1
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Leiter O, Brici D, Fletcher SJ, Yong XLH, Widagdo J, Matigian N, Schroer AB, Bieri G, Blackmore DG, Bartlett PF, Anggono V, Villeda SA, Walker TL. Platelet-derived exerkine CXCL4/platelet factor 4 rejuvenates hippocampal neurogenesis and restores cognitive function in aged mice. Nat Commun 2023; 14:4375. [PMID: 37587147 PMCID: PMC10432533 DOI: 10.1038/s41467-023-39873-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 06/20/2023] [Indexed: 08/18/2023] Open
Abstract
The beneficial effects of physical activity on brain ageing are well recognised, with exerkines, factors that are secreted into the circulation in response to exercise, emerging as likely mediators of this response. However, the source and identity of these exerkines remain unclear. Here we provide evidence that an anti-geronic exerkine is secreted by platelets. We show that platelets are activated by exercise and are required for the exercise-induced increase in hippocampal precursor cell proliferation in aged mice. We also demonstrate that increasing the systemic levels of the platelet-derived exerkine CXCL4/platelet factor 4 (PF4) ameliorates age-related regenerative and cognitive impairments in a hippocampal neurogenesis-dependent manner. Together these findings highlight the role of platelets in mediating the rejuvenating effects of exercise during physiological brain ageing.
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Affiliation(s)
- Odette Leiter
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - David Brici
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Stephen J Fletcher
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Xuan Ling Hilary Yong
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Nicholas Matigian
- Queensland Cyber Infrastructure Foundation Ltd, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Adam B Schroer
- Department of Anatomy, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Gregor Bieri
- Department of Anatomy, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Daniel G Blackmore
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Perry F Bartlett
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Saul A Villeda
- Department of Anatomy, University of California San Francisco, San Francisco, CA, 94143, USA
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, 94143, USA
- Bakar Aging Research Institute, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Tara L Walker
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
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2
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Schroer AB, Ventura PB, Sucharov J, Misra R, Chui MKK, Bieri G, Horowitz AM, Smith LK, Encabo K, Tenggara I, Couthouis J, Gross JD, Chan JM, Luke A, Villeda SA. Platelet factors attenuate inflammation and rescue cognition in ageing. Nature 2023; 620:1071-1079. [PMID: 37587343 PMCID: PMC10468395 DOI: 10.1038/s41586-023-06436-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 07/14/2023] [Indexed: 08/18/2023]
Abstract
Identifying therapeutics to delay, and potentially reverse, age-related cognitive decline is critical in light of the increased incidence of dementia-related disorders forecasted in the growing older population1. Here we show that platelet factors transfer the benefits of young blood to the ageing brain. Systemic exposure of aged male mice to a fraction of blood plasma from young mice containing platelets decreased neuroinflammation in the hippocampus at the transcriptional and cellular level and ameliorated hippocampal-dependent cognitive impairments. Circulating levels of the platelet-derived chemokine platelet factor 4 (PF4) (also known as CXCL4) were elevated in blood plasma preparations of young mice and humans relative to older individuals. Systemic administration of exogenous PF4 attenuated age-related hippocampal neuroinflammation, elicited synaptic-plasticity-related molecular changes and improved cognition in aged mice. We implicate decreased levels of circulating pro-ageing immune factors and restoration of the ageing peripheral immune system in the beneficial effects of systemic PF4 on the aged brain. Mechanistically, we identified CXCR3 as a chemokine receptor that, in part, mediates the cellular, molecular and cognitive benefits of systemic PF4 on the aged brain. Together, our data identify platelet-derived factors as potential therapeutic targets to abate inflammation and rescue cognition in old age.
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Affiliation(s)
- Adam B Schroer
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA.
| | - Patrick B Ventura
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA
| | - Juliana Sucharov
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Rhea Misra
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - M K Kirsten Chui
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA
| | - Gregor Bieri
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA
| | - Alana M Horowitz
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Lucas K Smith
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Katriel Encabo
- Department of Urology, University of California San Francisco, San Francisco, CA, USA
| | - Imelda Tenggara
- Department of Urology, University of California San Francisco, San Francisco, CA, USA
| | - Julien Couthouis
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Joshua D Gross
- Department of Cell Biology, Duke University, Durham, NC, USA
| | - June M Chan
- Department of Urology, University of California San Francisco, San Francisco, CA, USA
- Departments of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA
| | - Anthony Luke
- Department of Orthopaedics, University of California San Francisco, San Francisco, CA, USA
| | - Saul A Villeda
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA.
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA.
- Department of Physical Therapy and Rehabilitation Science, University of California San Francisco, San Francisco, CA, USA.
- Bakar Aging Research Institute, University of California San Francisco, San Francisco, CA, USA.
