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Full-Text Articles in Medical Sciences

Mitochondrial Dysfunction: At The Nexus Between Alcohol-Associated Immunometabolic Dysregulation And Tissue Injury, Robert W. Siggins, Patrick M. Mcternan, Liz Simon, Flavia M. Souza-Smith, Patricia E. Molina May 2023

Mitochondrial Dysfunction: At The Nexus Between Alcohol-Associated Immunometabolic Dysregulation And Tissue Injury, Robert W. Siggins, Patrick M. Mcternan, Liz Simon, Flavia M. Souza-Smith, Patricia E. Molina

School of Medicine Faculty Publications

Alcohol misuse, directly or indirectly as a result of its metabolism, negatively impacts most tissues, including four with critical roles in energy metabolism regulation: the liver, pancreas, adipose, and skeletal muscle. Mitochondria have long been studied for their biosynthetic roles, such as ATP synthesis and initiation of apoptosis. However, current research has provided evidence that mitochondria participate in myriad cellular processes, including immune activation, nutrient sensing in pancreatic β-cells, and skeletal muscle stem and progenitor cell differentiation. The literature indicates that alcohol impairs mitochondrial respiratory capacity, promoting reactive oxygen species (ROS) generation and disrupting mitochondrial dynamics, leading to dysfunctional mitochondria …


Sexual Dimorphism In Bidirectional Sr-Mitochondria Crosstalk In Ventricular Cardiomyocytes, Richard T Clements, Radmila Terentyeva, Shanna Hamilton, Paul M L Janssen, Karim Roder, Benjamin Y Martin, Fruzsina Perger, Timothy G Schneider, Zuzana Nichtova, Anindhya S Das, Roland Veress, Beth S Lee, Do-Gyoon Kim, Gideon Koren, Matthew S Stratton, György Csordás, Federica Accornero, Andriy E Belevych, Sandor Gyorke, Dmitry Terentyev May 2023

Sexual Dimorphism In Bidirectional Sr-Mitochondria Crosstalk In Ventricular Cardiomyocytes, Richard T Clements, Radmila Terentyeva, Shanna Hamilton, Paul M L Janssen, Karim Roder, Benjamin Y Martin, Fruzsina Perger, Timothy G Schneider, Zuzana Nichtova, Anindhya S Das, Roland Veress, Beth S Lee, Do-Gyoon Kim, Gideon Koren, Matthew S Stratton, György Csordás, Federica Accornero, Andriy E Belevych, Sandor Gyorke, Dmitry Terentyev

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Calcium transfer into the mitochondrial matrix during sarcoplasmic reticulum (SR) Ca2+ release is essential to boost energy production in ventricular cardiomyocytes (VCMs) and match increased metabolic demand. Mitochondria from female hearts exhibit lower mito-[Ca2+] and produce less reactive oxygen species (ROS) compared to males, without change in respiration capacity. We hypothesized that in female VCMs, more efficient electron transport chain (ETC) organization into supercomplexes offsets the deficit in mito-Ca2+ accumulation, thereby reducing ROS production and stress-induced intracellular Ca2+ mishandling. Experiments using mitochondria-targeted biosensors confirmed lower mito-ROS and mito-[Ca2+] in female rat VCMs challenged …


Micu1 Occludes The Mitochondrial Calcium Uniporter In Divalent-Free Conditions, Macarena Rodríguez-Prados, Elena Berezhnaya, Maria Teresa Castromonte, Sergio L. Menezes-Filho, Melanie Paillard, György Hajnóczky May 2023

Micu1 Occludes The Mitochondrial Calcium Uniporter In Divalent-Free Conditions, Macarena Rodríguez-Prados, Elena Berezhnaya, Maria Teresa Castromonte, Sergio L. Menezes-Filho, Melanie Paillard, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mitochondrial Ca2+ uptake is mediated by the mitochondrial uniporter complex (mtCU) that includes a tetramer of the pore-forming subunit, MCU, a scaffold protein, EMRE, and the EF-hand regulatory subunit, MICU1 either homodimerized or heterodimerized with MICU2/3. MICU1 has been proposed to regulate Ca2+ uptake via the mtCU by physically occluding the pore and preventing Ca2+ flux at resting cytoplasmic [Ca2+] (free calcium concentration) and to increase Ca2+ flux at high [Ca2+] due to cooperative activation of MICUs EF-hands. However, mtCU and MICU1 functioning when its EF-hands are unoccupied by Ca2+ is poorly studied due to technical limitations. To overcome this …


