bluuebunny/crossref_metadata_2025_split huggingface dataset:
EVIDENCES OF ANTIHYPERTENSIVE POTENTIAL OF EXTRACT FROM SOLANUM CAPSICOIDES ALL. IN SPONTANEOUSLY HYPERTENSIVE RATS
Authors: Simões Letícia Oliveira , da Silva Ana Quênia Gomes , Conceição‐Filho Ginaldo , Ribeiro Thácio , Niero Rivaldo , Filho Valdir Cechinel , Silva Darizy Flavia 
Published: November 2023

The aims of this study were to characterize the pharmacological activity of the crude extract of S. capsicoides All. (MeOH‐Sc) and its fractions, on the cardiovascular system in spontaneously hypertensive rats (SHR) and their normotensive controls Wistar Kyoto (WKY), and analyze the phytochemical extract of this plant drug. The HPLC indicated the presence of at least two main compounds previously isolated from this plant, Cilistadiol and Cilistol. Intravenous injections MeOH‐Sc (5, 10, 20 and 40 mg/kg) induced hypotension in both mouse strains in a dose‐dependent manner. The reduction was prominent in SHR compared to WKY (** p<0.01) in doses of 40 mg/kg. This hypotensive effect was associated with a tachycardia was significantly greater (* p< 0.05) in animals WKY compared to SHR. In animals receiving MeOH‐Sc orally for 21 days a significant antihypertensive effect was observed in comparison to control. In addition, treatment with captopril and MeOH‐Sc prevented the development of increased of cardiac mass. Significant increase in urine volume of animals treated with MeOH‐Sc (**p<0.001 and *p<0.05) in the fifth and fifteenth day of treatment was observed. Mesenteric artery rings from animals treated with MeOH‐Sc pre‐contracted with Phe, have suffered vasorelaxation by SNP (10‐13‐10‐4M) concentration‐dependent manner with increased potency of pharmacological significant manner (*** p< 0.001) compared to control. The concentration‐response curve of Phe in mesenteric rings of these animals showed a significant decrease (** p <0.01) the power to Phe compared to control. The cumulative addition of MeOH‐Sc (0,001–1000 μg/ml) in the isolated superior mesenteric artery of SHR and WKY rats, in the presence or absence of functional endothelium intact and rings precontracted with phenylephrine (Phe 1μM), induced a vasorelaxation concentration‐dependent. In vascular rings precontracted with depolarizing solution (KCl 80mM), we observed a significant decrease (*p<0.05 and ** p<0.01) of pharmacological potency induced by MeOH‐Sc in both SHR and WKY. Additionally, MeOH‐Sc reversed contractions induced by CaCl2 in depolarizing medium without nominally Ca2+ in both animal strains. When administered cumulatively in the tonic phase of the contraction induced by S‐(−)‐ Bay K 8644 (200 nM), MeOH‐Sc induced significant changes in the values Emax and CE50 besides demonstrating induce their vasorelaxant effect through inhibition of the influx Ca2+ by ROC and SOC. These results suggest that the MeOH‐Sc has hypotensive effect, vasorelaxant and antihypertensive effect potential, possibly due to an influence of the drug on the plant Ca2+ influx in rat vascular smooth muscle.Support or Funding InformationFundação de Amparo à Pesquisa do Estado da Bahia (FAPESB) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Dopamine β‐Hydroxylase Inhibitor Etamicastat Prevents High Blood Pressure in Mice Lacking Salt‐Inducible Kinase 1 (SIK1)
Authors: Pires Nuno , Igreja Bruno , Moura Eduardo , Bonifácio Maria João , Serrão Paula , Soares‐da‐Silva Patrício 
Published: November 2023

