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Zhang X, Shao J, Wang C, Liu C, Hao H, Li X, An Y, He J, Zhao W, Zhao Y, Kong Y, Jia Z, Wan S, Yuan Y, Zhang H, Zhang H, Du X. TMC7 functions as a suppressor of Piezo2 in primary sensory neurons blunting peripheral mechanotransduction. Cell Rep 2024; 43:114014. [PMID: 38568807 DOI: 10.1016/j.celrep.2024.114014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 02/20/2024] [Accepted: 03/14/2024] [Indexed: 04/05/2024] Open
Abstract
The transmembrane channel-like (TMC) protein family comprises eight members, with TMC1 and TMC2 being extensively studied. This study demonstrates substantial co-expression of TMC7 with the mechanosensitive channel Piezo2 in somatosensory neurons. Genetic deletion of TMC7 in primary sensory ganglia neurons in vivo enhances sensitivity in both physiological and pathological mechanosensory transduction. This deletion leads to an increase in proportion of rapidly adapting (RA) currents conducted by Piezo2 in dorsal root ganglion (DRG) neurons and accelerates RA deactivation kinetics. In HEK293 cells expressing both proteins, TMC7 significantly suppresses the current amplitudes of co-expressed Piezo2. Our findings reveal that TMC7 and Piezo2 exhibit physical interactions, and both proteins also physically interact with cytoskeletal β-actin. We hypothesize that TMC7 functions as an inhibitory modulator of Piezo2 in DRG neurons, either through direct inhibition or by disrupting the transmission of mechanical forces from the cytoskeleton to the channel.
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Affiliation(s)
- Xiaoxue Zhang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Jichen Shao
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Caixue Wang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China; The Forth Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Chao Liu
- Department of Animal Care, The Key Laboratory of Experimental Animal, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Han Hao
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xinmeng Li
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yating An
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Jinsha He
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Weixin Zhao
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yiwen Zhao
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Youzhen Kong
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Zhanfeng Jia
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Shaopo Wan
- Institute of Electrical Engineering, Yanshan University, Qinhuangdao, Hebei, China
| | - Yi Yuan
- Institute of Electrical Engineering, Yanshan University, Qinhuangdao, Hebei, China
| | - Huiran Zhang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Hailin Zhang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xiaona Du
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China.
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2
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Asiedu K. Neurophysiology of corneal neuropathic pain and emerging pharmacotherapeutics. J Neurosci Res 2024; 102:e25285. [PMID: 38284865 DOI: 10.1002/jnr.25285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/12/2023] [Accepted: 12/02/2023] [Indexed: 01/30/2024]
Abstract
The altered activity generated by corneal neuronal injury can result in morphological and physiological changes in the architecture of synaptic connections in the nervous system. These changes can alter the sensitivity of neurons (both second-order and higher-order projection) projecting pain signals. A complex process involving different cell types, molecules, nerves, dendritic cells, neurokines, neuropeptides, and axon guidance molecules causes a high level of sensory rearrangement, which is germane to all the phases in the pathomechanism of corneal neuropathic pain. Immune cells migrating to the region of nerve injury assist in pain generation by secreting neurokines that ensure nerve depolarization. Furthermore, excitability in the central pain pathway is perpetuated by local activation of microglia in the trigeminal ganglion and alterations of the descending inhibitory modulation for corneal pain arriving from central nervous system. Corneal neuropathic pain may be facilitated by dysfunctional structures in the central somatosensory nervous system due to a lesion, altered synaptogenesis, or genetic abnormality. Understanding these important pathways will provide novel therapeutic insight.
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Affiliation(s)
- Kofi Asiedu
- School of Optometry & Vision Science, University of New South Wales, Sydney, New South Wales, Australia
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3
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Hart DA. Regulation of Bone by Mechanical Loading, Sex Hormones, and Nerves: Integration of Such Regulatory Complexity and Implications for Bone Loss during Space Flight and Post-Menopausal Osteoporosis. Biomolecules 2023; 13:1136. [PMID: 37509172 PMCID: PMC10377148 DOI: 10.3390/biom13071136] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/04/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
During evolution, the development of bone was critical for many species to thrive and function in the boundary conditions of Earth. Furthermore, bone also became a storehouse for calcium that could be mobilized for reproductive purposes in mammals and other species. The critical nature of bone for both function and reproductive needs during evolution in the context of the boundary conditions of Earth has led to complex regulatory mechanisms that require integration for optimization of this tissue across the lifespan. Three important regulatory variables include mechanical loading, sex hormones, and innervation/neuroregulation. The importance of mechanical loading has been the target of much research as bone appears to subscribe to the "use it or lose it" paradigm. Furthermore, because of the importance of post-menopausal osteoporosis in the risk for fractures and loss of function, this aspect of bone regulation has also focused research on sex differences in bone regulation. The advent of space flight and exposure to microgravity has also led to renewed interest in this unique environment, which could not have been anticipated by evolution, to expose new insights into bone regulation. Finally, a body of evidence has also emerged indicating that the neuroregulation of bone is also central to maintaining function. However, there is still more that is needed to understand regarding how such variables are integrated across the lifespan to maintain function, particularly in a species that walks upright. This review will attempt to discuss these regulatory elements for bone integrity and propose how further study is needed to delineate the details to better understand how to improve treatments for those at risk for loss of bone integrity, such as in the post-menopausal state or during prolonged space flight.
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Affiliation(s)
- David A Hart
- Department of Surgery, Faculty of Kinesiology, and McCaig Institute for Bone & Joint Research, University of Calgary, Calgary, AB T2N 4N1, Canada
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4
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Sonkodi B, Marsovszky L, Csorba A, Balog A, Kopper B, Nagy ZZ, Resch MD. Neural Regeneration in Dry Eye Secondary to Systemic Lupus Erythematosus Is Also Disrupted like in Rheumatoid Arthritis, but in a Progressive Fashion. Int J Mol Sci 2023; 24:10680. [PMID: 37445856 DOI: 10.3390/ijms241310680] [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: 05/24/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023] Open
Abstract
Our objective in this study was to analyze the aberrant neural regeneration activity in the cornea by means of in vivo confocal microscopy in systemic lupus erythematosus patients with concurrent dry eye disease. We examined 29 systemic lupus erythematosus patients and 29 age-matched healthy control subjects. Corneal nerve fiber density (CNFD, the number of fibers/mm2) and peripheral Langerhans cell morphology were lower (p < 0.05) in systemic lupus erythematosus patients compared to the control group. Interestingly, corneal nerve branch density, corneal nerve fiber length, corneal nerve fiber total branch density, and corneal nerve fiber area showed a negative correlation with disease duration. A negative correlation was also demonstrated between average corneal nerve fiber density and central Langerhans cell density. This is in line with our hypothesis that corneal somatosensory terminal Piezo2 channelopathy-induced impaired Piezo2-Piezo1 crosstalk not only disrupts regeneration and keeps transcription activated, but could lead to Piezo1 downregulation and cell activation on Langerhans cells when we consider a chronic path. Hence, Piezo2 containing mechanosensory corneal nerves and dendritic Langerhans cells could also be regarded as central players in shaping the ocular surface neuroimmune homeostasis through the Piezo system. Moreover, lost autoimmune neuroinflammation compensation, lost phagocytic self-eating capacity, and lost transcription regulation, not to mention autoantibodies against vascular heparin sulfate proteoglycans and phospholipids, could all contribute to the progressive fashion of dry eye disease in systemic lupus erythematosus.
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Affiliation(s)
- Balázs Sonkodi
- Department of Health Sciences and Sport Medicine, Hungarian University of Sports Science, 1123 Budapest, Hungary
| | - László Marsovszky
- Department of Ophthalmology, Semmelweis University, 1085 Budapest, Hungary
| | - Anita Csorba
- Department of Ophthalmology, Semmelweis University, 1085 Budapest, Hungary
| | - Attila Balog
- Department of Rheumatology and Immunology, Faculty of Medicine, Albert Szent-Györgyi Health Center, University of Szeged, 6725 Szeged, Hungary
| | - Bence Kopper
- Faculty of Kinesiology, Hungarian University of Sports Science, 1123 Budapest, Hungary
| | - Zoltán Zsolt Nagy
- Department of Ophthalmology, Semmelweis University, 1085 Budapest, Hungary
| | - Miklós D Resch
- Department of Ophthalmology, Semmelweis University, 1085 Budapest, Hungary
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5
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Ran L, Feng J, Qi X, Liu T, Qi B, Jiang K, Zhang Z, Yu Y, Zhou Q, Xie L. Effect of TRPM8 Functional Loss on Corneal Epithelial Wound Healing in Mice. Invest Ophthalmol Vis Sci 2023; 64:19. [PMID: 36692471 PMCID: PMC9896868 DOI: 10.1167/iovs.64.1.19] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Purpose To reveal the role of cold-sensing transient receptor potential melastatin 8 (TRPM8) channels in corneal epithelial wound healing. Methods Cold sensitivity, tear production, corneal thickness, and corneal opacity assessments were used to evaluate the effect of Trpm8 knockout on the ocular surface. A corneal epithelial wounding model was generated by scraping the corneal epithelium once or multiple times using C57BL/6J (wild-type [WT]) and Trpm8-/- mice. The processes of corneal epithelial repair and corneal epitheliopathy were observed and recorded. Corneas were collected for sequencing, immunofluorescence staining, hematoxylin and eosin staining, and quantitative PCR. Results The perception of coldness, basal tear secretion, and corneal thickness were decreased in young Trpm8-/- mice compared with those in WT mice, except for the corneal sensitivity. Corneal opacity and increased corneal thickness were observed in aged Trpm8-/- mice. TRPM8 deficiency promoted corneal epithelial wound closure, consistent with the observed increase in Ki67-positive epithelial cells, and the pharmacological activation of TRPM8 in WT mice delayed corneal re-epithelization. After subjecting mice to multiple injuries, squamous metaplasia emerged in Trpm8-/- corneas, as verified by cytokeratin-1 and small proline-rich protein 1B-positive staining. The IFN-β and IFN-γ signaling pathways were significantly activated in Trpm8-/- mice, which was confirmed based on the up-regulated expression of the key mediators, signal transducer and activator of transcription-1 and phosphor-signal transducer and activator of transcription-1, as well as the induction of IFN-stimulated genes, compared with levels in WT mice. Conclusions In corneal wound healing, the loss of TRPM8 function could promote epithelial repair, but predispose the cornea to epithelial lesions.
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Affiliation(s)
- Lili Ran
- Qingdao University Medical College, Qingdao University, Qingdao, China,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China
| | - Jing Feng
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China
| | - Xia Qi
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China
| | - Ting Liu
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China
| | - Benxiang Qi
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China
| | - Kai Jiang
- Qingdao University Medical College, Qingdao University, Qingdao, China,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China,Department of Ophthalmology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Zhenzhen Zhang
- Qingdao University Medical College, Qingdao University, Qingdao, China,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China
| | - Yang Yu
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China
| | - Qingjun Zhou
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China
| | - Lixin Xie
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China
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6
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Asiedu K. Role of ocular surface neurobiology in neuronal-mediated inflammation in dry eye disease. Neuropeptides 2022; 95:102266. [PMID: 35728484 DOI: 10.1016/j.npep.2022.102266] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 01/18/2023]
Abstract
Inflammation is the consequence of dry eye disease regardless of its etiology. Several injurious or harmless processes to the ocular surface neurons promote ocular surface neurogenic inflammation, leading to the vicious cycle of dry eye disease. These processes include the regular release of neuromediators during the conduction of ocular surface sensations, hyperosmolarity-induced ocular surface neuronal damage, neuro-regenerative activities, and neuronal-mediated dendritic cell activities. Neurogenic inflammation appears to be the main culprit, instigating the self-perpetuating inflammation observed in patients with dry eye disease.
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Affiliation(s)
- Kofi Asiedu
- School of Optometry & Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, Australia.
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7
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Corneal nerves and their role in dry eye pathophysiology. Exp Eye Res 2022; 222:109191. [PMID: 35850173 DOI: 10.1016/j.exer.2022.109191] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/15/2022] [Accepted: 07/11/2022] [Indexed: 12/11/2022]
Abstract
As the cornea is densely innervated, its nerves are integral not only to its structure but also to its pathophysiology. Corneal integrity depends on a protective tear film that is maintained by corneal sensation and the reflex arcs that control tearing and blinking. Furthermore, corneal nerves promote epithelial growth and local immunoregulation. Thus, corneal nerves constitute pillars of ocular surface homeostasis. Conversely, the abnormal tear film in dry eye favors corneal epithelial and nerve damage. The ensuing corneal nerve dysfunction contributes to dry eye progression, ocular pain and discomfort, and other neuropathic symptoms. Recent evidence from clinical studies and animal models highlight the significant but often overlooked neural dimension of dry eye pathophysiology. Herein, we review the anatomy and physiology of corneal nerves before exploring their role in the mechanisms of dry eye disease.
