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Das D, Wong A, Friedman TN, Kerr BJ, Kurata HT, Lamothe SM. Reducing agents facilitate membrane patch seal integrity and longevity. Channels (Austin) 2024; 18:2297621. [PMID: 38154061 PMCID: PMC10761044 DOI: 10.1080/19336950.2023.2297621] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2023] Open
Abstract
The patch clamp method is a widely applied electrophysiological technique used to understand ion channel activity and cellular excitation. The formation of a high resistance giga-ohm seal is required to obtain high-quality recordings but can be challenging due to variables including operator experience and cell preparation. Therefore, the identification of methods to promote the formation and longevity of giga-ohm seals may be beneficial. In this report, we describe our observation that the application of reducing agents (DTT and TCEP) to the external bath solution during whole-cell patch clamp recordings of heterologous cells (HEK and LM) and cultured primary cells (DRG neurons) enhanced the success of giga-ohm seal formation. Reducing agents also maintained the integrity of the seal for longer periods of time at strong hyperpolarizing voltages, whereas an oxidizing agent (H2O2) appeared to have the opposite effect. In summary, we report a useful tool to improve the quality of patch clamp recordings that may be helpful in certain experimental contexts.
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Affiliation(s)
- Damayantee Das
- Dept. of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Anson Wong
- Dept. of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Timothy N. Friedman
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Bradley J Kerr
- Dept. of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
- Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, Canada
| | - Harley T. Kurata
- Dept. of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Shawn M. Lamothe
- Dept. of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
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Ostertag C, Friedman TN, Keough MB, Kerr BJ, Sankar T. Heightened presence of inflammatory mediators in the cerebrospinal fluid of patients with trigeminal neuralgia. Pain Rep 2023; 8:e1117. [PMID: 38125050 PMCID: PMC10732488 DOI: 10.1097/pr9.0000000000001117] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 10/06/2023] [Accepted: 10/31/2023] [Indexed: 12/23/2023] Open
Abstract
Introduction Trigeminal neuralgia (TN) is a chronic, debilitating facial pain disease causing stabbing pain attacks in the sensory distribution of the trigeminal nerve. The underlying pathophysiology of TN is incompletely understood, although microstructural abnormalities consistent with focal demyelination of the trigeminal nerve root have been shown in patients with TN. Studies of the cerebrospinal fluid (CSF) in patients with TN suggest an increased prevalence of inflammatory mediators, potentially implicating neuroinflammation in the pathophysiology of TN, as it has been implicated in other chronic pain conditions. Objectives This study aimed to further assess the inflammatory profile of CSF in TN. Methods Cerebrospinal fluid was collected from 8 medically refractory patients with TN undergoing microvascular decompression surgery and 4 pain-free controls (2 with hemifacial spasm; 2 with normal pressure hydrocephalus). Cerebrospinal fluid was collected from the cerebellopontine angle cistern intraoperatively in the patients with TN. Inflammatory profiles of CSF samples were analyzed using a 71-plex cytokine and chemokine multiplex assay. Results Ten inflammatory markers were found to be significantly higher in TN CSF, and no analytes were significantly lower. Elevated factors can be classified into pro-inflammatory cytokines (IL-9, IL-18, and IL-33), chemokines (RANTES and ENA-78), the tumor necrosis factor superfamily (TRAIL and sCD40L), and growth factors (EGF, PDGF-AB/BB, and FGF-2). Conclusion This study further supports the notion that neuroinflammation is present in TN, and that multiple molecular pathways are implicated.
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Affiliation(s)
- Curtis Ostertag
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Timothy N. Friedman
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Michael B. Keough
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Bradley J. Kerr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
- Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
| | - Tejas Sankar
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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3
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Friedman TN, La Caprara O, Zhang C, Lee K, May J, Faig CA, Baldwin T, Plemel JR, Taylor AMW, Kerr BJ. Sex differences in peripheral immune cell activation: Implications for pain and pain resolution. Brain Behav Immun 2023; 114:80-93. [PMID: 37544463 DOI: 10.1016/j.bbi.2023.07.029] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 07/28/2023] [Accepted: 07/30/2023] [Indexed: 08/08/2023] Open
Abstract
Decades of research into chronic pain has deepened our understanding of the cellular mechanisms behind this process. However, a failure to consider the biological variable of sex has limited the application of these breakthroughs into clinical application. In the present study, we investigate fundamental differences in chronic pain between male and female mice resulting from inflammatory activation of the innate immune system. We provide evidence that female mice are more sensitive to the effects of macrophages. Injecting small volumes of media conditioned by either unstimulated macrophages or macrophages stimulated by the inflammatory molecule TNFα lead to increased pain sensitivity only in females. Interestingly, we find that TNFα conditioned media leads to a more rapid resolution of mechanical hypersensitivity and altered immune cell recruitment to sites of injury. Furthermore, male and female macrophages exhibit differential polarization characteristics and motility after TNFα stimulation, as well as a different profile of cytokine secretions. Finally, we find that the X-linked gene Tlr7 is critical in the facilitating the adaptive resolution of pain in models of acute and chronic inflammation in both sexes. Altogether, these findings suggest that although the cellular mechanisms of pain resolution may differ between the sexes, the study of these differences may yield more targeted approaches with clinical applications.