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3
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de Sousa DMB, Poupardin R, Villeda SA, Schroer AB, Fröhlich T, Frey V, Staffen W, Mrowetz H, Altendorfer B, Unger MS, Iglseder B, Paulweber B, Trinka E, Cadamuro J, Drerup M, Schallmoser K, Aigner L, Kniewallner KM. The platelet transcriptome and proteome in Alzheimer's disease and aging: an exploratory cross-sectional study. Front Mol Biosci 2023; 10:1196083. [PMID: 37457829 PMCID: PMC10348715 DOI: 10.3389/fmolb.2023.1196083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/05/2023] [Indexed: 07/18/2023] Open
Abstract
Introduction: Alzheimer's disease (AD) and aging are associated with platelet hyperactivity. However, the mechanisms underlying abnormal platelet function in AD and aging are yet poorly understood. Methods: To explore the molecular profile of AD and aged platelets, we investigated platelet activation (i.e., CD62P expression), proteome and transcriptome in AD patients, non-demented elderly, and young individuals as controls. Results: AD, aged and young individuals showed similar levels of platelet activation based on CD62P expression. However, AD and aged individuals had a proteomic signature suggestive of increased platelet activation compared with young controls. Transcriptomic profiling suggested the dysregulation of proteolytic machinery involved in regulating platelet function, particularly the ubiquitin-proteasome system in AD and autophagy in aging. The functional implication of these transcriptomic alterations remains unclear and requires further investigation. Discussion: Our data strengthen the evidence of enhanced platelet activation in aging and provide a first glimpse of the platelet transcriptomic changes occurring in AD.
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Affiliation(s)
- Diana M. Bessa de Sousa
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
| | - Rodolphe Poupardin
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
- Experimental and Clinical Cell Therapy Institute, Paracelsus Medical University, Salzburg, Austria
| | - Saul A. Villeda
- Department of Anatomy, University of California San Francisco, San Francisco, CA, United States
| | - Adam B. Schroer
- Department of Anatomy, University of California San Francisco, San Francisco, CA, United States
| | - Thomas Fröhlich
- Laboratory of Functional Genome Analysis (LAFUGA), Gene Center, Ludwig Maximilian University of Munich, Munich, Germany
| | - Vanessa Frey
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
- Department of Neurology, Christian Doppler Clinic, Paracelsus Medical University, Salzburg, Austria
| | - Wolfgang Staffen
- Department of Neurology, Christian Doppler Clinic, Paracelsus Medical University, Salzburg, Austria
| | - Heike Mrowetz
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
| | - Barbara Altendorfer
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
| | - Michael S. Unger
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
| | - Bernhard Iglseder
- Department of Neurology, Christian Doppler Clinic, Paracelsus Medical University, Salzburg, Austria
| | - Bernhard Paulweber
- Department of Internal Medicine, St. Johanns University Hospital, Paracelsus Medical University, Salzburg, Austria
| | - Eugen Trinka
- Department of Neurology, Christian Doppler Clinic, Paracelsus Medical University, Salzburg, Austria
- Department of Public Health, Health Services Research and Health Technology Assessment, UMIT-University for Health Sciences, Medical Informatics and Technology, Hall in Tirol, Austria
- Neuroscience Institute, Christian Doppler University Hospital, Paracelsus Medical University and Centre for Cognitive Neuroscience Salzburg, Salzburg, Austria
| | - Janne Cadamuro
- Department of Laboratory Medicine, University Hospital SALK, Salzburg, Austria
| | - Martin Drerup
- Department of Urology, Paracelsus Medical University, Salzburg, Austria
| | - Katharina Schallmoser
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
- Department of Transfusion Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Ludwig Aigner
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
- Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Kathrin M. Kniewallner
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
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4
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Schroer AB, Branyan KW, Gross JD, Chantler PD, Kimple AJ, Vandenbeuch A, Siderovski DP. The stability of tastant detection by mouse lingual chemosensory tissue requires Regulator of G protein Signaling-21 (RGS21). Chem Senses 2021; 46:6414340. [PMID: 34718440 DOI: 10.1093/chemse/bjab048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The T1R and T2R families of G protein-coupled receptors (GPCRs) initiate tastant perception by signaling via guanine nucleotide exchange and hydrolysis performed by associated heterotrimeric G proteins (Gαβγ). Heterotrimeric G protein signal termination is sped up by Gα-directed GTPase-accelerating proteins (GAPs) known as the Regulators of G protein Signaling (RGS proteins). Of this family, RGS21 is highly expressed in lingual epithelial cells and we have shown it acting in vitro to decrease the potency of bitterants on cultured cells. However, constitutive RGS21 loss in mice reduces organismal response to GPCR-mediated tastants-opposite to expectations arising from observed in vitro activity of RGS21 as a GAP and inhibitor of T2R signaling. Here, we show reduced quinine aversion and reduced sucrose preference by mice lacking RGS21 does not result from post-ingestive effects, as taste-salient brief-access tests confirm the reduced bitterant aversion and reduced sweetener preference seen using two-bottle choice testing. Eliminating Rgs21 expression after chemosensory system development, via tamoxifen-induced Cre recombination in eight week-old mice, led to a reduction in quinine aversive behavior that advanced over time, suggesting that RGS21 functions as a negative regulator to sustain stable bitter tastant reception. Consistent with this notion, we observed downregulation of multiple T2R proteins in the lingual tissue of Rgs21-deficient mice. Reduced tastant-mediated responses exhibited by mice lacking Rgs21 expression either since birth or in adulthood has highlighted the potential requirement for a GPCR GAP to maintain the full character of tastant signaling, likely at the level of mitigating receptor downregulation.
