bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 465: The CB2 Cannabinoid Receptor Mediates the Anti-Proliferative Actions of Angiotensin-(1-7) in Vascular Smooth Muscle Cells
Authors: Tallant E. Ann , Howlett Allyn , Grabenauer Megan , Thomas Brian F , Gallagher Patricia E
Published: July 2021

Therapeutic interventions to reduce vascular proliferation are critical for the effective treatment of hypertension-induced end-organ damage, restenosis and atherosclerosis. We showed that angiotensin-(1-7) [Ang-(1-7)] reduces neointimal formation following vascular injury and inhibits vascular growth, through activation of the AT7 receptor mas and production of arachidonic acid derivatives. Endocannaboids (ECs) derived from membrane phospholipids also inhibit vascular proliferation and reduce growth following vascular injury, by stimulation of the CB2 receptor. The impact of CB2 receptor blockade on the anti-proliferative actions of Ang-(1-7) was investigated to assess a potential interaction between the EC and Ang-(1-7)/mas receptor systems. Rat thoracic aortic vascular smooth muscle cells (VSMCs) were treated with platelet-derived growth factor (PDGF) to stimulate growth and incubated with Ang-(1-7), the AT7 receptor antagonist [D-alanine7]-angiotensin-(1-7) [Dala], the CB2 receptor agonist HU308 and/or the CB2 receptor antagonist AM630. PDGF-stimulated VSMC growth was markedly reduced by Ang-(1-7) (74 ± 6% of control, n = 10, p<0.0001) and this effect was blocked by Dala (116 ± 14% of control, n = 4; n.s.). The Ang-(1-7)-mediated reduction in growth was abolished by the CB2 receptor antagonist AM630 (136 ± 16% of control, n = 4; n.s.); AM630 alone had no effect. In contrast, the CB1 receptor antagonist AM281 did not prevent the inhibitory actions of Ang-(1-7) on VSMC growth. CB2 receptor activation by the agonist HU308 also reduced PDGF-stimulated VSMC proliferation to a similar extent as Ang-(1-7) (67 ± 4% of control, n = 5, p<0.001); Dala did not influence the response to HU308 (50 ± 10% of control, n = 5, p<0.005). Ang-(1-7) significantly increased the endogenous cannabinoid 2-arachidonoylglycerol (2-AG) by 48% in VSMC by 24 h (p<0.05, n = 4). We conclude that the growth inhibitory properties of Ang-(1-7) involve a novel pathway culminating in the downstream formation of 2-AG and subsequent activation of the CB2 receptor in VSMC. Thus, Ang-(1-7) and/or CB2 receptor activation may constitute a new and beneficial therapeutic strategy for the prevention of vascular proliferation that is prevalent in cardiovascular disease.
Abstract 486: Increased Afterload In Sub-acute Phase Of Myocardial Infarction Exacerbates Heart Failure
Authors: Ishikawa Kiyotake , Aguero Jaume , Fish Kenneth , Leonardson Lauren , Hajjar Roger J
Published: July 2021

Background:
Hypertension (HT) increases cardiac afterload and is one of the risk factors of poor prognosis after myocardial infarction (MI). However, there is little information on how HT impacts the healing processes during sub-acute phase MI. We investigated the role of an increased afterload on left ventricular (LV) performance and remodeling shortly after MI.

Methods:
Anterior MIs were created in 15 Yorkshire pigs via percutaneous access. To mimic HT condition, 7 pigs (Banding, n=7) underwent surgical banding of the ascending aorta 10 days after the MI, and were compared to the remaining pigs (Control, n=8). LV remodeling and function were assessed one month after MI using 3-D echocardiography and invasive hemodynamic measurements.

Results:
Echocardiographic assessment at day 10 revealed no significant differences in LV ejection fraction (EF) or LV volumes. One month after MI, aortic banding increased the systemic vascular resistance index, but was not statistically significant (1658±282 dyn/s/cm5/m
2
vs 1153±658 dyn/s/cm5/m
2
, P=0.08). Banding group presented with significantly impaired LVEF (Figure, P=0.002), larger end systolic volume (Figure, P=0.045), lower cardiac index (3.1±0.9 L/min/m
2
vs 4.4±0.6 L/min/m
2
, P=0.01), and elevated LV end diastolic pressure (22.4±5.0 mmHg vs 14.4±7.5 mmHg: P=0.04, Banding vs Control, respectively). Reduced EF was associated with remote myocardial dysfunction and histological analysis revealed increased interstitial fibrosis in this area.

Conclusion:
Increased afterload in sub-acute phase of MI induces more severely impaired cardiac function and LV remodeling, and was associated with worse heart failure status.
Abstract 498: Increased Blood Pressure Variability and Baroreflex Impairment in Patients With End-stage Renal Disease Undergoing Hemodialysis
Authors: Scapini Kátia B , Hong Valéria C , Ferreira Janaína B , Souza Sílvia B , Ferreira Naomi V , Moraes Oscar A , Consolim-Colombo Fernanda M , de Lima José J , Mostarda Cristiano , Irigoyen Maria C
Published: July 2021

Background:
Patients with end-stage renal disease (ESRD) undergoing hemodialysis are susceptible to the development of autonomic dysfunction, which is associated with an increased risk of sudden death. Experimental and clinical evidence suggest a crucial role of autonomic dysfunction for both, the progression of renal disease and for the high rate of cardiovascular events in these patients. In the present study, we evaluated the heart rate variability (HRV), the blood pressure variability (BPV) and the baroreflex sensitivity (BRS) in ESRD patients undergoing hemodialysis and normal controls.

Methods:
Nine ESRD patients undergoing hemodialysis (mean age 53.4±10.2 years, 4 male) and nine age-matched healthy controls (mean age 52.8±10.2 years, 4 male) were assessed. Non−invasive curves of blood pressure (BP) were recorded continuously (Finometer ®) for 10 minutes, at rest, in the supine position. The heart rate variability (HRV) and systolic blood pressure variability (BPV) were estimated in the time and frequency domain (spectral analysis). The BRS was quantified by alpha index. Statistical analyzes were performed by Student's t test and the results were expressed as mean ± standard deviation.

