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Mansoor H, Lee IXY, Lin MTY, Ang HP, Xue YC, Krishaa L, Patil M, Koh SK, Tan HC, Zhou L, Liu YC. Topical and oral peroxisome proliferator-activated receptor-α agonist ameliorates diabetic corneal neuropathy. Sci Rep 2024; 14:13435. [PMID: 38862650 PMCID: PMC11167005 DOI: 10.1038/s41598-024-64451-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 06/10/2024] [Indexed: 06/13/2024] Open
Abstract
Diabetic corneal neuropathy (DCN) is a common diabetic ocular complication with limited treatment options. In this study, we investigated the effects of topical and oral fenofibrate, a peroxisome proliferator-activated receptor-α agonist, on the amelioration of DCN using diabetic mice (n = 120). Ocular surface assessments, corneal nerve and cell imaging analysis, tear proteomics and its associated biological pathways, immuno-histochemistry and western blot on PPARα expression, were studied before and 12 weeks after treatment. At 12 weeks, PPARα expression markedly restored after topical and oral fenofibrate. Topical fenofibrate significantly improved corneal nerve fibre density (CNFD) and tortuosity coefficient. Likewise, oral fenofibrate significantly improved CNFD. Both topical and oral forms significantly improved corneal sensitivity. Additionally, topical and oral fenofibrate significantly alleviated diabetic keratopathy, with fenofibrate eye drops demonstrating earlier therapeutic effects. Both topical and oral fenofibrate significantly increased corneal β-III tubulin expression. Topical fenofibrate reduced neuroinflammation by significantly increasing the levels of nerve growth factor and substance P. It also significantly increased β-III-tubulin and reduced CDC42 mRNA expression in trigeminal ganglions. Proteomic analysis showed that neurotrophin signalling and anti-inflammation reactions were significantly up-regulated after fenofibrate treatment, whether applied topically or orally. This study concluded that both topical and oral fenofibrate ameliorate DCN, while topical fenofibrate significantly reduces neuroinflammation.
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Affiliation(s)
| | - Isabelle Xin Yu Lee
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, 11 Third Hospital Ave, Singapore, 168751, Singapore
| | - Molly Tzu-Yu Lin
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, 11 Third Hospital Ave, Singapore, 168751, Singapore
| | - Heng Pei Ang
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, 11 Third Hospital Ave, Singapore, 168751, Singapore
| | - Yao Cong Xue
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, 11 Third Hospital Ave, Singapore, 168751, Singapore
| | - L Krishaa
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, 11 Third Hospital Ave, Singapore, 168751, Singapore
| | - Moushmi Patil
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, 11 Third Hospital Ave, Singapore, 168751, Singapore
| | - Siew-Kwan Koh
- Ocular Proteomic Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Hong Chang Tan
- Department of Endocrinology, Singapore General Hospital, Singapore, Singapore
| | - Lei Zhou
- Department of Applied Biology and Chemical Technology, School of Optometry, Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hung Hom, Hong Kong
- Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Pak Shek Kok, Hong Kong
| | - Yu-Chi Liu
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, 11 Third Hospital Ave, Singapore, 168751, Singapore.
- Cornea and Refractive Surgery Group, Singapore Eye Research Institute, Singapore, Singapore.
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore, Singapore.
- Eye-Academic Clinical Program, Singapore Graduate Medical School, Duke-National University, Singapore, Singapore.
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan.
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Xue Y, Xu P, Hu Y, Liu S, Yan R, Liu S, Li Y, Liu J, Fu T, Li Z. Stress systems exacerbate the inflammatory response after corneal abrasion in sleep-deprived mice via the IL-17 signaling pathway. Mucosal Immunol 2024; 17:323-345. [PMID: 38428739 DOI: 10.1016/j.mucimm.2024.02.009] [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: 01/18/2023] [Revised: 02/22/2024] [Accepted: 02/23/2024] [Indexed: 03/03/2024]
Abstract
Sleep deprivation (SD) has a wide range of adverse health effects. However, the mechanisms by which SD influences corneal pathophysiology and its post-wound healing remain unclear. This study aimed to examine the basic physiological characteristics of the cornea in mice subjected to SD and determine the pathophysiological response to injury after corneal abrasion. Using a multi-platform water environment method as an SD model, we found that SD leads to disturbances of corneal proliferative, sensory, and immune homeostasis as well as excessive inflammatory response and delayed repair after corneal abrasion by inducing hyperactivation of the sympathetic nervous system and hypothalamic-pituitary-adrenal axis. Pathophysiological changes in the cornea mainly occurred through the activation of the IL-17 signaling pathway. Blocking both adrenergic and glucocorticoid synthesis and locally neutralizing IL-17A significantly improved corneal homeostasis and the excessive inflammatory response and delay in wound repair following corneal injury in SD-treated mice. These results indicate that optimal sleep quality is essential for the physiological homeostasis of the cornea and its well-established repair process after injury. Additionally, these observations provide potential therapeutic targets to ameliorate SD-induced delays in corneal wound repair by inhibiting or blocking the activation of the stress system and its associated IL-17 signaling pathway.
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Affiliation(s)
- Yunxia Xue
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University Medical School, Guangzhou, China; Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Pengyang Xu
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University Medical School, Guangzhou, China; Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China; Department of Pathology, Nanyang Second General Hospital, Nanyang City, Henan, China
| | - Yu Hu
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University Medical School, Guangzhou, China
| | - Sijing Liu
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University Medical School, Guangzhou, China; Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Ruyu Yan
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University Medical School, Guangzhou, China; Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Shutong Liu
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University Medical School, Guangzhou, China
| | - Yan Li
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University Medical School, Guangzhou, China; Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Jun Liu
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University Medical School, Guangzhou, China; Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Ting Fu
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University Medical School, Guangzhou, China; Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Zhijie Li
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University Medical School, Guangzhou, China; Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China.