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Affiliation(s)
- Adam B Schroer
- Department of Neuroscience, West Virginia University School of Medicine, 64 Medical Center Drive, Morgantown, WV 26506, USA
| | - Kayla W Branyan
- Division of Exercise Physiology, West Virginia University School of Medicine, 64 Medical Center Drive, Morgantown, WV 26506, USA
| | - Joshua D Gross
- Department of Cell Biology, Duke University Medical Center, 307 Research Drive, Durham, NC 27710, USA
| | - Paul D Chantler
- Division of Exercise Physiology, West Virginia University School of Medicine, 64 Medical Center Drive, Morgantown, WV 26506, USA
| | - Adam J Kimple
- Department of Otolaryngology and Marsico Lung Institute, UNC School of Medicine , 170 Manning Drive, Chapel Hill, NC 27599-7070, USA
| | - Aurelie Vandenbeuch
- Department of Otolaryngology, University of Colorado-Denver, Anschutz Medical Campus, 12700 E. 19th Avenue, Aurora, CO 80045, USA
| | - David P Siderovski
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107, USA
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5
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Horowitz AM, Fan X, Bieri G, Smith LK, Sanchez-Diaz CI, Schroer AB, Gontier G, Casaletto KB, Kramer JH, Williams KE, Villeda SA. Blood factors transfer beneficial effects of exercise on neurogenesis and cognition to the aged brain. Science 2020; 369:167-173. [PMID: 32646997 DOI: 10.1126/science.aaw2622] [Citation(s) in RCA: 197] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 10/15/2019] [Accepted: 05/15/2020] [Indexed: 12/21/2022]
Abstract
Reversing brain aging may be possible through systemic interventions such as exercise. We found that administration of circulating blood factors in plasma from exercised aged mice transferred the effects of exercise on adult neurogenesis and cognition to sedentary aged mice. Plasma concentrations of glycosylphosphatidylinositol (GPI)-specific phospholipase D1 (Gpld1), a GPI-degrading enzyme derived from liver, were found to increase after exercise and to correlate with improved cognitive function in aged mice, and concentrations of Gpld1 in blood were increased in active, healthy elderly humans. Increasing systemic concentrations of Gpld1 in aged mice ameliorated age-related regenerative and cognitive impairments by altering signaling cascades downstream of GPI-anchored substrate cleavage. We thus identify a liver-to-brain axis by which blood factors can transfer the benefits of exercise in old age.
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Affiliation(s)
- Alana M Horowitz
- Department of Anatomy, University of California, San Francisco, CA, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA, USA
| | - Xuelai Fan
- Department of Anatomy, University of California, San Francisco, CA, USA
| | - Gregor Bieri
- Department of Anatomy, University of California, San Francisco, CA, USA
| | - Lucas K Smith
- Department of Anatomy, University of California, San Francisco, CA, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA, USA
| | | | - Adam B Schroer
- Department of Anatomy, University of California, San Francisco, CA, USA
| | - Geraldine Gontier
- Department of Anatomy, University of California, San Francisco, CA, USA
| | - Kaitlin B Casaletto
- Department of Neurology, University of California, San Francisco, CA, USA.,Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Joel H Kramer
- Department of Neurology, University of California, San Francisco, CA, USA.,Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Katherine E Williams
- Sandler-Moore Mass Spectrometry Core Facility, University of California, San Francisco, CA, USA
| | - Saul A Villeda
- Department of Anatomy, University of California, San Francisco, CA, USA. .,Biomedical Sciences Graduate Program, University of California, San Francisco, CA, USA.,Department of Physical Therapy and Rehabilitation Science, San Francisco, CA, USA.,Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, San Francisco, CA, USA
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6
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Abstract
Exercise boosts neural stem and progenitor cell proliferation and differentiation in the dentate gyrus region of the hippocampus. In this issue of Stem Cell Reports, Leiter et al. (2019) identify acute exercise-induced platelet activation and platelet factor-4 as novel systemic mediators of adult hippocampal neurogenesis.
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Affiliation(s)
- Adam B Schroer
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA
| | - Alana M Horowitz
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA; Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Saul A Villeda
- Department of Anatomy, University of California San Francisco, San Francisco, CA, USA; Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA; Department of Physical Therapy and Rehabilitation Science, San Francisco, CA, USA; The Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, San Francisco, CA, USA.
