Medicine and Health Sciences Commons^™

Metabolic Regulation Of Myocardial Adaptation To Exercise., Andrew Alan Gibb

Electronic Theses and Dissertations

While the benefits of exercise affect several organs, a significant adaptive response occurs within the heart. Exercise promotes cardiac growth, increases angiogenesis, and enhances cardiac function and these adaptations are associated with a cardioprotective phenotype. Additionally, extensive evidence shows that exercise dynamically regulates myocardial metabolism. This can be attributed to both changes in hormonal stimulation, increases in bioenergetic demand, and the bioavailability of circulating substrates. However, it is unclear whether these changes in metabolism contribute to physiologic cardiac growth. We reason that exercise-induced changes in metabolism are required to balance the catabolic and anabolic reactions needed for growth. Specifically, we …

Mechanism Of Transcription Anti-Termination In Human Mitochondria., Hauke S Hillen, Andrey V Parshin, Karen Agaronyan, Yaroslav I Morozov, James J Graber, Aleksandar Chernev, Kathrin Schwinghammer, Henning Urlaub, Michael Anikin, Patrick Cramer, Dmitry Temiakov

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

In human mitochondria, transcription termination events at a G-quadruplex region near the replication origin are thought to drive replication of mtDNA by generation of an RNA primer. This process is suppressed by a key regulator of mtDNA-the transcription factor TEFM. We determined the structure of an anti-termination complex in which TEFM is bound to transcribing mtRNAP. The structure reveals interactions of the dimeric pseudonuclease core of TEFM with mobile structural elements in mtRNAP and the nucleic acid components of the elongation complex (EC). Binding of TEFM to the DNA forms a downstream "sliding clamp," providing high processivity to the EC. …

Ros Control Mitochondrial Motility Through P38 And The Motor Adaptor Miro/Trak., Valentina Debattisti, Akos A. Gerencser, Masao Saotome, Sudipto Das, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mitochondrial distribution and motility are recognized as central to many cellular functions, but their regulation by signaling mechanisms remains to be elucidated. Here, we report that reactive oxygen species (ROS), either derived from an extracellular source or intracellularly generated, control mitochondrial distribution and function by dose-dependently, specifically, and reversibly decreasing mitochondrial motility in both rat hippocampal primary cultured neurons and cell lines. ROS decrease motility independently of cytoplasmic [Ca2+], mitochondrial membrane potential, or permeability transition pore opening, known effectors of oxidative stress. However, multiple lines of genetic and pharmacological evidence support that a ROS-activated mitogen-activated protein kinase (MAPK), p38α, is …

Hne-Modified Proteins In Down Syndrome: Involvement In Development Of Alzheimer Disease Neuropathology, Eugenio Barone, Elizabeth Head, D. Allan Butterfield, Marzia Perluigi

Sanders-Brown Center on Aging Faculty Publications

Down syndrome (DS), trisomy of chromosome 21, is the most common genetic form of intellectual disability. The neuropathology of DS involves multiple molecular mechanisms, similar to AD, including the deposition of beta-amyloid (Aβ) into senile plaques and tau hyperphosphorylating in neurofibrillary tangles. Interestingly, many genes encoded by chromosome 21, in addition to being primarily linked to amyloid-beta peptide (Aβ) pathology, are responsible for increased oxidative stress (OS) conditions that also result as a consequence of reduced antioxidant system efficiency. However, redox homeostasis is disturbed by overproduction of Aβ, which accumulates into plaques across the lifespan in DS as well as …

The Influence Of A Kdt501, A Novel Isohumulone, On Adipocyte Function In Humans, Brian S. Finlin, Beibei Zhu, Bernard P. Kok, Cristina Godio, Philip M. Westgate, Neile Grayson, Robert Sims, Jeffrey S. Bland, Enrique Saez, Philip A. Kern

Internal Medicine Faculty Publications

Objective: In a phase II clinical trial in nine obese, insulin-resistant humans, we observed that treatment with KDT501, a novel isohumulone drug, increased total and high-molecular weight (HMW) adiponectin in plasma. The objective was to determine whether KDT501 increased adiponectin secretion from subcutaneous white adipose tissue (SC WAT) and the underlying mechanism(s).

