1
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Taub DG, Woolf CJ. Age-dependent small fiber neuropathy: Mechanistic insights from animal models. Exp Neurol 2024; 377:114811. [PMID: 38723859 PMCID: PMC11131160 DOI: 10.1016/j.expneurol.2024.114811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/07/2024] [Accepted: 05/05/2024] [Indexed: 05/28/2024]
Abstract
Small fiber neuropathy (SFN) is a common and debilitating disease in which the terminals of small diameter sensory axons degenerate, producing sensory loss, and in many patients neuropathic pain. While a substantial number of cases are attributable to diabetes, almost 50% are idiopathic. An underappreciated aspect of the disease is its late onset in most patients. Animal models of human genetic mutations that produce SFN also display age-dependent phenotypes suggesting that aging is an important contributor to the risk of development of the disease. In this review we define how particular sensory neurons are affected in SFN and discuss how aging may drive the disease. We also evaluate how animal models of SFN can define disease mechanisms that will provide insight into early risk detection and suggest novel therapeutic interventions.
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Affiliation(s)
- Daniel G Taub
- F. M. Kirby Neurobiology Center and Department of Neurology, Boston Children's Hospital, Boston, MA, USA; Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
| | - Clifford J Woolf
- F. M. Kirby Neurobiology Center and Department of Neurology, Boston Children's Hospital, Boston, MA, USA; Department of Neurobiology, Harvard Medical School, Boston, MA, USA
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2
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Dasgupta I, Rangineni DP, Abdelsaid H, Ma Y, Bhushan A. Tiny Organs, Big Impact: How Microfluidic Organ-on-Chip Technology Is Revolutionizing Mucosal Tissues and Vasculature. Bioengineering (Basel) 2024; 11:476. [PMID: 38790343 PMCID: PMC11117503 DOI: 10.3390/bioengineering11050476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/04/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
Organ-on-chip (OOC) technology has gained importance for biomedical studies and drug development. This technology involves microfluidic devices that mimic the structure and function of specific human organs or tissues. OOCs are a promising alternative to traditional cell-based models and animals, as they provide a more representative experimental model of human physiology. By creating a microenvironment that closely resembles in vivo conditions, OOC platforms enable the study of intricate interactions between different cells as well as a better understanding of the underlying mechanisms pertaining to diseases. OOCs can be integrated with other technologies, such as sensors and imaging systems to monitor real-time responses and gather extensive data on tissue behavior. Despite these advances, OOCs for many organs are in their initial stages of development, with several challenges yet to be overcome. These include improving the complexity and maturity of these cellular models, enhancing their reproducibility, standardization, and scaling them up for high-throughput uses. Nonetheless, OOCs hold great promise in advancing biomedical research, drug discovery, and personalized medicine, benefiting human health and well-being. Here, we review several recent OOCs that attempt to overcome some of these challenges. These OOCs with unique applications can be engineered to model organ systems such as the stomach, cornea, blood vessels, and mouth, allowing for analyses and investigations under more realistic conditions. With this, these models can lead to the discovery of potential therapeutic interventions. In this review, we express the significance of the relationship between mucosal tissues and vasculature in organ-on-chip (OOC) systems. This interconnection mirrors the intricate physiological interactions observed in the human body, making it crucial for achieving accurate and meaningful representations of biological processes within OOC models. Vasculature delivers essential nutrients and oxygen to mucosal tissues, ensuring their proper function and survival. This exchange is critical for maintaining the health and integrity of mucosal barriers. This review will discuss the OOCs used to represent the mucosal architecture and vasculature, and it can encourage us to think of ways in which the integration of both can better mimic the complexities of biological systems and gain deeper insights into various physiological and pathological processes. This will help to facilitate the development of more accurate predictive models, which are invaluable for advancing our understanding of disease mechanisms and developing novel therapeutic interventions.
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Affiliation(s)
| | | | | | | | - Abhinav Bhushan
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL 60616, USA; (I.D.); (D.P.R.); (H.A.); (Y.M.)
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3
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Luedke KP, Yoshino J, Yin C, Jiang N, Huang JM, Huynh K, Parrish JZ. Dendrite intercalation between epidermal cells tunes nociceptor sensitivity to mechanical stimuli in Drosophila larvae. PLoS Genet 2024; 20:e1011237. [PMID: 38662763 DOI: 10.1371/journal.pgen.1011237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 05/07/2024] [Accepted: 03/29/2024] [Indexed: 05/07/2024] Open
Abstract
An animal's skin provides a first point of contact with the sensory environment, including noxious cues that elicit protective behavioral responses. Nociceptive somatosensory neurons densely innervate and intimately interact with epidermal cells to receive these cues, however the mechanisms by which epidermal interactions shape processing of noxious inputs is still poorly understood. Here, we identify a role for dendrite intercalation between epidermal cells in tuning sensitivity of Drosophila larvae to noxious mechanical stimuli. In wild-type larvae, dendrites of nociceptive class IV da neurons intercalate between epidermal cells at apodemes, which function as body wall muscle attachment sites, but not at other sites in the epidermis. From a genetic screen we identified miR-14 as a regulator of dendrite positioning in the epidermis: miR-14 is expressed broadly in the epidermis but not in apodemes, and miR-14 inactivation leads to excessive apical dendrite intercalation between epidermal cells. We found that miR-14 regulates expression and distribution of the epidermal Innexins ogre and Inx2 and that these epidermal gap junction proteins restrict epidermal dendrite intercalation. Finally, we found that altering the extent of epidermal dendrite intercalation had corresponding effects on nociception: increasing epidermal intercalation sensitized larvae to noxious mechanical inputs and increased mechanically evoked calcium responses in nociceptive neurons, whereas reducing epidermal dendrite intercalation had the opposite effects. Altogether, these studies identify epidermal dendrite intercalation as a mechanism for mechanical coupling of nociceptive neurons to the epidermis, with nociceptive sensitivity tuned by the extent of intercalation.
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Affiliation(s)
- Kory P Luedke
- Department of Biology, University of Washington, Seattle, Washington State, United States of America
| | - Jiro Yoshino
- Department of Biology, University of Washington, Seattle, Washington State, United States of America
| | - Chang Yin
- Department of Biology, University of Washington, Seattle, Washington State, United States of America
| | - Nan Jiang
- Department of Biology, University of Washington, Seattle, Washington State, United States of America
| | - Jessica M Huang
- Department of Biology, University of Washington, Seattle, Washington State, United States of America
| | - Kevin Huynh
- Department of Biology, University of Washington, Seattle, Washington State, United States of America
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, Washington State, United States of America
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4
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Qi L, Iskols M, Shi D, Reddy P, Walker C, Lezgiyeva K, Voisin T, Pawlak M, Kuchroo VK, Chiu IM, Ginty DD, Sharma N. A mouse DRG genetic toolkit reveals morphological and physiological diversity of somatosensory neuron subtypes. Cell 2024; 187:1508-1526.e16. [PMID: 38442711 PMCID: PMC10947841 DOI: 10.1016/j.cell.2024.02.006] [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: 04/22/2023] [Revised: 11/12/2023] [Accepted: 02/05/2024] [Indexed: 03/07/2024]
Abstract
Dorsal root ganglia (DRG) somatosensory neurons detect mechanical, thermal, and chemical stimuli acting on the body. Achieving a holistic view of how different DRG neuron subtypes relay neural signals from the periphery to the CNS has been challenging with existing tools. Here, we develop and curate a mouse genetic toolkit that allows for interrogating the properties and functions of distinct cutaneous targeting DRG neuron subtypes. These tools have enabled a broad morphological analysis, which revealed distinct cutaneous axon arborization areas and branching patterns of the transcriptionally distinct DRG neuron subtypes. Moreover, in vivo physiological analysis revealed that each subtype has a distinct threshold and range of responses to mechanical and/or thermal stimuli. These findings support a model in which morphologically and physiologically distinct cutaneous DRG sensory neuron subtypes tile mechanical and thermal stimulus space to collectively encode a wide range of natural stimuli.
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Affiliation(s)
- Lijun Qi
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Michael Iskols
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - David Shi
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Pranav Reddy
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Christopher Walker
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Karina Lezgiyeva
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Tiphaine Voisin
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - Mathias Pawlak
- Gene Lay Institute of Immunology and Inflammation, Brigham and Women's Hospital, Mass General Hospital, and Harvard Medical School, Boston, MA 02115, USA
| | - Vijay K Kuchroo
- Gene Lay Institute of Immunology and Inflammation, Brigham and Women's Hospital, Mass General Hospital, and Harvard Medical School, Boston, MA 02115, USA
| | - Isaac M Chiu
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
| | - Nikhil Sharma
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA.
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5
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Ummadisetty O, Akhilesh, Gadepalli A, Chouhan D, Tiwari V. Development and validation of clinically Mimicable model of frostbite injury-induced chronic pain. Cell Signal 2024; 115:111028. [PMID: 38176530 DOI: 10.1016/j.cellsig.2023.111028] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 12/17/2023] [Accepted: 12/28/2023] [Indexed: 01/06/2024]
Abstract
Frostbite, a debilitating condition, significantly affects the well-being of military veterans and high-altitude residents, causing severe clinical complications such as chronic pain that markedly impacts overall quality of life. There has been a notable increase in the development of pre-clinical models for studying frostbite injury, but their suitability for pain evaluation remains limited. The major hurdle in the development of novel therapeutics for the treatment of frostbite-induced chronic pain is the unavailability of well-established preclinical models. In this study, we employed deep-frozen magnets to induce frostbite injury and conducted validation for chronic pain through assessments of face, predictive, and mechanistic validity. Behavioral assays demonstrated that frostbite injury exhibited significant mechanical, thermal & cold hypersensitivity in rats. Further, molecular analysis indicated that frostbite injury triggered the activation of TRP channels (TRPA1, TRPV1 and TRPM8), microgliosis, and neuroinflammation in the dorsal root ganglion (DRG) and spinal cord of rats. Notably, NR2B protein expressions were significantly upregulated in the DRG of injured rats, while no changes were observed in spinal NR2B expressions. Furthermore, the administration of ibuprofen (25, 50, and 100 mg/kg, i.p.) resulted in a significant improvement in behavioral, biochemical, and molecular alterations in frostbite-injured rats. Overall, results suggested that established frostbite model effectively recapitulates face, pharmacological, and mechanistic validity, highlighting its potential for screening future treatment modalities and exploring the intricate mechanisms associated with frostbite-induced chronic pain.
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Affiliation(s)
- Obulapathi Ummadisetty
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, Uttar Pradesh, India
| | - Akhilesh
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, Uttar Pradesh, India
| | - Anagha Gadepalli
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, Uttar Pradesh, India
| | - Deepak Chouhan
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, Uttar Pradesh, India
| | - Vinod Tiwari
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, Uttar Pradesh, India.
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6
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Xie H, Li J, Lian N, Xie M, Wu M, Tang K, Kang Y, Lu P, Li T. Defective branched-chain amino acid catabolism in dorsal root ganglia contributes to mechanical pain. EMBO Rep 2023; 24:e56958. [PMID: 37721527 PMCID: PMC10626448 DOI: 10.15252/embr.202356958] [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: 02/07/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 09/19/2023] Open
Abstract
Impaired branched-chain amino acid (BCAA) catabolism has recently been implicated in the development of mechanical pain, but the underlying molecular mechanisms are unclear. Here, we report that defective BCAA catabolism in dorsal root ganglion (DRG) neurons sensitizes mice to mechanical pain by increasing lactate production and expression of the mechanotransduction channel Piezo2. In high-fat diet-fed obese mice, we observed the downregulation of PP2Cm, a key regulator of the BCAA catabolic pathway, in DRG neurons. Mice with conditional knockout of PP2Cm in DRG neurons exhibit mechanical allodynia under normal or SNI-induced neuropathic injury conditions. Furthermore, the VAS scores in the plasma of patients with peripheral neuropathic pain are positively correlated with BCAA contents. Mechanistically, defective BCAA catabolism in DRG neurons promotes lactate production through glycolysis, which increases H3K18la modification and drives Piezo2 expression. Inhibition of lactate production or Piezo2 silencing attenuates the pain phenotype of knockout mice in response to mechanical stimuli. Therefore, our study demonstrates a causal role of defective BCAA catabolism in mechanical pain by enhancing metabolite-mediated epigenetic regulation.
