bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P434: Role of Dusp5 in Hypertension Induced Chronic Renal Disease
Authors: He Xiaochen , Zhang Chao , Murphy Sydney , Mims Paige N , Fan Fan
Published: July 2021

We recently identified 4 single nucleotide polymorphisms in Dusp5 in FHH as compared with Brown-Norway (BN) rats, two of which alter CpG sites and another one causes G155R mutation. We then created a Dusp5 knockout (KO) rat in the FHH.1
BN
genetic background, in which a small region in Chr. 1 of BN rats containing 15 genes, including Dusp5 into the FHH rats. We found that knockout of Dusp5 enhances the myogenic response and autoregulation of cerebral circulation. In the present study, we evaluated whether Dusp5 also plays a role in the regulation renal function. The expression of Dusp5 was lower in FHH. 1
BN
. Dusp5 KO rats in comparison to the FHH.1
BN
rats. The levels of p-PKC and p-ERK1/2 were elevated in Dusp5 KO vs. FHH.1
BN
rats. The blood pressure and urinary protein excretion was similar in FHH. 1
BN
. Dusp5 KO (n = 43) and FHH.1
BN
rats (n = 30) when they were at 12-week of age (114 ± 2 vs. 115 ± 1 mmHg and 32 ± 2 vs. 29 ± 3 mg/day). The autoregulation of RBF was similar in FHH.1
BN
(n=22) and Dusp5 KO (n = 9) rats in response to elevation of MAP from 100 to 140 mmHg, but was impaired in FHH rats (n=21) that increased by 37.3 ± 2.3% when they were at 12-week of age. In response to an elevation in pressure from 60 to 120 mm Hg, the renal afferent arterioles constricted by 29 ± 2% and 11 ± 1%, respectively in Dusp5 KO (n = 6) in comparison to FHH.1
BN
rats (n = 17). Blood pressure was similar in Dusp5 KO (n = 11) vs. FHH.1
BN
rats (n = 14) after 3-week DOCA-salt treatment (169 ± 5 vs. 177 ± 5 mmHg). However, proteinuria was significantly reduced in Dusp5 KO rats (258 ± 22 mg/day, n = 12) in comparison to FHH.1
BN
rats (338 ± 30 mg/day, n = 12). The renal injury induced by DOCA-salt was markedly reduced in Dusp5 KO vs. FHH.1
BN
rats as the glomerular injury scores were 2.49 ± 0.03 vs. 2.54 ± 0.01; the areas of renal fibrosis were 5.5 ± 0.5% vs. 8.3 ± 0.3%; the areas of renal protein casts were 0.5 ± 0.2% vs. 2.4 ± 1.0% and renal arteriolar media-to-lumen ratios were 0.64 ± 0.03 vs. 0.81 ± 0.04, respectively. These results indicate that KO of Dusp5 enhances renal vascular function to protect against DOCA-salt hypertension induced chronic renal injury via activation of PKC/ERK signaling pathway. In conclusion, an activating mutation in Dusp5 may contribute to the impaired myogenic response and promote the development of chronic renal injury in FHH rats.
Abstract P476: 8-Aminoguanosine Exerts Diuretic and Natriuretic Activity via Conversion to 8-Aminoguanine
Authors: Jackson Edwin K , Mi Zaichuan
Published: July 2021

We previously reported that 8-aminoguanosine and 8-aminoguanine are potent and efficacious K
+
-sparing diuretics/natriuretics that may represent a new class of antihypertensive drugs. Moreover, because these compounds are endogenous, they may have physiological roles. It is possible that the diuretic/natriuretic activity of 8-aminoguanosine is mediated mostly via conversion to 8-aminoguanine. To test this concept, we conducted 3 protocols in anesthetized rats. The 1
st
protocol demonstrated that at 85 to 115 min post intravenous administration, both 8-aminoguanosine and 8-aminoguanine (33.5 μmol/kg) significantly increased urine volume [ml/min: 8-aminoguanosine from 0.3 ± 0.1 to 0.9 ± 0.1 (mean ± SEM; n=7); 8-aminoguanine from 0.3 ± 0.1 to 1.5 ± 0.2 (n=8)] and sodium excretion (μmol/min: 8-aminoguanosine from 12 ± 6 to 109 ± 21; 8-aminoguanine from 18 ± 8 to 216 ± 31). The 2
nd
protocol showed that intrarenal artery infusions of 8-aminoguanosine (from 0.1 to 1 μmol/kg/min) did not affect urine volume or sodium excretion in either the ipsilateral or contralateral kidney. In contrast, intrarenal artery infusions of 8-aminoguanine significantly increased ipsilateral (but not contralateral) urine volume [at 1 μmol/kg/min from 0.2 ± 0.02 to 0.7 ± 0.1 (n=17)] and sodium excretion (from 24 ± 4 to 216 ± 31). In a 3
rd
protocol we administered 8-aminoguanosine and 8-aminoguanine intravenously (33.5 μmol/kg) and measured renal interstitial (medulla) levels of 8-aminoguanosine and 8-aminoguanine using microdialysis combined with ultraperformance liquid chromatography-tandem mass spectrometry. Intravenous administration of 8-aminoguanosine and 8-aminoguanine similarly increased renal interstitial levels of 8-aminoguanine [ng/ml; 8-aminoguanosine from 4 ± 1 to 1025 ± 393 (n=6), and 8-aminoguanine from 2 ± 1 to 1069 ± 407 (n=6)]. Neither 8-aminoguanosine nor 8-aminoguanine affected renal interstitial levels of 8-aminoguanosine. Together these data clearly show that the renal effects of 8-aminoguanosine are not direct, but require conversion in the systemic circulation to 8-aminoguanine. If 8-aminoguanosine is physiologically important it should be viewed as a “pro-hormone.” As a pharmacological agent, it is best described as a “pro-drug.”
Abstract P497: Re-analysis of the Systolic Blood Pressure Intervention Trial (SPRINT): The Renal Consequences of Intensive versus Standard Blood Pressure Lowering
Authors: Branfield Day Leora , Naimark David M
Published: July 2021

Background:
BP management guidelines suggest that persons with CKD should be treated to a SBP ≤ 140 mmHg. SPRINT compared this target to intensive SBP lowering (≤ 120 mmHg) in persons with and without CKD and found a reduced rate of CV events and all-cause mortality (ACM). However intensive therapy was associated with an increased risk of AKI. We extrapolated the results of SPRINT over a lifetime horizon to determine whether in the long-term, the benefit in terms of the primary outcome would be less economically attractive when the risks of more frequent AKI and subsequent CKD progression were considered.

