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Valdés-Arias D, Locatelli EVT, Sepulveda-Beltran PA, Mangwani-Mordani S, Navia JC, Galor A. Recent United States Developments in the Pharmacological Treatment of Dry Eye Disease. Drugs 2024; 84:549-563. [PMID: 38652355 PMCID: PMC11189955 DOI: 10.1007/s40265-024-02031-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2024] [Indexed: 04/25/2024]
Abstract
Dry eye disease (DED) can arise from a variety of factors, including inflammation, meibomian gland dysfunction (MGD), and neurosensory abnormalities. Individuals with DED may exhibit a range of clinical signs, including tear instability, reduced tear production, and epithelial disruption, that are driven by different pathophysiological contributors. Those affected often report a spectrum of pain and visual symptoms that can impact physical and mental aspects of health, placing an overall burden on an individual's well-being. This cumulative impact of DED on an individual's activities and on society underscores the importance of finding diverse and effective management strategies. Such management strategies necessitate an understanding of the underlying pathophysiological mechanisms that contribute to DED in the individual patient. Presently, the majority of approved therapies for DED address T cell-mediated inflammation, with their tolerability and effectiveness varying across different studies. However, there is an emergence of treatments that target additional aspects of the disease, including novel inflammatory pathways, abnormalities of the eyelid margin, and neuronal function. These developments may allow for a more nuanced and precise management strategy for DED. This review highlights the recent pharmacological advancements in DED therapy in the United States. It discusses the mechanisms of action of these new treatments, presents key findings from clinical trials, discusses their current stage of development, and explores their potential applicability to different sub-types of DED. By providing a comprehensive overview of products in development, this review aims to contribute valuable insights to the ongoing efforts in enhancing the therapeutic options available to individuals suffering from DED.
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Affiliation(s)
- David Valdés-Arias
- Bascom Palmer Eye Institute, University of Miami, 900 NW 17th St, Miami, FL, 33136, USA
| | - Elyana V T Locatelli
- Bascom Palmer Eye Institute, University of Miami, 900 NW 17th St, Miami, FL, 33136, USA
- Surgical Services, Miami Veterans Affairs Medical Center, 1201 Northwest 16th Street, Miami, FL, 33125, USA
| | | | | | - Juan Carlos Navia
- Bascom Palmer Eye Institute, University of Miami, 900 NW 17th St, Miami, FL, 33136, USA
| | - Anat Galor
- Bascom Palmer Eye Institute, University of Miami, 900 NW 17th St, Miami, FL, 33136, USA.
- Surgical Services, Miami Veterans Affairs Medical Center, 1201 Northwest 16th Street, Miami, FL, 33125, USA.
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2
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Keller M, Mergler S, Li A, Zahn I, Paulsen F, Garreis F. Thermosensitive TRP Channels Are Functionally Expressed and Influence the Lipogenesis in Human Meibomian Gland Cells. Int J Mol Sci 2024; 25:4043. [PMID: 38612853 PMCID: PMC11012639 DOI: 10.3390/ijms25074043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 03/28/2024] [Accepted: 03/30/2024] [Indexed: 04/14/2024] Open
Abstract
While the involvement of thermosensitive transient receptor potential channels (TRPs) in dry eye disease (DED) has been known for years, their expression in the meibomian gland (MG) has never been investigated. This study aims to show their expression and involvement in the lipogenesis of the MG, providing a possible new drug target in the treatment of DED. Our RT-PCR, Western blot and immunofluorescence analysis showed the expression of TRPV1, TRPV3, TRPV4 and TRPM8 in the MG at the gene and the protein level. RT-PCR also showed gene expression of TRPV2 but not TRPA1. Calcium imaging and planar patch-clamping performed on an immortalized human meibomian gland epithelial cell line (hMGECs) demonstrated increasing whole-cell currents after the application of capsaicin (TRPV1) or icilin (TRPM8). Decreasing whole-cell currents could be registered after the application of AMG9810 (TRPV1) or AMTB (TRPM8). Oil red O staining on hMGECs showed an increase in lipid expression after TRPV1 activation and a decrease after TRPM8 activation. We conclude that thermo-TRPs are expressed at the gene and the protein level in MGs. Moreover, TRPV1 and TRPM8's functional expression and their contribution to their lipid expression could be demonstrated. Therefore, TRPs are potential drug targets and their clinical relevance in the therapy of meibomian gland dysfunction requires further investigation.
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Affiliation(s)
- Melina Keller
- Department of Functional and Clinical Anatomy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 19, 91054 Erlangen, Germany (F.P.)
| | - Stefan Mergler
- Department of Ophthalmology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 13353 Berlin, Germany; (S.M.); (A.L.)
| | - Aruna Li
- Department of Ophthalmology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 13353 Berlin, Germany; (S.M.); (A.L.)
| | - Ingrid Zahn
- Department of Functional and Clinical Anatomy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 19, 91054 Erlangen, Germany (F.P.)
| | - Friedrich Paulsen
- Department of Functional and Clinical Anatomy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 19, 91054 Erlangen, Germany (F.P.)
| | - Fabian Garreis
- Department of Functional and Clinical Anatomy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 19, 91054 Erlangen, Germany (F.P.)
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3
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Roucaute E, Huertas-Bello M, Sabater AL. Novel treatments for dry eye syndrome. Curr Opin Pharmacol 2024; 75:102431. [PMID: 38277944 DOI: 10.1016/j.coph.2024.102431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/26/2023] [Accepted: 01/01/2024] [Indexed: 01/28/2024]
Abstract
Dry eye syndrome (DES) is a prevalent and multifactorial disease that leads to a self-perpetuating cycle of inflammation and damage to the ocular surface. This results in symptoms such as redness, burning, and blurred vision, which can negatively affect a patient's quality of life. While treatments are available to manage DES, they only temporarily relieve symptoms. Furthermore, long-term use of certain medications can cause harm to the ocular surface. Therefore, there is a need for safer and effective treatments for DES. This review highlights the latest advancements in DES therapy, providing valuable insights into ongoing efforts to improve patient outcomes.
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Affiliation(s)
- Esther Roucaute
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Marcela Huertas-Bello
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Alfonso L Sabater
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States.
