bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of TRPV1 and TRPV2 channel expression and vasomotor function in human arterioles
Authors: Korishettar Ankush M , Nishijima Yoshinori , Cao Sheng , Zhang David 
Published: November 2023

Transient receptor potential vanilloid (TRPV) channels, act as sensory mediators and are activated by endogenous ligands, heat, mechanical and osmotic stress. Within the vasculature, TRPV channels are expressed in smooth muscle cells, endothelial cells and in perivascular nerves. We have previously demonstrated that Ca2+ influx through endothelial TRPV4 channels mediates flow‐induced dilation (FID) of human coronary arterioles (HCA) from subjects with coronary artery disease (CAD). Other studies have also implicated endothelial TRPV1 channels in FID, whereas a functional role for endothelial TRPV2 channels has yet to be determined. Recent unpublished studies from our lab showed that FID was not affected by TRPV4 inhibition in HCA from subjects without CAD (non‐CAD). Instead, inhibition of TRPV1 or TRPV2 reduced FID of HCA from non‐CAD subjects. Collectively, these data have led us to hypothesize that different TRPV channels contribute to FID of arteries from non‐CAD vs CAD subjects, with TRPV4 prominent in CAD vessels and TRPV1/2 more important in non‐CAD vessels. The objective of the current study was to characterize the expression and function of TRPV1 and TRPV2 channels in HCA and human adipose arterioles (HAA) from non‐CAD subjects, using molecular, immunological and vascular reactivity studies. We first examined TRPV1 and TRPV2 mRNA expression in HCA and HAA using RT‐PCR and consistently detected both transcripts in multiple samples. As a positive control, human brain tissue was found to express TRPV1 and TRPV2 transcripts. Consistent with mRNA expression, TRPV1 and TRPV2 proteins were detected in membrane fractions of HCA and HAA using western blot analysis. Antibody specificity was confirmed in TRPV1 or TRPV2 transfected versus non‐transfected HEK‐293 cells. We next examined the vasomotor effect of capsaicin, a selective TRPV1 agonist and cannabidiol, a selective TRPV2 agonist on freshly isolated HAA. HAA (100–200 μm), obtained from subjects without CAD, were cannulated under 60 mmHg and examined for diameter changes using videomicroscopy. Surprisingly, bath application of capsaicin induced constriction of HAA at concentrations of 10−7 M and 10−6 M (−46.82 ± 4.3%; n=3), with no significant effect at lower concentrations (10−10–10−8 M). In contrast, cannabidiol (10−6,10−5,3×10−5 M) induced a dose‐dependent dilation of HAA. These results suggest that TRPV1 and TRPV2 channels are expressed in human arterioles and contribute to vasomotor responses. Further studies are required to determine the specific role of the endothelium versus smooth muscle and perivascular nerves, in mediating the vascular responses to TRPV1 and TRPV2 activation.Support or Funding InformationSupport for this research was provided by the National Heart, Lung and Blood Institute Grant R01‐HL 096647
Loss of Nitric Oxide Contributes to Perturbations in Myocardial Oxygen Balance in Exercising Swine with Multiple Comorbidities
Authors: van de Wouw Jens , Sorop Oana , van Drie Ruben W.A. , Merkus Daphne , Duncker Dirk J. 
