Physiology Commons^™

Apoe Genetics Influence Murine Gut Microbiome, Diana J. Zajac, Stefan J. Green, Lance A. Johnson, Steven Estus

Physiology Faculty Publications

Apolipoprotein E (APOE) alleles impact pathogenesis and risk for multiple human diseases, making them primary targets for disease treatment and prevention. Previously, we and others reported an association between APOE alleles and the gut microbiome. Here, we evaluated effects of APOE heterozygosity and tested whether these overall results extended to mice maintained under ideal conditions for microbiome analyses. To model human APOE alleles, this study used APOE targeted replacement (TR) mice on a C57Bl/6 background. To minimize genetic drift, homozygous APOE3 mice were crossed to homozygous APOE2 or homozygous APOE4 mice prior to the study, and the resulting …

Inhibition Of Bruton Tyrosine Kinase Reduces Neuroimmune Cascade And Promotes Recovery After Spinal Cord Injury, Chen Guang Yu, Vimala Bondada, Hina Iqbal, Kate L. Moore, John C. Gensel, Subbarao Bondada, James W. Geddes

Physiology Faculty Publications

Microglia/astrocyte and B cell neuroimmune responses are major contributors to the neurological deficits after traumatic spinal cord injury (SCI). Bruton tyrosine kinase (BTK) activation mechanistically links these neuroimmune mechanisms. Our objective is to use Ibrutinib, an FDA-approved BTK inhibitor, to inhibit the neuroimmune cascade thereby improving locomotor recovery after SCI. Rat models of contusive SCI, Western blot, immunofluorescence staining imaging, flow cytometry analysis, histological staining, and behavioral assessment were used to evaluate BTK activity, neuroimmune cascades, and functional outcomes. Both BTK expression and phosphorylation were increased at the lesion site at 2, 7, 14, and 28 days after SCI. Ibrutinib …

Late-Life Exercise Mitigates Skeletal Muscle Epigenetic Aging, Kevin A. Murach, Andrea L. Dimet-Wiley, Yuan Wen, Camille R. Brightwell, Christine M. Latham, Cory M. Dungan, Christopher S. Fry, Stanley J. Watowich

Center for Muscle Biology Faculty Publications

There are functional benefits to exercise in muscle, even when performed late in life, but the contributions of epigenetic factors to late-life exercise adaptation are poorly defined. Using reduced representation bisulfite sequencing (RRBS), ribosomal DNA (rDNA) and mitochondrial-specific examination of methylation, targeted high-resolution methylation analysis, and DNAge™ epigenetic aging clock analysis with a translatable model of voluntary murine endurance/resistance exercise training (progressive weighted wheel running, PoWeR), we provide evidence that exercise may mitigate epigenetic aging in skeletal muscle. Late-life PoWeR from 22–24 months of age modestly but significantly attenuates an age-associated shift toward promoter hypermethylation. The epigenetic age of muscle …

Evidence Of Myomir Regulation Of The Pentose Phosphate Pathway During Mechanical Load-Induced Hypertrophy, Taylor Valentino, Vandre C. Figueiredo, C. Brooks Mobley, John J. Mccarthy, Ivan J. Vechetti Jr.

Physiology Faculty Publications

Many of the molecular and cellular mechanisms discovered to regulate skeletal muscle hypertrophy were first identified using the rodent synergist ablation model. This model reveals the intrinsic capability and necessary pathways of skeletal muscle growth in response to mechanical overload (MOV). Reminiscent of the rapid cellular growth observed with cancer, we hypothesized that in response to MOV, skeletal muscle would undergo metabolic programming to sustain increased demands to support hypertrophy. To test this hypothesis, we analyzed the gene expression of specific metabolic pathways taken from transcriptomic microarray data of a MOV time course. We found an upregulation of genes involved …

Rapid And Direct Action Of Lipopolysaccharide (Lps) On Skeletal Muscle Of Larval Drosophila, Rachel Potter, Alexis Meade, Samuel Potter, Robin L. Cooper

Biology Faculty Publications

The endotoxin lipopolysaccharide (LPS) from Gram-negative bacteria exerts a direct and rapid effect on tissues. While most attention is given to the downstream actions of the immune system in response to LPS, this study focuses on the direct actions of LPS on skeletal muscle in Drosophila melanogaster. It was noted in earlier studies that the membrane potential rapidly hyperpolarizes in a dose-dependent manner with exposure to LPS from Pseudomonas aeruginosa and Serratia marcescens. The response is transitory while exposed to LPS, and the effect does not appear to be due to calcium-activated potassium channels, activated nitric oxide synthase …

