bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 062: Inhibition of Phosphodiesterase 5 Attenuates Angiotensin II Dependent Hypertension and Renal Vascular Dysfunction in C57BL/6 but Not in eNOS-KO Mice
Authors: Thieme Manuel , Sivritas Sema , Potthoff Sebastian A , Yang Guang , Rump Lars C , Stegbauer Johannes 
Published: March 2022

Angiotensin (Ang) II is a key player in the pathogenesis of hypertension by influencing the NO/cGMP signaling cascade. Thus, Ang II induces vascular dysfunction by activating phosphodiesterase (PDE) 1 and PDE5 mediated cGMP-degradation. PDE1 is activated by increased intracellular Ca2+ concentrations observed during Ang II mediated vasoconstriction. PDE5 is activated by a cGMP mediated negative feedback mechanism. The present study examines the role of PDE1 and PDE5 in regulation of renal hemodynamics and blood pressure (BP) during Ang II induced hypertension.
In unconscious C57BL/6 (WT) mice, changes in renal blood flow (RBF) and BP was measured in the presence of specific PDE5- (sildenafil) or PDE1- (vinpocetine) inhibitors. Secondly, in WT and eNOS-KO mice, a mouse model characterized by low NO/cGMP levels, hypertension was induced by chronic Ang II infusion (500 ng/kg/min) for 14 days. Vascular relaxation was tested in the presence of acute or chronic PDE1 or PDE5 inhibition in isolated perfused kidneys.
During acute Ang II infusion, sildenafil increased RBF and decreased BP more potently than under baseline conditions. In contrast, vinpocetin had no effect on RBF and BP during normotensive or hypertensive conditions, Moreover, sildenafil but not vinpocetine improved NO (GSNO) dependent vasodilation in isolated perfused kidneys of Ang II treated WT mice. Next, we tested the impact of chronic PDE5 inhibition on Ang II dependent hypertension. Sildenafil (100mg/kg/d) attenuated Ang II dependent hypertension in WT (156±4 vs. 139±7mmHg; p<0.05) but not in eNOS-KO mice (166±4 vs. 172±4mmHg). Respectively, chronic Sildenafil treatment improved NO dependent vasodilation in isolated perfused kidneys of Ang II treated WT but not in eNOS-KO mice. In addition, urinary nitrite excretion, a marker for NO generation was significantly increased during Ang II-infusion compared to baseline in WT but not in eNOS-KO mice.
In conclusion, PDE5 seems to be the predominant PDE regulating RBF and renal vascular function. Moreover, sildenafil ameliorates Ang II dependent hypertension and improves vascular dysfunction. No effect of PDE5 inhibiton was observed in eNOS-KO mice supporting the hypothesis that Ang II activates PDE5 initially by increased NO/cGMP generation.
Abstract P148: Ambulatory Blood Pressure in Hypertensive Patients Treated with Different 2-Drug and 3-Drug Combinations
Authors: De la Sierra Alejandro , Gorostidi Manuel , Banegas Jose R , Segura Julian , Vinyoles Ernest , De la Cruz Juan J , Ruilope Luis M 
Published: March 2022

An elevated proportion of patients require 2-drug and 3-drug combinations to achieve BP control. There is scarce evidence regarding if there are differences in such BP control among different types of combinations in daily practice. We aimed to assess office and ambulatory BP values achieved, as well as the proportion of controlled patients, depending on the type of drug combination used.
From the Spanish ABPM Registry we selected 17187 patients treated with the 6 most common types of 2-drug combinations and 9724 treated with the 6 most common types of 3-drug combination. We looked for differences in achieved office and ambulatory BP, as well as nocturnal dip, and the proportion of controlled patients among types of combinations, after adjusting for confounders (age, gender, BMI, smoking, diabetes, dyslipidemia, and previous CV disease).
With respect to the combination of renin angiotensin system (RAS) blockers and diuretics (reference), none of the other combinations achieved lower BP values or better BP control. Ambulatory BP control (including 24-hour, daytime and nighttime) was worse with combinations of RAS blockers/beta blockers (OR: 1.06; 95%CI: 1.01-1.11), with combinations of calcium channel blockers (CCB)/beta blockers (1.1; 1.04-1.16) and with combinations of RAS blockers and CCB (1.38; 1.23-1.55). Nondipping was also more frequent in combinations other than RAS blockers/diuretics. In patients receiving 3-drug combinations, and with respect to RAS blockers/CCB/diuretic combinations (reference), ambulatory BP were higher and non dipping more frequent in other types of combinations. Ambulatory BP control was worse in RAS blockers/CCB/alpha blockers, RAS blockers/diuretics/alpha blockers, and CCB/beta blockers/diuretics combinations. No differences in office BP control were observed among types of 2-drug or 3-drug combinations.
We conclude that RAS/diuretic combinations and RAS/diuretic/CCB combinations are associated with better ambulatory BP control and more pronounced dipping in comparison with other types of 2-drug or 3-drug combinations, even with same rates of office BP control. These results can be helpful in deciding the way to combine antihypertensive agents in patients who require combination therapy.
Abstract P159: Effect of Pharmacological Kinin Receptor Activation on Brain Damage and Mortality in Experimental Cerebral Ischemia in Non-diabetic and Diabetic Mice
Authors: Desposito Dorinne , Taveau Christopher , Zadigue Georges , Adam Clovis , Bouby Nadine , Alhenc-Gelas Francois , Roussel Ronan 
Published: March 2022

