bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 10: Disparate Temporal Regulation of Blood Pressure by Estrogens During Systemic Lupus Erythematosus.
Authors: Gilbert Emily L , Mathis Keisa W , Venegas-Pont Marcia , Ryan Michael J
Published: July 2021

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that predominantly affects young women. Due to this partiality towards women, estrogen is commonly implicated in disease development. The potential for estrogens to promote SLE disease progression stems from data showing that removal of estrogens in young female mice with SLE (6-8 week old NZBWF1 mice) delays the development of renal injury and mortality. The primary cause of mortality in women with SLE is cardiovascular disease, and hypertension, a major cardiovascular risk factor, is highly prevalent in this patient population. Based on the presumed role of estrogen to promote SLE, we hypothesized that estrogen promotes hypertension during SLE. To test this, 30 week old SLE mice (NZBWF1) and control mice (NZW/LacJ) were subjected to either ovariectomy (OVX) or a sham operation and a subset of these mice were replete with 17β-estradiol (E2, 5μg/mouse, s.c., 2x/week). At 34 weeks of age, mean arterial pressure (MAP in mmHg) was measured by carotid catheter in conscious freely moving mice. MAP was higher in SLE sham mice compared to control shams (133±3, n=17 vs. 120±3, n=13, p<0.05). Contrary to our hypothesis, OVX at 30 weeks exacerbated the hypertension (154±3, n=9, p<0.05 vs. SLE sham) and prevalence of albuminuria in mice with SLE (83%, 10 of 12 vs 36%, 5 of 14 measured by dipstick > 100 mg/dL). OVX did not alter MAP (115±3, n=9) or albuminuria in control mice. The hypertensive response to OVX was prevented in OVX SLE mice replete with E2 (133±4, n=3) suggesting a protective role for E2 against SLE-associated hypertension. Because previous studies showed that estrogen removal in young mice delayed SLE disease progression, we tested whether OVX starting at 8 weeks of age delayed the development of hypertension. OVX in young SLE mice did not significantly alter the progression of SLE-associated hypertension (141±4, n=4 measured at 34 weeks of age). Consistent with previous work of others, OVX in young SLE mice reduced the prevalence of albuminuria (20%, 1 of 5 vs 33%, 1 of 3). These data suggest that estrogen has a complex temporal role in the pathogenesis of SLE with the potential to promote disease early in life, but protect against the progression of SLE associated hypertension later in the course of the disease.
Abstract 101: The Role of MicroRNAs in the Regulation of Human Aldosterone Synthase Gene Expression
Authors: Maharjan Shreekrishna , Mopidevi Brahmaraju , Pandey Varunkumar G. , Jain Sudhir , Kumar Ashok
Published: July 2021

The human aldosterone synthase (
hCYP11B2
) gene encodes a key enzyme for the biosynthesis of aldosterone which is part of the renin-angiotensin-aldosterone system. Molecular variants in this gene have been associated with essential hypertension. MicroRNAs (miRNAs) are a family of small, noncoding RNAs that bind to the 3’-untranslated region (3’UTR) of the gene and regulate its expression. Our main objective in this study was to investigate whether miRNAs bind at the polymorphic sites present in the 3’UTR of
hCYP11B2
gene and modulate its expression.

Previous studies have suggested that -344T/C (rs1799998) polymorphism in the
hCYP11B2
promoter is associated with hypertension. Here, we compared nucleotide sequences of the promoter and 3’UTR of
hCYP11B2
gene from hypertensive and normotensive subjects and found that rs1799998 is in linkage disequilibrium with 735G/A (rs28491316). Thus, variant -344T almost always occurs with variant 735G; whereas variant -344C almost always occurs with variant 735A. Bioinformatic algorithms of the full-length 3’UTR for miRNAs revealed that hsa-miR-766 was possibly binding at the 735G allele. To examine if this miRNA regulates
hCYP11B2
gene expression, reporter constructs were made where luciferase gene was attached to 1.4 kb of
hCYP11B2
3’UTR containing either 735G, or 735A and co-transfected into HEK293 cells with either pre-miR-766 or anti-pre-miR-766. Our results showed that pre-miR-766 reduced luciferase activity in a dose dependent manner in the presence of 735G allele. There was a significant decrease (65+2%) in the luciferase activity with pre-miR-766 (50 nM) in the presence of 735G allele, whereas it was insignificant (4+5%) in the presence of 735A allele. In H295R cells that express
hCYP11B2
gene, pre-miR-766 (50nM) reduced luciferase activity by 81+1% in the presence of 735G allele. We also showed that transfection of pre-mir-766 reduced
hCYP11B2
mRNA level by about 23.6% in H295R cells. In corroboration with these results, anti-pre-miR-766 did not decrease luciferase activity in presence of either allele in both cell cultures.

Our results suggest that
hCYP11B2
gene expression may be regulated by differential binding of miR-766 at 735G/A polymorphism present in its 3’UTR.
Abstract 138: Altered Vascular Reactivity in Mice Overexpressing Adipocyte Mineralocorticoid Receptors - Role of Rho Kinase.
Authors: Nguyen Dinh Cat Aurelie , Antunes Tayze T , Callera Glaucia E , Montezano Augusto C , He Ying , Carter Anthony , Jaisser Frederic , Touyz Rhian M
Published: July 2021

