bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P148: Loss of Ovarian Estrogen Downregulates Renal Steroidogenesis
Authors: Nasci Victoria , Gohar Eman
Published: October 2024

Hypertension impacts half of US adults and importantly is more prevalent in men than premenopausal women. Sex hormones, particularly estrogen, have been implicated in this sex-difference. Recently we showed renal medullary estrogenic signaling via the G protein-coupled estrogen receptor 1 promotes sodium excretion in female, but not male, Sprague Dawley (SD) rats which implicates estrogen as a possible female-specific natriuretic factor. This led us to question whether the kidney could produce its own steroids, including estrogen, to respond to salt load changes locally. Evidence in cultured COS-7 and fetal kidney cells indicates the expression and activity of steroidogenic enzymes. Recently, we showed the outer medulla of the female SD rat kidney expresses key enzymes and metabolites involved in sex steroid biosynthesis. It is unknown how ovarian estrogen regulates steroidogenesis in the kidney. We hypothesize that ovarian estrogen stimulates the intrarenal capacity to biosynthesize sex steroids. To test this, we measured mRNA expression of several steroidogenic enzymes in the renal outer medulla of gonadally-intact female or ovariectomized SD rats (N=6). Cholesterol is the initial substrate for steroid synthesis. Thus, we first measured HMG-CoA reductase (HMGCR), the key synthesizing enzyme for cholesterol and steroidogenic acute regulatory protein (StAR), which helps commit cholesterol to steroid synthesis. Ovariectomy (OVX) reduced mRNA expression of both when compared to intact females (HMGCR: 63.5 ± 6.2 vs 100.0 ± 10.7 P=0.0169; StAR: 66.6 ± 12.4 vs 100.0 ± 6.4 P=0.0298). Although not significantly different, OVX seemed to reduce the expression of hydroxysteroid 3-β Dehydrogenase, which converts several intermediate steps in androgen and estrogen synthesis, compared to intact females (73.4 ± 13.3 vs 100.0 ± 9.7 P=0.1283). Hydroxysteroid 17-β Dehydrogenase (17β-HSD) 1, which converts estrone to estradiol, was unchanged in OVX compared to intact females (107.6 ± 13.2 vs 100.0 ± 10.1 P=0.6537). OVX reduced expression of 17β-HSD2 (28.34 ± 7.8 vs 100.0 ± 12.85 P=0.0008) and 17β-HSD3 (71.1 ± 7.5 vs 100.0 ± 5.7 P=0.0097) which interconvert androstenedione and testosterone compared to intact females. Combined these data suggest that ovariectomy blunts the intrarenal machinery for steroidogenesis. Additional experiments are required to test whether menopause downregulates renal sex steroid biosynthesis and predisposes postmenopausal women to hypertension.
Abstract P151: National Estimates of Lifetime Risk of Hypertension in the US
Authors: Rayani Asma , Mok Yejin , Matsushita Kunihiro , Appel Lawrence
Published: October 2024

Background:
Although lifetime risk assessments provide valuable insights into disease burden, to our knowledge, there is only one study estimating the lifetime risk of hypertension in the US, using the current definition (≥130/80 mmHg). However, that study used data from three research cohorts not representative of the US population and lacks data on Hispanics.

Aim:
To estimate lifetime risk of hypertension in the US, using the contemporary definition and nationally representative data.

Methods:
Using the National Health and Nutrition Examination Survey 1999-2018 (N=44,056) and vital statistics, we estimated the prevalence and incidence of hypertension (i.e., ≥130/80 mmHg or antihypertensive medication use) at each year of age from birth to age 80 years) by sex and race/ethnicity (Whites, Blacks, and Hispanics). We, then, estimated the cumulative incidence of hypertension up to 80 years using Monte Carlo simulations.

Results:
The lifetime risk of hypertension reached ~80-85% regardless of sex and race/ethnicity (
Figure
). However, the patterns of reaching this level of lifetime risk of hypertension varied considerably by race/ethnicity, with the age reaching the cumulative incidence of 50% ~40 years in Blacks vs. ~50 years in Whites and Hispanics. Black women exhibited a higher cumulative incidence of hypertension than White and Hispanic men at any point in life.

Conclusions:
Four in five Americans develop hypertension in their lifetime, regardless of sex and race/ethnicity. However, Blacks develop hypertension much earlier than Whites and Hispanics. These findings emphasize the need for public health interventions to prevent hypertension in the US, and such an intervention should reach Black youth and younger adults.
Abstract P152: Association of Cannabis Use with Atherosclerotic Cardiovascular Diseases Outcomes: Insights from a Meta-Analysis of a Multinational Cohort of 1.9 Million Individuals
Authors: Sebastian Sneha Annie , Shah Yash , Krishnamoorthy Geetha
Published: October 2024

Background:
Despite numerous reports suggesting a link between cannabis use and the risk of atherosclerotic cardiovascular diseases (ASCVD), the nature of this relationship—whether causal or not—remains uncertain.

Objective:
We aimed to consolidate data from observational studies to examine the association between cannabis use and ASCVD outcomes compared to non-users or controls.

Methods:
RevMan 5.4 was used for statistical analyses employing a random effects model, and outcomes were presented as risk ratios (RR) with corresponding 95% confidence intervals (CI). The study protocol has been registered with PROSPERO (CRD42024530366).

Results:
Our analysis integrated data from 17 studies, including 1,902,481 individuals aged 18 to 74, with a mean follow-up duration of 8.5 years. The pooled analysis revealed no statistically significant association between cannabis use and the risk of myocardial infarction compared to non-users, with an RR of 1.25 (95% CI: 0.91 to 1.71, p = 0.17). Similarly, the risk of stroke did not show a significant association with cannabis use (RR: 1.38, 95% CI: 0.88 to 2.16, p = 0.16). However, a statistically significant association was found between cannabis use and the composite outcome of any adverse cardiovascular events (RR: 1.48, 95% CI: 1.16 to 1.90, p = 0.002).