Results:
ESRD patients presented lower HRV in time domain than healthy controls (SDNN: 25.8±10.7 vs. 44.6±11.7 ms, p<0.01; VAR NN: 768.3±607.4 vs. 2113.9±1261.6 ms
2
, p=0.01). All frequency domain analyzed indexes, i.e., total power (361.9±297.0 vs. 1227.2±696.3 ms
2
,

p<0.01), high-frequency (181.8±128.7 vs. 358.7±179.8 ms
2
, p=0.047), low-frequency (55.1±44.2 vs. 444.6±389.9 ms
2
, p=0.02) and very-low-frequency (72.5±75.1 vs. 279.2±119.5 ms
2
, p<0.01) of HRV were lower in ESRD patients. The BPV was higher in ESRD patients when compared to controls (VAR PAS: 98.4±72.0 vs. 35.4±21.4 ms
2
, p=0.03) and BRS was lower in ESRD patients (alpha index: 4.34±3.05 vs. 7.56±2.50 ms/mmHg, p<0.02).

Conclusion:
ESRD patients undergoing hemodialysis presents reduced HRV, increase in BPV and reduced baroreflex sensitivity. These impairments may be associated with mortality in ESRD.
Abstract 50: In-treatment Change in 24-Hour Imputed Aortic-to-Brachial Pulse Pressure Amplification Predicts Regression of Left Ventricular Mass Better Than 24-Hour Brachial Pressures
Authors: Norton Gavin R , Sibiya Moekanyi J , Libhaber Elena , Libhaber Carlos , Booysen Hendrik L , Millen Aletta , Maseko Muzi J , Brooksbank Richard , Dessein Patrick H , Sareli Pinhas , Woodiwiss Angela J
Published: July 2021

Whether changes in in-treatment 24-hour aortic blood pressure (BP) predict changes in left ventricular mass (LVM) in response to antihypertensive treatment better than 24-hour brachial BP is uncertain. We imputed 24-hour aortic pulse pressure (PPc) and the 24-hour aortic-to-brachial amplification ratio (PPb/PPc) from an equation that we derived in 1179 participants from a cross-sectional community study. Over a 4-month treatment period in 173 mild-to-moderate hypertensives, 24-hour BP decreased (change in systolic BP/diastolic BP=-22±16/-13±9 mm Hg, p<0.0001), 24-hour PPb/PPc increased (from 1.23±0.08 to 1.27±0.09, p<0.0001) and echocardiographic LVM indexed to height2.7 (LVMI) decreased (-8.8±14.4 g/m2.7, p<0.0001). In-treatment changes in neither 24-hour systolic BP (r=0.08, p=0.32) nor 24-hour PPc (r=0.12, p=0.13) were correlated with changes in LVMI. However, in-treatment increases in the 24-hour PPb/PPc amplification ratio were correlated with decreases in LVMI and these relationships were independent of changes in 24-hour brachial BP and persisted with adjustments for a number of confounders (partial r=-0.24, p<0.005). With or without appropriate adjustments, including baseline LVMI and 24-hour PPb/PPc, marked differences in the change in LVMI (mean±SD in g/m2.7) were noted across tertiles of the change in 24-hour PPb/PPc (Tertiles 1:-4.6±11.1; 2:-8.2±10.2; 3: -11.3±11.0, p<0.05 versus tertiles 1 and 2). With all adjustments including baseline LVMI and 24-hour PPb/PPc, a -6.7 g/m2.7 greater decrease in LVMI was noted in tertile 3 as compared to 1 for change in 24-hour PPb/PPc (p<0.005). In conclusion, the 24-hour aortic-to-brachial PP amplification ratio derived from imputed aortic BP predicts the regression of LVMI in response to antihypertensive treatment better than does 24-hour BP.
Abstract 505: An Iron Chelator, Deferasirox, Prevents Renal Iron Accumulation and Macrophage Infiltration But Not Cell Senescence in Type 1 Diabetic Mice
Authors: Nakano Daisuke , Morita Tatsuyori , Kitada Kento , Nishiyama Akira
Published: July 2021

We previously reported that streptozotocin (STZ)-induced type 1 diabetes caused renal tubular cell senescence through blood glucose- and p21-dependent pathway at week 4 of STZ administration in mice. We investigated the involvement of the cell senescence on accumulation of iron in the renal tubular cells in the present study. STZ mice (n=5) did not show the significant iron accumulation in the kidney at week 4. STZ mice (n=10) showed increases in renal tubular iron accumulation (Perl’s Prussian blue: 278.1±71.9 fold vs. non-diabetic control, p<0.01), F4/80-positive macrophage infiltration (2.6±0.6 fold vs. non-diabetic control, p<0.01), and cell senescence (senescence-associated β galactosidase: 3.7±0.4 fold, p16 mRNA: 2.3±0.2 fold vs. non-diabetic control, respectively, p<0.01, respectively) at week 28. Administering oral iron chelator, deferasirox (10 mg/kg/day, n=10), that removes only dietary iron, significantly attenuated the iron accumulation (38.1±12.4 fold vs. non-diabetic control, n.s.) in proximal tubules and the F4/80-positive cells number (1.3±0.3 fold, vs. non-diabetic control, n.s.) without the effect on blood glucose, hematocrit and hemoglobin levels. On the other hand, deferasirox did not affect renal cell senescence (senescence-associated β galactosidase: 3.9±0.5 fold, p16 mRNA: 2.4±0.3 fold vs. non-diabetic control, respectively, n.s.). The functional deletion of p21, a cyclin-dependent kinase inhibitor, in mice decreased the renal tubular iron accumulation (14.0±5.5 fold vs. non-diabetic control, p<0.01), and did not change the cell senescence at week 28. The animals showed an increase in p16, another cyclin-dependent kinase inhibitor, suggesting that p16 rather than p21 plays important role on cell senescence in the kidney of STZ mice at this time point. The results indicate that the chelation of dietary iron attenuates renal iron accumulation and macrophage infiltration through p21-dependent pathway in STZ mice. It seems likely that there is little interaction between renal tubular cell senescence and iron accumulation in the type 1 diabetic kidney.
Abstract 512: Drugs in the Elderly: Threats and Opportunities
Authors: Wehling Martin
Published: July 2021

Taking 10 and more drugs is unpredictable and may cause more harm than good, given that up to 100,000 medication-related deaths in the United States annually.

