Digital Commons Network^™

The Effects Of Diesel Exhaust Particle Exposure On Adipos Mitochondrial Bioenergetics And Inflammation, Cali Elizabeth Warren

Theses and Dissertations

Fine particulate matter (PM2.5) constitutes a significant component of ambient air pollution that has been implicated in the pathogenesis of metabolic disorders, including insulin resistance and type 2 diabetes. Among PM2.5 constituents, diesel exhaust particles (DEP) are prevalent particulates that infiltrate the bloodstream to drive systemic pathologies. The purpose of this study was to characterize the metabolic response of adipose tissue to DEP. We aimed to provide a comprehensive understanding by exploring mitochondrial bioenergetics, characterizing the inflammatory marker profile, including adipokines, and conducting a detailed histological analysis of adipocytes to provide valuable insights to the evolving understanding of the intricate …

Characterizing Stress Granule Regulation By Pas Kinase, Ataxin-2 And Ptc6 And Investigating The Lifespan Of Covid-19 Virus On Currency, Colleen R. Newey

Theses and Dissertations

The protein Ataxin-2 is a known positive regulator of stress granules in humans, mice and yeast (known as yeast PBP1). Due to the role that stress granules play in diseases including Amyotrophic Lateral Sclerosis (ALS) and cancer, this thesis investigates the role of Ataxin-2 and its protein binding partners in stress granule development and its effects on various metabolic phenotypes of the cell. PAS kinase is a sensory protein kinase, conserved from yeast to man, which regulates respiration and lipid biosynthesis. Our lab discovered that PAS kinase phosphorylates and activates Ataxin-2 in yeast, and that PAS kinase overexpression enhances localization …

Impaired Metabolic Flexibility In A Mouse Model Of Leigh Syndrome, Richard Sterling Mccain Jr

Theses and Dissertations

Metabolic dysfunction burdens tissues with high energy demands, particularly the brain. Leigh syndrome is a mitochondrial encephalopathy stemming from genetic defects in the electron transport chain. Leigh syndrome patients develop lactic acidosis, ataxia, bilateral necrotizing lesions in the brainstem and basal ganglia, lesion microgliosis, and eventually death due to respiratory failure. The NADH dehydrogenase [ubiquinone] iron-sulfur protein 4 (NDUFS4) knockout mouse is an established model of Leigh syndrome due to impaired assembly of mitochondrial Complex I that develops motoric deficits and necrotizing lesions in the brainstem vestibular nuclei and olfactory bulb. In addition to the Complex I-derived bioenergetics defect, altered …

The Role Of Sarcoplasmic Reticulum-Mitochondria Interplay In Shaping Pathological Phenotype Development In Cardiac Diseases Marked By Ryanodine Receptor Dysfunction, Brian Tow

Theses and Dissertations

Catecholaminergic polymorphic ventricular tachycardia (CPVT) and pre-diabetic cardiomyopathy (pre-DC) are two cardiac diseases characterized by dysfunction in sarcoplasmic reticulum (SR) Ca2+ release channel RyR2. Despite similar defects in RyR2 leading to aberrant Ca2+ release (ACR), CPVT and pre-DC display divergent pathological phenotypes. Recent findings suggest SR-mitochondria interplay could contribute to pathological development; therefore, the role of SR-mitochondria interplay in shaping intracellular Ca2+ signaling was examined in CPVT and pre-DC by pharmacologically modulating mitochondria Ca2+ handling. Mitochondria can affect cytosolic/global Ca2+ dynamics through at least two mechanisms: buffering cytosolic Ca2+, or generating ROS to modulate RyR2 functionality via posttranslational modifications. Our …

Evolution And Selection: From Suppression Of Metabolic Deficiencies To Bacteriophage Host Range And Resistance, Daniel Kurt Arens

Theses and Dissertations

The evolution and adaptation of microorganisms is so rapid it can be seen in the time frame of days. The root cause for their evolution comes from selective environmental pressures that see organisms with beneficial mutations survive otherwise deadly encounters or outperform members of its population who fail to adapt. This does not always result in strict improvement of the individual as in the case of antibiotic resistant bacteria who often display fitness tradeoffs to avoid death (see Reviews [1-3]). For example, when an ampicillin resistance gene (ampC) containing plasmid that is occasionally found in the wild was transformed into …

