bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 103: Soluble (Pro)Renin Receptor Targets Renal V2 Vasopressin Receptor to Enhance Urine Concentrating Capability
Authors: Wang Fei , Ramkumar Nirupama , Peng Kexin , Lu Xiaohan , Zhao Long , Kohan Donald E , Yang Tianxin
Published: June 2021

The extracellular domain of (pro)renin receptor (PRR) is cleaved to produce a 28 kDa soluble receptor (sPRR) which is detected in biological fluid and elevated under certain pathological conditions. Our recent work suggests that sPRR derived from collecting duct intercalated cells acts in a paracrine fashion to regulate water transport in the principal cells. The present study attempted to further define the role of sPRR in vasopressin (AVP) signaling with emphasis on V2R regulation. In primary rat IMCD cells, treatment with a recombinant sPRR termed as sPRR-His at 10 nM for 12 h induced a 2.8 -fold increase in V2R protein and a 2-fold increase in V2R mRNA. Following AVP treatment, V2R protein expression was increased by 3-fold, which was blunted by a PRR antagonist (PRO20) and a PRR neutralizing antibody. Mice with CD-specific (CD PRR KO) developed a medium level of diabetes insipidus (urine volume: KO: 2.2±0.4 versus Floxed: 1.2±0.3 ml/day;
P
<0.05), accompanied with a 60% reduction of renal V2R protein and a 25% reduction of urinary sPRR excretion. Adminstration of sPRR-His at for 3 d almost completely rescued the polyuria phenotype of CD PRR KO mice (urine volume: KO+sPRR-His: 1.6±0.3 vs. KO: 2.4±0.5 ml/day,
p
<0.05) associated with restoration of renal V2R protein and AQP2 protein abundances. Interestingly, nephron-specific PRR KO (Neph PRR KO) exhibited more robust polyuria (urine volume: KO: 7.3±1.1 vs. Floxed: 1.2±0.5 ml/day,
p
<0.01) associated with suppressed renal expression of AQP2, NKCC2, and V2R. Administration of sPRR-His to Neph PRR KO mice partially attenuated polyuria (urine volume: KO+sPRR-His: 4.1±1.2 vs. KO: 7.3±1.1 ml/day,
p
<0.01) accompanied by restored renal expression of V2R and AQP2, as well as AVP sensitivity. In contrast, the downregulation of NKCC2 expression in the null mice was unaffected by sPRR-His infusion nor was the upregulation of autophagosome marker microtubule-associated protein 1A/1B-light chain 3 (LC3b). Together, our data suggests that sPRR selectively targets the CD to determine V2R expression and hence AVP sensitivity and urine concentrating capability, independently of autophagosome accumulation.
Abstract 104: Dynamic Autoregulation of Glomerular Capillary Pressure
Authors: Thomson Scott C
Published: June 2021

It is generally accepted that renal blood flow (RBF) autoregulation is mediated by myogenic and tubuloglomerular feedback responses acting on the pre-glomerular resistance. If this is so, then autoregulation of RBF and glomerular capillary pressure (PGC) should change in the same direction throughout an autoregulatory step response. We computed autoregulatory step responses from time series recordings of arterial blood pressure (BP) and RBF (Transonics) blood flow or tubular stop-flow pressure (micropuncture), which is a surrogate for PGC in Wistar-Froemter rats fed for one week on low or high salt diets (n=6-10 ). Autoregulatory step responses were generated from time series by an algorithm that treats BP as a leading indicator of RBF or PGC and uses the projection theorem to solve for the impulse response which is integrated to obtain the step response. Step responses shown in the figure represent the uncompensated changes in RBF and PGC (mean + SEM) following a 1 mmHg BP step. The data clearly reveal that the time courses of RBF and PGC differ such that changes in RBF cannot predict changes in PGC. This implies that the renal hemodynamic response to a blood pressure disturbance is not confined to the pre-glomerular resistance. Furthermore, the participation of post-glomerular resistance in the autoregulatory response is sensitive to dietary salt such that PGC is more sensitive to BP on low salt diet.
Abstract 108: Relative Contributions of Arterial Stiffness and Hypertension to CVD Risk: The Framingham Heart Study
Authors: Niiranen Teemu J , Kalesan Bindu , Hamburg Naomi M , Benjamin Emelia J , Mitchell Gary F , Vasan Ramachandran S
Published: June 2021

Introduction:
The presence and implications of abnormal arterial stiffness, a potential independent predictor of outcomes, in community-dwelling treated hypertensives is unknown. Furthermore, limited data exist regarding the risk of cardiovascular disease (CVD) associated with arterial stiffness across the entire range of blood pressure.

Methods:
We measured carotid-femoral pulse wave velocity (PWV) and classical CVD risk factors in participants of The Framingham Offspring Cohort. The participants were divided into 4 groups according to hypertension (yes/no), and PWV status (high/low based on age- and sex-specific median values) and followed up for CVD events (CVD death, myocardial infarction, unstable angina, heart failure, and stroke).

Results:
We studied 2127 community-dwelling individuals (60 years, 57% women). 60% (233 of 390) of controlled and 90% (232 of 258) of uncontrolled treated hypertensives had high PWV. The multivariable-adjusted risk for CVD events (
n
=248, median follow-up 12.6 years; Figure) rose from normotension with low PWV (reference) to normotension with high PWV (hazard ratio [HR] 1.33, 95% confidence interval [95% CI] 0.86-2.05) and from hypertension with low PWV (HR 1.53, 95% CI 1.00-2.34) to hypertension with high PWV (HR 2.31, 95% CI 1.58-3.36).

