bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract MP04: Interleukin-33 Drives Cardiac Remodeling And Alters Macrophage Polarization In Doca-salt Hypertension
Authors: Smart Charles D , Fehrenbach Daniel , Dungan Matthew , Doran Amanda C , Peebles R. Stokes , Madhur Meena S
Published: August 2021

Interleukin-33 (IL-33) is an alarmin critical for alternative macrophage activation and has been linked to hypertension in humans. The goal of this study was to evaluate whether IL-33 contributes to (deoxycorticosterone acetate) DOCA-salt induced cardiac remodeling and macrophage polarization. C57Bl/6J (WT, n=8) and IL33-deficient (IL-33 KO, n=8) mice underwent uninephrectomy, implantation of a DOCA pellet, and 1% NaCl supplementation of drinking water for three weeks. A control group of WT mice (n=10) underwent a sham procedure and were maintained on normal water. Systolic blood pressure measured by tail cuff showed a significant increase in WT DOCA-salt mice (128±9 mmHg; mean±SD) and IL-33 KO DOCA-salt mice (129±11) compared to WT sham (103±11). Hypertension was accompanied by significantly increased heart to body weight ratios in WT DOCA-salt (7.0±1.0 mg/g) and IL-33 KO DOCA-salt (6.8±0.6) compared to WT sham (5.3±0.3) mice. Glomerular injury was assessed by urine albumin-to-creatinine ratios, which were similarly increased in WT DOCA-salt (0.92±0.4) and IL-33 KO DOCA-salt (0.42±0.09) mice compared to WT controls (0.03±0.003). Echocardiography was performed to assess left ventricle (LV) dimensions and systolic function. IL-33 KO DOCA-salt mice exhibited a significantly higher cardiac output (22±2 mL/min) compared to WT sham (16±3) and WT DOCA-salt (15±3) mice, driven by increased stroke volume. No significant changes in heart rate or ejection fraction were observed between groups. Additionally, IL33-KO DOCA-salt mice had an increased diastolic LV internal dimension (3.2±0.2 mm) compared to WT sham (2.7±0.3) and WT DOCA-salt (2.7±0.3). DOCA-salt induced increased mRNA expression of alternative macrophage activation markers in both LV (
Chil3, Il10)
and isolated peritoneal macrophages (
Arg1, Retnla, Tgfb1
). Peritoneal macrophages deficient in IL-33 expressed less
Il10
compared to WT. Cardiac fibrosis evaluated by Masson’s trichrome showed a significant increase in LV collagen deposition in WT DOCA-salt mice (1.09±0.8% trichrome positive) compared to WT sham (0.43±0.3) but no increase in IL-33 KO DOCA-salt mice (0.54±0.3). In conclusion, IL-33 deficiency alters macrophage and cardiac function in the DOCA-salt model of hypertension.
Abstract MP06: Insights Into The Role Of Anp In Hfpef During Ss Hypertension
Authors: Spicer Morgan , Schibalski Ryan , Domondon Mark , Williams Alexus , Troncoso Miguel , Stadler Krisztian , Deleon-pennell Kristine Y , Ilatovskaya Daria
Published: August 2021

Background:
Atrial natriuretic peptide (
ANP)
is a hormone produced primarily in the heart, which induces vasodilation and natriuresis. We showed previously that a knockout of ANP in Dahl SS rat results in hypertension and HFpEF phenotype. There is a
gap in knowledge
regarding the role of inflammation and mitochondrial function in HFpEF that accompanies SSH. We hypothesize that the ANP deficiency in SSH leads to pressure overload, which affects cardiac inflammation and mitochondrial function.

Methods:
At 8 weeks of age, male wild type (SS
WT
) and
Nppa
knockout (ANP knockout, SS
Nppa-/-
) Dahl SS rats were placed on normal salt (
NS
, 0.4% NaCl) or a high salt (
HS
, 4% NaCl) for 21 days. Tissues were harvested for histological and Western analysis. TEM was used to obtain electron micrographs. EPR spectroscopy was performed in snap-frozen tissues post injection of POBN. 2-way ANOVA was employed for statistical comparison.

Results:
Heart-to-body-weight ratio was higher in SS
Nppa-/-
rats (p<0.001), on NS and HS diet (
p
<0.001). SS
Nppa-/-
rats displayed increases in cardiac fibrosis following HS diet (
p
<0.01). EPR demonstrated that SS
Nppa-/-
hearts exhibit a trend for increased lipid peroxidation compared to SS
WT
. Cardiac cytokine profile demonstrated an increase in IL-1α, IL-1β, L-6, IL-17, TNF-α, sICAM-1, MIP-1α, MIP-3α, in the SS
WT
rats fed a HS diet vs NS diet, and lower levels of these in the HS-diet fed SS
Nppa-/-
rats vs SS
WT
. HS diet was sufficient to induce increases in mitochondrial area (
p
<0.001), and decreases in density (
p
0.001), and overall health score (
p
<0.001) in both SS
WT
and SS
Nppa-/-
rats, but no genotype-specific differences were reported. We observed changes in fission/fusion proteins: Opa1 expression was elevated in SS
Nppa-/-
vs SS
WT
(
p
<0.01), and Parkin expression was lower in all rats on a HS diet (
p
<0.05).