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8
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Jäntti H, Sitnikova V, Ishchenko Y, Shakirzyanova A, Giudice L, Ugidos IF, Gómez-Budia M, Korvenlaita N, Ohtonen S, Belaya I, Fazaludeen F, Mikhailov N, Gotkiewicz M, Ketola K, Lehtonen Š, Koistinaho J, Kanninen KM, Hernández D, Pébay A, Giugno R, Korhonen P, Giniatullin R, Malm T. Microglial amyloid beta clearance is driven by PIEZO1 channels. J Neuroinflammation 2022; 19:147. [PMID: 35706029 PMCID: PMC9199162 DOI: 10.1186/s12974-022-02486-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 05/15/2022] [Indexed: 02/06/2023] Open
Abstract
Background Microglia are the endogenous immune cells of the brain and act as sensors of pathology to maintain brain homeostasis and eliminate potential threats. In Alzheimer's disease (AD), toxic amyloid beta (Aβ) accumulates in the brain and forms stiff plaques. In late-onset AD accounting for 95% of all cases, this is thought to be due to reduced clearance of Aβ. Human genome-wide association studies and animal models suggest that reduced clearance results from aberrant function of microglia. While the impact of neurochemical pathways on microglia had been broadly studied, mechanical receptors regulating microglial functions remain largely unexplored. Methods Here we showed that a mechanotransduction ion channel, PIEZO1, is expressed and functional in human and mouse microglia. We used a small molecule agonist, Yoda1, to study how activation of PIEZO1 affects AD-related functions in human induced pluripotent stem cell (iPSC)-derived microglia-like cells (iMGL) under controlled laboratory experiments. Cell survival, metabolism, phagocytosis and lysosomal activity were assessed using real-time functional assays. To evaluate the effect of activation of PIEZO1 in vivo, 5-month-old 5xFAD male mice were infused daily with Yoda1 for two weeks through intracranial cannulas. Microglial Iba1 expression and Aβ pathology were quantified with immunohistochemistry and confocal microscopy. Published human and mouse AD datasets were used for in-depth analysis of PIEZO1 gene expression and related pathways in microglial subpopulations. Results We show that PIEZO1 orchestrates Aβ clearance by enhancing microglial survival, phagocytosis, and lysosomal activity. Aβ inhibited PIEZO1-mediated calcium transients, whereas activation of PIEZO1 with a selective agonist, Yoda1, improved microglial phagocytosis resulting in Aβ clearance both in human and mouse models of AD. Moreover, PIEZO1 expression was associated with a unique microglial transcriptional phenotype in AD as indicated by assessment of cellular metabolism, and human and mouse single-cell datasets. Conclusion These results indicate that the compromised function of microglia in AD could be improved by controlled activation of PIEZO1 channels resulting in alleviated Aβ burden. Pharmacological regulation of these mechanoreceptors in microglia could represent a novel therapeutic paradigm for AD. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-022-02486-y.
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Affiliation(s)
- Henna Jäntti
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Valeriia Sitnikova
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Yevheniia Ishchenko
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland.,Departments of Molecular Biophysics and Biochemistry and Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Anastasia Shakirzyanova
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Luca Giudice
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland.,Department of Computer Science, University of Verona, 37134, Verona, Italy
| | - Irene F Ugidos
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Mireia Gómez-Budia
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Nea Korvenlaita
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Sohvi Ohtonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Irina Belaya
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Feroze Fazaludeen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Nikita Mikhailov
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Maria Gotkiewicz
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Kirsi Ketola
- Institute of Biomedicine, University of Eastern Finland, 70210, Kuopio, Finland
| | - Šárka Lehtonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland.,Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Jari Koistinaho
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland.,Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Katja M Kanninen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Damian Hernández
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - Alice Pébay
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, Australia.,Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - Rosalba Giugno
- Department of Computer Science, University of Verona, 37134, Verona, Italy
| | - Paula Korhonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Rashid Giniatullin
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Tarja Malm
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland.
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9
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Sullivan C, Lee J, Bushey W, Demers D, Dinsdale S, Lowe K, Olmeda J, Meng ID. Evidence for a phenotypic switch in corneal afferents after lacrimal gland excision. Exp Eye Res 2022; 218:109005. [PMID: 35240196 PMCID: PMC9993327 DOI: 10.1016/j.exer.2022.109005] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 01/22/2022] [Accepted: 02/19/2022] [Indexed: 01/07/2023]
Abstract
Dry eye is a common cause of ocular pain. The aim of this study was to investigate corneal innervation, ongoing pain, and alterations in corneal afferent phenotypes in a mouse model of severe aqueous tear deficiency. Chronic dry eye was produced by ipsilateral excision of the extra- and intraorbital lacrimal glands in male and female mice. Tearing was measured using a phenol thread and corneal epithelial damage assessed using fluorescein. Changes in corneal ongoing ocular pain was evaluated by measuring palpebral opening ratio. Corneal axons were visualized using Nav1.8-Cre;tdTomato reporter mice. Immunohistochemistry was performed to characterize somal expression of calcitonin gene-related peptide (CGRP), the capsaicin sensitive transient receptor potential vanilloid 1 (TRPV1), and activating transcription factor-3 (ATF-3) in tracer labeled corneal neurons following lacrimal gland excision (LGE). LGE decreased tearing, created severe epithelial damage, and decreased palpebral opening, indicative of chronic ocular irritation, over the 28-day observation period. Corneal axon terminals exhibited an acute decrease in density after LGE, followed by a regenerative process over the course of 28 days that was greater in male animals. Corneal neurons expressing CGRP, TRPV1, and ATF3 increased following injury, corresponding to axonal injury and regeneration processes observed during the same period. CGRP and TRPV1 expression was notably increased in IB4-positive cells following LGE. These results indicate that dry eye-induced damage to corneal afferents can result in alterations in IB4-positive neurons that may enhance neuroprotective mechanisms to create resiliency after chronic injury.
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Affiliation(s)
- Cara Sullivan
- Center for Excellence in the Neurosciences, University of New England, Biddeford, ME, 04005, USA; Graduate Studies in Biomedical Sciences and Engineering, University of Maine, Orono, ME, 04469, USA
| | - Jun Lee
- Center for Excellence in the Neurosciences, University of New England, Biddeford, ME, 04005, USA; Department of Complete Denture Prosthodontics, School of Dentistry, Nihon University, Tokyo, 101-8310, Japan
| | - William Bushey
- Center for Excellence in the Neurosciences, University of New England, Biddeford, ME, 04005, USA; Department of Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, ME, 04005, USA
| | - Danielle Demers
- Center for Excellence in the Neurosciences, University of New England, Biddeford, ME, 04005, USA
| | - Samantha Dinsdale
- Center for Excellence in the Neurosciences, University of New England, Biddeford, ME, 04005, USA
| | - Katy Lowe
- Center for Excellence in the Neurosciences, University of New England, Biddeford, ME, 04005, USA
| | - Jessica Olmeda
- Center for Excellence in the Neurosciences, University of New England, Biddeford, ME, 04005, USA
| | - Ian D Meng
- Center for Excellence in the Neurosciences, University of New England, Biddeford, ME, 04005, USA; Graduate Studies in Biomedical Sciences and Engineering, University of Maine, Orono, ME, 04469, USA; Department of Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, ME, 04005, USA.
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10
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Yang S, Wu Y, Wang C, Jin X. Ocular Surface Ion-Channels Are Closely Related to Dry Eye: Key Research Focus on Innovative Drugs for Dry Eye. Front Med (Lausanne) 2022; 9:830853. [PMID: 35308542 PMCID: PMC8927818 DOI: 10.3389/fmed.2022.830853] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
Abundant ion-channels, including various perceptual receptors, chloride channels, purinergic receptor channels, and water channels that exist on the ocular surface, play an important role in the pathogenesis of dry eye. Channel-targeting activators or inhibitor compounds, which have shown positive effects in in vivo and in vitro experiments, have become the focus of the dry eye drug research and development, and individual compounds have been applied in clinical experimental treatment. This review summarized various types of ion-channels on the ocular surface related to dry eye, their basic functions, and spatial distribution, and discussed basic and clinical research results of various channel receptor regulatory compounds. Therefore, further elucidating the relationship between ion-channels and dry eye will warrant research of dry eye targeted drug therapy.
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Affiliation(s)
- Shuo Yang
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yaying Wu
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - ChunYang Wang
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiuming Jin
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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11
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Frutos-Rincón L, Gómez-Sánchez JA, Íñigo-Portugués A, Acosta MC, Gallar J. An Experimental Model of Neuro-Immune Interactions in the Eye: Corneal Sensory Nerves and Resident Dendritic Cells. Int J Mol Sci 2022; 23:ijms23062997. [PMID: 35328417 PMCID: PMC8951464 DOI: 10.3390/ijms23062997] [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] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/28/2022] [Accepted: 03/04/2022] [Indexed: 12/04/2022] Open
Abstract
The cornea is an avascular connective tissue that is crucial, not only as the primary barrier of the eye but also as a proper transparent refractive structure. Corneal transparency is necessary for vision and is the result of several factors, including its highly organized structure, the physiology of its few cellular components, the lack of myelinated nerves (although it is extremely innervated), the tightly controlled hydration state, and the absence of blood and lymphatic vessels in healthy conditions, among others. The avascular, immune-privileged tissue of the cornea is an ideal model to study the interactions between its well-characterized and dense sensory nerves (easily accessible for both focal electrophysiological recording and morphological studies) and the low number of resident immune cell types, distinguished from those cells migrating from blood vessels. This paper presents an overview of the corneal structure and innervation, the resident dendritic cell (DC) subpopulations present in the cornea, their distribution in relation to corneal nerves, and their role in ocular inflammatory diseases. A mouse model in which sensory axons are constitutively labeled with tdTomato and DCs with green fluorescent protein (GFP) allows further analysis of the neuro-immune crosstalk under inflammatory and steady-state conditions of the eye.
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Affiliation(s)
- Laura Frutos-Rincón
- Instituto de Neurociencias, Universidad Miguel Hernández—Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain; (L.F.-R.); (A.Í.-P.); (M.C.A.); (J.G.)
- The European University of Brain and Technology-NeurotechEU, 03550 San Juan de Alicante, Spain
| | - José Antonio Gómez-Sánchez
- Instituto de Neurociencias, Universidad Miguel Hernández—Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain; (L.F.-R.); (A.Í.-P.); (M.C.A.); (J.G.)
- Correspondence: ; Tel.: +34-965-91-9594
| | - Almudena Íñigo-Portugués
- Instituto de Neurociencias, Universidad Miguel Hernández—Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain; (L.F.-R.); (A.Í.-P.); (M.C.A.); (J.G.)
| | - M. Carmen Acosta
- Instituto de Neurociencias, Universidad Miguel Hernández—Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain; (L.F.-R.); (A.Í.-P.); (M.C.A.); (J.G.)
- The European University of Brain and Technology-NeurotechEU, 03550 San Juan de Alicante, Spain
| | - Juana Gallar
- Instituto de Neurociencias, Universidad Miguel Hernández—Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain; (L.F.-R.); (A.Í.-P.); (M.C.A.); (J.G.)
- The European University of Brain and Technology-NeurotechEU, 03550 San Juan de Alicante, Spain
- Instituto de Investigación Biomédica y Sanitaria de Alicante, 03010 Alicante, Spain
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12
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Puja G, Sonkodi B, Bardoni R. Mechanisms of Peripheral and Central Pain Sensitization: Focus on Ocular Pain. Front Pharmacol 2021; 12:764396. [PMID: 34916942 PMCID: PMC8669969 DOI: 10.3389/fphar.2021.764396] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 11/09/2021] [Indexed: 12/14/2022] Open
Abstract
Persistent ocular pain caused by corneal inflammation and/or nerve injury is accompanied by significant alterations along the pain axis. Both primary sensory neurons in the trigeminal nerves and secondary neurons in the spinal trigeminal nucleus are subjected to profound morphological and functional changes, leading to peripheral and central pain sensitization. Several studies using animal models of inflammatory and neuropathic ocular pain have provided insight about the mechanisms involved in these maladaptive changes. Recently, the advent of new techniques such as optogenetics or genetic neuronal labelling has allowed the investigation of identified circuits involved in nociception, both at the spinal and trigeminal level. In this review, we will describe some of the mechanisms that contribute to the perception of ocular pain at the periphery and at the spinal trigeminal nucleus. Recent advances in the discovery of molecular and cellular mechanisms contributing to peripheral and central pain sensitization of the trigeminal pathways will be also presented.