Mechanisms Of Cigarette Smoke-Induced Mitochondrial Dysfunction In Striated Muscle And Aorta, Stephen T. Decker Apr 2023

Mechanisms Of Cigarette Smoke-Induced Mitochondrial Dysfunction In Striated Muscle And Aorta, Stephen T. Decker

Doctoral Dissertations

Cigarette Smoke is a significant cause of morbidity and mortality in the United States, accounting for over 480,000 annual deaths. Of these deaths, the most common cause of mortality in chronic smokers is cardiometabolic diseases. Likewise, a significant portion of smokers experience some form of cardiac, vascular, or metabolic dysfunction throughout their lifetime. More specifically, smoking is shown to induce mitochondrial dysfunction in these tissues, causing an increase in oxidative damage and poor overall health. However, despite the advances in the health outcomes related to cigarette smoke exposure, the mechanisms underlying mitochondrial dysfunction in striated muscle and the vasculature remain …


Opa1 Disease-Causing Mutants Have Domain-Specific Effects On Mitochondrial Ultrastructure And Fusion, Benjamín Cartes-Saavedra, Daniel Lagos, Josefa Macuada, Duxan Arancibia, Florence Burté, Marcela K. Sjöberg-Herrera, María Estela Andrés, Rita Horvath, Patrick Yu-Wai-Man, György Hajnóczky, Verónica Eisner Mar 2023

Opa1 Disease-Causing Mutants Have Domain-Specific Effects On Mitochondrial Ultrastructure And Fusion, Benjamín Cartes-Saavedra, Daniel Lagos, Josefa Macuada, Duxan Arancibia, Florence Burté, Marcela K. Sjöberg-Herrera, María Estela Andrés, Rita Horvath, Patrick Yu-Wai-Man, György Hajnóczky, Verónica Eisner

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Inner mitochondrial membrane fusion and cristae shape depend on optic atrophy protein 1, OPA1. Mutations in OPA1 lead to autosomal dominant optic atrophy (ADOA), an important cause of inherited blindness. The Guanosin Triphosphatase (GTPase) and GTPase effector domains (GEDs) of OPA1 are essential for mitochondrial fusion; yet, their specific roles remain elusive. Intriguingly, patients carrying OPA1 GTPase mutations have a higher risk of developing more severe multisystemic symptoms in addition to optic atrophy, suggesting pathogenic contributions for the GTPase and GED domains, respectively. We studied OPA1 GTPase and GED mutations to understand their domain-specific contribution to protein function by analyzing …


Acute Acat1/Soat1 Blockade Increases Mam Cholesterol And Strengthens Er-Mitochondria Connectivity., Taylor C Harned, Radu V Stan, Ze Cao, Rajarshi Chakrabarti, Henry N Higgs, Catherine C Y Chang, Ta Yuan Chang Mar 2023

Acute Acat1/Soat1 Blockade Increases Mam Cholesterol And Strengthens Er-Mitochondria Connectivity., Taylor C Harned, Radu V Stan, Ze Cao, Rajarshi Chakrabarti, Henry N Higgs, Catherine C Y Chang, Ta Yuan Chang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Cholesterol is a key component of all mammalian cell membranes. Disruptions in cholesterol metabolism have been observed in the context of various diseases, including neurodegenerative disorders such as Alzheimer's disease (AD). The genetic and pharmacological blockade of acyl-CoA:cholesterol acyltransferase 1/sterol O-acyltransferase 1 (ACAT1/SOAT1), a cholesterol storage enzyme found on the endoplasmic reticulum (ER) and enriched at the mitochondria-associated ER membrane (MAM), has been shown to reduce amyloid pathology and rescue cognitive deficits in mouse models of AD. Additionally, blocking ACAT1/SOAT1 activity stimulates autophagy and lysosomal biogenesis; however, the exact molecular connection between the ACAT1/SOAT1 blockade and these observed benefits remain …


Conditioned Place Avoidance Is Associated With A Distinct Hippocampal Phenotype, Partly Preserved Pattern Separation, And Reduced Reactive Oxygen Species Production After Stress, D. Parker Kelley, Lucas Albrechet-Souza, Shealan Cruise, Rajani Maiya, Aspasia Destouni, Siva S.V.P. Sakamuri, Alexander Duplooy, Meghan Hibicke, Charles Nichols, Prasad V.G. Katakam, Nicholas W. Gilpin, Joseph Francis Feb 2023