Conclusions:
Although SS
Nppa-/-
rats develop a HFpEF phenotype, exacerbated cardiac fibrosis and higher lipid peroxidation vs SS
WT
rats, inflammation and overall mitochondrial damage are diminished in the hearts of these animals at day 21 of the HS diet. Further studies are needed to elucidate the mechanisms by which inflammation may affect the development of HFpEF during SS hypertension in a cell-specific and time-dependent manner.
Abstract MP07: Long-term Suppression Of The Renin-angiotensin System Leads To Concentric Arteriolar Hypertrophy By Activation Of Renin Cells.
Authors: Watanabe Hirofumi , Martini Alexandre , Brown Robin Isadora , Arend Lois J , Medrano Silvia , Narita Ichiei , Sequeira Maria L , Gomez Roberto A
Published: August 2021

Hypertensive patients are frequently treated with inhibitors of the renin-angiotensin system (RASi). In renin knockout mice, cells programmed for the renin phenotype (

Renin
null

cells) stimulate the concentric hypertrophy of intrarenal arteries and arterioles. The

Renin
null

cells invade the arteriolar walls and stimulate the concentric growth of smooth muscle cells (SMCs). EM exam showed disorganized glomerular arterioles, marked layering of SMCs and increased basement membrane, compared to a single organized SMC layer in WT mice. The hypertrophy leads to flow obstruction, ischemia, and renal failure.We hypothesize that

Renin
null

cells or renin-expressing cells from animals treated with RASi possess a unique transcriptome that drives their own abnormal fate and the concentric accumulation of SMCs.To test this, we performed single-cell RNA-seq in WT and

Renin
null

cells. We also tested genetically hypertensive mice and their normotensive controls treated with captopril for 6 months. Further, we examined renal biopsies from patients treated with RAS inhibitors for more than 5 years, age-matched controls without RAS inhibitors, and healthy control kidneys.The transcriptional profile of

Renin
null

cells was markedly different from the profile of WT cells. Gene ontology indicated that

Renin
null

cells possess a contractile rather than the endocrine phenotype of WT cells (
p
<0.0001). The wall thickness of the afferent arterioles in both BPN/3 and BPH/2 mice treated with captopril was significantly increased when compared to the untreated controls (BPN/3: control; 5.54 ± 0.27 μm vs. captopril; 10.57 ± 0.61 μm,
P
<0.0001, BPH/2: control; 5.46 ± 0.26 μm vs. captopril; 10.44 ± 0.43 μm,
P
<0.0001), with arterioles positive for renin. Patients with long-term use of RASi had significantly thicker arterioles compared to the other groups (control; 6.55 ± 0.73 μm, without RAS; 8.54 ± 1.71 μm, vs. long-term RAS; 12.46 ± 1.86 μm,
P
<0.001). The renin-positive area was also increased in the kidneys with long-term use of RASi (control; 307.3 ± 74.7 μm
2
, without RAS; 677.8 ± 313.4 μm
2
, vs. long-term RAS; 1347 ± 529.9 μm
2
,
P
=0.003).In conclusion, renin cells stimulated by inhibition of RAS have specific molecular programs that contribute to arterial disease.
Abstract MP13: Evaluation Of The Effect Of Low Grade Inflammation And Hypertension On The Development Of White Matter Lesions
Authors: Woldstad Chris , Rusinek Henry , Sweeney Elizabeth , Butler Tracy , Li Yi , Tanzi Emily , Mardy Chris , Harvey Patrick , de Leon Mony , Glodzik Lidia
Published: August 2021

Introduction:
The risk of degenerative disease development is closely linked to persistent and continuous systemic inflammation. Although relationships between chronic low-grade inflammation (LGI) measurements and the progression of cardiovascular diseases are becoming established, the burden of the cardio-pathology and LGI on the central nervous system has not been fully investigated. Specifically, there is limited data on how hypertension (HTN) and related LGI impact white matter lesion (WML) pathogenesis.

Methods:
We examined 448 subjects with a mean age of 69.3 ± 7.4 years, with 62% of the cohort being women (n=276), and 45% having hypertension (n=200). Components of the LGI score included white blood cell count, albumin levels, platelet counts, and granulocyte/lymphocyte ratio, modified after. Larger LGI scores represented an increase in measured LGI intensity at that time point. MR images were obtained on a 3T system using fluid attenuation inversion recovery (FLAIR) sequence. WML burden was ascertained using Fazekas scale, done separately for both deep WML and periventricular WML. Summated score of greater than or equal to 4 was considered high overall WML burden.

Results:
It was found that subjects with hypertension had significantly higher LGI score when compared to subjects without hypertension after accounting for sex and BMI (F=4.8, p=0.03). Using logistic regression. we found that LGI score was related to higher WML burden (p=0.047) within the entire cohort. However, further analyses have shown that this finding was driven by the normotensive group, in which the relationship between higher WML burden and respective LGI score was significant (p=0.007). This was not the case among hypertensive subjects.

Conclusion:
It is clear from the data presented that a relationship between LGI and hypertension exists, confirming that inflammation is an underlying process in cardiovascular pathogenesis. However, LGI scores were related to WML in only normotensive cohorts. We offer that the effects of chronic HTN (related to higher inflammatory score itself ) overshadow the effect of LGI among hypertensive subjects. It is worth emphasizing that even in subjects without HTN white matter damage is related to LGI
Abstract MP15: Arterial Hypertension And Cognitive Disorders: Cerebral Vascular Reserve
Authors: Krotova Viktoriia , Khomazyuk Tetyana
Published: August 2021

The study of functional and restructuring disorders of large and small cerebral vessels that are a target for arterial hypertension (AH) is important for the prognosis of cognitive disorders (CD). The relationship between cerebral vascular reserve and CD in 378 outpatients with controlled AH stage II and low SCORE risk of CVD examined. The median age – 57,3±8,91 years. The average duration of AH was 11,5±6,2 years. SCORE risk of CVD <5 %. All AH patients were examined according to the international recommendations and cognitive functioning was assessed by MoCA scale, blood flow in the middle cerebral artery was investigated by transcranial Doppler (TCD) on the HDI 7, Philips, USA with functional respiratory hypo- and hypercapnic ventilation tests.The integrative index of vasomotor reactivity (IVMR) was calculated for cerebral vascular reserve identification: IVMR=[(V
apnea
-V
hyper
)/V
0
]•100%, V
apnea
- the average maximum velocity of blood flow after 20s of apnea (cm/s), V
hyper
- the average maximum velocity of blood flow after 20s of hyperventilation (cm/s), V
0
- the average maximum velocity at rest (cm/s). Non-dementia cognitive disorders were found in 125 (33 %) - 24,32±0,11 points on MOCA scale. The significant decrease in the IVMR was found according to the results of the TCD examination of cerebralvascular reserve testing in patients with AH and CD (44.0±1.2, p<0,001), which indicates the close relationship between the value of IVMR and CD even in patients with controlled AH (rs = +0.54; p<0.001). It is necessary to clarify the cerebral vascular reserve and the vasomotor reactivity index even when controlling AH due to the high risk of the development and progression of cognitive disorders, which worsen the prognosis of cardiovascular events and quality of life.
Abstract MP18: The Impact Of Perivascular Adipose Tissue On Arterial Stiffness
Authors: Roccabianca Sara , Tuttle Tyler , Flood Emma , Watts Stephanie W
Published: August 2021