Aldosterone (aldo) plays a role in cardiovascular diseases, including hypertension and obesity. We previously demonstrated that adipocyte-derived factors regulate vascular function and cell signaling in cultured vascular smooth muscle cells. Moreover, adipocytes are able to produce aldo, which influences vascular reactivity. Plasma levels of aldo are positively correlated with obesity and hypertension. However, the pathophysiological role of aldo and mineralocorticoid receptors (MR) in adipose tissue and its interactions with the vasculature remains elusive. In our study, we investigated molecular mechanisms whereby activation of MR, in adipocytes, leads to release of vascular reactive factors and regulation of vascular tone, using a conditional transgenic mouse model that overexpresses MR only in the adipocytes. Vascular reactivity of resistance mesenteric arteries to acetylcholine (Ach), sodium nitroprusside and phenylephrine (Phe), in the absence or presence of fat conditioned medium (Fcm) from control and adipocyte overexpressing MR (DT) mice, was performed by myography. In basal conditions, endothelial dysfunction was not observed in DT or control mice. However, in the presence of Fcm from DT mice, relaxation to Ach was impaired in control mice (Ach 10
-6
M: 77.5±9.6% no Fcm vs. 49.8±7.5% Fcm, p<0.05), an effect blocked by N-acetyl-cysteine (anti-oxidant) (Ach 10
-6
M: 82.2±6.6%). Resistance arteries from DT mice had decreased Phe-induced contraction, compared to control mice (Phe 10
-5
M: 2.7±0.2 mN/mm CT vs. 1.7±0.2 mN/mm DT, p<0.05). Phosphorylation of ezrin, a marker of Rho kinase activation, measured by immunoblotting, was decreased in white and brown adipose tissues of DT (CT: 3.1±0.7 vs. DT: 0.6±0.1, arbitrary units, p<0.05). In conclusion, MR in adipocytes may play an important role in the regulation of vascular function, and may be involved in vascular oxidative stress. MR in adipocytes is also important to the anti-contractile properties of the adipose tissue through downregulation of Rho kinase signaling. Our study identiy novel mechanisms linking vascular and adipose biology through adipocyte MRs.
Abstract 175: The Role of Axl in Accumulation of Immune Cells in Kidney and the Onset of Hypertension
Authors: Batchu Sri Nagarjun , Hughson Angie , Gerloff Janice , Fowell Deborah J , Korshunov Vyacheslav A
Published: July 2021

Introduction:
Gas6/Axl pathway contributes to elevation of blood pressure. Immune cells are implicated in initiation and maintenance of hypertension. In this study we aimed to investigate the role of Axl in immune cells on kidney injury and initiation of hypertension.

Methods and Results:
Deoxycorticosterone-acetate (DOCA; 75mg, 60days release) and salt hypertension was induced for 1wk or 6wks in four groups of Axl chimeras (n=4-5) that were generated by bone marrow (BM) transplant. Multi parameter flow cytometry was used to quantify five major immune cell subsets in digested kidneys from Axl chimeras. Systolic blood pressure (SBP) increased by 30mmHg in Axl+/+ →Axl+/+, Axl-/- →Axl-/- and Axl+/+ →Axl-/- mice after 1wk of DOCA-salt. However, chimeras that lack Axl in the BM cells (Axl-/- →Axl+/+) showed reduction in early increase in SBP (16+2mmHg). We observed a significant decrease in urine protein levels in Axl-/- →Axl+/+ (0.3+0.1μg/μl) compared to other Axl chimeras (∼0.7μg/μl) after 1wk of DOCA-salt. Kidney glomeruli areas were reduced in Axl-/- →Axl+/+ (4,143+229μm
2
) compared to other Axl chimeras (∼6,000μm
2
) after 6wks of DOCA-salt. Kidneys from Axl-/- →Axl-/- showed an increase in total leukocytes (8 vs. 4%), B cells (29 vs. 12%) and decrease in monocytes/macrophages (16 vs. 22%) and dendritic cells (5 vs. 10%) compared to Axl+/+ →Axl+/+. Moreover, Axl-/- →Axl+/+ showed further increase in leukocytes (17%), B (39%) and dendritic (13%) cells in kidneys compared to other Axl chimeras. In addition a small percentage of wild type T cells was increased in the kidneys from Axl-/- →Axl+/+ chimeras.

Conclusions:
These findings suggest that Axl expression in BM-derived cells is critical for kidney injury in DOCA-salt hypertension. Axl-dependent pathways regulate immune cell populations in the kidneys during initiation of hypertension.
This study was supported by HL105623 grant (VAK)
Abstract 178: Effects of N-Acetyl-Seryl-Aspartyl-Lysyl-Proline in Experimental Autoimmune Mocarditis
Authors: Nakagawa Pablo , Nakagawa Pablo
Published: July 2021

Background:
Acetyl-Ser-Asp-Lys-Pro (Ac-SDKP), a naturally occurring tetrapeptide, prevents autoimmune cardiac dysfunction and remodeling. The mechanism by which this occurs remains unknown. Experimental autoimmune myocarditis (EAM), a T cell-mediated autoimmune disease, is a model of autoimmune cardiac injury. Cytokines and adhesion molecules are necessary for the development of EAM. We hypothesized that Ac-SDKP prevents autoimmune cardiac injury by reducing T cell response, pro-inflammatory cytokines and adhesion molecules.

Methods
and results: EAM was induced by immunization of rats with porcine cardiac myosin, followed by s.c. infusion of vehicle or Ac-SDKP (800 μg.kg-1.d-1) via osmotic minipumps. By 3 weeks post-immunization, we evaluated cell-mediated immunity by delayed-type hypersensitivity, myocardial T helper infiltration by immunohistochemistry and both cytokines and adhesion molecules were measured with a proteomic array kit. Ac-SDKP prevented increases in 1) Delayed-type sensitivity (EAM, 0.35±0.06 vs EAM + Ac-SDKP, 0.16±0.01** mm), 2) infiltration by T helper cells (148±20 vs 97±17*** CD4 cells/mm2), 3) pro-inflammatory cytokines [Tumor necrosis factor-α (0.98±0.20 vs 0.17±0.03** A.U.); Interleukin (IL)-1β (13.7±2.9 vs 0.29±0.07*** A.U.); IP-10, a T helper type 1 chemokine (1.54±0.23 vs 0.30±0.08*); IL-17, a T helper type 17 cytokine (1.9±0.3 vs 0.8±0.3* A.U.)] and 4) Cell adhesion molecules [L-selectin (42.4±4.8 vs 9.1±1.9***) and Intercellular adhesion molecule 1 (54.1±3.1 vs 19.1±2.8***)].

Conclusion:
Prevention of autoimmune cardiac injury by Ac-SDKP is correlated by decreased cell-mediated immunity. The protective effects of Ac-SDKP are likely mediated by reduction of T cell infiltration, pro-inflammatory cytokines and cell adhesion molecules. *p<0.05, **p<0.005, and ***p<0.001 EAM vs EAM + Ac-SDKP
Abstract 186: Blends of Sesame and Rice Bran oils Lowered Blood Pressure and Lipids in Mild to Moderate Hypertensive Patients
Authors: Sankar Devarajan , Singh Ravinder , Chatterjee Biprabuddha
Published: July 2021

Background and objectives:
Sesame oil supplementation reduces blood pressure and lipids in hypertensives. Rice bran oil exhibits good control over lipids. The current study examines how modest variations in blends of sesame and rice bran oils (80% physically refined high oryzanol rice bran oil and 20% unrefined sesame oil), rich in antioxidants and unsaturated fatty acids, intake may affect blood pressure and lipids in hypertensives.