In human genetic studies a single nucleotide polymorphism within the salt‐inducible kinase 1 (SIK1) gene was associated with hypertension (1). Moreover, it was recently shown that loss of SIK1 triggers an increase in blood pressure (BP) upon a chronic high‐salt intake in mice (2). Here, we addressed possible acute mechanisms that may relate to the observed high BP in mice lacking SIK1. SIK1 knockout (sik1−/−) and C57BL/6 wild‐type (sik1+/+) littermate mice were challenged for seven days with a normal‐ (0.3% NaCl) or high‐salt (8% NaCl) diet. Systolic BP (SBP) was significantly increased in sik1−/− mice (137.0±17.2 mmHg, n=6) after seven days of high‐salt intake, as compared to sik1+/+ mice counterparts (120.6±4.5 mmHg, n=6). The renin‐angiotensin system (RAS) and the sympathetic nervous system (SNS) were assayed in order to investigate the possible causes for the increase in SBP in sik1−/− mice fed a high‐salt diet. No differences in renin (normal‐salt: 463.4±17.9, high‐salt: 462.9±28.9 pg/ml) and angiotensin II (normal‐salt: 45.8±10.0, high‐salt: 39.0±8.5 pg/ml) serum levels were observed (n=6/group). The activity of dopamine β‐hydroxylase (DβH), the enzyme that converts dopamine (DA) to norepinephrine (NE), was significantly increased in adrenal glands of sik1−/− mice fed a high‐salt diet (356.7±32.8 nmol/mg protein, n=5) as compared to sik1−/− mice on a normal‐salt diet (184.4±14.4 nmol/mg protein, n=5). Similarly, urinary catecholamines (DA, NE and adrenaline) and L‐DOPA were significantly increased (3‐ to 7‐fold increase) in sik1−/− mice fed a high‐salt diet as compared to sik1−/− mice on a normal‐salt intake. Altogether, this data supports the view that sik1−/− mice fed a high‐salt diet develop SNS overactivity. Next, we addressed the question if reducing SNS activity in sik1−/− mice fed a high‐salt diet would ameliorate hypertension. For that purpose, the effect of the peripheral reversible DβH inhibitor etamicastat [also known as BIA 5–453; (R)‐5‐(2‐aminoethyl)‐1‐(6,8‐difluorochroman‐3‐yl)‐1,3‐dihydroimidazole‐2‐thione hydrochloride] was evaluated on the development of high BP upon high‐salt diet (3). Etamicastat treatment (50 mg/kg/day), started prior to high‐salt feeding, completely prevented SBP increase in sik1−/− mice fed a high‐salt diet (116.8±4.7 mmHg, n=5). In summary, it is concluded that the SNS is involved in the development of salt‐induced hypertension in sik1−/− mice and that the DβH inhibitor etamicastat is able to reduce SNS overactivity and high BP in this mouse model of hypertension.Support or Funding InformationThis work was supported by BIAL ‐ Portela & Ca, S.A.
Multi‐Gene Pharmacogenetics and Blood Pressure Control in Patients with Hypertension
Authors: Johnson Micah William , Sprissler Ryan , Olson Thomas P , Beenken Greg William , Snyder Eric M 
Published: November 2023

IntroductionSeveral common and functional genes are known to contribute to renal, blood vessel, and cardiac functional characteristics associated with sodium (Na+) handling, vascular reactivity, and cardiac output, respectively. Many of these same genes are suggested to contribute to differential responsiveness to blood pressure (BP) therapy. Few studies have explored the simultaneous phenotypic consequence of multiple genes critical for BP control. Despite a significant impulse of the medical community towards personalized medicine, BP therapy is typically guided by algorithms that do not include a patient's genetic information.PurposeThe purpose of this study was to determine the impact of 14 genes on time to BP control in response to common BP therapy, with a specific focus on genes associated with drug metabolism and protein function in the kidney, the blood vessels, and the heart.MethodsEighty‐six patients completed one study visit consisting of a buccal swab for DNA extraction and genotyping, measurement of ambulatory BP, and a medical chart review for objective BP history. Genes in the analysis included those that encode for one drug metabolizing enzyme (CYP2D6), renal Na+ handling (SCNN1A, WNK1, SLC12A3, and Alpha Adducin), vascular function (angiotensin, ACE, angiotensin‐II receptor type‐I, and renin), and cardiac function (the β1 and β2 adrenergic receptors ADRB1 and ADRB2, respectively).ResultsGenetic variation of WNK1 (rs1159744) demonstrated differential responses to diuretic therapy (determined as those with blood pressure under 140/90 vs. those above 140/90 according to genotype)(WNK1=GG>CG/CC, P<0.05). Genes that encode ADRB1 (rs1801252), ADRB2 (rs1042713), and CYP2D6 (rs3892097) demonstrated differential response to β‐blocker therapy (ADRB1=Ser/Ser>SerThr/ThrThr, ADRB2=GG>AG/AA, CYP2D6=CC>CT/TT, P<0.05). Genes that encode angiotensin (rs699), ACE (rs1799752), and renin (rs12750834) demonstrated differential response to ACE‐inhibition and angiotensin receptor blockade (angiotensin=CT/TT>CC, ACE=Ins/Ins>InsDel/DelDel, renin=AG/AA>GG, p<0.05).ConclusionThese results demonstrate that genetic variants encoding proteins involved in renal Na+ handling, vascular function, and cardiac output influence response to BP therapy for their respective drug classes.Support or Funding InformationFunded by Geneticure
Toll‐like receptor 9 contributes to increased vascular tone via small GTPase activation
Authors: McCarthy Cameron G. , Wenceslau Camilla F. , Ogbi Safia , Szasz Theodora , Webb R. Clinton 
Published: November 2023

