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Chen M, Seo S, Simmons X, Maroud Y, Wong T, Schubert W, Yiu SC. Precise longitudinal monitoring of corneal change through in vivo confocal microscopy in a rat dry eye disease model. Mol Vis 2024; 30:150-159. [PMID: 39076769 PMCID: PMC11286106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 03/18/2024] [Indexed: 07/31/2024] Open
Abstract
Purpose While lacrimal gland removal is commonly used in animal models to replicate dry eye disease, research into systematically monitoring dry eye disease's longitudinal pathological changes is limited. In vivo confocal microscopy (Heidelberg Retina Tomograph 3 with a Rostock Cornea Module, Heidelberg Engineering Inc., Franklin, MA) can non-invasively reveal corneal histopathological structures. To monitor dry-eye-disease-related changes in corneal structures, we developed a precise monitoring method using in vivo confocal microscopy in a rat double lacrimal gland removal model. Methods Five Sprague-Dawley rats (age 8-9 weeks, male) underwent double lacrimal gland removal. Modified Schirmer's tear test, blink tests, and in vivo confocal microscopy images were acquired pre-surgery and at 1, 2, and 4 weeks post-surgery. Three individual stromal nerves were selected per eye as guide images, and images of the corresponding sub-basal nerve plexus area were acquired via volume acquisition. The same area was re-imaged in subsequent weeks. Results After double lacrimal gland removal, tear production was reduced by 60%, and the blink rate increased 10 times compared to pre-surgery. Starting from 1 week after surgery, in vivo confocal microscopy showed increased sub-basal nerve plexus nerve fiber density with inflammatory cell infiltration at the sub-basal nerve plexus layer and remained at an elevated level at 2 and 4 weeks post-surgery. Conclusions We demonstrated that our precise monitoring method revealed detailed changes in the corneal nerves, the epithelium, and the stroma.
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Affiliation(s)
- Minjie Chen
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Stefanie Seo
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Xianni Simmons
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Youssef Maroud
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Trystin Wong
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | - Samuel C Yiu
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
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Wan MM, Jin T, Fu ZY, Lai SH, Gao WP. Electroacupuncture Alleviates Dry Eye Ocular Pain Through TNF-ɑ Mediated ERK1/2/P2X 3R Signaling Pathway in SD Rats. J Pain Res 2023; 16:4241-4252. [PMID: 38107367 PMCID: PMC10725190 DOI: 10.2147/jpr.s436258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 12/04/2023] [Indexed: 12/19/2023] Open
Abstract
Purpose This study aimed to examine electroacupuncture's influence on ocular pain and its potential modulation of the TNF-ɑ mediated ERK1/2/P2X3R signaling pathway in dry eye-induced rat models. Methods Male Sprague-Dawley rats with induced dry eye, achieved through extraorbital lacrimal gland removal, were treated with electroacupuncture. Comprehensive metrics such as the corneal mechanical perception threshold, palpebral fissure height, eyeblink frequency, eye wiping duration, behavioral changes in the open field test, and the forced swimming test were employed. Additionally, morphological changes in microglia and neurons were observed. Expression patterns of key markers, TNF-ɑ, TNFR1, p-ERK1/2, and P2X3R, in the trigeminal ganglion (TG) and spinal trigeminal nucleus caudalis (SpVc) regions, were studied with etanercept serving as a control to decipher the biochemistry of electroacupuncture's therapeutic effects. Results Electroacupuncture treatment demonstrated a notable decrease in the corneal mechanical perception threshold, improvement in palpebral fissure height, and significant reductions in both eyeblink frequency and eye wiping duration. Moreover, it exhibited a promising role in anxiety alleviation. Notably, the technique effectively diminished ocular pain by curbing microglial and neuronal activation in the TG and SpVc regions. Furthermore, it potently downregulated TNF-ɑ, TNFR1, p-ERK1/2, and P2X3R expression within these regions. Conclusion Electroacupuncture attenuated damage to sensory nerve pathways, reduced pain, and eased anxiety in dry eye-afflicted rats. The findings suggest a crucial role of TNF-ɑ mediated ERK1/2/P2X3R signaling pathway inhibition by electroacupuncture in these benefits.
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Affiliation(s)
- Mi-Mi Wan
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, People’s Republic of China
| | - Tuo Jin
- Department of Ophthalmology, Kunshan Hospital of Chinese Medicine, Suzhou, People’s Republic of China
| | - Zhang-Yitian Fu
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, People’s Republic of China
| | - Si-Hua Lai
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, People’s Republic of China
| | - Wei-Ping Gao
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, People’s Republic of China
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3
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Jin T, Liu X, Li Y, Li PC, Wan MM, Li LJ, Shi L, Fu ZY, Gao WP. Electroacupuncture Reduces Ocular Surface Neuralgia in Dry-Eyed Guinea Pigs by Inhibiting the Trigeminal Ganglion and Spinal Trigeminal Nucleus Caudalis P2X 3R-PKC Signaling Pathway. Curr Eye Res 2023; 48:546-556. [PMID: 36803321 DOI: 10.1080/02713683.2023.2176886] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
PURPOSE To observe the effects of electroacupuncture on ocular surface neuralgia and the P2X3R-PKC signaling pathway in guinea pigs with dry eye. METHODS A dry eye guinea pig model was established by subcutaneous injection of scopolamine hydrobromide. Guinea pigs were monitored for body weight, palpebral fissure height, number of blinks, corneal fluorescein staining score, phenol red thread test, and corneal mechanical perception threshold. Histopathological changes and mRNA expression of P2X3R and protein kinase C in the trigeminal ganglion and spinal trigeminal nucleus caudalis were observed. We performed a second part of the experiment, which involved the P2X3R-specific antagonist A317491 and the P2X3R agonist ATP in dry-eyed guinea pigs to further validate the involvement of the P2X3R-protein kinase C signaling pathway in the regulation of ocular surface neuralgia in dry eye. The number of blinks and corneal mechanical perception threshold were monitored before and 5 min after subconjunctival injection and the protein expression of P2X3R and protein kinase C was detected in the trigeminal ganglion and spinal trigeminal nucleus caudalis of guinea pigs. RESULTS Dry-eyed guinea pigs showed pain-related manifestations and the expression of P2X3R and protein kinase C in the trigeminal ganglion and spinal trigeminal nucleus caudalis was upregulated. Electroacupuncture reduced pain-related manifestations and inhibited the expression of P2X3R and protein kinase C in the trigeminal ganglion and spinal trigeminal nucleus caudalis. Subconjunctival injection of A317491 attenuated corneal mechanoreceptive nociceptive sensitization in dry-eyed guinea pigs, while ATP blocked the analgesic effect of electroacupuncture. CONCLUSIONS Electroacupuncture reduced ocular surface sensory neuralgia in dry-eyed guinea pigs, and the mechanism of action may be associated with the inhibition of the P2X3R-protein kinase C signaling pathway in the trigeminal ganglion and spinal trigeminal nucleus caudalis by electroacupuncture.