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Harrell CR, Feulner L, Djonov V, Pavlovic D, Volarevic V. The Molecular Mechanisms Responsible for Tear Hyperosmolarity-Induced Pathological Changes in the Eyes of Dry Eye Disease Patients. Cells 2023; 12:2755. [PMID: 38067183 PMCID: PMC10706334 DOI: 10.3390/cells12232755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 11/18/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
Dry eye disease (DED) is a multifactorial disorder of the lacrimal system and ocular surface, characterized by a deficiency in the quality and/or quantity of the tear fluid. The multifactorial nature of DED encompasses a number of interconnected underlying pathologies, including loss of homeostasis, instability and hyperosmolarity of the tears, and the induction and propagation of detrimental inflammatory responses in the eyes, which finally results in the development of neurosensory dysfunction and visual disruption. Dryness, grittiness, scratchiness, discomfort, inflammation, burning, watering, ocular fatigue, pain, and decreased functional visual acuity are common symptoms of DED. Eye dysfunction drastically attenuates patients' quality of life. Accordingly, a better understanding of the pathogenic processes that regulate the development and progression of DED is crucially important for the establishment of new and more effective DED-related treatment approaches, which would significantly improve the quality of life of DED patients. Since the process of osmoregulation, which guards the ocular surface epithelia and maintains normal vision, is affected when the osmolarity of the tears is greater than that of the epithelial cells, tear hyperosmolarity (THO) is considered an initial, important step in the development, progression, and aggravation of DED. In order to delineate the role of THO in the pathogenesis of DED, in this review article, we summarize current knowledge related to the molecular mechanisms responsible for the development of THO-induced pathological changes in the eyes of DED patients, and we briefly discuss the therapeutic potential of hypo-osmotic eye drops in DED treatment.
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Affiliation(s)
- Carl Randall Harrell
- Regenerative Processing Plant, LLC, 34176 US Highway 19 N, Palm Harbor, FL 34684, USA;
| | - Lisa Feulner
- Advanced Eye Care & Aesthetics, 104 Plumtree Rd Suite 107, Bel Air, MD 21015, USA;
| | - Valentin Djonov
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland;
| | - Dragica Pavlovic
- Departments of Genetics and Microbiology and Immunology, Center for Harm Reduction of Biological and Chemical Hazards, Faculty of Medical Sciences, University of Kragujevac, 69 Svetozar Markovic Street, 34000 Kragujevac, Serbia;
| | - Vladislav Volarevic
- Departments of Genetics and Microbiology and Immunology, Center for Harm Reduction of Biological and Chemical Hazards, Faculty of Medical Sciences, University of Kragujevac, 69 Svetozar Markovic Street, 34000 Kragujevac, Serbia;
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5
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Mangwani-Mordani S, Goodman CF, Galor A. Novel Treatments for Chronic Ocular Surface Pain. Cornea 2023; 42:261-271. [PMID: 36729473 PMCID: PMC9918665 DOI: 10.1097/ico.0000000000003193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 09/28/2022] [Indexed: 02/03/2023]
Abstract
ABSTRACT Several etiologies can contribute to ocular surface pain including nociceptive, peripheral neuropathic, and central neuropathic mechanisms. Clinical clues can help identify contributors to ocular surface pain in a patient. In individuals whose pain persists despite targeting nociceptive contributors, neuropathic mechanisms should be considered and addressed using oral, topical, and/or adjuvant agents.
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Affiliation(s)
- Simran Mangwani-Mordani
- Surgical Services, Miami Veterans Affairs Medical Center, 1201 NW 17 Street, Miami, FL, 33125, USA
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, 900 NW 17 Street, Miami, FL 33136, USA
| | - Courtney F. Goodman
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, 900 NW 17 Street, Miami, FL 33136, USA
| | - Anat Galor
- Surgical Services, Miami Veterans Affairs Medical Center, 1201 NW 17 Street, Miami, FL, 33125, USA
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, 900 NW 17 Street, Miami, FL 33136, USA
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Generation of a TRPM8 knockout hESC line (WAe009-A-A) derived from H9 using CRISPR/Cas9. Stem Cell Res 2023; 67:103040. [PMID: 36796252 DOI: 10.1016/j.scr.2023.103040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/11/2023] [Accepted: 01/30/2023] [Indexed: 02/09/2023] Open
Abstract
The transient receptor potential cation channel subfamily M member 8 (TRPM8) is a kind of non-selective cation channel which controls Ca2+ homeostasis. Mutations in TRPM8 were related to dry eye diseases (DED). Here we constructed a TRPM8 knockout cell line WAe009-A-A from the original embryonic stem cell line H9 using CRISPR/Cas9 technology, which maybe helpful for exploring the pathogenesis of DED. WAe009-A-A cells possess stem cell morphology and pluripotency as well as normal karyotype, and have the ability of differentiating into three germ layers in vitro.
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Lindgren ES, Cil O, Verkman AS, Pasricha ND. Ocular Surface Ion Transport and Dry Eye Disease. CURRENT OPHTHALMOLOGY REPORTS 2022; 10:188-197. [PMID: 38213468 PMCID: PMC10783585 DOI: 10.1007/s40135-022-00295-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2022] [Indexed: 10/24/2022]
Abstract
Purpose of Review To review the role of ocular surface epithelial (corneal and conjunctival) ion transporters in the pathogenesis and treatment of dry eye disease (DED). Recent Findings Currently, anti-inflammatory agents are the mainstay of DED treatment, though there are several agents in development that target ion transport proteins on the ocular surface, acting by pro-secretory or anti-absorptive mechanisms to increase the tear fluid Film volume. Activation or inhibition of selected ion transporters can alter tear fluid osmolality, driving water transport onto the ocular surface via osmosis. Several ion transporters have been proposed as potential therapeutic targets for DED, including the cystic fibrosis transmembrane conductance regulator (CFTR), calcium-activated chloride channels (CaCCs), and the epithelial sodium channel (ENaC). Summary Ocular surface epithelial cell ion transporters are promising targets for pro-secretory and anti-absorptive therapies of DED.