An early attempt to improve drug safety in the aged population was the establishment of criteria for drugs to avoid by Beers in 1997.

The evidence for the effectiveness of the Beers list is not compelling.. There should also be a positive labelling of drugs that are indispensable in elderly people as data on morbidity, mortality, and safety are available or emerging for this particular group. There is increasing clinical evidence for beneficial action of, for example, antihypertensive drugs (e.g., Hypertension in the Very Elderly Trial) in elderly people.

Drugs should be labelled taking into consideration their usefulness for elderly people (Table 1) This classification would be an extension of the Beers approach into the positive listing of valuable drugs. This seems necessary as overtreatment and undertreatment are both typical problems of the aged population. Undertreatment, for example, relates to the poor control of arterial hypertension elderly people and may leave more than half of the patients un- or undertreated.

The FORTA classification for antihypertensive drugs as an example is as follows: diuretics B, betablockers B, renin-angiotensin-system blockers A, long acting dihydropyridine calcium channel blockers (CCB) A, CCBs, verapamil type D, spironolactone C, alphablockers C, clonidine D, minoxidil D.

The typical use of the scheme would address general practitioners struggling with polypharmacy. They would then synthesize the recommendations into a rank order of drugs that they could use to cut the list short.
Abstract 517: The Use of Congenic Strains, Comparative Genome Hybridization, and Whole Genome Sequencing to Dissect the Genetic Basis of Chronic Kidney Disease in the Dahl S Rat
Authors: Johnson Ashley C , Guo Zibiao , Kyle Patrick B , Garrett Michael R
Published: July 2021

Chronic kidney disease is a major health issue, with hypertension playing a significant role in progression of kidney injury and decline in kidney function. Previously, genetic studies utilized the Dahl salt-sensitive (S) rat, a model of hypertensive related kidney disease and the spontaneously hypertensive rat (hypertensive, but resistant to kidney injury) to identify genomic regions associated with kidney injury. To confirm identified genomic intervals, congenic strains were developed for several chromosomes (RNO) by transfer of SHR genome to the genetic background of the S, including RNO2, 6, 8, 9, 10, 11, 13 and 19. Several of these congenic strains, with the exception of RNO6 and 19 have been extensively investigated. Here, we report that S.SHR(6) and (19) demonstrate significantly improved proteinuria (53±2.5 and 54±2.5 mg/24hr, respectively) compared to control S (116±7.2) and improved measures of kidney function (BUN= 24.3±0.6 and 24.6±0.6 vs. 28±1.3 mg/dl). To facilitate the identification of genetic variants that underlie each genomic region, especially on RNO6 and RNO19, comparative genome hybridization (CGH) was performed (NimbleGen and Agilent) to identify copy number variation (CNV) between the S and SHR. CNV was identified on RNO6 and RNO19 (as well as other chromosomes) which could be linked to the development of kidney injury. In addition, recent sequencing of the entire genomes of the S and SHR has identified essentially all genetic variation (SNP and INDEL) between the two inbred models. The 95% confidence interval of each causative locus spans ~10 Mb. The region on RNO6 contains 54 annotated genes (24 nonsynonymous SNP) and RNO19 contains 101 genes and/or miRNA (68 nonsynonymous SNP). The majority of SNP (>95%) are within intergenic or intronic regions, regardless of the genomic locus. A modest number of SNP (~5%) fall within the putative promoter region of genes which could impact gene expression. In summary, CGH and high quality genome sequence analysis will help guide upcoming congenic substrain analysis to expedite identification of the causative genetic variation(s) that underlie each genomic locus.
Abstract 526: Serum Levels of 25 Hidroxyvitamin D and Its Association With Body Fat, Metabolic Profile, Inflammatory Biomarkers, Blood Pressure and Endothelial Function
Authors: Ferreira Thaís d , Torres Márcia R , Valença Débora C , Rodrigues Maria d , Neto José F , Marques Ruy G , dos Santos Jeanny , Gomes Nathalia , Sanjuliani Antonio F
Published: July 2021

Background:
Recent evidence suggests that vitamin D deficiency is associated with an increased risk of cardiovascular morbidity and mortality. However, the relationship between vitamin D deficiency and cardiovascular disease risk factors has not been established.

Objectives:
To investigate the prevalence of vitamin D deficiency and its association with body adiposity, metabolic profile, inflammatory biomarkers, blood pressure (BP) and endothelial function in healthy premenopausal women.

Methods:
In this cross-sectional study were included 73 adult women who were submitted to the evaluation of: serum levels of 25 hidroxyvitamin D [25(OH)D]; body adiposity; metabolic profile (glucose, insulin, HOMA-IR, leptin, triglycerides and cholesterol); inflammatory biomarkers (adiponectin and C-reactive protein); BP; and endothelial function by serum concentrations of adhesion molecules and by reactive hyperemia index (RHI), determined by peripheral arterial tonometry, using Endo-PAT 2000®. Participants were stratified into 2 groups according to their vitamin D status: with vitamin D deficiency (Group 1; 25 (OH) D < 20ng/ml; n=12), and without vitamin D deficiency (Group 2; 25 (OH) D ≥ 20ng/ml; n=61).

Results:
The prevalence of vitamin D deficiency was 16% (12 of 73). Women in Group 1 compared with those in Group 2 were older (36.5±3.2 vs. 30.4±1.1 years; p=0.03) and showed higher values of BMI (28.7±1.4 vs. 25.1±0.7kg/m2; p=0.03); % body fat (35.3±1.7 vs. 31.1±0.7%; p=0.02); glucose (88.3±3.2 vs. 80.2±1.1 mg/dl; p=0.01); HOMA-IR (6.3±0.7 vs. 4.4±0.2; p=0.002); and leptin (29.6±3.5 vs. 20.9±1.7 ng/ml; p=0.04). RHI was lower in participants in Group 1 than in Group 2 (1.7±0.1 vs. 2.1±0.1; p=0.02). After adjustments for age and BMI, women with vitamin D deficiency remained with higher levels of glucose and HOMA-IR, and lower levels of RHI. Systolic and diastolic BP were higher in Group 1 than in Group 2 (110.2 ± 5.1 vs. 102.9 ± 1.4mmHg and 72.8 ± 4,0 vs. 68.6 ± 1.3mmHg, respectively), however without statistical significance. The other variables did not differ between groups.