PVAT is increasingly recognized as an essential layer of the functional vasculature, producing vasoactive substances and assisting arterial stress relaxation. We test the hypothesis that PVAT reduces arterial stiffness. Our model was the thoracic aorta of the male Sprague Dawley rat. Uniaxial mechanical tests for three tissue groups were performed: aorta +PVAT (+PVAT), aorta - PVAT (-PVAT), and PVAT ring separated from aorta (PVAT only) (N=5). Data are reported in the form of a Cauchy stress-stretch curve (fig 1a; line = mean;shaded = SDs). Low-stress stiffness (

E
o

), high-stress stiffness (

E
1

), and the stress corresponding to a stretch of 1.2 (sigma 1.2) were also measured (+PVAT sample in fig 1b) as metrics of distensibility (the higher the stress/stiffness, the less distensible).

E
1
and sigma
1.2

for PVAT-only samples could not be quantified. The low-stress stiffness

E
o

was the largest in the -PVAT samples and the smallest in PVAT-only samples (p < 0.05), while the +PVAT samples assumed values in the middle. Both the high-stress stiffness

E
1

and the stress at 1.2 stretch (sigma
1.2
) were significantly higher in -PVAT samples when compared to +PVAT samples (p < 0.05). Taken together these results suggest that -PVAT samples are stiffer both at low stress (not significant) as well as at high stress (significant) when compared to +PVAT samples. Moreover, -PVAT samples appear to also be less distensible (higher values of sigma
1.2
) when compared to +PVAT samples. Thus, PVAT contributes significantly to decreasing the stiffness of the aortic wall. As such, PVAT should be considered as a target for improving vascular function in diseases with elevated aortic stiffness, including hypertension.
Abstract MP21: Circadian Cycle Exaggerates Sympathoexcitatory Responses To Activation Of Chemosensitive Renal Sensory Nerves
Authors: DeLalio Leon J , Stocker Sean D
Published: August 2021

Renal sensory nerves contribute to hypertension and renal dysfunction in chronic kidney disease. Selective chemokines (e.g., bradykinin or capsaicin) activate renal sensory nerves and produce reflexive efferent sympathetic nerve activity (SNA) and arterial blood pressure (ABP) responses. SNA, ABP, and renal function exhibit circadian patterns; yet the impact of circadian cycle on chemosensitive responses is unknown. We hypothesized that SNA and hemodynamic responses would be greater during the active phrase or nighttime versus the inactive phase or daytime. In Inactin anesthetized rats, simultaneous renal and splanchnic SNA and ABP were measured during intrarenal arterial infusion of capsaicin or bradykinin (0.1 μM - 30.0 μM; 50 μl over 15 s) at nighttime (N; 20:00-04:00; n= 12M, 10F) versus daytime (D; 09:00-16:00; n= 8M, 8F). Baseline mean ABP was significantly elevated during nighttime (N: 104±2 mmHg; D: 97±2 mmHg, p=0.04). Intrarenal capsaicin infusion produced concentration-dependent increases in renal and splanchnic SNA. Renal SNA increased more at nighttime versus daytime at 10 μM (N: 723±136 vs D: 409±79 %; p=0.03) and 30 μM (N: 826±181 vs D: 509±80 %; p=0.03). Similarly, splanchnic SNA was greater during nighttime versus daytime at 10 μM (N: 501±117 vs D: 204±53 %, p=0.03) and 30 μM (N: 537±101 vs D: 295±68 %; p=0.03). However, ABP responses were similar between nighttime versus daytime (30uM: 7±1 vs 6±1 mmHg, respectively). Intrarenal infusion of bradykinin produced concentration-dependent increases in renal and splanchnic SNA. Renal SNA increased more at nighttime versus daytime at 10 μM (N: 1773±216 vs D: 1249±112 %; p=0.01) and 30 μM (N: 2605±263 vs D: 1783±163 %; p=0.001). Similarly, splanchnic SNA was exaggerated at nighttime versus daytime at 0.1 μM (N: 163±65 vs D: 0±0 %; p=0.02), 1.0 μM (N: 566±114 vs D: 184±52 %; p=0.005), 10 μM (N: 1110±193 vs D: 583±87 %; p=0.006) and 30 μM (N: 2008±193 vs D: 1044±162 %; p<0.001). ABP response were similar between nighttime versus daytime at 30 μM (10±2 vs 6±1 mmHg, respectively). Circadian cycle exaggerates sympathoexcitatory responses produced by chemosensitive renal sensory nerve activation.
Abstract MP22: Dietary Salt Restriction And High Salt Intake Exaggerate Sympathetic Reflexes And Sensitize Central Autonomic Networks: Potential Mechanisms Of The J-shaped Curve
Authors: Stocker Sean D , Wenner Megan M , Farquhar William B
Published: August 2021

