1
|
Manjunath J, Parthasarathy V, Joel MZ, Deng J, Ma EZ, Lee KK, Pritchard T, Guo S, Zhang C, Kwatra MM, Le A, Kwatra SG. Plasma metabolomic profiling reveals a novel circulating biomarker signature in chronic pruritus of unknown origin. Sci Rep 2024; 14:17472. [PMID: 39080299 PMCID: PMC11289434 DOI: 10.1038/s41598-024-67170-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 07/09/2024] [Indexed: 08/02/2024] Open
Abstract
Chronic pruritus of unknown origin (CPUO) is characterized by chronic itch for 6 weeks or greater without an identifiable primary cause. Studies are needed to investigate circulating blood biomarkers to elucidate disease pathogenesis. The objective of this study was to investigate changes in circulating blood metabolites in CPUO patients and to identify potential therapeutic targets. Our cross-sectional study collected plasma from 11 CPUO patients and 11 matched control patients for mass-spectrometry based metabolite data analysis. 15 metabolites differed significantly in the blood of CPUO patients compared to controls, including nine amino acids (isoleucine, L-tyrosine, threonine, DL-tryptophan, L-valine, methionine, glycine, lysine, and L-phenylalanine), four amino acid derivatives (creatinine, DL-carnitine, acetyl-L-carnitine, and indole-3-acrylic acid), and two aromatic and fatty acid derivatives (2-hydroxycinnamic acid and oleamide). These metabolites were also correlated with itch severity. Metabolic set enrichment analysis (MSEA) identified downregulation of several pathways in CPUO: phenylalanine, tyrosine, tryptophan biosynthesis; catecholamine biosynthesis; and glycine, serine, and threonine metabolism. Our study identified decreases in several circulating plasma metabolites in CPUO patients and downregulation of pathways related to catecholamine biosynthesis and tryptophan biosynthesis, providing insight into the pathogenesis of CPUO.
Collapse
Affiliation(s)
- Jaya Manjunath
- Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
- Maryland Itch Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Varsha Parthasarathy
- Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
- Maryland Itch Center, University of Maryland School of Medicine, Baltimore, MD, USA
- Dermatology, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Marina Z Joel
- Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
- Maryland Itch Center, University of Maryland School of Medicine, Baltimore, MD, USA
- Dermatology, Johns Hopkins University School of Medicine, Baltimore, USA
| | | | - Emily Z Ma
- Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
- Maryland Itch Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kevin K Lee
- Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
- Maryland Itch Center, University of Maryland School of Medicine, Baltimore, MD, USA
- Dermatology, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Thomas Pritchard
- Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
- Maryland Itch Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Shenghao Guo
- Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Cissy Zhang
- Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Madan M Kwatra
- Maryland Itch Center, Duke University Medical Center, Durham, NC, USA
| | - Anne Le
- Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Shawn G Kwatra
- Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
- Maryland Itch Center, University of Maryland School of Medicine, Baltimore, MD, USA.
- Joseph W. Burnett Professor and Chair, Department of Dermatology, University of Maryland School of Medicine, 419 W Redwood Street, Baltimore, MD, 21201, USA.
| |
Collapse
|
2
|
Weman HM, Ceder MM, Ahemaiti A, Magnusson KA, Henriksson K, Andréasson L, Lagerström MC. Spinal Glycine Receptor Alpha 3 Cells Communicate Sensations of Chemical Itch in Hairy Skin. J Neurosci 2024; 44:e1585232024. [PMID: 38553047 PMCID: PMC11079978 DOI: 10.1523/jneurosci.1585-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 01/31/2024] [Accepted: 02/15/2024] [Indexed: 05/12/2024] Open
Abstract
Glycinergic neurons regulate nociceptive and pruriceptive signaling in the spinal cord, but the identity and role of the glycine-regulated neurons are not fully known. Herein, we have characterized spinal glycine receptor alpha 3 (Glra3) subunit-expressing neurons in Glra3-Cre female and male mice. Glra3-Cre(+) neurons express Glra3, are located mainly in laminae III-VI, and respond to glycine. Chemogenetic activation of spinal Glra3-Cre(+) neurons induced biting/licking, stomping, and guarding behaviors, indicative of both a nociceptive and pruriceptive role for this population. Chemogenetic inhibition did not affect mechanical or thermal responses but reduced behaviors evoked by compound 48/80 and chloroquine, revealing a pruriceptive role for these neurons. Spinal cells activated by compound 48/80 or chloroquine express Glra3, further supporting the phenotype. Retrograde tracing revealed that spinal Glra3-Cre(+) neurons receive input from afferents associated with pain and itch, and dorsal root stimulation validated the monosynaptic input. In conclusion, these results show that spinal Glra3(+) neurons contribute to acute communication of compound 48/80- and chloroquine-induced itch in hairy skin.
Collapse
Affiliation(s)
- Hannah M Weman
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala 75108, Sweden
| | - Mikaela M Ceder
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala 75108, Sweden
| | - Aikeremu Ahemaiti
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala 75108, Sweden
| | - Kajsa A Magnusson
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala 75108, Sweden
| | - Katharina Henriksson
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala 75108, Sweden
| | - Linn Andréasson
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala 75108, Sweden
| | - Malin C Lagerström
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala 75108, Sweden
| |
Collapse
|
3
|
Yang YY, Du LX, Zhu JY, Yi T, Yang YC, Qiao Z, Maoying QL, Chu YX, Wang YQ, Mi WL. Antipruritic effects of geraniol on acute and chronic itch via modulating spinal GABA/GRPR signaling. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 119:154969. [PMID: 37516088 DOI: 10.1016/j.phymed.2023.154969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 06/12/2023] [Accepted: 07/15/2023] [Indexed: 07/31/2023]
Abstract
BACKGROUND AND PURPOSE Itch (pruritus) is a common unpleasant feeling, often accompanied by the urge of scratching the skin. It is the main symptom of many systemic and skin diseases, which can seriously affect the patient's quality of life. Geraniol (GE; trans-3,7-dimethyl-2,6-octadien-1-ol) is a natural monoterpene with diverse effects, including anti-inflammatory, antioxidant, neuroprotective, anti-nociceptive, and anticancer properties. The study aims to examine the effects of GE on acute and chronic itch, and explore the underlying mechanisms. METHODS Acute itch was investigated by using Chloroquine and compound 48/80 induced model, followed by manifestation of diphenylcyclopropenone (DCP)-induced allergic contact dermatitis and the acetone-ether-water (AEW)-induced dry skin model in mice. The scratching behavior, skin thickness, c-Fos expression, and GRPR protein expression in the spinal cord were subsequently monitored and evaluated by behavioral tests as well as pharmacological and pharmacogenetic technologies. RESULTS Dose-dependent intraperitoneal injection of GE alleviated the acute itch, induced by chloroquine and compound 48/80, as well as increased the spinal c-Fos expression. Intrathecal administration of GE suppressed the GABAA receptor inhibitor bicuculline-induced itch, GRP-induced itch, and the GABAergic neuron inhibition-induced itch. Furthermore, the subeffective dose of bicuculline blocked the anti-pruritic effect of GE on the chloroquine and compound 48/80 induced acute itch. GE also attenuated DCP and AEW-induced chronic itch, as well as the increase of spinal GRPR expression in DCP mice. CONCLUSION AND IMPLICATIONS GE alleviates both acute and chronic itch via modulating the spinal GABA/GRPR signaling in mice. Findings of this study reveal that GE may provide promising therapeutic options for itch management. Also, considering the pivotal role of essential oils in aromatherapy, GE has great application potential in aromatherapy for treating skin diseases, and especially the skin with severe pruritus.
Collapse
Affiliation(s)
- Ya-Yue Yang
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Li-Xia Du
- Department of Biochemistry, School of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jian-Yu Zhu
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Ting Yi
- Chinese Medicine Research Institute, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Ya-Chen Yang
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Zheng Qiao
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Qi-Liang Maoying
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yu-Xia Chu
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yan-Qing Wang
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Wen-Li Mi
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China.
| |
Collapse
|
4
|
Tian W, He D, Liu J, Chen F, Zhang W, Hu J, Wang S. Topical borneol relieves nonhistaminergic pruritus via targeting TRPA1 and TRPM8 channels in peripheral nerve terminals of mice. Eur J Pharmacol 2023:175833. [PMID: 37290679 DOI: 10.1016/j.ejphar.2023.175833] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 04/26/2023] [Accepted: 06/06/2023] [Indexed: 06/10/2023]
Abstract
Borneol has been used successfully for the treatment of itchy skin in traditional Chinese medicine. However, the antipruritic effect of borneol has rarely been studied, and the mechanism is unclear. Here, we showed that topical application of borneol on skin substantially suppressed pruritogen chloroquine- and compound 48/80-induced itching in mice. The potential targets of borneol, including transient receptor potential cation channel subfamily V member 3 (TRPV3), transient receptor potential cation channel subfamily A member 1 (TRPA1), transient receptor potential cation channel subfamily M member 8 (TRPM8), and gamma-aminobutyric acid type A (GABAA) receptor were pharmacologically inhibited or genetically knocked out one by one in mouse. Itching behavior studies demonstrated that the antipruritic effect of borneol is largely independent of TRPV3 and GABAA receptor, and TRPA1 and TRPM8 channels are responsible for a major portion of the effect of borneol on chloroquine-induced nonhistaminergic itching. Borneol activates TRPM8 and inhibits TRPA1 in sensory neurons of mice. Topical co-application of TRPA1 antagonist and TRPM8 agonist mimicked the effect of borneol on chloroquine-induced itching. Intrathecal injection of a group II metabotropic glutamate receptor antagonist partially attenuated the effect of borneol and completely abolished the effect of TRPM8 agonist on chloroquine-induced itching, suggesting that a spinal glutamatergic mechanism is involved. In contrast, the effect of borneol on compound 48/80-induced histaminergic itching occurs through TRPA1-and TRPM8-independent mechanisms. Our work demonstrates that borneol is an effective topical itch reliever, and TRPA1 inhibition and TRPM8 activation in peripheral nerve terminals account for its antipruritic effect.
