bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial Localization Determines Preferential Calcium Signal‐Target Coupling in Microvascular Endothelium
Authors: Ottolini Matteo , Marziano Corina , Cope Eric L , Sonkusare Swapnil K 
Published: June 2021

Localized, spatially restricted Ca2+ signals promote endothelium‐dependent vasodilation in systemic and pulmonary microcirculation. Unitary Ca2+ influx signals through endothelial transient receptor potential vanilloid 4 (TRPV4) channels, termed TRPV4 sparklets, promote endothelium‐dependent vasodilation in systemic and pulmonary resistance arteries. TRPV4 sparklets dilate small mesenteric arteries (MAs) via activation of intermediate and small conductance Ca2+‐activated K+ (IK and SK, respectively) channels, and small pulmonary arteries (PAs) via endothelial nitric oxide synthase (eNOS) activation. Although endothelial Ca2+ is known to activate different downstream signaling targets, the mechanisms for preferential Ca2+ signal‐target coupling remain undefined. We hypothesized that spatial co‐localization determines Ca2+ signal‐target linkage. High‐speed Ca2+ imaging experiments showed that endothelial TRPV4 sparklet activity per site is similar between MAs and PAs. Moreover, perforated whole‐cell patch clamp recordings showed that specific IK/SK channel activator NS309 induced comparable currents in freshly isolated endothelial cells (ECs) from MAs and PAs. While TRPV4 channel agonist GSK1016790A (GSK101) elicited IK and SK currents in the ECs from MAs, it was not able to activate IK and SK currents in ECs from PAs. Consistent with the presence of IK/SK currents in MAs and PAs, NS309 dilated both MAs and PAs in pressure myography experiments. GSK101 dilated MAs in a IK/SK channel‐dependent and eNOS‐independent manner. On the contrary, GSK101 dilated PAs in a eNOS‐dependent and IK/SK channel‐independent manner, further supporting differential TRPV4 sparklet‐target coupling. Immunostaining experiments indicated that TRPV4 channels were localized at endothelial projections to smooth muscle or myoendothelial projections (MEPs) in both MAs and PAs. Whereas IK and SK channels were localized at the MEPs in MAs, they were not concentrated at the MEPs in PAs. These results suggest that functional IK/SK channels exist in ECs from MAs and PAs, and support our hypothesis that spatial proximity is necessary for TRPV4 sparklet‐IK/SK channel coupling. Future studies will address the mechanisms for eNOS activation by TRPV4 sparklets in PAs. Understanding the differential coupling mechanisms may lead to novel therapeutic approaches to selectively dilate pulmonary versus systemic vasculature.Support or Funding InformationNIH (HL121484‐01, R56HL138496, S.K.S.)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Stress Strain Speckle‐Tacking Segmental Analysis Reveals Early Indications of Diastolic Dysfunction in a Type 2 Mouse Model of Diabetes Mellitus
Authors: Durr Andrya J , Hathaway Quincy A , Pinti Mark V. , Shepherd Danielle L , Kunovac Amina , Fink Garrett K. , Hollander John M 
Published: June 2021

Type 2 diabetes mellitus (T2DM) is becoming increasingly common, as there are currently 23.1 million people diagnosed and another 84.1 million adults diagnosed with pre‐diabetes in the United States alone. While many long‐term consequences are associated with T2DM, the leading cause of mortality is cardiovascular complications. Though reduction in ejection fraction and fractional shortening are well‐described indicators of cardiovascular dysfunction, these indices are usually present late in the progression of the pathology. Identification of predictors that can be observed earlier in the disease progression may aid in diagnosing and predicting future health outcomes for the patient. The goal of the current study was to evaluate cardiac contractile changes in a rodent model of type 2 diabetes mellitus using the well characterized db/db model mouse model. Db/Db FVB mice and wild‐type (WT) littermate controls were utilized for the study (WT = 22 and db/db = 14). Echocardiography, using the Vevo 2100 Imaging System, was implemented to evaluate cardiac function in both groups at 12 weeks of age. M‐mode was used for conventional measures of cardiac function, while B‐mode