bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 010: Interplay Between Nox5 And Endoplasmic Reticulum Stress Influences Vascular Smooth Muscle Cell Phenotypic Switching In Human Hypertension
Authors: Camargo Livia L , Montezano Augusto C , WANG YU , Rios Francisco J , Touyz Rhian M
Published: October 2023

Vascular remodelling, a hallmark of hypertension, involves vascular smooth muscle cell phenotypic switching. Molecular mechanisms underlying this process are unclear, but redox-dependent processes are important. Here we explored the role of Nox5, oxidative and ER stress in VSMC de-differentiation in hypertension. VSMCs from resistance arteries of normotensive (NT) and hypertensive (HT) subjects were studied. Nox5 compartmentalization (cell fractionation); ROS generation (chemiluminescence); activation of ER stress (IRE1α, PERK phosphorylation), and markers of phenotypic switching (αSMA, SM22, MYOCD KLF4) proliferation (PCNA) and inflammation/fibrosis (IL-6 and IL-8) were assessed. Nox5 and IRE1 were silenced with siRNA. In HT, Nox5 upregulation was compartment-specific: Nox5 levels were increased in the ER fraction (46 % vs NT, p<0.05). IRE1α (95%) and PERK arms (36%) of ER stress were activated in HT (vs NT, p<0.05). ROS scavenging (Tempol, 1mM) and Nox5 silencing reduced ER stress activation in HT (vs Ctl, p<0.05). ER stress (4-PBA, 1mM) and IRE1 inhibition (STF083010, 60μM) reduced ROS levels and Nox5 expression in HT subjects (vs Ctl, p<0.05). Induction of ER stress (tunicamycin, 5μg/ml, 24h) increased Nox5 expression (25% vs Ctl) in NT (p<0.05), suggesting association between Nox5-ROS and ER stress. Subsequently, we examined the impact of Nox5 and ER stress on VSMC phenotypic switching in HT. VSMCs from HT exhibited reduced expression of the VSMC markers αSMA (90%), SM22 (83%), and MYOCD (50%), whereas KLF4 levels (240%) were augmented (vs NT, p<0.05). Additionally, expression of the proliferation marker, PCNA (217%) and pro-collagen I (23±2 vs NT:13±0.3ng/ml), and production of pro-inflammatory cytokines IL-6 (501±23 vs NT:121±6pg/mL) and IL-8 (373±34 vs NT:262±24pg/mL) were increased in HT (vs NT, p<0.05). Nox5 and IRE1 silencing in VSMC from HT reduced PCNA expression, pro-collagen I release, and baseline and LPS-induced IL-6 and IL-8 release (vs Ctl, p<0.05). Our findings indicate a circuitous relationship between Nox5 and ER stress where Nox5 is both upstream and downstream of ER stress. Activation of this system is closely linked to VSMC phenotypic switching, a crucial process in vascular dysfunction associated with hypertension.
Abstract 014: Loss Of Resident Innate Immune Cells Prevents Salt-Induced Increases In Renal CD8
+
T Cells
Authors: Cowley Craig , Marvin James , Beaudin Anna , Wynne Brandi M
Published: October 2023

Hypertension is associated with an increase in pro-inflammatory cytokines and immune cells. Resident renal dendritic cells (rDCs) form an intricate network within the kidney. DCs can activate and recruit immune cells, as well as secrete pro-inflammatory cytokines. We previously showed that loss of renal DCs (rDC-depletion) prevents salt-sensitive hypertension and reduces intra-renal cytokines. We hypothesize that rDC-depletion alters the salt-induced immune cell profile within the kidney.

To test this hypothesis, male mice lacking a functional CX
3
CR
1
chemokine receptor (CX
3
CR
1
-
EGFP+/+
) or wild-type (Wt, C57Bl6) were used. CX
3
CR
1
is required for DC localization to the kidney; thus, these mice are renal DC-depleted. Mice were fed HS (4%) or normal chow (NC) for 6 days; kidneys harvested, digested and FACS analysis performed on total immune cell populations (n=4 Wt & rDC-depleted). Cells were gated on: CD45, MHCII, Ly6C, CD11c, CD11b, CCR2, CD3, CD8, CD4, F4/F80, NK1.1, XCR1, B220, CD64, Ly6G, CD86 and CX
3
CR
1
. Data were analyzed as a percent of total immune cells (CD45
+
). HS feeding increased CD8
+
T cells (7.9% ± 0.3
vs
. 4.2% ± 0.4 Wt NC, ***p<0.001), while reducing classical DC1 cells (1.7% ± 0.2
vs
. 3.4% ± 0.3 Wt NC, **p<0.01). This increase in CD8
+
T cell population was prevented in rDC-depleted mice (4.9% ± 0.4
vs
. 4.9% ± 0.5 rDC NC). We observed no CD4
+
T cell differences due to either HS or with rDC-depletion. Interestingly, NK cells were increased in rDC-depleted mice at baseline (1.8 fold, ***p<0.001), and were normalized following HS feeding. In HS-fed mice, classical DC2 cells were also trending towards a decrease in rDC-depleted kidneys as compared to Wt.

Here, we show that rDC-depletion prevents the salt-induced increases seen in renal CD8
+
T cells. Our data previously showed early salt- and blood pressure-induced increases in cytokines, such as IL-27 and IL-6, that were similarly reduced in rDC-depleted mice. These data suggest that resident innate immune cells may be compulsory for the immediate response to increased dietary salt by increasing pro-inflammatory cytokines and recruitment of cytotoxic T cells, and may be crucial for the pathogenesis of salt-sensitive hypertension.
Abstract 020:
Impact Of Sex Hormones On Renal Mitochondria Function In Sprague Dawley Rats
Authors: Schibalski Ryan , Spires Denisha , Jones Adam , Cherezova Alena , Ilatovskaya Daria
Published: October 2023

Introduction:
Until females reach menopause, they are generally protected from renal disease. Mitochondrial function is involved in sexual dimorphisms, however, there is a gap in knowledge regarding the contribution of mitochondrial bioenergetics to renal disease susceptibility. Our studies identified sex differences in renal mitochondrial metabolism, respiration, and ROS production in young healthy rats. We hypothesized here that sex hormones mediate the sex differences in renal mitochondrial bioenergetics.

