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Salib AMN, Crane MJ, Lee SH, Wainger BJ, Jamieson AM, Lipscombe D. Interleukin-1α links peripheral Ca V2.2 channel activation to rapid adaptive increases in heat sensitivity in skin. Sci Rep 2024; 14:9051. [PMID: 38643253 PMCID: PMC11032389 DOI: 10.1038/s41598-024-59424-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 04/10/2024] [Indexed: 04/22/2024] Open
Abstract
Neurons have the unique capacity to adapt output in response to changes in their environment. Within seconds, sensory nerve endings can become hypersensitive to stimuli in response to potentially damaging events. The underlying behavioral response is well studied, but several of the key signaling molecules that mediate sensory hypersensitivity remain unknown. We previously discovered that peripheral voltage-gated CaV2.2 channels in nerve endings in skin are essential for the rapid, transient increase in sensitivity to heat, but not to mechanical stimuli, that accompanies intradermal capsaicin. Here we report that the cytokine interleukin-1α (IL-1α), an alarmin, is necessary and sufficient to trigger rapid heat and mechanical hypersensitivity in skin. Of 20 cytokines screened, only IL-1α was consistently detected in hind paw interstitial fluid in response to intradermal capsaicin and, similar to behavioral sensitivity to heat, IL-1α levels were also dependent on peripheral CaV2.2 channel activity. Neutralizing IL-1α in skin significantly reduced capsaicin-induced changes in hind paw sensitivity to radiant heat and mechanical stimulation. Intradermal IL-1α enhances behavioral responses to stimuli and, in culture, IL-1α enhances the responsiveness of Trpv1-expressing sensory neurons. Together, our data suggest that IL-1α is the key cytokine that underlies rapid and reversible neuroinflammatory responses in skin.
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Affiliation(s)
- Anne-Mary N Salib
- Department of Neuroscience, Carney Institute for Brain Science, Brown University, Providence, RI, 02912, USA
| | - Meredith J Crane
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, 02912, USA
| | - Sang Hun Lee
- Department of Neurology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Brian J Wainger
- Department of Neurology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Amanda M Jamieson
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, 02912, USA
| | - Diane Lipscombe
- Department of Neuroscience, Carney Institute for Brain Science, Brown University, Providence, RI, 02912, USA.
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Salib AMN, Crane MJ, Lee SH, Wainger BJ, Jamieson AM, Lipscombe D. Interleukin-1α links peripheral Ca V2.2 channel activation to rapid adaptive increases in heat sensitivity in skin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.17.572072. [PMID: 38585803 PMCID: PMC10996502 DOI: 10.1101/2023.12.17.572072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Neurons have the unique capacity to adapt output in response to changes in their environment. Within seconds, sensory nerve endings can become hypersensitive to stimuli in response to potentially damaging events. The underlying behavioral response is well studied, but several of the key signaling molecules that mediate sensory hypersensitivity remain unknown. We previously discovered that peripheral voltage-gated CaV2.2 channels in nerve endings in skin are essential for the rapid, transient increase in sensitivity to heat, but not to mechanical stimuli, that accompanies intradermal capsaicin. Here we report that the cytokine interleukin-1α (IL-1α), an alarmin, is necessary and sufficient to trigger rapid heat and mechanical hypersensitivity in skin. Of 20 cytokines screened, only IL-1α was consistently detected in hind paw interstitial fluid in response to intradermal capsaicin and, similar to behavioral sensitivity to heat, IL-1α levels were also dependent on peripheral CaV2.2 channel activity. Neutralizing IL-1α in skin significantly reduced capsaicin-induced changes in hind paw sensitivity to radiant heat and mechanical stimulation. Intradermal IL-1α enhances behavioral responses to stimuli and, in culture, IL-1α enhances the responsiveness of Trpv1-expressing sensory neurons. Together, our data suggest that IL-1α is the key cytokine that underlies rapid and reversible neuroinflammatory responses in skin.