Collapse
Affiliation(s)
- Weifeng Tian
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China; State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China; Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, and Ion Channel Research and Drug Development Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Dongmei He
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Jingjing Liu
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Feiyu Chen
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Wenjie Zhang
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Jinsheng Hu
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China.
| | - Shu Wang
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China.
| |
Collapse
|
5
|
Guo Y, Liu Y, Rui B, Lei Z, Ning X, Liu Y, Li M. Crosstalk between the gut microbiota and innate lymphoid cells in intestinal mucosal immunity. Front Immunol 2023; 14:1171680. [PMID: 37304260 PMCID: PMC10249960 DOI: 10.3389/fimmu.2023.1171680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
The human gastrointestinal mucosa is colonized by thousands of microorganisms, which participate in a variety of physiological functions. Intestinal dysbiosis is closely associated with the pathogenesis of several human diseases. Innate lymphoid cells (ILCs), which include NK cells, ILC1s, ILC2s, ILC3s and LTi cells, are a type of innate immune cells. They are enriched in the mucosal tissues of the body, and have recently received extensive attention. The gut microbiota and its metabolites play important roles in various intestinal mucosal diseases, such as inflammatory bowel disease (IBD), allergic disease, and cancer. Therefore, studies on ILCs and their interaction with the gut microbiota have great clinical significance owing to their potential for identifying pharmacotherapy targets for multiple related diseases. This review expounds on the progress in research on ILCs differentiation and development, the biological functions of the intestinal microbiota, and its interaction with ILCs in disease conditions in order to provide novel ideas for disease treatment in the future.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Ming Li
- *Correspondence: Yinhui Liu, ; Ming Li,
| |
Collapse
|
6
|
Ueda Y, Uta D, Furue H, Ohtubo Y. An electrophysiological method for evaluation of topical antipruritic drugs on itch-related neuronal activities in the spinal cord in hairless mice. Eur J Pharmacol 2023; 952:175798. [PMID: 37207968 DOI: 10.1016/j.ejphar.2023.175798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 04/29/2023] [Accepted: 05/16/2023] [Indexed: 05/21/2023]
Abstract
To evaluate the effects of antipruritic drugs, it is important to determine whether the neural responses induced by physiological itch stimuli are suppressed. Although there are several behavioral assessments for topical antipruritic drugs applied to the skin, there are few established methods at neuronal levels using in vivo electrophysiological recordings for predicting local efficacy of antipruritic drugs for cutaneous application. To establish an assessment of topical antipruritic drugs applied to skin using in vivo extracellular recording from neurons in the superficial dorsal horn, we examined the relationships between itch-related biting behavior and spinal neuronal responses elicited by intradermal injection of pruritogen serotonin (5-HT) in hairless mice. The efficacy of topical occlusive application of local anesthetics was also evaluated by an in vivo electrophysiological method. 5-HT significantly increased the firing frequency in spinal neurons. The spinal firing frequency time course was similar to that of the biting behavior after the 5-HT injections. The 5-HT-induced spinal responses were significantly decreased by topical occlusive application of lidocaine or a Nav 1.7 channel blocker to the calf. The intradermal 5-HT injection-induced spinal neuronal responses appeared to be suppressed by topical occlusive application of lidocaine or a Nav1.7 channel blocker. The electrophysiological method for evaluating topical antipruritic drugs may be beneficial in assessing local effects on the skin.
Collapse
Affiliation(s)
- Yuhki Ueda
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Japan; Drug Development Laboratories, Kyoto R&D Center, Drug Development Research Laboratories, Maruho Co., Ltd., Kyoto, Japan.
| | - Daisuke Uta
- Department of Applied Pharmacology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
| | - Hidemasa Furue
- Department of Neurophysiology, Hyogo College of Medicine, Nishinomiya, Japan.
| | - Yoshitaka Ohtubo
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Japan.
| |
Collapse
|
7
|
Mazur M, Tomczak H, Łodyga M, Plagens-Rotman K, Merks P, Czarnecka-Operacz M. The Intestinal and Skin Microbiome in Patients with Atopic Dermatitis and Their Influence on the Course of the Disease: A Literature Review. Healthcare (Basel) 2023; 11:healthcare11050766. [PMID: 36900771 PMCID: PMC10001192 DOI: 10.3390/healthcare11050766] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/22/2023] [Accepted: 02/27/2023] [Indexed: 03/08/2023] Open
Abstract
Bacteria inhabiting the digestive tract are responsible for our health. The microbiome is essential for the development of the immune system and homeostasis of the body. Maintaining homeostasis is very important, but also extremely complicated. The gut microbiome is related to the skin microbiome. It can therefore be assumed that changes in the microbes inhabiting the skin are greatly influenced by the bacteria living in the intestines. Changes in the composition and function of microbes (dysbiosis in the skin and intestines) have recently been linked to changes in the immune response and the development of skin diseases, including atopic dermatitis (AD). This review was compiled by collaborating Dermatologists specializing in atopic dermatitis and psoriasis. A comprehensive review of the current literature was performed using PubMed and limited to relevant case reports and original papers on the skin microbiome in atopic dermatitis. The inclusion criterion was that the paper was published in a peer-reviewed journal in the last 10 years (2012-2022). No limitations on the language of the publication or the type of study were made. It has been shown that any rapid changes in the composition of the microflora may be associated with the appearance of clinical signs and symptoms of the disease. Various studies have proven that the microbiome of many systems (including the intestines) may have a significant impact on the development of the inflammatory process within the skin in the course of AD. It has been shown that an early interaction between the microbiome and immune system may result in a noticeable delay in the onset of atopic diseases. It seems to be of high importance for physicians to understand the role of the microbiome in AD, not only from the pathophysiological standpoint but also in terms of the complex treatment that is required. Perhaps young children diagnosed with AD present specific characteristics of the intestinal microflora. This might be related to the early introduction of antibiotics and dietary manipulations in breastfeeding mothers in the early childhood of AD patients. It is most likely related to the abuse of antibiotics from the first days of life.
Collapse
Affiliation(s)
- Małgorzata Mazur
- College of Health, Beauty Care and Education in Poznań, 60-133 Poznań, Poland
| | - Hanna Tomczak
- Central Microbiological Laboratory, H. Święcicki Clinical Hospital at the Poznan University of Medical Sciences, 60-366 Poznan, Poland
| | - Martha Łodyga
- Department of Medicine Berkshire Medical Center, Pittsfield, MA 01201, USA
| | - Katarzyna Plagens-Rotman
- Center for Pediatric, Adolescent Gynecology and Sexology Division of Gynecology, Department of Perinatology and Gynecology, Poznan University of Medical Sciences, 61-758 Poznan, Poland
- Correspondence:
| | - Piotr Merks
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medicine, Collegium Medicum, Cardinal Stefan Wyszyński University, 01-938 Warszawa, Poland
| | - Magdalena Czarnecka-Operacz
- Allergic and Occupational Skin Diseases Unit, Department of Dermatology, Medical University of Poznań, 60-355 Poznan, Poland
| |
Collapse
|
8
|
Al-shami SJ, Sandru F, Dumitrascu MC, Popa A. The intestinal microbiome and the role of probiotics/prebiotics in the therapeutic approach of atopic dermatitis: A review. ROMANIAN JOURNAL OF MILITARY MEDICINE 2022. [DOI: 10.55453/rjmm.2022.125.3.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Atopic dermatitis (AD) is the most common chronic inflammatory skin condition, characterized by multiple recurrent eczematous lesions and intense itchiness. It is a multifactorial skin disorder involving an association between genetic and environmental factors that lead to a defect of the epithelial barrier in conjunction with immunological dysregulation. Over the last decade, there has been an increasing understanding of the role of the human microbiota in preserving skin integrity and that a shift in the homeostasis of these microorganisms may lead to dysbiosis and disease. Diversity in the intestinal microbiome and its role in the etiopathogenesis of AD has been described and has become of great interest. In this report, we have reviewed the importance of the gut microbiome and the possible mechanism in the pathogenesis of AD as well as the therapeutic impact of probiotics and prebiotics
Collapse
|
9
|
Mechanisms and therapeutic targets for neuropathic itch. Curr Opin Neurobiol 2022; 75:102573. [PMID: 35689909 DOI: 10.1016/j.conb.2022.102573] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 04/05/2022] [Accepted: 05/06/2022] [Indexed: 01/04/2023]
Abstract
Neuropathic pruritus conditions arise from structural and/or functional damage of the peripheral or central nervous system. Novel findings of pruritus specific mediators and pathways strengthen the specificity theory of pruritus transmission, however electrophysiological studies suggest that focal activation of nociceptors and distinct discharge patterns of primary afferents also contribute to the development of the sensation of pruritus. A complex interplay between excitatory and inhibitory interneurons at spinal level, non-neuronal cells and descending modulation from upper centers contributes to neuronal sensitization and clinically to the chronicity of pruritus, as well as accompanying phenomena such as alloknesis and hyperknesis. Several topical, systemic and non-pharmacological therapeutic approaches directed at distinct targets are currently available.
Collapse
|
10
|
Fang Z, Pan T, Li L, Wang H, Zhu J, Zhang H, Zhao J, Chen W, Lu W. Bifidobacterium longum mediated tryptophan metabolism to improve atopic dermatitis via the gut-skin axis. Gut Microbes 2022; 14:2044723. [PMID: 35239463 PMCID: PMC8903757 DOI: 10.1080/19490976.2022.2044723] [Citation(s) in RCA: 71] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Gut microbial disturbance affects allergic diseases including asthma, atopic dermatitis (AD) via the aberrant immune response. Some Bifidobacterial species and strains have been reported to improve AD via modulating immune-microbe interactions in patients. However, the effective metabolites and mechanism of alleviating AD in bifidobacteria remain to be elucidated. This study aimed to explore the microbial metabolite and mechanism of Bifidobacterium longum to improve AD. Based on shotgun metagenomic sequencing and UHPLC Q-Exactive-MS targeted metabolic experiments in vitro and in vivo, we focused on tryptophan metabolism and indole derivatives, which are endogenous ligands for aryl hydrocarbon receptor (AHR). Indole-3-carbaldehyde (I3C), a tryptophan metabolite of B. longum CCFM1029 activated AHR-mediated immune signaling pathway to improve AD symptoms in animal and clinical experiments. B. longum CCFM1029 upregulated tryptophan metabolism and increased I3C to suppress aberrant T helper 2 type immune responses, but these benefits were eliminated by AHR antagonist CH223191. Furthermore, B. longum CCFM1029 reshaped gut microbial composition in AD patients, increased fecal and serum I3C, and maintained the abundance of Lachnospiraceae related to tryptophan metabolism of gut microbiota. The results suggested that based on the interactions of the gut-skin axis, B. longum CCFM1029 upregulated tryptophan metabolism and produced I3C to activate AHR-mediated immune response, alleviating AD symptoms. Indole derivates, microbial metabolites of tryptophan, may be the potential metabolites of bifidobacteria to alleviate AD via the AHR signaling pathway.
Collapse
Affiliation(s)
- Zhifeng Fang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Tong Pan
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Lingzhi Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Hongchao Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Jinlin Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, Jiangsu, China,(Yangzhou) Institute of Food Biotechnology, Jiangnan University, Yangzhou, Jiangsu, China
| | - Jianxin Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,(Yangzhou) Institute of Food Biotechnology, Jiangnan University, Yangzhou, Jiangsu, China
| | - Wei Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, Jiangsu, China
| | - Wenwei Lu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, Jiangsu, China,(Yangzhou) Institute of Food Biotechnology, Jiangnan University, Yangzhou, Jiangsu, China,International Joint Research Laboratory for Pharmabiotics & Antibiotic Resistance, Jiangnan University, Wuxi, Jiangsu, China,CONTACT Wenwei Lu State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
| |
Collapse
|
11
|
Brough HA, Lanser BJ, Sindher SB, Teng JMC, Leung DYM, Venter C, Chan SM, Santos AF, Bahnson HT, Guttman‐Yassky E, Gupta RS, Lack G, Ciaccio CE, Sampath V, Nadeau KC, Nagler CR. Early intervention and prevention of allergic diseases. Allergy 2022; 77:416-441. [PMID: 34255344 DOI: 10.1111/all.15006] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/09/2021] [Indexed: 12/12/2022]
Abstract
Food allergy (FA) is now one of the most common chronic diseases of childhood often lasting throughout life and leading to significant worldwide healthcare burden. The precise mechanisms responsible for the development of this inflammatory condition are largely unknown; however, a multifactorial aetiology involving both environmental and genetic contributions is well accepted. A precise understanding of the pathogenesis of FA is an essential first step to developing comprehensive prevention strategies that could mitigate this epidemic. As it is frequently preceded by atopic dermatitis and can be prevented by early antigen introduction, the development of FA is likely facilitated by the improper initial presentation of antigen to the developing immune system. Primary oral exposure of antigens allowing for presentation via a well-developed mucosal immune system, rather than through a disrupted skin epidermal barrier, is essential to prevent FA. In this review, we present the data supporting the necessity of (1) an intact epidermal barrier to prevent epicutaneous antigen presentation, (2) the presence of specific commensal bacteria to maintain an intact mucosal immune system and (3) maternal/infant diet diversity, including vitamins and minerals, and appropriately timed allergenic food introduction to prevent FA.
