So-called biological dressing effects of cultured epidermal sheets are mediated by the production of EGF family, TGF-beta and VEGF.
BACKGROUND
Cultured epidermal sheet (CES) grafts accelerate wound healing as a result of so-called biological dressing effect, which is thought to be mediated by various growth factors. However, the profile of growth factor expression in CESs is unclear.


OBJECTIVE
To investigate whether CESs produce growth factors along with stratification we investigated the production of growth factors and their regulation in CESs.


METHODS
CESs conditioned medium was harvested and the concentration of TGF-alpha, TGF-beta1, TGF-beta2, and VEGF was measured using ELISA. The mRNA of EGF family, TGF-beta family and VEGF was detected by Northern blot or RNase protection assay.


RESULTS
The concentration of TGF-alpha was 100 pg/ml in the monolayer culture, but dramatically increased to 600 pg/ml 2 days after stratification. It decreased to baseline, and then gradually increased to 300 pg/ml in the presence of EGF and remained at that level until day 20. TGF-beta1 increased from 50 to 400 pg/ml after stratification, and remained at that level day 20. TGF-beta2 was undetectable in the monolayer culture, but dramatically increased to 200 pg/ml 2 days after stratification. Unlike TGF-beta1, TGF-beta2 gradually increased over time after stratification. VEGF increased with stratification from 500 to 1500 pg/ml. The addition of EGF upregulated EGF family, TGF-beta, and VEGF production in CESs, as confirmed by ELISA, Northern blot, and RNase protection assay.


CONCLUSIONS
These results indicate that so-called biological dressing effect of CESs is mediated by production of the EGF family, TGF-beta, and VEGF. Our results also demonstrate the ability of EGF to enhance growth factor production in CESs.
D001684:Biological Dressings; D002478:Cells, Cultured; D003470:Culture Media / Q000737:chemistry; D004815:Epidermal Growth Factor / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D004817:Epidermis / Q000502:physiology*; D006801:Humans; D005810:Multigene Family; D020033:Protein Isoforms / Q000032:analysis / Q000096:biosynthesis; D016212:Transforming Growth Factor beta / Q000032:analysis / Q000096:biosynthesis; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis / Q000096:biosynthesis
D003470:Culture Media; D020033:Protein Isoforms; C508960:TGFB1 protein, human; C509041:TGFB2 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; D042461:Vascular Endothelial Growth Factor A; D004815:Epidermal Growth Factor