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.

Potential role for laminin 5 in hypoxia-mediated apoptosis of human corneal epithelial cells

2001 ◽  
Vol 114 (22) ◽  
pp. 4033-4040
Author(s):  
Miechia A. Esco ◽  
Zhiyu Wang ◽  
Mark L. McDermott ◽  
Michelle Kurpakus-Wheater
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Mitochondrial Membrane ◽  
Corneal Epithelial Cell ◽  
Corneal Epithelial Cells ◽  
Laminin 5 ◽  
Corneal Epithelial ◽  
Human Corneal Epithelial Cells ◽  
Cells Cultured

Laminin 5 functions to promote cell-matrix adhesion and therefore is hypothesized to abrogate apoptosis initiated through the loss of epithelial cell contact with extracellular matrix. Laminin 5 levels are decreased in epithelial cells cultured in a hypoxic environment. Exposure of epithelial cells to hypoxia may induce apoptotic pathways transmitted through changes in mitochondrial membrane potential. Using an apoptosis assay based on mitochondrial membrane integrity, the effect of hypoxia (2% oxygen) on human corneal epithelial cell viability was determined. Both a virally transformed corneal epithelial cell line and third passage corneal epithelial cells were resistant to hypoxia-mediated apoptosis for up to 5 days in culture. However, at 7 days in culture, a statistically significant increase in apoptosis was noted in hypoxic corneal epithelial cells compared to normoxic (20% oxygen) controls. Increased apoptosis in hypoxic epithelium at 7 days in culture correlated with decreased deposition of laminin 5 into the extracellular matrix, as determined by western blot analysis and immunofluorescence microscopy. Additionally, the extracellular processing of the α3 and γ2 chains of laminin 5 was negatively impacted by corneal epithelial cell exposure to hypoxia for 7 days. Treatment of human corneal epithelial cells cultured in 20% oxygen with function-inhibiting antibodies to laminin 5 for 2 or 3 days resulted in a statistically significant decrease in proliferation, and concomitant increase in apoptosis, compared with untreated normoxic controls. Based on these results, it appears that mechanisms of hypoxia-mediated apoptosis in human corneal epithelial cells may be initiated by the loss of processed laminin 5 in the extracellular matrix or by the loss of laminin 5-epithelial cell communication and transmitted through mitochondria.

scholarly journals Development of a novel hyaluronic acid membrane for the treatment of ocular surface diseases

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dong Ju Kim ◽  
Mi-Young Jung ◽  
Ha-Jin Pak ◽  
Joo-Hee Park ◽  
Martha Kim ◽  
...  
Keyword(s):  
Wound Healing ◽  
Hyaluronic Acid ◽  
Epithelial Cells ◽  
Ocular Surface ◽  
Corneal Epithelial Cell ◽  
Corneal Epithelial Cells ◽  
Toxic Response ◽  
Corneal Epithelial ◽  
Ocular Surface Diseases ◽  
Human Corneal Epithelial Cells

AbstractOcular surface diseases (OSD) can cause serious visual deterioration and discomfort. Commercial artificial tear solution containing hyaluronic acid (HA) show excellent biocompatibility and unique viscoelastic characteristics. Here, we developed a novel HA membrane (HAM) by chemical crosslinking using 1,4-butanediol diglycidyl ether for the effective treatment of OSDs. The main purpose of HAMs is to provide sustained release of HA to modulate the wound healing response in OSDs. The safety and efficacy of HAMs were investigated using primary cultured human corneal epithelial cells and various OSD rabbit models. In the dry state, the HAM is firm, transparent, and easy to manipulate. When hydrated, it swells rapidly with high water retention and over 90% transmission of visible light. Human corneal epithelial cells and rabbit eyes showed no toxic response to HAM. Addition of HAMs to the culture medium enhanced human corneal epithelial cell viability and expression of cell proliferation markers. Investigation of HAM wound healing efficacy using mechanical or chemical corneal trauma and conjunctival surgery in rabbits revealed that application of HAMs to the ocular surface enhanced healing of corneal epithelium and reduced corneal limbal vascularization, opacity and conjunctival fibrosis. The therapeutic potential of HAMs in various OSDs was successfully demonstrated.

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 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.

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