bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 480: ACE2 Independent Pathways of Angiotensin 1-7 Formation in the Murine Kidney
Authors: Domenig Oliver , Manzel Arndt , Stegbauer Johannes , Gurley Susan , Antlanger Marlies , Kovarik Johannes , Säemann Marcus , Linker Ralf , Poglitsch Marko
Published: July 2021

Fluid balance, salt retention and tissue remodeling is hormonally regulated by the Renin-Angiotensin-System. The sophisticated enzyme network serially cleaves peptide hormones generating various effector hormones including the vasoconstrictor Angiotensin 1-8 and its counterbalancing downstream metabolite Angiotensin 1-7.

LC-MS/MS based analysis of kidney and plasma of ACE2 knockout mice revealed unchanged Angiotensin 1-7 concentrations compared to wild type animals pointing to alternative pathways of Angiotensin 1-7 formation and suggesting a minor role for ACE2 in the formation of Angiotensin 1-7 in vivo. Moreover, we observed a decrease in the Angiotensin 1-8/Angiotensin 1-10 ratio in ACE2KO-mice indicating a changed conversion rate from Angiotensin 1-10 to Angiotensin 1-8.

We analyzed Angiotensin 1-7 metabolism in kidney homogenates by spiking natural substrates in the absence and presence of specific enzyme inhibitors. The metabolism of ex vivo spiked Angiotensins in kidney homogenates in presence and absence of the Prolyl-Carboxypepdidase (PCP) and Prolyl-Endopeptidase (PEP) Inhibitor ZPP and the ACE2-Inhibitor MLN-4760 revealed stronger contribution of PCP and PEP to Angiotensin 1-7 formation than ACE2.

Analyzing the formation of Angiotensin 1-8 from Angiotensin 1-10 in renal cortex and medulla homogenates of WT and ACE2KO mice in the absence and presence of an ACE-Inhibitor confirmed our observations on endogenous peptide levels and the ratio between Angiotensin 1-8 and Angiotensin 1-10 in plasma, revealing a reduced ACE activity in the renal cortex of ACE2KO.

Our study raises questions concerning the relevance of renal ACE2 for the local formation of Angiotensin 1-7. Moreover, the reduced ACE expression and activity in renal cortex might be a physiologically and therefore phenotype relevant consequence of the knockdown of ACE2 in these mice. The possible crosstalk between ACE and ACE2 expression and activity might give rise to further studies addressing the underlying mechanisms and might be important for our understanding of RAS dynamics in regard to therapeutic interventions.
Abstract 500: The Cardiorenal Effects Of An Angiotensin Receptor Blocker (Valsartan) And Neprilysin Inhibitor (AHU377) Co-administered Daily For 6 Weeks In The Dahl Salt-sensitive Rat Model Of Volume-dependent Hypertension
Authors: McNamara Alexander J , Hegde Laxminarayan G , Klein Uwe , Hill Craig , Yu Cecile , Araki Russell , Liu Henry , Hegde Sharath S , Martin William J
Published: July 2021

The endogenous natriuretic peptide system helps maintain cardiovascular homeostasis by counterbalancing the deleterious effects of renin angiotensin system activation. This study examined whether the co-administration of an ARB (valsartan: VAL) with a NEPi (AHU377: AHU) can reduce cardiorenal disease progression in the Dahl salt-sensitive (Dahl/SS) rat model of volume-dependent hypertension.

Methods:
Studies were conducted in conscious Dahl/SS hypertensive rats that were maintained on a high salt diet and surgically implanted with telemetry transmitters for monitoring blood pressure. Rats were treated for 6 weeks with either vehicle, VAL (30 mg/kg, PO) or VAL+AHU (30 + 30 mg/kg, PO). Changes in cardiac and renal functions were measured via Left Ventricle (LV) pressure-volume loops and biomarkers (KIM-1, NGAL and osteopontin).

Results:
Dahl/SS rats maintained on a high salt diet exhibited a progressive decrease in body weight gain, progressive increases in blood pressure and elevation of plasma and urinary biomarkers indicative of cardiac stress or renal injury. VAL and VAL+AHU both improved body weight gain and blunted the progressive hypertension. However, the magnitude of the antihypertensive effect was greater for VAL+AHU (peak change: - 33 ± 3 mmHg) than for VAL alone (peak change: -15 ± 5 mmHg). VAL+AHU treatment provided greater renal protective effects, based on renal biomarkers KIM-1 (286 ± 29 vs. 341 ± 59 ng), NGAL (58 ±9 vs. 108 ± 28 μg) and osteopontin (1637 ± 372 vs 2155 ± 748 ng), than VAL alone. The VAL+AHU treatment group demonstrated a greater normalization in LV function, with improved systolic contractility over VAL alone (preload-adjusted PWR
max
= 1 ± 0.1 vs. 2 ± 0.5 μWatt/uL). Most notably, the VAL+AHU group exhibited a greater survival rate (94%: 15 of 16) than either the VAL (75%: 12 of 16) or vehicle (70%: 14 of 20) groups.

Conclusion:
In summary, chronic co-administration of an ARB and NEPi to Dahl/SS rats significantly attenuated progression of hypertension, suppressed increases in biomarkers indicative of renal injury,

improved cardiac function and increased overall survival. These results suggest that co-administration of an ARB and NEPi may confer a beneficial therapeutic strategy for the treatment of cardiorenal disease.
Abstract 514: Jak2 Tyrosine Kinase Mediates Angiotensin II Renal Pathogenesis via its Pressor Dependent Actions
Authors: Sayeski Peter P , Park Sung O , Kirabo Annet , Baskin Rebekah , Seth Dale M , Navar L. G , Fogo Agnes B , Baylis Chris
Published: July 2021