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Abu-Romman A, Scholand KK, Govindarajan G, Yu Z, Pal-Ghosh S, Stepp MA, de Paiva CS. Age-Related Differences in the Mouse Corneal Epithelial Transcriptome and Their Impact on Corneal Wound Healing. Invest Ophthalmol Vis Sci 2024; 65:21. [PMID: 38739085 PMCID: PMC11098051 DOI: 10.1167/iovs.65.5.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 04/24/2024] [Indexed: 05/14/2024] Open
Abstract
Purpose Aging is a risk factor for dry eye. We sought to identify changes in the aged mouse corneal epithelial transcriptome and determine how age affects corneal sensitivity, re-epithelialization, and barrier reformation after corneal debridement. Methods Corneal epithelium of female C57BL/6J (B6) mice of different ages (2, 12, 18, and 24 months) was collected, RNA extracted, and bulk RNA sequencing performed. Cornea sensitivity was measured with an esthesiometer in 2- to 3-month-old, 12- to 13-month-old, 18- to 19-month-old, and 22- to 25-month-old female and male mice. The 2-month-old and 18-month-old female and male mice underwent unilateral corneal debridement using a blunt blade. Wound size and fluorescein staining were visualized and photographed at different time points, and a re-epithelialization rate curve was calculated. Results There were 157 differentially expressed genes in aged mice compared with young mice. Several pathways downregulated with age control cell migration, proteoglycan synthesis, and collagen trimerization, assembly, biosynthesis, and degradation. Male mice had decreased corneal sensitivity compared with female mice at 12 and 24 months of age. Aged mice, irrespective of sex, had delayed corneal re-epithelialization in the first 48 hours and worse corneal fluorescein staining intensity at day 14 than young mice. Conclusions Aged corneal epithelium has an altered transcriptome. Aged mice regardless of sex heal more slowly and displayed more signs of corneal epithelial defects after wounding than young mice. These results indicate that aging significantly alters the corneal epithelium and its ability to coordinate healing.
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Affiliation(s)
- Anmar Abu-Romman
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
| | - Kaitlin K. Scholand
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
- Department of Biosciences, Rice University, Houston, Texas, United States
| | - Gowthaman Govindarajan
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
| | - Zhiyuan Yu
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
| | - Sonali Pal-Ghosh
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC, United States
| | - Mary A. Stepp
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC, United States
- Department of Ophthalmology, The George Washington University School of Medicine and Health Sciences, Washington, DC, United States
| | - Cintia S. de Paiva
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
- Department of Biosciences, Rice University, Houston, Texas, United States
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Lu X, Chen Z, Lu J, Watsky MA. Effects of 1,25-Vitamin D3 and 24,25-Vitamin D3 on Corneal Nerve Regeneration in Diabetic Mice. Biomolecules 2023; 13:1754. [PMID: 38136625 PMCID: PMC10742127 DOI: 10.3390/biom13121754] [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: 11/07/2023] [Revised: 11/30/2023] [Accepted: 12/02/2023] [Indexed: 12/24/2023] Open
Abstract
Corneal nerve homeostasis is essential for the functional integrity of the ocular surface. Vitamin D deficiency (VDD) and vitamin D receptor knockout (VDR KO) have been found to reduce corneal nerve density in diabetic mice. This is the first study to comprehensively examine the influence of vitamin D on nerve regeneration following corneal epithelial injury in diabetic mice. Corneal nerve regeneration was significantly retarded by diabetes, VDR KO, and VDD, and it was accelerated following topical 1,25 Vit D and 24,25 Vit D administration. Furthermore, topical 1,25 Vit D and 24,25 Vit D increased nerve growth factor, glial cell line-derived neurotropic factor, and neurotropin-3 protein expression, and it increased secretion of GDNF protein from human corneal epithelial cells. CD45+ cells and macrophage numbers were significantly decreased, and vitamin D increased CD45+ cell and macrophage recruitment in these wounded diabetic mouse corneas. The accelerated nerve regeneration observed in these corneas following topical 1,25 Vit D and 24,25 Vit D administration may be related to the vitamin D-stimulated expression, secretion of neurotrophic factors, and recruitment of immune cells.
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Affiliation(s)
- Xiaowen Lu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15th Street, CB-2901, Augusta, GA 30912, USA
| | | | | | - Mitchell A. Watsky
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15th Street, CB-2901, Augusta, GA 30912, USA
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Liu LR, Chen D, Sheng ST, Xu JW, Xu W. Research progress on animal models of corneal epithelial-stromal injury. Int J Ophthalmol 2023; 16:1890-1898. [PMID: 38028511 PMCID: PMC10626350 DOI: 10.18240/ijo.2023.11.23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 08/31/2023] [Indexed: 12/01/2023] Open
Abstract
A corneal epithelial-stromal defect is recognized as a major contributor to corneal scarring. Given the rising prevalence of blindness caused by corneal scarring, increasing attention has been focused on corneal epithelial-stromal defects. Currently, the etiology and pathogenesis of these defects remain inadequately understood, necessitating further investigation through experimental research. Various modeling methods exist both domestically and internationally, each with distinct adaptive conditions, advantages, and disadvantages. This review primarily aims to summarize the techniques used to establish optimal animal models of corneal epithelial-stromal injury, including mechanical modeling, chemical alkali burns, post-refractive surgery infections, and genetic engineering. The intention is to provide valuable insights for studying the mechanisms underlying corneal epithelial-stromal injury and the development of corresponding therapeutic interventions.
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Affiliation(s)
- Li-Rui Liu
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Engineering Institute on Eye Diseases, Hangzhou 310009, Zhejiang Province, China
| | - Dan Chen
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Engineering Institute on Eye Diseases, Hangzhou 310009, Zhejiang Province, China
| | - Si-Ting Sheng
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Engineering Institute on Eye Diseases, Hangzhou 310009, Zhejiang Province, China
| | - Jing-Wei Xu
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Engineering Institute on Eye Diseases, Hangzhou 310009, Zhejiang Province, China
| | - Wen Xu
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Engineering Institute on Eye Diseases, Hangzhou 310009, Zhejiang Province, China
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Abu-Romman A, Scholand KK, Pal-Ghosh S, Yu Z, Kelagere Y, Yazdanpanah G, Kao WWY, Coulson-Thomas VJ, Stepp MA, de Paiva CS. Conditional deletion of CD25 in the corneal epithelium reveals sex differences in barrier disruption. Ocul Surf 2023; 30:57-72. [PMID: 37516317 PMCID: PMC10812880 DOI: 10.1016/j.jtos.2023.07.008] [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: 05/02/2023] [Revised: 07/06/2023] [Accepted: 07/25/2023] [Indexed: 07/31/2023]
Abstract
PURPOSE IL-2 promotes activation, clonal expansion, and deletion of T cells. IL-2 signals through its heterotrimeric receptor (IL-2R) consisting of the CD25, CD122 and CD132 chains. CD25 knockout (KO) mice develop Sjögren Syndrome-like disease. This study investigates whether corneal CD25/IL-2 signaling is critical for ocular health. METHODS Eyes from C57BL/6 mice were collected and prepared for immunostaining or in-situ hybridization. Bulk RNA sequencing was performed on the corneal epithelium from wild-type and CD25KO mice. We generated a conditional corneal-specific deletion of CD25 in the corneal epithelium (CD25Δ/ΔCEpi). Corneal barrier function was evaluated based on the uptake of a fluorescent dye. Mice were subjected to unilateral corneal debridement, followed by epithelial closure over time. RESULTS In C57BL/6 mice, CD25 mRNA was expressed in ocular tissues. Protein expression of CD25, CD122, and CD132 was confirmed in the corneal epithelium. Delayed corneal re-epithelization was seen in female but not male CD25KO mice. There were 771 differentially expressed genes in the corneal epithelium of CD25KO compared to wild-type mice. While barrier function is disrupted in CD25Δ/ΔCEpi mice, re-epithelialization rates are not delayed. CONCLUSIONS All three chains of the IL-2R are expressed in the corneal epithelium. Our results indicate for the first time, deleting CD25 systemically in all tissues in the mouse and deleting CD25 locally in just the corneal epithelium compromises corneal epithelial barrier function, leading to dry eye disease in female mice. Future studies are needed to delineate the pathways used by IL-2 signaling to influence cornea homeostasis.
