed good linear correlation (Cal1: r=0.72, p<0.01, Cal2: r=0.748, p<0.01), whereas error between them showed marked difference (Cal1: 17.7±16.3mmHg, Cal2: -7.5mmHg±18.1mmHg).

After excluding perturbing factors, the difference even enlarged (Cal1: 19.9±17.0mmHg, Cal2: -3.9±15.5mmHg), although linear correlation was each improved (Cal1: r=0.76, p<0.05, Cal2: r=0.84, p<0.01). Gender difference influenced the error.

Conclusions:
Mode of calibration significantly influences the calculated cBP with ARC Solver algorithm among Japanese patients with CV diseases. Consideration for the perturbing clinical factors and gender difference are also essential for its proper clinical application.
Abstract 271: Developmental Origin Of Obesity Related Hypertension: Trans-generational Cardiovascular Impact Of High Fat Diet Feeding In Rabbits
Authors: Lim Kyungjoon , Burke Sandra L , Davern Pamela J , Head Geoffery A
Published: July 2021

We determined if exposed to a high fat diet (HFD) during development have a similar phenotype (changes in blood pressure (BP), heart rate (HR) and renal sympathetic nerve activity (RSNA)) in the offspring as adult obesity when consuming a HFD.

New Zealand White breeder rabbits were placed on a normal or 13.5% high fat diet (HFD) from 3 weeks prior to mating, during pregnancy and during lactation. Maternal NFD (mNFD) offspring was divided to two groups and placed on HFD for 10 days (mNFD+10dHFD) to mimic adulthood obesity. Rabbit offspring were implanted with renal electrode to measure RSNA. At 18 weeks of age, rabbits were infused with alpha-melanocyte-stimulating hormone (αMSH, 10nmol), Leptin antagonist (100μg), SHU9119 (melanocortin 3 and 4 receptor antagonist, 0.0375nmol, 0.075nmol, 0.1875nmol and 0.375nmol) and vehicle intracerebroventricularly.

There was no difference in baseline BP between all diet groups but baseline RSNA was increased in mHFD offspring (17.6 normalised unit (nu)) and mNFD+10dHFD offspring (10.7 nu) when compared to mNFD offspring (5.6 nu). αMSH injection increased BP (from 68 to 75mmHG, p<0.01) in mNFD+10dHFD offspring and HR was increased (from 159bpm to 246bpm, p<0.01) in maternal HFD offspring. When SHU9119 was injected, there was a reduction in BP in both maternal HFD (from 71 to 65mmHG, p<0.001) and mNFD+10dHFD (from 78 to 72mmHG, p<0.01) offspring. Leptin antagonist had no effect on BP in all diet groups but RSNA was reduced (29% reduction from 13 normalised unit) in mHFD offspring.

The phenotype of developmental obesity shows similar characteristics of adulthood obesity where the elevation of RSNA induced by HFD is predominantly mediated by increased sensitivity of the leptin signalling pathway.
Abstract 293: Endothelial Type B Endothelin Receptor is a Critical Microvascular Target in Placental Ischemia and Tumor Necrosis Factor-Mediated Hypertensive Pregnancy
Authors: Mazzuca Marc Q , Mata Karina M , Khalil Raouf A
Published: July 2021