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Affiliation(s)
- Giulia Puja
- Department of Life Sciences, University of Modena and Reggio Emilia, Emilia-Romagna, Italy
| | - Balazs Sonkodi
- Department of Health Sciences and Sport Medicine, University of Physical Education, Budapest, Hungary
| | - Rita Bardoni
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Emilia-Romagna, Italy
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13
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Comes N, Gasull X, Callejo G. Proton Sensing on the Ocular Surface: Implications in Eye Pain. Front Pharmacol 2021; 12:773871. [PMID: 34899333 PMCID: PMC8652213 DOI: 10.3389/fphar.2021.773871] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/09/2021] [Indexed: 01/15/2023] Open
Abstract
Protons reaching the eyeball from exogenous acidic substances or released from damaged cells during inflammation, immune cells, after tissue injury or during chronic ophthalmic conditions, activate or modulate ion channels present in sensory nerve fibers that innervate the ocular anterior surface. Their identification as well as their role during disease is critical for the understanding of sensory ocular pathophysiology. They are likely to mediate some of the discomfort sensations accompanying several ophthalmic formulations and may represent novel targets for the development of new therapeutics for ocular pathologies. Among the ion channels expressed in trigeminal nociceptors innervating the anterior surface of the eye (cornea and conjunctiva) and annex ocular structures (eyelids), members of the TRP and ASIC families play a critical role in ocular acidic pain. Low pH (pH 6) activates TRPV1, a polymodal ion channel also activated by heat, capsaicin and hyperosmolar conditions. ASIC1, ASIC3 and heteromeric ASIC1/ASIC3 channels present in ocular nerve terminals are activated at pH 7.2–6.5, inducing pain by moderate acidifications of the ocular surface. These channels, together with TRPA1, are involved in acute ocular pain, as well as in painful sensations during allergic keratoconjunctivitis or other ophthalmic conditions, as blocking or reducing channel expression ameliorates ocular pain. TRPV1, TRPA1 and other ion channels are also present in corneal and conjunctival cells, promoting inflammation of the ocular surface after injury. In addition to the above-mentioned ion channels, members of the K2P and P2X ion channel families are also expressed in trigeminal neurons, however, their role in ocular pain remains unclear to date. In this report, these and other ion channels and receptors involved in acid sensing during ocular pathologies and pain are reviewed.
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Affiliation(s)
- Núria Comes
- Neurophysiology Laboratory, Department of Biomedicine, Medical School, Institute of Neurosciences, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Xavier Gasull
- Neurophysiology Laboratory, Department of Biomedicine, Medical School, Institute of Neurosciences, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Gerard Callejo
- Neurophysiology Laboratory, Department of Biomedicine, Medical School, Institute of Neurosciences, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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14
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Luna C, Quirce S, Aracil-Marco A, Belmonte C, Gallar J, Acosta MC. Unilateral Corneal Insult Also Alters Sensory Nerve Activity in the Contralateral Eye. Front Med (Lausanne) 2021; 8:767967. [PMID: 34869482 PMCID: PMC8634144 DOI: 10.3389/fmed.2021.767967] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/11/2021] [Indexed: 01/21/2023] Open
Abstract
After the unilateral inflammation or nerve lesion of the ocular surface, the ipsilateral corneal sensory nerve activity is activated and sensitized, evoking ocular discomfort, irritation, and pain referred to the affected eye. Nonetheless, some patients with unilateral ocular inflammation, infection, or surgery also reported discomfort and pain in the contralateral eye. We explored the possibility that such altered sensations in the non-affected eye are due to the changes in their corneal sensory nerve activity in the contralateral, not directly affected eye. To test that hypothesis, we recorded the impulse activity of the corneal mechano- and polymodal nociceptor and cold thermoreceptor nerve terminals in both eyes of guinea pigs, subjected unilaterally to three different experimental conditions (UV-induced photokeratitis, microkeratome corneal surgery, and chronic tear deficiency caused by removal of the main lacrimal gland), and in eyes of naïve animals ex vivo. Overall, after unilateral eye damage, the corneal sensory nerve activity appeared to be also altered in the contralateral eye. Compared with the naïve guinea pigs, animals with unilateral UV-induced mild corneal inflammation, showed on both eyes an inhibition of the spontaneous and stimulus-evoked activity of cold thermoreceptors, and increased activity in nociceptors affecting both the ipsilateral and the contralateral eye. Unilateral microkeratome surgery affected the activity of nociceptors mostly, inducing sensitization in both eyes. The removal of the main lacrimal gland reduced tear volume and increased the cold thermoreceptor activity in both eyes. This is the first direct demonstration that unilateral corneal nerve lesion, especially ocular surface inflammation, functionally affects the activity of the different types of corneal sensory nerves in both the ipsilateral and contralateral eyes. The mechanisms underlying the contralateral affectation of sensory nerves remain to be determined, although available data support the involvement of neuroimmune interactions. The parallel alteration of nerve activity in contralateral eyes has two main implications: a) in the experimental design of both preclinical and clinical studies, where the contralateral eyes cannot be considered as a control; and, b) in the clinical practice, where clinicians must consider the convenience of treating both eyes of patients with unilateral ocular conditions to avoid pain and secondary undesirable effects in the fellow eye.
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Affiliation(s)
- Carolina Luna
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, San Juan de Alicante, Spain
| | - Susana Quirce
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, San Juan de Alicante, Spain
| | - Adolfo Aracil-Marco
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, San Juan de Alicante, Spain
| | - Carlos Belmonte
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, San Juan de Alicante, Spain
| | - Juana Gallar
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, San Juan de Alicante, Spain.,Instituto de Investigación Sanitaria y Biomédica de Alicante, San Juan de Alicante, Spain
| | - M Carmen Acosta
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, San Juan de Alicante, Spain
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15
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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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16
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Hwang DDJ, Lee SJ, Kim JH, Lee SM. The Role of Neuropeptides in Pathogenesis of Dry Dye. J Clin Med 2021; 10:4248. [PMID: 34575359 PMCID: PMC8471988 DOI: 10.3390/jcm10184248] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 09/07/2021] [Accepted: 09/14/2021] [Indexed: 12/29/2022] Open
Abstract
Neuropeptides are known as important mediators between the nervous and immune systems. Recently, the role of the corneal nerve in the pathogenesis of various ocular surface diseases, including dry eye disease, has been highlighted. Neuropeptides are thought to be important factors in the pathogenesis of dry eye disease, as suggested by the well-known role between the nervous and immune systems, and several recently published studies have elucidated the previously unknown pathogenic mechanisms involved in the role of the neuropeptides secreted from the corneal nerves in dry eye disease. Here, we reviewed the emerging concept of neurogenic inflammation as one of the pathogenic mechanisms of dry eye disease, the recent results of related studies, and the direction of future research.
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Affiliation(s)
- Daniel Duck-Jin Hwang
- Department of Ophthalmology, HanGil Eye Hospital, Incheon 21388, Korea;
- Department of Ophthalmology, College of Medicine, Catholic Kwandong University, Incheon 21388, Korea
| | - Seok-Jae Lee
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul 03080, Korea; (S.-J.L.); (J.-H.K.)
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Korea
| | - Jeong-Hun Kim
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul 03080, Korea; (S.-J.L.); (J.-H.K.)
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Korea
- Department of Ophthalmology, College of Medicine, Seoul National University, Seoul 03080, Korea
- Advanced Biomedical Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon 34141, Korea
| | - Sang-Mok Lee
- Department of Ophthalmology, HanGil Eye Hospital, Incheon 21388, Korea;
- Department of Ophthalmology, College of Medicine, Catholic Kwandong University, Incheon 21388, Korea
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17
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Liu M, Li Y, Zhong J, Xia L, Dou N. The effect of IL-6/Piezo2 on the trigeminal neuropathic pain. Aging (Albany NY) 2021; 13:13615-13625. [PMID: 33893246 PMCID: PMC8202871 DOI: 10.18632/aging.202887] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 03/04/2021] [Indexed: 01/27/2023]
Abstract
The nature of trigeminal neuropathic pain (TN) attacks is regarded as the ignition of ectopic action potentials from the trigeminal root following vascular compression, which seemed to be related to transmembrane proteins and inflammation factors. This study focused on the mechanosensitive channel Piezo2 and cytokine IL-6. The chronic constriction injury of infraorbital nerve in SD rats was used to establish the TN model. The trigeminal ganglion was then achieved to perform immunocytochemistry studies. A significant upregulation of Piezo2 and IL-6 was showed in the TN model rats. The Piezo2 positive accounted for 72.3±9.5% in those IL-6 positive neurons. The Piezo2 co-localized with CGRP, IB4 and NF-200 but not with GFAP, which implied that it was expressed in both the C-type and the A-type neurons. After administration of GsMTx4 or anti-rat IL-6 antibody in the TN model, the dynamic allodynia and pinprick hyperalgesia scores as well as the mechanical threshold changed significantly. In the sham-operation rates, with local administration of IL-6, an upregulation of Piezo2 was also exhibited. Our study demonstrated that the up-regulation of Piezo2 in the pain afferent neurons following trigeminal nerve injury may play a role in the development of the neuralgia. Meanwhile, the expression of Piezo2 may be modulated by inflammatory cytokines, such as IL-6.
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Affiliation(s)
- MingXing Liu
- Department of Neurosurgery, Qingdao Municipal Hospital, Qingdao 266000, China
| | - Yan Li
- Department of Neurosurgery, Qingdao Municipal Hospital, Qingdao 266000, China
| | - Jun Zhong
- Department of Neurosurgery, XinHua Hospital, The Cranial Nerve Disease Center of Shanghai, Shanghai JiaoTong University School of Medicine, Shanghai 200092, China
| | - Lei Xia
- Department of Neurosurgery, XinHua Hospital, The Cranial Nerve Disease Center of Shanghai, Shanghai JiaoTong University School of Medicine, Shanghai 200092, China
| | - NingNing Dou
- Department of Neurosurgery, XinHua Hospital, The Cranial Nerve Disease Center of Shanghai, Shanghai JiaoTong University School of Medicine, Shanghai 200092, China
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18
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Keenan RJ, Oberrauch S, Bron R, Nowell CJ, Challis LM, Hoyer D, Jacobson LH. Decreased Orexin Receptor 1 mRNA Expression in the Locus Coeruleus in Both Tau Transgenic rTg4510 and Tau Knockout Mice and Accompanying Ascending Arousal System Tau Invasion in rTg4510. J Alzheimers Dis 2021; 79:693-708. [PMID: 33361602 DOI: 10.3233/jad-201177] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Sleep/wake disturbances (e.g., insomnia and sleep fragmentation) are common in neurodegenerative disorders, especially Alzheimer's disease (AD) and frontotemporal dementia (FTD). These symptoms are somewhat reminiscent of narcolepsy with cataplexy, caused by the loss of orexin-producing neurons. A bidirectional relationship between sleep disturbance and disease pathology suggests a detrimental cycle that accelerates disease progression and cognitive decline. The accumulation of brain tau fibrils is a core pathology of AD and FTD-tau and clinical evidence supports that tau may impair the orexin system in AD/FTD. This hypothesis was investigated using tau mutant mice. OBJECTIVE To characterize orexin receptor mRNA expression in sleep/wake regulatory brain centers and quantify noradrenergic locus coeruleus (LC) and orexinergic lateral hypothalamus (LH) neurons, in tau transgenic rTg4510 and tau-/- mice. METHODS We used i n situ hybridization and immunohistochemistry (IHC) in rTg4510 and tau-/- mice. RESULTS rTg4510 and tau-/- mice exhibited a similar decrease in orexin receptor 1 (OX1R) mRNA expression in the LC compared with wildtype controls. IHC data indicated this was not due to decreased numbers of LC tyrosine hydroxylase-positive (TH) or orexin neurons and demonstrated that tau invades TH LC and orexinergic LH neurons in rTg4510 mice. In contrast, orexin receptor 2 (OX2R) mRNA levels were unaffected in either model. CONCLUSION The LC is strongly implicated in the regulation of sleep/wakefulness and expresses high levels of OX1R. These findings raise interesting questions regarding the effects of altered tau on the orexin system, specifically LC OX1Rs, and emphasize a potential mechanism which may help explain sleep/wake disturbances in AD and FTD.