Conclusions:
A substantial proportion of treated hypertensives have high arterial stiffness, a finding that may explain some of the notable residual CVD risk associated in this group. High PWV is associated with a trend towards increasing CVD risk in both non-hypertensives and hypertensives supporting the use of arterial stiffness measurements in both populations.
Abstract 111: Xanthine Oxidoreductase Plays a Key Role in Nitrate, Nitrite and Nitric Oxide Homeostasis When the Endothelial Nitric Oxide Synthase is Compromised
Authors: Peleli Maria , Zollbrecht Christa , Montenegro Marcelo , Hezel Michael , Weitzberg Eddie , Lundberg Jon O , Carlström Mattias
Published: June 2021

Xanthine oxidoreductase (XOR) is generally known as a source of superoxide production, but this enzyme has also been suggested to mediate NO production via reduction of inorganic nitrate (NO
3
-
) and nitrite(NO
2
-
). This pathway for NO generation is of particular importance during certain pathologies, whereas endothelial NO synthase (eNOS) is the primary source of vascular NO generation under normal physiological conditions. The exact interplay between the NOS and XOR-derived NO is not yet fully elucidated. The aim of the present study was to investigate if eNOS deficiency is partly compensated by XOR upregulation and sensitization of the NO
3
-
- NO
2
-
- NO pathway. NO
3
-
and NO
2
-
were similar between naïve eNOS KO and wildtype (wt) mice, but reduced upon chronic treatment with the non-selective NOS inhibitor L-NAME (wt: 25.0±5.2, eNOS KO: 39.2±6.4, L-NAME: 8.2±1.6 μ NO
3
-
-, wt: 0.38±0.07, eNOS KO: 0.42±0.04, L-NAME: 0.12±0.02 μ NO
2
-
). XOR function was upregulated in eNOS KO compared with wt mice [(mRNA: wt 1±0.07, eNOS KO 1.38±0.17), (activity: wt 825±54, eNOS KO 1327±280 CLU/mg/min), (uric acid: wt 32.87±1.53, eNOS KO 43.23±3.54 μ)]. None of these markers of XOR activity was increased in nNOS KO and iNOS KO mice. Following acute dose of NO
3
-
(10 mg/kg bw, i.p.), the increase of plasma NO
2
-
was more pronounced in eNOS KO (+0.51±0.13 μ) compared with wt (+0.22±0.09 μ), and this augmented response in the eNOS KO was abolished by treatment with the highly selective XOR inhibitor febuxostat (FEB). Liver from eNOS KO had higher reducing capacity of NO
2
-
to NO compared with wt, and this effect was attenuated by FEB (Δppb of NO: wt +8.7±4.2, eNOS KO +44.2±15.0, wt+FEB +22.2±9.6, eNOS KO+FEB +26.8±10.2). Treatment with FEB increased blood pressure in eNOS KO (ΔMAP:+10.2±5.6 mmHg), but had no effect in wt (ΔMAP:-0.6±3.3 mmHg). Supplementation with NO
3
-
(10 mM, drinking water) reduced blood pressure in eNOS KO (ΔMAP: -6.3±2.2 mmHg), and this effect was abolished by FEB (ΔMAP: +1.1±1.9 mmHg). In conclusion, upregulated and altered XOR function in conditions with eNOS deficiency can facilitate the NO
3
-
- NO
2
-
- NO pathway and hence play a significant role in vascular NO homeostasis.
Abstract 121: Afferent Renal Nerve Chemo- and Mechanosensitive Responses and the Modulation of Sodium Homeostasis and Blood Pressure
Authors: Frame Alissa A , Carmichael Casey Y , Walsh Kathryn R , Wainford Richard D
Published: June 2021

Aim:
We hypothesize that challenges to sodium homeostasis differentially activate chemo- vs. mechanosensitive afferent renal nerves to evoke sympathoinhibition, sodium homeostasis and normotension in the Sprague-Dawley (SD) rat.

Methods:
Conscious SD rats, post sham (S) or afferent renal nerve ablation (Renal-CAP; capsaicin 33 mM) underwent IV volume expansion (VE; 5% BW) or IV sodium loading (1M NaCl Infusion – constant infusion volume) and HR, MAP, natriuresis and PVN neuronal activation (c-Fos expression) were assessed (N=4/gp). Naïve SD rats were fed a 0.6% (NS) or 4% NaCl (HS) diet for 21 days and afferent renal nerve activity was assessed as norepinephrine (NE) (1250 pmol) and NaCl-evoked (450mM) substance P (SP) release in a renal pelvic assay (N=4/gp). Radiotelemetered SD rats post S or Renal-CAP immediately prior a 0.6% (NS) or 4% NaCl (HS) diet underwent continuous MAP monitoring. On day-21 plasma and renal NE content was assessed (N=5/group).

Results:
Renal-CAP attenuated the natriuretic and PVN parvocellular responses to IV VE (peak UNaV [μeq/min]; S 43±4 vs Renal-CAP 26±6, P<0.05, PVN Medial Parvocellular neuronal activation [c-fos positive cells]; S 49±6 vs Renal-CAP 22±5 P<0.05) and evoked increased MAP (MAP 90min post-VE [mmHg] S 118±3 vs Renal-CAP 132±4, P<0.05). In contrast Renal-CAP did not alter the natriuresis to IV 1M NaCl (UNaV [μeq/min]; S 21±4 vs Renal-CAP 21±3) or increase MAP. In naïve SD rats HS-intake did not alter MAP and suppressed plasma and renal NE (P<0.05). HS intake increased NE, but not NaCl, mediated afferent renal nerve activity (NE-evoked peak ΔSP [ng/ml); NS 14±2, HS 22±3, P<0.05, NaCl-evoked peak ΔSP [ng/ml]; NS 17±3, HS 16±2). Renal-CAP immediately prior to a HS-intake persistently increased MAP (Day 21 MAP [mmHg] S HS 106±4, Renal-CAP HS 123±5, P<0.05) and attenuated HS-evoked global and renal sympathoinhibition (P<0.05).

Conclusion:
The mechanosensitive afferent renal nerves mediate acute natriuresis and blood pressure regulation via activation of PVN sympathoinhibitory neurons. During HS intake the afferent renal nerves counter the development of salt-sensitive hypertension via a mechanism involving increased mechano but not chemosensitive afferent nerve responsiveness to potentiate sympathoinhibition.
Abstract 134: Association Between Kidney Size, Function and Blood Pressure in Young Adults Born Extremely Preterm
Authors: Paquette Katryn , LUU Thuy Mai , Cloutier Anik , Lukaszewski Marie-Amélie , Bertagnolli Mariane , El-Jalbout Ramy , Lapeyraque Anne-Laure , Nuyt Anne-Monique
Published: June 2021

Background:
Children born extremely preterm (EPT; ≤29 weeks) have higher blood pressure (BP), lower nephron mass, and increased risk in later life of renal and cardiovascular dysfunction. Whether nephron mass and renal function impact BP in EPT subjects is unknown. We correlated BP with renal size and function in young adults born EPT vs term (T).