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Affiliation(s)
- Anmar Abu-Romman
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States.
| | - Kaitlin K Scholand
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States; Department of Biosciences, Rice University, Houston, TX, United States.
| | - Sonali Pal-Ghosh
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC, United States.
| | - Zhiyuan Yu
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States.
| | - Yashaswini Kelagere
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States.
| | - Ghasem Yazdanpanah
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States.
| | - Winston W-Y Kao
- Department of Ophthalmology, University of Cincinnati, Cincinnati, OH, United States.
| | | | - Mary Ann Stepp
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC, United States; Department of Ophthalmology, The George Washington University School of Medicine and Health Sciences, Washington, DC, United States.
| | - Cintia S de Paiva
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States; Department of Biosciences, Rice University, Houston, TX, United States.
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Wareham LK, Holden JM, Bossardet OL, Baratta RO, Del Buono BJ, Schlumpf E, Calkins DJ. Collagen mimetic peptide repair of the corneal nerve bed in a mouse model of dry eye disease. Front Neurosci 2023; 17:1148950. [PMID: 37260844 PMCID: PMC10228686 DOI: 10.3389/fnins.2023.1148950] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 04/21/2023] [Indexed: 06/02/2023] Open
Abstract
The intraepithelial sub-basal nerve plexus of the cornea is characterized by a central swirl of nerve processes that terminate between the apical cells of the epithelium. This plexus is a critical component of maintaining homeostatic function of the ocular surface. The cornea contains a high concentration of collagen, which is susceptible to damage in conditions such as neuropathic pain, neurotrophic keratitis, and dry eye disease. Here we tested whether topical application of a collagen mimetic peptide (CMP) is efficacious in repairing the corneal sub-basal nerve plexus in a mouse model of ocular surface desiccation. We induced corneal tear film reduction, epithelial damage, and nerve bed degradation through a combination of environmental and pharmaceutical (atropine) desiccation. Mice were subjected to desiccating air flow and bilateral topical application of 1% atropine solution (4× daily) for 2 weeks. During the latter half of this exposure, mice received topical vehicle [phosphate buffered saline (PBS)] or CMP [200 μm (Pro-Pro-Gly)7, 10 μl] once daily, 2 h prior to the first atropine treatment for that day. After euthanasia, cornea were labeled with antibodies against βIII tubulin to visualize and quantify changes to the nerve bed. For mice receiving vehicle only, the two-week desiccation regimen reduced neuronal coverage of the central sub-basal plexus and epithelial terminals compared to naïve, with some corneas demonstrating complete degeneration of nerve beds. Accordingly, both sub-basal and epithelial βIII tubulin-labeled processes demonstrated increased fragmentation, indicative of nerve disassembly. Treatment with CMP significantly reduced nerve fragmentation, expanded both sub-basal and epithelial neuronal coverage compared to vehicle controls, and improved corneal epithelium integrity, tear film production, and corneal sensitivity. Together, these results indicate that topical CMP significantly counters neurodegeneration characteristic of corneal surface desiccation. Repairing underlying collagen in conditions that damage the ocular surface could represent a novel therapeutic avenue in treating a broad spectrum of diseases or injury.
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Affiliation(s)
- Lauren K. Wareham
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Joseph M. Holden
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Olivia L. Bossardet
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | | | | | - Eric Schlumpf
- Stuart Therapeutics, Inc., Stuart, FL, United States
| | - David J. Calkins
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
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He J, Pham TL, Bazan HEP. Neuroanatomy of Adult and Aging Chicken Cornea. Curr Eye Res 2022; 47:1374-1380. [PMID: 35904450 PMCID: PMC9844890 DOI: 10.1080/02713683.2022.2104321] [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: 03/28/2022] [Revised: 05/05/2022] [Accepted: 07/15/2022] [Indexed: 01/19/2023]
Abstract
PURPOSE To provide a complete nerve architecture and main sensory neuropeptide distribution in the chicken cornea. METHODS Adult chickens aged 6 months and 4 years were used. The whole cornea was stained with protein gene product (PGP) 9.5 antibody-a pan marker for nerve fibers, calcitonin gene-related peptide (CGRP), and substance P (SP) antibodies; whole-mount images were acquired to build an entire view of corneal innervation. Relative corneal epithelial nerve fiber densities, including subbasal bundles and superficial terminals, were assessed by computer-assisted analysis. RESULTS An average of about 76.3 ± 5.7 (n = 8 corneas, 4 M/4F) stromal nerve trunks enter the cornea radially and are evenly distributed around the limbus with no significant difference between male and female chickens. The subbasal nerve bundles do not extend in a given direction and, as a result, do not form a vortex in the center of the cornea. Furthermore, the chicken cornea contains more SP-positive nerves than CGRP-positive nerves. It is also shown that aging significantly reduces corneal epithelial nerve density in chickens. CONCLUSIONS This is the first study to provide a complete map of the entire corneal nerves and CGRP and SP sensory neuropeptide distribution in the adult chicken cornea. The findings show chicken corneal innervation has many differences to human and mammal cornea.