Methods:
In this prospective, randomized, open-label dietary intervention, 300 hypertensive patients (mean age, 57 years; 160% men; 140% women) were equally randomized for 60 days to one of the three groups: 1) calcium channel blocker 30 mg/d; 2) sesame oil blend (Vivo
TM
) ; 3) sesame oil blend + calcium channel blocker 30mg/d. The patients except group 1 were supplied with sesame oil blend and instructed to use ∼35g of oil/day/person for cooking, salad preparation etc., Blood pressure was measured at baseline, and after 15, 30, 45 and 60 days, respectively. Lipid profile was measured at baseline and at the end of 60 days.

Results:
Calcium channel blocker or sesame oil blend or combination of calcium channel blocker and sesame oil blend induced significant fall of systolic/diastolic blood pressure [SBP -16.2mmHg, -14 mmHg and -36mmHg/DBP -12mmHg,-10.8mmHg and -23.8 mmHg, respectively vs baseline). Calcium channel blocker and sesame oil combination induced greater reduction and the dose of the drug was also reduced as there was remarkable fall in blood pressure. Total cholesterol, LDL cholesterol and triglycerides levels in the blood were significantly reduced while HDL cholesterol levels increased in sesame oil blend alone (18%, 26%, 12.6% and 9.5%, respectively vs baseline) or combination therapies (19.7%, 27%, 13.5% and 10.9% respectively, vs baseline).

Conclusion:
We have demonstrated, for the first time that dietary intervention with blends of sesame and rice bran oils lowers blood pressure and lipids in hypertensive individuals. Furthermore, our results suggest that the reduction of blood pressure and lipids will have important implications for population health and lowering the risk of stroke and ischaemic heart disease.
Abstract 336: Rats with Adenine-Induced Chronic Renal Failure Develop Low-Renin Hypertension That is Aggravated by High NaCl Diet and Associated with Increased Aortic Stiffness
Authors: Guron Gregor , Nguy Lisa , Johansson Maria , Teerlink Tom
Published: July 2021

We have shown that rats with adenine-induced chronic renal failure (A-CRF) develop modest hypertension, left ventricular hypertrophy, and a marked decrease in aortic relaxation rate. The aim of this study was to investigate mechanisms causing hypertension in this model and to assess aortic stiffness by measuring aortic pulse wave velocity (PWV). Male Sprague-Dawley rats were equipped with radiotelemetry probes and subsequently received either chow containing adenine (0.5% for 3 weeks, 0.3% for 2 w., and 0.15% thereafter) or were pair-fed with a normal control diet. At 7 to 11 weeks blood pressure responses to high NaCl diet (4%) and pharmacological interventions were performed. In separate groups aortic PWV was analyzed in isoflurane-anesthetized animals. Values are means±SD. Baseline 24-h mean arterial pressure (MAP) was 101±10 and 119±9 mmHg in controls and A-CRF animals, respectively (P < 0.01). After 5 days of 4% NaCl diet MAP had increased by 24±6 mmHg in A-CRF animals vs. 2±1 mmHg in controls (P<0.001 between groups). Administration of L-NAME in the drinking water (50 mg/kg/day) increased MAP by 37±9 and 24±4 mmHg in A-CRF animals and controls, respectively (P< 0.01 between groups). Candesartan (10 mg/kg by gavage) produced a more pronounced reduction of MAP in controls vs. A-CRF animals (-12±3 vs. -5±5 mmHg, P<0.05). Aortic PWV was elevated in A-CRF rats (5.10±0.51 vs. 4.58±0.17 m/s, P<0.05) although histological analysis did not show aortic calcifications. At sacrifice, plasma levels of creatinine (259±46 vs. 31±2 μM, P<0.001) and asymmetric dimethylarginine (ADMA, 0.65±0.04 vs. 0.45±0.02 μM, P < 0.001) were elevated in A-CRF animals whereas plasma renin activity was markedly suppressed (0.7±0.5 vs. 15.1±7.5 μg/L/h, P<0.001). Hypertension in A-CRF animals is characterized by low renin levels and is aggravated by high NaCl diet suggesting a pathogenic role for hypervolemia secondary to severe renal insufficiency. Although ADMA concentrations were elevated, A-CRF animals showed a more pronounced increase in MAP in response to L-NAME than controls, suggesting that reduced nitric oxide synthase activity was not a major cause of hypertension in this model. Finally, aortic stiffness was elevated in A-CRF animals as indicated by increased aortic PWV.
Abstract 344: Intrarenal Ghrelin Receptors Mediate Sodium Reabsorption via an ENaC-Dependent Pathway
Authors: Kemp Brandon A , Howell Nancy L , Gildea John J , Keller Susanna R , Padia Shetal H
Published: July 2021

Intrarenal ghrelin infusion stimulates distal nephron-dependent sodium (Na+) reabsorption in normal rats, but the mechanism is unknown. The main Na+ transporters of the distal nephron segment are the Na+-Cl- co-transporter (NCC) and the epithelial Na+ channel (ENaC). To determine which of these transporters is involved in the antinatriuretic actions of intrarenal ghrelin receptors, uninephrectomized Sprague-Dawley rats received 3 cumulative 1h renal interstitial (RI) infusions of ghrelin (0.3-3 μg/min, N=8) or vehicle (5% dextrose in water, D5W, N=8), prior to harvesting the infused kidney for determination of NCC and ENaC protein expression. Ghrelin-infused rats demonstrated significantly reduced Na+ excretion rates (UNaV) compared to D5W-infused rats (66.7±7.1% of baseline, P<0.01) and significantly increased cortical collecting duct ENaC expression (2.46±0.17 and 1.56±0.19 densitometric units respectively, P<0.01). Renal NCC expression did not change in response to either ghrelin or D5W infusion (4.21±0.58 and 4.13±0.44 densitometric units respectively, P=NS). To test whether the ghrelin-induced increase in collecting duct ENaC expression was responsible for the antinatriuretic actions of ghrelin, we infused ghrelin into the kidney in the presence of amiloride, a selective inhibitor of ENaC activity. Following uninephrectomy, rats were implanted with either a subcutaneous osmotic minipump which systemically delivered amiloride (1.4 ng/min) for 72h to block ENaC activity (N=6), or a minipump that was filled with D5W (N=6). On the day of the study, RI ghrelin (0.3-3 μg/min) or D5W infusion was initiated. RI ghrelin infusion (in the absence of amiloride) significantly reduced UNaV to 58.9±7.2% of baseline, P<0.01; however, in the presence of amiloride, RI ghrelin failed to reduce UNaV, demonstrating values identical to rats that did not receive RI ghrelin. In contrast, studies carried out in the presence of chlorothiazide pumps (to block NCC activity, 1.1 μg/min, N=6), continued to demonstrate ghrelin-induced antinatriuresis (UNaV decreased to 65.3±8.8% of baseline, P<0.01). Mean arterial pressures did not change during any of the acute RI infusions. Thus, intact ENaC function is necessary for ghrelin-induced Na+ reabsorption.
Abstract 414: Intrinsic Osmosensitivity of Neurons in the Organum Vasculosum of the Lamina Termialis is Mediated by Benzamil-Sensitive Channels
Authors: Browning Kirsteen N , Stocker Sean D
Published: July 2021