Brain ischemia is a major complication of arterial diseases and has a poorer prognosis in diabetic patients. As activation of the kallikrein-kinin system has been shown to enhance cardiac and renal tolerance to ischemia we tested effect of kinin receptor activation by pharmacological agonists, selective B1R or B2R, in a mouse model of transient middle cerebral artery occlusion [C57bl6 male, 10 week-old, anaesthesia, occlusion 60 min (MCAO)]. Treatment with the B1R agonist NG29 (B1Rago) or the B2R agonist NG291 (B2Rago) was started at reperfusion using osmotic micropumps. Neurological deficit (ND) was evaluated at 1 and 2 days using a panel of 8 established tests combined in a 0-30 deficit score. Brain infarction was quantified at day 2 using TTC and hematoxylin-eosin staining. In some mice diabetes was induced by streptozotocin 8 weeks before MCAO.
MCAO induced bradychardia, mild hypotension (mean -11.3 mmHg), ND (19.7 ± 2.4) and resulted in partial brain infarction (18 ± 1.4 %), all p<0.05 compared to sham, n=10/group. B2Rago (720 nmol/kg.day-1) increased ND to 27 ± 1.8 at day 1 and mortality to 60% at day 2 (both p<0.05, n=10) while decreasing brain infarct size by 66% (p<0.01). B2Rago reduced BP by 16 mmHg and increased plasma creatinine (73 ± 25 μmol/l, p<0.05). Although B1R mRNA level increased by 1.3 fold in the ischemic brain B1Rago had no effect on ND, mortality or brain infarction.
In diabetic mice MCAO increased ND (28 ± 1), mortality (25%) and infarct size (40 ± 3 %) more than in non-diabetic mice (n=8, p<0.05). B2Rago increased mortality to 80% (p<0.05, n=9). B1Rago, tested at two different dosages (720 or 240 nmol/kg.day-1, n= 8/group) reduced ND (22 ± 2 at day 2 for the low dosage, p< 0.05) and did not increase mortality or alter renal function. B1Rago reduced infarct size by 66 and 71 %, at the two dosages, respectively (p<0.01).
Thus, B2R activation reduces brain infarction but paradoxically increases mortality by mechanisms that may involve brain oedema and renal insufficiency. B1R activation has no effect in non-diabetic mice but in diabetic animals it reduces infarct size and improves ND without adverse effect on renal function and survival. Longer follow-up studies are in progress for further evaluating interest and limitation of B1R activation in MCAO.
Abstract P209: RAS-Equilibrium Analysis: Simplified Biochemical Characterization of the Renin-angiotensin-system and Implications for Diagnosis and Treatment of Hypertension
Authors: Poglitsch Marko , Schwager Cornelia , van Oyen Dunja , Aigner Claudia , Domenig Oliver 
Published: March 2022

