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Biazus Soares G, Hashimoto T, Yosipovitch G. Atopic Dermatitis Itch: Scratching for an Explanation. J Invest Dermatol 2024; 144:978-988. [PMID: 38363270 DOI: 10.1016/j.jid.2023.10.048] [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: 08/26/2023] [Revised: 10/20/2023] [Accepted: 10/31/2023] [Indexed: 02/17/2024]
Abstract
Chronic pruritus is a cardinal symptom of atopic dermatitis (AD). The mechanisms underlying atopic itch involve intricate crosstalk among skin, immune components, and neural components. In this review, we explore these mechanisms, focusing on key players and interactions that induce and exacerbate itch. We discuss the similarities and differences between pruritus and pain in patients with AD as well as the relationship between pruritus and factors such as sweat and the skin microbiome. Furthermore, we explore novel targets that could provide significant itch relief in these patients as well as exciting future research directions to better understand atopic pruritus in darker skin types.
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Affiliation(s)
- Georgia Biazus Soares
- Miami Itch Center, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Takashi Hashimoto
- Department of Dermatology, National Defense Medical College, Tokorozawa, Japan
| | - Gil Yosipovitch
- Miami Itch Center, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA.
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2
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Takahashi S, Ochiai S, Jin J, Takahashi N, Toshima S, Ishigame H, Kabashima K, Kubo M, Nakayama M, Shiroguchi K, Okada T. Sensory neuronal STAT3 is critical for IL-31 receptor expression and inflammatory itch. Cell Rep 2023; 42:113433. [PMID: 38029739 DOI: 10.1016/j.celrep.2023.113433] [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: 01/17/2023] [Revised: 08/21/2023] [Accepted: 10/30/2023] [Indexed: 12/01/2023] Open
Abstract
IL-31 receptor blockade suppresses pruritus of atopic dermatitis. However, cell-type-specific contributions of IL-31 receptor to itch, its expression mechanism, and the downstream signaling pathway to induce itch remain unknown. Here, using conditional knockout mice, we demonstrate that IL-31-induced itch requires sensory neuronal IL-31 receptor and STAT3. We find that IL-31 receptor expression is dependent on STAT3 in sensory neurons. In addition, pharmacological experiments suggest that STAT3 activation is important for the itch-inducing signaling downstream of the IL-31 receptor. A cutaneous IL-31 injection induces the nuclear accumulation of activated STAT3 first in sensory neurons that abundantly express IL-31 receptor and then in other itch-transmitting neurons. IL-31 enhances itch induced by various pruritogens including even chloroquine. Finally, pruritus associated with dermatitis is partially dependent on sensory neuronal IL-31 receptor and strongly on sensory neuronal STAT3. Thus, sensory neuronal STAT3 is essential for IL-31-induced itch and further contributes to IL-31-independent inflammatory itch.
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Affiliation(s)
- Sonoko Takahashi
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences (RIKEN IMS), Yokohama, Kanagawa 230-0045, Japan
| | - Sotaro Ochiai
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences (RIKEN IMS), Yokohama, Kanagawa 230-0045, Japan
| | - Jianshi Jin
- Laboratory for Prediction of Cell Systems Dynamics, RIKEN Center for Biosystems Dynamics Research (RIKEN BDR), Suita, Osaka 565-0874, Japan
| | - Noriko Takahashi
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences (RIKEN IMS), Yokohama, Kanagawa 230-0045, Japan
| | - Susumu Toshima
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences (RIKEN IMS), Yokohama, Kanagawa 230-0045, Japan; Department of Dermatology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Harumichi Ishigame
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences (RIKEN IMS), Yokohama, Kanagawa 230-0045, Japan
| | - Kenji Kabashima
- Department of Dermatology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan; Singapore Immunology Network and Skin Research Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Masato Kubo
- Laboratory for Cytokine Regulation, RIKEN IMS, Yokohama, Kanagawa 230-0045, Japan; Division of Molecular Pathology, Research Institute for Biomedical Science, Tokyo University of Science, Noda, Chiba 278-0022, Japan
| | - Manabu Nakayama
- Department of Frontier Research and Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan
| | - Katsuyuki Shiroguchi
- Laboratory for Prediction of Cell Systems Dynamics, RIKEN Center for Biosystems Dynamics Research (RIKEN BDR), Suita, Osaka 565-0874, Japan
| | - Takaharu Okada
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences (RIKEN IMS), Yokohama, Kanagawa 230-0045, Japan; Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa 230-0045, Japan.
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3
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Kiguchi N, Ding H, Park SH, Mabry KM, Kishioka S, Shiozawa Y, Alfonso Romero-Sandoval E, Peters CM, Ko MC. Functional roles of neuromedin B and gastrin-releasing peptide in regulating itch and pain in the spinal cord of non-human primates. Biochem Pharmacol 2022; 198:114972. [PMID: 35189108 PMCID: PMC10980179 DOI: 10.1016/j.bcp.2022.114972] [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: 01/03/2022] [Revised: 02/15/2022] [Accepted: 02/15/2022] [Indexed: 11/15/2022]
Abstract
Despite accumulating evidence in rodents, the functional role of neuromedin B (NMB) in regulating somatosensory systems in primate spinal cord is unknown. We aimed to compare the expression patterns of NMB and its receptor (NMBR) and the behavioral effects of intrathecal (i.t.) NMB with gastrin-releasing peptide (GRP) on itch or pain in non-human primates (NHPs). We used six adult rhesus monkeys. The mRNA or protein expressions of NMB, GRP, and their receptors were evaluated by quantitative reverse transcription polymerase chain reaction, immunohistochemistry, or in situ hybridization. We determined the behavioral effects of NMB or GRP via acute thermal nociception, capsaicin-induced thermal allodynia, and itch scratching response assays. NMB expression levels were greater than those of GRP in the dorsal root ganglia and spinal dorsal horn. Conversely, NMBR expression was significantly lower than GRP receptor (GRPR). I.t. NMB elicited only mild scratching responses, whereas GRP caused robust scratching responses. GRP- and NMB-elicited scratching responses were attenuated by GRPR (RC-3095) and NMBR (PD168368) antagonists, respectively. Moreover, i.t. NMB and GRP did not induce thermal hypersensitivity and GRPR and NMBR antagonists did not affect peripherally elicited thermal allodynia. Consistently, NMBR expression was low in both itch- and pain-responsive neurons in the spinal dorsal horn. Spinal NMB-NMBR system plays a minimal functional role in the neurotransmission of itch and pain in primates. Unlike the functional significance of the GRP-GRPR system in itch, drugs targeting the spinal NMB-NMBR system may not effectively alleviate non-NMBR-mediated itch.
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Affiliation(s)
- Norikazu Kiguchi
- Department of Physiological Sciences, School of Pharmaceutical Sciences, Wakayama Medical University, Wakayama City, Wakayama 640-8156, Japan.
| | - Huiping Ding
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Sun H Park
- Department of Cancer Biology and Wake Forest Baptist Comprehensive Cancer Center, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Kelsey M Mabry
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Shiroh Kishioka
- Faculty of Wakayama Health Care Sciences, Takarazuka University of Medical and Health Care, Wakayama City, Wakayama 640-8392, Japan
| | - Yusuke Shiozawa
- Department of Cancer Biology and Wake Forest Baptist Comprehensive Cancer Center, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | | | - Christopher M Peters
- Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Mei-Chuan Ko
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.