Collapse
Affiliation(s)
- Helen A. Brough
- Department Women and Children’s Health (Pediatric Allergy) School of Life Course Sciences Faculty of Life Sciences and Medicine King’s College London London UK
- Peter Gorer Department of Immunobiology School of Immunology and Microbial Sciences King’s College London London UK
- Children’s Allergy Service Evelina Children’s Hospital Guy’s and St. Thomas’s NHS Foundation Trust London UK
| | - Bruce Joshua Lanser
- Division of Pediatric Allergy‐Immunology Department of Pediatrics National Jewish Health Denver CO USA
| | - Sayantani B. Sindher
- Sean N. Parker Center for Allergy and Asthma Research at Stanford University Stanford University Stanford CA USA
- Division of Pulmonary and Critical Care Medicine Department of Medicine Stanford University Stanford CA USA
- Division of Allergy, Immunology and Rheumatology Department of Medicine Stanford University Stanford CA USA
| | - Joyce M. C. Teng
- Department of Dermatology Lucile Packard Children's Hospital at the Stanford University School of Medicine Palo Alto CA USA
| | - Donald Y. M. Leung
- Division of Pediatric Allergy‐Immunology Department of Pediatrics National Jewish Health Denver CO USA
| | - Carina Venter
- Section of Allergy & Immunology School of Medicine University of Colorado DenverChildren's Hospital Colorado Aurora CO USA
| | - Susan M. Chan
- Department Women and Children’s Health (Pediatric Allergy) School of Life Course Sciences Faculty of Life Sciences and Medicine King’s College London London UK
- Peter Gorer Department of Immunobiology School of Immunology and Microbial Sciences King’s College London London UK
- Children’s Allergy Service Evelina Children’s Hospital Guy’s and St. Thomas’s NHS Foundation Trust London UK
| | - Alexandra F. Santos
- Department Women and Children’s Health (Pediatric Allergy) School of Life Course Sciences Faculty of Life Sciences and Medicine King’s College London London UK
- Peter Gorer Department of Immunobiology School of Immunology and Microbial Sciences King’s College London London UK
- Children’s Allergy Service Evelina Children’s Hospital Guy’s and St. Thomas’s NHS Foundation Trust London UK
- Asthma UK Centre in Allergic Mechanisms of Asthma London UK
| | - Henry T. Bahnson
- Benaroya Research Institute and Immune Tolerance Network Seattle WA USA
| | - Emma Guttman‐Yassky
- Department of Dermatology and the Immunology Institute Icahn School of Medicine at Mount Sinai New York NY USA
- Laboratory for Investigative Dermatology The Rockefeller University New York NY USA
| | - Ruchi S. Gupta
- Center for Food Allergy and Asthma Research Northwestern University Feinberg School of Medicine Chicago IL USA
- Ann & Robert H. Lurie Children's Hospital of Chicago Chicago IL USA
| | - Gideon Lack
- Department Women and Children’s Health (Pediatric Allergy) School of Life Course Sciences Faculty of Life Sciences and Medicine King’s College London London UK
- Peter Gorer Department of Immunobiology School of Immunology and Microbial Sciences King’s College London London UK
- Children’s Allergy Service Evelina Children’s Hospital Guy’s and St. Thomas’s NHS Foundation Trust London UK
| | | | - Vanitha Sampath
- Sean N. Parker Center for Allergy and Asthma Research at Stanford University Stanford University Stanford CA USA
| | - Kari C. Nadeau
- Sean N. Parker Center for Allergy and Asthma Research at Stanford University Stanford University Stanford CA USA
- Division of Pulmonary and Critical Care Medicine Department of Medicine Stanford University Stanford CA USA
- Division of Allergy, Immunology and Rheumatology Department of Medicine Stanford University Stanford CA USA
| | - Cathryn R. Nagler
- Department of Pathology and Pritzker School of Molecular Engineering University of Chicago Chicago IL USA
| |
Collapse
|
12
|
Mahmud MR, Akter S, Tamanna SK, Mazumder L, Esti IZ, Banerjee S, Akter S, Hasan MR, Acharjee M, Hossain MS, Pirttilä AM. Impact of gut microbiome on skin health: gut-skin axis observed through the lenses of therapeutics and skin diseases. Gut Microbes 2022; 14:2096995. [PMID: 35866234 PMCID: PMC9311318 DOI: 10.1080/19490976.2022.2096995] [Citation(s) in RCA: 89] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 06/10/2022] [Accepted: 06/27/2022] [Indexed: 02/08/2023] Open
Abstract
The human intestine hosts diverse microbial communities that play a significant role in maintaining gut-skin homeostasis. When the relationship between gut microbiome and the immune system is impaired, subsequent effects can be triggered on the skin, potentially promoting the development of skin diseases. The mechanisms through which the gut microbiome affects skin health are still unclear. Enhancing our understanding on the connection between skin and gut microbiome is needed to find novel ways to treat human skin disorders. In this review, we systematically evaluate current data regarding microbial ecology of healthy skin and gut, diet, pre- and probiotics, and antibiotics, on gut microbiome and their effects on skin health. We discuss potential mechanisms of the gut-skin axis and the link between the gut and skin-associated diseases, such as psoriasis, atopic dermatitis, acne vulgaris, rosacea, alopecia areata, and hidradenitis suppurativa. This review will increase our understanding of the impacts of gut microbiome on skin conditions to aid in finding new medications for skin-associated diseases.
Collapse
Affiliation(s)
- Md. Rayhan Mahmud
- Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Sharmin Akter
- Department of Microbiology, Jagannath University, Dhaka, Bangladesh
| | | | - Lincon Mazumder
- Department of Microbiology, Jagannath University, Dhaka, Bangladesh
| | - Israt Zahan Esti
- Department of Microbiology, Jagannath University, Dhaka, Bangladesh
| | | | - Sumona Akter
- Department of Microbiology, Jagannath University, Dhaka, Bangladesh
| | | | - Mrityunjoy Acharjee
- Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, Shizuoka, Japan
| | | | | |
Collapse
|
13
|
Haahtela T, Alenius H, Lehtimäki J, Sinkkonen A, Fyhrquist N, Hyöty H, Ruokolainen L, Mäkelä MJ. Immunological resilience and biodiversity for prevention of allergic diseases and asthma. Allergy 2021; 76:3613-3626. [PMID: 33959980 DOI: 10.1111/all.14895] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/27/2021] [Accepted: 04/29/2021] [Indexed: 02/07/2023]
Abstract
Increase of allergic conditions has occurred at the same pace with the Great Acceleration, which stands for the rapid growth rate of human activities upon earth from 1950s. Changes of environment and lifestyle along with escalating urbanization are acknowledged as the main underlying causes. Secondary (tertiary) prevention for better disease control has advanced considerably with innovations for oral immunotherapy and effective treatment of inflammation with corticosteroids, calcineurin inhibitors, and biological medications. Patients are less disabled than before. However, primary prevention has remained a dilemma. Factors predicting allergy and asthma risk have proven complex: Risk factors increase the risk, while protective factors counteract them. Interaction of human body with environmental biodiversity with micro-organisms and biogenic compounds as well as the central role of epigenetic adaptation in immune homeostasis have given new insight. Allergic diseases are good indicators of the twisted relation to environment. In various non-communicable diseases, the protective mode of the immune system indicates low-grade inflammation without apparent cause. Giving microbes, pro- and prebiotics, has shown some promise in prevention and treatment. The real-world public health programme in Finland (2008-2018) emphasized nature relatedness and protective factors for immunological resilience, instead of avoidance. The nationwide action mitigated the allergy burden, but in the lack of controls, primary preventive effect remains to be proven. The first results of controlled biodiversity interventions are promising. In the fast urbanizing world, new approaches are called for allergy prevention, which also has a major cost saving potential.
Collapse
Affiliation(s)
- Tari Haahtela
- Skin and Allergy Hospital Helsinki University HospitalUniversity of Helsinki Helsinki Finland
| | - Harri Alenius
- Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
- Department of Bacteriology and Immunology Medicum University of Helsinki Helsinki Finland
| | | | - Aki Sinkkonen
- Natural Resources Institute Finland, Horticulture Technologies Turku Finland
| | - Nanna Fyhrquist
- Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
- Department of Bacteriology and Immunology Medicum University of Helsinki Helsinki Finland
| | - Heikki Hyöty
- Faculty of Medicine and Health Technology Tampere University Tampere Finland
- Fimlab Laboratories Pirkanmaa Hospital District Tampere Finland
| | - Lasse Ruokolainen
- Lasse Ruokolainen Department of Biosciences University of Helsinki Helsinki Finland
| | - Mika J. Mäkelä
- Skin and Allergy Hospital Helsinki University HospitalUniversity of Helsinki Helsinki Finland
| |
Collapse
|
14
|
Abstract
Itch is one of the most primal sensations, being both ubiquitous and important for the well-being of animals. For more than a century, a desire to understand how itch is encoded by the nervous system has prompted the advancement of many theories. Within the past 15 years, our understanding of the molecular and neural mechanisms of itch has undergone a major transformation, and this remarkable progress continues today without any sign of abating. Here I describe accumulating evidence that indicates that itch is distinguished from pain through the actions of itch-specific neuropeptides that relay itch information to the spinal cord. According to this model, classical neurotransmitters transmit, inhibit and modulate itch information in a context-, space- and time-dependent manner but do not encode itch specificity. Gastrin-releasing peptide (GRP) is proposed to be a key itch-specific neuropeptide, with spinal neurons expressing GRP receptor (GRPR) functioning as a key part of a convergent circuit for the conveyance of peripheral itch information to the brain.
Collapse
|
15
|
Yin W, Liu L, Zhou Y, Zhang Y, Kong D, Xu S, Tang D, Huang D, Wen D, Jiao Y, Fan Y, Gao P, Yu W. Complete Freund's adjuvant-induced decrement of pruriceptor-mediated suppression of itch. Acta Biochim Biophys Sin (Shanghai) 2021; 53:538-546. [PMID: 33693534 DOI: 10.1093/abbs/gmab027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Indexed: 11/13/2022] Open
Abstract
Peripheral inflammation is always accompanied by a noxious sensation, either pain or itch, providing a protective warning for the occurrence of pathological changes; however, the mechanisms determining whether pain, itch, or both will be elicited under certain inflammatory statuses are still far from clear. Complete Freund's adjuvant (CFA) contains heat killed and dried Mycobacterium tuberculosis widely used to induce inflammatory pain models, but how CFA treatment affects itch sensation and the possible mechanisms are still unclear. In this study, using itch behavior testing and calcium imaging, we showed that both the behaviors and calcium responses associated with Transient Receptor Potential Vanilloid 1 (TRPV1)-mediated histamine-dependent itch and Transient Receptor Potential Ankyrin 1 (TRPA1)-mediated histamine-independent itch were significantly suppressed by CFA treatment. Furthermore, to explore the possible cellular mechanisms, high-throughput single-cell RNA sequencing and real-time PCR were used to detect CFA-induced changes of itch-related genes in dorsal root ganglion (DRG) neurons. Our results revealed that although both nociceptive Trpv1+ and Trpa1+ DRG neurons were increased after CFA treatment, most known pruriceptors, including Hrh1+, Mrgpra3+, Mrgprd+, Htr3a+, Htr1f+, IL31ra+, Osmr+, and Lpar3+ DRG neurons, were significantly decreased, which may explain that CFA treatment caused itch suppression. This study indicated that itch sensation was affected after CFA treatment, although negatively, and comprehensive but not specific suppression of different pruriceptors was observed after CFA treatment, suggesting that a unified adaptive change of increased pain and decreased itch will occur simultaneously under CFA-induced inflammatory conditions.