Conditioned Place Avoidance Is Associated With A Distinct Hippocampal Phenotype, Partly Preserved Pattern Separation, And Reduced Reactive Oxygen Species Production After Stress, D. Parker Kelley, Lucas Albrechet-Souza, Shealan Cruise, Rajani Maiya, Aspasia Destouni, Siva S.V.P. Sakamuri, Alexander Duplooy, Meghan Hibicke, Charles Nichols, Prasad V.G. Katakam, Nicholas W. Gilpin, Joseph Francis

School of Medicine Faculty Publications

Stress is associated with contextual memory deficits, which may mediate avoidance of trauma-associated contexts in posttraumatic stress disorder. These deficits may emerge from impaired pattern separation, the independent representation of similar experiences by the dentate gyrus-Cornu Ammonis 3 (DG-CA3) circuit of the dorsal hippocampus, which allows for appropriate behavioral responses to specific environmental stimuli. Neurogenesis in the DG is controlled by mitochondrial reactive oxygen species (ROS) production, and may contribute to pattern separation. In Experiment 1, we performed RNA sequencing of the dorsal hippocampus 16 days after stress in rats that either develop conditioned place avoidance to a predator urine-associated …


Mitochondria As Causes Of And Therapeutic Targets In Chronic Post-Sepsis Skeletal Muscle Weakness, Meagan Scott Kingren Jan 2023

Mitochondria As Causes Of And Therapeutic Targets In Chronic Post-Sepsis Skeletal Muscle Weakness, Meagan Scott Kingren

Theses and Dissertations--Pharmacology and Nutritional Sciences

Sepsis, or the organ damage that ensues after the body fails to properly contain a local infection, is the leading cause of in-patient hospitalization in the United States. Advances in critical care medicine over the last 20 years have enabled most sepsis patients to survive the life-threatening dysregulated immune response. However, a majority of survivors report chronic weakness and fatigue years after sepsis, and the cause of this weakness remains largely unknown. This dissertation work focused first on elucidating the major causes of post-sepsis muscle weakness (Aim 1). This aim involved a time-course study to determine when muscle weakness was …


High Energy Blue Light Induces Oxidative Stress And Retinal Cell Apoptosis, Jessica Malinsky Jan 2023

High Energy Blue Light Induces Oxidative Stress And Retinal Cell Apoptosis, Jessica Malinsky

Capstone Showcase

Blue light (BL) is a high energy, short wavelength spanning 400 to 500 nm. Found in technological and environmental forms, BL has been shown to induce photochemical damage of the retina by reactive oxygen species (ROS) production. Excess ROS leads to oxidative stress, which disrupts retinal mitochondrial structure and function. As mitochondria amply occupy photoreceptors, they also contribute to oxidative stress due to their selectively significant absorption of BL at 400 to 500 nm. ROS generation that induces oxidative stress subsequently promotes retinal mitochondrial apoptosis. BL filtering and preventative mechanisms have been suggested to improve or repair BL-induced retinal damage, …


Therapies For Mitochondrial Disorders, Kayli Sousa Smyth, Anne Mulvihill Dec 2022

Therapies For Mitochondrial Disorders, Kayli Sousa Smyth, Anne Mulvihill

SURE Journal: Science Undergraduate Research Experience Journal

Mitochondria are cytoplasmic, double-membrane organelles that synthesise adenosine triphosphate (ATP). Mitochondria contain their own genome, mitochondrial DNA (mtDNA), which is maternally inherited from the oocyte. Mitochondrial proteins are encoded by either nuclear DNA (nDNA) or mtDNA, and both code for proteins forming the mitochondrial oxidative phosphorylation (OXPHOS) complexes of the respiratory chain. These complexes form a chain that allows the passage of electrons down the electron transport chain (ETC) through a proton motive force, creating ATP from adenosine diphosphate (ADP). This study aims to explore current and prospective therapies for mitochondrial disorders (MTDS). MTDS are clinical syndromes coupled with abnormalities …


Capture At The Er-Mitochondrial Contacts Licenses Ip, Máté Katona, Ádám Bartók, Zuzana Nichtova, György Csordás, Elena Berezhnaya, David Weaver, Arijita Ghosh, Péter Várnai, David I. Yule, György Hajnóczky Nov 2022