Conclusion:
The statistical correlations between cannabis use and composite adverse cardiovascular outcomes underscore its potential as a risk factor for cardiovascular disease. With rising trends in medical cannabis use and cannabis use disorder across age demographics, heightened risk awareness, CVD screening, and informed decision-making regarding cannabis consumption are critical priorities in healthcare and public health initiatives.
Abstract P153: The Role of Lipoprotein Lipase Activation in Vascular Aging
Authors: dos Passos Rinaldo , Wilson Emily , JanuarioDa Costa Tiago , Vieira Cintia , Fontes Milene , Waigi Emily , Townsend Paul , McQuail Joseph , Wenceslau Camilla , Webb R Clinton , McCarthy Cam
Published: October 2024

Lipoprotein metabolism plays a role in cardiovascular diseases and becomes impaired with aging. Angiopoietin-like proteins (ANGPTLs) regulate lipoprotein lipase (LPL) and endothelial lipase (EL), key hydrolases in triglyceride catabolism. We hypothesized that ANGPTL3 and ANGPTL4 would be elevated in aging and that the response to LPL activation would be impaired in mesenteric resistance arteries (MRAs) from old rats. To assess this, MRAs were isolated from 3 and 16-month-old male and female Fischer344 rats and mounted on wire myographs. Concentration-response curves (CRC) to phenylephrine (PE, 10nM-100μM), Ca
2+
channel agonist Bay-K8644 (10nM-30nM), and acetylcholine (ACh, 0.1nM-100uM) were performed with or without LPL activator, NO-1886 (10uM and 50uM). Protein expression was assessed by Western blot. We show for the first time that circulating ANGPTL3 (young: 1.5±0.8 vs old: 5±0.7) and ANGPTL4 (young: 1.7±0.3 vs old: 2.5±0.5) are increased in aging. In MRAs from young rats, NO-1886 attenuated PE-induced contraction in males (Emax; vehicle: 106±3 vs NO-1886 10uM: 86 ± 5* vs NO-1886 50uM: 69±8*, p<0.05) and females (Emax; vehicle: 104±4 vs NO-1886 10uM: 91±5* vs NO-1886 50uM: 75±8*, p<0.05). While 16-month-old males presented a similar reduction in contraction (Emax; vehicle: 105±6 vs NO-1886 10uM: 88±11* vs NO-1886 50uM: 73±17*, p<0.05), in females only 50uM showed a significant anti-contractile effect in a sex-dependent manner (Emax; vehicle: 100±7 vs NO-1886 10uM: 95±7 vs NO-1886 50uM: 83±22*, p<0.05). CRC to bay-K8644 showed decreased contraction after NO-1886 incubation (Emax; vehicle: 16±8 vs NO-1886 50uM: 5±3) indicating that L-type Ca
2+
channel Ca
2+
influx isn’t involved in NO-1886’s anti-contractile effect. NO-1886 incubation did not change the maximal ACh response in young rat MRAs, but a rightward shift in the curve was seen in both sexes. As expected, MRAs from old males (Emax; young: 97±2 vs old: 86±7) and females (Emax; young: 95±2 vs old: 92±6) had decreased maximal relaxation to ACh, compared to young rats. Interestingly, in old rats NO-1886 induced further impaired relaxation to ACh in males (Emax; vehicle: 86±7 vs NO-1886 10uM: 78±14) and females (Emax; vehicle: 92±6 vs NO-1886 10uM: 77±22). Together, this data suggests (1) ANGPTL3 and ANGPTL4 are increased in old rats, (2) LPL/EL activity diminished with age in females, but not males, and (3) while NO-1886 exerts an anti-contractile effect, it can also induce endothelial dysfunction.
Abstract P155: Elevated Long-Term Triglyceride-to-High Density Lipoprotein Cholesterol Ratio Variability From Childhood Is Linked To Higher Risk Of Early-Onset Hypertension: The Bogalusa Heart Study
Authors: Kang Soo Jung , Gill Eunsun , Hwang Phillip , De Anda-Duran Ileana , JIN XUANYI , Fernández Alonso Camilo , Bazzano Lydia
Published: October 2024

Background:
Early-onset hypertension is linked to higher risk of hypertensive organ damage compared to late-onset hypertension. Insulin resistance has been shown to be associated with greater risk of hypertension. Greater triglyceride-to-high density lipoprotein cholesterol ratio (TG/HDL-C), a surrogate marker of insulin resistance, has been linked to higher risk of hypertension. However, whether elevated long-term TG/HDL-C variability from childhood is associated with higher risk of early-onset hypertension is unclear.

Methods:
We studied 1271 participants of the Bogalusa Heart Study (age at enrollment: 9.9 ± 4.0 years, follow-up : 38.3 ± 3.8 years, age at last exam: 48.2 ± 5.2 years, 59.5% women, 34.4% Black participants) with ≥3 lipid measurements during follow-up. TG/HDL-C was obtained as TG (mg/dL) divided by HDL-C (mg/dL). Onset of hypertension was defined as blood pressure ≥140/90 mmHg or taking antihypertensive medications detected during follow-up. According to age at onset of hypertension, 4 subgroups were formed: <35 years (early-onset hypertension), 35-44 years, ≥45 years, and people without hypertension. Long-term TG/HDL-C variability from childhood was calculated as the deviation from age predicted values (DEV) and residual SD (RSD). DEV and RSD were obtained from the growth curves derived from linear mixed effect models, as the mean and SD of the residuals of observed and predicted TG/HDL-C levels. Associations between TG/HDL-C variability and hypertension onset subgroups were evaluated using multinomial logistic regression models. People who did not have hypertension during follow-up were the reference group. Interactions by race and sex were performed.

Results:
Among the 1271 participants, 585 (46.0%) had hypertension at last exam; among the 585, 124 (21.2%) had early-onset hypertension. For 1 SD increase in DEV and RSD of TG/HDL-C, the odds of early-onset hypertension increased by 30.6% (95% CI 1.06, 1.61) and 28.8% (95% CI 1.06,1.57), compared to people without hypertension, after adjusting for race, sex, diabetes, obesity, and smoking status, education, and TG/HDL-C at last exam. No significant associations were observed between DEV and RSD of TG/HDL-C and other hypertension onset subgroups. No significant interactions were found between both DEV and RSD and race and sex.

