Cardiology Commons^™

Prolylcarboxypeptidase Alleviates Hypertensive Cardiac Remodeling By Regulating Myocardial Tissue Angiotensin Ii, Binh Y Nguyen, Fangchao Zhou, Pablo Binder, Wei Liu, Susanne S Hille, Xiaojing Luo, Min Zi, Hongyuan Zhang, Antony Adamson, Fozia Z Ahmed, Sam Butterworth, Elizabeth J Cartwright, Oliver J Müller, Kaomei Guan, Elizabeth M Fitzgerald, Xin Wang

Faculty, Staff and Student Publications

Background Prolonged activation of angiotensin II is the main mediator that contributes to the development of heart diseases, so converting angiotensin II into angiotensin 1-7 has emerged as a new strategy to attenuate detrimental effects of angiotensin II. Prolylcarboxypeptidase is a lysosomal pro-X carboxypeptidase that is able to cleave angiotensin II at a preferential acidic pH optimum. However, insufficient attention has been given to the cardioprotective functions of prolylcarboxylpeptidase. Methods and Results We established a CRISPR/CRISPR-associated protein 9-mediated global prolylcarboxylpeptidase-knockout and adeno-associated virus serotype 9-mediated cardiac prolylcarboxylpeptidase overexpression mouse models, which were challenged with the angiotensin II infusion (2 mg/kg …

Targeting Neddylation And Sumoylation In Chemoresistant Triple Negative Breast Cancer, Wei Ruan, Jiwen Li, Seungwon Choi, Xinxin Ma, Yafen Liang, Ragini Nair, Xiaoyi Yuan, Tingting W Mills, Holger K Eltzschig

Faculty, Staff and Student Publications

Previous studies implicate extracellular adenosine signaling in attenuating myocardial ischemia and reperfusion injury (IRI). This extracellular adenosine signaling is terminated by its uptake into cells by equilibrative nucleoside transporters (ENTs). Thus, we hypothesized that targeting ENTs would function to increase cardiac adenosine signaling and concomitant cardioprotection against IRI. Mice were exposed to myocardial ischemia and reperfusion injury. Myocardial injury was attenuated in mice treated with the nonspecific ENT inhibitor dipyridamole. A comparison of mice with global Ent1 or Ent2 deletion showed cardioprotection only in Ent1-/- mice. Moreover, studies with tissue-specific Ent deletion revealed that mice with myocyte-specific Ent1 deletion (Ent1loxP/loxP …

Mechanisms Underlying The Antiarrhythmic Effect Of Arumenamide-787 In Experimental Models Of The J Wave Syndromes And Hypothermia, José M. Di Diego, Hector Barajas-Martinez, Robert Cox, Victoria M Robinson, Joseph Jung, Mohamed Fouda, Mena Abdelsayed, Peter C Ruben, Charles Antzelevitch

Department of Medicine Faculty Papers

BACKGROUND: Brugada (BrS) and early repolarization syndromes (ERS), the so-called J wave syndromes (JWS), are associated with life-threatening ventricular arrhythmias. Pharmacologic approaches to therapy are currently limited. In this study, we examine the effects of ARumenamide-787 (AR-787) to suppress the electrocardiographic and arrhythmic manifestations of JWS and hypothermia.

METHODS: We studied the effects of AR-787 on INa and IKr in HEK-293 cells stably expressing the α- and β1-subunits of the cardiac (NaV1.5) sodium channel and hERG channel, respectively. In addition, we studied its effect on Ito, INa and ICa in dissociated canine ventricular myocytes along with action potentials and ECG …

Control Of Sars-Cov-2 Infection By Mt1-Mmp-Mediated Shedding Of Ace2, Xuanming Guo, Jianli Cao, Jian-Piao Cai, Jiayan Wu, Jiangang Huang, Pallavi Asthana, Sheung Kin Ken Wong, Zi-Wei Ye, Susma Gurung, Yijing Zhang, Sheng Wang, Zening Wang, Xin Ge, Hiu Yee Kwan, Aiping Lyu, Kui Ming Chan, Nathalie Wong, Jiandong Huang, Zhongjun Zhou, Zhao-Xiang Bian, Shuofeng Yuan, Hoi Leong Xavier Wong