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4
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Meng QT, Liu XY, Liu XT, Liu J, Munanairi A, Barry DM, Liu B, Jin H, Sun Y, Yang Q, Gao F, Wan L, Peng J, Jin JH, Shen KF, Kim R, Yin J, Tao A, Chen ZF. BNP facilitates NMB-encoded histaminergic itch via NPRC-NMBR crosstalk. eLife 2021; 10:71689. [PMID: 34919054 PMCID: PMC8789279 DOI: 10.7554/elife.71689] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 12/16/2021] [Indexed: 11/13/2022] Open
Abstract
Histamine-dependent and -independent itch is conveyed by parallel peripheral neural pathways that express gastrin-releasing peptide (GRP) and neuromedin B (NMB), respectively, to the spinal cord of mice. B-type natriuretic peptide (BNP) has been proposed to transmit both types of itch via its receptor NPRA encoded by Npr1. However, BNP also binds to its cognate receptor, NPRC encoded by Npr3 with equal potency. Moreover, natriuretic peptides (NP) signal through the Gi-couped inhibitory cGMP pathway that is supposed to inhibit neuronal activity, raising the question of how BNP may transmit itch information. Here, we report that Npr3 expression in laminae I-II of the dorsal horn partially overlaps with NMB receptor (NMBR) that transmits histaminergic itch via Gq-couped PLCβ-Ca2+ signaling pathway. Functional studies indicate that NPRC is required for itch evoked by histamine but not chloroquine (CQ), a nonhistaminergic pruritogen. Importantly, BNP significantly facilitates scratching behaviors mediated by NMB, but not GRP. Consistently, BNP evoked Ca2+ responses in NMBR/NPRC HEK 293 cells and NMBR/NPRC dorsal horn neurons. These results reveal a previously unknown mechanism by which BNP facilitates NMB-encoded itch through a novel NPRC-NMBR cross-signaling in mice. Our studies uncover distinct modes of action for neuropeptides in transmission and modulation of itch in mice. An itch is a common sensation that makes us want to scratch. Most short-term itches are caused by histamine, a chemical that is released by immune cells following an infection or in response to an allergic reaction. Chronic itching, on the other hand, is not usually triggered by histamine, and is typically the result of neurological or skin disorders, such as atopic dermatitis. The sensation of itching is generated by signals that travel from the skin to nerve cells in the spinal cord. Studies in mice have shown that the neuropeptides responsible for delivering these signals differ depending on whether or not the itch involves histamine: GRPs (short for gastrin-releasing proteins) convey histamine-independent itches, while NMBs (short for neuromedin B) convey histamine-dependent itches. It has been proposed that another neuropeptide called BNP (short for B-type natriuretic peptide) is able to transmit both types of itch signals to the spinal cord. But it remains unclear how this signaling molecule is able to do this. To investigate, Meng, Liu, Liu, Liu et al. carried out a combination of behavioral, molecular and pharmacological experiments in mice and nerve cells cultured in a laboratory. The experiments showed that BNP alone cannot transmit the sensation of itching, but it can boost itching signals that are triggered by histamine. It is widely believed that BNP activates a receptor protein called NPRA. However, Meng et al. found that the BNP actually binds to another protein which alters the function of the receptor activated by NMBs. These findings suggest that BNP modulates rather than initiates histamine-dependent itching by enhancing the interaction between NMBs and their receptor. Understanding how itch signals travel from the skin to neurons in the spinal cord is crucial for designing new treatments for chronic itching. The work by Meng et al. suggests that treatments targeting NPRA, which was thought to be a key itch receptor, may not be effective against chronic itching, and that other drug targets need to be explored.
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Affiliation(s)
- Qing-Tao Meng
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Xian-Yu Liu
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Xue-Ting Liu
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Juan Liu
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Admire Munanairi
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Devin M Barry
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Benlong Liu
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Hua Jin
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Yu Sun
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Qianyi Yang
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Fang Gao
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Li Wan
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Jiahang Peng
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Jin-Hua Jin
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Kai-Feng Shen
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Ray Kim
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Jun Yin
- Center for the Study of Itch and Sensory Disorders, Washington University in St. Louis, St Louis, United States
| | - Ailin Tao
- Guangdong Provincial Key Laboratory of Allergy and Clinical Immunology, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zhou-Feng Chen
- Department of Anesthesiology, Washington University in St. Louis, St Louis, United States
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Goto T, Sapio MR, Maric D, Robinson JM, Domenichiello AF, Saligan LN, Mannes AJ, Iadarola MJ. Longitudinal peripheral tissue RNA-Seq transcriptomic profiling, hyperalgesia, and wound healing in the rat plantar surgical incision model. FASEB J 2021; 35:e21852. [PMID: 34499774 PMCID: PMC9293146 DOI: 10.1096/fj.202100347r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/24/2021] [Accepted: 07/28/2021] [Indexed: 02/06/2023]
Abstract
Postoperative pain and delayed healing in surgical wounds, which require complex management strategies have understudied complicated mechanisms. Here we investigated temporal changes in behavior, tissue structure, and transcriptomic profiles in a rat model of a surgical incision, using hyperalgesic behavioral tests, histological analyses, and next‐generation RNA sequencing, respectively. The most rapidly (1 hour) expressed genes were the chemokines, Cxcl1 and Cxcl2. Consequently, infiltrating leukocytes were abundantly observed starting at 6 and peaking at 24 hours after incising which was supported by histological analysis and appearance of the neutrophil markers, S100a8 and S100a9. At this time, hyperalgesia was at a peak and overall transcriptional activity was most highly activated. At the 1‐day timepoint, Nppb, coding for natriuretic peptide precursor B, was the most strongly upregulated gene and was localized by in situ hybridization to the epidermal keratinocytes at the margins of the incision. Nppb was basically unaffected in a peripheral inflammation model transcriptomic dataset. At the late phase of wound healing, five secreted, incision‐specific peptidases, Mmp2, Aebp1, Mmp23, Adamts7, and Adamtsl1, showed increased expression, supporting the idea of a sustained tissue remodeling process. Transcripts that are specifically upregulated at each timepoint in the incision model may be potential candidates for either biomarkers or therapeutic targets for wound pain and wound healing. This study incorporates the examination of longitudinal temporal molecular responses, corresponding anatomical localization, and hyperalgesic behavioral alterations in the surgical incision model that together provide important and novel foundational knowledge to understand mechanisms of wound pain and wound healing.