Toll‐like receptor (TLR)9 is a pattern recognition receptor of the innate immune system. We have previously reported that TLR9 stimulation causes resistance artery dysfunction via increased sensitivity to norepinephrine, and this contributed to the pathogenesis of hypertension. However, the mechanisms underlying this increased vascular tone after TLR9 activation need to be further clarified. We hypothesized that TLR9 activation would increase expression of small GTPases, indicative of actin cytoskeleton remodeling. Isolated mesenteric resistance arteries from Sprague‐Dawley rats (n=4–6) were divided into three sections for Western blot analysis of Rho family small GTPases. Each section was incubated for 20 minutes in Krebs solution with either vehicle (endotoxin free water), TLR9 agonist ODN2395 (2 μM), or ODN2395 after a 5‐minute pre‐incubation with TLR9 antagonist ODN2088 (20 μM). ODN2395 alone increased protein expression of cdc42 (1.7 fold vs. Veh, p<0.05) and RhoA (1.4 fold vs. Veh, p<0.05), and this increase in expression was inhibited by pre‐incubation with ODN2088 (p>0.05). On the other hand, Rac1 was unchanged after incubation with ODN2395 (p>0.05). These results show that TLR9 stimulation leads to activation of some Rho family small GTPases and suggests another mechanism by which TLR9 causes increased vascular tone is actin cytoskeleton remodeling.Support or Funding InformationAmerican Heart Association (AHA) and National Institutes of Health (NIH)
The First Intracellular Loop Regulates The Platelet Thromboxane A2 Receptor‐Gq‐Dependent Signaling And Function
Authors: Karim Zubair A , Lin Olivia , Khasawneh Fadi T 
Published: November 2023

While the molecular signaling pathways for the thromboxane A2 receptor (TPR) have been elucidated from multiple organ systems, much less research efforts have focused on the TPR‐ G‐protein (GP) coupling domains (particularly in platelets). In this connection, studies conducted thus far (mostly mutagenesis in nature) have implicated regions from all of the intracellular domains of TPR in coupling to GPs. However, since alterations in the amino acid sequence can lead to effects on protein structure, at least some of these receptor alterations may not be at the critical GP coupling sites. Based on these considerations, we attempted to map the GP coupling domains and investigate human platelet signaling through TPR by employing site‐specific peptides targeted against regions potentially‐involved in the receptor‐Gα subunits interaction process. Our findings revealed that a myristoylated peptide that mimics the first intracellular loop (IL1) of human TPR (i.e., amino acids A52 ‐ F63; abbreviated as Myr‐IL1pep) blocked TPR‐mediated human and mouse platelet aggregation, but (interestingly) it had no detectable effects on platelet shape change (SC). This finding suggests that the IL1 domain of TPR participates in receptor coupling to Gαq but not Gα13. Furthermore, these data are consistent with previous findings that while platelet aggregation is a Gαq‐dependent event, SC is Gα13 dependent. The specificity of this inhibition was shown by the findings that: 1. the control random sequence for IL1 (Myr‐IL1random) did not produce any detectable effect on platelet aggregation induced by TPR activation; and 2. the Myr‐IL1pep itself did not interfere with ADP‐triggered aggregation. Regarding a potential mechanism, immunoaffinity co‐purification experiments revealed that Myr‐IL1pep uncoupled Gαq but not Gα13 from TPR, whereas the Myr‐IL1random did not produce any apparent effects. Finally, the Myr‐IL1pep was found to protect against thrombogenesis, but it does so while also prolonging the tail bleeding time, in mice; whereas control peptides were without any effect on thrombosis or bleeding time. Collectively, our results provide novel information concerning TPR's structural biology and signaling, and may identify new and novel therapeutic agents for the prevention and/or treatment of thrombotic disorders.Support or Funding InformationThis work was supported by the National Heart, Lung, And Blood Institute of the National Institutes of Health under Award Number R15HL115567 (to F.T.K). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Inhibition of vWF Secretion with Novel Gα12 N‐terminal α‐SNAP Binding Domain Peptide Increases Survival in Septic Mice
Authors: Rusu Luiza , Christman John W , Du Xiaoping , Minshall Richard 
Published: November 2023