Faculty, Staff and Student Publications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic. Angiotensin-converting enzyme 2 (ACE2) is an entry receptor for SARS-CoV-2. The full-length membrane form of ACE2 (memACE2) undergoes ectodomain shedding to generate a shed soluble form (solACE2) that mediates SARS-CoV-2 entry via receptor-mediated endocytosis. Currently, it is not known how the physiological regulation of ACE2 shedding contributes to the etiology of COVID-19 in vivo. The present study identifies Membrane-type 1 Matrix Metalloproteinase (MT1-MMP) as a critical host protease for solACE2-mediated SARS-CoV-2 infection. SARS-CoV-2 infection leads to increased activation of MT1-MMP that is colocalized with ACE2 in human lung …

Anesthesia For Echocardiography And Magnetic Resonance Imaging In The African Clawed Frog (Xenopus Laevis), Antonio F Corno, Noelia E Flores, Wen Li, Thomas H Gomez, Jorge D Salazar

Faculty, Staff and Student Publications

This report describes an anesthesia technique that we used to study cardiovascular anatomy and physiology with echocardiography and cardiac magnetic resonance (CMR) in 46 African clawed frogs (Xenopus laevis) (n = 24 for electrocardiography and n = 22 for CMR). For administration of anesthesia, 3 holding tanks, one each for transportation, sedation, and recovery, were filled with filtered water, with 0.05% buffered tricaine methasulfonate solution (MS-222) added into the sedation tank. Fifteen minutes after the frog was placed in the sedation tank, a paper towel was soaked in MS-222 solution, and the frog was placed in a …

Sirpα Mediates Igf1 Receptor In Cardiomyopathy-Induced By Chronic Kidney Disease, Sandhya S Thomas, Jiao Wu, Giovanni Davogustto, Michael W Holliday, Kristin Eckel-Mahan, Daniela Verzola, Giacomo Garibotto, Zhaoyong Hu, William E Mitch, Heinrich Taegtmeyer

Faculty, Staff and Student Publications

BACKGROUND: Chronic kidney disease (CKD) is characterized by increased myocardial mass despite near-normal blood pressure, suggesting the presence of a separate trigger. A potential driver is SIRPα (signal regulatory protein alpha)-a mediator impairing insulin signaling. The objective of this study is to assess the role of circulating SIRPα in CKD-induced adverse cardiac remodeling.

METHODS: SIRPα expression was evaluated in mouse models and patients with CKD. Specifically, mutant, muscle-specific, or cardiac muscle-specific SIRPα KO (knockout) mice were examined after subtotal nephrectomy. Cardiac function was assessed by echocardiography. Metabolic responses were confirmed in cultured muscle cells or cardiomyocytes.

RESULTS: We demonstrate that …

Prolonged Cardiac Nr4a2 Activation Causes Dilated Cardiomyopathy In Mice, Sadia Ashraf, Heinrich Taegtmeyer, Romain Harmancey

Faculty, Staff and Student Publications

Transcription factors play a fundamental role in cardiovascular adaptation to stress. Nuclear receptor subfamily 4 group A member 2 (NR4A2; NURR1) is an immediate-early gene and transcription factor with a versatile role throughout many organs. In the adult mammalian heart, and particularly in cardiac myocytes, NR4A2 is strongly up-regulated in response to beta-adrenergic stimulation. The physiologic implications of this increase remain unknown. In this study, we aimed to interrogate the consequences of cardiac NR4A2 up-regulation under normal conditions and in response to pressure overload. In mice, tamoxifen-dependent, cardiomyocyte-restricted overexpression of NR4A2 led to cardiomyocyte hypertrophy, left ventricular dilation, heart failure, …