Cardiac Arrest And Global Ischemia Reperfusion Injury: Role Of Mitochondria And Cannabinoid Receptor 2 Signaling., Jennifer L. Bradley

Theses and Dissertations

We explored the effects of cardiac arrest on mitochondria populations and heart whole tissue lysate proteomics utilizing the Weil Institute’s in vivo rat model of cardiac arrest and cardiopulmonary resuscitation. We have discovered that brain mitochondria are more sensitive to global ischemia compared to heart mitochondria. Additionally, complex I is the most sensitive electron transport chain complex to ischemic injury and is a major control point of the rate of oxidative phosphorylation following cardiac arrest and cardiopulmonary resuscitation. Preservation of brain mitochondrial activity and function during cardiac arrest may enhance outcomes and recovery.

A recent article focusing on acute myocardial …

Deterministic Model Of The Voltage Dependent Anion Channel (Vdac) Kinetics, Viren Shah

Theses and Dissertations

The voltage-dependent anion channel (VDAC) is a voltage gated channel residing on the outer mitochondrial membrane (OMM) that facilitates the flow of metabolites between the cytosol and mitochondria. The channel is regulated through conformational changes driven by electrostatic effects along with numerous regulatory mechanisms. The aim of this study is to mechanistically model kinetics of substrate flow through VDAC and incorporate them into existing mechanistic computational models of mitochondrial function. The resulting model is used in two ways: 1) to establish mitochondrial bioenergetics (conductance, permeability, and current/flux) under physiological conditions, and 2) to conduct perturbations simulating the effect of altered …

Acetoacetate Enhances Oxidative Metabolism And Response To Toxicants Of Cultured Renal Cells, Trudi Maria Denoon

Theses and Dissertations

In vitro methods can be cost effective and facilitate large scale drug screening in the pharmaceutical industry. Renal proximal tubular cells have been a prime target for drug induced toxicity. LLC-PK1 cells possess many transport functions of the proximal tubule epithelia, however, its energy metabolism differs from the highly oxidative tubule metabolism in vivo. This may impact its reliability in predicting toxicity. Modulating the growth media composition has been shown to shift cultured liver and muscle cells from high glycolytic activity to increased oxidative metabolism, but few studies have been done on renal cells. This study is designed to test …

Examining The Relationship Between Yoga Participation And Health. You Down, Dog?, Bethany Forseth Hanson

Theses and Dissertations

The prevalence of debilitating chronic diseases, such as cardiovascular disease (CVD) and Alzheimer’s disease, are increasing in the United States. Inflammation, mitochondrial dysfunction, stress and depression are common pathologies associated with these chronic diseases. Many individuals engage in yoga because they believe it will improve their health. However, research examining the impact of yoga on markers of health associated with chronic diseases is limited and often reports conflicting results. Therefore, the purpose of this dissertation is to examine the relationship between yoga and inflammation, protein content of oxidative phosphorylation complexes, stress and depression, which may support the use of lifestyle …

Effects Of Feeding Endophyte-Infected Tall Fescue Seed On Beef Cattle Performance, Hepatic Enzyme Activity, Lipid Oxidation, Metmyoglobin Reductase Activity, And Mitochondrial Lipid Composition, Brandon J. Mcclenton

Theses and Dissertations

The objective of this study was to determine the effects of feeding endophyte-infected tall fescue seed to Angus steers on average daily gain, carcass characteristics, ergovaline concentration, lipid oxidation, hepatic enzyme activity, metmyoglobin reductase activity, and mitochondrial lipid composition. Animals were blocked into light, medium, and heavy body weight groups and were randomly assigned to either a KY31 seed treatment (6796 ppb ergovaline; 20 MUg/kg BW; E+; n = 6) or a KY32 control (< 100 ppb; E-; n = 6). There was a 2-way treatment × time interaction effect on ADG (P < 0.001). The E+ steers gained 0.56 kg/d less than the E- steers from d 0 to 14 (P < 0.001) until d 56 (ADG difference = 0.27 kg/d; P = 0.007) but both group had similar ADG from d 70 till the end of the feeding period 2 (ADG = 0.53 kg/d; P > 0.070). No difference in carcass characteristics were found between the E+ and E- steers by at the time of ultrasonography (P >= 0.120) or at …