Collapse
Affiliation(s)
- Wen Yin
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Li Liu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Yuxi Zhou
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Yunchun Zhang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Dexu Kong
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Saihong Xu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Dan Tang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Dan Huang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Daxiang Wen
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Yingfu Jiao
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Yinghui Fan
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Po Gao
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Weifeng Yu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| |
Collapse
|
16
|
Abstract
Mechanistic theories of itch are based on neuronal specificity, stimulus intensity, and temporal or spatial discharge patterns. Traditionally, these theories are conceptualized as mutually exclusive, assuming that finding evidence for one theory would exclude the others and could sufficiently explain itch. Current experimental data primarily support the specificity or pattern theory of itch. However, in contrast to an assumed inherent exclusivity, recent results have shown that even within itch-specific pathways in the spinal cord, temporal discharge patterns are important as sustained pruriceptor is required to allow successful transsynaptic signal progression. Also, optogenetic activation of pruriceptors suggest that the combination of neuronal specificity and temporal pattern determines the sensory effect: tonic activation of pruriceptors is required to induce scratching behavior whereas short-lasting stimulation rather causes withdrawal. In addition to the mere duration of discharge, also the temporal pattern or spatial aspects could critically contribute to elicit pruritus instead of pain. Basic neurophysiological studies trying to validate neuronal theories for pruritus in their pure form provide unitary concepts leading from neuronal discharge to the itch sensation. However, the crucial clinical questions have the opposite perspective: which mechanisms explain the chronic itch in a given patient or a given disease? In trying to solve these clinical problems we should not feel bound to the mutual exclusive nature of itch theories, but rather appreciate blending several theories and also accept combinations of itch and pain. Thus, blended versions of itch theories might better suffice for an explanation of chronic itch in patients and will improve the basis for mechanistic treatment options.
Collapse
Affiliation(s)
- Martin Schmelz
- Department of Experimental Pain Research, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| |
Collapse
|
17
|
Wang Z, Jiang C, Yao H, Chen O, Rahman S, Gu Y, Zhao J, Huh Y, Ji RR. Central opioid receptors mediate morphine-induced itch and chronic itch via disinhibition. Brain 2021; 144:665-681. [PMID: 33367648 DOI: 10.1093/brain/awaa430] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 09/29/2020] [Accepted: 10/22/2020] [Indexed: 02/27/2024] Open
Abstract
Opioids such as morphine are mainstay treatments for clinical pain conditions. Itch is a common side effect of opioids, particularly as a result of epidural or intrathecal administration. Recent progress has advanced our understanding of itch circuits in the spinal cord. However, the mechanisms underlying opioid-induced itch are not fully understood, although an interaction between µ-opioid receptor (MOR) and gastrin-releasing peptide receptor (GRPR) in spinal GRPR-expressing neurons has been implicated. In this study we investigated the cellular mechanisms of intrathecal opioid-induced itch by conditional deletion of MOR-encoding Oprm1 in distinct populations of interneurons and sensory neurons. We found that intrathecal injection of the MOR agonists morphine or DAMGO elicited dose-dependent scratching as well as licking and biting, but this pruritus was totally abolished in mice with a specific Oprm1 deletion in Vgat+ neurons [Oprm1-Vgat (Slc32a1)]. Loss of MOR in somatostatin+ interneurons and TRPV1+ sensory neurons did not affect morphine-induced itch but impaired morphine-induced antinociception. In situ hybridization revealed Oprm1 expression in 30% of inhibitory and 20% of excitatory interneurons in the spinal dorsal horn. Whole-cell recordings from spinal cord slices showed that DAMGO induced outward currents in 9 of 19 Vgat+ interneurons examined. Morphine also inhibited action potentials in Vgat+ interneurons. Furthermore, morphine suppressed evoked inhibitory postsynaptic currents in postsynaptic Vgat- excitatory neurons, suggesting a mechanism of disinhibition by MOR agonists. Notably, morphine-elicited itch was suppressed by intrathecal administration of NPY and abolished by spinal ablation of GRPR+ neurons with intrathecal injection of bombesin-saporin, whereas intrathecal GRP-induced itch response remained intact in mice lacking Oprm1-Vgat. Intrathecal bombesin-saporin treatment reduced the number of GRPR+ neurons by 97% in the lumber spinal cord and 91% in the cervical spinal cord, without changing the number of Oprm1+ neurons. Additionally, chronic itch from DNFB-induced allergic contact dermatitis was decreased by Oprm1-Vgat deletion. Finally, naloxone, but not peripherally restricted naloxone methiodide, inhibited chronic itch in the DNFB model and the CTCL model, indicating a contribution of central MOR signalling to chronic itch. Our findings demonstrate that intrathecal morphine elicits itch via acting on MOR on spinal inhibitory interneurons, leading to disinhibition of the spinal itch circuit. Our data also provide mechanistic insights into the current treatment of chronic itch with opioid receptor antagonist such as naloxone.
Collapse
Affiliation(s)
- Zilong Wang
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Changyu Jiang
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Hongyu Yao
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ouyang Chen
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Sreya Rahman
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Yun Gu
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Junli Zhao
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Yul Huh
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| |
Collapse
|
18
|
De Pessemier B, Grine L, Debaere M, Maes A, Paetzold B, Callewaert C. Gut-Skin Axis: Current Knowledge of the Interrelationship between Microbial Dysbiosis and Skin Conditions. Microorganisms 2021; 9:353. [PMID: 33670115 PMCID: PMC7916842 DOI: 10.3390/microorganisms9020353] [Citation(s) in RCA: 203] [Impact Index Per Article: 67.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/25/2021] [Accepted: 02/07/2021] [Indexed: 02/06/2023] Open
Abstract
The microbiome plays an important role in a wide variety of skin disorders. Not only is the skin microbiome altered, but also surprisingly many skin diseases are accompanied by an altered gut microbiome. The microbiome is a key regulator for the immune system, as it aims to maintain homeostasis by communicating with tissues and organs in a bidirectional manner. Hence, dysbiosis in the skin and/or gut microbiome is associated with an altered immune response, promoting the development of skin diseases, such as atopic dermatitis, psoriasis, acne vulgaris, dandruff, and even skin cancer. Here, we focus on the associations between the microbiome, diet, metabolites, and immune responses in skin pathologies. This review describes an exhaustive list of common skin conditions with associated dysbiosis in the skin microbiome as well as the current body of evidence on gut microbiome dysbiosis, dietary links, and their interplay with skin conditions. An enhanced understanding of the local skin and gut microbiome including the underlying mechanisms is necessary to shed light on the microbial involvement in human skin diseases and to develop new therapeutic approaches.
Collapse
Affiliation(s)
- Britta De Pessemier
- Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; (B.D.P.); (M.D.); (A.M.)
| | - Lynda Grine
- Department of Head & Skin, Ghent University, Corneel Heymanslaan 10, 9000 Ghent, Belgium;
| | - Melanie Debaere
- Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; (B.D.P.); (M.D.); (A.M.)
| | - Aglaya Maes
- Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; (B.D.P.); (M.D.); (A.M.)
| | | | - Chris Callewaert
- Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; (B.D.P.); (M.D.); (A.M.)
| |
Collapse
|
19
|
Najafi P, Dufor O, Ben Salem D, Misery L, Carré JL. Itch processing in the brain. J Eur Acad Dermatol Venereol 2020; 35:1058-1066. [PMID: 33145804 DOI: 10.1111/jdv.17029] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 09/17/2020] [Accepted: 10/02/2020] [Indexed: 01/04/2023]
Abstract
Itch is a sensation defined as the urge to scratch. The central mechanisms of itch are being increasingly studied. These studies are usually based on experimental itch induction methods, which can be classified into the following categories: histamine-induced, induction by other non-histamine chemicals (e.g. cowhage), physically induced (e.g. electrical) and mentally induced (e.g. audio-visual). Because pain has been more extensively studied, some extrapolations to itch can be proposed and verified by experiments. Recent studies suggest that the itch-processing network in the brain could be disrupted in certain diseases. This disruption could be related to the implication of new regions or the exclusion of already engaged brain regions from itch-processing network in the brain.
Collapse
Affiliation(s)
| | - O Dufor
- LIEN, Univ Brest, Brest, France.,LabISEN Yncréa Ouest ISEN, Brest, France
| | - D Ben Salem
- Univ Brest, LaTIM, INSERM, UMR 1101, Brest, France.,University Hospital of Brest, Brest, France
| | - L Misery
- LIEN, Univ Brest, Brest, France.,University Hospital of Brest, Brest, France
| | - J-L Carré
- LIEN, Univ Brest, Brest, France.,University Hospital of Brest, Brest, France
| |
Collapse
|
20
|
Faye LJ, Budgell BS. Presumptive spondylogenic pruritus: a case study. THE JOURNAL OF THE CANADIAN CHIROPRACTIC ASSOCIATION 2020; 64:139-143. [PMID: 33012813 PMCID: PMC7500236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
OBJECTIVE To describe a case of a patient with chronic pruritus of the upper back and arms who underwent complete resolution of his complaint following a short course of chiropractic care. CASE PRESENTATION A 36-year-old male suffering with chronic, severe pruritus affecting the upper back and both arms, presented for chiropractic treatment after pharmacological treatment and dietary restrictions failed to resolve his complaint. Physical examination revealed restrictions of thoracic and cervical intervertebral motion. However, radiological examination did not identify any substantial pathology of the spine. Following a short course of chiropractic treatment, which included spinal manipulation and home exercises, his complaint of pruritus resolved completely. SUMMARY In this case, a severe and chronic complaint of pruritus which was refractory to other forms of care resolved quickly after the institution of chiropractic care. It is therefore hypothesized that the patient's pruritus was etiologically linked to biomechanical problems of the spine.
Collapse
|
21
|
Abstract
Itch is a unique sensation that helps organisms scratch away external threats; scratching itself induces an immune response that can contribute to more itchiness. Itch is induced chemically in the peripheral nervous system via a wide array of receptors. Given the superficial localization of itch neuron terminals, cells that dwell close to the skin contribute significantly to itch. Certain mechanical stimuli mediated by recently discovered circuits also contribute to the itch sensation. Ultimately, in the spinal cord, and likely in the brain, circuits that mediate touch, pain, and itch engage in cross modulation. Much of itch perception is still a mystery, but we present in this review the known ligands and receptors associated with itch. We also describe experiments and findings from investigations into the spinal and supraspinal circuitry responsible for the sensation of itch.
Collapse
Affiliation(s)
- Mark Lay
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA;,
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA;,
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| |
Collapse
|
22
|
Cevikbas F, Lerner EA. Physiology and Pathophysiology of Itch. Physiol Rev 2020; 100:945-982. [PMID: 31869278 PMCID: PMC7474262 DOI: 10.1152/physrev.00017.2019] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 10/31/2019] [Accepted: 12/04/2019] [Indexed: 02/06/2023] Open
Abstract
Itch is a topic to which everyone can relate. The physiological roles of itch are increasingly understood and appreciated. The pathophysiological consequences of itch impact quality of life as much as pain. These dynamics have led to increasingly deep dives into the mechanisms that underlie and contribute to the sensation of itch. When the prior review on the physiology of itching was published in this journal in 1941, itch was a black box of interest to a small number of neuroscientists and dermatologists. Itch is now appreciated as a complex and colorful Rubik's cube. Acute and chronic itch are being carefully scratched apart and reassembled by puzzle solvers across the biomedical spectrum. New mediators are being identified. Mechanisms blur boundaries of the circuitry that blend neuroscience and immunology. Measures involve psychophysics and behavioral psychology. The efforts associated with these approaches are positively impacting the care of itchy patients. There is now the potential to markedly alleviate chronic itch, a condition that does not end life, but often ruins it. We review the itch field and provide a current understanding of the pathophysiology of itch. Itch is a disease, not only a symptom of disease.