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Affiliation(s)
- Tuo Jin
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Xue Liu
- Department of Ophthalmology, Affiliated Hospital of Gansu University of Chinese Medicine, Lanzhou, China
| | - Ying Li
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Pei-Chen Li
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Mi-Mi Wan
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Liu-Jiao Li
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Li Shi
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Zhang-Yitian Fu
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Wei-Ping Gao
- Department of Ophthalmology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
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4
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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: 16] [Impact Index Per Article: 8.0] [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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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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6
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Bereiter DA, Rahman M, Ahmed F, Thompson R, Luong N, Olson JK. Title: P2x7 Receptor Activation and Estrogen Status Drive Neuroinflammatory Mechanisms in a Rat Model for Dry Eye. Front Pharmacol 2022; 13:827244. [PMID: 35479310 PMCID: PMC9037241 DOI: 10.3389/fphar.2022.827244] [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: 12/01/2021] [Accepted: 03/16/2022] [Indexed: 11/30/2022] Open
Abstract
Dry eye disease (DED) is recognized as a chronic inflammatory condition with an increase in tear osmolarity and loss of tear film integrity. DED is often accompanied by adverse ocular symptoms which are more prevalent in females than males. The basis for ocular hyperalgesia in DED remains uncertain; however, both peripheral and central neural mechanisms are implicated. A model for aqueous deficient DED, exorbital gland excision, was used to determine if activation of the purinergic receptor subtype 7, P2X7R, expressed by non-neural cells in peripheral and central trigeminal nerve pathways, contributed to persistent ocular hyperalgesia. Densitometry of trigeminal brainstem sections revealed increases in P2X7R, the myeloid cell marker Iba1, and the inflammasome, NLRP3, of estradiol-treated DED females compared to estradiol-treated sham females, while expression in DED males and DED females not given estradiol displayed minor changes. No evidence of immune cell infiltration into the trigeminal brainstem was seen in DED rats; however, markers for microglia activation (Iba1) were increased in all groups. Isolated microglia expressed increased levels of P2X7R and P2X4R, IL-1β (Ιnterleukin-1β), NLRP3, and iNOS (nitric oxide synthase). Further, estradiol-treated DED females displayed greater increases in P2X7R, IL-1β and NLRP3 expression compared to untreated DED females. Orbicularis oculi muscle activity (OOemg) evoked by ocular instillation of hypertonic saline (HS) was recorded as a surrogate measure of ocular hyperalgesia and was markedly enhanced in all DED groups compared to sham rats. Systemic minocycline reduced HS-evoked OOemg in all DED groups compared to sham rats. Local microinjection in the caudal trigeminal brainstem of an antagonist for P2X7R (A804598) greatly reduced HS-evoked OOemg activity in all DE groups, while responses in sham groups were not affected. Intra-trigeminal ganglion injection of siRNA for P2X7R significantly reduced HS-evoked OOemg activity in all DED groups, while evoked responses in sham animals were not affected. These results indicated that activation of P2X7R at central and peripheral sites in trigeminal pain pathways contributed to an increase in ocular hyperalgesia and microglia activation in DED males and females. Estrogen treatment in females further amplified ocular hyperalgesia and neuroimmune responses in this model for aqueous deficient DED.
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Affiliation(s)
- David A Bereiter
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States
| | - Mostafeezur Rahman
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States
| | - Fabeeha Ahmed
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States
| | - Randall Thompson
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States
| | - Nhungoc Luong
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States
| | - Julie K Olson
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States
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7
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Hamity MV, Kolker SJ, Hegarty DM, Blum C, Langmack L, Aicher SA, Hammond DL. Nicotinamide Riboside Alleviates Corneal and Somatic Hypersensitivity Induced by Paclitaxel in Male Rats. Invest Ophthalmol Vis Sci 2022; 63:38. [PMID: 35084430 PMCID: PMC8802023 DOI: 10.1167/iovs.63.1.38] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 12/28/2021] [Indexed: 12/13/2022] Open
Abstract
Purpose Patients receiving chemotherapy may experience ocular discomfort and dry eye-like symptoms; the latter may be neuropathic in nature. This study assessed corneal and somatic hypersensitivity in male rats treated with paclitaxel and whether it was relieved by nicotinamide riboside (NR). Methods Corneal sensitivity to tactile and chemical stimulation, basal tear production, and sensitivity of the hindpaw to tactile and cool stimuli were assessed before and after paclitaxel in the absence and presence of sustained treatment with 500 mg/kg per os NR. Corneal nerve density and hindpaw intraepidermal nerve fiber (IENF) density were also examined. Results Paclitaxel-treated rats developed corneal hypersensitivity to tactile stimuli, enhanced sensitivity to capsaicin but not hyperosmolar saline, and increased basal tear production. Corneal nerve density visualized with anti-β-tubulin or calcitonin gene-related peptide (CGRP) was unaffected. Paclitaxel induced tactile and cool hypersensitivity of the hindpaw and a loss of nonpeptidergic hindpaw IENFs visualized with anti-protein gene product (PGP) 9.5 and CGRP. NR reversed tactile hypersensitivity of the cornea without suppressing tear production or chemosensitivity; it did not alter corneal afferent density. NR also reversed tactile and cool hypersensitivity of the hindpaw without reversing the loss of hindpaw IENFs. Conclusions These findings suggest that paclitaxel may be a good translational model for chemotherapy-induced ocular discomfort and that NR may be useful for its relief. The ability of NR to relieve somatic tactile hypersensitivity independent of changes in sensory nerve innervation suggests that reversal of terminal arbor degeneration is not critical to the actions of NR.
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Affiliation(s)
- Marta V. Hamity
- Department of Anesthesia, University of Iowa, Iowa City, Iowa, United States
| | - Sandra J. Kolker
- Department of Anesthesia, University of Iowa, Iowa City, Iowa, United States
| | - Deborah M. Hegarty
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon, United States
| | - Christopher Blum
- Department of Anesthesia, University of Iowa, Iowa City, Iowa, United States
| | - Lucy Langmack
- Department of Anesthesia, University of Iowa, Iowa City, Iowa, United States
| | - Sue A. Aicher
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon, United States
| | - Donna L. Hammond
- Department of Anesthesia, University of Iowa, Iowa City, Iowa, United States
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, Iowa, United States
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8
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Tei Y, Mikami Y, Ito M, Tomida T, Ohshima D, Hori Y, Adachi-Akahane S. Pathogenic Mechanism of Dry Eye-Induced Chronic Ocular Pain and a Mechanism-Based Therapeutic Approach. Invest Ophthalmol Vis Sci 2022; 63:7. [PMID: 34989761 PMCID: PMC8742529 DOI: 10.1167/iovs.63.1.7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Purpose Dry eye–induced chronic ocular pain is also called ocular neuropathic pain. However, details of the pathogenic mechanism remain unknown. The purpose of this study was to elucidate the pathogenic mechanism of dry eye–induced chronic pain in the anterior eye area and develop a pathophysiology-based therapeutic strategy. Methods We used a rat dry eye model with lacrimal gland excision (LGE) to elucidate the pathogenic mechanism of ocular neuropathic pain. Corneal epithelial damage, hypersensitivity, and hyperalgesia were evaluated on the LGE side and compared with the sham surgery side. We analyzed neuronal activity, microglial and astrocytic activity, α2δ–1 subunit expression, and inhibitory interneurons in the trigeminal nucleus. We also evaluated the therapeutic effects of ophthalmic treatment and chronic pregabalin administration on dry eye–induced ocular neuropathic pain. Results Dry eye caused hypersensitivity and hyperalgesia on the LGE side. In the trigeminal nucleus of the LGE side, neuronal hyperactivation, transient activation of microglia, persistent activation of astrocytes, α2δ–1 subunit upregulation, and reduced numbers of inhibitory interneurons were observed. Ophthalmic treatment alone did not improve hyperalgesia. In contrast, continuous treatment with pregabalin effectively ameliorated hypersensitivity and hyperalgesia and normalized neural activity, α2δ–1 subunit upregulation, and astrocyte activation. Conclusions These results suggest that dry eye–induced hypersensitivity and hyperalgesia are caused by central sensitization in the trigeminal nucleus with upregulation of the α2δ–1 subunit. Here, we showed that pregabalin is effective for treating dry eye–induced ocular neuropathic pain even after chronic pain has been established.
