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Chaudhari P, Satarker S, Thomas R, Theruveethi N, Ghate V, Nampoothiri M, Lewis SA. Rodent models for dry eye syndrome: Standardization using benzalkonium chloride and scopolamine hydrobromide. Life Sci 2023; 317:121463. [PMID: 36731648 DOI: 10.1016/j.lfs.2023.121463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 01/15/2023] [Accepted: 01/27/2023] [Indexed: 02/01/2023]
Abstract
Dry eye disease is a highly prevalent ocular condition that significantly affects the quality of life and presents a major challenge in ophthalmology. Animal models play a crucial role in investigating the pathophysiology and developing effective treatments. The goal of this study was to compare and standardize two dry eye disease rodent models and explore their recovery aspects. We have standardized benzalkonium chloride and scopolamine-induced dry eye disease models which represents two different classes of the dry eye i.e., evaporative dry eye and aqueous deficient dry eye, respectively. After the development of dry eye conditions, a self-recovery period of seven days was granted to assess the reversal of the induced changes. The dry eye condition was assessed by measuring tear volume, corneal slit lamp imaging, and histological examination of the cornea, the lacrimal and the harderian gland. The study indicated the development of chronic inflammation of the cornea and lacrimal gland in the case of benzalkonium after five days of the treatment, while the scopolamine treated group showed chronic inflammation of the lacrimal gland after five days and corneal inflammation after seven days of administration. The recovery study suggested that after discontinuation of inducing agent, the dry eye symptoms were still persistent suggesting the utility of the model in evaluating dry eye treatments. The study highlights the comparative changes in both models along with recovery which can serve as a base for drug discovery and development against dry eye disease.
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Affiliation(s)
- Pinal Chaudhari
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India
| | - Sairaj Satarker
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India
| | - Rinu Thomas
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
| | - Nagarajan Theruveethi
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
| | - Vivek Ghate
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India
| | - Madhavan Nampoothiri
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India
| | - Shaila A Lewis
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India.
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2
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Tan J, Qiu R, Ding X, Dai C, Meng J, Zhao J, Ma F, Qi S. Correction of refractive distortion in whole-eye optical coherence tomography imaging of the mouse eye. JOURNAL OF BIOPHOTONICS 2022; 15:e202200146. [PMID: 36053933 DOI: 10.1002/jbio.202200146] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/22/2022] [Accepted: 08/10/2022] [Indexed: 06/15/2023]
Abstract
Optical coherence tomography (OCT) is an imaging modality that acquires high-resolution cross-sectional images of living tissues and it has become the standard in ophthalmological diagnoses. However, most quantitative morphological measurements are based on the raw OCT images which are distorted by several mechanisms such as the refraction of probe light in the sample and the scan geometries and thus the analysis of the raw OCT images inevitably induced calculation errors. In this paper, based on Fermat's principle and the concept of inverse light tracing, image distortions due to refraction occurred at tissue boundaries in the whole-eye OCT imaging of mouse by telecentric scanning were corrected. Specially, the mathematical correction models were deducted for each interface, and the high-precision whole-eye image was recovered segment by segment. We conducted phantom and in vivo experiments on mouse and human eyes to verify the distortion correction algorithm, and several parameters of the radius of curvature, thickness of tissues and error, were calculated to quantitatively evaluate the images. Experimental results demonstrated that the method can provide accurate and reliable measurements of whole-eye parameters and thus be a valuable tool for the research and clinical diagnosis.
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Affiliation(s)
- Jinzhen Tan
- School of Computer, Qufu Normal University, Rizhao, China
| | - Rui Qiu
- College of Science, Shanghai Institute of Technology, Shanghai, China
| | - Xueqing Ding
- College of Science, Shanghai Institute of Technology, Shanghai, China
| | - Cuixia Dai
- College of Science, Shanghai Institute of Technology, Shanghai, China
| | - Jing Meng
- School of Computer, Qufu Normal University, Rizhao, China
| | - Jingxiu Zhao
- School of Computer, Qufu Normal University, Rizhao, China
| | - Fei Ma
- School of Computer, Qufu Normal University, Rizhao, China
| | - Sumin Qi
- School of Computer, Qufu Normal University, Rizhao, China
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3
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Park S, Lee K, Kang H, Lee Y, Lee J, Kim JH, Song HB, Ryu W. Single Administration of a Biodegradable, Separable Microneedle Can Substitute for Repeated Application of Eyedrops in the Treatment of Infectious Keratitis. Adv Healthc Mater 2021; 10:e2002287. [PMID: 33930253 DOI: 10.1002/adhm.202002287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 03/22/2021] [Indexed: 11/07/2022]
Abstract
Infectious keratitis is mainly treated with topical antibiotics. To achieve and maintain the required therapeutic concentration in the cornea where the tear fluid continuously rinses the surface, the antibiotics must be frequently applied, even while the patient is sleeping, and oral medication is sometimes required. However, the inevitably poor compliance and avascular nature of the cornea decrease drug bioavailability. In this study, a single microneedle (MN) is injected into the cornea to substitute for the repeated application of eyedrops in the treatment of infectious keratitis. After comparing the mechanical integrity and drug release profiles of three different drug-tips, the drug-tip with the "high" drug concentration that releases 12.5 ng drug within 3 days is applied to a cornea to evaluate the transferability and in vivo drug release. In the treatment of infectious keratitis with repeated application of eyedrops for six consecutive days, a single MN injection is substituted for the initial 3 days of eyedrop applications. The progression remains similarly attenuated after 3 days without eyedrops, and comparable efficacy is achieved on day 6 when combined with delayed eyedrop treatment from day 3. Thus, the single administration of a biodegradable MN can substitute for the repeated application of eyedrops in the treatment of infectious keratitis.