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Affiliation(s)
- Huijing Xie
- Department of Anesthesiology, National Clinical Research Center for GeriatricsWest China Hospital of Sichuan UniversityChengduChina
- Laboratory of Mitochondria and Metabolism, National‐Local Joint Engineering Research Centre of Translational Medicine of AnesthesiologyWest China Hospital of Sichuan UniversityChengduChina
| | - Ju Li
- Department of Anesthesiology, National Clinical Research Center for GeriatricsWest China Hospital of Sichuan UniversityChengduChina
- Laboratory of Mitochondria and Metabolism, National‐Local Joint Engineering Research Centre of Translational Medicine of AnesthesiologyWest China Hospital of Sichuan UniversityChengduChina
| | - Nan Lian
- Department of Anesthesiology, National Clinical Research Center for GeriatricsWest China Hospital of Sichuan UniversityChengduChina
- Laboratory of Mitochondria and Metabolism, National‐Local Joint Engineering Research Centre of Translational Medicine of AnesthesiologyWest China Hospital of Sichuan UniversityChengduChina
- Huaxi MR Research Center (HMRRC), Department of RadiologyWest China Hospital of Sichuan University, Functional and Molecular Imaging Key Laboratory of Sichuan ProvinceChengduChina
| | - Min Xie
- Department of Anesthesiology, National Clinical Research Center for GeriatricsWest China Hospital of Sichuan UniversityChengduChina
- Laboratory of Mitochondria and Metabolism, National‐Local Joint Engineering Research Centre of Translational Medicine of AnesthesiologyWest China Hospital of Sichuan UniversityChengduChina
| | - Minming Wu
- Department of Anesthesiology, National Clinical Research Center for GeriatricsWest China Hospital of Sichuan UniversityChengduChina
- Laboratory of Mitochondria and Metabolism, National‐Local Joint Engineering Research Centre of Translational Medicine of AnesthesiologyWest China Hospital of Sichuan UniversityChengduChina
| | - Kuo Tang
- Department of Anesthesiology, National Clinical Research Center for GeriatricsWest China Hospital of Sichuan UniversityChengduChina
- Laboratory of Mitochondria and Metabolism, National‐Local Joint Engineering Research Centre of Translational Medicine of AnesthesiologyWest China Hospital of Sichuan UniversityChengduChina
| | - Yi Kang
- Department of Anesthesiology, National Clinical Research Center for GeriatricsWest China Hospital of Sichuan UniversityChengduChina
- Laboratory of Mitochondria and Metabolism, National‐Local Joint Engineering Research Centre of Translational Medicine of AnesthesiologyWest China Hospital of Sichuan UniversityChengduChina
| | - Peilin Lu
- Department of Anesthesiology, National Clinical Research Center for GeriatricsWest China Hospital of Sichuan UniversityChengduChina
- Laboratory of Mitochondria and Metabolism, National‐Local Joint Engineering Research Centre of Translational Medicine of AnesthesiologyWest China Hospital of Sichuan UniversityChengduChina
| | - Tao Li
- Department of Anesthesiology, National Clinical Research Center for GeriatricsWest China Hospital of Sichuan UniversityChengduChina
- Laboratory of Mitochondria and Metabolism, National‐Local Joint Engineering Research Centre of Translational Medicine of AnesthesiologyWest China Hospital of Sichuan UniversityChengduChina
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7
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Mogilski S, Kubacka M, Świerczek A, Wyska E, Szczepańska K, Sapa J, Kieć-Kononowicz K, Łażewska D. Efficacy of the Multi-Target Compound E153 in Relieving Pain and Pruritus of Different Origins. Pharmaceuticals (Basel) 2023; 16:1481. [PMID: 37895952 PMCID: PMC10609854 DOI: 10.3390/ph16101481] [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: 08/18/2023] [Revised: 10/04/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Itch and pain are closely related but distinct sensations that share largely overlapping mediators and receptors. We hypothesized that the novel, multi-target compound E153 has the potential to attenuate pain and pruritus of different origins. After the evaluation of sigma receptor affinity and pharmacokinetic studies, we tested the compound using different procedures and models of pain and pruritus. Additionally, we used pharmacological tools, such as PRE-084, RAMH, JNJ 5207852, and S1RA, to precisely determine the role of histamine H3 and sigma 1 receptors in the analgesic and antipruritic effects of the compound. In vitro studies revealed that the test compound had potent affinity for sigma 1 and sigma 2 receptors, moderate affinity for opioid kappa receptors, and no affinity for delta or μ receptors. Pharmacokinetic studies showed that after intraperitoneal administration, the compound was present at high concentrations in both the peripheral tissues and the central nervous system. The blood-brain barrier-penetrating properties indicate its ability to act centrally at the levels of the brain and spinal cord. Furthermore, the test compound attenuated different types of pain, including acute, inflammatory, and neuropathic. It also showed a broad spectrum of antipruritic activity, attenuating histamine-dependent and histamine-independent itching. Finally, we proved that antagonism of both sigma 1 and histamine H3 receptors is involved in the analgesic activity of the compound, while the antipruritic effect to a greater extent depends on sigma 1 antagonism.
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Affiliation(s)
- Szczepan Mogilski
- Department of Pharmacodynamics, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (M.K.); (J.S.)
| | - Monika Kubacka
- Department of Pharmacodynamics, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (M.K.); (J.S.)
| | - Artur Świerczek
- Department of Pharmacokinetics and Physical Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (A.Ś.); (E.W.)
| | - Elżbieta Wyska
- Department of Pharmacokinetics and Physical Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (A.Ś.); (E.W.)
| | - Katarzyna Szczepańska
- Department of Technology and Biotechnology of Drugs, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (K.S.); (K.K.-K.); (D.Ł.)
- Department of Medicinal Chemistry, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Jacek Sapa
- Department of Pharmacodynamics, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (M.K.); (J.S.)
| | - Katarzyna Kieć-Kononowicz
- Department of Technology and Biotechnology of Drugs, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (K.S.); (K.K.-K.); (D.Ł.)
| | - Dorota Łażewska
- Department of Technology and Biotechnology of Drugs, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (K.S.); (K.K.-K.); (D.Ł.)
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8
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Luedke KP, Yoshino J, Yin C, Jiang N, Huang JM, Huynh K, Parrish JZ. Dendrite intercalation between epidermal cells tunes nociceptor sensitivity to mechanical stimuli in Drosophila larvae. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.14.557275. [PMID: 37745567 PMCID: PMC10515945 DOI: 10.1101/2023.09.14.557275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
An animal's skin provides a first point of contact with the sensory environment, including noxious cues that elicit protective behavioral responses. Nociceptive somatosensory neurons densely innervate and intimately interact with epidermal cells to receive these cues, however the mechanisms by which epidermal interactions shape processing of noxious inputs is still poorly understood. Here, we identify a role for dendrite intercalation between epidermal cells in tuning sensitivity of Drosophila larvae to noxious mechanical stimuli. In wild-type larvae, dendrites of nociceptive class IV da neurons intercalate between epidermal cells at apodemes, which function as body wall muscle attachment sites, but not at other sites in the epidermis. From a genetic screen we identified miR-14 as a regulator of dendrite positioning in the epidermis: miR-14 is expressed broadly in the epidermis but not in apodemes, and miR-14 inactivation leads to excessive apical dendrite intercalation between epidermal cells. We found that miR-14 regulates expression and distribution of the epidermal Innexins ogre and Inx2 and that these epidermal gap junction proteins restrict epidermal dendrite intercalation. Finally, we found that altering the extent of epidermal dendrite intercalation had corresponding effects on nociception: increasing epidermal intercalation sensitized larvae to noxious mechanical inputs and increased mechanically evoked calcium responses in nociceptive neurons, whereas reducing epidermal dendrite intercalation had the opposite effects. Altogether, these studies identify epidermal dendrite intercalation as a mechanism for mechanical coupling of nociceptive neurons to the epidermis, with nociceptive sensitivity tuned by the extent of intercalation.
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Affiliation(s)
- Kory P. Luedke
- Department of Biology, University of Washington, Campus Box 351800, Seattle, WA 98195, USA
| | - Jiro Yoshino
- Department of Biology, University of Washington, Campus Box 351800, Seattle, WA 98195, USA
| | - Chang Yin
- Department of Biology, University of Washington, Campus Box 351800, Seattle, WA 98195, USA
| | - Nan Jiang
- Department of Biology, University of Washington, Campus Box 351800, Seattle, WA 98195, USA
| | - Jessica M. Huang
- Department of Biology, University of Washington, Campus Box 351800, Seattle, WA 98195, USA
| | - Kevin Huynh
- Department of Biology, University of Washington, Campus Box 351800, Seattle, WA 98195, USA
| | - Jay Z. Parrish
- Department of Biology, University of Washington, Campus Box 351800, Seattle, WA 98195, USA
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9
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Qi L, Iskols M, Shi D, Reddy P, Walker C, Lezgiyeva K, Voisin T, Pawlak M, Kuchroo VK, Chiu I, Ginty DD, Sharma N. A DRG genetic toolkit reveals molecular, morphological, and functional diversity of somatosensory neuron subtypes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.22.537932. [PMID: 37131664 PMCID: PMC10153270 DOI: 10.1101/2023.04.22.537932] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Mechanical and thermal stimuli acting on the skin are detected by morphologically and physiologically distinct sensory neurons of the dorsal root ganglia (DRG). Achieving a holistic view of how this diverse neuronal population relays sensory information from the skin to the central nervous system (CNS) has been challenging with existing tools. Here, we used transcriptomic datasets of the mouse DRG to guide development and curation of a genetic toolkit to interrogate transcriptionally defined DRG neuron subtypes. Morphological analysis revealed unique cutaneous axon arborization areas and branching patterns of each subtype. Physiological analysis showed that subtypes exhibit distinct thresholds and ranges of responses to mechanical and/or thermal stimuli. The somatosensory neuron toolbox thus enables comprehensive phenotyping of most principal sensory neuron subtypes. Moreover, our findings support a population coding scheme in which the activation thresholds of morphologically and physiologically distinct cutaneous DRG neuron subtypes tile multiple dimensions of stimulus space.
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Affiliation(s)
- Lijun Qi
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115
| | - Michael Iskols
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115
| | - David Shi
- Department of Molecular Pharmacology and Therapeutics, Department of Systems Biology, Columbia University, New York, NY
| | - Pranav Reddy
- Department of Molecular Pharmacology and Therapeutics, Department of Systems Biology, Columbia University, New York, NY
| | - Christopher Walker
- Department of Molecular Pharmacology and Therapeutics, Department of Systems Biology, Columbia University, New York, NY
| | - Karina Lezgiyeva
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115
| | - Tiphaine Voisin
- Department of Immunology, Harvard Medical School, Boston, MA 02115
| | - Mathias Pawlak
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Vijay K. Kuchroo
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Isaac Chiu
- Department of Immunology, Harvard Medical School, Boston, MA 02115
| | - David D. Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115
| | - Nikhil Sharma
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115
- Department of Molecular Pharmacology and Therapeutics, Department of Systems Biology, Columbia University, New York, NY
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10
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Kumar V, Kingsley D, Perikamana SM, Mogha P, Goodwin CR, Varghese S. Self-assembled innervated vasculature-on-a-chip to study nociception. Biofabrication 2023; 15:10.1088/1758-5090/acc904. [PMID: 36996841 PMCID: PMC10152403 DOI: 10.1088/1758-5090/acc904] [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: 10/30/2022] [Accepted: 03/30/2023] [Indexed: 04/01/2023]
Abstract
Nociceptor sensory neurons play a key role in eliciting pain. An active crosstalk between nociceptor neurons and the vascular system at the molecular and cellular level is required to sense and respond to noxious stimuli. Besides nociception, interaction between nociceptor neurons and vasculature also contributes to neurogenesis and angiogenesis.In vitromodels of innervated vasculature can greatly help delineate these roles while facilitating disease modeling and drug screening. Herein, we report the development of a microfluidic-assisted tissue model of nociception in the presence of microvasculature. The self-assembled innervated microvasculature was engineered using endothelial cells and primary dorsal root ganglion (DRG) neurons. The sensory neurons and the endothelial cells displayed distinct morphologies in presence of each other. The neurons exhibited an elevated response to capsaicin in the presence of vasculature. Concomitantly, increased transient receptor potential cation channel subfamily V member 1 (TRPV1) receptor expression was observed in the DRG neurons in presence of vascularization. Finally, we demonstrated the applicability of this platform for modeling nociception associated with tissue acidosis. While not demonstrated here, this platform could also serve as a tool to study pain resulting from vascular disorders while also paving the way towards the development of innervated microphysiological models.