short and long axis images were used for stress strain speckle‐tracking analyses. In addition, Pulse Wave Doppler analyses were utilized to examine changes in flow across the mitral valve. At 12 weeks of age, db/db mice exhibit lower ejection fractions (P ≤ 0.05) and increased stroke volumes (P ≤ 0.0018) when compared to WT. Concomitantly, db/db mice presented with significant increases in both systolic and diastolic ventricular diameters and volumes, along with an increased LV mass (P ≤ 0.0001). To determine whether spatial differences in cardiac dysfunction was associated with T2DM, we assessed regional changes in cardiac function. Speckle‐tracking strain analyses revealed significant changes in radial displacement at systole in the short axis (P ≤ 0.0024) and diastole at both the short axis (P ≤ 0.033), and long axis (P ≤ 0.0001). Segmental analysis revealed that the lateral wall portion of the left ventricle, in all axes, was significantly altered during diabetic stress. In summary, echocardiography and specifically speckle‐tracking strain analysis has the potential to indicate early dysfunction of the left ventricle during the progression of type 2 diabetes mellitus through segmentally isolated cardiac function, potentially aiding in diagnosis and future outcomes.Support or Funding InformationR01 HL‐128485 (JMH), AHA‐17PRE33660333 (QAH), AHA 17PRE33660333 (QAH), and the Community Foundation for the Ohio Valley Whipkey Trust.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cell Type‐Specific Ephrin expression in the Diabetic Coronary Circulation
Authors: McCallinhart Patricia , Trask Aaron J. 
Published: June 2021

Ephrin signaling between vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) is crucial during normal vascular development and homeostasis, primarily by influencing cell behavior, resulting in alterations of the cell cytoskeleton and cell adhesion. Ephrins are re‐expressed in vascular injury and disease states such as cancer and chronic inflammation; therefore the goal of this study was to determine the impact of type 2 diabetes on ephrin expression in coronary VSMCs and ECs. Low‐passage primary coronary VMSCs were isolated from normal (n=6) and type 2 diabetic db/db mice (n=4) and were either cultured alone or co‐cultured with normal or type 2 diabetic human coronary microvascular endothelial cells (hCMECs), respectively, and RNA was collected for PCR analysis. Normal (n=5) and type 2 diabetic (T2DM) (n=4) human coronary vascular smooth muscle cells (CVSMCs) were also cultured and protein lysates collected for Western Blot analysis. Ephrin B2 ligand gene expression was significantly increased in diabetic CRM VSMCs in both mono‐ and co‐culture conditions (1.00 ± 0.13 vs. 1.57 ± 0.24, p=0.049 and 1.00 ± 0.14 vs. 1.60 ± 0.22, p=0.044, respectively). There were no significant differences in ephrin B4 receptor levels in normal vs. diabetic coronary VMSCs. In human coronary VSMCs, ephrin B2 ligand protein expression was also significantly increased in diabetic coronary VSMCs over control VSMCs (normal 1.00±0.05 vs. T2DM 2.91±0.29, p=0.019). Interestingly, there was a different trend in the diabetic hCMECs. Ephrin B2 gene expression was significantly reduced in diabetic hCMECs in both mono‐ and co‐culture conditions (1.00 ± 0.05 vs. 0.75 ± 0.07, p=0.02 and 1.00 ± 0.10 vs. 0.50 ± 0.07, p=0.007, respectively). Ephrin B4 receptor gene expression was significantly reduced in diabetic hCMECs in both mono‐ and co‐culture conditions (1.00 ± 0.07 vs. 0.55 ± 0.05, p=0.002 and 1.00 ± 0.03 vs. 0.77 ± 0.03, p=0.0008, respectively). Collectively, these data demonstrate that, in both mice and humans, diabetes alters ephrin expression in VSMCs and ECs in a cell‐specific manner. Further studies will address how alterations in ephrin expression influence coronary cell behavior in the setting of diabetes.Support or Funding InformationNIH R00 HL116769, NIH R21 EB026518, and Nationwide Children's Hospital to AJTThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Diastolic Function at Rest and During Handgrip is Impaired in Patients with Peripheral Arterial Disease
Authors: Gao Zhaohui , Cui Jian , Kuroki Marcos T. , Kim Danielle Jin‐Kwang , Blaha Cheryl , Cauffman Aimee , Pai Samuel , Sinoway Lawrence I. 