Preeclampsia is a pregnancy-related hypertensive disorder (HTN-Preg) with unclear mechanism, and a role of cytokines and endothelin-1 (ET-1) has been suggested. We have recently shown downregulation of endothelial type B ET-1 receptor (ET
B
R) in Preg rats with reduced uterine perfusion pressure (RUPP). To test if cytokines are a possible mechanism linking RUPP to downregulation of ET
B
R, day 14-Preg rats were either nontreated or infused with TNFα (200 ng/kg/day), and RUPP rats were either nontreated or infused with the TNFα decoy receptor etanercept (0.4 mg/kg/day) for 5 days by osmotic minipump. On day 19, BP was recorded and mesenteric microvessels were isolated for simultaneous measurement of diameter and [Ca
2+
]
i
(fura-2 340/380 ratio). BP was in TNFα-Preg (127±8) > Preg (97±5mmHg) and in etanercept-RUPP (113±2) < RUPP (124±3mmHg). ET-1 vasoconstriction was in TNFα-Preg (86.1±4.7) > Preg (58.1±5.2%), and in etanercept-RUPP (65.9±5.0) < RUPP (86.2±3.7%). ET-1 caused parallel increases in microvascular [Ca
2+
]
i
that were in TNFα-Preg (0.90±0.01) > Preg (0.86±0.01), and in etanercept-RUPP (0.85±0.01) < RUPP (0.92±0.01). Endothelium removal or microvessel treatment with ET
B
R antagonist BQ-788 enhanced ET-1 vasoconstriction and [Ca
2+
]
i
in Preg and etanercept-RUPP, but not in TNFα-Preg or RUPP. ET
B
R-mediated relaxation with IRL-1620 was in TNFα-Preg (4.11±6.1) < Preg (28.8±4.2%), and in etanercept-RUPP (20.2±4.6) > RUPP (10.17±2.9%). The NOS inhibitor L-NAME partially reduced ACh-induced and ET
B
R-mediated relaxation in Preg and etanercept-RUPP, but not TNFα-Preg or RUPP, suggesting decreased NO-dependent and ET
B
R-mediated vasorelaxation in HTN-Preg. Addition of the K
+
channel blocker teraethylammonium (non specific), or apamin (SK
Ca
) plus TRAM-34 (IK
Ca
) abolished the remaining ET
B
R-mediated relaxation in all groups, suggesting equal role of EDHF. Thus similar to RUPP, increasing TNFα in Preg rats increases ET-1 microvascular constriction and decreases ET
B
R-mediated NO-dependent vasodilation, and counteracting TNFα reduces BP and ET-1 vasoconstriction, and enhances ET
B
R-mediated vasodilation in RUPP rats. The results support that endothelial ET
B
R is a major microvascular target in placental ischemia and TNFα-mediated HTN-Preg.
Abstract 299: Blockade of Toll-like Receptor 4 During Acute Lipopolysaccharide Treatment Preserves Afferent Arteriolar Autoregulatory Behavior.
Authors: Van Beusecum Justin , Cook Anthony K , Zhang Shali , Webb R. C , Inscho Edward W
Published: July 2021

Lipopolysaccharide (LPS), a component of the bacterial wall of gram-negative bacteria is a ligand for toll-like receptor 4 (TLR4). Immune system activation and generation of reactive oxygen species (ROS) is linked to blunted renal autoregulatory behavior. Accordingly, we hypothesize that blockade of TLR4 during acute LPS treatment preserves afferent arteriolar autoregulatory behavior. Rats received a bolus injection of LPS (1 mg/kg i.p.) and were treated with either anti-TLR4 antibody (1μg; i.p.) or TLR4 receptor antagonist (LPS-RS; 5mg; i.p.). Kidneys were harvested 4 hours later for juxtamedullary nephron studies. Autoregulatory behavior was assessed in these groups by increasing perfusion pressure in 15 mmHg increments from 65 to 170 mmHg. In control kidneys, afferent arteriolar diameter decreased by 29 ± 5% when perfusion pressure was increased from 65 to 170 mmHg. LPS alone (4 hrs.) significantly blunted the autoregulatory response such that afferent arteriolar diameter remains essentially unchanged between 65 (12.4 ± 0.9 μm) and 170 mmHg (12.7 ± 1.2 μm). In kidneys co-treated with LPS and anti-TLR4 antibody, afferent arteriolar diameter decreased by 26 ± 6% (P < 0.05; n=6) during increments in perfusion pressure from 65 to 170mmHg. In kidneys co-treated with LPS and the TLR4 receptor antagonist, LPS-RS, afferent arteriolar diameter decreased by 24 ± 5% (P < 0.05; n=4) over the same pressure range, indicating preservation of pressure-induced vasoconstriction. Reactive oxygen species play a role in blunting rat afferent arteriolar autoregulatory resistance adjustments. Therefore, we assessed autoregulatory behavior in LPS treated kidneys during acute exposure to the superoxide dismutase mimetic, Tempol (10-6 mol/L). In these kidneys, afferent arteriolar diameter decreased by 28 ± 3% (P < 0.05; n=6) indicating restoration of autoregulatory capability. These data indicate that LPS treatment induces TLR4 activation, and stimulates ROS generation. Blocking TLR4 with anti-TLR4 antibody or LPS-RS or scavenging ROS with Tempol preserves and restores afferent arteriolar autoregulatory behavior suggesting that blockade of TLR4 may open novel therapeutic targets for inflammatory kidney disease.
Abstract 416: Hypertension During Pregnancy is Associated with Cerebral Damage in an Animal Model of severe preeclampsia
Authors: Wallace Kedra , Tremble Sarah , Pabbidi Malikarjuna R , Morris Rachael , Spencer Shauna-Kay , Cipolla Marilyn
Published: July 2021