Methods:
Anthropometric measurements, serum and urine chemistry, renal ultrasound, and 24 hour ambulatory BP were obtained in 40 EPT and 40 T born young adults matched for age, sex, race, and socioeconomic status. Comparisons were made using paired T and Wilcoxon signed ranked tests and correlations using Pearson correlation.

Results:
Study population characteristics are in Table 1. Young adults born EPT had higher systolic BP (SBP) and diastolic BP (DBP), and smaller kidneys (Table 2). Awake SBP and DBP loads in the hypertensive range inversely correlated with kidney size only in EPT participants.

Conclusion:
Young adults born EPT have higher BP and smaller kidneys vs T controls. EPT young adults with smaller kidneys have a greater BP load in the hypertensive range.
Abstract P110: Low Dose Minocycline Lowers BP and Improves Inflammatory Status in Patients with Treatment Resistant Hypertension
Authors: Qi YanFei , Kim Seungbum , Leach Dana D , Long Sarah J , Handberg Eileen M , Rodriguez Vermali , Mandloi Avinash , Raizada Mohan K , Pepine Carl J
Published: June 2021

Background:
About 15% of hypertensive patients have treatment resistant hypertension (TRH), which substantially increases mortality risk. Based on our previous studies and evidence from literature, we have proposed that systemic and neuro-inflammation is crucial in development and establishment of TRH. This study was to test the hypothesis that minocycline (Mino), an anti-inflammatory antibiotic, would lower BP and inflammatory markers in patient with TRH. Selection of Mino was based on our preliminary studies showing that Mino can inhibit systemic inflammation and penetrate the blood brain barrier to attenuate neuroinflammation in addition to its antibiotic effects.

Methods:
A total of 29 subjects was recruited for this study. Exclusion and inclusion criteria are described at Clinicaltrials.gov (NCT02133872). Office and ambulatory BP measurements (ABPM) were used to confirm TRH diagnosis and subsequently measured 30d and 60 d after Mino administration (50mg/d). If BP failed to decline after 60 d Mino treatment (50mg/d), Mino was increased to 100mg/d and patients were monitored at 60 d. Circulating high-sensitivity C-reactive protein (hs-CRP), high-mobility group box 1 (HMGB1), and Th17 levels were measured.

Results:
Average BP of TRH patients was 149.5/78.5mmHg, 67% responded to 50mg/d Mino and 33% to 100mg/d. ABPM 24h average BP for all m-TRH was <136/69mmHg 60 d after Mino, and ABPM showed systolic and diastolic BP were significantly reduced by 14.5/10.5 mmHg. Plasma HMGB1 levels were 8- and 5-fold higher in TRH than normotensive (N) and controlled hypertensive (CH) patients, respectively (TRH: 45.2±25.10 vs N: 5.5±3.8 and CH: 8.9±10.2, ng/ml, p<0.05). Mino reduced HMGB1 level in TRH (m-TRH 3.0±0.7, ng/ml p<0.05). Furthermore, there were 3-4-fold increases in Th17 cells and 67% increase in hs-CRP levels in TRH patients compared to N and CH. Mino treatment resulted in significant reduction in these parameters and did not change BMI in TRH patients.

Conclusions:
This study demonstrates that a low dose Mino has a significant antihypertensive effect and lowers inflammatory markers in TRH patients. Thus, Mino could be considered a promising therapeutic option for TRH patients.
Abstract P114: Cardiac and Renal Adrenergic Receptor Expression in Spontaneously Hypertensive Caribbean Vervets
Authors: Rhoads Megan K , Osborn Jeffrey L
Published: June 2021

Sympathetic nerve activity and adrenergic receptor stimulation causes development and maintenance of hypertension in patients and experimental animal models. The Caribbean vervet (
Chlorocebus aethiops sabaeus
), an Old World non-human primate, is a translational model of human cardiovascular disease due to its recent divergence, genetic similarity, upright posture, complex social structure, and diurnal behavior. Outbred and randomly selected adult Caribbean vervets exhibit systolic blood pressures (SBP) >140 mmHg in 36% of our cohort (124 of 345 individuals). We hypothesized that gene expression of adrenergic receptor subtypes in renal and cardiac tissue would be elevated in HT Caribbean vervets, and may contribute to spontaneous hypertension. Gene expression was measured using qRT-PCR and RQs compared using the Mann-Whitney U Test. HT animals (n=18, SBP: 168.24±7.25mmHg) had increased expression of both α- and β-adrenergic receptor subtypes in renal outer medulla (a
1a
: NT RQ 1 ± 0.43 vs. HT RQ 2.26 ± 0.50, p<0.05; a
1d
: NT RQ 1 ± 0.34 vs. HT RQ 2.25 ± 0.32, p<0.05; a
2a
:

NT RQ 1 ± 0.24 vs. HT RQ 1.92 ± 0.19, p<0.05; a
2c
: NT RQ 1 ± 0.15 vs HT RQ 1.65 ± 0.15, p<0.05: β
1
: NT RQ 1 ± 0.24 vs. HT RQ 1.88 ± 0.18, p<0.05; and β
2
: NT RQ 1 ± 0.21 vs. HT RQ 1.87 ± 0.24, p<0.05) compared to NT animals (n=18, SBP: 96.61±3.2 mmHg). All α- and β
1
-adrenergic receptor expression in renal cortex and inner medulla was similar between the two groups. Inner medullary β
2
adrenergic receptor expression was elevated in HT animals (NT RQ 1 ± 0.25 vs HT RQ 1.62 ± 0.10, p<0.05). In the heart, β
1
adrenergic receptor expression was upregulated in the left ventricular myocardium of HT animals (NT RQ 1 ± 0.16 vs HT RQ 1.88 ± 0.35). Together, these data suggest that the HT Caribbean vervet may exhibit an exaggerated response to sympathetic nerve activity due to increased adrenergic receptor expression in the kidney and heart, which could contribute to the spontaneous hypertension observed in this translational large animal model.
Abstract P124: “Beyond Silos” Model of Homecare Improves Blood Pressure Control in Multimorbid Hypertensive Patients
Authors: Pascale Antonietta Valeria , Finelli Rosa , Giannotti Rocco , Visco Valeria , Matula Ida , Vairo Giuseppe , Ciccarelli Michele , Coscioni Enrico , Iaccarino Guido
Published: June 2021