We previously found that Jak2 kinase, expressed within vascular smooth muscle cells (VSMC), plays a critical role in angiotensin II (Ang II)-mediated hypertension. Given that Jak2 mediates both pressor-dependent and pressor-independent events, we sought to determine the role of blood pressure (BP), per se, on the deleterious effects of Jak2 within the kidney. To investigate this, three groups of mice were examined; i) wild type mice (Controls) that received Ang II infusion, ii) mice lacking Jak2 expression within the VSMC (VSMC Jak2 Null) that also received Ang II, and iii) Control mice that received Ang II plus an anti-hypertensive triple therapy (3Rx). After baseline BP recordings, Ang II was infused (1000 ng/kg/min, SC) to all groups and the 3Rx regimen (80 mg/L hydralazine, 5 mg/L reserpine, 30 mg/L hydrochlorothiazide in the drinking water) was initiated two days later to the 3Rx group, in order to maintain BP at similar levels to the VSMC Jak2 Null group. After 28 days of Ang II, mice were euthanized and the kidneys were assessed via histological, molecular, and functional approaches. Chronic Ang II infusion significantly increased the levels of intrarenal Ang II in all three groups; Control = 1,262±283 fmol/g, VSMC Jak2 Null = 1,655±666 fmol/g, and 3Rx = 2,174±588. While Ang II infusion significantly increased the mean BP in the Control group (152 ± 2 mm Hg), it was significantly, and similarly, lower in both the VSMC Jak2 Null and 3Rx groups (125 ± 5 mm Hg and 131 ± 5 mm Hg, respectively). Glomerular sclerosis was absent and interstitial fibrosis ranged from absent- mild- moderate, and was similar in all groups. The increases in i) perivascular infiltration of CD3+ lymphocytes, ii) CTGF gene expression, iii) tubule casts and iv) albuminuria that were observed in the Control mice, were significantly reduced in both the VSMC Jak2 Null and 3Rx groups. [CTGF mRNA Levels: Control = 100%±17, VSMC Jak2 Null = 70%±12*, 3Rx= 56%±17*. Urine Albumin (ng/day): Control = 414 ± 262, VSMC Jak2 Null = 138 ± 172*, 3Rx= 101 ± 89* (*, p<0.05 vs. Control)]. Thus, the early renal injury due to chronic Ang II infusion correlates with increased BP and not with the expression of VSMC-derived Jak2, suggesting that Jak2 contributes to early Ang II-mediated renal injury via its pressor-dependent actions.
Abstract 538: Overexpression of the Catalytic Subunit of Telomerase Protects Against Ang II Induced Vascular Dysfunction
Authors: Hockenberry Joe , Gutterman David D , Beyer Andreas M
Published: July 2021

Rational:
Angiotensin II (A II) produces endothelial dysfunction by elevating vascular reactive oxygen species (ROS) production from mitochondria. Telomerase, prominent in cellular senescence and tissue aging, reduces mitochondrial ROS production. Conversely, loss of the catalytic subunit of telomerase (TERT-/-) causes hypertension and reduced NO bioavailability. We have shown previously that decreased TERT abrogates NO mediated dilation and increases mtROS levels.

We hypothesized that overexpression of TERT attenuates A II induced endothelial dysfunction by suppressing ROS production, while loss of TERT predisposes to A II induced endothelial dysfunction.

Results:
Mouse mesenteric arterioles (~250 μm) from hTERT transgenic, TERT-/- and control mice were infused with A II (via osmotic mini pump, 2 weeks) were used. Flow-mediated dilation (FMD) to graded degrees of shear was measured in vessels constricted with norepinephrine.

A II (400ng/kg/min) reduced FMD in TERT-/- but not in WT controls (left). The mechanism of FMD was changed in TERT-/- from NO to H2O2 as previously shown. TERT transgenic mice showed hyper relaxation to shear which was normalized by A II treatment (1000ng/kg/min), while in WT control animals the same dose of A II reduced endothelium-dependent dilation (right).

Conclusions:
We conclude that up-regulation of TERT is sufficient to prevent A II mediated endothelial dysfunction, likely by suppressing ROS formation and preserving physiological NO levels in the microvascular.
Abstract 555: The Effect Of Dipeptidyl Peptidase 4 Inhibition On Arterial Blood Pressure Is Context Dependent
Authors: Jackson Edwin K , Mi Zaichuan , Tofovic Stevan P , Gillespie Delbert G
Published: July 2021

Dipeptidyl peptidase 4 (DPP4) inhibitors decrease the metabolism of endogenous glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) agonists, such as GLP-1(7-36)NH
2
, and GLP-1R agonists are antihypertensive. However, DPP4 inhibitors also impair the metabolism of endogenous Y
1
receptor (Y
1
R) agonists, such as neuropeptide Y
1-36
(NPY
1-36
), and Y
1
R agonists are pro-hypertensive. Consequently, the long-term effect of DPP4 inhibition on blood pressure may be context dependent. To test this, we conducted radiotelemetry studies under highly controlled conditions to quantify the effects of chronic sitagliptin (80 mg/kg/day; DPP4 inhibitor) on blood pressure in spontaneously hypertensive rats (SHR), Wistar-Kyoto rats (WKY) and Zucker Diabetic-Sprague Dawley rats (ZDSD; model of the metabolic syndrome developed by PreClinOmics). In SHR, chronic (3 weeks) administration of sitagliptin significantly increased systolic, mean and diastolic blood pressures by 10.3, 9.2 and 7.9 mmHg, respectively (p<0.01). Sitagliptin also significantly (p<0.01) increased blood pressure in SHR treated with hydralazine (vasodilator; 25 mg/kg/day) or enalapril (ACE inhibitor; 10 mg/kg/day). Co-administration of BIBP3226 (2 mg/kg/day; Y
1
R antagonist) abolished the pro-hypertensive effects of sitagliptin in SHR. In WKY, chronic sitagliptin slightly decreased (p<0.01) systolic, mean and diastolic blood pressures (-1.8, -1.1 and -0.4 mmHg, respectively). In ZDSD, chronic sitagliptin markedly decreased systolic, mean and diastolic blood pressures (-7.7, -5.8, -4.3 mmHg, respectively). In isolated, perfused ZDSD kidneys pretreated with norepinephrine to induce basal tone, NPY
1-36
and GLP-1(7-36)NH
2
exerted little effect on renovascular tone. In contrast, in isolated SHR kidneys, both NPY
1-36
and GLP-1(7-36)NH
2
elicited potent and efficacious vasoconstriction (increased perfusion pressure by 171 and 132 mmHg, respectively).