Methods:
We re-configured the CKD Simulator, a Markov model of CKD progression, AKI events, fatal and non-fatal CV events, and ESRD. We recalibrated the model to be representative of the SPRINT cohort and compared intensive vs. standard blood pressure control among 10 million simulated persons with and without CKD over their lifetimes. Marginal treatment costs were calculated and hazard ratios for AKI, CV events and ACM observed in SPRINT were applied to the monthly probabilities of these events in the intensive SBP arm.

Results:
Lifetime average, discounted, costs per person associated with intensive vs. standard SBP lowering were predicted to be $35,811 and $30,584, respectively. Quality-adjusted, discounted average lifespans were 196.05 and 190.47 months, respectively. The cost of each quality-adjusted life-year gained by adopting intensive over standard BP lowering would be $11,220, significantly below the accepted cost-effectiveness threshold of $50,000. Intensive SBP control would reduce the lifetime incidence of at least one CV event by 5.5%, but increase the incidence of at least one AKI episode and ESRD by 1.7% and 0.7%, respectively. These differences were associated with average lifetime cost savings per person of $459 for CV events, but losses of $161 and $2,889 for AKI and ESRD.

Discussion:
Intensive SBP management would be cost-effective and associated with a significant lifetime reduction in CV events. However, there would be an increase in the lifetime risk of AKI and ESRD, contributing to 58% of the total increase in cost of intensive relative to usual SBP control. Intensive SBP lowering should be adopted judiciously in persons at high risk of ESRD.
Abstract P509: Identification of Radial Vascular Wall Abnormalities by Very-high Frequency Ultrasound in Patients With Fibromuscular Dysplasia: The Fuchsia Study
Authors: Bruno Rosa Maria , Di Lascio Nicole , Guarino Daniela , Vitali Saverio , Rossi Piercarlo , Caramella Davide , Taddei Stefano , Ghiadoni Lorenzo , Faita Francesco
Published: July 2021

Aim:
This case-control study is aimed at identifying radial vascular wall abnormalities in patients with fibromuscular dysplasia (FMD).

Methods:
High-frequency ultrasound scans of the radial arteries and of FMD patients and healthy controls were obtained by Vevo MD (70 MHz probe, FUJIFILM, VisualSonics, Toronto, Canada). Radial wall showed in all individuals two echogenic interfaces: the 1
st
( lumen-media) and the 2
nd
(media-adventitia). Intima-media (IMT), adventitia (AT), and global thickness (IMAT) were measured and wall cross-sectional area (WCSA) calculated. The disarray level of the two echogenic interfaces was assessed calculating the root mean square error (RMSE) between 20 gray-level profiles crossing the two interfaces and the profile obtained averaging them. For each echogenic interface, the RMSE was normalized for the maximum value of the corresponding mean profile (RMSE/mean).

Results:
11 treated hypertensive female FMD patients and 8 healthy control women (C) were enrolled (age 52±5 vs 45±13 years, p=0.51; BMI 26±3 vs 23±3, p=0.12; mean BP 97±7 vs 85±10, p=0.01). Radial internal diameter was similar (1.938±0.432 vs 1.701±0.532 mm, p=0.21). IMT (0.166±0.037 vs 0.128±0.022 mm, p=0.03), AT (0.114±0.029 vs 0.083±0.019 mm, p=0.008) and IMAT (0.281±0.042 vs 0.211±0.027 mm, p=0.003) were higher in FMD. Wall/lumen ratio was similar and WCSA increased in FMD, calculated with either IMT or IMAT. The maximum values of 1
st
(121±43 vs 157±22, p=0.09) and 2
nd
interface 109 ±44 vs133±18, p=0.09) tended to be lower, whereas RMSE/mean was higher in FMD (1
st
1.31±0.24 vs 0.83±0.32, p=0.006; 2
nd
1.37±0.38 vs 0.94±0.32, p=0.03). The difference was attenuated for the 1
st
but not for the 2
nd
interface when considering age and mean BP as covariates (p=0.054 and p=0.016 respectively).

Conclusions:
Wall ultrastructure of radial arteries of hypertensive FMD patients showed eutrophic remodeling. Furthermore, a peculiar “blurred” pattern occurred, characterized of loss of echogenicity and inhomogeneity of the two echogenic layers, independent of age and mean BP.
Abstract P519: Arterial Stiffness is Associated With Lower Performance on the Cognitive Tests at Different Domains in Hypertensive Patients
Authors: Muela Henrique , Costa-Hong Valeria , Machado Michel F , Moraes Natalia C , Memória Claudia M , Yassuda Monica S , Shu Edson B , Massaro Ayrton R , Nitrini Ricardo , Mansur Alfredo , Bortolotto Luiz
Published: July 2021

Background:
Cognitive impairment and elevated arterial stiffness are described in patients with arterial hypertension(AH), but its correlations are not well studied.

Objectives:
To study the cognitive function at different domains and arterial properties in patients with AH stage 1 to 3 compared to normotensives and to evaluate the correlations between these variables.

Methods:
We evaluated 221 subjects, 71 normotensives (52±14yrs,47%male,65%white) and 150 patients with stage 1-3 AH (52±12yrs,45%male,70%white) under treatment. The global cognitive function was assessed by Mini Mental State Examination(MMSE) and Montreal Cognitive Assessment(MoCA). There was done a validated comprehensive battery of neuropsychological tests(NPE) assessed the following main cognitive areas: memory, language, visuospatial ability, executive function, attention. Pulse wave velocity(PWV) was measured by Complior® device. Carotid properties were assessed by radiofrequency ultrasound(WTS®). Central arterial pressure and augmentation index (AIx) were obtained using applanation tonometry(Sphygmocor®).