Adult Spiny Mice (Acomys) Exhibit Endogenous Cardiac Recovery In Response To Myocardial Infarction, Hsuan Peng, Kazuhiro Shindo, Renée R. Donahue, Erhe Gao, Brooke M. Ahern, Bryana M. Levitan, Himi Tripathi, David Powell, Ahmed Noor, Garrett A. Elmore, Jonathan Satin, Ashley W. Seifert, Ahmed K. Abdel-Latif

Physiology Faculty Publications

Complex tissue regeneration is extremely rare among adult mammals. An exception, however, is the superior tissue healing of multiple organs in spiny mice (Acomys). While Acomys species exhibit the remarkable ability to heal complex tissue with minimal scarring, little is known about their cardiac structure and response to cardiac injury. In this study, we first examined baseline Acomys cardiac anatomy and function in comparison with commonly used inbred and outbred laboratory Mus strains (C57BL6 and CFW). While our results demonstrated comparable cardiac anatomy and function between Acomys and Mus, Acomys exhibited a higher percentage of cardiomyocytes displaying …

Editorial: Perturbations In Metabolic Cues: Implications For Adverse Cardiac Function Leading To Sudden Cardiac Death, Brian P. Delisle, Ademuyiwa S. Aromolaran

Physiology Faculty Publications

No abstract provided.

Fibroblast Growth Factor 19 Increases The Excitability Of Pre-Motor Glutamatergic Dorsal Vagal Complex Neurons From Hyperglycemic Mice, Jordan B. Wean, Bret N. Smith

Physiology Faculty Publications

Intracerebroventricular administration of the protein hormone fibroblast growth factor 19 (FGF19) to the hindbrain produces potent antidiabetic effects in hyperglycemic mice that are likely mediated through a vagal parasympathetic mechanism. FGF19 increases the synaptic excitability of parasympathetic motor neurons in the dorsal motor nucleus of the vagus (DMV) from hyperglycemic, but not normoglycemic, mice but the source of this synaptic input is unknown. Neurons in the area postrema (AP) and nucleus tractus solitarius (NTS) express high levels of FGF receptors and exert glutamatergic control over the DMV. This study tested the hypothesis that FGF19 increases glutamate release in the DMV …

Editorial: Recent Advances In Cardiotoxicity Testing, Tamer M. A. Mohamed, Javid Moslehi, Jonathan Satin

Physiology Faculty Publications

No abstract provided.

Editorial: The Metabolism Of The Neuron-Glia Unit, Yannick Poitelon, Lance A. Johnson, Marie-Ève Tremblay

Physiology Faculty Publications

No abstract provided.

Apoε4 Lowers Energy Expenditure In Females And Impairs Glucose Oxidation By Increasing Flux Through Aerobic Glycolysis, Brandon C. Farmer, Holden C. Williams, Nicholas A. Devanney, Margaret A. Piron, Grant K. Nation, David J. Carter, Adeline E. Walsh, Rebika Khanal, Lyndsay E. A. Young, Jude C. Kluemper, Gabriela Hernandez, Elizabeth J. Allenger, Rachel Mooney, Lesley R. Golden, Cathryn T. Smith, J. Anthony Brandon, Vedant A. Gupta, Philip A. Kern, Matthew S. Gentry, Josh M. Morganti, Ramon C. Sun, Lance A. Johnson

Physiology Faculty Publications

BACKGROUND: Cerebral glucose hypometabolism is consistently observed in individuals with Alzheimer's disease (AD), as well as in young cognitively normal carriers of the Ε4 allele of Apolipoprotein E (APOE), the strongest genetic predictor of late-onset AD. While this clinical feature has been described for over two decades, the mechanism underlying these changes in cerebral glucose metabolism remains a critical knowledge gap in the field.

METHODS: Here, we undertook a multi-omic approach by combining single-cell RNA sequencing (scRNAseq) and stable isotope resolved metabolomics (SIRM) to define a metabolic rewiring across astrocytes, brain tissue, mice, and human subjects expressing APOE4.