HELLP (hemolysis, elevated liver enzymes, low platelet) syndrome is a severe form of preeclampsia that is accompanied by hypertension, headaches, visual disturbances and cerebral infarctions during pregnancy. HELLP is associated with hypertension and elevations in TNF-α and IL-6, both of which have been shown to activate the endothelin-1 system (ET-1). The objective of the current study was to determine if hypertension in an animal model of HELLP is associated with cerebral impairment. On gestational day (GD) 12 miniosmotic pumps infusing sEndoglin and sFlt-1 (7 and 4.7ug/kg/day) were implanted into normal pregnant (NP) rats to induce HELLP. On GD18 carotid catheters were inserted into HELLP and NP rats and mean arterial pressure (MAP) was recorded on GD19 followed by brain collection. Myogenic tone was calculated from the middle cerebral artery; brain water content was measured to determine cerebral edema. Blood brain barrier (BBB) permeability was determined by exposing cerebral vessels from non-pregnant rats intraluminally to plasma from NP or HELLP rats. MAP increased from 92±2.6mmHg in NP rats (n=10) to 120.6±3.6mmHg in HELLP rats (n=11; p<0.01). HELLP rats had significant cerebral edema compared to NP rats (p=0.04). Myogenic tone in HELLP rats was significantly impaired (p<0.05) at pressures greater than or equal to 80mmHg compared to NP rats (n=2/group). Plasma from HELLP rats (n=6) significantly increased BBB permeability at 100mmHg compared to plasma from NP rats (n=5). Administration of an endothelin
A
(ET
A
) receptor antagonist (ABT-627, 5mg/kg on GD12-19), significantly decreased MAP in HELLP rats compared to untreated HELLP rats (97±5.3mmHg, n=5, p<0.01) and decreased cerebral edema to levels comparable to NP rats. Data from this study demonstrates that high MAP in HELLP rats is accompanied by cerebral edema, increased BBB permeability and impaired myogenic tone. Any of which could contribute to the neurologic complications that plague women with HELLP. Furthermore, as elevated ET-1 can damage the BBB and lead to cerebral damage we administered an ET
A
receptor antagonist which significantly decreased MAP and cerebral edema; future studies will determine if these changes are accompanied by improvement in myogenic tone and BBB permeability.
Abstract 438: Association between Insomnia and Use of BP-lowering Drugs in hypertensive Patients: a Cross-sectional Cohort Study
Authors: Bruno Rosa Maria , Palagini Laura , Mancuso Veronica , Cargiolli Martina , Gemignani Angelo , Mauri Mauro , Virdis Agostino , Ghiadoni Lorenzo , Taddei Stefano
Published: July 2021

Purpose:
Insomnia and short sleep duration have been associated with increased prevalence, incidence and severity of hypertension. However, the relationship between insomnia and use of different antihypertensive drug classes has not been ascertained yet.

Methods:
371 hypertensive patients at their first visit in a tertiary Hypertension Outpatient Unit were enrolled. Insomnia Severity Index (ISI), Beck Depression Inventory (BDI), and State-Trait Anxiety Inventory (STAY-Y2) were administered. Insomnia was defined as ISI>8, depressive symptoms as BDI>10, trait anxiety as STAI -Y2>40. Patients with self-reported sleep apneas or snoring (n=29) or with incomplete data (n=12) were excluded.

Results:
Data from 330 patients were analyzed (males 51%, mean age 57±13 years, antihypertensive treatment 84%, previous CV events 9%, diabetes 7%, obesity 24%, smoking 13%, hypercholesterolemia 67%). Insomniacs (n=70, 21%) were older than non-insomniacs (60±11 vs 56±13 years, p=0.02); female gender (62 vs 46%, p=0.01), anxiety (68 vs 34%, p<0.0001) and depressive symptoms (30 vs 6%, p<0.0001) were more prevalent in insomniacs. Insomniacs were treated with higher number of antihypertensive drugs (1.8±1.0 vs 1.5±1.0, p=0.04) and more frequently with angiotensin-receptor-blockers (ARBs, 49 vs 31%, p=0.009) and diuretics (50 vs 28%, p=0.0007), whereas the use of other drug classes was similar.

In a multiple logistic regression analysis, adjusted for cardiovascular and psychiatric variables, ARBs use (OR 2.4, CL95% 1.1-5.2), depressive symptoms (OR 3.2, CL95%1.2-8.7) and anxiety (OR 2.9, CL95%1.4-6.1) were associated with a higher probability of insomnia.