Prolonged Cardiac Nr4a2 Aactivation Causes Dilated Cardiomyopathy In Mice, Sadia Ashraf, Heinrich Taegtmeyer, Romain Harmancey

Faculty, Staff and Student Publications

Transcription factors play a fundamental role in cardiovascular adaptation to stress. Nuclear receptor subfamily 4 group A member 2 (NR4A2; NURR1) is an immediate-early gene and transcription factor with a versatile role throughout many organs. In the adult mammalian heart, and particularly in cardiac myocytes, NR4A2 is strongly up-regulated in response to beta-adrenergic stimulation. The physiologic implications of this increase remain unknown. In this study, we aimed to interrogate the consequences of cardiac NR4A2 up-regulation under normal conditions and in response to pressure overload. In mice, tamoxifen-dependent, cardiomyocyte-restricted overexpression of NR4A2 led to cardiomyocyte hypertrophy, left ventricular dilation, heart failure, …

Guidelines On Models Of Diabetic Heart Disease, Lisa C Heather, Anne D Hafstad, Ganesh V Halade, Romain Harmancey, Kimberley M Mellor, Paras K Mishra, Erin E Mulvihill, Miranda Nabben, Michinari Nakamura, Oliver J Rider, Matthieu Ruiz, Adam R Wende, John R Ussher

Faculty, Staff and Student Publications

Diabetes is a major risk factor for cardiovascular diseases, including diabetic cardiomyopathy, atherosclerosis, myocardial infarction, and heart failure. As cardiovascular disease represents the number one cause of death in people with diabetes, there has been a major emphasis on understanding the mechanisms by which diabetes promotes cardiovascular disease, and how antidiabetic therapies impact diabetic heart disease. With a wide array of models to study diabetes (both type 1 and type 2), the field has made major progress in answering these questions. However, each model has its own inherent limitations. Therefore, the purpose of this guidelines document is to provide the …

Free Cholesterol Bioavailability And Atherosclerosis, Rei J Abe, Jun-Ichi Abe, Minh T H Nguyen, Elizabeth A Olmsted-Davis, Abrar Mamun, Priyanka Banerjee, John P Cooke, Longhou Fang, Henry Pownall, Nhat-Tu Le

Faculty, Staff and Student Publications

Purpose of review: As both a cholesterol acceptor and carrier in the reverse cholesterol transport (RCT) pathway, high-density lipoprotein (HDL) is putatively atheroprotective. However, current pharmacological therapies to increase plasma HDL cholesterol (HDL-c) concentration have paradoxically failed to prevent or reduce atherosclerosis and cardiovascular disease (CVD). Given that free cholesterol (FC) transfer between surfaces of lipoproteins and cells is reversible, excess plasma FC can be transferred to the cells of peripheral tissue sites resulting in atherosclerosis. Here, we summarize potential mechanisms contributing to this paradox and highlight the role of excess free cholesterol (FC) bioavailability in atherosclerosis vs. atheroprotection.