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Affiliation(s)
- SeungHyun Park
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - KangJu Lee
- Department of Healthcare and Biomedical Engineering, Chonnam National University, Yeosu, 59626, Republic of Korea
| | - Heekyoung Kang
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
- Department of Ophthalmology, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - YeJin Lee
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - JiYong Lee
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Jeong Hun Kim
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
- Department of Ophthalmology, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Hyun Beom Song
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
- Department of Ophthalmology, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - WonHyoung Ryu
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
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4
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Gelling hypotonic polymer solution for extended topical drug delivery to the eye. Nat Biomed Eng 2020; 4:1053-1062. [PMID: 32895514 PMCID: PMC7655548 DOI: 10.1038/s41551-020-00606-8] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 07/28/2020] [Indexed: 01/19/2023]
Abstract
Eye-drop formulations should hold as high a concentration of soluble drug in contact with ocular epithelium for as long as possible. However, eye tears and frequent blinking limit drug retention on the ocular surface, and gelling drops typically form clumps that blur vision. Here, we describe a gelling hypotonic solution containing a low concentration of a thermosensitive triblock copolymer, for extended ocular drug delivery. On topical application, the hypotonic formulation forms a highly uniform and clear thin layer that conforms to the ocular surface and resists clearance from blinking, significantly increasing the intraocular absorption of hydrophilic and hydrophobic drugs and extending the drug–ocular-epithelium contact time with respect to conventional thermosensitive gelling formulations and commercial eye drops. We also show that the conformal gel layer allows for therapeutically relevant drug delivery to the eyeball’s posterior segment in pigs. Our findings highlight the importance of formulations that conform to the ocular surface prior to viscosity enhancement, for increased and prolonged ocular-surface contact and drug absorption.
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Guo ZH, Zeng YM, Lin JS. Dynamic spatiotemporal expression pattern of limbal stem cell putative biomarkers during mouse development. Exp Eye Res 2020; 192:107915. [PMID: 31911164 DOI: 10.1016/j.exer.2020.107915] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 12/20/2019] [Accepted: 01/02/2020] [Indexed: 02/07/2023]
Abstract
Limbal stem cells (LSCs), a subpopulation of limbal epithelial basal cells, are crucial to the homeostasis and wound healing of corneal epithelium. The identification and isolation of LSCs remains a challenge due to lack of specific LSCs biomarkers. In this study, Haematoxylin-eosin (HE), 4', 6-diamidino-2-phenylindole (DAPI), and immunohistochemistry (IHC) stains were performed on the pre- and post-natal limbus tissues of mice which has the advantage of more controllable in term of sampling age relative to human origin. By morphological analysis, we supported that there is an absence of the Palisades of Vogt (POV) in the mouse. The development of prenatal and neonatal cornea was dominated by its stroma, whereas after eyelids opened at P14, the corneal epithelial cells (CECs) quickly go stratification in response to the liquid-air interface. Based on IHC staining, we found that the expression of LSCs putative biomarkers in limbal epithelial basal cells appeared in chronological order as follows: Vim = p63 > CK14 > CK15 (where = represents same time; > represents earlier), and in corneal epithelial basal cells were weakened in chronological order as follows: Vim > p63 > CK15 > CK14, which might also represent the stemness degree. Furthermore, the dynamic spatial expression of the examined LSCs putative biomarkers during mouse development also implied a temporal restriction. The expression of Vim in epithelial cells of mouse ocular surface occurred during E12-E19 only. The expression of CK15 was completely undetectable in CECs after P14, whereas the others putative molecular markers of LSCs, such as p63 and CK14, still remained weak expression, suggesting that CK15 was suitable to serve as the mouse LSCs biomarkers after P14. In this study, our data demonstrated the dynamic spatiotemporal expression pattern of LSCs putative biomarkers in mouse was age-related and revealed the time spectrum of the expression of LSCs in mouse, which adds in our knowledge by understanding the dynamic expression pattern of biomarkers of stem cells relate to maintenance of their stemness.
