scholarly journals Characterisation of the prereceptor regulation of glucocorticoids in the anterior segment of the rabbit eye

2006 ◽  
Vol 190 (2) ◽  
pp. 483-493 ◽  
Author(s):  
Claire U Onyimba ◽  
Neelima Vijapurapu ◽  
S John Curnow ◽  
Pamela Khosla ◽  
Paul M Stewart ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Corneal Epithelium ◽  
Ciliary Body ◽  
Primary Cultures ◽  
Anterior Segment ◽  
Body Tissue ◽  
Corneal Epithelial Cell ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial ◽  
Rabbit Eye

The prereceptor regulation of glucocorticoids (GCs) by 11β-hydroxysteroid dehydrogenase type-1 (11β-HSD1), a bidirectional isozyme that interconverts active (cortisol) and inactive (cortisone) GCs, is an established determinant of GC function in tissues such as liver, adipose and bone. Although the therapeutic use of GCs is abundant in ophthalmic practice, where GC interactions with nuclear receptors modulate gene transcription, the prereceptor regulation of endogenous cortisol is not well described in ocular tissues. Recent descriptive studies have localised 11β-HSD1 to the human corneal epithelium and non-pigmented epithelium (NPE) of the ciliary body, indicating a link to corneal epithelial physiology and aqueous humour production. In this study, we characterise the functional aspects of the autocrine regulation of GCs in the anterior segment of the rabbit eye. Using our in-house generated primary antibody to human 11β-HSD1, immunohistochemical analyses were performed on paraffin-embedded sections of whole New Zealand white albino rabbits, (NZWAR) eyes. As in human studies, 11β-HSD1 was localised to the corneal epithelium and the NPE. No staining was seen in the albino ‘pigmented’ ciliary epithelium. Specific enzyme assays for oxo-reductase (cortisone→cortisol) and dehydrogenase (cortisol→cortisone) activity indicated predominant 11β-HSD1 oxo-reductase activity from both the intact ciliary body tissue (n=12, median 2.1 pmol/mg per h and range 1.25–2.8 pmol/mg per h; P=0.006) and primary cultures of corneal epithelial cells (n=12, median 3.0 pmol/mg per h and range 1.0–7.4 pmol/mg per h, P=0.008) compared with dehydrogenase activity (median 1.0 pmol/mg per h and range 0.5–2.0 pmol/mg per h; median 0.5 pmol/mg per h and range 0.25–1.9 pmol/mg per h respectively). These findings were supported by expression of 11β-HSD1 protein as visualised by Western blotting of ciliary body tissue and immunocytochemistry of corneal epithelial cells. Reduction of corneal epithelial cell proliferation was seen after primary cultures were co-incubated with cortisol and cortisone. 11β-HSD1 activity was not demonstrated in naïve conjunctival fibroblasts or corneal stromal keratocytes. Our results indicate that the distribution of 11β-HSD1 in the rabbit resembles that of the human eye and activates cortisone to cortisol in both corneal and uveal tissues. The NZWAR provides a suitable in vivo model for the further evaluation of 11β-HSD1 activity in the eye, especially its role in corneal epithelial and ciliary body physiology.

scholarly journals The core planar cell polarity gene, Vangl2 , directs adult corneal epithelial cell alignment and migration

2016 ◽  
Vol 3 (10) ◽  
pp. 160658 ◽  
Author(s):  
Amy S. Findlay ◽  
D. Alessio Panzica ◽  
Petr Walczysko ◽  
Amy B. Holt ◽  
Deborah J. Henderson ◽  
...  
Keyword(s):  
Cell Migration ◽  
Epithelial Cells ◽  
Cell Polarity ◽  
Corneal Epithelium ◽  
Planar Cell Polarity ◽  
Corneal Epithelial Cell ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial ◽  
The Core

This study shows that the core planar cell polarity (PCP) genes direct the aligned cell migration in the adult corneal epithelium, a stratified squamous epithelium on the outer surface of the vertebrate eye. Expression of multiple core PCP genes was demonstrated in the adult corneal epithelium. PCP components were manipulated genetically and pharmacologically in human and mouse corneal epithelial cells in vivo and in vitro . Knockdown of VANGL2 reduced the directional component of migration of human corneal epithelial (HCE) cells without affecting speed. It was shown that signalling through PCP mediators, dishevelled, dishevelled-associated activator of morphogenesis and Rho-associated protein kinase directs the alignment of HCE cells by affecting cytoskeletal reorganization. Cells in which VANGL2 was disrupted tended to misalign on grooved surfaces and migrate across, rather than parallel to the grooves. Adult corneal epithelial cells in which Vangl2 had been conditionally deleted showed a reduced rate of wound-healing migration. Conditional deletion of Vangl2 in the mouse corneal epithelium ablated the normal highly stereotyped patterns of centripetal cell migration in vivo from the periphery (limbus) to the centre of the cornea. Corneal opacity owing to chronic wounding is a major cause of degenerative blindness across the world, and this study shows that Vangl2 activity is required for directional corneal epithelial migration.