Conclusions:
1) The effects of DPP4 inhibitors on blood pressure are context dependent; 2) The context-dependent effects of DPP4 inhibitors are due in part to differential renovascular responses to its most important substrates (NPY
1-36
and GLP-1(7-36)NH
2
); 3) Y
1
R antagonists may augment the beneficial effects of DPP4 inhibitors.
Abstract 562: Association Of The Heteroplasmic Level Of The Mitochondrial Gene Nd2 5178c>A Variant With Essential Hypertension
Authors: Yin Tong , Zhang Yusong , Chen Xi , Yang Jie , Zhang Yuxiao , Li Yang
Published: July 2021

BACKGROUND:
The mitochondrial genetic variant of nicotinamide adenine dinucleotide dehydrogenase subunit-2 (ND2) 5178C>A (Leu237Met) was previously found to have a protective effect against essential hypertension (EH) in Chinese and Japanese populations.

AIM:
The present study aimed to determine whether the protective effect of ND2 5178C>A against EH is associated with the mitochondrial heteroplasmy level of the variant.

METHODS:
This case-control study involved 109 unrelated Chinese-Han matched pairs of essential hypertension and healthy normotensive controls. All consented subjects were recruited consecutively from Institute of Geriatric Cardiology and Health Examination Center in General Hospital of Chinese People’s Liberation Army from February 2013 to January 2014. Demographic and clinical characteristics were recorded. Mitochondrial DNA was isolated from the blood leukocytes for each subject. The level of heteroplasmy for 5178C>A variant occurring in the coding region of ND2 was quantified using real-time polymerase chain reaction (PCR) method.

RESULTS:
The ND2 5178C>A heteroplasmy level ranged between 27% and 77%, with a median level of 44%. Between the upper and lower quartiles of 5178C>A heteroplasmy distribution, significant differences were observed for systolic blood pressure (116±17 vs. 129±25 mmHg, P=0.004) , body mass index (BMI) (24.6±3.3 vs.26.5±3.6, P=0.008) , total cholesterol (4.0±0.8 vs. 3.4±0.9 mmol/L, P<0.001) , low density lipoprotein (2.5±0.7 vs. 1.5±0.7 mmol/L, P<0.001) and triglyceride levels (1.8±1.6 vs. 4.0±1.6 mmol/L, P<0.001). ND2 5178C>A heteroplasmic level was negatively correlated with the presence of hypertension (r = -0.38, P < 0.001), BMI (r = -0.19, P = 0.007), and the level of total cholesterol (r = -0.18, P = 0.01). Logistic regression analysis showed that participants with higher ND2 5178C>A heteroplasmy level (≥44%) were found to have significantly lower prevalence of essential hypertension (29%, 32 in 109), as compared to those with lower (< 44%) ND2 5178C>A heteroplasmy level (71%, 77 in 109) (OR: 0.18, 95% CI: 0.10-0.31, P<0.001).

CONCLUSION:
The protective effect of mitochondrial ND2 5178C>A against EH is associated with the heteroplasmy level of the variant.
Abstract 579: Increased Role of COX-derived Prostanoids in Regulating Ang II Induced Uterine Artery Contraction at Early Pregnancy in a Transgenic Model of Preeclampsia
Authors: Pulgar Victor M , Yamaleyeva Liliya M , Varagic Jasmina , McGee Carolynne M , Bader Michael , Dechend Ralf , Brosnihan K. Bridget
Published: July 2021

The balance between vasodilatory and vasoconstrictor prostanoids contributes to vascular control during pregnancy. Alterations in this balance are involved in the development of hypertensive pregnancy. The transgenic female rat containing the human angiotensinogen (hAGN) gene mated with the male transgenic containing human renin (hREN) is a model of preeclampsia (TgA), and shows hypertension and proteinuria at late gestation. We investigated the role COX-derived mediators have on contractility of the uterine artery (UA) in TgA rats before the hypertensive phenotype develops. UA were isolated from transgenic TgA (n=9) and Sprague-Dawley (n=7) control rats at 7 days of gestation. UA were mounted in a wire myograph for determinations of isometric tension (DMT USA, 620M). Responses to acetylcholine (ACh), phenylephrine (Phe) and sodium nitroprusside (SNP) were measured in control conditions and after preincubation with indomethacin (Indo, 10-5M). Data were fitted to a dose response curve, vasodilatation was expressed as percent of pre-constriction and sensitivity as pD2 (pD2= -Log [EC50]). Responses to ACh reached similar maximal relaxations (64±8 vs 75±6%, p>0.05), and an increased contraction in TgA UA at ACh >10μM (p<0.05) was eliminated by Indo. Contraction to Phe was similar in both groups with an inhibitory effect of Indo on TgA UA (p<0.05). Relaxation to SNP was lower in TgA vs SD UA (92±2 vs 74±5%, p<0.05), this difference was abolished by Indo. Thus, inhibition of COX enzymes had a greater effect on TgA UA suggesting an imbalance towards an increased prostanoids-derived constrictor tone in TgA UA. This imbalance appears before the hypertensive phenotype is established.
Abstract 582: A Novel Adipocytokine, Omentin, Prevents Monocrotaline-induced Pulmonary Arterial Hypertension In Rats
Authors: kazama kyosuke , Okada Muneyoshi , Yamawaki Hideyuki
Published: July 2021

Background:
Omentin is a novel adipocytokine mainly expressed in visceral rather than subcutaneous adipose tissue. Several epidemiological reports demonstrate the negative relationship between serum omentin level and occurrence of obesity, type 2 diabetes and hypertension. Increase of inflammatory responses, contractile reactivity and structural remodeling of vascular wall contributes to hypertension development. Our in vitro and ex vivo studies previously demonstrated that omentin prevented those hypertension-related pathological processes. In addition, our in vivo study demonstrated that intravenously injected omentin acutely inhibited agonists-induced increases of blood pressure in rats. However, the chronic effects of omentin on hypertension development are not determined. In the present study, we tested the hypothesis that chronic omentin treatment may prevent monocrotaline (MCT)-induced pulmonary arterial (PA) hypertension (PAH).

Methods and Results:
MCT-induced PAH was induced by a single intraperitoneal injection of MCT (60 mg/kg) to rats. Omentin (18 μg/kg/day) was intraperitoneally treated for 14 days. Chronic omentin inhibited MCT-induced increases in PA pressure (n=8-10, p<0.05). Omentin inhibited MCT-induced increases in right ventricular hypertrophy (n=6-8, p<0.01) as well as lung to body weight ratio (n=8, p<0.01). Histologically, omentin inhibited MCT-induced PA hyperplasia (n=8, p<0.01). Omentin prevented the impairment of both endothelium-dependent and-independent relaxations mediated by acetylcholine and sodium nitroprusside, respectively (n=7-13, p<0.01).

