The expression levels of endogenous aFGF mRNA in microwave burn wound tissues and its clinical significance / 华中科技大学学报（医学）（英德文版）

The expression levels and changes of endogenous acid fibroblast growth factor (aFGF) in microwave burn wound tissues were detected in order to investigate how to get better therapeutic effects by using the exogenous aFGF for repairing trauma. A burnt-wound animal model was established by NS-F II multifunction spectrum therapeutics equipment, and reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry assay were applied to detect the expression levels of endogenous aFGF mRNA in microwave burn wound tissues. The expression level of endogenous aFGF mRNA was significantly increased in the burn wound tissues 12 h after burn, reached the peak at 48 h, and gradually deceased 96 h after burn. The expression of endogenous aFGF mRNA after tissue damage was reversible, and its intensity was in accordance with the repair process of tissue damage, suggesting endogenous aFGF may take part in the cell metabolism and proliferation, and then promote the repair of the burn wound.

Structure and function of fibroblast growth factor

We describe some structural requirements od the fibroblast growth factor (FGF) signaling system for the stimulation of the mitogenic response in terms of the design, synthesis and mitogenic activity of linear peptides related to the human FGF-1 sequence and the structural requirements of heparin for the potentiation of the mitogenic activity of FGF-1. The best mitogenic peptide we have synthesized so far is Ac-WFVGLKKNGSSKRGPRT-NH2, that has been shown: 1)to bind to heparin-Sepharose columns with moderate affinity, requiring about 0.5 M NaCl to be eluted from the resin; 2) to be mitogenic upon BALB/c 3T3 fibroblasts in culture (ED50=10-20 muM) and 3)to compete with human FGF-1 for cellular binding (ID50=30-50 muM). The potentiating activity of heparin upon FGF-1 has shown to be dependent on the oligosaccharide size, degree of sulfation and carboxylation. Apparently, these same requirements hold for the heparan sulfate molecules. Based on the reported studies, ee propose some important requirements of an oligosaccharide to potentiate FGF-1 mitogenic activity: 1) to have a minimum of twelve units, organized as disaccharides where one of the units is a uronic acid and the second is glycosamine; 2) to have at least one iduronic acid sulfated at position 2 and 3) to have N-sulfated glycosamines, preferentially 6-O-sulfated. To have groups of negative charges is not enough: they need to be localized in a correct conformation.