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Full-Text Articles in Physiology

Does Vdac2 Have A Bh3 Domain?, Lillian Ferkany May 2023

Does Vdac2 Have A Bh3 Domain?, Lillian Ferkany

Honors Theses

Mitochondrial outer membrane permeabilization (MOMP) by Bax oligomerization triggers apoptosis. BCl-2 family proteins, classified as BH3 only proteins, pro-survival proteins, or pro-apoptotic proteins, control apoptosis partly through their agonist or antagonistic effects on Bax, which are mediated by their conserved BH3 domains. All BH3 domains form an alpha helix containing 5-7 conserved hydrophobic residues, designated H0-H5, and one conserved aspartic acid that drive interaction with Bax and other ‘multi-domain’ BCl-2 members. BH3 agonists induce Bax oligomerization, while BH3 antagonists sequester Bax to prevent MOMP. We discovered that voltage dependent anion channels (VDACs) in the MOM contain a putative BH3-like domain …


Characterizing The Effects Of Pyrroloquinoline Quinone (Pqq) Supplementation On Skeletal Muscle Mitochondrial Function And Myogenesis During Oxidative Stress And Iugr., Allyson J. Wood May 2021

Characterizing The Effects Of Pyrroloquinoline Quinone (Pqq) Supplementation On Skeletal Muscle Mitochondrial Function And Myogenesis During Oxidative Stress And Iugr., Allyson J. Wood

Electronic Thesis and Dissertation Repository

Intrauterine growth restriction (IUGR) affects 10-15% of births and is associated with placental insufficiency (PI), resulting in fetal oxidative stress (OS). This OS is a factor in the predisposition to postnatal noncommunicable disease (NCD) of which muscle mitochondrial dysfunctional is a key aspect. Pyrroloquinoline quinone (PQQ), an antioxidant-like compound, is capable of OS reduction and promotes mitochondrial function, though limited research has focused on its effects in in utero skeletal muscle. This study sought to investigate the impact of in vitro H2O2, a model of OS, and an in vivo model of OS associated IUGR, with …


Seasonal Variation In Mitochondrial Bioenergetics Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow Midwest River, Derick Isaac Lamptey Jan 2020

Seasonal Variation In Mitochondrial Bioenergetics Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow Midwest River, Derick Isaac Lamptey

Masters Theses

As average global temperature increase, the frequency and magnitude of extreme temperatures in shallow aquatic ecosystems are more ubiquitous. In order to understand how these changing thermal regimes affect aquatic ectotherms, it is essential to develop studies evaluating the response of ectotherms to seasonal fluctuating thermal regimes. Previous studies on fluctuating temperature regimes have reported an increased physiological stress leading to morphological, behavioral and biochemical adaptations. From the latter, the adaptive capacity and seasonal performance associated with optimal function of the oxidative phosphorylation system (OXPHOS) are key for species persistence. However, studies on this matter are scarce. This study explores …


A Dedicated Chaperone Mediates The Safe Transfer Of Mitoribosomal Proteins To Their Site Of Assembly, Gabrielle Ashley Hillman May 2019

A Dedicated Chaperone Mediates The Safe Transfer Of Mitoribosomal Proteins To Their Site Of Assembly, Gabrielle Ashley Hillman

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial ribosomes are functionally specialized for the synthesis of several essential inner membrane proteins of the respiratory chain. While remarkable progress has recently been made towards understanding the structure of mitoribosomes, the unique pathways and factors that facilitate their biogenesis remain largely unknown. This dissertation defines the physiological role of an evolutionarily conserved yeast protein called Mam33 in mitochondrial ribosome assembly. The biomedical relevance of this finding stems from the fact that mutations or changes in its expression of the human ortholog p32 result in mitochondrial dysfunction. In human patients, bi-allelic mutations cause severe multisystemic defects in mitochondrial energy metabolism, …


Cigarette Smoke Increases Cardiomyocyte Ceramide Accumulation And Inhibits Mitochondrial Respiration, Trevor Stanley Tippetts Jun 2015