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Affiliation(s)
- Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, USA
- Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, USA
| | - Thang Luong Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, USA
| | - Haydee E. P. Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, USA
- Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, USA
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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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Cao J, Qu J, Odilov B, Lu B, Zhang Y, Li L, Zhang Y, Xiong Q, Hong Y, Li J, Shen Y, Hou X. Corneal Nerve Parameter Reference Values for Chinese Adults Assessed by Corneal Confocal Microscopy. J Diabetes Res 2022; 2022:4913031. [PMID: 35265718 PMCID: PMC8898861 DOI: 10.1155/2022/4913031] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 02/09/2022] [Indexed: 11/18/2022] Open
Abstract
Background Confocal corneal microscopy is an excellent new noninvasive tool for assessing diabetic peripheral neuropathy. We aimed to investigate the clinical variables associated with corneal nerve parameters and establish reference values for clinical use in healthy Chinese adults. Methods The study enlisted 257 healthy volunteers (137 females and 120 males) from two clinical academic centers in China. Two experts captured and selected images of the central corneal subbasal nerve plexus at each center using the same corneal confocal microscopy instrument according to a commonly adopted protocol. Corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), and corneal nerve fiber length (CNFL) were measured using fully automated software (ACCMetrics). The correlation between clinical indicators and confocal corneal microscopy measures was determined using partial correlation. Quantile regression was used to calculate reference values and estimate the effects of clinical factors on the normative values of confocal corneal microscopy measures. Results Females had significantly higher CNFD, CNBD, and CNFL than males. There was no correlation between age, glycated hemoglobin (HbA1c), height, weight, body mass index (BMI), and any corneal nerve fiber parameter in both sexes. In either sex, age, weight, height, BMI, and HbA1c did not affect the 0.05th quantile values of any corneal nerve parameter. Conclusions This study establishes sex-adjusted reference values for corneal confocal microscopy measures in Chinese adults and provides a reference for clinical practice and research with this technique.
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Affiliation(s)
- Juan Cao
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
- Department of Health Management Center, Qilu Hospital of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
| | - Jingru Qu
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
- Institute of Endocrine and Metabolic Diseases of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
- Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, 107 Wenhua W Road, Jinan, Shandong 250012, China
- Jinan Clinical Research Center for Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, 107 Wenhua W Road, Jinan, Shandong 250012, China
| | - Bekzod Odilov
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Bin Lu
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, 12 Wulumuqi Middle Road, Shanghai 200040, China
| | - Yuanpin Zhang
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, 12 Wulumuqi Middle Road, Shanghai 200040, China
| | - Lili Li
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
- Department of Ultrasound, Qilu Hospital of Shandong University, 758 Hefei Road, Qingdao, Shandong 266000, China
| | - Yuan Zhang
- Clinical Epidemiology Unit, Qilu Hospital of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
- Clinical Research Center of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
| | - Qian Xiong
- Department of Endocrinology and Metabolism, Gonghui Hospital, 315 Shimen No. 1 Road, Shanghai 200040, China
| | - Yu Hong
- Department of Endocrinology and Metabolism, Gonghui Hospital, 315 Shimen No. 1 Road, Shanghai 200040, China
| | - Jianqiao Li
- Department of Ophthalmology, Qilu Hospital of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
| | - Yunfeng Shen
- Department of Endocrinology and Metabolism, Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, The Second Affiliated Hospital of Nanchang University, 1 Minde Road, Nanchang, Jiangxi 330006, China
| | - Xinguo Hou
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
- Institute of Endocrine and Metabolic Diseases of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
- Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, 107 Wenhua W Road, Jinan, Shandong 250012, China
- Jinan Clinical Research Center for Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, 107 Wenhua W Road, Jinan, Shandong 250012, China
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Pham TL, Kakazu AH, He J, Nshimiyimana R, Petasis NA, Jun B, Bazan NG, Bazan HEP. Elucidating the structure and functions of Resolvin D6 isomers on nerve regeneration with a distinctive trigeminal transcriptome. FASEB J 2021; 35:e21775. [PMID: 34245621 PMCID: PMC8362171 DOI: 10.1096/fj.202100686r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/16/2021] [Accepted: 06/21/2021] [Indexed: 12/26/2022]
Abstract
Innervation sustains cornea integrity. Pigment epithelium‐derived factor (PEDF) plus docosahexaenoic acid (DHA) regenerated damaged nerves by stimulating the synthesis of a new stereoisomer of Resolvin D6 (RvD6si). Here, we resolved the structure of this lipid isolated from mouse tears after injured corneas were treated with PEDF + DHA. RvD6si synthesis was inhibited by fluvoxamine, a cytochrome P450 inhibitor, but not by 15‐ or 5‐LOX inhibitors, suggesting that the 4‐ and 17‐hydroxy of DHA have an RR‐ or SR‐configuration. The two compounds were chemically synthesized. Using chiral phase HPLC, four peaks of RvD6si1‐4 from tears were resolved. The RR‐RvD6 standard eluted as a single peak with RvD61 while pure SR‐RvD6 eluted with RvD63. The addition of these pure mediators prompted a trigeminal ganglion transcriptome response in injured corneas and showed that RR‐RvD6 was the more potent, increasing cornea sensitivity and nerve regeneration. RR‐RvD6 stimulates Rictor and hepatocyte growth factor (hgf) genes specifically as upstream regulators and a gene network involved in axon growth and suppression of neuropathic pain, indicating a novel function of this lipid mediator to maintain cornea integrity and homeostasis after injury.
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Affiliation(s)
- Thang L Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Azucena H Kakazu
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Robert Nshimiyimana
- Department of Chemistry and Loker Hydrocarbon Research Institute, University of Southern California, Los Angeles, CA, USA
| | - Nicos A Petasis
- Department of Chemistry and Loker Hydrocarbon Research Institute, University of Southern California, Los Angeles, CA, USA
| | - Bokkyoo Jun
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Nicolas G Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Haydee E P Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
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12
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Shang Z, Li C, Liu X, Xu M, Zhang X, Li X, Barnstable CJ, Zhao S, Tombran-Tink J. PEDF Gene Deletion Disrupts Corneal Innervation and Ocular Surface Function. Invest Ophthalmol Vis Sci 2021; 62:18. [PMID: 34132748 PMCID: PMC8212434 DOI: 10.1167/iovs.62.7.18] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The cornea is richly innervated by the trigeminal ganglion (TG) and its function supported by secretions from the adjacent lacrimal (LG) and meibomian glands (MG). In this study we examined how pigment epithelium–derived factor (PEDF) gene deletion affects the cornea structure and function. Methods We used PEDF hemizygous and homozygous knockout mice to study effects of PEDF deficiency on corneal innervation assessed by beta tubulin staining, mRNA expression of trophic factors, and PEDF receptors by adjacent supporting glands, corneal sensitivity measured using a Cochet-Bonnet esthesiometer, and tear production using phenol red cotton thread wetting. Results Loss of PEDF was accompanied by reduced corneal innervation and sensitivity, increased corneal surface injury and tear production, thinning of the corneal stroma and loss of stromal cells. PEDF mRNA was expressed in the cornea and its supporting tissues, the TG, LG, and MG. Deletion of one or both PEDF alleles resulted in decreased expression of essential trophic support in the TG, LG, and MG including nerve growth factor, brain-derived neurotrophic growth factor, and GDNF with significantly increased levels of NT-3 in the LG and decreased EGF expression in the cornea. Decreased transcription of the putative PEDF receptors, adipose triglyceride lipase, lipoprotein receptor–related protein 6, laminin receptor, PLXDC1, and PLXDC2 was also evident in the TG, LG and MG with the first three showing increased levels in corneas of the Pedf+/− and Pedf−/− mice compared to wildtype controls. Constitutive inactivation of ERK1/2 and Akt was pronounced in the TG and cornea, although their protein levels were dramatically increased in Pedf−/− mice. Conclusions This study highlights an essential role for PEDF in corneal structure and function and confirms the reported rescue of exogenous PEDF treatment in corneal pathologies. The pleiotropic effects of PEDF deletion on multiple trophic factors, receptors and signaling molecules are strong indications that PEDF is a key coordinator of molecular mechanisms that maintain corneal function and could be exploited in therapeutic options for several ocular surface diseases.