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Affiliation(s)
- Ryan J Keenan
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Sara Oberrauch
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Romke Bron
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia
| | - Cameron J Nowell
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia
| | - Leesa M Challis
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Daniel Hoyer
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia.,Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Laura H Jacobson
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia.,Melbourne Dementia Research Centre, University of Melbourne, The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
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19
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Guerrero-Moreno A, Baudouin C, Melik Parsadaniantz S, Réaux-Le Goazigo A. Morphological and Functional Changes of Corneal Nerves and Their Contribution to Peripheral and Central Sensory Abnormalities. Front Cell Neurosci 2020; 14:610342. [PMID: 33362474 PMCID: PMC7758484 DOI: 10.3389/fncel.2020.610342] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/18/2020] [Indexed: 11/24/2022] Open
Abstract
The cornea is the most densely innervated and sensitive tissue in the body. The cornea is exclusively innervated by C- and A-delta fibers, including mechano-nociceptors that are triggered by noxious mechanical stimulation, polymodal nociceptors that are excited by mechanical, chemical, and thermal stimuli, and cold thermoreceptors that are activated by cooling. Noxious stimulations activate corneal nociceptors whose cell bodies are located in the trigeminal ganglion (TG) and project central axons to the trigeminal brainstem sensory complex. Ocular pain, in particular, that driven by corneal nerves, is considered to be a core symptom of inflammatory and traumatic disorders of the ocular surface. Ocular surface injury affecting corneal nerves and leading to inflammatory responses can occur under multiple pathological conditions, such as chemical burn, persistent dry eye, and corneal neuropathic pain as well as after some ophthalmological surgical interventions such as photorefractive surgery. This review depicts the morphological and functional changes of corneal nerve terminals following corneal damage and dry eye disease (DED), both ocular surface conditions leading to sensory abnormalities. In addition, the recent fundamental and clinical findings of the importance of peripheral and central neuroimmune interactions in the development of corneal hypersensitivity are discussed. Next, the cellular and molecular changes of corneal neurons in the TG and central structures that are driven by corneal nerve abnormalities are presented. A better understanding of the corneal nerve abnormalities as well as neuroimmune interactions may contribute to the identification of a novel therapeutic targets for alleviating corneal pain.
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Affiliation(s)
| | - Christophe Baudouin
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, IHU FOReSIGHT, Paris, France.,CHNO des Quinze-Vingts, IHU FOReSIGHT, INSERM-DGOS CIC 1423, Paris, France.,Department of Ophthalmology, Ambroise Paré Hospital, AP-HP, University of Versailles Saint-Quentin-en-Yvelines, Boulogne-Billancourt, France
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20
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Piezo2 Mediates Low-Threshold Mechanically Evoked Pain in the Cornea. J Neurosci 2020; 40:8976-8993. [PMID: 33055278 DOI: 10.1523/jneurosci.0247-20.2020] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 12/22/2022] Open
Abstract
Mammalian Piezo2 channels are essential for transduction of innocuous mechanical forces by proprioceptors and cutaneous touch receptors. In contrast, mechanical responses of somatosensory nociceptor neurons evoking pain, remain intact or are only partially reduced in Piezo2-deficient mice. In the eye cornea, comparatively low mechanical forces are detected by polymodal and pure mechanosensory trigeminal ganglion neurons. Their activation always evokes ocular discomfort or pain and protective reflexes, thus being a unique model to study mechanotransduction mechanisms in this particular class of nociceptive neurons. Cultured male and female mouse mechano- and polymodal nociceptor corneal neurons display rapidly, intermediately and slowly adapting mechanically activated currents. Immunostaining of the somas and peripheral axons of corneal neurons responding only to mechanical force (pure mechano-nociceptor) or also exhibiting TRPV1 (transient receptor potential cation channel subfamily V member 1) immunoreactivity (polymodal nociceptor) revealed that they express Piezo2. In sensory-specific Piezo2-deficient mice, the distribution of corneal neurons displaying the three types of mechanically evoked currents is similar to the wild type; however, the proportions of rapidly adapting neurons, and of intermediately and slowly adapting neurons were significantly reduced. Recordings of mechano- and polymodal-nociceptor nerve terminals in the corneal surface of Piezo2 conditional knock-out mice revealed a reduced number of mechano-sensitive terminals and lower frequency of nerve terminal impulse discharges under mechanical stimulation. Eye blinks evoked by von Frey filaments applied on the cornea were lower in Piezo2-deficient mice compared with wild type. Together, our results provide direct evidence that Piezo2 channels support mechanically activated currents of different kinetics in corneal trigeminal neurons and contributes to transduction of mechanical forces by corneal nociceptors.SIGNIFICANCE STATEMENT The cornea is a richly innervated and highly sensitive tissue. Low-threshold mechanical forces activate corneal receptors evoking discomfort or pain. To examine the contribution of Piezo2, a low-threshold mechanically activated channel, to acute ocular pain, we characterized the mechanosensitivity of corneal sensory neurons. By using Piezo2 conditional knock-out mice, we show that Piezo2 channels, present in the cell body and terminals of corneal neurons, are directly involved in acute corneal mechano-nociception. Inhibition of Piezo2 for systemic pain treatment is hindered because of its essential role for mechano-transduction processes in multiple body organs. Still, topical modulation of Piezo2 in the cornea may be useful to selectively relief unpleasant sensations and pain associated with mechanical irritation accompanying many ocular surface disorders.
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21
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Abstract
Ocular surface pain is a frequent cause of visits to an eye care provider and has a substantial impact on healthcare cost, yet a complete understanding of its causative factors and tools for diagnostic workup are notably missing in many eye clinics. The cornea has the densest sensory innervation in the human body and has the potential to be a powerful producer of pain. Pain can manifest as a result of a noxious stimulus or disruption in the ocular surface anatomy (nociceptive pain), or it can result from abnormalities in the ocular surface neurosensory apparatus itself (neuropathic pain). Novel advances in neurobiology have sought to differentiate the two entities, particularly to identify when chronic dry eye symptomatology is driven by neuropathic ocular pain. In this review, we seek to provide an overview of the prevalence, physiologic factors, and management of ocular surface pain complaints.
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Affiliation(s)
- Divy Mehra
- Surgical Services, Miami Veterans Affairs Medical Center, Miami, FL, USA
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Noah K Cohen
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Anat Galor
- Surgical Services, Miami Veterans Affairs Medical Center, Miami, FL, USA.
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA.
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22
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Capsaicin-induced pain sensitivity in short tear break-up time dry eye. Ocul Surf 2020; 18:620-626. [PMID: 32712260 DOI: 10.1016/j.jtos.2020.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 07/08/2020] [Accepted: 07/12/2020] [Indexed: 11/21/2022]
Abstract
PURPOSE To evaluate transient receptor potential vanilloid 1 (TRPV1)-mediated pain sensitivity in patients with short tear break-up time (TBUT) dry eye (DE) by using the capsaicin stimulus test. METHODS This prospective cross-sectional comparative study included 22 eyes of 22 patients with short TBUT DE and 11 eyes of 11 non-DE control subjects. Patients were divided into two groups based on response to standard DE treatments: 10 non-responders (intractable DE) and 12 responders (responsive DE). Mechanical touch (M-touch) and mechanical pain (M-pain) were measured using a Cochet-Bonnet esthesiometer. Capsaicin-induced pain (C-pain) and C-pain duration (C-pain DT) were measured using a capsaicin stimulus test. Psychological distress was also assessed. RESULTS M-touch sensitivity was similar among all three groups. M-pain sensitivity was higher in the responsive DE group than in the intractable DE and control groups (P < .001). C-pain sensitivity was lower (P < .001) in the intractable DE group than in the responsive DE and control groups, and C-pain DT was shorter (P = .006) in the intractable DE group than in the responsive DE group. Psychological distress was higher in the intractable DE group than in the control group (P < .001). CONCLUSIONS Patients with intractable short TBUT DE were less sensitive to the effects of capsaicin than patients with responsive short TBUT DE and controls. Altered neural activation may contribute to the development of DE symptoms in the short TBUT DE subjects. The capsaicin stimulus test may be used to better understand pain sensitivity in short TBUT DE patients.
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23
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Liu M, Zhong J. Mechanism underlying cranial nerve rhizopathy. Med Hypotheses 2020; 142:109801. [PMID: 32413700 DOI: 10.1016/j.mehy.2020.109801] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/09/2020] [Accepted: 05/02/2020] [Indexed: 12/27/2022]
Abstract
The cranial nerve rhizophathy, commonly presented with trigeminal neuralgia (TN) or hemifacial spasm (HFS), is a sort of hyperexcitability disorders with higher incidence in senior Asian. In this paper, a novel hypothesis on the pathogenesis is proposed and with which some clinical phenomena are explained. In those with crowded cerebellopontine angle in anatomy, the cranial nerve root and surrounding vessel are getting closer and closer to each other with aging and finally the neurovascular conflict happens. As the interfacial friction associated with pulse, the nerve incurs demyelination. Since this pathological change develops to a certain degree, some transmembrane proteins emerge from the nerve due to a series of signaling pathway mediated by inflammatory cytokines. Among them, voltage-gated (Nav1.3) and mechanosensitive (Piezo2) ion channels may play the important role. With pulsatile compressions, the Piezo2 drives the resting potential toward depolarization forming a state of subthreshold membrane potential oscillation. Under this condition, just an appropriate pressure can make the membrane potential easy to reach threshold and activate the sodium channel, eventually generating conductible action potentials from the axon. When these ectopic action potentials propagate to the central nerve system, an illusion of sharp pain is perceived; while to the nerve-muscle junctions, an attack of irregular muscle constriction occurs. This hypothesis can well explain the symptomatic manifestation of paroxysmal attacks aroused by emotions. When we get nervous or excited, our heart rate and blood pressure alter correspondingly, which may give rise to "a just right pressure" - with specific frequency, amplitude and angle - impacting the suffered nerve to reach the threshold of impulse ignition. After a successful microvascular decompression surgery, the trigger is gone (there is no compression anymore) and the symptom is alleviated. While the postoperative recurrence could be attributable to Teflon granuloma development if had been placed improperly - for this nerve root has been susceptible no matter to arteries or to neoplasms. Besides, it may illustrate the clinical phenomenon that secondary TN or HFS cases are seldom caused by schwannoma: with a proliferative sheath, the nerve root is actually insulated. By contrast, not all neurovascular contacts can lead to the onset: it demands an exclusive extent of demyelination firstly.
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Affiliation(s)
- Mingxing Liu
- Dept. Neurosurgery, QingDao Municipal Hospital, No.1 Jiaozhou Rd., Qingdao 266000, China.
| | - Jun Zhong
- Dept. Neurosurgery, XinHua Hospital, Shanghai JiaoTong University School of Medicine, 1665 KongJiang Rd., Shanghai 200092, China.
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24
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Yamakawa M, Santosa SM, Chawla N, Ivakhnitskaia E, Del Pino M, Giakas S, Nadel A, Bontu S, Tambe A, Guo K, Han KY, Cortina MS, Yu C, Rosenblatt MI, Chang JH, Azar DT. Transgenic models for investigating the nervous system: Currently available neurofluorescent reporters and potential neuronal markers. Biochim Biophys Acta Gen Subj 2020; 1864:129595. [PMID: 32173376 DOI: 10.1016/j.bbagen.2020.129595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/24/2020] [Accepted: 03/03/2020] [Indexed: 02/06/2023]
Abstract
Recombinant DNA technologies have enabled the development of transgenic animal models for use in studying a myriad of diseases and biological states. By placing fluorescent reporters under the direct regulation of the promoter region of specific marker proteins, these models can localize and characterize very specific cell types. One important application of transgenic species is the study of the cytoarchitecture of the nervous system. Neurofluorescent reporters can be used to study the structural patterns of nerves in the central or peripheral nervous system in vivo, as well as phenomena involving embryologic or adult neurogenesis, injury, degeneration, and recovery. Furthermore, crucial molecular factors can also be screened via the transgenic approach, which may eventually play a major role in the development of therapeutic strategies against diseases like Alzheimer's or Parkinson's. This review describes currently available reporters and their uses in the literature as well as potential neural markers that can be leveraged to create additional, robust transgenic models for future studies.
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Affiliation(s)
- Michael Yamakawa
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Samuel M Santosa
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Neeraj Chawla
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Evguenia Ivakhnitskaia
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Matthew Del Pino
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Sebastian Giakas
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Arnold Nadel
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Sneha Bontu
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Arjun Tambe
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Kai Guo
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Kyu-Yeon Han
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Maria Soledad Cortina
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Charles Yu
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Mark I Rosenblatt
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Jin-Hong Chang
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America.
| | - Dimitri T Azar
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America.