RESULTS: Single-cell …

Fusion And Beyond: Satellite Cell Contributions To Loading-Induced Skeletal Muscle Adaptation, Kevin A. Murach, Christopher S. Fry, Esther E. Dupont-Versteegden, John J. Mccarthy, Charlotte A. Peterson

Center for Muscle Biology Faculty Publications

Satellite cells support adult skeletal muscle fiber adaptations to loading in numerous ways. The fusion of satellite cells, driven by cell-autonomous and/or extrinsic factors, contributes new myonuclei to muscle fibers, associates with load-induced hypertrophy, and may support focal membrane damage repair and long-term myonuclear transcriptional output. Recent studies have also revealed that satellite cells communicate within their niche to mediate muscle remodeling in response to resistance exercise, regulating the activity of numerous cell types through various mechanisms such as secretory signaling and cell–cell contact. Muscular adaptation to resistance and endurance activity can be initiated and sustained for a period of …

Dietary And Pharmacologic Manipulations Of Host Lipids And Their Interaction With The Gut Microbiome In Non-Human Primates, Jennifer M. Lang, Leslie R. Sedgeman, Lei Cai, Joseph D. Layne, Zhen Wang, Calvin Pan, Richard Lee, Ryan E. Temel, Aldons J. Lusis

Physiology Faculty Publications

The gut microbiome influences nutrient processing as well as host physiology. Plasma lipid levels have been associated with the microbiome, although the underlying mechanisms are largely unknown, and the effects of dietary lipids on the gut microbiome in humans are not well-studied. We used a compilation of four studies utilizing non-human primates (Chlorocebus aethiops and Macaca fascicularis) with treatments that manipulated plasma lipid levels using dietary and pharmacological techniques, and characterized the microbiome using 16S rDNA. High-fat diets significantly reduced alpha diversity (Shannon) and the Firmicutes/Bacteroidetes ratio compared to chow diets, even when the diets had different compositions …

Intravesical Cd74 And Cxcr4, Macrophage Migration Inhibitory Factor (Mif) Receptors, Mediate Bladder Pain, Shaojing Ye, Fei Ma, Dlovan F. D. Mahmood, Katherine L. Meyer-Siegler, Raymond E. Menard, David E. Hunt, Lin Leng, Richard Bucala, Pedro L. Vera

Physiology Faculty Publications

BACKGROUND: Activation of intravesical protease activated receptor 4 (PAR4) leads to release of urothelial macrophage migration inhibitory factor (MIF). MIF then binds to urothelial MIF receptors to release urothelial high mobility group box-1 (HMGB1) and elicit bladder hyperalgesia. Since MIF binds to multiple receptors, we investigated the contribution of individual urothelial MIF receptors to PAR4-induced HMGB1 release in vivo and in vitro and bladder pain in vivo.

METHODOLOGY/PRINCIPAL FINDINGS: We tested the effect of intravesical pre-treatment with individual MIF or MIF receptor (CD74, CXCR4, CXCR2) antagonists on PAR4-induced HMGB1 release in vivo (female C57/BL6 mice) and in vitro (primary …

Reduced Mitochondrial Dna And Oxphos Protein Content In Skeletal Muscle Of Children With Cerebral Palsy, Ferdinand Von Walden, Ivan J. Vechetti Jr., Davis A. Englund, Vandré C. Figueiredo, Rodrigo Fernandez-Gonzalo, Kevin A. Murach, Jessica Pingel, John J. Mccarthy, Per Stål, Eva Pontén

Physiology Faculty Publications

AIM: To provide a detailed gene and protein expression analysis related to mitochondrial biogenesis and assess mitochondrial content in skeletal muscle of children with cerebral palsy (CP).

METHOD: Biceps brachii muscle samples were collected from 19 children with CP (mean [SD] age 15y 4mo [2y 6mo], range 9-18y, 16 males, three females) and 10 typically developing comparison children (mean [SD] age 15y [4y], range 7-21y, eight males, two females). Gene expression (quantitative reverse transcription polymerase chain reaction [PCR]), mitochondrial DNA (mtDNA) to genomic DNA ratio (quantitative PCR), and protein abundance (western blotting) were analyzed. Microarray data sets (CP/aging/bed rest) were …

