1
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Li Y, Acosta FM, Jiang JX. Gap Junctions or Hemichannel-Dependent and Independent Roles of Connexins in Fibrosis, Epithelial-Mesenchymal Transitions, and Wound Healing. Biomolecules 2023; 13:1796. [PMID: 38136665 PMCID: PMC10742173 DOI: 10.3390/biom13121796] [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: 12/09/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Fibrosis initially appears as a normal response to damage, where activated fibroblasts produce large amounts of the extracellular matrix (ECM) during the wound healing process to assist in the repair of injured tissue. However, the excessive accumulation of the ECM, unresolved by remodeling mechanisms, leads to organ dysfunction. Connexins, a family of transmembrane channel proteins, are widely recognized for their major roles in fibrosis, the epithelial-mesenchymal transition (EMT), and wound healing. Efforts have been made in recent years to identify novel mediators and targets for this regulation. Connexins form gap junctions and hemichannels, mediating communications between neighboring cells and inside and outside of cells, respectively. Recent evidence suggests that connexins, beyond forming channels, possess channel-independent functions in fibrosis, the EMT, and wound healing. One crucial channel-independent function is their role as the primary functional component for cell adhesion. Other channel-independent functions of connexins involve their roles in mitochondria and exosomes. This review summarizes the latest advances in the channel-dependent and independent roles of connexins in fibrosis, the EMT, and wound healing, with a particular focus on eye diseases, emphasizing their potential as novel, promising therapeutic targets.
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Affiliation(s)
- Yuting Li
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
- Department of Pathology, Basic Medical School, Ningxia Medical University, Yinchuan 750004, China
| | - Francisca M. Acosta
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
| | - Jean X. Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
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2
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DeDreu J, Basta MD, Walker JL, Menko AS. Immune Responses Induced at One Hour Post Cataract Surgery Wounding of the Chick Lens. Biomolecules 2023; 13:1615. [PMID: 38002297 PMCID: PMC10668984 DOI: 10.3390/biom13111615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/25/2023] [Accepted: 11/02/2023] [Indexed: 11/26/2023] Open
Abstract
While the lens is an avascular tissue with an immune-privileged status, studies have now revealed that there are immune responses specifically linked to the lens. The response to lens injury, such as following cataract surgery, has been shown to involve the activation of the resident immune cell population of the lens and the induction of immunomodulatory factors by the wounded epithelium. However, there has been limited investigation into the immediate response of the lens to wounding, particularly those induced factors that are intrinsic to the lens and its associated resident immune cells. Using an established chick embryo ex vivo cataract surgery model has made it possible to determine the early immune responses of this tissue to injury, including its resident immune cells, through a transcriptome analysis. RNA-seq studies were performed to determine the gene expression profile at 1 h post wounding compared to time 0. The results provided evidence that, as occurs in other tissues, the resident immune cells of the lens rapidly acquired a molecular signature consistent with their activation. These studies also identified the expression of many inflammatory factors by the injured lens that are associated with both the induction and regulation of the immune response.
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Affiliation(s)
- JodiRae DeDreu
- Department of Pathology and Genomic Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA (M.D.B.); (J.L.W.)
| | - Morgan D. Basta
- Department of Pathology and Genomic Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA (M.D.B.); (J.L.W.)
| | - Janice L. Walker
- Department of Pathology and Genomic Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA (M.D.B.); (J.L.W.)
- Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - A. Sue Menko
- Department of Pathology and Genomic Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA (M.D.B.); (J.L.W.)
- Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
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3
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Pan Y, Liu Z, Zhang H. Research progress of lens zonules. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2023; 3:80-85. [PMID: 37846380 PMCID: PMC10577871 DOI: 10.1016/j.aopr.2023.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/23/2023] [Accepted: 02/23/2023] [Indexed: 10/18/2023]
Abstract
Background The lens zonule, a circumferential system of fibres connecting the ciliary body to the lens, is responsible for centration of the lens. The structural, functional, and positional abnormalities of the zonular apparatus can lead to the abnormality of the intraocular structure, presenting a significant challenge to cataract surgery. Main text The lens zonule is the elaborate system of extracellular fibers, which not only centers the lens in the eye but also plays an important role in accommodation and lens immunity, maintains the shape of the lens, and corrects spherical aberration. The zonules may directly participate in the formation of cataract via the immune mechanism. Abnormal zonular fibers that affect the position and shape of the lens may play an important role in the pathogenesis of angle closure disease and increase the complexity of the surgery. Capsular tension rings and related endocapsular devices are used to provide sufficient capsular bag stabilization and ensure the safety of cataract surgery procedures. Better preoperative and intraoperative evaluation methods for zonules are needed for clinicians. Conclusions The microstructure, biomechanical properties, and physiological functions of the lens zonules help us to better understand the pathogenesis of cataract and glaucoma, facilitating the development of safer surgical procedures for cataract. Further studies are needed to carefully analyze the structure-function relationship of the zonular apparatus to explore new treatment strategies for cataract and glaucoma.
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Affiliation(s)
- Yingying Pan
- Department of Ophthalmology, Shandong Provincial Hospital, Shandong University, Jinan, China
| | - Zhaoqiang Liu
- Department of Ophthalmology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Han Zhang
- Department of Ophthalmology, Shandong Provincial Hospital, Shandong University, Jinan, China
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4
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Takahashi A, Arima T, Toda E, Kobayakawa S, Shimizu A, Takahashi H. A Novel Multi-Observation System to Study the Effects of Anterior Ocular Inflammation in Zinn’s Zonule Using One Specimen. Int J Mol Sci 2023; 24:ijms24076254. [PMID: 37047225 PMCID: PMC10093946 DOI: 10.3390/ijms24076254] [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: 02/06/2023] [Revised: 03/24/2023] [Accepted: 03/24/2023] [Indexed: 03/29/2023] Open
Abstract
Zinn’s zonule is a fragile and thin tissue, and little is known about its pathogenesis. The aim of this study was to develop an experimental setup for a comprehensive analysis of Zinn’s zonule. Rats were divided into two groups: a control group (n = 4) and an alkali injury group (n = 4). Seven days after injury, the eyes were enucleated, the anterior eye was dissected and embedded in gelatin, and macroscopic observations were made. The gelatin specimens were then embedded in paraffin and observed in detail by low-vacuum scanning electron microscopy, immunofluorescence, and quantitative reverse transcription polymerase chain reaction (RT-qPCR). The results show qualitative changes in Zinn’s zonules in both macroscopic and microscopic observations. In addition, macrophage infiltration and increased matrix metalloproteinase 2 (MMP2) expression were observed in the injured group, consistent with the RT-qPCR results. The experimental system in this study allowed us to capture the morphological and molecular biological changes of Zinn’s zonule and to gain insight into its pathogenesis. In conclusion, this study presents a new experimental setup for the comprehensive analysis of the rat Zinn’s zonule. The results suggest that this system can be used in the future to study and analyze a variety of paraffin-embedded tissues and specimens.
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Affiliation(s)
- Akira Takahashi
- Department of Ophthalmology, Nippon Medical School, Tokyo 113-8602, Japan; (A.T.)
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo 113-8602, Japan
| | - Takeshi Arima
- Department of Ophthalmology, Nippon Medical School, Tokyo 113-8602, Japan; (A.T.)
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo 113-8602, Japan
- Correspondence:
| | - Etsuko Toda
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo 113-8602, Japan
| | - Shinichiro Kobayakawa
- Department of Ophthalmology, Nippon Medical School, Musashikosugi Hospital, Kanagawa 211-8533, Japan
| | - Akira Shimizu
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo 113-8602, Japan
| | - Hiroshi Takahashi
- Department of Ophthalmology, Nippon Medical School, Tokyo 113-8602, Japan; (A.T.)