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Affiliation(s)
- Timothy N Friedman
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Olivia La Caprara
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Celine Zhang
- Department of Pharmacology, University of Alberta, Edmonton, AB T6E 2H7, Canada
| | - Kelly Lee
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Julia May
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Christian A Faig
- Department of Pharmacology, University of Alberta, Edmonton, AB T6E 2H7, Canada
| | - Troy Baldwin
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Jason R Plemel
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Anna M W Taylor
- Department of Pharmacology, University of Alberta, Edmonton, AB T6E 2H7, Canada; Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Bradley J Kerr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada; Department of Pharmacology, University of Alberta, Edmonton, AB T6E 2H7, Canada; Department of Psychiatry (NRU), University of Alberta, Edmonton, AB T6G 2B7, Canada; Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB T6G 2G3, Canada.
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4
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Maguire AD, Friedman TN, Villarreal Andrade DN, Haq F, Dunn J, Pfeifle K, Tenorio G, Buro K, Plemel JR, Kerr BJ. Sex differences in the inflammatory response of the mouse DRG and its connection to pain in experimental autoimmune encephalomyelitis. Sci Rep 2022; 12:20995. [PMID: 36470947 PMCID: PMC9722825 DOI: 10.1038/s41598-022-25295-y] [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: 09/06/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Multiple Sclerosis (MS) is an autoimmune disease with notable sex differences. Women are not only more likely to develop MS but are also more likely than men to experience neuropathic pain in the disease. It has been postulated that neuropathic pain in MS can originate in the peripheral nervous system at the level of the dorsal root ganglia (DRG), which houses primary pain sensing neurons (nociceptors). These nociceptors become hyperexcitable in response to inflammation, leading to peripheral sensitization and eventually central sensitization, which maintains pain long-term. The mouse model experimental autoimmune encephalomyelitis (EAE) is a good model for human MS as it replicates classic MS symptoms including pain. Using EAE mice as well as naïve primary mouse DRG neurons cultured in vitro, we sought to characterize sex differences, specifically in peripheral sensory neurons. We found sex differences in the inflammatory profile of the EAE DRG, and in the TNFα downstream signaling pathways activated intracellularly in cultured nociceptors. We also found increased cell death with TNFα treatment. Given that TNFα signaling has been shown to initiate intrinsic apoptosis through mitochondrial disruption, this led us to investigate sex differences in the mitochondria's response to TNFα. Our results demonstrate that male sensory neurons are more sensitive to mitochondrial stress, making them prone to neuronal injury. In contrast, female sensory neurons appear to be more resistant to mitochondrial stress and exhibit an inflammatory and regenerative phenotype that may underlie greater nociceptor hyperexcitability and pain. Understanding these sex differences at the level of the primary sensory neuron is an important first step in our eventual goal of developing sex-specific treatments to halt pain development in the periphery before central sensitization is established.