Introduction:
Less than 40% of hypertensive on antihypertensive treatment have pressure <140/90 mmHg. Among the most common causes is poor adherence to therapy, in particular in multimorbid, polytreated patients. ICT based new models of care like Smartcare or Beyond Silos (www.beyondsilos.eu) that offer patient-centered home care including telemonitoring, represent a new tool to strengthen the doctor-patient interaction, and improve compliance of chronic patients.

Methods:
To verify the impact of home care strategy to improve pressure control, from February 1 to March 31 2016 we selected patients who accessed the Outpatient Clinic for Hypertension at the AOU San Giovanni e Ruggi in Salerno, those with 1) poor BP control >140 and/or DBP>90 mmHg) after at least three follow-up visits in the last year, 2) optimal drug therapy, 3) poor adherence to therapy, 4) at least one concurrently treated chronic condition. Patients who signed informed consent received “Beyond Silos” home care program, including a weekly nurse access, for four weeks, and telemonitoring through 3G-connected devices of systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR) and body weight measuring and Oxygen Saturation. Each patient was instructed to scheduled self-assesment of the above parameters that were stored on the Local Health Authority server of Salerno. Treatment compliance was verified weekly by the nurse through drug blister count. After 4 weeks, patients were evaluated at the hospital premises.

Results:
We selected seven patients (M/F=5/2; age 73.4 ± 2.3 years). In this population BP control that went from ambulatory SBP/DBP 155±5/74±4mmHg to 111±1.7/95.9±2.7mmHg,
p
<0.001). Adherence scores assessed at the home of the patients also were improved. No changes were observed in HR, weight and oxygen saturation.

Conclusion:
Our data show that patients with a hitory of loose BP control despite optimal therapy can achieve controlled BP through Beyond Silos home care program within a month. This suggest that strategies of ICT based home care might represent a real breackthrough in the management of chronic conditions, in particular for multimorbid, poor compliant patients. Future large scale studies are needed for assessing long term effects on cardiovascular outcome.
Abstract P127: EET-mediated Recruitment of PGC-1α, Restores Mitochondrial Function, LV Function, and Ameliorates Development of Cardiovascular Disease in Db Mice That is Reversed by Lentiviral- PGC-1α (Sh)
Authors: Bellner Lars , Cao Jian , Joseph Gregory , Schragenheim Joseph , Singh Shailendra P , Kappas Attallah , Abraham Nader
Published: June 2021

Background:
Obesity and diabetes are independently associated with the development of cardiac events that occur in db mice that are linked to a decrease in heme oxygenase-1 (HO-1) and epoxyeicosatrienoics (EETs). An increase in HO-1 and EET levels is associated with a decrease of ROS, adiposity and increased mitochondrial function in several animal models. The roles and inter-relationship of HO-1, EET, and PGC-1α in cardiomyopathy pathogenesis has not been investigated.

Methods:
Obese (db) mice 5 wks of age were allowed to acclimate for 17 wks, and then divided into 3 groups. A) Control, B) EET-A in drinking water, and C) EET-A and lentiviral (Ln) PGC-1α Sh, which decreased PGC1α by 40-60 %. Echocardiography was performed at 5 and 34 wks, serum and heart tissue were harvested to measure signaling and mitochondrial fusion proteins.

Results:
Group A) developed hyperglycemia, insulin resistance, and LV dysfunction. These changes were associated with decreases in PGC-1α, HO-1, MnSOD, and mitochondrial fusion associated proteins; Mfn 1/2 and OPA-1: Group B), received EET-A, and displayed normal levels of glucose, adipose adiponectin (p<0.05), insulin sensitivity, and increased levels of HO-1, PGC1α (p<0.02), insulin receptor phosphorylation (p<0.05), and Mfn 1/2 and OPA1 (p<0.001) when compared to normal levels of young (5 wks) db mice, before the development of cardiomyopathy: and group C) inhibition of PGC1α by Ln-PGC1- (Sh) prevented EET from restoring LV function and fractional shortening (p<0.05) EET-A- Ln-PGC1α (Sh) animals display a worsening of intrinsic myocardial contraction compared to db control. This is likely related to a decrease in the cardiac mitochondrial network. The latter was reciprocally correlated to HO-1-PGC1α levels that diminished as obesity/diabetes progressed.

Conclusion:
An EET-A agonist ameliorates adiposity, BP elevation, mitochondrial function and cardiomyopathy as a result of increased levels of PGC1α and HO-1-expression. Suppression of PGC1α by Ln PGC1α (Sh) worsened insulin resistance suggesting targeting mitochondrial fusion/fission may be a promising therapy for diabetes and heart disease.
Abstract P137: Mir-122 is Associated With Stress-response Protein, Hemeoxygenase-1, for Regulation of Extracellular Matrix Remodeling in Renal Hypertension
Authors: Das Purkayastha Biswa P , Ren Lu , Pushpakumar Sathnur , Sen Utpal
Published: June 2021

