1
|
Borgonetti V, Morozzi M, Galeotti N. Neuroinflammation evoked mechanisms for neuropathic itch in the spared nerve injury mouse model of neuropathic pain. Neuropharmacology 2024; 259:110120. [PMID: 39159835 DOI: 10.1016/j.neuropharm.2024.110120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 08/11/2024] [Accepted: 08/16/2024] [Indexed: 08/21/2024]
Abstract
A large portion of neuropathic pain suffering patients may also concurrently experience neuropathic itch, with a negative impact on the quality of life. The limited understanding of neuropathic itch and the low efficacy of current anti-itch therapies dictate the urgent need of a better comprehension of molecular mechanisms involved and development of relevant animal models. This study was aimed to characterize the itching phenotype in a model of trauma-induced peripheral neuropathy, the spared nerve injury (SNI), and the molecular events underlying the overlap with the nociceptive behavior. SNI mice developed hyperknesis and spontaneous itch 7-14 days after surgery that was prevented by gabapentin treatment. Itch was associated with pain hypersensitivity, loss of intraepidermal nerve fiber (IENF) density and increased epidermal thickness. In coincidence with the peak of scratching behavior, SNI mice showed a spinal overexpression of IBA1 and GFAP, microglia and astrocyte markers respectively. An increase of the itch neuropeptide B-type natriuretic peptide (BNP) in NeuN+ cells, of its downstream effector interleukin 17 (IL17) along with increased pERK1/2 levels occurred in the spinal cord dorsal horn and DRG. A raise in BNP and IL17 was also detected at skin level. Stimulation of HaCat cells with conditioned medium from BV2-stimulated SH-SY5Y cells produced a dramatic reduction of HaCat cell viability. This study showed that SNI mice might represent a model for neuropathic itch and pain. Collectively, our finding suggest that neuropathic itch might initiate at spinal level, then affecting skin epidermis events, through a glia-mediated neuroinflammation-evoked BNP/IL17 mechanism.
Collapse
Affiliation(s)
- Vittoria Borgonetti
- Department of Neurosciences, Psychology, Drug Research and Child Health (Neurofarba), University of Florence, Viale G. Pieraccini 6, Florence, Italy
| | - Martina Morozzi
- Department of Neurosciences, Psychology, Drug Research and Child Health (Neurofarba), University of Florence, Viale G. Pieraccini 6, Florence, Italy
| | - Nicoletta Galeotti
- Department of Neurosciences, Psychology, Drug Research and Child Health (Neurofarba), University of Florence, Viale G. Pieraccini 6, Florence, Italy.
| |
Collapse
|
2
|
Shin JY, Cho BO, Park JH, Kang ES, Kim JH, Ha HY, Kim YS, Jang SI. Diospyros lotus leaf extract and its main component myricitrin inhibit itch‑related IL‑6 and IL‑31 by suppressing microglial inflammation and microglial‑mediated astrocyte activation. Mol Med Rep 2024; 30:178. [PMID: 39129303 PMCID: PMC11338241 DOI: 10.3892/mmr.2024.13303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Accepted: 07/11/2024] [Indexed: 08/13/2024] Open
Abstract
Diospyros lotus has been traditionally used in Asia for medicinal purposes, exhibiting a broad spectrum of pharmacological effects including antioxidant, neuroprotective and anti‑inflammatory properties. While the anti‑itch effect of D. lotus leaves has been reported, studies on the detailed mechanism of action in microglia and astrocytes, which are members of the central nervous system, have yet to be revealed. The present study aimed to investigate effects of D. lotus leaf extract (DLE) and its main component myricitrin (MC) on itch‑related cytokines and signaling pathways in lipopolysaccharide (LPS)‑stimulated microglia. The effect of DLE and MC on activation of astrocyte stimulated by microglia was also examined. Cytokine production was evaluated through reverse transcription PCR and western blot analysis. Signaling pathway was analyzed by performing western blotting and immunofluorescence staining. The effect of microglia on astrocytes activation was evaluated via western blotting for receptors, signaling molecules and itch mediators and confirmed through gene silencing using short interfering RNA. DLE and MC suppressed the production of itch‑related cytokine IL‑6 and IL‑31 in LPS‑stimulated microglia. These inhibitory effects were mediated through the blockade of NF‑κB, MAPK and JAK/STAT pathways. In astrocytes, stimulation by microglia promoted the expression of itch‑related molecules such as oncostatin M receptor, interleukin 31 receptor a, inositol 1,4,5‑trisphosphate receptor 1, lipocalin‑2 (LCN2), STAT3 and glial fibrillary acidic protein. However, DLE and MC significantly inhibited these receptors. Additionally, astrocytes stimulated by microglia with IL‑6, IL‑31, or both genes silenced did not show activation of LCN2 or STAT3. The findings of the present study demonstrated that DLE and MC could suppress pruritic activity in astrocytes induced by microglia‑derived IL‑6 and IL‑31. This suggested the potential of DLE and MC as functional materials capable of alleviating pruritus.