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 Mar 2015

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 …


The Role Of Ceramides In Mediating Endotoxin-Induced Mitochondrial Disruption, Melissa Ellen Hansen Dec 2014

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 …


Intrinsic Apoptotic Pathway: Effects Of Calcium On Murine Cytochrome C Release In Brain And Liver Mitochondria, Dane M. Edwards Apr 2013

Intrinsic Apoptotic Pathway: Effects Of Calcium On Murine Cytochrome C Release In Brain And Liver Mitochondria, Dane M. Edwards

Senior Honors Theses

A cell may use one of three main apoptotic pathways leading to programmed cell death: the extrinsic pathway, the perforin/granzyme pathway and the intrinsic pathway. The most pertinent to this discussion is the intrinsic pathway, which utilizes the mitochondria as an essential intermediary. Mitochondria’s primary function in relation to this pathway is the subsequent release of pro-apoptotic factors including cytochrome c, which activate a caspase cascade leading to the death of the cell. Cytochrome c is released partly due to an increase in cytosolic calcium levels. Two methods of the release of cytochrome c have been proposed. The first is …


Treatment Of Aortic Heart Valve Conduit With Glutamine And Heat Shock As A Means To Deter The Constituent Cellular Population From Becoming Apoptotic, Alyce Marie Linthurst Jones Apr 2012

Treatment Of Aortic Heart Valve Conduit With Glutamine And Heat Shock As A Means To Deter The Constituent Cellular Population From Becoming Apoptotic, Alyce Marie Linthurst Jones

Theses and Dissertations in Biomedical Sciences

Cryopreserved allograft heart valves represent the best solution for a patient with a failing heart valve. However, the constituent cells become apoptotic and within months of transplant the heart valve becomes acellular and the recipient's cells do not repopulate the allograft (3, 51). A strategy to prevent this situation would be to minimize or prevent apoptosis from occurring by strategically altering steps during heart valve processing. Recently it has been demonstrated that: 1) Heat shock protein 70 is a negative modulator of the apoptotic cascade; 2) Cells in culture exposed to hypothermic conditions produce heat shock protein 70 upon rewarming; …


Liver Kinase B1/Amp-Activated Protein Kinase Signaling In The Diaphragm, Jacob D. Brown Jun 2010

Liver Kinase B1/Amp-Activated Protein Kinase Signaling In The Diaphragm, Jacob D. Brown

Theses and Dissertations

The Liver Kinase B1 (LKB1)/AMP-Activated Protein Kinase (AMPK) signaling pathway is a major regulator of skeletal muscle metabolic processes. During exercise, LKB1-mediated phosphorylation of AMPK leads to its activation, promoting mitochondrial biogenesis and glucose transport, among other effects. The roles of LKB1 and AMPK have not been fully characterized in the diaphragm. Two methods of AMPK activation were used to characterize LKB1/AMPK signaling in diaphragms from muscle-specific LKB1 knockout (KO) and littermate control (C) mice: (1) acute injection of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) and (2) 5-min direct electrical stimulation (ES) of the diaphragm. Diaphragms were excised 60 minutes post-AICAR injection and …


Effects Of Endurance Training On The Ampk Response To Exercise., David Gerald Chesser Dec 2007

Effects Of Endurance Training On The Ampk Response To Exercise., David Gerald Chesser

Theses and Dissertations

Activation of AMP-activated protein kinase (AMPK) results in the upregulation of several intracellular systems which help to prepare a cell for a high energy challenge. The magnitude of the AMPK response to a 10 min bout of exercise has been found to decrease in red quadriceps (RQ) following training, while putative AMPK roles seem to be maintained; specifically, the biogenesis of mitochondria and higher levels of hexokinase II and glucose transporter 4 (GLUT4). If the AMPK response to exercise is responsible in part for these adaptations, how can they be maintained if the AMPK response is attenuated? The purpose of …