Oxidative stress is a major contributing factor in hypertension-induced kidney injury. Hemeoxygenase-1 (Ho-1) is stress response protein constitutively expressed by the proximal tubular epithelial cells in response to oxidative stress. MicroRNAs are single stranded RNA involved in the regulation of gene expression. MicroRNA-122 has been shown to regulate Ho-1 expression in hepatitis; however whether miR-122 regulates Ho-1 in hypertensive kidney is not known. The purpose of the study was to investigate the miRNA-122 Ho-1 regulation and determine its role in extracellular matrix remodeling in renal hypertension.
In vitro
experiments were done using mesangial cells, treated with/without 200 μM of Angiotensin-II (Ang-II). Ho-1 was induced by ~3.5 folds with Ang-II treatment. miR-122, Ho-1 regulator, was downregulated by >15 times in Ang-II treated cells.
In vivo
experiments were performed on WT (C57BL6/J) mice aged 12-14 wk and 75-78 wk. The animals were treated with Ang-II (1000ng/kg/min) for 4 weeks.
Ho-1
is ~6 folds less in kidney of aged mice as compared to that in the young mice. Hypertension increases miR-122 expression to a greater extent (~5 folds) in aged animals. In
Ho-1
knocked down mesangial cells, the extracellular matrix component, Collagen 1A1 (Col1a1), was increased by ~2 folds. In contrast, vascular endothelial growth factor (
Vegf
) and hypoxia-inducible factor (
Hif1
α
) were downregulated in
Ho-1
depleted cells. In conclusion, micro RNA, miR-122, transcriptionally regulates
Ho-1
as a repressor in kidney and thus affects Ho-1 mediated regulation of the extracellular remodeling in hypertension-induced renal damage.
Abstract P141: GYY4137, a H
2
S Donor, Normalizes miR-132 Targeted Sirt1 and Ace2 Expression to Improve Kidney Function in Hypertension
Authors: Weber Gregory , Pushpakumar Sathnur , Sen Utpal
Published: June 2021

MicroRNAs regulate several physiological processes and are implicated in various pathologies, including hypertension. Previous work indicates miR-132 targets Sirtuin 1 (Sirt1), a histone deacetylase and regulator of epigenetic gene silencing in various cellular processes. Sirt1 is expressed in the kidney; however, its role in hypertensive kidney and whether it is regulated by physiological gaseous molecules, such as hydrogen sulfide (H
2
S), is not known. In this study, we sought to determine the role of miR-132 in regulating Sirt1, Ace2 and At1 in hypertensive kidney and whether H
2
S donor, GYY4137 (GYY), could reverse these effects and mitigates renal dysfunction. Wild-type mice were treated without or with Ang-II (1000 ng/Kg/Min) and GYY (133 μM) for 4 weeks. Quantitative PCR, Western blot, and immunofluorescence assays were performed. Increased expression levels of miR-132 in hypertensive mice (3.79 fold vs control) were reduced in mice receiving GYY treatment (2.43 fold vs control).
Sirt1
expression was reduced (-1.15 fold) in Ang-II mice but was upregulated in GYY (1.25 fold) and Ang-II+GYY (1.9 fold) groups. A similar effect was seen with Sirt1 protein where the expression was increased in animals treated with GYY and Ang-II+GYY (1.16, 1.03 respectively) compared to Ang-II (0.47). Ace2 in Ang-II+GYY (0.45) was increased compared to Ang-II (0.17), while At1 was reduced (0.46) compared to Ang-II (0.86). Immunofluorescence showed decreased signal of Sirt1 in the glomerulus in Ang-II mice and increased At1 in the blood vessels surrounding the glomerulus, leading to constriction of renal artery, decreased blood flow, and kidney dysfunction. These effects were alleviated in mice treated with GYY. Our data suggests that upregulation of miR-132 in hypertensive kidney decreases Sirt1 and Ace2 expression, leading to increased Ang-II signaling through the At1 receptor and GYY supplementation reverses these expression patterns, leading to increased blood flow and kidney function.
Abstract P149: Bilateral Renal Denervation Attenuates Hypertension in Male Rats Deficient of Functional Endothelin B Receptors but Does Not Affect Salt-Sensitivity
Authors: Becker Bryan K , Feagans Amanda C , Jin Chunhua , Pollock David M
Published: June 2021

Independent studies of renal sympathetic nerves and the endothelin (ET) system have demonstrated important contributions of each in the progression of hypertension. Very few studies, however, have investigated the interaction between the ET system and renal nerves in relation to blood pressure control and electrolyte homeostasis. Although endothelin B (ETB) receptors in the renal medulla promote natriuresis, ETB receptors on sympathetic neurons are thought to increase neuronal activity. We hypothesized that renal denervation reduces blood pressure in a salt-sensitive, hypertensive model of ET dysfunction, the ETB-deficient (ETB-def) rat, which lacks functional ETB receptors in all tissues except neurons. After bilateral renal sympathetic denervation (Dnx) or sham operation of ETB-def and transgenic control (TG) rats, baseline blood pressure was recorded via telemetry for 5 days on a normal salt (0.49% NaCl) diet followed by a high salt (4.0%) diet. At baseline, ETB-def Dnx rats had a lower 24-hr systolic blood pressure (SBP) (152.6 ± 3.6 mmHg) relative to ETB-def sham (167.8 ± 2.6 mmHg; p < 0.005; n = 7/group). Denervation did not significantly affect TG rats relative to sham on normal salt (138.8 ± 2.5 vs. 144.7 ± 0.5 mmHg respectively; p = 0.53; n = 6/group). Following 10 days of high salt diet, ETB-def sham rats had an increased 24-hr SBP (+10.59 ± 2.8 mmHg relative to baseline; p < 0.005). There was a similar increase in SBP in ETB-def Dnx rats (+10.03 ± 2.3 mmHg relative to baseline; p < 0.005), although the ETB-def Dnx group remained lower than ETB-def sham. High salt had no effect on TG sham or Dnx animals (-2.2 ± 1.3 and -0.6 ± 2.8 mmHg relative to baseline). Preliminary evidence from a subset of the animals in this experiment indicated a dramatically reduced inner medullary ET-1 content in ETB-def sham rats vs. TG sham (97.9 ± 15.4 vs. 327.0 ± 25.4 ng/mg total protein; p < 0.005; n = 3-4/group) in both ETB-def and TG groups, Dnx tended to increase inner medullary ET-1 content (181.8 ± 75.8 and 402.7 ± 19.6 ng/mg total protein respectively). We conclude that in a model of ET dysfunction, the renal nerves are integral mediators of hypertension during normal salt diet, but do not mediate the increase in pressure following high salt diet in this model of salt-sensitive hypertension.
Abstract P154: Hypertension in Obese African American Women is Not Caused by Increased Sympathetic Activity
Authors: Shibao Cyndya A , Marinos Alejandro , Celedonio Jorge E , Okamoto Luis E , Arnold Amy C , Gamboa Alfredo , Biaggioni Italo
Published: June 2021