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5
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Liu Z, Huang S, Zheng Y, Zhou T, Hu L, Xiong L, Li DWC, Liu Y. The lens epithelium as a major determinant in the development, maintenance, and regeneration of the crystalline lens. Prog Retin Eye Res 2023; 92:101112. [PMID: 36055924 DOI: 10.1016/j.preteyeres.2022.101112] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/28/2022] [Accepted: 08/02/2022] [Indexed: 02/01/2023]
Abstract
The crystalline lens is a transparent and refractive biconvex structure formed by lens epithelial cells (LECs) and lens fibers. Lens opacity, also known as cataracts, is the leading cause of blindness in the world. LECs are the principal cells of lens throughout human life, exhibiting different physiological properties and functions. During the embryonic stage, LECs proliferate and differentiate into lens fibers, which form the crystalline lens. Genetics and environment are vital factors that influence normal lens development. During maturation, LECs help maintain lens homeostasis through material transport, synthesis and metabolism as well as mitosis and proliferation. If disturbed, this will result in loss of lens transparency. After cataract surgery, the repair potential of LECs is activated and the structure and transparency of the regenerative tissue depends on postoperative microenvironment. This review summarizes recent research advances on the role of LECs in lens development, homeostasis, and regeneration, with a particular focus on the role of cholesterol synthesis (eg., lanosterol synthase) in lens development and homeostasis maintenance, and how the regenerative potential of LECs can be harnessed to develop surgical strategies and improve the outcomes of cataract surgery (Fig. 1). These new insights suggest that LECs are a major determinant of the physiological and pathological state of the lens. Further studies on their molecular biology will offer possibility to explore new approaches for cataract prevention and treatment.
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Affiliation(s)
- Zhenzhen Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Shan Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Yingfeng Zheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Tian Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Leyi Hu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Lang Xiong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - David Wan-Cheng Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China; Research Unit of Ocular Development and Regeneration, Chinese Academy of Medical Sciences, Beijing, 100085, China.
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6
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DeDreu J, Le PM, Menko AS. The ciliary zonules provide a pathway for immune cells to populate the avascular lens during eye development. Exp Biol Med (Maywood) 2022; 247:2251-2273. [PMID: 36633170 PMCID: PMC9899985 DOI: 10.1177/15353702221140411] [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: 06/24/2022] [Accepted: 10/20/2022] [Indexed: 01/13/2023] Open
Abstract
The eye is an immune-privileged site, with both vasculature and lymphatics absent from the central light path. Unique adaptations have made it possible for immune cells to be recruited to this region of the eye in response to ocular injuries and pathogenic insults. The induction of such immune responses is typically activated by tissue resident immune cells, considered the sentinels of the immune system. We discovered that, despite the absence of an embedded vasculature, the embryonic lens becomes populated by resident immune cells. The paths by which they travel to the lens during development were not known. However, our previous studies show that in response to corneal wounding immune cells travel to the lens from the vascular-rich ciliary body across the zonules that link these two tissues. We now examined whether the zonule fibers provide a path for immune cells to the embryonic lens, and the zonule-associated matrix molecules that could promote immune cell migration. The vitreous also was examined as a potential source of lens resident immune cells. This matrix-rich site in the posterior of the eye harbors hyalocytes, an immune cell type with macrophage-like properties. We found that both the zonules and the vitreous of the embryonic eye contained fibrillin-2-based networks and that migration-promoting matrix proteins like fibronectin and tenascin-C were linked to these fibrils. Immune cells were seen emerging from the ciliary body, migrating along the ciliary zonules to the lens, and invading through the lens capsule at its equator. This is just adjacent to where immune cells take up residence in the embryonic lens. In contrast, the immune cells of the vitreous were not detected in the region of the lens. These results strongly suggest that the ciliary zonules are a primary path of immune cell delivery to the developing lens.