Capture At The Er-Mitochondrial Contacts Licenses Ip, Máté Katona, Ádám Bartók, Zuzana Nichtova, György Csordás, Elena Berezhnaya, David Weaver, Arijita Ghosh, Péter Várnai, David I. Yule, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Endoplasmic reticulum-mitochondria contacts (ERMCs) are restructured in response to changes in cell state. While this restructuring has been implicated as a cause or consequence of pathology in numerous systems, the underlying molecular dynamics are poorly understood. Here, we show means to visualize the capture of motile IP3 receptors (IP3Rs) at ERMCs and document the immediate consequences for calcium signaling and metabolism. IP3Rs are of particular interest because their presence provides a scaffold for ERMCs that mediate local calcium signaling, and their function outside of ERMCs depends on their motility. Unexpectedly, in a cell model with little ERMC Ca2+ coupling, IP3Rs …


All The Brain's A Stage For Serotonin: The Forgotten Story Of Serotonin Diffusion Across Cell Membranes, Paul W. Andrews, Catherine Bosyj, Luke Brenton, Laura Green, Paul J. Gasser, Christopher A. Lowry, Virginia M. Pickel Nov 2022

All The Brain's A Stage For Serotonin: The Forgotten Story Of Serotonin Diffusion Across Cell Membranes, Paul W. Andrews, Catherine Bosyj, Luke Brenton, Laura Green, Paul J. Gasser, Christopher A. Lowry, Virginia M. Pickel

Biomedical Sciences Faculty Research and Publications

In the conventional model of serotonin neurotransmission, serotonin released by neurons in the midbrain raphe nuclei exerts its actions on forebrain neurons by interacting with a large family of post-synaptic receptors. The actions of serotonin are terminated by active transport of serotonin back into the releasing neuron, which is mediated by the serotonin reuptake transporter (SERT). Because SERT is expressed pre-synaptically and is widely thought to be the only serotonin transporter in the forebrain, the conventional model does not include serotonin transport into post-synaptic neurons. However, a large body of evidence accumulating since the 1970s has shown that serotonin, despite …


Mesoscale Structure-Function Relationships In Mitochondrial Transcriptional Condensates, Marina Feric, Azadeh Sarfallah, Furqan Dar, Dmitry Temiakov, Rohit V. Pappu, Tom Misteli Oct 2022

Mesoscale Structure-Function Relationships In Mitochondrial Transcriptional Condensates, Marina Feric, Azadeh Sarfallah, Furqan Dar, Dmitry Temiakov, Rohit V. Pappu, Tom Misteli

Department of Biochemistry and Molecular Biology Faculty Papers

In live cells, phase separation is thought to organize macromolecules into membraneless structures known as biomolecular condensates. Here, we reconstituted transcription in condensates from purified mitochondrial components using optimized in vitro reaction conditions to probe the structure-function relationships of biomolecular condensates. We find that the core components of the mt-transcription machinery form multiphasic, viscoelastic condensates in vitro. Strikingly, the rates of condensate-mediated transcription are substantially lower than in solution. The condensate-mediated decrease in transcriptional rates is associated with the formation of vesicle-like structures that are driven by the production and accumulation of RNA during transcription. The generation of RNA alters …


Stromal Vascular Fraction Restores Vasodilatory Function By Reversing Mitochondrial Dysfunction And Oxidative Stress In Aging-Induced Coronary Microvascular Disease., Evan Paul Tracy Aug 2022

Stromal Vascular Fraction Restores Vasodilatory Function By Reversing Mitochondrial Dysfunction And Oxidative Stress In Aging-Induced Coronary Microvascular Disease., Evan Paul Tracy

Electronic Theses and Dissertations

Background: Coronary Microvascular Disease (CMD) presents in aging post-menopausal women with chronic angina due to microvascular hyperconstriction. The objective was to identify mechanisms of adipose stromal vascular fraction’s (SVF) restorative effects on vasodilation. We hypothesize aging-induced CMD is caused by a) abrogated flow-mediated dilation (FMD) due to loss of nitric oxide signaling and b) ROS-dependent βADR desensitization & internalization, reversible by ameliorating mitochondrial dysfunction and oxidative stress with SVF. Methods: Coronary microvessels were isolated from female rats either young, old, or old with SVF tail-vein injection (OSVF). Pressure myography, RNA-sequencing, immunofluorescence, Western blotting, and morphological analysis were performed to …


Weight Maintenance, A Prognostic Factor That Mediates The Incidence Of Dementia: From Genetics To Etiologies, Sunny Chen Aug 2022

Weight Maintenance, A Prognostic Factor That Mediates The Incidence Of Dementia: From Genetics To Etiologies, Sunny Chen

All Dissertations

Objectives: Alzheimer’s disease-related dementia is a devastating neurodegenerative disease that affects millions of people. The goal of this work is to investigate biological mechanisms such as weight loss and mitochondrial function that can serve as prognostic factors for dementia, healthy aging, and longevity.

