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Full-Text Articles in Physiology

Igf1-Stimulated Posttraumatic Hippocampal Remodeling Is Not Dependent On Mtor, Erica L. Littlejohn, Anthony J. Desana, Hannah C. Williams, Rudy T. Chapman, Binoy Joseph, Jelena A. Juras, Kathryn E. Saatman May 2021

Igf1-Stimulated Posttraumatic Hippocampal Remodeling Is Not Dependent On Mtor, Erica L. Littlejohn, Anthony J. Desana, Hannah C. Williams, Rudy T. Chapman, Binoy Joseph, Jelena A. Juras, Kathryn E. Saatman

Physiology Faculty Publications

Adult hippocampal neurogenesis is stimulated acutely following traumatic brain injury (TBI). However, many hippocampal neurons born after injury develop abnormally and the number that survive long-term is debated. In experimental TBI, insulin-like growth factor-1 (IGF1) promotes hippocampal neuronal differentiation, improves immature neuron dendritic arbor morphology, increases long-term survival of neurons born after TBI, and improves cognitive function. One potential downstream mediator of the neurogenic effects of IGF1 is mammalian target of rapamycin (mTOR), which regulates proliferation as well as axonal and dendritic growth in the CNS. Excessive mTOR activation is posited to contribute to aberrant plasticity related to posttraumatic epilepsy, …


K2p2.1 (Trek-1) Potassium Channel Activation Protects Against Hyperoxia-Induced Lung Injury, Tatiana Zyrianova, Benjamin Lopez, Riccardo Olcese, John Belperio, Christopher M. Waters, Leanne Wong, Victoria Nguyen, Sriharsha Talapaneni, Andreas Schwingshackl Dec 2020

K2p2.1 (Trek-1) Potassium Channel Activation Protects Against Hyperoxia-Induced Lung Injury, Tatiana Zyrianova, Benjamin Lopez, Riccardo Olcese, John Belperio, Christopher M. Waters, Leanne Wong, Victoria Nguyen, Sriharsha Talapaneni, Andreas Schwingshackl

Physiology Faculty Publications

No targeted therapies exist to counteract Hyperoxia (HO)-induced Acute Lung Injury (HALI). We previously found that HO downregulates alveolar K2P2.1 (TREK-1) K+ channels, which results in worsening lung injury. This decrease in TREK-1 levels leaves a subset of channels amendable to pharmacological intervention. Therefore, we hypothesized that TREK-1 activation protects against HALI. We treated HO-exposed mice and primary alveolar epithelial cells (AECs) with the novel TREK-1 activators ML335 and BL1249, and quantified physiological, histological, and biochemical lung injury markers. We determined the effects of these drugs on epithelial TREK-1 currents, plasma membrane potential (Em), and intracellular Ca …


Ceramide Analog [18F]F-Hpa-12 Detects Sphingolipid Disbalance In The Brain Of Alzheimer’S Disease Transgenic Mice By Functioning As A Metabolic Probe, Simone M. Crivelli, Daan Van Kruining, Qian Luo, Jo A. A. Stevens, Caterina Giovagnoni, Andreas Paulus, Matthias Bauwens, Dusan Berkes, Helga E. De Vries, Monique T. Mulder, Jochen Walter, Etienne Waelkens, Rita Derua, Johannes V. Swinnen, Jonas Dehairs, Felix M. Mottaghy, Mario Losen, Erhard Bieberich, Pilar Martinez-Martinez Nov 2020

Ceramide Analog [18F]F-Hpa-12 Detects Sphingolipid Disbalance In The Brain Of Alzheimer’S Disease Transgenic Mice By Functioning As A Metabolic Probe, Simone M. Crivelli, Daan Van Kruining, Qian Luo, Jo A. A. Stevens, Caterina Giovagnoni, Andreas Paulus, Matthias Bauwens, Dusan Berkes, Helga E. De Vries, Monique T. Mulder, Jochen Walter, Etienne Waelkens, Rita Derua, Johannes V. Swinnen, Jonas Dehairs, Felix M. Mottaghy, Mario Losen, Erhard Bieberich, Pilar Martinez-Martinez