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7
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Gross JD, Kaski SW, Schmidt KT, Cogan ES, Boyt KM, Wix K, Schroer AB, McElligott ZA, Siderovski DP, Setola V. Role of RGS12 in the differential regulation of kappa opioid receptor-dependent signaling and behavior. Neuropsychopharmacology 2019; 44:1728-1741. [PMID: 31141817 PMCID: PMC6785087 DOI: 10.1038/s41386-019-0423-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 05/14/2019] [Accepted: 05/17/2019] [Indexed: 12/23/2022]
Abstract
Kappa opioid receptor (KOR) agonists show promise in ameliorating disorders, such as addiction and chronic pain, but are limited by dysphoric and aversive side effects. Clinically beneficial effects of KOR agonists (e.g., analgesia) are predominantly mediated by heterotrimeric G protein signaling, whereas β-arrestin signaling is considered central to their detrimental side effects (e.g., dysphoria/aversion). Here we show that Regulator of G protein Signaling-12 (RGS12), via independent signaling mechanisms, simultaneously attenuates G protein signaling and augments β-arrestin signaling downstream of KOR, exhibiting considerable selectivity in its actions for KOR over other opioid receptors. We previously reported that RGS12-null mice exhibit increased dopamine transporter-mediated dopamine (DA) uptake in the ventral (vSTR), but not dorsal striatum (dSTR), as well as reduced psychostimulant-induced hyperlocomotion; in the current study, we found that these phenotypes are reversed following KOR antagonism. Fast-scan cyclic voltammetry studies of dopamine (DA) release and reuptake suggest that striatal disruptions to KOR-dependent DAergic neurotransmission in RGS12-null mice are restricted to the nucleus accumbens. In both ventral striatal tissue and transfected cells, RGS12 and KOR are seen to interact within a protein complex. Ventral striatal-specific increases in KOR levels and KOR-induced G protein activation are seen in RGS12-null mice, as well as enhanced sensitivity to KOR agonist-induced hypolocomotion and analgesia-G protein signaling-dependent behaviors; a ventral striatal-specific increase in KOR levels was also observed in β-arrestin-2-deficient mice, highlighting the importance of β-arrestin signaling to establishing steady-state KOR levels in this particular brain region. Conversely, RGS12-null mice exhibited attenuated KOR-induced conditioned place aversion (considered a β-arrestin signaling-dependent behavior), consistent with the augmented KOR-mediated β-arrestin signaling seen upon RGS12 over-expression. Collectively, our findings highlight a role for RGS12 as a novel, differential regulator of both G protein-dependent and -independent signaling downstream of KOR activation.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Animals
- Avoidance Learning/drug effects
- Behavior, Animal/drug effects
- Dopamine/metabolism
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Enkephalin, Leucine-2-Alanine/pharmacology
- Female
- Locomotion/drug effects
- Male
- Mice
- Mice, Knockout
- Nucleus Accumbens/drug effects
- Nucleus Accumbens/metabolism
- RGS Proteins/genetics
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/metabolism
- Signal Transduction
- Synaptic Transmission/drug effects
- Ventral Striatum/drug effects
- Ventral Striatum/metabolism
- beta-Arrestins/metabolism
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Affiliation(s)
- Joshua D Gross
- Department of Physiology & Pharmacology, 3048 HSN, West Virginia University Health Sciences Center, 64 Medical Center Drive, Morgantown, WV, 26508, USA
- Department of Neuroscience, West Virginia University, Morgantown, WV, 26506-9229, USA
- Department of Behavioral Medicine & Psychiatry, West Virginia University, Morgantown, WV, 26506-9229, USA
| | - Shane W Kaski
- Department of Physiology & Pharmacology, 3048 HSN, West Virginia University Health Sciences Center, 64 Medical Center Drive, Morgantown, WV, 26508, USA
- Department of Neuroscience, West Virginia University, Morgantown, WV, 26506-9229, USA
- Department of Behavioral Medicine & Psychiatry, West Virginia University, Morgantown, WV, 26506-9229, USA
| | - Karl T Schmidt
- Bowles Center for Alcohol Studies and Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Elizabeth S Cogan
- Bowles Center for Alcohol Studies and Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Kristen M Boyt
- Bowles Center for Alcohol Studies and Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Kim Wix
- Department of Physiology & Pharmacology, 3048 HSN, West Virginia University Health Sciences Center, 64 Medical Center Drive, Morgantown, WV, 26508, USA
| | - Adam B Schroer
- Department of Physiology & Pharmacology, 3048 HSN, West Virginia University Health Sciences Center, 64 Medical Center Drive, Morgantown, WV, 26508, USA
| | - Zoe A McElligott
- Bowles Center for Alcohol Studies and Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - David P Siderovski
- Department of Physiology & Pharmacology, 3048 HSN, West Virginia University Health Sciences Center, 64 Medical Center Drive, Morgantown, WV, 26508, USA.