Collapse
Affiliation(s)
- Jae Young Shin
- Institute of Health and Science, Jeonju University, Jeonju-si, Jeollabuk-do 55069, Republic of Korea
- Department of Food Science and Technology, Jeonbuk National University, Jeonju-si, Jeollabuk-do 54896, Republic of Korea
| | - Byoung Ok Cho
- Institute of Health and Science, Jeonju University, Jeonju-si, Jeollabuk-do 55069, Republic of Korea
| | - Ji Hyeon Park
- Institute of Health and Science, Jeonju University, Jeonju-si, Jeollabuk-do 55069, Republic of Korea
| | - Eun Seo Kang
- Institute of Health and Science, Jeonju University, Jeonju-si, Jeollabuk-do 55069, Republic of Korea
| | - Jang Ho Kim
- Institute of Health and Science, Jeonju University, Jeonju-si, Jeollabuk-do 55069, Republic of Korea
| | - Hun Yong Ha
- Department of Pharmaceutical Science and Engineering, Seowon University, Cheongju-si, Chungcheongbuk-do 28674, Republic of Korea
| | - Young-Soo Kim
- Department of Food Science and Technology, Jeonbuk National University, Jeonju-si, Jeollabuk-do 54896, Republic of Korea
| | - Seon Il Jang
- Institute of Health and Science, Jeonju University, Jeonju-si, Jeollabuk-do 55069, Republic of Korea
- Department of Health Management, Jeonju University, Jeonju-si, Jeollabuk-do 55069, Republic of Korea
| |
Collapse
|
3
|
Mack MR, Miron Y, Chen F, Miller PE, Zhang A, Korotzer A, Richman D, Bryce PJ. Type 2 cytokines sensitize human sensory neurons to itch-associated stimuli. Front Mol Neurosci 2023; 16:1258823. [PMID: 37868811 PMCID: PMC10586051 DOI: 10.3389/fnmol.2023.1258823] [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: 07/14/2023] [Accepted: 09/18/2023] [Indexed: 10/24/2023] Open
Abstract
Introduction Chronic itch is a central symptom of atopic dermatitis. Cutaneous afferent neurons express receptors interleukins (IL)-4, IL-13, and IL-33, which are type 2 cytokines that are elevated in atopic dermatitis. These neuronal cytokine receptors were found to be required in several murine models of itch. Prior exposure of neurons to either IL-4 or IL-33 increased their response to subsequent chemical pruritogens in mice but has not been previously examined in humans. The objective of the present study was to determine if type 2 cytokine stimulation sensitizes sensory neurons to future itch stimuli in a fully human ex vivo system. Methods We measured calcium flux from human dorsal root ganglia cultures from cadaveric donors in response to pruritogens following transient exposure to type 2 cytokines. We also measured their effect on neuronal calcium flux and changes in gene expression by RNA sequencing. Results Type 2 cytokines (IL-4, IL-13, and IL-33) were capable of sensitizing human dorsal root ganglia neurons to both histaminergic and nonhistaminergic itch stimuli. Sensitization was observed after only 2 h of pruritogen incubation. We observed rapid neuronal calcium flux in a small subset of neurons directly in response to IL-4 and to IL-13, which was dependent on the presence of extracellular calcium. IL-4 and IL-13 induced a common signature of upregulated genes after 24 h of exposure that was unique from IL-33 and non-type 2 inflammatory stimuli. Discussion This study provides evidence of peripheral neuron sensitization by type 2 cytokines as well as broad transcriptomic effects in human sensory ganglia. These studies identify both unique and overlapping roles of these cytokines in sensory neurons.