Observational cohort studies suggest that severe salt restriction increases cardiovascular morbidity/mortality, and the relationship between cardiovascular morbidity and dietary salt intake resembles a J-shaped curve. A high salt diet exaggerates sympathetic nerve activity (SNA) and arterial blood pressure (ABP) responses to several cardiovascular reflexes in salt-resistant animals. This study assessed whether salt restriction also exaggerates cardiovascular reflex responses and sensitizes central autonomic networks. To test this hypothesis, male Sprague-Dawley rats were fed low (0.01% NaCl), normal (0.1% NaCl), and high (4.0% NaCl) salt diet for 14-21 days. Baseline mean ABP was not different across groups (low: 104±4, normal: 107±4, high: 107±4mmHg). Activation of sciatic afferents (1ms pulse, 500uA, 5s duration, 2-20Hz) produced significantly greater increases in renal SNA (5Hz; low: 196±12, normal: 136±9, high: 177±8%, n=8, P<0.05) and ABP (5Hz; low: 29±3, normal: 16±1, high: 24±2 mmHg, n=8, P<0.05) of rats fed low and high versus normal NaCl diets. Activation of the aortic depressor nerve (2ms pulse, 500uA, 15s duration, 2-20Hz) produced significantly greater decreases in renal SNA (5Hz; low: -55±9, normal: -34±8, high: -63±13%, n=7-8, P<0.05) and ABP (5Hz; low: -31±3, normal: -15±5, high: -32±5 mmHg, n=7-8, P<0.05) of rats fed low and high versus normal NaCl diets. To test whether dietary salt intake sensitized central sympathetic circuits, microinjection of L-glutamate (0.1-1nmol, 30nL) in the rostral ventrolateral medulla produced significantly greater increases in renal SNA (0.1nmol; low: 212±15, normal: 149±8, high: 183±17%, n=7-8, P<0.05) and ABP (0.1Hz; low: 20±2, normal: 12±2, high: 22±2 mmHg, n=7-8, P<0.05) of rats fed low and high versus normal NaCl diets. Finally, rats fed low or high NaCl versus normal NaCl diets displayed exaggerated cardiovascular responses to cage switch or mild restraint and increased 24-h blood pressure variability. The present findings show that severe salt restriction and excess dietary salt intake exaggerate sympathetic and cardiovascular responses, and may be explained by a parallel change in the sensitivity of central autonomic networks to resemble a J-shaped curve.
Abstract MP23: Arterial Depressor Responses Induced By Neuromodulation Of Deep Peroneal Nerve In Spontaneously Hypertensive Rats
Authors: Gonzalez-Gonzalez Maria A , Beitter John , Romero Kevin , Lam Danny , Hernandez-Reynoso Ana G , Kanneganti Aswini , Kim Han K , Kjune Caroline K , Smith Scott , Vongpatanasin Wanpen , Romero-ortega Mario
Published: August 2021

Hypertension affects nearly half of the US population but only 43% achieved blood pressure control with medication alone. Medical devices for hypertension include implantable lead electrodes that stimulate the carotid baroreceptors with promising results, albeit with significant adverse complications. To address these limitations, we have proposed the use of deep peroneal nerve stimulation (DPNS), which elicited a depressor response in anesthetized, breathing supported, spontaneously hypertensive rats (SHR). In this study, we further define the electrical stimulation parameters that optimize the DPNS depressor response, and demonstrated that increasing the pulse duration from 0.15 ms to 1ms, of 1.0 mA pulses at 2 Hz for 10 sec, significantly reduced the mean arterial pressure (MAP) by 8±4 mmHg (p<0.005; n=4) in this animal model. DPNS also caused an immediate increase in renal nerve activity (RNA; p< 0.004, n=5), which may represent afferent sensory axons from the kidney, although this possibility needs to be further investigated. In a separate cohort of anesthetized SHR animals, breathing spontaneously, we demonstrated that optimal DPNS stimulation reduced the MAP from 121±3 to 108±4; p=0.02; n=10). To confirm if DPNS is able to evoke a depressor response in fully awake SHR animals, we developed a novel miniaturized wireless microchannel electrode (w-μCE) with a L-shaped microchannel, through which the DPN slides and locks into a recording/stimulation chamber, causing no discomfort to the animal during locomotion. Two weeks after implantation of the w-μCE neural stimulation device, animals were movement-retrained to received wireless DPNS for 10 min daily for 2 weeks. Blood pressure was measured by tail-cuff at baseline, 10 days after device implantation, and 1 and 2-hr 15 days after DPNS. After two weeks of DPNS, the acute neuromodulation treatment reduced the initial systolic BP of 154±20 mmHg to 127±7 and 119±2 mmHg at 1 and 2 hr; respectively (p< 0.001, n=15-19 measurements; n=2 animals). These results provide evidence of the effectiveness and reliability of DPN neuromodulation as a possible treatment for drug-resistant hypertension.
Abstract MP24: Selective Activation Of DMV Neurons Improves Renal Injury In Systemic Lupus Erythematosus
Authors: Shimoura Caroline G , Stubbs Cassandra Y , Brooks Calvin , Mathis Keisa W
Published: August 2021

The cholinergic anti-inflammatory pathway is a vagally-mediated mechanism that controls inflammation. Our published data suggest that an impaired cholinergic anti-inflammatory pathway contributes to hypertension and renal disease in female mice with systemic lupus erythematosus (SLE), since pharmacological potentiation of the efferent vagus via administration of galantamine reduces renal inflammation, mean arterial pressure (MAP) and glomerulosclerosis. The aim of the current study is to selectively target neurons within the dorsal motor nucleus of the vagus (DMV) to stimulate the efferent vagus and the cholinergic anti-inflammatory pathway using designer receptors exclusively activated by designer drugs (DREADDs). We hypothesized that selective activation of DMV neurons would reduce inflammation, eliminating the associated end organ damage in SLE. To study this, female SLE (
NZBWF1
) and parental control (
NZW
) mice received bilateral microinjections of pAAV-hSyn-hM3D(Gq)-mCherry or pAAV-hSyn-mCherry (control virus) into the DMV at 31 weeks of age using the following coordinates with calamus as reference: 0 mm caudal, 0.25 mm lateral and 0.48 mm ventral. Two weeks post-microinjection, DREADD agonist CNO (3mg/kg) was administered subcutaneously for 2 weeks starting at 33 weeks. At 35 weeks, mice were housed in metabolic cages for urine collection and catheters were implanted in the carotid artery for MAP measurement. Mice were subsequently euthanized and the brain collected to confirm the site of virus microinjection. Selective activation of DMV neurons decreased the incidence of albuminuria [> 300 mg/dL; 66% (4 out of 6) vs. 0% (0 out of 7)], urinary leukocytes [62.5% (5 out of 8) vs. 50% (3 out of 6)] and blood in the urine [50% (4 out of 8) vs. 16% (1 out of 6)] in SLE mice. MAP did not significantly change with the chemogenetic activation of DMV neurons in SLE mice or parental controls (SLE/control virus: 146 ± 6, n=7; SLE/Gq DREADD: 142 ± 3, n=6; NZW/control virus: 126 ± 4, n=4; NZW/Gq DREADD: 132 ± 2, n=5). These results suggests that this timeline of selective activation of DMV neurons in SLE mice reduces renal injury without altering blood pressure, but future studies will confirm the effect on hypertension and renal inflammation in SLE mice
Abstract MP26: Angiotensin-(1-7) Increases Vascular Beta-2 Adrenergic Receptor Expression In Aging Mice
Authors: Miller Amanda J , Bingaman Sarah , Arnold Amy
Published: August 2021