Published: November 2023

IntroductionMultiple comorbidities, including diabetes mellitus (DM), hypercholesterolemia, hypertension (HT) and chronic kidney disease (CKD) are thought to cause coronary microvascular dysfunction and reduce microvascular NO‐production, leading to impaired myocardial perfusion and contributing to the development of left ventricular diastolic dysfunction. In the present study, we aimed to investigate the detrimental effects of DM, CKD and high fat diet (HFD) on microvascular function and myocardial blood flow regulation and the role of NO bioavailability herein in swine.MethodsDM and CKD were induced in 5 female swine that were subsequently fed HFD (DM+HFD+CKD), while 6 female healthy swine on normal pig chow served as controls (CON). At 6 months follow‐up coronary flow regulation was studied at rest and during treadmill exercise with/without eNOS inhibitor, nitro‐L‐arginine in 6 CON and 5 DM+HFD+CKD chronically instrumented animals.ResultsDM+HFD+CKD animals had hyperglycemia (glucose: 18.7±1.9 vs 7.5±0.6 mmol/L), renal dysfunction (reduced glomerular filtration rate: 123±12 vs 202±8 ml/min) and hypercholesterolemia (total cholesterol: 7.3±0.7 vs 1.7±0.1 mmol/l, all P<0.05). In vivo, myocardial oxygen delivery was impaired in DM+HFD+CKD swine, forcing the myocardium to increase its oxygen extraction (MO2ex) both at rest and during exercise (Figure), and resulting in reduced coronary venous oxygen content compared to CON (all P<0.05). eNOS‐inhibition resulted in coronary microvascular constriction in CON, reflected in an increased MO2ex (P<0.05), while it had no effect in DM+HFD+CKD, suggesting that loss of NO was responsible for the increased oxygen extraction in DM+HFD+CKD. This was supported by lower myocardial levels of NO metabolites NO2−+NO3− in DM+HC+HT compared to CON (0.20±0.02 vs 0.34±0.06 μmol/mg protein, P<0.05).ConclusionProlonged exposure to DM, HFD and CKD results in impaired coronary microvascular NO production, thereby hampering myocardial perfusion.Support or Funding InformationFunding: This study was supported by grants from the European Commission FP7‐Health‐2010 grant MEDIA‐261409, the Netherlands CardioVascular Research Initiative: an initiative with support of the Dutch Heart Foundation [CVON2014‐11 (RECONNECT)].
Glucocorticoids modulate Kvβ1 dependent cardiac function through potassium channel (Kv) activity
Authors: Tur Jared , Badole Sachin L , Chapalamadagu Kalyan C , Tipparaju Srinivas M 
Published: November 2023

Cortisone is a glucocorticoid used for treatments including arthritis, immune system disorders, allergic reactions, and eye conditions. Glucocorticoids however, have the propensity to produce multiple cardiovascular effects including hypertension, hyperglycemia and dyslipidemia. Therefore in patients with history of cardiovascular diseases corticosteroids are used with caution due to high risk of myocardial injury. In vitro research has demonstrated cortisone and its analogs alter voltage‐gated potassium channels (Kv) via the Kvβ1.1 subunit. Recently we published that both male and female Kvβ1.1 knockdown (KO) mice demonstrate significant prolongation in left ventricular action potentials in addition only females presented with significantly elevated blood pressure levels including systolic and diastolic.Based upon glucocorticoids cardiovascular effects and cortisones high affinity to bind with Kvβ1.1 we hypothesis that glucocorticoid treatment may induce cardiovascular effects through Kvβ1.1 generating a novel role of Kvβ1.1 regulation in the heart.Initial experiments with Left ventricular action potentials measured through monophasic action potential (MAP) recordings demonstrated perfusion with cortisone (500μmole/L) showed significantly (p<0.01) prolonged MAP durations at APD 50%, 70%, and 90% repolarization within the wild type (WT) hearts however, no significant difference was noted in Kvβ1.1 KO hearts with cortisone perfusion. KO hearts were significantly prolonged at baseline in comparison with WT baseline similar to our previous work. Results were obtained with fluticasone propionate (100nmole/L) in which left ventricular action potentials showed significantly (p<0.01) prolonged MAP durations in the WT hearts at APD 50%, 70%, and 90% repolarization however, no significant difference was noted in Kvβ1.1 knockout mice (KO). Application of a combination cortisone plus 4‐aminopyridine (4‐AP) perfused WT and KO hearts resulted in MAP durations significantly (p<0.01) prolonged at APD 20%, 50%, and 70% repolarization in both WT and KO hearts. However, prolongation observed in KO hearts was due solely to 4‐AP exposure, showing no additive effects from cortisone.Based on the results we identified that cortisone modulates cardiac electrical activity by binding and inhibiting Kvβ1.1‐Kv channel interaction in the mouse heart. This is the first report demonstrating the modulation of electrical activity by cortisone and the role of Kvβ1.1 subunit in mouse hearts. WT hearts demonstrated significant action potential prolongation while Kvβ1.1 KO hearts showed no significant cortisone induced action potential prolongation.