Results:
Mean BP of the normotensive group (122.1±8/76.7±7mmHg) was significantly lower than hypertensive patients (135.2±13/83.3±10 and 149.9±29/91.5±16mmHg). Severe HTN group had worse performance in cognitive evaluation either by MMSE (26.8±2.1 vs 27.4±2.1 vs. 28.0±2.0, p=0.004) or MoCA test (23.4±3.7 vs. 24.9±2.8 vs. 25.5±3.2, p<0.001). On the neuropsychological tests hypertensive patients had worse performance mainly in visuoperceptual and visuospatial capacities and executive function. On the multivariate regression analysis, the following independent associations were observed: Aix-language, executive function, visuospatial and attention; cSBP-MoCA; IMT-memory and attention; PWV-memory, executive function, visuospatial and attention. Higher PWV group had more cognitive dysfunction.

Conclusions:
Cognitive impairment at different domains was more frequent in patients with different stages of AH. Arterial functional and structural properties were diversely associated with cognitive performance at different domains
Abstract P545: Prehypertension is Associated With Metabolic Disturbance and Delayed Heart Rate Recovery: Potential Link Between Prehypertension and Metabolic-autonomic Dysfunction
Authors: Jung Mi-Hyang , Ihm Sang-Hyun , Lee Dong-Hyeon , Jung Hae Ok , Youn Ho-Joong
Published: July 2021

Background:
Prehypertension is a highly prevalent condition, but its pathophysiology is still poorly understood. Heart rate recovery (HRR), noninvasive parameter acquired during treadmill test, is an index of autonomic dysfunction. We aimed to evaluate the association of prehypertension with autonomic dysfunction, and further, to identify the determinants of autonomic dysfunction.

Methods:
We retrospectively identified 557 asymptomatic participants who did not have hypertension and underwent comprehensive health check-ups including cardiopulmonary exercise test. They were categorized into two groups: optimal blood pressure (BP) (systolic BP<120mmHg and diastolic BP<80mmHg, n=277) and prehypertension (120≤systolic BP<140mmHg and/or 80 ≤diastolic BP<89mmHg, n=280). HRR at 1 minute (HRR
1
) was also calculated as follows: peak heart rate (HR) minus HR after 1-minute recovery.

Results:
Prehypertension group exhibited more obese feature (waist circumference, 83.3±7.3 vs. 87.4±8.1cm; p<0.001) and metabolic disturbance (HOMA-IR, 0.93±0.85 vs. 1.26±1.06; uric acid 5.5±1.4 vs. 5.9±1.4; HDL-cholesterol 52.4±13.6 vs. 48.5±12.2 mg/dL; all p<0.005). They also had high pulse wave velocity (PWV, 1315.7±143.0 vs. 1453.1±187.1cm/sec, p<0.001). Although the resting HR and peak exercise HR did not differ between the groups, prehypertension group exhibited a significantly lower HRR
1
level, suggesting an impaired parasympathetic reactivation in the prehypertension (39.3±14.7 vs. 36.2±14.9 beats/min, p=0.016). In a multivariate linear regression analysis, resting HR (
ß
=-0.360, p<0.001), waist circumference (
ß
=-0.195, p=0.018), PWV (
ß
=-0.008, p=0.017), and HDL-cholesterol (
ß
=0.105, p=0.036) were independent determinants of the HRR
1
.

Conclusions:
Prehypertension is associated with metabolic disturbance and autonomic dysfunction. HRR is mainly determined by waist circumference, arterial stiffness, and dyslipidemia even after adjustment for the resting HR. Our observation suggests the possible role of metabolic-autonomic abnormality in the pathogenesis of prehypertension.
Abstract P546: Sleep Quality in Medical Students A Cross-sectional Study
Authors: Costa Lilian S , Marins Marina C , Ansel Jocasta C , Tavares Carolina P , Queiroz Fernanda T , Rocha Jéssica B , Banharo Mariana M , Magalhães Gabriela C , Moreira Camilla S , Schittini Daniela C , Pavani Thaynã A , Aleix Beatriz V , Leig Livia B , Nascimento Carlos Eduardo C , Santos Junior Egberto B , Oliveira Suellen S , Batista Luiza O , Palheiro Maria Clara A , Jandre Renata M , Salles Rodrigo I , Freitas Bernardo P , Camara Eduardo O , Martins Letícia N , Freire Isabelle M , Lucca Karina B
Published: July 2021

Introduction:
Medical students, susceptible to sleep disorders, have irregular sleep-awake cycle, with repercussions on the quality of life and reduced academic performance, often with greater incidence of psychiatric disorders, estimated at 15% to 25% during your academic training.

Objective:
To evaluate the sleep habits in students of medical school in a private college of Rio de Janeiro, Brazil.

Method:
This subset study is a part of an observational study with cross-sectional delineation, with data collected through the application of an anonymous questionnaire, where they were asked about the number (and modification) of hours they sleep daily, in addition to reports of “stress and anxiety”. These data collected formed the basis of an instrument for assessing the quality of life on the medical students of this College.

Results:
We analyzed data from 481 students: 82 (17%) at the first year, 118 (24.5%) at the second year, 99 (20.6%) at the third, 64 (13.3%) and 118 (24.5%) within the fifth and sixth years. The average age was 21.7 years (16-42) and 306 (63.6%) of female gender. As for the hours of sleep, 445 students (92.5%) report 5 to 8 hours of sleep, and 216 (44.9%) a minimum of 6 hours. In the sleep of the weekends, 394 (81.9%) reported change in the number of hours and, 313 (65.1%) referred to a reduction after the entrance into college. It was reported "some level of stress and anxiety,“ not related to the least number of hours sleepping (0.07). Comparing the data obtained among the 199 students of the first and second years (62.8% female-group A) to 117 at fifth and sixth years (70.9% female-group B), we observed similarity in relation to (1) number of 5 to 8 hours sleepping (A 92.9% x 90.5% B), (2) change the hours of sleepping on the weekends (A 81.9% x 79.5% B), and (3) reduction of sleepping hours after the entrance into College (A 81.9% x 78.6% B). With regard to the report of "stress and anxiety”, we observed statistically significant difference between the groups (A 100% x 88% B, p < 0.03).