The concentrations of angiotensins are maintained by equal rates of formation and degradation. The resulting steady-state angiotensin levels are affected by local molecular factors including tissue, endothelium or blood cell associated angiotensin receptors and processing enzymes as well as plasma soluble RAS components. The high concentration of the pro-hormone angiotensinogen in human plasma in combination with reported ranges for plasma renin activity result in a long-lasting and stable Ang I formation rate without significantly reducing angiotensinogen levels within several hours. This phenomenon can be utilized for the generation of an ex vivo situation that is characterized by significantly higher but stable angiotensin peptide levels. These ex vivo equilibrium angiotensin levels provide an integrated picture about plasma angiotensinase activities and therefore represent a powerful diagnostic tool for analyzing the systemic RAS in clinical samples. Moreover, these ex vivo levels remain stable over hours of incubation at 37°C and show a very high correlation (>90%) with angiotensin levels obtained by a state-of-the art sample collection procedure using complex inhibitor cocktails for stabilizing angiotensin peptides during blood collection.
The quantification of equilibrium angiotensin levels does not require any special sample collection procedures and can be applied to frozen serum and heparin plasma samples. It turned out that ex vivo angiotensin levels represent a measure for the consumption of angiotensin metabolites by the organism, therefore providing a powerful and versatile tool for assessing in vivo angiotensin signaling on the patient specific level enabling new diagnosis based rationales for anti-hypertensive therapies. The application of ex vivo RAS-Fingerprinting in clinical studies could substantially enhance our understanding of the regulation and physiology of the human RAS and could further lead to the development of powerful personalized approaches in the future treatment of hypertension.
Abstract P604: Equivalency Validation of a Novel Freely Moving Animal Based Telemetry System versus a Stationary Cage Bound System for Blood Pressure Recordings
Authors: Knot Harm , Miller Gary 
Published: March 2022

Traditional rodent blood pressure (BP) monitoring required single housing, a known stressor for rodents. We developed a microprocessor based long range wireless telemetry system with large internal memory that allows rodents to live in groups, interact, exercise and be housed in large enriched environments. BP is recorded with a solid-state sensor along with core temperature and 3D axial activity within the implant. The measurement protocol is transmitted once to the programmable implant via a single room antenna mobile base station. The implant becomes an autonomous recording device until contacted again by the base station with an updated protocol. The implanted animals are thus allowed to undergo procedures, leave the room or be subject other tests while the recording is running. Data can be automatically downloaded periodically within the protocol.
In order to objectively validate this system we contracted a study with the Michigan State University INVIVO facility. 8 male SD rats of 275g were implanted with a model PTA-M TSE Stellar telemetry implant. After 8 days of recovery the animals entered a crossover study and were dosed with vehicle, 3, 10, and 100 mg/kg L-NAME or Verapamil at t=0 hrs. BP was recorded for 10s hourly for 24hrs sampled at 200Hz following drug administration. The BP responses were compared to a control group of 8 animals implanted with a similar conventional implant from a competitor. Drug responses were qualitatively the same between the groups. Mean arterial pressures (MAP) at +12hrs in the 100 mg/kg LNAME group with the TSE implant increased by 26±11 versus 26±9 mmHg in the control group. MAP in the 100 mg/kg Verapamil group at +12 hrs dropped by 31±9 versus 20±6 mm Hg in the control group. Baseline MAP was significantly elevated to 118±5 versus 92±11 in the control group with the conventional implant which may account for the blunted verapamil response.
We conclude that there are no significant differences in quantitative blood pressure responses to L-NAME or Verapamil in animals implanted with a TSE Stellar device versus a leading competing device. We also conclude that the short hourly recordings used for the TSE device produced equivalent MAP values while significantly prolonging implant battery life, thus extending possible study length.
Abstract P629: Effect of Circulating ACE2 Activity on plasma Angiotensin Peptides
Authors: Wysocki Jan , Ye Minghao , Khattab Ahmed M , Serfozo Peter D , Osborn Mark , Batlle Daniel 
Published: March 2022