Cardiomyocyte Deletion Of Bmal1 Exacerbates Qt- And Rr-Interval Prolongation In Scn5a+/Δkpq Mice, Elizabeth A. Schroder, Jennifer L. Wayland, Kaitlyn M. Samuels, Syed F. Shah, Don E. Burgess, Tanya S. Seward, Claude S. Elayi, Karyn A. Esser, Brian P. Delisle

Physiology Faculty Publications

Circadian rhythms are generated by cell autonomous circadian clocks that perform a ubiquitous cellular time-keeping function and cell type-specific functions important for normal physiology. Studies show inducing the deletion of the core circadian clock transcription factor Bmal1 in adult mouse cardiomyocytes disrupts cardiac circadian clock function, cardiac ion channel expression, slows heart rate, and prolongs the QT-interval at slow heart rates. This study determined how inducing the deletion of Bmal1 in adult cardiomyocytes impacted the in vivo electrophysiological phenotype of a knock-in mouse model for the arrhythmogenic long QT syndrome (Scn5a+/ΔKPQ). Electrocardiographic telemetry showed inducing the …

Hypertrophic Cardiomyopathy Β-Cardiac Myosin Mutation (P710r) Leads To Hypercontractility By Disrupting Super Relaxed State, Alison Schroer Vander Roest, Chao Liu, Makenna M. Morck, Kristina Bezold Kooiker, Gwanghyun Jung, Dan Song, Aminah Dawood, Arnav Jhingran, Gaspard Pardon, Sara Ranjbarvaziri, Giovanni Fajardo, Mingming Zhao, Kenneth S. Campbell, Beth L. Pruitt, James A. Spudich, Kathleen M. Ruppel, Daniel Bernstein

Physiology Faculty Publications

Hypertrophic cardiomyopathy (HCM) is the most common inherited form of heart disease, associated with over 1,000 mutations, many in β-cardiac myosin (MYH7). Molecular studies of myosin with different HCM mutations have revealed a diversity of effects on ATPase and load-sensitive rate of detachment from actin. It has been difficult to predict how such diverse molecular effects combine to influence forces at the cellular level and further influence cellular phenotypes. This study focused on the P710R mutation that dramatically decreased in vitro motility velocity and actin-activated ATPase, in contrast to other MYH7 mutations. Optical trap measurements of single myosin molecules revealed …

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, …

Acute Inflammatory Profiles Differ With Sex And Age After Spinal Cord Injury, Andrew N. Stewart, John L. Lowe, Ethan P. Glaser, Caitlin A. Mott, Ryan K. Shahidehpour, Katelyn E. Mcfarlane, William M. Bailey, Bei Zhang, John C. Gensel

Physiology Faculty Publications

Background

Sex and age are emerging as influential variables that affect spinal cord injury (SCI) recovery. Despite a changing demographic towards older age at the time of SCI, the effects of sex or age on inflammation remain to be elucidated. This study determined the sex- and age-dependency of the innate immune response acutely after SCI.

Methods

Male and female mice of ages 4- and 14-month-old received T9 contusion SCI and the proportion of microglia, monocyte-derived macrophages (MDM), and neutrophils surrounding the lesion were determined at 3- and 7-day post-injury (DPI) using flow cytometry. Cell counts of microglia and MDMs were …

The Effects Of Myelin On Macrophage Activation Are Phenotypic Specific Via Cpla2 In The Context Of Spinal Cord Injury Inflammation, Timothy J. Kopper, Bei Zhang, William M. Bailey, Kara E. Bethel, John C. Gensel

Physiology Faculty Publications

Spinal cord injury (SCI) produces chronic, pro-inflammatory macrophage activation that impairs recovery. The mechanisms driving this chronic inflammation are not well understood. Here, we detail the effects of myelin debris on macrophage physiology and demonstrate a novel, activation state-dependent role for cytosolic phospholipase-A2 (cPLA₂) in myelin-mediated potentiation of pro-inflammatory macrophage activation. We hypothesized that cPLA₂ and myelin debris are key mediators of persistent pro-inflammatory macrophage responses after SCI. To test this, we examined spinal cord tissue 28-days after thoracic contusion SCI in 3-month-old female mice and observed both cPLA₂ activation and intracellular accumulation of lipid-rich myelin …