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Affiliation(s)
- Zhenying Shang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Chenxi Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Xuemei Liu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Manhong Xu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Xiaomin Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Xiaorong Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Colin J Barnstable
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.,Department of Neural and Behavioral Sciences, Penn State College of Medicine, Hershey, Pennsylvania, United States.,Department of Ophthalmology, Penn State College of Medicine, Hershey, Pennsylvania, United States
| | - Shaozhen Zhao
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Joyce Tombran-Tink
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.,Department of Neural and Behavioral Sciences, Penn State College of Medicine, Hershey, Pennsylvania, United States.,Department of Ophthalmology, Penn State College of Medicine, Hershey, Pennsylvania, United States
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13
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Liu X, Liu H, Lu X, Zhao S. N-acetylcysteine alleviates ocular surface damage in STZ-induced diabetic mice by inhibiting the ROS/NLRP3/Caspase-1/IL-1β signaling pathway. Exp Eye Res 2021; 209:108654. [PMID: 34102208 DOI: 10.1016/j.exer.2021.108654] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 05/19/2021] [Accepted: 06/01/2021] [Indexed: 02/06/2023]
Abstract
Diabetes mellitus (DM) induces damage to the ocular surface, which leads to vision decline. In the current study, we investigated whether N-acetylcysteine (NAC) plays a protective role in diabetes-induced ocular surface damage. The diabetic mice model was treated with 0.3% NAC topically. Corneal epithelial integrity, tear volume and corneal sensitivity were examined by sodium fluorescein staining, phenol red cotton thread and esthesiometer respectively. The level of reactive oxygen species (ROS) was measured with 2',7-dichlorofluorescein diacetate. The expression of NLRP3, IL-1β and caspase-1 were evaluated by RT-PCR, western blot and immunostaining. The level of SOD1 was assessed by RT-PCR. We found that the expression of NLRP3, IL-1β and caspase-1 were elevated in diabetic cornea and conjunctiva. Treatment with NAC improved corneal epithelial integrity, increased tear production and corneal sensitivity in diabetic mice. Moreover, NAC markedly attenuated ROS accumulation and decreased NLRP3, IL-1β and caspase-1 levels in diabetic cornea and conjunctiva. These results suggest that NAC improves ocular surface damage in STZ-induced diabetic mice, which may be related to the inhibition of the ROS/NLRP3/Caspase-1/IL-1β signaling pathway.
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Affiliation(s)
- Xuemei Liu
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Hui Liu
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Xiaoxiao Lu
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Shaozhen Zhao
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
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14
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Pham TL, Bazan HEP. Docosanoid signaling modulates corneal nerve regeneration: effect on tear secretion, wound healing, and neuropathic pain. J Lipid Res 2021; 62:100033. [PMID: 32788291 PMCID: PMC7933495 DOI: 10.1194/jlr.tr120000954] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/31/2020] [Indexed: 12/30/2022] Open
Abstract
The cornea is densely innervated, mainly by sensory nerves of the ophthalmic branch of the trigeminal ganglia (TG). These nerves are important to maintain corneal homeostasis, and nerve damage can lead to a decrease in wound healing, an increase in corneal ulceration and dry eye disease (DED), and neuropathic pain. Pathologies, such as diabetes, aging, viral and bacterial infection, as well as prolonged use of contact lenses and surgeries to correct vision can produce nerve damage. There are no effective therapies to alleviate DED (a multifunctional disease) and several clinical trials using ω-3 supplementation show unclear and sometimes negative results. Using animal models of corneal nerve damage, we show that treating corneas with pigment epithelium-derived factor plus DHA increases nerve regeneration, wound healing, and tear secretion. The mechanism involves the activation of a calcium-independent phospholipase A2 that releases the incorporated DHA from phospholipids and enhances the synthesis of the docosanoids, neuroprotectin D1 (NPD1) and a new resolvin stereoisomer, resolvin D6i (RvD6i). NPD1 stimulates the synthesis of brain-derived neurotrophic factor, nerve growth factor, and semaphorin 7A. RvD6i treatment of injured corneas modulates gene expression in the TG resulting in enhanced neurogenesis, decreased neuropathic pain, and increased sensitivity. Taken together, these results represent a promising therapeutic option to reestablish the homeostasis of the cornea.
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Affiliation(s)
- Thang L Pham
- Neuroscience Center of Excellence and Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Haydee E P Bazan
- Neuroscience Center of Excellence and Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA.
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15
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He J, Pham TL, Bazan HEP. Neuroanatomy and neurochemistry of rat cornea: Changes with age. Ocul Surf 2020; 20:86-94. [PMID: 33340717 DOI: 10.1016/j.jtos.2020.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/04/2020] [Accepted: 11/09/2020] [Indexed: 12/20/2022]
Abstract
PURPOSE To characterize the entire rat corneal nerve architecture, the changes that occur with aging, and its sensory, sympathetic, and parasympathetic fiber distribution. METHODS Sprague-Dawley rats (aged 1 day to 2 years old) of both sexes were euthanized, and the whole corneas were immunostained with protein gene product 9.5 (PGP9.5). The specimens were double-labeled with antibodies against calcitonin gene-related peptide (CGRP) and substance P (SP) as sensory nerve markers, vasoactive intestinal peptide (VIP) as a parasympathetic nerve marker, and neuropeptide Y (NPY) and tyrosine hydroxylase (TH) as markers of sympathetic fibers. Relative nerve density positive for each antibody was assessed by computer-assisted image analysis. RESULTS Thick nerve trunks enter the cornea in the middle of the stroma and run towards the anterior stroma, subsequently dividing into smaller branches that penetrate upwards into the epithelium to form the subbasal nerve bundles. There was no significant difference in corneal innervation between sexes. CGRP and SP were the major sensory neuropeptides with 47.6% ± 3.5% and 34.9% ± 5.1%, respectively, of the total nerves. VIP was 18.4% ± 5.7%, and NPY and TH positive fibers took up 6.92% ± 2.66% and 2.92% ± 1.52%, respectively. Epithelial nerve density increased with age, reached full development at 5 weeks, and decreased at 120 weeks. CONCLUSION This study provides a complete nerve architecture and content of components of sensory, parasympathetic, and sympathetic nerves in the rat cornea. The normal innervation pattern described here will provide an essential baseline for investigators who use the rat model for assessing corneal pathologies that involve nerve alterations.