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Affiliation(s)
- Zhi Hou Guo
- School of Medicine, Huaqiao University, Quanzhou, 362021, Fujian, China; Stem Cell Laboratory, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, 362000, China.
| | - Yi Ming Zeng
- The Second Affiliated Hospital of Fujian Medical University, China.
| | - Jun Sheng Lin
- School of Medicine, Huaqiao University, Quanzhou, 362021, Fujian, China.
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Messner A, Fischak C, Pfister M, Schützenberger K, Garreis F, Paulsen F, Stegmann H, Aranha dos Santos V, Garhöfer G, Schmetterer L, Werkmeister RM. Characterization of dry eye disease in a mouse model by optical coherence tomography and fluorescein staining. BIOMEDICAL OPTICS EXPRESS 2019; 10:4884-4895. [PMID: 31565532 PMCID: PMC6757454 DOI: 10.1364/boe.10.004884] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 06/10/2023]
Abstract
A custom-built ultrahigh-resolution optical coherence tomography (UHR-OCT) system and fluorescein staining were employed for investigation of a scopolamine induced dry eye mouse model. Acquired data was used to evaluate common and complementary findings of the two modalities. Central corneal thickness as measured by UHR-OCT increased significantly over the study period of 24 hours, from 89.0 ± 3.57 µm to 92.2 ± 4.07 µm. Both techniques were able to show corneal lesions with a large range of severity. Localized fluorescein staining was detected in 5% and diffuse staining in 45% of cases where no epithelial damage was visible with OCT. However, OCT revealed stromal defects in 6% and endothelial defects in 18% of the cases, which could not be visualized via fluorescein staining. Thus, while fluorescein staining widely detected defects of the corneal surface in a mouse model of dry eye disease, OCT non-invasively revealed additional information about defect depth and involvement of particular layers.
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Affiliation(s)
- Alina Messner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Corinna Fischak
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Christian Doppler Laboratory for Ocular and Dermal Effects of Thiomers, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Martin Pfister
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Christian Doppler Laboratory for Ocular and Dermal Effects of Thiomers, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Institute of Applied Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria
| | - Kornelia Schützenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Christian Doppler Laboratory for Ocular and Dermal Effects of Thiomers, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Fabian Garreis
- Department of Functional and Clinical Anatomy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Friedrich Paulsen
- Department of Functional and Clinical Anatomy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Hannes Stegmann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Christian Doppler Laboratory for Ocular and Dermal Effects of Thiomers, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Valentin Aranha dos Santos
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Leopold Schmetterer
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Christian Doppler Laboratory for Ocular and Dermal Effects of Thiomers, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower Level 6, 169856, Singapore
- Institute for Health Technologies, Nanyang Technological University, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - René M. Werkmeister
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Christian Doppler Laboratory for Ocular and Dermal Effects of Thiomers, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
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7
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Şencan İ, Esipova TV, Yaseen MA, Fu B, Boas DA, Vinogradov SA, Shahidi M, Sakadžić S. Two-photon phosphorescence lifetime microscopy of retinal capillary plexus oxygenation in mice. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-9. [PMID: 30516039 PMCID: PMC6278707 DOI: 10.1117/1.jbo.23.12.126501] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 11/07/2018] [Indexed: 05/23/2023]
Abstract
Impaired oxygen delivery and/or consumption in the retinal tissue underlies the pathophysiology of many retinal diseases. However, the essential tools for measuring oxygen concentration in retinal capillaries and studying oxygen transport to retinal tissue are still lacking. We show that two-photon phosphorescence lifetime microscopy can be used to map absolute partial pressures of oxygen (pO2) in the retinal capillary plexus. Measurements were performed at various retinal depths in anesthetized mice under systemic normoxic and hyperoxic conditions. We used a newly developed two-photon phosphorescent oxygen probe, based on a two-photon absorbing platinum tetraphthalimidoporphyrin, and commercially available optics without correction for optical aberrations of the eye. The transverse and axial distances within the tissue volume were calibrated using a model of the eye's optical system. We believe this is the first demonstration of in vivo depth-resolved imaging of pO2 in retinal capillaries. Application of this method has the potential to advance our understanding of oxygen delivery on the microvascular scale and help elucidate mechanisms underlying various retinal diseases.