Conclusion:
We for the first time demonstrate that chronic omentin treatment inhibits MCT-induced PAH in rats via preventing endothelial dysfunction and/or vascular structural remodeling.
Abstract 601: A Biased AT1 Receptor Agonist Stimulates COX2 Expression In Intercalated Cells
Authors: Chen Daian , Tan Min , Stegbauer Johannes , Herrera Marcela , Hall Gentzon , Sparks Matthew A , Coffman Thomas M
Published: July 2021

We recently discovered a pathway by which angiotensin (Ang) II, acting via angiotensin type 1 receptors (AT1R), triggers expression of cyclo-oxygenase (COX)-2 in intercalated cells (IC) of the collecting duct (CD), generating vasodilator prostaglandins, and attenuating the development of hypertension. We found that AT1R-dependent activation of COX2 could be recapitulated in isolated medullary collecting ducts (IMCDs) and in the C11 clone of the Madin-Darby canine kidney (MDCK) cell line permanently transfected with the AT1AR. This cell line has many features resembling ICs including expression of V-ATPase B1. The robust increase in COX2 expression in C11 cells after AngII was blunted after p38 inhibition (5.1*±0.8 vs. 1.4*±0.4; p=0.014), while PKC and MEK1 inhibition had negligible effects. Ang II activation of AT1R triggers both canonical G-protein and β-arrestin pathways and each pathway may have distinct physiological consequences. In IMCDs, we found that stimulation of COX2 by Ang II requires β-arrestin2, as this response was abrogated in IMCDs from mice lacking β-arrestin2. We next tested the capacity for an AT1R β-arrestin-biased ligand, TRV120023, to activate COX2 in C11 cells. These biased ligands block G-protein signalling like conventional AT1R blockers (ARBs), while stimulating β-arrestin-dependent pathways. TRV120023 caused significant stimulation of COX2 at concentrations of 0.1μM-10μM, indicating that activation of AT1R-linked β-arrestin pathways alone is sufficient to stimulate COX2. Exposure of the IC cell line by TRV also triggered phosphorylation of ERK1/2. The p38 inhibitor SB203580 attenuated TRV-dependent stimulation of ERK1/2 and reduced COX2 expression. In summary, activation of β-arrestin with TRV120023 is sufficient to induce COX2 expression via a pathway involving ERK1/2 and p38 MAPK. This suggests that β-arrestin-biased AT1R agonists might have added beneficial effects compared to conventional ARBs by blocking detrimental G-protein-dependent pathways while preserving beneficial β-arrestin-dependent pathways, such as enhanced expression of COX2.
Abstract 608: Uric Acid Potentially Interacts With Parathyroid Hormone To Promote Left Ventricular Diastolic Dysfunction In Mice Fed A Western Diet
Authors: Jia Guanghong , Bostick Brian P , Habibi Javad , Aroor Annayya R. , DeMarco Vincent G. , Ma Lixin , Hayden Melvin R. , Sowers James R.
Published: July 2021

Hyperuricemia is frequently observed in obese people and rising obesity rates parallel increased consumption of a high-fat/high-fructose western diet (WD). Epidemiologic and clinical data suggest that serum uric acid (UA) is positively associated with serum parathyroid hormone (PTH) and may be linked with left ventricular (LV) hypertrophy and LV diastolic dysfunction. Accordingly, we hypothesized that allopurinol, a potent xanthine oxidase (XO) inhibitor, would prevent development of LV diastolic dysfunction, independent of blood pressure, by reducing the levels of UA and PTH. Four week-old C57BL6/J male mice were fed a WD and water with 125mg/L allopurinol. After 16 weeks, we assessed levels of UA, XO activity, PTH, as well as diastolic function by cardiac MRI and cardiac ultrastructure by transmission electron microscopy (TEM). Body weight and fat composition were obtained along with HOMA -IR testing for insulin resistance. Allopurinol has been show to exert no effect on blood pressure. High resolution cardiac MRI revealed diastolic dysfunction with WD feeding that was prevented by allopurinol (LV diastolic relaxation time 35.3 ms for WD, 25.4 ms for CD and 27.7 ms for WD+ allopurinol, p value <0.01; Initial filling rate 0. 28 μl/ms for WD, 0.43 μl/ms for CD and 0.42 μl/ms for WD+ allopurinol, p value <0.05). Body weight, fat mass, and HOMA-IR were increased by WD feeding but not significantly improved by allopurinol. However, allopurinol markedly decreased the WD-induced increase in heart weight associated with activation of translational S6 kinase. TEM examination of myocardial ultrastructure revealed that WD induced remodeling changes with large mitochondria with disordered cristae and increased lysosomes. The ultrastructural changes were improved with treatment by allopurinol. Furthermore, allopurinol significantly inhibited both of plasma and urine UA levels and cardiac XO activity caused by WD.
Interestingly
, WD increased PTH levels which were decreased in parallel with reductions in uric acid with allopurinol. These findings support the notion that increased plasma levels of UA, in concert with elevated PTH, may play a key role in LV hypertrophy and associated LV diastolic dysfunction that result from consuming a WD high in fructose and fat.
Abstract 615: Healthy Eating And Living Spiritually (HEALS): An Efficacious model for Hypertension Control in American African churches
Authors: Dodani Sunita , Arora Sahel , Sealey-Potts Claudia , Christie catherine , Aldridge Petra , Kraemer Dale
Published: July 2021

Background:
African Americans (AAs) living in the “Stroke Belt” region are at elevated risk for cardiovascular diseases (CVDs) including stroke. Our long-term goal is to eliminate this ethnic/regional health disparity by targeting a major modifiable risk factor for stroke, hypertension (HTN). Besides medications, lifestyle interventions are effective in lowering blood pressure (BP), and the “DASH diet has been shown to lower BP, however, in the PREMIER program, DASH with lifestyle modifications was less effective in AAs with regards to BP reduction. We hereby present a PREMIER modified, faith-based, socio-culturally tailored, multi-level HTN control behavioral intervention called HEALS adopted by AA churches. The objective is to determine the efficacy of HEALS on BP and other related outcomes.