Collapse
Affiliation(s)
- Madison R. Mack
- Immunology and Inflammation Research Therapeutic Area, Sanofi, Cambridge, MA, United States
| | | | | | | | - Annie Zhang
- Medical Affairs, Sanofi, Cambridge, MA, United States
| | - Andrew Korotzer
- Medical Affairs, Regeneron Pharmaceuticals, Tarrytown, NY, United States
| | | | - Paul J. Bryce
- Immunology and Inflammation Research Therapeutic Area, Sanofi, Cambridge, MA, United States
| |
Collapse
|
4
|
Shin JY, Cho BO, Park JH, Kang ES, Kim YS, Jang SI. Diospyros lotus leaf extract and its main component myricitrin regulate pruritus through the inhibition of astrocyte activation. Exp Ther Med 2023; 26:323. [PMID: 37346401 PMCID: PMC10280317 DOI: 10.3892/etm.2023.12022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 03/29/2023] [Indexed: 06/23/2023] Open
Abstract
Diospyros lotus is a deciduous plant native to Asian countries, including Korea, Japan and China, and southeast Europe. In traditional medicine, Diospyros lotus is used as an anticancer, antidiabetic and antipyretic agent. The present study aimed to evaluate the effect of Diospyros lotus leaf extract (DLE) in ameliorating histamine-independent pruritus. Activation of signal transducer and activator of transcription 3 (STAT3) in astrocytes contributes to pruritus. In this study, the effects of DLE and its main component, myricetin (MC), on the activation of STAT3, expression of glial fibrillary acidic protein (GFAP), and production of lipocalin-2 (LCN2) in IL-6-treated astrocytes and chloroquine-injected mice were investigated through western blot, reverse transcription-quantitative PCR, and immunofluorescence staining. DLE and MC inhibited STAT3 activation, GFAP expression and LCN2 release via inositol 1,4,5-trisphosphate receptor type 1 blockade in astrocytes. DLE and MC ameliorated scratching behavior, expression of GFAP, mast cell infiltration and serum IL-6 levels in chloroquine-injected mice. These results suggested that DLE and MC can be used as oral therapeutic agents for the treatment and management of pruritus.
Collapse
Affiliation(s)
- Jae Young Shin
- Department of Food Science and Technology, Jeonbuk National University, Deokjin, Jeonju, Jeollabuk 54896, Republic of Korea
- Institute of Health and Science, Jeonju University, Wansan, Jeonju, Jeollabuk 55069, Republic of Korea
| | - Byoung Ok Cho
- Institute of Health and Science, Jeonju University, Wansan, Jeonju, Jeollabuk 55069, Republic of Korea
| | - Ji Hyeon Park
- Institute of Health and Science, Jeonju University, Wansan, Jeonju, Jeollabuk 55069, Republic of Korea
| | - Eun Seo Kang
- Institute of Health and Science, Jeonju University, Wansan, Jeonju, Jeollabuk 55069, Republic of Korea
| | - Young Soo Kim
- Department of Food Science and Technology, Jeonbuk National University, Deokjin, Jeonju, Jeollabuk 54896, Republic of Korea
| | - Seon Il Jang
- Institute of Health and Science, Jeonju University, Wansan, Jeonju, Jeollabuk 55069, Republic of Korea
- Department of Health Management, Jeonju University, Wansan, Jeonju, Jeollabuk 55069, Republic of Korea
| |
Collapse
|
5
|
Gao X, Wang Z, Du L. Glial Cells and Itch: Possible Targets for Novel Antipruritic Therapies. ACS Chem Neurosci 2023; 14:331-339. [PMID: 36655585 DOI: 10.1021/acschemneuro.2c00638] [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: 01/20/2023] Open
Abstract
Glial cells, which are the non-neuronal cells of the nervous system, play essential roles in brain development, homeostasis, and diseases. Glial cells have attracted attention because of their active involvement in many neurological disorders. In recent years, substantial progress has been made in our understanding of the roles of glial cells in the pathogenesis of itch. Mechanistically, central and peripheral glial cells modulate acute and chronic pruritus via different mechanisms. In this review, we present the current knowledge about the involvement of glial cells in the modulation of itch processing and the mechanism of glial cell activation under itch stimuli. Targeting glial cells may provide novel approaches for itch therapy.