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25
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Pain, Dryness, and Itch Sensations in Eye Surface Disorders Are Defined By a Balance Between Inflammation and Sensory Nerve Injury. Cornea 2019; 38 Suppl 1:S11-S24. [DOI: 10.1097/ico.0000000000002116] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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26
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Situ P, Begley CG, Simpson TL. Effects of Tear Film Instability on Sensory Responses to Corneal Cold, Mechanical, and Chemical Stimuli. Invest Ophthalmol Vis Sci 2019; 60:2935-2941. [PMID: 31284310 PMCID: PMC6615367 DOI: 10.1167/iovs.19-27298] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Purpose To investigate the effects of tear film instability (TFI) induced by sustained tear exposure (STARE) on sensory responses to corneal cold, mechanical, and chemical stimuli. Methods Fifteen normal subjects were enrolled. TFI was induced during 10 repeated trials of STARE. Pneumatic cold, mechanical, and chemical stimuli were delivered using a computer-controlled Belmonte esthesiometer on three separate visits. The magnitude of the sensory responses to threshold and suprathreshold (1.25 and 1.50 times threshold levels) stimuli were assessed for intensity, coolness or warmness, irritation and pain, using a 0 (none) to 100 (very strong) scale, before and after STARE trials. Symptoms of ocular discomfort were evaluated using the Current Symptom Questionnaire (CSQ). Repeated measures ANOVA was used for data analysis. Results Following STARE trials, the intensity and coolness ratings to cooling stimuli decreased (P = 0.043 and 0.044 for intensity and coolness, respectively), while rated irritation to mechanical stimuli was increased (P = 0.024). The CSQ scores also increased regardless of visits (all P < 0.001). Intensity ratings, coolness to room temperature stimuli and irritation to mechanical and chemical stimuli increased for all suprathreshold stimuli with increasing stimulus levels (P ≤ 0.005). Conclusions Repeated TFI induced by STARE affects neurosensory function of the ocular surface. The decrease in reports of cooling and increase in irritation after repeated TFI suggest a complex interaction of neural mechanisms (particularly nonnociceptive cold and nociceptive mechanical) giving rise to ocular surface sensation in humans.
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Affiliation(s)
- Ping Situ
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Carolyn G Begley
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Trefford L Simpson
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
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27
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Abstract
The trigeminal sensory nerve fiber branches supply afferent information from the skin and mucous membranes of the face and head and the oral cavity regarding information on temperature, touch, and pain. Under normal conditions, the trigeminal nerve serves to provide important information from nerve fibers and tissues using specialized receptors sensitive for irritant and painful stimuli. The current scientific consensus indicates that nerve endings responsible for chemical and thermal sensitivity of the skin and mucous membranes are the same nerves responsible for nociception. This "chemesthetic sense" allows many vertebrates to detect chemical agonists that induce sensations such as touch, burning, stinging, tingling, or changes in temperature. Research has been under way for many years to determine how exposure of the oral and/or nasal cavity to compounds that elicit pungent or irritant sensations can produce these sensations. In addition, these chemicals can alter other sensory information such as taste and smell to affect the flavor of foods and beverages. We now know that these 'chemesthetic molecules' are agonists of molecular receptors, which exist on primary afferent nerve fibers that innervate the orofacial area. However, under pathophysiologic conditions, over- or underexpression or activity of these receptors may lead to painful orotrigeminal syndromes. Some of these individual receptors are discussed in detail, including transient receptor potential channels and acid sensing ion channels, among others.
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Affiliation(s)
- Amanda H Klein
- Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota, Duluth, MN, United States. //
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28
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Genetic Analysis of the Organization, Development, and Plasticity of Corneal Innervation in Mice. J Neurosci 2018; 39:1150-1168. [PMID: 30587537 DOI: 10.1523/jneurosci.1401-18.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 10/05/2018] [Accepted: 11/24/2018] [Indexed: 11/21/2022] Open
Abstract
The cornea has the densest sensory innervation of the body, originating primarily from neurons in the trigeminal ganglion. The basic principles of cornea nerve patterning have been established many years ago using classic neuroanatomical methods, such as immunocytochemistry and electrophysiology. Our understanding of the morphology and distribution of the sensory nerves in the skin has considerably progressed over the past few years through the generation and analysis of a variety of genetically modified mouse lines. Surprisingly, these lines were not used to study corneal axons. Here, we have screened a collection of transgenic and knockin mice (of both sexes) to select lines allowing the visualization and genetic manipulation of corneal nerves. We identified multiple lines, including some in which different types of corneal axons can be simultaneously observed with fluorescent proteins expressed in a combinatorial manner. We also provide the first description of the morphology and arborization of single corneal axons and identify three main types of branching pattern. We applied this genetic strategy to the analysis of corneal nerve development and plasticity. We provide direct evidence for a progressive reduction of the density of corneal innervation during aging. We also show that the semaphorin receptor neuropilin-1 acts cell-autonomously to control the development of corneal axons and that early axon guidance defects have long-term consequences on corneal innervation.SIGNIFICANCE STATEMENT We have screened a collection of transgenic and knockin mice and identify lines allowing the visualization and genetic manipulation of corneal nerves. We provide the first description of the arborization pattern of single corneal axons. We also present applications of this genetic strategy to the analysis of corneal nerve development and remodeling during aging.
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29
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Joubert F, Acosta MDC, Gallar J, Fakih D, Sahel JA, Baudouin C, Bodineau L, Mélik Parsadaniantz S, Réaux-Le Goazigo A. Effects of corneal injury on ciliary nerve fibre activity and corneal nociception in mice: A behavioural and electrophysiological study. Eur J Pain 2018; 23:589-602. [DOI: 10.1002/ejp.1332] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 09/18/2018] [Accepted: 10/20/2018] [Indexed: 01/18/2023]
Affiliation(s)
- Fanny Joubert
- INSERM; CNRS; Institut de la Vision; Sorbonne Université; Paris France
| | - Maria del Carmen Acosta
- Instituto de Neurosciencas; Universidad Miguel Hernández-CSIC; San Juan de Alicante; Alicante Spain
| | - Juana Gallar
- Instituto de Neurosciencas; Universidad Miguel Hernández-CSIC; San Juan de Alicante; Alicante Spain
| | - Darine Fakih
- INSERM; CNRS; Institut de la Vision; Sorbonne Université; Paris France
- Laboratoires Théa; Clermont-Ferrand France
| | - José-Alain Sahel
- INSERM; CNRS; Institut de la Vision; Sorbonne Université; Paris France
- INSERM-DGOS CIC 1423; CHNO des Quinze-Vingts; DHU Sight Restore; Paris France
| | - Christophe Baudouin
- INSERM; CNRS; Institut de la Vision; Sorbonne Université; Paris France
- INSERM-DGOS CIC 1423; CHNO des Quinze-Vingts; DHU Sight Restore; Paris France
- University Versailles Saint Quentin en Yvelines; Versailles France
| | - Laurence Bodineau
- INSERM; Sorbonne Université; UMR_S1158 Neurophysiologie Respiratoire Expérimentale et Clinique; Paris France
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30
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Carr R, Frings S. Neuropeptides in sensory signal processing. Cell Tissue Res 2018; 375:217-225. [PMID: 30377783 DOI: 10.1007/s00441-018-2946-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/09/2018] [Indexed: 12/21/2022]
Abstract
Peptides released from trigeminal fibers fulfill well-understood functions in neuroinflammatory processes and in the modulation of nociceptive signal processing. In particular, calcitonin gene-related peptide (CGRP) and substance P (SP), released from afferent nerve terminals, exert paracrine effects on the surrounding tissue and this has been recently highlighted by the prominent parcrine role of CGRP in the development of headache and migraine. Some recent communications suggest that these sensory neuropeptides may also modulate the workings of sensory organs and influence afferent signals from nose, tongue, eyes and ears. Here, we briefly review the evidence for modulatory effects of CGRP and SP in the sensory periphery.
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Affiliation(s)
- Richard Carr
- Department of Experimental Pain Research, Medical Faculty Mannheim, University of Heidelberg, Ludolf-Krehl-Str. 13-17, 68167, Mannheim, Germany.
| | - Stephan Frings
- Department of Animal Physiology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
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31
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Melik Parsadaniantz S, Rostène W, Baudouin C, Réaux-Le Goazigo A. [Understanding chronic ocular pain]. Biol Aujourdhui 2018; 212:1-11. [PMID: 30362450 DOI: 10.1051/jbio/2018017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Indexed: 11/15/2022]
Abstract
Dry eye disease (DED) is a common chronic condition with multifactorial etiologies that is increasing in prevalence worldwide, up to 20% in the elderly. The economic burden and impact of DED on vision, quality of life, work productivity, psychological and physical impact of pain, are considerable. Chronic ocular pain is the most common symptom of DED and there is currently no topical ocular analgesic therapy available to treat this debilitating disease. Eye pain can be perceived as itch, irritation, dryness, grittiness, burning, aching, and light sensitivity. Ocular pain is triggered by corneal nociceptors (cornea being the most sensory innervated tissue of the body). It was clearly established that repeated direct damage to ocular surface and per se corneal nerves can cause peripheral and central sensitization mechanisms explaining the ocular pain in some patients with DED. However, the brain regions and the neuronal pathways associated with ocular pain are still unclear. Thus, a better characterization of chronic ocular pain and an understanding of the peripheral and central molecular and cellular mechanisms involved are crucial issues for developing effective management and therapeutic strategy to alleviate ocular pain. In this review, we first describe the nociceptive corneal nerve pathways and the classification and the neurochemistry of primary afferents innervating the cornea. Then, an update of the fundamental and clinical studies related to the inflammatory processes linked to ocular pain is detailed. The last part of the review presents the diagnostic tools used in clinic for evaluating corneal sensitivity and corneal inflammation.
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Affiliation(s)
| | - William Rostène
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Christophe Baudouin
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France - Département d'Ophtalmologie III, Hôpital National des Quinze-Vingts, Paris, France - Département d'Ophtalmologie, Hôpital Ambroise Paré, APHP, Université de Versailles Saint-Quentin en Yvelines, Versailles, France
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32
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Matías-Pérez D, García-Montaño LA, Cruz-Aguilar M, García-Montalvo IA, Nava-Valdéz J, Barragán-Arevalo T, Villanueva-Mendoza C, Villarroel CE, Guadarrama-Vallejo C, la Cruz RVD, Chacón-Camacho O, Zenteno JC. Identification of novel pathogenic variants and novel gene-phenotype correlations in Mexican subjects with microphthalmia and/or anophthalmia by next-generation sequencing. J Hum Genet 2018; 63:1169-1180. [PMID: 30181649 DOI: 10.1038/s10038-018-0504-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/21/2018] [Accepted: 08/03/2018] [Indexed: 01/01/2023]
Abstract
Severe congenital eye malformations, particularly microphthalmia and anophthalmia, are one of the main causes of visual handicap worldwide. They can arise from multifactorial, chromosomal, or monogenic factors and can be associated with extensive clinical variability. Genetic analysis of individuals with these defects has allowed the recognition of dozens of genes whose mutations lead to disruption of normal ocular embryonic development. Recent application of next generation sequencing (NGS) techniques for genetic screening of patients with congenital eye defects has greatly improved the recognition of monogenic cases. In this study, we applied clinical exome NGS to a group of 14 Mexican patients (including 7 familial and 7 sporadic cases) with microphthalmia and/or anophthalmia. Causal or likely causal pathogenic variants were demonstrated in ~60% (8 out of 14 patients) individuals. Seven out of 8 different identified mutations occurred in well-known microphthalmia/anophthalmia genes (OTX2, VSX2, MFRP, VSX1) or in genes associated with syndromes that include ocular defects (CHD7, COL4A1) (including two instances of CHD7 pathogenic variants). A single pathogenic variant was identified in PIEZO2, a gene that was not previously associated with isolated ocular defects. NGS efficiently identified the genetic etiology of microphthalmia/anophthalmia in ~60% of cases included in this cohort, the first from Mexican origin analyzed to date. The molecular defects identified through clinical exome sequencing in this study expands the phenotypic spectra of CHD7-associated disorders and implicate PIEZO2 as a candidate gene for major eye developmental defects.