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Affiliation(s)
- Ethan S. Lindgren
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA
| | - Onur Cil
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Alan S. Verkman
- Departments of Medicine and Physiology, University of California San Francisco, San Francisco, CA, USA
| | - Neel D. Pasricha
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA
- Francis I. Proctor Foundation, University of California San Francisco, San Francisco, CA, USA
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Wirta DL, Senchyna M, Lewis AE, Evans DG, McLaurin EB, Ousler GW, Hollander DA. A randomized, vehicle-controlled, Phase 2b study of two concentrations of the TRPM8 receptor agonist AR-15512 in the treatment of dry eye disease (COMET-1). Ocul Surf 2022; 26:166-173. [PMID: 35970431 DOI: 10.1016/j.jtos.2022.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/05/2022] [Accepted: 08/09/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE Dry eye disease (DED) symptoms can negatively impact quality of life (QoL). AR-15512, a transient receptor potential melastatin 8 (TRPM8) agonist, was evaluated as a potential therapy for DED. METHODS In a Phase 2b study, patients with DED were randomized 1:1:1 to 0.0014% AR-15512, 0.003% AR-15512, or vehicle twice daily for 12 weeks. Eligibility criteria included DED signs and symptoms of prespecified severity levels. Outcomes assessed were DED signs (Schirmer score ± anesthetic, ocular surface staining, hyperemia), symptoms (Ocular Discomfort [ODS-VAS], Symptoms Assessment iN Dry Eye [SANDE], Eye Dryness-VAS, Ocular Pain-VAS), QoL-VAS, and adverse events. Co-primary endpoints were changes from baseline in ODS-VAS and anesthetized Schirmer score at Day 28. RESULTS 0.003% AR-15512 (n = 122) was associated with early and sustained improvements in unanesthetized Schirmer score (Days 1 and 14, p < 0.0001), as well as improvements in ocular surface staining (Days 14 and 84, p ≤ 0.0365) and hyperemia (Day 84, p < 0.0215). Statistically significant improvements in symptoms were observed for the 0.003% concentration on SANDE (Days 14, 28, and 84, p ≤ 0.0254), ODS-VAS (Day 84, p = 0.0281), Eye Dryness-VAS (Day 84, p = 0.0302), and multiple QoL measures (Days 14, 28, and 84, p < 0.05). There were no significant differences between active and vehicle groups for the co-primary endpoints. The most common adverse events were burning and stinging upon instillation. CONCLUSIONS Although predefined co-primary study endpoints were not met, AR-15512 demonstrated statistically significant improvements in DED signs, symptoms, and disease-related QoL.
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9
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Transient Receptor Potential Channels: Important Players in Ocular Pain and Dry Eye Disease. Pharmaceutics 2022; 14:pharmaceutics14091859. [PMID: 36145607 PMCID: PMC9506338 DOI: 10.3390/pharmaceutics14091859] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/26/2022] [Accepted: 08/26/2022] [Indexed: 11/20/2022] Open
Abstract
Dry eye disease (DED) is a multifactorial disorder in which the eyes respond to minor stimuli with abnormal sensations, such as dryness, blurring, foreign body sensation, discomfort, irritation, and pain. Corneal pain, as one of DED’s main symptoms, has gained recognition due to its increasing prevalence, morbidity, and the resulting social burden. The cornea is the most innervated tissue in the body, and the maintenance of corneal integrity relies on a rich density of nociceptors, such as polymodal nociceptor neurons, cold thermoreceptor neurons, and mechano-nociceptor neurons. Their sensory responses to different stimulating forces are linked to the specific expression of transient receptor potential (TRP) channels. TRP channels are a group of unique ion channels that play important roles as cellular sensors for various stimuli. These channels are nonselective cation channels with variable Ca2+ selectivity. TRP homologs are a superfamily of 28 different members that are subdivided into 7 different subfamilies based on differences in sequence homology. Many of these subtypes are expressed in the eye on both neuronal and non-neuronal cells, where they affect various stress-induced regulatory responses essential for normal vision maintenance. This article reviews the current knowledge about the expression, function, and regulation of TRPs in ocular surface tissues. We also describe their implication in DED and ocular pain. These findings contribute to evidence suggesting that drug-targeting TRP channels may be of therapeutic benefit in the clinical setting of ocular pain.
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Galor A, Hamrah P, Haque S, Attal N, Labetoulle M. Understanding chronic ocular surface pain: An unmet need for targeted drug therapy. Ocul Surf 2022; 26:148-156. [PMID: 35970433 DOI: 10.1016/j.jtos.2022.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 07/29/2022] [Accepted: 08/09/2022] [Indexed: 10/15/2022]
Abstract
Chronic ocular surface pain (COSP) may be defined as a feeling of pain, perceived as originating from the ocular surface, that persists for >3 months. COSP is a complex multifactorial condition associated with several risk factors that may significantly interfere with an individual's daily activities, resulting in poor quality of life (QoL). COSP is also likely to have a high burden on patients with substantial implications on global healthcare costs. While patients may use varied terminology to describe symptoms of COSP, any ocular surface damage in the ocular sensory apparatus (nociceptive, neuropathic, inflammatory, or combination thereof) resulting in low tear production, chronic inflammation, or nerve abnormalities (functional and/or morphological), is typically associated with COSP. Considering the heterogeneity of this condition, it is highly recommended that advanced multimodal diagnostic tools are utilized to help discern the nociceptive and neuropathic pain pathways in order to provide targeted treatment and effective clinical management. The current article provides an overview of COSP, including its multifactorial pathophysiology, etiology, prevalence, clinical presentation, impact on QoL, diagnosis, current management, and unmet medical needs.
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Affiliation(s)
- Anat Galor
- Surgical Services, Miami Veterans Affairs Medical Centre and Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Pedram Hamrah
- Tufts Medical Centre, New England Eye Center, 260 Tremont Street Biewend Building, Boston, MA, USA
| | | | - Nadine Attal
- CHU Paris IdF Ouest - Hôpital Ambroise Paré, 9 avenue Charles de Gaulle, 92100, Boulogne-Billancourt, INSERM U 987 and Université Paris Saclay, France
| | - Marc Labetoulle
- Service d'Ophtalmologie, hôpital Bicêtre, AP-HP, Université Paris Saclay, 94275, Le Kremlin-Bicêtre, France; IMVA-HB/IDMI, CEA, Inserm U1184, 92265, Fontenay-aux-Roses, France.