Methodologies: This work consists of two separate systematic literature reviews, and an investigational study. The first review examined existing studies on weight trends in dementia. The second review investigated the role of mitochondria and its associated gene TOMM40 in aging. The third paper included a nested case control analysis of weight change patterns before and …


Genetically Encoded Atp Biosensors For Direct Monitoring Of Cellular Atp Dynamics, Donnell White, Qinglin Yang Jun 2022

Genetically Encoded Atp Biosensors For Direct Monitoring Of Cellular Atp Dynamics, Donnell White, Qinglin Yang

School of Medicine Faculty Publications

Adenosine 5′-triphosphate, or ATP, is the primary molecule for storing and transferring energy in cells. ATP is mainly produced via oxidative phosphorylation in mitochondria, and to a lesser extent, via glycolysis in the cytosol. In general, cytosolic glycolysis is the primary ATP producer in proliferative cells or cells subjected to hypoxia. On the other hand, mitochondria produce over 90% of cellular ATP in differentiated cells under normoxic conditions. Under pathological conditions, ATP demand rises to meet the needs of biosynthesis for cellular repair, signaling transduction for stress responses, and biochemical processes. These changes affect how mitochondria and cytosolic glycolysis function …


Lysosomal Zn 2+ Release Triggers Rapid, Mitochondria-Mediated, Non-Apoptotic Cell Death In Metastatic Melanoma, Wanlu Du, Mingxue Gu, Meiqin Hu, Timothy Nold, Prateeksunder Pinchi, Wei Chen, Michael Ryan, Ahmed Bannaga, Haoxing Xu Jun 2022

Lysosomal Zn 2+ Release Triggers Rapid, Mitochondria-Mediated, Non-Apoptotic Cell Death In Metastatic Melanoma, Wanlu Du, Mingxue Gu, Meiqin Hu, Timothy Nold, Prateeksunder Pinchi, Wei Chen, Michael Ryan, Ahmed Bannaga, Haoxing Xu

Medical Student Research Symposium

During tumor progression, lysosome function is often maladaptively upregulated to match the high energy demand required for cancer cell hyper-proliferation and invasion. Here, we report that mucolipin TRP channel 1 (TRPML1), a lysosomal Ca2+ and Zn2+ release channel that regulates multiple aspects of lysosome function, is dramatically upregulated in metastatic melanoma cells compared with normal cells. TRPML-specific synthetic agonists (ML-SAs) are sufficient to induce rapid (within hours) lysosomal Zn2+-dependent necrotic cell death in metastatic melanoma cells while completely sparing normal cells. ML-SA-caused mitochondria swelling and dysfunction lead to cellular ATP depletion. While pharmacological inhibition or genetic silencing of TRPML1 in …


Alcohol Impairs Immunometabolism And Promotes Naïve T Cell Differentiation To Pro-Inflammatory Th1 Cd4+ T Cells, Patrick M. Mcternan, Danielle E. Levitt, David A. Welsh, Liz Simon, Robert W. Siggins, Patricia E. Molina May 2022

Alcohol Impairs Immunometabolism And Promotes Naïve T Cell Differentiation To Pro-Inflammatory Th1 Cd4+ T Cells, Patrick M. Mcternan, Danielle E. Levitt, David A. Welsh, Liz Simon, Robert W. Siggins, Patricia E. Molina

School of Medicine Faculty Publications

CD4+ T cell differentiation to pro-inflammatory and immunosuppressive subsets depends on immunometabolism. Pro-inflammatory CD4+ subsets rely on glycolysis, while immunosuppressive Treg cells require functional mitochondria for their differentiation and function. Previous pre-clinical studies have shown that ethanol (EtOH) administration increases pro-inflammatory CD4+ T cell subsets; whether this shift in immunophenotype is linked to alterations in CD4+ T cell metabolism had not been previously examined. The objective of this study was to determine whether ethanol alters CD4+ immunometabolism, and whether this affects CD4+ T cell differentiation. Naïve human CD4+ T cells were plated on anti-CD3 coated plates with soluble anti-CD28, and …


Acute Oxygen-Sensing Via Mitochondria-Generated Temperature Transients In Rat Carotid Body Type I Cells, Ryan J. Rakoczy, Clay M. Schiebrel, Christopher N. Wyatt Apr 2022

Acute Oxygen-Sensing Via Mitochondria-Generated Temperature Transients In Rat Carotid Body Type I Cells, Ryan J. Rakoczy, Clay M. Schiebrel, Christopher N. Wyatt