Conclusion:
The change in lifestyle imposed on joining a new school learning model, generates anxiety and loss of sleep hours among students. The development of resilience and adaptation to change, both individual and institutional, may have been responsible to varying degrees of stress.
Abstract P550: High Uric Acid Levels Correlate With Treatment- Resistant Hypertension
Authors: Valaiyapathi Badhma , Siddiqui Mohammed , Oparil Suzanne , Calhoun David A , Dudenbostel Tanja
Published: July 2021

Background:
Serum uric acid (sUA) levels have been found to be positively associated with increased risk of hypertension (HTN), independent of other cardiovascular risk factors. The role of sUA elevation in patients with resistant hypertension (RHTN) is unknown. We hypothesized that sUA levels are higher in RHTN patients compared to patients with controlled HTN.

Methods:
This retrospective study included, 140 patients from the University of Alabama at Birmingham Hypertension Clinic. Patient characteristics including body mass index (BMI), office blood pressure (BP) and sUA levels were analyzed. RHTN was defined as office BP > 140/90 mmHg on ≥ 3 or more different antihypertensive agents including a diuretic. Patients with RHTN were compared with a control group with controlled hypertension. Patients with sUA levels <3 mg/dl, who were on treatment with allopurinol, and those with missing values were excluded from the study.

Results:
Patient characteristics of 91 included patients were: 53.4% female, 40.7% African American, mean age 58.8 ± 12.4 years, mean BMI 33.1 ± 7.5 kg/m
2
, mean sUA 6.6 ± 1.9 mg/dL. Mean sUA was higher among RHTN patients compared to the control group (p = 0.0031). Treatment resistance was found to be strongly correlated with sUA levels of ≥ 6 mg/dl (p = 0.0065).

Conclusion:
In this retrospective study, sUA levels were found to be significantly higher among resistant HTN patients compared to controlled HTN patients, indicating that high sUA levels (≥ 6 mg/dl) may play a role in treatment resistance among hypertensive patients.
Prohibitin‐1 Is a Dynamically Regulated Blood Protein With Cardioprotective Effects in Sepsis
Authors: Mattox Taylor A. , Psaltis Christine , Weihbrecht Katie , Robidoux Jacques , Kilburg‐Basnyat Brita , Murphy Michael P. , Gowdy Kymberly M. , Anderson Ethan J.
Published: July 2021

Background

In sepsis, circulating cytokines and lipopolysaccharide elicit mitochondrial dysfunction and cardiomyopathy, a major cause of morbidity and mortality with this condition. Emerging research places the PHB1 (lipid raft protein prohibitin‐1) at the nexus of inflammation, metabolism, and oxidative stress. PHB1 has also been reported in circulation, though its function in this compartment is completely unknown.

Methods and Results

Using a wide‐ranging approach across multiple in vitro and in vivo models, we interrogated the functional role of intracellular and circulating PHB1 in the heart during sepsis, and elucidated some of the mechanisms involved. Upon endotoxin challenge or sepsis induction in rodent models, PHB1 translocates from mitochondria to nucleus in cardiomyocytes and is secreted into the circulation from the liver in a manner dependent on nuclear factor (erythroid‐derived 2)‐like 2, a key transcriptional regulator of the antioxidant response. Overexpression or treatment with recombinant human PHB1 enhances the antioxidant/anti‐inflammatory response and protects HL‐1 cardiomyocytes from mitochondrial dysfunction and toxicity from cytokine stress. Importantly, administration of recombinant human PHB1 blunted inflammation and restored cardiac contractility and ATP production in mice following lipopolysaccharide challenge. This cardioprotective, anti‐inflammatory effect of recombinant human PHB1 was determined to be independent of nuclear factor (erythroid‐derived 2)‐like 2, but partially dependent on PI3K/AKT  signaling in the heart.

Conclusions

These findings reveal a previously unknown cardioprotective effect of PHB1 during sepsis, and illustrate a pro‐survival, protective role for PHB1 in the circulation. Exploitation of circulating PHB1 as a biomarker and/or therapeutic could have widespread benefit in the clinical management of sepsis and other severe inflammatory disorders.
The Gut Microbiome of Heart Failure With Preserved Ejection Fraction
Authors: Beale Anna L. , O’Donnell Joanne A. , Nakai Michael E. , Nanayakkara Shane , Vizi Donna , Carter Kaye , Dean Eliza , Ribeiro Rosilene V. , Yiallourou Stephanie , Carrington Melinda J. , Marques Francine Z. , Kaye David M.
Published: July 2021

Background

Risk factors for heart failure with preserved ejection fraction (HFpEF) include hypertension, age, sex, and obesity. Emerging evidence suggests that the gut microbiota independently contributes to each one of these risk factors, potentially mediated via gut microbial‐derived metabolites such as short‐chain fatty acids. In this study, we determined whether the gut microbiota were associated with HFpEF and its risk factors.

Methods and Results

We recruited 26 patients with HFpEF and 67 control participants from 2 independent communities. Patients with HFpEF were diagnosed by exercise right heart catheterization. We assessed the gut microbiome by bacterial 16S rRNA sequencing and food intake by the food frequency questionnaire. There was a significant difference in α‐diversity (eg, number of microbes) and β‐diversity (eg, type and abundance of microbes) between both cohorts of controls and patients with HFpEF (
P
=0.001). We did not find an association between β‐diversity and specific demographic or hemodynamic parameters or risk factors for HFpEF. The Firmicutes to Bacteroidetes ratio, a commonly used marker of gut dysbiosis, was lower, but not significantly so (
P
=0.093), in the patients with HFpEF. Compared with controls, the gut microbiome of patients with HFpEF was depleted of bacteria that are short‐chain fatty acid producers. Consistent with this, participants with HFpEF consumed less dietary fiber (17.6±7.7 versus 23.2±8.8 g/day;
P
=0.016).