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11
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Patel S, Mittal R, Sarantopoulos KD, Galor A. Neuropathic ocular surface pain: Emerging drug targets and therapeutic implications. Expert Opin Ther Targets 2022; 26:681-695. [PMID: 36069761 PMCID: PMC9613591 DOI: 10.1080/14728222.2022.2122438] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 09/05/2022] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Dysfunction at various levels of the somatosensory system can lead to ocular surface pain with a neuropathic component. Compared to nociceptive pain (due to noxious stimuli at the ocular surface), neuropathic pain tends to be chronic and refractory to therapies, making it an important source of morbidity in the population. An understanding of the options available for neuropathic ocular surface pain, including new and emerging therapies, is thus an important topic. AREAS COVERED This review will examine studies focusing on ocular surface pain, emphasizing those examining patients with a neuropathic component. Attention will be placed toward recent (after 2017) studies that have examined new and emerging therapies for neuropathic ocular surface pain. EXPERT OPINION Several therapies have been studied thus far, and continued research is needed to identify which individuals would benefit from specific therapies. Gaps in our understanding exist, especially with availability of in-clinic diagnostics for neuropathic pain. A focus on improving diagnostic capabilities and researching gene-modulating therapies could help us to provide more specific mechanism-based therapies for patients. In the meantime, continuing to uncover new modalities and examining which are likely to work depending on pain phenotype remains an important short-term goal.
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Affiliation(s)
- Sneh Patel
- University of Miami Miller School of Medicine, Miami, FL, USA
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Rhiya Mittal
- University of Miami Miller School of Medicine, Miami, FL, USA
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Konstantinos D. Sarantopoulos
- Department of Anesthesiology, Perioperative Medicine, and Pain Management, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Anat Galor
- University of Miami Miller School of Medicine, Miami, FL, USA
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Surgical services, Miami Veterans Affairs Medical Center, Miami, FL, USA
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12
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Huang R, Su C, Fang L, Lu J, Chen J, Ding Y. Dry eye syndrome: comprehensive etiologies and recent clinical trials. Int Ophthalmol 2022; 42:3253-3272. [PMID: 35678897 PMCID: PMC9178318 DOI: 10.1007/s10792-022-02320-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 04/18/2022] [Indexed: 12/07/2023]
Abstract
Dry eye syndrome (DES) is multifactorial and likely to be a cause of concern more so than ever given the rapid pace of modernization, which is directly associated with many of the extrinsic causative factors. Additionally, recent studies have also postulated novel etiologies that may provide the basis for alternative treatment methods clinically. Such insights are especially important given that current approaches to tackle DES remains suboptimal. This review will primarily cover a comprehensive list of causes that lead to DES, summarize all the upcoming and ongoing clinical trials that focuses on treating this disease as well as discuss future potential treatments that can improve inclusivity.
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Affiliation(s)
- Ruojing Huang
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Huangpu Avenue West 613, Tianhe District, Guangzhou, 510630, China
| | - Caiying Su
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Huangpu Avenue West 613, Tianhe District, Guangzhou, 510630, China
| | - Lvjie Fang
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Huangpu Avenue West 613, Tianhe District, Guangzhou, 510630, China
| | - Jiaqi Lu
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Huangpu Avenue West 613, Tianhe District, Guangzhou, 510630, China
| | - Jiansu Chen
- Institute of Ophthalmology, Medical College, Jinan University, Huangpu Avenue West 601, Tianhe District, Guangzhou, 510632, China.
| | - Yong Ding
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Huangpu Avenue West 613, Tianhe District, Guangzhou, 510630, China.
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13
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Yang S, Wu Y, Wang C, Jin X. Ocular Surface Ion-Channels Are Closely Related to Dry Eye: Key Research Focus on Innovative Drugs for Dry Eye. Front Med (Lausanne) 2022; 9:830853. [PMID: 35308542 PMCID: PMC8927818 DOI: 10.3389/fmed.2022.830853] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
Abundant ion-channels, including various perceptual receptors, chloride channels, purinergic receptor channels, and water channels that exist on the ocular surface, play an important role in the pathogenesis of dry eye. Channel-targeting activators or inhibitor compounds, which have shown positive effects in in vivo and in vitro experiments, have become the focus of the dry eye drug research and development, and individual compounds have been applied in clinical experimental treatment. This review summarized various types of ion-channels on the ocular surface related to dry eye, their basic functions, and spatial distribution, and discussed basic and clinical research results of various channel receptor regulatory compounds. Therefore, further elucidating the relationship between ion-channels and dry eye will warrant research of dry eye targeted drug therapy.
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Affiliation(s)
- Shuo Yang
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yaying Wu
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - ChunYang Wang
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiuming Jin
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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14
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Mucosal immunology of the ocular surface. Mucosal Immunol 2022; 15:1143-1157. [PMID: 36002743 PMCID: PMC9400566 DOI: 10.1038/s41385-022-00551-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/26/2022] [Accepted: 06/10/2022] [Indexed: 02/04/2023]
Abstract
The eye is a sensory organ exposed to the environment and protected by a mucosal tissue barrier. While it shares a number of features with other mucosal tissues, the ocular mucosal system, composed of the conjunctiva, Meibomian glands, and lacrimal glands, is specialized to address the unique needs of (a) lubrication and (b) host defense of the ocular surface. Not surprisingly, most challenges, physical and immunological, to the homeostasis of the eye fall into those two categories. Dry eye, a dysfunction of the lacrimal glands and/or Meibomian glands, which can both cause, or arise from, sensory defects, including those caused by corneal herpes virus infection, serve as examples of these perturbations and will be discussed ahead. To preserve vision, dense neuronal and immune networks sense various stimuli and orchestrate responses, which must be tightly controlled to provide protection, while simultaneously minimizing collateral damage. All this happens against the backdrop of, and can be modified by, the microorganisms that colonize the ocular mucosa long term, or that are simply transient passengers introduced from the environment. This review will attempt to synthesize the existing knowledge and develop trends in the study of the unique mucosal and immune elements of the ocular surface.