Conclusions:
Our results suggest that individuals with higher long-term variability in insulin resistance may be at a greater risk of having early-onset hypertension.
Abstract P158: Frailty and Sex are associated with Discordant Blood Pressure Measures among Very Old Adults: Results from the Atherosclerosis Risk in Communities (ARIC) Study
Authors: Larbi Fredrick , Khan Md Marufuzzaman , Col Hannah , Patil Dhrumil , Zhang Mingyu , Turkson-Ocran Ruth-Alma , Ngo Long , Cluett Jennifer , Mukamal Kenneth , Coresh Joe , Selvin Elizabeth , Wagenknecht Lynne , Hughes Timothy , Windham B Gwen , Mosley Thomas , Lutsey Pamela , Ring Kimberly , Juraschek Stephen
Published: October 2024

Background:
Home blood pressure monitoring (HBPM) is increasingly used as a more accessible alternative to office blood pressure (BP). However, agreement between office and home BP among very old adults has not been characterized.

Objective:
To identify clinical factors related to discordance between office and home BP among very old adults.

Methods:
ARIC participants underwent 3 office BP measures, using an Omron HEM907XL after a 5-minute rest with a 60-second pause interval (2023). In addition, using Omron Series 10 BP7450, participants measured BP three times at home in the morning and evening after a 5-minute rest with a 60-second pause interval over an 8-day period. We subtracted mean home systolic BP (SBP) from mean office SBP to determine discordance and characterized it via Bland-Altman plots. We used adjusted linear regression to determine whether age, sex, obesity, diabetes, frailty, or hypertension medications, were associated with discordance.

Results:
Among 776 participants (59.3% female; mean age 84.1±3.9 [SD] years), we observed no difference between office and home SBP; however, bias increased with higher mean SBP (
Figure, Panel 1
). Compared to home, office SBP was significantly lower among the oldest, male, and frail participants, and higher among female and robust participants (
Figure, Panel 2
).

Conclusion:
In this population of very old adults, office and HBPM generated similar estimates of resting SBP. Nevertheless, resting SBP, sex, and frailty may result in discordant measures that could influence treatment decisions. Comprehensive BP monitoring, including office and HBPM, may be necessary for accurate hypertension diagnosis and management in these subgroups of very old adults.
Abstract P159: Conditional deletion of ADAM17 (A disintegrin and metalloprotease 17) in microglia attenuates hypertension and associated inflammation.
Authors: Mohan Uma Priya , Dinh Paula , Yue Xinping , Lazartigues Eric
Published: October 2024

Microglia, the resident immune cell in the brain, contributes to neuroinflammation and neurogenic hypertension by secreting various cytokines and chemokines. ADAM17 shedding of these signaling molecules) in microglia modulates synaptic function but the consequences of this process have not been studied in neurogenic hypertension. Accordingly, we hypothesize that deletion of ADAM17 in microglia opposes microglia activation and cytokine secretion thus preventing the development of neuroinflammation in salt-sensitive hypertension. To test our hypothesis, a new mouse model (ADAM17::CX3CR1-CreERT2; A17-Mic-/-) amenable for selective deletion of ADAM17 in microglia was developed. Following the initiation of deoxycorticosterone acetate plus salt (DOCA-salt) hypertension, tamoxifen was injected intracerebroventricularly to delete ADAM17 in microglia and blood pressure (BP) monitored over 3 weeks. In A17-Mic-/- mice, lacking ADAM17 in microglia, the BP increase induced by DOCA-salt treatment was blunted compared to control mice (127.4±5 vs. 143.4±4 mmHg, P<0.05). However, it was not abated in iRhom2-/- mice (149.5±3 mmHg), lacking the rhomboid protein involved in ADAM17 maturation in microglia, suggesting possible compensation by iRhom1. Interestingly, A17-Mic-/- mice showed a reduced level of proinflammatory cytokines and chemokines in the plasma, including TNF-α (A17-Mic-/-: 5.21±0.97, iRhom2-/-: 3.867±1 vs. control: 20.72±4 pg/mL), IL-6 (A17-Mic-/-: 36.53±11.33, iRhom2-/-: 91.41±14 vs. control: 79.65±15.72 pg/mL) and G-CSF (A17-Mic-/-: 508.4±98.7, iRhom2-/-: 3523±897 vs. 838.2±238.2 pg/mL) and MCP-1 (A17-Mic-/-: 38.41±9, iRhom2-/-: 51.87±7 vs. control: 75.52±12 pg/mL), respectively (P<0.05). Together, our data suggests that conditional deletion of ADAM17 opposes the activation of microglia and reduces pro-inflammatory cytokine and chemokine expression in hypertension. Overall, our data highlights the pivotal role of microglial ADAM17 in regulating salt-sensitive hypertension and the associated inflammation.
Abstract P167: Sex Dependent Associations of the Gut Microbiota with Hypertension – A Prospective Cohort
Authors: Leung Bernice , Virwani Preeti , Qian Gordon , HSU Matthew , Pijarnvanit Tommy K.K.T.S. , CHEUNG Carman Nga-Man , Chow Yick Hin , TANG Lok Kan , TSE YIU-HEI , XIAN Jia-Wen , LAM Shirley Sau-Wing , LEE Pek Iok Crystal , Lo Chelsea , Liu Roxanna , HO Tsi Lok , CHOW Bak Yue , Leung Kin Sum , Lo Kwun Kwan Emily , Yuen Man-Fung , Leung Suet Yi , HUNG Ivan FN , LOUIE Jimmy Chun Yu , El-Nezami Hani , Ho Joshua , Lau Kui Kai
Published: October 2024

Background:
Whilst there is emerging evidence that the associations of the gut microbiota (GM) with hypertension differ between sexes, it remains uncertain whether the GM 1) is altered with antihypertensive-use, 2) can predict blood pressure (BP) trajectories, and 3) whether these associations are also sex-dependent. We therefore aimed to determine the sex-dependent associations of the GM with baseline hypertensive state in untreated versus treated participants and BP changes over time.