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Affiliation(s)
- Yuto Tei
- Department of Ophthalmology, Toho University Graduate School of Medicine, Tokyo, Japan.,Department of Ophthalmology, Faculty of Medicine, Toho University, Tokyo, Japan.,Department of Physiology, Toho University Graduate School of Medicine, Tokyo, Japan
| | - Yoshinori Mikami
- Department of Physiology, Faculty of Medicine, Toho University, Tokyo, Japan
| | - Masanori Ito
- Department of Physiology, Faculty of Medicine, Toho University, Tokyo, Japan
| | - Taichiro Tomida
- Department of Physiology, Toho University Graduate School of Medicine, Tokyo, Japan.,Department of Physiology, Faculty of Medicine, Toho University, Tokyo, Japan
| | - Daisuke Ohshima
- Department of Physiology, Faculty of Medicine, Toho University, Tokyo, Japan
| | - Yuichi Hori
- Department of Ophthalmology, Toho University Graduate School of Medicine, Tokyo, Japan.,Department of Ophthalmology, Faculty of Medicine, Toho University, Tokyo, Japan
| | - Satomi Adachi-Akahane
- Department of Physiology, Toho University Graduate School of Medicine, Tokyo, Japan.,Department of Physiology, Faculty of Medicine, Toho University, Tokyo, Japan
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9
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Mecum NE, Russell R, Lee J, Sullivan C, Meng ID. Optogenetic Inhibition of Nav1.8 Expressing Corneal Afferents Reduces Persistent Dry Eye Pain. Invest Ophthalmol Vis Sci 2021; 62:15. [PMID: 34787642 PMCID: PMC8606841 DOI: 10.1167/iovs.62.14.15] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The aim of the present study was to investigate the contribution of Nav1.8 expressing corneal afferent neurons to the presence of ongoing pain in lacrimal gland excision (LGE)-induced dry eye. Methods The proton pump archaerhodopsin-3/eGFP (ArchT/eGFP) was conditionally expressed in corneal afferents using Nav1.8-cre mice. Dry eye was produced by unilateral LGE. Real time place preference was assessed using a three-chamber apparatus. A neutral, unlit center chamber was flanked by one illuminated with a control light and one illuminated with an ArchT activating light. For real-time preference, animals were placed in the neutral chamber and tracked over five 10-minute sessions, with the lights turned on during the second and fourth sessions. In other studies, movement was tracked over three 10-minute sessions (the lights turned on only during the second session), with animals tested once per day over the course of 4 days. A local anesthetic was used to examine the role of ongoing corneal afferent activity in producing place preference. Results The corneal afferent nerves and trigeminal ganglion cell bodies showed a robust eGFP signal in Nav1.8-cre;ArchT/eGFP mice. After LGE, Nav1.8-cre;ArchT/eGFP mice demonstrated a preference for the ArchT activating light paired chamber. Preference was prevented with pre-application to the cornea of a local anesthetic. Nav1.8-cre;ArchT/eGFP mice with sham surgery and LGE wild-type control mice did not develop preference. Conclusions Results indicate LGE-induced persistent, ongoing pain, driven by Nav1.8 expressing corneal afferents. Inhibition of these neurons represents a potential strategy for treating ongoing dry eye-induced pain.
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Affiliation(s)
- Neal E Mecum
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States.,Molecular and Biomedical Sciences, University of Maine, Orono, Maine, United States
| | - Rachel Russell
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States
| | - Jun Lee
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States.,Department of Complete Denture Prosthodontics, School of Dentistry, Nihon University, Tokyo, Japan
| | - Cara Sullivan
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States.,Graduate Studies in Biomedical Sciences and Engineering, University of Maine, Orono, Maine, United States
| | - Ian D Meng
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States.,Graduate Studies in Biomedical Sciences and Engineering, University of Maine, Orono, Maine, United States.,Department of Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine, United States
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10
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Huang W, Tourmouzis K, Perry H, Honkanen RA, Rigas B. Animal models of dry eye disease: Useful, varied and evolving (Review). Exp Ther Med 2021; 22:1394. [PMID: 34650642 PMCID: PMC8506913 DOI: 10.3892/etm.2021.10830] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/10/2021] [Indexed: 02/07/2023] Open
Abstract
Dry eye disease (DED), which is a prevalent disease that still lacks successful treatment options, remains a major challenge in ophthalmology. Multiple animal models of DED have been used to decipher its pathophysiology and to develop novel treatments. These models use mice, rats, rabbits, cats, dogs and non-human primates. Each model assesses aspects of DED by focusing on elements of the lacrimal functional unit, which controls the homeostasis of the tear film. The present review outlines representative DED animal models and assesses their contribution to the study of DED. Murine models are the most extensively used, followed by rabbit models; the latter offer the advantage of larger eyes, a favorable biochemical profile for drug studies, experimental ease and relatively low cost, contrasting with non-human primates, which, although closer to humans, are not as accessible and are expensive. No comprehensive ‘ideal’ animal model encompassing all aspects of human DED exists nor is it feasible. Investigators often choose an animal model based on their experimental needs and the following four features of a given model: The size of the eye, its biochemical composition, the available research reagents and cost. As research efforts in DED expand, more refined animal models are needed to supplement the enormous contribution made to date by existing models.
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Affiliation(s)
- Wei Huang
- Department of Ophthalmology, Stony Brook University, Stony Brook, NY 11794, USA.,Department of Ophthalmology, Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | | | - Henry Perry
- Ophthalomology Consultants of Long Island, Westbury, NY 11590, USA
| | - Robert A Honkanen
- Department of Ophthalmology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Basil Rigas
- Department of Preventive Medicine, Stony Brook University, Stony Brook, NY 11794, USA
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11
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Diel RJ, Mehra D, Kardon R, Buse DC, Moulton E, Galor A. Photophobia: shared pathophysiology underlying dry eye disease, migraine and traumatic brain injury leading to central neuroplasticity of the trigeminothalamic pathway. Br J Ophthalmol 2021; 105:751-760. [PMID: 32703784 PMCID: PMC8022288 DOI: 10.1136/bjophthalmol-2020-316417] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/26/2020] [Accepted: 06/29/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Photophobia is a potentially debilitating symptom often found in dry eye disease (DE), migraine and traumatic brain injury (TBI). METHODS We conducted a review of the literature via a PubMed search of English language articles with a focus on how photophobia may relate to a shared pathophysiology across DE, migraine and TBI. RESULTS DE, migraine and TBI are common conditions in the general population, are often comorbid, and share photophobia as a symptom. Across the three conditions, neural dysregulation of peripheral and central nervous system components is implicated in photophobia in various animal models and in humans. Enhanced activity of the neuropeptide calcitonin gene-related peptide (CGRP) is closely linked to photophobia. Current therapies for photophobia include glasses which shield the eyes from specific wavelengths, botulinum toxin, and inhibition of CGRP and its receptor. Many individuals have persistent photophobia despite the use of these therapies, and thus, development of new therapies is needed. CONCLUSIONS The presence of photophobia in DE, migraine and TBI suggests shared trigeminothalamic pathophysiologic mechanisms, as explained by central neuroplasticity and hypersensitivity mediated by neuropeptide CGRP. Treatment strategies which target neural pathways (ie, oral neuromodulators, transcutaneous nerve stimulation) should be considered in patients with persistent photophobia, specifically in individuals with DE whose symptoms are not controlled with traditional therapies.
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Affiliation(s)
- Ryan J Diel
- Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals & Clinics, Iowa City, Iowa, USA
| | - Divy Mehra
- Ophthalmology, VA Medical Center Miami, Miami, Florida, USA
- Ophthalmology, University of Miami Bascom Palmer Eye Institute, Miami, Florida, USA
| | - Randy Kardon
- Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals & Clinics, Iowa City, Iowa, USA
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, Iowa City, IA, USA
| | - Dawn C Buse
- Albert Einstein College of Medicine Department of Neurology, Bronx, New York, USA
| | - Eric Moulton
- Department of Anesthesiology, Center for Pain and the Brain; Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Anat Galor
- Ophthalmology, VA Medical Center Miami, Miami, Florida, USA
- Ophthalmology, University of Miami Bascom Palmer Eye Institute, Miami, Florida, USA
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12
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Capsazepine decreases corneal pain syndrome in severe dry eye disease. J Neuroinflammation 2021; 18:111. [PMID: 33975636 PMCID: PMC8114509 DOI: 10.1186/s12974-021-02162-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/29/2021] [Indexed: 11/26/2022] Open
Abstract
Background Dry eye disease (DED) is a multifactorial disease of the ocular surface accompanied by neurosensory abnormalities. Here, we evaluated the effectiveness of transient receptor potential vanilloid-1 (TRPV1) blockade to alleviate ocular pain, neuroinflammation, and anxiety-like behavior associated with severe DED. Methods Chronic DED was induced by unilateral excision of the Harderian and extraorbital lacrimal glands of adult male mice. Investigations were conducted at 21 days after surgery. The mRNA levels of TRPV1, transient receptor potential ankyrin-1 (TRPA1), and acid-sensing ion channels 1 and 3 (ASIC1 and ASIC3) in the trigeminal ganglion (TG) were evaluated by RNAscope in situ hybridization. Multi-unit extracellular recording of ciliary nerve fiber activity was used to monitor spontaneous and stimulated (cold, heat, and acid) corneal nerve responsiveness in ex vivo eye preparations. DED mice received topical instillations of the TRPV1 antagonist (capsazepine) twice a day for 2 weeks from d7 to d21 after surgery. The expression of genes involved in neuropathic and inflammatory pain was evaluated in the TG using a global genomic approach. Chemical and mechanical corneal nociception and spontaneous ocular pain were monitored. Finally, anxiety-like behaviors were assessed by elevated plus maze and black and white box tests. Results First, in situ hybridization showed DED to trigger upregulation of TRPV1, TRPA1, ASIC1, and ASIC3 mRNA in the ophthalmic branch of the TG. DED also induced overexpression of genes involved in neuropathic and inflammatory pain in the TG. Repeated instillations of capsazepine reduced corneal polymodal responsiveness to heat, cold, and acidic stimulation in ex vivo eye preparations. Consistent with these findings, chronic capsazepine instillation inhibited the upregulation of genes involved in neuropathic and inflammatory pain in the TG of DED animals and reduced the sensation of ocular pain, as well as anxiety-like behaviors associated with severe DED. Conclusion These data provide novel insights on the effectiveness of TRPV1 antagonist instillation in alleviating abnormal corneal neurosensory symptoms induced by severe DED, opening an avenue for the repositioning of this molecule as a potential analgesic treatment for patients suffering from chronic DED.