Collapse
Affiliation(s)
- Ferda Cevikbas
- Dermira, Inc., Menlo Park, California; and Harvard Medical School and the Cutaneous Biology Research Center at Massachusetts General Hospital, Charlestown, Massachusetts
| | - Ethan A Lerner
- Dermira, Inc., Menlo Park, California; and Harvard Medical School and the Cutaneous Biology Research Center at Massachusetts General Hospital, Charlestown, Massachusetts
| |
Collapse
|
23
|
Schmelz M. [Pruritus-a long journey from neurophysiology to the clinic]. Hautarzt 2020; 71:487-492. [PMID: 32468292 DOI: 10.1007/s00105-020-04614-2] [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] [Indexed: 11/26/2022]
Abstract
BACKGROUND The mutual exchange of results between basic sciences and clinical research as well as their translation into practice, also with regard to chronic pruritus, is currently to be seen as an ambition or hope rather than established practice. OBJECTIVE In view of the rapid developments in the field of neurophysiological basics of pruritus, the aim is to clarify how these new concepts can be brought in line with clinical understanding. MATERIALS AND METHODS A review is provided. RESULTS After the peripheral and spinal processing pathways for pruritus in the mouse were characterized with molecular markers, we are currently working on the translation of this information to the only functionally defined nerve fiber classes in humans. However, it is still unclear whether these processing pathways are crucial for the explanation of chronic pruritus in patients, since inflammation or neuropathy can significantly alter nerve populations and neuronal networks. Therefore, molecular target structures, which have emerged from results of basic research, need to be verified in patients. The gold standard, however, remains the patient with clinical observation and testing. Specific stimulation methods from neurophysiology can help to test hypotheses from basic research directly on patients, while also providing impulses for further development of research concepts. CONCLUSIONS Translation in medical research is now perceived by many researchers as a hackneyed buzzword. In the field of pruritus research, however, the exchange of results and concepts based on the mutual appreciation of expertise appears attractive, highly relevant, and promising.
Collapse
Affiliation(s)
- M Schmelz
- Abteilung Experimentelle Schmerzforschung, MCTN, Med. Fakultät Mannheim, Universität Heidelberg, Ludolf-Krehl-Str. 13-17, 68167, Mannheim, Deutschland.
| |
Collapse
|
24
|
Abstract
Basic mechanisms and pathways of itch signaling are reviewed, with an emphasis on the progress to date as well as remaining challenges in translating current knowledge to the clinical treatment of chronic itch. Recent studies reveal 3 subsets of pruriceptive sensory neurons highly expressing itch-related genes. Their fibers project into the spinal cord to activate neurons expressing gastrin releasing peptide (GRP) and its receptor (GRPR), which connect to neurons that express the substance P (NK-1) receptor and project to the parabrachial nucleus and thalamus. Spinal inhibitory interneurons release GABA, glycine and dynorphin to modulate segmental itch transmission. However, nearly all pruriceptive neurons also respond to algogens such as capsaicin. Alternative theories of itch-pain discrimination, such as intensity or spatial contrast, are based on the observation that focal stimulation of nociceptive nerve endings elicits itch while more widespread stimulation elicits pain. These findings cloud the issue of a labeled line for itch- a long-debated but currently unresolved challenge. In higher primates there is a dichotomy of histaminergic and non-histaminergic itch-signaling pathways which is less demarcated in rodents, suggesting species differences. A cardinal symptom of chronic itch is alloknesis, i.e., mechanical or touch-evoked itch. Recent evidence indicates that low-threshold mechanosensory afferents can access the spinal itch pathway, but are normally kept in check by inhibitory interneurons expressing neuropeptide Y (NPY). In chronic itch, NPY-mediated inhibition is reduced, allowing touch to excite itch-signaling pathways. These recent advances provide novel targets for development of therapeutic strategies to relieve chronic itch.
Collapse
|
25
|
Freitag FB, Ahemaiti A, Jakobsson JET, Weman HM, Lagerström MC. Spinal gastrin releasing peptide receptor expressing interneurons are controlled by local phasic and tonic inhibition. Sci Rep 2019; 9:16573. [PMID: 31719558 PMCID: PMC6851355 DOI: 10.1038/s41598-019-52642-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 10/18/2019] [Indexed: 11/09/2022] Open
Abstract
Dorsal horn gastrin-releasing peptide receptor (GRPR) neurons have a central role in itch transmission. Itch signaling has been suggested to be controlled by an inhibitory network in the spinal dorsal horn, as increased scratching behavior can be induced by pharmacological disinhibition or ablation of inhibitory interneurons, but the direct influence of the inhibitory tone on the GRPR neurons in the itch pathway have not been explored. Here we have investigated spinal GRPR neurons through in vitro and bioinformatical analysis. Electrophysiological recordings revealed that GRPR neurons receive local spontaneous excitatory inputs transmitted by glutamate and inhibitory inputs by glycine and GABA, which were transmitted either by separate glycinergic and GABAergic synapses or by glycine and GABA co-releasing synapses. Additionally, all GRPR neurons received both glycine- and GABA-induced tonic currents. The findings show a complex inhibitory network, composed of synaptic and tonic currents that gates the excitability of GRPR neurons, which provides direct evidence for the existence of an inhibitory tone controlling spontaneous discharge in an itch-related neuronal network in the spinal cord. Finally, calcium imaging revealed increased levels of neuronal activity in Grpr-Cre neurons upon application of somatostatin, which provides direct in vitro evidence for disinhibition of these dorsal horn interneurons.
Collapse
Affiliation(s)
- Fabio B Freitag
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | | | | | - Hannah M Weman
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | | |
Collapse
|
26
|
Pain Inhibits GRPR Neurons via GABAergic Signaling in the Spinal Cord. Sci Rep 2019; 9:15804. [PMID: 31676846 PMCID: PMC6825123 DOI: 10.1038/s41598-019-52316-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/11/2019] [Indexed: 11/30/2022] Open
Abstract
It has been known that algogens and cooling could inhibit itch sensation; however, the underlying molecular and neural mechanisms remain poorly understood. Here, we show that the spinal neurons expressing gastrin releasing peptide receptor (GRPR) primarily comprise excitatory interneurons that receive direct and indirect inputs from C and Aδ fibers and form contacts with projection neurons expressing the neurokinin 1 receptor (NK1R). Importantly, we show that noxious or cooling agents inhibit the activity of GRPR neurons via GABAergic signaling. By contrast, capsaicin, which evokes a mix of itch and pain sensations, enhances both excitatory and inhibitory spontaneous synaptic transmission onto GRPR neurons. These data strengthen the role of GRPR neurons as a key circuit for itch transmission and illustrate a spinal mechanism whereby pain inhibits itch by suppressing the function of GRPR neurons.
Collapse
|
27
|
Samineni VK, Grajales-Reyes JG, Sundaram SS, Yoo JJ, Gereau RW. Cell type-specific modulation of sensory and affective components of itch in the periaqueductal gray. Nat Commun 2019; 10:4356. [PMID: 31554789 PMCID: PMC6761157 DOI: 10.1038/s41467-019-12316-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 08/28/2019] [Indexed: 01/07/2023] Open
Abstract
Itch is a distinct aversive sensation that elicits a strong urge to scratch. Despite recent advances in our understanding of the peripheral basis of itch, we know very little regarding how central neural circuits modulate acute and chronic itch processing. Here we establish the causal contributions of defined periaqueductal gray (PAG) neuronal populations in itch modulation in mice. Chemogenetic manipulations demonstrate bidirectional modulation of scratching by neurons in the PAG. Fiber photometry studies show that activity of GABAergic and glutamatergic neurons in the PAG is modulated in an opposing manner during chloroquine-evoked scratching. Furthermore, activation of PAG GABAergic neurons or inhibition of glutamatergic neurons resulted in attenuation of scratching in both acute and chronic pruritis. Surprisingly, PAG GABAergic neurons, but not glutamatergic neurons, may encode the aversive component of itch. Thus, the PAG represents a neuromodulatory hub that regulates both the sensory and affective aspects of acute and chronic itch.
Collapse
Affiliation(s)
- Vijay K Samineni
- Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA
- Washington University Pain Center, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA
| | - Jose G Grajales-Reyes
- Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA
- Washington University Pain Center, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA
- Medical Scientist Training Program, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA
- Neuroscience Program, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA
| | - Saranya S Sundaram
- Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA
- Washington University Pain Center, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA
| | - Judy J Yoo
- Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA
- Washington University Pain Center, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA
| | - Robert W Gereau
- Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA.
- Washington University Pain Center, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA.
- Department of Neuroscience, Department of Biomedical Engineering, Washington University School of Medicine, 660 S. Euclid Ave, Box 8054, St. Louis, MO, 63110, USA.
| |
Collapse
|
28
|
Abstract
Itching can result from activity of specialized primary afferent neurons (“pruriceptors”) that have been shown to express certain molecular markers such as B-type natriuretic peptide and several members of the Mrgpr-family in rodents. On the other hand, neurons involved in pain processing (“nociceptors”) can also provoke itching when the activation site is restricted to an isolated tiny spot within the epidermis. Individuals classified as having sensitive skin report increased itching and pain sensations upon weak external stimuli that are not painful or itchy in the control group. Numerous possible factors could contribute to sensitive skin along the pathway of transduction of the external stimuli into peripheral neuronal signals, followed by neuronal processing, finally resulting in the perception: (a) reduced local protective factors leading to impaired skin barrier function, (b) increased production of excitatory skin mediators, (c) sensitized peripheral neurons, (d) facilitated spinal and central processing, and (e) reduced descending inhibition from the central nervous system. For all of those pathophysiological mechanisms there are clinical examples such as atopic dermatitis (a,b,c), neuropathic itching (c,e), and restless leg syndrome (d,e). However, none of these factors have been directly linked to the occurrence of sensitive skin. Moreover, individuals reporting sensitive skin are heterogeneous and a subpopulation with defined pathophysiology has not yet been identified. Given that the condition is reported in about 50% of women, and thereby includes many healthy individuals, it appears problematic to assign a definitive pathophysiological mechanism to it.
Collapse
Affiliation(s)
- Martin Schmelz
- Department Experimental Pain Research, CBTM, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| |
Collapse
|
29
|
Acton D, Ren X, Di Costanzo S, Dalet A, Bourane S, Bertocchi I, Eva C, Goulding M. Spinal Neuropeptide Y1 Receptor-Expressing Neurons Form an Essential Excitatory Pathway for Mechanical Itch. Cell Rep 2019; 28:625-639.e6. [PMID: 31315043 PMCID: PMC6709688 DOI: 10.1016/j.celrep.2019.06.033] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 05/20/2019] [Accepted: 06/06/2019] [Indexed: 01/08/2023] Open
Abstract
Acute itch can be generated by either chemical or mechanical stimuli, which activate separate pathways in the periphery and spinal cord. While substantial progress has been made in mapping the transmission pathway for chemical itch, the central pathway for mechanical itch remains obscure. Using complementary genetic and pharmacological manipulations, we show that excitatory neurons marked by the expression of the neuropeptide Y1 receptor (Y1Cre neurons) form an essential pathway in the dorsal spinal cord for the transmission of mechanical but not chemical itch. Ablating or silencing the Y1Cre neurons abrogates mechanical itch, while chemogenetic activation induces scratching. Moreover, using Y1 conditional knockout mice, we demonstrate that endogenous neuropeptide Y (NPY) acts via dorsal-horn Y1-expressing neurons to suppress light punctate touch and mechanical itch stimuli. NPY-Y1 signaling thus regulates the transmission of innocuous tactile information by establishing biologically relevant thresholds for touch discrimination and mechanical itch reflexes.