Neurons of the Organum Vasculosum of the Lamina Terminalis (OVLT) play a pivotal role in body fluid homeostasis and blood pressure regulation. Lesion of OVLT neurons severely disrupts drinking, antidiuretic hormone secretion, and sympathetic-cardiovascular responses to acute sodium loads. Importantly, OVLT lesions also lower blood pressure in several models of salt-sensitive hypertension. Similarly, intracerebroventricular administration of the non-voltage dependent channel blocker benzamil attenuates sympathetic-cardiovascular responses to acute sodium loads and salt-sensitive hypertension. Therefore, the purpose of the present study was two-fold: 1) to establish OVLT neurons are sensitive to physiological changes in osmolality, and 2) to identify whether benzamil-sensitive channels mediate the osmosensitivity of OVLT neurons. Whole-cell patch-clamp recordings were performed in OVLT neuronal slices of male Sprague-Dawley rats (250-350g). 71% (17/24) of OVLT neurons responded to increased bath osmolality by addition of mannitol (5-20 mOsm/L). There were no differences in basic electrophysiological properties (ie, input resistance, membrane capacitance, etc) between responsive and non-responsive neurons. Increases in bath osmoality produced dose-dependent decreases in membrane potential (5 mOsm: 5.0±0.63 mV, 10 mOsm: 6.1±1.24 mV, 15 mOsm: 12.4±2.1; n=5, P<0.05) and increases in firing rates (5 mOsm: 208±32%, 10 mOsm: 246±55%, 15 mOsm: 274±101%, 20 mOsm: 496±53%; n=5, P<0.05). Bath application of benzamil (0.5 uM) significantly attenuated the membrane depolarization (0.2±0.7 vs 5.3±0.4 mV) and increased firing rate (98±6% vs 219±20%) during a 10mOsm/L increase in bath osmolality. These findings suggest OVLT neurons are sensitive to physiological changes in osmolality, and the intrinsic sensitivity of OVLT neurons are mediated by benzamil-sensitive channels.
Abstract 422: Role of Brain Salt-inducible Kinase 1 in Responses to Central Sodium in Salt-induced Hypertension
Authors: Huang Bing S , White Roselyn A , Leenen Frans H
Published: July 2021

In Dahl salt sensitive (S) rats, sympatho-excitatory and pressor responses to CSF Na
+
are enhanced. Salt-inducible kinase 1 (SIK1) increases Na
+
/K
+
-ATPase activity in kidney cells. We tested the possible role of SIK1 in regulation of sympatho-excitatory and pressor responses to Na
+
in the brain. Icv injection of the protein kinase inhibitor staurosporine (staur, 5ng) to inhibit SIK1 similarly enhanced renal sympathetic nerve activity (RSNA), BP and HR responses to icv infusion of Na
+
-rich aCSF in Wistar and salt-resistant Dahl SS.BN13. The enhancement in Dahl S rats was only 1/3 of that in other strains. Staur had no effect on BP responses to icv Ang II or carbachol, whereas the specific protein kinase C inhibitor GF109203X attenuated pressor responses to icv Na
+
-rich aCSF or Ang II. Hypothalamic SIK1 protein and activity, measured by Western blot and phosphocellulose binding technique, were lower in Dahl S vs SS.BN13 rats after high salt diet for 2 weeks. Staur at 5-50 nM inhibited SIK1 activity in a dose-related manner. These data suggest that the SIK1 -Na
+
/K
+
-ATPase network in neurons acts as a feedback mechanism to attenuate sympatho-excitatory and pressor responses to increases in brain [Na
+
]. Lower neuronal SIK1 protein expression and activity in Dahl S rats may contribute to enhanced responses to CSF Na
+
and thereby to their salt-induced hypertension. Data= means±SE (n=4-7). * p<0.05, vs. SS.BN13 or Wistar rats.
Abstract 432: Race Differences in the Relationship between Urinary ET-1 and BP-related Target Organ Damage in Youth
Authors: Harshfield Gregory A , Harshfield Gregory A , Pollock Jennifer , Pollock David
Published: July 2021

The overall goal of this study was to determine race/ethnic differences in the associations between renal ET-1 and indices of blood pressure-related target organ damage in healthy adolescents. The subjects ranged in age between 15-19 years, had no history of any disease, and were not on any prescription medications. The 92 subjects consisted of 48 Caucasians (CA) and 44 African-Americans (AA). The two groups were similar with respect to height, weight, body mass index, blood pressure, ET-1), albumin excretion rate (AER), and left ventricular mass).