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Kanda T, Gotoh M, Makino A, Furumoto K, Shimizu Y, Itoi T, Maeta N, Furukawa T. Effect of Different Doses of Atipamezole on Reversal of Medetomidine-Induced Tear-Flow Decrease in Rats. Vet Sci 2020; 7:vetsci7040197. [PMID: 33287407 PMCID: PMC7761856 DOI: 10.3390/vetsci7040197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/28/2020] [Accepted: 12/02/2020] [Indexed: 11/16/2022] Open
Abstract
It has been reported that α2-adrenoceptor agonists such as medetomidine decrease tear flow in many species, including rats. Few studies have investigated the involvement of α2-adrenoceptor in decreased tear flow; the issue has not been illustrated sufficiently. Therefore, we aimed to investigate the effect of different doses of atipamezole on the reversal of medetomidine-induced tear-flow decrease to reveal the specific involvement of α2-adrenoceptor. Treatment with 400, 800, or 1600 µg/kg atipamezole (or saline as the control) was intramuscularly administered to rats 15 min following intramuscular administration of 200 µg/kg medetomidine. After medetomidine administration, tear flow was measured using a phenol red thread test (PRTT). PRTT values decreased significantly after 200 µg/kg medetomidine administration. The PRTT values after 800 (optimal dose to reverse) and 1600 µg/kg atipamezole administration reached baseline, but never exceeded it significantly. Treatment with 400 µg/kg atipamezole also reversed the decrease in PRTT value but the PRTT remained lower than baseline. The optimal dose and the higher dose of atipamezole fully reversed the medetomidine-induced decrease in tear flow to the baseline level in rats, while the lower dose of atipamezole partially recovered tear flow.
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Affiliation(s)
- Teppei Kanda
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan; (K.F.); (Y.S.); (T.I.); (N.M.)
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
- Correspondence:
| | - Manami Gotoh
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Ayumi Makino
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Kayo Furumoto
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan; (K.F.); (Y.S.); (T.I.); (N.M.)
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Yuki Shimizu
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan; (K.F.); (Y.S.); (T.I.); (N.M.)
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Takamasa Itoi
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan; (K.F.); (Y.S.); (T.I.); (N.M.)
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Noritaka Maeta
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan; (K.F.); (Y.S.); (T.I.); (N.M.)
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Toshinori Furukawa
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
- Department of Animal Pharmaceutical Science, School of Pharmaceutical Science, Kyushu University of Health and Welfare, 1714-1 Yoshino-cho, Nobeoka, Miyazaki 882-8508, Japan
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Lelescu CA, Urdă-Cîmpean AE, Dumitraș DA, Taulescu M, Mureșan C. Effects of topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution and 1% ropivacaine hydrochloride on corneal sensitivity in rats. PLoS One 2020; 15:e0241567. [PMID: 33151993 PMCID: PMC7644035 DOI: 10.1371/journal.pone.0241567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 10/19/2020] [Indexed: 11/23/2022] Open
Abstract
The aim of the present study was to determine and compare the degree and duration of corneal anesthesia following topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution and 1% ropivacaine hydrochloride treatment in healthy rats. A randomized, blinded, crossover study was conducted on 20 healthy adult Wistar rats, following complete physical and ophthalmological examination. Baseline corneal touch threshold (CTT) was determined in the central corneal area of both eyes with a Cochet–Bonnet aesthesiometer, in mm filament length. Oxybuprocaine was randomly applied to one eye and 0.9% sterile sodium chloride solution was instilled into the contralateral eye. Subsequent CTT measurements were performed in both eyes 5 minutes after topical application and at 5-minute intervals thereafter for 75-minutes in the anesthetized eye. Following a 2-week washout period, this protocol was repeated with ropivacaine. Quantitative data were summarized as mean ± standard deviation, median and inter-quartile range (Q1–Q3). Repeated measures data were analyzed over time and between treatments using Friedman test and Wilcoxon signed-rank test with Bonferroni adjustment (p < 0.05). Baseline CTT values were 60 mm in all eyes. With oxybuprocaine, CTT values decreased significantly for 65 minutes (0–55 mm; p = 0.002) when compared with baseline; the maximal anesthetic effect (no blink response at 5 mm filament length) was maintained for up to 15 minutes (p < 0.0001). With ropivacaine, CTT values were significantly lower than baseline for 30 minutes (0–55 mm; p = 0.002), with a maximal anesthetic effect recorded at 5 minutes in 18 eyes (p < 0.0001). Oxybuprocaine induced a significantly lower CTT than ropivacaine (p = 0.002) from 10 to 65 minutes following topical application. Both anesthetic agents induced significant corneal anesthesia; however, oxybuprocaine provided a greater and longer anesthetic effect, making it more suitable for potentially painful ophthalmologic procedures.
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Affiliation(s)
| | - Andrada E. Urdă-Cîmpean
- Department of Medical Informatics and Biostatistics, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Daria A. Dumitraș
- Department of Biochemistry, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania
| | - Marian Taulescu
- Department of Pathology, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania
| | - Cosmin Mureșan
- Department of Surgery, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania
- * E-mail:
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Kaido M, Inoue S, Kawashima M, Ishida R, Nakamura S, Tsubota K. Role of transient receptor potential melastatin 8 activity in menthol-induced cold sensitivity and its qualitative perception in dry eye. Ocul Surf 2020; 19:307-312. [PMID: 33127598 DOI: 10.1016/j.jtos.2020.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/21/2020] [Accepted: 10/25/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate the role of transient receptor potential melastatin 8 (TRPM8) activity in menthol-induced cold sensitivity and its qualitative perception in patients with dry eye (DE). METHODS This prospective, cross-sectional, comparative study included 52 eyes of 52 subjects (mean age: 66.8 ± 9.2 years; range: 44-86) with a tear break-up time (TBUT) of ≤5 s. The participants were classified into three groups: 17 patients with DE symptoms and keratoconjunctival (KC) staining scores of ≥3 points (positive KC-DE group), 18 patients with DE symptoms and KC staining scores of <3 points (negative KC-DE group), and 17 individuals with KC staining scores of <3 points and no symptoms (non-DE control group). The menthol-induced cool sensation (M-cool) and TBUT were measured after administration of 2 μl of 1.0 mM menthol eye drops. Furthermore, participants answered a questionnaire regarding their stimulus perception (pleasant, unpleasant, or neither). RESULTS M-cool values were similar in the three groups. TBUT significantly increased in the negative KC-DE and control groups (P < 0.05) and remained unchanged in the positive KC-DE group (P > 0.05) after menthol administration. DE patients reported the sensation as pleasant or unpleasant, whereas most control participants were indifferent (P < 0.05). CONCLUSIONS While M-cold sensitivity was similar in DE and control groups, its qualitative perception differed between these groups. Thus, TRPM8 activation at the peripheral level alone may not be sufficient to account for the manifestation of discomfort symptoms associated with DE.
