Molecular Biology Commons^™

Targeting Metabolic Alterations Associated With Smooth Muscle Α-Actin Pathogenic Variant Attenuates Moyamoya-Like Cerebrovascular Disease, Anita Kaw

Dissertations & Theses (Open Access)

Heterozygous pathogenic variants in ACTA2, encoding smooth muscle α-actin (α-SMA), predispose to thoracic aortic aneurysms and dissections. De novo missense variants disrupting ACTA2 arginine 179 (p.Arg179) cause a multisystemic disease termed smooth muscle dysfunction syndrome (SMDS), which is characterized by early onset thoracic aortic disease and moyamoya disease-like (MMD) cerebrovascular disease. The MMD-like cerebrovascular disease in SMDS patients is marked by bilateral steno-occlusive lesions in the distal internal carotid arteries (ICAs) and their branches. To study the molecular mechanisms that underlie the ACTA2 p.Arg179 variants, a smooth muscle-specific Cre-lox knock-in mouse model of the heterozygous Acta2 R179C variant, termed …

Ankyrin Dependent Mitochondrial Function And Bioenergetics In The Heart, Janani Subramaniam, Janani Subramaniam

Dissertations & Theses (Open Access)

ANK2 mutations in patients are associated with numerous arrhythmias, cardiomyopathies, and other heart defects. In the heart, AnkB, the protein encoded by ANK2, clusters relevant ion channels and cell adhesion molecules in several important domains; however, its role at Mitochondria Associated ER/SR Membranes (MAMs) has yet to be investigated. MAMs are crucial to mitochondrial function and metabolism and are signaling hubs implicated in various cardiac pathologies. Among several functions, these sites mediate the direct transfer of calcium from the ER/SR to the mitochondria to modulate ATP synthesis. Given that mitochondrial function and energy production are paramount to cardiovascular heath, …

Amelioration Of Mitochondrial Bioenergetic Dysfunction In Diabetes Mellitus: Delving Into Specialized And Non-Specific Therapeutics For The Ailing Heart, Andrya Jean Durr

Graduate Theses, Dissertations, and Problem Reports

Morbidity and mortality of the diabetic population is influenced by many confounding factors, but cardiovascular disease (CVD), remains the leading cause of death. Mitochondrial dysfunction is central in the development of cardiac contractile dysfunction, with decreased mitochondrial bioenergetic function, increased dependence on free fatty acid utilization, and a decrease in glucose utilization having been shown to contribute to contractile dysfunction. Strategies targeting the amelioration of mitochondrial bioenergetic function are attractive for limiting diabetes-induced heart failure, and preserving health-span. The goals of this dissertation were to assess two mitochondrial-centric approaches for the amelioration of mitochondrial and cardiac contractile dysfunction in diabetes …

Impact Of Pank1 Deletion On Mitochondrial Acetylation And Cardiac Function During Pressure Overload., Timothy N. Audam

Electronic Theses and Dissertations

Recent studies have associated elevated protein acetylation levels with heart failure in humans. Although mechanisms promoting elevated acetylation levels are not fully known, excess acetyl-CoA may drive enzyme-independent acetylation of cardiac proteins. Accumulation of acetyl-CoA depends on the availability of sufficient CoA, whose production is regulated by pantothenate kinases in the CoA biosynthetic pathway. We show that cardiac proteins are hyperacetylated during heart failure in humans and tested in mice whether limiting CoA abundance would improve ventricular remodeling during pressure overload-induced hypertrophy. We limited cardiac CoA levels by deleting the rate-limiting enzyme in CoA biosynthesis, Pank1 (one of three PANK-encoding …

Defining The Role Of Tyrosine Phosphorylation In The Regulation Of Connexin43 In Cardiac Diseases, Li Zheng

Theses & Dissertations

Connexins are integral membrane proteins that oligomerize to form gap junction channels. Ions and small molecules diffuse intercellularly through these channels, allowing individual cellular events to synchronize into the functional response of an entire organ. Gap junction channels composed of Connexin43 (Cx43) mediate electrical coupling and impulse propagation in the normal working myocardium. In the failing heart, Cx43 remodeling (decreased expression, altered phosphorylation state, loss at intercalated discs, and increased presence at lateral membranes) contributes to rhythm disturbances and contractile dysfunction. While there is considerable information regarding key interactions of Cx43 in the regulation of gap junction channels, unfortunately, the …

Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli

Electronic Thesis and Dissertation Repository

Elevated plasma lipoprotein(a) (Lp(a)) is the most prevalent heritable risk factor in the development of cardiovascular disease. The apolipoprotein(a) (apo(a)) component of Lp(a) is strongly implicated in the pathogenicity of Lp(a). It is hypothesized that the inflammatory potential of Lp(a)/apo(a) is mediated by the lysine binding ability of the apo(a) kringle IV10 (KIV10) domain, along with its covalently bound oxidized phospholipid (oxPL). Using targeted mutagenesis, two novel null alleles for the LPA gene that generate non-secretable apo(a) species have been identified, resulting from amino acid substitutions in the KIV10 domain. A potential mechanism by which KIV10 oxPL modification is enriched …

Microvascular Stenosis In Critical Limb Ischemia: Role Of Partial Endothelial To Mesenchymal Transition, Jacqueline M. Chevalier

Electronic Thesis and Dissertation Repository

Critical limb ischemia (CLI) is a widespread and debilitating manifestation of atherosclerosis. Unfortunately, revascularization strategies are often precluded or unsuccessful, resulting in amputation. A major reason for treatment failure is likely co-existing abnormalities in ­­the microvasculature. However, the specific microvascular defects present in end-stage PAD in humans remain unknown.

The purpose of this study was to delineate abnormalities in the microvascular wall in the critically ischemic skeletal muscle of patients with CLI.

To elucidate the microvascular landscape in CLI, we studied human tibialis anterior and gastrocnemius muscles harvested from below-knee amputations of 10 individuals with CLI. Control muscles are from …

Bayesian Analytical Approaches For Metabolomics : A Novel Method For Molecular Structure-Informed Metabolite Interaction Modeling, A Novel Diagnostic Model For Differentiating Myocardial Infarction Type, And Approaches For Compound Identification Given Mass Spectrometry Data., Patrick J. Trainor

Electronic Theses and Dissertations

Metabolomics, the study of small molecules in biological systems, has enjoyed great success in enabling researchers to examine disease-associated metabolic dysregulation and has been utilized for the discovery biomarkers of disease and phenotypic states. In spite of recent technological advances in the analytical platforms utilized in metabolomics and the proliferation of tools for the analysis of metabolomics data, significant challenges in metabolomics data analyses remain. In this dissertation, we present three of these challenges and Bayesian methodological solutions for each. In the first part we develop a new methodology to serve a basis for making higher order inferences in metabolomics, …

Role Of Cannabinoid Receptor Type 2 (Cb2) In Late Stage Atherosclerosis, Makenzie Fulmer

Electronic Theses and Dissertations

Atherosclerosis is a chronic inflammatory disorder of medium and large vessels. Immune signaling and dyslipidemia are two of several processes which influence lesion development in atherosclerosis. Cannabinoids, such as those found in marijuana, exert their effects through two cannabinoid receptors, CB1 and CB2. Recent studies using CB2 knockout mice and CB2-selective ligands have shed light on a protective role of CB2 in early stages of atherosclerosis. However, the role of CB2 in advanced stages of atherosclerosis remains unclear. To determine if CB2 plays a role in advanced atherosclerotic lesion composition and progression, we investigated the effects of systemic CB2 gene …

The Effects Of Pulmonary Hypertension In Diabetic Zucker Rats On Pulmonary Vascular Contraction And Right Ventricular Size, Michael Franzetti

Biological Sciences Undergraduate Honors Theses

Pulmonary hypertension is a life-threatening disease that is identified by a resting mean pulmonary arterial pressure over 25 mmHg and established by right heart catheterization (Saglam et al., 2015). The symptoms commonly associated with pulmonary hypertension include fatigue, dyspnea, syncope, and chest pain, which severely limit quality of life in diagnosed patients (Saglam et al., 2015). According to recent studies in patients with pulmonary hypertension, the one, three and five year mortality rates are 8%, 25%, and 34%, respectively (Burudpakdee, Shah, Joish, Divers, & Yaldo, 2014). Although some advances have been made in therapies for pulmonary hypertension, the prognosis is …

Molecular Basis Of Sex Differences In Cardiac Hypertrophy And Heart Failure, Maya James

Online Theses and Dissertations

Transforming growth factor beta ligands and receptors are known to be pro-hypertrophic and pro-fibrotic factors in the heart, and are known to contribute to the development of cardiac hypertrophy and heart failure. It is well established that premenopausal females possess a lower incidence of these pathologies. We and others have observed a greater level of fibrosis in male hearts compared to female hearts in rodent models of cardiac hypertrophy. It is well established that estrogen is cardioprotective in that it can prevent the development of cardiac hypertrophy, as well as abrogate the development of heart failure following sustained cardiac hypertrophy. …

Regulation Of C-Reactive Protein Gene Expression And Function, Avinash N. Thirumalai

Electronic Theses and Dissertations

Human C-reactive protein (CRP) is the prototypic acute phase protein whose serum concentration increases rapidly during inflammation. CRP is also associated with atherosclerosis; it is deposited at lesion sites where it may interact with modified lipoproteins. There are 2 major questions regarding CRP: 1. How is the serum concentration of CRP regulated? 2. What are the functions of CRP in atherosclerosis?