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Affiliation(s)
| | - Leopoldo A García-Montaño
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | - Marisa Cruz-Aguilar
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | | | - Jessica Nava-Valdéz
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | - Tania Barragán-Arevalo
- Department of Human Genetics, National Institute of Pediatrics of Mexico, Mexico City, Mexico
| | - Cristina Villanueva-Mendoza
- Department of Genetics, Hospital "Dr. Luis Sanchez Bulnes", Asociación Para Evitar la Ceguera en México, Mexico City, Mexico
| | - Camilo E Villarroel
- Department of Human Genetics, National Institute of Pediatrics of Mexico, Mexico City, Mexico
| | - Clavel Guadarrama-Vallejo
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | - Rocío Villafuerte-de la Cruz
- Ciencias Basicas, Escuela de Medicina, Instituto Tecnológico y de Estudios Superiores de Monterrey, Monterrey, NL, Mexico
| | - Oscar Chacón-Camacho
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | - Juan C Zenteno
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico. .,Department of Biochemistry, Faculty of Medicine, UNAM, Mexico City, Mexico.
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33
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Dua HS, Said DG, Messmer EM, Rolando M, Benitez-del-Castillo JM, Hossain PN, Shortt AJ, Geerling G, Nubile M, Figueiredo FC, Rauz S, Mastropasqua L, Rama P, Baudouin C. Neurotrophic keratopathy. Prog Retin Eye Res 2018; 66:107-131. [DOI: 10.1016/j.preteyeres.2018.04.003] [Citation(s) in RCA: 179] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 04/05/2018] [Accepted: 04/06/2018] [Indexed: 01/09/2023]
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34
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Guerrero-Alba R, Valdez-Morales EE, Jiménez-Vargas NN, Bron R, Poole D, Reed D, Castro J, Campaniello M, Hughes PA, Brierley SM, Bunnett N, Lomax AE, Vanner S. Co-expression of μ and δ opioid receptors by mouse colonic nociceptors. Br J Pharmacol 2018; 175:2622-2634. [PMID: 29579315 DOI: 10.1111/bph.14222] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND AND PURPOSE To better understand opioid signalling in visceral nociceptors, we examined the expression and selective activation of μ and δ opioid receptors by dorsal root ganglia (DRG) neurons innervating the mouse colon. EXPERIMENTAL APPROACH DRG neurons projecting to the colon were identified by retrograde tracing. δ receptor-GFP reporter mice, in situ hybridization, single-cell RT-PCR and μ receptor-specific antibodies were used to characterize expression of μ and δ receptors. Voltage-gated Ca2+ currents and neuronal excitability were recorded in small diameter nociceptive neurons (capacitance <30 pF) by patch clamp and ex vivo single-unit afferent recordings were obtained from the colon. KEY RESULTS In situ hybridization of oprm1 expression in Fast Blue-labelled DRG neurons was observed in 61% of neurons. μ and δ receptors were expressed by 36-46% of colon DRG neurons, and co-expressed by ~25% of neurons. μ and δ receptor agonists inhibited Ca2+ currents in DRG, effects blocked by opioid antagonists. One or both agonists inhibited action potential firing by colonic afferent endings. Incubation of neurons with supernatants from inflamed colon segments inhibited Ca2+ currents and neuronal excitability. Antagonists of μ, but not δ receptors, inhibited the effects of these supernatant on Ca2+ currents, whereas both antagonists inhibited their actions on neuronal excitability. CONCLUSIONS AND IMPLICATIONS A significant number of small diameter colonic nociceptors co-express μ and δ receptors and are inhibited by agonists and endogenous opioids in inflamed tissues. Thus, opioids that act at μ or δ receptors, or their heterodimers may be effective in treating visceral pain.
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Affiliation(s)
- Raquel Guerrero-Alba
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, ON, Canada
| | | | | | - Romke Bron
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC, Australia
| | - Daniel Poole
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC, Australia.,Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - David Reed
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, ON, Canada
| | - Joel Castro
- Visceral Pain Research Group, Human Physiology, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.,Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, University of Adelaide, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
| | - Melissa Campaniello
- Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, University of Adelaide, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
| | - Patrick A Hughes
- Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, University of Adelaide, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
| | - Stuart M Brierley
- Visceral Pain Research Group, Human Physiology, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.,Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, University of Adelaide, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
| | - Nigel Bunnett
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC, Australia.,Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, VIC, Australia.,Departments of Surgery and Pharmacology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Alan E Lomax
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, ON, Canada
| | - Stephen Vanner
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, ON, Canada
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Alamri AS, Wood RJ, Ivanusic JJ, Brock JA. The neurochemistry and morphology of functionally identified corneal polymodal nociceptors and cold thermoreceptors. PLoS One 2018; 13:e0195108. [PMID: 29590195 PMCID: PMC5874071 DOI: 10.1371/journal.pone.0195108] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 03/17/2018] [Indexed: 11/19/2022] Open
Abstract
It is generally believed that the unencapsulated sensory nerve terminals of modality specific C- and Aδ-neurons lack structural specialization. Here we determined the morphology of functionally defined polymodal receptors and cold thermoreceptors in the guinea pig corneal epithelium. Polymodal receptors and cold thermoreceptors were identified by extracellular recording at the surface of the corneal epithelium. After marking the recording sites, corneas were processed to reveal immunoreactivity for the transient receptor potential channels TRPV1 (transient receptor potential cation channel, subfamily V, member 1) or TPRM8 (transient receptor potential cation channel subfamily M member 8). Polymodal receptor nerve terminals (n = 6) were TRPV1-immunoreactive and derived from an axon that ascended from the sub-basal plexus to the squamous cell layer where it branched into fibers that ran parallel to the corneal surface and terminated with small bulbar endings (ramifying endings). Cold thermoreceptor nerve terminals were TRPM8-immunoreactive (n = 6) and originated from an axon that branched as it ascended through the wing cell and squamous cell layers and terminated with large bulbar endings (complex endings). These findings indicate that modality specific corneal sensory neurons with unencapsulated nerve endings have distinct nerve terminal morphologies that are likely to relate to their function.
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Affiliation(s)
- Abdulhakeem S. Alamri
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
| | - Rhiannon J. Wood
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jason J. Ivanusic
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
| | - James A. Brock
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
- * E-mail:
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Schneider ER, Anderson EO, Mastrotto M, Matson JD, Schulz VP, Gallagher PG, LaMotte RH, Gracheva EO, Bagriantsev SN. Molecular basis of tactile specialization in the duck bill. Proc Natl Acad Sci U S A 2017; 114:13036-13041. [PMID: 29109250 PMCID: PMC5724259 DOI: 10.1073/pnas.1708793114] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Tactile-foraging ducks are specialist birds known for their touch-dependent feeding behavior. They use dabbling, straining, and filtering to find edible matter in murky water, relying on the sense of touch in their bill. Here, we present the molecular characterization of embryonic duck bill, which we show contains a high density of mechanosensory corpuscles innervated by functional rapidly adapting trigeminal afferents. In contrast to chicken, a visually foraging bird, the majority of duck trigeminal neurons are mechanoreceptors that express the Piezo2 ion channel and produce slowly inactivating mechano-current before hatching. Furthermore, duck neurons have a significantly reduced mechano-activation threshold and elevated mechano-current amplitude. Cloning and electrophysiological characterization of duck Piezo2 in a heterologous expression system shows that duck Piezo2 is functionally similar to the mouse ortholog but with prolonged inactivation kinetics, particularly at positive potentials. Knockdown of Piezo2 in duck trigeminal neurons attenuates mechano current with intermediate and slow inactivation kinetics. This suggests that Piezo2 is capable of contributing to a larger range of mechano-activated currents in duck trigeminal ganglia than in mouse trigeminal ganglia. Our results provide insights into the molecular basis of mechanotransduction in a tactile-specialist vertebrate.
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Affiliation(s)
- Eve R Schneider
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520
| | - Evan O Anderson
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520
| | - Marco Mastrotto
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06520
| | - Jon D Matson
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520
| | - Vincent P Schulz
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520
| | - Patrick G Gallagher
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520
| | - Robert H LaMotte
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520
- Department of Anesthesiology, Yale University School of Medicine, New Haven, CT 06520
| | - Elena O Gracheva
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520;
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06520
| | - Sviatoslav N Bagriantsev
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520;
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Solé-Magdalena A, Martínez-Alonso M, Coronado CA, Junquera LM, Cobo J, Vega JA. Molecular basis of dental sensitivity: The odontoblasts are multisensory cells and express multifunctional ion channels. Ann Anat 2017; 215:20-29. [PMID: 28954208 DOI: 10.1016/j.aanat.2017.09.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 08/22/2017] [Accepted: 09/10/2017] [Indexed: 12/26/2022]
Abstract
Odontoblasts are the dental pulp cells responsible for the formation of dentin. In addition, accumulating data strongly suggest that they can also function as sensory cells that mediate the early steps of mechanical, thermic, and chemical dental sensitivity. This assumption is based on the expression of different families of ion channels involved in various modalities of sensitivity and the release of putative neurotransmitters in response to odontoblast stimulation which are able to act on pulp sensory nerve fibers. This review updates the current knowledge on the expression of transient-potential receptor ion channels and acid-sensing ion channels in odontoblasts, nerve fibers innervating them and trigeminal sensory neurons, as well as in pulp cells. Moreover, the innervation of the odontoblasts and the interrelationship been odontoblasts and nerve fibers mediated by neurotransmitters was also revisited. These data might provide the basis for novel therapeutic approaches for the treatment of dentin sensibility and/or dental pain.
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Affiliation(s)
- A Solé-Magdalena
- Departamento de Morfología y Biología Celular Universidad de Oviedo, Spain
| | - M Martínez-Alonso
- Departamento de Morfología y Biología Celular Universidad de Oviedo, Spain
| | - C A Coronado
- Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Temuco, Chile
| | - L M Junquera
- Departamento de Especialidades Médico-Quirúrgicas, Universidad de Oviedo, Spain; Servicio de Cirugía Maxilofacial, Hospital Universitario Central de Asturias, Oviedo, Spain
| | - J Cobo
- Departamento de Especialidades Médico-Quirúrgicas, Universidad de Oviedo, Spain; Instituto Asturiano de Odontología, Oviedo, Spain
| | - J A Vega
- Departamento de Morfología y Biología Celular Universidad de Oviedo, Spain; Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Temuco, Chile.
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Réaux-Le Goazigo A, Labbé A, Baudouin C, Melik Parsadaniantz S. La douleur oculaire chronique : mieux la comprendre pour mieux la traiter. Med Sci (Paris) 2017; 33:749-757. [DOI: 10.1051/medsci/20173308020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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García-Mesa Y, García-Piqueras J, García B, Feito J, Cabo R, Cobo J, Vega JA, García-Suárez O. Merkel cells and Meissner's corpuscles in human digital skin display Piezo2 immunoreactivity. J Anat 2017; 231:978-989. [PMID: 28905996 DOI: 10.1111/joa.12688] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2017] [Indexed: 12/13/2022] Open
Abstract
The transformation of mechanical energy into electrical signals is the first step in mechanotransduction in the peripheral sensory nervous system and relies on the presence of mechanically gated ion channels within specialized sensory organs called mechanoreceptors. Piezo2 is a vertebrate stretch-gated ion channel necessary for mechanosensitive channels in mammalian cells. Functionally, it is related to light touch, which has been detected in murine cutaneous Merkel cell-neurite complexes, Meissner-like corpuscles and lanceolate nerve endings. To the best of our knowledge, the occurrence of Piezo2 in human cutaneous mechanoreceptors has never been investigated. Here, we used simple and double immunohistochemistry to investigate the occurrence of Piezo2 in human digital glabrous skin. Piezo2 immunoreactivity was detected in approximately 80% of morphologically and immunohistochemically characterized (cytokeratin 20+ , chromogranin A+ and synaptophisin+ ) Merkel cells. Most of them were in close contact with Piezo2- nerve fibre profiles. Moreover, the axon, but not the lamellar cells, of Meissner's corpuscles was also Piezo2+ , but other mechanoreceptors, i.e. Pacinian or Ruffini's corpuscles, were devoid of immunoreactivity. Piezo2 was also observed in non-nervous tissue, especially the basal keratinocytes, endothelial cells and sweat glands. The present results demonstrate the occurrence of Piezo2 in cutaneous sensory nerve formations that functionally work as slowly adapting (Merkel cells) and rapidly adapting (Meissner's corpuscles) low-threshold mechanoreceptors and are related to fine and discriminative touch but not to vibration or hard touch. These data offer additional insight into the molecular basis of mechanosensing in humans.