Methods:
A total of 451 community-dwelling middle-aged Hong Kong Chinese without symptomatic cardiovascular diseases were recruited (50% men, 14% on antihypertensive agents, mean age, 54.6±6.5 years). Shotgun metagenomic sequencing of stool samples and 24-hour ambulatory blood pressure monitoring (ABPM) were performed. The 24hr-ABPM was repeated on 139 returned subjects after 4 years. Statistical analysis was conducted with 4 covariate models that include age, sex, menopause status, body mass index (BMI), smoking, fasting glucose, triglyceride, cholesterol, sodium intake, and fatty liver status.

Results:
Amongst the 389/451 subjects not on antihypertensive agents, 167/389 (42.9%) had newly diagnosed hypertension at baseline. Females drove the significantly different b-diversity of the GM composition (
p
<0.01) between the normotensives and hypertensives in the baseline study. Multiple GM species were significantly associated with hypertension. In sex stratified analysis,
Faecalimonas umbilicate
was significantly enriched in hypertensive females while
Roseburia sp Am16-25
and
Eubacterium ramulus
were enriched in hypertensive males (all
p
<0.05-0.01). When comparing the 62 treated and 167 nontreated hypertensive subjects, the GM abundance, a-, and b-diversity were not significantly different. However, there were significant GM species associated with the use of antihypertensive medication. Notably,
Lachnospiraceae bacterium
and
Flavonifractor plautii
were significantly enriched in treated and untreated individuals, respectively (all
p
<0.05-0.001). During a mean follow up of 51.2±4.5 months, 73.2% of the 71 untreated subjects remained normotensive and were associated with enriched
Bacteroides uniformis
in their baseline metagenomic data under models adjusted for age, sex, and BMI.

Conclusion:
The GM displayed sex-dependent associations with hypertension within untreated and treated individuals and can potentially predict BP trajectory changes within a Chinese population.
Abstract P169: SGLT2 Colocalizes on the Nucleus Tractus Solitarii Neurons in Normotensive and Hypertensive Rats in a Location-Dependent Manner
Authors: Ahwin Priscilla , Martinez Diana
Published: October 2024

Introduction/Background:
Hypertension affects ~45% adults in the US and is associated with a high sodium diet. The nucleus tractus solitarii (nTS) in the brainstem influences blood pressure through the interplay between glutamate and GABA. Sodium-glucose cotransporter 2 (SGLT2) is a protein recently found within the nTS, and its expression in the nTS may impact blood pressure. In this study, we investigated the distribution of SGLT2 in the nTS of normotensive and hypertensive rats, focusing on its presence in glutamatergic (Glu) and GABAergic neurons. Within the nTS, increases in glutamate lowers blood pressure, and increases of GABA raises blood pressure. The interaction between SGLT2 and glutamate/GABAergic neurons within the nTS is not well-understood.

Hypothesis:
We hypothesize that SGLT2 colocalizes on both Glu and GABAergic nTS neurons but increases due to a high salt diet.

Methods:
Male Dahl-Salt Sensitive Rats were fed a normal 0.4% salt diet (NSD) for 2 weeks and randomly placed to a NSD or a high 4% salt diet (HSD) for 7 weeks. After 9 weeks total, the brainstem section containing the nTS of each rat was isolated at 9AM.

Goals/Aims:
We used immunohistochemistry to identify either Glu (CAMKII) and GABAergic (GAD67) and localize SGLT2. Using a confocal microscope, a Z-stack image was compiled at 40x magnification and colocalization analysis was completed to determine if SGLT2 is found greater on Glu or GABAergic neurons.

Results:
We examined 3 areas within the nTS: caudal, rostral, and mid (area postrema, a region where cardiorespiratory afferent information is received). We first found that SGLT2 colocalizes to different extents on both Glu and GABAergic nTS neurons. We used Pearson’s R correlation to determine the strength and linear relationship between cell type and SGLT2. In GABAergic neurons, we found a positive correlation (r=0.319) in NSD, which decreased significantly in HSD (p=0.013, t-test) in the nTS at area postrema. Conversely, within the caudal nTS, SGLT2 colocalizes to a greater extent on Glu neurons in HSD (r=0.434) and lower in NSD (r=0.308), (p=0.04, t-test).

Conclusions:
In our model, we find that SGLT2 colocalization with Glu and GABAergic neurons is present within the nTS in a location-dependent manner, which may affect its function in the development of hypertension. Further experiments exploring the SGLT2 within normotensive and hypertensive rats may better reveal the function of the protein within the nTS.
Abstract P170: Angiotensin II Receptor Associated Protein Expression Within the PVN of Spontaneously Hypertensive Rats
Authors: Aitken Andrew , Foradori Chad , Griffett Kristine , Biancardi Vinicia
Published: October 2024

Increased levels of circulating Angiotensin II (Ang II) have been linked to the development of neurogenic hypertension and elevated sympathetic activity, primarily through the Angiotensin II Receptor 1 (AT1R). Angiotensin II Receptor Associated Protein (ATRAP) is a transmembrane protein that regulates Ang II signaling by promoting the internalization of AT1R. Studies have demonstrated that in a model of Ang II-induced hypertension, enhancing ATRAP expression in the paraventricular nucleus of the hypothalamus (PVN) via Lentivirus infection reduced high blood pressure. However, whether ATRAP is differentially expressed in Spontaneously Hypertensive Rats (SHR) is unknown.

We hypothesized that ATRAP gene and protein expression decreases during the development of hypertension in SHRs, leading to increased Ang II signaling. To test this, we used male SHRs at 4 (pre-hypertensive) and 12-weeks-old (wo, hypertensive; mean arterial pressure (MAP) 128.0±2.7 vs. 149.2±5.30 mmHg, respectively, measured by tail-cuff recording [Kent Scientific]) and age-matched normotensive Wistar rats (WIS, 92.6±3.3 vs. 123.6±4.6 mmHg, respectively). We measured ATRAP and AT1R mRNA expression in PVN samples using real-time PCR. Protein expression density of ATRAP was assessed using immunofluorescence (IF) and confocal imaging.