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Affiliation(s)
- Aislinn D. Maguire
- grid.17089.370000 0001 2190 316XNeuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1 Canada
| | - Timothy N. Friedman
- grid.17089.370000 0001 2190 316XNeuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1 Canada
| | - Dania N. Villarreal Andrade
- grid.17089.370000 0001 2190 316XNeuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1 Canada
| | - Fajr Haq
- grid.17089.370000 0001 2190 316XDepartment of Anesthesiology and Pain Medicine, University of Alberta, Clinical Sciences Building, 2-150, Edmonton, AB T6G 2G3 Canada
| | - Jacob Dunn
- grid.17089.370000 0001 2190 316XNeuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1 Canada
| | - Keiana Pfeifle
- grid.17089.370000 0001 2190 316XNeuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1 Canada
| | - Gustavo Tenorio
- grid.17089.370000 0001 2190 316XDepartment of Anesthesiology and Pain Medicine, University of Alberta, Clinical Sciences Building, 2-150, Edmonton, AB T6G 2G3 Canada
| | - Karen Buro
- grid.418296.00000 0004 0398 5853Department of Mathematics and Statistics, MacEwan University, Edmonton, AB T5J 2P2 Canada
| | - Jason R. Plemel
- grid.17089.370000 0001 2190 316XNeuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1 Canada
| | - Bradley J. Kerr
- grid.17089.370000 0001 2190 316XNeuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1 Canada ,grid.17089.370000 0001 2190 316XDepartment of Pharmacology, University of Alberta, Edmonton, AB T6E 2H7 Canada ,grid.17089.370000 0001 2190 316XDepartment of Anesthesiology and Pain Medicine, University of Alberta, Clinical Sciences Building, 2-150, Edmonton, AB T6G 2G3 Canada
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Yousuf MS, Samtleben S, Lamothe SM, Friedman TN, Catuneanu A, Thorburn K, Desai M, Tenorio G, Schenk GJ, Ballanyi K, Kurata HT, Simmen T, Kerr BJ. Endoplasmic reticulum stress in the dorsal root ganglia regulates large-conductance potassium channels and contributes to pain in a model of multiple sclerosis. FASEB J 2020; 34:12577-12598. [PMID: 32677089 DOI: 10.1096/fj.202001163r] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/25/2020] [Accepted: 07/09/2020] [Indexed: 01/22/2023]
Abstract
Neuropathic pain is a common symptom of multiple sclerosis (MS) and current treatment options are ineffective. In this study, we investigated whether endoplasmic reticulum (ER) stress in dorsal root ganglia (DRG) contributes to pain hypersensitivity in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS. Inflammatory cells and increased levels of ER stress markers are evident in post-mortem DRGs from MS patients. Similarly, we observed ER stress in the DRG of mice with EAE and relieving ER stress with a chemical chaperone, 4-phenylbutyric acid (4-PBA), reduced pain hypersensitivity. In vitro, 4-PBA and the selective PERK inhibitor, AMG44, normalize cytosolic Ca2+ transients in putative DRG nociceptors. We went on to assess disease-mediated changes in the functional properties of Ca2+ -sensitive BK-type K+ channels in DRG neurons. We found that the conductance-voltage (GV) relationship of BK channels was shifted to a more positive voltage, together with a more depolarized resting membrane potential in EAE cells. Our results suggest that ER stress in sensory neurons of MS patients and mice with EAE is a source of pain and that ER stress modulators can effectively counteract this phenotype.
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Affiliation(s)
- Muhammad Saad Yousuf
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Samira Samtleben
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada
| | - Shawn M Lamothe
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Timothy N Friedman
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Ana Catuneanu
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Kevin Thorburn
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Mansi Desai
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Gustavo Tenorio
- Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
| | - Geert J Schenk
- Department of Anatomy and Neurosciences, Neuroscience Amsterdam, Amsterdam UMC, VU University Medical Center, VUmc MS Center Amsterdam, Amsterdam, The Netherlands
| | - Klaus Ballanyi
- Department of Physiology, University of Alberta, Edmonton, AB, Canada
| | - Harley T Kurata
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Thomas Simmen
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada
| | - Bradley J Kerr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Pharmacology, University of Alberta, Edmonton, AB, Canada.,Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
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Plemel JR, Stratton JA, Michaels NJ, Rawji KS, Zhang E, Sinha S, Baaklini CS, Dong Y, Ho M, Thorburn K, Friedman TN, Jawad S, Silva C, Caprariello AV, Hoghooghi V, Yue J, Jaffer A, Lee K, Kerr BJ, Midha R, Stys PK, Biernaskie J, Yong VW. Microglia response following acute demyelination is heterogeneous and limits infiltrating macrophage dispersion. Sci Adv 2020; 6:eaay6324. [PMID: 31998844 PMCID: PMC6962036 DOI: 10.1126/sciadv.aay6324] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/08/2019] [Indexed: 05/22/2023]
Abstract
Microglia and infiltrating macrophages are thought to orchestrate the central nervous system (CNS) response to injury; however, the similarities between these cells make it challenging to distinguish their relative contributions. We genetically labeled microglia and CNS-associated macrophages to distinguish them from infiltrating macrophages. Using single-cell RNA sequencing, we describe multiple microglia activation states, one of which was enriched for interferon associated signaling. Although blood-derived macrophages acutely infiltrated the demyelinated lesion, microglia progressively monopolized the lesion environment where they surrounded infiltrating macrophages. In the microglia-devoid sciatic nerve, the infiltrating macrophage response was sustained. In the CNS, the preferential proliferation of microglia and sparse microglia death contributed to microglia dominating the lesion. Microglia ablation reversed the spatial restriction of macrophages with the demyelinated spinal cord, highlighting an unrealized macrophages-microglia interaction. The restriction of peripheral inflammation by microglia may be a previously unidentified mechanism by which the CNS maintains its "immune privileged" status.