Conclusions:
This cross-sectional analysis suggests that ARBs use may be associated with insomnia in a cohort of hypertensive patients
Abstract 442: Cardiomyocyte Specific mTORC1 Deletion Precipitates Interstitial Fibrosis, Heart Failure And Loss Of Female Cardio Protection
Authors: Guergen Dennis , Kusch Angelika , Kauz Nelli , Catar Rusan A , Brink Marijke , Dragun Duska
Published: July 2021

Mechanistic target of rapamycin (mTOR) kinase operates in two functionally and structurally distinct multiprotein complexes mTORC1 and mTORC2. mTORC1 including its defining raptor protein is a critical mediator of myocardial growth. We induced cardiomyocyte specific raptor-KO (cKO) deletion to investigate a sex specific role of mTORC1 during cardiac adaptation in normotensive DOCA-salt mice. Untypical for this mild cardiac stress model, raptor-cKO females had sharper decrease in EF (51 vs. 26%) than males (50 vs. 32%) already at 3 weeks after start of DOCA-salt challenge. Male raptor-cKO mice mounted eccentric hypertrophic response upon DOCA-salt indicated by heart weight/tibia length ratios (6.7 to 8.0) as compared to their WT litters (6.6 to 7.6). In contrast female raptor-cKO (5.8 to 6.4) minimally differed from their litters (5.8 to 6.6). Severe dilative phenotype was detected in both sexes regardless of DOCA-salt challenge. In addition, we found tremendous diffuse left ventricular fibrosis which was also more prominent in raptor-cKO females. Collagen depositions in the LV visualized by Sirius red staining increased 10fold in males (1.0 to 10.6%) and 15fold in females (0.9 to 15.7%), respectively. Expression of raptor protein in the heart was diminished by 80% in raptor cKO mice of both sexes what lead to similar extent of decreased activity of direct mTORC1 downstream targets phospho-S6 ribosomal protein and phospho-4E-BP1Ser65 (68% reduction in males vs. 61% in females. Over-compensatory mTORC2 activation in cKO animals via phospho-AKTSer473 (12fold increase) and induction of anti-apoptotic signaling was similar in both sexes. However, raptor-cKO females failed to up-regulate expression of mitochondrial genes such as Mtnd1 (ND1), mt-Co1 (COX1) and Atp5i (ATP5k), stressing sex differences in mTORC1 dependent mitochondrial adaptation. In addition, transmission electron microscopy (TEM) points towards structural alterations of mitochondrial morphology.

Intact mTORC1 function is important for myocardial adaptation in both sexes. More severe phenotype in females further implicates mTORC1 to be essential for intrinsic female cardio protection.
Abstract 444: Flotillin-1 Facilitates Toll-like Receptor 3 Signaling In Human Endothelial Cells
Authors: Fork Christian , Hitzel Juliane , Brandes Ralf P
Published: July 2021

Objective:
Endothelial cells are important elements in the vascular response to danger associated molecules signaling through Toll-like receptors (TLRs). Flotillin-1 and -2 are markers of membrane rafts but their true endothelial function is unknown. We hypothesized that flotillins are required for TLR signaling in human umbilical vein endothelial cells (HUVECs).

Approach and Results:
Knockdown of flotillin-1 by shRNA decreased the TLR3 mediated poly-I:C-induced but not the TLR4-mediated LPS-induced inflammatory activation of HUVEC. As TLR3 but not TLR4 signal through the endosomal compartment, flotillin-1 might be involved in the transport of poly-I:C to its receptor. Consistently, uptake of poly-I:C was attenuated by flotillin-1 knockdown and probably involved the scavenger receptor SCARA4 as revealed by knockdown of this receptor. To determine the underlying mechanism, SILAC proteomics was performed. Down-regulation of flotillin-1 lead to a reduction of the structural caveolae proteins caveolin-1, cavin-1 and -2, suggesting a role of flotillin-1 in caveolae formation. Flotillin-1 and caveolin-1 colocalized within the cell, and knockdown of flotillin-1 decreased caveolin-1 expression. Importantly, downregulation of caveolin-1 also attenuated TLR3-induced signaling. To demonstrate the importance of this finding, cell adhesion was studied. Flotillin-1 shRNA attenuated the poly-I:C-mediated induction of the adhesion molecules VCAM-1 and ICAM-1. As a consequence, the oly-I:C-induced adhesion of peripheral blood mononuclear cells onto HUVECs was significantly attenuated by flotillin-1 shRNA.