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Affiliation(s)
- Minako Kaido
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan; Wada Eye Clinic, Chiba, Japan; Ishida Eye Clinic, Shizuoka, Japan.
| | - Sachiko Inoue
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan; Haneginomori Eye Clinic, Tokyo, Japan
| | - Motoko Kawashima
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Reiko Ishida
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan; Ishida Eye Clinic, Shizuoka, Japan
| | - Shigeru Nakamura
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan; Tsubota Laboratory, Inc., Tokyo, Japan
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Lacrimal gland excision in male and female mice causes ocular pain and anxiety-like behaviors. Sci Rep 2020; 10:17225. [PMID: 33057056 PMCID: PMC7560880 DOI: 10.1038/s41598-020-73945-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 09/22/2020] [Indexed: 12/24/2022] Open
Abstract
Lacrimal gland excision (LGE) induced dry eye produces more severe corneal damage in female mice, yet signs of LGE-induced ocular pain and anxiety in male and female mice have not been characterized. Excision of either the extraorbital gland (single LGE), or both the extraorbital and intraorbital glands (double LGE) was performed in male and female C57BL/6J mice to induce moderate and severe dry eye. Ongoing pain was assessed by quantifying palpebral opening and evoked nociceptive responses after corneal application of capsaicin and menthol. The open-field and plus maze were used to assess anxiety. Single LGE caused a reduction in palpebral opening and an increase in capsaicin and menthol-evoked responses only in female mice. Furthermore, single LGE produced signs of increased anxiety in female but not male mice. Overall, female mice appear more susceptible to signs of ocular pain, irritation, and anxiety in response to aqueous tear deficiency.
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17
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Kanda T, Mizoguchi Y, Furumoto K, Shimizu Y, Maeta N, Furukawa T. Effect of Intramuscular Medetomidine Administration on Tear Flow in Rats. Vet Sci 2020; 7:vetsci7020042. [PMID: 32294903 PMCID: PMC7356148 DOI: 10.3390/vetsci7020042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 01/30/2023] Open
Abstract
Medetomidine has been reported to decrease tear flow significantly in dogs, cats, and pigs when used as a sedative or analgesic; however, there are no such reports when it comes to rats. The present study aimed to investigate the effect of medetomidine on tear flow in rats. Medetomidine in doses of 50, 100, or 200 µg/kg or a physiological saline solution as the control, were administered intramuscularly to male Slc:Wistar/ST rats. After the administration of medetomidine, tear flow in both eyes was measured using a phenol red thread tear test. The area under the curve (AUC) of phenol red thread test values from baseline to 8 h was calculated. Data were plotted against the dose of medetomidine and simple linear regression analysis was performed. The effect of the drug on phenol red thread test values was considered dose-related when linear analysis yielded a significant relationship. In all medetomidine-treated groups, tear flow decreased significantly in both eyes after administration, while no significant changes were observed in either eye in the control group. The AUC values from baseline to 8 h after administration in groups treated with 100 and 200 µg/kg of medetomidine were significantly lower in both the left and right eyes compared to the control group. The linear regression of the AUC values was significant for both eyes. Our results indicated that the intramuscular administration of medetomidine in rats decreased tear flow significantly in a dose-dependent manner.
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Affiliation(s)
- Teppei Kanda
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan
- Correspondence:
| | - Yuka Mizoguchi
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan
| | - Kayo Furumoto
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan
| | - Yuki Shimizu
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan
| | - Noritaka Maeta
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan
| | - Toshinori Furukawa
- Department of Animal Pharmaceutical Science, School of Pharmaceutical Science, Kyushu University of Health and Welfare, 1714-1 Yoshino-cho, Nobeoka, Miyazaki 882-8508, Japan
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18
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Abstract
Blinking sustains the corneal tear film generated by sexually dimorphic lacrimal and meibomian glands. Our study examines whether trigeminal control of blinking is also sexually dimorphic by investigating trigeminal reflex blinking, associative blink modification, and spontaneous blinking in male and female rats before and after unilateral dry eye caused by exorbital gland removal. Before gland removal, female rats exhibited a lower threshold for evoking trigeminal reflex blinks, a weaker effect of associative blink modification, and longer-duration spontaneous blinks than males. Spontaneous blink rate, reflex blink excitability, and occurrence of blink oscillations did not differ between the sexes. Reanalysis of previous data showed that humans showed the same blink sexual dimorphisms as rats. During the first 2 wk of dry eye, trigeminal blink circuit excitability and blink oscillations steadily rose in male rats, whereas excitability and blink oscillations did not change in females. Following dry eye, spontaneous blink duration increased for both males and females, whereas spontaneous blink rate remained constant for males but decreased for females. The associative modification treatment to depress trigeminal blink amplitude initially produced blink depression in males that converted to blink potentiation as trigeminal excitability rose, whereas females exhibited progressively more blink depression. These data indicated that dry eye increased excitability in male trigeminal reflex blink circuits at the expense of circuit modifiability, whereas trigeminal modifiability increased in females. This increased modifiability of female trigeminal blink circuits with dry eye may contribute to the preponderance of females developing the focal dystonia, benign essential blepharospasm.NEW & NOTEWORTHY All the elements controlling the corneal tear film are sexually dimorphic. Blinking, which smooths and maintains the tear film, also exhibits sex differences. Dry eye increases the sexual dimorphisms of blinking, including increased exaggeration of excitability in males and enhanced modifiability of the female trigeminal complex. This increased modifiability may explain female predominance in the development of the focal dystonia, benign essential blepharospasm.
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Affiliation(s)
- Ashley Culoso
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, New York
| | - Cynthia Lowe
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, New York
| | - Craig Evinger
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, New York
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Mecum NE, Cyr D, Malon J, Demers D, Cao L, Meng ID. Evaluation of Corneal Damage After Lacrimal Gland Excision in Male and Female Mice. Invest Ophthalmol Vis Sci 2019; 60:3264-3274. [PMID: 31369671 PMCID: PMC6675517 DOI: 10.1167/iovs.18-26457] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Lacrimal gland excision (LGE) has been utilized in several studies to model aqueous tear deficiency, yet sex as a biological variable has not been factored in to these reports. This study compared corneal pathology in male and female mice following LGE-induced dry eye. Methods An LGE of either the extraorbital lacrimal gland (single LGE) or both the extraorbital and intraorbital lacrimal glands (double LGE) was performed in male and female C57BL/6J and Balb/cJ mice to produce dry eye of graded severity. Following excision, tearing was evaluated with phenol red thread, and corneal fluorescein staining was scored to quantify the severity of damage. Corneas were evaluated for apoptosis by the TUNEL assay and for cell proliferation using Ki67 staining. Furthermore, corneas were harvested and analyzed for macrophages via flow cytometry. Results Baseline tearing levels were similar in male and female mice, and LGE resulted in comparable reductions in tearing with the lowest levels recorded after double LGE. As determined by fluorescein staining, LGE produced more severe damage to the cornea in female C57BL/6J and Balb/cJ mice. Double LGE increased TUNEL and Ki67 staining in the cornea, with greater increases found in female mice. Furthermore, LGE produced a greater increase in the total number of corneal macrophages in female mice. Conclusions These results indicate that female mice are more susceptible to LGE-induced corneal damage. The mechanisms involved in producing these sex differences still need to be elucidated but may involve increased inflammation and macrophage infiltration.