Conclusions:
In the present study, vitamin D deficiency was associated with higher body adiposity, greater insulin resistance and worse endothelial function in women.
Abstract 541: Blood Pressure at 20 Weeks’ Gestation is Predictive of Hypertensive Disease in Pregnancy and is Independently Associated With 5-year Hypertensive Morbidity Post Delivery
Authors: Mito Asako , Arata Naoko , Qiu Dongmei , Sakamoto Naoko , Oya Yukihiro , Matsuoka Ryu , Sekizawa Akihiko , Ichihara Atsuhiro , Murashima Atsuko , Kitagawa Michihiro
Published: July 2021

[Background]
Hypertensive disease in pregnancy (HDP) is associated with a risk of subsequent hypertension. However the influence of normotensive blood pressure (BP) during pregnancy on future BP is not clear.

[Purpose]
To investigate the association between BP measurements at their lowest levels in pregnancy, 20 weeks’ gestation (20 wks BP), and the risk of hypertension both ①during pregnancy and ②5 years after delivery.

[Methods]
A total of 1542 women who delivered singletons at the National Center for Child Health and Development and Showa University Hospital were recruited between 2003 and 2007. They were invited to undergo a physical examination 5 years after delivery. Following exclusions (see below), 772 women completed the analysis. The influence of 20 wks BP on HDP and 5-year hypertension was assessed by multiple logistic regression analysis. The odds ratio for HDP was adjusted by age at delivery, pre-pregnancy BMI, familial history of hypertension (FH), previous history of HDP and parity (Model 1) and that for subsequent hypertension was adjusted by existence of HDP in index pregnancy, age, BMI, FH and renal disease (Model 2).

[Criteria]
HDP was defined as sBP ≥ 140 mm Hg or dBP ≥ 90 mm Hg from 20 weeks’ gestation which remits by 12 weeks postpartum w/o proteinuria.

Hypertension at physical examination was defined as average sBP ≥ 140 mm Hg or average dBP ≥ 90 mm Hg or treatment with antihypertensive agents.

[Exclusion criteria]
Chronic hypertension / Women who were pregnant and nursing when the physical examination was done

[Results]
There were 26 HDP cases and 25 cases of 5-year hypertension (HDP: 6, normotensive control: 19).

① The odds ratio (95%CI) for HDP (adjusted by Model 1) is sBP:1.11 (for every 1 mmHg rise) (1.05~1.17), dBP:1.15(1.06~1.24) and BP category defined by the American Heart Association : 5.82 (for every 1 category increase)(2.15~15.76). A positive correlation between 20 wks BP and HDP risk was observed.

② The odds ratio for subsequent hypertension (adjusted by Model 2) is sBP: 1.06 (1.01-1.11), dBP:1.15(1.06-1.24) and BP category: 4.50(1.64-12.33).

20 wks BP is associated with subsequent hypertension,
independent of HDP
.

[Conclusions]
20 wks BP may predict both HDP and subsequent hypertension 5 years post delivery.
Abstract 542: Progesterone Supplementation Attenuates Hypertension And AT1-AA in Response Tt Elevated IL-6 During Pregnancy
Authors: Amaral Lorena M , Cornelius Denise , Wallace Kedra , Kipprono Luissa , Moseley Janae , Herse Florian , Wallukat Gerd , Martin James N , Dechend Ralf , LaMarca Babbette
Published: July 2021

Preeclampsia is a multi-system disorder defined as new-onset hypertension with proteinuria developing after 20 weeks gestation. Preeclampsia remains a significant contributor to maternal morbidity and mortality, with great impact in perinatal morbidity. Research efforts throughout the world have focused on alternative therapies for the treatment of preeclampsia to the mainstay treatment of delivery of the fetus and placenta. 17-alpha-hydroxyprogesterone caproate (17-OHP) is a synthetic metabolite of progesterone used effectively for the prevention of recurrent preterm birth in singleton pregnancies. Previously we identified potential role for 17-OHP as an anti-inflammatory that suppressed inflammatory cytokines, hypertension and endothelin-1 in response to placental ischemia in the RUPP rat model of preeclampsia. In the current study we examined a role 17-OHP to blunt the pathophysiological effects to elevated IL-6 during pregnancy. IL-6 induced hypertension during pregnancy occurs with increased renin activity, autoantibodies to the angiotensin II type I receptor (AT1-AA) and reduced kidney function. This experiment was performed in the following groups of normal pregnant rats: NP (n=5); NP+17-OHP (n=6); NP+IL-6 (n=10); NP+IL-6+17-OHP (n=10). To test our hypothesis IL-6 (5ng/day) was infused via miniosmotic pump into normal pregnant rats beginning on day 14 of gestation and 17-OHP (3.32mg/kg) was diluted in normal saline and injected on day 18. Blood pressure (MAP) determination and serum collection was performed on day 19 of gestation. MAP in NP was 100+3mmHg which increased with IL-6 to 112+4mmHg, p <0.05. Pregnant rats given 17-OHP alone had a MAP of 99+3mmHg and MAP only increased to 103+2mmHg in IL-6+17-OHP. AT1-AA was 1.2+0.5 bpm in NP rats and increased to 17+9 bpm with IL-6 infusion. Administration of 17-OHP significantly blunted AT1-AA to 4+0.8bpm in NP+IL-6+17-OHP. Importantly, this study illustrates that 17-OHP attenuates hypertension and AT1-AA in response to elevated IL-6 during pregnancy and could lend hope to a new potential therapeutic for preeclampsia.
Abstract 548: Reduced Urinary Angiotensinogen Excretion in Preeclampsia
Authors: Uddin Mohammad N , Horvat Darijana , Allen Steven R , Jones Richard O , Kuehl Thomas J
Published: July 2021

Objective:
Preeclampsia (preE) is a hypertensive disorder of pregnancy. We reported the suppression of circulatory renin-angiotensin system (RAS) in a rat model of preE. Urinary angiotensinogen has been considered as an indicator of intrarenal angiotensin status in hypertension. Little is known about the urinary angiotensinogen in preE. This study evaluates the level of urinary excretion of angiotensinogen in preE to assess the RAS status.