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Affiliation(s)
- Taichi Goto
- Symptoms Biology Unit, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Matthew R Sapio
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Dragan Maric
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Jeffrey M Robinson
- Translational Life Science Technology Program, University of Maryland, Baltimore County, Baltimore, MD, USA
| | - Anthony F Domenichiello
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Leorey N Saligan
- Symptoms Biology Unit, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Andrew J Mannes
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
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6
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Meng J, Li Y, Fischer MJM, Steinhoff M, Chen W, Wang J. Th2 Modulation of Transient Receptor Potential Channels: An Unmet Therapeutic Intervention for Atopic Dermatitis. Front Immunol 2021; 12:696784. [PMID: 34276687 PMCID: PMC8278285 DOI: 10.3389/fimmu.2021.696784] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 06/15/2021] [Indexed: 12/12/2022] Open
Abstract
Atopic dermatitis (AD) is a multifaceted, chronic relapsing inflammatory skin disease that affects people of all ages. It is characterized by chronic eczema, constant pruritus, and severe discomfort. AD often progresses from mild annoyance to intractable pruritic inflammatory lesions associated with exacerbated skin sensitivity. The T helper-2 (Th2) response is mainly linked to the acute and subacute phase, whereas Th1 response has been associated in addition with the chronic phase. IL-17, IL-22, TSLP, and IL-31 also play a role in AD. Transient receptor potential (TRP) cation channels play a significant role in neuroinflammation, itch and pain, indicating neuroimmune circuits in AD. However, the Th2-driven cutaneous sensitization of TRP channels is underappreciated. Emerging findings suggest that critical Th2-related cytokines cause potentiation of TRP channels, thereby exaggerating inflammation and itch sensation. Evidence involves the following: (i) IL-13 enhances TRPV1 and TRPA1 transcription levels; (ii) IL-31 sensitizes TRPV1 via transcriptional and channel modulation, and indirectly modulates TRPV3 in keratinocytes; (iii) The Th2-cytokine TSLP increases TRPA1 synthesis in sensory neurons. These changes could be further enhanced by other Th2 cytokines, including IL-4, IL-25, and IL-33, which are inducers for IL-13, IL-31, or TSLP in skin. Taken together, this review highlights that Th2 cytokines potentiate TRP channels through diverse mechanisms under different inflammatory and pruritic conditions, and link this effect to distinct signaling cascades in AD. This review strengthens the notion that interrupting Th2-driven modulation of TRP channels will inhibit transition from acute to chronic AD, thereby aiding the development of effective therapeutics and treatment optimization.
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Affiliation(s)
- Jianghui Meng
- School of Life Sciences, Henan University, Kaifeng, China.,National Institute for Cellular Biotechnology, Dublin City University, Dublin, Ireland
| | - Yanqing Li
- School of Life Sciences, Henan University, Kaifeng, China
| | - Michael J M Fischer
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Martin Steinhoff
- Department of Dermatology and Venereology, Hamad Medical Corporation, Doha, Qatar.,Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar.,Dermatology Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar.,Department of Dermatology, Weill Cornell Medicine-Qatar, Doha, Qatar.,Qatar University, College of Medicine, Doha, Qatar.,Department of Dermatology, Weill Cornell Medicine, New York, NY, United States
| | - Weiwei Chen
- School of Life Sciences, Henan University, Kaifeng, China
| | - Jiafu Wang
- School of Life Sciences, Henan University, Kaifeng, China.,School of Biotechnology, Faculty of Science and Health, Dublin City University, Dublin, Ireland
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Naseri Kouzehgarani G, Feldsien T, Engelhard HH, Mirakhur KK, Phipps C, Nimmrich V, Clausznitzer D, Lefebvre DR. Harnessing cerebrospinal fluid circulation for drug delivery to brain tissues. Adv Drug Deliv Rev 2021; 173:20-59. [PMID: 33705875 DOI: 10.1016/j.addr.2021.03.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/10/2021] [Accepted: 03/01/2021] [Indexed: 12/31/2022]
Abstract
Initially thought to be useful only to reach tissues in the immediate vicinity of the CSF circulatory system, CSF circulation is now increasingly viewed as a viable pathway to deliver certain therapeutics deeper into brain tissues. There is emerging evidence that this goal is achievable in the case of large therapeutic proteins, provided conditions are met that are described herein. We show how fluid dynamic modeling helps predict infusion rate and duration to overcome high CSF turnover. We posit that despite model limitations and controversies, fluid dynamic models, pharmacokinetic models, preclinical testing, and a qualitative understanding of the glymphatic system circulation can be used to estimate drug penetration in brain tissues. Lastly, in addition to highlighting landmark scientific and medical literature, we provide practical advice on formulation development, device selection, and pharmacokinetic modeling. Our review of clinical studies suggests a growing interest for intra-CSF delivery, particularly for targeted proteins.
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Kiguchi N, Fukazawa Y, Saika A, Uta D, Saika F, Nakamura TY, Ko M, Kishioka S. Chemogenetic activation of central gastrin-releasing peptide-expressing neurons elicits itch-related scratching behavior in male and female mice. Pharmacol Res Perspect 2021; 9:e00790. [PMID: 34000759 PMCID: PMC8128314 DOI: 10.1002/prp2.790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 04/19/2021] [Indexed: 12/11/2022] Open
Abstract
Several lines of evidence have clarified that the key transmission pathways of itching sensation travel from the periphery to the central nervous system (CNS). Despite the functional significance of gastrin-releasing peptide (GRP) and its cognate receptor in the itch processing mechanism in the spinal dorsal horn (SDH), the roles of GRP-expressing (GRP+ ) neurons in different regions remain unclear. This study aimed to determine whether GRP+ neurons in the CNS directly modulated itch processing. To specifically activate spinal and supraspinal GRP neurons by the designer receptors exclusively activated by designer drugs (DREADDs) system, CAG-LSL-Gq-DREADD mice were crossed with GRP-Cre mice, resulting in the development of GRP-hM3Dq mice. Immunohistochemistry showed that hM3Dq was highly expressed in the SDH and brainstem closely related to sensory processing. The intraperitoneal, intrathecal, or intracerebroventricular administration of clozapine-N-oxide, an agonist of hM3Dq, strongly elicited dermatome-dependent itch-related scratching behavior, but did not change pain sensitivity. Importantly, GRP-Gq-DREADD-mediated scratching behavior in GRP-hM3Dq mice was not affected by the ablation of transient receptor potential vanilloid 1+ sensory C-fibers, and it was also observed to a similar degree under chronic itch conditions. Furthermore, there were no significant sex differences in the scratching behavior elicited by GRP-Gq-DREADD, suggesting that itch-dominant roles of central GRP+ neurons might be common in both sexes, at least under normal physiological conditions. These novel findings not only contribute to understanding the functional roles of central GRP+ neurons further, but also propose the development of future effective therapeutics for intractable itching.