- Department of Neuroscience, West Virginia University, Morgantown, WV, 26506-9229, USA.
| | - Vincent Setola
- Department of Physiology & Pharmacology, 3048 HSN, West Virginia University Health Sciences Center, 64 Medical Center Drive, Morgantown, WV, 26508, USA
- Department of Neuroscience, West Virginia University, Morgantown, WV, 26506-9229, USA
- Department of Behavioral Medicine & Psychiatry, West Virginia University, Morgantown, WV, 26506-9229, USA
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8
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Schroer AB, Mohamed JS, Willard MD, Setola V, Oestreich E, Siderovski DP. A role for Regulator of G protein Signaling-12 (RGS12) in the balance between myoblast proliferation and differentiation. PLoS One 2019; 14:e0216167. [PMID: 31408461 PMCID: PMC6691989 DOI: 10.1371/journal.pone.0216167] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/15/2019] [Indexed: 12/28/2022] Open
Abstract
Regulators of G Protein Signaling (RGS proteins) inhibit G protein-coupled receptor (GPCR) signaling by accelerating the GTP hydrolysis rate of activated Gα subunits. Some RGS proteins exert additional signal modulatory functions, and RGS12 is one such protein, with five additional, functional domains: a PDZ domain, a phosphotyrosine-binding domain, two Ras-binding domains, and a Gα·GDP-binding GoLoco motif. RGS12 expression is temporospatially regulated in developing mouse embryos, with notable expression in somites and developing skeletal muscle. We therefore examined whether RGS12 is involved in the skeletal muscle myogenic program. In the adult mouse, RGS12 is expressed in the tibialis anterior (TA) muscle, and its expression is increased early after cardiotoxin-induced injury, suggesting a role in muscle regeneration. Consistent with a potential role in coordinating myogenic signals, RGS12 is also expressed in primary myoblasts; as these cells undergo differentiation and fusion into myotubes, RGS12 protein abundance is reduced. Myoblasts isolated from mice lacking Rgs12 expression have an impaired ability to differentiate into myotubes ex vivo, suggesting that RGS12 may play a role as a modulator/switch for differentiation. We also assessed the muscle regenerative capacity of mice conditionally deficient in skeletal muscle Rgs12 expression (via Pax7-driven Cre recombinase expression), following cardiotoxin-induced damage to the TA muscle. Eight days post-damage, mice lacking RGS12 in skeletal muscle had attenuated repair of muscle fibers. However, when mice lacking skeletal muscle expression of Rgs12 were cross-bred with mdx mice (a model of human Duchenne muscular dystrophy), no increase in muscle degeneration was observed over time. These data support the hypothesis that RGS12 plays a role in coordinating signals during the myogenic program in select circumstances, but loss of the protein may be compensated for within model syndromes of prolonged bouts of muscle damage and repair.
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Affiliation(s)
- Adam B. Schroer
- Department of Physiology & Pharmacology, WVU School of Medicine, West Virginia University, Morgantown, WV, United States of America
| | - Junaith S. Mohamed
- Division of Exercise Physiology, West Virginia University, Morgantown, WV, United States of America
| | - Melinda D. Willard
- Department of Pharmacology, The University of North Carolina, Chapel Hill, NC, United States of America
| | - Vincent Setola
- Department of Neuroscience, West Virginia University, Morgantown, WV, United States of America
| | - Emily Oestreich
- Department of Pharmacology, The University of North Carolina, Chapel Hill, NC, United States of America
- * E-mail: (EO); (DPS)
| | - David P. Siderovski
- Department of Physiology & Pharmacology, WVU School of Medicine, West Virginia University, Morgantown, WV, United States of America
- * E-mail: (EO); (DPS)
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9
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Schroer AB, Gross JD, Kaski SW, Wix K, Siderovski DP, Vandenbeuch A, Setola V. Development of Full Sweet, Umami, and Bitter Taste Responsiveness Requires Regulator of G protein Signaling-21 (RGS21). Chem Senses 2018; 43:367-378. [PMID: 29701767 PMCID: PMC6276893 DOI: 10.1093/chemse/bjy024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The mammalian tastes of sweet, umami, and bitter are initiated by activation of G protein-coupled receptors (GPCRs) of the T1R and T2R families on taste receptor cells. GPCRs signal via nucleotide exchange and hydrolysis, the latter hastened by GTPase-accelerating proteins (GAPs) that include the Regulators of G protein Signaling (RGS) protein family. We previously reported that RGS21, uniquely expressed in Type II taste receptor cells, decreases the potency of bitter-stimulated T2R signaling in cultured cells, consistent with its in vitro GAP activity. However, the role of RGS21 in organismal responses to GPCR-mediated tastants was not established. Here, we characterized mice lacking the Rgs21 fifth exon. Eliminating Rgs21 expression had no effect on body mass accumulation (a measure of alimentation), fungiform papillae number and morphology, circumvallate papillae morphology, and taste bud number. Two-bottle preference tests, however, revealed that Rgs21-null mice have blunted aversion to quinine and denatonium, and blunted preference for monosodium glutamate, the sweeteners sucrose and SC45647, and (surprisingly) NaCl. Observed reductions in GPCR-mediated tastant responses upon Rgs21 loss are opposite to original expectations, given that loss of RGS21-a GPCR signaling negative regulator-should lead to increased responsiveness to tastant-mediated GPCR signaling (all else being equal). Yet, reduced organismal tastant responses are consistent with observations of reduced chorda tympani nerve recordings in Rgs21-null mice. Reduced tastant-mediated responses and behaviors exhibited by adult mice lacking Rgs21 expression since birth have thus revealed an underappreciated requirement for a GPCR GAP to establish the full character of tastant signaling.