Conclusions

We demonstrate key changes in the gut microbiota in patients with HFpEF, including the depletion of bacteria that generate metabolites known to be important for cardiovascular homeostasis. Further studies are required to validate the role of these gut microbiota and metabolites in the pathophysiology of HFpEF.
Double Deletion of Angiotensin II Type 2 and Mas Receptors Accelerates Aging‐Related Muscle Weakness in Male Mice
Authors: Takeshita Hikari , Yamamoto Koichi , Mogi Masaki , Wang Yu , Nozato Yoichi , Fujimoto Taku , Yokoyama Serina , Hongyo Kazuhiro , Nakagami Futoshi , Akasaka Hiroshi , Takami Yoichi , Takeya Yasushi , Sugimoto Ken , Horiuchi Masatsugu , Rakugi Hiromi
Published: July 2021

Background

The activation of AT2 (angiotensin II type 2 receptor ) and Mas receptor by angiotensin II and angiotensin‐(1‐7), respectively, is the primary process that counteracts activation of the canonical renin‐angiotensin system (RAS). Although inhibition of canonical RAS could delay the progression of physiological aging, we recently reported that deletion of Mas had no impact on the aging process in mice. Here, we used male mice with a deletion of only AT2 or a double deletion of AT2 and Mas to clarify whether these receptors contribute to the aging process in a complementary manner, primarily by focusing on aging‐related muscle weakness.

Methods and Results

Serial changes in grip strength of these mice up to 24 months of age showed that AT2/Mas knockout mice, but not AT2 knockout mice, had significantly weaker grip strength than wild‐type mice from the age of 18 months. AT2/Mas knockout mice exhibited larger sizes, but smaller numbers and increased frequency of central nucleation (a marker of aged muscle) of single skeletal muscle fibers than AT2 knockout mice. Canonical RAS‐associated genes, inflammation‐associated genes, and senescence‐associated genes were highly expressed in skeletal muscles of AT2/Mas knockout mice. Muscle angiotensin II content increased in AT2/Mas knockout mice.

Conclusions

Double deletion of AT2 and Mas in mice exaggerated aging‐associated muscle weakness, accompanied by signatures of activated RAS, inflammation, and aging in skeletal muscles. Because aging‐associated phenotypes were absent in single deletions of the receptors, AT2 and Mas could complement each other in preventing local activation of RAS during aging.
Age and Acute Ischemic Stroke Outcome in North American Patients With COVID‐19
Authors: Dmytriw Adam A. , Dibas Mahmoud , Schirmer Clemens M. , Settecase Fabio , Heran Manraj K. S. , Efendizade Aslan , Kühn Anna Luisa , Puri Ajit S. , Ospel Johanna , Menon Bijoy , Sivakumar Sanjeev , Mowla Ashkan , Vela‐Duarte Daniel , Linfante Italo , Dabus Guilherme , Regenhardt Robert W. , Patel Aman B. , Leslie‐Mazwi Thabele , D’Amato Salvatore , Rosenthal Joseph , Zha Alicia , Talukder Nafee , Sheth Sunil , Cooke Daniel , Leung Lester Y. , Malek Adel , Voetsch Barbara , Sehgal Siddharth , Wakhloo Ajay K. , Wu Hannah , Cohen Jake , Turkel‐Parella David , Xavier Andrew , Tiwari Ambooj ,   the North American Neurovascular COVID‐19 (NAN‐C) Consortium
Published: July 2021

Background

Acute ischemic stroke (AIS) in the context of COVID‐19 has received considerable attention for its propensity to affect patients of all ages. We aimed to evaluate the effect of age on functional outcome and mortality following an acute ischemic event.

Methods and Results

A prospectively maintained database from comprehensive stroke centers in Canada and the United States was analyzed for patients with AIS from March 14 to September 30, 2020 who tested positive for SARS‐CoV‐2. The primary outcome was Modified Rankin Scale score at discharge, and the secondary outcome was mortality. Baseline characteristics, laboratory values, imaging, and thrombectomy workflow process times were assessed. Among all 126 patients with COVID‐19 who were diagnosed with AIS, the median age was 63 years (range, 27–94). There were 35 (27.8%) patients with AIS in the aged ≤55 years group, 47 (37.3%) in the aged 56 to 70 group, and 44 (34.9%) in the aged >70 group. Intravenous tissue plasminogen activator and thrombectomy rates were comparable across these groups, (
P
=0.331 and 0.212, respectively). There was a significantly lower rate of mortality between each group favoring younger age (21.9% versus 45.0% versus 48.8%,
P
=0.047). After multivariable adjustment for possible confounders, a 1‐year increase in age was significantly associated with fewer instances of a favorable outcome of Modified Rankin Scale 0 to 2 (odds ratio [OR], 0.95; 95 CI%, 0.90–0.99;
P
=0.048) and higher mortality (OR, 1.06; 95 CI%, 1.02–1.10;
P
=0.007).

Conclusions

AIS in the context of COVID‐19 affects young patients at much greater rates than pre‐pandemic controls. Nevertheless, instances of poor functional outcome and mortality are closely tied to increasing age.
Association of Nonacute Opioid Use and Cardiovascular Diseases: A Scoping Review of the Literature
Authors: Singleton Jade H. , Abner Erin L. , Akpunonu Peter D. , Kucharska‐Newton Anna M.
Published: July 2021

BACKGROUND

In this scoping review, we identified and reviewed 23 original articles from the PubMed database that investigated the relationship between nonacute opioid use (NOU) and cardiovascular outcomes.

METHODS AND RESULTS

We defined NOU to include both long‐term opioid therapy and opioid use disorder. We summarized the association between NOU and 5 classes of cardiovascular disease, including infective endocarditis, coronary heart disease (including myocardial infarction), congestive heart failure, cardiac arrythmia (including cardiac arrest), and stroke. The most commonly studied outcomes were coronary heart disease and infective endocarditis. There was generally consistent evidence of a positive association between community prevalence of injection drug use (with opioids being the most commonly injected type of drug) and community prevalence of infective endocarditis, and between (primarily medically indicated) NOU and myocardial infarction. There was less consensus about the relationship between NOU and congestive heart failure, cardiac arrhythmia, and stroke.

