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Giordano KR, Saber M, Green TR, Rojas-Valencia LM, Ortiz JB, Murphy SM, Lifshitz J, Rowe RK. Colony-Stimulating Factor-1 Receptor Inhibition Transiently Attenuated the Peripheral Immune Response to Experimental Traumatic Brain Injury. Neurotrauma Rep 2023; 4:284-296. [PMID: 37139183 PMCID: PMC10150725 DOI: 10.1089/neur.2022.0092] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
To investigate microglial mechanisms in central and peripheral inflammation after experimental traumatic brain injury (TBI), we inhibited the colony-stimulating factor-1 receptor (CSF-1R) with PLX5622 (PLX). We hypothesized that microglia depletion would attenuate central inflammation acutely with no effect on peripheral inflammation. After randomization, male mice (n = 105) were fed PLX or control diets (21 days) and then received midline fluid percussion injury or sham injury. Brain and blood were collected at 1, 3, or 7 days post-injury (DPI). Immune cell populations were quantified in the brain and blood by flow cytometry. Cytokines (interleukin [IL]-6, IL-1β, tumor necrosis factor-α, interferon-γ, IL-17A, and IL-10) were quantified in the blood using a multi-plex enzyme-linked immunosorbent assay. Data were analyzed using Bayesian multi-variate, multi-level models. PLX depleted microglia at all time points and reduced neutrophils in the brain at 7 DPI. PLX also depleted CD115+ monocytes, reduced myeloid cells, neutrophils, and Ly6Clow monocytes in blood, and elevated IL-6. TBI induced a central and peripheral immune response. TBI elevated leukocytes, microglia, and macrophages in the brain and elevated peripheral myeloid cells, neutrophils, Ly6Cint monocytes, and IL-1β in the blood. TBI lowered peripheral CD115+ and Ly6Clow monocytes in the blood. TBI PLX mice had fewer leukocytes and microglia in the brain at 1 DPI, with elevated neutrophils at 7 DPI compared to TBI mice on a control diet. TBI PLX mice also had fewer peripheral myeloid cells, CD115+, and Ly6Clow monocytes in the blood at 3 DPI, but elevated Ly6Chigh, Ly6Cint, and CD115+ monocyte populations at 7 DPI, compared to TBI mice on a control diet. TBI PLX mice had elevated proinflammatory cytokines and lower anti-inflammatory cytokines in the blood at 7 DPI compared to TBI mice on a control diet. CSF-1R inhibition reduced the immune response to TBI at 1 and 3 DPI, but elevated peripheral inflammation at 7 DPI.
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Affiliation(s)
- Katherine R. Giordano
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA
- Department of Child Health, University of Arizona College of Medicine–Phoenix, Phoenix, Arizona, USA
- Phoenix Veteran Affairs Health Care System, Phoenix, Arizona, USA
| | - Maha Saber
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA
- Department of Child Health, University of Arizona College of Medicine–Phoenix, Phoenix, Arizona, USA
| | - Tabitha R.F. Green
- Department of Child Health, University of Arizona College of Medicine–Phoenix, Phoenix, Arizona, USA
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Luisa M. Rojas-Valencia
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA
- Department of Child Health, University of Arizona College of Medicine–Phoenix, Phoenix, Arizona, USA
- Phoenix Veteran Affairs Health Care System, Phoenix, Arizona, USA
| | - J. Bryce Ortiz
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA
- Department of Child Health, University of Arizona College of Medicine–Phoenix, Phoenix, Arizona, USA
- Phoenix Veteran Affairs Health Care System, Phoenix, Arizona, USA
| | - Sean M. Murphy
- Department of Child Health, University of Arizona College of Medicine–Phoenix, Phoenix, Arizona, USA
| | - Jonathan Lifshitz
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA
- Department of Child Health, University of Arizona College of Medicine–Phoenix, Phoenix, Arizona, USA
- Phoenix Veteran Affairs Health Care System, Phoenix, Arizona, USA
| | - Rachel K. Rowe
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, USA
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Roe KL, Giordano KR, Ezzell GA, Lifshitz J. Public Awareness of the Fencing Response as an Indicator of Traumatic Brain Injury: Quantitative Study of Twitter and Wikipedia Data. JMIR Form Res 2023; 7:e39061. [PMID: 36930198 PMCID: PMC10132037 DOI: 10.2196/39061] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 01/23/2023] [Accepted: 01/24/2023] [Indexed: 03/18/2023] Open
Abstract