Physiology Faculty Publications

The metabolism of ceramides is deregulated in the brain of Alzheimer’s disease (AD) patients and is associated with apolipoprotein (APO) APOE4 and amyloid-β pathology. However, how the ceramide metabolism changes over time in AD, in vivo, remains unknown. Distribution and metabolism of [18F]F-HPA-12, a radio-fluorinated version of the ceramide analog N-(3-hydroxy-1-hydroxymethyl-3-phenylpropyl) dodecanamide, was investigated in the brain of AD transgenic mouse models (FAD) on an APOE4 or APOE3 genetic background, by positron emission tomography and by gamma counter. We found that FAD mice displayed a higher uptake of [18F]F-HPA-12 in the brain, independently from the APOE4 …


Serum Amyloid A Binds To Gibrin(Ogen), Promoting Fibrin Amyloid Formation, Martin J. Page, Greig J. A. Thomson, J. Massimo Nunes, Anna-Mart Engelbrecht, Theo A. Nell, Willem J. S. De Villiers, Maria C. De Beer, Lize Engelbrecht, Douglas B. Kell, Etheresia Pretorius Feb 2019

Serum Amyloid A Binds To Gibrin(Ogen), Promoting Fibrin Amyloid Formation, Martin J. Page, Greig J. A. Thomson, J. Massimo Nunes, Anna-Mart Engelbrecht, Theo A. Nell, Willem J. S. De Villiers, Maria C. De Beer, Lize Engelbrecht, Douglas B. Kell, Etheresia Pretorius

Physiology Faculty Publications

Complex associations exist between inflammation and thrombosis, with the inflammatory state tending to promote coagulation. Fibrinogen, an acute phase protein, has been shown to interact with the amyloidogenic ß-amyloid protein of Alzheimer’s disease. However, little is known about the association between fibrinogen and serum amyloid A (SAA), a highly fibrillogenic protein that is one of the most dramatically changing acute phase reactants in the circulation. To study the role of SAA in coagulation and thrombosis, in vitro experiments were performed where purified human SAA, in concentrations resembling a modest acute phase response, was added to platelet-poor plasma (PPP) and whole …


Apolipoprotein E4 Alters Astrocyte Fatty Acid Metabolism And Lipid Droplet Formation, Brandon C. Farmer, Jude Kluemper, Lance A. Johnson Feb 2019

Apolipoprotein E4 Alters Astrocyte Fatty Acid Metabolism And Lipid Droplet Formation, Brandon C. Farmer, Jude Kluemper, Lance A. Johnson

Physiology Faculty Publications

Lipid droplets (LDs) serve as energy rich reservoirs and have been associated with apolipoprotein E (APOE) and neurodegeneration. The E4 allele of APOE (E4) is the strongest genetic risk factor for the development of late onset Alzheimer’s disease (AD). Since both E4 carriers and individuals with AD exhibit a state of cerebral lipid dyshomeostasis, we hypothesized that APOE may play a role in regulating LD metabolism. We found that astrocytes expressing E4 accumulate significantly more and smaller LDs compared to E3 astrocytes. Accordingly, expression of perilipin-2, an essential LD protein component, was higher in E4 astrocytes. We then …


Hdl In Endocrine Carcinomas: Biomarker, Drug Carrier, And Potential Therapeutic, Emily E. Morin, Xiang-An Li, Anna Schwendeman Nov 2018

Hdl In Endocrine Carcinomas: Biomarker, Drug Carrier, And Potential Therapeutic, Emily E. Morin, Xiang-An Li, Anna Schwendeman