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Design, synthesis and biological evaluation of new thiazole scaffolds as potential TRPM8 antagonists. Bioorg Med Chem Lett 2021; 52:128392. [PMID: 34606996 DOI: 10.1016/j.bmcl.2021.128392] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 11/21/2022]
Abstract
The preliminary results on the development of a viable methodology for the further functionalization of 4-hydroxythiazole derivatives to afford target TRPM8 antagonists are reported. The combined Sonogashira coupling/annulation reactions of the ethyl 2-(3-fluorophenyl)-4-tifluoromethylsulfonyloxy-1,3-thiazole-5-carboxylate have been applied to the synthesis of analogues of the selective blocker of TRPM8 DFL23448. Among all the synthetised derivatives, the most promising compound resulted to be active as TRPM8 blocker (IC50 = 4.06 µM), showing an excellent metabolic stability and no cytotoxic effects. Finally, in silico characterisation of the derivatives showed no violation of the drug-likeness rules.
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Advances in TRP channel drug discovery: from target validation to clinical studies. Nat Rev Drug Discov 2021; 21:41-59. [PMID: 34526696 PMCID: PMC8442523 DOI: 10.1038/s41573-021-00268-4] [Citation(s) in RCA: 185] [Impact Index Per Article: 61.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2021] [Indexed: 12/20/2022]
Abstract
Transient receptor potential (TRP) channels are multifunctional signalling molecules with many roles in sensory perception and cellular physiology. Therefore, it is not surprising that TRP channels have been implicated in numerous diseases, including hereditary disorders caused by defects in genes encoding TRP channels (TRP channelopathies). Most TRP channels are located at the cell surface, which makes them generally accessible drug targets. Early drug discovery efforts to target TRP channels focused on pain, but as our knowledge of TRP channels and their role in health and disease has grown, these efforts have expanded into new clinical indications, ranging from respiratory disorders through neurological and psychiatric diseases to diabetes and cancer. In this Review, we discuss recent findings in TRP channel structural biology that can affect both drug development and clinical indications. We also discuss the clinical promise of novel TRP channel modulators, aimed at both established and emerging targets. Last, we address the challenges that these compounds may face in clinical practice, including the need for carefully targeted approaches to minimize potential side-effects due to the multifunctional roles of TRP channels.
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17
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Izquierdo C, Martín-Martínez M, Gómez-Monterrey I, González-Muñiz R. TRPM8 Channels: Advances in Structural Studies and Pharmacological Modulation. Int J Mol Sci 2021; 22:ijms22168502. [PMID: 34445208 PMCID: PMC8395166 DOI: 10.3390/ijms22168502] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 12/13/2022] Open
Abstract
The transient receptor potential melastatin subtype 8 (TRPM8) is a cold sensor in humans, activated by low temperatures (>10, <28 °C), but also a polymodal ion channel, stimulated by voltage, pressure, cooling compounds (menthol, icilin), and hyperosmolarity. An increased number of experimental results indicate the implication of TRPM8 channels in cold thermal transduction and pain detection, transmission, and maintenance in different tissues and organs. These channels also have a repercussion on different kinds of life-threatening tumors and other pathologies, which include urinary and respiratory tract dysfunctions, dry eye disease, and obesity. This compendium firstly covers newly described papers on the expression of TRPM8 channels and their correlation with pathological states. An overview on the structural knowledge, after cryo-electron microscopy success in solving different TRPM8 structures, as well as some insights obtained from mutagenesis studies, will follow. Most recently described families of TRPM8 modulators are also covered, along with a section of molecules that have reached clinical trials. To finalize, authors provide an outline of the potential prospects in the TRPM8 field.
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Affiliation(s)
- Carolina Izquierdo
- Departamento de Biomiméticos, Instituto de Química Médica, Juan de la Cierva 3, 28006 Madrid, Spain; (C.I.); (M.M.-M.)
- Programa de Doctorado en Química Orgánica, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Mercedes Martín-Martínez
- Departamento de Biomiméticos, Instituto de Química Médica, Juan de la Cierva 3, 28006 Madrid, Spain; (C.I.); (M.M.-M.)
| | - Isabel Gómez-Monterrey
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Via D. Montesano 49, 80131 Naples, Italy
- Correspondence: (I.G.-M.); (R.G.-M.)
| | - Rosario González-Muñiz
- Departamento de Biomiméticos, Instituto de Química Médica, Juan de la Cierva 3, 28006 Madrid, Spain; (C.I.); (M.M.-M.)
- Correspondence: (I.G.-M.); (R.G.-M.)
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18
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Abstract
Transient receptor potential melastatin 8 (TRPM8) channels play a central role in the detection of environmental cold temperatures in the somatosensory system. TRPM8 is found in a subset of unmyelinated (C-type) afferents located in the dorsal root (DRG) and trigeminal ganglion (TG). Cold hypersensitivity is a common symptom of neuropathic pain conditions caused by cancer therapy, spinal cord injury, viral infection, multiple sclerosis, diabetes, or withdrawal symptoms associated with chronic morphine treatment. Therefore, TRPM8 has received great attention as a therapeutic target. However, as the activity of TRPM8 is unique in sensing cool temperature as well as warming, it is critical to understand the signaling transduction pathways that control modality-specific activity of TRPM8 in healthy versus pathological settings. This review summarizes recent advances in our understanding of the mechanisms involved in the regulation of the TRPM8 activity.
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Affiliation(s)
- Mircea Iftinca
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary , Calgary, Alberta, Canada
| | - Christophe Altier
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary , Calgary, Alberta, Canada
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Rodrigues-Braz D, Zhao M, Yesilirmak N, Aractingi S, Behar-Cohen F, Bourges JL. Cutaneous and ocular rosacea: Common and specific physiopathogenic mechanisms and study models. Mol Vis 2021; 27:323-353. [PMID: 34035646 PMCID: PMC8131178] [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: 11/25/2020] [Accepted: 05/11/2021] [Indexed: 11/21/2022] Open
Abstract
Rosacea is a chronic inflammatory disease that affects the face skin. It is clinically classified into the following four subgroups depending on its location and severity: erythematotelangiectatic, papulopustular, phymatous, and ocular. Rosacea is a multifactorial disease triggered by favoring factors, the pathogenesis of which remains imperfectly understood. Recognized mechanisms include the innate immune system, with the implication of Toll-like receptors (TLRs) and cathelicidins; neurovascular deregulation involving vascular endothelial growth factor (VEGF), transient receptor potential (TRP) ion channels, and neuropeptides; and dysfunction of skin sebaceous glands and ocular meibomian glands. Microorganisms, genetic predisposition, corticosteroid treatment, and ultraviolet B (UVB) radiation are favoring factors. In this paper, we review the common and specific molecular mechanisms involved in the pathogenesis of cutaneous and ocular rosacea and discuss laboratory and clinical studies, as well as experimental models.