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Affiliation(s)
- Anne-Mary N Salib
- Department of Neuroscience, Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Meredith J Crane
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912, USA
| | - Sang Hun Lee
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Brian J Wainger
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Amanda M Jamieson
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912, USA
| | - Diane Lipscombe
- Department of Neuroscience, Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
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Steinberger KJ, Eubank TD. The Underexplored Landscape of Hypoxia-Inducible Factor 2 Alpha and Potential Roles in Tumor Macrophages: A Review. OXYGEN (BASEL, SWITZERLAND) 2023; 3:45-76. [PMID: 37124241 PMCID: PMC10137047 DOI: 10.3390/oxygen3010005] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Low tissue oxygenation, termed hypoxia, is a characteristic of solid tumors with negative consequences. Tumor-associated macrophages (TAMs) accumulate in hypoxic tumor regions and correlate with worse outcomes in cancer patients across several tumor types. Thus, the molecular mechanism in which macrophages respond to low oxygen tension has been increasingly investigated in the last decade. Hypoxia stabilizes a group of hypoxia-inducible transcription factors (HIFs) reported to drive transcriptional programs involved in cell survival, metabolism, and angiogenesis. Though both tumor macrophage HIF-1α and HIF-2α correlate with unfavorable tumor microenvironments, most research focuses on HIF-1α as the master regulator of hypoxia signaling, because HIF-1α expression was originally identified in several cancer types and correlates with worse outcome in cancer patients. The relative contribution of each HIFα subunit to cell phenotypes is poorly understood especially in TAMs. Once thought to have overlapping roles, recent investigation of macrophage HIF-2α has demonstrated a diverse function from HIF-1α. Little work has been published on the differential role of hypoxia-dependent macrophage HIF-2α when compared to HIF-1α in the context of tumor biology. This review highlights cellular HIF-2α functions and emphasizes the gap in research investigating oxygen-dependent functions of tumor macrophage HIF-2α.
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Affiliation(s)
- Kayla J. Steinberger
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV 26505, USA
- In Vivo Multifunctional Magnetic Resonance Center, West Virginia University, Morgantown, WV 26505, USA
- West Virginia University Cancer Institute, Morgantown, WV 26505, USA
- Correspondence: (K.J.S.); (T.D.E.)
| | - Timothy D. Eubank
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV 26505, USA
- In Vivo Multifunctional Magnetic Resonance Center, West Virginia University, Morgantown, WV 26505, USA
- West Virginia University Cancer Institute, Morgantown, WV 26505, USA
- Correspondence: (K.J.S.); (T.D.E.)
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Kaisis E, Thei LJ, Stephens GJ, Dallas ML. Protofibrillar Amyloid Beta Modulation of Recombinant hCaV2.2 (N-Type) Voltage-Gated Channels. Pharmaceuticals (Basel) 2022; 15:ph15121459. [PMID: 36558910 PMCID: PMC9783047 DOI: 10.3390/ph15121459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
Cav2.2 channels are key regulators of presynaptic Ca2+ influx and their dysfunction and/or aberrant regulation has been implicated in many disease states; however, the nature of their involvement in Alzheimer's disease (AD) is less clear. In this short communication, we show that recombinant hCav2.2/b1b/a2d1 channels are modulated by human synthetic AD-related protofibrillar amyloid beta Ab1-42 peptides. Structural studies revealed a time-dependent increase in protofibril length, with the majority of protofibrils less than 100 nm at 24 h, while at 48 h, the majority were longer than 100 nm. Cav2.2 modulation by Ab1-42 was different between a 'low' (100 nM) and 'high' (1 µM) concentration in terms of distinct effects on individual biophysical parameters. A concentration of 100 nM Ab1-42 caused no significant changes in the measured biophysical properties of Cav2.2 currents. In contrast, 1 µM Ab1-42 caused an inhibitory decrease in the current density (pA/pF) and maximum conductance (Gmax), and a depolarizing shift in the slope factor (k). These data highlight a differential modulation of Cav2.2 channels by the Ab1-42 peptide. Discrete changes in the presynaptic Ca2+ flux have been reported to occur at an early stage of AD; therefore, this study reveals a potential mechanistic link between amyloid accumulation and Cav2.2 channel modulation.