Methods:
Male and female Sprague Dawley rats were randomly divided into groups that underwent a gonadectomy or a sham surgery (4 weeks of age). At 6 months of age renal cortex and medulla were used for
ex vivo
experiments. Mitochondria were isolated and spectrofluorimetry was employed to measure membrane potential (TMRM) and H
2
O
2
production (Amplex Red) along with a Seahorse assay for oxygen consumption rate (OCR). OriginPro was used for analysis (two-way ANOVA with post hoc test).

Results:
Spectrofluorimetry revealed that oophorectomy reduced membrane potential in mitochondria from the renal medulla compared to shams (p=0.001); this effect was not observed in the medulla of orchiectomized males. Female sham rats had higher H
2
O
2
compared to male sham rats (cortex p<0.001, medulla p<0.001). Removing sex hormones’ influence lowered H
2
O
2
production in both the female cortex and medulla (p<0.001, p<0.001), while in males, the loss of sex hormones led to higher H
2
O
2
production in the medulla (p<0.001). Orchiectomy increased ATP-linked respiration in both the cortex and medulla compared to shams (p=0.02, p=0.04), while an oophorectomy did not alter respiration in either region. ATP-linked respiration was increased in the female shams compared to male shams for both regions (p=0.04, p=0.04). Basal OCR was similar between all groups, with cortical mitochondria exhibiting lower OCR compared to medullary mitochondria for all groups (p<0.001).

Conclusions:
We report that renal membrane potential, H
2
O
2
, and OCR are uniquely impacted by sex hormones in healthy rats 5 months post-gonadectomy. The observed dissimilarities resulting from sex hormones’ highlight the need to consider sex for the prevention and treatment of renal diseases.
Abstract 021: Betamethasone Prevents Preeclamptic Phenotypes By Upregulating Regulator Of G Protein Signaling 2
Authors: Schickling Brandon M , Clark Chris , Gumusoglu Serena , Santillan Donna A , Santillan Mark K
Published: October 2023

Preeclampsia (PreE), a prevalent gestational disorder, is characterized by high blood pressure and kidney damage. Currently, the only known treatment for PreE is to deliver the baby. Chronic infusion of AVP in mice has been shown to recapitulate clinical symptoms of preeclampsia including pregnancy-specific hypertension. Corticosteroids are commonly given during pregnancy to promote fetal lung development. However, it is not known whether they can be used to manage PreE. C57Bl6/J mice received 24ng/hr of AVP throughout gestation until necropsy on gestational day 18. Betamethasone, a steroid, was administered at gestational day 7. An increase of 8.093 mmHg (110.72 vs 118.81, p=0.01) in systolic blood pressure was observed in AVP-infused mice compared to saline-infused pregnant mice and addition of BMTZ in AVP-infused mice returned blood pressure to baseline (109.59 mmHg, p=0.030). AVP treated mice had elevated expression of renal collagen 1A (4.99 fold, p=0.01) and TGFβ (2.58 fold, p=0.009) compared to saline infused mice. BMTZ reversed renal collagen 1A (0.98 fold, p=0.03) and TGFβ (0.75 fold, p=0.004) compared to AVP only infused mice. Trophoblast invasion of the uterine spiral arteries early in pregnancy is abnormal in women who develop PreE resulting in poor placental profusion. HTR8, a placental trophoblast cell, was treated with AVP or the combination of AVP and BMTZ. AVP decreased trophoblast migration by 34 units (p<0.001) and BMTZ rescued migration by 42.1 units (p<0.001). Similarly, AVP treatment decreased trophoblast invasion (0.58 vs 0.49 units, p=0.11) and BMTZ rescued invasion (0.62 units vs 0.49 units, p=0.032). Previously published data demonstrated that Regulator of G Protein Signaling 2 (RGS2) is decreased in placentas of PreE patients and RGS2 decreases AVP signaling. Trophoblasts treated with AVP show a 0.49 fold decrease in RGS2 expression and BMTZ rescues RGS2 expression (1.29 fold, p=0.038). Overexpression of RGS2 in AVP treated cells resulted in a 20 unit increase in migration (248.7 vs 268.7, p=0.01). These data demonstrate that BMTZ can prevent PreE phenotypes as well as abnormal trophoblast invasion and migration caused by AVP. RGS2 regulation by BMTZ may be the mechanism by which BMTZ is protective in preclinical models of PreE.
Abstract 023: Prior Sflt1 Induced Preeclampsia Exacerbates Post-partum Hypertension-mediated Aortic Stiffness And Hypercholesterolemia-induced Atherosclerotic Inflammation
Authors: Biwer Lauren , Man Joshua , Ibarrola Ulzurrun Jaime F , Camarda Nicholas , Carvajal Brigett , Zsengeller Zsuzsanna K , Karumanchi Ananth A , Jaffe Iris Z
Published: October 2023