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Affiliation(s)
- Daniela Rodrigues-Braz
- Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, UMRS1138, Team 17, Physiopathology of ocular diseases: therapeutic innovations, Paris, France
| | - Min Zhao
- Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, UMRS1138, Team 17, Physiopathology of ocular diseases: therapeutic innovations, Paris, France
| | - Nilufer Yesilirmak
- Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, UMRS1138, Team 17, Physiopathology of ocular diseases: therapeutic innovations, Paris, France
- Department of Ophthalmology, Ankara Yildirim Beyazit University, Ankara, Turkey
- Ophtalmopole, Assistance Publique -Hôpitaux de Paris (AP-HP), Cochin Hospital, Paris, France
| | - Selim Aractingi
- Department of Dermatology, AP-HP, Cochin Hospital, Paris, France
| | - Francine Behar-Cohen
- Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, UMRS1138, Team 17, Physiopathology of ocular diseases: therapeutic innovations, Paris, France
- Ophtalmopole, Assistance Publique -Hôpitaux de Paris (AP-HP), Cochin Hospital, Paris, France
| | - Jean-Louis Bourges
- Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, UMRS1138, Team 17, Physiopathology of ocular diseases: therapeutic innovations, Paris, France
- Ophtalmopole, Assistance Publique -Hôpitaux de Paris (AP-HP), Cochin Hospital, Paris, France
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20
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Hwang J, Dermer H, Galor A. Can in vivo confocal microscopy differentiate between sub-types of dry eye disease? A review. Clin Exp Ophthalmol 2021; 49:373-387. [PMID: 33769651 DOI: 10.1111/ceo.13924] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 03/16/2021] [Accepted: 03/20/2021] [Indexed: 12/25/2022]
Abstract
Many studies utilised in vivo confocal microscopy (IVCM) to associate variations in corneal structures with dry eye disease (DED). However, DED is an umbrella term that covers various aetiologies and presentations. This review analyses populations by DED aetiology to determine the relationships between IVCM parameters and specific DED sub-types. It focuses on the most commonly examined structures, sub-basal nerves and dendritic cells. Across the literature, most studies found individuals with immune-mediated DED had lower sub-basal nerve fibre number and density than controls, with smaller differences between non-immune DED and controls. However, wide ranges of values reported across studies demonstrate considerable overlap between DED sub-types and controls, rendering these metrics less helpful when diagnosing an individual patient. Dendritic cell density was considerably higher in individuals with immune-mediated DED than in non-immune DED or controls. As such, dendritic cell density may be a better indicator of DED associated with a systemic immune-mediated process.
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Affiliation(s)
- Jodi Hwang
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, Miami, Florida, USA.,Department of Ophthalmology, Miami Veterans Administration Medical Center, Miami, Florida, USA
| | - Harrison Dermer
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, Miami, Florida, USA.,Department of Ophthalmology, Miami Veterans Administration Medical Center, Miami, Florida, USA
| | - Anat Galor
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, Miami, Florida, USA.,Department of Ophthalmology, Miami Veterans Administration Medical Center, Miami, Florida, USA
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21
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Baiula M, Spampinato S. Experimental Pharmacotherapy for Dry Eye Disease: A Review. J Exp Pharmacol 2021; 13:345-358. [PMID: 33790661 PMCID: PMC8001578 DOI: 10.2147/jep.s237487] [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: 11/30/2020] [Accepted: 03/11/2021] [Indexed: 01/22/2023] Open
Abstract
Dry eye disease (DED) is a complex multifactorial disease showing heterogenous symptoms, including dryness, photophobia, ocular discomfort, irritation and burning but also pain. These symptoms can affect visual function leading to restrictions in daily life activities and reduction in work productivity with a consequently high impact on quality of life. Several pathological mechanisms contribute to the disease: evaporative water loss leads to impairment and loss of tear homeostasis inducing either directly or indirectly to inflammation, in a self-perpetuating vicious cycle. Dysregulated ocular immune responses result in ocular surface damage, which further contributes to DED pathogenesis. Currently, DED treatment is based on a flexible stepwise approach to identify the most beneficial intervention. Although most of the available treatments may control to a certain extent some signs and symptoms of DED, they show significant limitations and do not completely address the needs of patients suffering from DED. This review provides an overview of the emerging experimental therapies for DED. Several promising therapeutic strategies are under development with the aim of dampening inflammation and restoring the homeostasis of the ocular surface microenvironment. Results from early phase clinical trials, testing the effects of EnaC blockers, TRPM8 agonist or mesenchymal stem cells in DED patients, are especially awaited to demonstrate their therapeutic value for the treatment of DED. Moreover, the most advanced experimental strategies in the pipeline for DED, tivanisiran, IL-1R antagonist EBI-005 and SkQ1, are being tested in Phase III clinical trials, still ongoing. Nevertheless, although promising results, further studies are still needed to confirm efficacy and safety of the new emerging therapies for DED.