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Affiliation(s)
- Vardhman Kumar
- Department of Biomedical Engineering, Duke University, Durham NC
| | - David Kingsley
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham NC
| | | | - Pankaj Mogha
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham NC
| | - C Rory Goodwin
- Department of Neurosurgery, Spine Division, Duke University Medical Center, Durham, NC
| | - Shyni Varghese
- Department of Biomedical Engineering, Duke University, Durham NC
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham NC
- Department of Mechanical Engineering and Material Science, Duke University, Durham NC
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11
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Moayedi Y, Xu S, Obayashi SK, Hoffman BU, Gerling GJ, Lumpkin EA. The cellular basis of mechanosensation in mammalian tongue. Cell Rep 2023; 42:112087. [PMID: 36763499 PMCID: PMC10409885 DOI: 10.1016/j.celrep.2023.112087] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 11/16/2022] [Accepted: 01/23/2023] [Indexed: 02/11/2023] Open
Abstract
Mechanosensory neurons that innervate the tongue provide essential information to guide feeding, speech, and social grooming. We use in vivo calcium imaging of mouse trigeminal ganglion neurons to identify functional groups of mechanosensory neurons innervating the anterior tongue. These sensory neurons respond to thermal and mechanical stimulation. Analysis of neuronal activity patterns reveal that most mechanosensory trigeminal neurons are tuned to detect moving stimuli across the tongue. Using an unbiased, multilayer hierarchical clustering approach to classify pressure-evoked activity based on temporal response dynamics, we identify five functional classes of mechanosensory neurons with distinct force-response relations and adaptation profiles. These populations are tuned to detect different features of touch. Molecular markers of functionally distinct clusters are identified by analyzing cluster representation in genetically marked neuronal subsets. Collectively, these studies provide a platform for defining the contributions of functionally distinct mechanosensory neurons to oral behaviors crucial for survival in mammals.
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Affiliation(s)
- Yalda Moayedi
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA; Department of Neurology, Columbia University, New York, NY 10032, USA; Department of Otolaryngology - Head & Neck Surgery, Columbia University, New York, NY 10032, USA
| | - Shan Xu
- School of Engineering and Applied Science, University of Virginia, Charlottesville, VA 22904, USA
| | - Sophie K Obayashi
- Department of Molecular & Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Benjamin U Hoffman
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA
| | - Gregory J Gerling
- School of Engineering and Applied Science, University of Virginia, Charlottesville, VA 22904, USA.
| | - Ellen A Lumpkin
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA; Department of Molecular & Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
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12
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Moradi Tuchayi S, Wang Y, Khodorova A, Pence IJ, Evans CL, Anderson RR, Lerner EA, Woolf CJ, Garibyan L. Cryoneurolysis with Injectable Ice Slurry Modulates Mechanical Skin Pain. J Invest Dermatol 2023; 143:134-141.e1. [PMID: 35985498 DOI: 10.1016/j.jid.2022.07.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/30/2022] [Accepted: 07/21/2022] [Indexed: 11/16/2022]
Abstract
Cutaneous pain is a common symptom of skin disease, and available therapies are inadequate. We developed a neural selective and injectable method of cryoneurolysis with ice slurry, which leads to a long-lasting decrease in mechanical pain. The aim of this study is to determine whether slurry injection reduces cutaneous pain without inducing the side effects associated with conventional cryoneurolysis. Using the rat sciatic nerve, we examined the effects of slurry on nerve structure and function in comparison with the effects of a Food and Drug Administration‒approved cryoneurolysis device (Iovera). Coherent anti-Stokes Raman scattering microscopy and immunofluorescence staining were used to investigate histological effects on the sciatic nerve and on downstream cutaneous nerve fibers. Complete Freund's Adjuvant model of cutaneous pain was used to study the effect of the slurry on reducing pain. Structural changes in myelin induced by slurry were comparable with those induced by Iovera, which uses much colder temperatures. Compared with that of Iovera, the decrease in mechanical pain due to slurry was less profound but lasted longer without signs of dysesthesia. Slurry did not cause a reduction of epidermal nerve fibers or a change in thermal pain sensitivity. Slurry-treated rats showed reduced cutaneous mechanical pain in response to Complete Freund's Adjuvant. Slurry injection can be used to successfully reduce cutaneous pain without causing dysesthesia.
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Affiliation(s)
- Sara Moradi Tuchayi
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA; Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
| | - Ying Wang
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA; Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
| | - Alla Khodorova
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA; Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
| | - Isaac J Pence
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA; Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
| | - Conor L Evans
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA; Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
| | - R Rox Anderson
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA; Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
| | - Ethan A Lerner
- Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA; Cutaneous Biology Research Center, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts, USA; Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Lilit Garibyan
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA; Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA.
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13
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Tsai NW, Lin CC, Yeh TY, Chiu YA, Chiu HH, Huang HP, Hsieh ST. An induced pluripotent stem cell-based model identifies molecular targets of vincristine neurotoxicity. Dis Model Mech 2022; 15:dmm049471. [PMID: 36518084 PMCID: PMC10655812 DOI: 10.1242/dmm.049471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 09/29/2022] [Indexed: 11/19/2023] Open
Abstract
To model peripheral nerve degeneration and investigate molecular mechanisms of neurodegeneration, we established a cell system of induced pluripotent stem cell (iPSC)-derived sensory neurons exposed to vincristine, a drug that frequently causes chemotherapy-induced peripheral neuropathy. Sensory neurons differentiated from iPSCs exhibit distinct neurochemical patterns according to the immunocytochemical phenotypes, and gene expression of peripherin (PRPH, hereafter referred to as Peri) and neurofilament heavy chain (NEFH, hereafter referred to as NF). The majority of iPSC-derived sensory neurons were PRPH positive/NEFH negative, i.e. Peri(+)/NF(-) neurons, whose somata were smaller than those of Peri(+)/NF(+) neurons. On exposure to vincristine, projections from the cell body of a neuron, i.e. neurites, were degenerated quicker than somata, the lethal concentration to kill 50% (LC50) of neurites being below the LC50 for somata, consistent with the clinical pattern of length-dependent neuropathy. We then examined the molecular expression in the MAP kinase signaling pathways of, extracellular signal-regulated kinases 1/2 (MAPK1/3, hereafter referred to as ERK), p38 mitogen-activated protein kinases (MAPK11/12/13/14, hereafter referred to as p38) and c-Jun N-terminal kinases (MAPK8/9/10, hereafter referred to as JNK). Regarding these three cascades, only phosphorylation of JNK was upregulated but not that of p38 or ERK1/2. Furthermore, vincristine-treatment resulted in impaired autophagy and reduced autophagic flux. Rapamycin-treatment reversed the effect of impaired autophagy and JNK activation. These results not only established a platform to study peripheral degeneration of human neurons but also provide molecular mechanisms for neurodegeneration with the potential for therapeutic targets.
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Affiliation(s)
- Neng-Wei Tsai
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
| | - Cheng-Chen Lin
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
| | - Ti-Yen Yeh
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
| | - Yu-An Chiu
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
| | - Hsin-Hui Chiu
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
| | - Hsiang-Po Huang
- Department of Medical Genomics and Proteomics, National Taiwan University College of Medicine, Taipei 100, Taiwan
- Department of Pediatrics, National Taiwan University Children's Hospital, Taipei 100, Taiwan
| | - Sung-Tsang Hsieh
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
- Department of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei 100, Taiwan
- Department of Neurology, National Taiwan University Hospital, Taipei 100, Taiwan
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14
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Bataille A, Le Gall C, Misery L, Talagas M. Merkel Cells Are Multimodal Sensory Cells: A Review of Study Methods. Cells 2022; 11:cells11233827. [PMID: 36497085 PMCID: PMC9737130 DOI: 10.3390/cells11233827] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 12/05/2022] Open
Abstract
Merkel cells (MCs) are rare multimodal epidermal sensory cells. Due to their interactions with slowly adapting type 1 (SA1) Aβ low-threshold mechanoreceptor (Aβ-LTMRs) afferents neurons to form Merkel complexes, they are considered to be part of the main tactile terminal organ involved in the light touch sensation. This function has been explored over time by ex vivo, in vivo, in vitro, and in silico approaches. Ex vivo studies have made it possible to characterize the topography, morphology, and cellular environment of these cells. The interactions of MCs with surrounding cells continue to be studied by ex vivo but also in vitro approaches. Indeed, in vitro models have improved the understanding of communication of MCs with other cells present in the skin at the cellular and molecular levels. As for in vivo methods, the sensory role of MC complexes can be demonstrated by observing physiological or pathological behavior after genetic modification in mouse models. In silico models are emerging and aim to elucidate the sensory coding mechanisms of these complexes. The different methods to study MC complexes presented in this review may allow the investigation of their involvement in other physiological and pathophysiological mechanisms, despite the difficulties in exploring these cells, in particular due to their rarity.
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Affiliation(s)
- Adeline Bataille
- LIEN—Laboratoire Interactions Epithélium Neurones, Brest University, F-29200 Brest, France
- Correspondence:
| | - Christelle Le Gall
- LIEN—Laboratoire Interactions Epithélium Neurones, Brest University, F-29200 Brest, France
- Department of Dermatology, Brest University Hospital, F-29200 Brest, France
| | - Laurent Misery
- LIEN—Laboratoire Interactions Epithélium Neurones, Brest University, F-29200 Brest, France
- Department of Dermatology, Brest University Hospital, F-29200 Brest, France
| | - Matthieu Talagas
- LIEN—Laboratoire Interactions Epithélium Neurones, Brest University, F-29200 Brest, France
- Department of Dermatology, Brest University Hospital, F-29200 Brest, France
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15
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Chirila AM, Rankin G, Tseng SY, Emanuel AJ, Chavez-Martinez CL, Zhang D, Harvey CD, Ginty DD. Mechanoreceptor signal convergence and transformation in the dorsal horn flexibly shape a diversity of outputs to the brain. Cell 2022; 185:4541-4559.e23. [PMID: 36334588 PMCID: PMC9691598 DOI: 10.1016/j.cell.2022.10.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/22/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022]
Abstract
The encoding of touch in the spinal cord dorsal horn (DH) and its influence on tactile representations in the brain are poorly understood. Using a range of mechanical stimuli applied to the skin, large-scale in vivo electrophysiological recordings, and genetic manipulations, here we show that neurons in the mouse spinal cord DH receive convergent inputs from both low- and high-threshold mechanoreceptor subtypes and exhibit one of six functionally distinct mechanical response profiles. Genetic disruption of DH feedforward or feedback inhibitory motifs, comprised of interneurons with distinct mechanical response profiles, revealed an extensively interconnected DH network that enables dynamic, flexible tuning of postsynaptic dorsal column (PSDC) output neurons and dictates how neurons in the primary somatosensory cortex respond to touch. Thus, mechanoreceptor subtype convergence and non-linear transformations at the earliest stage of the somatosensory hierarchy shape how touch of the skin is represented in the brain.