Our first aim was to determine the role of the constitutively expressed transcription factor Oct-1 in regulating CRP gene expression. We found that Oct-1 overexpression inhibited (IL-6+IL-1β)- induced CRP gene expression; maximal inhibition required the binding of Oct-1 to …

Regulation Of Lipid Homeostasis, Inflammatory Signalling And Atherosclerosis By The Peroxisome Proliferator-Activated Receptor Delta, Lazar A. Bojic

Electronic Thesis and Dissertation Repository

The peroxisome proliferator-activated receptor (PPAR) δ is a ligand-dependent transcription factor that has been implicated in metabolic and inflammatory regulation. The molecular and physiological mechanisms by which PPARδ activation regulates lipid metabolism, inflammatory signaling and protection from atherosclerosis in states of metabolic disturbance such as insulin resistance and dyslipidemia, were investigated in a series of in vitro and in vivo studies. In vitro experiments demonstrated that PPARδ activation inhibits atherogenic lipoprotein-induced lipid accumulation and the associated proinflammatory responses. The primary mechanisms for these effects were increased fatty acid β-oxidation, decreased lipoprotein lipase (LPL) activity, reduced MAPK signaling and improved insulin …

Involvement Of Interleukin-33/St2 In Myocardial Dysfunction In Murine Model Of Sepsis, Yoonmi Choe

Electronic Thesis and Dissertation Repository

The disruption of myocardial extracellular matrix (ECM) has been implicated in myocardial dysfunction during sepsis. However, the underlying mechanism(s) are not clear. Interleukin-33 (IL-33) is a cytokine which regulates collagen synthesis in various cardiac pathologies. The purpose of the present study is to test whether IL-33 contributes to sepsis-induced myocardial dysfunction through regulation of matrix metalloproteinase-9 (MMP-9). The in vivo, feces-induced peritonitis (FIP) in mice and in vitro lipopolysaccharide (LPS) treatments to isolated cardiomyocytes were used. In FIP mice, myocardial IL-33 and MMP-9 expression were increased and myocardial contractility was decreased. Myocardial function in FIP mice was improved when treated …

Characterization Of Cardiomyopathy In A Mouse Model Of Duchenne Muscular Dystrophy (Dmd) Using Echocardiography, Dce-Ct, And Pet-Fdg, Seyed Hamed Moazami

Electronic Thesis and Dissertation Repository

Duchenne muscular dystrophy (DMD) is an X-linked recessive neuromuscular disease that is the result of a loss of functional dystrophin, which causes cardiomyocyte fibrosis and death, leading to cardiomyopathy. In this thesis, I have utilized dynamic contrast-enhanced computed tomography (DCE-CT), positron emission tomography-fluorodeoxyglucose (PET-FDG), echocardiography, and traditional histology to longitudinally assess disease progression and degree of cardiomyopathy in a murine model of DMD (mdx:utrn-/-). No significant changes were observed in the blood flow, blood volume, or cardiac volume measured via DCE-CT, nor in standard uptake value (SUV) of glucose as measured by PET-FDG in the left myocardium between and within …

Development Of A Protocol To Measure Gene Expression In The Mouse Tibia, Daniel Hoover

Biomedical Engineering

Numerous molecular factors active in bone tissue direct fracture repair and remodeling which can be altered by disease conditions such as Peripheral Arterial Disease (PAD) and Osteoporosis. Methods of molecular biology are commonly applied to investigate the expression and role of these molecular factors. This project presents a robust three-step protocol for examining gene expression in the mouse tibia. The protocol begins with isolating RNA from a flash frozen tibia sample. The isolated RNA is reverse transcribed into cDNA. Finally, PCR is performed to indentify expressed genes. Establishing this protocol will allow further research into the mechanisms of bone remodeling …

Regulation Of Protein Degradation In The Heart By Amp-Activated Protein Kinase, Kedryn K. Baskin

Dissertations & Theses (Open Access)

The degradation of proteins by the ubiquitin proteasome system is essential for cellular homeostasis in the heart. An important regulator of metabolic homeostasis is AMP-activated protein kinase (AMPK). During nutrient deprivation, AMPK is activated and intracellular proteolysis is enhanced through the ubiquitin proteasome system (UPS). Whether AMPK plays a role in protein degradation through the UPS in the heart is not known. Here I present data in support of the hypothesis that AMPK transcriptionally regulates key players in the UPS, which, under extreme conditions can be detrimental to the heart. The ubiquitin ligases MAFbx /Atrogin-1 and MuRF1, key regulators of …