African American (AA) women have the highest prevalence of hypertension and obesity in the United States. We tested the hypothesis that sympathetic activity contributes to hypertension in obese AA women, as we previously shown to be the case in Caucasians. We studied 42 obese women (16 whites, body mass index (BMI) 36± 4 kg/m
2
, 44% with diagnosis of hypertension (HTN) and 26 AA, BMI 35± 4 kg/m
2
, 46% HTN). Anti-HTN medications were discontinued for 2 weeks prior to the study day. All subjects underwent complete autonomic blockade with the ganglionic blockade trimethaphan at doses of 4 mg/min. Autonomic blockade was evaluated by the lack of heart rate changes in response to ~25 mm Hg increase in blood pressure produced by a bolus infusion of the alpha 1 adrenergic agonist, phenylephrine and the decrease in norepinephrine levels.

Results:
Plasma norepinephrine significantly decreased during trimethaphan infusion (from baseline 253±1107 to 61±29 pg/ml, trimethaphan). The decrease in mean arterial blood pressure (MAP) produced by trimethaphan was greater in obese HTN compared with normotensive (NTN) Caucasians (-27±10 vs. -15±8 mm Hg, P=0.016). In contrast, no difference in the decrease in MAP induced by trimethaphan was found between HTN and NTN obese AA women (-16±11 vs. -12±10, P=0.451,
figure
). Heart rate increased similarly with trimethaphan between HTN and NTN caucasians (+9.1± 6 vs. 16± 9, P=0.109) and AA women (+22± 7 vs. 21±12 bpm, P=0.760). MAP remained elevated in HTN obese AA women during trimethaphan infusion (84±15 vs. 72±9.8 mm Hg in NTN AA, P=0.021).

Conclusion:
Sympathetic activity does not contribute to hypertension in AA women
Abstract P159: Scavengers of Isolevuglandins as Novel Therapeutic Approaches for Treating Hypertension & Associated Inflammation
Authors: Chen Wei , Xiao Liang , Kirabo Annet , Michell Danielle L , Davies Sean S , Amarnath Venkataraman , Roberts Jackson L , Harrison David
Published: June 2021

Adaptive immunity and especially T lymphocytes play a crucial role in the development of hypertension. Proteins that are oxidatively modified by highly reactive isolevuglandins (isoLGs) accumulate in dendritic cells & lead to subsequent activation of T lymphocytes. This process can be prevented by compounds known to scavenge isoLGs, such as 2-hydroxybenzylamine (2-HOBA). The overall goal of current study is to develop novel antihypertensive drugs based on this isoLG scavenging strategy, that will not only prevent but will also reverse hypertension and its associated inflammatory end-organ damage. Initially, the preventative effects of 10 putative isoLG scavengers were tested. C57Bl/6 mice received angiotensin (Ang) II (490 ng/kg/min) infusion for 14 days. Each compound was administered in the drinking water (1mg/ml) at the onset of Ang II infusion for 7 days to a half of the mice & for entire 14 day period to another half of the animals. Blood pressure was measured by tail cuff method. Among 10 compounds, we found that 2-HOBA, methyl 2HOBA (Me2HOBA) & 3-methoxy2-HOBA (3-Mo2HOBA) were most effective in lowering blood pressure. Interestingly, the pyridoxamine analogs were not effectively lowered blood pressure. We further examined the efficacy of our 3 most effective compounds in reversing established hypertension. Mice received Ang II infusion for 6 weeks and received each study drug (2 mg/ml) during the last 4 weeks. We employed radiotelemetry to monitor blood pressure. Compared with untreated mice, Me2-HOBA, 3-Mo2-HOBA & 2-HOBA were equally effective in lowering blood pressure by 20 mmHg (all p < 0.05 vs no drug). Six weeks of Ang II infusion caused 2- to 4-fold increases in renal T cell (CD3
+
) & monocyte/macrophage (F4/80
+
) infiltration as measured by immunohistochemistry & all three compounds markedly reduced these by 50%. These treatments also reduced aortic fibrosis as measured by Masson’s Trichrome blue staining. We conclude that these isoLG scavengers can be potentially used as new effective therapy for lowering blood pressure & attenuating hypertensive renal & vascular damage. Variability of in vivo effectiveness for the different scavengers likely reflects differences in bioavailability due to structure & lypophilicity.
Abstract P169: Dipeptidyl Peptidase-4 Regulates Hematopoietic Stem Cell Activation in Response to Chronic Stress
Authors: Cheng Xian Wu , Zhu Enbo , Hu Lina , Lei Yanna , Piao Limei , Inoue Aiko , Kuzuya Masafumi
Published: June 2021

Background:
Dipeptidyl peptidase-4 (DPP4) inhibition exhibits multiple pleotrophic effects. Hematopoietic stem cell (HSC) activation has been implicated in the pathogenesis of stress-related metabolic disorder and cardiovascular disease. Given that interaction between β3-adrenergic receptor (Adrβ3) signaling and the immune system may link stress and the initiation and progression of disorders, we investigated whether DPP4 regulates immune over-reactions in a chronic stress mouse model, focusing on HSC activation.

Methods and Results:
Male 8-week-old mice fed a normal diet underwent chronic stress were randomly assigned to one of three groups and administered vehicle or a low or high dose of the DPP4 inhibitor anagliptin. Control mice were left undisturbed. The stress increased the blood and brain DPP4 activity, the levels of plasma adrenaline and noradrenaline, and the bone marrow (BM) niche cell adrenergic receptor (Adrβ3) expression, and it decreased the levels of plasma glucagon-like peptide (GLP-1) as well as brain GLP-1 receptor (GLP-1R) and BM Cxcl12 expressions. These changes were reversed by DPP4 inhibition. The stress activated the BM sca-1
high
c-Kit
high
CD48
low
CD150
high
HSC proliferation, giving rise to high levels of blood leukocytes and monocytes. These DPP4 inhibition-related benefits were mimicked by DPP4 depletion and by GLP-1R activation. Adrβ3 inhibition mitigated BM Cxcl12 expressions and HSC activation.