Collapse
Affiliation(s)
- David Acton
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Xiangyu Ren
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Biology Graduate Program, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Stefania Di Costanzo
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Biology Graduate Program, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Antoine Dalet
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Steeve Bourane
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Ilaria Bertocchi
- Department of Neuroscience, University of Torino, Neuroscience Institute of the Cavalieri-Ottolenghi Foundation, Regione Gonzole 1, 10043 Orbassano, Italy
| | - Carola Eva
- Department of Neuroscience, University of Torino, Neuroscience Institute of the Cavalieri-Ottolenghi Foundation, Regione Gonzole 1, 10043 Orbassano, Italy
| | - Martyn Goulding
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
| |
Collapse
|
30
|
Dong X, Dong X. Peripheral and Central Mechanisms of Itch. Neuron 2019; 98:482-494. [PMID: 29723501 DOI: 10.1016/j.neuron.2018.03.023] [Citation(s) in RCA: 222] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/12/2018] [Accepted: 03/15/2018] [Indexed: 12/15/2022]
Abstract
Itch is a unique sensory experience that is encoded by genetically distinguishable neurons both in the peripheral nervous system (PNS) and central nervous system (CNS) to elicit a characteristic behavioral response (scratching). Itch interacts with the other sensory modalities at multiple locations, from its initiation in a particular dermatome to its transmission to the brain where it is finally perceived. In this review, we summarize the current understanding of the molecular and neural mechanisms of itch by starting in the periphery, where itch is initiated, and discussing the circuits involved in itch processing in the CNS.
Collapse
Affiliation(s)
- Xintong Dong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
31
|
Miyahara Y, Funahashi H, Naono-Nakayama R, Haruta-Tsukamoto A, Nishimori T, Ishida Y. Role of serotonin and noradrenaline in the acute itch processing in mice. Eur J Pharmacol 2019; 850:118-125. [PMID: 30763572 DOI: 10.1016/j.ejphar.2019.02.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 01/20/2019] [Accepted: 02/11/2019] [Indexed: 12/22/2022]
Abstract
The contribution of serotonin and noradrenaline to the modulation of pruriceptive processing was evaluated by administrating antidepressants or noradrenaline reuptake inhibitors. The pretreatment with milnacipran, a serotonin and noradrenaline reuptake inhibitor, and mirtazapine, a noradrenergic and specific serotonergic antidepressant, attenuated the induction of scratching behavior by chloroquine, a representative pruritogen, indicating the involvement of serotonin and/or noradrenaline in the modulation of pruriceptive processing. By contrast, the single administration of noradrenaline reuptake inhibitor such as atomoxetine and nisoxetine or serotonin reuptake inhibitor such as fluvoxamine and escitalopram had little effect on chloroquine-induced scratching, whereas the induction of scratching behavior by chloroquine was significantly ameliorated by co-administration of serotonin reuptake inhibitors and noradrenaline reuptake inhibitors. These results indicate that the simultaneous increases of serotonin and noradrenaline elicit the attenuating effect on pruriceptive processing induced by acute itch, and may also play a crucial role in the descending itch inhibitory system.
Collapse
Affiliation(s)
- Yu Miyahara
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki 889-1692, Japan
| | - Hideki Funahashi
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki 889-1692, Japan
| | - Rumi Naono-Nakayama
- Division of Anatomy and Cell Biology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, 1-15-1 Fukumuro, Miyagino-ku, Sendai 983-8536, Japan
| | - Ayaka Haruta-Tsukamoto
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki 889-1692, Japan
| | - Toshikazu Nishimori
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki 889-1692, Japan
| | - Yasushi Ishida
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki 889-1692, Japan.
| |
Collapse
|
32
|
Abstract
Neuropathic itch is clinically important but has received much less attention as compared to neuropathic pain. In the past decade, itch-specific pathways have been characterized on a cellular and molecular level, but their exact role in the pathophysiology of neuropathic itch is still unclear. Traditionally, mutually exclusive theories for itch such as labeled line, temporal/spatial pattern, or intensity theory have been proposed, and experimental studies in mice mainly favor the specificity theory of itch. By contrast, results in humans also suggest a role for spatial and temporal patterns in neuropathic itch. Rarefication of skin innervation in neuropathy could provide a "spatial contrast" discharge pattern, and axotomy could induce de novo expression of the itch-specific spinal neuropeptide, gastrin-releasing peptide, in primary afferent nociceptors, thereby modulating itch processing in the dorsal horn. Thus, clinical neuropathy may generate itch by changes in the spatial and temporal discharge patterns of nociceptors, hijacking the labeled line processing of itch and abandoning the canonical scheme of mutual exclusive itch theories. Moreover, the overlap between itch and pain symptoms in neuropathy patients complicates direct translation from animal experiments and, on a clinical level, necessitates collaboration between medical specialities, such as dermatologists, anesthesiologists, and neurologists.
Collapse
|
33
|
Su XY, Chen M, Yuan Y, Li Y, Guo SS, Luo HQ, Huang C, Sun W, Li Y, Zhu MX, Liu MG, Hu J, Xu TL. Central Processing of Itch in the Midbrain Reward Center. Neuron 2019; 102:858-872.e5. [PMID: 31000426 DOI: 10.1016/j.neuron.2019.03.030] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 12/28/2018] [Accepted: 03/19/2019] [Indexed: 10/27/2022]
Abstract
Itch is an aversive sensation that evokes a desire to scratch. Paradoxically, scratching the itch also produces a hedonic experience. The specific brain circuits processing these different aspects of itch, however, remain elusive. Here, we report that GABAergic (GABA) and dopaminergic (DA) neurons in the ventral tegmental area (VTA) are activated with different temporal patterns during acute and chronic itch. DA neuron activation lags behind GABA neurons and is dependent on scratching of the itchy site. Optogenetic manipulations of VTA GABA neurons rapidly modulated scratching behaviors through encoding itch-associated aversion. In contrast, optogenetic manipulations of VTA DA neurons revealed their roles in sustaining recurrent scratching episodes through signaling scratching-induced reward. A similar dichotomy exists for the role of VTA in chronic itch. These findings advance understanding of circuit mechanisms of the unstoppable itch-scratch cycles and shed important insights into chronic itch therapy.
Collapse
Affiliation(s)
- Xin-Yu Su
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Ming Chen
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China
| | - Yuan Yuan
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Ying Li
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Su-Shan Guo
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Huo-Qing Luo
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Chen Huang
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Wenzhi Sun
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Yong Li
- Collaborative Innovation Center for Brain Science, Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai 201210, China
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Ming-Gang Liu
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
| | - Ji Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai 201210, China.
| | - Tian-Le Xu
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai 201210, China.
| |
Collapse
|
34
|
Dou J, Zeng J, Wu K, Tan W, Gao L, Lu J. Microbiosis in pathogenesis and intervention of atopic dermatitis. Int Immunopharmacol 2019; 69:263-269. [DOI: 10.1016/j.intimp.2019.01.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 01/21/2019] [Indexed: 12/19/2022]
|
35
|
|
36
|
Riccio D, Andersen HH, Arendt-Nielsen L. Antipruritic effects of transient heat stimulation on histaminergic and nonhistaminergic itch. Br J Dermatol 2019; 181:786-795. [PMID: 30802929 DOI: 10.1111/bjd.17825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/11/2019] [Indexed: 01/21/2023]
Abstract
BACKGROUND Chronic itch is notoriously difficult to treat. Counterstimuli are able to inhibit itch, but this principle is difficult to apply in clinical practice, and the mechanisms behind counterstimulation-induced itch suppression in humans are unclear. OBJECTIVES Firstly, to analyse the stimulus-response effects of transient heat stimuli on histaminergic and nonhistaminergic itch, and secondly, to investigate whether the antipruritic effect depends on homotopic (peripheral mediation) or heterotopic (central mediation) counterstimulation relative to the itch provocation site. METHODS Eighteen healthy volunteers participated (eight female, mean age 25·7 ± 0·8 years). Itch was evoked on premarked areas of the volar forearms, by either histamine (1% solution) or cowhage (35-40 spicules). In addition to the itch provocations (experiment 1), 5-s homotopic heat stimuli at 32, 40, 45 or 50 °C were applied. In experiment 2, heat stimuli were applied either homotopically, intrasegmentally (next to the provocation site) or extrasegmentally (dorsal forearm). Itch intensity was evaluated throughout the procedures using a digital visual analogue scale. RESULTS Homotopic counterstimuli inhibited histaminergic itch by 41·3% at 45 °C (P < 0·01) and by 76·7% at 50 °C (P < 0·001). Cowhage-induced itch was less prone to counterstimulation and was significantly diminished only at 50 °C, by 43·6% (P = 0·009). Counterstimulations applied heterotopically were not able to inhibit itch significantly. CONCLUSIONS Itch pathway-specific effects of counterstimuli were observed between homo- and heterotopic stimulation. Histaminergic itch was robustly inhibited by short-term homotopic noxious heat stimuli for up to 10 min. Nonhistaminergic itch was only weakly inhibited. The inhibitory effects exerted by the short-term heat stimuli only occurred following homotopic counterstimulation.
Collapse
Affiliation(s)
- D Riccio
- Center for Neuroplasticity and Pain (CNAP), Aalborg University, Aalborg, Denmark.,Laboratory for Experimental Cutaneous Pain and Itch Research, SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark
| | - H H Andersen
- Laboratory for Experimental Cutaneous Pain and Itch Research, SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark
| | - L Arendt-Nielsen
- Center for Neuroplasticity and Pain (CNAP), Aalborg University, Aalborg, Denmark.,Laboratory for Experimental Cutaneous Pain and Itch Research, SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark
| |
Collapse
|
37
|
Fujii M, Ohgami S, Asano E, Nakayama T, Toda T, Nabe T, Ohya S. Brain allopregnanolone induces marked scratching behaviour in diet-induced atopic dermatitis mouse model. Sci Rep 2019; 9:2364. [PMID: 30787375 PMCID: PMC6382911 DOI: 10.1038/s41598-019-38858-3] [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: 08/23/2018] [Accepted: 01/07/2019] [Indexed: 12/12/2022] Open
Abstract
Allopregnanolone (ALLO) is a neurosteroid produced in the brain, but so far, no study has explored its link with itching. Herein, we used a diet-induced atopic dermatitis mouse model to examine whether exogenously administered and endogenously produced ALLO contribute to inducing scratching. Systemic administration of ALLO elicited robust scratching in the atopic dermatitis model, while it did not affect spontaneous and pruritogen-induced scratching in normal mice. ALLO caused scratching when administered intracisternally, but not when administered intrathecally or intradermally, suggesting the involvement of supraspinal mechanisms. Pharmacological analyses suggested that both γ-aminobutyric acid type A receptor activation and serotonin type 3 receptor inhibition were involved in ALLO-induced scratching. We next examined whether endogenously produced ALLO is involved in ethanol-induced scratching in atopic dermatitis mice, because ethanol administration increases ALLO in rodent brain. Acute ethanol administration increased brain ALLO levels, which coincided with increased scratching. Pre-treatment with finasteride, a synthetic ALLO inhibitor, suppressed ethanol-induced scratching and ALLO production in the brain. Collectively, our results demonstrated for the first time that ALLO administration caused marked scratching in atopic dermatitis mice, and ethanol-induced scratching may be mediated through endogenously produced brain ALLO.