BACKGROUND Traumatic brain injury (TBI) is a disruption in normal brain function caused by an impact of external forces on the head. TBI affects millions of individuals per year, many potentially experiencing chronic symptoms and long-term disability, creating a public health crisis and an economic burden on society. The public discourse around sport-related TBIs has increased in recent decades; however, recognition of a possible TBI remains a challenge. The fencing response is an immediate posturing of the limbs, which can occur in individuals who sustain a TBI and can be used as an overt indicator of TBI. Typically, an individual demonstrating the fencing response exhibits extension in 1 arm and flexion in the contralateral arm immediately upon impact to the head; variations of forearm posturing among each limb have been observed. The tonic posturing is retained for several seconds, sufficient for observation and recognition of a TBI. Since the publication of the original peer-reviewed article on the fencing response, there have been efforts to raise awareness of the fencing response as a visible sign of TBI through publicly available web-based platforms, such as Twitter and Wikipedia. OBJECTIVE We aimed to quantify trends that demonstrate levels of public discussion and awareness of the fencing response over time using data from Twitter and Wikipedia. METHODS Raw Twitter data from January 1, 2010, to December 31, 2019, were accessed using the RStudio package academictwitteR and queried for the text "fencing response." Data for page views of the Fencing Response Wikipedia article from January 1, 2010, to December 31, 2019, were accessed using the RStudio packages wikipediatrend and pageviews. Data were clustered by weekday, month, half-year (to represent the American football season vs off-season), and year to identify trends over time. Seasonal regression analysis was used to analyze the relationship between the number of fencing response tweets and page views and month of the year. RESULTS Twitter mentions of the fencing response and Wikipedia page views increased overall from 2010 to 2019, with hundreds of tweets and hundreds of thousands of Wikipedia page views per year. Twitter mentions peaked during the American football season, especially on and following game days. Wikipedia page views did not demonstrate a clear weekday or seasonal pattern, but instead had multiple peaks across various months and years, with January having more page views than May. CONCLUSIONS Here, we demonstrated increased awareness of the fencing response over time using public data from Twitter and Wikipedia. Effective scientific communication through free public platforms can help spread awareness of clinical indicators of TBI, such as the fencing response. Greater awareness of the fencing response as a "red-flag" sign of TBI among coaches, athletic trainers, and sports organizations can help with medical care and return-to-play decisions.
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Affiliation(s)
- Kyle L Roe
- Department of Psychiatry, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, United States
| | - Katherine R Giordano
- Department of Psychiatry, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, United States.,Phoenix Veteran Affairs Health Care System, Phoenix, AZ, United States
| | - Gary A Ezzell
- Department of Psychiatry, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, United States
| | - Jonathan Lifshitz
- Department of Psychiatry, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, United States.,Phoenix Veteran Affairs Health Care System, Phoenix, AZ, United States
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3
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Wilson RJ, Bell MR, Giordano KR, Seyburn S, Kozlowski DA. Repeat subconcussion in the adult rat gives rise to behavioral deficits similar to a single concussion but different depending upon sex. Behav Brain Res 2023; 438:114206. [PMID: 36356721 DOI: 10.1016/j.bbr.2022.114206] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/20/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022]
Abstract
Although concussions are a popular focus of neurotrauma research, subconcussions occur with higher frequency but are less well-studied. A subconcussion is an impact to the head that does not result in immediately diagnosable concussion but can result in later neurological consequences. Repeat subconcussions can produce behavioral impairments and neuropathology that is similar to or worse than those seen following a single concussion. The current study modified a previously established closed head injury model of concussion to create a subconcussion model and examines sex differences in behavioral responses to repeated subconcussion in the adult rat. Rats received a single concussion, single or repeat subconcussions, or no impact and behavior was monitored from 2 h through 31 days post-injury. A single concussion or repeat subconcussion resulted in deficits in locomotion, righting reflexes, and recognition memory. The degree of deficit induced by repeat subconcussions were either similar (righting reflexes) or greater/more persistent (locomotor deficits and recognition memory) than that of a concussion. Single subconcussion resulted in acute deficits that were mild and limited to righting reflexes and locomotion. Sex differences were observed in responses to repeat subconcussion: females showed greater deficits in righting reflexes, locomotion, and vestibular function, while males showed greater alterations in anxiety and depressive-like behavior. This study established a model of subconcussive impact where a single subconcussive impact resulted in minimal behavioral deficits but repeat subconcussions resulted in deficits similar to or worse than a single concussion. Our data also suggest sex differences in behavioral responses to both concussive and subconcussive impacts.