Severe sepsis is associated with disseminated intravascular coagulation (DIC) as a result of interdependent mechanisms of systemic inflammation, microvascular thrombosis, and thrombocytopenia. Currently, no drug is available to concomitantly treat these events in sepsis. A poorly understood mechanism and yet critical determinant of sepsis‐induced microvascular thrombosis is von Willebrand Factor (vWF) secretion by activated endothelial cells. We recently discovered that heterotrimeric G protein alpha subunit G12 plays a critical role in basal and evoked vWF secretion by endothelial cells by promoting Weibel‐Palade body (WPB) exocytosis. Based on the observed interaction of Gα12 with αSNAP, a critical member of the exocyst complex required for plasma membrane fusion and exocytosis of WPB contents, we generated a myristoylated Gα12 N‐terminal αSNAP binding domain blocking peptide (Myr‐SBD) and tested the hypothesis that this would selectively and potently inhibit vWF secretion, limit platelet adhesion, and prevent microvascular thrombosis associated with cecal ligation and puncture (CLP) induced sepsis. CLP‐induced fulminant sepsis in mice was associated with a 2–3‐fold increase in plasma vWF within 24 hrs. Importantly, we observed reduced plasma vWF levels 24 hrs after CLP surgery in mice given a one‐time i.v. bolus (80 μg/30 g mouse) of micellar Myr‐SBD (lipid to peptide molar ratio of 90:4) at the time of surgery as compared to Myr‐scrambled peptide or vehicle only group. Strikingly, this was associated with increased survival without adversely inducing hemorrhage and vascular leakage. Furthermore, and consistent with the hypothesis that Gα12‐dependent increase in vWF secretion during sepsis leads to poor outcome, control WT mice succumbed to sepsis in less than 96 hrs whereas 80% of Gα12−/− mice shown previously to have significantly reduced plasma vWF levels survived. Inhibition of Gα12/αSNAP dependent vWF secretion may therefore be an effective strategy for blocking microvascular thrombosis, disseminated intravascular coagulation, and death due to sepsis.Support or Funding InformationAHA Postdoctoral Fellowship for LR
Angiotensin II Inhibits T‐type Ca2+ Channels in Cerebral Arterial Smooth Muscle Cells
Authors: Hashad Ahmed Mohamed , Sancho Maria , Welsh Donald 
Published: November 2023

T‐type Ca2+ channels (CaV3.1 and CaV3.2) are expressed in cerebral arterial smooth muscle cells and they play a key role in regulating arterial tone. In this study, we investigated whether and by what mechanism Angiotensin II (Ang II), a vasoactive peptide produced within the cerebral arterial wall, influences T‐type Ca2+ channels. Using patch clamp electrophysiology and rat cerebral arterial myocytes, Ang II (100 nM) was shown to inhibit T‐type Ca2+ currents in a time‐dependent manner (~ 40% after 15 min); it also shifted the voltage‐dependency of activation by 7 mV. Ang II induced inhibition was mediated through the AT1 receptor, as preincubation with Losartan (1 μM) abolished the effect. Protein kinase C (PKC) blockade by GF 109203X (100 nM) did not eliminate Ang II‐mediated inhibition, demonstrating that this signaling protein was not involved. In contrast, NADPH oxidase inhibitors abolished the inhibitory effect of Ang II revealing a role for reactive oxygen species (ROS) on T‐type Ca2+ channels. To delineate if Ang II is targeting a particular T‐type channel, Ni2+ (50 μM) was added to selectively block CaV3.2. In the presence of Ni2+, Ang II did not induce further inhibition of the residual current, indicating that Ang II was selectively targeting CaV3.2. In summary, Ang II inhibits CaV3.2 channels in cerebral myocytes through the generation of ROS. These findings suggest that T‐type channels are a regulatory target of vasoactive stimuli, known to facilitate the “constrictive” phenotype prevalent with cerebrovascular disease.Support or Funding InformationCanadian Institutes of Health Research, Alberta Innovates Health Solutions, Vanier Graduate Scholarship (CIHR)
Endogenous dipeptidyl‐peptidase IV modulates skeletal muscle arteriolar diameter in rats
Authors: Neidert Leslie E , Al‐Tarhuni Mohammed , Goldman Daniel , Kluess Heidi A , Jackson Dwayne N 
Published: November 2023