Preeclampsia (PE) is new high blood pressure (BP) and organ damage occurring late in pregnancy in association with increased soluble VEGF receptor (sFlt1). PE survivors have increased risk of future hypertension and myocardial infarction/stroke. We hypothesized that exposure to high sFlt1 during pregnancy exacerbates hypertension and atherosclerosis post-partum. PE was induced by transient adenoviral expression of sFlt1 compared to control virus in pregnant mice. PE mice had elevated sFlt1, BP and kidney damage during pregnancy which resolve post partum. Two months post-partum, prior PE mice had significantly increased BP response to high salt diet. After high BP stimuli, we studied large and small artery function. Prior PE mice had diminished nitric oxide-mediated vasodilation and stiffer aortas with more fibrosis as measured by pulse wave velocity (Con:3.7 vs sFlt:5.9 mm/ms, p<0.0001) and trichrome staining (Con:13.7% vs sFlt:33.9%, p=0.0009). Atherosclerosis studies exposed LDLR knockout mice to PE followed by high fat diet feeding for 8 weeks. Body weight, fasting glucose and cholesterol were not altered by prior PE. Aortic roots were histologically analyzed for plaque size and composition. Aortic root plaque size (Con:73.3 vs sFlt:78.0 AU, p=0.60) and necrotic core were not different between groups. Aortic arch plaque inflammation was quantified via flow cytometry showing significantly increased plaque CD45+ leukocytes (sFlt:1.6 fold, p=0.036) and T cells (sFlt:1.8 fold, p=0.031) from mice with prior PE. Atheroprone mice with prior PE had significantly increased aortic expression of CCL22 (sFlt:1.5 fold, p=0.047), providing a potential mechanism for increased T cell infiltration into atherosclerotic plaques. Experimental PE produces a state of enhanced sensitivity to hypertensive stimuli and increased vascular inflammation in atherosclerotic plaques supporting the concept that PE directly exacerbates hypertension, vascular stiffness, and atherosclerotic inflammation independent of pre-existing risk factors.
Abstract 029: Hypertensive Disorder Of Pregnancy Results In Loss Of Pancreatic Beta Cell Area In Female Rat Offspring Without Development Of Glucose Intolerance
Authors: Regal Jean F , Root Kate M , Cedars Melissa A , Alejandro Emilyn
Published: October 2023

Hypertensive disorders of pregnancy can result in increased risk for type 2 diabetes (T2D) in offspring. Reduced pancreatic beta cell area can also influence development of glucose intolerance or T2D. Using a rat model of reduced uterine perfusion pressure (RUPP) which leads to hypertension during pregnancy and intrauterine growth restriction, we previously demonstrated reduced beta cell area in female RUPP offspring vs Sham at embryonic day 19 persisting to postnatal day (PD)13. To determine if this alteration in beta cell area is associated with phenotypic changes in glucose handling as offspring mature, we assessed IPGTT (intraperitoneal glucose tolerance test), OGTT (oral glucose tolerance test) and ITT (insulin tolerance test) in PD14, PD28, 8 week and 6 month female offspring (n=5-11/group). Our results demonstrate no change in fasting blood glucose and no alteration in glucose handling with IP glucose administration at any age. However, peak glucose following oral glucose administration was significantly less in RUPP offspring at PD14 (196.3+/-8.6 mg/dl, RUPP; 218.3+/-9.5 mg/dl, Sham; p=0.05), PD28 (220.0+/-4.1 mg/dl, RUPP; 280.0+/-12.8 mg/dl, Sham; p<0.05) and 6 months (139.6+/-3.8 mg/dl, RUPP; 150.9+/-4.5 mg/dl, Sham; p<0.05) compared to Sham, suggesting the incretin effect on pancreas and non-pancreas tissues is more effective in controlling blood glucose in RUPP offspring vs Sham. In addition, the decrease in glucose level in response to insulin injection in ITT was significantly greater in RUPP offspring vs Sham at PD28 (58.9+/-5.0 mg/dl, RUPP; 78.3+/-8.9 mg/dl, Sham; p<0.05) suggesting increased insulin sensitivity in non-pancreatic tissues in RUPP compared to Sham offspring. Our studies demonstrate female offspring of hypertensive pregnancies are not glucose intolerant by 6 months of age. Despite reduced pancreatic beta cell area in female RUPP offspring early in development, glucose handling was maintained and even improved after oral glucose challenge in older RUPP offspring. Overall, these data suggest that increased peripheral insulin sensitivity may reduce the demand for beta cell function, and our studies reinforce the idea that adverse pregnancy can have a lasting effect on development and function of the pancreas.
Abstract 031: Adverse Childhood Experiences And Cardiovascular Disease Risk In Childhood: A Pilot Study
Authors: Wass Anastasia , Garofano Jeffrey , Parrish Carisa , Brady Tammy M
Published: October 2023

Adverse Childhood Experiences and Cardiovascular Disease Risk in Childhood: A Pilot Study

Anastasia Wass
1
, Jeffrey Garofano
1
, Carisa Parrish
1
, Tammy Brady
1
1
Johns Hopkins University, Baltimore, MD

Background:
Adverse childhood experiences (ACE) are associated with increased cardiovascular disease (CVD) risk in adults. We aimed to determine if ACE associate with CVD risk factors among youth with obesity and elevated blood pressure (EBP).

Methods:
This was a cross-sectional pilot study of 25 youth aged 5-22 yrs with obesity and EBP who completed ACE questionnaires. Triplicate manual BPs and 24-hr ambulatory BPs were obtained and BP indexes were calculated (measured BP/age-sex-height specific 95
th
%ile BP; values ≥1 are elevated). Students t-tests, Wilcoxon rank sum, Chi-squared analyses compared characteristics between youth with ACE≥4 vs<4. Regression analyses determined associations of ACE with CVD risk factors, adjusting for age, sex, race, BMI z-score.

Results:
Overall mean age was 14.8 yrs, 56% were female, 84% were Black. 28% reported ≥4 ACE. Those with ACE≥4 had higher resting systolic BP (SBP), resting SBP index, and non-HDL cholesterol than those with ACE<4 (Table). Having ≥4 ACE was independently associated with resting SBP [β 11.0, 95% confidence interval (CI) 4, 18.1, p=0.004) and resting SPB index (β 0.09, 95% CI 0.03, 0.14; p= 0.004). No ABPM measures or other CVD risk factors were associated with ACE.