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Affiliation(s)
- Rebecca J Wilson
- Department of Biological Sciences, DePaul University, 2325 N. Clifton, Chicago, IL, USA.
| | - Margaret R Bell
- Department of Biological Sciences, DePaul University, 2325 N. Clifton, Chicago, IL, USA; Department of Health Sciences, DePaul University, 1110 W. Belden, Chicago, IL, USA.
| | - Katherine R Giordano
- Department of Biological Sciences, DePaul University, 2325 N. Clifton, Chicago, IL, USA.
| | - Serena Seyburn
- Department of Biological Sciences, DePaul University, 2325 N. Clifton, Chicago, IL, USA.
| | - Dorothy A Kozlowski
- Department of Biological Sciences, DePaul University, 2325 N. Clifton, Chicago, IL, USA; Neuroscience Program, DePaul University, 2325 N. Clifton, Chicago, IL, USA.
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Rowe RK, Green TRF, Giordano KR, Ortiz JB, Murphy SM, Opp MR. Microglia Are Necessary to Regulate Sleep after an Immune Challenge. Biology 2022; 11:biology11081241. [PMID: 36009868 PMCID: PMC9405260 DOI: 10.3390/biology11081241] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 07/29/2022] [Accepted: 08/17/2022] [Indexed: 12/31/2022]
Abstract
Microglia play a critical role in the neuroimmune response, but little is known about the role of microglia in sleep following an inflammatory trigger. Nevertheless, decades of research have been predicated on the assumption that an inflammatory trigger increases sleep through microglial activation. We hypothesized that mice (n = 30) with depleted microglia using PLX5622 (PLX) would sleep less following the administration of lipopolysaccharide (LPS) to induce inflammation. Brains were collected and microglial morphology was assessed using quantitative skeletal analyses and physiological parameters were recorded using non-invasive piezoelectric cages. Mice fed PLX diet had a transient increase in sleep that dissipated by week 2. Subsequently, following a first LPS injection (0.4 mg/kg), mice with depleted microglia slept more than mice on the control diet. All mice were returned to normal rodent chow to repopulate microglia in the PLX group (10 days). Nominal differences in sleep existed during the microglia repopulation period. However, following a second LPS injection, mice with repopulated microglia slept similarly to control mice during the dark period but with longer bouts during the light period. Comparing sleep after the first LPS injection to sleep after the second LPS injection, controls exhibited temporal changes in sleep patterns but no change in cumulative minutes slept, whereas cumulative sleep in mice with repopulated microglia decreased during the dark period across all days. Repopulated microglia had a reactive morphology. We conclude that microglia are necessary to regulate sleep after an immune challenge.
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Affiliation(s)
- Rachel K. Rowe
- Department of Integrative Physiology, University of Colorado, Boulder, CO 80301, USA
- Barrow Neurological Institute at Phoenix Children’s Hospital, Phoenix, AZ 85016, USA
- Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
- Correspondence: ; Tel.: +1-303-735-0309
| | - Tabitha R. F. Green
- Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
| | - Katherine R. Giordano
- Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
- Phoenix Veterans Affairs Health Care System, Phoenix, AZ 85012, USA
| | - J. Bryce Ortiz
- Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
- Phoenix Veterans Affairs Health Care System, Phoenix, AZ 85012, USA
| | - Sean M. Murphy
- Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
| | - Mark R. Opp
- Department of Integrative Physiology, University of Colorado, Boulder, CO 80301, USA
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5
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Giordano KR, Law LM, Henderson J, Rowe RK, Lifshitz J. Time Course of Remote Neuropathology Following Diffuse Traumatic Brain Injury in the Male Rat. Exp Neurobiol 2022; 31:105-115. [PMID: 35673999 PMCID: PMC9194637 DOI: 10.5607/en21027] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 12/15/2021] [Accepted: 04/12/2022] [Indexed: 11/19/2022] Open
Abstract
Traumatic brain injury (TBI) can affect different regions throughout the brain. Regions near the site of impact are the most vulnerable to injury. However, damage to distal regions occurs. We investigated progressive neuropathology in the dorsal hippocampus (near the impact) and cerebellum (distal to the impact) after diffuse TBI. Adult male rats were subjected to midline fluid percussion injury or sham injury. Brain tissue was stained by the amino cupric silver stain. Neuropathology was quantified in sub-regions of the dorsal hippocampus at 1, 7, and 28 days post-injury (DPI) and coronal cerebellar sections at 1, 2, and 7 DPI. The highest observed neuropathology in the dentate gyrus occurred at 7 DPI which attenuated by 28 DPI, whereas the highest observed neuropathology was at 1 DPI in the CA3 region. There was no significant neuropathology in the CA1 region at any time point. Neuropathology was increased at 7 DPI in the cerebellum compared to shams and stripes of pathology were observed in the molecular layer perpendicular to the cerebellar cortical surface. Together these data show that diffuse TBI can result in neuropathology across the brain. By describing the time course of pathology in response to TBI, it is possible to build the temporal profile of disease progression.