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Regulation of Aging and Longevity by Ion Channels and Transporters. Cells 2022; 11:cells11071180. [PMID: 35406743 PMCID: PMC8997527 DOI: 10.3390/cells11071180] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/22/2022] [Accepted: 03/29/2022] [Indexed: 12/10/2022] Open
Abstract
Despite significant advances in our understanding of the mechanisms that underlie age-related physiological decline, our ability to translate these insights into actionable strategies to extend human healthspan has been limited. One of the major reasons for the existence of this barrier is that with a few important exceptions, many of the proteins that mediate aging have proven to be undruggable. The argument put forth here is that the amenability of ion channels and transporters to pharmacological manipulation could be leveraged to develop novel therapeutic strategies to combat aging. This review delves into the established roles for ion channels and transporters in the regulation of aging and longevity via their influence on membrane excitability, Ca2+ homeostasis, mitochondrial and endolysosomal function, and the transduction of sensory stimuli. The goal is to provide the reader with an understanding of emergent themes, and prompt further investigation into how the activities of ion channels and transporters sculpt the trajectories of cellular and organismal aging.
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Alles SRA, Smith PA. Peripheral Voltage-Gated Cation Channels in Neuropathic Pain and Their Potential as Therapeutic Targets. FRONTIERS IN PAIN RESEARCH 2022; 2:750583. [PMID: 35295464 PMCID: PMC8915663 DOI: 10.3389/fpain.2021.750583] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/10/2021] [Indexed: 11/25/2022] Open
Abstract
The persistence of increased excitability and spontaneous activity in injured peripheral neurons is imperative for the development and persistence of many forms of neuropathic pain. This aberrant activity involves increased activity and/or expression of voltage-gated Na+ and Ca2+ channels and hyperpolarization activated cyclic nucleotide gated (HCN) channels as well as decreased function of K+ channels. Because they display limited central side effects, peripherally restricted Na+ and Ca2+ channel blockers and K+ channel activators offer potential therapeutic approaches to pain management. This review outlines the current status and future therapeutic promise of peripherally acting channel modulators. Selective blockers of Nav1.3, Nav1.7, Nav1.8, Cav3.2, and HCN2 and activators of Kv7.2 abrogate signs of neuropathic pain in animal models. Unfortunately, their performance in the clinic has been disappointing; some substances fail to meet therapeutic end points whereas others produce dose-limiting side effects. Despite this, peripheral voltage-gated cation channels retain their promise as therapeutic targets. The way forward may include (i) further structural refinement of K+ channel activators such as retigabine and ASP0819 to improve selectivity and limit toxicity; use or modification of Na+ channel blockers such as vixotrigine, PF-05089771, A803467, PF-01247324, VX-150 or arachnid toxins such as Tap1a; the use of Ca2+ channel blockers such as TTA-P2, TTA-A2, Z 944, ACT709478, and CNCB-2; (ii) improving methods for assessing “pain” as opposed to nociception in rodent models; (iii) recognizing sex differences in pain etiology; (iv) tailoring of therapeutic approaches to meet the symptoms and etiology of pain in individual patients via quantitative sensory testing and other personalized medicine approaches; (v) targeting genetic and biochemical mechanisms controlling channel expression using anti-NGF antibodies such as tanezumab or re-purposed drugs such as vorinostat, a histone methyltransferase inhibitor used in the management of T-cell lymphoma, or cercosporamide a MNK 1/2 inhibitor used in treatment of rheumatoid arthritis; (vi) combination therapy using drugs that are selective for different channel types or regulatory processes; (vii) directing preclinical validation work toward the use of human or human-derived tissue samples; and (viii) application of molecular biological approaches such as clustered regularly interspaced short palindromic repeats (CRISPR) technology.