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Affiliation(s)
- Adam B Schroer
- Department of Physiology, Pharmacology, and Neuroscience, West Virginia School of Medicine, One Medical Center Drive, Morgantown, WV, USA
| | - Joshua D Gross
- Department of Physiology, Pharmacology, and Neuroscience, West Virginia School of Medicine, One Medical Center Drive, Morgantown, WV, USA
| | - Shane W Kaski
- Department of Physiology, Pharmacology, and Neuroscience, West Virginia School of Medicine, One Medical Center Drive, Morgantown, WV, USA
| | - Kim Wix
- Department of Physiology, Pharmacology, and Neuroscience, West Virginia School of Medicine, One Medical Center Drive, Morgantown, WV, USA
| | - David P Siderovski
- Department of Physiology, Pharmacology, and Neuroscience, West Virginia School of Medicine, One Medical Center Drive, Morgantown, WV, USA
| | - Aurelie Vandenbeuch
- Department of Otolaryngology, University of Colorado - Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Vincent Setola
- Department of Physiology, Pharmacology, and Neuroscience, West Virginia School of Medicine, One Medical Center Drive, Morgantown, WV, USA
- Department of Behavioral Medicine and Psychiatry, West Virginia School of Medicine, Morgantown, WV, USA
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10
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Gross JD, Kaski SW, Schroer AB, Wix KA, Siderovski DP, Setola V. Regulator of G protein signaling-12 modulates the dopamine transporter in ventral striatum and locomotor responses to psychostimulants. J Psychopharmacol 2018; 32:191-203. [PMID: 29364035 PMCID: PMC5942192 DOI: 10.1177/0269881117742100] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Regulators of G protein signaling are proteins that accelerate the termination of effector stimulation after G protein-coupled receptor activation. Many regulators of G protein signaling proteins are highly expressed in the brain and therefore considered potential drug discovery targets for central nervous system pathologies; for example, here we show that RGS12 is highly expressed in microdissected mouse ventral striatum. Given a role for the ventral striatum in psychostimulant-induced locomotor activity, we tested whether Rgs12 genetic ablation affected behavioral responses to amphetamine and cocaine. RGS12 loss significantly decreased hyperlocomotion to lower doses of both amphetamine and cocaine; however, other outcomes of administration (sensitization and conditioned place preference) were unaffected, suggesting that RGS12 does not function in support of the rewarding properties of these psychostimulants. To test whether observed response changes upon RGS12 loss were caused by changes to dopamine transporter expression and/or function, we prepared crude membranes from the brains of wild-type and RGS12-null mice and measured dopamine transporter-selective [3H]WIN 35428 binding, revealing an increase in dopamine transporter levels in the ventral-but not dorsal-striatum of RGS12-null mice. To address dopamine transporter function, we prepared striatal synaptosomes and measured [3H]dopamine uptake. Consistent with increased [3H]WIN 35428 binding, dopamine transporter-specific [3H]dopamine uptake in RGS12-null ventral striatal synaptosomes was found to be increased. Decreased amphetamine-induced locomotor activity and increased [3H]WIN 35428 binding were recapitulated with an independent RGS12-null mouse strain. Thus, we propose that RGS12 regulates dopamine transporter expression and function in the ventral striatum, affecting amphetamine- and cocaine-induced increases in dopamine levels that specifically elicit acute hyperlocomotor responses.