We found no differences in ATRAP mRNA expression in the PVN between groups (
p
>0.05). On the other hand, we found a significant increase in AT1R mRNA expression after hypertension is developed (WIS 12wo: 1.12 ± 0.35; vs. SHR 12wo: 4.17 ± 1.07,
p
=0.02). While no differences were found in ATRAP, using ATRAP/AT1R ratio as an indicator of AT1R overactivity and decrease in ratio after the development of hypertension (SHR 12wo: 0.23 ± 0.06 vs. WIS 12wo:1.05 ± 0.25) further indicate increased AngII signaling. As observed with ATRAP mRNA expression, no statistical differences were observed in ATRAP protein density within the SHR at 12wo as measured in a separate cohort of animals (MAP SHR 12wo:149.0 ± 3.7 vs. WIS 12wo:115.8 ± 4.0;
p
>0.05). These results suggest that the increased AngII signaling within the PVN of SHR are most likely due to increased AT1r expression rather than a differential expression of ATRAP. This work was partially funded by AHA 953524 to VCB.
Abstract P171: 2-Methoxyestradiol By Inhibiting Central Action of 12S-Hydroxyeicosatetraenoic Acid Protects Ovariectomized Mice From Hypertension
Authors: Dutta Shubha , Singh Purnima , Song Chi Young , Shin Ji Soo , Malik Kafait
Published: October 2024

Previously, we reported that 17β-estradiol (E2)- cytochrome P450 (CYP) 1B1-generated metabolite 2-methoxyestradiol (2-ME) in the paraventricular nucleus (PVN) protects from angiotensin (Ang) II-induced hypertension. Recently, we showed that intracerebroventricular (ICV) administration of 12(S)-hydroxyeicosatetraenoic acid (12S-HETE), an arachidonic acid-12/15-lipoxygenase (LO) metabolite produces a greater increase in blood pressure (BP) in ovariectomized (OVX) than intact LO knockout (KO) mice. These observations led to the hypothesis that 2-ME protects from Ang II-induced hypertension by inhibiting the production and action of 12S-HETE in the brain in female mice. ICV 2-ME (1.5 µg/2 µL/ alternate day) but not its vehicle (20% w/v hydroxypropyl-β-cyclodextrin) minimized the effect of Ang II (700 ng/kg/min, subcutaneous, osmotic pump, two weeks) to increase mean arterial blood pressure (MAP: Day 0 vs Day 12; 105±3 to 121±2 vs 105±3 to 153±8, mmHg) measured by radiotelemetry, urinary norepinephrine level (ELISA, 445±27 vs 898±20, ng/mL),
lo
mRNA expression (RT-PCR, 1.5±0 vs 2.0±1, arbitrary unit), 12S-HETE level (ELISA, 136±26 vs 285±44, pg/mg protein), and GFAP+ (immunostaining, astrocyte marker, 35±3 vs 67±3, number of cells per PVN section) cells in PVN and kidney fibrosis (histochemical-staining, 4.0±0.3 vs 9.8±0.7, arbitrary unit) in OVX-LOKO mice transduced with ICV-adenovirus-LO-DNA (1.28X10
11
pfu/ml, 2 µL, single injection) that have 12S-HETE in the brain (PVN) but not in plasma (n=4/group; P<0.05). ICV siRNA (0.4 nM, 2 µL, single injection) against 12S-HETE receptors LTB4 and GPR31 minimized Ang II-induced increased systolic BP measured by tail-cuff in intact CYP1B1 KO mice that have E2 but lacks 2-ME (mmHg, control: 108±3 to 175±6, siRNA-LTB4r2: 110±5 to 141±3, siRNA-GPR31: 114±1 to 145±2; n=8 per group). Moreover, the actions of ICV 12S-HETE (50 ng/2 µL every 3rd day) to enhance the effect of Ang II-induced increase in MAP were also minimized by ICV siRNA-LTB4 and GPR31 respectively in OXV-LOKO mice (mmHg, control: 102±2 to 168±1, siRNA-LTB4r2: 101±2 to 122±6, siRNA-GPR31: 101±3 to 129±3; n=4 per group). These data suggest that E2-CYP1B1 metabolite 2-ME, by inhibiting the production and action of 12S-HETE in the brain via LTB4r2 and GPR31 receptors protect from Ang II-induced hypertension in female mice. Thus, 2-ME and/or 12S-HETE receptor blockers could be useful for treating hypertension and its pathogenesis in females with ovarian failure.
Abstract P178: Sex Differences in the Role of the Immune ET-1/ET
A
Axis in Controlling Blood Pressure during a Hypertension Challenge
Authors: Brooks Abigail , Biswal Sara , De Miguel Carmen
Published: October 2024