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Affiliation(s)
- Anda M Chirila
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Genelle Rankin
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Shih-Yi Tseng
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Alan J Emanuel
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Carmine L Chavez-Martinez
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Dawei Zhang
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Christopher D Harvey
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - David D Ginty
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
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16
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Chen L, Hu Y, Wang S, Cao K, Mai W, Sha W, Ma H, Zeng LH, Xu ZZ, Gao YJ, Duan S, Wang Y, Gao Z. mTOR-neuropeptide Y signaling sensitizes nociceptors to drive neuropathic pain. JCI Insight 2022; 7:159247. [PMID: 36194480 DOI: 10.1172/jci.insight.159247] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 09/29/2022] [Indexed: 12/15/2022] Open
Abstract
Neuropathic pain is a refractory condition that involves de novo protein synthesis in the nociceptive pathway. The mTOR is a master regulator of protein translation; however, mechanisms underlying its role in neuropathic pain remain elusive. Using the spared nerve injury-induced neuropathic pain model, we found that mTOR was preferentially activated in large-diameter dorsal root ganglion (DRG) neurons and spinal microglia. However, selective ablation of mTOR in DRG neurons, rather than microglia, alleviated acute neuropathic pain in mice. We show that injury-induced mTOR activation promoted the transcriptional induction of neuropeptide Y (Npy), likely via signal transducer and activator of transcription 3 phosphorylation. NPY further acted primarily on Y2 receptors (Y2R) to enhance neuronal excitability. Peripheral replenishment of NPY reversed pain alleviation upon mTOR removal, whereas Y2R antagonists prevented pain restoration. Our findings reveal an unexpected link between mTOR and NPY/Y2R in promoting nociceptor sensitization and neuropathic pain.
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Affiliation(s)
- Lunhao Chen
- Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yaling Hu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Siyuan Wang
- Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Kelei Cao
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Weihao Mai
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
| | - Weilin Sha
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong, China
| | - Huan Ma
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Ling-Hui Zeng
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Zhejiang University City College, Hangzhou, China
| | - Zhen-Zhong Xu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Yong-Jing Gao
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong, China
| | - Shumin Duan
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Yue Wang
- Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhihua Gao
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
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17
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Gong J, Chen J, Gu P, Shang Y, Ruppell KT, Yang Y, Wang F, Wen Q, Xiang Y. Shear stress activates nociceptors to drive Drosophila mechanical nociception. Neuron 2022; 110:3727-3742.e8. [PMID: 36087585 DOI: 10.1016/j.neuron.2022.08.015] [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: 09/23/2021] [Revised: 06/07/2022] [Accepted: 08/11/2022] [Indexed: 12/15/2022]
Abstract
Mechanical nociception is essential for animal survival. However, the forces involved in nociceptor activation and the underlying mechanotransduction mechanisms remain elusive. Here, we address these problems by investigating nocifensive behavior in Drosophila larvae. We show that strong poking stimulates nociceptors with a mixture of forces including shear stress and stretch. Unexpectedly, nociceptors are selectively activated by shear stress, but not stretch. Both the shear stress responses of nociceptors and nocifensive behavior require transient receptor potential A1 (TrpA1), which is specifically expressed in nociceptors. We further demonstrate that expression of mammalian or Drosophila TrpA1 in heterologous cells confers responses to shear stress but not stretch. Finally, shear stress activates TrpA1 in a membrane-delimited manner, through modulation of membrane fluidity. Together, our study reveals TrpA1 as an evolutionarily conserved mechanosensitive channel specifically activated by shear stress and suggests a critical role of shear stress in activating nociceptors to drive mechanical nociception.
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Affiliation(s)
- Jiaxin Gong
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jiazhang Chen
- Department of Physics, Worcester Polytechnic Institute, Worcester, MA 01605, USA
| | - Pengyu Gu
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ye Shang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA; Program in Neuroscience, Morningside Graduate School of Biomedical Sciences, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Kendra Takle Ruppell
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA; Program in Neuroscience, Morningside Graduate School of Biomedical Sciences, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ying Yang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Fei Wang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA; Program in Neuroscience, Morningside Graduate School of Biomedical Sciences, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Qi Wen
- Department of Physics, Worcester Polytechnic Institute, Worcester, MA 01605, USA.
| | - Yang Xiang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA; Program in Neuroscience, Morningside Graduate School of Biomedical Sciences, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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18
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Tsujimura T, Nakajima Y, Chotirungsan T, Kawada S, Tsutsui Y, Yoshihara M, Suzuki T, Nagoya K, Magara J, Inoue M. Inhibition of Water-Evoked Swallowing During Noxious Mechanical Stimulation of Tongue in Anesthetized Rats. Dysphagia 2022; 38:965-972. [PMID: 36127446 DOI: 10.1007/s00455-022-10522-5] [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: 01/11/2022] [Accepted: 09/11/2022] [Indexed: 11/30/2022]
Abstract
Dysphagia is sometimes accompanied by pain. Because orofacial structures subserve mastication and swallowing, orofacial pain might impair both functions. Tongue biting can occur not only accidentally while eating but also in some pathological conditions. However, it remains unclear whether noxious mechanical stimulation of the tongue affects swallowing. To explore this question, we evaluated the effects of lingual pinch stimulation on the initiation of swallowing evoked by distilled water (DW) infusion with a flow rate of 5.0 µL/s for 20 s into the pharyngolaryngeal region in anesthetized rats. The swallowing reflex was identified by electromyographic (EMG) bursts in the suprahyoid muscles which include the anterior belly of the digastric muscle, mylohyoid and geniohyoid muscles, and laryngeal elevation by visual inspection. The number of DW-evoked swallows during pinch stimulation was significantly smaller than that in a control condition or during pressure stimulation. The onset latency of the first swallow during pinch stimulation was significantly longer than that in the control condition. DW-evoked swallowing was almost abolished following bilateral transection of the superior laryngeal nerve (SLN) compared with the control condition, suggesting that the SLN plays a crucial role in the initiation of DW-evoked swallowing. Finally, electrophysiological data indicated that some SLN-responsive neurons in the nucleus tractus solitarii (nTS) exhibited delayed latency from a single SLN stimulation during lingual pinch stimulation. These results suggest that noxious mechanical stimulation of the tongue inhibits the initiation of swallowing and modulates neuronal activity in the nTS.
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Affiliation(s)
- Takanori Tsujimura
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan.
| | - Yuta Nakajima
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Titi Chotirungsan
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Satomi Kawada
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Yuhei Tsutsui
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Midori Yoshihara
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Taku Suzuki
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Kouta Nagoya
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Jin Magara
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Makoto Inoue
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
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19
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Mikesell AR, Isaeva O, Moehring F, Sadler KE, Menzel AD, Stucky CL. Keratinocyte PIEZO1 modulates cutaneous mechanosensation. eLife 2022; 11:65987. [PMID: 36053009 PMCID: PMC9512397 DOI: 10.7554/elife.65987] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 09/01/2022] [Indexed: 11/13/2022] Open
Abstract
Epidermal keratinocytes mediate touch sensation by detecting and encoding tactile information to sensory neurons. However, the specific mechanotransducers that enable keratinocytes to respond to mechanical stimulation are unknown. Here, we found that the mechanically-gated ion channel PIEZO1 is a key keratinocyte mechanotransducer. Keratinocyte expression of PIEZO1 is critical for normal sensory afferent firing and behavioral responses to mechanical stimuli in mice.
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Affiliation(s)
- Alexander R Mikesell
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Wauwatosa, United States
| | - Olena Isaeva
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, United States
| | - Francie Moehring
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, United States
| | - Katelyn E Sadler
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, United States
| | - Anthony D Menzel
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, United States
| | - Cheryl L Stucky
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, United States
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20
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Latragna A, Sabaté San José A, Tsimpos P, Vermeiren S, Gualdani R, Chakrabarti S, Callejo G, Desiderio S, Shomroni O, Sitte M, Kricha S, Luypaert M, Vanhollebeke B, Laumet G, Salinas G, Smith ESJ, Ris L, Bellefroid EJ. Prdm12 modulates pain-related behavior by remodeling gene expression in mature nociceptors. Pain 2022; 163:e927-e941. [PMID: 34961757 PMCID: PMC9341233 DOI: 10.1097/j.pain.0000000000002536] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 10/29/2021] [Accepted: 11/03/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT Prdm12 is a conserved epigenetic transcriptional regulator that displays restricted expression in nociceptors of the developing peripheral nervous system. In mice, Prdm12 is required for the development of the entire nociceptive lineage. In humans, PRDM12 mutations cause congenital insensitivity to pain, likely because of the loss of nociceptors. Prdm12 expression is maintained in mature nociceptors suggesting a yet-to-be explored functional role in adults. Using Prdm12 inducible conditional knockout mouse models, we report that in adult nociceptors Prdm12 is no longer required for cell survival but continues to play a role in the transcriptional control of a network of genes, many of them encoding ion channels and receptors. We found that disruption of Prdm12 alters the excitability of dorsal root ganglion neurons in culture. Phenotypically, we observed that mice lacking Prdm12 exhibit normal responses to thermal and mechanical nociceptive stimuli but a reduced response to capsaicin and hypersensitivity to formalin-induced inflammatory pain. Together, our data indicate that Prdm12 regulates pain-related behavior in a complex way by modulating gene expression in adult nociceptors and controlling their excitability. The results encourage further studies to assess the potential of Prdm12 as a target for analgesic development.
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Affiliation(s)
- Aurore Latragna
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, Belgium
- Laboratory of Neuroscience, UMONS Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
| | - Alba Sabaté San José
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Panagiotis Tsimpos
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Simon Vermeiren
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Roberta Gualdani
- Laboratory of Neuroscience, UMONS Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
| | | | - Gerard Callejo
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Simon Desiderio
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Orr Shomroni
- NGS Integrative Genomics, Department of Human Genetics at the University Medical Center Göttingen (UMG), Göttingen, Germany
| | - Maren Sitte
- NGS Integrative Genomics, Department of Human Genetics at the University Medical Center Göttingen (UMG), Göttingen, Germany
| | - Sadia Kricha
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Maëlle Luypaert
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Benoit Vanhollebeke
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Geoffroy Laumet
- Department of Physiology, Michigan State University, East Lansing, MI, United States
| | - Gabriela Salinas
- NGS Integrative Genomics, Department of Human Genetics at the University Medical Center Göttingen (UMG), Göttingen, Germany
| | - Ewan St. John Smith
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Laurence Ris
- Laboratory of Neuroscience, UMONS Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
| | - Eric J. Bellefroid
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Gosselies, Belgium
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21
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Bogdanova OV, Bogdanov VB, Pizano A, Bouvard M, Cazalets JR, Mellen N, Amestoy A. The Current View on the Paradox of Pain in Autism Spectrum Disorders. Front Psychiatry 2022; 13:910824. [PMID: 35935443 PMCID: PMC9352888 DOI: 10.3389/fpsyt.2022.910824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/17/2022] [Indexed: 01/18/2023] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder, which affects 1 in 44 children and may cause severe disabilities. Besides socio-communicational difficulties and repetitive behaviors, ASD also presents as atypical sensorimotor function and pain reactivity. While chronic pain is a frequent co-morbidity in autism, pain management in this population is often insufficient because of difficulties in pain evaluation, worsening their prognosis and perhaps driving higher mortality rates. Previous observations have tended to oversimplify the experience of pain in autism as being insensitive to painful stimuli. Various findings in the past 15 years have challenged and complicated this dogma. However, a relatively small number of studies investigates the physiological correlates of pain reactivity in ASD. We explore the possibility that atypical pain perception in people with ASD is mediated by alterations in pain perception, transmission, expression and modulation, and through interactions between these processes. These complex interactions may account for the great variability and sometimes contradictory findings from the studies. A growing body of evidence is challenging the idea of alterations in pain processing in ASD due to a single factor, and calls for an integrative view. We propose a model of the pain cycle that includes the interplay between the molecular and neurophysiological pathways of pain processing and it conscious appraisal that may interfere with pain reactivity and coping in autism. The role of social factors in pain-induced response is also discussed. Pain assessment in clinical care is mostly based on subjective rather than objective measures. This review clarifies the strong need for a consistent methodology, and describes innovative tools to cope with the heterogeneity of pain expression in ASD, enabling individualized assessment. Multiple measures, including self-reporting, informant reporting, clinician-assessed, and purely physiological metrics may provide more consistent results. An integrative view on the regulation of the pain cycle offers a more robust framework to characterize the experience of pain in autism.