Circulating ACE2, an enzyme that degrades Ang II, has been reported to be increased in rodent models of diabetes. Upregulation of ACE2 by increasing hydrolysis of Ang II could help downregulate RAS overactivity in a compensatory way and/or reflect increased Ang II metabolism. ACE2 activity in plasma, however, is relatively low even in diabetic conditions. Therefore, further increases in ACE2 effected by exogenous ACE2 administration could have a therapeutic action as a result of enhanced Ang II degradation and formation of Ang 1-7.
We examined the effect of a massive increase in circulating ACE2 activity on plasma levels of Ang II and other Ang peptides in mice rendered diabetic by STZ. Circulating ACE2 was amplified using ACE2 mini-circle (ACE2MC) gene delivery. Multiple Ang peptides were evaluated in plasma from STZ-mice that received ACE2MC and sham STZ-mice (n=6/group).
Plasma Ang II in STZ-ACE2MC mice were markedly lower than in STZ sham mice (3±1 vs. 22±13, pg/mL, respectively), but the difference was not significant owing to high variability. Since the seemingly lower Ang II levels could be influenced by either lower levels of the precursor peptide Ang I, increased degradation of Ang II, or both, a ratio between Ang II and Ang I was calculated. Ang II/Ang I ratio was significantly lower in STZ-ACE2MC as compared to STZ sham mice (0.15±0.05 vs. 0.35±0.06, p<0.05) indicating that per given amount of Ang I, there is significantly less Ang II in STZ-ACE2MC mice. This is consistent with enhanced Ang II degradation. Plasma levels of Ang 1-7 and Ang 1-9, the direct products of ACE2 cleavage of Ang I and Ang II, respectively, were very low and mostly below the level of detection. In plasma, Ang 1-7 is quickly converted to Ang 1-5, by ACE. Therefore, as an index of Ang II conversion to Ang 1-7, and as a surrogate for this conversion, we used Ang 1-5/Ang II ratio. This ratio was markedly higher in STZ-ACE2MC than in sham STZ-mice (3.15±1.5 vs. 0.38±0.07, p<0.05, respectively) suggesting an increased conversion of Ang II to Ang 1-7, and later to Ang 1-5 as a result of plasma ACE2 overexpression.
We conclude that a massive increase in circulating ACE2 is associated with an accelerated metabolism of Ang II. The increase in Ang II degradation seems best reflected by an increase in Ang 1-5/Ang II ratio.
Abstract P197: Vitamin D, Paratohormone and Cardiovascular Risk: The Good, the Bad and the Ugly
Authors: Giannotti Rocco , Pascale Valeria , Finelli Rosa , Visco Valeria , Matula Ida , Ragosa Nicola , massari Angelo , Di Sevo Maria G , Ciccarelli Michele , Iaccarino Guido 
Published: March 2022

25OH Vitamin D (VitD) insufficiency and increased cardiovascular risk (CVR) association is still debated. The VitD dependendent paratohormone (PTH), is considered as the possible actuator of VitD effects on CVR. In an overall population observational study, we assessed the role of PTH in predicting CVR. We recruited 412 persons during the World Hypertension Day, in the area of Salerno, Southern Italy. Through means of dedicated questionnaires, blood pressure measurements and a blood draught, we collected dietary habits, anamnestic, clinical and metabolic data. CVR was calculated according to the Framingham CVR charts. The overall population mean age±SD was 49.9±20 yrs, and female sex was slightly prevalent (53.2%). VitD deficiency (<20 uMol/ml) was most frequent (65.4%). In this population VitD and CVR did not correlate. VitD and PTH inversely correlated (r=-0.236, p<0.001) as expected. PTH was in direct linear regression with CVR (F=14,982, p<0.0001).
Elevated PTH (>=56 mg/dl) levels identify a population with higher CVR (11.9±6.2 vs 9.2±7.1, p<0.01) and larger prevalence of cardiovascular events (10,2 vs 4.1, p<0,04). Since PTH increases with age and kidney function, we selected a 41-60 years old population (N=150). Also in this homogenous group, people with elevated PTH present a larger cardiovascular risk (8.4±10.5 vs 4.1±4.8, p<0,01) due to higher systolic blood pressure (137.2±20.4 vs 130.1±16.0, p<0.05). In conclusion, VitD deficiency causes PTH elevation that in the overall population increases the CVR. Our data let hypothesize that VitD supplementation may represent a major presidium to reduce PTH level and consequently CVR.
Abstract P336: Constitutive Activation of ROCK1 in Mouse Heart Leads to Fibrotic Cardiomyopathy
Authors: Yang Xiangsheng , Li Qi , Lin Xi , Ma Yanlin , Yue Xiaojing , Tao Zhengyin , Chang Jiang 
Published: March 2022

Background:

Our previous study demonstrated that genetic deletion of ROCK1 inhibited stress-induced cardiac fibrosis and ROCK1 was cleaved by caspase 3 into a constitutively active Rho kinase isoform, ROCKΔ1 that led to increase in Rho kinase activity in human failing hearts. However, the function of truncated ROCK1 accumulated in human failing myocardium and the molecular signaling linked between ROCKΔ1 and cardiac remodeling remain obscure.