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Affiliation(s)
- Sascha R A Alles
- Department of Anesthesiology and Critical Care Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Peter A Smith
- Department of Pharmacology, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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Akaishi T, Yamamoto S, Abe K. 3',4',7-Trihydroxyflavone Downregulates NO Production in LPS- or IFN-γ-Activated MG6 Microglial Cells by Attenuating the JNK-STAT1 Pathway. Biol Pharm Bull 2022; 45:301-308. [PMID: 35228396 DOI: 10.1248/bpb.b21-00841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neuroinflammation induced by activated microglia is a key feature of neurodegenerative diseases such as Alzheimer's disease. The natural flavonoid 3',4',7-trihydroxyflavone protects nerve cells from oxidative stress-mediated apoptosis and inhibits the aggregation of amyloid β protein in vitro. However, little is known about its effects on microglial activation. In this study, we investigated the effects of 3',4',7-trihydroxyflavone on lipopolysaccharide (LPS)- or interferon-γ (IFN-γ)-induced neuroinflammatory responses in MG6 microglial cells. 3',4',7-Trihydroxyflavone inhibited LPS- or IFN-γ-mediated nitric oxide (NO) generation and the upregulation of inducible NO synthase (iNOS) in MG6 cells. 3',4',7-Trihydroxyflavone also suppressed LPS- or IFN-γ-mediated phosphorylation of signal transducer and activator of transcription 1 (STAT1), which is crucial for iNOS expression. LPS stimulation induced rapid phosphorylation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and extracellular signal-regulated kinase (ERK) in MG6 cells. 3',4',7-Trihydroxyflavone significantly inhibited the LPS-mediated phosphorylation of JNK, but not that of ERK and p38 MAPK. The inhibitory effect of 3',4',7-trihydroxyflavone on NO generation was mimicked by pharmacological inhibition of the JNK signaling pathway with SP600125. Furthermore, SP600125 significantly inhibited LPS- or IFN-γ-mediated phosphorylation of STAT1 in MG6 cells. These results suggest that 3',4',7-trihydroxyflavone exerts anti-neuroinflammatory effects via inhibition of the JNK-STAT1 pathway in microglia.
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Affiliation(s)
- Tatsuhiro Akaishi
- Laboratory of Pharmacology, Faculty of Pharmacy and Research Institute of Pharmaceutical Sciences, Musashino University
| | - Shohei Yamamoto
- Laboratory of Pharmacology, Faculty of Pharmacy and Research Institute of Pharmaceutical Sciences, Musashino University
| | - Kazuho Abe
- Laboratory of Pharmacology, Faculty of Pharmacy and Research Institute of Pharmaceutical Sciences, Musashino University
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Huntula S, Lalert L, Punsawad C. The Effects of Exercise on Aging-Induced Exaggerated Cytokine Responses: An Interdisciplinary Discussion. SCIENTIFICA 2022; 2022:3619362. [PMID: 35106183 PMCID: PMC8801319 DOI: 10.1155/2022/3619362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 01/10/2022] [Indexed: 06/14/2023]
Abstract
Aging is generally known to be associated with dynamic biological changes, physiological dysfunction, and environmental and psychological decline. Several studies have suggested that aging is associated with increased inflammatory cytokines, causing several diseases. However, the effect of exercise on aging has been less delineated, and the relationships between cytokine activation, aging, and exercise also need further study. Here, we discuss some ideas about the effect of exercise on aging-induced exaggerated cytokine responses and discuss the possible roles of the aging-induced exaggerated cytokine response following exercise. Evidence from these findings suggests that exercise is a beneficially applicable model to use in studies on the mechanisms underlying the age-associated gradated cytokine response, and these results may provide guidelines for health professionals with diverse backgrounds.
