J T Daniels1, P T Khaw. 1. Wound Healing Research Unit, Institute of Ophthalmology, University College. Moorfields Eye Hospital, London, United Kingdom. j.daniels@ucl.ac.uk
Abstract
PURPOSE: To determine whether differentiating corneal epithelium can temporally stimulate fibroblast activity. METHODS: Corneal epithelial cells were cultured to confluence and then stimulated to mature into multilayered epithelia with addition of serum-containing medium. Differentiation was assessed morphologically and immunocytochemically using a monoclonal antibody to cytokeratin 3. At intervals after onset of differentiation serum-free conditioned medium was collected up to 28 days. Preliminary experiments deduced the optimum concentration of conditioned medium to be used for assessing fibroblast activity. Conditioned medium (25% vol/vol) was added to donor-matched corneal fibroblasts in migration chambers, WST-1 reagent proliferation assays, and fibroblast-populated collagen gel contraction assays. Platelet-derived growth factor (PGDF)-AB and interleukin (IL)-1beta in conditioned media were quantified by enzyme-linked immunosorbent assay (ELISA). Fibroblast migration and collagen contraction assays were performed with concentrations of PDGF-AB. RESULTS: Conditioned medium collected from differentiating epithelium stimulated fibroblast migration and collagen gel contraction, with activity peaks occurring with medium collected on day 14 (P < 0.05). No significant difference was detected between fibroblast growth rates in each of the conditioned media. Levels of PDGF-AB increased during epithelial culture up to 22 days (up to approximately 360 pg/ml) with a subsequent decrease by 28 days. IL-1beta inversely correlated with fibroblast activity induced by conditioned medium, with a trough in concentration (2 pg/ml) occurring at 14 days. Both fibroblast migration and collagen contraction were stimulated in a dose-dependent manner by PDGF-AB. CONCLUSIONS: Corneal epithelium is capable of temporally stimulating fibroblast wound-healing characteristics during its differentiation. One of the growth factors potentially involved in this epithelial-stromal interaction is PDGF. This work demonstrated that developing epithelium (possibly similar to repairing epithelium in vivo) regulated fibroblast behavior and may indicate a mechanism of fibroblast recruitment to a wound after epithelial closure.
PURPOSE: To determine whether differentiating corneal epithelium can temporally stimulate fibroblast activity. METHODS: Corneal epithelial cells were cultured to confluence and then stimulated to mature into multilayered epithelia with addition of serum-containing medium. Differentiation was assessed morphologically and immunocytochemically using a monoclonal antibody to cytokeratin 3. At intervals after onset of differentiation serum-free conditioned medium was collected up to 28 days. Preliminary experiments deduced the optimum concentration of conditioned medium to be used for assessing fibroblast activity. Conditioned medium (25% vol/vol) was added to donor-matched corneal fibroblasts in migration chambers, WST-1 reagent proliferation assays, and fibroblast-populated collagen gel contraction assays. Platelet-derived growth factor (PGDF)-AB and interleukin (IL)-1beta in conditioned media were quantified by enzyme-linked immunosorbent assay (ELISA). Fibroblast migration and collagen contraction assays were performed with concentrations of PDGF-AB. RESULTS: Conditioned medium collected from differentiating epithelium stimulated fibroblast migration and collagen gel contraction, with activity peaks occurring with medium collected on day 14 (P < 0.05). No significant difference was detected between fibroblast growth rates in each of the conditioned media. Levels of PDGF-AB increased during epithelial culture up to 22 days (up to approximately 360 pg/ml) with a subsequent decrease by 28 days. IL-1beta inversely correlated with fibroblast activity induced by conditioned medium, with a trough in concentration (2 pg/ml) occurring at 14 days. Both fibroblast migration and collagen contraction were stimulated in a dose-dependent manner by PDGF-AB. CONCLUSIONS: Corneal epithelium is capable of temporally stimulating fibroblast wound-healing characteristics during its differentiation. One of the growth factors potentially involved in this epithelial-stromal interaction is PDGF. This work demonstrated that developing epithelium (possibly similar to repairing epithelium in vivo) regulated fibroblast behavior and may indicate a mechanism of fibroblast recruitment to a wound after epithelial closure.
Authors: Julie T Daniels; Gregory S Schultz; Timothy D Blalock; Qian Garrett; Gary R Grotendorst; Nicholas M Dean; Peng T Khaw Journal: Am J Pathol Date: 2003-11 Impact factor: 4.307