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Affiliation(s)
- Monica Baiula
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Santi Spampinato
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
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22
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Topical TRPM8 Agonist for Relieving Neuropathic Ocular Pain in Patients with Dry Eye: A Pilot Study. J Clin Med 2021; 10:jcm10020250. [PMID: 33445485 PMCID: PMC7826705 DOI: 10.3390/jcm10020250] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/31/2020] [Accepted: 01/10/2021] [Indexed: 12/30/2022] Open
Abstract
Background: Activation of TRPM8, a cold-sensing receptor located on the cornea and eyelid, has the potential to relieve the neuropathic ocular pain (NOP) in dry eye (DE) by inhibiting other aberrant nociceptive inputs. We aimed to investigate the effect of a topical TRPM8 agonist, cryosim-3 (C3), on relieving DE-associated NOP. Methods: We conducted a prospective pilot study of 15 patients with DE-associated NOP. These patients applied topical C3 to their eyelid, 4 times/day for 1 month. The patients underwent clinical examinations. They also completed the Ocular Pain Assessment Survey (OPAS), which is a validated questionnaire for NOP, at baseline, 1 week, and 1 month after treatment. Result: At 1 week, the OPAS scores of eye pain intensity, quality of life (driving/watching TV, general activity, sleep, and enjoying life/relations with other people), and associated factors (burning sensation, light sensitivity, and tearing) improved. The total OPAS scores of eye pain intensity, quality of life, and associated factors remained improved at 1 month. The Schirmer test scores also improved at 1 month. Conclusion: TRPM8 agonist (C3) could be a novel agent for treating patients with DE-associated NOP who are unresponsive to conventional treatments.
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23
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Shah AM, Galor A. Impact of Ocular Surface Temperature on Tear Characteristics: Current Insights. CLINICAL OPTOMETRY 2021; 13:51-62. [PMID: 33623465 PMCID: PMC7894805 DOI: 10.2147/opto.s281601] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 01/20/2021] [Indexed: 05/12/2023]
Abstract
Infrared (IR) thermographic assessment of ocular surface temperature (OST) is gaining interest as an adjuvant method to evaluate the ocular surface. It is a quick, non-invasive test that causes minimal, if any, discomfort to patients. The purpose of this article was to summarize research on how OST relates to tear film parameters and dry eye disease (DED). PubMed, Google Scholar, and Scopus searches for specific terms were carried out and eligible articles reviewed. OST of the central cornea is ~34-35°C when measured as a single time-point (typically right after a blink). Dynamically, OST values decrease over time at a rate of ~ -0.01 °C/s in healthy eyes. Single time-point OST values are impacted by temperature, with positive correlations noted with both ambient (1°C↓ results in ~0.16°C↓ in OST) and body (1°C↑ results in ~0.98°C↑ in OST) temperature. Single time-point OST values are also impacted by tear parameters, with negative correlations noted with tear break-up time (TBUT; r=-0.61) and positive correlations with lipid layer thickness (~r=0.50). Dynamically, the rate of OST cooling over the interblink period correlates with various tear parameters including Schirmer's test scores (r=-0.39), tear meniscus height (r=-0.52) and the rate of tear film break-up (r=-0.74). These data imply that OST decreases more rapidly in individuals with greater tear production, larger tear volumes, and shorter tear break-up times (faster rates of tear film break-up). There are discrepancies in relationships between OST and DED across studies, which is not surprising given that DED encompasses a number of different phenotypic presentations. However, most studies found that OST decreases at a more rapid rate in DED vs. control groups. As such, cooling rate may have utility as a screening tool in DED in combination with established point-of-care tests.
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Affiliation(s)
- Ankit M Shah
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Anat Galor
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
- Surgical Services, Miami Veterans Affairs (VA) Medical Center, Miami, FL, USA
- Correspondence: Anat Galor Bascom Palmer Eye Institute, 900 NW 17th St, Miami, FL, 33136, USA Email
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24
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Zhang X. Direct Gα q Gating Is the Sole Mechanism for TRPM8 Inhibition Caused by Bradykinin Receptor Activation. Cell Rep 2020; 27:3672-3683.e4. [PMID: 31216483 PMCID: PMC6595177 DOI: 10.1016/j.celrep.2019.05.080] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 04/03/2019] [Accepted: 05/21/2019] [Indexed: 11/29/2022] Open
Abstract
Activation of Gαq-coupled receptors by inflammatory mediators inhibits cold-sensing TRPM8 channels, aggravating pain and inflammation. Both Gαq and the downstream hydrolysis of phosphatidylinositol 4, 5-bisphosphate (PIP2) inhibit TRPM8. Here, I demonstrate that direct Gαq gating is essential for both the basal cold sensitivity of TRPM8 and TRPM8 inhibition elicited by bradykinin in sensory neurons. The action of Gαq depends on binding to three arginine residues in the N terminus of TRPM8. Neutralization of these residues markedly increased sensitivity of the channel to agonist and membrane voltage and completely abolished TRPM8 inhibition by both Gαq and bradykinin while sparing the channel sensitivity to PIP2. Interestingly, the bradykinin receptor B2R also binds to TRPM8, rendering TRPM8 insensitive to PIP2 depletion. Furthermore, TRPM8-Gαq binding impaired Gαq coupling and signaling to PLCβ-PIP2. The crosstalk in the TRPM8-Gαq-B2R complex thus determines Gαq gating rather than PIP2 as a sole means of TRPM8 inhibition by bradykinin.
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Affiliation(s)
- Xuming Zhang
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
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25
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Genomic analysis of 21 patients with corneal neuralgia after refractive surgery. Pain Rep 2020; 5:e826. [PMID: 32766464 PMCID: PMC7390595 DOI: 10.1097/pr9.0000000000000826] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/30/2020] [Accepted: 05/13/2020] [Indexed: 12/19/2022] Open
Abstract
Background Refractive surgery, specifically laser-assisted in situ keratomileusis and photorefractive keratectomy, are widely applied procedures to treat myopia, hyperopia, and astigmatism. After surgery, a subgroup of cases suffers from persistent and intractable pain of obscure etiology, thought to be neuropathic. We aimed to investigate the contribution of genomic factors in the pathogenesis of these patients with corneal neuralgia. Methods We enrolled 21 cases (6 males and 15 females) from 20 unrelated families, who reported persistent pain (>3 months), after refractive surgery (20 laser-assisted in situ keratomileusis and 1 photorefractive keratectomy patients). Whole-exome sequencing and gene-based association test were performed. Results Whole-exome sequencing demonstrated low-frequency variants (allele frequency < 0.05) in electrogenisome-related ion channels and cornea-expressed collagens, most frequently in SCN10A (5 cases), SCN9A (4 cases), TRPV1 (4 cases), CACNA1H and CACNA2D2 (5 cases each), COL5A1 (6 cases), COL6A3 (5 cases), and COL4A2 (4 cases). Two variants, p.K655R of SCN9A and p.Q85R of TRPV1, were previously characterized as gain-of-function. Gene-based association test assessing "damaging" missense variants against gnomAD exome database (non-Finnish European or global), identified a gene, SLC9A3R1, with statistically significant effect (odds ratio = 17.09 or 17.04; Bonferroni-corrected P-value < 0.05). Conclusion These findings in a small patient cohort did not identify a common gene/variant among most of these cases, as found in other disorders, for example small-fiber neuropathy. Further studies of these candidate genes/variants might enhance understanding of the role of genetic factors in the pathogenesis of corneal neuralgia.