Published: June 2021

Peripheral arterial disease (PAD) patients have larger increases in systolic BP with exercise. Thus it is not surprising that patients with PAD may have diastolic dysfunction. This link has also been suggested by an observed association between elevated BNP levels and the transmitral E‐wave/early diastolic mitral annular velocity (E/E′) ratio in PAD. The characteristics of diastolic function at rest and with exercise in patients with PAD has not been examined. In this study, we used isometric handgrip exercise echocardiography to noninvasively assess left ventricular diastolic function. The aim of this study is to determine whether left ventricular diastolic function at baseline and during isometric handgrip exercise (at 30% of their maximal voluntary contraction) differ in patients with PAD and age, gender‐matched healthy controls. We recruited 15 PAD patients (10 M, 5 F, 66 ± 6 yrs), and 11 control subjects (7 M, 4 F, 65 ± 6yrs). The ankle‐brachial pressure index (ABI) in the most affected leg in the patients was (0.58 ± 0.15). Beat‐by‐beat blood pressure (BP, Finometer) and ECG were recorded at baseline and during handgrip. Conventional non‐invasive methods including pulsed wave Doppler and tissue Doppler imaging were used to measure early mitral inflow diastolic wave velocity (E), late mitral inflow diastolic wave velocity (A), E/A ratio, early diastolic myocardial wave velocity (E′) and late diastolic myocardial wave velocity (A′). E/ E′ was also calculated. Systemic, hemodynamic values at rest and during isometric handgrip (blood pressure and heart rate) were not different in the two groups. At rest: mitral inflow E and A were significantly higher in patients than in controls (E: 78.7 ± 4.2 vs. 64.5 ± 4.9 cm/s P value <0.05; A:82.2 ± 3.9 vs. 65.5 ± 4.4 cm/s P value <0.01); E/A ratio was similar. E/E′ ratios were in the normal range, however, this ratio was significantly higher in PAD patients (8.9 ± 0.6 vs. 6.7 ± 0.5 P value <0.05) than in controls indicating higher left ventricular filling pressures in PAD. During handgrip, hemodynamic responses increased in both groups. Of note, late mitral inflow: increased much less in PAD than in controls (mitral inflow A wave increase 10% ± 4% vs. 25% ± 4% in controls, P value <0.05). This suggests that with exercise atrial contraction contributes less to filling in PAD than it does in controls. Collectively, these data indicate that PAD patients have impaired diastolic function at rest and a reduced left atrial contractile reserve.Support or Funding InformationSupported by National Institutes of Health Grants P01 HL134609 (Sinoway) and UL1 TR002014 (Sinoway).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Discovery of Protein Degradation Machinery at the Desmosome Reveals Novel Triggers of the Desmosomal Disease, Arrhythmogenic Right Ventricular Cardiomyopathy
Authors: Liang Yan , Lyon Robert C. , Pellman Jason , Mezzano Valeria , Gu Yusu , Dalton Nancy , Bradford William , Bogomolovas Julius , Lee Mong‐Hong , Iwakuma Tomoo , Nigam Vishal , Scheinman Melvin , Peterson Kirk , Sheikh Farah 
Published: June 2021

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic‐based cardiac disease which is characterized by right/bi‐ventricular dysfunction, fibro‐fatty replacement of the myocardium and ventricular arrhythmias, leading to sudden death in young people and athletes. ARVC is termed a “disease of the desmosome” (mechanical cell‐cell junction) as 40% of ARVC patients harbor mutations and/or loss of desmosomal components. However, limited information exists on how cardiac desmosomal protein loss/degradation triggers ARVC. Through a yeast‐two‐hybrid screen in an adult human heart cDNA library, we uncovered a new interaction between the desmosomal protein, desmoplakin (DSP, N terminus) and a protein degradation machinery component, CSN6 (COP9 signalosome subunit 6). Traditionally, CSN proteins are thought to prevent proteins from being degraded; however, a role for CSN6 in the heart is undefined. We show that CSN6 localizes to desmosomal junctions in cardiac muscle and structurally complex with desmoplakin, suggesting that the novel hypothesis that CSN6 may protect the cardiac desmosome from degradation and loss/destablization this pathway may lead to ARVC. Using two novel cardiac‐specific CSN6 knockout (CSN6‐KO) mice, we further show that CSN6 loss accelerates desmosome destruction and triggers ARVC, as CSN6‐KO hearts exhibit selective loss of desmosomal proteins and recapitulate