Methods:
Normal pregnant (n=57) and preE (n=32) patients were recruited from Scott & White Hospital and had their blood drawn between 21 to 40 weeks of pregnancy. Criteria for diagnosis of preE included blood pressure >140/90 mm Hg and proteinuria >300 mg of protein/24h. Two groups of rats were used: normal pregnant (n=10) and preE rats (n=10) which were given weekly injections of desoxycorticosterone acetate and 0.9% saline to drink. Urinary angiotensinogen levels and the plasma AngII levels were assayed by ELISA. The kidney expression of (pro)renin receptor, AT
1
receptor, AT
2
receptor, and renin for the two groups of rats was measured by western blot. Results are expressed as means with SD and comparisons made using Student’s t test with p<0.05 considered significant.

Results:
In preE patients, the mean urinary excretion of angiotensinogen (2.0 ± 1.1 ng/mg creatinine) differed (p<0.05) from that in patients with normal pregnancy (2.7 ± 1.5 ng/mg creatinine). The urinary excretion of angiotensinogen (PreE: 1.5 ± 0.3, NP: 2. 3 ± 0.4 nmol/day) also differed (p<0.05) in preE rats compared to NP. The plasma concentration of Ang II for preE rats (25 ± 3 fmol/ml) differed (p<0.05) compared to NP rats (39 ± 5 fmol/ml). The kidney expression of (pro)renin receptor was downregulated (p=0.008), while the AT
1
receptor was upregulated (p=0.01) in preE rats compared to NP. However, the kidney expression of AT
2
receptor (1.0 vs 1.1) and renin (1.0 vs 1.4) were similar in NP and PDS rats (p=0.63 and p=0.12, respectively).

Conclusions:
We demonstrated that urinary excretion of angiotensinogen is reduced in both patients with preE and in a rat model of preE. The kidney expression of RAS components was either downregulated or remained unchanged in preE rats. This finding indicates that preE is an Ang-II independent form of systemic hypertension.
Abstract 550: Large Blood Pressure Variability Aggravates Arteriolosclerosis and Ischemic Changes in the Kidney in Hypertensive Rats
Authors: Aoki Yuji , Kai Hisashi , Kajimoto Hidemi , Kudo Hiroshi , Takayama Narimasa , Yasuoka Suguru , Anegawa Takahiro , Iwamoto Yoshiko , Uchiwa Hiroki , Fukuda Kenji , Kage Masayoshi , Kato Seiya , Imaizumi Tsutomu
Published: July 2021

Background:
Increased blood pressure (BP) variability (BPV) is a characteristic feature of hypertensive patients. Large BPV aggravates hypertensive target organ damage, such as left ventricular hypertrophy, carotid atherosclerosis, and microalbuminuria. We have shown that angiotensin II (AngII)-mediated inflammation plays a role in the aggravation of hypertensive cardiac remodeling in spontaneously hypertensive rats (SHR) with large BPV. However, little was known regarding renal damages induced by large BPV. The aims of this study were to investigate pathological changes of the kidney and to examine whether candesartan would prevent the renal damages in SHR with large BPV.

Methods and Results:
A model of a combination of hypertension and large BPV was created by bilateral sino-aortic denervation (SAD) in SHR at 12 weeks old. SAD increased BPV without changes in mean BP. At 19 weeks old, SAD induced patchy cortical interstitial lesions associated with ischemic changes of glomeruli and tubules and interstitial fibrosis. The interlobular or afferent arterioles around ischemic lesions showed remarkable arteriolosclerotic changes characterized by vascular smooth muscle cell proliferation and extracellular matrix deposition, leading to the luminal narrowing and occlusion (Figure). Chronic treatment with a subdepressor dose of candesartan prevented not only arteriolosclerotic changes but also interstitial fibrosis and ischemic changes in SHR with SAD.

Conclusion:
Large BPV aggravates renal arteriolosclerosis, which results in the cortical ischemic changes and fibrosis in the kidney of hypertensive rats through angII-mediated mechanisms.
Abstract 555: Glucagon-producing Cells are Increased in Mas-deficient Mice
Authors: Braga Janaina F , Alenina Natalia , Bader Michael , Santos Robson A
Published: July 2021

Glucagon is produced by the pancreatic α-cells and has an important role in diabetes. Genetic deletion of the angiotensin-(1-7)/receptor Mas is associated with metabolic disturbances. However, the role of Mas in the pancreatic morphology/function is not known. In the present study we investigated the number of pancreatic α-cells and indirectly β-cells number in C57BL/6J and FVB/N Mas-deficient (KO-Mas) mice. After overnight fasting, 12 weeks-old male KO-Mas mice were sacrificed by i.p. administration of ketamin/xylazine. The pancreas was dissected and the splenic part was fixed in formalin for immunohistochemistry analysis. Tissues were cut (5μm thick), with 150μm interval between cuts to obtain different pancreatic islets, and incubated with anti-glucagon primary antibody. Peroxidase activity was visualized by exposing the sections to DAB solution. Ten islets per mouse pancreas were randomly chosen and all the cells present in the islet were counted. After that, each marked α-cell was also counted using a light microscope. The estimated β-cell content was obtained subtracting the total cells from the α-cells. Mas-deficiency resulted in an increase in the number and percentage of the pancreatic α-cell in both backgrounds compared to wild-type mice (C57BL6/J number of α-cell: 146±21 vs. 67±8 in WT, p<0.001; percentage per islet: 17.9±0.91 vs. 12.3±0.9% in WT, p<0.0001; FVB/N number of α-cell: 260±22 vs. 156±12 in WT, p<0.001; percentage per islet: 16±0.8 vs. 10±0.5% in WT, p<0.0001). The estimated β-cell number was not significantly different in both backgrounds. However the percentage of β-cells were reduced in both backgrounds (C57BL6/J: 82.1±0.91 vs. 87.7±0.9%, in WT p<0.0001; FVB/N: 83.53±1.2 vs. 88.6±0.9% in WT, p<0.001). No significant differences were observed in total amount of cells in pancreatic islets, although a trend for increase in Mas-KO was observed. These data suggest that the Mas/Ang-(1-7) axis is important for the maintenance of normal pancreatic morphology. The imbalance of α and β-cell in Mas-KO might be involved in the metabolic alterations produced by Mas deletion, in mice.
Abstract 561: The ex vivo RAS-Fingerprint - A Novel Approach for the Biochemical Chatracterization of the Renin-Angiotensin-System in Clinical Samples
Authors: Poglitsch Marko , Haschke Manuel , Stoller Andrea , Schwager Cornelia , Domenig Oliver , van Oyen Dunja
Published: July 2021