Collapse
Affiliation(s)
- Xinyi Gao
- School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zhifei Wang
- School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Lixia Du
- Department of Biochemistry, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| |
Collapse
|
6
|
Fang XX, Wang H, Song HL, Wang J, Zhang ZJ. Neuroinflammation Involved in Diabetes-Related Pain and Itch. Front Pharmacol 2022; 13:921612. [PMID: 35795572 PMCID: PMC9251344 DOI: 10.3389/fphar.2022.921612] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 05/12/2022] [Indexed: 12/25/2022] Open
Abstract
Diabetes mellitus (DM) is a global epidemic with increasing incidence, which results in diverse complications, seriously affects the patient quality of life, and brings huge economic burdens to society. Diabetic neuropathy is the most common chronic complication of DM, resulting in neuropathic pain and chronic itch. The precise mechanisms of diabetic neuropathy have not been fully clarified, hindering the exploration of novel therapies for diabetic neuropathy and its terrible symptoms such as diabetic pain and itch. Accumulating evidence suggests that neuroinflammation plays a critical role in the pathophysiologic process of neuropathic pain and chronic itch. Indeed, researchers have currently made significant progress in knowing the role of glial cells and the pro-inflammatory mediators produced from glial cells in the modulation of chronic pain and itch signal processing. Here, we provide an overview of the current understanding of neuroinflammation in contributing to the sensitization of the peripheral nervous system (PNS) and central nervous system (CNS). In addition, we also summarize the inflammation mechanisms that contribute to the pathogenesis of diabetic itch, including activation of glial cells, oxidative stress, and pro-inflammatory factors. Targeting excessive neuroinflammation may provide potential and effective therapies for the treatment of chronic neuropathic pain and itch in DM.
Collapse
Affiliation(s)
- Xiao-Xia Fang
- Department of Human Anatomy, School of Medicine, Nantong University, Nantong, China
- Department of Medical Functional Laboratory, School of Medicine, Nantong University, Nantong, China
| | - Heng Wang
- Department of Human Anatomy, School of Medicine, Nantong University, Nantong, China
| | - Hao-Lin Song
- Department of Human Anatomy, School of Medicine, Nantong University, Nantong, China
| | - Juan Wang
- Department of Human Anatomy, School of Medicine, Nantong University, Nantong, China
| | - Zhi-Jun Zhang
- Department of Human Anatomy, School of Medicine, Nantong University, Nantong, China
| |
Collapse
|
7
|
Koizumi S. Glial pharmacology in Asia & Beyond. Pharmacol Res Perspect 2021; 9:e00881. [PMID: 34676997 PMCID: PMC8532131 DOI: 10.1002/prp2.881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Schuichi Koizumi
- Department of NeuropharmacologyGraduate School of MedicineUniversity of YamanashiYamanashiJapan
- GLIA CenterUniversity of YamanashiYamanashiJapan
| |
Collapse
|