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Affiliation(s)
- Katherine R Giordano
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ 85013, USA.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ 85004, USA.,Phoenix Veterans Affairs Health Care System, Phoenix, AZ 85012, USA
| | - L Matthew Law
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ 85013, USA.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ 85004, USA.,Phoenix Veterans Affairs Health Care System, Phoenix, AZ 85012, USA
| | - Jordan Henderson
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ 85013, USA.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ 85004, USA
| | - Rachel K Rowe
- Department of Integrative Physiology, University of Colorado, Boulder, CO 80309, USA
| | - Jonathan Lifshitz
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ 85013, USA.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ 85004, USA.,Phoenix Veterans Affairs Health Care System, Phoenix, AZ 85012, USA
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6
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Apostol CR, Bernard K, Tanguturi P, Molnar G, Bartlett MJ, Szabò L, Liu C, Ortiz JB, Saber M, Giordano KR, Green TRF, Melvin J, Morrison HW, Madhavan L, Rowe RK, Streicher JM, Heien ML, Falk T, Polt R. Design and Synthesis of Brain Penetrant Glycopeptide Analogues of PACAP With Neuroprotective Potential for Traumatic Brain Injury and Parkinsonism. Front Drug Discov (Lausanne) 2022; 1. [PMID: 35237767 PMCID: PMC8887546 DOI: 10.3389/fddsv.2021.818003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
There is an unmet clinical need for curative therapies to treat neurodegenerative disorders. Most mainstay treatments currently on the market only alleviate specific symptoms and do not reverse disease progression. The Pituitary adenylate cyclase-activating polypeptide (PACAP), an endogenous neuropeptide hormone, has been extensively studied as a potential regenerative therapeutic. PACAP is widely distributed in the central nervous system (CNS) and exerts its neuroprotective and neurotrophic effects via the related Class B GPCRs PAC1, VPAC1, and VPAC2, at which the hormone shows roughly equal activity. Vasoactive intestinal peptide (VIP) also activates these receptors, and this close analogue of PACAP has also shown to promote neuronal survival in various animal models of acute and progressive neurodegenerative diseases. However, PACAP's poor pharmacokinetic profile (non-linear PK/PD), and more importantly its limited blood-brain barrier (BBB) permeability has hampered development of this peptide as a therapeutic. We have demonstrated that glycosylation of PACAP and related peptides promotes penetration of the BBB and improves PK properties while retaining efficacy and potency in the low nanomolar range at its target receptors. Furthermore, judicious structure-activity relationship (SAR) studies revealed key motifs that can be modulated to afford compounds with diverse selectivity profiles. Most importantly, we have demonstrated that select PACAP glycopeptide analogues (2LS80Mel and 2LS98Lac) exert potent neuroprotective effects and anti-inflammatory activity in animal models of traumatic brain injury and in a mild-toxin lesion model of Parkinson's disease, highlighting glycosylation as a viable strategy for converting endogenous peptides into robust and efficacious drug candidates.