Recent …

Common Genetic Variants Contribute To Risk Of Transposition Of The Great Arteries, Doris Škorić-Milosavljević, Rafik Tadros, Fernanda M Bosada, Federico Tessadori, Jan Hendrik Van Weerd, Odilia I Woudstra, Fleur V Y Tjong, Najim Lahrouchi, Fanny Bajolle, Heather J Cordell, A J Agopian, Gillian M Blue, Daniela Q C M Barge-Schaapveld, Marc Gewillig, Christoph Preuss, Elisabeth M Lodder, Phil Barnett, Aho Ilgun, Leander Beekman, Karel Van Duijvenboden, Regina Bokenkamp, Martina Müller-Nurasyid, Hubert W Vliegen, Thelma C Konings, Joost P Van Melle, Arie P J Van Dijk, Roland R J Van Kimmenade, Jolien W Roos-Hesselink, Gertjan T Sieswerda, Folkert Meijboom, Hashim Abdul-Khaliq, Felix Berger, Sven Dittrich, Marc-Phillip Hitz, Julia Moosmann, Frank-Thomas Riede, Stephan Schubert, Pilar Galan, Mark Lathrop, Hans M Munter, Ammar Al-Chalabi, Christopher E Shaw, Pamela J Shaw, Karen E Morrison, Jan H Veldink, Leonard H Van Den Berg, Sylvia Evans, Marcelo A Nobrega, Ivy Aneas, Milena Radivojkov-Blagojević, Thomas Meitinger, Erwin Oechslin, Tapas Mondal, Lynn Bergin, John F Smythe, Luis Altamirano-Diaz, Jane Lougheed, Berto J Bouma, Marie-A Chaix, Jennie Kline, Anne S Bassett, Gregor Andelfinger, Roel L F Van Der Palen, Patrice Bouvagnet, Sally-Ann B Clur, Jeroen Breckpot, Wilhelmina S Kerstjens-Frederikse, David S Winlaw, Ulrike M M Bauer, Seema Mital, Elizabeth Goldmuntz, Bernard Keavney, Damien Bonnet, Barbara J Mulder, Michael W T Tanck, Jeroen Bakkers, Vincent M Christoffels, Cornelis J Boogerd, Alex V Postma, Connie R Bezzina

Faculty, Staff and Student Publications

RATIONALE: Dextro-transposition of the great arteries (D-TGA) is a severe congenital heart defect which affects approximately 1 in 4,000 live births. While there are several reports of D-TGA patients with rare variants in individual genes, the majority of D-TGA cases remain genetically elusive. Familial recurrence patterns and the observation that most cases with D-TGA are sporadic suggest a polygenic inheritance for the disorder, yet this remains unexplored.

OBJECTIVE: We sought to study the role of common single nucleotide polymorphisms (SNPs) in risk for D-TGA.

METHODS AND RESULTS: We conducted a genome-wide association study in an international set of 1,237 patients …

Ucp3 (Uncoupling Protein 3) Insufficiency Exacerbates Left Ventricular Diastolic Dysfunction During Angiotensin Ii-Induced Hypertension, Xu Chen, Sadia Ashraf, Nadia Ashraf, Romain Harmancey

Faculty, Staff and Student Publications

Background Left ventricular diastolic dysfunction, an early stage in the pathogenesis of heart failure with preserved ejection fraction, is exacerbated by joint exposure to hypertension and obesity; however, the molecular mechanisms involved remain uncertain. The mitochondrial UCP3 (uncoupling protein 3) is downregulated in the heart with obesity. Here, we used a rat model of UCP3 haploinsufficiency (ucp3

Ucp3 (Uncoupling Protein 3) Insufficiency Exacerbates Left Ventricular Diastolic Dysfunction During Angiotensin Ii-Induced Hypertension, Xu Chen, Sadia Ashraf, Nadia Ashraf, Romain Harmancey

Faculty, Staff and Student Publications

Background Left ventricular diastolic dysfunction, an early stage in the pathogenesis of heart failure with preserved ejection fraction, is exacerbated by joint exposure to hypertension and obesity; however, the molecular mechanisms involved remain uncertain. The mitochondrial UCP3 (uncoupling protein 3) is downregulated in the heart with obesity. Here, we used a rat model of UCP3 haploinsufficiency (ucp3

Alcohol Ablation Of Cardiac Tissues Quantified And Evaluated Using Cielab Euclidean Distances, Ashley Rook, Mathews M John, Allison Post, Mehdi Razavi

The Texas Heart Institute Journal

Ethanol solubilizes cell membranes, making it useful for various ablation applications. We examined the effect of time and alcohol type on the extent of ablation, quantified as Euclidean distances between color coordinates. We obtained biopsy punch samples (diameter, 6 mm) of left atrial appendage, atrial, ventricular, and septal tissue from porcine hearts and placed them in transwell plates filled with ethanol or methanol for 10, 20, 30, 40, 50, or 60 min. Control samples were taken for each time point. At each time point, samples were collected, cut transversely, and photographed. With use of a custom MATLAB program, all images …