Exercise Training Fails to Protect against Development of Ischemia‐Induced Ventricular Fibrillation in Isolated Rat Hearts
Authors: Clements‐Jewery Hugh , Radich Patricia , Rawson Nicholas , Hatcher Amanda Shea 
Published: November 2023

Background and purposeSudden cardiac death continues to be a major cause of mortality in the United States and beyond, with the predominant cause of death being ventricular fibrillation in the setting of ischemic heart disease. Pharmacological therapy has proven to be a limited strategy for preventing ventricular fibrillation as a consequence of the safety and efficacy of available drugs. Exercise training has been found to be effective in reducing susceptibility to spontaneous VF in a canine in vivo model (Bonila et al., 2012), but it is not known if exercise training would be effective in reducing susceptibility to ischemia‐induced VF in isolated perfused rat hearts.MethodsMale and female 6 week old Sprague‐Dawley rats were separated into exercise (EX) and sedentary (SED) groups (N=15 per group). Rats in the exercise group were trained for 60 min on a treadmill 4 days/week for 8 weeks. Workloads were matched for bodyweight. Rats in the SED group were given equivalent handling time. Hearts were excised under pentobarbital anesthesia after the end of the 8‐week period in a randomized and blinded manner and perfused in the Langendorff mode using modified Krebs solution (3mM K+). After a 10 min baseline perfusion period, regional ischemia was induced by occlusion of the left main coronary artery and maintained for 30 min. Hearts were subsequently reperfused for 10 min. The ECG was monitored for the occurrence of VF and other arrhythmias during ischemia and used for the measurement of electrocardiographic intervals. An intraventricular balloon was used to record left ventricular developed pressure (LVDP) and end diastolic pressure (EDP). Coronary flow was recorded digitally using a calibrated signal from a pump controller.ResultsThe incidence of VF during ischemia in the EX group was 87% (13/15), which was not different from the incidence of VF in the SED group (67%; 10/15). In addition, the time to onset of VF during ischemia (950±157s vs 1035±127s in SED and EX groups respectively) as well as susceptibility to reperfusion VF (93% in the SED group vs 87% in the EX group) was similar in the two groups. There was no difference in ischemic zone size between groups. Changes in heart rate, coronary flow, EDP and LVDP with onset of ischemia were all similar in both SED and EX groups with no significant differences at any time point.ConclusionsExercise training did not confer protection against ischemia‐induced VF in an established in vitro model. Thus the protection afforded by exercise training in the canine in vivo model may indicate a species dependence of exercise training‐induced protection, or that protection is due to factors absent from isolated rat hearts such as an intact autonomic system or factors circulating in the blood.Support or Funding InformationThis study was supported by an intramural grant from the West Virginia School of Osteopathic Medicine.
Heterozygous Deletion of Mediator Subunit 1 Causes Heart Failure in Mice
Authors: Spitler Kathryn , Grueter Chad 
Published: November 2023

Cardiac gene expression is altered during heart failure, but the mechanisms underlying these transcriptional changes remains unclear. The Mediator complex governs gene transcription by linking upstream cellular signals with transcriptional machinery. Mediator subunit 1 (Med1) plays a pivotal role in regulating gene expression by serving as a transcriptional coactivator for nuclear receptors. Our objective is to elucidate the role for Med1 in cardiac transcriptional regulation. Expression of Med1 in the heart is essential as cardiac deletion of Med1 results in rapid progression into heart failure and death within 2–3 weeks. Given this early lethality during an important developmental time period for the heart, we generated a heterozygous cardiac‐specific deletion of Med1 (cMed1+/−) using the alpha myosin heavy chain expressing cre recombinase bred into Med1 floxed mice. These mice allow us the ability to