Immune cells like dendritic cells (DCs) and T cells are essential for the development of hypertension. Upregulation of the vasoactive peptide endothelin-1 (ET-1) is key in the progression of hypertension. ET-1 acting
via
its ET
A
receptor raises blood pressure and promotes end-organ damage and inflammation. DCs and T cells express ET-1 receptors and respond to changing levels of ET-1. However, it is unknown whether activation of the ET-1/ET
A
receptor axis on DCs or T cells is critical in driving hypertension, or if a differential activation of this axis in immune cells leads to the sex differences that exist in the pathophysiology of this disease. We hypothesized that activation of the ET-1/ ET
A
axis on immune cells is crucial in the development of hypertension, with a more prominent role in males than females. Male and female mice lacking ET
A
receptor on DCs (DC ET
A
KO) or on T cells (T cell ET
A
KO) and floxed ET
A
control mice were given the nitric oxide synthase inhibitor L-NAME (0.5 mg/mL) in drinking water for 3 wks to induce hypertension. Systolic blood pressure (SBP) was measured 3 times/wk
via
tail cuff plethysmography. Glomerular filtration rate (GFR) was evaluated at baseline and after L-NAME treatment
via
the transcutaneous FITC-sinistrin clearance method. Absence of ET
A
receptor on DCs resulted in a ~10 mmHg decrease in SBP at baseline in both sexes, and this difference increased throughout the protocol in males (Floxed ET
A
vs. DC ET
A
KO: L-NAME: 150.8±6.7 vs. 130.8±2.6 mmHg, n=4/group, p=0.002), but not in females (137.4±5.7 vs. 137.2±2.4 mmHg, n=3/group). Lack of the ET
A
receptor on T cells led to a similar decrease of ~10 mmHg in SBP at baseline. However, the difference in SBP widened when males were challenged with L-NAME (Floxed ET
A
vs. T cell ET
A
KO: 135.2±2.0 vs. 118.0±4.1, n=11/group, p=0.003), whereas the group difference in SBP disappeared in females (131.5±4.0 vs. 132.4±4.7, n=8-9/group). Following L-NAME, GFR trended to decline in control male mice, while it increased in T cell ET
A
KO males. Our data suggest that activation of ET
A
receptors on DCs and T cells modulates SBP in response to a hypertensive insult in males, but not in females. Additionally, absence of ET-1/ ET
A
axis activation on T cells suggests improved renal function during hypertension. Our results suggest that the use of ET
A
antagonism in the clinic may be more protective during hypertension in males than females.
Abstract P179: The Role of Sodium Induced-RGMa in Salt-Sensitive Hypertension
Authors: Desta Selam , Mutchler Ashley , Ertuglu Lale , Saleem Mohammad , Ishimwe Jeanne , Sheng Quanhu , Kirabo Annet
Published: October 2024

Salt sensitivity of blood pressure, characterized by blood pressure fluctuations that mirror dietary sodium (Na) intake, is an independent risk factor for cardiovascular morbidity and mortality in people with and without hypertension. We previously found that elevated Na uptake via the amiloride-sensitive epithelial sodium channel (ENaC) in antigen-presenting cells leads to the upregulation of isolevuglandins and proinflammatory cytokines ultimately leading to T cell activation and salt-sensitive hypertension. In addition, we also showed that SMAD3 activation plays a role in inflammation and salt-sensitive hypertension. In previous studies, RGMa has been shown to be upstream of SMAD3. Furthermore, previous studies have also shown that knockdown of RGMa leads to reduced levels of TGFβ1-induced SMAD3 phosphorylation. The exact mechanism by which elevated extracellular Na leads to increased blood pressure remains unknown. We hypothesized that RGMa complexes with TGFβ1R1 to promote SMAD3 phosphorylation ultimately contributing to inflammation in salt-sensitive hypertension. To test our hypothesis, we isolated monocytes from human participants (N =11) and treated them with either high (190 mMol/L) or normal (150 mMol/L) Na in vitro for 72 hours and subsequently performed bulk RNA sequencing. In additional experiments, we performed an in vivo high Na treatment by utilizing a rigorous salt-loading/depletion protocol on human participants (N = 9) and conducted single-cell transcriptomic analyses. Our bulk RNA sequencing analyses revealed there was no difference in expression of TGFβ1R1 (8837 ± 780.9 vs. 9688 ± 942.5, p =0.350) and TGFβ1R2 (7012 ± 717.0 vs. 7176 ± 633.9, p = 0.059). Interestingly, RGMa (2253 ± 441.0 vs. 516 ± 84.1, p <0.001) and TGFβ1 (5118 ± 353.9 vs. 9067 ± 826.4, p = 0.073) were significantly upregulated in human monocytes after high Na treatment compared to normal salt. However, single-cell transcriptomic analyses found no correlation between the changes in pulse pressure and RGMa (r = 0.5154, p = 0.1911). Our data suggest that RGMa mediates Na-induced inflammation but may not play a role in salt-sensitive hypertension.
Abstract P180: Female mice with systemic lupus erythematosus produce antibodies to mitochondrial antigens and have impaired renal mitochondrial function
Authors: Frambes Noelle , Hollis Fiona , Taylor Erin , Srivastava Baruk , Sullivan Kelly , Ryan Michael
Published: October 2024

Patients with autoimmune disorders like systemic lupus erythematosus (SLE) are at significant risk for renal and cardiovascular mortality. The pathology of SLE is driven by a loss of immune tolerance with the subsequent production of autoantibodies (IgG), and our laboratory previously demonstrated a mechanistic role for autoantibodies in autoimmune mediated hypertension. While anti-double stranded DNA (dsDNA) antibodies are pathognomonic for SLE, a breadth of autoantibodies may contribute to disease pathology. The goal of this study is to identify autoantibodies that may contribute to the renal and cardiovascular consequences associated with SLE. To accomplish this goal, an antigen array was performed (University of Texas Southwestern Genomics & Microarray Core Facility) using plasma samples collected from an established experimental mouse model of SLE (30 week old female NZBWF1, n=8) and healthy controls (30 week old female NZWLacJ, n=7). As anticipated, autoantibodies raised to nuclear antigens were prominently represented in the array and were significantly increased relative to control mice. This includes antibodies to dsDNA, ssRNA, chromatin, and histones (total) (p<0.02). In addition, SLE mice produce antibodies to mitochondrial antigens including cardiolipin and cytochrome C (p<0.02 vs control mice), critical components of the inner mitochondrial membrane and respiratory chain, respectively. In a separate study, renal mitochondrial function was tested using high resolution respirometry (Oroboros Instruments) in whole kidney homogenates from 30 week old female SLE (n=6) and control mice (n=5). Results show that coupled respiration, an estimation of oxidative phosphorylation, is significantly impaired at Complex I in kidneys from SLE mice compared to healthy controls (62±9 vs. 90±7 pmol/s/mg tissue, p<0.05). Uncoupled respiration, an estimation of maximal electron transport, is also reduced in the kidneys of female SLE mice compared to controls (157±23 vs. 212±14 pmol/s/mg tissue, p=0.07). These data provide insight for new mechanistic pathways to pursue in understanding the underlying mechanisms promoting cardiovascular risk factors like hypertension during SLE.
Abstract P184: Increased Granulopoiesis, Kidney Neutrophil Infiltration, and Renal Damage in a Mouse Model of Psoriasis
Authors: Chen Ziche , Tessmer Garrett , Nguyen Bianca , Meyer Jason , Saleem Mohammad , Ahmad Taseer , Yang Tzushan Sharon , Kirabo Annet , Ward Nicole , Alexander Matthew
Published: October 2024