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Affiliation(s)
- Y García-Mesa
- Departamento de Morfología y Biología Celular, Grupo SINPOs, Sección de Anatomía y Embriología Humana, Universidad de Oviedo, Oviedo, Spain
| | - J García-Piqueras
- Departamento de Morfología y Biología Celular, Grupo SINPOs, Sección de Anatomía y Embriología Humana, Universidad de Oviedo, Oviedo, Spain
| | - B García
- Departamento de Biología Funcional, Universidad de Oviedo, Oviedo, Spain
| | - J Feito
- Servicio de Anatomía Patológica, Complejo Asistencial Universitario de Salamanca, Salamanca, Spain
| | - R Cabo
- Departamento de Morfología y Biología Celular, Grupo SINPOs, Sección de Anatomía y Embriología Humana, Universidad de Oviedo, Oviedo, Spain
| | - J Cobo
- Departamento de Cirugía y Especialidades Médico-Quirúrgicas, Universidad de Oviedo, Oviedo, Spain.,Instituto Asturiano de Odontología, Oviedo, Spain
| | - J A Vega
- Departamento de Morfología y Biología Celular, Grupo SINPOs, Sección de Anatomía y Embriología Humana, Universidad de Oviedo, Oviedo, Spain.,Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Temuco, Chile
| | - O García-Suárez
- Departamento de Morfología y Biología Celular, Grupo SINPOs, Sección de Anatomía y Embriología Humana, Universidad de Oviedo, Oviedo, Spain
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40
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Ivanusic JJ. Molecular Mechanisms That Contribute to Bone Marrow Pain. Front Neurol 2017; 8:458. [PMID: 28955292 PMCID: PMC5601959 DOI: 10.3389/fneur.2017.00458] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/18/2017] [Indexed: 12/11/2022] Open
Abstract
Pain associated a bony pathology puts a significant burden on individuals, society, and the health-care systems worldwide. Pathology that involves the bone marrow activates sensory nerve terminal endings of peripheral bone marrow nociceptors, and is the likely trigger for pain. This review presents our current understanding of how bone marrow nociceptors are influenced by noxious stimuli presented in pathology associated with bone marrow. A number of ion channels and receptors are emerging as important modulators of the activity of peripheral bone marrow nociceptors. Nerve growth factor (NGF) sequestration has been trialed for the management of inflammatory bone pain (osteoarthritis), and there is significant evidence for interaction of NGF with bone marrow nociceptors. Activation of transient receptor potential cation channel subfamily V member 1 sensitizes bone marrow nociceptors and could contribute to increased sensitivity of patients to noxious stimuli in various bony pathologies. Acid-sensing ion channels sense changes to tissue pH in the bone marrow microenvironment and could be targeted to treat pathology that involves acidosis of the bone marrow. Piezo2 is a mechanically gated ion channel that has recently been reported to be expressed by most myelinated bone marrow nociceptors and might be a target for treatments directed against mechanically induced bone pain. These ion channels and receptors could be useful targets for the development of peripherally acting drugs to treat pain of bony origin.
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Affiliation(s)
- Jason J Ivanusic
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC, Australia
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41
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Abstract
Pain associated with mechanical, chemical, and thermal heat stimulation of the ocular surface is mediated by trigeminal ganglion neurons, while cold thermoreceptors detect wetness and reflexly maintain basal tear production and blinking rate. These neurons project into two regions of the trigeminal brain stem nuclear complex: ViVc, activated by changes in the moisture of the ocular surface and VcC1, mediating sensory-discriminative aspects of ocular pain and reflex blinking. ViVc ocular neurons project to brain regions that control lacrimation and spontaneous blinking and to the sensory thalamus. Secretion of the main lacrimal gland is regulated dominantly by autonomic parasympathetic nerves, reflexly activated by eye surface sensory nerves. These also evoke goblet cell secretion through unidentified efferent fibers. Neural pathways involved in the regulation of meibomian gland secretion or mucin release have not been identified. In dry eye disease, reduced tear secretion leads to inflammation and peripheral nerve damage. Inflammation causes sensitization of polymodal and mechano-nociceptor nerve endings and an abnormal increase in cold thermoreceptor activity, altogether evoking dryness sensations and pain. Long-term inflammation and nerve injury alter gene expression of ion channels and receptors at terminals and cell bodies of trigeminal ganglion and brainstem neurons, changing their excitability, connectivity and impulse firing. Perpetuation of molecular, structural and functional disturbances in ocular sensory pathways ultimately leads to dysestesias and neuropathic pain referred to the eye surface. Pain can be assessed with a variety of questionaires while the status of corneal nerves is evaluated with esthesiometry and with in vivo confocal microscopy.
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42
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Nencini S, Ivanusic J. Mechanically sensitive Aδ nociceptors that innervate bone marrow respond to changes in intra-osseous pressure. J Physiol 2017; 595:4399-4415. [PMID: 28295390 DOI: 10.1113/jp273877] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 02/22/2017] [Indexed: 12/28/2022] Open
Abstract
KEY POINTS Sensory neurons that innervate the bone marrow provide the CNS with information about pain associated with bone disease and pathology, but little is known of their function. Here we use a novel in vivo bone-nerve electrophysiological preparation to study how they respond to noxious mechanical stimulation delivered by increasing intra-osseous pressure. We provide evidence that sensory neurons that innervate the bone marrow respond to high threshold noxious mechanical stimulation, have response properties consistent with a role in nociception, provide information about different features of an intra-osseous pressure stimulus and express the Piezo2 mechano-transducer molecule. Our findings show how some bone marrow nociceptors signal pain in bony diseases and pathologies that involve a mechanical disturbance or increased intra-osseous pressure, and that the Piezo2 mechano-transducer may be involved. ABSTRACT Whilst the sensory neurons and nerve terminals that innervate bone marrow have a morphology and molecular phenotype consistent with a role in nociception, little is known about their physiology or the mechanisms that generate and maintain bone pain. In the present study, we provide evidence that Aδ nociceptors that innervate the bone marrow respond to high threshold noxious mechanical stimulation, exhibit fatigue in response to prior stimulation and in some cases can be sensitized by capsaicin. They can be classified on the basis of their response properties as either phasic-tonic units that appear to code for different intensities of intra-osseous pressure, or phasic units that code for the rate of change in intra-osseous pressure. Three different subclasses of mechanically sensitive Aδ units were observed: phasic units that were sensitized by capsaicin, phasic units that were not sensitized by capsaicin and phasic-tonic units (that were not sensitized by capsaicin). These could also, in part, be distinguished by differences in their thresholds for activation, mean discharge frequency, latency to peak activation and peak-to-peak action potential amplitude. The majority of small-diameter myelinated sensory neurons projecting to the bone marrow expressed Piezo2. Our findings indicate that Aδ mechano-nociceptors are likely to play an important role in generating and maintaining pain in response to bony pathologies that involve a mechanical disturbance or increased intra-osseous pressure, and imply that Piezo2 signalling may be involved in mechano-transduction in these receptors.
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Affiliation(s)
- Sara Nencini
- Department of Anatomy and Neuroscience, University of Melbourne, Victoria, 3010, Australia
| | - Jason Ivanusic
- Department of Anatomy and Neuroscience, University of Melbourne, Victoria, 3010, Australia
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43
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Won J, Vang H, Lee P, Kim Y, Kim H, Kang Y, Oh S. Piezo2 Expression in Mechanosensitive Dental Primary Afferent Neurons. J Dent Res 2017; 96:931-937. [DOI: 10.1177/0022034517702342] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mechanosensitive ion channels have been suggested to be expressed in dental primary afferent (DPA) neurons to transduce the movement of dentinal fluid since the proposal of hydrodynamic theory. Piezo2, a mechanosensitive, rapidly inactivating (RI) ion channel, has been recently identified in dorsal root ganglion (DRG) neurons to mediate tactile transduction. Here, we examined the expression of Piezo2 in DPA neurons by in situ hybridization, single-cell reverse transcriptase polymerase chain reaction, and whole-cell patch-clamp recordings. DPA neurons with Piezo2 messenger RNA (mRNA) or Piezo2-like currents were further characterized based on their neurochemical and electrophysiological properties. Piezo2 mRNA was found mostly in medium- to large-sized DPA neurons, with the majority of these neurons also positive for Nav1.8, CGRP, and NF200, whereas only a minor population was positive for IB4 and peripherin. Whole-cell patch-clamp recordings revealed Piezo2-like, RI currents evoked by mechanical stimulation in a subpopulation of DPA neurons. RI currents were pharmacologically blocked by ruthenium red, a compound known to block Piezo2, and were also reduced by small interfering RNA-mediated Piezo2 knockdown. Piezo2-like currents were observed almost exclusively in IB4-negative DPA neurons, with the current amplitude larger in capsaicin-insensitive DPA neurons than the capsaicin-sensitive population. Our findings show that subpopulation of DPA neurons is indeed mechanically sensitive. Within this subpopulation of mechanosensitive DPA neurons, we have identified the Piezo2 ion channel as a potential transducer for mechanical stimuli, contributing to RI inward currents. Piezo2-positive DPA neurons were characterized as medium- to large-sized neurons with myelinated A-fibers, containing nociceptive peptidergic neurotransmitters.
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Affiliation(s)
- J. Won
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - H. Vang
- Dental Research Institute and Department of Neurobiology & Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - P.R. Lee
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Y.H. Kim
- Dental Research Institute and Department of Neurobiology & Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
- Department of Physiology, College of Medicine, Gachon University, Incheon, Republic of Korea (present address)
| | - H.W. Kim
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Y. Kang
- Dental Research Institute and Department of Neurobiology & Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - S.B. Oh
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
- Dental Research Institute and Department of Neurobiology & Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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44
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Schneider ER, Gracheva EO, Bagriantsev SN. Evolutionary Specialization of Tactile Perception in Vertebrates. Physiology (Bethesda) 2017; 31:193-200. [PMID: 27053733 DOI: 10.1152/physiol.00036.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Evolution has endowed vertebrates with the remarkable tactile ability to explore the world through the perception of physical force. Yet the sense of touch remains one of the least well understood senses at the cellular and molecular level. Vertebrates specializing in tactile perception can highlight general principles of mechanotransduction. Here, we review cellular and molecular adaptations that underlie the sense of touch in typical and acutely mechanosensitive vertebrates.
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Affiliation(s)
- Eve R Schneider
- Department of Cellular & Molecular Physiology, Yale University, New Haven, Connecticut
| | - Elena O Gracheva
- Department of Cellular & Molecular Physiology, Yale University, New Haven, Connecticut; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University, New Haven, Connecticut; and Department of Neuroscience, Yale University, New Haven, Connecticut
| | - Slav N Bagriantsev
- Department of Cellular & Molecular Physiology, Yale University, New Haven, Connecticut;
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45
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Anderson E, Schneider E, Bagriantsev S. Piezo2 in Cutaneous and Proprioceptive Mechanotransduction in Vertebrates. CURRENT TOPICS IN MEMBRANES 2017; 79:197-217. [PMID: 28728817 PMCID: PMC5630267 DOI: 10.1016/bs.ctm.2016.11.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Mechanosensitivity is a fundamental physiological capacity, which pertains to all life forms. Progress has been made with regard to understanding mechanosensitivity in bacteria, flies, and worms. In vertebrates, however, the molecular identity of mechanotransducers in somatic and neuronal cells has only started to appear. The Piezo family of mechanogated ion channels marks a pivotal milestone in understanding mechanosensitivity. Piezo1 and Piezo2 have now been shown to participate in a number of processes, ranging from arterial modeling to sensing muscle stretch. In this review, we focus on Piezo2 and its role in mediating mechanosensation and proprioception in vertebrates.
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46
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Lieu T, Savage E, Zhao P, Edgington-Mitchell L, Barlow N, Bron R, Poole DP, McLean P, Lohman RJ, Fairlie DP, Bunnett NW. Antagonism of the proinflammatory and pronociceptive actions of canonical and biased agonists of protease-activated receptor-2. Br J Pharmacol 2016; 173:2752-65. [PMID: 27423137 PMCID: PMC4995288 DOI: 10.1111/bph.13554] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 07/05/2016] [Accepted: 07/05/2016] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND AND PURPOSE Diverse proteases cleave protease-activated receptor-2 (PAR2) on primary sensory neurons and epithelial cells to evoke pain and inflammation. Trypsin and tryptase activate PAR2 by a canonical mechanism that entails cleavage within the extracellular N-terminus revealing a tethered ligand that activates the cleaved receptor. Cathepsin-S and elastase are biased agonists that cleave PAR2 at different sites to activate distinct signalling pathways. Although PAR2 is a therapeutic target for inflammatory and painful diseases, the divergent mechanisms of proteolytic activation complicate the development of therapeutically useful antagonists. EXPERIMENTAL APPROACH We investigated whether the PAR2 antagonist GB88 inhibits protease-evoked activation of nociceptors and protease-stimulated oedema and hyperalgesia in rodents. KEY RESULTS Intraplantar injection of trypsin, cathespsin-S or elastase stimulated mechanical and thermal hyperalgesia and oedema in mice. Oral GB88 or par2 deletion inhibited the algesic and proinflammatory actions of all three proteases, but did not affect basal responses. GB88 also prevented pronociceptive and proinflammatory effects of the PAR2-selective agonists 2-furoyl-LIGRLO-NH2 and AC264613. GB88 did not affect capsaicin-evoked hyperalgesia or inflammation. Trypsin, cathepsin-S and elastase increased [Ca(2+) ]i in rat nociceptors, which expressed PAR2. GB88 inhibited this activation of nociceptors by all three proteases, but did not affect capsaicin-evoked activation of nociceptors or inhibit the catalytic activity of the three proteases. CONCLUSIONS AND IMPLICATIONS GB88 inhibits the capacity of canonical and biased protease agonists of PAR2 to cause nociception and inflammation.