the key cardiomyopathy features and sudden death associated with ARVC, similar to classic mouse model of ARVC (DSP‐cKO). CSN6‐KO and DSP‐cKO hearts also harbor underlying hyper‐accumulation of protein degradation machinery specifically at cell‐cell junctions. Restoration of CSN function by the protein degradation inhibitor (MLN4924) could rescue the loss of desmosomal protein expression associated with CSN6 loss in vitro, further highlighting that the cardiac desmosome is regulated by protein degradation. CSN6 pathways are also relevant to human ARVC as a N‐terminus desmoplakin mutation (R315C) identified in a human ARVC patient was sufficient to abrogate DSP‐CSN6 binding and result in loss of CSN6 localization at the cell‐cell junction in cardiac biopsies. DSP R315C knock‐in mice also exhibited cardiac CSN6 reduction and early electrical defects found in ARVC. We altogether identify CSN6 as a novel “brake” to prevent desmosomal protein degradation, and reveal that disruption of this complex is an important “accelerator” of sudden death and ARVC.Support or Funding InformationAmerican Heart Association Postdoctoral Fellowship 17POST33670205This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Characterization of Klotho/FGF23 signaling in cardiorenal syndrome‐induced cardiac hypertrophy
Authors: da Cruz Junho Carolina V , Caio‐Silva Wellington , Ruiz‐Hurtado Gema , Carneiro‐Ramos Marcela Sorelli 
Published: June 2021

IntroductionIn diseases that generate an inflammatory situation, such as cardiorenal syndrome, different clinical conditions promote cardiac and renal dysfunction. There are type 3 and 4 which are characterized by renal insults that subject the heart to dysfunctions; Among the changes that renal injury can lead, we can mention the modulation in Klotho levels, a gene that is negatively regulated by fibroblast growth factor 23 (FGF23). The objective of this study is to evaluate the participation of this axis in cardiac hypertrophy induced by renal ischemiaMethodsC57BL/6 male mice were subjected to surgical occlusion of left renal pedicle for 60 min followed by reperfusion in acute term (24, 48 and 72h), short term (for 8 and 15 days) and long term (4,6 and 8 weeks). Total heart RNA was extracted for gene expression of Klotho, FGF23 and hypertrophy markers using real‐time PCR.ResultsThe renal injury was confirmed by decreasing of left kidney weight and urea/creatinine levels starting at the 15th day of reperfusion. Cardiac hypertrophy was confirmed by increased a‐actin levels at day 15 and 4 weeks of renal reperfusion; however, heart weight has maintained increased until the 8th week of reperfusion. Concerning the FGF23/Klotho axis, both genes were modulated during the cardiorenal syndrome type 3. FGF23 gene expression was mostly increased in heart tissue after 8 days of reperfusion, having its peak during the 4th week. In renal tissue, FGF23 did not present a pattern, although it shows a peak in the first 24 hours, in the 8th day and 15th day (the same timepoints which the heart tissue is affect which electrophysiological and immunological changes). By the other side, Klotho gene expression was mostly reduced in renal tissue after 48h of reperfusion, evidencing even more the renal injury (once some authors consider Klotho is a renal injury biomarker). In heart tissue, klotho expression is reduced since the first 24h, but this is attenuated around the 4th week of reperfusion.ConclusionWe found that cardiac FGF23/Klotho axis dynamics are affected by renal I/R indicating a possible interaction between these two responses during cardiorenal syndrome.Support or Funding InformationFinancial Support: FAPESP 2015/19107‐5 and 2018/03089‐6.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A Novel MYH6E1503V Variant in a Family with a History of Heart Disease, including Hypoplastic Left Heart Syndrome
Authors: Anfinson Melissa , Kim Min‐Su , Lough John , Geddes Gabrielle , James Jeanne , Geurts Aron , Mitchell Michael , Tomita‐Mitchell Aoy 
Published: June 2021