CONCLUSIONS

There is a dearth of high‐quality evidence on the relationship between NOU and cardiovascular disease. Innovative approaches to the assessment of opioid exposure over extended periods of time will be required to address this need.
Abstract P001: HDAC1 Plays an Important Role in the Differentiation of Embryonic Stem Cells and Induced Pluripotent Stem Cells into Cardiovascular Lineages
Authors: Hoxha Eneda , Lambers Erin , Ramirez Veronica , Krishnamurthy Prasanna , Verma Suresh , Thal Melissa , Kishore Raj
Published: July 2021

Despite advancements in the treatment of myocardial infarction (MI), the majority of patients are at increased risk for developing heart failure due to the loss of cardiomyocytes and microvasculature. Some of the main obstacles in the realization of the full potential of iPS/ES cells arise from incomplete and poorly understood molecular mechanisms and epigenetic modifications that govern their pluripotency and directed differentiation. Real-time array experiments revealed that HDAC1 is highly expressed in pluripotent cells. Additionally the lack of this molecule is embryonic lethal, suggesting it plays a key role in development. Thus, we hypothesized that HDAC1 plays a critical role in directing cardiovascular differentiation of mES and iPS cells in vitro. HDAC1 was knocked down in mES cells (C57BL/6) and iPS cells using a shRNA vector. Differentiation through embryoid body (EB) was induced in wild type mES cells and iPS cells and in their HDAC1-null counterparts and the ability of these cells to differentiate into three early embryonic lineages and more specifically cardiovascular lineage was monitored. EBs lacking HDAC1 differentiated slower and showed delayed suppression of pluripotent genes such as Oct4 and Sox2. ChiP experiments revealed high histone acetylation levels at the promoter regions of these genes during early differentiation. In addition cells lacking HDAC1 showed reduced expression of early markers for all three germ layers. HDAC1-null EBs also showed delayed and reduced spontaneous beating. Expression of cardiomyocite markers as well as markers of other cardiovascular lineages was repressed in HDAC1 -null cells. However, supplementation with BMP2 during early differentiation recovered the ability in the HDAC1-null cells to differentiate into endodermal and mesodermal lineages, but not ectodermal. We propose that HDAC1 plays a critical role in early development and cardiovascular differentiation of mES and iPS cells by repressing pluripotent genes and allowing for expression of early developmental genes such as SOX17 and BMP2. Further research in the molecular mechanisms involved in this process will greatly aid our understanding of the epigenetic circuitry of pluripotency and differentiation in ES and iPS cells.
Abstract P005: Direct Differentiation of Atrial and Ventricular Myocytes from Human Embryonic Stem Cells
Authors: Ma Yue
Published: July 2021

Although cell transplantation studies have suggested promising therapeutic potentials for myocardial infarction, the leading cause of death worldwide, the incapability to obtain relatively homogeneous ventricular myocytes for transplantation is one major obstacle to the development of clinical therapies for myocardial repair1. Human embryonic stem cell (hESC) is a promising source of cardiomyocytes. Here we show that both Noggin and pan-retinoic acid receptor antagonist BMS-1894532 (RAi) significantly increase the cardiac differentiation efficiency of hESCs. Investigating retinoid function by comparing Noggin+RAi-treated cultures with Noggin+RA-treated cultures, we found that with 64±0.88% (mean ±s.e.m) cardiac differentiation efficiency, 83% of the cardiomyocytes in Noggin+RAi-treated cultures had embryonic ventricular-like action potentials (AP); while, with 50±1.76% cardiac differentiation efficiency, 94% of those in Noggin+RA-treated cultures had embryonic atrial-like APs. These findings demonstrating that relatively homogeneous embryonic atrial and ventricular myocyte populations can be efficiently derived from hESCs by specifically influencing signaling cascades.
Abstract P019: Exosomes from Human CD34+ Cells: Critical Mediators of Proangiogenic Paracrine Effect of EPCs
Authors: Sahoo Susmita , Misener Sol , Thorne Tina , Millay Meredith , Schultz Kathryn M , Liu Ting , Ito Aiko , Kamide Christine , Klyachko Ekaterina A , Losordo Douglas W
Published: July 2021

Local transplantation of human CD34+ hematopoietic stem cells has been shown to promote neovascularization in pre-clinical studies in models of myocardial and limb ischemia. In early phase clinical trials, transplantation of CD34+ cells has been associated with reduced angina, improved exercise time and reduced amputation rates. Several studies have suggested that paracrine effects by these pro-angiogenic cells mediate the effects induced by cell transplantation. We hypothesized that CD34+ cells secrete exosomes (Exo), which mediate at least a part of the therapeutic function of the cells.

Methods and Results:
We isolated Exo from the conditioned media of adult human peripheral blood (PB) CD34+ cells. The angiogenic and therapeutic potency of CD34+ Exo was compared with the intact CD34+ cells and also with PB mononuclear cell (MNC) Exo. Exo from both CD34+ cells and MNC are 50–90nm in size, have cup shaped morphology, and carry known Exo-marker proteins such as CD63, TSG101 and Annexin V as shown by electron microscopy, Western blot and flow cytometry. Compared to CD34+ cells or MNC Exo, CD34+ Exo significantly induces in vitro angiogenic activities such as viability, proliferation and tube formation of HUVECs on matrigel- in a dose dependent manner. In vivo, CD34+ Exo stimulated significant neovascularization in mouse corneal angiogenesis assay (14±4 mm v MNC Exo, 4±1 mm, p<0.01) and incorporation of endothelial (CD31+) cells in mouse matrigel-plug assay (6±1.7% v CD34+ cells, 2±0.8%, p<0.01). Finally, in a mouse model of hind limb ischemia (HLI), CD34+ Exo significantly improved perfusion (ratio: 1.01±0.04 v 0.57±0.1, P<0.05), increased capillary density (1.8±0.3/HPF v 0.9±0.1/HPF, p<0.001) and prevented ischemic leg amputation (16% v 100%), as compared with MNC Exo.