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Affiliation(s)
- JodiRae DeDreu
- Department of Pathology and Genomic
Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia,
PA 19107, USA
| | - Phuong M Le
- Department of Pathology and Genomic
Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia,
PA 19107, USA
| | - A. Sue Menko
- Department of Pathology and Genomic
Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia,
PA 19107, USA
- Department of Ophthalmology, Sidney
Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107,
USA
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7
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Thompson B, Davidson EA, Chen Y, Orlicky DJ, Thompson DC, Vasiliou V. Oxidative stress induces inflammation of lens cells and triggers immune surveillance of ocular tissues. Chem Biol Interact 2022; 355:109804. [PMID: 35123994 PMCID: PMC9136680 DOI: 10.1016/j.cbi.2022.109804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 12/24/2021] [Accepted: 01/05/2022] [Indexed: 11/03/2022]
Abstract
Recent reports have challenged the notion that the lens is immune-privileged. However, these studies have not fully identified the molecular mechanism(s) that promote immune surveillance of the lens. Using a mouse model of targeted glutathione (GSH) deficiency in ocular surface tissues, we have investigated the role of oxidative stress in upregulating cytokine expression and promoting immune surveillance of the eye. RNA-sequencing of lenses from postnatal day (P) 1-aged Gclcf/f;Le-CreTg/- (KO) and Gclcf/f;Le-Cre-/- control (CON) mice revealed upregulation of many cytokines (e.g., CCL4, GDF15, CSF1) and immune response genes in the lenses of KO mice. The eyes of KO mice had a greater number of cells in the aqueous and vitreous humors at P1, P20 and P50 than age-matched CON and Gclcw/w;Le-CreTg/- (CRE) mice. Histological analyses revealed the presence of innate immune cells (i.e., macrophages, leukocytes) in ocular structures of the KO mice. At P20, the expression of cytokines and ROS content was higher in the lenses of KO mice than in those from age-matched CRE and CON mice, suggesting that oxidative stress may induce cytokine expression. In vitro administration of the oxidant, hydrogen peroxide, and the depletion of GSH (using buthionine sulfoximine (BSO)) in 21EM15 lens epithelial cells induced cytokine expression, an effect that was prevented by co-treatment of the cells with N-acetyl-l-cysteine (NAC), a antioxidant. The in vivo and ex vivo induction of cytokine expression by oxidative stress was associated with the expression of markers of epithelial-to-mesenchymal transition (EMT), α-SMA, in lens cells. Given that EMT of lens epithelial cells causes posterior capsule opacification (PCO), we propose that oxidative stress induces cytokine expression, EMT and the development of PCO in a positive feedback loop. Collectively these data indicate that oxidative stress induces inflammation of lens cells which promotes immune surveillance of ocular structures.
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Affiliation(s)
- Brian Thompson
- Department of Environmental Health Sciences, Yale School of Public Health, Yale University, 60 College Street, New Haven, CT, USA
| | - Emily A. Davidson
- Department of Environmental Health Sciences, Yale School of Public Health, Yale University, 60 College Street, New Haven, CT, USA.,Department of Cellular & Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Ying Chen
- Department of Environmental Health Sciences, Yale School of Public Health, Yale University, 60 College Street, New Haven, CT, USA
| | - David J. Orlicky
- Department of Pathology, Anschutz School of Medicine, University of Colorado, Aurora, CO, USA
| | - David C. Thompson
- Department of Environmental Health Sciences, Yale School of Public Health, Yale University, 60 College Street, New Haven, CT, USA.,Department of Clinical Pharmacy, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO, USA
| | - Vasilis Vasiliou
- Department of Environmental Health Sciences, Yale School of Public Health, Yale University, 60 College Street, New Haven, CT, USA.
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8
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DeDreu J, Pal-Ghosh S, Mattapallil MJ, Caspi RR, Stepp MA, Menko AS. Uveitis-mediated immune cell invasion through the extracellular matrix of the lens capsule. FASEB J 2021; 36:e21995. [PMID: 34874579 PMCID: PMC9300120 DOI: 10.1096/fj.202101098r] [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: 07/02/2021] [Revised: 09/20/2021] [Accepted: 10/04/2021] [Indexed: 12/05/2022]
Abstract
While the eye is considered an immune privileged site, its privilege is abrogated when immune cells are recruited from the surrounding vasculature in response to trauma, infection, aging, and autoimmune diseases like uveitis. Here, we investigate whether in uveitis immune cells become associated with the lens capsule and compromise its privilege in studies of C57BL/6J mice with experimental autoimmune uveitis. These studies show that at D14, the peak of uveitis in these mice, T cells, macrophages, and Ly6G/Ly6C+ immune cells associate with the lens basement membrane capsule, burrow into the capsule matrix, and remain integrated with the capsule as immune resolution is occurring at D26. 3D surface rendering image analytics of confocal z‐stacks and scanning electron microscopy imaging of the lens surface show the degradation of the lens capsule as these lens‐associated immune cells integrate with and invade the lens capsule, with a subset infiltrating both epithelial and fiber cell regions of lens tissue, abrogating its immune privilege. Those immune cells that remain on the surface often become entwined with a fibrillar net‐like structure. Immune cell invasion of the lens capsule in uveitis has not been described previously and may play a role in induction of lens and other eye pathologies associated with autoimmunity.