Methods:
Based on Community advisory board (CAB) recommendations, a church selected from a pool of 26 participating churches. Trained church leaders enrolled eligible participants and delivered weekly HEALS sessions for 12 weeks. Target population included church members 25-75 years, with known or newly diagnosed HTN/pre-HTN as per JNC-7 classification. Information was obtained on BP, weight, waist circumference, diets and physical activity.

Results:
A total of 36 eligible church members were recruited, 32 provided data that was used in this analysis n=32 (89% retention). At baseline, 28 members were known HTN and remaining were newly diagnosed (22%). After the completion of the 12 weeks intervention, the mean reduction in systolic BP (SBP) and diastolic BP (DBP) were 6.72mmHg (p=.0425) and 4 mmHg (p=.0073), respectively. A weight reduction of 1.7 Kg was also significant (p=0.0023). Similarly, diet changes were significant and showed that more than half consumed dark green or other vegetables frequently, while 75% consumed at least one fruit daily or weekly. Lower percentages (44%) reported consumption of 100% fruit juices or cooked beans regularly. Study is currently in its 6-month maintenance phase.

Conclusion:
Under controlled settings, community-based interventions can be successful in producing desirable outcomes and in maintaining high retention rates. HEALS intervention can be used as a model of efficacious program in church settings.
Abstract 618: Sympathetic Nervous System-Mediated Low Frequency Fluctuations in Blood Pressure are Independent of Baroreflex Modulation in Autonomic Failure
Authors: Arnold Amy C , Diedrich Andre , Okamoto Luis E , Gamboa Alfredo , Raj Satish R , Robertson David , Shibao Cyndya , Biaggioni Italo
Published: July 2021

Autonomic cardiovascular regulation involves sympathetic rhythms that contribute to blood pressure fluctuations in the low frequency range. It has been suggested that fluctuations in sympathetic vasomotor tone reflect a resonance phenomenon due to interplay between the vasculature and baroreflex. Alternatively, this could reflect an intrinsic rhythm of pacemaker neurons. To dissect the autonomic origin of this cardiovascular rhythm, we studied autonomic failure patients with loss of baroreflex buffering. We hypothesized that if this rhythm originates in pacemaker neurons, it would be present in multiple systems atrophy (MSA) patients in whom residual sympathetic tone is intact but not regulated by the baroreflex, and absent in pure autonomic failure (PAF) patients with postganglionic sympathetic denervation. We studied 28 MSA and 34 PAF patients with severe autonomic impairment and neurogenic orthostatic hypotension. Low-frequency systolic blood pressure variability (LFSBP), an index of sympathetic modulation of vasomotor tone, and baroreflex sensitivity (BRS) were assessed by spectral analysis of continuous blood pressure and heart rate recordings. MSA patients had higher LFSBP during supine rest compared with PAF patients (3.3±0.5 versus 1.5±0.2 mmHg2, respectively; p=0.003), despite similarly low BRS (3.6±0.6 PAF versus 4.3±0.7 msec/mmHg MSA; p=0.380). LFSBP was higher in MSA patients with supine hypertension compared with normotensive patients (4.1±0.6 versus 2.3±0.6 mmHg2; p=0.041), with no differences in PAF patients (1.5±0.2 hypertensive versus 1.6±0.3 mmHg2 normotensive, respectively; p=0.984). These findings suggest that LFSBP is driven by an intrinsic rhythm originating in central sympathetic pathways in MSA patients, independent of baroreflex-mediated blood pressure fluctuations. The precise origin of this rhythm is unclear but may include central pacemaker neurons, spinal cord neurons or loops, or hormonal mechanisms. In addition, LFSBP is higher in MSA patients with sympathetically-mediated hypertension, but low and fixed in PAF patients with sympathetic-independent hypertension. Overall, these findings provide new insight into neural regulatory mechanisms involved in blood pressure control.
Abstract 631: Maternal Separation (msep) Alters Baroreflex Function And Renal Blood Flow Responsiveness
Authors: Loria Analia S
Published: July 2021

An impairment of the baroreflex buffering has been shown to precede the development of hypertension. Formerly, we reported that MSep, a model of behavioral stress during early life, impairs chronic blood pressure control and renal filtration capacity. Thus, the aim of this study was to study the baroreflex function and renal blood flow regulation in MSep rats. We used 3 month-old MSep male rats, anesthetized with isoflurane. Femoral vein catheter was fitted to infuse saline (3 ml/hr, baseline), PE (phenylephrine, 1 ug/ml, 9 ml/hr) or SNP (sodium nitroprusside, 0.5 ug/ml, 9 ml/hr). Femoral artery catheter was fitted to collect blood pressure and HR data (ADInstruments). In addition, a flow probe was placed in the left renal artery for renal blood flow (RBF) assessment (Transonic). After 45 minutes of baseline, PE infusion (2 min) was performed. Following 30-minute recovery period, SNP infusion (2 min) was achieved. Delta heart rate (HR)/Delta mean arterial pressure (MAP) relationship shows a significant difference in the slopes between MSep vs. control rats (-0.5 ±0.07 vs. -1.08 ±0.08, p<0.05). PE-induced decrease in RBF was attenuated in a dose dependent manner in MSep rats (max. delta RBF -4.8±0.8 ml/min) compared to controls (max. delta RBF -7±1.5 ml/min, p<0.05, respectively). Yet, renal vascular resistance (MAP/RBF) was not different between MSep and control rats along the 2-min period (slope: 0.43±0.02 vs. 0.42±0.03 mmHg/ml/min, respectively). These data suggest that MSep rats fail to increase HR in response to a vasodilatory agent and lower HR in response to vasoactive stimulus. Furthermore, attenuated alpha-adrenergic-induced renal vascular responses support the existence of a compensatory mechanism in response to an increased sympathetic outflow to the kidney, as previously suggested. The contribution of the different components of the autonomic nervous system is the focus of ongoing studies.
Abstract 633: Pharmacodynamic Interactions Between Nebivolol and Valsartan in Healthy Volunteers
Authors: Chen Chun Lin , Desai-Krieger Daksha , Ortiz Stephan , Kerolous Majid , Wright Harold
Published: July 2021

Background:
Combining different classes of antihypertensive drugs is more effective for achieving blood pressure (BP) control than increasing the dose of monotherapies. An aim of this study was to investigate pharmacodynamic (PD) interactions between nebivolol, a β1 selective, vasodilatory beta blocker and valsartan, an angiotensin II type 1 receptor blocker.