Conclusion:
In this pilot study of youth with obesity and EBP, ACE were associated with higher resting SBP. Further research in larger cohorts are needed to better elucidate how ACE associate with CVD risk in children and adolescents.
Abstract 036: The Single-cell Gene Expression Landscape Of The Hypothalamus During The Development Of Hypertension In Three Major Models
Authors: Qiu Qiongzi , Liu Yong , Xue Hong , Liu Jing , Therani Bhavika , Usa Kristie , Huang Jing , Greene Andrew S , Rao Sridhar , Geurts Aron M , Cowley Allen W , Liu Pengyuan , Liang Mingyu
Published: October 2023

The hypothalamus plays a key role in blood pressure regulation through coordinating and integrating signals in the central nervous system. However, it’s remains underexplored how the cell signaling network in the hypothalamus changes during the progression of hypertension, the key regulators involved, and whether shared or distinct pathophysiological mechanisms underlie the development of hypertension triggered by various genetic susceptibility or environmental factors. To address these questions, we applied the single-nucleus RNA sequencing technology to analyze hypothalamus samples from three well-established models of hypertension with distinct pathogenesis - mice treated with Ang II, the Dahl salt-sensitive rat, and the spontaneous hypertensive rat - along with their respective controls. Data were obtained from 238,445 nuclei from 24 samples under 12 experimental conditions. By characterizing the cellular composition under different disease conditions, we discovered an elevated glia-to-neuron ratio in Ang II-induced hypertension, with increases of 3.1-fold in astrocytes, 4.0-fold in microglia, and 3.4-fold in oligodendrocytes. Moreover, astrocytes underwent a transition from the resting state to a reactive mode associated with neuroinflammation and stronger neuron adhesion. Additionally, multiple neuronal signal communication pathways were overactivated in response to Ang II, including neurexin-neuroligin signaling, nitric oxide-guanylate cyclase pathway, and glutamate and its receptors. In the salt-sensitive hypertension, a 2.3-fold expansion of pro-inflammatory microglia via Cd74 activation was observed after a short-term high-sodium diet, which leveled off thereafter. With a prolonged high-salt intake, there was a 1.7-fold increase in the proportion of Plagl1+ GABA-ergic neurons. In 26 weeks old spontaneously hypertensive rats, a distinctive 1.4-fold increase in the proportion of Slit3+ Glu-ergic neurons was observed, setting them apart from WKY rats. These findings provide new insights into how the hypothalamus may be involved in the development of hypertension under different disease conditions.
Abstract 040: Evidence Of Increased Glycolysis In Renal Cortex Of High Salt Fed Sprague Dawley Rats
Authors: Shimada Satoshi , Hoffmann Brian , Yang Chun , Kurth Theresa , Greene Andrew , Liang Mingyu , Dash Ranjan K , Cowley Allen W
Published: October 2023

To determine whole kidney O
2
and substance metabolism in an unanesthetized state, arterial (A), renal venous (Vr) blood and urine (U) were analyzed together with measurements of renal blood flow (RBF), blood pressure (BP) and GFR in conscious freely moving male SD rats. RBF and BP were measured continuously (24/7) via chronically implanted ultrasonic flow probe and A-line respectively. A and Vr blood through chronically implanted catheters and urine (U) were sampled intermittently when rats were fed a 0.4% NaCl (LS) diet and on days 7, 14, and 21 after switching to a 4.0% NaCl (HS) diet (HS7, HS14, HS21). A and Vr O
2
contents were determined by radiometer and a global metabolomic analysis was performed at the JAX Laboratory (LC-MS-MS). GFR was determined in another group of rats by transcutaneous detection of the attenuation of i.v. injected FITC sinistrin. Cortical (Cx) and outer medullary (OM) tissues were obtained from the other group of rats and underwent metabolomic and mRNAseq analyses (Novogene). From another group of rats, glomeruli (Glo), proximal tubules (PT) and non-PT were isolated for RT-PCR. BP and RBF slightly increased by HS3 (P<0.05) and were sustained at these levels. O
2
extraction rose progressively from 0.10 ± 0.01 at LS to 0.14 ± 0.01 at HS21 (P<0.05). GFR increased from 0.64 to 0.83 mL/min/100 g (P<0.05) at HS7 and sustained. Na
+
reabsorption and O
2
consumption were positively correlated. Clear distinctions were observed in a sparse partial least squares discriminant analysis of tissue metabolomics among LS, HS14, and HS21. The mRNAseq analysis found that the HS diet resulted in the activation of immune system-related genes in both Cx and OM and the downregulation of genes related to the TCA cycle and metabolism of amino acids and fatty acids in Cx only. In contrast, glycolysis-related genes including hexokinase (
Hk
) and pyruvate kinase (
Pkm
) were upregulated in Cx. Metabolic fluxes (A-Vr-U) showed the increased release of lactate and pyruvate from the kidney when fed HS. Increased mRNA expression of
Hk
and
Pkm
in HS21 was observed only in PT but not in Glo and non-PT. In summary, SD rats fed a HS diet underwent changes in RBF, O
2
extraction, and utilization of substrates with evidence of increased glycolysis.
Abstract 041: Adipocyte (Pro)Renin Receptor Via SPRR Regulates Renal Sodium-glucose Cotransporter-2 Expression And Glomerular Filtration Rate In Mice
Authors: Zheng Huaqing , zou Changjiang , Kaewsaro Kannaree , Wang Fei , Fu Ziwei , Yang Tianxin
Published: October 2023