Broad Kinase Inhibition Mitigates Early Neuronal Dysfunction In Tauopathy, Shon A. Koren, Matthew J. Hamm, Ryan Cloyd, Sarah N. Fontaine, Emad Chishti, Chiara Lanzillotta, Jennifer Rodriguez-Rivera, Alexandria Ingram, Michelle Bell, Sara M. Galvis-Escobar, Nicholas Zulia, Fabio Di Domenico, Duc Duong, Nicholas T. Seyfried, David K. Powell, Moriel Vandsburger, Tal Frolinger, Anika M. S. Hartz, John Koren Iii, Jeffrey M. Axten, Nicholas J. Laping, Jose F. Abisambra

Sanders-Brown Center on Aging Faculty Publications

Tauopathies are a group of more than twenty known disorders that involve progressive neurodegeneration, cognitive decline and pathological tau accumulation. Current therapeutic strategies provide only limited, late-stage symptomatic treatment. This is partly due to lack of understanding of the molecular mechanisms linking tau and cellular dysfunction, especially during the early stages of disease progression. In this study, we treated early stage tau transgenic mice with a multi-target kinase inhibitor to identify novel substrates that contribute to cognitive impairment and exhibit therapeutic potential. Drug treatment significantly ameliorated brain atrophy and cognitive function as determined by behavioral testing and a sensitive imaging …

Arginase 1 Insufficiency Precipitates Amyloid-Β Deposition And Hastens Behavioral Impairment In A Mouse Model Of Amyloidosis, Chao Ma, Jerry B. Hunt, Maj-Linda B. Selenica, Awa Sanneh, Leslie A. Sandusky-Beltran, Mallory Watler, Rana Daas, Andrii Kovalenko, Huimin Liang, Devon Placides, Chuanhai Cao, Xiaoyang Lin, Michael B. Orr, Bei Zhang, John C. Gensel, David J. Feola, Marcia N. Gordon, Dave Morgan, Paula C. Bickford, Daniel C. Lee

Sanders-Brown Center on Aging Faculty Publications

Alzheimer’s disease (AD) includes several hallmarks comprised of amyloid-β (Aβ) deposition, tau neuropathology, inflammation, and memory impairment. Brain metabolism becomes uncoupled due to aging and other AD risk factors, which ultimately lead to impaired protein clearance and aggregation. Increasing evidence indicates a role of arginine metabolism in AD, where arginases are key enzymes in neurons and glia capable of depleting arginine and producing ornithine and polyamines. However, currently, it remains unknown if the reduction of arginase 1 (Arg1) in myeloid cell impacts amyloidosis. Herein, we produced haploinsufficiency of Arg1 by the hemizygous deletion in myeloid cells using Arg1 …

Lat1 Protein Content Increases Following 12 Weeks Of Resistance Exercise Training In Human Skeletal Muscle, Paul A. Roberson, Christopher Brooks Mobley, Matthew A. Romero, Cody T. Haun, Shelby C. Osburn, Petey W. Mumford, Christopher G. Vann, Rory A. Greer, Arny A. Ferrando, Michael D. Roberts

Physiology Faculty Publications

Introduction: Amino acid transporters are essential for cellular amino acid transport and promoting protein synthesis. While previous literature has demonstrated the association of amino acid transporters and protein synthesis following acute resistance exercise and amino acid supplementation, the chronic effect of resistance exercise and supplementation on amino acid transporters is unknown. The purpose herein was to determine if amino acid transporters and amino acid metabolic enzymes were related to skeletal muscle hypertrophy following resistance exercise training with different nutritional supplementation strategies.

Methods: 43 college-aged males were separated into a maltodextrin placebo (PLA, n = 12), leucine (LEU, n = 14), …

Mitochondria Exert Age-Divergent Effects On Recovery From Spinal Cord Injury, Andrew N. Stewart, Katelyn E. Mcfarlane, Hemendra J. Vekaria, William M. Bailey, Stacey A. Slone, Lauren A. Tranthem, Bei Zhang, Samir P. Patel, Patrick G. Sullivan, John C. Gensel

Physiology Faculty Publications

The extent that age-dependent mitochondrial dysfunction drives neurodegeneration is not well understood. This study tested the hypothesis that mitochondria contribute to spinal cord injury (SCI)-induced neurodegeneration in an age-dependent manner by using 2,4-dinitrophenol (DNP) to uncouple electron transport, thereby increasing cellular respiration and reducing reactive oxygen species (ROS) production. We directly compared the effects of graded DNP doses in 4- and 14-month-old (MO) SCI-mice and found DNP to have increased efficacy in mitochondria isolated from 14-MO animals. In vivo, all DNP doses significantly exacerbated 4-MO SCI neurodegeneration coincident with worsened recovery. In contrast, low DNP doses (1.0-mg/kg/day) improved tissue …