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Affiliation(s)
- Christopher R Apostol
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - Kelsey Bernard
- Graduate Interdisciplinary Program in Physiological Sciences, The University of Arizona, Tucson, AZ, United States
| | | | - Gabriella Molnar
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Mitchell J Bartlett
- Department of Neurology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Lajos Szabò
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - Chenxi Liu
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - J Bryce Ortiz
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Phoenix Veteran Affairs Health Care System, Phoenix, AZ, United States
| | - Maha Saber
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States
| | - Katherine R Giordano
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Phoenix Veteran Affairs Health Care System, Phoenix, AZ, United States
| | - Tabitha R F Green
- Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States
| | - James Melvin
- Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Biological Sciences, University of Bath, Bath, United Kingdom
| | - Helena W Morrison
- College of Nursing, University of Arizona, Tucson, AZ, United States
| | - Lalitha Madhavan
- Graduate Interdisciplinary Program in Physiological Sciences, The University of Arizona, Tucson, AZ, United States.,Department of Neurology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Rachel K Rowe
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States
| | - John M Streicher
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Michael L Heien
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - Torsten Falk
- Graduate Interdisciplinary Program in Physiological Sciences, The University of Arizona, Tucson, AZ, United States.,Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States.,Department of Neurology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Robin Polt
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
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7
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Giordano KR, Denman CR, Dubisch PS, Akhter M, Lifshitz J. An update on the rod microglia variant in experimental and clinical brain injury and disease. Brain Commun 2021; 3:fcaa227. [PMID: 33501429 PMCID: PMC7811762 DOI: 10.1093/braincomms/fcaa227] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [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: 09/11/2020] [Revised: 11/12/2020] [Accepted: 11/17/2020] [Indexed: 12/15/2022] Open
Abstract
Contemporary microglia morphologies include ramified, activated and amoeboid, with the morphology of microglia considered highly coupled to the cellular function. Rod microglia are an additional activated microglia variant observed in the ageing, injured and diseased brain. Rod microglia were reported frequently in the early 1900s by neuropathologists in post-mortem cases of general paresis, Alzheimer's disease and encephalitis, and then remained largely ignored for almost 100 years. Recent reports have renewed interest in rod microglia, most notably after experimental traumatic brain injury. Rod microglia are formed by the narrowing of the soma and retraction of planar processes, which results in the appearance of an elongated, rod-shaped cell. Rod microglia are most commonly observed in the cortex, aligned perpendicular to the dural surface and adjacent to neuronal processes; in the hippocampus, they are aligned perpendicular to hippocampal layers. Furthermore, rod microglia form trains with one another, apical end to basal end. By replicating the process of sketching microscopic observation, rod microglia are re-defined by circumnutation around the long axis. In this update, we summarize the rod microglia variant in clinical and experimental literature and advocate for investigation into mechanisms of rod microglia origin and function.
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Affiliation(s)
- Katherine R Giordano
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA.,Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Charlotte R Denman
- Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA.,Department of Biology and Biochemistry, University of Bath, Bath, UK
| | | | - Murtaza Akhter
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA.,Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA.,Department of Emergency Medicine, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA.,Maricopa Integrated Healthcare System, Phoenix, AZ, USA
| | - Jonathan Lifshitz
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA.,Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA.,Phoenix VA Health Care System, Phoenix, AZ, USA
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8
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Giordano KR, Rojas-Valencia LM, Bhargava V, Lifshitz J. Beyond Binary: Influence of Sex and Gender on Outcome after Traumatic Brain Injury. J Neurotrauma 2020; 37:2454-2459. [PMID: 32808570 DOI: 10.1089/neu.2020.7230] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [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: 12/15/2022] Open
Abstract
Traumatic brain injury (TBI) affects millions of individuals each year and is a leading cause of death and disability worldwide. TBI is heterogeneous and outcome is influenced by a combination of factors that include injury location, severity, genetics, and environmental factors. More recently, sex as a biological variable has been incorporated into TBI research, although there is conflicting literature regarding clinical outcomes in males versus females after TBI. We review the current clinical literature investigating sex differences after TBI. We focus our discussion on differences within contemporary gender categories to suggest that binary categories of male and female are not sufficient to guide clinical decisions for neurotrauma. Some studies have considered physiological variables that influence sex such as hormone cycles and stages in males and females pre- and post-TBI. These data suggest that there are phasic differences within male populations and within female populations that influence an individual's outcome after TBI. Finally, we discuss the impact of gender identity and expression on outcome after TBI and highlight the lack of neurotrauma research that includes non-binary individuals. Social constructs regarding gender impact an individual's vulnerability to violence and consequent TBI, including the successful reintegration to society after TBI. We call for incorporation of gender beyond the binary in TBI education, research, and clinical care. Precision medicine necessarily must progress beyond the binary to treat individuals after TBI.