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Affiliation(s)
- Norikazu Kiguchi
- Department of PharmacologyWakayama Medical UniversityWakayama CityWakayamaJapan
- Department of Physiological SciencesSchool of Pharmaceutical SciencesWakayama Medical UniversityWakayama CityWakayamaJapan
| | - Yohji Fukazawa
- Department of AnatomyKansai University of Health SciencesSennan‐gunOsakaJapan
| | - Ayano Saika
- Department of PharmacologyWakayama Medical UniversityWakayama CityWakayamaJapan
| | - Daisuke Uta
- Department of Applied PharmacologyFaculty of Pharmaceutical SciencesUniversity of ToyamaToyama CityToyamaJapan
| | - Fumihiro Saika
- Department of PharmacologyWakayama Medical UniversityWakayama CityWakayamaJapan
| | - Tomoe Y. Nakamura
- Department of PharmacologyWakayama Medical UniversityWakayama CityWakayamaJapan
| | - Mei‐Chuan Ko
- Department of Physiology and PharmacologyWake Forest University School of MedicineWinston‐SalemNCUSA
| | - Shiroh Kishioka
- Faculty of Wakayama Health Care SciencesTakarazuka University of Medical and Health CareWakayama CityWakayamaJapan
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9
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Li HP, Wang XY, Chen C, Li JJ, Yu C, Lin LX, Yu ZE, Jin ZY, Zhu H, Xiang HC, Hu XF, Cao J, Jing XH, Li M. 100 Hz Electroacupuncture Alleviated Chronic Itch and GRPR Expression Through Activation of Kappa Opioid Receptors in Spinal Dorsal Horn. Front Neurosci 2021; 15:625471. [PMID: 33664646 PMCID: PMC7921323 DOI: 10.3389/fnins.2021.625471] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/20/2021] [Indexed: 11/19/2022] Open
Abstract
Background Clinical studies have shown that electroacupuncture (EA) alleviates chronic itch. Gastrin-releasing peptide receptor (GRPR) and dynorphin (DYN) in the spinal dorsal horn positively or negatively regulate itch, respectively. However, which frequency of EA is effective on relieving chronic itch and reducing the expression of GRPR, whether DYN-A in the spinal cord is involved in the underlying mechanism of the antipruritus effect of EA remains unknown. Methods The mixture of acetone and diethyl ether (1:1) [designated as AEW (acetone/diethyl ether and water) treatment] was used to induce the dry skin model of chronic itch. EA was applied to Quchi (LI11) and Hegu (LI4). Western blot was used to detect the expression of GRPR and DYN-A. Immunofluorescence was used to detect the expression of DYN-A. Results The AEW administration induced remarkable spontaneous scratching, enhanced the expression of GRPR, and reduced the expression of DYN-A. Compared with the sham EA, 2 Hz EA, or 15 Hz EA group, 100 Hz EA was the most effective frequency for relieving chronic itch, reducing the expression of GRPR, and increasing the expression of DYN-A in the cervical dorsal horn. Furthermore, intraperitoneal injection of kappa opioid receptors (KORs) antagonist nor-Binaltorphimine dihydrochloride (nor-BNI) significantly reversed the effect of 100 Hz EA on the inhibition of both itching behavior and GRPR expression. Conclusion EA at 100 Hz is the most effective frequency that inhibits chronic itch and GRPR expression through activation of KORs in the spinal dorsal horn, which can effectively guide the clinical treatment and improve the antipruritic effect of acupuncture.
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Affiliation(s)
- Hong-Ping Li
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Yu Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Chao Chen
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jing-Jing Li
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chi Yu
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Li-Xue Lin
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zi-E Yu
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhi-Yuan Jin
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - He Zhu
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hong-Chun Xiang
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xue-Fei Hu
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jie Cao
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiang-Hong Jing
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Man Li
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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10
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Li JN, Ren JH, Zhao LJ, Wu XM, Li H, Dong YL, Li YQ. Projecting neurons in spinal dorsal horn send collateral projections to dorsal midline/intralaminar thalamic complex and parabrachial nucleus. Brain Res Bull 2021; 169:184-195. [PMID: 33508400 DOI: 10.1016/j.brainresbull.2021.01.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/12/2021] [Accepted: 01/15/2021] [Indexed: 10/22/2022]
Abstract
Itch is an annoying sensation that always triggers scratching behavior, yet little is known about its transmission pathway in the central nervous system. Parabrachial nucleus (PBN), an essential transmission nucleus in the brainstem, has been proved to be the first relay station in itch sensation. Meanwhile, dorsal midline/intralaminar thalamic complex (dMITC) is proved to be activated with nociceptive stimuli. However, whether the PBN-projecting neurons in spinal dorsal horn (SDH) send collateral projections to dMITC, and whether these projections involve in itch remain unknown. In the present study, a double retrograde tracing method was applied when the tetramethylrhodamine-dextran (TMR) was injected into the dMITC and Fluoro-gold (FG) was injected into the PBN, respectively. Immunofluorescent staining for NeuN, substance P receptor (SPR), substance P (SP), or FOS induced by itch or pain stimulations with TMR and FG were conducted to provide morphological evidence. The results revealed that TMR/FG double-labeled neurons could be predominately observed in superficial laminae and lateral spinal nucleus (LSN) of SDH; Meanwhile, most of the collateral projection neurons expressed SPR and some of them expressed FOS in acute itch model induced by histamine. The present results implicated that some of the SPR-expressing neurons in SDH send collateral projections to the dMITC and PBN in itch transmission, which might be involved in itch related complex affective/emotional processing to the higher brain centers.
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Affiliation(s)
- Jia-Ni Li
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
| | - Jia-Hao Ren
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
| | - Liu-Jie Zhao
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China
| | - Xue-Mei Wu
- Department of Human Anatomy, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041, China
| | - Hui Li
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
| | - Yu-Lin Dong
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China.
| | - Yun-Qing Li
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China; Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China; Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Haikou, China.
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11
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Ting SW, Fan PC, Lin YS, Lin MS, Lee CC, Kuo G, Chang CH. Uremic pruritus and long-term morbidities in the dialysis population. PLoS One 2020; 15:e0241088. [PMID: 33104746 PMCID: PMC7588085 DOI: 10.1371/journal.pone.0241088] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 10/07/2020] [Indexed: 12/11/2022] Open
Abstract
Background Uremic pruritus (UP) is a multifactorial problem that contributes to low quality of life in dialysis patients. The long-term influences of UP on dialysis patients are still poorly understood. This study aims to elucidate the contribution of UP to long-term outcomes. Materials and method We used the Taiwan National Health Insurance Research Database to conduct this study. Patients on chronic dialysis were included and divided into UP and non-UP groups according to the long-term prescription of antihistamine in the absence of other indications. The outcomes include infection-related hospitalization, catheter-related infection, major adverse cardiac and cerebrovascular events (MACCE) and parathyroidectomy. Results After propensity score matching, 14,760 patients with UP and 29,520 patients without UP were eligible for analysis. After a mean follow-up of 5 years, we found that infection-related hospitalization, MACCE, catheter-related infection, heart failure and parathyroidectomy were all slightly higher in the UP than non-UP group (hazard ratio: 1.18 [1.16–1.21], 1.05 [1.01–1.09], 1.16 [1.12–1.21], 1.08 [1.01–1.16] and 1.10 [1.01–1.20], respectively). Subgroup analysis revealed that the increased risk of adverse events by UP was generally more apparent in younger patients and patients who underwent peritoneal dialysis. Conclusion UP may be significantly associated with an increased risk of long-term morbidities.