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Affiliation(s)
- Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA; Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Thang Luong Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Haydee E P Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA; Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA.
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16
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Kamil S, Mohan RR. Corneal stromal wound healing: Major regulators and therapeutic targets. Ocul Surf 2020; 19:290-306. [PMID: 33127599 DOI: 10.1016/j.jtos.2020.10.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/16/2020] [Accepted: 10/25/2020] [Indexed: 12/12/2022]
Abstract
Corneal stromal wound healing is a complex event that occurs to restore the transparency of an injured cornea. It involves immediate apoptosis of keratocytes followed by their activation, proliferation, migration, and trans-differentiation to myofibroblasts. Myofibroblasts contract to close the wound and secrete extracellular matrix and proteinases to remodel it. Released proteinases may degenerate the basement membrane allowing an influx of cytokines from overlying epithelium. Immune cells infiltrate the wound to clear cellular debris and prevent infections. Gradually basement membrane regenerates, myofibroblasts and immune cells disappear, abnormal matrix is resorbed, and transparency of the cornea is restored. Often this cascade deregulates and corneal opacity results. Factors that prevent corneal opacity after an injury have always intrigued the researchers. They hold clinical relevance as they can guide the outcomes of corneal surgeries. Studies in the past have shed light on the role of various factors in stromal healing. TGFβ (transforming growth factor-beta) signaling is the central player guiding stromal responses. Other major regulators include myofibroblasts, basement membrane, collagen fibrils, small leucine-rich proteoglycans, biophysical cues, proteins derived from extracellular matrix, and membrane channels. The knowledge about their roles helped to develop novel therapies to prevent corneal opacity. This article reviews the role of major regulators that determine the outcome of stromal healing. It also discusses emerging therapies that modulate the role of these regulators to prevent stromal opacity.
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Affiliation(s)
- Sabeeh Kamil
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, USA; One-Health Vision Research Program, Department of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Rajiv R Mohan
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, USA; One-Health Vision Research Program, Department of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA; Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, USA.
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17
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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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18
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Liu X, Liu H, Lu X, Tombran-Tink J, Zhao S. PEDF Attenuates Ocular Surface Damage in Diabetic Mice Model Through Its Antioxidant Properties. Curr Eye Res 2020; 46:302-308. [PMID: 32862727 DOI: 10.1080/02713683.2020.1805770] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PURPOSE To investigate the antioxidative effect and mechanism of pigment epithelium-derived factor (PEDF) on the ocular surface damage in diabetic mice. METHODS C57BL/6 mice were injected intraperitoneally with streptozocin to generate diabetic models and then 50 nM PEDF or artificial tears were used to treat the diabetic mice. Treatment was given three times a day for eight weeks. Corneal epithelial damage, corneal sensitivity, and tear volume were quantified by fluorescein staining, esthesiometer, and phenol red cotton thread, respectively. Animals were sacrificed at 16 weeks after diabetes and the whole globe specimens were subjected to histochemical staining. Reactive oxygen species (ROS) generation was detected by 2',7-dichlorodihydrofluorescein probe. The levels of receptor for advanced glycation end products (RAGE) and superoxide dismutase 1 (SOD1) were examined by quantitative real-time PCR and western blotting. RESULTS Topical application of PEDF improved corneal epithelial damage, increased corneal sensitivity, and tear volume in diabetic mice. ROS levels in the cornea were significantly higher in the diabetic mice than in the normal mice. Moreover, PEDF attenuated the accumulation of ROS, decreased the expression of RAGE, and elevated SOD1 expression in the cornea. CONCLUSIONS Topical application of PEDF can alleviate diabetes-related ocular surface damage and increase tear volume, along with the improvement of oxidative stress status.
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Affiliation(s)
- Xuemei Liu
- College of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Tianjin Medical University Eye Institute, Tianjin Medical University , Tianjin, China
| | - Hui Liu
- College of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Tianjin Medical University Eye Institute, Tianjin Medical University , Tianjin, China
| | - Xiaoxiao Lu
- College of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Tianjin Medical University Eye Institute, Tianjin Medical University , Tianjin, China
| | - Joyce Tombran-Tink
- Department of Neural and Behavioral Sciences and Department of Ophthalmology, Penn State College of Medicine , Hershey, PA, USA
| | - Shaozhen Zhao
- College of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Tianjin Medical University Eye Institute, Tianjin Medical University , Tianjin, China
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19
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Jiao H, Downie LE, Huang X, Wu M, Oberrauch S, Keenan RJ, Jacobson LH, Chinnery HR. Novel alterations in corneal neuroimmune phenotypes in mice with central nervous system tauopathy. J Neuroinflammation 2020; 17:136. [PMID: 32345316 PMCID: PMC7189727 DOI: 10.1186/s12974-020-01803-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 04/03/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Tauopathy in the central nervous system (CNS) is a histopathological hallmark of frontotemporal dementia (FTD) and Alzheimer's disease (AD). Although AD is accompanied by various ocular changes, the effects of tauopathy on the integrity of the cornea, which is densely innervated by the peripheral nervous system and is populated by resident dendritic cells, is still unknown. The aim of this study was to investigate if neuroimmune interactions in the cornea are affected by CNS tauopathy. METHODS Corneas from wild type (WT) and transgenic rTg4510 mice that express the P301L tau mutation were examined at 2, 6, 8, and 11 months. Clinical assessment of the anterior segment of the eye was performed using spectral domain optical coherence tomography. The density of the corneal epithelial sensory nerves and the number and field area of resident epithelial dendritic cells were assessed using immunofluorescence. The immunological activation state of corneal and splenic dendritic cells was examined using flow cytometry and compared between the two genotypes at 9 months of age. RESULTS Compared to age-matched WT mice, rTg4510 mice had a significantly lower density of corneal nerve axons at both 8 and 11 months of age. Corneal nerves in rTg4510 mice also displayed a higher percentage of beaded nerve axons and a lower density of epithelial dendritic cells compared to WT mice. From 6 months of age, the size of the corneal dendritic cells was significantly smaller in rTg4510 compared to WT mice. Phenotypic characterization by flow cytometry demonstrated an activated state of dendritic cells (CD86+ and CD45+ CD11b+CD11c+) in the corneas of rTg4510 compared to WT mice, with no distinct changes in the spleen monocytes/dendritic cells. At 2 months of age, there were no significant differences in the neural or immune structures between the two genotypes. CONCLUSIONS Corneal sensory nerves and epithelial dendritic cells were altered in the rTg4510 mouse model of tauopathy, with temporal changes observed with aging. The activation of corneal dendritic cells prior to the gradual loss of neighboring sensory nerves suggests an early involvement of corneal immune cells in tau-associated pathology originating in the CNS.