Conclusions:
These data demonstrate that CD34+ Exo induce angiogenic activity and ischemic tissue repair in the absence of CD34+ cells, and suggest that Exo represent important mediators of the therapeutic effects associated with CD34+ cell therapy. We speculate that Exo derived from CD34+ cells may represent a significant component of the paracrine effect of progenitor-cell transplantation for therapeutic angiogenesis.
Abstract P025: Modulatory Effect of Angiotensin II on Endothelial Differentiation and Vasculogenic Capacity of Human MSCs
Authors: Bellio Michael , Sanina Cristina , Balkan Wayne , Rodrigues Claudia O , Gomes Samirah A , McNiece Ian , Hare Joshua M , Schulman Ivonne H
Published: July 2021

Human bone marrow-derived mesenchymal stem cell (MSC)-based therapy holds great promise as a new approach for cardiovascular regeneration. In heart failure, there is activation of the renin-angiotensin system and increased formation of angiotensin (Ang) II. We tested the hypothesis that Ang II impairs endothelial differentiation and vasculogenic capacity of human MSCs. MSCs were cultured in endothelial growth media (EGM) and treated with vehicle, 1µM Ang II, or 10µM Ang II for 7 days to assess by real time RT-PCR the expression of two markers of endothelial differentiation, platelet endothelial cell adhesion molecule (PECAM) and von Willebrand factor (vWF). Expression of PECAM and vWF increased similarly in each treatment group at day 7, suggesting endothelial differentiation of MSCs. To assess vasculogenesis, MSCs were cultured in EGM for 7 days and then plated on growth factor reduced Matrigel for 5 hours under the following conditions: vehicle, Ang II (1µM), Ang II + type 1 receptor (AT1R) inhibitor (10µM losartan), or Ang II + type 2 receptor (AT2R) inhibitor (0.1µM PD123177). The vascular index (VI) was determined by multiplying the average number of endothelial tubes formed by the average tube length. MSCs treated for 5 hours with 1µM Ang II exhibited a reduced VI (84.5 ± 2.6% of vehicle treated cells, P<0.05). Treatment with Ang II+AT1R inhibitor increased VI (115 ± 4.9% of vehicle, P<0.05) whereas Ang II+AT2R inhibitor decreased VI (77.1 ± 4.1% of vehicle, P<0.05). Chronic treatment for 7 days in EGM with 1µM or 10µM Ang II also showed decreased VI compared to vehicle (75.4 ± 5.4% and 60.7 ± 2% of vehicle, respectively, P<0.01). These results reveal that both acute and chronic treatment with Ang II produces a negative effect on the vasculogenic potential of endothelial-differentiated human MSCs and suggests opposing effects of AT1R and AT2R on vasculogenesis. In conclusion, we propose that selective modulation of AT1R and AT2R mediated pathways may serve as a promising means for enhancing the regenerative capacity of human MSCs in cardiovascular disease.
Abstract P031: Enhanced Cardiac Progenitor Cell Function and Differentiation in a Naturally Derived Extracellular Matrix
Authors: French Kristin M , DeQuach Jessica A , Christman Karen L , Davis Michael E
Published: July 2021

Cardiovascular disease, including myocardial infarction, is a leading cause of death worldwide. Though several pharmacological treatments for severe dysfunction exist, much recent work has focused on the transplantation of adult-derived stem and progenitor cells. Early acute functional improvements have been noted, however long-term clinical efficacy is hampered by poor cell survival and engraftment. While the current treatment is infusion into the coronary artery, biomaterials may play an important role in modulating implanted cell function. This work aims to establish the role that a naturally derived extracellular matrix plays in the differentiation of cardiac progenitor cells (CPCs) and their potentially protective enzymatic systems. To test this hypothesis, we cultured rat CPCs in a naturally derived porcine ECM (pECM) and compared it to Collagen I. Quantitative real-time PCR was used to assess expression of cardiac, endothelial and smooth muscle markers. Additionally, angiotensin receptor (AT1R and AT2R) and antioxidant gene expressions were evaluated to determine the protective qualities of pECM. Preliminary data at 2 days following LIF removal demonstrate an increase in the expression of cardiac lineage markers (Nkx-2.5, Gata-4, α-MHC, and troponin I) in pECM compared to collagen. Smooth muscle markers, smooth muscle α-actin and sm22α as well as the endothelial marker Flk1 were also increased in pECM samples. Increased expression was also seen for antioxidant genes GPX1, SOD1, SOD2 and catalase in pECM cultured cells. Culturing in pECM for 7 days demonstrated an increase in Flt-1 and α-myosin heavy chain, indicating a potential increase in cardiogenesis. Moreover a 60% reduction in AT1R gene expression was observed with no significant change in AT2R expression. Our data demonstrate that culturing CPCs in naturally derived matrices may provide protection and enhance differentiation compared to collagen (present in high amounts in scarred myocardium). Future work will further elucidate this protective effect of AT1R downregulation and antioxidant increases in functional studies. In conclusion, pECM may be a potential cell delivery scaffold in post-MI treatment given its protective nature and improved differentiation influence.
Abstract P034: Bone Marrow--Derived Cells Are Not an Essential Component in Cardiosphere Formation
Authors: Ye Jianqin , Boyle Andrew , Yeghiazarians Yerem
Published: July 2021

Background:
Cardiospheres (CS) are composed of heterogeneous population of cells but it is unknown whether bone marrow derived cells are an essential cell component in CS formation.

Methods:
Chimera mice were generated by transplantation of bone morrow cells from GFP transgenic mice to irradiated C57BL mice. Mice were randomized into 3 groups 5 months after transplantation: 1) myocardial infarction; 2) sham operated; 3) un-operated (n=5/group). Hearts were harvested 2-weeks post-surgery. Cardiac explants were cultured and putative cardiosphere forming cells (CFCs) (small cells migrating out from the explants) were collected 14 days later and reseeded on new culture dishes for CS formation. The number of CS from each heart was counted at 3 days. CS cell composition was analyzed by FACS. To further analyze the role of bone marrow derived CD45+ cells in forming CS, CD45+ cells was isolated from CFCs by CD45 antibody coated immunomagnetic beads. The number of CS formed from 1×10
5
putative CFCs, CFCs without CD45+ cells and CD45+ cells from CFCs (n=6-9/cell type) respectively were also counted at 3 days in culture.