Conclusion:
Interaction between flotillin-1 and caveolin-1 may facilitate the transport of TLR3-ligands to its intracellular receptor and enables inflammatory TLR3 signaling.
Abstract 445: A Pro-Fibrotic Role of Interleukin-4 in Cardiac Remodeling and Dysfunction
Authors: Peng Hongmei , Carretero Oscar , Yang Xiao-Ping , Nakagawa Pablo , Xu Jiang , Peterson Edward , Rhaleb Nour-Eddine
Published: July 2021

Elevated interleukin-4 (IL-4) levels are positively related to cardiac fibrosis in heart failure and hypertension. Using Balb/c exhibiting high circulating IL-4, Balb/c-

Il4
tm2Nnt

(IL-4 knockout with Balb/c background, IL-4
-/-
) and C57BL/6 mice, as well as cultured cardiac fibroblasts (CFs), we hypothesized that 1) high levels of IL-4 result in cardiac fibrosis, making the heart susceptible to angiotensin II (Ang II)-induced damage, and 2) IL-4 potently stimulates collagen production by CFs. Each strain (9- to 12-week old male) received vehicle or Ang II (1.4 mg/kg/day, s.c.
via
osmotic mini-pump) for 8 weeks. Cardiac fibrosis and function were determined by histology and echocardiography, respectively. Compared to C57BL/6, Balb/c mice had doubled interstitial collagen in the heart, enlarged left ventricle and decreased cardiac function along with elevated cardiac IL-4 protein (1.00±0.08 in C57BL/6
vs
2.61±0.46 in Balb/c,
p
<0.05); all those changes were significantly attenuated in IL-4
-/-
(Table 1). Ang II further deteriorated cardiac fibrosis and dysfunction in Balb/c; these detrimental effects were attenuated in IL-4
-/-
, although the three strains had a similar level of hypertension.
In vitro
study revealed that IL-4Rα was constitutively expressed in CFs (Western blot), and IL-4 potently stimulated collagen production by CFs (hydroxproline assay, from 18.89±0.85 to 38.81±3.61 μg/mg at 10 ng/ml,
p
<0.01). Our study demonstrates for the first time that IL-4, as a potent pro-fibrotic cytokine in the heart, contributes to cardiac fibrotic remodeling and dysfunction. Thus IL-4 may be a potential therapeutic target for cardiac fibrosis and dysfunction.
Abstract 483: Mas/AT2 Receptor Deficient Mice Present A Pronounced Endothelial Dysfunction That Is Exclusively Mas-Related
Authors: Villela Daniel C , Todiras Mihail , Unger Thomas , Alenina Natalia , Bader Michael , Steckelings U. Muscha , Santos Robson A
Published: July 2021

The angiotensin type 2 (AT2) receptor and the angiotensin-(1-7) receptor MAS belong to the protective arm of the Renin Angiotensin System (RAS). They behave in a very similar way in terms of their physiological (tissue-protective) actions. Here we evaluate the endothelial function of Mas/AT2 double knockout mice (DKO) in two different backgrounds, C57BL/6 and FVB/N-C57BL/6 mixed background. Endothelial function in conscious mice was evaluated by measuring changes in mean arterial pressure (MAP) in response to bolus intra-aortic acetylcholine (ACh) and sodium nitroprusside (SNP) administration. The substances were given in 1μL per 10 g of body weight at the following doses: 25, 50, 100 ng/kg for ACh and 10 μg/kg for SNP. To correct the differences in vascular smooth muscle reactivity, the response to ACh was normalized by the SNP response. Our main results show that regarding the absolute response to ACh, Mas/AT2 DKO animals in both backgrounds had markedly decreased vasodilation response when compared with wild type (WT) over the dose range of 25 to 100 ng/kg (table 1). The MasKO animals had similar impairment of the vasodilatory response as the DKO mice when compared with WT animals, thus there was no statistical difference between the MasKO and DKO animals. No significant difference between the AT2KO and WT animals was observed in regard to the vasodilatory response to ACh. Normalization of ACh response with the SNP effect reinforced the observation that endothelium-dependent vascular reactivity was impaired. The evidence provided in this study suggests that the endothelial dysfunction observed in the Mas/AT2 DKO animals is exclusively due to the deletion of Mas.
Abstract 512: Anorectic and Thermogenic Effects of Chronic Vagal Nerve Stimulation in Mice
Authors: Dias Daniel P , Morgan Donald A , Stauss Harald M , Rahmouni Kamal
Published: July 2021