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Affiliation(s)
- İkbal Şencan
- Massachusetts General Hospital, Harvard Medical School, Athinuola A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Tatiana V. Esipova
- University of Pennsylvania, Departments of Biochemistry and Biophysics and of Chemistry, Philadelphia, Pennsylvania, United States
| | - Mohammad A. Yaseen
- Massachusetts General Hospital, Harvard Medical School, Athinuola A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Buyin Fu
- Massachusetts General Hospital, Harvard Medical School, Athinuola A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - David A. Boas
- Massachusetts General Hospital, Harvard Medical School, Athinuola A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Sergei A. Vinogradov
- University of Pennsylvania, Departments of Biochemistry and Biophysics and of Chemistry, Philadelphia, Pennsylvania, United States
| | - Mahnaz Shahidi
- University of Southern California, Departments of Ophthalmology and Biomedical Engineering, Los Angeles, California, United States
| | - Sava Sakadžić
- Massachusetts General Hospital, Harvard Medical School, Athinuola A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
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8
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Jiao H, Hill LJ, Downie LE, Chinnery HR. Anterior segment optical coherence tomography: its application in clinical practice and experimental models of disease. Clin Exp Optom 2018; 102:208-217. [PMID: 30270476 DOI: 10.1111/cxo.12835] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 08/13/2018] [Accepted: 08/13/2018] [Indexed: 12/19/2022] Open
Abstract
Optical coherence tomography (OCT) provides non-invasive, high-resolution in vivo imaging of the ocular surface and anterior segment. Over the years, it has become an essential tool for evaluating the anterior segment of the eye to monitor ocular development and ocular pathologies in both the clinical and research fields of ophthalmology and optometry. In this review, the clinical applications relating to the use of anterior segment OCT for imaging and quantifying normal and pathological features of the ocular surface, cornea, anterior chamber, and aqueous outflow system are summarised in a range of human ocular diseases. Applications of anterior segment OCT technology that have improved imaging and quantitation of ocular inflammation in experimental animal models of ocular diseases, such as anterior uveitis, microbial keratitis and glaucoma, are also described. The capacity to longitudinally evaluate anterior segment anatomical changes during development, and inflammation facilitates the understanding of the dynamics of tissue responses, and further enhances the intra-operative in vivo imaging during procedures, such as corneal transplantation and drug delivery. Future developments including in vivo ultrahigh-resolution anterior segment OCT, automated analyses of anterior segment OCT images and functional extensions of the technique, may revolutionise the clinical evaluation of anterior segment, corneal and ocular surface diseases.
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Affiliation(s)
- Haihan Jiao
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Lisa J Hill
- Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
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9
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Shojaati G, Khandaker I, Sylakowski K, Funderburgh ML, Du Y, Funderburgh JL. Compressed Collagen Enhances Stem Cell Therapy for Corneal Scarring. Stem Cells Transl Med 2018; 7:487-494. [PMID: 29654654 PMCID: PMC5980128 DOI: 10.1002/sctm.17-0258] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/17/2018] [Indexed: 12/13/2022] Open
Abstract
Stem cells from human corneal stroma (CSSC) suppress corneal stromal scarring in a mouse wound‐healing model and promote regeneration of native transparent tissue (PMID:25504883). This study investigated efficacy of compressed collagen gel (CCG) as a vehicle to deliver CSSC for corneal therapy. CSSC isolated from limbal stroma of human donor corneas were embedded in soluble rat‐tendon collagen, gelled at 37°C, and partially dehydrated to a thickness of 100 µm by passive absorption. The CCG disks were dimensionally stable, easy to handle, and could be adhered securely to de‐epithelialized mouse cornea with fibrin‐based adhesive. CSSC in CCG maintained >80% viability for >1 week in culture media and could be cryopreserved in 20% fetal bovine serum‐10%DMSO in liquid nitrogen. CCG containing as few as 500 CSSC effectively prevented visible scarring and suppressed expression of fibrotic Col3a1 mRNA. CSSC in CCG were more effective at blocking scarring on a per‐cell basis than CSSC delivered directly in a fibrin gel as previously described. Collagen‐embedded cells retained the ability to suppress corneal scarring after conventional cryopreservation. This study demonstrates use of a common biomaterial that can facilitate storage and handling of stem cells in a manner that may provide off‐the‐shelf delivery of stem cells as a therapy for corneal scarring. stemcellstranslationalmedicine2018;7:487–494
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Affiliation(s)
- Golnar Shojaati
- Department of Ophthalmology, Kantonsspital Winterthur, Zurich, Switzerland.,Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Irona Khandaker
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kyle Sylakowski
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Martha L Funderburgh
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Yiqin Du
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - James L Funderburgh
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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10
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Pillay S, Byrne HM, Maini PK. The impact of exclusion processes on angiogenesis models. J Math Biol 2018; 77:1721-1759. [PMID: 29511857 PMCID: PMC6280878 DOI: 10.1007/s00285-018-1214-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 01/26/2018] [Indexed: 11/28/2022]
Abstract
Angiogenesis is the process by which new blood vessels form from existing vessels. During angiogenesis, tip cells migrate via diffusion and chemotaxis, new tip cells are introduced through branching, loops form via tip-to-tip and tip-to-sprout anastomosis, and a vessel network forms as endothelial cells, known as stalk cells, follow the paths of tip cells (a process known as the snail-trail). Using a mean-field approximation, we systematically derive one-dimensional non-linear continuum models from a lattice-based cellular automaton model of angiogenesis in the corneal assay, explicitly accounting for cell volume. We compare our continuum models and a well-known phenomenological snail-trail model that is linear in the diffusive, chemotactic and branching terms, with averaged cellular automaton simulation results to distinguish macroscale volume exclusion effects and determine whether linear models can capture them. We conclude that, in general, both linear and non-linear models can be used at low cell densities when single or multi-species exclusion effects are negligible at the macroscale. When cell densities increase, our non-linear model should be used to capture non-linear tip cell behavior that occurs when single-species exclusion effects are pronounced, and alternative models should be derived for non-negligible multi-species exclusion effects.
