Purpose: Human corneal epithelial cells (HCECs) were functionally depleted of erbB2 to elucidate its role in epidermal growth factor (EGF) receptor (EGFR) activation-dependent cell migration.
Methods: The retrovirus pBabe-5R, which encodes an erbB2 single-chain antibody with an endoplasmic reticulum (ER)-targeting sequence, and control pBabe-puro were used to infect THCE cells (an SV40-immortalized HCEC line). Several cell lines expressing 5R were selected along with a pBabe-puro control line. The depletion of erbB2 was verified by cell surface biotinylation of proteins, followed by streptavidin precipitation and subsequent detection of erbB2 by immunoblot analysis. Activation of erbBs was analyzed by immunoprecipitation using the phosphotyrosine antibody pY20, followed by Western blot analysis with erbB1 or erbB2 antibodies. Phosphorylation of extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3'-kinase (PI3K) was analyzed by Western blot with antibodies specific to phosphorylated proteins. Effects of erbB2 depletion on heparin-binding EGF-like growth factor (HB-EGF)-induced cell migration were determined by Boyden chamber migration assay and by scratch wound assay.
Results: Wounding induced erbB2 tyrosine phosphorylation. Expression of 5R encoding an erbB2 single-chain antibody with an endoplasmic reticulum-targeting sequence depleted the cell surface expression of erbB2 in HCECs. Wounding resulted in a rapid increase in the phosphorylation of erbB1 in both 5R-expressing and control cells, whereas wound-induced erbB2 phosphorylation in 5R-expressing cells was not detectable. Depletion of functional erbB2 attenuated the healing of scratch wounds in the presence of HB-EGF and impaired both chemotactic migration stimulated by HB-EGF and haptotactic migration toward a fibronectin-collagen I (3:1; FNC) coating mix. Expression of 5R affected both the intensity and the duration of wound-induced, EGFR-elicited ERK and PI3K activation. Inhibition of ERK and PI3K pathways in cultured porcine corneas impaired ex vivo epithelial wound healing.
Conclusions: ErbB2 serves as a critical component that couples erbB receptor tyrosine kinase to the migration machinery of corneal epithelial cells.
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http://dx.doi.org/10.1167/iovs.04-0119 | DOI Listing |
Clin Ophthalmol
January 2025
Ophthalmology Department, College of Medicine, King Faisal University, Alahsa, Saudi Arabia.
Purpose: The corneal epithelium is the outermost layer of the cornea. It plays a vital role in both normal and pathological conditions of the eye surface and serves as a protective layer. This study aimed to evaluate corneal epithelial thickness (ET) and create a normative database of corneal ET for pediatric and adult age groups using MS-39 AS-OCT.
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Nankai University Eye Institute, Nankai University, Tianjin, 300071, China.
Reproducing the microstructure of the natural cornea remains a significant challenge in achieving the mechanical and biological functionality of artificial corneas. Therefore, the development of cascade structures that mimic the natural extracellular matrix (ECM), achieving both macro-stability and micro-structure, is of critical importance. This study proposes a novel, efficient, and general photo-functionalization strategy for modifying natural biomaterials.
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Department of Ophthalmology, Medical University of Graz, Graz, Austria.
Purpose: To retrospectively describe the performance of topical insulin in persistent corneal epithelial defects (CED) and persistent corneal ulcers.
Methods: We reviewed cases of patients treated for persistent CED and persistent corneal ulcers using topical insulin in a concentration of 25 IU per milliliter three times per day. The closure rate of CED and corneal ulcers was the main outcome measure.
Viruses
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Department of Ophthalmology, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou 450003, China.
COVID-19, caused by SARS-CoV-2, has presented formidable challenges to global health since its emergence in late 2019. While primarily known for respiratory symptoms, it can also affect the ocular surface. This review summarizes the effects of SARS-CoV-2 on ocular surface immunity and inflammation, focusing on infection mechanisms, immune responses, and clinical manifestations.
View Article and Find Full Text PDFJ Clin Med
January 2025
Ophthalmology Section, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy.
To report the cosmetic, clinical, and visual outcomes of a combined surgical approach for treating a corneal/limbal dermoid using excision and a three-layered amniotic membrane graft with fibrin glue. An 18-year-old female presented with impaired vision and ocular discomfort caused by a prominent dome-shaped limbal congenital dermoid on the inferotemporal cornea, resulting in a significant aesthetic concern. A full assessment, including refraction, best-corrected visual acuity (BCVA), corneal topography, aberrometry and anterior segment OCT (AS-OCT) was conducted to plan the surgical approach.
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