Aging is associated with increased sympathetic tone, which desensitizes vascular beta-2 adrenergic receptors (B2AR) to impair vasodilation and promote hypertension. We recently demonstrated that chronic treatment with angiotensin (Ang)-(1-7), a protective hormone of the renin-angiotensin system, decreases blood pressure and cardiac sympathetic tone in aging mice. In this study, we hypothesized that sympathoinhibitory effects of Ang-(1-7) would restore vascular B2AR expression to lower blood pressure in aging. To test this, aging (16-month-old) and young (2-month-old) male C57BL/6J mice received Ang-(1-7) [400 ng/kg/min, n=4] or saline (n=4) infusion for 6 weeks via subcutaneous osmotic mini-pump. At end of treatment, alpha- and beta-adrenergic receptor gene expression was measured in mesenteric arteries, thoracic aorta, and cardiac tissue by quantitative real-time PCR and quantified with 2-ΔΔCT methods. In a separate experiment, male C57BL/6J mice received a single subcutaneous injection of Ang-(1-7) (2 mg/mg, n=4), saline (n=3), or the B2AR antagonist ICI 118,551 (1 mg/kg) plus Ang-(1-7) (n=3). Blood pressure was measured via a carotid artery catheter at baseline and post-treatment. We found that aging mice have decreased mesenteric B2AR gene expression, which was restored by Ang-(1-7) (young saline: 1.04±0.35; aged saline: 0.46±0.17; aged Ang-(1-7): 1.04±0.31 A.U., p=0.026). As a control, Ang-(1-7) did not induce significant changes in B2AR mRNA in thoracic aorta or cardiac tissue, or changes in other adrenergic receptor subtypes (alpha1 or beta1) in any of the tissues studied in aging mice (p>0.05). We further found that depressor effects of acute Ang-(1-7) in mice are attenuated by B2AR blockade (saline: Δ -11±4 mmHg; Ang-(1-7): Δ -26±3 mmHg; ICI 118,551+Ang-(1-7): Δ -4±4 mmHg, p=0.009). Overall, these findings suggest that Ang-(1-7) restores B2AR expression in mesenteric resistance vessels in aging mice, and depressor effects of acute Ang-(1-7) are partially mediated by B2AR. These data support the concept that Ang-(1-7) decreases blood pressure in aging by restoring B2AR-mediated vasodilation. More broadly, Ang-(1-7) may provide a novel treatment target for age-related hypertension and cardiovascular disease.
Abstract MP27: Adipose-derived Human Soluble (Pro)renin Receptor Causes Resistance To Losartan Treatment In High-Fat Diet Male And Female Mice
Authors: Nichols Kellea , Poupeau Audrey , Gatineau Eva , Arthur Gertrude , Yiannikouris Frederique B
Published: August 2021

Obesity, affecting more that 37% of the US, contributes to hypertension. Despite the use of one or more anti-hypertensive treatments, 48% of the hypertensive population remains with resistant hypertension, which prompts the development for new therapeutic targets. We demonstrated that obesity increased the expression of prorenin receptor (PRR) in the adipose tissue and elevated plasma soluble PRR (sPRR). In addition, the infusion of mouse sPRR increased blood pressure in male mice fed high fat-diet (HF); indicating that adipose-derived sPRR could increase circulating sPRR and contribute to hypertension. However, there is a critical gap in the functional role of human sPRR in obesity-hypertension. In this study, we aim to define whether adipose-derived human sPRR contributes to obesity-hypertension. Human sPRR-Myc-tag transgenic mice were bred with mice expressing adiponectin/Cre to selectively express human sPRR in adipocytes (adi-HsPRR). Adi-HsPRR and control littermate (CTL) male and female mice were fed HF-diet for 20 weeks (N=8-15/group). Body weight was assessed weekly and body composition monthly. Blood pressure was measured by telemetry after 15 weeks of diet. Adipose-derived human sPRR did not significantly elevate body weight or fat mass (Male: CTL.18.3±1.0g; adi-HsPRR. 17.5±0.8g. Female: CTL. 15.6±1.5g; adi-HsPRR. 11.9±1.3g; p>0.05). Systolic blood pressure (SBP) significantly increased in HF-fed male and female mice however; adipose-derived human sPRR did not further elevate SBP (24h SBP. Male: CTL. 136.0±1.7 mmHg; adi-HsPRR: 133.4±1.5mmHg; Female: CTL. 131.9±2.8 mmHg; adi-HsPRR: 130.6±3.1 mmHg; p>0.05). Surprisingly, the anti-hypertensive effect of losartan (Los) to lower blood pressure was significantly reduced in adi-HsPRR male and female mice (Male: CTL. ΔSBP: -12.1±1.5 ΔmmHg; adi-HsPRR: -7.8±0.6 ΔmmHg; Female: CTL. ΔSBP: -13.4±1.1 ΔmmHg; adi-HsPRR: -5.7±2.3 ΔmmHg; p<0.05). In 3T3-L1 cells, sPRR significantly increased phosphorylation of ERK1/2, which was not completely blunted by Los indicating that human sPRR could act as a partial agonist of AT1R or activate ERK1/2 independently of AT1R. Our data suggests that adipose-derived sPRR does not stimulate AT1R-mediated contractility, instead impairs Los efficacy.
Abstract MP31: A20 In Renal Tubular Cells Protects Against Hypertension
Authors: Lu Xiaohan , Ren Jiafa , Griffiths Robert , Hammer Gianna , Yang Ting , Crowley Steven D
Published: August 2021