Physiology Faculty Publications

High-density lipoprotein (HDL) have long been studied for their protective role against cardiovascular diseases, however recently relationship between HDL and cancer came into focus. Several epidemiological studies have shown an inverse correlation between HDL-cholesterol (HDL-C) and cancer risk, and some have even implied that HDL-C can be used as a predictive measure for survival prognosis in for specific sub-population of certain types of cancer. HDL itself is an endogenous nanoparticle capable of removing excess cholesterol from the periphery and returning it to the liver for excretion. One of the main receptors for HDL, scavenger receptor type B-I (SR-BI), is highly …


Minimal Information For Studies Of Extracellular Vesicles 2018 (Misev2018): A Position Statement Of The International Society For Extracellular Vesicles And Update Of The Misev2014 Guidelines, Clotilde Théry, Kenneth W. Witwer, Elena Aikawa, Maria Jose Alcaraz, Johnathon D. Anderson, Ramaroson Andriantsitohaina, Anna Antoniou, Tanina Arab, Fabienne Archer, Georgia K. Atkin-Smith, D. Craig Ayre, Jean-Marie Bach, Daniel Bachurski, Hossein Baharvand, Leonora Balaj, Shawn Baldacchino, Natalie N. Bauer, Amy A. Baxter, Mary Bebawy, Carla Beckham, Apolonija Bedina Zavec, Adberrahim Benmoussa, Anna C. Berardi, Paolo Bergese, Ewa Bielska, Cherie Blenkiron, Sylwia Bobis-Wozowicz, Eric Boilard, Wilfred Boireau, Antonella Bongiovanni, Ivan Vechetti Nov 2018

Minimal Information For Studies Of Extracellular Vesicles 2018 (Misev2018): A Position Statement Of The International Society For Extracellular Vesicles And Update Of The Misev2014 Guidelines, Clotilde Théry, Kenneth W. Witwer, Elena Aikawa, Maria Jose Alcaraz, Johnathon D. Anderson, Ramaroson Andriantsitohaina, Anna Antoniou, Tanina Arab, Fabienne Archer, Georgia K. Atkin-Smith, D. Craig Ayre, Jean-Marie Bach, Daniel Bachurski, Hossein Baharvand, Leonora Balaj, Shawn Baldacchino, Natalie N. Bauer, Amy A. Baxter, Mary Bebawy, Carla Beckham, Apolonija Bedina Zavec, Adberrahim Benmoussa, Anna C. Berardi, Paolo Bergese, Ewa Bielska, Cherie Blenkiron, Sylwia Bobis-Wozowicz, Eric Boilard, Wilfred Boireau, Antonella Bongiovanni, Ivan Vechetti

Physiology Faculty Publications

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines …


Transcriptional Profiling Reveals Extraordinary Diversity Among Skeletal Muscle Tissues, Erin E. Terry, Xiping Zhang, Christy Hoffmann, Laura D. Hughes, Scott A. Lewis, Jiajia Li, Matthew J. Wallace, Lance A. Riley, Collin M. Douglas, Miguel A. Gutierrez-Monreal, Nicholas F. Lahens, Ming C. Gong, Francisco H. Andrade, Karyn A. Esser, Michael E. Hughes May 2018

Transcriptional Profiling Reveals Extraordinary Diversity Among Skeletal Muscle Tissues, Erin E. Terry, Xiping Zhang, Christy Hoffmann, Laura D. Hughes, Scott A. Lewis, Jiajia Li, Matthew J. Wallace, Lance A. Riley, Collin M. Douglas, Miguel A. Gutierrez-Monreal, Nicholas F. Lahens, Ming C. Gong, Francisco H. Andrade, Karyn A. Esser, Michael E. Hughes

Physiology Faculty Publications

Skeletal muscle comprises a family of diverse tissues with highly specialized functions. Many acquired diseases, including HIV and COPD, affect specific muscles while sparing others. Even monogenic muscular dystrophies selectively affect certain muscle groups. These observations suggest that factors intrinsic to muscle tissues influence their resistance to disease. Nevertheless, most studies have not addressed transcriptional diversity among skeletal muscles. Here we use RNAseq to profile mRNA expression in skeletal, smooth, and cardiac muscle tissues from mice and rats. Our data set, MuscleDB, reveals extensive transcriptional diversity, with greater than 50% of transcripts differentially expressed among skeletal muscle tissues. We detect …