Collapse
Affiliation(s)
- Masanori Fujii
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina, Kyoto, 607-8414, Japan.
| | - Sayaka Ohgami
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina, Kyoto, 607-8414, Japan
| | - Erika Asano
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina, Kyoto, 607-8414, Japan
| | - Takanori Nakayama
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina, Kyoto, 607-8414, Japan
| | - Takahiro Toda
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina, Kyoto, 607-8414, Japan
| | - Takeshi Nabe
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina, Kyoto, 607-8414, Japan.,Laboratory of Immunopharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka, 573-0101, Japan
| | - Susumu Ohya
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina, Kyoto, 607-8414, Japan.,Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho, Nagoya, 467-8601, Japan
| |
Collapse
|
38
|
Follansbee T, Akiyama T, Fujii M, Davoodi A, Nagamine M, Iodi Carstens M, Carstens E. Effects of pruritogens and algogens on rostral ventromedial medullary ON and OFF cells. J Neurophysiol 2018; 120:2156-2163. [PMID: 29947594 PMCID: PMC6295534 DOI: 10.1152/jn.00208.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/03/2018] [Accepted: 06/03/2018] [Indexed: 11/22/2022] Open
Abstract
Rostroventromedial medulla (RVM) ON and OFF cells are thought to facilitate and inhibit spinal nociceptive transmission, respectively. However, it is unknown how ON and OFF cells respond to pruritic stimuli or how they contribute to descending modulation of spinal itch signaling. In pentobarbital sodium-anesthetized mice, single-unit recordings were made in RVM from ON and OFF cells identified by their respective increase or decrease in firing that occurred just before nocifensive hindlimb withdrawal elicited by paw pinch. Of RVM ON cells, 75% (21/28) were excited by intradermal histamine, 50% (10/20) by intradermal chloroquine, and 75% (27/36) by intradermal capsaicin. Most chemically responsive units also responded to a scratch stimulus applied to the injected hindpaw. Few ON cells responded to intradermal injection of vehicle (saline: 5/32; Tween 2/17) but still responded to scratching. For OFF cells, intradermal histamine and scratching inhibited 32% (6/19) with no effect of histamine in the remainder. Intradermal chloroquine inhibited 44% (4/9) and intradermal capsaicin inhibited 61% (11/18) of OFF cells. Few OFF cells were affected by vehicles (Tween: 1 inhibited, 7 unaffected; saline: 3 excited, 1 inhibited, 8 unaffected). Both ON and OFF cells that responded to one chemical usually also responded to others, whereas units unresponsive to the first-tested chemical tended not to respond to others. These results indicate that ascending pruriceptive signals activate RVM ON cells and inhibit RVM OFF cells. These effects are considered to facilitate and disinhibit spinal pain transmission, respectively. It is currently not clear if spinal itch transmission is similarly modulated. NEW & NOTEWORTHY The rostroventromedial medulla (RVM) contains ON and OFF cells that are, respectively, excited and inhibited by noxious stimuli and have descending projections that facilitate and inhibit spinal nociceptive transmission. Most RVM ON cells were excited, and OFF cells inhibited, by intradermal injection of the pruritogens histamine and chloroquine, as well as the algogen capsaicin. These results indicate that itchy stimuli activate RVM neurons that presumably give rise to descending modulation of spinal itch transmission.
Collapse
Affiliation(s)
- T. Follansbee
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
- Center for Neuroscience, University of California, Davis, California
| | - T. Akiyama
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
| | - M. Fujii
- Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - A. Davoodi
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
| | - M. Nagamine
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
| | - M. Iodi Carstens
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
| | - E. Carstens
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
| |
Collapse
|
39
|
Ehling S, Butler A, Thi S, Ghashghaei HT, Bäumer W. To scratch an itch: Establishing a mouse model to determine active brain areas involved in acute histaminergic itch. IBRO Rep 2018; 5:67-73. [PMID: 30364768 PMCID: PMC6197726 DOI: 10.1016/j.ibror.2018.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/13/2018] [Indexed: 12/30/2022] Open
Abstract
The specific histamine H4 receptor agonist ST-1006 induces acute itch in mice. Histaminergic itch increases neuronal activity in the medial habenula. Selective H4R activation in the skin increases neuronal activity in the medial habenula.
Background Strategies to efficiently control itch require a deep understanding of the underlying mechanisms. Several areas in the brain involved in itch and scratching responses have been postulated, but the central mechanisms that drive pruritic responses are still unknown. Histamine is recognized as a major mediator of itch in humans, and has been the most frequently used stimulus as an experimental pruritogen for brain imaging of itch. Objective Histaminergic itch via histamine and the selective histamine H4 receptor (H4R) agonist, ST-1006, recruit brain nuclei through c-fos activation and activate specific areas in the brain. Methods An acute itch model was established in c-fos-EGFP transgenic mice using ST-1006 and histamine. Coronal brain sections were stained for c-fos immunoreactivity and the forebrain was mapped for density of c-fos + nuclei. Results Histamine and ST-1006 significantly increased scratching response in c-fos-EGFP mice compared to vehicle controls. Mapping c-fos immunostained brain sections revealed neuronal activity in the cortex, striatum, hypothalamus, thalamus, amygdala, and the midbrain. Conclusions Histaminergic itch and selective H4R activation significantly increased the density of c-fos + nuclei in the medial habenula (MHb). Thus, the MHb may be a new target to investigate and subsequently develop novel mechanism-based strategies to treat itch and possibly provide a locus for pharmacological control of pruritus.
Collapse
Affiliation(s)
- Sarah Ehling
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, NC, USA.,Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Ashley Butler
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, NC, USA
| | - Stephanie Thi
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, NC, USA
| | - H Troy Ghashghaei
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, NC, USA
| | - Wolfgang Bäumer
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, NC, USA.,Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
40
|
Carstens E, Carstens MI, Akiyama T, Davoodi A, Nagamine M. Opposing effects of cervical spinal cold block on spinal itch and pain transmission. ITCH (PHILADELPHIA, PA.) 2018; 3:e16. [PMID: 34136640 PMCID: PMC8204798 DOI: 10.1097/itx.0000000000000016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Inactivation of descending pathways enhanced responses of spinal dorsal horn neurons to noxious stimuli, but little is known regarding tonic descending modulation of spinal itch transmission. To study effects of cervical spinal cold block on responses of dorsal horn neurons to itch-evoking and pain-evoking stimuli, single-unit recordings were made from superficial dorsal horn wide dynamic range and nociceptive-specific-type neurons in pentobarbital-anesthetized mice. Intradermal histamine excited 17 units. Cold block starting 1 minute after intradermal injection of histamine caused a marked decrease in firing. The histamine-evoked response during and following cold block was significantly lower compared with control histamine-evoked responses in the absence of cold block. A similar but weaker depressant effect of cold block was observed for dorsal horn unit responses to chloroquine. Twenty-six units responded to mustard oil allyl isothiocyanate (AITC), with a further significant increase in firing during the 1-minute period of cold block beginning 1 minute after AITC application. Activity during cold block was significantly greater compared with the same time period of control responses to AITC in the absence of cold block. Ten units' responses to noxious heat were significantly enhanced during cold block, while 6 units' responses were reduced and 18 unaffected. Cold block had no effect on mechanically evoked responses. These results indicate that spinal chemonociceptive transmission is under tonic descending inhibitory modulation, while spinal pruriceptive transmission is under an opposing, tonic descending facilitatory modulation.
Collapse
Affiliation(s)
- Earl Carstens
- Department of Neurobiology, Physiology, University of California, Davis, CA
| | | | - Tasuku Akiyama
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, FL
| | - Auva Davoodi
- Department of Neurobiology, Physiology, University of California, Davis, CA
| | - Masaki Nagamine
- Department of Neurobiology, Physiology, University of California, Davis, CA
| |
Collapse
|
41
|
Braz JM, Etlin A, Juarez-Salinas D, Llewellyn-Smith IJ, Basbaum AI. Rebuilding CNS inhibitory circuits to control chronic neuropathic pain and itch. PROGRESS IN BRAIN RESEARCH 2018; 231:87-105. [PMID: 28554402 DOI: 10.1016/bs.pbr.2016.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cell transplantation offers an attractive alternative to pharmacotherapy for the management of a host of clinical conditions. Most importantly, the transplanted cells provide a continuous, local delivery of therapeutic compounds, which avoids many of the adverse side effects associated with systemically administered drugs. Here, we describe the broad therapeutic utility of transplanting precursors of cortical inhibitory interneurons derived from the embryonic medial ganglionic eminence (MGE), in a variety of chronic pain and itch models in the mouse. Despite the cortical environment in which the MGE cells normally develop, these cells survive transplantation and will even integrate into the circuitry of an adult host spinal cord. When transplanted into the spinal cord, the cells significantly reduce the hyperexcitability that characterizes both chronic neuropathic pain and itch conditions. This MGE cell-based strategy differs considerably from traditional pharmacological treatments as the approach is potentially disease modifying (i.e., the therapy targets the underlying etiology of the pain and itch pathophysiology).
Collapse
Affiliation(s)
- Joao M Braz
- University of California-San Francisco, San Francisco, CA, United States
| | - Alex Etlin
- University of California-San Francisco, San Francisco, CA, United States
| | | | - Ida J Llewellyn-Smith
- Cardiovascular Medicine, Human Physiology and Centre for Neuroscience, Flinders University, Bedford Park, SA, Australia
| | - Allan I Basbaum
- University of California-San Francisco, San Francisco, CA, United States.
| |
Collapse
|
42
|
Huang J, Polgár E, Solinski HJ, Mishra SK, Tseng PY, Iwagaki N, Boyle KA, Dickie AC, Kriegbaum MC, Wildner H, Zeilhofer HU, Watanabe M, Riddell JS, Todd AJ, Hoon MA. Circuit dissection of the role of somatostatin in itch and pain. Nat Neurosci 2018; 21:707-716. [PMID: 29556030 PMCID: PMC5923877 DOI: 10.1038/s41593-018-0119-z] [Citation(s) in RCA: 157] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 01/25/2018] [Indexed: 11/09/2022]
Abstract
Stimuli that elicit itch are detected by sensory neurons that innervate the skin. This information is processed by the spinal cord; however, the way in which this occurs is still poorly understood. Here we investigated the neuronal pathways for itch neurotransmission, particularly the contribution of the neuropeptide somatostatin. We find that in the periphery, somatostatin is exclusively expressed in Nppb+ neurons, and we demonstrate that Nppb+somatostatin+ cells function as pruriceptors. Employing chemogenetics, pharmacology and cell-specific ablation methods, we demonstrate that somatostatin potentiates itch by inhibiting inhibitory dynorphin neurons, which results in disinhibition of GRPR+ neurons. Furthermore, elimination of somatostatin from primary afferents and/or from spinal interneurons demonstrates differential involvement of the peptide released from these sources in itch and pain. Our results define the neural circuit underlying somatostatin-induced itch and characterize a contrasting antinociceptive role for the peptide.