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Affiliation(s)
- Soontaraporn Huntula
- Department of Sport and Exercise Science, School of Medicine, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Laddawan Lalert
- Department of Medical Science, School of Medicine, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Chuchard Punsawad
- Department of Medical Science, School of Medicine, Walailak University, Nakhon Si Thammarat 80160, Thailand
- Research Center in Tropical Pathobiology, Walailak University, Nakhon Si Thammarat 80160, Thailand
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Luo L, Song S, Ezenwukwa CC, Jalali S, Sun B, Sun D. Ion channels and transporters in microglial function in physiology and brain diseases. Neurochem Int 2020; 142:104925. [PMID: 33248207 DOI: 10.1016/j.neuint.2020.104925] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/19/2022]
Abstract
Microglial cells interact with all components of the central nervous system (CNS) and are increasingly recognized to play essential roles during brain development, homeostasis and disease pathologies. Functions of microglia include maintaining tissue integrity, clearing cellular debris and dead neurons through the process of phagocytosis, and providing tissue repair by releasing anti-inflammatory cytokines and neurotrophic factors. Changes of microglial ionic homeostasis (Na+, Ca2+, K+, H+, Cl-) are important for microglial activation, including proliferation, migration, cytokine release and reactive oxygen species production, etc. These are mediated by ion channels and ion transporters in microglial cells. Here, we review the current knowledge about the role of major microglial ion channels and transporters, including several types of Ca2+ channels (store-operated Ca2+ entry (SOCE) channels, transient receptor potential (TRP) channels and voltage-gated Ca2+ channels (VGCCs)) and Na+ channels (voltage-gated Na+ channels (Nav) and acid-sensing ion channels (ASICs)), K+ channels (inward rectifier K+ channels (Kir), voltage-gated K+ channels (KV) and calcium-activated K+ channels (KCa)), proton channels (voltage-gated proton channel (Hv1)), and Cl- channels (volume (or swelling)-regulated Cl- channels (VRCCs) and chloride intracellular channels (CLICs)). In addition, ion transporter proteins such as Na+/Ca2+ exchanger (NCX), Na+-K+-Cl- cotransporter (NKCC1), and Na+/H+ exchanger (NHE1) are also involved in microglial function in physiology and brain diseases. We discussed microglial activation and neuroinflammation in relation to the ion channel/transporter stimulation under brain disease conditions and therapeutic aspects of targeting microglial ion channels/transporters for neurodegenerative disease, ischemic stroke, traumatic brain injury and neuropathic pain.
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Affiliation(s)
- Lanxin Luo
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Shanshan Song
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | | | - Shayan Jalali
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Baoshan Sun
- Pólo DoisPortos, Instituto National de InvestigaçãoAgrária e Veterinária, I.P., Quinta da Almoinha, DoisPortos, 2565-191, Portugal.
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, PA, 15213, USA.
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Aging-Related Phenotypic Conversion of Medullary Microglia Enhances Intraoral Incisional Pain Sensitivity. Int J Mol Sci 2020; 21:ijms21217871. [PMID: 33114176 PMCID: PMC7660637 DOI: 10.3390/ijms21217871] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 12/12/2022] Open
Abstract
Activated microglia involved in the development of orofacial pain hypersensitivity have two major polarization states. The aim of this study was to assess the involvement of the aging-related phenotypic conversion of medullary microglia in the enhancement of intraoral pain sensitivity using senescence-accelerated mice (SAM)-prone/8 (SAMP8) and SAM-resistant/1 (SAMR1) mice. Mechanical head-withdrawal threshold (MHWT) was measured for 21 days post palatal mucosal incision. The number of CD11c-immunoreactive (IR) cells [affective microglia (M1)] and CD163-IR cells [protective microglia (M2)], and tumor-necrosis-factor-α (TNF-α)-IR M1 and interleukin (IL)-10-IR M2 were analyzed via immunohistochemistry on days 3 and 11 following incision. The decrease in MHWT observed following incision was enhanced in SAMP8 mice. M1 levels and the number of TNF-α-IR M1 were increased on day 3 in SAMP8 mice compared with those in SAMR1 mice. On day 11, M1 and M2 activation was observed in both groups, whereas IL-10-IR M2 levels were attenuated in SAMP8 mice, and the number of TNF-α-IR M1 cells increased, compared to those in SAMR1 mice. These results suggest that the mechanical allodynia observed following intraoral injury is potentiated and sustained in SAMP8 mice due to enhancement of TNF-α signaling, M1 activation, and an attenuation of M2 activation accompanying IL-10 release.