Results:
Compared to sham (122± 23/heart) and un-operated hearts (18± 5/heart), infarcted hearts formed more CS (357± 64/heart, P<0.01). In all groups, irrespective of any surgery, 18.4± 4.5% of cells in CS co-expressed GFP and CD45, indicating they originated in bone marrow. Low percentage of bone marrow stem/progenitor cells (3.9% Sca-1+GFP+CD45+ and 1% c-Kit+GFP+CD45+ cells) were detected in CS, but a high percentage of cells within CS were cardiac stem/progenitor cells (26.3± 9.4% cells were Sca-1+GFP-CD45-, 0.10± 0.04% c-Kit+GFP-CD45-). Depleting CD45+ cells from putative CFCs actually increased the formation of CS (67±10 CS/1×10
5
cells) compared to un-depleted CFCs (51± 6 CS/1×10
5
cells, P<0.0001). Purified CD45+ cells from CFCs did not form CS in culture.

Conclusion:
Myocardial infarction increases the formation of CS in culture. Bone marrow derived CD45+ cells make up a small percentage of CS, but are not necessary for CS formation.
Abstract P053: Impaired Autophagosome Removal in Cardiomyocytes Triggers Programmed Necrosis in Mouse Hearts
Authors: Su Huabo , Tian Zongwen , Wang Changhua , Said Suleman , Li Jie , Ranek Mark J , Wang Xuejun (XJ)
Published: July 2021

Programmed cell death includes apoptosis and programmed necrosis. The latter is also known as necroptosis. A well-recognized feature of necrosis is the loss of membrane integrity of the dying cell, resulting in inflammatory responses at the surrounding tissue. Cells undergoing apoptosis, however, maintain their membrane integrity very well and hence do not trigger inflammation. These features are effectively captivated to detect necrotic cells. By assessing Evans Blue Dye (EBD) uptake and CD45+ leukocytes, we previously detected massive cardiomyocyte (CM) necrosis, before increased apoptosis was evident, in mouse hearts deficient of COP9 signalosome (CSN) subunit 8 (Csn8) (
Circ Res 2011; 108:40–50
). We show here that the detection of necrosis is confirmed by immuno-detection of endogenous IgG inside the CM. We found that virtually all EBD positive cells were also mouse IgG positive whereas some of the IgG positive CMs, as expected, did not show increased EBD uptake, suggesting that probing intracellular IgG offers a simpler and even more sensitive method for detecting necrotic CMs in vivo. Notably, we were able to demonstrate that both the EBD uptake assay and the immuno-detection of intracellular IgG clearly have a resolution at the single cell level. We then explored the mechanism by which Csn8/CSN deficiency causes necrosis. Autophagosomes are accumulated due to a defect in their fusion with lysosomes in mouse hearts with perinatal CM-restricted Csn8 knockout (CR-Csn8KO) but the accumulation is heterogeneous among CMs likely due to a temporal heterogeneity of Csn8 gene ablation and/or a spatial difference in the microenvironment and functionality of different CMs. A remarkably higher percentage of CMs with greater autophagosome accumulation were undergoing necrosis than those with less or without autophagosome accumulation. Importantly, chronic lysosomal inhibition caused CM necrosis in wild type mice. Moreover, the protein levels of RIP1, RIP3 kinases and the RIP1-bound RIP3 were all significantly increased in the CR-Csn8KO heart. Taken together, these novel findings strongly suggest that impaired autophagosome removal causes CM necrosis in Csn8/CSN deficient hearts through likely activating the RIP1-RIP3 mediated necroptotic pathway.
Abstract P081: Voltage-Gated TTX-Sensitive Nav1.1 Brain Sodium Channels Are Important for Cardiac Contractile Function
Authors: Varghese Susan T , Humphrey Stephanie , Xie An , Escayg Andrew P , Dudley Samuel C
Published: July 2021

Background:
Mutations in voltage gated brain sodium channel Nav1.1 have been linked to many disorders, including Generalized Epilepsy with Febrile Seizures Plus (GEFS+) and Severe Myoclonic Epilepsy of Infancy (SMEI). Recent studies have identified TTX- sensitive Nav1.1 brain sodium channels in the SA node and ventricular T-tubules of the heart, though their role in cardiac function is still controversial. We tested the functional significance of Nav1.1 sodium channels in the heart by creating a novel knock-in of human epilepsy GEFS+ mutation SCN1A-R1648H at the Scn1a locus of a C57BL/6J X 129 mouse.

Method:
In vivo 2-D echocardiography was performed on 2 week old (juvenile) and 8 week old (adult) wild-type and heterozygote (Scn1aRH/+) mice after extracardiac neuronal block through intraperitoneal injections of atropine and propranolol (2.5mg/kg each). Calcium and contractility studies on adult ventricular cardiomyocytes isolated from the wild type and Scn1aRH/+ mice paced at 0.5Hz were followed by administration of TTX (100nM, a brain sodium channel inhibitor) and pacing at 2Hz. qRT-PCR and Western blot of the isolated cells and whole heart samples was also done.

Results:
A decrease in Nav1.1 gene expression in the Scn1aRH/+ juvenile (by 31%, 0.69 of 1) and adult (by 60%, 0.4 of 1) whole heart samples and isolated cells (p<0.05) was seen. Echocardiography revealed concentric hypertrophy in the juvenile Scn1aRH/+ mice by a significant increase in LV mass, LV mass/body weight ratio, and relative wall thickness (p<0.05). In the adult Scn1aRH/+ mice, systolic isovolumic contraction time (IVCT) was reduced (p=0.03) and decrease in diastolic function was evident through significant decreases in isovolumic relaxation time (IVRT) and E’/A’ ratio, and increase in E/E’ ratio. Isolated adult ventricular Scn1aRH/+ cardiomyocytes showed significant reduction in percent sarcomere shortening, maximum rate of contraction and relaxation, and time to peak contraction, exaggerated with TTX and pacing at 2Hz (p<0.5).

Conclusions:
Our study demonstrates the importance of voltage gated TTX-sensitive Nav1.1 brain sodium channels in cardiac contractile function and their possible role in cardiac complications in epilepsy.