Collapse
Affiliation(s)
- Jing Huang
- Molecular Genetics Unit, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA
- Department of Anatomy, Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, PR China
| | - Erika Polgár
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Hans Jürgen Solinski
- Molecular Genetics Unit, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA
| | - Santosh K Mishra
- Molecular Genetics Unit, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University; and Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA
| | - Pang-Yen Tseng
- Molecular Genetics Unit, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA
| | - Noboru Iwagaki
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Kieran A Boyle
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Allen C Dickie
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Mette C Kriegbaum
- Molecular Genetics Unit, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA
| | - Hendrik Wildner
- Institute of Pharmacology and Toxicology, University of Zurich; and Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland
| | - Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zurich; and Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo, Japan
| | - John S Riddell
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Andrew J Todd
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
| | - Mark A Hoon
- Molecular Genetics Unit, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA.
| |
Collapse
|
43
|
Lee SY, Lee E, Park YM, Hong SJ. Microbiome in the Gut-Skin Axis in Atopic Dermatitis. ALLERGY, ASTHMA & IMMUNOLOGY RESEARCH 2018; 10:354-362. [PMID: 29949831 PMCID: PMC6021588 DOI: 10.4168/aair.2018.10.4.354] [Citation(s) in RCA: 162] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 12/16/2017] [Accepted: 12/29/2017] [Indexed: 01/01/2023]
Abstract
The microbiome is vital for immune system development and homeostasis. Changes in microbial composition and function, termed dysbiosis, in the skin and the gut have recently been linked to alterations in immune responses and to the development of skin diseases, such as atopic dermatitis (AD). In this review, we summarize the recent findings on the gut and skin microbiome, highlighting the roles of major commensals in modulating skin and systemic immunity in AD. Although our understanding of the gut-skin axis is only beginning, emerging evidence indicates that the gut and skin microbiome could be manipulated to treat AD.
Collapse
Affiliation(s)
- So Yeon Lee
- Department of Pediatrics, Childhood Asthma Atopy Center, Environmental Health Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Eun Lee
- Department of Pediatrics, Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Korea
| | - Yoon Mee Park
- Asan Institute for Life Science, University of Ulsan College of Medicine, Seoul, Korea
| | - Soo Jong Hong
- Department of Pediatrics, Childhood Asthma Atopy Center, Environmental Health Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
| |
Collapse
|
44
|
Jung MJ, Choi YW, Chung BY, Park CW, Kim HO. Pathophysiology and new treatment of itch. JOURNAL OF THE KOREAN MEDICAL ASSOCIATION 2018. [DOI: 10.5124/jkma.2018.61.11.670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Min Je Jung
- Department of Dermatology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Yong Won Choi
- Department of Dermatology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Bo Young Chung
- Department of Dermatology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Chun Wook Park
- Department of Dermatology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Hye One Kim
- Department of Dermatology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| |
Collapse
|
45
|
Specific activation of inhibitory interneurons in the spinal dorsal horn suppresses repetitive scratching in mouse models of chronic itch. J Dermatol Sci 2017; 88:251-254. [DOI: 10.1016/j.jdermsci.2017.05.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/12/2017] [Accepted: 05/25/2017] [Indexed: 11/22/2022]
|
46
|
Nocebo-induced modulation of cerebral itch processing - An fMRI study. Neuroimage 2017; 166:209-218. [PMID: 29107770 DOI: 10.1016/j.neuroimage.2017.10.056] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 10/12/2017] [Accepted: 10/25/2017] [Indexed: 12/29/2022] Open
Abstract
It has been shown repeatedly that perceiving itch-related pictures or listening to a lecture on itch can enhance itch sensation and scratching behaviour (Niemeier and Gieler, 2000; Holle et al., 2012; Lloyd et al., 2013), indicating that itch is strongly influenced by expectations. Using fMRI, we investigated the neural correlates of the itch-related nocebo effect in healthy male and female human subjects. Itch sensation on the left forearm was induced by cutaneous histamine application and thermally modulated, with cooling leading to higher itch. Nocebo-induced aggravation of histaminergic itch was achieved by ostensibly treating volunteers with "transcutaneous electrical nerve stimulation (TENS)" about which subjects were instructed that it would increase itch. During a conditioning phase subjects indeed experienced stronger itch due to slightly altered cooling and histamine concentrations, but attributed it to the alleged "TENS stimulation". Importantly, in the subsequent test phase where no "TENS" or electrical stimulation was applied, volunteers significantly reported stronger itch during the nocebo as compared to the control condition. Comparing BOLD responses during nocebo in contrast to control, we observed increased activity in contralateral (right) rolandic operculum. Opercular involvement was repeatedly reported in studies related to the expectation of stimulus intensification and might thus represent an early area integrating expectation information with somatosensory information. Finally, functional coupling between the insula and the periaqueductal gray (PAG) was enhanced specifically in the nocebo condition. This cortex-PAG interaction indicates that context-dependent top-down modulation during itch might represent a shared mechanism with other modalities such as pain.
Collapse
|
47
|
Rashid S, Trivedi DD, Al-Shathir M, Moulton M, Baumrucker SJ. Is There a Role for 5-HT 3 Receptor Antagonists in the Treatment of Opioid-Induced Pruritus? Am J Hosp Palliat Care 2017; 35:740-744. [PMID: 29020799 DOI: 10.1177/1049909117736062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Pruritus is an unpleasant irritation symptom that can be related to various systemic and dermatological conditions. Although underreported, pruritus is a common adverse event noted after use of opioid pain medications. This article reviews the current understanding of the mechanism of opioid-induced pruritus (OIP) and various pharmacological therapies. 5-Hydroxytryptamine 3 (5-HT3) receptor antagonists are potentially effective for treating OIP and may be a valuable treatment option if further controlled studies are encouraging.
Collapse
Affiliation(s)
- Saima Rashid
- 1 Department of Pulmonary and Critical Care, Mercy Health, Cincinnati, OH, USA
| | | | - Mudher Al-Shathir
- 3 Department of Pulmonary and Critical Care, Mercy Health, Cincinnati, OH
| | - Marie Moulton
- 1 Department of Pulmonary and Critical Care, Mercy Health, Cincinnati, OH, USA
| | - Steven J Baumrucker
- 4 Hospice and Palliative Medicine, Wellmont Health System, Kingsport, TN, USA
| |
Collapse
|
48
|
Liu BW, Li ZX, He ZG, Liu C, Xiong J, Xiang HB. Altered expression of target genes of spinal cord in different itch models compared with capsaicin assessed by RT-qPCR validation. Oncotarget 2017; 8:74423-74433. [PMID: 29088797 PMCID: PMC5650352 DOI: 10.18632/oncotarget.20148] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 05/23/2017] [Indexed: 11/25/2022] Open
Abstract
Spinal cord plays a central role in the development and progression of pathogenesis of obstinate pruritus. In the current study, four groups of adult male C57Bl/6 mice were investigated; one group treated with saline, while the other groups intradermally injected with compound 48/80, histamine, α-Me-5-HT and capsaicin (algogenic substance), respectively. The intradermal microinjection of pruritic and algogenic compound resulted in a dramatic increase in the itch/algogenic behavior. Analysis of the microarray data showed that 15 genes in spinal cord (C5-C8) were differentially expressed between control group and 48/80 group, in which 9 genes were up-regulated and 6 genes were down-regulated. Furthermore, the results of RT-qPCR validation studies in C5-C8 spinal cord revealed that the 9 mRNA (Sgk1, Bag4, Fos, Ehd2, Edn3, Wdfy, Corin, 4921511E18Rik and 4930423020Rik) showed very different patterns for these different drugs, especially when comparing α-Me-5-HT and capsaicin. In three itch models, Fos and Ehd2 were up-regulated whereas Corin, 4921511E18Rik and 4930423020Rik were down-regulated. Furthermore, Corin and 4930423020Rik were down-regulated in itch model group compared to capsaicin group. Thus the application of microarray technique, coupled with RT-qPCR validation, further explain the mechanism behind itching evoked by pruritic compounds. It can contribute to our understanding of pharmacological methods for prevention or treatment of obstinate pruritus.
Collapse
Affiliation(s)
- Bao-Wen Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhi-Xiao Li
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhi-Gang He
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Cheng Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jun Xiong
- Hepatobiliary Surgery Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hong-Bing Xiang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
49
|
Mueller SM, Hogg S, Mueller JM, McKie S, Itin P, Reinhardt J, Griffiths CE, Kleyn CE. Functional magnetic resonance imaging in dermatology: The skin, the brain and the invisible. Exp Dermatol 2017; 26:845-853. [DOI: 10.1111/exd.13305] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2017] [Indexed: 01/05/2023]
Affiliation(s)
- Simon M. Mueller
- Department of Dermatology; University Hospital Basel; Basel Switzerland
- Dermatology Centre; The Manchester Academic Health Science Centre; The University of Manchester; Manchester UK
| | - Samuel Hogg
- Department of Dermatology; University Hospital Basel; Basel Switzerland
| | - Jannis M. Mueller
- Department of Neurology; Kantonsspital Muensterlingen; Muensterlingen Switzerland
| | - Shane McKie
- Neuroscience and Psychiatry Unit; The Manchester Academic Health Science Centre; The University of Manchester; Manchester UK
| | - Peter Itin
- Dermatology Centre; The Manchester Academic Health Science Centre; The University of Manchester; Manchester UK
| | - Julia Reinhardt
- Division of Diagnostic & Interventional Neuroradiology; University Hospital Basel; Basel Switzerland
| | | | | |
Collapse
|
50
|
Liu T, He Z, Tian X, Kamal GM, Li Z, Liu Z, Liu H, Xu F, Wang J, Xiang H. Specific patterns of spinal metabolites underlying α-Me-5-HT-evoked pruritus compared with histamine and capsaicin assessed by proton nuclear magnetic resonance spectroscopy. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1222-1230. [PMID: 28344131 DOI: 10.1016/j.bbadis.2017.03.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 03/22/2017] [Accepted: 03/22/2017] [Indexed: 12/29/2022]
Abstract
The mechanism behind itching is not well understood. Proton nuclear magnetic resonance (1H-NMR) spectroscopic analysis of spinal cord extracts provides a quick modality for evaluating the specific metabolic activity of α-Me-5-HT-evoked pruritus mice. In the current study, four groups of young adult male C57Bl/6 mice were investigated; one group treated with saline, while the other groups intradermally injected with α-Me-5-HT (histamine independent pruritogen), histamine (histamine dependent pruritogen) and capsaicin (algogenic substance), respectively. The intradermal microinjection of α-Me-5-HT and histamine resulted in a dramatic increase in the itch behavior. Furthermore, the results of NMR studies of the spinal cord extracts revealed that the metabolites show very different patterns for these different drugs, especially when comparing α-Me-5-HT and capsaicin. All the animals in the groups of α-Me-5-HT and capsaicin were completely separated using the metabolite parameters and principal component analysis. For α-Me-5-HT, the concentrations of glutamate, GABA, glycine and aspartate increased significantly, especially for GABA (increased 17.2%, p=0.008). Furthermore, the concentration of NAA increased, but there was no significant difference (increased 11.3%, p=0.191) compared to capsaicin (decreased 29.1%, p=0.002). Thus the application of magnetic resonance spectroscopy technique, coupled with statistical analysis, could further explain the mechanism behind itching evoked by α-Me-5-HT or other drugs. It can thus improve our understanding of itch pathophysiology and pharmacological therapies which may contribute to itch relief.
Collapse
Affiliation(s)
- Taotao Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, PR China; Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
| | - Zhigang He
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, PR China
| | - Xuebi Tian
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, PR China
| | - Ghulam Mustafa Kamal
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Zhixiao Li
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, PR China
| | - Zeyuan Liu
- College of Life Science, Wuhan University, Wuhan, Hubei 430076, PR China
| | - Huili Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei 430071, PR China
| | - Fuqiang Xu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Jie Wang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Hongbing Xiang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, PR China.
| |
Collapse
|