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Affiliation(s)
- Neal E Mecum
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States.,Molecular and Biomedical Sciences, University of Maine, Orono, Maine, United States
| | - Dan Cyr
- Department of Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine, United States
| | - Jennifer Malon
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States
| | - Danielle Demers
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States
| | - Ling Cao
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States.,Department of Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine, United States
| | - Ian D Meng
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States.,Department of Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine, United States
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Chronic dry eye induced corneal hypersensitivity, neuroinflammatory responses, and synaptic plasticity in the mouse trigeminal brainstem. J Neuroinflammation 2019; 16:268. [PMID: 31847868 PMCID: PMC6918709 DOI: 10.1186/s12974-019-1656-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 11/25/2019] [Indexed: 12/17/2022] Open
Abstract
Background Dry eye disease (DED) is a multifactorial disease associated with ocular surface inflammation, pain, and nerve abnormalities. We studied the peripheral and central neuroinflammatory responses that occur during persistent DED using molecular, cellular, behavioral, and electrophysiological approaches. Methods A mouse model of DED was obtained by unilateral excision of the extraorbital lachrymal gland (ELG) and Harderian gland (HG) of adult female C57BL/6 mice. In vivo tests were conducted at 7, 14, and 21 days (d) after surgery. Tear production was measured by a phenol red test and corneal alterations and inflammation were assessed by fluorescein staining and in vivo confocal microscopy. Corneal nerve morphology was evaluated by nerve staining. Mechanical corneal sensitivity was monitored using von Frey filaments. Multi-unit extracellular recording of ciliary nerve fiber activity was used to monitor spontaneous corneal nerve activity. RT-qPCR and immunostaining were used to determine RNA and protein levels at d21. Results We observed a marked reduction of tear production and the development of corneal inflammation at d7, d14, and d21 post-surgery in DED animals. Chronic DE induced a reduction of intraepithelial corneal nerve terminals. Behavioral and electrophysiological studies showed that the DED animals developed time-dependent mechanical corneal hypersensitivity accompanied by increased spontaneous ciliary nerve fiber electrical activity. Consistent with these findings, DED mice exhibited central presynaptic plasticity, demonstrated by a higher Piccolo immunoreactivity in the ipsilateral trigeminal brainstem sensory complex (TBSC). At d21 post-surgery, mRNA levels of pro-inflammatory (IL-6 and IL-1β), astrocyte (GFAP), and oxidative (iNOS2 and NOX4) markers increased significantly in the ipsilateral trigeminal ganglion (TG). This correlated with an increase in Iba1, GFAP, and ATF3 immunostaining in the ipsilateral TG of DED animals. Furthermore, pro-inflammatory cytokines (IL-6, TNFα, IL-1β, and CCL2), iNOS2, neuronal (ATF3 and FOS), and microglial (CD68 and Itgam) markers were also upregulated in the TBSC of DED animals at d21, along with increased immunoreactivity against GFAP and Iba1. Conclusions Overall, these data highlight peripheral sensitization and neuroinflammatory responses that participate in the development and maintenance of dry eye-related pain. This model may be useful to identify new analgesic molecules to alleviate ocular pain.
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Meng ID, Barton ST, Goodney I, Russell R, Mecum NE. Progesterone Application to the Rat Forehead Produces Corneal Antinociception. Invest Ophthalmol Vis Sci 2019; 60:1706-1713. [PMID: 31013343 PMCID: PMC6736375 DOI: 10.1167/iovs.18-26049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Ocular pain and discomfort are the most defining symptoms of dry eye disease. We determined the ability of topical progesterone to affect corneal sensitivity and brainstem processing of nociceptive inputs. Methods Progesterone or vehicle gel was applied to the shaved forehead in male Sprague Dawley rats. As a site control, gel also was applied to the cheek on the side contralateral to corneal stimulation. Corneal mechanical thresholds were determined using the Cochet-Bonnet esthesiometer in intact and lacrimal gland excision–induced dry eye animals. Eye wipe behaviors in response to hypertonic saline and capsaicin were examined, and corneal mustard oil-induced c-Fos immunohistochemistry was quantified in the brainstem spinal trigeminal nucleus. Results Progesterone gel application to the forehead, but not the contralateral cheek, increased corneal mechanical thresholds in intact and lacrimal gland excision animals beginning <30 minutes after treatment. Subcutaneous injection of the local anesthetic bupivacaine into the forehead region before application of progesterone prevented the increase in corneal mechanical thresholds. Furthermore, progesterone decreased capsaicin-evoked eye wipe behavior in intact animals and hypertonic saline evoked eye wipe behavior in dry eye animals. The number of Fos-positive neurons located in the caudal region of the spinal trigeminal nucleus after corneal mustard oil application was reduced in progesterone-treated animals. Conclusions Results from this study indicate that progesterone, when applied to the forehead, produces analgesia as indicated by increased corneal mechanical thresholds and decreased nociceptive responses to hypertonic saline and capsaicin.
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Affiliation(s)
- Ian D Meng
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States.,Department of Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine, United States
| | - Stephen T Barton
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States
| | - Ian Goodney
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States
| | - Rachel Russell
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States
| | - Neal E Mecum
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, United States.,Molecular and Biomedical Sciences, University of Maine, Orono, Maine, United States
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22
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Hegarty DM, David LL, Aicher SA. Lacrimal Gland Denervation Alters Tear Protein Composition and Impairs Ipsilateral Eye Closures and Corneal Nociception. Invest Ophthalmol Vis Sci 2019; 59:5217-5224. [PMID: 30372750 PMCID: PMC6203219 DOI: 10.1167/iovs.18-25267] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Purpose To evaluate spontaneous and evoked ocular sensory responses in rats after denervation of the lacrimal gland, as well as protein changes in tears that may mediate functional changes. Methods Sprague-Dawley rats served as subjects. The left lacrimal gland was partially denervated with saporin toxin conjugated to p75. Unilateral and bilateral eye closures (winks and blinks) and grooming behaviors were measured weekly. Nociceptive responses were evoked by ocular application of menthol; tear production was assessed using the phenol thread test. Relative changes in tear protein abundances were measured using a Tandem Mass Tagging approach. Results Denervation of the lacrimal gland reduced eye closure behavior, particularly in the ipsilateral eye, and eye wipe responses to noxious menthol were also reduced. Tear volume did not change, but tear protein composition was altered. Proteins implicated in the structural integrity of epithelial cells and in protective functions were reduced by lacrimal denervation, including keratins, serotransferrin, and beta-defensin. Other proteins that may modulate TRPM8 channels and alter sensory neuronal function were reduced, including arachidonate 15-lipoxygenase B. A low-abundance protein that responds to oxidative stress and injury, proteasome subunit beta type 10, was upregulated in denervated rats. Conclusions Denervation of the lacrimal gland causes long-lasting hypoalgesia, impairs the blink response, and alters tear proteins. Tear proteins were altered without changing tear volume. We speculate that impaired TRPM8 function in corneal sensory nerves may contribute to ocular hypoalgesia, supporting growing evidence that this transduction molecule is important for both nociceptive and spontaneous blinking behaviors.
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Affiliation(s)
- Deborah M Hegarty
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, Oregon, United States
| | - Larry L David
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon, United States
| | - Sue A Aicher
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, Oregon, United States
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23
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Honkanen R, Huang W, Huang L, Kaplowitz K, Weissbart S, Rigas B. A New Rabbit Model of Chronic Dry Eye Disease Induced by Complete Surgical Dacryoadenectomy. Curr Eye Res 2019; 44:863-872. [PMID: 30983427 DOI: 10.1080/02713683.2019.1594933] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Purpose/Aim: Dry eye disease (DED), common and suboptimally treated, is in need of novel animal models to understand its pathophysiology and assess the efficacy and other parameters of new pharmacological agents for its treatment. The more than 10 rabbit models of DED described to date have significant limitations including induction of mild disease, lack of consistency, and off-target effects when chemical agents are used for disease induction. Our aim was to develop a new model of chronic DED in rabbits that overcomes the limitations of existing models. MATERIALS AND METHODS We performed a complete surgical resection of all orbital lacrimal glands (LGs; dacryoadenectomy) in normal adult New Zealand White rabbits. One week after removal of the nictitating membrane, we surgically removed the orbital superior LG, followed by removal of the palpebral superior LG, and finally removal of the inferior LG. Surgery was performed under anesthesia, required about 1 h/eye, and was well-tolerated. RESULTS Dacryoadenectomy induced severe DED, evidenced by >90% reduction in the tear break up time test, 50% reduction in the Schirmer tear test, 10% increase in tear osmolarity, and a marked increase in the rose bengal staining score. DED was sustained and essentially unchanged for the eight weeks of observation. Sham-operated rabbits showed no such changes, with the exception of a non-significant and transient reduction in the tear break up time test, a response to ocular surgery. CONCLUSIONS This model of stable, chronic, predominantly aqueous-deficient DED recapitulates key clinical and histological features of human DED and is suitable for the study of ocular surface homeostasis, of the pathophysiology of DED, and of the efficacy of candidate drugs for DED treatment.