Angiotensin concentrations are affected by multiple molecular components including receptors and enzymes which might be either dissolved in plasma or attached to blood cells or endothelial surfaces throughout the body, giving rise to a concentration determining local enzymatic environment. This environment substantially changes during blood collection leading to a rapid and fundamental shift in angiotensin peptide levels. Therefore, a clearly defined and properly controlled sample stabilization procedure is essential for the accurate measurement of in vivo angiotensin peptide levels.

Surprisingly, standard samples collected by anti-coagulation with heparin can be used for analyzing the human RAS under well-defined steady-state conditions, allowing RAS-Fingerprint based conclusions about the activities of circulating enzymes involved in angiotensin metabolism. The mass spectrometry based measurements of in vivo RAS-Fingerprints (immediate sample stabilization) or heparin plasma derived ex vivo RAS-Fingerprints in plasma or whole blood provide unique insights into the physiology of the human RAS. RAS-Fingerprinting provides an integrated view about the activity of the enzymes involved in angiotensin metabolism in a plasma sample and therefore represents a powerful tool for characterization of the patient specific “Biochemical Hardware”, which determines angiotensin peptide levels in vivo.

The assay is compatible with undiluted plasma and whole blood and can be further applied to long-term stored frozen plasma samples. The utilization of RAS-Fingerprinting in clinical studies will substantially enhance our understanding of the human RAS and could lead to the development of personalized approaches for the treatment and prevention of cardiovascular diseases in the near future.
Abstract 566: Angiotensin II Promotes Proliferation and Fibrosis in Parietal Epithelial Cells Contributing to the Development of Crescentic Glomerulonephritis
Authors: Shibayama Yuki , Urushihara Maki , Nishiyama Akira , Kobori Hiroyuki
Published: July 2021

Introduction:
Parietal epithelial cells (PECs) contribute to the glomerular crescent formation of crescentic glomerulonephritis. Co-cultured model consisting of mesangial cells (MCs), PECs, and macrophages which play a pivotal role in the development of crescentic glomerulonephritis showed an increase in Angiotensin (Ang) II-induced cell proliferation and collagen secretion in PECs. Moreover, Ang II type 1 receptor blocker (ARB) treatment completely prevented an increase in cell proliferation and collagen secretion in PECs under the co-cultured model. However, it is not clear whether Ang II directly promotes PEC fibrosis and proliferation under the monoculture in PECs.

Aim:
The aim of present study is to demonstrate that Ang II stimulation directly affects PEC proliferation and fibrosis.

Methods:
Primary fluorescein isothiocyanate (FITC)-labeled PEC population was collected from glomeruli in rats using high-speed cell sorter. ERK1/2 phosphorylation was evaluated by Western blotting. Cell proliferation ability was measured by water-soluble tetrazolium salts (WST)-1 and the soluble collagen levels in culture supernatants was determined by the Sircol collagen assay.

Results:
FITC-labeled PECs could be identified as a distinct cell population by high-speed cell sorter. The ERK 1/2 phosphorylation in PECs was stimulated by Ang II (100 nmol/l) by about 1.7-fold. After the treatment with 100 nmol/l Ang II for 24 hrs, cell proliferation ability significantly increased in PECs (mean ± SEM: 1.60 ± 0.03 vs. 1.00 ± 0.04, relative ratio). However, the proliferation ability in Ang II-stimulated PECs was suppressed by Ang II plus 10 nmol/l olmesartan (an ARB) or Ang II plus 100 nmol/l PD98059 (a MEK inhibitor). PECs also promoted a collagen secretion after the stimulation by 100 nmol/l Ang II for 24 hrs (52.1 ± 8.1 vs. 16.8 ± 2.4 μg/ml). Furthermore, the significant decrease in soluble collagen secretion was observed by the treatments with Ang II plus 10 nmol/l olmesartan or Ang II plus 10 μg/ml pan-specific neutralizing TGF-β antibody.

Conclusion:
These data indicate that Ang II-stimulated PECs promote proliferation and fibrosis and may suggest contributing to the development of crescentic glomerulonephritis by PECs independently from MCs or macrophages.
Abstract 619: Blockage Of Toll-Like Receptor 4 Inhibits Renin Stimulation Of NF-KB-Mediated Cytokine Signaling In Brain Neurons
Authors: Shan Zhiying , Yuan Wei
Published: July 2021