Methods:
This was a single-center, randomized, open-label, multiple-dose, three-way crossover trial in 30 healthy adults aged 18-45 years. Participants were randomized into one of six treatment sequences (1:1:1:1:1:1) consisting of three 7-day treatment periods followed by a 7-day washout. Once-daily oral treatments comprised nebivolol 20 mg, valsartan 320 mg, or nebivolol 20 mg plus valsartan 320 mg. Outcomes included changes in BP, heart rate (HR), plasma angiotensin II, plasma renin activity (PRA), and 24-hour urinary aldosterone.

Results:
The drop in least square mean values of systolic and diastolic BP was significantly greater following the concomitant administration of nebivolol and valsartan than either monotherapy alone. The mean HR after treatment with nebivolol alone, as well as after the combined treatment, was consistently lower than valsartan monotherapy. A sharp increase in mean Day 7 PRA and plasma angiotensin II occurred in subjects receiving valsartan alone and this was significantly attenuated with concomitant nebivolol administration. Mean 24-hour urine aldosterone at Day 7 was substantially decreased after combined treatment, as compared to either monotherapy treatment. All treatments were safe and well tolerated.

Conclusion:
Nebivolol and valsartan co-administration led to greater reductions in BP compared to either monotherapy. Nebivolol attenuated valsartan-induced increases in angiotensin II levels and PRA and reduced urinary aldosterone levels. Hence, these mechanisms for BP lowering are complementary and provide a rationale for further investigation of this combination in patients with essential hypertension.
Abstract 668: Deficiency of miR-155 Attenuates TLR3-Induced Preeclampsia-Like Symptoms in Mice
Authors: Charles Derek , Jamison Ashley , Chiasson Valorie L , Mitchell Brett M , Chatterjee Piyali
Published: July 2021

Preeclampsia (PE) is one of the leading causes of maternal morbidity and mortality worldwide. PE is diagnosed by new onset hypertension and proteinuria or end-organ damage at or after mid-gestation. Although it is known that excessive maternal inflammation contributes to PE, the underlying mechanisms that cause hypertension during pregnancy are still unclear. Excessive maternal inflammation may be in part mediated by ligation of Toll-like receptors (TLRs) by pathogen- or danger-associated molecular patterns. MicroRNAs are small endogenous regulators of gene expression and recently numerous inflammation-related microRNAs have been identified. Several clinical studies reported that miR-155 expression, which is known to regulate inflammation in various disease conditions, is also up-regulated in the placentas of women with PE. We confirmed by qRT-PCR that miR-155 expression was significantly increased in formalin-fixed paraffin-embedded placentas from patients with PE compared to normal pregnant women. Poly I:C (a TLR3 agonist) treatment of human placental cytotrophoblasts (CTBs) for 24 hours significantly increased miR-155 expression compared to vehicle-treated CTBs. Based on these data we hypothesized that TLR3 activation induces placental miR-155 expression which in turn contributes to excessive maternal inflammation leading to PE whereas miR-155 deficiency will attenuate PE-like symptoms in a TLR3-induced PE mouse model. Pregnant WT and miR-155 KO mice were treated with poly I:C or saline on gestational days (gd) 13, 15, and 17 prior to sacrifice on gd 18. Poly I:C treatment induced hypertension in pregnant WT mice (P-PIC WT) (gd 17 SBP: 139±4 mmHg) compared to P WT mice (99±4 mmHg), however this was attenuated in P-PIC miR-155 KO mice (100±1 mmHg ). P-PIC WT mice exhibited endothelial dysfunction and splenomegaly compared to P WT mice and these were also attenuated in PPIC miR-155 KO mice. Our data taken together suggest that miR-155 plays a role in the pathogenesis of PE likely by increasing the maternal inflammatory response.
Abstract MP06: The Protein Tyrosine Phosphatase Inhibitors Induce The Vasoconstriction Via Src/epidermal growth factor/rho-kinase Cascade
Authors: Yayama Katsutoshi , Sasahara Tomoya , Ohba Hisaaki , Ohkura Natsumi , Kobe Asami , Okamoto Hiroshi
Published: July 2021

Orthovanadate (OVA), a protein tyrosine phosphatase (PTPase) inhibitor, exerts contractile effects on smooth muscle in a Rho-kinase-dependent manner, but the precise mechanisms are not elucidated. The aim of this study was to determine the potential roles of Src and epidermal growth factor receptor (EGFR) in the OVA-induced contraction of rat aortas and the phosphorylation of myosin phosphatase target subunit 1 (MYPT1; an index of Rho-kinase activity) in vascular smooth muscle cells (VSMCs). The concentration-response curves for OVA (8–1000μM) were constructed in endothelium-denuded rings using stepwise increases in the concentration of OVA, and the maximal force was observed at concentrations of >500 μM (16 ± 2 in % of 60 mmol/L KCl). OVA (500 μM) evoked rapid contraction of endothelium-denuded aortas, presenting as a hyperbolic rise in tension development within 10 min followed by a slow linear rise. Aortic contraction by OVA was significantly blocked not only by Rho kinase inhibitors Y-27632 and hydroxyfasudil, but also by Src inhibitors PP2 and Src inhibitor No. 5 and the EGFR inhibitors AG1478 and EGFR inhibitor 1. OVA induced rapid increases in the phosphorylation of MYPT1 (Thr-853; 180 ± 24 % in OVA vs 98 ± 22 in vehicle), Src (Tyr-416; 225 ± 34 % in OVA vs 102 ± 30 in vehicle), and EGFR (Tyr-1173; 173 ± 31 % in OVA vs 101 ± 18 in vehicle) in VSMCs, and Src inhibitors abolished these effects. OVA-induced Src phosphorylation was abrogated by Src inhibitors, but not affected by inhibitors of EGFR and Rho-kinase. Inhibitors of Src and EGFR, but not Rho-kinase, also blocked OVA-induced EGFR phosphorylation. Furthermore, a metalloproteinase inhibitor TAPI-0 and an inhibitor of heparin-binding EGF not only abrogated the OVA-induced aortic contraction, but also OVA-induced EGFR and MYPT1 phosphorylation, suggesting the involvement of EGFR transactivation. OVA also induced EGFR phosphorylation at Tyr-845, one of residues phosphorylated by Src. These results suggest that OVA-induced vasocontraction is mediated by the Rho-kinase-dependent inactivation of myosin light chain phosphatase via signaling downstream of Src-induced transactivation of EGFR.
Abstract 008: Early Life Stress Induces Renal Pro-inflammatory Immune Responses
Authors: De Miguel Carmen , Ho Dao H , Loria Analia S , Obi Ijeoma , Pollock Jennifer S
Published: July 2021