A High Fructose Diet Alters Affective-Like Behavior And Metrics Of Synaptic Mitochondrial Function Differentially In Male And Female Rats, Alix H. Kloster

Theses and Dissertations

Fructose consumption has become a normalized part of the standard American diet over the past 40 years. While fructose consumption is a known risk factor of metabolic syndrome, there is increasing evidence that fructose consumption influences brain and behavior. Recently, more interest has been focused on mitochondrial dysfunction as a potential link between metabolic stress and modifications of the central nervous system. Mitochondria are in the unique position of both regulating and being vulnerable to alterations in energy homeostasis. Sex-differences are well categorized in the presentation of metabolic symptoms associated with excessive fructose consumption. Thus, it is important to characterize …

Modulation Of Electron Transport By Metformin In Cardiac Protection: Role Of Complex I, Ahmed Abdul Hussein Mohsin

Theses and Dissertations

Modulation of mitochondrial complex I during reperfusion reduces cardiac injury. Complex I exists in two structural states: active (A) and deactive (D) with transition from A→D during ischemia. Reperfusion reactivates D→A with an increase in ROS production. Metformin preserves the D-Form. Our aim was to study the contribution of maintenance of deactivation of complex I during early reperfusion by metformin to protect against ischemia reperfusion injury. Our results showed that metformin decreased H9c2 cardiomyoblast apoptosis and total cell death following simulated ischemia for six hours followed by reoxygenation for twenty four hours compared to untreated cells. Reactive oxygen species (ROS) …

Acylation Of Superoxide Dismutase 1 (Sod1) At K122 Alters Sod1 Localization And Sod1-Mediated Inhibition Of Mitochondrial Respiration, Nathan William Rodriguez

Theses and Dissertations

Cu/Zn Superoxide Dismutase (SOD1), is a ubiquitous antioxidant enzyme with several emerging roles outside of its canonical function. SOD1 is also emerging in central roles in cancer and neurodegenerative pathologies. Little is known about SOD1 regulation, particularly at a post-translational level. Post-translational modifications (PTMs) play an important role in enabling proteins to rapidly respond to their environment. Therefore, identifying specific PTMs involved in protein regulation represents a powerful opportunity to interfere with any associated pathologies. This work employs proteomics to identify mechanisms of post-translation regulation on cell survival signaling proteins. We focused on SOD1, which protects cells from oxidative stress. …

Effects Of Curcumin And Ursolic Acid On The Mitochondrial Coupling Efficiency And Hydrogen Peroxide Emission Of Intact Skeletal Myoblasts, Daniel J. Tueller

Theses and Dissertations

Curcumin is a natural compound that improves blood glucose management. While some evidence from isolated mitochondria indicates that curcumin uncouples electron transport from oxidative phosphorylation, the effects of curcumin on mitochondrial respiration and hydrogen peroxide emission in intact skeletal muscle cells are not known. By assessing rates of oxygen consumption, we demonstrated for the first time that curcumin (40 µM) reduced the mitochondrial coupling efficiency (percentage of oxygen consumption that supports ATP synthesis) of intact skeletal muscle cells. A 30-minute incubation with curcumin decreased mitochondrial coupling efficiency by 17.0 ± 0.4% relative to vehicle (p < 0.008). Curcumin also decreased the rate of hydrogen peroxide emission by 43 ± 13% compared to vehicle (p < 0.05). Analysis of cell respiration in the presence of curcumin revealed a 40 ± 4% increase in the rate of oxygen consumption upon curcumin administration (p < 0.05 compared to vehicle). In additional experiments, no difference in mitochondrial coupling efficiency was observed between vehicle- and curcumin-pretreated cells after permeabilization of cell membranes (p > 0.7). The possibility of synergistic …