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Affiliation(s)
- Samara Pillay
- Mathematical Institute, University of Oxford, Woodstock Road, Oxford, OX2 6GG, UK.
| | - Helen M Byrne
- Mathematical Institute, University of Oxford, Woodstock Road, Oxford, OX2 6GG, UK
| | - Philip K Maini
- Mathematical Institute, University of Oxford, Woodstock Road, Oxford, OX2 6GG, UK
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11
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Shull OR, Reilly CM, Davis LB, Murphy CJ, Thomasy SM. Phenotypic Characterization of Corneal Endothelial Dystrophy in German Shorthaired and Wirehaired Pointers Using In Vivo Advanced Corneal Imaging and Histopathology. Cornea 2018; 37:88-94. [PMID: 29077583 PMCID: PMC5799001 DOI: 10.1097/ico.0000000000001431] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE To evaluate corneal morphology using ultrasonic pachymetry (USP), Fourier-domain optical coherence tomography (FD-OCT), and in vivo confocal microscopy (IVCM) in 2 related canine breeds-German shorthaired pointers (GSHPs) and German wirehaired pointers (GWHPs)-with and without corneal endothelial dystrophy (CED). This condition is characterized by premature endothelial cell degeneration leading to concomitant corneal edema and is similar to Fuchs endothelial corneal dystrophy. METHODS Corneas of 10 CED-affected (4 GSHP and 6 GWHP) and 19 unaffected, age-matched (15 GSHP and 4 GWHP) dogs were examined using USP, FD-OCT, and IVCM. A 2-sample t test or Mann-Whitney rank-sum test was used to statistically compare parameters between both groups. Data are presented as mean ± SD or median (range). RESULTS Central corneal thickness determined using USP was significantly greater in CED-affected than in unaffected dogs at 1179 (953-1959) and 646 (497-737) μm, respectively (P < 0.001). Central epithelial thickness was found to be significantly decreased in CED-affected versus unaffected dogs at 47 ± 7.1 and 55 ± 7.1 μm, respectively (P = 0.011), using FD-OCT. With IVCM, corneal endothelial density was significantly less (P < 0.001) in 5 dogs with CED versus 19 unaffected controls at 499 ± 315 versus 1805 ± 298 cells/mm, respectively. CED-affected dogs exhibited endothelial pleomorphism and polymegethism, whereas CED-unaffected dogs had regular hexagonal arrangement of cells. CONCLUSIONS GSHPs and GWHPs with CED exhibit marked differences in corneal morphology when compared with age-matched control dogs. These 2 CED-affected breeds represent spontaneous, large animal models for human Fuchs endothelial corneal dystrophy.
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Affiliation(s)
- Olivia R. Shull
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
| | | | - Lola B. Davis
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
| | - Christopher J. Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, Davis, CA
| | - Sara M. Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, Davis, CA
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12
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Li J, Xiao Y, Coursey TG, Chen X, Deng R, Lu F, Pflugfelder SC, Li DQ. Identification for Differential Localization of Putative Corneal Epithelial Stem Cells in Mouse and Human. Sci Rep 2017; 7:5169. [PMID: 28701781 PMCID: PMC5507988 DOI: 10.1038/s41598-017-04569-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/17/2017] [Indexed: 01/22/2023] Open
Abstract
Human Corneal epithelial stem cells (CESCs) have been identified to reside in limbus for more than 2 decades. However, the precise location of CESCs in other mammalian remains elusive. This study was to identify differential localization of putative CESCs in mice. Through a series of murine corneal cross-sections from different directions, we identified that anatomically and morphologically the murine limbus is composed of the thinnest epithelium and the thinnest stroma without any palisades of Vogt-like niche structure. The cells expressing five of stem/progenitor cell markers are localized in basal layer of entire murine corneal epithelium. BrdU label-retaining cells, a key characteristic of epithelial stem cells, are detected in both limbal and central cornea of mouse eye. Functionally, corneal epithelium can be regenerated in cultures from central and limbal explants of murine cornea. Such a distribution of mouse CESCs is different from human cornea, where limbal stem cell concept has been well established and accepted. We are aware that some new evidence supports limbal stem cell concept in mouse recently. However, it is important to know that central cornea may provide an alternative source of stem cells when one utilizes mice as animal model for corneal research.