understand the role of Med1 under more physiological conditions and enables examination into gene expression changes in response to cardiac stresses that lead to heart failure. cMed1+/− resulted in a more gradual lethality phenotype starting at 10 months of age. At one year of age echocardiography, qPCR and Western blot analysis was performed. cMed1+/− male hearts had the expected ~50% reduction in Med1 mRNA and protein levels, resulting in reduced ejection fraction (47% vs. 87%) and increased heart mass (50%) compared to Med1 floxed controls. Transverse sections of cMed1+/− hearts revealed ventricular dilation. Expression of heart failure marker genes (Nppa, Nppb, and Myh7) and pro‐fibrotic genes (Tgfb2 and Col11a1) was increased in hearts from cMed1+/− mice compared to Med1 floxed controls while there was an decrease in the major adult‐associated contractile component Myh6. Taken together, these data indicate that physiological Med1 levels are essential for cardiac gene expression and function as Med1 haploinsufficiency causes cardiac dysfunction and failure.Support or Funding InformationNIH/NHLBI R01 HL125436‐02, Fraternal Order of Eagles Diabetes Research Center, the University of Iowa Carver College of Medicine, and NIH T32 Postdoctoral Fellowship‐5T32HL007121‐38
MULTIPLE CO‐MORBIDITIES HAVE DETRIMENTAL EFFECTS ON MYOCARDIAL FUNCTION AND PERFUSION IN A LARGE ANIMAL MODEL OF DIASTOLIC DYSFUNCTION
Authors: Sorop Oana , van de Wouw Jens , van Drie Ruben W.A. , Heinonen Ilkka , de Beer Vincent J. , van den Meiracker Anton H. , van der Velden Jolanda , Joles Jaap A. , Merkus Daphne , Duncker Dirk J. 
Published: November 2023

Comorbidities such as diabetes mellitus (DM), hypercholesterolemia (HC) and chronic kidney disease (CKD), are often associated with diastolic dysfunction. We tested the hypothesis that the co‐morbidities produce systemic inflammation and microvascular dysfunction resulting in impaired myocardial perfusion, structural changes in the myocardium as well as cardiac dysfunction in swine.Methods and ResultsDM (streptozotocin, 150mg/kg i.v.), HC (high fat diet) and CKD (renal artery embolization), (DM+HC+CKD) were induced in 16 female swine, which were followed for 6 months. 15 female healthy swine on normal pig‐chow served as controls. Myocardial vascular tone control and function were studied at rest and during graded treadmill exercise. The DM+HC+CKD group showed hyperglycemia (22.7±0.9mmol/l in DM+HC+CKD vs 6.1±0.7mmol/l in CON), hypercholesterolemia (16.9±3.4 vs 2.2±0.1mmol/l), hypertriglyceridemia (1.20±0.36 vs 0.28±0.05mmol/l) and impaired kidney function (Glomerular Filtration Rate: 139±19 vs 197±10 ml/min, all P<0.05), which were associated with systemic inflammation and impaired coronary small artery endothelium‐dependent vasodilation to bradykinin. These abnormalities were accompanied by increased myocardial collagen content, reduced capillary/fiber ratio and elevated passive cardiomyocyte stiffness, resulting in increased left ventricular end‐diastolic stiffness (pressure‐volume catheter at sacrifice, 0.15±0.02 vs 0.07±0.01 mmHg/ml, P<0.05), while ejection fraction was maintained (45±4 vs 54±3%, P=NS). A subgroup of animals, studied during exercise, showed reduced cardiac index (CI, P<0.05), increased levels of left atrial pressure required for similar CI, reduced stroke volume index and impaired myocardial efficiency (Figure, all P<0.05). Furthermore, the animals with the three comorbidities demonstrated perturbations in myocardial blood flow, requiring an increased myocardial oxygen extraction (Figure), resulting in lower coronary venous oxygen content levels during exercise.ConclusionThe combination of three common comorbidities leads to systemic inflammation, coronary microvascular dysfunction, which associate with impaired vascular tone control, myocardial stiffening and LV diastolic dysfunction with preserved ejection fraction.Support or Funding InformationFunding: This study was supported by grants from the European Commission FP7‐Health‐2010 grant MEDIA‐261409, the Netherlands CardioVascular Research Initiative: an initiative with support of the Dutch Heart Foundation [CVON2014‐11 (RECONNECT)].