Results:
The CA’s were slightly older 17±1 v 16±1 (p=.02). The protocol was preceded by a 3 day self-selected sodium controlled diet of 250 mEq/day day which the subject picked up each day. The test day began with an echocardiogram for the assessment of left ventricular mass. Next, the subjects were seated for 60 minutes of rest during which the subjects consumed 200 ml of water. This was followed by the collection of a urine sample for the measurement of ET-1 and AER. Overall, ET-1 excretion was correlated with AER (r=.278), LV mass/ht
2.7
(r=.341), and systolic blood pressure (SBP; r=.365; p=.01 for each). The significant overall correlations were the result of significant correlations in AAs for AER (r=.344; p=.05), LV mass/ht
2.7
(r=.520; p=.01), and SBP (r=.645; p=.01) which were not apparent in CA’s. These findings suggest urinary ET-1 contributes to the development of BP-related target organ damage in AA youths prior to the development of increases in blood pressure.
Abstract 453: The Role of PD-1/PDL-1 in Myocardial Ischemia Reperfusion Injury.
Authors: Mozaffari Mahmood , Liu Jun Yao , Baban Babak
Published: July 2021

Programmed Death-1 (PD-1) and its ligand, PDL-1, are expressed on immune cells and have emerged as negative regulators of immune and inflammatory mechanisms. Aside from the contribution of systemic immune and inflammatory mechanisms to myocardial ischemia reperfusion (IR) injury, isolated heart studies have shown that the myocardium is capable of mounting a robust inflammatory response to an IR insult. However, potential involvement of PD-1/PDL-1 in the setting of cardiac IR injury is not established. We tested the hypothesis that an IR insult downregulates PD-1/PDL-1 pathway thereby exacerbating the inflammatory response and cell death. According, Langendorff-perfused rat hearts were subjected to 40 min of ischemia and 15 min of reperfusion; normoxic hearts served as controls. Thereafter, cardiac cells were prepared and subjected to flow-cytometry-based assays. The ischemic-reperfused hearts displayed a marked increase in the pro-inflammatory cytokine interleukin-17 in association with disruption of mitochondrial membrane potential (JC-1 assay) and apoptotic and necrotic cell death. Importantly, the ischemic-reperfused hearts showed a significant increase in PD-1 and PDL-1 positive cells. The results suggest that cardiac PD-1/ PDL-1 pathway likely constitutes an endogenous mechanism whose upregulation in the ischemic-reperfused heart curbs the inflammatory response and associated tissue injury.
Abstract 458: Obesity-related Alterations in Cardiac Lipid Profile During the Transition to Diastolic Dysfunction
Authors: DeMarco Vincent G , Ford David A , Henriksen Erik , Aroor Annayya , Habibi Javad , Ma Lixin , Yang Ming , Johnson Megan S , Pulakat Lakshmi , Albert Carolyn , Lally John , Ford Caleb , Prasannarong Mujalin , Hayden Melvin R , Whaley-Connell Adam , Sowers James R
Published: July 2021

Myocardial accumulation of fatty acids and lipid intermediates may contribute to cardiac dysfunction, but the interrelationship between different lipid species to diastolic dysfunction is not clearly understood. Herein, we examined changes in levels and composition of different lipid species during the progression to diastolic dysfunction in a clinically relevant model of obese insulin-resistant db/db mice at 12 and 15 wks of age. Obese db/db mice manifested loss of circadian BP dipping and diastolic dysfunction at 15 wks. Myocardial lipidomic analysis demonstrated elevated ceramides and fatty acids in db/db at 12 wks, but their levels were decreased at 15 wk and this was accompanied by increased fatty acid oxidation and enhanced production of reactive oxygen species. Triacylglyceride and diacylglyceride levels remained elevated at both 12 and 15 wk, but their composition changed to consist of more saturated and less unsaturated fatty acyl at 15 wks of age compared to 12 wk. Dysregulation of phospholipid metabolism persisted at 15 wk in db/db. Changes in triacylglyceride and diacylglyceride composition, phospholipid metabolism, β-oxidation, and oxidative stress that are temporally related to non-dipping of BP and diastolic dysfunction suggest a switch in metabolism of lipid intermediates contributes to the development of diastolic dysfunction in over-nutrition.
Abstract 459: Gene-Gene Interaction Among Endothelial Nitric Oxide Syntase (eNOS), Matrix Metalloproteinase-9 (MMP-9) and Vascular Endothelial Growth Factor (VEGF) in the Childhood Obesity
Authors: Belo Vanessa , Luizon Marcelo , Carneiro Patría , Souza-Costa Debora , Lanna Carla , Tanus-Santos Joséduardo
Published: July 2021

Obesity is the most common cause of hypertension in children. Important features of this condition include expansion of adipose tissue mass and angiogenesis. In this context, genes encoding for regulators of endothelial function, vascular permeability, and extracellular matrix remodeling have been suggested as important candidate genes. However, although gene-gene interactions are suggested to be an important component to complex disease, no studies focused on this issue in obesity. Therefore, we sought to characterize the possible interactions among polymorphisms of clinical relevance in the eNOS, MMP-9 and VEGF genes with obesity. Seven clinically relevant

polymorphisms of eNOS (T-786C, rs2070744, a variable number of tandem repeats in intron 4 and Glu298Asp, rs1799983), MMP-9 (C-1562T, rs3918242 and -90(CA)14-24, rs2234681) and VEGF (C-2578A,
rs699947
, and G-634C, rs2010963) were genotyped by TaqMan allelic discrimination assays or PCR and fragment separation by electrophoresis in 153 healthy controls and 52 obese patients. A robust multifactor dimensionality reduction analysis was used to characterize gene-gene interactions. We observed a model of interaction among the SNPs T-786C, C-2578A and 90(CA)(14-24) at the promoter of eNOS, VEGF and MMP-9 genes, respectively (Accuracy=0.6274 and CVC=10/10; P=0.05) when we compared healthy controls with obese patients. More specially, the combination eNOS-786TT, VEGF-2578CC, and MMP-9(CA)(14-24)LH was more frequent in healthy controls than obese children and adolescents (18% versus 2%, respectively; P<0.05) thus suggesting protection against obesity. These results are obscured when single polymorphisms in these genes are considered and suggest that specific genotype combinations of these genes contribute to protection against childhood obesity.