Dietary Fat And Sugar Differentially Affect Β-Adrenergic Stimulation Of Cardiac Erk And Akt Pathways In C57bl/6 Male Mice Subjected To High-Calorie Feeding, Sadia Ashraf, Gizem Yilmaz, Xu Chen, Romain Harmancey

Faculty, Staff and Student Publications

BACKGROUND: High dietary fat and sugar promote cardiac hypertrophy independently from an increase in blood pressure. The respective contribution that each macronutrient exerts on cardiac growth signaling pathways remains unclear.

OBJECTIVE: The goal of this study was to investigate the mechanisms by which high amounts of dietary fat and sugar affect cardiac growth regulatory pathways.

METHODS: Male C57BL/6 mice (9 wk old; n = 20/group) were fed a standard rodent diet (STD; kcal% protein-fat-carbohydrate, 29-17-54), a high-fat diet (HFD; 20-60-20), a high-fat and high-sugar Western diet (WD; 20-45-35), a high-sugar diet with mixed carbohydrates (HCD; 20-10-70), or a high-sucrose diet …

Nuclear Receptor Subfamily 4 Group A Member 2 Inhibits Activation Of Erk Signaling And Cell Growth In Response To Β-Adrenergic Stimulation In Adult Rat Cardiomyocytes, Sadia Ashraf, Yassmin K Hegazy, Romain Harmancey

Faculty, Staff and Student Publications

Sustained elevation of sympathetic activity is an important contributor to pathological cardiac hypertrophy, ventricular arrhythmias, and left ventricular contractile dysfunction in chronic heart failure. The orphan nuclear receptor NR4A2 is an immediate early-response gene activated in the heart under β-adrenergic stimulation. The goal of this study was to identify the transcriptional remodeling events induced by increased NR4A2 expression in cardiomyocytes and their impact on the physiological response of those cells to sustained β-adrenergic stimulation. Treatment of adult rat ventricular myocytes with isoproterenol induced a rapid (<4 >h) increase in NR4A2 levels that was accompanied by a transient (<24 >h) increase …

Nuclear Receptor Subfamily 4 Group A Member 2 Inhibits Activation Of Erk Signaling And Cell Growth In Response To Β-Adrenergic Stimulation In Adult Rat Cardiomyocytes, Sadia Ashraf, Yassmin K Hegazy, Romain Harmancey

Faculty, Staff and Student Publications

Sustained elevation of sympathetic activity is an important contributor to pathological cardiac hypertrophy, ventricular arrhythmias, and left ventricular contractile dysfunction in chronic heart failure. The orphan nuclear receptor NR4A2 is an immediate early-response gene activated in the heart under β-adrenergic stimulation. The goal of this study was to identify the transcriptional remodeling events induced by increased NR4A2 expression in cardiomyocytes and their impact on the physiological response of those cells to sustained β-adrenergic stimulation. Treatment of adult rat ventricular myocytes with isoproterenol induced a rapid (<4 >h) increase in NR4A2 levels that was accompanied by a transient (<24 >h) increase …

Phospholipases D: Making Sense Of Redundancy And Duplication, Andrew J. Morris

Internal Medicine Faculty Publications

Why have two genes when one would suffice? Evolutionary pressure means that biology, unlike government, is generally intolerant of wasted effort. Therefore, when multiple genes exist presumably they are there to provide some benefit to the organism even if that benefit is not immediately obvious to us scientists. A recent report from Raghu and colleagues (Biosci. Rep. (2018) 38, pii: BSR20181690) [1] sheds some light on one possible reason for the existence of two Phospholipases D genes in chordates when only one is present in invertebrates.