Toll-like receptor 4 (TLR4) has been shown to play an important role in inflammation and initiation and progression of cardiovascular pathologies. This, coupled with the observation that activation of the brain (pro)renin receptor (PRR) initiates NF-Kappa B (KB) -cytokine signaling to induce neurogenic hypertension has led us to hypothesize that brain PRR activation, in part, stimulates TLR4 to induce NF-KB-cytokine signal pathway. Thus, blockage of TLR4 should attenuate the expression of NF-KB and proinflammatory cytokines induced by PRR activation. To test this hypothesis, we harvested neuronal cells from neonatal Sprague Dawley rat brain that abundantly express PRR, and incubated with 20 nM of renin for 6 hours. Real time PCR was performed to analyze expression of NF-KB and other inflammatory mediators. Renin treatment resulted in significant increases in interleukin-1 β (IL-1β, 1200-fold), IL-6 (33-fold), tumor necrosis factor (TNF-α, 17-fold), leukemia inhibitory factor (LIF, 18-fold) and C-C ligand 5 (CCL5, 330-fold). In addition, the mRNA levels of P50, a subunit of NF-KB was increased by 5-fold, and nfkbia, a subunit of I-kappa B kinase (IKK), was increased by 7-fold. Furthermore, mRNA levels of inducible nitric oxide synthase (iNOS) was increased by 8000-fold, and a neuronal activation maker, c-FOS was increased by 28 fold as compared with control neurons. However, Quinazoline (10μM), a NF-KB activation inhibitor, effectively blocked renin-induced increases in IL-1β, IL-6, TNF-α, CCL5, iNOS and P50 by more than 85%, but failed to inhibit LIF, nfkbia and c-FOS. In contrast, renin stimulation of all the above genes (IL-1β, IL-6, TNF-α, CCL5, iNOS, LIF, P50, nfkbia and c-FOS) was almost entirely blocked (>90%) by the TLR4 inhibitor, TAK-242 (2 μM), indicating a novel PRR mediated activation of TLR4 signaling. This PRR regulation of neuronal inflammatory mediators and neuronal activity was not affected by AT1 receptor antagonist losartan, demonstrating that the effect is not mediated by PRR-induced Ang-II generation. Our studies suggest that PRR plays a central role in the development of inflammatory mediated neurogenic hypertension through activation of TLR4.
Abstract 71: Novel Bach1 Modulators Increase HMOX1 and Suppress Hypertension in the Goldblatt Model of Renovascular Hypertension
Authors: Kostura Matthew , Attucks Otis , Kassis Jareer , Gupta Suparna , Victory Samuel , Guzel Mustafa , Polisetti Dharma , Schwartzman Michal L , Abraham Nader G , Mjalli Adnan M
Published: July 2021

We report for the first time a novel class of compounds that specifically modulate the Bach1 transcriptional repressor pathway. In cellula, the compounds selectively inhibit the activity of the transcriptional repressor Bach1 resulting in transcription of a network of antioxidant and cytoprotective genes including HMOX1. HPP-1971, a member of this class, is a potent and selective Bach1 inhibitor that induces HMOX1 > 40-fold with a potency of 408 nM in human lung fibroblasts. To assess activity in vivo, we tested HPP-1971 in the Goldblatt model of renovascular hypertension. Sprague Dawley rats were implanted with in dwelling pressure telemeter probes and subsequently underwent sham surgery or placement of a 0.25 mm silver clip around the left renal artery. HPP-1971 treatment, dosed orally at 1,3,10 and 30 mpk, commenced three days following clip surgery, and continued for 18 days. At study completion, blood pressure, clipped kidney weight, renal HMOX1 enzyme activity and plasma aldosterone levels were measured (see Table). HPP-1971 attenuated both kidney atrophy and the increase in blood pressure in a dose dependent manner with significant differences seen at 3, 10 and 30 mpk (p<.0001). HMOX1 enzyme activity in the clipped kidney increased with treatment, reaching a maximum of 5.7 ± 0.9 nM/hr/mg at 30 mpk relative to sham operated animals (p<.0001). Plasma aldosterone levels increased in 2K1C animals compared to sham controls but were reduced by HPP-1971 treatment. These findings define a novel role for Bach1 suppressors in counteracting the influence of the RAAS system on hypertension and kidney atrophy in the 2K1C model of renovascular hypertension.
Abstract 87: The Accumulation of Myeloid-derived Suppressor Cells Is a Compensatory Response to the Development of Hypertension
Authors: Shen Xiao Z , Shi Peng , Giani Jorge , Bernstein Ellen , Bernstein Kenneth E
Published: July 2021

The immune system plays a critical role in the development of hypertension. The immune response consists of pro-inflammatory cells, but also immunosuppressive cells that reduce T cell function. An important category of natural immunosuppressive cell is myeloid-derived suppressor cells (MDSC). We now show that blood and spleen CD11b+ Gr1+ myeloid cells are elevated 2-fold in both angiotensin II and L-NAME induced hypertension. These increased myeloid cells are MDSC in that they elevate IL-4R expression and suppress T cell proliferation. When hypertensive mice were depleted of MDSC, using either anti-Gr1 antibody or gemcitabine, there was a 15 mmHg rise in blood pressure and aggravation of T cells activation with increased production of IFN-γ, TNFα and IL-17 in both spleen and kidney. In contrast, adoptive transfer of MDSC reduced blood pressure in angiotensin-II induced hypertension by 25 mmHg (see Figure). These data suggest a new concept, that the accumulation of MDSC is a compensatory response to the inflammation induced by hypertension. They also indicate that MDSC play an important role in regulating blood pressure.
Abstract 006: Mutation of SH2B3, a GWAS Candidate Gene for Hypertension, Attenuates Dahl SS Pathology
Authors: Rudemiller Nathan P , Lund Hayley , Geurts Aron , Mattson David L
Published: July 2021

The immune system mediates hypertension in many experimental models, though the mechanisms remain unclear. In the Dahl salt-sensitive (SS) rat, infiltration of T lymphocytes and macrophages in the kidneys parallels the onset of hypertension and renal disease in response to high salt diet (4% NaCl). Immunosuppressive treatment blunts the infiltration of immune cells in the kidneys and attenuates the hypertensive pathology. SH2B3, a gene associated with human hypertension in many GWAS, encodes an intracellular adaptor protein shown to play an important role in inflammatory signaling. Mutation of SH2B3 via zinc-finger nucleases on the Dahl SS genetic background reduces immune cell infiltration in the kidneys and significantly attenuates the hypertensive pathology. Bone marrow transplant studies (n=5-6/group; below) show that Dahl SS or SH2B3 mutant rats receiving the SH2B3 mutant bone marrow (open circles, light bars) have significantly attenuated hypertension and albuminuria compared to rats receiving the Dahl SS bone marrow (closed circles, dark bars; * indicates P<0.05 vs. final day of 0.4% NaCl, † indicates P<0.05 vs. Dahl SS on the same day).