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Affiliation(s)
- JodiRae DeDreu
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Sonali Pal-Ghosh
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
| | - Mary J Mattapallil
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Rachel R Caspi
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Mary Ann Stepp
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA.,Department of Ophthalmology, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
| | - A Sue Menko
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.,Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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9
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Immune responses to injury and their links to eye disease. Transl Res 2021; 236:52-71. [PMID: 34051364 PMCID: PMC8380715 DOI: 10.1016/j.trsl.2021.05.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/12/2021] [Accepted: 05/24/2021] [Indexed: 12/31/2022]
Abstract
The eye is regarded as an immune privileged site. Since the presence of a vasculature would impair vision, the vasculature of the eye is located outside of the central light path. As a result, many regions of the eye evolved mechanisms to deliver immune cells to sites of dysgenesis, injury, or in response to the many age-related pathologies. While the purpose of these immune responses is reparative or protective, cytokines released by immune cells compromise visual acuity by inducing inflammation and fibrosis. The response to traumatic or pathological injury is distinct in different regions of the eye. Age-related diseases impact both the anterior and posterior segment and lead to reduced quality of life and blindness. Here we focus attention on the role that inflammation and fibrosis play in the progression of age-related pathologies of the cornea and the lens as well as in glaucoma, the formation of epiretinal membranes, and in proliferative vitreoretinopathy.
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Key Words
- 2ryERM
- A T-helper cell that expresses high levels of IL-17 which can suppress T-regulatory cell function
- A cytokine expressed early during inflammation that attracts neutrophils
- A cytokine expressed early during inflammation that attracts neutrophils, sometimes referred to as monocyte chemoattractant protein-1 (MCP-1))
- A mouse model that lacks functional T and B cells and used to study the immune response
- A pigmented mouse strain used for research and known to mount a primarily Th1 response to infection
- A protein encoded by the ADGRE1 gene that, in mice, is expressed primarily on macrophages
- A strain of pigmented mice used in glaucoma research
- ACAID
- APCs
- ASC
- An albino mouse strain used for research and known to mount a primarily Th2 response to infection
- Antigen Presenting Cells, this class includes dendritic cells and monocytes
- BALB/c
- BM
- C57BL6
- CCL2
- CD45
- CNS
- CXCL1
- Central Nervous System
- Cluster of differentiation 45 antigen
- DAMPs
- DBA/2J
- EBM
- ECM
- EMT
- ERM
- Epithelial Basement Membrane
- F4/80
- FGF2
- HA =hyaluronic acid
- HSK
- HSP
- HSPGs
- HSV
- ICN
- IL-20
- IL6
- ILM
- IOP
- Inner (or internal) limiting membrane
- Interleukin 6
- Interleukin-20
- MAGP1
- MHC-II
- Major histocompatibility complex type II, a class of MHC proteins typically found only on APCs
- Microfibril-associated glycoprotein 1
- N-cad
- N-cadherin
- NEI
- NK
- National Eye Institute
- Natural killer T cells
- PCO
- PDGF
- PDR
- PVD
- PVR
- Platelet derived growth factor
- Posterior capsular opacification
- RGC
- RPE
- RRD
- Rag1-/-
- Retinal ganglion cells
- Retinal pigment epithelial cells
- SMAD
- Sons of Mothers Against Decapentaplegic, SMADs are a class of molecules that mediate TGF and bone morphogenetic protein signaling
- T-helper cell 1 response, proinflammatory adaptive response involving interferon gamma and associated with autoimmunity
- T-helper cell 2 response involving IgE and interleukins 4,5, and 13, also induces the anti-inflammatory interleukin 10 family cytokines
- T-regulatory cell
- TG
- TGF1
- TM
- TNF
- Th1
- Th17
- Th2
- Transforming growth factor 1
- Treg
- Tumor necrosis factor a cytokine produced during inflammation
- VEGF
- Vascular endothelial growth factor
- WHO
- World Health Organization
- anterior chamber immune deviation
- anterior subcapsular cataracts
- basement membrane
- damage-associated molecular patterns
- epiretinal membrane
- epiretinal membrane secondary to disease pathology
- epithelial-mesenchymal transition
- extracellular matrix
- fibroblast growth factor 2, also referred to as basic FGF
- heat shock protein
- heparan sulfate proteoglycans
- herpes simplex virus
- herpes stromal keratitis
- iERM
- idiopathic epiretinal membrane
- intraepithelial corneal nerves
- intraocular pressure
- mTOR
- mechanistic target of rapamycin, a protein kinase encoded by the MTOR genes that regulates a variety of signal transduction events including cell growth, autophagy and actin cytoskeleton
- posterior vitreous detachment
- proliferative diabetic retinopathy
- proliferative vitreoretinopathy
- rhegmatogenous (rupture, tear) retinal detachment