The ubiquitin-editing protein A20 suppresses NF-κB signaling, which contributes to hypertension and kidney inflammation. However, whether A20 generated directly in the kidney tubule regulates blood pressure requires elucidation. To examine the role of tubular A20 in hypertension, we bred

A20
flox/flox

mice with the Pax8-rtTA and Tet-On lines to generate inducible renal epithelial cell A20 knockout mice (A20 iKKO). Mice with all 3 transgenes were used as the A20 iKKO group, while mice lacking the Pax8-rtTA or Tet-On transgene acted as wild-type (WT) controls. Prior to experiments, all mice were given 2mg/ml of doxycycline in the drinking water for 2 weeks to ablate A20 in renal tubular cells. By qPCR, mRNA levels for A20 were selectively reduced by 63% in A20 iKKO kidneys vs WT controls. Baseline blood pressures were similar in the groups. During 3 weeks of chronic angiotensin (Ang) II infusion (500ng/kg/min), A20 iKKO mice exhibited higher mean arterial pressures measured by telemetry compared to WTs (155±2 vs. 143±4 mmHg;
p
=0.024). As a result, the A20 iKKOs had worse cardiac hypertrophy than the WTs after AngII (7.10±0.17 vs. 6.27±0.16 mg heart/g body weight;
p
<0.005.). In addition, mRNA levels for TNF-α were markedly increased (1.54±0.21 vs. 1.0±0.1 arbitrary units;
p
<0.05) in A20 iKKO kidneys compared to WTs, whereas the genes encoding IL-1β and IFNγ were similarly expressed in the groups. In the 3
rd
week of AngII, levels of sodium-hydrogen exchanger 3 (NHE3) protein (1.50±0.10 vs. 1.0±0.1;
p
<0.0005) and NF-κB p50 subunit mRNA (1.30±0.14 vs. 1.0±0.06;
p
<0.05) were increased in A20 iKKO kidneys compared to WTs. Treating both WTs and A20 iKKOs with the TNF-α inhibitor (R7050, 12mg/body weight) every other day during the 1
st
week of AngII infusion yielded similar levels of blood pressure elevation (141.57±4.54 vs. 140.35±5.60 mmHg;
p
=0.87). These data suggest that tubular A20 limits sodium reabsorption and blood pressure elevation by inhibiting NF-κB/ TNF-dependent NHE3 induction in the kidney.
Abstract MP38: Identification Of A Gut Microbe That Attenuates The Blood Pressure Lowering Effect Of ACEi Quinapril
Authors: Yang Tao , Mei Xue , Tackie-Yarboi Ethel , Kyoung Jun , Mell Blair , Yeo Ji-Youn , Cheng Xi , Zubcevic Jasenka , Richards Elaine M , Pepine Carl J , Raizada Mohan K , Schiefer Isaac T , Joe Bina
Published: August 2021

Introduction:
Treatment resistant hypertension (rHTN) is present in ~20% of all hypertensive patients. rHTN is critical in African American patients who experience early onset, severe outcomes, and weak responsiveness to angiotensin converting enzyme inhibitor (ACEi). The mechanism for drug resistance is unknown. Gut microbiota harbors biotransformative enzymes such as esterase, which may hydrolyze ACEis, reducing absorption. Our study was to identify microbe responsible for ACEi resistance.

Methods:
16-week-old male Spontaneously Hypertensive Rats (SHR) were gavaged with (N=12) or without (N=6) Vancomycin, Meropenem, and Omeprazole (VMO) 50 mg/kg/day for five days to deplete the gut microbiota. A single 8mg/kg dose of quinapril was given to SHR and SHR+VMO before blood pressure (BP) recording via telemetry. Quinapril catabolism was quantified by liquid chromatography-mass spectrometry. Bacterial esterase activity was monitored by hydrolysis of p-nitro-phenylbutyrate. Cecal microbiota was analyzed by 16S rDNA. Fecal microbiota were analyzed by metagenomics in 29 (16 black, 13 white) HTN patients.

Results:
Quinapril lowered BP more in the SHR+VMO than SHR (
P
<0.0001). With a 50% reduction in bacterial 16S copy numbers (
P
<0.0001), the SHR+VMO group showed (1) reduced
Coprococcus
(
P
<0.0001); (2) lower esterase activity per gram of cecal microbiota to hydrolyze quinapril (
P
=0.0065); (3) a 50% lower reduction in quinapril quantity (nmol) after incubation with 1mg of cecal lysate for 3 hr (
P
<0.0001); (4) decreased bacterial genes in KEGG drug metabolism pathway (
P
<0.0001). The abundance of
Coprococcus
positively correlated with genes in drug metabolism (
P
<0.0001). Importantly, co-administration of quinapril with
C. comes,
a species in
Coprococcus
genus, reduced the BP-lowering effects of quinapril in the SHR (
P
<0.0001). Comparison of human microbiota demonstrated a higher abundance of
C. comes
in the black hypertensives (poor ACEi responder) than the white (ACEi responder) (
P
=0.0167).

Conclusion:
We, for the first time, demonstrate a previously unrecognized role of gut microbes in reducing ACEi effectiveness. This serves a foundation for expanding clinical management of antihypertensive drug resistance via manipulation of gut microbiota.
Abstract MP39: Metabolic And Gene Expression Profiling Reveal Disparities In Absorption And Metabolism Of Butyrate And Lysine In The Colon Of Spontaneously Hypertensive Rodents
Authors: Martyniuk Christopher J , Yang Tao , Reznikov Leah , Garrett Timothy , Joe Bina , Zubcevic Jasenka
Published: August 2021

Introduction:
Metabolic dysregulation and gut dysbiosis are linked to hypertension. The proximal colon is the main site of metabolism and absorption of short chain fatty acid butyrate. Reduced circulating butyrate concurrently with elevated fecal levels have been reported in human and rodent hypertension. We tested the hypothesis that both the transport and metabolism of butyrate as well as the overall metabolic profile are dysregulated in the colon of the Spontaneously Hypertensive rats (SHR) compared to the Wistar Kyoto (WKY) rats.