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Affiliation(s)
- Joshua D Gross
- Department of Physiology, Pharmacology and Neuroscience, West Virginia School of Medicine, Morgantown, USA
| | - Shane W Kaski
- Department of Physiology, Pharmacology and Neuroscience, West Virginia School of Medicine, Morgantown, USA
| | - Adam B Schroer
- Department of Physiology, Pharmacology and Neuroscience, West Virginia School of Medicine, Morgantown, USA
| | - Kimberley A Wix
- Department of Physiology, Pharmacology and Neuroscience, West Virginia School of Medicine, Morgantown, USA
| | - David P Siderovski
- Department of Physiology, Pharmacology and Neuroscience, West Virginia School of Medicine, Morgantown, USA
| | - Vincent Setola
- Department of Physiology, Pharmacology and Neuroscience, West Virginia School of Medicine, Morgantown, USA,Department of Behavioral Medicine and Psychiatry, West Virginia School of Medicine, Morgantown, USA
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11
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Luden ND, Saunders MJ, D'Lugos AC, Pataky MW, Baur DA, Vining CB, Schroer AB. Carbohydrate Mouth Rinsing Enhances High Intensity Time Trial Performance Following Prolonged Cycling. Nutrients 2016; 8:nu8090576. [PMID: 27657117 PMCID: PMC5037560 DOI: 10.3390/nu8090576] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 09/12/2016] [Accepted: 09/14/2016] [Indexed: 11/17/2022] Open
Abstract
There is good evidence that mouth rinsing with carbohydrate (CHO) solutions can enhance endurance performance (≥30 min). The impact of a CHO mouth rinse on sprint performance has been less consistent, suggesting that CHO may confer benefits in conditions of ‘metabolic strain’. To test this hypothesis, the current study examined the impact of late-exercise mouth rinsing on sprint performance. Secondly, we investigated the effects of a protein mouth rinse (PRO) on performance. Eight trained male cyclists participated in three trials consisting of 120 min of constant-load cycling (55% Wmax) followed by a 30 km computer-simulated time trial, during which only water was provided. Following 15 min of muscle function assessment, 10 min of constant-load cycling (3 min at 35% Wmax, 7 min at 55% Wmax) was performed. This was immediately followed by a 2 km time trial. Subjects rinsed with 25 mL of CHO, PRO, or placebo (PLA) at min 5:00 and 14:30 of the 15 min muscle function phase, and min 8:00 of the 10-min constant-load cycling. Magnitude-based inferential statistics were used to analyze the effects of the mouth rinse on 2-km time trial performance and the following physiological parameters: Maximum Voluntary Contract (MVC), Rating of Perceived Exertion (RPE), Heart Rate (HR), and blood glucose levels. The primary finding was that CHO ‘likely’ enhanced performance vs. PLA (3.8%), whereas differences between PRO and PLA were unclear (0.4%). These data demonstrate that late-race performance is enhanced by a CHO rinse, but not PRO, under challenging metabolic conditions. More data should be acquired before this strategy is recommended for the later stages of cycling competition under more practical conditions, such as when carbohydrates are supplemented throughout the preceding minutes/hours of exercise.
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Affiliation(s)
- Nicholas D Luden
- Human Performance Lab, Department of Kinesiology, James Madison University, Harrisonburg, VA 22807, USA.
| | - Michael J Saunders
- Human Performance Lab, Department of Kinesiology, James Madison University, Harrisonburg, VA 22807, USA.
| | - Andrew C D'Lugos
- Human Performance Lab, Department of Kinesiology, James Madison University, Harrisonburg, VA 22807, USA.
| | - Mark W Pataky
- Human Performance Lab, Department of Kinesiology, James Madison University, Harrisonburg, VA 22807, USA.
| | - Daniel A Baur
- Human Performance Lab, Department of Kinesiology, James Madison University, Harrisonburg, VA 22807, USA.
| | - Caitlin B Vining
- Human Performance Lab, Department of Kinesiology, James Madison University, Harrisonburg, VA 22807, USA.
| | - Adam B Schroer
- Human Performance Lab, Department of Kinesiology, James Madison University, Harrisonburg, VA 22807, USA.
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12
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Gall BJ, Schroer AB, Gross JD, Setola V, Siderovski DP. Reduction of GPSM3 expression akin to the arthritis-protective SNP rs204989 differentially affects migration in a neutrophil model. Genes Immun 2016; 17:321-7. [PMID: 27307211 PMCID: PMC5009006 DOI: 10.1038/gene.2016.26] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/03/2016] [Accepted: 05/09/2016] [Indexed: 12/11/2022]
Abstract
G Protein Signaling Modulator-3 (GPSM3) is a leukocyte-specific regulator of G protein-coupled receptors (GPCRs), which binds inactivated Gαi·GDP subunits and precludes their reassociation with Gβγ subunits. GPSM3 deficiency protects mice from inflammatory arthritis and, in humans, GPSM3 single nucleotide polymorphisms (SNPs) are inversely associated with the risk of rheumatoid arthritis development; recently, these polymorphisms were linked to one particular SNP (rs204989) that decreases GPSM3 transcript abundance. However, the precise role of GPSM3 in leukocyte biology is unknown. Here we show that GPSM3 is induced in the human promyelocytic leukemia NB4 cell line following retinoic acid treatment, which differentiates this cell line into a model of neutrophil physiology (NB4*). Reducing GPSM3 expression in NB4* cells, akin to the effect ascribed to the rs204989 C>T transition, disrupts cellular migration toward leukotriene B4 (LTB4) and (to a lesser extent) interleukin-8 (a.k.a. IL-8 or CXCL8), but not migration toward formylated peptides (fMLP). As the chemoattractants LTB4 and CXCL8 are involved in recruitment of neutrophils to the arthritic joint, our results suggest that the arthritis-protective GPSM3 SNP rs204989 may act to decrease neutrophil chemoattractant responsiveness.
