Abstract
Abstract: :
Purpose:Interactions between epithelial cells and keratocytes are important to maintain a healthy cornea and its ability to respond to an insult. We have assessed cytokine production, as an indication of intercellular communication, following chemical insults in tissue culture models of stratified epithelia with and without a stromal construct. Methods:Using immortalized human corneal cells, epithelial models were built and stratified at the air–liquid interface in a fully defined medium. Models were also built with the epithelium stratified on top of a collagen gel seeded with primary human keratocytes from donor eyes. The stratified constructs were treated for 10 min with NaOH (Sigma, Seelze, Germany), sodium dodecyl sulfate (SLS, Merck, Darmstadt, Germany) and TomadolTM 45–7 (Tomadol, Tomah3, Los Angeles, USA) at a concentration of 0.66%. Cytokine production was assessed using Human Cytometric Bead Array kits (BD Biosciences) as well as fluorescein leakage, LDH release, protein and metabolic assays. Results:IL–8 and IL–6 were detected in the Araki–Sasaki cell line, whilst IL–10, 8, 6 and 12p70 was produced by the USA line. The cytokine responses were different with different toxicants. On addition of a stromal layer to the USA epithelium, IL–8 production increased ten–fold, whilst there was a four–fold increase in IL–6. The stromal constructs without an epithelium did not produce any measurable cytokines. The response following chemical injury was also changed if the epithelium was grown on a stromal layer. Conclusions:Different corneal cell lines behave differently with respect to cytokine production. Upon addition of further layers to the constructs cytokine patterns changed, implying communication between the layers.
Keywords: ocular irritancy/toxicity testing • wound healing • cytokines/chemokines