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Affiliation(s)
- Jin Li
- Zhejiang Eye Hospital, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China.,Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - Yangyan Xiao
- Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, China.,Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - Terry G Coursey
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - Xin Chen
- Zhejiang Eye Hospital, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China.,Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - Ruzhi Deng
- Zhejiang Eye Hospital, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China.,Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - Fan Lu
- Zhejiang Eye Hospital, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China.
| | - Stephen C Pflugfelder
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - De-Quan Li
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA.
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13
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Thomasy SM, Cortes DE, Hoehn AL, Calderon AC, Li JY, Murphy CJ. In Vivo Imaging of Corneal Endothelial Dystrophy in Boston Terriers: A Spontaneous, Canine Model for Fuchs' Endothelial Corneal Dystrophy. Invest Ophthalmol Vis Sci 2017; 57:OCT495-503. [PMID: 27454658 PMCID: PMC4968913 DOI: 10.1167/iovs.15-18885] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose Boston Terriers (BTs) have a greater prevalence of corneal endothelial dystrophy (CED), in comparison to other canine breeds. Similar to Fuchs' endothelial corneal dystrophy (FECD), this condition is characterized by endothelial cell degeneration with secondary corneal edema. This study assessed corneal morphology using in vivo confocal microscopy (IVCM) and Fourier-domain optical coherence tomography (FD-OCT) in BTs with and without CED. Methods The corneas of 16 BTs with CED and 15 unaffected, age-matched BTs underwent clinical evaluation and were imaged using IVCM and FD-OCT. A two-sample t-test or Mann-Whitney rank sum test were used to statistically compare parameters between groups. Data are presented as mean ± SD or median (range). Results Mean age did not significantly differ between affected and unaffected dogs at 10.0 ± 2.0 and 10.6 ± 2.4 years, respectively (P = 0.437). Females (69%) were overrepresented among the CED-affected dogs. In CED patients, IVCM demonstrated endothelial polymegathism and pleomorphism. Corneal endothelial density was significantly less (P < 0.001) in dogs with CED (1026 ± 260 cells/mm2) versus age-matched controls (2297 ± 372 cells/mm2). Fourier-domain OCT demonstrated a significant increase (P < 0.01) in central corneal and endothelium-Descemet's complex thickness in dogs with CED versus age-matched controls at 1019 (485–1550) or 536 (464–650) μm and 32 (22–56) or 25 (15–34) μm, respectively. Conclusions Corneal endothelial dystrophy in BTs is a bilateral, adult-onset condition that shares many similarities with FECD. Thus, CED could serve as a spontaneous disease model to study the pathogenesis of and develop novel treatments for FECD.
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Affiliation(s)
- Sara M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Dennis E Cortes
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Alyssa L Hoehn
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Allison C Calderon
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Jennifer Y Li
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, California, United States
| | - Christopher J Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States 2Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, California, Uni
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14
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Zhu Y, Reinach PS, Zhu H, Tan Q, Zheng Q, Qu J, Chen W. High-intensity corneal collagen crosslinking with riboflavin and UVA in rat cornea. PLoS One 2017. [PMID: 28644862 PMCID: PMC5482453 DOI: 10.1371/journal.pone.0179580] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Corneal collagen cross-linking (CXL) halts human corneal ectasias progression by increasing stromal mechanical stiffness. Although some reports describe that this procedure is effective in dealing with some infectious and immunologic corneal thinning diseases, there is a need for more animal models whose corneal thickness more closely resemble those occurring in these patients. To meet this need, we describe here high-intensity protocols that are safe and effective for obtaining CXL in rat corneas. Initially, a range of potentially effective UVA doses were evaluated based on their effectiveness in increasing tissue enzymatic resistance to dissolution. At UVA doses higher than a threshold level of 0.54 J/cm2, resistance to enzymatic digestion increased relative to that in non-irradiated corneas. Based on the theoretical threshold CXL dose, a CXL regimen was established in which the UVA tissue irradiance was 9 mW/cm2, which was delivered at doses of either 2.16, 2.7 or 3.24 J/cm2. Their dose dependent effects were evaluated on ocular surface morphological integrity, keratocyte apoptotic frequency, tissue thickness and endothelial cell layer density. Doses of 2.16 and 2.7 J/cm2 transiently decreased normal corneal transparency and increased thickness. These effects were fully reversed after 14 days. In contrast, 3.24 J/cm2 had more irreversible side effects. Three days after treatment, apoptotic frequency in the CXL-2.16 group was lower than that at higher doses. Endothelial cell losses remained evident only in the CXL-3.24 group at 42 days posttreatment. Stromal fiber thickening was evident in all the CXL-treated groups. We determined both the threshold UVA dose using the high-intensity CXL procedure and identified an effective dose range that provides optimal CXL with minimal transient side effects in the rat cornea. These results may help to provide insight into how to improve the CXL outcome in patients afflicted with a severe corneal thinning disease.