Hypoplastic Left Heart Syndrome (HLHS) is a severe form of congenital heart disease (CHD), requiring prompt surgical intervention and eventual transplant. Despite significant advances in detection and treatment of HLHS, genetic risk factors have been identified in <5% of patients. Our prior studies of 190 HLHS patients identified 19 distinct, rare variants in the gene encoding for a‐myosin heavy chain (MYH6), with variant carriers exhibiting reduced transplant‐free survival (p < 1 × 10−3). In‐depth genetic analysis was performed on the family of one HLHS subject who exhibited a novel E1503V variant in the tail domain of MYH6. The variant was identified in six additional members of the family, all of whom were related to the proband via the maternal grandmother. Four of those individuals also exhibited adult heart disease, with varying ages of onset. Though MYH6 variants have been implicated in a number of heart diseases – including arrhythmias, familial cardiomyopathies, as well as various forms of CHD – to our knowledge this is the first association of a single variant with both adult heart disease and HLHS.α‐myosin heavy chain (α‐MHC) is a cardiac‐specific protein that functions as a component of the sarcomere, the major contractile unit of the heart muscle. We therefore sought to evaluate functional consequences of MYH6E1503V on a‐MHC in vitro. Using CRISPR‐Cas9 gene editing technology, we successfully introduced the variant into induced pluripotent stem cells (iPSCs) from an unrelated individual, which were then used to generate cardiomyocytes. Subsequent evaluation of these cells revealed key insights into the effect of MYH6E1503V on sarcomere organization and contractile properties in cardiomyocytes, as well as their proliferation and differentiation capacity.Support or Funding InformationChildren's Research Institute at the Children's Hospital of Wisconsin, Little Hearts for Life Foundation, M.A is a member of the Medical Scientist Training Program at MCW, which is partially supported by a training grant from NIGMS T32‐GM080202This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Proximity‐Labeling by BioID Reveals Pleiotropic Role of Ski in Cardiac Fibrosis
Authors: Landry Natalie M , Rattan Sunil G , Hnatowich Mark , Dixon Ian MC 
Published: June 2021

Despite recent improvements made in cardiac patient treatment and outcomes, current therapies only serve to alleviate the symptoms of cardiac fibrosis, rather than correct the disease itself. Our lab has previously established Ski as a potent inhibitor of TGF‐β signalling in cardiac myofibroblasts, the primary effectors of fibrosis; however our recent investigations suggest that Ski may inhibit a multitude of pro‐fibrotic pathways, including Hippo. We have specifically observed upon Ski overexpression in primary cardiac fibroblasts, a marked reduction in the expression of TAZ (or WWTR1), one of the main nuclear effectors of the Hippo pathway. To further expand the current knowledge on Ski's anti‐fibrotic properties, and provide insight into potential mechanisms of action, we mapped its interactome using enzyme‐catalyzed biotin proximity labelling (BioID2). Using the BioID2 vector, E. coli BirA* biotin ligase was fused to the N‐terminus of human Ski and the fusion protein was then expressed in fibroblasts in the presence of an excess of free biotin. Whole cell lysates were then subject to streptavidin‐mediated protein capture and potential Ski binding partners were identified by tandem time‐of‐flight mass spectrometry. The resulting candidates included several known Ski interactors (eg. RSmad2 and co‐Smad4), but also revealed novel interactors which potentially link Ski's anti‐fibrotic capacity and interaction with the Hippo signaling pathway. We also observed several interactions with cytoskeletal components, including those involved in actin dynamics and stress fiber formation. To confirm results from the affinity capture, candidate interactors were verified using immunoblotting. In addition, the expression of potential Ski interactors was examined in a rat model of cardiac fibrosis, post‐myocardial infarction. Our data suggest that Ski serves not only as a Smad‐dependent TGF‐β inhibitor, but also interacts with the Hippo, Wnt/β‐catenin, and FoxO signaling pathways‐‐all of which are suspected contributors to fibrosis. In addition, Ski's interaction with various points of cytoskeletal organization further indicates that its functions in the cell go beyond simple inhibitory protein‐protein interactions.Support or Funding InformationNM Landry's research has been funded by studentships from the Canadian Institutes of Health Research (CIHR), Research Manitoba, as well as the Bank of Montreal (BMO). IMC Dixon is grateful to the Heart & Stroke Foundation of Canada for a grant (G‐17‐10018631) in support of this research, as well as the St. Boniface Hospital and Research Foundation for their continued operating patronage.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.