- trabecular meshwork
- trigeminal ganglion
- αSMA
- α−Smooth muscle actin, a class of actin expressed in mesenchymal cells
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10
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Menko AS, DeDreu J, Logan CM, Paulson H, Levin AV, Walker JL. Resident immune cells of the avascular lens: Mediators of the injury and fibrotic response of the lens. FASEB J 2021; 35:e21341. [PMID: 33710665 PMCID: PMC8200928 DOI: 10.1096/fj.202002200r] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/09/2020] [Accepted: 12/21/2020] [Indexed: 12/12/2022]
Abstract
Tissues typically harbor subpopulations of resident immune cells that function as rapid responders to injury and whose activation leads to induction of an adaptive immune response, playing important roles in repair and protection. Since the lens is an avascular tissue, it was presumed that it was absent of resident immune cells. Our studies now show that resident immune cells are a shared feature of the human, mouse, and chicken lens epithelium. These resident immune cells function as immediate responders to injury and rapidly populate the wound edge following mock cataract surgery to function as leader cells. Many of these resident immune cells also express MHCII providing them with antigen presenting ability to engage an adaptive immune response. We provide evidence that during development immune cells migrate on the ciliary zonules and localize among the equatorial epithelial cells of the lens adjacent to where the ciliary zonules associate with the lens capsule. These findings suggest that the vasculature‐rich ciliary body is a source of lens resident immune cells. We identified a major role for these cells as rapid responders to wounding, quickly populating each wound were they can function as leaders of lens tissue repair. Our findings also show that lens resident immune cells are progenitors of myofibroblasts, which characteristically appear in response to lens cataract surgery injury, and therefore, are likely agents of lens pathologies to impair vision like fibrosis.
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Affiliation(s)
- A Sue Menko
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.,Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - JodiRae DeDreu
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Caitlin M Logan
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Heather Paulson
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Alex V Levin
- Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.,Wills Eye Hospital, Philadelphia, PA, USA
| | - Janice L Walker
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.,Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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11
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Zhou Y, Bennett TM, Shiels A. Mutation of the TRPM3 cation channel underlies progressive cataract development and lens calcification associated with pro-fibrotic and immune cell responses. FASEB J 2021; 35:e21288. [PMID: 33484482 DOI: 10.1096/fj.202002037r] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/23/2020] [Accepted: 12/03/2020] [Indexed: 12/11/2022]
Abstract
Transient-receptor-potential cation channel, subfamily M, member 3 (TRPM3) serves as a polymodal calcium sensor in diverse mammalian cell-types. Mutation of the human TRPM3 gene (TRPM3) has been linked with inherited forms of early-onset cataract with or without other eye abnormalities. Here, we have characterized the ocular phenotypes of germline "knock-in" mice that harbor a human cataract-associated isoleucine-to-methionine mutation (p.I65M) in TRPM3 (Trpm3-mutant) compared with germline "knock-out" mice that functionally lack TRPM3 (Trpm3-null). Despite strong expression of Trpm3 in lens epithelial cells, neither heterozygous (Trpm3+/- ) nor homozygous (Trpm3-/- ) Trpm3-null mice developed cataract; however, the latter exhibited a mild impairment of lens growth. In contrast, homozygous Trpm3-M/M mutants developed severe, progressive, anterior pyramid-like cataract with microphthalmia, whereas heterozygous Trpm3-I/M and hemizygous Trpm3-M/- mutants developed anterior pyramidal cataract with delayed onset and progression-consistent with a semi-dominant lens phenotype. Histochemical staining revealed abnormal accumulation of calcium phosphate-like deposits and collagen fibrils in Trpm3-mutant lenses and immunoblotting detected increased αII-spectrin cleavage products consistent with calpain hyper-activation. Immunofluorescent confocal microscopy of Trpm3-M/M mutant lenses revealed fiber cell membrane degeneration that was accompanied by accumulation of alpha-smooth muscle actin positive (α-SMA+ve) myofibroblast-like cells and macrosialin positive (CD68+ve) macrophage-like cells. Collectively, our mouse model data support an ocular disease association for TRPM3 in humans and suggest that (1) Trpm3 deficiency impaired lens growth but not lens transparency and (2) Trpm3 dysfunction resulted in progressive lens degeneration and calcification coupled with pro-fibrotic (α-SMA+ve) and immune (CD68+ve) cell responses.