Conclusions:
DPP4 activity appears to regulate chronic stress-induced BM HSC activation and inflammatory cell production via an Adrβ3-CXCLl12-dependent mechanism that is mediated by the GLP-1-GLP-1R axis, suggesting that the inhibition of DPP4 or the stimulation of GLP-1R may have applications in the treatment of inflammatory diseases.
Abstract P177: Reduced Expression of Regulator of G-Protein Signaling-2 (RGS2) in the Placenta During Preeclampsia
Authors: Perschbacher Katherine J , Santillan Donna A , Devor Eric J , Scroggins Sabrina M , Sandgren Jeremy A , Pierce Gary L , Santillan Mark K , Fisher Rory A , Gibson-Corley Katherine N , Grobe Justin L
Published: June 2021

Preeclampsia (PE) is a serious cardiovascular condition of late pregnancy. Genetic risk factors and the early-gestational etiology remain largely unclear, though evidence supports excessive activation of Gαq signaling within the placenta in response to various hormones including vasopressin, endothelin, and angiotensin. Regulator of G-protein Signaling 2 (RGS2) acts as an endogenous terminator of Gαq signaling, and previous association studies have identified an increased risk for PE and its sequelae in women carrying a single nucleotide polymorphism that is expected to reduce levels of RGS2. We hypothesized that RGS2 is expressed in placental trophoblasts, and that reduced expression of RGS2 in placental tissue may represent a risk factor for the development of PE. Whole placenta samples and clinical data from preeclamptic and clinically-matched control pregnancies were obtained from the University of Iowa Maternal-Fetal Tissue Bank (IRB#200910784) and examined for mRNA levels of the B/R4 family of RGS proteins, including RGS2. Of the members examined (RGS2, -3, -4.2, -4.3, -4.4, -4.5, and -5) in control placentas (n=9), only RGS2 (Ct 28.8±0.7 vs 18S Ct 12.1±0.4) and RGS4.3 (Ct 23.0±0.4 vs 18S Ct 13.3±0.3) transcripts were expressed above background levels. RGS2 protein expression was then confirmed in human placental tissues by Western blot. RGS2 mRNA expression was 3-fold higher in fetal (amniotic, p<0.05) layers than maternal (decidual) layers. In preeclamptic placenta (n=11), RGS2 may be suppressed (1.0±0.4 vs 0.2±0.3-fold, p=0.1) while RGS4.3 remains unchanged (1.0±0.4 vs 1.1±0.4 fold, p=0.8). Initial immunohistochemical detection confirms cytoplasmic localization of RGS2 in trophoblasts of wildtype mouse placenta, despite exclusive nuclear localization in other tissues. We conclude that human placenta expresses RGS2, and that this expression may be suppressed during preeclampsia. Loss of RGS2 expression may result in disinhibited trophoblast Gαq signaling, and ultimately placental insufficiency.
Abstract P180: Quantification of Substance P in Human Blood by Mass Spectroscopy
Authors: Hubers Scott , Wei Shouzuo , Brown Nancy
Published: June 2021

Background:
Substance P (SP), a tachykinin, may contribute to the effects of ACE inhibitors. Measurement of SP has been limited by its short half-life and cross-reactivity with metabolites. Here we quantify SP in human blood using mass spectroscopy (MS).

Methods:
Venous blood was obtained from healthy subjects before and during arterial infusion of SP (2, 4, and 8 pmol/min). Venous blood (3 mL) was immediately added to 9 mL chilled ethanol to denature proteases. After 30 min at 4°C, samples were centrifuged and the supernatant stored at -70°C.
13
C
6
,
15
N
4
SP internal standard was then added to the ethanolic supernatant. Samples were purified with Nexus and C
18
Sep-Pak cartridges. Sample was further resolved by UPLC (40°C) on a C18 column using solvent mixture of 5% acetonitrile/0.1% formic acid at a flow rate 0.14 mL/min to 30% acetonitrile/0.1% formic acid in 7 min with a linear gradient, and quantified by positive ESI-MS/MS on a “Vantage” triple quadrupole MS with SRM.

Results:
The lower limit of detection of SP was 0.1 pg. Linearity was confirmed over a 100-fold concentration range. Precision was measured by analyzing five 2-mL aliquots of pooled ethanolic supernatant from 3 volunteers collected during SP 8 pmol/min. The coefficient of variation was 2.2%. The mean SP concentration was 2.3 pg/mL at baseline and increased with intra-arterial dose (Figure).

Conclusion:
SP can be measured in blood using MS. This assay can be used to study the effects of ACE, DPP4, and neprilysin inhibitors on SP.
Abstract P187: Partial Renal Infarction Induces Hypertension
Authors: Zhang Jie , Wei Jin , Zhang Gensheng , Wang Shaohui , Wang Lei , Buggs Jacentha , Liu Ruisheng
Published: June 2021