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Affiliation(s)
- Sze-Wen Ting
- Department of Dermatology, New Taipei City Tu-Cheng Municipal Hospital, New Taipei City (Built and Operated by Chang Gung Medical Foundation), Taoyuan, Taiwan
| | - Pei-Chun Fan
- Department of Nephrology, Kidney Research Center, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yu-Sheng Lin
- Department of Cardiology, Chiayi Chang Gung Memorial Hospital, Puzi City, Taiwan
- Chang Gung University, College of Medicine, Taoyuan, Taiwan
| | - Ming-Shyan Lin
- Department of Cardiology, Chiayi Chang Gung Memorial Hospital, Puzi City, Taiwan
| | - Cheng-Chia Lee
- Department of Nephrology, Kidney Research Center, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - George Kuo
- Department of Nephrology, Kidney Research Center, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Chih-Hsiang Chang
- Department of Nephrology, Kidney Research Center, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Chang Gung University, College of Medicine, Taoyuan, Taiwan
- * E-mail: ,
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12
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GRPR/Extracellular Signal-Regulated Kinase and NPRA/Extracellular Signal-Regulated Kinase Signaling Pathways Play a Critical Role in Spinal Transmission of Chronic Itch. J Invest Dermatol 2020; 141:863-873. [PMID: 33039402 DOI: 10.1016/j.jid.2020.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/26/2020] [Accepted: 09/17/2020] [Indexed: 02/07/2023]
Abstract
Intractable or recurrent chronic itch greatly reduces the patients' QOL and impairs their daily activities. In this study, we investigated whether there are certain key signaling molecules downstream of the recently identified peptides mediating itch in the spinal cord. RNA sequencing analysis of mouse spinal cord in chronic itch models induced by squaric acid dibutylester and imiquimod showed that extracellular signal-regulated kinase (ERK) 1/2 cascade is the most significantly upregulated gene cluster in both models. In four different mouse models of chronic itch, sustained ERK phosphorylation was detected mainly in spinal neurons, and MAPK/ERK kinase inhibitors significantly inhibited chronic itch in these models. Phosphorylated ERK was observed in the interneurons expressing the receptors of different neuropeptides for itch, including gastrin-releasing peptide receptor, natriuretic peptide receptor A, neuromedin B receptor, and sst2A. Blocking gastrin-releasing peptide receptor and natriuretic peptide receptor A by genetic approaches or toxins in mice significantly attenuated or ablated spinal phosphorylated ERK. When human embryonic kidney 293T cells transfected with these receptors were exposed to their respective agonists, ERK was the most significantly activated intracellular signaling molecule. Together, our work showed that phosphorylated ERK is a unique marker for itch signal transmission in the spinal cord and an attractive target for the treatment of chronic itch.
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13
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Introducing the Amphibious Mudskipper Goby as a Unique Model to Evaluate Neuro/Endocrine Regulation of Behaviors Mediated by Buccal Sensation and Corticosteroids. Int J Mol Sci 2020; 21:ijms21186748. [PMID: 32938015 PMCID: PMC7555618 DOI: 10.3390/ijms21186748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/04/2020] [Accepted: 09/08/2020] [Indexed: 11/19/2022] Open
Abstract
Some fish have acquired the ability to breathe air, but these fish can no longer flush their gills effectively when out of water. Hence, they have developed characteristic means for defense against external stressors, including thirst (osmolarity/ions) and toxicity. Amphibious fish, extant air-breathing fish emerged from water, may serve as models to examine physiological responses to these stressors. Some of these fish, including mudskipper gobies such as Periophthalmodon schlosseri, Boleophthalmus boddarti and our Periophthalmus modestus, display distinct adaptational behaviors to these factors compared with fully aquatic fish. In this review, we introduce the mudskipper goby as a unique model to study the behaviors and the neuro/endocrine mechanisms of behavioral responses to the stressors. Our studies have shown that a local sensation of thirst in the buccal cavity—this being induced by dipsogenic hormones—motivates these fish to move to water through a forebrain response. The corticosteroid system, which is responsive to various stressors, also stimulates migration, possibly via the receptors in the brain. We suggest that such fish are an important model to deepen insights into the stress-related neuro/endocrine-behavioral effects.
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14
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Liu X, Wang D, Wen Y, Zeng L, Li Y, Tao T, Zhao Z, Tao A. Spinal GRPR and NPRA Contribute to Chronic Itch in a Murine Model of Allergic Contact Dermatitis. J Invest Dermatol 2020; 140:1856-1866.e7. [DOI: 10.1016/j.jid.2020.01.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/02/2020] [Accepted: 01/07/2020] [Indexed: 11/25/2022]
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15
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Critical role of GRP receptor-expressing neurons in the spinal transmission of imiquimod-induced psoriatic itch. Neuropsychopharmacol Rep 2020. [PMID: 32584520 DOI: 10.3760/cma.j.cn131073.20200218.00307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
AIM Ample evidence indicates that gastrin-releasing peptide receptor (GRPR)-expressing neurons play a critical role in the transmission of acute itch. However, the pathophysiology of spinal mechanisms underlying intractable itch such as psoriasis remains unclear. In this study, we aimed to determine whether itch-responsive GRPR+ neurons contribute to the spinal transmission of imiquimod (IMQ)-induced psoriatic itch. METHODS To generate a psoriasis model, C57BL/6J mice received a daily topical application of 5% IMQ cream on their shaved back skin for 7-10 consecutive days. GRP+ neurons were inhibited using Cre-dependent expression of Gi-designer receptors exclusively activated by designer drugs (DREADDs), while GRPR+ neurons were ablated by intrathecal administration of bombesin-saporin. RESULTS Repeated topical application of IMQ elicited psoriasis-like dermatitis and scratching behaviors. The mRNA expression levels of GRP and GRPR were upregulated in the cervical spinal dorsal horn (SDH) on days 7 and 10 after IMQ application. Either chemogenetic silencing of GRP+ neurons by Gi-DREADD or ablation of GRPR+ neurons significantly attenuated IMQ-induced scratching behaviors. CONCLUSION The GRP-GRPR system might be enhanced in the SDH, and itch-responsive GRPR+ neurons largely contribute to intractable itch in a mouse model of psoriasis.
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16
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Solinski HJ, Dranchak P, Oliphant E, Gu X, Earnest TW, Braisted J, Inglese J, Hoon MA. Inhibition of natriuretic peptide receptor 1 reduces itch in mice. Sci Transl Med 2020; 11:11/500/eaav5464. [PMID: 31292265 DOI: 10.1126/scitranslmed.aav5464] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 02/19/2019] [Accepted: 05/30/2019] [Indexed: 12/14/2022]
Abstract
There is a major clinical need for new therapies for the treatment of chronic itch. Many of the molecular components involved in itch neurotransmission are known, including the neuropeptide NPPB, a transmitter required for normal itch responses to multiple pruritogens in mice. Here, we investigated the potential for a novel strategy for the treatment of itch that involves the inhibition of the NPPB receptor NPR1 (natriuretic peptide receptor 1). Because there are no available effective human NPR1 (hNPR1) antagonists, we performed a high-throughput cell-based screen and identified 15 small-molecule hNPR1 inhibitors. Using in vitro assays, we demonstrated that these compounds specifically inhibit hNPR1 and murine NPR1 (mNPR1). In vivo, NPR1 antagonism attenuated behavioral responses to both acute itch- and chronic itch-challenged mice. Together, our results suggest that inhibiting NPR1 might be an effective strategy for treating acute and chronic itch.
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Affiliation(s)
- Hans Jürgen Solinski
- Molecular Genetics Section, National Institute of Dental and Craniofacial Research/NIH, 35 Convent Drive, Bethesda, MD 20892, USA
| | - Patricia Dranchak
- Division of Pre-Clinical Investigation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Erin Oliphant
- Division of Pre-Clinical Investigation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Xinglong Gu
- Molecular Genetics Section, National Institute of Dental and Craniofacial Research/NIH, 35 Convent Drive, Bethesda, MD 20892, USA
| | - Thomas W Earnest
- Molecular Genetics Section, National Institute of Dental and Craniofacial Research/NIH, 35 Convent Drive, Bethesda, MD 20892, USA
| | - John Braisted
- Division of Pre-Clinical Investigation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - James Inglese
- Division of Pre-Clinical Investigation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Mark A Hoon
- Molecular Genetics Section, National Institute of Dental and Craniofacial Research/NIH, 35 Convent Drive, Bethesda, MD 20892, USA.