Evidence is available to suggest a potential role of adipocyte-derived factors to control renal function but the nature of these endocrine factors largely remains elusive. Sodium-glucose cotransporter 2 (SGLT2) controls Na
+
delivery to the macula densa thereby determining tubuloglomerular feedback and thus glomerular filtration rate (GFR), providing the molecular basis for attenuation of glomerular hyperfiltration and diabetic kidney disease by SGLT2 inhibitors. Furthermore, we previously reported that soluble (pro)renin receptor (sPRR) inhibits obesity-induced renal SGLT2 expression, thus reducing GFR and albuminuria in a mouse model of diet-induced obesity. In the present study, we examined adipocytes as a potential source of sPRR that acts in an endocrine manner to regulate renal function, particularly GFR, through regulation of renal SGLT2 expression. PRR floxed mice was crossed with Adipoq-CreERT2 mice and gene inactivation was induced by tamoxifen in adulthood (termed as Adipo PRR KO). Under basal condition, male 4-month old Adipo PRR KO mice exhibited a 33.65% increase in GFR as assessed by transdermal measurement of GFR as compared with floxed controls (1318.26± 38.35 in KO group
vs
. 986.33± 14.31 ul/min/100g
b.w.
in floxed group, n = 6,
p
< 0.01). Dapagliflozin-sensitive SGLT2 activity as assessed by 6-h urinary glucose excretion was increased by 1.93 folds in Adipo PRR KO mice (SGLT2 activity: 13.19± 1.64 in KO group vs. 6.83± 1.20 mg/6h in floxed group, n=7-10,
p
< 0.05). Immunoblotting analysis detected a more than 10-fold increase in renal protein abundance of SGLT2 in the null mice (12.38± 1.51 in KO group vs.1.00± 0.26 in floxed group, n=6, p < 0.01) whereas the increase in renal SGLT2 mRNA was quite modest (1.25± 0.08 in KO group
vs
. 1.00± 0.06 in floxed group; n = 6, p < 0.05). As compared with floxed mice, Adipo PRR KO mice showed a 44.62% fall in plasma sPRR concentration as assessed by ELISA (1.18± 0.09 in KO group
vs
. 2.12± 0.10 ng/ml in floxed group, n = 6, p < 0.01). Taken together, the present study, for the first time, provides evidence for an endocrine action of adipocyte PRR to regulate renal SGLT2 expression and GFR likely through sPRR.
Abstract 043: The Role Of Nicotine-induced Nitrosative And Oxidative Stress In The Development Of Podocyte Damage In The Dahl Ss Rat
Authors: Ilatovskaya Daria , Semenikhina Marharyta , Fedoriuk Mykhailo , Stefanenko Mariia , Cherezova Alena , Jones Adam , Stadler Krisztian , Palygin Oleg
Published: October 2023

Introduction:
Patients with hypertension or renal disease are more likely to exhibit glomerular pathology associated with smoking. Smoking has been linked to lower nitric oxide (NO) bioavailability, oxidative and nitrosative stress. Nicotine triggers the formation of peroxynitrite (ONOO
-
), a highly damaging redox molecule, and was also recently implicated as a contributor to hypertensive renal disease. Here we hypothesize that nicotine induces podocyte damage through peroxynitrite formation, thus causing glomerular function decline and aggravation of kidney damage in the Dahl SS rat.

Methods:
We performed live confocal imaging on human podocytes to detect the production of ONOO
-
(HPF), Ca
2+
(Fluo-8), and nitric oxide NO (DAF-FM) in response to nicotine. Seahorse assay was used to detect changes in mitochondrial health. Then, nicotine was chronically infused in the Dahl SS rats using Alzet pumps (0.2 mg/kg/day s.c., 0.4% NaCl, 21 days). Electron microscopy (EM) and Masson's trichrome staining were used to blindly evaluate glomerular and mitochondrial damage. ANOVA with post-hoc comparisons was used for statistical analysis.

Results:
IHC indicated that human and rat glomerular podocytes express nAChRs. Acute application of nicotine promoted intracellular Ca
2+
and ONOO
-
transients. The ONOO
-
response was blocked in the presence of SOD, indicating that ONOO
-
production requires superoxide. The application of specific nAChR agonists elicited Ca
2+
transients but did not produce ONOO
-
, suggesting that nitrosative processes may occur independently from Ca
2+
influx or nAChR activation. Incubation with nicotine (12-hrs) resulted in a significant decrease in podocytes’ NO bioavailability (p<0.05) and mitochondrial respiration (p<0.05).
In vivo,
in the Dahl SS rat nicotine infusion promoted mitochondrial damage in podocytes, which exhibited swelling, loss of cristae, and signs of mitophagy. Masson's trichrome staining and the assessment of glomerular damage showed deterioration of glomerular health.

Conclusion:
The pathological shift in redox balance in the podocyte is directly associated with nicotine. It may be the primary mechanism responsible for podocyte damage, renal function decline, and blood pressure development in smokers.
Abstract 047: Understanding Patient And Practitioner Use Of The US Validated Device Listing (VDL™)
Authors: Ramkissoon Nar , McReynolds Matthew
Published: October 2023

Hypertension is the leading preventable risk factor for cardiovascular disease, yet according to research, only one in four adults with hypertension have their blood pressure (BP) controlled. Clinical guidelines recommend the use of self-measured blood pressure to improve (SMBP) BP control among individuals with hypertension, however, research has shown that most BP devices available for purchase are not validated, raising concerns about the accuracy of BP readings taken by a patient. In response, the American Medical Association (AMA) launched the US Validated Device Listing (VDL)™, the first U.S. list of BP measurement devices developed to assist physicians and patients in identifying devices that have been validated for clinical accuracy.

The VDL website, validateBP.org, has had more than 660,000 visitors since it launched in 2020. There are currently 60 devices from 16 manufacturers listed on the site. To better understand awareness and use of SMBP, the VDL, and validated devices, the AMA commissioned a survey from a panel of practitioners and patients. Results from over 300 practitioners indicate that while the vast majority of primary care physicians recommend at-home blood pressure devices to their patients (99%; 151/152), and most are aware of validation and accuracy concerns (58%; 88/152), less than one third of primary care physicians were aware of the Validated Device Listing (29%; 44/152).

In a survey of over 300 patients, data indicate that over half prefer to measure blood pressure using a personal device (55%; 166/301), and among self-identified hypertensive patients with a device, the vast majority view accuracy of blood pressure readings as the most important factor when comparing blood pressure devices (83%; 146/176).