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Affiliation(s)
- Katherine R Giordano
- Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, Arizona, USA
| | - Luisa M Rojas-Valencia
- Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, Arizona, USA
| | - Vedanshi Bhargava
- Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, Arizona, USA
| | - Jonathan Lifshitz
- Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, Arizona, USA.,Phoenix VA Health Care System, Phoenix, Arizona, USA
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9
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Saber M, Giordano KR, Hur Y, Ortiz JB, Morrison H, Godbout JP, Murphy SM, Lifshitz J, Rowe RK. Acute peripheral inflammation and post-traumatic sleep differ between sexes after experimental diffuse brain injury. Eur J Neurosci 2020; 52:2791-2814. [PMID: 31677290 PMCID: PMC7195243 DOI: 10.1111/ejn.14611] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [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: 04/15/2019] [Revised: 10/15/2019] [Accepted: 10/22/2019] [Indexed: 12/17/2022]
Abstract
Identifying differential responses between sexes following traumatic brain injury (TBI) can elucidate the mechanisms behind disease pathology. Peripheral and central inflammation in the pathophysiology of TBI can increase sleep in male rodents, but this remains untested in females. We hypothesized that diffuse TBI would increase inflammation and sleep in males more so than in females. Diffuse TBI was induced in C57BL/6J mice and serial blood samples were collected (baseline, 1, 5, 7 days post-injury [DPI]) to quantify peripheral immune cell populations and sleep regulatory cytokines. Brains and spleens were harvested at 7DPI to quantify central and peripheral immune cells, respectively. Mixed-effects regression models were used for data analysis. Female TBI mice had 77%-124% higher IL-6 levels than male TBI mice at 1 and 5DPI, whereas IL-1β and TNF-α levels were similar between sexes at all timepoints. Despite baseline sex differences in blood-measured Ly6Chigh monocytes (females had 40% more than males), TBI reduced monocytes by 67% in TBI mice at 1DPI. Male TBI mice had 31%-33% more blood-measured and 31% more spleen-measured Ly6G+ neutrophils than female TBI mice at 1 and 5DPI, and 7DPI, respectively. Compared with sham, TBI increased sleep in both sexes during the first light and dark cycles. Male TBI mice slept 11%-17% more than female TBI mice, depending on the cycle. Thus, sex and TBI interactions may alter the peripheral inflammation profile and sleep patterns, which might explain discrepancies in disease progression based on sex.
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Affiliation(s)
- Maha Saber
- BARROW Neurological Institute at Phoenix Children’s Hospital, Phoenix, AZ
- Department of Child Health, University of Arizona College of Medicine – Phoenix, Phoenix, AZ
| | - Katherine R. Giordano
- BARROW Neurological Institute at Phoenix Children’s Hospital, Phoenix, AZ
- Department of Child Health, University of Arizona College of Medicine – Phoenix, Phoenix, AZ
| | - Yerin Hur
- BARROW Neurological Institute at Phoenix Children’s Hospital, Phoenix, AZ
- Department of Child Health, University of Arizona College of Medicine – Phoenix, Phoenix, AZ
| | - J. Bryce Ortiz
- BARROW Neurological Institute at Phoenix Children’s Hospital, Phoenix, AZ
- Department of Child Health, University of Arizona College of Medicine – Phoenix, Phoenix, AZ
| | | | - Jonathan P. Godbout
- Department of Neuroscience, The Ohio State University, Columbus, OH, USA
- Center for Brain and Spinal Cord Repair, The Ohio State University, Columbus, OH, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Sean M. Murphy
- Department of Child Health, University of Arizona College of Medicine – Phoenix, Phoenix, AZ
| | - Jonathan Lifshitz
- BARROW Neurological Institute at Phoenix Children’s Hospital, Phoenix, AZ
- Department of Child Health, University of Arizona College of Medicine – Phoenix, Phoenix, AZ
- Phoenix Veteran Affairs Health Care System, Phoenix, AZ, USA
| | - Rachel K. Rowe
- BARROW Neurological Institute at Phoenix Children’s Hospital, Phoenix, AZ
- Department of Child Health, University of Arizona College of Medicine – Phoenix, Phoenix, AZ
- Phoenix Veteran Affairs Health Care System, Phoenix, AZ, USA
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