Electrical vagal nerve stimulation (VNS) has emerged as a new tool to treat human diseases including obesity. Indeed, chronic VNS has been shown to cause weight loss in humans and in experimental animal models. However, the mechanisms by which chronic VNS causes weight loss are largely unknown due in part to the unavailability of implantable nerve stimulators for mice excluding the use of genetically engineered mouse models to investigate these mechanisms. Identification such mechanisms promises to identify novel approaches for weight loss. Here, we report the development of a miniaturized microprocessor-operated nerve stimulator for chronic use in conscious mice. Effectiveness of the stimulator was verified by the bradycardia induced at stimulation frequencies above 5 Hz (3V, 1mA, 1ms pulses). Next, we used the stimulator to test whether changes in metabolic rate, caloric intake and feeding efficiency (body weight gain per calories consumed) contribute to chronic VNS-induced weight loss. Male C57Bl/6 mice (16 weeks old, on standard mouse chow diet) were instrumented with nerve stimulators (3V, 1mA, 1ms pulses at 5 Hz) on the right cervical vagal nerve and body weight, food intake and metabolic rate (indirect calorimetry) were determined at baseline and weekly thereafter. After the initial post-surgical weight loss, sham animals (n=9, stimulators off) regained pre-surgical body weight within 16 days (100.0±2.7%). In contrast, mice with chronic VNS (n=12) never re-established pre-surgical body weight (94.5±0.9% on day 16, P<0.05 vs. sham). Caloric intake was significantly reduced in mice with chronic VNS compared to sham group (74.7±2.4 vs. 84.6±4.2 kcal/week, P<0.05). Likewise, mice with chronic VNS showed significantly reduced feeding efficiency compared to sham mice (2.6±2.0 vs. 10.6±2.4 mg body weight gain per kcal consumed). Oxygen consumption tended to be elevated (2734±152 vs. 2490±124 mL/kg/h) during the first week, but not thereafter. In conclusion, reduced food intake and lower feeding efficiency contribute to VNS-induced weight loss in mice. We speculate that an initial increase in metabolic rate (assessed by oxygen consumption) may be antagonized by compensatory mechanisms triggered by chronic VNS.
Abstract 522: Contribution of Reactive Oxygen Species and Rho Kinase in Sphingosine-1-phosphate Mediated Afferent Arteriolar Vasoconstriction of Ischemia-Reperfusion Rats
Authors: Guan Zhengrong , Inscho Edward W.
Published: July 2021

Our recent studies indicate that sphingosine-1-phosphate (S1P) is a potent vasoconstrictor of afferent arterioles (AA) and is enhanced in renal ischemia-reperfusion (IR) injury. We hypothesized that renal IR-induced increases in reactive oxygen species (ROS) and activation of the rho kinase pathway contribute to the enhanced S1P sensitivity of AA in IR rats. IR injury was induced by bilateral renal artery occlusion for 60 min followed by 24 hrs reperfusion. Renal function was assessed by plasma creatinine (Cr) or glomerular filtration rate (GFR). The AA response to S1P was assessed using the
in vitro
blood-perfused juxtamedullary nephron preparation with and without superfusion with the ROS scavenger, Tempol, or the rho kinase inhibitor, Y27623. Plasma Cr was markedly increased in IR (3.86±0.20 vs. 0.93±0.07 mg/L in sham, n=5-7, P < 0.05). GFR, calculated from the half time (T
1/2
) of sinistrin clearance, was significantly reduced in IR rats. The T
1/2
averaged 166±28 min in IR vs. 25±4 min in sham rats corresponding to GFRs of 0.20±0.02 and 1.33±0.23 ml/min (P < 0.05, n=3 each), respectively. The basal AA diameter was significantly decreased in IR compared to sham rats (10.2±0.5 vs. 15.0±0.4 μm, P < 0.05, n=9 each). Superfusion of Tempol (10
-4
M) did not alter the basal AA diameter in sham but increased diameter in IR by 8±1% (P < 0.05, n=6 each). S1P superfusion evoked concentration-dependent AA vasoconstriction in both groups, however, Tempol significantly shifted the S1P response

curve to the right in IR. Increasing concentrations of S1P (10
-10
-10
-5
M) reduced AA diameter to 98±2, 96±2, 98±2, 94±3, 81±9 and 59±5% of control in IR rats similar to the response in Tempol-treated sham rats (99±1, 99±2, 96±2, 88±5, 65±6 and 48±4%, respectively, P > 0.05). In contrast, superfusion of Y27632 (10
-5
M) markedly increased the basal AA diameter in both groups. AA diameter increased by 81±17% from 10.6±1.3 to 19.2±3.3 μm in IR vs. a 53±21% increase in sham rats (P > 0.05, n=3 each). Y27632 also significantly blunted S1P-mediated AA vasoconstriction similarly in both groups. These results indicate a significant contribution of ROS and rho kinase to both the elevated afferent arteriolar tone and the enhanced S1P sensitivity of AA in IR induced acute kidney injury.
Abstract 525: Morphological and Functional Characterization of Targeted Renal Gene Silencing via Medullary Interstitial vs. Subcapsular siRNA Infusion in Mice
Authors: Asico Laureano D , Wang Xiaoyan , Villar Van Anthony M , Yang Yu , Konkalmatt Prasad , Jose Pedro A
Published: July 2021