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Affiliation(s)
- T Lieu
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Australia
| | - E Savage
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Australia
| | - P Zhao
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Australia
| | - L Edgington-Mitchell
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Australia
| | - N Barlow
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Australia
| | - R Bron
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Australia
| | - D P Poole
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Australia
- Departments of Anatomy and Neuroscience, University of Melbourne, Melbourne, Australia
| | - P McLean
- Takeda Pharmaceuticals, Zurich, Switzerland
| | - R-J Lohman
- Centre for Inflammation and Disease Research and Centre for Pain Research, Institute of Molecular Bioscience, University of Queensland, Brisbane, Australia
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, University of Queensland, Brisbane, Australia
| | - D P Fairlie
- Centre for Inflammation and Disease Research and Centre for Pain Research, Institute of Molecular Bioscience, University of Queensland, Brisbane, Australia
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, University of Queensland, Brisbane, Australia
| | - N W Bunnett
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Australia
- Departments of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Australia
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47
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Matynia A, Nguyen E, Sun X, Blixt FW, Parikh S, Kessler J, Pérez de Sevilla Müller L, Habib S, Kim P, Wang ZZ, Rodriguez A, Charles A, Nusinowitz S, Edvinsson L, Barnes S, Brecha NC, Gorin MB. Peripheral Sensory Neurons Expressing Melanopsin Respond to Light. Front Neural Circuits 2016; 10:60. [PMID: 27559310 PMCID: PMC4978714 DOI: 10.3389/fncir.2016.00060] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 07/26/2016] [Indexed: 01/17/2023] Open
Abstract
The ability of light to cause pain is paradoxical. The retina detects light but is devoid of nociceptors while the trigeminal sensory ganglia (TG) contain nociceptors but not photoreceptors. Melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) are thought to mediate light-induced pain but recent evidence raises the possibility of an alternative light responsive pathway independent of the retina and optic nerve. Here, we show that melanopsin is expressed in both human and mouse TG neurons. In mice, they represent 3% of small TG neurons that are preferentially localized in the ophthalmic branch of the trigeminal nerve and are likely nociceptive C fibers and high-threshold mechanoreceptor Aδ fibers based on a strong size-function association. These isolated neurons respond to blue light stimuli with a delayed onset and sustained firing, similar to the melanopsin-dependent intrinsic photosensitivity observed in ipRGCs. Mice with severe bilateral optic nerve crush exhibit no light-induced responses including behavioral light aversion until treated with nitroglycerin, an inducer of migraine in people and migraine-like symptoms in mice. With nitroglycerin, these same mice with optic nerve crush exhibit significant light aversion. Furthermore, this retained light aversion remains dependent on melanopsin-expressing neurons. Our results demonstrate a novel light-responsive neural function independent of the optic nerve that may originate in the peripheral nervous system to provide the first direct mechanism for an alternative light detection pathway that influences motivated behavior.
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Affiliation(s)
- Anna Matynia
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLALos Angeles, CA, USA; Brain Research Institute, UCLALos Angeles, CA, USA
| | - Eileen Nguyen
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLA Los Angeles, CA, USA
| | - Xiaoping Sun
- Department of Neurobiology and Medicine, David Geffen School of Medicine, UCLA Los Angeles, CA, USA
| | - Frank W Blixt
- Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University Lund, Sweden
| | - Sachin Parikh
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLALos Angeles, CA, USA; Brain Research Institute, UCLALos Angeles, CA, USA
| | - Jason Kessler
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLA Los Angeles, CA, USA
| | | | - Samer Habib
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLA Los Angeles, CA, USA
| | - Paul Kim
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLA Los Angeles, CA, USA
| | - Zhe Z Wang
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLA Los Angeles, CA, USA
| | - Allen Rodriguez
- Department of Neurobiology and Medicine, David Geffen School of Medicine, UCLA Los Angeles, CA, USA
| | - Andrew Charles
- Brain Research Institute, UCLALos Angeles, CA, USA; Department of Neurology, David Geffen School of Medicine, UCLALos Angeles, CA, USA
| | - Steven Nusinowitz
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLA Los Angeles, CA, USA
| | - Lars Edvinsson
- Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University Lund, Sweden
| | - Steven Barnes
- Department of Neurobiology and Medicine, David Geffen School of Medicine, UCLALos Angeles, CA, USA; Departments of Physiology & Biophysics and Ophthalmology and Visual Sciences, Dalhousie UniversityHalifax, NS, Canada
| | - Nicholas C Brecha
- Brain Research Institute, UCLALos Angeles, CA, USA; Department of Neurobiology and Medicine, David Geffen School of Medicine, UCLALos Angeles, CA, USA; Veterans Administration Greater Los Angeles Health SystemLos Angeles, CA, USA
| | - Michael B Gorin
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLALos Angeles, CA, USA; Brain Research Institute, UCLALos Angeles, CA, USA
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48
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Giblin JP, Comes N, Strauss O, Gasull X. Ion Channels in the Eye: Involvement in Ocular Pathologies. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2015; 104:157-231. [PMID: 27038375 DOI: 10.1016/bs.apcsb.2015.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The eye is the sensory organ of vision. There, the retina transforms photons into electrical signals that are sent to higher brain areas to produce visual sensations. In the light path to the retina, different types of cells and tissues are involved in maintaining the transparency of avascular structures like the cornea or lens, while others, like the retinal pigment epithelium, have a critical role in the maintenance of photoreceptor function by regenerating the visual pigment. Here, we have reviewed the roles of different ion channels expressed in ocular tissues (cornea, conjunctiva and neurons innervating the ocular surface, lens, retina, retinal pigment epithelium, and the inflow and outflow systems of the aqueous humor) that are involved in ocular disease pathophysiologies and those whose deletion or pharmacological modulation leads to specific diseases of the eye. These include pathologies such as retinitis pigmentosa, macular degeneration, achromatopsia, glaucoma, cataracts, dry eye, or keratoconjunctivitis among others. Several disease-associated ion channels are potential targets for pharmacological intervention or other therapeutic approaches, thus highlighting the importance of these channels in ocular physiology and pathophysiology.
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Affiliation(s)
- Jonathan P Giblin
- Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Nuria Comes
- Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | | | - Xavier Gasull
- Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
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49
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Launay PS, Reboussin E, Liang H, Kessal K, Godefroy D, Rostene W, Sahel JA, Baudouin C, Melik Parsadaniantz S, Reaux Le Goazigo A. Ocular inflammation induces trigeminal pain, peripheral and central neuroinflammatory mechanisms. Neurobiol Dis 2015; 88:16-28. [PMID: 26747211 DOI: 10.1016/j.nbd.2015.12.017] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 12/22/2015] [Accepted: 12/25/2015] [Indexed: 12/30/2022] Open
Abstract
Ocular surface diseases are among the most frequent ocular pathologies, with prevalence ranging from 20% of the general population. In addition, ocular pain following corneal injury is frequently observed in clinic. The aim of the study was to characterize the peripheral and central neuroinflammatory process in the trigeminal pathways in response to cornea alteration induced by chronic topical instillations of 0.2% benzalkonium chloride (BAC) in male C57BL/6J mice. In vitro BAC induced neurotoxicity and increases neuronal (FOS, ATF3) and pro-inflammatory (IL-6) markers in primary mouse trigeminal ganglion culture. BAC-treated mice exhibited 7days after the treatment reduced aqueous tear production and increased inflammatory cell infiltration in the cornea. Hypertonic saline-evoked eye wipe behavior was enhanced in BAC-treated animals that exhibited increased FOS, ATF3 and Iba1 immunoreactivity in the trigeminal ganglion. Ocular inflammation is associated with a significant increase in IL-6 and TNF-α mRNA expression in the trigeminal ganglion. We reported a strong increase in FOS and Iba1 positive cells in particular in the sensory trigeminal complex at the ipsilateral interpolaris/caudalis (Vi/Vc) transition and Vc/upper cervical cord (Vc/C1) regions. In addition, activated microglial cells were tightly wrapped around activated FOS neurons in both regions and phosphorylated p38 mitogen-activated protein kinase was markedly enhanced specifically in microglial cells during ocular inflammation. Similar data were obtained in the facial motor nucleus. These neuroanatomical data correlated with the increase in mRNA expression of pro-inflammatory (TNF-α, IL-6, CCL2) and neuronal (FOS and ATF3) markers. Interestingly, the suppression of corneal inflammation 10days following the end of BAC treatment resulted in a marked attenuation of peripheral and central changes observed in pathological conditions. This study provides the first demonstration that corneal inflammation induces activation of neurons and microglial p38 MAPK pathway within sensory trigeminal complex. These results suggest that this altered activity in intracellular signaling caused by ocular inflammation might play a priming role in the central sensitization of ocular related brainstem circuits, which represents a significant factor in ocular pain development.
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Affiliation(s)
- Pierre-Serge Launay
- INSERM, U968, Paris, F-75012, France; Sorbonne Universités, Université UPMC, Paris 06, UM 80, Institut de la Vision, 75012 Paris, France; CNRS, UMR 7210, Paris F-75012, France
| | - Elodie Reboussin
- INSERM, U968, Paris, F-75012, France; Sorbonne Universités, Université UPMC, Paris 06, UM 80, Institut de la Vision, 75012 Paris, France; CNRS, UMR 7210, Paris F-75012, France
| | - Hong Liang
- INSERM, U968, Paris, F-75012, France; Sorbonne Universités, Université UPMC, Paris 06, UM 80, Institut de la Vision, 75012 Paris, France; CNRS, UMR 7210, Paris F-75012, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris F-75012, France
| | - Karima Kessal
- INSERM, U968, Paris, F-75012, France; Sorbonne Universités, Université UPMC, Paris 06, UM 80, Institut de la Vision, 75012 Paris, France; CNRS, UMR 7210, Paris F-75012, France
| | - David Godefroy
- INSERM, U968, Paris, F-75012, France; Sorbonne Universités, Université UPMC, Paris 06, UM 80, Institut de la Vision, 75012 Paris, France; CNRS, UMR 7210, Paris F-75012, France
| | - William Rostene
- INSERM, U968, Paris, F-75012, France; Sorbonne Universités, Université UPMC, Paris 06, UM 80, Institut de la Vision, 75012 Paris, France; CNRS, UMR 7210, Paris F-75012, France
| | - Jose-Alain Sahel
- INSERM, U968, Paris, F-75012, France; Sorbonne Universités, Université UPMC, Paris 06, UM 80, Institut de la Vision, 75012 Paris, France; CNRS, UMR 7210, Paris F-75012, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris F-75012, France
| | - Christophe Baudouin
- INSERM, U968, Paris, F-75012, France; Sorbonne Universités, Université UPMC, Paris 06, UM 80, Institut de la Vision, 75012 Paris, France; CNRS, UMR 7210, Paris F-75012, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris F-75012, France
| | - Stéphane Melik Parsadaniantz
- INSERM, U968, Paris, F-75012, France; Sorbonne Universités, Université UPMC, Paris 06, UM 80, Institut de la Vision, 75012 Paris, France; CNRS, UMR 7210, Paris F-75012, France
| | - Annabelle Reaux Le Goazigo
- INSERM, U968, Paris, F-75012, France; Sorbonne Universités, Université UPMC, Paris 06, UM 80, Institut de la Vision, 75012 Paris, France; CNRS, UMR 7210, Paris F-75012, France.
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50
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Bron R, Bunnett NW. Antibodies: friend or foe? Am J Physiol Gastrointest Liver Physiol 2015; 309:G717-8. [PMID: 26381706 DOI: 10.1152/ajpgi.00312.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 09/10/2015] [Indexed: 01/31/2023]
Affiliation(s)
- Romke Bron
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Nigel W Bunnett
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
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