Methods: Nine obese participants with either prediabetes or with normal glucose tolerance plus three features of metabolic syndrome were part of the study. SC WAT biopsies were performed before and after 28 days of KDT501 treatment in a clinical research setting. In addition, a cold stimulus was used …

Maternal Nicotine Exposure Leads To Decreased Cardiac Protein Disulfide Isomerase And Impaired Mitochondrial Function In Male Rat Offspring., Nicole G Barra, Maria Lisyansky, Taylor A Vanduzer, Sandeep Raha, Alison C Holloway, Daniel B Hardy

Physiology and Pharmacology Publications

Smoking throughout pregnancy can lead to complications during gestation, parturition and neonatal development. Thus, nicotine replacement therapies are a popular alternative thought to be safer than cigarettes. However, recent studies in rodents suggest that fetal and neonatal nicotine exposure alone results in cardiac dysfunction and high blood pressure. While it is well known that perinatal nicotine exposure causes increased congenital abnormalities, the mechanisms underlying longer-term deficits in cardiac function are not completely understood. Recently, our laboratory demonstrated that nicotine impairs placental protein disulfide isomerase (PDI) triggering an increase in endoplasmic reticulum stress, leading us to hypothesize that this may also …

Mitochondrial Dna Heteroplasmy In Cardiac Tissue From Individuals With And Without Coronary Artery Disease, Erik Hefti, Javier G. Blanco

Harrisburg University Faculty Works

The cellular environment associated with coronary artery disease (CAD) can lead to mitochondrial DNA (mtDNA) damage. Mitochondrial variants in some copies of mtDNA (heteroplasmy) and mtDNA content are potential genetic biomarkers for CAD-associated disease states. Massively parallel sequencing and qRT-PCR techniques were used to measure heteroplasmic variants and mtDNA content in heart samples from donors with (n = 8) and without (n = 7) documented CAD. Both groups showed increased numbers of heteroplasmic mtDNA variants in the control region (CR) (p < .0010, ANOVA). The donors with CAD displayed a 41.07% increase in heteroplasmic mtDNA variant number in the CR (p = .043), an 87.50% increase in the number of heteroplasmic mtDNA deletions (p = …

Temperature Induces Significant Changes In Both Glycolytic Reserve And Mitochondrial Spare Respiratory Capacity In Colorectal Cancer Cell Lines, Mihail I. Mitov, Jennifer W. Harris, Michael Alstott, Yekaterina Y. Zaytseva, B. Mark Evers, D. Allan Butterfield

Markey Cancer Center Faculty Publications

Thermotherapy, as a method of treating cancer, has recently attracted considerable attention from basic and clinical investigators. A number of studies and clinical trials have shown that thermotherapy can be successfully used as a therapeutic approach for various cancers. However, the effects of temperature on cancer bioenergetics have not been studied in detail with a real time, in a microplate, label-free detection approach.

This study investigate how changes in temperature affect the bioenergetics characteristics (mitochondrial function and glycolysis) of three colorectal cancer (CRC) cell lines utilizing the Seahorse XF96 technology. Experiments were performed at 32°C, 37°C and 42°C using assay …

Mitochondrial Dynamics Controls T Cell Fate Through Metabolic Programming, Michael Buck

Arts & Sciences Electronic Theses and Dissertations

Activated effector T (TE) cells augment anabolic pathways of metabolism, such as aerobic glycolysis, while memory T (TM) cells engage catabolic pathways, like fatty acid oxidation (FAO). However, signals that drive these differences remain unclear. Mitochondria are metabolic organelles that actively transform their ultrastructure. Therefore, we questioned whether mitochondrial dynamics controls T cell metabolism. We show that TE cells have punctate mitochondria, while TM cells maintain fused networks. The fusion protein Opa1 is required for TM, but not TE cells after infection, and enforcing fusion in TE cells imposes TM cell characteristics and enhances antitumor function. Our data suggest that, …

Enhancement Of Reactive Oxygen Species Production And Chlamydial Infection By The Mitochondrial Nod-Like Family Member Nlrx1, Ali A. Abdul-Sater, Najwene Saïd-Sadier, Verissa M. Lam, Bhavni Singh, Matthew A. Pettengill, Fraser Soares, Ivan Tattoli, Simone Lipinski, Stephen E. Girardin, Philip Rosenstiel, David M. Ojcius