Oxidative Insults Disrupt Mitochondrial Dynamics, Iraselia A. Garcia

Theses and Dissertations

Mitochondria form an organellar network to provide ATP to the cell. Mitochondrial DNA (mtDNA) combines with nuclear DNA to encode polypeptides critical to forming the complexes of oxidative phosphorylation in the mitochondrial inner membrane, which generate a transmembrane potential (ΔΨm) to synthesize ATP. This ΔΨm is required to maintain mitochondria fission/fusion dynamics: organellar fusion (mediated by OPA1) and fission events (mediated by DRP1) coordinately regulate mitochondrial dynamics. While oxidative stress correlates with mitochondrial dysfunction, it is unclear how oxidants affect mitochondrial structure/function homeostasis. This project seeks to establish and examine the impact of reactive oxygen species (ROS) on mitochondrial dynamics. …

Insulin And Ketones: Their Roles In Brain Mitochondrial Function, Sheryl Teresa Carr

Theses and Dissertations

The prevalence of both Type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) is increasing worldwide, and the trends are unfortunately expected to continue. AD has recently been tied with mitochondrial dysfunction and insulin resistance, creating a mechanistic tie between AD and T2DM. Unfortunately, insulin resistance is often increased with aging and therefore, all individuals are at risk of brain mitochondrial dysfunction. Without proper mitochondrial function, the brain will degenerate, causing impaired cognitive function and reduced quality of life. The purpose of this study is two-fold: first, to understand the role of ceramides in insulin-induced brain mitochondrial dysfunction, and; second, …

Insulin And Ketones: Their Roles In Brain Mitochondrial Function, Sheryl Teresa Carr

Theses and Dissertations

The prevalence of both Type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) is increasing worldwide, and the trends are unfortunately expected to continue. AD has recently been tied with mitochondrial dysfunction and insulin resistance, creating a mechanistic tie between AD and T2DM. Unfortunately, insulin resistance is often increased with aging and therefore, all individuals are at risk of brain mitochondrial dysfunction. Without proper mitochondrial function, the brain will degenerate, causing impaired cognitive function and reduced quality of life. The purpose of this study is two-fold: first, to understand the role of ceramides in insulin-induced brain mitochondrial dysfunction, and; second, …

Insulin Treatment Increases Myocardial Ceramide Accumulation And Disrupts Cardiometabolic Function, Aimee Elizabeth Hodson

Theses and Dissertations

Prevalence of diabetes, especially type 2 diabetes mellitus (T2DM) is increasing worldwide. Millions of people are already affected by T2DM and estimates predict over half a billion people will likely be suffering from the disease by 2030. T2DM is associated with an increased risk of developing cardiovascular disease. Cardiovascular dysfunction is the leading cause of mortality among type 2 diabetics. Treatment for T2DM has changed over time. Though it was once known as insulin independent, a large portion of type 2 diabetics are now treated with insulin injections. However, type 2 diabetics treated with insulin are more likely to suffer …

Functional Significance Of Mtdna Cytosine Modification Tested By Genome Editing, Jason M. Robinson

Theses and Dissertations

The field of epigenetics is gaining popularity and speed, due in part to its capability to answer lingering questions about the root cause of certain diseases. Epigenetics plays a crucial role in regulation of the cell and cell survival, particularly by cytosine methylation. It remains controversial if DNMT’s which facilitate methylation are present in mammalian mitochondria and what the functional significance they may have on modification of mitochondrial DNA. CRISPR-Cas9 technology enabled genome editing to remove the MTS (mitochondrial targeting sequence) from DNMT1 of HCT116 cells, purposefully minimizing effects on nuclear cytosine methylation, while exclusively impacting mitochondrial modification. Removal of …

Dynamic Regulation Of Mitochondrial Stat3 And Its Association With Cypd, Jeremy A. Meier