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Affiliation(s)
- Yuefang Zhou
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Thomas M Bennett
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Alan Shiels
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
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12
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Walker JL, Menko AS. Immune cells in lens injury repair and fibrosis. Exp Eye Res 2021; 209:108664. [PMID: 34126081 DOI: 10.1016/j.exer.2021.108664] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/26/2021] [Accepted: 05/28/2021] [Indexed: 12/18/2022]
Abstract
Immune cells, both tissue resident immune cells and those immune cells recruited in response to wounding or degenerative conditions, are essential to both the maintenance and restoration of homeostasis in most tissues. These cells are typically provided to tissues by their closely associated vasculatures. However, the lens, like many of the tissues in the eye, are considered immune privileged sites because they have no associated vasculature. Such absence of immune cells was thought to protect the lens from inflammatory responses that would bring with them the danger of causing vision impairing opacities. However, it has now been shown, as occurs in other immune privileged sites in the eye, that novel pathways exist by which immune cells come to associate with the lens to protect it, maintain its homeostasis, and function in its regenerative repair. Here we review the discoveries that have revealed there are both innate and adaptive immune system responses to lens, and that, like most other tissues, the lens harbors a population of resident immune cells, which are the sentinels of danger or injury to a tissue. While resident and recruited immune cells are essential elements of lens homeostasis and repair, they also become the agents of disease, particularly as progenitors of pro-fibrogenic myofibroblasts. There still remains much to learn about the function of lens-associated immune cells in protection, repair and disease, the knowledge of which will provide new tools for maintaining the core functions of the lens in the visual system.
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Affiliation(s)
- Janice L Walker
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA; Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - A Sue Menko
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA; Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA.
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13
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Galletti JG, de Paiva CS. Age-related changes in ocular mucosal tolerance: Lessons learned from gut and respiratory tract immunity. Immunology 2021; 164:43-56. [PMID: 33837534 DOI: 10.1111/imm.13338] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/28/2021] [Accepted: 03/24/2021] [Indexed: 12/12/2022] Open
Abstract
The ocular surface is the part of the visual system directly exposed to the environment, and it comprises the cornea, the first refractive tissue layer and its surrounding structures. The ocular surface has evolved to keep the cornea smooth and wet, a prerequisite for proper sight, and also protected. To this aim, the ocular surface is a bona fide mucosal niche with an immune system capable of fighting against dangerous pathogens. However, due to the potential harmful effects of uncontrolled inflammation, the ocular surface has several mechanisms to keep the immune response in check. Specifically, the ocular surface is maintained inflammation-free and functional by a particular form of peripheral tolerance known as mucosal tolerance, markedly different from the immune privilege of intraocular structures. Remarkably, conjunctival tolerance is akin to the oral and respiratory tolerance mechanisms found in the gut and airways, respectively. And also similarly, this form of immunoregulation in the eye is affected by ageing just as it is in the digestive and respiratory tracts. With ageing comes an increased prevalence of immune-based ocular surface disorders, which could be related to an age-related impairment of conjunctival tolerance. The purpose of this review was to summarize the present knowledge of ocular mucosal tolerance and how it is affected by the ageing process in the light of the current literature on mucosal immunoregulation of the gut and airways.