Advances in gene knockout technology have enhanced gene function studies, paving the way for the development of mouse lines for the functional analysis of genes, such as those that are germane to blood pressure regulation. Classic gene knockout requires gene disruption at the embryonic stem cell level, which may allow for compensatory mechanisms to develop. The development of conditional knockouts allows tissue-specific gene manipulation and reversible gene silencing. However, this technology involves a substantial investment of time and resources, and is fraught with low success rate. To address these limitations, we compared two novel approaches for targeting renal genes against the classic tail vein delivery technique. These techniques involved the use of osmotic minipumps to infuse gene-specific siRNA directly into either the renal medullary parenchyma or subcapsular space and required only a fraction of the tail vein siRNA concentration. The dopamine D5 receptor (D5R) gene Drd5 was selected because Drd5 knockout mice have the highest blood pressure among all the dopamine receptor null mice. The D5R is distributed in the PCT, DCT CCT PST, TAL and OMCD. In vivo xenograph imaging studies using AAV9-luciferase conjugate showed the infusate distribution was restricted to the target kidney. The lack of extra-renal spillage of the infusate was confirmed by the restricted distribution of exogenous siRNA-Alexa488 in the kidney, but not in the liver of the same mouse. Subcapsular and intramedullary infusion of Drd5-specific siRNA (vs. non-silencing “mock” siRNA) resulted in decreased expression of D5R (subcapsular: mock, 100±2 vs. Drd5-siRNA, 72±6; intramedullary: 100±6 vs. 78±6); However, there was no difference in D5R expression after tail vein infusion. The reduction in D5R expression was accompanied by a markedly increased systolic blood pressure in both subcapsular and intramedullary approaches (subcapsular: mock, 94±2 mm Hg vs. Drd5-siRNA, 116±3; intramedullary: 103±1.5 vs. 109±0.9), but not in the tail vein approach. There was no significant difference in body weight, heart rate and 24-hr urine Na+/K+. Our novel alternative techniques offer an economical, efficient, and kidney-restricted targeted gene silencing.
Abstract 527: Natriuretic Effect Mediated by the Renal Medullary α7 Nicotinic Acetylcholine Receptor
Authors: Wang Weili , Han Wei-Qing , Zhu Qing , Damaj Imad , Li Pin-Lan , Li Ningjun
Published: July 2021

Although there are extensive studies on the regulation of renal sodium excretion by adrenergic pathway, the role of cholinergic pathway in the renal sodium excretion is largely unknown. The present study characterized the expression of α7 nicotinic acetylcholine receptor (nAChR) in the kidneys and determined the functional role of this nAChR subtype in urinary sodium excretion in Sprague Dawley rats. RT-PCR and Western blot analyses showed that α7 nAChR was present in the kidneys. Immunohistochemistry analysis demonstrated that the strongest immunostaining of α7 nAChR was observed in the distal tubules and collecting ducts in the kidneys. Infusion of an α7 nAChR agonist PNU-282987 (2.7 μM, 10 μl/min) into the renal medulla dramatically increased the urine volume (from 15.4 ± 2.1 to 42.5 ± 3.9 μl/min/g kwt) and sodium excretion (from 1.26 ± 0.18 to 4.15 ± 0.60 μmole/min/g kwt), which was blocked by an α7 nAChR antagonist methyllycaconitine (MLA, 5 μM, 10 μl/min), in anesthetized rats. Infusion of PNU-282987 did not cause any change in renal medullary blood flow as measured by Laser Doppler flowmeter. In addition, intra-renal medullary infusion of MLA (5 μM, 10 μl/min) significantly inhibited the volume expansion-induced increase of urine volume and sodium excretion by 25%. These data suggest that activation of renal medullary α7 nAChR produces a natriuretic effect through its tubular action in rats. (Supported by NIH grant HL89563 and HL106042)
Abstract 554: Vitamin D in Chronic Kidney Disease is Not Associated with Insulin Resistance
Authors: BARRETO SILVA MARIA INES , VICENTE VANESSA , LEMOS CARLA , KLEIN MARCIA R , BREGMAN RACHEL
Published: July 2021

INTRODUCTION:
Vitamin D deficiency is reported to be associated with Insulin Resistance (IR) in general population. Although the impaired homeostasis of vitamin D and IR are common conditions in chronic kidney disease (CKD), the underlying mechanisms of IR remain unclear and it is not known if vitamin D status is associated with IR in nondialyzed CKD patients.

OBJECTIVE:
To investigate if serum levels of 25 hidroxivitamin D [25(OH)D] are associated with IR in nondialyzed CKD patients.