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Affiliation(s)
- Robert Honkanen
- a Department of Ophthalmology, Health Sciences Center L2 , NY , USA
| | - Wei Huang
- a Department of Ophthalmology, Health Sciences Center L2 , NY , USA.,b Second Xiangya Hospital, Central South University , Hunan , China
| | - Liqun Huang
- c Department of Medicine, Health Sciences Center L17 , NY , USA.,d Medicon Pharmaceuticals, Inc, Long Island High Technology Incubator , Stony Brook , NY , USA
| | - Kevin Kaplowitz
- a Department of Ophthalmology, Health Sciences Center L2 , NY , USA
| | - Sarah Weissbart
- a Department of Ophthalmology, Health Sciences Center L2 , NY , USA
| | - Basil Rigas
- e Department of Preventive Medicine, Stony Brook University , Stony Brook , NY , USA
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24
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Bereiter DA, Rahman M, Thompson R, Stephenson P, Saito H. TRPV1 and TRPM8 Channels and Nocifensive Behavior in a Rat Model for Dry Eye. Invest Ophthalmol Vis Sci 2019; 59:3739-3746. [PMID: 30046815 PMCID: PMC6059730 DOI: 10.1167/iovs.18-24304] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Persistent ocular surface pain occurs in moderate to severe dry eye disease (DE); however, the mechanisms that underlie this symptom remain uncertain. The aim of this study was to determine if the transient receptor potential vanilloid ion channels play a role in hypertonic saline (HS)-evoked corneal reflexes in a model for aqueous tear deficient DE. Methods Eye wipe behavior and orbicularis oculi muscle activity (OOemg) were measured after ocular instillation of HS, capsaicin, or menthol 14 days after exorbital gland removal. Total RNA and protein were measured from anterior eye segment and trigeminal ganglia of sham and DE rats. Results Eye wipe behavior was enhanced in DE rats after HS and capsaicin instillation, but not after menthol when compared to sham rats. DE rats displayed greater OOemg activity after HS and capsaicin, but not after menthol, compared to sham rats. HS-evoked OOemg activity was reduced by selective TRPV1 antagonists and by coapplication of capsaicin plus QX-314, a charged lidocaine derivative. Menthol did not affect OOemg activity; however, selective antagonism of TRPM8 reduced HS-evoked OOemg activity. TRPV1 protein levels were increased in anterior eye segment and trigeminal ganglion samples from DE rats, whereas TRPM8 levels were not affected. Conclusions These results suggest that TRPV1 plays a significant role in mediating enhanced nocifensive behavior in DE, while TRPM8 may play a lesser role. Strategies to target specific transducer molecules on corneal nerves may prove beneficial as adjunct therapies in managing ocular pain in moderate to severe cases of DE.
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Affiliation(s)
- David A Bereiter
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, Minnesota, United States
| | - Mostafeezur Rahman
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, Minnesota, United States
| | - Randall Thompson
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, Minnesota, United States
| | - Pannaporn Stephenson
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, Minnesota, United States
| | - Hiroto Saito
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, Minnesota, United States
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Shah M, Cabrera-Ghayouri S, Christie LA, Held KS, Viswanath V. Translational Preclinical Pharmacologic Disease Models for Ophthalmic Drug Development. Pharm Res 2019; 36:58. [PMID: 30805711 PMCID: PMC6394514 DOI: 10.1007/s11095-019-2588-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 02/08/2019] [Indexed: 12/14/2022]
Abstract
Preclinical models of human diseases are critical to our understanding of disease etiology, pathology, and progression and enable the development of effective treatments. An ideal model of human disease should capture anatomical features and pathophysiological mechanisms, mimic the progression pattern, and should be amenable to evaluating translational endpoints and treatment approaches. Preclinical animal models have been developed for a variety of human ophthalmological diseases to mirror disease mechanisms, location of the affected region in the eye and severity. These models offer clues to aid in our fundamental understanding of disease pathogenesis and enable progression of new therapies to clinical development by providing an opportunity to gain proof of concept (POC). Here, we review preclinical animal models associated with development of new therapies for diseases of the ocular surface, glaucoma, presbyopia, and retinal diseases, including diabetic retinopathy and age-related macular degeneration (AMD). We have focused on summarizing the models critical to new drug development and described the translational features of the models that contributed to our understanding of disease pathogenesis and establishment of preclinical POC.
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Affiliation(s)
- Mihir Shah
- Biological Research, Allergan plc, 2525 Dupont Drive, Irvine, California, 92612, USA
| | - Sara Cabrera-Ghayouri
- Biological Research, Allergan plc, 2525 Dupont Drive, Irvine, California, 92612, USA
| | - Lori-Ann Christie
- Biological Research, Allergan plc, 2525 Dupont Drive, Irvine, California, 92612, USA
| | - Katherine S Held
- Biological Research, Allergan plc, 2525 Dupont Drive, Irvine, California, 92612, USA
| | - Veena Viswanath
- Biological Research, Allergan plc, 2525 Dupont Drive, Irvine, California, 92612, USA.
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26
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Skrzypecki J, Tomasz H, Karolina C. Variability of Dry Eye Disease Following Removal of Lacrimal Glands in Rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1153:109-115. [DOI: 10.1007/5584_2019_348] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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27
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Park B, Lee IS, Hyun SW, Jo K, Lee TG, Kim JS, Kim CS. The Protective Effect of Polygonum cuspidatum (PCE) Aqueous Extract in a Dry Eye Model. Nutrients 2018; 10:E1550. [PMID: 30347752 PMCID: PMC6212923 DOI: 10.3390/nu10101550] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/16/2018] [Accepted: 10/16/2018] [Indexed: 12/23/2022] Open
Abstract
Dry eyes are caused by highly increased osmolarity of tear film, inflammation, and apoptosis of the ocular surface. In this study, we investigated the effect of Polygonum cuspidatum (PCE) aqueous extract in in vivo and in vitro dry eye models. Dry eye was induced by excision of the lacrimal gland and hyperosmotic media. In vivo, oral administration of PCE in exorbital lacrimal gland-excised rats recovered tear volume and Mucin4 (MUC4) expression by inhibiting corneal irregularity and expression of inflammatory cytokines. In vitro, hyperosmotic media induced human corneal epithelial cell (HCEC) cytotoxicity though increased inflammation, apoptosis, and oxidative stress. PCE treatment significantly inhibited expression of cyclooxygenase-2 and inflammatory cytokines (interleukin-6 and tumor necrosis factor-α), and activation of NF-κB p65 in hyperosmolar stress-induced HCECs. Hyperosmolarity-induced increase in Bcl-2-associated X protein (BAX) expression and activation of cleaved poly (ADP-ribose) polymerase and caspase 3 were attenuated in a concentration-dependent manner by PCE. PCE treatment restored anti-oxidative proteins such as heme oxygenase-1 (HO-1), superoxide dismutase-1 (SOD-1), and glutathione peroxidase (GPx) in hyperosmolar stress-induced HCECs. These data demonstrate that PCE prevents adverse changes in the ocular surface and tear fluid through inhibition of hyperosmolar stress-induced inflammation, apoptosis, and oxidation, suggesting that PCE may have the potential to preserve eye health.
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Affiliation(s)
- Bongkyun Park
- Clinical Medicine Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
| | - Ik Soo Lee
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
| | - Soo-Wang Hyun
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
| | - Kyuhyung Jo
- Clinical Medicine Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
| | - Tae Gu Lee
- Clinical Medicine Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
| | - Jin Sook Kim
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
| | - Chan-Sik Kim
- Clinical Medicine Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
- Korean Medicine Life Science, University of Science Technology (UST), Daejeon 34113, Korea.