Pathologic Gene Network Rewiring Implicates Ppp1r3a As A Central Regulator In Pressure Overload Heart Failure., Pablo Cordero, Victoria N Parikh, Elizabeth T Chin, Ayca Erbilgin, Michael J Gloudemans, Ching Shang, Yong Huang, Alex C Chang, Kevin S Smith, Frederick Dewey, Kathia Zaleta, Michael Morley, Jeff Brandimarto, Nicole Glazer, Daryl Waggott, Aleksandra Pavlovic, Mingming Zhao, Christine S Moravec, W H Wilson Tang, Jamie Skreen, Christine Malloy, Sridhar Hannenhalli, Hongzhe Li, Scott Ritter, Mingyao Li, Daniel Bernstein, Andrew Connolly, Hakon Hakonarson, Aldons J Lusis, Kenneth B Margulies, Anna A Depaoli-Roach, Stephen B Montgomery, Matthew T Wheeler, Thomas Cappola, Euan A Ashley

Articles, Abstracts, and Reports

Heart failure is a leading cause of mortality, yet our understanding of the genetic interactions underlying this disease remains incomplete. Here, we harvest 1352 healthy and failing human hearts directly from transplant center operating rooms, and obtain genome-wide genotyping and gene expression measurements for a subset of 313. We build failing and non-failing cardiac regulatory gene networks, revealing important regulators and cardiac expression quantitative trait loci (eQTLs). PPP1R3A emerges as a regulator whose network connectivity changes significantly between health and disease. RNA sequencing after PPP1R3A knockdown validates network-based predictions, and highlights metabolic pathway regulation associated with increased cardiomyocyte size and …

Proteomic Alterations Of Hdl In Youth With Type 1 Diabetes And Their Associations With Glycemic Control: A Case-Control Study, Evgenia Gourgari, Junfeng Ma, Martin P. Playford, Nehal N. Mehta, Radoslav Goldman, Alan T. Remaley, Scott M. Gordon

Saha Cardiovascular Research Center Faculty Publications

Background: Patients with type 1 diabetes (T1DM) typically have normal or even elevated plasma high density lipoprotein (HDL) cholesterol concentrations; however, HDL protein composition can be altered without a change in cholesterol content. Alteration of the HDL proteome can result in dysfunctional HDL particles with reduced ability to protect against cardiovascular disease (CVD). The objective of this study was to compare the HDL proteomes of youth with T1DM and healthy controls (HC) and to evaluate the influence of glycemic control on HDL protein composition.

Methods: This was a cross-sectional case–control study. Blood samples were obtained from patients with T1DM and …

The Future Of Tissue Engineering In Heart Transplantation, Doris A Taylor

The Texas Heart Institute Journal

No abstract provided.

Antisense Oligonucleotides Targeting Angiotensinogen: Insights From Animal Studies, Chia-Hua Wu, Ya Wang, Murong Ma, Adam E. Mullick, Rosanne M. Crooke, Mark J. Graham, Alan Daugherty, Hong S. Lu

Saha Cardiovascular Research Center Faculty Publications

Angiotensinogen (AGT) is the unique substrate of all angiotensin peptides. We review the recent preclinical research of AGT antisense oligonucleotides (ASOs), a rapidly evolving therapeutic approach. The scope of the research findings not only opens doors for potentially new therapeutics of hypertension and many other diseases, but also provides insights into understanding critical physiological and pathophysiological roles mediated by AGT.

Macrophage-Derived Netrin-1 Promotes Abdominal Aortic Aneurysm Formation By Activating Mmp3 In Vascular Smooth Muscle Cells, Tarik Hadi, Ludovic Boytard, Michele Silvestro, Dornazsadat Alebrahim, Samson Jacob, Jordyn Feinstein, Krista Barone, Wes Spiro, Susan Hutchison, Russell Simon, Debra L. Rateri, Florence Pinet, David Fenyo, Mark Adelman, Kathryn J. Moore, Holger K. Eltzschig, Alan Daugherty, Bhama Ramkhelawon