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Affiliation(s)
- Yirui Zhu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Zhejiang, China
| | - Peter S. Reinach
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Zhejiang, China
| | - Hanlei Zhu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Zhejiang, China
| | - Qiufan Tan
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Zhejiang, China
| | - Qinxiang Zheng
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Zhejiang, China
| | - Jia Qu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Zhejiang, China
- * E-mail: (JQ); (WC)
| | - Wei Chen
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Zhejiang, China
- * E-mail: (JQ); (WC)
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15
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Pillay S, Byrne HM, Maini PK. Modeling angiogenesis: A discrete to continuum description. Phys Rev E 2017; 95:012410. [PMID: 28208423 DOI: 10.1103/physreve.95.012410] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Indexed: 11/07/2022]
Abstract
Angiogenesis is the process by which new blood vessels develop from existing vasculature. During angiogenesis, endothelial tip cells migrate via diffusion and chemotaxis, loops form via tip-to-tip and tip-to-sprout anastomosis, new tip cells are produced via branching, and a vessel network forms as endothelial cells follow the paths of tip cells. The latter process is known as the snail trail. We use a mean-field approximation to systematically derive a continuum model from a two-dimensional lattice-based cellular automaton model of angiogenesis in the corneal assay, based on the snail-trail process. From the two-dimensional continuum model, we derive a one-dimensional model which represents angiogenesis in two dimensions. By comparing the discrete and one-dimensional continuum models, we determine how individual cell behavior manifests at the macroscale. In contrast to the phenomenological continuum models in the literature, we find that endothelial cell creation due to tip cell movement (vessel formation via the snail trail) manifests as a source term of tip cells on the macroscale. Further, we find that phenomenological continuum models, which assume that endothelial cell creation is proportional to the flux of tip cells in the direction of increasing chemoattractant concentration, qualitatively capture vessel formation in two dimensions, but must be modified to accurately represent vessel formation. Additionally, we find that anastomosis imposes restrictions on cell density, which, if violated, leads to ill-posedness in our continuum model. We also deduce that self-loops should be excluded when tip-to-sprout anastomosis is active in the discrete model to ensure propagation of the vascular front.
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Affiliation(s)
- Samara Pillay
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Woodstock Road, Oxford OX2 6GG, United Kingdom
| | - Helen M Byrne
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Woodstock Road, Oxford OX2 6GG, United Kingdom
| | - Philip K Maini
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Woodstock Road, Oxford OX2 6GG, United Kingdom
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Li J, Li Z, Zhou T, Zhang J, Xia H, Li H, He J, He S, Wang L. Positively charged micelles based on a triblock copolymer demonstrate enhanced corneal penetration. Int J Nanomedicine 2015; 10:6027-37. [PMID: 26451109 PMCID: PMC4592048 DOI: 10.2147/ijn.s90347] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
PURPOSE The cornea is a main barrier to drug penetration after topical application. The aim of this study was to evaluate the abilities of micelles generated from a positively charged triblock copolymer to penetrate the cornea after topical application. METHODS The triblock copolymer poly(ethylene glycol)-poly(ε-caprolactone)-g-polyethyleneimine was synthesized, and the physicochemical properties of the self-assembled polymeric micelles were investigated, including hydrodynamic size, zeta potential, morphology, drug-loading content, drug-loading efficiency, and in vitro drug release. Using fluorescein diacetate as a model drug, the penetration capabilities of the polymeric micelles were monitored in vivo using a two-photon scanning fluorescence microscopy on murine corneas after topical application. RESULTS The polymer was successfully synthesized and confirmed using nuclear magnetic resonance and Fourier transform infrared. The polymeric micelles had an average particle size of 28 nm, a zeta potential of approximately +12 mV, and a spherical morphology. The drug-loading efficiency and drug-loading content were 75.37% and 3.47%, respectively, which indicates that the polymeric micelles possess a high drug-loading capacity. The polymeric micelles also exhibited controlled-release behavior in vitro. Compared to the control, the positively charged polymeric micelles significantly penetrated through the cornea. CONCLUSION Positively charged micelles generated from a triblock copolymer are a promising vehicle for the topical delivery of hydrophobic agents in ocular applications.