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Affiliation(s)
- Olena V. Bogdanova
- CNRS, Aquitaine Institute for Cognitive and Integrative Neuroscience, INCIA, UMR 5287, Université de Bordeaux, Bordeaux, France
| | - Volodymyr B. Bogdanov
- Laboratoire EA 4136 – Handicap Activité Cognition Santé HACS, Collège Science de la Sante, Institut Universitaire des Sciences de la Réadaptation, Université de Bordeaux, Bordeaux, France
| | - Adrien Pizano
- CNRS, Aquitaine Institute for Cognitive and Integrative Neuroscience, INCIA, UMR 5287, Université de Bordeaux, Bordeaux, France
- Centre Hospitalier Charles-Perrens, Pôle Universitaire de Psychiatrie de l’Enfant et de l’Adolescent, Bordeaux, France
| | - Manuel Bouvard
- CNRS, Aquitaine Institute for Cognitive and Integrative Neuroscience, INCIA, UMR 5287, Université de Bordeaux, Bordeaux, France
- Centre Hospitalier Charles-Perrens, Pôle Universitaire de Psychiatrie de l’Enfant et de l’Adolescent, Bordeaux, France
| | - Jean-Rene Cazalets
- CNRS, Aquitaine Institute for Cognitive and Integrative Neuroscience, INCIA, UMR 5287, Université de Bordeaux, Bordeaux, France
| | - Nicholas Mellen
- Department of Neurology, University of Louisville, Louisville, KY, United States
| | - Anouck Amestoy
- CNRS, Aquitaine Institute for Cognitive and Integrative Neuroscience, INCIA, UMR 5287, Université de Bordeaux, Bordeaux, France
- Centre Hospitalier Charles-Perrens, Pôle Universitaire de Psychiatrie de l’Enfant et de l’Adolescent, Bordeaux, France
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22
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Wang CM, Green DP, Dong X. Transcription Factor MAFA Regulates Mechanical Sensation by Modulating Piezo2 Expression. Neurosci Bull 2022; 38:933-937. [PMID: 35585476 PMCID: PMC9352837 DOI: 10.1007/s12264-022-00879-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 03/17/2022] [Indexed: 11/30/2022] Open
Affiliation(s)
- Chang-Ming Wang
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Dustin P Green
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch, Galveston, TX, USA
| | - Xinzhong Dong
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Howard Hughes Medical Institute, Chevy Chase, MD, USA.
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23
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Fujimori K, Sekine M, Watanabe M, Tashima R, Tozaki-Saitoh H, Tsuda M. Chemogenetic silencing of spinal cord-projecting cortical neurons attenuates Aβ fiber-derived neuropathic allodynia in mice. Neurosci Res 2022; 181:115-119. [DOI: 10.1016/j.neures.2022.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 04/27/2022] [Accepted: 05/02/2022] [Indexed: 11/27/2022]
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24
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Reyes-Pardo H, Sánchez-Herrera DP, Santillan M. On the effects of diabetes mellitus on the mechanical properties of DRG sensory neurons and their possible relation with diabetic neuropathy. Phys Biol 2022; 19. [PMID: 35417901 DOI: 10.1088/1478-3975/ac6722] [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: 11/24/2021] [Accepted: 04/13/2022] [Indexed: 11/12/2022]
Abstract
Diabetic neuropathy (DN) is one of the principal complications of diabetes mellitus (DM). Dorsal root ganglion (DRG) neurons are the primary sensory neurons that transduce mechanical, chemical, thermal, and pain stimuli. Diabetes-caused sensitivity alterations and presence of pain are due to cellular damage originated by persistent hyperglycemia, microvascular insufficiency, and oxidative and nitrosative stress. However, the underlying mechanisms have not been fully clarified. The present work addresses this problem by hypothesizing that sensitivity changes in DN result from mechanotransduction-system alterations in sensory neurons; especially, plasma membrane affectations. This hypothesis is tackled by means of elastic-deformation experiments performed on DGR neurons from a murine model for type-1 DM, as well a mathematical model of the cell mechanical structure. The obtained results suggest that the plasma-membrane fluidity of DRG sensory neurons is modified by the induction of DM, and that this alteration may correlate with changes in the cell calcium transient that results from mechanical stimuli.
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Affiliation(s)
- Humberto Reyes-Pardo
- School of Engineering and Sciences, Tecnologico de Monterrey, Av. Eugenio Garza Sada, Monterrey, Nuevo Leon, 64849, MEXICO
| | - Daniel P Sánchez-Herrera
- Via del Conocimiento 201, Centro de Investigación y de Estudios Avanzados Unidad Monterrey, Parque PIIT, Apodaca, Nuevo León, 66628, MEXICO
| | - Moises Santillan
- Via del Conocimiento 201, Centro de Investigación y de Estudios Avanzados Unidad Monterrey, Parque PIIT, Apodaca, Nuevo León, 66628, MEXICO
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25
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Ma Q. A functional subdivision within the somatosensory system and its implications for pain research. Neuron 2022; 110:749-769. [PMID: 35016037 PMCID: PMC8897275 DOI: 10.1016/j.neuron.2021.12.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 10/07/2021] [Accepted: 12/09/2021] [Indexed: 12/12/2022]
Abstract
Somatosensory afferents are traditionally classified by soma size, myelination, and their response specificity to external and internal stimuli. Here, we propose the functional subdivision of the nociceptive somatosensory system into two branches. The exteroceptive branch detects external threats and drives reflexive-defensive reactions to prevent or limit injury. The interoceptive branch senses the disruption of body integrity, produces tonic pain with strong aversive emotional components, and drives self-caring responses toward to the injured region to reduce suffering. The central thesis behind this functional subdivision comes from a reflection on the dilemma faced by the pain research field, namely, the use of reflexive-defensive behaviors as surrogate assays for interoceptive tonic pain. The interpretation of these assays is now being challenged by the discovery of distinct but interwoven circuits that drive exteroceptive versus interoceptive types of behaviors, with the conflation of these two components contributing partially to the poor translation of therapies from preclinical studies.
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Affiliation(s)
- Qiufu Ma
- Dana-Farber Cancer Institute and Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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26
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Hoffmann T, Klemm F, I Kichko T, Sauer SK, Kistner K, Riedl B, Raboisson P, Luo L, Babes A, Kocher L, Carli G, Fischer MJM, Reeh PW. The formalin test does not probe inflammatory pain but excitotoxicity in rodent skin. Physiol Rep 2022; 10:e15194. [PMID: 35340127 PMCID: PMC8957662 DOI: 10.14814/phy2.15194] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/19/2022] [Accepted: 01/24/2022] [Indexed: 01/21/2023] Open
Abstract
The most widely used formalin test to screen antinociceptive drug candidates is still apostrophized as targeting inflammatory pain, in spite of strong opposing evidence published. In our rat skin-nerve preparation ex vivo, recording from all classes of sensory single-fibers (n = 32), 30 units were transiently excited by formaldehyde concentrations 1-100 mM applied to receptive fields (RFs) for 3 min, C and Aδ-fibers being more sensitive (1-30 mM) than Aβ-fibers. From 30 mM on, ~1% of the concentration usually injected in vivo, all RFs were defunctionalized and conduction in an isolated sciatic nerve preparation was irreversibly blocked. Thus, formaldehyde, generated a state of 'anesthesia dolorosa' in the RFs in so far as after a quiescent interphase all fibers with unmyelinated terminals developed a second phase of vigorous discharge activity which correlated well in time course and magnitude with published pain-related behaviors. Sural nerve filament recordings in vivo confirmed that higher formalin concentrations (> 42 mM) have to be injected to the skin to induce this second phase of discharge. Patch-clamp and calcium-imaging confirmed TRPA1 as the primary transducer of formaldehyde (10 mM) effects on mouse sensory neurons. However, stimulated CGRP release from isolated skin of TRPA1+/+ and TRPA1-/- mice showed a convergence of the saturating concentration-response curves at 100 mM formaldehyde, which did not occur with nerve and trachea preparations. Finally, skin-nerve recordings from C and Aδ-fibers of TRPA1-/- mice revealed a massive reduction in formaldehyde (30 mM)-evoked discharge. However, the remaining activity was still biphasic, thus confirming additional unspecific excitotoxic actions of the fixative that diffuses along still excitable axons as previously published. The multiplicity of formaldehyde's actions requires extensive discussion and literature review, leading to a fundamental reevaluation of the formalin test.
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Affiliation(s)
- Tal Hoffmann
- Institute of Physiology and PathophysiologyUniversity of Erlangen‐NürnbergErlangenGermany
| | - Florian Klemm
- Institute of Physiology and PathophysiologyUniversity of HeidelbergHeidelbergGermany
| | - Tatjana I Kichko
- Institute of Physiology and PathophysiologyUniversity of Erlangen‐NürnbergErlangenGermany
| | - Susanne K Sauer
- Institute of Physiology and PathophysiologyUniversity of Erlangen‐NürnbergErlangenGermany
| | - Katrin Kistner
- Institute of Physiology and PathophysiologyUniversity of Erlangen‐NürnbergErlangenGermany
| | - Bernhard Riedl
- Institute of Physiology and PathophysiologyUniversity of Erlangen‐NürnbergErlangenGermany
| | | | - Lei Luo
- AstraZeneca, CNS and Pain Innovative Medicines UnitSödertäljeSweden
| | - Alexandru Babes
- Institute of Physiology and PathophysiologyUniversity of Erlangen‐NürnbergErlangenGermany
- Department of Anatomy, Physiology and BiophysicsUniversity of BucharestBucharestRomania
| | - Laurence Kocher
- Institute of Physiology and PathophysiologyUniversity of HeidelbergHeidelbergGermany
- Laboratoire de PhysiologieCentre Hospitalier Lyon SudFaculté de MédecineUniversité de LyonFrance
| | - Giancarlo Carli
- Institute of Physiology and PathophysiologyUniversity of HeidelbergHeidelbergGermany
- Department of PhysiologyUniversità degli Studi di SienaSienaItaly
| | - Michael J. M. Fischer
- Institute of Physiology and PathophysiologyUniversity of Erlangen‐NürnbergErlangenGermany
- Center of Physiology and PharmacologyMedical University of ViennaViennaAustria
| | - Peter W. Reeh
- Institute of Physiology and PathophysiologyUniversity of Erlangen‐NürnbergErlangenGermany
- Institute of Physiology and PathophysiologyUniversity of HeidelbergHeidelbergGermany
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27
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Weng L, Peerdeman KJ, Della Porta D, van Laarhoven AIM, Evers AWM. Can placebo and nocebo effects generalize within pain modalities and across somatosensory sensations? Pain 2022; 163:548-559. [PMID: 34232926 DOI: 10.1097/j.pain.0000000000002390] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 06/23/2021] [Indexed: 11/27/2022]
Abstract
Pain and other somatosensory sensations, such as itch, can be effectively decreased by placebo effects and increased by nocebo effects. There are indications that placebo effects on pain generalize to other sensations and that nocebo effects generalize within itch modalities. However, it has not yet been investigated whether learned effects can generalize within pain stimulus modalities or from pain to itch. Our aims were to test whether placebo and nocebo effects can generalize within pain modalities, ie, from heat pain to pressure pain, and across somatosensory sensations with psychophysiological similarities, ie, from heat pain to cowhage-evoked itch. For this purpose, 65 healthy participants were randomized to either a placebo or nocebo group. All participants first underwent a conditioning and verbal suggestion procedure with heat pain stimuli. Subsequently, responses to heat pain, pressure pain, and cowhage-evoked itch stimuli were tested. Results showed altered levels of heat and pressure pain with the conditioned cue in both placebo and nocebo groups in the expected directions, but no significant difference in itch in both groups. In conclusion, placebo and nocebo effects on pain may generalize within but not across stimulus modalities. This study provides a novel perspective on the role that response generalization plays in physical symptoms.