David M. Ojcius

Chlamydia trachomatis infections cause severe and irreversible damage that can lead to infertility and blindness in both males and females. Following infection of epithelial cells, Chlamydia induces production of reactive oxygen species (ROS). Unconventionally, Chlamydiae use ROS to their advantage by activating caspase-1, which contributes to chlamydial growth. NLRX1, a member of the Nod-like receptor family that translocates to the mitochondria, can augment ROS production from the mitochondria following Shigella flexneri infections. However, in general, ROS can also be produced by membrane-bound NADPH oxidases. Given the importance of ROS-induced caspase-1 activation in growth of the chlamydial vacuole, we investigated the …

Metabolic Dysfunction Underlying Autism Spectrum Disorder And Potential Treatment Approaches, Ning Cheng, Jong M. Rho, Susan A. Masino

Faculty Scholarship

Autism spectrum disorder (ASD) is characterized by deficits in sociability and communication, and increased repetitive and/or restrictive behaviors. While the etio-pathogenesis of ASD is unknown, clinical manifestations are diverse and many possible genetic and environmental factors have been implicated. As such, it has been a great challenge to identify key neurobiological mechanisms and to develop effective treatments. Current therapies focus on co-morbid conditions (such as epileptic seizures and sleep disturbances) and there is no cure for the core symptoms. Recent studies have increasingly implicated mitochondrial dysfunction in ASD. The fact that mitochondria are an integral part of diverse cellular functions …

The Mitochondrial Ca(2+) Uniporter: Structure, Function, And Pharmacology., Jyotsna Mishra, Bong Sook Jhun, Stephen Hurst, Jin O-Uchi, György Csordás, Shey-Shing Sheu

Center for Translational Medicine Faculty Papers

Mitochondrial Ca(2+) uptake is crucial for an array of cellular functions while an imbalance can elicit cell death. In this chapter, we briefly reviewed the various modes of mitochondrial Ca(2+) uptake and our current understanding of mitochondrial Ca(2+) homeostasis in regards to cell physiology and pathophysiology. Further, this chapter focuses on the molecular identities, intracellular regulators as well as the pharmacology of mitochondrial Ca(2+) uniporter complex.

Autophagy In Mitochondrial Quality Control And Proteotoxicity In Neurons, Matthew Redmann

All ETDs from UAB

Parkinson’s disease (PD) is the 2nd most common neurodegenerative disorder with aging as a significant risk factor. Sharing with aging brains, postmortem PD brains exhibit cellular deficits including autophagic dysfunction, mitochondrial dysfunction, and intracellular protein aggregates of alpha-synuclein. This dissertation will focus on the interplay between these key disease features. To that end, we coupled primary cortical neuronal cultures from either rats or mice with Seahorse extracellular flux, metabolomics and biochemical techniques. Autophagy is an important cell recycling program responsible for the clearance of damaged proteins and organelles. Bafilomycin A1 and chloroquine are compounds that inhibit autophagy by targeting the …

Activation Of Ampk To Diminish Sepsis-Induced Lung Injury, Nathaniel Bone

All ETDs from UAB

Sepsis is the most frequent cause of death of hospitalized patients in modern ICUs. Severe infection, trauma, hemorrhage, burns, and surgery are significant causes of multi-organ injury and immune dysfunction that in turn primes for a high risk of secondary lung infections. In addition to detrimental inflammation, sepsis is linked to loss of metabolic plasticity due to mitochondrial dysfunction in immune cells and lung tissue. In particular, mitochondrial failure in lungs of critically ill septic patients is correlated with high mortality rates. We proposed that AMP-activated protein kinase (AMPK) activation, a major bioenergetic sensor and metabolic regulator, is a plausible …

The Impact Of Mitochondrial Genetic Background On Development Of Complex Multifactorial Diseases, Alexander Wendell Bray

All ETDs from UAB

Complex multifactorial diseases such as cardiovascular disease (CVD) and cancer are a pervasive and inescapable component of modern society. However, the genetic elements that modulate individual susceptibility to these diseases remain poorly defined. Excessive mitochondrial oxidant production has been implicated in the initiation and progression of both CVD and cancer. Moreover, polymorphisms inherited on the mitochondria genome appear to influence mammalian mitochondrial function and oxidant generation. In the present study, mitochondrial-nuclear-eXchange (MNX) mice were used to directly assess the contribution of mitochondrial DNA (mtDNA) polymorphisms to atherosclerosis in the apoE deficient (apoE-/-) mouse model of hypercholesterolemia induced atherogenesis. ApoE-/- mice …