Methods:
Proximal colons from adult male WKY and SHR were placed in oxygenated warmed Ussing chamber buffer containing dextrose, and physiologically relevant concentration of butyrate (40mM) was applied to the luminal side of the colon. Following 1hr incubation, butyrate levels from the luminal and basolateral sides of the Ussing chamber were measured with high performance liquid chromatography to establish butyrate colonic transport and metabolism. Global metabolomics was performed in Ussing chamber media and in the plasma of WKY and SHR to determine the overall metabolic profile. RNA-seq data in the gut epithelium of WKY and SHR was used to elucidate putative signaling pathways altered in rodent hypertension.

Results:
Both the colonic transport and metabolism of butyrate were significantly impaired in the SHR. In addition, global metabolomics identified reduced levels of essential amino acid L-lysine, among other metabolites, on the basolateral side of the Ussing chamber and in the plasma of the SHR compared to WKY. Enriched metabolite pathways disrupted in the SHR included lysine degradation. RNA-seq revealed differential expression of several fatty acid and amino acid transporters in the colonic epithelium of the SHR.

Conclusion:
Colonic transport and metabolism of butyrate are reduced in the SHR, accompanied by dysregulation in the metabolism of the essential amino acid lysine in the gut. This, coupled with reduced expression levels of several fatty acid and amino acid transporters in the gut, suggest aberrant host-microbiota communication and colonic metabolic dysfunction in the context of hypertension.
Abstract MP40: Microbiome-associated Metabolites Are Altered In Mouse Models Of Hypertension
Authors: Arenaz Cristina M , Baranwal Gaurav , Goodlett Bethany L , Rutkowski Joseph M , Alaniz Robert C , Mitchell Brett M
Published: August 2021

Recent studies suggest that the microbiome plays a key role in hypertension and associated inflammation. Microbiota produce metabolites that may lead to activated pro-inflammatory immune cells and contribute to hypertension; however, the altered metabolites in multiple models of hypertension is currently unknown. We hypothesized that there are significant differences in metabolomic profiles between normotensive and hypertensive mice. We utilized two mouse models of hypertension: L-arginine methyl ester hydrochloride (L-NAME)/high salt diet induced hypertension (LSHTN) and angiotensin II induced hypertension (A2HTN). Serum and fecal samples were collected at the end of the treatment period. Ultra-high performance liquid chromatography and tandem mass spectrometry were performed to identify the biochemical composition of each sample. Random Forest Analysis was performed to classify each sample based on similarities and differences in metabolite composition. These procedures were performed by Metabolon, Inc. A total of 1,066 and 1,028 biochemicals were measured in serum and feces, respectively. There were 263 biochemicals in LSHTN serum and 122 biochemicals in A2HTN serum that were statistically different from controls (p≤0.05). There were 298 biochemicals in LSHTN feces and 64 biochemicals in A2HTN feces that were statistically different from controls (p≤0.05). Five biochemical metabolite groups were shown to have significant differences between hypertensive groups and controls: aromatic amino acids, bile acids and sterols, benzoates, fatty acids, and diacylglycerols. Tryptophan metabolites were significantly reduced in the serum of LSHTN mice but not in the serum of A2HTN mice. Serum tyrosine and benzoate metabolites showed varied differences between the two hypertensive groups. Serum fatty acid beta oxidation metabolites were significantly reduced in both hypertensive models but were significantly increased in the feces of mice with LSHTN. In conclusion, this study provided significant analysis of metabolite changes in two hypertension mouse models. Further investigation of the roles these metabolites play in hypertension may lead to targeted therapeutic interventions.
Abstract MP41: Isolation Of Gastrointestinal Interstitial Fluid As A Novel Method To Capture Host-microbiome Crosstalk
Authors: Avery Ellen G , Kirchner Marieluise , Geisberger Sabrina Y , Karlsen Tine V , Yarritu Alejandro , Kedziora Sarah , Maifeld Andras , Ulrike Bruning , Bartolomaeus Hendrik , Bartolomaeus Theda U , Wimmer Moritz I , Klopfleisch Robert , Kirwan Jennifer A , Kempa Stefan , Mertins Philipp , Wiig Helge , Mueller Dominik N
Published: August 2021

Metabolites produced by the microbiome such as short chain fatty acids (SCFAs) and tryptophan metabolites have been shown to impact the pathogenesis of hypertension. The microenvironment of the host gastrointestinal (GI) tract acts as the site-of-action for many host-microbiome interactions, although this space is not readily accessible. Fecal or serum samples are commonly used as a proxy, relying on the assumption that the obtained information should in some respect represent what is seen at the host epithelial interface. We surmised that it would be feasible to overcome the limitations of such indirect analysis by isolating interstitial fluid (IF) from the gut mucosa. We have established two methodologies to isolate IF from small segments of along GI tract, a centrifugation-based and elution-based approach in rats and mice. For rats and mice,
51
Cr-EDTA tracer experiments were used to demonstrate that fluid obtained was from an extracellular origin and can be reliably considered IF. Using GC-MS, we could identify several SCFAs (acetate, butyrate, propionate, valerate) within eluted IF samples. We were able to empirically measure the enrichment of these metabolites in eluted IF from the colon of rats compared to the duodenum (for propionate; mean difference=59.57 μM, p-value < 0.0001) or the serum (for propionate; mean difference= 60.25 μM, p-value < 0.0001). LC-MS based shotgun proteomics revealed that proteins annotated to the extracellular phase were site-specifically identifiable in IF and were differentially expressed when compared to matched serum samples. Furthermore, we could demonstrate that the use of tissue for IF isolation does not impede the use of other methods such as immunophenotyping or histology. Absolute CD45+ cells from the lamina propria measured using flow cytometry were not influenced by IF methods (p-value = 0.8344) but were unsurprisingly influenced by the gut segment which was analyzed (p-value = 0.0010). The ability to collect IF and directly measure metabolites at the site-of-action overcomes the limitations of indirect analysis of fecal samples or serum from the systemic circulation, and thus offers direct insight into this hitherto underexplored compartment.
Abstract MP42: Metabolomic Study To Identify Common Metabolites In Two Different Mouse Models Of Hypertension
Authors: Baranwal Gaurav , PILLA RACHEL , Goodlett Bethany , Jayaraman Arul , Rutkowski Joseph M , Alaniz Robert , Mitchell Brett M
Published: August 2021