How does the overexpression of DGKζ can improve the survival and rescue the heart failure associated loss of contractility?
Authors: Aslam Naveed 
Published: November 2023

The most frequently encountered forms of heart failure in the clinical practice are diastolic heart failure (DHF) and systolic heart failure (SHF). These syndromes are characterized by a progressive loss in contractility, ejection failure, ventricular chamber dilation, ventricular wall thinning, increased peripheral vascular resistance and dysregulated fluid homeostasis. The propensity towards these forms of cardiac insufficiency could be linked to the activation of PKCα molecule in DHF & SHF condition. The PKCα molecule act as a nodal integrator of cardiac contractility and is now considered as a milder and probably more effective alternative to positive inotropes. Clinical evidence suggests the positive inotropes worsens the prognosis in individuals with somewhat stable heart failure. Data from previous studies suggests that overexpression of DGKζ molecule can improve the survival and reduce the propensity of contractile dysfunction in HF. Here, I address the question that how the overexpression of DGKζ molecule could improve the survival and reduce the propensity towards heart failure? This becomes interesting as GPCR agonists such as angiotensin II and phenylephrine not only leads to the activation of PKCα but also the braking mechanism to check the increase in PKCα activity during HF. So, one could wonder that why the PKCα activity is increased and sustained during HF? Here, through a DGKζ overexpression model I show that DGKζ modulates the PKCα activity through inducing the metabolism of its activator DAG. My results suggest that in the wild type models the expression of DGKζ & PKCα could be in same proportions therefore, once activated by DAG, the PKCα molecule could deactivate the DGKζ through phosphorylation, thus blunting the braking mechanism and sustaining its activity during DHF & SHF conditions. My results imply that in overexpression model the DGKζ proportions increases compared to PKCα thus, counteracting the negative effects of PKCα on its activity by enhancing the DAG metabolism in the plasma membrane compartment. My results also show that the DGKζ overexpression can reduce the cytosol to membrane translocation of PKCα in a dose dependent manner. These results are also consistent with previously reported dose‐dependent effects of DGKζ overexpression on the translocation characteristics & activity of PKCα molecule in HF. Results presented in this study could provide interesting possibilities for DGKζ as another potential translation target for DHF and SHF conditions.Support or Funding InformationPrivately funded
Reinstallation of Glucocorticoid Receptor (GR) in the Heart Rescues Left Ventricular Systolic Function of Cardiac GR Knockout mice
Authors: He Bo , Oakley Robert H. , Myers Page H , Cidlowski John A 
Published: November 2023

Glucocorticoidsare primary stress hormones necessary for life. In recent years, stress isincreasingly associated with cardiovasculardiseases. We have previously demonstrated that adeficiencyin glucocorticoid receptor (GR) signaling in cardiomyocytes resulted in cardiachypertrophy, left ventricular (LV) systolic dysfunction, and heart failure. This suggested a crucial role for cardiomyocyte GR signaling in the function of the heart. In order to rescue the phenotypes of cardiomyocyte‐specific GR Knockout mice (cardioGRKO), we recently created an Adeno‐Associated Virus (AAV) to express mouse GR under the control of the cardiac‐specific troponin T(TnT) promoter to achieve cardiomyocytes‐specific GR expression (AAV‐GFP was used as a control). Our approach successfully achieved GR expression in the heart of 1‐month‐old CardioGRKO mice. We found that reinstallation of GR by AAV‐mediated gene transfer in cardiomyocytes completely rescued cardiovascular function in CardioGRKO mice. Specifically, ejection fraction (EF) and fractional shortening (FS) are significantly increased in the CardioGRKO treated with AAV‐mGRα compared to vector backbone (AAV‐GFP)‐treated control, suggesting the improvement of systolic function. In addition, left ventricular end‐systolic dimension (LVESD) and volume in systole (LV VolS) are significantly increased and restored to normal level compared to wild‐type controls. Further studies will be focused on the gene expression changes in genome wide expression analysis. In summary, the AAV‐mediated gene delivery system has allowed us to reinstall mGRα in cardioGRKO heart and thus to study the significance of GR signaling in heart diseases.Support or Funding InformationNIH