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Affiliation(s)
- B J Gall
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA
| | - A B Schroer
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA
| | - J D Gross
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA
| | - V Setola
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA.,Department of Behavioral Medicine and Psychiatry, West Virginia University School of Medicine, Morgantown, WV, USA
| | - D P Siderovski
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA
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Gall BJ, Wilson A, Schroer AB, Gross JD, Stoilov P, Setola V, Watkins CM, Siderovski DP. Genetic variations in GPSM3 associated with protection from rheumatoid arthritis affect its transcript abundance. Genes Immun 2016; 17:139-47. [PMID: 26821282 PMCID: PMC4777669 DOI: 10.1038/gene.2016.3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 12/16/2022]
Abstract
G protein signaling modulator 3 (GPSM3) is a regulator of G protein-coupled receptor signaling, with expression restricted to leukocytes and lymphoid organs. Previous genome-wide association studies have highlighted single-nucleotide polymorphisms (SNPs; rs204989 and rs204991) in a region upstream of the GPSM3 transcription start site as being inversely correlated to the prevalence of rheumatoid arthritis (RA)-this association is supported by the protection afforded to Gpsm3-deficient mice in models of inflammatory arthritis. Here, we assessed the functional consequences of these polymorphisms. We collected biospecimens from 50 volunteers with RA diagnoses, 50 RA-free volunteers matched to the aforementioned group and 100 unmatched healthy young volunteers. We genotyped these individuals for GPSM3 (rs204989, rs204991), CCL21 (rs2812378) and HLA gene region (rs6457620) polymorphisms, and found no significant differences in minor allele frequencies between the RA and disease-free cohorts. However, we identified that individuals homozygous for SNPs rs204989 and rs204991 had decreased GPSM3 transcript abundance relative to individuals homozygous for the major allele. In vitro promoter activity studies suggest that SNP rs204989 is the primary cause of this decrease in transcript levels. Knockdown of GPSM3 in THP-1 cells, a human monocytic cell line, was found to disrupt ex vivo migration to the chemokine MCP-1.
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Affiliation(s)
- BJ Gall
- Department of Physiology & Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA 26506-9229
| | - A Wilson
- Department of Orthopaedics, West Virginia University School of Medicine, Morgantown, WV, USA 26506-9229
| | - AB Schroer
- Department of Physiology & Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA 26506-9229
| | - JD Gross
- Department of Physiology & Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA 26506-9229
| | - P Stoilov
- Department of Biochemistry, West Virginia University School of Medicine, Morgantown, WV, USA 26506-9229
| | - V Setola
- Department of Physiology & Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA 26506-9229
- Department of Behavioral Medicine & Psychiatry, West Virginia University School of Medicine, Morgantown, WV, USA 26506-9229
| | - CM Watkins
- Department of Orthopaedics, West Virginia University School of Medicine, Morgantown, WV, USA 26506-9229
| | - DP Siderovski
- Department of Physiology & Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA 26506-9229
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Baur DA, Schroer AB, Luden ND, Womack CJ, Smyth SA, Saunders MJ. Glucose-fructose enhances performance versus isocaloric, but not moderate, glucose. Med Sci Sports Exerc 2015; 46:1778-86. [PMID: 25134001 DOI: 10.1249/mss.0000000000000284] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE The effects of glucose-and-fructose (GF) coingestion on cycling time trial (TT) performance and physiological responses to exercise were examined under postprandial conditions. METHODS Eight trained male cyclists (age, 25 ± 6 yr; height, 180 ± 4 cm; weight, 77 ± 9 kg; V˙O2max, 62 ± 6 mL·kg·min) completed the study. Subjects ingested either an artificially sweetened placebo (PL), a moderate-glucose beverage (MG, 1.03 g·min), a high-glucose beverage (HG, 1.55 g·min), or a GF beverage (1.55 g·min, 2:1 ratio) during approximately 3 h of exercise, including 2 h of constant-load cycling (55% Wmax, 195 ± 17 W), immediately followed by a computer-simulated 30-km TT. Physiological responses (V˙E, V˙O2, RER, HR, blood glucose level, blood lactate level, and RPE) and incidences of gastrointestinal distress were assessed during early (15-20 min), middle (55-60 min), and late exercise (115-120 min) and during the TT. Magnitude-based qualitative inferences were used to evaluate differences between treatments. RESULTS In comparison with that in PL (52.9 ± 3.7 min), TT performances were faster with GF (50.4 ± 2.2 min, "very likely" benefit), MG (51.1 ± 2.4 min, "likely" benefit), and HG (52.0 ± 3.7 min, "possible" benefit). GF resulted in a "likely" improvement versus HG (3.0%) and an "unclear" effect relative to MG (1.2%). MG was "possibly" beneficial versus HG (1.8%). Few incidences of GI distress were reported in any trials. CONCLUSIONS GF ingestion seems to enhance performance, relative to PL and HG. However, it is unclear whether GF improves performance versus moderate doses of glucose.
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Affiliation(s)
- Daniel A Baur
- Human Performance Laboratory, Department of Kinesiology, James Madison University, Harrisonburg, VA
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Baur DA, Schroer AB, Luden ND, Womack CJ, Smyth SA, Saunders MJ. Glucose and Fructose Coingestion Augments Cycling Performance Versus Isocaloric, But Not Moderate, Glucose Intake. Med Sci Sports Exerc 2014. [DOI: 10.1249/01.mss.0000493635.48965.f2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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