Research support: FAPESP and CNPQ
Abstract 466: Combined Telmisartan and Amlodipine Reduces Albuminuria via Reduction in Renal Inflammation in Animal Model of Metabolic Syndrome
Authors: Siragy Helmy M , Pitkin William
Published: July 2021

The utilization of combined Telmisartan (T) and amlodipine (A) is well established in management of Hypertension. However, it is not known if this combination would be beneficial in metabolic syndrome (MS). We hypothesized that combined T+A decreases albuminuria in obese Zucker (OZ) rats, a model of MS, via reduction of renal inflammation. Studies were conducted in lean Zucker (LZ) and OZ rats fed high fat diet and treated for 6 wks with oral administration of vehicle (V), T (3mg/kg/d), or A (10mg/kg/d) individually and combined. We monitored changes in body weight (BW), systolic BP (SBP), 24h UV, fasting blood glucose (FBG), urine albumin/creatinine ratio (UACR), urine aldosterone/creatinine ratio (UaldoCR), and renal interstitial fluid (RIF) recovery rate of nitric oxide (NO), IL-6 and TNFα. Data are shown (Table) as mean±SE. *p<0.01 vs ZL, +p<0.01 vs ZO+V, #p<0.01 vs ZO+T or ZO+A. Different treatments did not cause significant changes in BW, FBG or UV. These results demonstrate that T, A or their combination reduce albuminuria in a model of metabolic syndrome via reduction in renal inflammation. In addition to SBP reduction, combined T and A have more favorable renal effects than either individual treatment.
Abstract 468: The 3’-utr of Adiponectin Q Gene Harbours Common Susceptibility Variants and Haplotypes for Metabolic Risk Traits
Authors: Dzimiri Nduna , Al-Najai Mohammed , Andres Editha , El-Hawari Samar , Vigilla Mary Grace , Gueco Daisy , Muiya Paul , Alshahid Maie
Published: July 2021

Adiponectin (ADIPOQ) is a hormone that modules several metabolic processes and is thought to contribute to the suppression of the metabolic derangements that may lead to metabolic syndrome. In the present study, we performed a population-based association study by real-time PCR for 8 SNPs in a total of 4650 Saudi individuals harbouring various metabolic risk traits. Among these SNPs, rs1063537 T allele [Odds ratio(95% Confidence Interval = 1.16(1.04-1.30); p=0.011], rs1063537 CT+TT genotypes [1.16(1.02-1.33); p=0.024], rs2082940 T [1.12(1.01-1.24); p=0.035] and CT+TT [1.37(1.02-1.83); p=0.039] as well as rs1063539 C [1.13(1.01-1.20); p=0.035] conferred risk for myocardial infarction (MI; 3060 cases vs 1590 controls). The rs2241766 T [1.26(1.02-1.54); p=0.028], rs6773957 AG+GG [1.15(1.01-1.31); p=0.030], rs4686804 CT+ TT [1.15(1.01-1.30); p=0.033] were associated with obesity (1757 vs 2576). The rs2241766 T was likewise implicated in low high density lipoprotein levels (lHDL; 1926 vs 2393) [1.29(1.06-1.58); p=0.013] and primary hypertension (HTN; 3533 cases vs 1590) [1.25(1.01-1.55); p=0.039], while rs9842733 T was associated with HTN [1.44(1.03-2.01); p=0.032] and hypercholesterolaemia (hChol; 1681 vs 2739) [1.32(1.01-1.72); p=0.043]. An 8-mer haplotype GTGCCTCA constructed from the 8 SNPs and its derivatives were commonly implicated in MI (Χ
2
=4.12; p=0.042) and HTN (Χ
2
=6.40; p=0.011) and obesity (Χ
2
=5.18; p=0.023). On the other hand, hChol levels were associated with the 5-mer TTATT (Χ
2
= 9.56; p = 0.002) and its 4-mer derivative TTAT (Χ
2
= 7.56; p=0.006) while lHDL was linked with the TCCA (Χ
2
= 5.06; p = 0.025). These results demonstrate that the 3’UTR of the
ADIPOQ
gene harbours common susceptibility variants and haplotypes for the important determinants of metabolic syndrome and cardiovascular risk traits, possibly pointing to a common underlying pathway to coronary artery disease.
Abstract 469: Intra-vital FRET Imaging Reveals Basal α-adrenergic Dominated Tone in Mouse Femoral Conduit Arteries
Authors: Wang Youhua , Wier W. G , Zhang Jin
Published: July 2021

Enhanced vascular tone is always observed and responsible for the blood pressure elevation in hypertension. The cellular mechanisms that control vascular tone
in vivo,
particularly in hypertension, however, are not known with certainty. Here, using intra-vital FRET imaging in smooth muscle-specific exogenous myosin light chain kinase biosensor mice, we aimed to study the mechanism(s) that control the basal tone in femoral conduit arteries under normal physiological conditions (Zhang et al.,
Am J Physiol
299:
H946-56, 2010). Quantification of arterial [Ca
2+
]
i
and diameter revealed that, in the basal state, femoral arteries exhibit 33 ± 3% tone (percentage of passive diameter, 400 ± 30 μm, obtained in Ca
2+
-free solution), [Ca
2+
]
i
is 233 ± 18 nM. Acute ganglionic blockade with hexamethonium (30 mg/kg wt, i.p.) lowered [Ca
2+
]
i
by 216 ± 23 nM, reduced the basal tone by 67 ± 12%, and decreased mean blood pressure by ∼60 mm Hg, suggesting a dominant autonomic/sympathetic control of the basal tone. To assess contribution of the major sympathetic neurotransmitters, noradrenaline (NE), ATP and neuropeptide Y (NPY), to the basal tone
in vivo
, respective agonists and antagonists were applied locally to segments of exposed arteries. Prazosin (0.01-3 μM), an α1 adrenoceptor blocker, dose-dependently decreased [Ca
2+
]
i
and basal tone, without affecting blood pressure or heart rate. Yohimbine (0.1-1 μM), an α2 adrenoceptor blocker, reduced tone with negligible effect on [Ca
2+
]
i
(
n
= 4). These effects were abolished by chemical destruction of sympathetic nerves locally with hydroxydopamine (2 mM), indicating that the basal tone is maintained by neurotransmitters released from nerve terminals, but not activated by circulating neurotransmitter-like factors. Suramin (a purinergic receptor blocker), BIBO 3304 (a NPY receptor blocker), and losartan (angiotensin II AT1 receptor blocker), had negligible effect on either [Ca
2+
]
i
or diameter. Our results indicate that femoral arteries possess basal neurogenic tone, primarily α-adrenergic, under normal physiological condition. This basal tone observed in femoral arteries could be particularly useful for assessing sympathetic nerve activity in disease models, such as hypertension.
Abstract 473: Evidence for Afferent Re-innervation After Renal Denervation in Rats
Authors: Ditting Tilmann , Fiedler Christian , Freisinger Wolfgang , Siegel Kirsten , Heinlein Sonja , Schmidt Stephanie T , Neuhuber Winfried , Ott Christian , Schmieder Roland E , Amann Kerstin , Veelken Roland
Published: July 2021