Metabolomic Study to Identify Common Metabolites in Two Different Mouse Models of Hypertension

Recent studies have reflected the importance of the body’s microbiome and associated metabolites and their changes in hypertension. In the current study, we hypothesized that metabolite changes common between hypertension models may unify hypertension’s pathophysiology with respect to metabolites. Two different mice models of experimental hypertension were used in the study: (1) L-arginine methyl ester hydrochloride (L-NAME)/High salt diet induced hypertension (LSHTN) and (2) angiotensin II induced hypertension (AHTN). Untargeted global metabolomics analysis in serum and urine samples were performed to identify common metabolites altered across both hypertensive models, and the resulting data were analyzed using MetaboAnalyst software and compared to control mice. A list of metabolites that were altered significantly in both models of hypertension were identified. A total of 41 serum metabolites were identified as being altered significantly in any hypertensive model compared to controls. Of these, however, only 4 were increased significantly, and 10 were decreased significantly in common across both hypertensive groups. In the urine, 6 metabolites were altered significantly in any hypertensive group with respect to control, however, 0 of them were common between the hypertensive groups. These findings demonstrate that a modest, but potentially important, number of serum metabolites are commonly altered between experimental hypertension models. Further studies to understand the role of these identified metabolites may lead to a greater understanding of the association between gut dysbiosis and hypertension. Submitted to American Heart Association Council on Hypertension Scientific Sessions (September 27-29, 2021, Virtual)Abstract#: 21-HBPR-A-578-AHA
Abstract MP55: Bardet-biedl Syndrome 3 Gene In Pomc Neurons Regulates Glucose Homeostasis And Baroreflex Sensitivity
Authors: Guo Deng-Fu , Morgan Donald A , Williams Paul , Zhao Yuying , Shaban Mohamed , Zhang Qihong , Sheffield Val , Rahmouni Kamal
Published: August 2021

Bardet-Biedl syndrome (BBS) proteins have emerged as critical regulators of various physiological functions including energy and glucose homeostasis, autonomic function and blood pressure. BBS3 protein is a cilia related protein that mediates the ciliary localization of the BBSome, a protein complex composed of eight BBS protein. Consistent with this, we found that
BBS3
gene knockout in human RPE1 cells disrupt the ciliary localization of BBS2 and BBS9 proteins, indicating a loss of BBSome-mediated cargo trafficking to cilia. We previously demonstrated that disruption of the BBSome through
Bbs1
gene deletion in the anorexigenic pro-opiomelanocortin (POMC)
neurons
altered energy homeostasis and sympathetic nerve traffic. However, the significance of BBS3-mediated ciliary localization of the BBSome in POMC neurons is not clear. To address this, we investigated the consequence of
Bbs3
gene deletion in POMC
neurons
. We generated mice lacking the
Bbs3
gene in POMC neurons by crossing Bbs3
fl/fl
mice with mice expressing inducible Cre in POMC neurons (POMC
ERCre
). To visualize Cre recombinase we further crossed POMC
ERCre
/Bbs3
fl/fl
mice with tdTomato reporter mice. To induce Cre expression tamoxifen (75 mg/kg for 5 days) was injected at 6 weeks of age. Interestingly, both male and female POMC
ERCre
/Bbs3
fl/fl
mice did not develop obesity as indicated by the lack of difference in body weight (male 28.1
+
0.5 vs 28.3
+
1.2g, female 21.9
+
0.7 vs 21.4
+
0.5g), fat mass (male 2.9
+
.0.4 vs 3.4
+
0.5g, female 2.7
+
.3 vs 2.3
+
0.2g) and weight of white and brown fat pads. Insulin and glucose tolerance tests revealed that POMC
ERCre
/Bbs3
fl/fl
mice have glucose intolerance, whereas insulin sensitivity was normal. Blood pressure and renal SNA were comparable between POMC
ERCre
/Bbs3
fl/fl
and control mice measured in the conscious state. In contrast, measurement of renal SNA response to changes in arterial pressure evoked by infusion of sodium nitroprusside and phenylephrine showed reduced baroreflex sensitivity in POMC
ERCre
/Bbs3
fl/fl
mice. These findings demonstrate that POMC neuron BBS3, that mediate cargo transport to cilia, is not necessary for the regulation of energy homeostasis, but is involved in the regulation of glucose homeostasis and baroreflex sensitivity.
Abstract MP56: Transcriptomic Analysis Of Francisella Tularensis Infected Lungs From Human Angiotensin-II Receptor Type-1 Over-expressing Hypertensive Mice
Authors: Ketkar Harshada , Tang Samantha , Alqahtani Maha , Bakshi Chandra S , Jain Sudhir
Published: August 2021

Human angiotensin-II receptor type-I (hAT1R) over-expression may cause adverse pathological outcomes due to renin-angiotensin system overactivity. We have shown that transgenic (TG) mice containing Hap-I (hypertensive genotype) of hAT1R gene are more prone to develop metabolic syndrome (MetS) disorders as compared to the TG mice with Hap-II (normotensive genotype). Aging together with an increased risk of hypertension, can affect multiple organ systems, including increased susceptibility to various pathogenic infections. The current study, therefore, was designed to examine the potential role of aging and hypertension on lung pathology and altered transcriptome, in our TG mice, in response to
Francisella tularensis
live vaccine strain (LVS) intranasal infection. Our results showed that in comparison to Hap-II, aged Hap-I TG mice had a significantly higher mortality post-infection; elevated lung pathology; and altered gene expression profile. Consistent with worsened phenotype in aged Hap-I mice post LVS infection, RNA-seq data from their lungs revealed that >1400 genes (p <0.005) were significantly altered. Bioinformatics analysis identified major alterations in canonical pathways related to immune responses including interferon signaling, antigen presentation, agranulocyte adhesion and dendritic cell maturation. These alterations in turn resulted in disorders including, lung infection, inflammation, and immunological diseases. Importantly, IFNG, STAT1, STAT3 and TNF were among the top upstream regulators significantly affected by LVS infection. Overall, these results provide a deeper insight in molecular signaling associated with hypertension associated lung infections in aged subjects.