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Affiliation(s)
- Lingling Weng
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition (LIBC), Leiden University, Leiden, the Netherlands
| | - Kaya J Peerdeman
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition (LIBC), Leiden University, Leiden, the Netherlands
| | - Delia Della Porta
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, the Netherlands
| | - Antoinette I M van Laarhoven
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition (LIBC), Leiden University, Leiden, the Netherlands
| | - Andrea W M Evers
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition (LIBC), Leiden University, Leiden, the Netherlands
- Department of Psychiatry, Leiden University Medical Center, Leiden, the Netherlands
- Medical Delta, Leiden University, Technical University Delft, Rotterdam University, the Netherlands
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28
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Taghizadeh B, Jaafari MR, Zarghami N. New insight into the importance of formulation variables on parenteral growth hormone preparations: potential effect on the injection-site pain. Front Endocrinol (Lausanne) 2022; 13:963336. [PMID: 36263321 PMCID: PMC9576007 DOI: 10.3389/fendo.2022.963336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/16/2022] [Indexed: 11/16/2022] Open
Abstract
Reducing injection-site pain (ISP) in patients with chronic conditions such as growth hormone deficiency is a valuable strategy to improve patient compliance and therapeutic efficiency. Thus understanding different aspects of pain induction following subcutaneous injection of biotherapeutics and identifying the responsible factors are vital. Here we have discussed the effects of formulation's viscosity, concentration, osmolality, buffering agents, pH, and temperature as well as injection volume, dosing frequency, and different excipients on ISP following subcutaneous injection of commercially available recombinant human growth hormone products. Our literature review found limited available data on the effects of different components of parenteral rhGH products on ISP. This may be due to high cost associated with conducting various clinical trials to assess each excipient in the formulation or to determine the complex interactions of different components and its impact on ISP. Recently, conducting molecular dynamics simulation studies before formulation design has been recommended as an alternative and less-expensive approach. On the other hand, the observed inconsistencies in the available data is mainly due to different pain measurement approaches used in each study. Moreover, it is difficult to translate data obtained from animal studies to human subjects. Despite all these limitations, our investigation showed that components of parenteral rhGH products can significantly contribute to ISP. We suggest further investigation is required for development of long acting, buffer-free, preservative-free formulations. Besides, various excipients are currently being investigated for reducing ISP which can be used as alternatives for common buffers, surfactants or preservatives in designing future rhGH formulations.
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Affiliation(s)
- Bita Taghizadeh
- Department of Medical Biotechnology, School of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahmoud Reza Jaafari
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
- Department of Pharmaceutical Nanotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Nosratollah Zarghami
- Department of Medical Biotechnology, School of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Clinical Biochemistry and Laboratory Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
- *Correspondence: Nosratollah Zarghami,
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29
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Vincent-Dospital T, Toussaint R, Måløy KJ. Heat Emitting Damage in Skin: A Thermal Pathway for Mechanical Algesia. Front Neurosci 2021; 15:780623. [PMID: 34776861 PMCID: PMC8581405 DOI: 10.3389/fnins.2021.780623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 10/05/2021] [Indexed: 12/03/2022] Open
Abstract
Mechanical pain (or mechanical algesia) can both be a vital mechanism warning us for dangers or an undesired medical symptom important to mitigate. Thus, a comprehensive understanding of the different mechanisms responsible for this type of pain is paramount. In this work, we study the tearing of porcine skin in front of an infrared camera, and show that mechanical injuries in biological tissues can generate enough heat to stimulate the neural network. In particular, we report local temperature elevations of up to 24°C around fast cutaneous ruptures, which shall exceed the threshold of the neural nociceptors usually involved in thermal pain. Slower fractures exhibit lower temperature elevations, and we characterise such dependency to the damaging rate. Overall, we bring experimental evidence of a novel—thermal—pathway for direct mechanical algesia. In addition, the implications of this pathway are discussed for mechanical hyperalgesia, in which a role of the cutaneous thermal sensors has priorly been suspected. We also show that thermal dissipation shall actually account for a significant portion of the total skin's fracture energy, making temperature monitoring an efficient way to detect biological damages.
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Affiliation(s)
- Tom Vincent-Dospital
- SFF Porelab, The Njord Centre, Department of Physics, University of Oslo, Oslo, Norway
| | - Renaud Toussaint
- SFF Porelab, The Njord Centre, Department of Physics, University of Oslo, Oslo, Norway.,Université de Strasbourg, CNRS, Institut Terre & Environnement de Strasbourg, UMR 7063, Strasbourg, France
| | - Knut Jørgen Måløy
- SFF Porelab, The Njord Centre, Department of Physics, University of Oslo, Oslo, Norway
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30
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Shin SM, Moehring F, Itson-Zoske B, Fan F, Stucky CL, Hogan QH, Yu H. Piezo2 mechanosensitive ion channel is located to sensory neurons and nonneuronal cells in rat peripheral sensory pathway: implications in pain. Pain 2021; 162:2750-2768. [PMID: 34285153 PMCID: PMC8526381 DOI: 10.1097/j.pain.0000000000002356] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 05/18/2021] [Indexed: 11/25/2022]
Abstract
ABSTRACT Piezo2 mechanotransduction channel is a crucial mediator of sensory neurons for sensing and transducing touch, vibration, and proprioception. We here characterized Piezo2 expression and cell specificity in rat peripheral sensory pathway using a validated Piezo2 antibody. Immunohistochemistry using this antibody revealed Piezo2 expression in pan primary sensory neurons of dorsal root ganglia in naïve rats, which was actively transported along afferent axons to both central presynaptic terminals innervating the spinal dorsal horn (DH) and peripheral afferent terminals in the skin. Piezo2 immunoreactivity (IR) was also detected in the postsynaptic neurons of the DH and in the motor neurons of the ventral horn, but not in spinal glial fibrillary acidic protein-positive and Iba1-positive glia. Notably, Piezo2-IR was clearly identified in peripheral nonneuronal cells, including perineuronal glia, Schwann cells in the sciatic nerve and surrounding cutaneous afferent endings, as well as in skin epidermal Merkel cells and melanocytes. Immunoblots showed increased Piezo2 in dorsal root ganglia ipsilateral to plantar injection of complete Freund's adjuvant, and immunostaining revealed increased Piezo2-IR intensity in the DH ipsilateral to complete Freund's adjuvant injection. This elevation of DH Piezo2-IR was also evident in various neuropathic pain models and monosodium iodoacetate knee osteoarthritis pain model, compared with controls. We conclude that (1) the pan neuronal profile of Piezo2 expression suggests that Piezo2 may function extend beyond simply touch or proprioception mediated by large-sized low-threshold mechanosensitive primary sensory neurons; (2) Piezo2 may have functional roles involving sensory processing in the spinal cord, Schwann cells, and skin melanocytes; and (3) aberrant Piezo2 expression may contribute pain pathogenesis.
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Affiliation(s)
- Seung Min Shin
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Francie Moehring
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Brandon Itson-Zoske
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Fan Fan
- Department of Pharmacology and Toxicology, Mississippi University Medical Center, Jackson, Mississippi 39216
| | - Cheryl L. Stucky
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Quinn H. Hogan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226
- Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin 53295
| | - Hongwei Yu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226
- Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin 53295
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31
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Ducza L, Szücs P, Hegedűs K, Bakk E, Gajtkó A, Wéber I, Holló K. NLRP2 Is Overexpressed in Spinal Astrocytes at the Peak of Mechanical Pain Sensitivity during Complete Freund Adjuvant-Induced Persistent Pain. Int J Mol Sci 2021; 22:ijms222111408. [PMID: 34768839 PMCID: PMC8584130 DOI: 10.3390/ijms222111408] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/09/2021] [Accepted: 10/17/2021] [Indexed: 12/15/2022] Open
Abstract
Our earlier findings revealed that interleukin-1 receptor type-1 (IL-1R1) was overexpressed in spinal neurons, and IL-1R1-deficient mice showed significant attenuation of thermal and mechanical allodynia during the course of the Complete Freund adjuvant (CFA)-induced persistent pain model. In the present study, we found that a ligand of IL-1R1, termed interleukin-1β (IL-1β), is also significantly overexpressed at the peak of mechanical pain sensitivity in the CFA-evoked pain model. Analysis of cellular distribution and modeling using IMARIS software showed that in the lumbar spinal dorsal horn, IL-1β is significantly elevated by astrocytic expression. Maturation of IL-1β to its active form is facilitated by the formation of the multiprotein complex called inflammasome; thus, we tested the expression of NOD-like receptor proteins (NLRPs) in astrocytes. At the peak of mechanical allodynia, we found expression of the NLRP2 inflammasome sensor and its significantly elevated co-localization with the GFAP astrocytic marker, while NLRP3 was moderately present and NLRP1 showed total segregation from the astrocytic profiles. Our results indicate that peripheral CFA injection induces NLRP2 inflammasome and IL-1β expression in spinal astrocytes. The release of mature IL-1β can contribute to the maintenance of persistent pain by acting on its neuronally expressed receptor, which can lead to altered neuronal excitability.
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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.
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Wimalasena NK, Milner G, Silva R, Vuong C, Zhang Z, Bautista DM, Woolf CJ. Dissecting the precise nature of itch-evoked scratching. Neuron 2021; 109:3075-3087.e2. [PMID: 34411514 PMCID: PMC8497439 DOI: 10.1016/j.neuron.2021.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 06/10/2021] [Accepted: 07/26/2021] [Indexed: 01/17/2023]
Abstract
Itch is a discrete and irritating sensation tightly coupled to a drive to scratch. Acute scratching developed evolutionarily as an adaptive defense against skin irritants, pathogens, or parasites. In contrast, the itch-scratch cycle in chronic itch is harmful, inducing escalating itch and skin damage. Clinically and preclinically, scratching incidence is currently evaluated as a unidimensional motor parameter and believed to reflect itch severity. We propose that scratching, when appreciated as a complex, multidimensional motor behavior, will yield greater insight into the nature of itch and the organization of neural circuits driving repetitive motor patterns. We outline the limitations of standard measurements of scratching in rodent models and present new approaches to observe and quantify itch-evoked scratching. We argue that accurate quantitative measurements of scratching are critical for dissecting the molecular, cellular, and circuit mechanisms underlying itch and for preclinical development of therapeutic interventions for acute and chronic itch disorders.
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Affiliation(s)
- Nivanthika K Wimalasena
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - George Milner
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Ricardo Silva
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Cliff Vuong
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Zihe Zhang
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Diana M Bautista
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Hellen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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Handler A, Ginty DD. The mechanosensory neurons of touch and their mechanisms of activation. Nat Rev Neurosci 2021; 22:521-537. [PMID: 34312536 PMCID: PMC8485761 DOI: 10.1038/s41583-021-00489-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2021] [Indexed: 02/07/2023]
Abstract
Our sense of touch emerges from an array of mechanosensory structures residing within the fabric of our skin. These tactile end organ structures convert innocuous forces acting on the skin into electrical signals that propagate to the CNS via the axons of low-threshold mechanoreceptors (LTMRs). Our rich capacity for tactile discrimination arises from the dissimilar intrinsic properties of the LTMR subtypes that innervate different regions of the skin and the structurally distinct end organ complexes with which they associate. These end organ structures comprise a range of non-neuronal cell types, which may themselves actively contribute to the transformation of tactile forces into neural impulses within the LTMR afferents. Although the mechanism and the site of transduction across end organs remain unclear, PIEZO2 has emerged as the principal mechanosensitive channel involved in light touch of the skin. Here we review the physiological properties of LTMR subtypes and discuss how features of their cutaneous end organ complexes shape subtype-specific tuning.