These studies indicate a role for the immune system in the altered phenotype in the SH2B3 mutant rat. One possible immune mechanism involved is interleukin 6 (IL-6) signaling, a proinflammatory pathway in which SH2B3 functions. After 21 days on 4% NaCl diet (n=5-6/group), SH2B3 mutants have significantly lower mRNA expression of IL-6 (expressed as fold change of Dahl SS) in the renal cortex (0.54, p<0.05) and renal medulla (0.45, p<0.05). Further studies of IL-6 signaling will elucidate its role in Dahl SS hypertension.
Abstract 044: Ddah-1 And Adma Regulate Proximal Tubular Fluid Reabsorption: Comparison Of Pharmacological Blockade Of Ddah-1 With Gene Knockdown
Authors: Wilcox Christopher S , Bell Tracy , Tomlinson James A , Leiper James , Welch William J
Published: July 2021

Background:
Proximal tubule (PT) fluid reabsorption (Jv) is diminished by knockout of NOS-I or III. ADMA is an endogenous inhibitor of NOS, but its effects on tubular function are unknown. ADMA is degradated by DDAH whose type 1 isoform (DDAH-1) is richly expressed in the PT. SNIPs of DDAH-1 predict the decline of GFR in chronic kidney disease (CKD).

Hypothesis:
that DDAH-1 metabolizes ADMA in the PT thereby reducing its plasma concentration and enhancing Jv.

Methods:
Jv was measured in anesthetized rats and mice in S2 segments of the PT by direct in vivo micropuncture and microperfusion of artificial tubular fluid (ATF).

Results:
Addition of L-257 (10
-4
M; DDAH-1 inhibitor) vs vehicle to ATF perfusing the PT of rats for 10 mins did not affect Jv (3.4 ± 0.20 vs 3.1±0.39 nl/min/mm). However, a bolus i.v. injection (60mg/kg) of L-257 2hrs before and 10 mins of PT perfusion significantly (P< 0.005) reduced Jv by 33% to 2.3±0.17 nl/min/mm and increased plasma ADMA (systemic Veh: 0.46 ± 0.030 vs. systemic L-257: 0.67 ± 0.029 μmol/l; P < 0.0001) without changing SDMA. Microperfusion of ADMA (10
-4
M) or L-NAME (10
-4
M) in rats both reduced Jv significantly by >40% to 2.0±0.24 and 1.8±0.22 nl/min/mm, respectively (P<0.05). An IV 1 ml bolus of saline containing Transit and siRNA targeted to DDAH-1 (hydrodynamic in vivo gene silencing in mice) three days later reduced Jv significantly by 36% compared to scrambled siRNA (2.2 ± 0.16 vs 1.4 ± 0.26 nl/min/mm; P<0.05). Surprisingly, PT cell-specific DDAH-1 knockdown in mice did not affect Jv significantly compared to wild type (PTC-D1WT: 1.7 ± 0.21 vs PTC-D1KO: 2.0 ± 0.15).

Conclusions:
PT fluid reabsorption is regulated by ADMA and its tubular metabolism by DDAH-1. The two-hour delay for L-257 to diminish Jv likely was required for accumulation of sufficient tubular ADMA to impair PT reabsorption. Whereas systemic DDAH-1 gene knockdown in mice was as effective as systemic DDAH-1 blockade with L-257 in rats in reducing Jv in the PT, lifelong deletion of PT DDAH-1 was ineffective, suggesting robust adaptive mechanisms that restore PT reabsorption. Thus, L-257 is a novel regulator of PT function. SNIPs that alter DDAH-1 in the PT may change tubular function and thereby contribute to CKD progression.
Abstract 074: Endothelial Caveolin-1 Mediates The Effects Of Dietary Sodium On Cardiovascular And Metabolic Function
Authors: Abidin Fatthy , Garza Amanda E , Trefts Elijah , Romero Jose R , Adler Gail K , Williams Gordon H , Pojoga Luminita H
Published: July 2021

Hypertension and insulin resistance (IR) are often associated with endothelial dysfunction; however, the underpinnings of their association are not well understood.
Caveolin-1
(cav1) is a transmembrane protein identified in many cell types including cardiovascular (CV) and adipose cells. Our recent findings in mice and humans consistently suggest a role of cav1 in IR, dyslipidemia, CV dysfunction and hypertension in response to sodium loading. While adipose cav1 has been established as a critical mediator of glucose and lipid homeostasis, the role of endothelial cav1 in
cardiometabolic dysfunction
, and its relationship with
dietary sodium
is unclear. To test whether the cav1 in the endothelium mediates the effect of dietary sodium on CV and metabolic function, we used the Cre-
loxP
technology to generate a novel, endothelium-specific cav1 KO mouse model (Ecav1 KO). Glucose tolerance, BP, fasting insulin, lipids and the state of circulating RAAS were measured in Ecav1 KO and WT mice studied on low- and high-sodium diets (0.03 vs 1.6% Na) for 7 days. Ecav1 KO and WT mice had similar BW, food and water intake and urinary output on either diet. Compared to the WT, Ecav1 KO animals had significantly higher fasting blood glucose levels on a LS diet (103±4 vs 87±3 mg/dl, p<0.01) but not on a HS diet. Ecav1 KO mice also had impaired glucose tolerance vs the WT, especially on a HS diet; however, the glucose intolerance was not as pronounced in the Ecav1 KO as in the full cav1 KO. There were no differences in fasting insulin or lipid levels between the genotypes. On a HS diet, Ecav1 KO vs WT mice had significantly higher SBP levels (117±2 vs 109±3 mmHg, p<0.05). In addition, they had significantly higher pulse pressure (38±2 vs 29±1 mmHg, p<0.01), heart rates (802±11 vs 725±12 bpm, p<0.01) and rate pressure products, consistent with increased arterial stiffness and myocardial workload. These changes could not be explained by differences in kidney function; however, aldosterone levels were increased in Ecav1 KO vs WT animals (74±11 vs 48±5 ng/dl) despite no changes in PRA. Our findings are consistent with a direct role of endothelial cav1 in the development of IR and CV dysfunction, and highlight the importance of endothelial function in cardiometabolic homeostasis.