Physiology Faculty Publications

Abdominal aortic aneurysms (AAA) are characterized by extensive extracellular matrix (ECM) fragmentation and inflammation. However, the mechanisms by which these events are coupled thereby fueling focal vascular damage are undefined. Here we report through single-cell RNA-sequencing of diseased aorta that the neuronal guidance cue netrin-1 can act at the interface of macrophage-driven injury and ECM degradation. Netrin-1 expression peaks in human and murine aneurysmal macrophages. Targeted deletion of netrin-1 in macrophages protects mice from developing AAA. Through its receptor neogenin-1, netrin-1 induces a robust intracellular calcium flux necessary for the transcriptional regulation and persistent catalytic activation of matrix metalloproteinase-3 (MMP3) …

Azithromycin Therapy Reduces Cardiac Inflammation And Mitigates Adverse Cardiac Remodeling After Myocardial Infarction: Potential Therapeutic Targets In Ischemic Heart Disease, Ahmed Al-Darraji, Dalia Haydar, Lakshman Chelvarajan, Himi Tripathi, Bryana R. Levitan, Erhe Gao, Vincent J. Venditto, John C. Gensel, David James Feola, Ahmed Abdel-Latif

Gill Heart & Vascular Institute Faculty Publications

Introduction

Acute myocardial infarction (MI) is a primary cause of worldwide morbidity and mortality. Macrophages are fundamental components of post-MI inflammation. Pro-inflammatory macrophages can lead to adverse cardiac remodeling and heart failure while anti-inflammatory/reparative macrophages enhance tissue healing. Shifting the balance between pro-inflammatory and reparative macrophages post-MI is a novel therapeutic strategy. Azithromycin (AZM), a commonly used macrolide antibiotic, polarizes macrophages towards the anti-inflammatory phenotype, as shown in animal and human studies. We hypothesized that AZM modulates post-MI inflammation and improves cardiac recovery.

Methods and results

Male WT mice (C57BL/6, 6–8 weeks old) were treated with either oral AZM (160 …

Computational Sensitivity Investigation Of Hydrogel Injection Characteristics For Myocardial Support, Hua Wang, Christopher B. Rodell, Madonna E. Lee, Neville N. Dusaj, Joseph H. Gorman Iii, Jason A. Burdick, Robert C. Gorman, Jonathan F. Wenk

Mechanical Engineering Faculty Publications

Biomaterial injection is a potential new therapy for augmenting ventricular mechanics after myocardial infarction (MI). Recent in vivo studies have demonstrated that hydrogel injections can mitigate the adverse remodeling due to MI. More importantly, the material properties of these injections influence the efficacy of the therapy. The goal of the current study is to explore the interrelated effects of injection stiffness and injection volume on diastolic ventricular wall stress and thickness. To achieve this, finite element models were constructed with different hydrogel injection volumes (150 µL and 300 µL), where the modulus was assessed over a range of 0.1 kPa …

The Dual Role Of Group V Secretory Phospholipase A2 In Pancreatic Β-Cells, Preetha Shridas, Victoria P. Noffsinger, Andrea C. Trumbauer, Nancy R. Webb

Saha Cardiovascular Research Center Faculty Publications

Purpose

Group X (GX) and group V (GV) secretory phospholipase A₂ (sPLA₂) potently release arachidonic acid (AA) from the plasma membrane of intact cells. We previously demonstrated that GX sPLA₂ negatively regulates glucose-stimulated insulin secretion (GSIS) by a prostaglandin E2 (PGE2)-dependent mechanism. In this study we investigated whether GV sPLA₂ similarly regulates GSIS.