Interventional renal ablation is a promising treatment procedure for therapy-resistant arterial hypertension. However, the underlying mechanisms are not completely understood: The efferent sympathetic renal nerves are known to play a key role in salt retention and renin release, but the role of the afferent nerves is not yet clearly defined, although strong evidence exists for a sympathoinhibitory function. It is widely accepted that there is some re-innervation of efferent sympathetic nerves after the denervation procedure, but re-innervation of afferent nerves is still doubted. Hence, we wanted to test the hypothesis that besides a sympathetic re-innervation a considerable afferent re-innervation occurs after renal denervation in rats. 50μm kidney slices from 12 male SD rats were stained for thyrosin hydroxylase (TH), calctonine gene related peptide (CGRP) and smooth muscle actin (SMA). Kidneys were examined 1, 4 and 12 weeks after left sided surgical renal denervation. The right innervated kidney served as control. Image stacks were generated using a confocal laser scanning microscope (0.5μm z-axis steps). Analysis of nerve density was done by 4 blinded investigators in 183 image stacks. Staining for TH (i.e. efferent) and CGRP (i.e. afferent) was visually scored (0-3). Stacks were visualized by Fiji Image J software. At week 1 both efferent [TH+] and afferent [CGRP+] fiber density was clearly reduced but was still detectable ([TH+]: right 2.43±0.10 vs. left 1.47±0.11; [CGRP+]: right 1.96±0.17 vs. left 0.86±0.12; P<0.001, each). After 4 weeks a clear-cut increase in nerve densities could be detected in the denervated kidneys, which further increased until week 12 ([TH+]: right 2.67±0.07 vs. left 2.35±0.12, P<0.03; [CGRP+]: right 2.06±0.16 vs. left 1.82±0.17, P=ns). Our study clearly indicates for the first time that there is not only a relevant sympathetic re-innervation but also a re-innervation of afferent nerves in the kidney. The afferent re-innervation process even seems to be more complete compared to sympathetic nerve fiber re-growth. Further studies have to be done to prove the functional relevance of our findings.
Abstract 475: Autonomic Blockade Improves Obesity-Associated Insulin Resistance
Authors: Gamboa Alfredo , Okamoto Luis , Arnold Amy , Raj Satish , Abumrad Naji N , Diedrich Andre , Biaggioni Italo
Published: July 2021

A hallmark of obesity is the development of insulin resistance. Increased secretion of insulin is an initial compensatory mechanism and is thought to contribute to sympathetic activation in an attempt to restore energy balance. We have previously shown, however, that sympathetic activity has no beneficial effect on resting energy expenditure in obesity. On the contrary, we hypothesize that sympathetic activation contributes to insulin resistance providing a negative feedback loop. To test this hypothesis we determined insulin sensitivity (hyperinsulinemic euglycemic clamp) in obese subjects (30<BMI<40 kg/m2) during intact and during pharmacologically induced autonomic blockade (trimethaphan 4 mg/min IV infusion). Blood pressure was clamped during autonomic blockade by concomitant titrated IV infusion of the NOS inhibitor L-NMMA. Eleven obese subjects (41±3.6 years, 35±0.8 kg/m2, 144±4/90±4 mm Hg) were studied on two separate occasions randomly assigned. Seven were found to be insulin resistance and four to be insulin sensitive (GIR>4.5 mg/kg/min). There were no differences in age, total fat percentage, blood pressure or muscle sympathetic activity between groups. GIR increased during autonomic blockade only among subjects with insulin resistance (2.96±0.54 to 4.03±0.67 mg/kg/min for the intact and blocked days, p=0.018, figure group A). No improvement was seen in the insulin sensitive group (6.08±0.88 to 5.99±1.34 mg/kg/min for the intact and blocked days, p=0.5, Group B). Our results support the concept that sympathetic activation has a detrimental effect on glucose utilization in obesity, and provides the rational to explore it as a therapeutic target.
Abstract 488: Arteriolar Smooth Muscle Calcium Waves Depend on Calcium Influx through Voltage-gated Calcium Channels
Authors: Jackson William F , Westcott Erika B
Published: July 2021

Smooth muscle cells (SMCs) in arterioles from striated muscle display IP
3
receptor-dependent Ca
2+
waves that contribute to global myoplasmic Ca
2+
concentration and myogenic tone. However, the contribution of voltage-gated Ca
2+
channels (VGCC) to these arteriolar Ca
2+
signals is unknown. We tested the hypothesis that Ca
2+
waves depend on Ca
2+
influx through VGCC in cremaster muscle arterioles loaded with Fluo-4 and imaged by confocal microscopy. At rest, with vessels pressurized to 80 cm H
2
O in 2 mM Ca
2+
, arteriolar diameter was 28 ± 2 μm (n = 5), and SMCs displayed Ca
2+
waves with frequency (FREQ) = 0.21 ± 0.06 Hz, occurrence (OCC) = 3.5 ± 1.0 waves/SMC and amplitude (AMP) = 1.7 ± 0.1 F/Fo. Removal of extracellular Ca
2+
dilated the arterioles to 39 ± 1 μm, and inhibited Ca
2+
waves (FREQ = 0.1 ± 0.03, OCC = 1.7 ± 0.5 waves/SMC and AMP = 1.4 ± 0.06 F/Fo; p < 0.05 vs. rest) indicating that Ca
2+
waves depended, in part, on influx of extracellular Ca
2+
. Similarly, the VGCC antagonist, nifedipine (1 μM), dilated the arterioles to 34 ± 1.3 μm and also inhibited Ca
2+
waves (FREQ = 0.07 ± 0.02 Hz, OCC = 1.1 ± 0.5 waves/SMC, AMP = 1.4 ± 0.05 F/Fo; p < 0.05 vs. rest). Hyperpolarization of SMCs with the K
+
channel agonist, cromakalim (10 μM), dilated arterioles from 49 ± 3 to 59 ± 4 μm (n = 4, p < 0.05) and also reduced Ca
2+
wave FREQ (0.1 ± 0.04 to 0.03 ± 0.003 Hz), OCC (1.7 ± 0.04 to 0.5 ± 0.05 waves/SMC) and AMP (1.5 ± 0.04 to 1.2 ± 0.004 F/Fo) (p < 0.05). Conversely, depolarization of SMCs with the BK
Ca
channel blocker, TEA (1 mM), constricted arterioles from 28 ± 2 to 16 ± 1 μm (n = 5, p < 0.05) and increased wave FREQ (0.2 ± 0.1 to 0.5 ± 0.1 Hz, p < 0.05) and OCC (4 ± 1 to 8 ± 2 waves/SMC, p < 0.05), effects blocked by nifedipine (1μM) (p < 0.05). Similarly, in arterioles pressurized to 20 cm H
2
O to eliminate myogenic tone and reduce basal VGCC activity, application of the VGCC agonist, BayK 8644 (5 nM) constricted the arterioles from 14 ± 1 to 8 ± 1 μm and increased wave FREQ (0.2 ± 0.1 to 0.6 ± 0.1 Hz) and OCC (3 ± 1 to 10 ± 1 waves/SMC) (n = 6; p < 0.05), effects that were independent of ryanodine receptors, as Ca
2+
waves were unaffected by ryanodine (50 μM) in the absence or presence of BayK 8644 (n = 6; p > 0.05). These data support the hypothesis that Ca
2+
waves in arteriolar SMCs depend, in part, on Ca
2+
influx through VGCC.
Abstract 49: Blood Pressure is Correlated with Arterial Stiffness in Previous Preterm Preeclamptics
Authors: Hale Sarah A , McBride Carole , Bernstein Ira M
Published: July 2021