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Affiliation(s)
- Annie Handler
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
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Luo X, Chen O, Wang Z, Bang S, Ji J, Lee SH, Huh Y, Furutani K, He Q, Tao X, Ko MC, Bortsov A, Donnelly CR, Chen Y, Nackley A, Berta T, Ji RR. IL-23/IL-17A/TRPV1 axis produces mechanical pain via macrophage-sensory neuron crosstalk in female mice. Neuron 2021; 109:2691-2706.e5. [PMID: 34473953 DOI: 10.1016/j.neuron.2021.06.015] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/16/2021] [Accepted: 06/14/2021] [Indexed: 12/16/2022]
Abstract
Although sex dimorphism is increasingly recognized as an important factor in pain, female-specific pain signaling is not well studied. Here we report that administration of IL-23 produces mechanical pain (mechanical allodynia) in female but not male mice, and chemotherapy-induced mechanical pain is selectively impaired in female mice lacking Il23 or Il23r. IL-23-induced pain is promoted by estrogen but suppressed by androgen, suggesting an involvement of sex hormones. IL-23 requires C-fiber nociceptors and TRPV1 to produce pain but does not directly activate nociceptor neurons. Notably, IL-23 requires IL-17A release from macrophages to evoke mechanical pain in females. Low-dose IL-17A directly activates nociceptors and induces mechanical pain only in females. Finally, deletion of estrogen receptor subunit α (ERα) in TRPV1+ nociceptors abolishes IL-23- and IL-17-induced pain in females. These findings demonstrate that the IL-23/IL-17A/TRPV1 axis regulates female-specific mechanical pain via neuro-immune interactions. Our study also reveals sex dimorphism at both immune and neuronal levels.
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Affiliation(s)
- Xin Luo
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA.
| | - Ouyang Chen
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC, USA
| | - Zilong Wang
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Sangsu Bang
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Jasmine Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Sang Hoon Lee
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Yul Huh
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC, USA
| | - Kenta Furutani
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Qianru He
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Xueshu Tao
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Mei-Chuan Ko
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Andrey Bortsov
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Christopher R Donnelly
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Yong Chen
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Andrea Nackley
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA; Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA
| | - Temugin Berta
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.
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Yoshida S, Funato H. Physical contact in parent-infant relationship and its effect on fostering a feeling of safety. iScience 2021; 24:102721. [PMID: 34235413 PMCID: PMC8250458 DOI: 10.1016/j.isci.2021.102721] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The infant-caregiver relationship involves physical contact for feeding, moving, and other cares, and such contact also encourages the infant to form an attachment, an emotional bond with the caregivers. Physical contact always accompanies somatosensory perception, which is detected by mechanosensory neurons and processed in the brain. Physical contact triggers sensorimotor reflexes such as Transport Response in rodent infants, and calm human infants while being carried. Tactile sensation and deep pressure in physical interactions, such as hugging, can function as emotional communication between infant and caregiver, which can alter the behavior and mood of both the infant and caregiver. This review summarizes the findings related to physical contact between the infant and the caregiver in terms of pleasant, noxious, and neutral somatosensation and discusses how somatosensory perceptions foster a feeling of safety that is important for infant's psychosocial development.
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Affiliation(s)
- Sachine Yoshida
- Department of Anatomy, Faculty of Medicine, Toho University, Ota-ku, Tokyo 143-8540, Japan
| | - Hiromasa Funato
- Department of Anatomy, Faculty of Medicine, Toho University, Ota-ku, Tokyo 143-8540, Japan
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
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Chen L, Wang X, Zhang X, Wan H, Su Y, He W, Xie Y, Jing X. Electroacupuncture and Moxibustion-Like Stimulation Relieves Inflammatory Muscle Pain by Activating Local Distinct Layer Somatosensory Afferent Fibers. Front Neurosci 2021; 15:695152. [PMID: 34335169 PMCID: PMC8319633 DOI: 10.3389/fnins.2021.695152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/07/2021] [Indexed: 11/23/2022] Open
Abstract
Recent studies have shown that both superficial and deep acupuncture produced clinically relevant and persistent effect on chronic pain, and several subtypes of somatic primary afferents played critical roles in acupuncture and moxibustion analgesia. However, which kind of primary afferents in the superficial and deep tissue of the acupoint is activated by acupuncture or moxibustion to relieve pain persistently remains unclear. The aim of this study is to investigate the roles of distinct peripheral afferents in different layers of the tissue (muscle or skin) in the acupoint for pain relief. Muscular A-fibers activated by deep electroacupuncture (dEA) with lower intensity (approximately 1 mA) persistently alleviated inflammatory muscle pain. Meanwhile, cutaneous C-nociceptors excited by noxious moxibustion-like stimulation (MS) and topical application of capsaicin (CAP) on local acupoint area produced durable analgesic effect. Additionally, spontaneous activity of C-fibers caused by muscular inflammation was also inhibited by dEA and CAP. Furthermore, decreases in pain behavior induced by dEA disappeared after deep A-fibers were demyelinated by cobra venom, whereas CAP failed to relieve pain following cutaneous denervation. Collectively, these results indicate that dEA and MS ameliorate inflammatory muscle pain through distinct primary afferents in different layers of somatic tissue; the former is achieved by activating muscular A-fibers, while the latter is mediated by activating cutaneous C-fibers.
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Affiliation(s)
- Lizhen Chen
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaoyu Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaoning Zhang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Hongye Wan
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yangshuai Su
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Wei He
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yikuan Xie
- School of Basic Medicine, Peking Union Medical College, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing, China
| | - Xianghong Jing
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
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Key B, Zalucki O, Brown DJ. Neural Design Principles for Subjective Experience: Implications for Insects. Front Behav Neurosci 2021; 15:658037. [PMID: 34025371 PMCID: PMC8131515 DOI: 10.3389/fnbeh.2021.658037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/07/2021] [Indexed: 02/04/2023] Open
Abstract
How subjective experience is realized in nervous systems remains one of the great challenges in the natural sciences. An answer to this question should resolve debate about which animals are capable of subjective experience. We contend that subjective experience of sensory stimuli is dependent on the brain's awareness of its internal neural processing of these stimuli. This premise is supported by empirical evidence demonstrating that disruption to either processing streams or awareness states perturb subjective experience. Given that the brain must predict the nature of sensory stimuli, we reason that conscious awareness is itself dependent on predictions generated by hierarchically organized forward models of the organism's internal sensory processing. The operation of these forward models requires a specialized neural architecture and hence any nervous system lacking this architecture is unable to subjectively experience sensory stimuli. This approach removes difficulties associated with extrapolations from behavioral and brain homologies typically employed in addressing whether an animal can feel. Using nociception as a model sensation, we show here that the Drosophila brain lacks the required internal neural connectivity to implement the computations required of hierarchical forward models. Consequently, we conclude that Drosophila, and those insects with similar neuroanatomy, do not subjectively experience noxious stimuli and therefore cannot feel pain.
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Affiliation(s)
- Brian Key
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Oressia Zalucki
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Deborah J. Brown
- School of Historical and Philosophical Inquiry, The University of Queensland, Brisbane, QLD, Australia
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Shi GH, Pisupati K, Parker JG, Corvari VJ, Payne CD, Xu W, Collins DS, De Felippis MR. Subcutaneous Injection Site Pain of Formulation Matrices. Pharm Res 2021; 38:779-793. [PMID: 33942212 DOI: 10.1007/s11095-021-03047-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 04/21/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE The objective of this work was to systematically evaluate the effects of formulation composition on subcutaneous injection site pain (ISP) using matrices comprising of common pharmaceutical excipients. METHODS Two randomized, blinded, crossover studies in healthy subjects were conducted at a single site, where subjects received 1 mL SC injections of the buffer matrices. ISP intensity was measured using a 100 mm visual analogue scale (VAS), which was then analyzed via heatmap, categorical grouping, subgroup analysis, and paired delta analysis. RESULTS Buffer type, buffer concentration and tonicity agent showed a substantial impact on ISP. Citrate buffer demonstrated a higher ISP than acetate buffer or saline). The 20 mM citrate buffer was more painful than 10 or 5 mM citrate buffers. NaCl and propylene glycol were significantly more painful than sugar alcohols (mannitol, sucrose, trehalose or glycerol). Histidine buffers exhibited ISP in the descending order of 150 mM > 75 mM > 25 mM > 0 mM NaCl, while histidine buffers containing Arginine-HCl at 0, 50, or 150 mM all showed very low ISP. Histidine buffer at pH 6.5 showed a lower ISP than pH 5.7. CONCLUSIONS This systematic study via orthogonal analyses demonstrated that subcutaneous ISP is significantly influenced by solution composition.
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Affiliation(s)
- Galen H Shi
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana, 46285, USA
| | - Karthik Pisupati
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana, 46285, USA
| | - Jonathan G Parker
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana, 46285, USA
| | - Vincent J Corvari
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana, 46285, USA.
| | - Christopher D Payne
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana, 46285, USA
| | - Wen Xu
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana, 46285, USA
| | - David S Collins
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana, 46285, USA
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Burand AJ, Stucky CL. Fabry disease pain: patient and preclinical parallels. Pain 2021; 162:1305-1321. [PMID: 33259456 PMCID: PMC8054551 DOI: 10.1097/j.pain.0000000000002152] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/31/2020] [Accepted: 11/18/2020] [Indexed: 02/07/2023]
Abstract
ABSTRACT Severe neuropathic pain is a hallmark of Fabry disease, a genetic disorder caused by a deficiency in lysosomal α-galactosidase A. Pain experienced by these patients significantly impacts their quality of life and ability to perform everyday tasks. Patients with Fabry disease suffer from peripheral neuropathy, sensory abnormalities, acute pain crises, and lifelong ongoing pain. Although treatment of pain through medication and enzyme replacement therapy exists, pain persists in many of these patients. Some has been learned in the past decades regarding clinical manifestations of pain in Fabry disease and the pathological effects of α-galactosidase A insufficiency in neurons. Still, it is unclear how pain and sensory abnormalities arise in patients with Fabry disease and how these can be targeted with therapeutics. Our knowledge is limited in part due to the lack of adequate preclinical models to study the disease. This review will detail the types of pain, sensory abnormalities, influence of demographics on pain, and current strategies to treat pain experienced by patients with Fabry disease. In addition, we discuss the current knowledge of Fabry pain pathogenesis and which aspects of the disease preclinical models accurately recapitulate. Understanding the commonalities and divergences between humans and preclinical models can be used to further interrogate mechanisms causing the pain and sensory abnormalities as well as advance development of the next generation of therapeutics to treat pain in patients with Fabry disease.
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Affiliation(s)
- Anthony J. Burand
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, United States
| | - Cheryl L. Stucky
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, United States
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Sensory neuron-associated macrophages as novel modulators of neuropathic pain. Pain Rep 2021; 6:e873. [PMID: 33981924 PMCID: PMC8108583 DOI: 10.1097/pr9.0000000000000873] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/13/2020] [Accepted: 10/19/2020] [Indexed: 12/28/2022] Open
Abstract
The peripheral nervous system comprises an infinity of neural networks that act in the communication between the central nervous system and the most diverse tissues of the body. Along with the extension of the primary sensory neurons (axons and cell bodies), a population of resident macrophages has been described. These newly called sensory neuron-associated macrophages (sNAMs) seem to play an essential role in physiological and pathophysiological processes, including infection, autoimmunity, nerve degeneration/regeneration, and chronic neuropathic pain. After different types of peripheral nerve injury, there is an increase in the number and activation of sNAMs in the sciatic nerve and sensory ganglia. The activation of sNAMs and their participation in neuropathic pain development depends on the stimulation of pattern recognition receptors such as Toll-like receptors and Nod-like receptors, chemokines/cytokines, and microRNAs. On activation, sNAMs trigger the production of critical inflammatory mediators such as proinflammatory cytokines (eg, TNF and IL-1β) and reactive oxygen species that can act in the amplification of primary sensory neurons sensitization. On the other hand, there is evidence that sNAMs can produce antinociceptive mediators (eg, IL-10) that counteract neuropathic pain development. This review will present the cellular and molecular mechanisms behind the participation of sNAMs in peripheral nerve injury-induced neuropathic pain development. Understanding how sNAMs are activated and responding to nerve injury can help set novel targets for the control of neuropathic pain.