We previously reported that maternal separation (MatSep), an animal model of early life stress, sensitizes rats to pro-hypertensive stimuli in adulthood. We hypothesized that MatSep induces a renal pro-inflammatory immune response. Immune cell populations and expression of cytokines were assessed by magnetic bead isolation, FACS analysis, ELISA and RT-PCR in adult male MatSep and normally-reared littermate control rats. Circulating and renal mononuclear or T cell numbers were similar between control and MatSep rats (n=4-11/group, p>0.05). Both groups presented similar percentages of circulating macrophages and T
H
, T
C
, and T
reg
cells (n=4, p>0.05). However, the percentage of circulating B cells was significantly decreased in MatSep rats (23.7±1.2% vs. 20.1±0.7%; n=4, p<0.05). Pro-inflammatory cytokine IL-1Beta was significantly elevated in kidneys from MatSep rats (4.4±0.5 vs. 7.9±1.0 pg/mg prot; n=7-8/group; p<0.05). However, IFN-gamma, IL-6, and IL-4 were not different between control and MatSep rats. To further assess the immune system in MatSep and control rats, we acutely challenged adult rats with lipopolysaccharide (LPS; 2 mg/kg; i.v., 14 h). LPS significantly elevated renal expression of pro-inflammatory chemokine receptors (CCR3, CCR4, CXCR4), cytokines (IFN-gamma, CCL3, CCL4, IL-16), and activation markers (CD40, CD40lg) in MatSep rats (4 to 6 fold increase; n=5/group, p<0.05), suggesting that MatSep induces an exaggerated pro-inflammatory renal immune response to LPS. In conclusion, early life stress induces a renal pro-inflammatory status in adulthood that leads to sensitization to further immune challenges. Funded by P01 HL 69999 to JSP, NIH T32 DK007545 to CDM, F32 HL 116145 to DHH and K99/R00 HL 111354 to ASL.
Abstract 010: The Role of Angiotensin AT
1A
Receptors in Leptin-sensitive Cells in Resting Metabolic Rate Control
Authors: Claflin Kristin E , Grobe Justin L
Published: July 2021

The brain renin-angiotensin system (RAS) and leptin contribute to the control of resting metabolic rate (RMR) and their receptors are co-expressed in areas of the brain critical for metabolic control; thus angiotensin and leptin may interact within the brain to regulate RMR and obesity. Inhibition of the brain RAS attenuates sympathetic nerve activity (SNA) responses to leptin, leading us to hypothesize that the brain RAS mediates the RMR effects of leptin. Mice lacking angiotensin AT
1A
receptors in leptin receptor-expressing cells (ObRb-Cre x AT
1A
flox/flox
; “KO”) exhibited normal body weight (15 weeks of age: control n=28, 26.0 ± 0.7, vs KO n=35, 25.8 ± 0.6 g), food intake (control n=12, 3.1 ± 0.15, vs KO n=15, 3.4 ± 0.14 g) and RMR (control n=13, 0.15 ± 0.004, vs KO n=15, 0.16 ± 0.006 kcal/hr) on standard chow diet. Brown adipose SNA responses to acute leptin injection, however, were completely attenuated in KO mice. When maintained on a 45% high fat diet (HFD), KO mice gained significantly more fat mass (control n=35, 5.6 ± 0.4, vs KO n=31, 7.4 ± 0.5 g, P<0.05) and body mass (control, 27.4 ± 0.6, vs KO, 29.6 ± 0.6 g, P<0.05) due to a loss of diet-induced thermogenesis (control n=22, 0.18 ± 0.008, vs. KO n=12, 0.16 ± 0.004 kcal/hr, P<0.05). KO mice exhibited attenuated hypothalamic proopiomelanocortin (POMC) gene expression and partially attenuated RMR responses to alpha-melanocyte stimulating hormone (αMSH; control n=3, 0.25 ± 0.01, vs KO n=7, 0.2 ± 0.01 kcal/hr, P<0.05) indicating that the interaction between leptin and AT
1A
modulates both αMSH production and action. To localize the site of the brain RAS-leptin interaction, we developed novel multi-transgenic mouse models which expresses GFP via the AT
1A
promoter (NZ44, from GenSat) and/or conditional activation of a tdTomato reporter (ROSA-stop
flox
-tdTomato) in cells expressing the leptin receptor (ObRb-Cre) or agouti-related peptide (AgRP-Cre). Immunohistochemical staining of adrenocorticotropin in brain tissue from NZ44 mice revealed no localization of AT
1A
to POMC neurons; in contrast, AT
1A
was strongly localized with AgRP promoter activity. Taken together, these data support a critical role for angiotensin AT
1A
receptors on AgRP neurons in the arcuate nucleus in resting metabolic rate control.
Abstract 021: Nephron Specific Deletion of the Prorenin Receptor Modulates Blood Pressure and Urinary Na+ Excretion
Authors: Ramkumar Nirupama , Stuart Deborah , Mironova Elena V , Bugay Vladislav , Mamenko Mykola , Wang Shuping , Ichihara Atsuhiro , Pochynyuk Oleh M , Stockand James D , Kohan Donald E
Published: July 2021