Blood pressure (BP) and arterial stiffness are known to be correlated and have independent value in assessing risk for future cardiovascular disease. The objective of the current study was to evaluate the relationship between arterial stiffness, as measured by pulse wave velocity (PWV), and BP, in nulliparous women (CTL) as compared to women with a history of preterm preeclampsia (PE). Twenty-eight nulliparous women and 19 PEs were evaluated during the follicular phase of the menstrual cycle. There were no differences in age: CTL: 30.9 ± 0.9 vs. PE: 31.3 ± 1.1 yrs, p = 0.78. BMI was significantly lower in CTL: 24.4 ± 1.1 vs. PE: 28.5 ± 1.6 kg/m
2
, p = 0.02. Time interval from delivery to evaluation in PE was 2.46 ± 0.29 yrs. PWV was measured using simultaneous electrocardiographic tracings and ultrasound determined arterial flow waveforms and calculated as the estimated distance divided by the time interval between EKG r-wave peak and ultrasound derived peak popliteal artery flow. Beat to beat BPs were measured in the seated position using the Finapres Pro and averaged over one minute. The data are expressed as mean ± SE. P < 0.05 accepted for significance. MAP was significantly lower in CTLs than in PEs: 87.7 ± 1.4 vs PE: 94.4 ± 2.4, p = 0.02. There was no difference in PWV between CTL and PE: CTL: 2.51 ± 0.05, PE: 2.52 ± 0.06, p = 0.88. Pulse pressure was significantly correlated with PWV in PEs, but not in CTLs, CTL: r = 0.26, p = 0.18, PE: r = 0.54, p = 0.02. Systolic BP was significantly correlated in both CTL and PE with PWV: CTL: r = 0.43, p = 0.02, PE: r = 0.53, p = 0.02. There was a trend for a significant positive correlation between diastolic BP and PWV in the PE group, but not in the CTL: r = 0.11, p = 0.57, PE: r = 0.44, p = 0.06. The same trend existed in the PE for MAP and PWV: CTL: r = 0.27, p = 0.17, PE: 0.44, p = 0.06. For women who have had previous PE, a significant relationship exists between BP and arterial stiffness, while women who have not had a pregnancy do not exhibit this relationship. Pregnancy likely unmasks subclinical cardiovascular derangement resulting in PE, and persisting years beyond delivery. Our observations suggest that for women who have had prior PE evaluating the relationship between arterial stiffness and BP may be more informative for cardiovascular risk than assessing PWV alone.
Abstract 60: Reduced Macrophage-dependent Inflammation Improves Endothelial Function and Vascular Remodeling, Oxidative Stress and Inflammation in a Model Of Endothelin-1 Induced Vascular Injury
Authors: Barhoumi Tlili , Javeshghani Danesh , Paradis Pierre , Schiffrin Ernesto L
Published: July 2021

Background:
Transgenic mice with endothelium specific preproendothelin-1 overexpression (eET-1) exhibit endothelial dysfunction and vascular remodeling, oxidative stress and inflammation independently of hemodynamic effects. However, it is unclear whether vascular inflammation is causally implicated in adverse vascular effects of endothelin-1 (ET-1). We hypothesized that ET-1-induced vascular injury is decreased in a model of reduced macrophage-dependent inflammation,
macrophage colony stimulating factor
(
mCsf
) mice heterozygote for the osteopetrosis (Op) mutation.

Methods and Results:
Wild type (WT), eET-1,

mCsf
Op/+

and eET-1/

mCsf
Op/+

mice were studied. There was no difference in tail-cuff systolic blood pressure between groups. Endothelial function and vascular structure were determined on a pressurized myograph. Endothelium-dependent relaxation in response to acetylcholine was similar in eET-1 and eET-1/

mCsf
Op/+

. However, in the presence of L-NAME, the magnitude of NO-independent relaxation was greater in eET-1/

mCsf
Op/+

compared to eET-1 (72.4±6.7% vs. 40.8±14.4%,
P
<0.001). Media-to-lumen ratio was greater in eET-1 than WT (0.13±0.01 vs. 0.08±0.01,
P
<0.01) and unchanged in eET-1/

mCsf
Op/+

(0.10±0.01). Media cross-sectional area (μm
2
) was greater in eET-1 than WT (13521±2106 vs. 8112±381,
P
<0.05) and unchanged in eET-1/

mCsf
Op/+

(8966±1125). Dihydroethidium staining revealed that reactive oxygen species production in aorta was 4-fold higher in eET-1 than WT (
P
<0.01) and unchanged in eET-1/mCsf
Op/+
. Aortic monocyte/macrophage infiltration was increased 2.6-fold in eET-1 (
P
<0.01) and tended to decrease by 45% in eET-1/mCsf
Op/+
compared to WT.

Conclusion:
Reduction of macrophage-dependent inflammation in mice overexpressing ET-1 in endothelium results in improved vascular relaxation and reduced vascular remodeling, oxidative stress and inflammation, providing evidence for a role of macrophages and innate immunity in ET-1-induced vascular damage.