scholarly journals Expression of immune response genes in human corneal epithelial cells interacting with Aspergillus flavus conidia

BMC Genomics ◽  
2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Divya Arunachalam ◽  
Shruthi Mahalakshmi Ramanathan ◽  
Athul Menon ◽  
Lekshmi Madhav ◽  
Gopalakrishna Ramaswamy ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Line ◽  
Differentially Expressed Genes ◽  
Primary Cultures ◽  
Differentially Expressed ◽  
Corneal Epithelial Cell ◽  
Epithelial Cell Line ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial ◽  
Human Corneal Epithelial Cells

Abstract Background Aspergillus flavus, one of the causative agents of human fungal keratitis, can be phagocytosed by human corneal epithelial (HCE) cells and the conidia containing phagosomes mature into phagolysosomes. But the immunological responses of human corneal epithelial cells interacting with A. flavus are not clear. In this study, we report the expression of immune response related genes of HCE cells exposed to A. flavus spores using targeted transcriptomics. Methods Human corneal epithelial cell line and primary cultures were grown in a six-well plate and used for coculture experiments. Internalization of the conidia was confirmed by immunofluorescence microscopy of the colocalized endosomal markers CD71 and LAMP1. Total RNA was isolated, and the quantity and quality of the isolated RNA were assessed using Qubit and Bioanalyzer. NanoString nCounter platform was used for the analysis of mRNA abundance using the Human Immunology panel. R-package and nSolver software were used for data analysis. KEGG and FunRich 3.1.3 tools were used to analyze the differentially expressed genes. Results Different morphotypes of conidia were observed after 6 h of coculture with human corneal epithelial cells and found to be internalized by epithelial cells. NanoString profiling showed more than 20 differentially expressed genes in immortalized human corneal epithelial cell line and more than ten differentially expressed genes in primary corneal epithelial cells. Distinct set of genes were altered in their expression in cell line and primary corneal epithelial cells. KEGG pathway analysis revealed that genes associated with TNF signaling, NF-KB signaling, and Th17 signaling were up-regulated, and genes associated with chemokine signaling and B cell receptor signaling were down regulated. FunRich pathway analysis showed that pathways such as CDC42 signaling, PI3K signaling, and Arf6 trafficking events were activated by the clinical isolates CI1123 and CI1698 in both type of cells. Conclusions Combining the transcript analysis data from cell lines and primary cultures, we showed the up regulation of immune defense genes in A. flavus infected cells. At the same time, chemokine signaling and B cell signaling pathways are downregulated. The variability in the expression levels in the immortalized cell line and the primary cultures is likely due to the variable epigenetic reprogramming in the immortalized cells and primary cultures in the absence of any changes in the genome. It highlights the importance of using both cell types in host-pathogen interaction studies.

Recombinant TIMP-1 and -2 enhance the proliferation of rabbit corneal epithelial cells in vitro and the spreading of rabbit corneal epithelium in situ

1998 ◽  
Vol 17 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Shizuya Saika ◽  
Yoshiji Kawashima ◽  
Yuka Okada ◽  
Sai-Ichi Tanaka ◽  
Osamu Yamanaka ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Corneal Epithelium ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial

Cornea and Lens Problems in Aniridia

2010 ◽  
Author(s):  
Edward J. Holland ◽  
Mayank Gupta
Keyword(s):  
Stem Cells ◽  
Epithelial Cells ◽  
Corneal Epithelium ◽  
Basal Layer ◽  
Limbal Stem Cells ◽  
Corneal Epithelial Cells ◽  
Film Stability ◽  
Corneal Epithelial ◽  
Corneal Erosion ◽  
Peripheral Cornea