Neuroscience, Cell Biology & Physiology Faculty Publications

The Carotid Bodies (CB) are peripheral chemoreceptors that detect changes in arterial oxygenation and, via afferent inputs to the brainstem, correct the pattern of breathing to restore blood gas homeostasis. Herein, preliminary evidence is presented supporting a novel oxygen-sensing hypothesis which suggests CB Type I cell “hypoxic signaling” may in part be mediated by mitochondria-generated thermal transients in TASK-channel-containing microdomains. Distances were measured between antibody-labeled mitochondria and TASK-potassium channels in primary rat CB Type I cells. Sub-micron distance measurements (TASK-1: 0.33 ± 0.04 µm, n = 47 vs TASK-3: 0.32 ± 0.03 µm, n = …


Long-Lasting Impairments In Quadriceps Mitochondrial Health, Muscle Size, And Phenotypic Composition Are Present After Non-Invasive Anterior Cruciate Ligament Injury, Steven M. Davi, Ahram Ahn, Mckenzie S. White, Timothy A. Butterfield, Kate Kosmac, Oh Sung Kwon, Lindsey K. Lepley Jan 2022

Long-Lasting Impairments In Quadriceps Mitochondrial Health, Muscle Size, And Phenotypic Composition Are Present After Non-Invasive Anterior Cruciate Ligament Injury, Steven M. Davi, Ahram Ahn, Mckenzie S. White, Timothy A. Butterfield, Kate Kosmac, Oh Sung Kwon, Lindsey K. Lepley

Center for Muscle Biology Faculty Publications

Introduction: Despite rigorous rehabilitation aimed at restoring muscle health, anterior cruciate ligament (ACL) injury is often hallmarked by significant long-term quadriceps muscle weakness. Derangements in mitochondrial function are a common feature of various atrophying conditions, yet it is unclear to what extent mitochondria are involved in the detrimental sequela of quadriceps dysfunction after ACL injury. Using a preclinical, non-invasive ACL injury rodent model, our objective was to explore the direct effect of an isolated ACL injury on mitochondrial function, muscle atrophy, and muscle phenotypic transitions.

Methods: A total of 40 male and female, Long Evans rats (16-week-old) were exposed to …


Regulation Of The Protease Activity For The Mitochondrial Omi/Htra2, Simon Larson Jan 2022

Regulation Of The Protease Activity For The Mitochondrial Omi/Htra2, Simon Larson

Honors Undergraduate Theses

Human High Temperature requirement A2 (HtrA2) also known as Omi, is a serine protease located in the mitochondria with an important function in both cell survival and death. My results show the proteolytic activity of Omi/HtrA2 varies under different conditions. I characterized the optimal condition for Omi/HtrA2 protease activity using an in vitro assay system. Additionally, I identified a new allosteric regulation of Omi/HtrA2 through interaction with a specific substrate, the MUL1 protein. MUL1 is a multifunctional E3 ubiquitin ligase anchored in the outer mitochondrial membrane with domains both inside mitochondria and in the cytoplasm. The data shown here strongly …


Mitochondrial Unfolded Protein Response Regulator Atf5 In Mitochondrial Targeted Therapies In Aml, Ran Zhao Dec 2021

Mitochondrial Unfolded Protein Response Regulator Atf5 In Mitochondrial Targeted Therapies In Aml, Ran Zhao

Dissertations & Theses (Open Access)

Mitochondrial unfolded protein response (UPRmt) is an adaptive transcriptional response induced by damaged proteins accumulated in mitochondria. UPRmt signaling involves induction of mitochondrial specific chaperones and proteases such as HSP60, LonP1 and ClpP, aiding in the restoration of mitochondrial protein pool homeostasis. However, the cell-protective roles of UPRmt in the context of mitochondrial stress-induced cell death in AML has not been well explored. We demonstrate that AML cells are susceptible to mitochondrial targeted agents such as ONC201, an agonist of the mitochondrial protease ClpP, and gamitrinib, an inhibitor of mitochondrial chaperone TRAP1, however, these agents also …


Mitochondrial Phenotypes In Purified Human Immune Cell Subtypes And Cell Mixtures, Shannon Rausser, Caroline Trumpff, Marlon A. Mcgill, Alex Junker, Wei Wang, Siu-Hong Ho, Anika Mitchell, Kalpita R. Karan, Catherine Monk, Suzanne C. Segerstrom, Rebecca G. Reed, Martin Picard Oct 2021