Psoriasis is an autoimmune skin disease marked by T cell-mediated hyperproliferation of epidermal keratinocytes. Most psoriasis-related morbidity and mortality stems from an elevated risk of renal and cardiovascular disease, but mechanisms remain unclear. Although neutrophils are not directly targeted with current psoriasis therapies, neutrophils are increased in the skin and circulation of these patients. We hypothesized that excess skin inflammation in psoriasis drives increased G-CSF-dependent granulopoiesis leading to renal neutrophil infiltration and dysfunction. Employing a KC-Tie2 mouse model of psoriasis with keratinocyte-specific overexpression of the angiopoietin receptor Tie2 (KC-Tie2), we observed 2-3-fold elevations in multiple indices of renal damage including urine albumin, urine NGAL, and glomerulosclerosis in KC-Tie2 mice compared to littermate controls (all P<0.05). KC-Tie2 mice also demonstrated 13 mm Hg higher daytime systolic blood pressure compared to littermate controls (P<0.05). Using flow cytometry, we found that KC-Tie2 mice had an increase not only in cutaneous neutrophils but also an approximate 10-fold increase in renal neutrophils (P<0.001). KC-Tie2 kidneys also exhibited increased vital and suicidal neutrophil extracellular trap (NET) formation, representing a potential mechanism for the observed renal damage. Interestingly, the increase in renal neutrophils was selective relative to other major immune cell populations such as dendritic cells, lymphocytes, monocytes, and macrophages. Similar selective increases in neutrophils were noted in the circulation, aorta, and spleen. We thus examined neutrophil production in the bone marrow, and observed significant increases in immature Ly6g
low
and Ly6g
intermediate
neutrophils (P<0.0001) as well as total Ly6g
+
neutrophils (P<0.05), with no change in mature Ly6g
high
neutrophils in the bone marrow of KC-Tie2 mice. These findings are consistent with increased granulopoiesis, prompting an examination of the key mediator of granulopoiesis, granulocyte colony-stimulating factor (G-CSF). KC-Tie2 mice exhibited marked increases in G-CSF in both the skin and plasma (P<.001 for both). In conclusion, our findings demonstrate increased renal damage in a mouse model of psoriasis, concomitant with increases in granulopoiesis and total and NETotic renal neutrophils, potentially unveiling a novel link between skin inflammation and renal damage via enhanced G-CSF-mediated granulopoiesis.
Abstract P189: Maternal Hyperandrogenemia Programs Hypoandrogenemia and Intrarenal Activation of Histone Deacetylase in Adult Male Offspring
Authors: Agbo John , Kumar Prerna , Reckelhoff Jane , Shawky Noha
Published: October 2024

Polycystic ovary syndrome (
PCOS
) is the most common endocrinopathy in young women. In-utero, children of ~80% of PCOS women in the US are exposed to maternal “hyperandrogenemia and obesity”. It remains unclear whether this exposure affects their cardiovascular (
CV
) health later in life. Using a well-characterized rat model of maternal PCOS, the hyperandrogenemic obese (
HAO
) dams, we previously showed that adult male, not female, offspring (

HAO
F1

) have enhanced blood pressure (
BP
) response to chronic angiotensin (
Ang
) II compared to sex-matched control offspring (

CON
F1

), suggesting their increased risk of later CV disease. Sex steroids have the potential to modulate epigenetics. Histone deacetylase (
HDAC
) and histone acetyltransferase (
HAT
) are markers of epigenetic modifications. HDACs have been shown to promote tumor necrosis factor (
TNF
)-α expression and play a role in Ang II-induced hypertension. The present study was designed to test the hypothesis that male HAO
F1
have intra-renal activation of HDAC and increased TNF-α that could play a role in their Ang II BP response.

Methods:
At 4 weeks (
wks
) of age, female SD rats were implanted (s.c.) with either 5α-dihydrotestosterone pellets (7.5 mg/90 d; HAO) or placebo pellets (CON) and mated at 9-12 wks. Offspring were obtained and weaned at 3 wks. Serum testosterone (
T;
by LC/MS-MS), renal cortical TNF-α (Bioplex) and renal cortical nuclear HDAC and HAT activities (colorimetric assays) were measured in male offspring (1/litter, 16-24 wks, n=5-9).

Results:
Male HAO
F1
had significantly lower serum T, higher renal cortical HDAC activity and TNF-α (430.2±124 vs 120.6±14 ng/dl, 0.97±0.1 vs 4.51±0.96 OD/min/mg protein and 423.7±47 vs 579.8±47 pg/g tissue, in male CON
F1
vs male HAO
F1
, respectively, p<0.05), and no change in their renal cortical HAT activity (vs male CON
F1
).

Conclusion:
Male offspring born to HAO dams develop hypoandrogenemia that is associated with intra-renal activation of HDAC that could be mediating their increased intra-renal inflammation (TNF-α expression) and mediating their exaggerated BP response to Ang II. Future studies will determine the causative relationship between hypoandrogenemia, HDAC activation and TNF-a and their role in the exaggerated pressor response to Ang II in those male offspring.