Neuropeptide Y1‐36 is a potent vasoconstrictor that plays an important role in resistance of smaller arterioles. The enzyme, dipeptidyl‐peptidase IV (DPP‐IV), is present on the smooth muscle cell membrane and converts NPY1‐36 to its non‐vasoconstricting form, NPY3‐36. New research suggests that DPP‐IV is also released from skeletal muscle as a myokine in response to different stimuli including muscle contractions and whey protein supplementation. The role of DPP‐IV as a myokine is unknown. It was hypothesized that whey protein will release DPP‐IV from the muscle and will attenuate neuropeptide Y Y1‐mediated vasoconstriction in skeletal muscle arterioles.The left gluteus maximus (GM) muscle of anesthetized male Sprague‐Dawley rats (n=8) was exposed for intravital video microscopy and superfused with physiological salt solution (5 ml/min; pH 7.4, 35°C). Once a stable baseline was established, the GM arteriolar network was scanned and imaged from 1st to 6th order arterioles (1A to 6A). Following baseline imaging, superfusion solution was switched to 100mM whey protein isolate (WPI) dissolved in PSS, to stimulate release of DPP‐IV from the muscle. Imaging of the network was repeated after arteriolar responses stabilized. Next, a DPP‐IV inhibitor (K579; 4μm) was added to the PSS + WPI superfusion and imaging of the GM arteriolar network was repeated. One‐Way ANOVA for each branch of the network was used to determine statistical significance with alpha set at 0.05.When the WPI solution was suffused over the muscle the entire arteriolar network vasodilated. The magnitude of change in arteriolar diameter increased with progressing arteriolar order, where WPI promoted a 14% increase in arteriolar diameter in 1A (p=0.0002), 17% in 3A (p<0.0001), and 23% in 6A (p<0.0001). However, when the DPP‐IV inhibitor was added to the WPI superfusion vasodilation was lost and arteriolar diameters across the network returned to baseline. These findings show that DPP‐IV is released from skeletal muscle in response to topically applied WPI, which has potential to vasodilate skeletal muscle arteriolar networks, likely via conversion of NPY1‐36 to NPY3‐36. Future research should address if muscle contractions increase DPP‐IV secretion from skeletal muscle and affect local blood flow control.Support or Funding InformationFunded by NSERC and Western Visiting Scholars Program
Bulk Flow of Interstitial Fluid: a Watershed in the Brain Parenchyma
Authors: Bedussi Beatrice , van Lier Monique GJTB , Bartstra Jonas W , de Vos Judith , Siebes Maria , van Bavel Ed , Bakker Erik NTP 
Published: November 2023

Brain interstitial fluid (ISF) and cerebrospinal fluid are involved in the clearance of waste products from the brain. So far, different pathways of fluid drainage have been hypothesized. In particular, previous work pointed towards the perivascular space along cerebral vessels as a major drainage path. However, the pattern of fluid flow in the brain is still controversial. The aim of the current study was to visualize extravascular fluid transport in the normal mouse brain. Therefore, we injected FITC‐dextran (500 kD ) and Texas Red‐dextran (3 kD) in the striatum and in the cisterna magna and allowed the dyes to spread for 30 minutes. Horizontal and coronal brain sections were imaged using confocal microscopy and a 3D imaging cryomicrotome to reveal the pattern of distribution. We observed the tracers to distribute from the striatum towards the ventricular system, where they mixed with the cerebrospinal fluid and moved to the subarachnoid spaces. From there, tracers drained from the brain via olfactory nerves via the cribriform plate. Occasionally we observed that tracer close to the cortical surface found its way to the brain surface along blood vessels. This last observation suggests that there might be a point of highest interstitial pressure, close to the cortex, where ISF flows to either the ventricles or the cortex. After injection in the cisterna magna, tracers distributed over the subarachnoid space and followed the olfactory route out of the brain. Tracers were observed around blood vessels in the SAS and cisterns, but penetration into the brain parenchyma along perivascular spaces was limited. In conclusion, ISF, possibly originating from the capillaries, may generate a cumulating flow, small in regions far from the ventricles and much larger when approaching the ventricles. Disturbances in this transport pathway could influence the drainage of amyloid β and other waste products, which may be relevant for the pathophysiology of Alzheimer's disease.Support or Funding InformationThis work received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 606998.