The nephron prorenin receptor (PRR) may modulate blood pressure (BP) and Na+ balance. Since previous models of PRR knockout (KO) mice had early lethality and/or structural defects, we developed an inducible nephron-wide PRR KO using the Pax8/LC1 transgenes. Disruption of nephron PRR at 1 month of age caused no renal histological abnormalities. On a normal Na+ diet, wild-type (WT) and PRR KO mice had similar BP and Na+ excretion. However, PRR KO mice had elevated PRC (KO- 377 ± 77 vs WT- 127 ± 19 ng Ang-I/ml/hr) and a 50% decrease in renal ENaC-α protein. Protein levels of NHE3, NKCC2, NCC and ENaC-β/γ were similar between the two groups. Treatment with mouse prorenin (10 nM for 30 min) increased ENaC channel number by 2-fold, but not open probability, in isolated split-open cortical collecting ducts (CCD) from WT mice; this was prevented by Akt inhibition (A6730) but unaffected by blockade of AT-1 (losartan), ERK1/2 (U0126) or p38 MAPK (SB203580). Addition of prorenin (10 nM) did not change isolated CCD [Ca2+]i as assessed by Fura-2 loading (10 min exposure with readings every 3 sec). On a low Na+ diet, PRR KO mice had increased Na+ excretion (Day 2: KO - 66 ± 11 vs WT- 42 ± 6 μmol/day; Day 6: KO - 39 ± 4 vs ET- 23 ± 4 μmol/day) however, no differences in BP were observed. PRC was elevated in PRR KO mice on a low Na+ diet (KO- 384 ± 40 vs WT-174 ± 12 ng/ Ang-I/ml/hr). PRR KO mice had an attenuated hypertensive response to Angiotensin-II (Ang-II) infusion at 600 ng/Kg/min for 2 weeks (MAP: KO - 117 ± 4 vs WT - 133 ± 4 mm Hg over the course of Ang-II infusion). Urinary Na+ excretion was elevated in Ang-II treated PRR KO mice as compared to WT mice (KO-344 ± 14 vs WT-268 ±30 μmol/day). Taken together, these data indicate that nephron PRR, likely via direct prorenin/renin stimulation of an Akt-dependent pathway, stimulates CCD ENaC activity. Absence of nephron PRR promotes Na+ wasting and reduces the hypertensive response to Ang-II.
Abstract 030: Microbial Short Chain Fatty Acid (SCFA) Metabolites Lower Blood Pressure (BP) via Endothelial G-protein Coupled Receptor 41 (gpr41)
Authors: Natarajan Niranjana , Hori Daijiro , Berkowitz Dan E , Pluznick Jennifer L
Published: July 2021

Short chain fatty acid (SCFA) metabolites (acetate, propionate and butyrate) are byproducts of gut microbial metabolism that affect host physiology, and have been shown to dilate blood vessels
ex vivo
. We have previously shown that intravenous delivery of SCFAs to anesthetized mice decreases BP by activating Gpr41, which is expressed in blood vessels. Here, our aim was to identify the cellular localization of Gpr41 and to determine the role of Gpr41 in BP regulation. Using RT-PCR we observe that Gpr41 is readily detected in vessels with an intact endothelium, but is absent from vessels where the endothelium has been denuded. Thus Gpr41 is expressed in the endothelium. Since Gpr41 was previously found to mediate a hypotensive response to acute SCFA administration, we hypothesized that Gpr41 knockout (KO) mice would be hypertensive at baseline. Concordant with our hypothesis, we find that Gpr41 KO (n=4) have elevated systolic hypertension and pulse pressures compared to wild-type (WT, n=4) mice (Table 1); diastolic BP was not different between genotypes. In agreement with a phenotype of systolic hypertension, KO mice also exhibit elevated pulse wave velocity (Table 1). Administration of 200mM sodium propionate (a Gpr41 ligand) in the drinking water worsens the systolic hypertension in KO (Table 1), while administration of equimolar sodium chloride (control) does not affect BP in WT or KO. We hypothesize that the hypertensive effect of propionate in KO is mediated by another SCFA receptor, Olfactory receptor 78 (which we have previously shown to mediate increases in BP upon activation). In sum, these studies demonstrate that endothelial Gpr41 acts to lower baseline BP.
Abstract 032: Microglial TLR4 Mediate Angiotensin II-induced Reactive Oxygen Species Production within the Paraventricular Nucleus in Hypertension
Authors: Biancardi Vinicia C , Stern Javier E
Published: July 2021

Angiotensin II (AngII) contribution to hypertension involves CNS inflammation that includes cytokine release and reactive oxygen species (ROS) production. The innate immune system, via TLR4 signaling, has been implicated in AngII-mediated inflammatory responses. Yet, whether microglia, the immune cells of the CNS, are key cell targets mediating these effects is still unknown. Thus, we studied here whether TLR4 is a molecular link connecting AngII mediated microglia activation and ROS production within the paraventricular nucleus (PVN) during hypertension. TLR4 and AngII type 1 receptor (AT1) mRNA expression was found in isolated PVN microglia, providing molecular evidence for AT1/TLR4 crosstalk. Isolated microglia TLR4 mRNA expression was 2.56*-fold higher in hypertension. TLR4 and microglia (IBA1) immunoreactivity density were increased in the PVN of SHR vs WKY (TLR4 1.8±0.02 vs 1.3±0.1*; IBA1 23±3.03 vs 13.6±0.6* Arbitrary units - AU). Altered density was attenuated in SHR treated with AT1 blocker Losartan (1.3±0.05 and 14.9±0.9 AU). Higher TLR4/IBA1 co-localization was found in SHR vs WKY (4.6±0.9 vs 1.3±0.2* AU), supporting microglia activation and TLR4 upregulation in hypertension. To study whether AngII-induced microglia activation and ROS production involved TLR4, we used TLR4 deficient (TLR4-D, C3H/HeJ) and sufficient (TLR4-S, C3H/OuJ) mice. Acute hypothalamic slices exposed to AngII (1μM, 60 min) showed increased IBA1 density in the PVN of TLR4-S (3.9±0.1 to 6.5±0.3*%) and WKY (9.8±1.1 to 16.2±1.4*%). This effect was blunted in TLR4-D (4.3±0.1 to 5.2±0.5%). In SHR, AngII failed to further promote microglia activation (17.3±1.8 vs 14.1±1.1 AU). AngII (1 μΜ) increased dihydroethidium (DHE) staining (an indirect measure of ROS) in the PVN of WKY (166±2*) and TLR4-S (129±2*) compared to vehicle (100±3%). This effect was blunted in TLR4-D (102±2%). AngII-induced ROS production was attenuated by the microglia inhibitor minocycline (100 μΜ, 131±2*%) and blunted by Losartan (2 μΜ, 111±6%), suggesting AngII-ROS production involves microglia and AT1. Our results support a major contribution of microglial TLR4 to AngII-mediated ROS and microglia activation within the PVN, actions that are upregulated in hypertension. *P<0.05.