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Affiliation(s)
- Jeremias G Galletti
- Innate Immunity Laboratory, Institute of Experimental Medicine (IMEX), National Academy of Medicine/CONICET, Buenos Aires, Argentina
| | - Cintia S de Paiva
- Department of Ophthalmology, Ocular Surface Center, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, USA
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14
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DeDreu J, Walker JL, Menko AS. Dynamics of the lens basement membrane capsule and its interaction with connective tissue-like extracapsular matrix proteins. Matrix Biol 2021; 96:18-46. [PMID: 33383103 PMCID: PMC7902460 DOI: 10.1016/j.matbio.2020.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/24/2020] [Accepted: 12/24/2020] [Indexed: 12/11/2022]
Abstract
The lens, suspended in the middle of the eye by tendon-like ciliary zonule fibers and facing three different compartments of the eye, is enclosed in what has been described as the thickest basement membrane in the body. While the protein components of the capsule have been a subject of study for many years, the dynamics of capsule formation, and the region-specific relationship of its basement membrane components to one another as well as to other matrix molecules remains to be explored. Through high resolution confocal and super-resolution imaging of the lens capsule and 3D surface renderings of acquired z-stacks, our studies revealed that each of its basement membrane proteins, laminin, collagen IV, nidogen and perlecan, has unique structure, organization, and distribution specific both to the region of the lens that the capsule is located in and the position of the capsule within the eye. We provide evidence of basal membrane gradients across the depth of the capsule as well as the synthesis of distinct basement membrane lamella within the capsule. These distinctions are most prominent in the equatorial capsule zone where collagen IV and nidogen span the capsule depth, while laminin and perlecan are located in two separate lamellae located at the innermost and outermost capsule domains. We discovered that an extracapsular matrix compartment rich in the connective tissue-like matrix molecules fibronectin, tenascin-C, and fibrillin is integrated with the superficial surface of the lens capsule. Each matrix protein in this extracapsular zone also exhibits region-specific distribution with fibrils of fibrillin, the matrix protein that forms the backbone of the ciliary zonules, inserting within the laminin/perlecan lamella at the surface of the equatorial lens capsule.
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Affiliation(s)
- JodiRae DeDreu
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, 564 Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, United States.
| | - Janice L Walker
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, 564 Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, United States.
| | - A Sue Menko
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, 564 Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, United States.
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15
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DeDreu J, Bowen CJ, Logan CM, Pal-Ghosh S, Parlanti P, Stepp MA, Menko AS. An immune response to the avascular lens following wounding of the cornea involves ciliary zonule fibrils. FASEB J 2020; 34:9316-9336. [PMID: 32452112 PMCID: PMC7384020 DOI: 10.1096/fj.202000289r] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 04/22/2020] [Accepted: 04/28/2020] [Indexed: 12/12/2022]
Abstract
The lens and central cornea are avascular. It was assumed that the adult lens had no source of immune cells and that the basement membrane capsule surrounding the lens was a barrier to immune cell migration. Yet, microfibril‐associated protein‐1 (MAGP1)‐rich ciliary zonules that originate from the vasculature‐rich ciliary body and extend along the surface of the lens capsule, form a potential conduit for immune cells to the lens. In response to cornea debridement wounding, we find increased expression of MAGP1 throughout the central corneal stroma. The immune cells that populate this typically avascular region after wounding closely associate with this MAGP1‐rich matrix. These results suggest that MAGP1‐rich microfibrils support immune cell migration post‐injury. Using this cornea wound model, we investigated whether there is an immune response to the lens following cornea injury involving the lens‐associated MAGP1‐rich ciliary zonules. Our results provide the first evidence that following corneal wounding immune cells are activated to travel along zonule fibers that extend anteriorly along the equatorial surface of the lens, from where they migrate across the anterior lens capsule. These results demonstrate that lens‐associated ciliary zonules are directly involved in the lens immune response and suggest the ciliary body as a source of immune cells to the avascular lens.
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Affiliation(s)
- JodiRae DeDreu
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Caitlin J Bowen
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Caitlin M Logan
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Sonali Pal-Ghosh
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Paola Parlanti
- George Washington University Nanofabrication and Imaging Center, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Mary Ann Stepp
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA.,Department of Ophthalmology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - A Sue Menko
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.,Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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