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42
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Spinal Inhibitory Interneurons: Gatekeepers of Sensorimotor Pathways. Int J Mol Sci 2021; 22:ijms22052667. [PMID: 33800863 PMCID: PMC7961554 DOI: 10.3390/ijms22052667] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 02/26/2021] [Accepted: 03/04/2021] [Indexed: 12/20/2022] Open
Abstract
The ability to sense and move within an environment are complex functions necessary for the survival of nearly all species. The spinal cord is both the initial entry site for peripheral information and the final output site for motor response, placing spinal circuits as paramount in mediating sensory responses and coordinating movement. This is partly accomplished through the activation of complex spinal microcircuits that gate afferent signals to filter extraneous stimuli from various sensory modalities and determine which signals are transmitted to higher order structures in the CNS and to spinal motor pathways. A mechanistic understanding of how inhibitory interneurons are organized and employed within the spinal cord will provide potential access points for therapeutics targeting inhibitory deficits underlying various pathologies including sensory and movement disorders. Recent studies using transgenic manipulations, neurochemical profiling, and single-cell transcriptomics have identified distinct populations of inhibitory interneurons which express an array of genetic and/or neurochemical markers that constitute functional microcircuits. In this review, we provide an overview of identified neural components that make up inhibitory microcircuits within the dorsal and ventral spinal cord and highlight the importance of inhibitory control of sensorimotor pathways at the spinal level.
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Herzig M, Krüger S, Hilberg T. A single bout of coordination training does not lead to EIH in young healthy men - a RCT. Scand J Pain 2021; 21:145-151. [PMID: 32892184 DOI: 10.1515/sjpain-2020-0036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 08/08/2020] [Indexed: 12/27/2022]
Abstract
OBJECTIVES Physical activity can lead to hypoalgesic effects and is often recommended as part of multidisciplinary pain management. Based on the idea, that in future specific and more differentiated sports therapeutic interventions could be used for a multidisciplinary pain management, various type of sports and their effects on pain sensitivity should be analysed. Whereas endurance as well as strengthening exercises are associated with a decrease in pain sensitivity in healthy people as well as people with chronic pain states, the effects of a specific coordination training (CT) on pain sensitivity have not yet been sufficiently investigated. Therefore, aim of the present study was to examine if a single bout of CT leads to exercised-induced hypoalgesia in young healthy men. METHODS Thirty five healthy men (mean age 27 ± 3 years) were examined in a randomised crossover design before and after a single bout of 45-min CT and a 45-min resting session as control condition by means of Quantitative Sensory Testing (QST). The QST is a validated instrument to assess the function of the somatosensory system, by applying thermal and mechanical stimuli. By doing so, various detection and pain thresholds were determined at the dorsum of one foot. Exercises of CT were chosen to generate high proprioceptive input for the ankle joints. RESULTS Analysis of the QST data in respect of the factors group (CT/control condition), time (pre/post) and stimuli (parameter of QST) revealed no statistically significant main effects of a single bout of CT on somatosensory system, neither for the factors group*time (p=0.51), nor the factors group*time*stimuli (p=0.32). All stimuli remained constant in the course of both conditions (e.g. mean ± sd of heat pain threshold pre/post in °C: coordination: 44.7 ± 3.1/44.8 ± 2.9; rest: 45.5 ± 3.0/44.9 ± 3.0). CONCLUSIONS In this setting, a single bout of CT had no effect on the somatosensory system in young healthy men. Therefore, this specific CT did not lead to an exercised-induced hypoalgesia in healthy people. Intensity of sensory input during training intervention might be too low to generate analgesic effects in a non-pathological altered somatosensory system of young healthy men. Further research is needed to clarify if a CT can induce exercised-induced hypoalgesia in people with pathological alterations of the somatosensory system. In addition, it has to examined if analgesic effects can be induced by changing the intensity of CT in healthy people. Detailed knowledge regarding the effects of different training interventions on pain modulation is needed to completely understand the mechanism of exercised-induced hypoalgesia.
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Affiliation(s)
- Marie Herzig
- Department of Sports Medicine, University of Wuppertal, Wuppertal, Germany
| | - Steffen Krüger
- Department of Sports Medicine, University of Wuppertal, Wuppertal, Germany
| | - Thomas Hilberg
- Department of Sports Medicine, University of Wuppertal, Wuppertal, Germany
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von Buchholtz LJ, Ghitani N, Lam RM, Licholai JA, Chesler AT, Ryba NJP. Decoding Cellular Mechanisms for Mechanosensory Discrimination. Neuron 2021; 109:285-298.e5. [PMID: 33186546 PMCID: PMC9909446 DOI: 10.1016/j.neuron.2020.10.028] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/27/2020] [Accepted: 10/20/2020] [Indexed: 01/29/2023]
Abstract
Single-cell RNA-sequencing and in vivo functional imaging provide expansive but disconnected views of neuronal diversity. Here, we developed a strategy for linking these modes of classification to explore molecular and cellular mechanisms responsible for detecting and encoding touch. By broadly mapping function to neuronal class, we uncovered a clear transcriptomic logic responsible for the sensitivity and selectivity of mammalian mechanosensory neurons. Notably, cell types with divergent gene-expression profiles often shared very similar properties, but we also discovered transcriptomically related neurons with specialized and divergent functions. Applying our approach to knockout mice revealed that Piezo2 differentially tunes all types of mechanosensory neurons with marked cell-class dependence. Together, our data demonstrate how mechanical stimuli recruit characteristic ensembles of transcriptomically defined neurons, providing rules to help explain the discriminatory power of touch. We anticipate a similar approach could expose fundamental principles governing representation of information throughout the nervous system.
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Affiliation(s)
- Lars J. von Buchholtz
- National Institute of Dental and Craniofacial Research, NIH, Bethesda MD 20892, USA,These authors contributed equally
| | - Nima Ghitani
- National Center for Integrative and Complementary Health, Bethesda MD 20892, USA,These authors contributed equally
| | - Ruby M. Lam
- National Center for Integrative and Complementary Health, Bethesda MD 20892, USA,Brown-National Institutes of Health Graduate Partnerships Program, Brown University, Providence, RI, USA
| | - Julia A. Licholai
- National Institute of Dental and Craniofacial Research, NIH, Bethesda MD 20892, USA,Brown-National Institutes of Health Graduate Partnerships Program, Brown University, Providence, RI, USA
| | - Alexander T. Chesler
- National Center for Integrative and Complementary Health, Bethesda MD 20892, USA,Lead contact: ,Correspondence: or
| | - Nicholas J. P. Ryba
- National Institute of Dental and Craniofacial Research, NIH, Bethesda MD 20892, USA,Correspondence: or
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45
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Abstract
Objective: Acupuncture, as an important part of Traditional Chinese Medicine, has been practiced for thousands of years in China and now all over the world, but the underlying neuroanatomical basis is still poorly understood. This article explores how acupuncture drives autonomic reflexes and why the widely used Streitberger sham-needling control should be revisited. Method: This article summarizes modern studies, suggesting that functional connections between somatic tissues and internal organs may be explained via somato-autonomic reflexes. Results: Modern studies have revealed a few organizational rules regarding how acupuncture drives distinct somatosensory autonomic pathways, including acupoint selectivity and intensity dependence. Activation of these autonomic pathways modulates various body physiologic functions, such as gastrointestinal motility and systemic inflammation. Meanwhile, extensive anatomical and functional characterization of the somatosensory system raises a question about the widely used Streitberger sham-needling control. Specifically, the skin epidermis and hair follicles contain mechanically sensitive afferents, whose activation by this sham stimulation could modulate pain and the autonomic nervous system. Conclusions: A deeper understanding of the underlying neuroanatomical basis of acupuncture is crucial for optimizing stimulation parameters and designing proper sham-controls to demonstrate and improve the efficacy and the safety of using this modality to treat human conditions.
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Affiliation(s)
- Qiufu Ma
- Dana-Farber Cancer Institute and Department of Neurobiology, Harvard Medical School, Boston, MA, USA
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46
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Haussler KK. Pressure Algometry for the Detection of Mechanical Nociceptive Thresholds in Horses. Animals (Basel) 2020; 10:ani10122195. [PMID: 33255216 PMCID: PMC7760268 DOI: 10.3390/ani10122195] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/19/2020] [Accepted: 11/21/2020] [Indexed: 01/01/2023] Open
Abstract
Simple Summary It is difficult to measure pain in horses. As animals are not able to verbalize what they feel, we are left with trying to interpret the different signs that they display when they are in pain. Many of these signs are vague (e.g., not eating their food), but some are more readily identified if the animal moves away or lifts their leg when pressure is applied to a sensitive area. Pressure algometry is a tool used to detect responses to applied mechanical stimuli within painful and nonpainful tissues. Pressure algometry has been used in many different studies, but there is no consensus on how to synthesize this information to better diagnose and treat pain in horses. The purpose of this study was to summarize the results of these studies. Based on that review, we conclude that there is good evidence that pressure algometry is a reliable and objective method to measure pain responses. This information will help to improve the diagnosis and treatment of pain in horses. Abstract The clinical assessment of pain is subjective; therefore, variations exist between practitioners in their ability to identify and localize pain. Due to differing interpretations of the signs or severity of pain equine practitioners may assign varying levels of clinical significance and treatment options. There is a critical need to develop better tools to qualify and quantify pain in horses. Palpation is the most common method to detect local tenderness or sensitivity. To quantify this applied pressure, pressure algometry has been used to gradually apply pressure over specified landmarks until an avoidance response is noted, which is defined as the mechanical nociceptive threshold (MNT). Numerous studies have used pressure algometry in different applications to measure MNTs in horses. There is an acute need to establish normative values within different body regions and to develop standardized methods of testing MNTs to better guide practitioners in the diagnosis and treatment of pain. The aim of this systematic review was to summarize the evidence for the use of pressure algometry in horses. There is good evidence that pressure algometry is a repeatable, semi-objective method that can be used in a wide array of clinical and research applications to assess MNTs in horses.
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Affiliation(s)
- Kevin K Haussler
- Equine Orthopaedic Research Laboratory, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
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47
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Chen W, Yi M, Yang F. Transcriptional Control of the Development of Myelinated Mechano-nociceptors. Neurosci Bull 2020; 36:683-684. [PMID: 32613495 DOI: 10.1007/s12264-020-00541-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 06/03/2020] [Indexed: 11/25/2022] Open
Affiliation(s)
- Wen Chen
- Department of Neurobiology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 100069, China
| | - Ming Yi
- Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, 100083, China.,Neuroscience Research Institute, Peking University, Beijing, 100083, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health Commission of China, Peking University, Beijing, 100083, China
| | - Fei Yang
- Department of Neurobiology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 100069, China.
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48
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Abstract
A limited number of peripheral targets generate pain. Inflammatory mediators can sensitize these. The review addresses targets acting exclusively or predominantly on sensory neurons, mediators involved in inflammation targeting sensory neurons, and mediators involved in a more general inflammatory process, of which an analgesic effect secondary to an anti-inflammatory effect can be expected. Different approaches to address these systems are discussed, including scavenging proinflammatory mediators, applying anti-inflammatory mediators, and inhibiting proinflammatory or facilitating anti-inflammatory receptors. New approaches are contrasted to established ones; the current stage of progress is mentioned, in particular considering whether there is data from a molecular and cellular level, from animals, or from human trials, including an early stage after a market release. An overview of publication activity is presented, considering a IuPhar/BPS-curated list of targets with restriction to pain-related publications, which was also used to identify topics.
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Affiliation(s)
- Cosmin I Ciotu
- Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Michael J M Fischer
- Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria.
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