The corneal epithelium is a rapidly regenerating, stratified squamous epithelium. Homeostasis of corneal epithelial cells is an important prerequisite, not only for the integrity of the ocular surface, but also for the visual function. The maintenance of a healthy corneal epithelium under both normal and wound-healing conditions is achieved by a population of stem cells located in the basal layer of limbal epithelium. The Limbus represents the transition zone between the peripheral cornea and the bulbar conjunctiva. The stem cells from the limbus generate the transient amplifying cells that migrate, proliferate, and differentiate to replace lost or damaged corneal epithelial cells. In patients with aniridia, there is a primary dysfunction of these limbal stem cells (see Figure 6.1). The cornea is affected clinically in 90 percent of the patients with aniridia. In most cases, the cornea in aniridic patients appears normal and transparent during infancy and childhood. However, during the early teens, the cornea begins to show changes. The early changes are marked by the in-growth of opaque epithelium from the limbal region into the peripheral cornea, which represents conjunctival epithelial cells, goblet cells, and blood vessels in the corneal epithelium. These changes gradually progress toward the central cornea and may cause corneal epithelial erosions and epithelial abnormalities that eventually culminate in opacification of the corneal stroma, which leads to vision loss. With the gradual loss of limbal stem cells, the entire cornea becomes covered with conjunctival cells. Eventually, many patients develop total limbal stem cell deficiency. These abnormalities usually become more pronounced with aging. The corneal abnormalities seen in aniridia are collectively termed “aniridic keratopathy”. Significant corneal opacification may occasionally be the initial manifestation of aniridia. Abnormal tear film stability and meibomian gland dysfunction are also observed in patients with aniridia. This can lead to dry eyes, aggravating corneal erosion and ulceration observed in aniridic patients. Sometimes, aniridia is associated with “Peter’s anomaly,” in which central corneal opacity is present at birth along with defects in the corneal endothelium and Descemet’s membrane.

The Immunohistochemical Characterisation of an SV40-immortalised Human Corneal Epithelial Cell Line

2003 ◽  
Vol 31 (4) ◽  
pp. 409-417 ◽  
Author(s):  
Anne Huhtala ◽  
Sami K. Nurmi ◽  
Hanna Tähti ◽  
Lotta Salminen ◽  
Päivi Alajuuma ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Single Cell ◽  
Cell Line ◽  
Cell Cultures ◽  
Corneal Epithelium ◽  
Culture Medium ◽  
Corneal Epithelial Cell ◽  
Cell Type ◽  
Corneal Epithelial ◽  
Single Cell Type

Alternatives to the Draize rabbit eye irritation test are currently being investigated. Because of morphological and biochemical differences between the rabbit and the human eye, continuous human cell lines have been proposed for use in ocular toxicology studies. Single cell-type monolayer cultures in culture medium have been used extensively in ocular toxicology. In the present study, an SV40-immortalised human corneal epithelial (HCE) cell line was characterised immunohistochemically, by using 13 different monoclonal antibodies to cytokeratins (CKs), ranging from CK3 to CK20. The results from the monolayer HCE cell cultures were compared with those from the corneal epithelium of human corneal cryostat sections. Previous studies have shown that the morphology of the HCE cell is similar to that of primary cultured human corneal epithelial cells, and that the cells express the cornea-specific CK3. In the study reported here, we show that the cell line also expresses CKs 7, 8, 18 and 19. These CKs are typically expressed by simple epithelial cells, and are not found in the human cornea in vivo. Therefore, the monolayer HCE cell line grown in culture medium does not express the CK pattern that is typical of human corneal epithelium. This should be taken into consideration when using HCE cell cultures in similar single cell-type experiments for ocular toxicology.

scholarly journals The O-GlcNAc modification promotes terminal differentiation of human corneal epithelial cells

Glycobiology ◽  
2020 ◽  
Vol 30 (11) ◽  
pp. 872-880 ◽  
Author(s):  
Nicole M McColgan ◽  
Marissa N Feeley ◽  
Ashley M Woodward ◽  
Damien Guindolet ◽  
Pablo Argüeso
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Ocular Surface ◽  
Barrier Function ◽  
Terminal Differentiation ◽  
Corneal Epithelial Cell ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial ◽  
Human Corneal Epithelial Cells ◽  
Glcnac Transferase