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Affiliation(s)
- Jingguo Li
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China
| | - Zhanrong Li
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China
| | - Tianyang Zhou
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China
| | - Junjie Zhang
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China
| | - Huiyun Xia
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China
| | - Heng Li
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China
| | - Jijun He
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China
| | - Siyu He
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China
| | - Liya Wang
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China
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Zhang H, He S, Liu S, Xie Y, Chen G, Zhang J, Sun S, Liang D, Wang L. Measurement of In Vivo Three-Dimensional Corneal Cell Density and Size Using Two-Photon Imaging in C57BL/6 Mice. Curr Eye Res 2015; 41:448-55. [PMID: 26084010 DOI: 10.3109/02713683.2015.1031253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To measure the cell size and cell density in five layers of the central cornea in the widely used inbred C57BL/6 mouse strain using in vivo three-dimensional (3D) two-photon (2PH) imaging. METHODS Corneas were scanned using a 2PH laser scanning fluorescence microscope after staining with plasma membrane stain and Hoechst 33342. Good quality 3D images were selected for the cell density and cell size analysis. Cell density was determined by counting the cell nuclei in a predefined cube of 3D images. Cell size measurements, including cell surface area, cell volume, nuclear surface area and nuclear volume, were automatically quantified using the Imaris software. The cell and nuclear surface-area-to-volume ratio (S:V ratio) and the cell nuclear-cytoplasmic ratio (N:C ratio) were calculated. RESULTS The highest cell density was observed in the basal epithelium and the lowest in the posterior stroma. The highest cell surface area was found in the anterior stroma, and the highest cell volume was observed in the superficial epithelium. The lowest cell surface area and cell volume were both found in the basal epithelium. The highest S:V ratio was observed in the basal epithelium and the lowest in the superficial epithelium. The highest cell nuclear surface area and volume were both observed in the superficial epithelium and the lowest in the basal epithelium. The highest cell nuclear S:V ratio was observed in the basal epithelium and the lowest in the superficial epithelium. The highest N:C ratio was found in the basal epithelial cells and the lowest in the posterior keratocytes. CONCLUSIONS We are the first to quantify the cell density and size parameters, including cell surface area and volume, cell nuclear surface area and volume, and the S:V ratio, in the five layers of the central cornea. These data provide important cell morphology features for the study of corneal physiology, pathology and disease in mice, particularly in C57BL/6 mice.
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Affiliation(s)
- Hongmin Zhang
- a Henan Eye Institute, Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital and People's Hospital of Zhengzhou University , Zhengzhou , People's Republic of China and
| | - Siyu He
- a Henan Eye Institute, Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital and People's Hospital of Zhengzhou University , Zhengzhou , People's Republic of China and
| | - Susu Liu
- a Henan Eye Institute, Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital and People's Hospital of Zhengzhou University , Zhengzhou , People's Republic of China and
| | - Yanting Xie
- a Henan Eye Institute, Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital and People's Hospital of Zhengzhou University , Zhengzhou , People's Republic of China and
| | - Guoming Chen
- a Henan Eye Institute, Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital and People's Hospital of Zhengzhou University , Zhengzhou , People's Republic of China and
| | - Junjie Zhang
- a Henan Eye Institute, Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital and People's Hospital of Zhengzhou University , Zhengzhou , People's Republic of China and
| | - Shengtao Sun
- a Henan Eye Institute, Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital and People's Hospital of Zhengzhou University , Zhengzhou , People's Republic of China and
| | - David Liang
- b Penn State Hershey Eye Center, Penn State Milton S. Hershey Medical Center, Penn State College of Medicine , Hershey , PA , USA
| | - Liya Wang
- a Henan Eye Institute, Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital and People's Hospital of Zhengzhou University , Zhengzhou , People's Republic of China and
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The impact of type 1 diabetes mellitus on corneal epithelial nerve morphology and the corneal epithelium. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:2662-70. [PMID: 25102563 DOI: 10.1016/j.ajpath.2014.06.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 05/14/2014] [Accepted: 06/17/2014] [Indexed: 12/23/2022]
Abstract
Diabetic corneal neuropathy can result in chronic, sight-threatening corneal pathology. Although the exact etiology is unknown, it is believed that a reduction in corneal sensitivity and loss of neurotrophic support contributes to corneal disease. Information regarding the relationship between nerve loss and effects on the corneal epithelium is limited. We investigated changes in the corneal epithelium and nerve morphology using three-dimensional imaging in vivo and in situ in a streptozotocin-induced diabetic mouse model. Streptozotocin-treated mice showed increased levels of serum glucose and growth retardation consistent with a severe diabetic state. A reduction in the length of the subbasal nerve plexus was evident after 6 weeks of disease. Loss of the subbasal nerve plexus was associated with corneal epithelial thinning and a reduction in basal epithelial cell density. In contrast, loss of the terminal epithelial nerves was associated with animal age. Importantly, this is the first rodent model of type 1 diabetes that shows characteristics of corneal epithelial thinning and a reduction in basal epithelial cell density, both previously have been documented in humans with diabetic corneal neuropathy. These findings indicate that in type 1 diabetes, nerve fiber damage is evident in the subbasal nerve plexus before terminal epithelial nerve loss and that neurotrophic support from both the subbasal nerve plexus and terminal epithelial nerves is essential for the maintenance of corneal epithelial homeostasis.
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