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17
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Kiguchi N, Saika F, Fukazawa Y, Matsuzaki S, Kishioka S. Critical role of GRP receptor-expressing neurons in the spinal transmission of imiquimod-induced psoriatic itch. Neuropsychopharmacol Rep 2020; 40:287-290. [PMID: 32584520 PMCID: PMC7722649 DOI: 10.1002/npr2.12120] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/11/2020] [Accepted: 05/22/2020] [Indexed: 11/08/2022] Open
Abstract
AIM Ample evidence indicates that gastrin-releasing peptide receptor (GRPR)-expressing neurons play a critical role in the transmission of acute itch. However, the pathophysiology of spinal mechanisms underlying intractable itch such as psoriasis remains unclear. In this study, we aimed to determine whether itch-responsive GRPR+ neurons contribute to the spinal transmission of imiquimod (IMQ)-induced psoriatic itch. METHODS To generate a psoriasis model, C57BL/6J mice received a daily topical application of 5% IMQ cream on their shaved back skin for 7-10 consecutive days. GRP+ neurons were inhibited using Cre-dependent expression of Gi-designer receptors exclusively activated by designer drugs (DREADDs), while GRPR+ neurons were ablated by intrathecal administration of bombesin-saporin. RESULTS Repeated topical application of IMQ elicited psoriasis-like dermatitis and scratching behaviors. The mRNA expression levels of GRP and GRPR were upregulated in the cervical spinal dorsal horn (SDH) on days 7 and 10 after IMQ application. Either chemogenetic silencing of GRP+ neurons by Gi-DREADD or ablation of GRPR+ neurons significantly attenuated IMQ-induced scratching behaviors. CONCLUSION The GRP-GRPR system might be enhanced in the SDH, and itch-responsive GRPR+ neurons largely contribute to intractable itch in a mouse model of psoriasis.
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Affiliation(s)
- Norikazu Kiguchi
- Department of Pharmacology, Wakayama Medical University, Wakayama, Japan
| | - Fumihiro Saika
- Department of Pharmacology, Wakayama Medical University, Wakayama, Japan
| | - Yohji Fukazawa
- Department of Anatomy, Kansai University of Health Sciences, Osaka, Japan
| | - Shinsuke Matsuzaki
- Department of Pharmacology, Wakayama Medical University, Wakayama, Japan
| | - Shiroh Kishioka
- Department of Pharmacology, Wakayama Medical University, Wakayama, Japan.,Faculty of Wakayama Health Care Sciences, Takarazuka University of Medical and Health Care, Wakayama, Japan
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18
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Kiguchi N, Uta D, Ding H, Uchida H, Saika F, Matsuzaki S, Fukazawa Y, Abe M, Sakimura K, Ko MC, Kishioka S. GRP receptor and AMPA receptor cooperatively regulate itch-responsive neurons in the spinal dorsal horn. Neuropharmacology 2020; 170:108025. [PMID: 32142790 DOI: 10.1016/j.neuropharm.2020.108025] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/10/2020] [Accepted: 02/27/2020] [Indexed: 01/19/2023]
Abstract
Gastrin-releasing peptide (GRP) receptor-expressing (GRPR)+ neurons have a central role in the spinal transmission of itch. Because their fundamental regulatory mechanisms are not yet understood, it is important to determine how such neurons are excited and integrate itch sensation. In this study, we investigated the mechanisms for the activation of itch-responsive GRPR+ neurons in the spinal dorsal horn (SDH). GRPR+ neurons expressed the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) containing the GluR2 subunit. In mice, peripherally elicited histaminergic and non-histaminergic itch was prevented by intrathecal (i.t.) administration of the AMPAR antagonist NBQX, which was consistent with the fact that firing of GRPR+ neurons in SDH under histaminergic and non-histaminergic itch was completely blocked by NBQX, but not by the GRPR antagonist RC-3095. Because GRP+ neurons in SDH contain glutamate, we investigated the role of GRP+ (GRP+/Glu+) neurons in regulating itch. Chemogenetic inhibition of GRP+ neurons suppressed both histaminergic and non-histaminergic itch without affecting the mechanical pain threshold. In nonhuman primates, i.t. administration of NBQX also attenuated peripherally elicited itch without affecting the thermal pain threshold. In a mouse model of diphenylcyclopropenone (DCP)-induced contact dermatitis, GRP, GRPR, and AMPAR subunits were upregulated in SDH. DCP-induced itch was prevented by either silencing GRP+ neurons or ablation of GRPR+ neurons. Altogether, these findings demonstrate that GRP and glutamate cooperatively regulate GRPR+ AMPAR+ neurons in SDH, mediating itch sensation. GRP-GRPR and the glutamate-AMPAR system may play pivotal roles in the spinal transmission of itch in rodents and nonhuman primates.
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Affiliation(s)
- Norikazu Kiguchi
- Department of Pharmacology, Wakayama Medical University, Wakayama City, Wakayama, 641-0012, Japan.
| | - Daisuke Uta
- Department of Applied Pharmacology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama City, Toyama, 930-0194, Japan
| | - Huiping Ding
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, 27157, USA
| | - Hitoshi Uchida
- Department of Cellular Neuropathology, Brain Research Institute Niigata University, Niigata City, Niigata, 951-8585, Japan
| | - Fumihiro Saika
- Department of Pharmacology, Wakayama Medical University, Wakayama City, Wakayama, 641-0012, Japan
| | - Shinsuke Matsuzaki
- Department of Pharmacology, Wakayama Medical University, Wakayama City, Wakayama, 641-0012, Japan
| | - Yohji Fukazawa
- Department of Anatomy, Kansai University of Health Sciences, Sennan-gun, Osaka, 590-0482, Japan
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata City, Niigata, 951-8585, Japan
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata City, Niigata, 951-8585, Japan
| | - Mei-Chuan Ko
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, 27157, USA; W.G. Hefner Veterans Affairs Medical Center, Salisbury, NC, 28144, USA
| | - Shiroh Kishioka
- Department of Pharmacology, Wakayama Medical University, Wakayama City, Wakayama, 641-0012, Japan
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19
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Meng J, Chen W, Wang J. Interventions in the B-type natriuretic peptide signalling pathway as a means of controlling chronic itch. Br J Pharmacol 2020; 177:1025-1040. [PMID: 31877230 DOI: 10.1111/bph.14952] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 11/08/2019] [Accepted: 11/19/2019] [Indexed: 12/22/2022] Open
Abstract
Chronic itch poses major health care and economic burdens worldwide. In 2013, B-type natriuretic peptide (BNP) was identified as an itch-selective neuropeptide and shown to be both necessary and sufficient to produce itch behaviour in mice. Since then, mechanistic studies of itch have increased, not only at central levels of the spinal relay of itch signalling but also in the periphery and skin. In this review, we have critically analysed recent findings from complementary pharmacological and physiological approaches, combined with genetic strategies to examine the role of BNP in itch transduction and modulation of other pruritic proteins. Additionally, potential targets and possible strategies against BNP signalling are discussed for developing novel therapeutics in itch. Overall, we aim to provide insights into drug development by altering BNP signalling to modulate disease symptoms in chronic itch, including conditions for which no approved treatment exists.