Abstract Dynamic modification of nuclear and cytoplasmic proteins with O-linked β-N-acetylglucosamine (O-GlcNAc) plays an important role in orchestrating the transcriptional activity of eukaryotic cells. Here, we report that the O-GlcNAc modification contributes to maintaining ocular surface epithelial homeostasis by promoting mucin biosynthesis and barrier function. We found that induction of human corneal epithelial cell differentiation stimulated the global transfer of O-GlcNAc to both nuclear and cytosolic proteins. Inflammatory conditions, on the other hand, were associated with a reduction in the expression of O-GlcNAc transferase at the ocular surface epithelia. Loss- and gain-of-function studies using small interfering RNA targeting O-GlcNAc transferase, or Thiamet G, a selective inhibitor of O-GlcNAc hydrolase, respectively, revealed that the presence of O-GlcNAc was necessary to promote glycocalyx barrier function. Moreover, we found that Thiamet G triggered a correlative increase in both surface expression of MUC16 and apical epithelial cell area while reducing paracellular permeability. Collectively, these results identify intracellular protein O-glycosylation as a novel pathway responsible for promoting the terminal differentiation of human corneal epithelial cells.

scholarly journals Biocompatibility of Nanocellulose-Reinforced PVA Hydrogel with Human Corneal Epithelial Cells for Ophthalmic Applications

2019 ◽  
Vol 10 (3) ◽  
pp. 35 ◽  
Author(s):  
Tummala ◽  
Lopes ◽  
Mihranyan ◽  
Ferraz
Keyword(s):  
Epithelial Cells ◽  
Cell Viability ◽  
Protein Adsorption ◽  
Direct Contact ◽  
Corneal Epithelial Cell ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial ◽  
Human Corneal Epithelial Cells ◽  
Hydrogel Surface

Transparent composite hydrogel in the form of a contact lens made from poly(vinyl alcohol) (PVA) and cellulose nanocrystals (CNCs) was subjected to in vitro biocompatibility evaluation with human corneal epithelial cells (HCE-2 cells). The cell response to direct contact with the hydrogels was investigated by placing the samples on top of confluent cell layers and evaluating cell viability, morphology, and cell layer integrity subsequent to 24 h culture and removal of the hydrogels. To further characterize the lens–cell interactions, HCE-2 cells were seeded on the hydrogels, with and without simulated tear fluid (STF) pre-conditioning, and cell viability and morphology were evaluated. Furthermore, protein adsorption on the hydrogel surface was investigated by incubating the materials with STF, followed by protein elution and quantification. The hydrogel material was found to have affinity towards protein adsorption, most probably due to the interactions between the positively charged lysozyme and the negatively charged CNCs embedded in the PVA matrix. The direct contact experiment demonstrated that the physical presence of the lenses did not affect corneal epithelial cell monolayers in terms of integrity nor cell metabolic activity. Moreover, it was found that viable corneal cells adhered to the hydrogel, showing the typical morphology of epithelial cells and that such response was not influenced by the STF pre-conditioning of the hydrogel surface. The results of the study confirm that PVA-CNC hydrogel is a promising ophthalmic biomaterial, motivating future in vitro and in vivo biocompatibility studies.

scholarly journals Hyaluronate Acid-Dependent Protection and Enhanced Corneal Wound Healing against Oxidative Damage in Corneal Epithelial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Jing Zhong ◽  
Yuqing Deng ◽  
Bishan Tian ◽  
Bowen Wang ◽  
Yifang Sun ◽  
...  
Keyword(s):  
Wound Healing ◽  
Cell Migration ◽  
Epithelial Cells ◽  
Cell Apoptosis ◽  
Corneal Epithelial Cell ◽  
Corneal Epithelial Cells ◽  
Corneal Wound Healing ◽  
Corneal Epithelial ◽  
Expression Levels ◽  
Corneal Wound

Purpose. To evaluate the effects and mechanism of exogenous hyaluronate (HA) in promoting corneal wound healing.Methods. Human corneal epithelial cells (HCECs) were incubated with different concentrations of HA to evaluate their efficiency in promoting cell migration and their modulation of repair factors. After inducing hyperosmolar conditions, the cell morphologies, cell apoptosis, and expression levels of TNF-αand MMP-9 were detected to assess the protective role of HA. Corneal epithelium-injured rat models were established to test the therapeutic effects of 0.3% HA. Then, the wound healing rates, the RNA expression levels of inflammatory cytokines, and repair factors were examined.Results. HCECs in the 0.03% and 0.3% HA groups showed fewer morphological alterations and lower rates of cell apoptosis following preincubation with HA under hyperosmolar conditions, as well as the expression levels of MMP-9 and TNF-α. In the rat model, the areas of fluorescein staining in the corneas of 0.3% HA group were significantly smaller than the control group. The expression levels of IL-1βand MMP-9 were decreased, while CD44 and FN were increased in the 0.3% HA group.Conclusion. HA enhanced corneal epithelial cell wound healing by promoting cell migration, upregulating repair responses, and suppressing inflammatory responses.

Sign in / Sign up

Export Citation Format

Share Document