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Neuroinflammaging underlies emotional disturbances and circadian rhythm disruption in young male senescence-accelerated mouse prone 8 mice. Exp Gerontol 2020; 142:111109. [PMID: 33069781 DOI: 10.1016/j.exger.2020.111109] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 09/27/2020] [Accepted: 10/01/2020] [Indexed: 12/13/2022]
Abstract
Aging causes psychological dysfunction and neurodegeneration, and can lead to cognitive impairments. Although numerous studies have reported that neurodegeneration and subsequent cognitive impairments are involved in neuroinflammation, relationship between psychological disturbance and neuroinflammation with aging (neuroinflammaging) remains unclear. Here, to clarify the relationship, we examined whether neuroinflammaging affects emotional behaviors in senescence-accelerated mouse prone 8 (SAMP8) mice. Microglial inflammatory responses to a subsequent lipopolysaccharide (LPS) challenge were significantly enhanced in male SAMP8 mice relative to normal aging senescence-accelerated mouse resistant 1 (SAMR1) mice at 17 weeks, but not 8 weeks of age. LPS injection also significantly increased brain and systemic inflammation in SAMP8 mice at 17 weeks. In a battery of behavioral tests, SAMP8 mice at 17 weeks, but not 8 weeks, exhibited anxiety- and depression-like behaviors and circadian rhythm disruption. Taken together, SAMP8 mice at 17 weeks possess a brain microenvironment in which it is easier to trigger neuroinflammatory priming; this may lead to an emergence of anxiety- and depression-like behaviors and circadian rhythm disruption. These findings provide new insights into the temporal relationship between neuroinflammaging and emotion.
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Saegusa H, Li X, Wang X, Kayakiri M, Tanabe T. Knockdown of microglial Cav2.2 N-type voltage-dependent Ca 2+ channel ameliorates behavioral deficits in a mouse model of Parkinson's disease. FEBS Lett 2020; 594:2914-2922. [PMID: 32484574 DOI: 10.1002/1873-3468.13853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/13/2020] [Accepted: 05/20/2020] [Indexed: 11/09/2022]
Abstract
Cav2.2 N-type voltage-dependent Ca2+ channel (VDCC) expressed in neurons is known to be essential for neurotransmitter release. We have shown previously that this channel is also expressed in nonexcitable microglia and plays pivotal roles in microglial functions. Here, we have examined the effects of microglia-specific knockdown (KD) of Cav2.2 channel in a mouse model of Parkinson's disease (PD). We found that the KD of Cav2.2 channel reduces the accumulation of microglia in the substantia nigra and ameliorates the behavioral deficits in PD model mice. These results are in marked contrast with those found in microglia-specific KD of Cav1.2 L-type channel, where exacerbated symptoms are observed. Our results suggest that blockade of microglial Cav2.2 N-type VDCC is beneficial for the treatment of PD.
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Affiliation(s)
- Hironao Saegusa
- Department of Pharmacology and Neurobiology, Graduate School of Medicine, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Xu Li
- Department of Pharmacology and Neurobiology, Graduate School of Medicine, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Xinshuang Wang
- Department of Pharmacology and Neurobiology, Graduate School of Medicine, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Midori Kayakiri
- Department of Pharmacology and Neurobiology, Graduate School of Medicine, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Tsutomu Tanabe
- Department of Pharmacology and Neurobiology, Graduate School of Medicine, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
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