Investigation Of Salt Tolerance Mechanisms Across A Root Developmental Gradient In Almond Rootstocks, Yuhang Shao, Yukun Cheng, Hongguang Pang, Mingqin Chang, Fang He, Minmin Wang, Destiny J. Davis, Shuxiao Zhang, Oliver Betz, Chuck Fleck, Tingbo Dai, Shahab Madahhosseini, Thomas E. Wilkop, Judy Jernstedt, Georgia Drakakaki

Physiology Faculty Publications

The intensive use of groundwater in agriculture under the current climate conditions leads to acceleration of soil salinization. Given that almond is a salt-sensitive crop, selection of salt-tolerant rootstocks can help maintain productivity under salinity stress. Selection for tolerant rootstocks at an early growth stage can reduce the investment of time and resources. However, salinity-sensitive markers and salinity tolerance mechanisms of almond species to assist this selection process are largely unknown. We established a microscopy-based approach to investigate mechanisms of stress tolerance in and identified cellular, root anatomical, and molecular traits associated with rootstocks exhibiting salt tolerance. We characterized three …

Diverse And Complex Muscle Spindle Afferent Firing Properties Emerge From Multiscale Muscle Mechanics, Kyle P. Blum, Kenneth S. Campbell, Brian C. Horslen, Paul Nardelli, Stephen N. Housley, Timothy C. Cope, Lena H. Ting

Physiology Faculty Publications

Despite decades of research, we lack a mechanistic framework capable of predicting how movement-related signals are transformed into the diversity of muscle spindle afferent firing patterns observed experimentally, particularly in naturalistic behaviors. Here, a biophysical model demonstrates that well-known firing characteristics of mammalian muscle spindle Ia afferents – including movement history dependence, and nonlinear scaling with muscle stretch velocity – emerge from first principles of muscle contractile mechanics. Further, mechanical interactions of the muscle spindle with muscle-tendon dynamics reveal how motor commands to the muscle (alpha drive) versus muscle spindle (gamma drive) can cause highly variable and complex activity during …

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 K_2P2.1 (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 …

Lung Epithelial Trpa1 Mediates Lipopolysaccharide-Induced Lung Inflammation In Bronchial Epithelial Cells And Mice, Hsin-Kuo Ko, An-Hsuan Lin, Diahn-Warng Perng, Tzong-Shyuan Lee, Yu Ru Kou

Physiology Faculty Publications

Toll-like receptor (TLR) 4 was originally thought to be the sole pattern recognition receptor for lipopolysaccharide (LPS). Transient receptor potential ankyrin 1 (TRPA1), a Ca²⁺-permeant channel, has been suggested as a non-TLR receptor membrane-bound sensor of LPS. We recently reported that TRPA1 is expressed in lung epithelial cells (LECs) and mediates lung inflammation induced by cigarette smoke. However, the role of TRPA1 in LPS-induced lung inflammation has not been conclusively defined, and its underlying cellular mechanisms remain unclear. In this study, our in vitro results showed that LPS sequentially produced a cascade of events, including the elevation of …

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 …

Rats Genetically Selected For High Aerobic Exercise Capacity Have Elevated Plasma Bilirubin By Upregulation Of Hepatic Biliverdin Reductase-A (Bvra) And Suppression Of Ugt1a1, Terry D. Hinds Jr., Justin F. Creeden, Darren M. Gordon, Adam C. Spegele, Steven L. Britton, Lauren G. Koch, David E. Stec

Pharmacology and Nutritional Sciences Faculty Publications

Exercise in humans and animals increases plasma bilirubin levels, but the mechanism by which this occurs is unknown. In the present study, we utilized rats genetically selected for high capacity running (HCR) and low capacity running (LCR) to determine pathways in the liver that aerobic exercise modifies to control plasma bilirubin. The HCR rats, compared to the LCR, exhibited significantly higher levels of plasma bilirubin and the hepatic enzyme that produces it, biliverdin reductase-A (BVRA). The HCR also had reduced expression of the glucuronyl hepatic enzyme UGT1A1, which lowers plasma bilirubin. Recently, bilirubin has been shown to activate the peroxisome …