Visualizing Mutation-Specific Differences In The Trafficking-Deficient Phenotype Of Kv11.1 Proteins Linked To Long Qt Syndrome Type 2, Allison R. Hall, Corey L. Anderson, Jennifer L. Smith, Tooraj Mirshahi, Samy-Claude Elayi, Craig T. January, Brian P. Delisle May 2018

Visualizing Mutation-Specific Differences In The Trafficking-Deficient Phenotype Of Kv11.1 Proteins Linked To Long Qt Syndrome Type 2, Allison R. Hall, Corey L. Anderson, Jennifer L. Smith, Tooraj Mirshahi, Samy-Claude Elayi, Craig T. January, Brian P. Delisle

Physiology Faculty Publications

KCNH2 encodes the Kv11.1 α-subunit that underlies the rapidly activating delayed-rectifier K+ current in the heart. Loss-of-function KCNH2 mutations cause long QT syndrome type 2 (LQT2), and most LQT2-linked missense mutations inhibit the trafficking of Kv11.1 channel protein to the cell surface membrane. Several trafficking-deficient LQT2 mutations (e.g., G601S) generate Kv11.1 proteins that are sequestered in a microtubule-dependent quality control (QC) compartment in the transitional endoplasmic reticulum (ER). We tested the hypothesis that the QC mechanisms that regulate LQT2-linked Kv11.1 protein trafficking are mutation-specific. Confocal imaging analyses of HEK293 cells stably expressing the trafficking-deficient LQT2 mutation F805C showed that, …


Mechanotransduction Current Is Essential For Stability Of The Transducing Stereocilia In Mammalian Auditory Hair Cells, A. Catalina Vélez-Ortega, Mary J. Freeman, Artur A. Indzhykulian, Jonathan M. Grossheim, Gregory I. Frolenkov Mar 2017

Mechanotransduction Current Is Essential For Stability Of The Transducing Stereocilia In Mammalian Auditory Hair Cells, A. Catalina Vélez-Ortega, Mary J. Freeman, Artur A. Indzhykulian, Jonathan M. Grossheim, Gregory I. Frolenkov

Physiology Faculty Publications

Mechanotransducer channels at the tips of sensory stereocilia of inner ear hair cells are gated by the tension of 'tip links' interconnecting stereocilia. To ensure maximal sensitivity, tip links are tensioned at rest, resulting in a continuous influx of Ca2+ into the cell. Here we show that this constitutive Ca2+ influx, usually considered as potentially deleterious for hair cells, is in fact essential for stereocilia stability. In the auditory hair cells of young postnatal mice and rats, a reduction in mechanotransducer current, via pharmacological channel blockers or disruption of tip links, leads to stereocilia shape changes and shortening. …


Melanocortin 1 Receptor: Structure, Function, And Regulation, Erin M. Wolf Horrell, Mary C. Boulanger, John A. D'Orazio May 2016

Melanocortin 1 Receptor: Structure, Function, And Regulation, Erin M. Wolf Horrell, Mary C. Boulanger, John A. D'Orazio

Physiology Faculty Publications

The melanocortin 1 receptor (MC1R) is a melanocytic Gs protein coupled receptor that regulates skin pigmentation, UV responses, and melanoma risk. It is a highly polymorphic gene, and loss of function correlates with a fair, UV-sensitive, and melanoma-prone phenotype due to defective epidermal melanization and sub-optimal DNA repair. MC1R signaling, achieved through adenylyl cyclase activation and generation of the second messenger cAMP, is hormonally controlled by the positive agonist melanocortin, the negative agonist agouti signaling protein, and the neutral antagonist β-defensin 3. Activation of cAMP signaling up-regulates melanin production and deposition in the epidermis which functions to limit UV …