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Affiliation(s)
- Jianghui Meng
- School of Life Sciences, Henan University, Henan, China.,National Institute for Cellular Biotechnology, Dublin City University, Dublin, Ireland.,School of Biotechnology, Faculty of Science and Health, Dublin City University, Dublin, Ireland
| | - Weiwei Chen
- School of Life Sciences, Henan University, Henan, China
| | - Jiafu Wang
- School of Life Sciences, Henan University, Henan, China.,School of Biotechnology, Faculty of Science and Health, Dublin City University, Dublin, Ireland
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20
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Wyatt CM, Drueke TB. Scratching the itch: a new therapeutic target for dialysis-associated pruritus? Kidney Int 2020; 97:444-447. [PMID: 31932070 DOI: 10.1016/j.kint.2019.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 10/18/2019] [Indexed: 11/25/2022]
Affiliation(s)
- Christina M Wyatt
- Division of Nephrology, Department of Medicine, Duke University and Duke Clinical Research Institute, Durham, North Carolina, USA.
| | - Tilman B Drueke
- Inserm Unit 1018, Team 5, CESP, Hôpital Paul Brousse, Paris-Sud University (UPS), Villejuif, France; Versailles Saint-Quentin-en-Yvelines University (Paris-Ile-de-France-Ouest University, UVSQ), Villejuif, France
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21
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Liu BW, Li ZX, He ZG, Wang Q, Liu C, Zhang XW, Yang H, Xiang HB. Altered expression of itch‑related mediators in the lower cervical spinal cord in mouse models of two types of chronic itch. Int J Mol Med 2019; 44:835-846. [PMID: 31257468 PMCID: PMC6657970 DOI: 10.3892/ijmm.2019.4253] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 06/13/2019] [Indexed: 01/08/2023] Open
Abstract
In this study, we focused on several itch-related molecules and receptors in the spinal cord with the goal of clarifying the specific mediators that regulate itch sensation. We investigated the involvement of serotonin receptors, opioid receptors, glia cell markers and chemokines (ligands and receptors) in models of acetone/ether/water (AEW)- and diphenylcyclopropenone (DCP)-induced chronic itch. Using reverse transcription-quantitative polymerase chain reaction, we examined the expression profiles of these mediators in the lower cervical spinal cord (C5-8) of two models of chronic itch. We found that the gene expression levels of opioid receptor mu 1 (Oprm1), 5-hydroxytryptamine receptor 1A (Htr1a) and 5-hydroxytryptamine receptor 6 (Htr6) were upregulated. Among the chemokines, the expression levels of C-C motif chemokine ligand (Ccl)21, Cxcl3 and Cxcl16 and their receptors, Ccr7, Cxcr2 and Cxcr6, were simultaneously upregulated in the spinal cords of the mice in both models of chronic itch. By contrast, the expression levels of Ccl2, Ccl3, Ccl4 and Ccl22 were downregulated. These findings indicate that multiple mediators, such as chemokines in the spinal cord, are altered and may be central candidates in further research into the mechanisms involved in the development of chronic itch.
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Affiliation(s)
- Bao-Wen Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Zhi-Xiao Li
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Zhi-Gang He
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Qian Wang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Cheng Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Xian-Wei Zhang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Hui Yang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Hong-Bing Xiang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
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22
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Abstract
Neuropathic itch is a pathological condition that is due to damage within the nervous system. This type of itch can be severe and unrelenting, which has a very negative impact on quality of life. Neuropathic itch is more common than generally appreciated because most types of neuropathic pain have a neuropathic itch counterpart. Unfortunately, much like neuropathic pain, there is a lack of effective treatments for neuropathic itch. Here, we consider the neural basis of itch and then describe how injuries within these neural circuits can lead to neuropathic itch in both animal models and human disease states.
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Gene Expression of Neurotrophins and Their Receptors in Keloids. Ann Plast Surg 2018; 81:646-652. [PMID: 30325834 DOI: 10.1097/sap.0000000000001648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The aim of this study was to assess gene expression of neurotrophins and their receptors in keloids. Skin samples of normal skin and keloids were obtained from patients in the control (n = 12) and keloid (n = 12) groups, respectively. Ribonucleic acid was extracted from the skin specimens, purified, evaluated by spectrophotometry, and used to synthesize complementary DNA. Real-time quantitative polymerase chain reaction analysis of 84 human neurotrophin genes and their receptors was performed. Twelve genes, including heat shock 27-kDa protein 1, gastrin-releasing peptide receptor, corticotropin-releasing hormone receptor 2, neuropeptide Y Y2 receptor, interleukin 6 signal transducer, nerve growth factor, metallothionein 3, B-cell chronic lymphocytic leukemia/lymphoma 2, cholecystokinin A receptor, persephin, galanin receptor 2, and fibroblast growth factor receptor 3, were down-regulated in keloid tissue compared with normal skin. The genes 27-kDa heat shock protein 1, gastrin-releasing peptide receptor, corticotropin-releasing hormone receptor 2, nerve growth factor, metallothionein 3, B-cell chronic lymphocytic leukemia/lymphoma 2, and persephin protein were considered priority genes associated with keloid formation.
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Qu X, Wang H, Liu R. Recent insights into biological functions of mammalian bombesin-like peptides and their receptors. Curr Opin Endocrinol Diabetes Obes 2018; 25:36-41. [PMID: 29120926 DOI: 10.1097/med.0000000000000375] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW The current review highlights recent advances in physiological and pharmacological researches in biology of mammalian bombesin-like peptides (BLPs). RECENT FINDINGS BLPs and their receptors were found to have regulatory roles in many biological processes in central nervous system. Two BLPs, neuromedin B and gastrin-releasing peptide (GRP), and their receptors are required for regulation of basal and induced sighing activity in rodents. This is the first study demonstrating central pathways involved in regulation of sighing activity. GRP receptor (GRPR) expressing neurons are excitatory glutamatergic interneurons located in the dorsal lamina without projections outside the spinal cord and mediate itch signals via vesicular glutamate transporter 2. Those neurons receive itch signals and make synapses with the parabrachial nucleus projecting spinal neurons to transmit itch signals to parabrachial nucleus. GRP expressing interneurons function in a proposed 'leaky gate model' to interpret the mechanism of both pain and itch transmission. In addition to recent advances of biology in nervous system, BLPs and their receptors were found to play potential regulatory roles in innate and adaptive immune responses and tissue development. SUMMARY Several important biological roles of BLPs and their receptors in nervous system were identified. Together with researches regarding central roles of BLPs, studies revealing the regulatory roles of BLPs and their receptors in immunology and tissue development provide us with novel insights into understanding of the biology of BLPs and their receptors.
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Affiliation(s)
- Xiangping Qu
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, PR China
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25
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Barten DM, Cadelina GW, Weed MR. Dosing, collection, and quality control issues in cerebrospinal fluid research using animal models. HANDBOOK OF CLINICAL NEUROLOGY 2018; 146:47-64. [PMID: 29110779 DOI: 10.1016/b978-0-12-804279-3.00004-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cerebrospinal fluid (CSF) is a complex fluid filling the ventricular system and surrounding the brain and spinal cord. Although the bulk of CSF is created by the choroid plexus, a significant fraction derives from the interstitial fluid in the brain and spinal cord parenchyma. For this reason, CSF can often be used as a source of pharmacodynamic and prognostic biomarkers to reflect biochemical changes occurring within the brain. For instance, CSF biomarkers can be used to diagnose and track progression of disease as well as understand pharmacokinetic and pharmacodynamic relationships in clinical trials. To facilitate the use of these biomarkers in humans, studies in preclinical species are often valuable. This review summarizes methods for preclinical CSF collection for biomarkers from mice, rats, and nonhuman primates. In addition, dosing directly into CSF is increasingly being used to improve drug levels in the brain. Therefore, this review also summarizes the state of the art in CSF dosing in these preclinical species.