Mitochondrial Phenotypes In Purified Human Immune Cell Subtypes And Cell Mixtures, Shannon Rausser, Caroline Trumpff, Marlon A. Mcgill, Alex Junker, Wei Wang, Siu-Hong Ho, Anika Mitchell, Kalpita R. Karan, Catherine Monk, Suzanne C. Segerstrom, Rebecca G. Reed, Martin Picard

Psychology Faculty Publications

Using a high-throughput mitochondrial phenotyping platform to quantify multiple mitochondrial features among molecularly defined immune cell subtypes, we quantify the natural variation in mitochondrial DNA copy number (mtDNAcn), citrate synthase, and respiratory chain enzymatic activities in human neutrophils, monocytes, B cells, and naïve and memory T lymphocyte subtypes. In mixed peripheral blood mononuclear cells (PBMCs) from the same individuals, we show to what extent mitochondrial measures are confounded by both cell type distributions and contaminating platelets. Cell subtype-specific measures among women and men spanning four decades of life indicate potential age- and sex-related differences, including an age-related elevation in mtDNAcn, …


Multiple Autonomous Cell Death Suppression Strategies Ensure Cytomegalovirus Fitness, Pratyusha Mandal, Lynsey Nagrani, Liliana Hernandez, Anita Louise Mccormick, Christopher Dillon, Heather Koehler, Linda Roback, Emad S Alnemri, Douglas Green, Edward Mocarski Aug 2021

Multiple Autonomous Cell Death Suppression Strategies Ensure Cytomegalovirus Fitness, Pratyusha Mandal, Lynsey Nagrani, Liliana Hernandez, Anita Louise Mccormick, Christopher Dillon, Heather Koehler, Linda Roback, Emad S Alnemri, Douglas Green, Edward Mocarski

Department of Biochemistry and Molecular Biology Faculty Papers

Programmed cell death pathways eliminate infected cells and regulate infection-associated inflammation during pathogen invasion. Cytomegaloviruses encode several distinct suppressors that block intrinsic apoptosis, extrinsic apoptosis, and necroptosis, pathways that impact pathogenesis of this ubiquitous herpesvirus. Here, we expanded the understanding of three cell autonomous suppression mechanisms on which murine cytomegalovirus relies: (i) M38.5-encoded viral mitochon-drial inhibitor of apoptosis (vMIA), a BAX suppressor that functions in concert with M41.1-encoded viral inhibitor of BAK oligomerization (vIBO), (ii) M36-encoded viral inhibitor of caspase-8 activation (vICA), and (iii) M45-encoded viral inhibitor of RIP/RHIM activation (vIRA). Following infection of bone marrow-derived macrophages, the virus initially …


A Cancer Ubiquitome Landscape Identifies Metabolic Reprogramming As Target Of Parkin Tumor Suppression, Ekta Agarwal, Aaron R Goldman, Hsin-Yao Tang, Andrew V Kossenkov, Jagadish C Ghosh, Lucia Languino, Valentina Vaira, David W Speicher, Dario C Altieri Aug 2021

A Cancer Ubiquitome Landscape Identifies Metabolic Reprogramming As Target Of Parkin Tumor Suppression, Ekta Agarwal, Aaron R Goldman, Hsin-Yao Tang, Andrew V Kossenkov, Jagadish C Ghosh, Lucia Languino, Valentina Vaira, David W Speicher, Dario C Altieri

Department of Cancer Biology Faculty Papers

Changes in metabolism that affect mitochondrial and glycolytic networks are hallmarks of cancer, but their impact in disease is still elusive. Using global proteomics and ubiquitome screens, we now show that Parkin, an E3 ubiquitin ligase and key effector of mitophagy altered in Parkinson's disease, shuts off mitochondrial dynamics and inhibits the non-oxidative phase of the pentose phosphate pathway. This blocks tumor cell movements, creates metabolic and oxidative stress, and inhibits primary and metastatic tumor growth. Uniformly down-regulated in cancer patients, Parkin tumor suppression requires its E3 ligase function, is reversed by antioxidants, and is independent of mitophagy. These data …


Mitochondrial Distribution Of Glycine Receptors In Motor Neuron Cell Lines, Katsiaryna Milashevich May 2021

Mitochondrial Distribution Of Glycine Receptors In Motor Neuron Cell Lines, Katsiaryna Milashevich