Results from the small-scale survey point to the continued need for validation resources for SMBP devices, and the need to continue developing a greater awareness of the VDL amongst practitioners and patients.
Abstract 049: The Effect Of Temperate Seasonality On Systolic Blood Pressure Is Amplified In Population Control Rates
Authors: Barrett Robert B , Martin Ben , Riesser Benjamin , Sutherland Susan E , Rakotz Michael , Egan Brent M
Published: October 2023

Background:
Temperate seasonal effects have a significant influence on blood pressure (BP). Changes in average systolic (S)BP have an exaggerated effect on population BP control (BP <140/90) rates, in part due to patients bordering the control target. We assessed the influence of seasonal effects on average SBP, as well as the corresponding effect on control rates across a patient cohort.

Methods:
A prospective patient cohort was selected from six diverse healthcare organizations engaged in a quality improvement program. Patients with a diagnosis of hypertension (HTN), no medication changes, and at least one visit in each temperate season during the assessment period were included. The seasonal effect on average SBP and control was determined from multivariable mixed effects linear and logistic regression models, respectively.

Results:
A cohort of 60,676 patients, mean age 62.3±12.0 years, meeting all inclusion criteria was selected. The population had 453,787 qualifying visits, where SBP during winter months averaged 0.47 mmHg higher (95% CI [0.364-0.573]) than the yearly mean, with a significantly lower odds ratio for BP control (OR 0.92, 95% CI [0.91-0.94]). In contrast, average SBP was 0.92 mmHg lower during the summer - with a higher likelihood of BP control (OR 1.10, 95% CI [1.07-1.12]).

Conclusion:
The seasonal effect on SBP was confirmed in a diverse group of adults with hypertension. The novel observation is the nearly 5% variation in BP control related to seasonal SBP variation of 1.4 mmHg. From a practical perspective, BP control is typically defined by values at the last visit of the calendar year, which occur disproportionately in months with higher SBP and lower control.
Abstract 050: Leveraging Electronic Health Records To Assess Delay In Hypertension Diagnosis: Insights From A Large Regional Health System
Authors: Lu Yuan , Brush John E , Liu Yuntian , Sawano Mitsuaki , Asher Jordan , Young Patrick , Schulz Wade , Anderson Mark , Burrows John , Krumholz Harlan M
Published: October 2023

Introduction:
Timely hypertension diagnosis is vital for effective management and prevention of complications. This study assessed hypertension diagnosis delays in a large regional health system using electronic health records (EHRs).

Methods:
Retrospective analysis of EHR data (2010-2021) in Sentara Healthcare System was conducted. Hypertension diagnosis was defined as two outpatient blood pressure (BP) readings >=140/90 mmHg within two years, with at least 30 days separation. The delay in diagnosis was determined as the time elapsed from the computable diagnosis to the structured diagnosis documented in the EHR.

Results:
Among 302,774 patients with computable hypertension diagnosis, 23.6% lacked a structured diagnosis. Furthermore, 23.8% received early structured diagnosis (after first BP elevation), and 18.6% received eventual structured diagnosis (after second BP elevation). Among those who received an eventual structured diagnosis, the median delay in hypertension diagnosis was 21.7 months (interquartile range: 7.5-45.5 months). Prescription rate for antihypertensive medication was significantly lower for patients with no structured diagnosis (44.2%) and eventual structured diagnosis (38.1%) than for those with early structured diagnosis (82.3%). Longer delays were associated with older age, male gender, and Black patients.

Conclusions:
The study highlights concerning delays in hypertension diagnosis, impacting timely intervention and complication prevention. By leveraging EHR data, health systems can identify areas for improvement and enhance the efficiency of hypertension diagnosis, leading to improved patient outcomes.
Abstract 052: Vascular Endothelin-1 Mediates Hyperoxia-induced Cellular Stress In Kidney Vessels
Authors: Biswal Sara N , Johnston William A , Kraus Abigayle C , Coleman Gabriel J , De Miguel Carmen
Published: October 2023

Despite its common use in the clinic, therapeutic oxygen supplementation can result in organdamage. We recently reported in a mouse model that hyperoxia leads to elevated levels ofendothelin-1 (ET-1) in plasma and kidney, as well as exaggerated extracellular matrixdeposition, cell death and expression of mitochondria-related genes in the kidney. ET-1 is avasoactive peptide that is linked to various forms of cell stress pathways and kidney damage;however, the specific role that vasculature-derived ET-1 may play in hyperoxia-induced cellularstress in this organ is unknown. We hypothesized that, during hyperoxia, the lack ofvasculature-derived ET-1 results in ameliorated activation of endoplasmic reticulum andmitochondrial stress in kidney vessels. Male and female floxed ET-1 and vascular endothelialcell ET-1 knockout (VEET KO) mice were exposed to >95% O2 for 72 hours. After this time,mice were sacrificed, and renal vessels were isolated. Expression of genes involved inendoplasmic reticulum (ER) and mitochondrial stress was assessed by RT-PCR. Absence ofET-1 in the vasculature led to a significantly decreased expression of the ER stress marker
ATF-4
after hyperoxia (floxed ET-1 vs. VEET KO: 1 ± 0.1 vs. 0.58 ± 0.08, n=8-12/group,p=0.0036). In response to high oxygen, VEET KO mice also presented with reduced expressionof mitochondrial genes
FIS1
(1 ± 0.14 vs. 0.67 ± 0.15, p=0.0036),
MFN2
(1 ± 0.16 vs. 0.58 ±0.12, p=0.0495), and
PINK1
(1 ± 0.18 vs. 0.73 ± 0.28, p=0.048). No sex differences weredetected. Our data demonstrate that vascular ET-1 stimulates ER stress and mitochondrialstress pathways in the kidney vessels during hyperoxia, possibly inducing downstream kidneydamage. Our findings may provide new insights into novel therapeutic targets to preventhyperoxia-induced organ damage.
Abstract 055: Estrogen And Smooth Muscle Cell Estrogen Receptor Alpha Modulate Arterial Stiffness
Authors: Turner Casey G , Martin Gregory , Lu Qing , Sun Zhe , Jaffe Iris Z , Hill Michael A , Dupont Jennifer
Published: October 2023

Background:
Arterial stiffness increases with age and contributes to cardiovascular disease. Although sex differences in arterial stiffness are clinically observed, the underlying mechanisms are unknown. Specifically, the role of estrogen (E2) and estrogen receptor alpha (ERα) in sex-dependent differences in arterial stiffness have not been defined. We hypothesize that E2 and ERα contribute to sex differences in arterial stiffness.