Theses and Dissertations

In recent years, a number of nuclear transcription factors have been shown to be present in the mitochondria where they have distinct roles in regulating mitochondrial function. Signal Transducer and Activator of Transcription 3 (STAT3), classically activated by the JAK family of receptor associated tyrosine kinases to drive nuclear gene expression, is one such transcription factor with a unique mitochondrial role. There, it has been shown to support oxidative phosphorylation, regulate mitochondrial-encoded transcripts, and be key for the transformation and growth of a number of different cancers. Despite its well-characterized functional importance at the level of the mitochondria, the mechanism …

A Mechanistic Study Of An Ipsc Model For Leigh’S Disease Caused By Mtdna Mutataion (8993 T>G), John P. Galdun

Theses and Dissertations

Mitochondrial diseases encompass a broad range of devastating disorders that typically affect tissues with high-energy requirements. These disorders have been difficult to diagnose and research because of the complexity of mitochondrial genetics, and the large variability seen among patient populations. We have devised and carried out a mechanistic study to generate a cell based model for Leigh’s disease caused by mitochondrial DNA mutation 8993 T>G. Leigh’s disease is a multi-organ system disorder that depends heavily on the mutation burden seen within various tissues. Using new reprogramming and sequencing technologies, we were able to show that Leigh’s disease patient fibroblasts …

Determining The Effect Of Knocking Out Microrna-21 On Subsarcolemmal And Interfibrillar Mitochondria, Madhur Batra

Theses and Dissertations

Type 2 diabetes mellitus is a growing problem across the world and has significant pathological changes associated with it, including diabetic cardiomyopathy, wherein cardiac function is reduced. MicroRNA-21 has been shown to play a role in both the heart and diabetes so it was thought that knocking out miR-21 could have a protective effect on oxidative phosphorylation function in diabetic mice. Subsarcolemmal and interfibrillar mitochondria were isolated from adult male WT, miR-21 KO, db/db, and double knockout mice (db/db and miR-21 KO cross) and evaluated for function. Knocking out miR-21 in diabetic mice showed a restorative effect in Complex I …

Cigarette Smoke Increases Cardiomyocyte Ceramide Accumulation And Inhibits Mitochondrial Respiration, Trevor Stanley Tippetts

Theses and Dissertations

Cigarette smoking is a common and lethal worldwide habit, with considerable mortality stemming from its deleterious effects on heart function. While current theories posit altered blood lipids and fibrinogen metabolism as likely mediators, none have explored the role of the sphingolipid ceramide in exacerbating heart function with smoke exposure. Ceramide production is a consequence of cigarette smoke in the lung, and considering ceramide's harmful effects on mitochondrial function, we sought to elucidate the role of ceramide in mediating smoke-induced altered heart mitochondrial respiration. Lung cells were exposed to cigarette smoke extract and heart cells were exposed to the lung-cell conditioned …

The Role Of Receptors For Advanced Glycation End-Products (Rage) And Ceramide In Cardiovascular Disease, Michael Bruce Nelson

Theses and Dissertations

Type 2 diabetes and cigarette smoke exposure are associated with an increased risk of cardiovascular complications. The role of advanced glycation end-products (AGEs) is already well-established in numerous comorbidities including cardiomyopathy. Given the role of AGEs and their receptor, RAGE, in activating inflammatory pathways, we sought to determine whether ceramides could be a mediator of RAGE-induced altered heart mitochondrial function. Using an in vitro model, we treated H9C2 cardiomyocytes with carboxy-methyl lysine-BSA, followed by mitochondrial respiration assessment. We found that mitochondrial respiration was significantly impaired in AGE-treated cells, but not when co-treated with myriocin, an inhibitor of de novo …

Mitochondrial Biogenesis And Electrical Properties Of Hpsc-Derived Motor Neurons, Laura O'Brien

Theses and Dissertations

Human pluripotent stem cells (hPSCs), including human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) hold great promise in the fields of drug development and regenerative medicine. If iPSCs reprogrammed from patient cells replicate what is seen in vivo they may be used as a model of disease. A process that is disrupted in many neurodegenerative diseases is mitochondrial biogenesis. One of these diseases is amyotrophic lateral sclerosis (ALS), which is characterized by loss of motor neurons in the brain and spinal cord. Differentiation of hPSCs into motor neurons offers a way to study a previous unavailable cell …