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Affiliation(s)
- Haihan Jiao
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Australia
| | - Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Australia
| | - Xin Huang
- Innate Phagocytosis Laboratory, Florey Institute of Neuroscience and Mental Health, Parkville, Australia
| | - Mengliang Wu
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Australia
| | - Sara Oberrauch
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Australia.,Sleep and Cognition Laboratory, Florey Institute of Neuroscience and Mental Health, Parkville, Australia
| | - Ryan J Keenan
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Australia.,Sleep and Cognition Laboratory, Florey Institute of Neuroscience and Mental Health, Parkville, Australia
| | - Laura H Jacobson
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Australia. .,Sleep and Cognition Laboratory, Florey Institute of Neuroscience and Mental Health, Parkville, Australia.
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Australia.
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Pham TL, Kakazu AH, He J, Jun B, Bazan NG, Bazan HEP. Novel RvD6 stereoisomer induces corneal nerve regeneration and wound healing post-injury by modulating trigeminal transcriptomic signature. Sci Rep 2020; 10:4582. [PMID: 32165657 PMCID: PMC7067818 DOI: 10.1038/s41598-020-61390-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/24/2020] [Indexed: 01/20/2023] Open
Abstract
The high-density corneal innervation plays a pivotal role in sustaining the integrity of the ocular surface. We have previously demonstrated that pigment epithelium-derived factor (PEDF) plus docosahexaenoic acid (DHA) promotes corneal nerve regeneration; here, we report the mechanism involved and the discovery of a stereospecific Resolvin D6-isomer (RvD6si) that drives the process. RvD6si promotes corneal wound healing and functional recovery by restoring corneal innervation after injury. RvD6si applied to the eye surface elicits a specific transcriptome signature in the trigeminal ganglion (TG) that includes Rictor, the rapamycin-insensitive complex-2 of mTOR (mTORC2), and genes involved in axon growth, whereas genes related to neuropathic pain are decreased. As a result, attenuation of ocular neuropathic pain and dry eye will take place. Thus, RvD6si opens up new therapeutic avenues for pathologies that affect corneal innervation.
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Affiliation(s)
- Thang L Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Azucena H Kakazu
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Bokkyoo Jun
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Nicolas G Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Haydee E P Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA.
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He J, Pham TL, Kakazu AH, Bazan HEP. Remodeling of Substance P Sensory Nerves and Transient Receptor Potential Melastatin 8 (TRPM8) Cold Receptors After Corneal Experimental Surgery. Invest Ophthalmol Vis Sci 2019; 60:2449-2460. [PMID: 31157834 PMCID: PMC6545819 DOI: 10.1167/iovs.18-26384] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose To investigate changes in corneal nerves positive to substance P (SP) and transient receptor potential melastatin 8 (TRPM8) and gene expression in the trigeminal ganglia (TG) following corneal surgery to unveil peripheral nerve mechanism of induced dry eye-like pain (DELP). Methods Surgery was performed on mice by removing the central epithelial and anterior stromal nerves. Mice were euthanized at different times up to 15 weeks. Immunostaining was performed with TRPM8, SP, or protein gene product 9.5 (PGP9.5) antibodies, and epithelial nerve densities were calculated. The origin of TRPM8- and SP-TG neurons were analyzed by retrograde tracing. Gene expression in TG was studied by real-time PCR analysis. Results SP-positive epithelial corneal nerves were more abundant than TRPM8 and were expressed in different TG neurons. After injury, epithelial nerve regeneration occurs in two distinct stages. An early regeneration of the remaining epithelial bundles reached the highest density on day 3 and then rapidly degraded. From day 5, the epithelial nerves originated from the underlying stromal nerves were still lower than normal levels by week 15. The SP- and TRPM8-positive nerve fibers followed the same pattern as the total nerves. TRPM8-positive terminals increased slowly and reached only half of normal values by 3 months. Corneal sensitivity gradually increased and reached normal values on day 12. Corneal injury also induced significant changes in TG gene expression, decreasing trpm8 and tac1 genes. Conclusions Abnormal SP expression, low amounts of TRPM8 terminals, and hypersensitive nerve response occur long after the injury and changes in gene expression in the TG suggest a contribution to the pathogenesis of corneal surgery-induced DELP.
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Affiliation(s)
- Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States.,Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
| | - Thang Luong Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
| | - Azucena H Kakazu
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
| | - Haydee E P Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States.,Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
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Marfurt C, Anokwute MC, Fetcko K, Mahony-Perez E, Farooq H, Ross E, Baumanis MM, Weinberg RL, McCarron ME, Mankowski JL. Comparative Anatomy of the Mammalian Corneal Subbasal Nerve Plexus. Invest Ophthalmol Vis Sci 2019; 60:4972-4984. [PMID: 31790560 PMCID: PMC6886725 DOI: 10.1167/iovs.19-28519] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 10/24/2019] [Indexed: 12/20/2022] Open
Abstract
Purpose The subbasal nerve plexus (SNP) is the densest and most recognizable component of the mammalian corneal innervation; however, the anatomical configuration of the SNP in most animal models remains incompletely described. The purpose of the current study is to describe in detail the SNP architecture in eight different mammals, including several popular animal models used in cornea research. Methods Corneal nerves in mouse, rat, guinea pig, rabbit, dog, macaque, domestic pig, and cow eyes were stained immunohistochemically with antiserum directed against neurotubulin. SNP architecture was documented by digital photomicrography and large-scale reconstructions, that is, corneal nerve maps, using a drawing tube attached to a light microscope. Results Subbasal nerve fibers (SNFs) in mice, rats, guinea pigs, dogs, and macaques radiated centrally from the corneoscleral limbus toward the corneal apex in a whorl-like or spiraling pattern. SNFs in rabbit and bovine corneas swept horizontally across the ocular surface in a temporal-to-nasal direction and converged on the inferonasal limbus without forming a spiral. SNFs in the pig cornea radiated centrifugally in all directions, like a starburst, from a focal point located equidistant between the corneal apex and the superior pole. Conclusions The results of the present study have demonstrated for the first time substantial interspecies differences in the architectural organization of the mammalian SNP. The physiological significance of these different patterns and the mechanisms that regulate SNP pattern formation in the mammalian cornea remain incompletely understood and warrant additional investigation.
