Epidermal growth factor effect on lipopolysaccharide-induced inflammation in fibroblasts derived from diabetic foot ulcer.

In this research article, we analyse the putative anti-inflammatory effect of epidermal growth factor (EGF) on fibroblast isolated from diabetic foot ulcer (DFU) granulation tissue. To induce the inflammatory response, the cells were treated with lipopolysaccharide (LPS), simulating the gram-negative bacterial infection that takes place in the wounds of diabetic patients. We studied the expression of genes involved in bacterial recognition receptors signalling pathway and those that code for different pro-inflammatory cytokines.We obtained primary fibroblasts from biopsies of a neuropathic diabetic ulcer and from healthy skin, the former was used as the control. Cells were isolated and grown in high glucose Dulbecco's Modified Eagle Medium (DMEM) culture medium, to simulate the hyperglycaemic insult. The effect of increasing concentrations of LPS on cell proliferation was analysed. Relative transcriptional expression of genes in the study was quantified by quantitative polymerase chain reaction (qPCR) in cells treated with LPS, EGF or a combination. Untreated cells served to normalise the expression.In the present study, we demonstrated that EGF modulated the primary immune response by reducing the activation of pathogen-recognition receptors and common genes involved in these signalling pathways, even in hyperglycaemic conditions. This effect translated in a decreased expression of pro-inflammatory cytokines. These results contribute to explain our previous observations about the reduction of circulating levels of inflammatory cytokines after local administration of human recombinant EGF in DFU. Further molecular studies should be carried out to fully understand the biological mechanisms elicited by EGF in this clinical scenario.