Methods and Results:

To recapitulate this human pathophysiological situation and define the pathogenic role of ROCKΔ1 in heart, we generated transgenic mice expressing ROCKΔ1 in heart. Significant increase in Rho kinase activity was achieved. The mice developed fibrotic cardiomyopathy along with upregulation of TGFβ1 and NF-κB signaling. Significant increases in fibrotic factors were observed. Echocardiography revealed diastolic dysfunction in the transgenic heart. The transgenic mice were predisposed to angiotensin II treatment that led to massive fibrotic cardiomyopathy. Rho kinase inhibitor Fasudil treatment attenuated the fibrotic maladaption.

To elucidate the molecular mechanism underlying ROCKΔ1-mediated fibrotic cardiomyopathy, wild-type cardiac fibroblasts were co-cultured with transgenic cardiomyocytes. Large amount of fibroblasts were activated and induced to express α-SMA by the transgenic cardiomyocytes but not by the wild-type control cardiomyocytes. Addition of Rho kinase, TGFβR1 and NF-κB inhibitors to the culture media attenuated the fibroblast activation. The results suggested that the pro-fibrotic TGFβ and NF-κB signaling are responsible for ROCKΔ1-mediated fibrotic cardiomyopathy.
Finally, we demonstrated TGFβ1 was a SRF (serum response factor) new target gene. EMSA, luciferase and CHIP assay revealed SRF binding to TGFβ1 promoter. Genetic deletion of SRF in mouse heart resulted in marked decrease in TGFβ1 expression.

Conclusions:

Our studies demonstrated the pro-fibrotic role of truncated ROCK1
in vivo
and provided an animal model that recapitulated human heart failure. The results elucidated that activation of NF-κB and TGFβ1 signaling contributed to Rho kinase-mediated fibrotic cardiomyopathy, the later was regulated by SRF.
Abstract 278: PGC1α Activation Corrects Cardiac Dysfunction Caused by Anti-diabetic Dual-PPARα/γ Therapy
Authors: Kalliora Charikleia , Lieu Melissa J , Yue Yujia , Pol Christine , Valenti Mesele C , Tian Ying , Scerbo Diego , Schulze Christian , Madesh Muniswamy , Civelek Mete , Finck Brian N , Goldberg Ira J , Drosatos Konstantinos 
Published: March 2022

Peroxisome proliferator-activated receptor (PPAR) agonists are used in metabolic diseases. PPARα agonists target hyperlipidemia and PPARγ agonists correct hyperglycemia. Dual PPARα/γ agonists were developed to combine the benefits in type 2 diabetes patients. Despite their beneficial effect, PPARα/γ agonists caused cardiac dysfunction. We studied the mechanisms that underlie this toxic effect aiming to improve a failed therapy.
Wild type mice were fed with chow and high fat diets containing Tesaglitazar (TESA) a dual PPARα/γ agonist for 6 weeks. Although, TESA lowered plasma triglyceride and glucose levels compared to controls, 2D-echo revealed severe cardiac dysfunction. Assessment of the expression of cardiac fatty acid metabolism genes that are regulated by PPARs showed that mRNA and protein levels of PPARγ-coactivator (PGC1α), a regulator of mitochondrial biogenesis, had the most profound reduction. Furthermore, we observed increased acetylation of PGC1α levels, which indicates lower activation and lower mitochondrial respiration.
We then examined the mechanisms that underlie lower expression of PGC1α upon activation of PPARα and PPARγ. Thus, we administered C57BL/6 mice with both single PPARα and PPARγ agonists (WY14643 and rosiglitazone). This treatment reproduced the reduction in PGC1α expression that we observed with TESA. Moreover, mitochondria abundance was lower. Luciferase promoter analysis in a human cardiomyocyte cell line showed that PPARα and PPARγ compete for binding on PPAR elements of the human Pgc1a promoter, as well as that PPARα binding compromises PPARγ-mediated activation of the Pgc1α promoter.
Aiming to decipher the mechanism via which dual PPARα/γ activation increases acetylation and thus inhibits PGC1α, we measured cardiac protein levels of the deacetylase sirtuin 1 (SIRT1), which were lower in primary cardiomyocytes from TESA-treated mice.
We then treated mice with diet containing TESA and Resveratrol (RSV), which stimulates SIRT1. RSV attenuated TESA-driven cardiac dysfunction and corrected mitochondrial respiratory rates in primary cardiomyocytes.
We propose that SIRT1-mediated activation of PGC1α blunts the cardiotoxic effect of dual PPARα/γ agonists and improves their therapeutic potential.