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28
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Gilger BC. Immune Relevant Models for Ocular Inflammatory Diseases. ILAR J 2018; 59:352-362. [DOI: 10.1093/ilar/ily002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/18/2018] [Accepted: 01/27/2018] [Indexed: 02/03/2023] Open
Abstract
Abstract
Ocular inflammatory diseases, such as dry eye and uveitis, are common, painful, difficult to treat, and may result in vision loss or blindness. Ocular side effects from the use of antiinflammatory drugs (such as corticosteroids or nonsteroidal antiinflammatories) to treat ocular inflammation have prompted development of more specific and safer medications to treat inflammatory and immune-mediated diseases of the eye. To assess the efficacy and safety of these new therapeutics, appropriate immune-relevant animal models of ocular inflammation are needed. Both induced and naturally-occurring models have been described, but the most valuable for translating treatments to the human eye are the animal models of spontaneous, immunologic ocular disease, such as those with dry eye or uveitis. The purpose of this review is to describe common immune-relevant models of dry eye and uveitis with an overview of the immuno-pathogenesis of each disease and reported evaluation of models from small to large animals. We will also review a selected group of naturally-occurring large animal models, equine uveitis and canine dry eye, that have promise to translate into a better understanding and treatment of clinical immune-relevant ocular disease in man.
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Affiliation(s)
- Brian C Gilger
- Professor of Ophthalmology, Comparative Medicine Institute, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, USA
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29
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Optimising tear replacement rheology in canine keratoconjunctivitis sicca. Eye (Lond) 2018; 32:195-199. [PMID: 29303147 DOI: 10.1038/eye.2017.272] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 10/08/2017] [Indexed: 12/16/2022] Open
Abstract
Dry eye is a substantial problem in a large number of human and canine patients. Numerous laboratory models for tear deficiency exist using genetically predisposed rodent models, animals treated with topical anti-muscarinics, or those kept in environments with increased air flow to produce the ocular surface changes seen in human patients. Canine keratoconjunctivitis sicca, seen in many thousands of dogs kept as companion animals, can provide a valuable spontaneous model for testing tear replacement medications that might better model disease in human patients, existing as it does in an outbred population that live in the same environments as their owners. Here the development of a crosslinked hyaluronic acid topical drop is described together with the results of trials on dogs with spontaneous keratoconjunctivitis sicca. Although hyaluronic acid in its native form in tear replacement drops shows a Newtonian rheology, the crosslinked product described here behaves in a non-Newtonian manner, with the same shear thinning shown by the tear film itself. The crosslinked product thus shows itself as a potentially valuable tear replacement medication for the human dry eye population as well as for dogs with the same condition.
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30
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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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31
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Tamaddonfard E, Erfanparast A. Role of μ-opioid receptor in parafascicular nucleus of thalamus on morphine-induced antinociception in a rat model of acute trigeminal pain. VETERINARY RESEARCH FORUM : AN INTERNATIONAL QUARTERLY JOURNAL 2017; 8:29-34. [PMID: 28473894 PMCID: PMC5413308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Accepted: 10/10/2016] [Indexed: 10/25/2022]
Abstract
The parafascicular nucleus (PFN) of thalamus, as a supraspinal structure, has an important role in processing of nociceptive information. In addition, μ-opioid receptor contributes to supraspinal modulation of nociception. In the present study, the effects of microinjection of naloxone (a non-specific opioid-receptor antagonist) and naloxonazine (a specific μ-opioid receptor antagonist) were investigated on morphine-induced antinociception in a rat model of acute trigeminal pain. Right and left sides of PFN of thalamus were implanted with two guide cannulas. Acute trigeminal pain was induced by local corneal surface application of hypertonic saline and the number of eye wipes as a pain index was recorded for 30 sec. Microinjection of morphine at doses of 1, 2 and 4 μg per site significantly (p < 0.05) decreased the number of eye wipes. Alone microinjection of naloxone (4 μg per site) and naloxonazine (1 and 2 μg per site) significantly (p < 0.05) increased corneal pain severity. Prior microinjection of naloxone (2 and 4 μg per site) and naloxonazine (1 and 2 μg per site) significantly (p < 0.05) prevented the antinociceptive effect induced by morphine (4 μg per site). All the above-mentioned chemicals did not alter locomotor behavior in an open-field test. The results of the present study showed an antinociceptive effect of morphine at the PFN level of thalamus. Mu-opioid receptor of the PFN of thalamus may be involved in morphine-induced antinociception.
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Affiliation(s)
- Esmaeal Tamaddonfard
- Department of Basic Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
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32
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Topical Application of Apricot Kernel Extract Improves Dry Eye Symptoms in a Unilateral Exorbital Lacrimal Gland Excision Mouse. Nutrients 2016; 8:nu8110750. [PMID: 27886047 PMCID: PMC5133132 DOI: 10.3390/nu8110750] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/15/2016] [Accepted: 11/17/2016] [Indexed: 11/23/2022] Open
Abstract
The purpose of this study was to investigate the therapeutic effects of topical application of apricot kernel extract (AKE) in a unilateral exorbital lacrimal gland excision mouse model of experimental dry eye. Dry eye was induced by surgical removal of the lacrimal gland. Eye drops containing 0.5 or 1 mg/mL AKE were administered twice a day from day 3 to day 7 after surgery. Tear fluid volume and corneal irregularity scores were determined. In addition, we examined the immunohistochemical expression level of Muc4. The topical administration of AKE dose-dependently improved all clinical dry eye symptoms by promoting the secretion of tear fluid and mucin. Thus, the results of this study indicate that AKE may be an efficacious topical agent for treating dry eye disease.
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33
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Is the main lacrimal gland indispensable? Contributions of the corneal and conjunctival epithelia. Surv Ophthalmol 2016; 61:616-27. [PMID: 26968256 DOI: 10.1016/j.survophthal.2016.02.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/26/2016] [Indexed: 11/24/2022]
Abstract
The ocular surface system is responsible for ensuring that the precorneal tear film is sufficient in both quality and quantity to preserve optimal vision. Tear secretion is a complex, multifactorial process, and dysfunction of any component of the ocular surface system can result in tear film instability and hyperosmolarity with resultant dry eye disease. The tear film is primarily composed of lipids, aqueous, and mucins, with aqueous accounting for most of its thickness. The aqueous is produced by the main lacrimal gland, accessory lacrimal glands, and corneal and conjunctival epithelia. Although the main lacrimal gland has long been considered an indispensable source of the aqueous component of tears, there is evidence that adequate tear secretion can exist in the absence of the main lacrimal gland. We review and discuss the basics of tear secretion, the tear secretory capacity of the ocular surface, and emerging treatments for dry eye disease.
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Aicher SA, Hermes SM, Hegarty DM. Denervation of the Lacrimal Gland Leads to Corneal Hypoalgesia in a Novel Rat Model of Aqueous Dry Eye Disease. Invest Ophthalmol Vis Sci 2016; 56:6981-9. [PMID: 26513503 DOI: 10.1167/iovs.15-17497] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
PURPOSE Some dry eye disease (DED) patients have sensitized responses to corneal stimulation, while others experience hypoalgesia. Many patients have normal tear production, suggesting that reduced tears are not always the cause of DED sensory dysfunction. In this study, we show that disruption of lacrimal innervation can produce hypoalgesia without changing basal tear production. METHODS Injection of a saporin toxin conjugate into the extraorbital lacrimal gland of male Sprague-Dawley rats was used to disrupt cholinergic innervation to the gland. Tear production was assessed by phenol thread test. Corneal sensory responses to noxious stimuli were assessed using eye wipe behavior. Saporin DED animals were compared to animals treated with atropine to produce aqueous DED. RESULTS Cholinergic innervation and acetylcholine content of the lacrimal gland were significantly reduced in saporin DED animals, yet basal tear production was normal. Saporin DED animals demonstrated normal eye wipe responses to corneal application of capsaicin, but showed hypoalgesia to corneal menthol. Corneal nerve fiber density was normal in saporin DED animals. Atropine-treated animals had reduced tear production but normal responses to ocular stimuli. CONCLUSIONS Because only menthol responses were impaired, cold-sensitive corneal afferents appear to be selectively altered in our saporin DED model. Hypoalgesia is not due to reduced tear production, since we did not observe hypoalgesia in an atropine DED model. Corneal fiber density is unaltered in saporin DED animals, suggesting that molecular mechanisms of nociceptive signaling may be impaired. The saporin DED model will be useful for exploring the mechanism underlying corneal hypoalgesia.
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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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