Methods/Results:
We measured aortic pulse wave velocity, an index of arterial stiffness, at 3, 12, and 18 months old, in male and female mice. Arterial stiffness increased in males at 12 and 18m but was delayed until 18m in females (p<0.05). Circulating E2 decreased with age in females (p<0.05), suggesting a link between estrogens and arterial stiffness. In young female mice, arterial stiffness increased with ovariectomy (OVX) versus sham surgery but was restored in OVX mice plus E2 pellet (p<0.05). Aortic gene expression for the vasoprotective angiotensin II type 2 receptor (AT2R) decreased with OVX versus sham and was restored in OVX mice plus E2 pellet (p<0.05). These data suggest a link between arterial stiffness, E2, and AT2R. We therefore created novel SMC-specific ERα knockout (SMC-ERα-KO) mice to assess the role of SMC-ERα in sex differences in arterial stiffness. Differences in arterial stiffness with age persist in ERα-intact mice, but 18m SMC-ERα-KO males and females exhibited less stiffness vs. age-matched ERα-intact littermates (p<0.05). Trends persist in repeat PWV measures at 12 and 16-18m in individual males and females. Blood pressure (via telemetry) did not differ between 18m intact and KO males or females (p=0.73). In young ERα-intact females, OVX increased stiffness and decreased aortic AT2R expression, while OVX had no effect in SMC-ERα-KO females (all p<0.05), supporting a role for E2 and SMC-ERα in arterial stiffness.

Conclusion:
These data suggest that estrogen contributes to sex differences in arterial stiffness and that with advancing age, SMC-ERα is unliganded due to the loss of estrogen and contributes to arterial stiffness in females, potentially via alterations in vascular AT2R function. These results also suggest a detrimental role for SMC-ERα in aging-associated arterial stiffness in males.
Abstract 058: Factors Contributing To Postprandial Hypotension In Neurogenic Orthostatic Hypotension
Authors: Mehr Pouya E , Hay Kaitlyn R , Castro Robert , Ding Tan , Claassen Daniel O , Biaggioni Italo , Peltier Amanda , Shibao Cyndya A
Published: October 2023

Postprandial hypotension (PPH) is defined as a sudden and substantial decrease (>20 mmHg or >10 mmHg) in blood pressure (BP) within two hours post meal intake; This condition is highly prevalent in neurogenic orthostatic hypotension (nOH) and is associated with pre-syncopal symptoms and postprandial syncope. We studied factors contributing to PPH in nOH. Patients were admitted at the Vanderbilt clinical research center and placed on a sodium-controlled diet. Autonomic function testing, including continuous recording of BP and heart rate (HR) during head up tilt, sinus arrhythmia, and Valsalva Maneuver, was performed. Subjects took a high-carbohydrate meal (~500 Kcal). Hemodynamic parameters were monitored every 5 mins for 30 minutes before and up to 120 minutes afterwards. Results: We recruited 13 patients with peripheral autonomic failure (Parkinson’s Disease), 62% males, 73±9.08 y.o. and 13 with central autonomic failure (Multiple System Atrophy), 69% males, 62±8.23 y.o. All subjects had a substantial SBP (-42.9 ±27.90 mmHg) and DBP (-20.8 ±15.2 mmHg) decrease within 3 mins of standing, without compensatory HR increase (11.64 ± 5.97 bpm). The orthostatic increase in HR adjusted by decrease in SBP was abnormal (0.4±0.43, normal>0.5), sinus arrhythmia ratio was abnormal (1.05±0.04, normal>1.2). Pressor response in Valsalva Maneuver showed impaired sympathetic vasoconstriction. Postprandial hemodynamic changes were analyzed with area under the curve (AUC) and at 30-min timepoint post meal, which was the nadir. PD had a larger DBP increase (907±214.83 mmHg vs.1209±277.68 mmHg MSA, P=0.016), MSA had a higher HR increase (1102±236 mmHg vs. 1318±199.82 mmHg, P=0.029). No difference was found in AUC SBP, however at 30-min post-meal, SBP was lower in PD (-25±24.19 mmHg vs. -3.3±15.05 mmHg MSA, P=0.026). Only supine SBP predicted the postprandial decrease in SBP at 30 min (r=-0.5, P=0.04). Conclusion: PPH is more severe in peripheral autonomic failure; supine BP was associated with PPH.
Abstract 061: Continuous And Cyclic Components Of Blood Pressure Profile Have Impact On Different Brain Areas In Controlled Hypertensive Patients
Authors: Carnevale Lorenzo , Carnevale Daniela , Grassi Guido , Lembo Giuseppe
Published: October 2023

Increase in arterial blood pressure consistently damages the connectivity and function of the brain. While this evidence is becoming more widely accepted, the effects of daily fluctuations and variability in blood pressure levels on the brain are still not well understood. Our study investigated the impact of blood pressure variability (BPV) on cognitive function and white matter brain structure in a cohort of hypertensive patients under optimal BP control. We used diffusion tensor imaging (DTI-MRI) to assess white matter injury, neuropsychological tests such as the Montreal Cognitive Assessment (MoCA) to evaluate cognitive function, and 24-hour ambulatory blood pressure monitoring to measure BPV. Spectral analysis of BPV allowed us to measure both the cyclic and the continuous components of arterial blood pressure profile. We found that the Fractional Anisotropy of the Middle Cerebellar Peduncle was correlated with the cyclic component of both diastolic and systolic blood pressure. Additionally, a significant association between the continuous component of both diastolic and systolic blood pressure and the Anterior Thalamic Radiation was detected.. Finally, cognitive functions measured by MoCA were correlated with the continuous component of both diastolic and systolic blood pressure (Table).