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Affiliation(s)
- Donna M Barten
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, United States
| | - Gregory W Cadelina
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, United States
| | - Michael R Weed
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, United States; RxGen, Inc, New Haven, CT, United States.
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26
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Astrocytes in the spinal dorsal horn and chronic itch. Neurosci Res 2017; 126:9-14. [PMID: 28870604 DOI: 10.1016/j.neures.2017.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 11/22/2022]
Abstract
Chronic itch is a hallmark symptom of inflammatory skin conditions, such as atopic dermatitis. Existing treatment for chronic itch is largely ineffective. Despite recent progress in our understanding of the neuronal basis for itch sensation in the peripheral and central nervous systems, the mechanisms underlying how itch turns into a pathological chronic state remain poorly understood. Recent studies have uncovered the causal role of astrocytes in the spinal dorsal horn using mouse models of chronic itch, including atopic dermatitis. Understanding the key roles of astrocytes may provide us with exciting insights into the mechanisms for the chronicity of itch sensation and clues to develop novel therapeutic agents for treating chronic itch.
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Spinal cord interneurons expressing the gastrin-releasing peptide receptor convey itch through VGLUT2-mediated signaling. Pain 2017; 158:945-961. [PMID: 28157737 PMCID: PMC5402714 DOI: 10.1097/j.pain.0000000000000861] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Supplemental Digital Content is Available in the Text. Gastrin-releasing peptide receptor–expressing cells are interneurons that use glutamate to transmit the perception of chemical itch to the next step in the labeled line of itch in the spinal cord. Itch is a sensation that promotes the desire to scratch, which can be evoked by mechanical and chemical stimuli. In the spinal cord, neurons expressing the gastrin-releasing peptide receptor (GRPR) have been identified as specific mediators of itch. However, our understanding of the GRPR population in the spinal cord, and thus how these neurons exercise their functions, is limited. For this purpose, we constructed a Cre line designed to target the GRPR population of neurons (Grpr-Cre). Our analysis revealed that Grpr-Cre cells in the spinal cord are predominantly excitatory interneurons that are found in the dorsal lamina, especially in laminae II-IV. Application of the specific agonist gastrin-releasing peptide induced spike responses in 43.3% of the patched Grpr-Cre neurons, where the majority of the cells displayed a tonic firing property. Additionally, our analysis showed that the Grpr-Cre population expresses Vglut2 mRNA, and mice ablated of Vglut2 in Grpr-Cre cells (Vglut2-lox;Grpr-Cre mice) displayed less spontaneous itch and attenuated responses to both histaminergic and nonhistaminergic agents. We could also show that application of the itch-inducing peptide, natriuretic polypeptide B, induces calcium influx in a subpopulation of Grpr-Cre neurons. To summarize, our data indicate that the Grpr-Cre spinal cord neural population is composed of interneurons that use VGLUT2-mediated signaling for transmitting chemical and spontaneous itch stimuli to the next, currently unknown, neurons in the labeled line of itch.
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28
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Abstract
Itch is a protective sensation producing a desire to scratch. Pathologic itch can be a chronic symptom of illnesses such as uremia, cholestatic liver disease, neuropathies and dermatitis, however current therapeutic options are limited. Many types of cell surface receptors, including those present on cells in the skin, on sensory neurons and on neurons in the spinal cord, have been implicated in itch signaling. The role of G protein signaling in the regulation of pruriception is poorly understood. We identify here 2 G protein signaling components whose mutation impairs itch sensation. R7bp (a.k.a. Rgs7bp) is a palmitoylated membrane anchoring protein expressed in neurons that facilitates Gαi/o -directed GTPase activating protein activity mediated by the Gβ5/R7-RGS complex. Knockout of R7bp diminishes scratching responses to multiple cutaneously applied and intrathecally-administered pruritogens in mice. Knock-in to mice of a GTPase activating protein-insensitive mutant of Gαo (Gnao1 G184S/+) produces a similar pruriceptive phenotype. The pruriceptive defect in R7bp knockout mice was rescued in double knockout mice also lacking Oprk1, encoding the G protein-coupled kappa-opioid receptor whose activation is known to inhibit itch sensation. In a model of atopic dermatitis (eczema), R7bp knockout mice showed diminished scratching behavior and enhanced sensitivity to kappa opioid agonists. Taken together, our results indicate that R7bp is a key regulator of itch sensation and suggest the potential targeting of R7bp-dependent GTPase activating protein activity as a novel therapeutic strategy for pathological itch.
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Barry DM, Li H, Liu XY, Shen KF, Liu XT, Wu ZY, Munanairi A, Chen XJ, Yin J, Sun YG, Li YQ, Chen ZF. Critical evaluation of the expression of gastrin-releasing peptide in dorsal root ganglia and spinal cord. Mol Pain 2016; 12:12/0/1744806916643724. [PMID: 27068287 PMCID: PMC4972254 DOI: 10.1177/1744806916643724] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 02/18/2016] [Indexed: 01/29/2023] Open
Abstract
There are substantial disagreements about the expression of gastrin-releasing peptide (GRP) in sensory neurons and whether GRP antibody cross-reacts with substance P (SP). These concerns necessitate a critical revaluation of GRP expression using additional approaches. Here, we show that a widely used GRP antibody specifically recognizes GRP but not SP. In the spinal cord of mice lacking SP (Tac1 KO), the expression of not only GRP but also other peptides, notably neuropeptide Y (NPY), is significantly diminished. We detected Grp mRNA in dorsal root ganglias using reverse transcription polymerase chain reaction, in situ hybridization and RNA-seq. We demonstrated that Grp mRNA and protein are upregulated in dorsal root ganglias, but not in the spinal cord, of mice with chronic itch. Few GRP+ immunostaining signals were detected in spinal sections following dorsal rhizotomy and GRP+ cell bodies were not detected in dissociated dorsal horn neurons. Ultrastructural analysis further shows that substantially more GRPergic fibers form synaptic contacts with gastrin releasing peptide receptor-positive (GRPR+) neurons than SPergic fibers. Our comprehensive study demonstrates that a majority of GRPergic fibers are of primary afferent origin. A number of factors such as low copy number of Grp transcripts, small percentage of cells expressing Grp, and the use of an eGFP GENSAT transgenic as a surrogate for GRP protein have contributed to the controversy. Optimization of experimental procedures facilitates the specific detection of GRP expression in dorsal root ganglia neurons.
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Affiliation(s)
- Devin M Barry
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA Departments of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Hui Li
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA Department of Anatomy, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, PR China
| | - Xian-Yu Liu
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA Departments of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kai-Feng Shen
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Chongqing, PR China
| | - Xue-Ting Liu
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, The State Key Laboratory of Respiratory Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangdong, PR China
| | - Zhen-Yu Wu
- Department of Anatomy, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, PR China
| | - Admire Munanairi
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA Departments of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Xiao-Jun Chen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jun Yin
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA Departments of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Yan-Gang Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yun-Qing Li
- Department of Anatomy, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, PR China
| | - Zhou-Feng Chen
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA Departments of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA Departments of Psychiatry, Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA Departments of Developmental Biology, Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA
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