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Affiliation(s)
- Carl Marfurt
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Miracle C. Anokwute
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Kaleigh Fetcko
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Erin Mahony-Perez
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Hassan Farooq
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Emily Ross
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Maraya M. Baumanis
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Rachel L. Weinberg
- Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Megan E. McCarron
- Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Joseph L. Mankowski
- Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
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Jolivalt CG, Marquez A, Quach D, Navarro Diaz MC, Anaya C, Kifle B, Muttalib N, Sanchez G, Guernsey L, Hefferan M, Smith DR, Fernyhough P, Johe K, Calcutt NA. Amelioration of Both Central and Peripheral Neuropathy in Mouse Models of Type 1 and Type 2 Diabetes by the Neurogenic Molecule NSI-189. Diabetes 2019; 68:2143-2154. [PMID: 31492662 PMCID: PMC6804627 DOI: 10.2337/db19-0271] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 08/26/2019] [Indexed: 02/06/2023]
Abstract
While peripheral neuropathy is the most common complication of long-term diabetes, cognitive deficits associated with encephalopathy and myelopathy also occur. Diabetes is a risk factor for Alzheimer disease (AD) and increases the risk of progression from mild cognitive impairment to AD. The only current recommendation for preventing or slowing the progression of peripheral neuropathy is to maintain close glycemic control, while there is no recommendation for central nervous system disorders. NSI-189 is a new chemical entity that when orally administered promotes neurogenesis in the adult hippocampus, increases hippocampal volume, enhances synaptic plasticity, and reduces cognitive dysfunction. To establish the potential for impact on peripheral neuropathy, we first showed that NSI-189 enhances neurite outgrowth and mitochondrial functions in cultured adult rat primary sensory neurons. Oral delivery of NSI-189 to murine models of type 1 (female) and type 2 (male) diabetes prevented multiple functional and structural indices of small and large fiber peripheral neuropathy, increased hippocampal neurogenesis, synaptic markers and volume, and protected long-term memory. NSI-189 also halted progression of established peripheral and central neuropathy. NSI-189, which is currently in clinical trials for treatment of major depressive disorder, offers the opportunity for the development of a single therapeutic agent against multiple indices of central and peripheral neuropathy.
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Affiliation(s)
- Corinne G Jolivalt
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - Alexandra Marquez
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | | | | | - Carlos Anaya
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - Betelhem Kifle
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - Nabeel Muttalib
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - Gabriela Sanchez
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - Lucy Guernsey
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | | | - Darrel R Smith
- St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
| | - Paul Fernyhough
- St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Manitoba, Canada
| | | | - Nigel A Calcutt
- Department of Pathology, University of California, San Diego, La Jolla, CA
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Tripathi R, Giuliano EA, Gafen HB, Gupta S, Martin LM, Sinha PR, Rodier JT, Fink MK, Hesemann NP, Chaurasia SS, Mohan RR. Is sex a biological variable in corneal wound healing? Exp Eye Res 2019; 187:107705. [PMID: 31226339 PMCID: PMC9250696 DOI: 10.1016/j.exer.2019.107705] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/16/2019] [Accepted: 06/17/2019] [Indexed: 01/03/2023]
Abstract
Wound healing differs significantly between men and women in a tissue-dependent manner. Dermal wounds heal faster in women whereas mucosal wounds heal faster in men. However, the effect of sex as a variable in corneal wound healing is largely unknown. The primary objective of this study was to test whether sex is a biological variable in corneal wound healing activated by the trauma or injury using an established in vivo rabbit model with male and female New Zealand White rabbits. Corneal wounds in rabbits were produced by a single topical alkali (0.5N Sodium hydroxide) application. Serial slit-lamp, stereo biomicroscopy, and applanation tonometry evaluated corneal opacity, anterior segment ocular health, and intraocular pressure (IOP), respectively, at various times during the study. Fourteen days after alkali-wound, corneal tissues were collected after humane euthanasia to examine cellular and molecular wound healing parameters. Quantitative PCR (qPCR) and immunofluorescence were used to quantify changes in the extracellular modeling protein levels of alpha-smooth muscle actin (α-SMA), Fibronectin (FN), Collagen-I (Col-I), and Transforming growth factor beta 1 (TGFβ1) involved in corneal healing. Hematoxylin and Eosin (H&E) staining was used to study histopathological changes in morphology and TUNEL assay to evaluate levels of apoptotic cell death. Male and female rabbits showed no significant differences in corneal opacity (Fantes score) or intraocular pressure (IOP) values (9.5 ± 0.5 mm Hg) in live animals. Likewise, no statistically significant sex-based differences in the mRNA levels of α-SMA (male = 5.95 ± 0.21 fold vs. female = 5.32 ± 0.043), FN (male = 3.02 ± 0.24 fold vs. female = 3.23 ± 0.27), Col-I (male = 3.12 ± 0.37 fold vs. female = 3.31 ± 0.24), TGFβ1 (male = 1.65 ± 0.06 fold vs. female = 1.59 ± 0.053); and protein levels of α-SMA (male = 74.16 ± 4.6 vs. female = 71.58 ± 7.1), FN (male = 60.11 ± 4.6 vs. female = 57.41 ± 8.3), Col-I (male = 84.11 ± 2.8 vs. female = 84.55 ± 3.6), TGFβ1 (male = 11.61 ± 2.8 vs. female = 9.5 ± 3.04) were observed. Furthermore, H&E and TUNEL analyses found no statistically significant differences in cellular structures and apoptosis, respectively, in male vs. female corneas. Consistent with earlier reports, wounded corneas showed significantly increased levels of these parameters compared to the unwounded corneas. Our data suggest that sex is not a major biological variable during active early stages of corneal wound healing in rabbits in vivo.
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Affiliation(s)
- Ratnakar Tripathi
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States
| | - Elizabeth A Giuliano
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States
| | - Hannah B Gafen
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States
| | - Suneel Gupta
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States
| | - Lynn M Martin
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States
| | - Prashant R Sinha
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States
| | - Jason T Rodier
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States; Mason Eye Institute, University of Missouri, Columbia, MO, United States
| | - Michael K Fink
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States
| | - Nathan P Hesemann
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States; Mason Eye Institute, University of Missouri, Columbia, MO, United States
| | - Shyam S Chaurasia
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States
| | - Rajiv R Mohan
- One-Health One-Medicine Ophthalmology and Vision Research Center, Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; Mason Eye Institute, University of Missouri, Columbia, MO, United States.
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