Funding:
AHA-24DIVSUP1273026 (JA), NIH-NIGMS P20GM121334 (JFR, NMS), R01HL135089 & R01AG075963 (JFR), AHA-22CDA938320 and 2024 Dean Franklin Award (NMS).
Abstract P191: Progesterone Supplementation Ameliorates the Maternal Syndrome of Preeclampsia in the Dahl Salt-Sensitive Rats
Authors: Chambers Christy , Franks Michael , Campbell Nathan , Phillips Raegyn , Turner Ty , Roseburgh Montianah , Williams Jan , Amaral Lorena
Published: October 2024

Introduction:
Preeclampsia (PreE) is characterized by new onset hypertension after 20 weeks of gestation. PreE is associated with activated CD4+ T cells, inflammation, autoantibodies to angiotensin II type 1 receptor (AT1-AA) and hypertension. To date, the best treatment remains early delivery of the feto-placental unit.

Hypothesis:
This study was designed to test the hypothesis that progesterone, in the form of 17-hydroxyprogesterone caproate (17-OHPC), reduces inflammation and blood pressure in the Dahl Salt-Sensitive (Dahl S) rat model of PreE.

Methods:
A subset of pregnant Sprague-Dawley (SD) and Dahl S rats were injected with 17-OHPC (3.32mg/kg, human dose equivalent) or vehicle (saline) at day 15 (GD15) of gestation. On GD 18, Uterine Artery Resistance Index (UARI) was measured by Doppler Ultrasound and carotid catheters were inserted for mean arterial blood pressure (MAP) measurement on GD19. Circulating and placental populations of CD4+ T cells were quantified by flow cytometry. TNF-alpha and IL-6 were measured by ELISA and AT1-AA were quantified by the chronotropic responses to angiotensin II type 1 receptor-mediated stimulation of cultured neonatal rat cardiomyocytes. Results are reported as means ± standard error means (SEM) and statistically significant when p < 0.05.

Results:
MAP was 105±5 mmHg in SD+ vehicle rats (n=6), 104±4 in SD+17-OHPC rats (n=6), 136±3 in Dahl S+ saline rats (p <0.05, n=11), which improved to 125±4 in DS+17-OHPC rats (p <0.05, n=7). Pup and Placenta weights were 2.1± 0.1, 0.6 ± 0.1 g in SD+ vehicle rats and reduced to 1.4±0.1 (p<0.05), 0.5±0.1 g in Dahl S +vehicle. UARI was 0.5 ±0.1 in SD+ vehicle rats (n=6) and 0.5 ±0.1 in in SD+17-OHPC (n=6), 0.7±0.1 in Dahl S+ vehicle rats (n=6, p<0.05), which reduced to 0.5±0.1 in Dahl S+17-OHPC (n=7, p<0.05). TNF-alpha and IL-6 levels (n=4-5/group) were 3.0±1.0, 45±11 pg/mL in SD+ vehicle rats, 11.0±1.2, 78±21 in Dahl S+ vehicle rats, which reduced to 4.1±1.6 (p<0.05), 62±12 in Dahl S+17-OHPC. Circulating and placental CD4+ T cells were 9.3±3.7 %, 6.4± 1.6 % gate in SD+ vehicle rats (n=4), 38.9 ±2.9, 33.1±4.3 % gate Dahl S+ Saline rats (n=6), which significantly reduced to 26.3 ± 0.1 %, 3.4±1.2 % gate in DahlS+17-OHPC. AT1-AA were -1 ± 2 ΔBPM (beats per minute) in SD+ vehicle rats, 4 ± 1 in Dahl S+ Saline rats and -0.6±2 Dahl S+17-OHPC rats (n=5, p<0.05).

Conclusion:
Our findings demonstrate that 17-OHPC ameliorates the maternal syndrome in the Dahl Salt-Sensitive rat model of PreE.
Abstract P192: The Impact of Sleep Apnea on Preeclampsia or Eclampsia: The Mediation Role of Large High-Density Lipoprotein Components
Authors: Chen Pei , Wang Yueying , Yuan Jinjin , Liu Fan , Qin Jiuhang , Jiahui Zhang , pan Yang , Zhu Bingqian
Published: October 2024

Introduction:
Sleep apnea is increasingly recognized as a significant risk factor for preeclampsia/eclampsia (PE). Research increasingly shows that large high-density lipoprotein (L-HDL) may influence the PE development. This study aimed to investigate the association between sleep apnea and PE and the proportion of this association that is mediated through different L-HDL components.

Hypothesis:
Modifications in the L-HDL components induced by sleep apnea significantly contribute to the pathogenesis of PE.

Methods:
A two-sample Mendelian randomization (MR) was conducted using genetic variants associated with relative sleep apnea from the FinnGen study and different L-HDL components from UK Biobank. The single-nucleotide polymorphisms (SNPs) were combined into multi-allelic models and odds ratios (ORs) and 95% confidence intervals (95% CIs) were generated using inverse-variance weighted random-effects models. Then the multivariable MR analysis was performed to estimate the effect of the mediators on the risk of PE with adjustment for sleep apnea. The MR-Egger and MR pleiotropy residual sum and outlier (MR-PRESSO) were mainly used for sensitivity analyses. In mediation analyses, the direct effect of different L-HDL components estimated in multivariable MR was compared with the total effect estimated in the main univariable MR analysis.

Results:
This study found that sleep apnea significantly affects the risk of PE, as well as various L-HDL components, including large high-density lipoprotein cholesterol (L-HDL-C), large high-density lipoprotein cholesteryl ester (L-HDL-CE), large high-density lipoprotein concentration (L-HDL concentration), cholesterol to total lipids ratio in large high-density lipoprotein (C/TL-L-HDL), cholesteryl esters to total lipids ratio in large high-density lipoprotein (CE/TL-L-HDL), and phospholipids to total lipids ratio in large high-density lipoprotein (P/TL-L-HDL). In multivariable MR analysis, these components were also significantly associated with the risk of PE. Additionally, mediation analysis identified P/TL-L-HDL as the only significant mediator between sleep apnea and PE (mediation effect = 0.0224; 95% CI=0.0005, 0.0443; p-value=0.0455).

Conclusion:
This study establishes a causal link between sleep apnea and an increased risk of preeclampsia/eclampsia, mediated by P/TL-L-HDL.

Key Words:
Sleep apnea; Preeclampsia; Eclampsia; Large HDL; Mendelian randomization; Mediation analysis