Methods:
Cross-sectional study conducted in nondialyzed CKD outpatients under regular treatment, clinically stable, age≥18 years, estimated glomerular filtration rate (CKD-EPI) (eGFR)≤ 60 ml/min., not using vitamin D, corticosteroids and immunosuppressive drugs and without malignant diseases. Body adiposity: body mass index (BMI); total body adiposity by dual-energy X-ray absorptiometry-DXA; waist-to-height ratio (WheiR). Vitamin D was determined by analysing 25(OH)D by Passing-Bablok method; insulin by radioimmunoassay; Homeostasis Model Assessment of Insulin Resistance (HOMA-IR).

Results:
Patients included in this study were 158 (men:55%/n=87) nondialyzed CKD patients presenting age=66±13years; eGFR=29±13ml/min.; BMI=26±5kg/m2 (54%/n=86 overweight/obese: BMI>25). Total body adiposity-DXA=34±9% and central body adiposity-WheiR=0.6±0.08. Patients were grouped according to HOMA-IR as: Group 1 (HOMA-IR<2.7; n=110) and Group 2 (HOMA-IR ≥2.7; n=48). VitD levels (ng/ml) were not different (p≥0.05) between Group 1 (27±9) and Group 2 (28±9). Participants were also stratified as: VitD-deficient (<20ng/ml; 25%/n=40) and VitD-no-deficient (≥20 ng/ml; 75%/n=118). VitD-deficient patients compared to VitD-no-deficient presented, respectively, similar values (p≥0.05) of HOMA-IR (median; interquartil interval: 1.7; 1-3 vs. 1.6; 1-3.4), insulin (7; 5-12 vs. 6; 5-13 μU/mL); glucose (105±28 vs. 109±62 mg/dl), glycosylated hemoglobin (GHb=6±1 vs. 6±2 %). No correlation (adjusted for confounders) was observed between VitD with HOMA-IR (r=0.01,p=0.87), insulin (r=0.02,p=0.8), glucose (r=-0.05,p=0.5) and GHb (r=-0.1,p=0.6).

Conclusion:
The present study suggests that serum levels of 25(OH)D are not associated with IR in nondialyzed CKD patients.
Abstract 576: Relaxin Dit Not Improve Outcome In An Established Preeclamptic Transgenic Rodent Rat Model
Authors: Haase Nadine , Golic Michaela , Herse Florian , Przybyl Lukasz , Müller Dominik N , Dechend Ralf
Published: July 2021

Preeclampsia affects 5% of pregnancies in industrialized nations and consists of hypertension and proteinuria and characterized by maternal endothelial dysfunction and excessive vascular inflammation starting after 20 weeks of gestation. It represents a major cause for fetal and maternal morbidity and mortality and is an established risk factor for subsequent cardiovascular disease.

Relaxin is a peptide hormone secreted by the corpus luteum, circulating in maternal blood during pregnancy. Its administration leads to rapid and sustained vasodilation. We hypothesized that relaxin ameliorates symptoms of preeclampsia in an established rat model. We used rats transgenic for the human angiotensinogen (hAogen) gene and the human rennin (hRen) gene and crossed the strains to produce a model of preeclampsia in the dams. On gestational day 9, hAogen TGR dams (PE rat) were randomly assigned to 2 experimental groups: vehicle (20 mM sodium acetate, pH 5.0,) or relaxin, at a dose of 2 μg/h of relaxin by subcutaneous osmotic minipump (Alzet, Typ 2002) until day 21 of gestation. Mean blood pressure was continuously recorded by radiotelemetry and 24 hour urine samples were collected in metabolic cages at day 18 of gestation. Rats were killed at day 21 of gestation. The fetuses and organs were removed and weighed.

Vehicle treated PE rats developed hypertension abruptly at gestational day 13 and had sustained hypertension. Relaxin treatment did not prevent the increase in blood pressure in the last third of pregnancy (MAP on day 16 of gestation: 151.1 ± 2.2 mmHg vehicle vs. 156.6 ± 1.3 mmHg relaxin). Proteinuria was not ameliorated by relaxin (14.6 ± 5.5 mg/d vehicle vs. 20.8 ± 3.8 mg/d relaxin treated group). The number of live fetuses was similar between the groups. In addition, reduced fetal and uteroplacental unit weights were unaffected by relaxin treatment. Furthermore, relaxin treatment had no influence on intra uterine growth restriction, measured by brain to liver ratio (0.795 ± 0.021 vehicle vs. 0.795 ± 0.016 relaxin). Our data demonstrate that relaxin did not ameliorate hypertension, proteinuria or IUGR in a transgenic rat model for preeclampsia.