Student Theses and Dissertations

Although non-essential, glycine plays an important role in major metabolic reactions and is most known for its anti-inflammatory effects. An accumulation of contemporary research has shown that glycine is able to stabilize membrane potential using glycine receptors at the cellular level and to protect mitochondrial function directly, whether it is from inflammation, heavy metal poisoning, or ischemia-induced neuroinflammation. In this research, the existence of a hypothetical mitochondrial glycine receptor is examined. Immunofluorescence imaging was used to examine the presence of the glycine receptor subunits alpha 1 and alpha 2 in both non- differentiated and differentiated neuroblastoma cell lines. The preliminary …


Measuring Mitochondrial Respiration In Vivo: From Mouse To Human, Arthur Orchanian, Brennan Schilling, Bruce Berkowitz Phd Jan 2021

Measuring Mitochondrial Respiration In Vivo: From Mouse To Human, Arthur Orchanian, Brennan Schilling, Bruce Berkowitz Phd

Medical Student Research Symposium

Introduction: The mitochondrial energy ecosystem can be non-invasively interrogated in photoreceptors by combing a clinical tool, optical coherence tomography (OCT), with a mitochondrial protonophore (2,4 dinitrophenol, DNP). It remains unclear if only supra-clinical doses of DNP will be useful for mouse studies or if lower but clinically relevant doses of DNP would facilitate translation from mice to humans.

Methods: The experiment was a paired longitudinal design that took place over 2 days. On day 1, C57BL/6J mice were overnight dark adapted, then light-adapted for 5 h before OCT examination before regaining consciousness; a similar procedure was followed on day 2 …


Genetic Approach To Elucidate The Role Of Cyclophilin D In Traumatic Brain Injury Pathology, Ryan D. Readnower, W. Brad Hubbard, Olivia J. Kalimon, James W. Geddes, Patrick G. Sullivan Jan 2021

Genetic Approach To Elucidate The Role Of Cyclophilin D In Traumatic Brain Injury Pathology, Ryan D. Readnower, W. Brad Hubbard, Olivia J. Kalimon, James W. Geddes, Patrick G. Sullivan

Spinal Cord and Brain Injury Research Center Faculty Publications

Cyclophilin D (CypD) has been shown to play a critical role in mitochondrial permeability transition pore (mPTP) opening and the subsequent cell death cascade. Studies consistently demonstrate that mitochondrial dysfunction, including mitochondrial calcium overload and mPTP opening, is essential to the pathobiology of cell death after a traumatic brain injury (TBI). CypD inhibitors, such as cyclosporin A (CsA) or NIM811, administered following TBI, are neuroprotective and quell neurological deficits. However, some pharmacological inhibitors of CypD have multiple biological targets and, as such, do not directly implicate a role for CypD in arbitrating cell death after TBI. Here, we reviewed the …


Mechanisms And Therapeutic Interventions For Breast Cancer-Induced Fatigue And Mitochondrial Dysfunction, David Andrew Stanton Jan 2021

Mechanisms And Therapeutic Interventions For Breast Cancer-Induced Fatigue And Mitochondrial Dysfunction, David Andrew Stanton

Graduate Theses, Dissertations, and Problem Reports

According to the latest statistics from the National Cancer Institute (NCI), about 1 in 8 U.S. women (~13%) will develop invasive breast cancer over the course of their lifetime. This translates to an estimated 268,600 new cases of breast cancer for the year 2019, and these diagnoses will collectively make up 15% of all new cancer cases across all cancer types. The majority of these women will experience the often-debilitating symptom of breast cancer-induced fatigue. these patients often have difficulty performing normal activities of daily living, have decreased tolerance to traditional tumor-directed therapies, and have higher rates of cancer recurrence. …


Ssh1 Impedes P62/Sqstm1 Flux And Tau Clearance Independent Of Cofilin Activation, Cenxiao Fang Oct 2020

Ssh1 Impedes P62/Sqstm1 Flux And Tau Clearance Independent Of Cofilin Activation, Cenxiao Fang

USF Tampa Graduate Theses and Dissertations

Accumulation of toxic protein assemblies and damaged mitochondria are key features of neurodegenerative diseases, which arise in large part from clearance defects in the autophagy-lysosome system. The autophagy cargo receptor p62/SQSTM1 plays a major role in the clearance of ubiquitinated cargo through Ser403 phosphorylation by multiple kinases. However, no phosphatase is known to physiologically dephosphorylate p62 on this activating residue. RNAi-mediated knockdown and overexpression experiments using genetically encoded fluorescent reporters and defined mutant constructs in cell lines, primary neurons, and brains show that SSH1, the canonical cofilin phosphatase, mediates the dephosphorylation of phospho-Ser403-p62, thereby impairing p62 flux and phospho-tau clearance. …