Our results suggest that the continuous component of blood pressure negatively impacts white matter regions associated with cognitive impairment, while the cyclic component is associated with alterations in brainstem regions where nervous vagal control is coordinated.
Abstract 064: CD4+ T Cells Mediate Pregnancy-induced Renal Damage In The Dahl SS In A Process Dependent Upon NADPH Oxidase 2 (NOX2)
Authors: Dasinger John Henry , Walton Samuel D , Abais-Battad Justine M , Burns Emily , Shaw Mary , Mattson David L
Published: October 2023

Previous work from our lab demonstrated that adoptive transfer of Dahl SS splenocytes into rats lacking T cells (SS
CD247-/-
) led to significant renal damage and impairment in uterine artery blood flow during pregnancy. In contrast, transfer of SS
p67phox-/-
splenocytes, which lack the ability to generate NOX2-derived ROS, did not amplify pregnancy-induced renal damage. It is unknown what cell type in splenocytes mediates these effects. The present study tested the hypothesis that adoptive transfer of Dahl SS CD4+ T cells would induce a preeclamptic-like phenotype in the SS
CD247-/-
in a process dependent on NOX2. CD4+ T cells from Dahl SS or SS
p67phox-/-
were transferred into SS
CD247-/-
rats by intraperitoneal injection at postnatal day 5 to investigate the oxidative capacity of CD4+ T cells. Injected SS
CD247-/-
rats were aged to 10 weeks when they were mated with naïve littermate males. Prior to mating, baseline MAP and protein excretion rates were comparable between the groups (136±6 vs 134±3 mmHg, 33±5 vs 28±3 mg/day,
p>
0.05, n=5/group, SS vs SS
p67phox-/-
, respectively). At the end of the pregnancy, the SS treated rats develop significant proteinuria that is not observed in the rats that received SS
p67phox-/-
CD4+ T cells (138±14 vs 83±16 mg/day,
p<
0.05) despite no difference in MAP. In addition, there was an increase in uterine artery resistance index as assessed by Doppler ultrasound at GD20 in the SS treated relative to SS
p67phox-/-
(0.70±0.03 vs 0.62±0.02,
p
<0.05) indicating an impairment in blood flow leading to the placenta. There was a trending reduction in placental efficiency (fetal/placental weight) observed in the rats injected with SS CD4+ T cells versus those injected with SS
p67phox-/-
CD4+ T cells (3.99±0.3 vs 4.57±0.1, p=0.06) suggesting there is an impairment in placental function. Taken together, the present data suggest a causal role for NOX2 in CD4+ T cells in pregnancy-associated renal damage and impairment of vascular function.
Abstract 065: Reduction Of Endoplasmic Reticulum Stress By Treatment With Nifedipine In A Mouse Model Of Pre-eclampsia And In Human Placental Endothelial Cells
Authors: Achille Allahnah , Atioui Rim , Marc Casandra , Frégeau Geneviève , Hannou Lydia , Vachon Isabelle , Lavoie Julie L , Bertagnolli Mariane
Published: October 2023

Introduction:
Pre-eclampsia (PE) is characterized by high blood pressure (BP) and metabolic disorders during pregnancy, being the leading cause of maternal-neonatal mortality worldwide. The causes of PE are still unclear. We observed enhanced endoplasmic reticulum (ER) stress and increased cytoplasmic mobility of calreticulin, a Ca2+ ion binding chaperone protein, in placental endothelial cells (pECs) of mice with PE, indicating changes in Ca2+ mobilization. We aimed to describe the effect of nifedipine, a Ca2+ channel blocker, on ER stress in placentas of mice with PE and in human pECs exposed to hypoxia.

Methods:
We used heterozygous mice overexpressing human renin and angiotensinogen, developing high BP from gestational day (GD) 13.5, and controls (C57BL/6). Nifedipine (1 mg/kg in 0.5 ml saline, s.c.) or saline was administered at GD14.5 and placentas removed at GD18.5 (n=8-12/group). Protein expressions of IREα, ATF6 and PERK were evaluated by western blot. ECs were extracted from human placentas of healthy pregnancies by magnetic sorting and exposed to hypoxia (0.5% O2) or control conditions (8% O2) for 24h while treated with nifedipine (0.1 μM) or DMSO. Angiogenesis was assessed by tube formation assay on matrigel. Results were compared by 2-way ANOVA (mean±SD).

Results:
IREα expression was higher in placentas of PE mice treated with saline versus control (+306±64%, p=0.020) and significantly reduced with nifedipine versus saline in PE mice (-235±66%, p=0.009). Results were similar with PERK, which was increased in placentas of saline-treated PE mice versus saline controls (116±40%, p=0.037) and significantly reduced with nifedipine versus saline in PE mice (-141±38%, p=0.006). ATF6 was not different between groups, but was significantly reduced by nifedipine versus saline in PE mice (-76±24%, p=0.022). In pECs, nifedipine increased 17x the numbers of tubes formed on matrigel of cells exposed to hypoxia in comparison to DMSO control (p<0.001).

Conclusion:
The results describe an enhanced ER stress in placentas of PE mice and a positive effect of nifedipine on this stress. The pro-angiogenic effect of nifedipine was shown in pECs exposed to hypoxia. Further investigations are needed to confirm a potential angiogenic effect of nifedipine in PE.