Renal infarction is an under-diagnosed and under-reported phenomenon. The U.S. incidence of renal infarction is estimated at 1.4%. Systemically thromboembolic originate from thrombus in the heart or aorta while renal infarction in situ typically involves the main renal artery or its branches. Acute or aggravated hypertension is commonly observed in previously normotensive or hypertensive patients with renal infarction. However, these pathophysiological mechanisms have not been elucidated. The goal of this study was to develop a hypertensive mouse model of renal infarction. Partial renal infarction was performed in C57BL/6 mice by ligating either the upper (LU) or lower (LL) branch of the renal artery in the left kidney while the right kidney remained intact. The mean arterial pressure (MAP) was continuously measured with a telemetry system in conscious mice fed 4 weeks of normal salt diet (NS) (0.4% NaCl) followed by 4 weeks of high salt diet (HS) (4% NaCl). Plasma renin concentration (PRC), renin mRNA in the kidney and TNF-α were measured. Body weight, salt and fluid intakes were similar in mice with LU and LL ligation compared with sham operated mice. The weight of the left kidney decreased by 16.3% in LU (118.1±8.9 mg) and 14.2% in LL (121.5±7.8 mg) compared with sham operated mice (141.0±9.5 mg) (n=6; p<0.05 vs sham). The right kidney weight increased by 41.5% in LU (201.3±15.6 mg) and 38.2% in LL (196.6±8.1 mg) compared with sham mice (142.2±8.8 mg) (n=6; p<0.01 vs sham). MAP in mice fed NS elevated by 25% in LU (119.4±12.9 mmHg) and 19.1% in LL (113.7±10.6 mmHg), compared with sham (95.4±4.7 mmHg) (n=4; p<0.05 vs sham). HS further increased the MAP to 124.2±17.4 mmHg in LU and 118.6±14.8 mmHg in LL mice. PRC decreased by 50.0% in LU (30.7±8.63 ng/ml) and 62.7% in LL (22.9±10.8 ng/ml), compared with sham operated mice (61.4±12.6 ng/ml) (n=6; p<0.05 vs sham). Expression of local renin mRNA in the left kidney was upregulated by 113.4% in LU and 64.1% in LL mice, compared with the sham. Inflammatory cytokines TNF-α was increased by 174.2% in LU and 106.3% in LL mice. In conclusion, we developed a mouse model of partial renal infarction with hypertension in C57BL/6 mice. The mechanism of hypertension may be due to the upregulation of local renin angiotensin system and inflammation.
Abstract P194: A New Role of Sox6 in Blood Pressure Through Renin Regulation
Authors: Gomez Jose A , Hodgkinson Conrad P , Payne Alan , Harrison David G , Dzau Victor J
Published: June 2021

Hypertension afflicts 33% of the U.S. adult population. Despite current treatments, approximately 50% of people are unresponsive to treatment. There is a critical need to develop new therapies to treat this disease and its complications. The Renin Angiotensin Aldosterone System plays a key role in regulating blood pressure in humans. Renin controls the rate-limiting step in the conversion of angiotensinogen to angiotensin I. In adults, renin is produced and stored by Juxtaglomerular (JG) cells in the kidney. However, the transcriptional mechanisms that govern formation of renin expressing cells under normal or pathophysiological conditions remain poorly understood. During blood pressure changes the number of adult renal cells expressing renin increase through a process known as JG cell expansion. We found that this process involves differentiation of mesenchymal stromal-like cells (MSC) to renin expressing cells among others. We aim to determine new regulators of renin expression and blood pressure control. Renin expression
in vitro
was induced by treatment of MSCs with 3-isobutyl-1-methylxanthine (IBMX) and Forskolin. MSCs were transduced with lentivirus carrying vectors Sox6 shRNA or control shRNA. A new transgenic mouse, in which Sox6 is deleted specifically in renin expressing cells (Ren1dCre/Sox6
fl/fl
), was used to study the impact of Sox6 in renin expression
in vivo
. Gene array comparing renal MSC and JG cells identified potential genes that control MSC differentiation, including Sox6.
In vitro
silencing of Sox6 by shRNA decreased differentiation of renal MSCs into renin producing cells (3.5 fold, n=4, P= 0.01). Preliminary IHC data showed that the transcription factor Sox6 is expressed by renin producing cells in the adult kidney during JG cell expansion. Plasma renin concentration (PRC) increased during JG cell expansion (induced with low sodium diet and furosemide) in wild type mice (27-fold), whereas in mice lacking Sox6 in JG cells PRC was as low as non-treated mice. We conclude that Sox6 has a novel role in modulating renin expression and thereby can contribute to renal physiology, opening new possibilities of addressing questions regarding physiological regulation of renin and hypertension.
Abstract P198: Increased Urinary Angiotensinogen Reflects Intrarenal Renin-angiotensin System Activation in High Fat Diet Induced-type 2diabetic Mice
Authors: Reverte Virginia , Castro Musial Diego , Gallaty Michael R , Rosales Carla B , Parra-Vitela Alberto J , Prieto Minolfa C
Published: June 2021

Obesity is a risk factor for diabetes mellitus (DM) and patients with DM are often hypertensive and exhibit inappropriate activation of the intrarenal renin-angiotensin system (RAS), which increases the risk for diabetic nephropathy and progression to chronic kidney disease. Enhanced intrarenal AGT levels contribute to increased intrarenal Angiotensin II levels. To examine the role of an activated RAS in DM, we measured urinary AGT along with albuminuria and other metabolic parameters in high fat diet induced-type 2 DM mice. Immediately after weaning, male C57BL/6J mice (N=18) were fed either a normal fat diet (18 % Kcal from fat; CT mice) or high fat diet (42.0 % Kcal from fat; HF mice) for 24 wk. Body weight (BW), food intake, and systolic blood pressure (SBP) by telemetry, were measured weekly. Glucose tolerance test (GTT) and homeostasis model assessment index of insulin resistance (HOMA-IR) were further assayed. At wks 0, 12, and 24 on dietary regimen, measurements of albuminuria and uAGT by ELISA were used as markers of renal injury and intrarenal RAS activation, respectively. Body weight increased by 140% in HF mice compared to 66 % in CT mice (from 18±0.5 to 44±1.4 g and 17±0.6 to 28±0.6 g, respectively) with no differences in daily energy intake (15.02±1.3 kcal/day and 15.4±0.8 kcal/day). Plasma glucose, area under curve (AUC) of GTT, and HOMA-IR were significantly increased in HF mice (121± 6mg/dL; 32,865±6,222; 5±1) compared to CT mice (220± 27mg/dL; 55,549±4,611; 54±9). In HF mice, SBP was augmented by wk 10 compared to CT mice (126±5 vs. 113±1 mmHg; P<0.05). Interestingly, no differences in albuminuria were found between HF and CT mice either at wk 12(50±13 vs. 40±6 ug/day) or at wk 24 (57±7 vs. 43±3 ug/day). However, uAGT excretion was increased by wk 24 in HF mice but not in CT mice (
wk 0
: 4±1.5 vs. 4±1.5ng/day;
wk 12
: 4.6±2.3 vs. 2.3±0.9 ng/day;
wk 24
: 11.8±2.9 vs. 3.9±0.3 ng/day; P<0.05). During HF diet induced-type 2 DM, the elevation of uAGT reflects the increase of intrarenal RAS which may contribute to the development of renal injury.