Methods

GSIS and pancreatic islet-size were assessed in wild-type (WT) and GV sPLA₂-knock out (GV KO) mice. GSIS was also assessed ex vivo in isolated islets and in vitro using MIN6 pancreatic beta cell lines with or without GV sPLA …

Targeting Hepatic Heparin-Binding Egf-Like Growth Factor (Hb-Egf) Induces Anti-Hyperlipidemia Leading To Reduction Of Angiotensin Ii-Induced Aneurysm Development, Seonwook Kim, Lihua Yang, Seongu Kim, Richard G. Lee, Mark J. Graham, Judith A. Berliner, Aldons J. Lusis, Lei Cai, Ryan E. Temel, Debra L. Rateri, Sangderk Lee

Saha Cardiovascular Research Center Faculty Publications

Objective

The upregulated expression of heparin binding EGF-like growth factor (HB-EGF) in the vessel and circulation is associated with risk of cardiovascular disease. In this study, we tested the effects of HB-EGF targeting using HB-EGF-specific antisense oligonucleotide (ASO) on the development of aortic aneurysm in a mouse aneurysm model.

Approach and results

Low-density lipoprotein receptor (LDLR) deficient mice (male, 16 weeks of age) were injected with control and HB-EGF ASOs for 10 weeks. To induce aneurysm, the mice were fed a high fat diet (22% fat, 0.2% cholesterol; w/w) at 5 week point of ASO administration and infused with angiotensin …

Early Gadolinium Enhancement For Area At Risk Determination: A Preclinical Validation Study, Sophia Hammer-Hansen, Steve W. Leung, Li-Yueh Hsu, Joel R. Wilson, Joni Taylor, Anders M. Greve, Jens Jakob Thune, Lars Køber, Peter Kellman, Andrew E. Arai

Internal Medicine Faculty Publications

Objectives—The aim of this study was to determine if early gadolinium enhancement (EGE) by cardiovascular magnetic resonance (CMR) imaging in a canine model of reperfused myocardial infarction depicts the area at risk (AAR) as determined by microsphere blood flow analysis.

Background—It remains controversial whether only the irreversibly injured myocardium enhances when performing CMR imaging in the setting of acute myocardial infarction. Recently, EGE has been proposed as a measure of the AAR in acute myocardial infarction as it correlates well with T2-weighted imaging of the AAR, but still requires pathological validation.

Methods—Eleven dogs underwent 2 hours of …

Myocardial Relaxation Is Accelerated By Fast Stretch, Not Reduced Afterload, Charles S. Chung, Charles W. Hoopes, Kenneth S. Campbell

Physiology Faculty Publications

Fast relaxation of cross-bridge generated force in the myocardium facilitates efficient diastolic function. Recently published research studying mechanisms that modulate the relaxation rate has focused on molecular factors. Mechanical factors have received less attention since the 1980s when seminal work established the theory that reducing afterload accelerates the relaxation rate. Clinical trials using afterload reducing drugs, partially based on this theory, have thus far failed to improve outcomes for patients with diastolic dysfunction. Therefore, we reevaluated the protocols that suggest reducing afterload accelerates the relaxation rate and identified that myocardial relengthening was a potential confounding factor. We hypothesized that the …

Comparative Efficacy Of Nebivolol And Metoprolol To Prevent Tachycardia-Induced Cardiomyopathy In A Porcine Model, Alireza Nazeri, Macarthur A Elayda, Ana Maria Segura, Raymond F Stainback, Joanna Nathan, Vei-Vei Lee, Christina Bove, Luiz Sampaio, Brian Grace, Ali Massumi, Mehdi Razavi

The Texas Heart Institute Journal

Chronic tachycardia is a well-known cause of nonischemic cardiomyopathy. We hypothesized that nebivolol, a β-blocker with nitric oxide activity, would be superior to a pure β-blocker in preventing tachycardia-induced cardiomyopathy in a porcine model.

Fifteen healthy Yucatan pigs were randomly assigned to receive nebivolol, metoprolol, or placebo once a day. All pigs underwent dual-chamber pacemaker implantation. The medication was started the day after the pacemaker implantation. On day 7 after implantation, each pacemaker was set at atrioventricular pace (rate, 170 beats/min), and the pigs were observed for another 7 weeks. Transthoracic echocardiograms, serum catecholamine levels, and blood chemistry data were …