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Affiliation(s)
- Jason R. Plemel
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Medicine, Division of Neurology, University of Alberta, Edmonton, Alberta, Canada
- Corresponding author. (J.R.P.); (J.B.); (V.W.Y.)
| | - Jo Anne Stratton
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Nathan J. Michaels
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Khalil S. Rawji
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Eric Zhang
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sarthak Sinha
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Charbel S. Baaklini
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Medicine, Division of Neurology, University of Alberta, Edmonton, Alberta, Canada
| | - Yifei Dong
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Madelene Ho
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Kevin Thorburn
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
| | - Timothy N. Friedman
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Sana Jawad
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Claudia Silva
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Andrew V. Caprariello
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Vahid Hoghooghi
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Julie Yue
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Arzina Jaffer
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Kelly Lee
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Bradley J. Kerr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Raj Midha
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Peter K. Stys
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jeff Biernaskie
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
- Corresponding author. (J.R.P.); (J.B.); (V.W.Y.)
| | - V. Wee Yong
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Corresponding author. (J.R.P.); (J.B.); (V.W.Y.)
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7
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Friedman TN, Yousuf MS, Catuneanu A, Desai M, Juźwik CA, Fournier AE, Kerr BJ. Profiling the microRNA signature of the peripheral sensory ganglia in experimental autoimmune encephalomyelitis (EAE). J Neuroinflammation 2019; 16:223. [PMID: 31729981 PMCID: PMC6858636 DOI: 10.1186/s12974-019-1600-7] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 09/24/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Multiple sclerosis is an autoimmune disease with a distinct female bias, as well as a high prevalence of neuropathic pain in both sexes. The dorsal root ganglia (DRG) contain the primary sensory neurons that give rise to pain, and damage to these neurons may lead to neuropathic pain. Here, we investigate the sex differences of the DRG transcriptome in a mouse model of MS. METHODS Next-generation sequencing was used to establish RNA and microRNA profiles from the DRG of mice with MOG35-55-induced EAE, a model of CNS inflammation that mimics aspects of MS. Differential expression and multiple meta-analytic approaches were used to compare expression profiles in immunized female and male mice. Differential expression of relevant genes and microRNAs were confirmed by qPCR. RESULTS Three thousand five hundred twenty genes and 29 microRNAs were differentially expressed in the DRG of female mice with MOG35-55-EAE, while only 189 genes and 3 microRNAs were differentially expressed in males with MOG35-55-EAE. Genes related to the immune system were uniquely regulated in immunized female mice. Direct comparison of sex within disease indicates significant differences in interferon and phagosomal pathways between the sexes. miR-21a-5p is the primary dysregulated microRNA in both sexes, with females having additional dysregulated microRNAs, including miR-122-5p. CONCLUSIONS This study provides evidence that females are uniquely affected by MOG35-55-EAE and that this difference may result from additional signaling not present in the male. The altered transcriptome of females correlates with other studies finding hyperactivity of pain-sensing neurons and suggests underlying sex-specific pathways for neuropathic pain.
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Affiliation(s)
- Timothy N Friedman
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada
| | - Muhammad Saad Yousuf
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada
| | - Ana Catuneanu
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, T6E 2H7, Canada
| | - Mansi Desai
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, T6E 2H7, Canada
| | - Camille A Juźwik
- Montreal Neurological Institute, McGill University, Montreal, Quebec, H3A 2B4, Canada
| | - Alyson E Fournier
- Montreal Neurological Institute, McGill University, Montreal, Quebec, H3A 2B4, Canada
| | - Bradley J Kerr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada. .,Department of Pharmacology, University of Alberta, Edmonton, Alberta, T6E 2H7, Canada. .,Department of Psychiatry (NRU), University of Alberta, Edmonton, Alberta, T6G 2B7, Canada. .,Department of Anesthesiology and Pain Medicine, University of Alberta, Clinical Sciences Building, 2-150, Edmonton, Alberta, T6G 2G3, Canada.
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