Mitochondrial Therapeutics During Ischemia-Reperfusion; Modulation Of Complex I: Effect Of Metformin., Shawn Y. Sunu

Theses and Dissertations

The modulation of the electron transport during ischemia-reperfusion has been shown to be protective. We hypothesized that metformin, a Complex I inhibitor, may exhibit characteristics of a pharmacological agent that could achieve long-term therapeutic intervention against ischemia-reperfusion injury. Mitochondria were harvested from adult male mice and incubated with or without metformin at 30^oC for 15 minutes, while being shaken at 300 rpm. Metformin decreased Complex I oxidative phosphorylation and Complex I activity. However, metformin also increased injury and decreased the maximum membrane potential. Even though there was a decrease in maximum membrane potential, the proton motive force (PMF) …

Ferric Reductases And Transporters That Contribute To Mitochondrial Iron Homeostasis, Anshika Jain

Theses and Dissertations

Iron (Fe) is the fourth most abundant element in the Earth’s crust, yet the availability of Fe to plants is often limited. This is because in most soil types, Fe precipitates as ferric-oxyhydroxy complexes, making it unavailable for uptake by plants. While the mechanisms involved in Fe uptake from the soil are relatively well understood, the mechanisms involved in its further distribution to the aerial portion of the plant and to subcellular compartments are not fully understood. During Fe deprivation, plants up-regulate root Fe acquisition machinery. How plants sense Fe deprivation and tie the Fe status of the plant to …

The Role Of Ceramides In Mediating Endotoxin-Induced Mitochondrial Disruption, Melissa Ellen Hansen

Theses and Dissertations

Ceramides are sphingolipids that serve as important second messengers in an increasing number of stress-induced pathways. Ceramide has long been known to affect the mitochondria, altering both morphology and physiology. Lipopolysaccharide (LPS) is a prevalent circulating inflammatory agent in obesity, potentially mediating some of the pathologies associated with weight gain. Given previous findings of TLR4-mediated ceramide accrual and ceramide-mediated mitochondrial disruption, we questioned whether ceramide is necessary for LPS-induced mitochondrial disruption. We found that LPS treatment increased gene transcript levels of ceramide synthesis enzymes and mitochondrial fission proteins and increased ceramide content in cultured myotubes and in mouse tissue. Mitochondrial …

Relationship Of Mitochondrial Enzymes To Fatigue Intensity And Health-Related Quality Of Life In Men With Prostate Cancer Receiving External Beam Radiation Therapy, Kristin Filler

Theses and Dissertations

Introduction: Cancer-related fatigue is often described by patients as a lack of energy, mental or physical tiredness, diminished endurance, and prolonged recovery after activity. Etiologic mechanisms underlying CRF are not well understood. Methods: A literature review was conducted to examine studies that had investigated the association of mitochondrial dysfunction with fatigue. The major conclusion from this review was that alterations in energy metabolism may contribute to fatigue. Therefore, the dissertation study focused on laboratory techniques for measuring mitochondrial oxidative phosphorylation enzymes (complexes I-V) and a mitochondrial-specific oxidative stress marker (superoxide dismutase 2 [SOD2]). The primary aim of the dissertation research …

The Effect Of Isocitrate Dehydrogenase On The Epigenetics Of Human Mitochondrial Dna, John Strang

Theses and Dissertations

Aberrant metabolism has become an increasingly interesting area of cancer biology. In many cancers including lower grade glioma, glioblastomas and some leukemias, a mutation in the metabolic enzyme Isocitrate Dehydrogenase (IDH), has been found in more than 70% of cases and has been shown to lead to a distinct hypermethylator phenotype. IDH commonly converts isocitrate to alpha-ketoglutarate in normal cell metabolism. Three isoforms of this enzyme are found in humans: IDH1, IDH2 and IDH3. Studies on IDH1, the cytosolic isoform, have revealed that mutations in the enzyme’s binding site lead to a novel gain of function: the synthesis of an …