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Negative Modulation of TRPM8 Channel Function by Protein Kinase C in Trigeminal Cold Thermoreceptor Neurons. Int J Mol Sci 2020; 21:ijms21124420. [PMID: 32580281 PMCID: PMC7352406 DOI: 10.3390/ijms21124420] [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: 04/30/2020] [Revised: 05/30/2020] [Accepted: 06/12/2020] [Indexed: 01/19/2023] Open
Abstract
TRPM8 is the main molecular entity responsible for cold sensing. This polymodal ion channel is activated by cold, cooling compounds such as menthol, voltage, and rises in osmolality. In corneal cold thermoreceptor neurons (CTNs), TRPM8 expression determines not only their sensitivity to cold, but also their role as neural detectors of ocular surface wetness. Several reports suggest that Protein Kinase C (PKC) activation impacts on TRPM8 function; however, the molecular bases of this functional modulation are still poorly understood. We explored PKC-dependent regulation of TRPM8 using Phorbol 12-Myristate 13-Acetate to activate this kinase. Consistently, recombinant TRPM8 channels, cultured trigeminal neurons, and free nerve endings of corneal CTNs revealed a robust reduction of TRPM8-dependent responses under PKC activation. In corneal CTNs, PKC activation decreased ongoing activity, a key parameter in the role of TRPM8-expressing neurons as humidity detectors, and also the maximal cold-evoked response, which were validated by mathematical modeling. Biophysical analysis indicated that PKC-dependent downregulation of TRPM8 is mainly due to a decreased maximal conductance value, and complementary noise analysis revealed a reduced number of functional channels at the cell surface, providing important clues to understanding the molecular mechanisms of how PKC activity modulates TRPM8 channels in CTNs.
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27
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Talarico C, Gervasoni S, Manelfi C, Pedretti A, Vistoli G, Beccari AR. Combining Molecular Dynamics and Docking Simulations to Develop Targeted Protocols for Performing Optimized Virtual Screening Campaigns on The hTRPM8 Channel. Int J Mol Sci 2020; 21:E2265. [PMID: 32218173 PMCID: PMC7177470 DOI: 10.3390/ijms21072265] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/19/2020] [Accepted: 03/20/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND There is an increasing interest in TRPM8 ligands of medicinal interest, the rational design of which can be nowadays supported by structure-based in silico studies based on the recently resolved TRPM8 structures. Methods: The study involves the generation of a reliable hTRPM8 homology model, the reliability of which was assessed by a 1.0 μs MD simulation which was also used to generate multiple receptor conformations for the following structure-based virtual screening (VS) campaigns; docking simulations utilized different programs and involved all monomers of the selected frames; the so computed docking scores were combined by consensus approaches based on the EFO algorithm. Results: The obtained models revealed very satisfactory performances; LiGen™ provided the best results among the tested docking programs; the combination of docking results from the four monomers elicited a markedly beneficial effect on the computed consensus models. Conclusions: The generated hTRPM8 model appears to be amenable for successful structure-based VS studies; cross-talk modulating effects between interacting monomers on the binding sites can be accounted for by combining docking simulations as performed on all the monomers; this strategy can have general applicability for docking simulations involving quaternary protein structures with multiple identical binding pockets.
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Affiliation(s)
- Carmine Talarico
- Dompé Farmaceutici SpA, Via Campo di Pile, 67100 L’Aquila, Italy; (C.T.); (C.M.)
| | - Silvia Gervasoni
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Mangiagalli, 25, I-20133 Milano, Italy; (S.G.); (A.P.); (G.V.)
| | - Candida Manelfi
- Dompé Farmaceutici SpA, Via Campo di Pile, 67100 L’Aquila, Italy; (C.T.); (C.M.)
| | - Alessandro Pedretti
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Mangiagalli, 25, I-20133 Milano, Italy; (S.G.); (A.P.); (G.V.)
| | - Giulio Vistoli
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Mangiagalli, 25, I-20133 Milano, Italy; (S.G.); (A.P.); (G.V.)
| | - Andrea R. Beccari
- Dompé Farmaceutici SpA, Via Campo di Pile, 67100 L’Aquila, Italy; (C.T.); (C.M.)
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González-Muñiz R, Bonache MA, Martín-Escura C, Gómez-Monterrey I. Recent Progress in TRPM8 Modulation: An Update. Int J Mol Sci 2019; 20:ijms20112618. [PMID: 31141957 PMCID: PMC6600640 DOI: 10.3390/ijms20112618] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 05/24/2019] [Accepted: 05/25/2019] [Indexed: 12/30/2022] Open
Abstract
The transient receptor potential melastatin subtype 8 (TRPM8) is a nonselective, multimodal ion channel, activated by low temperatures (<28 °C), pressure, and cooling compounds (menthol, icilin). Experimental evidences indicated a role of TRPM8 in cold thermal transduction, different life-threatening tumors, and other pathologies, including migraine, urinary tract dysfunction, dry eye disease, and obesity. Hence, the modulation of the TRPM8 channel could be essential in order to understand its implications in these pathologies and for therapeutic intervention. This short review will cover recent progress on the TRPM8 agonists and antagonists, describing newly reported chemotypes, and their application in the pharmacological characterization of TRPM8 in health and disease. The recently described structures of the TRPM8 channel alone or complexed with known agonists and PIP2 are also discussed.
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Affiliation(s)
| | - M Angeles Bonache
- Instituto de Química Médica, IQM-CSIC. Juan de la Cierva 3, 28006 Madrid, Spain.
| | | | - Isabel Gómez-Monterrey
- Dipartimento di Farmacia, Università "Federico II" de Napoli, Via D. Montesano 49, 80131 Naples, Italy.
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