Paracrine stimulation of keratinocytes in vitro and continuous delivery of epidermal growth factor to wounds in vivo by genetically modified fibroblasts transfected with a novel chimeric construct.
BACKGROUND
Growth factors play an important role in tissue repair. While the effectiveness of growth factor therapy in animal wound healing models and limited human clinical trials has been demonstrated, the ideal method for their administration to the wound remains unclear. Experimental data suggest that the continuous presence in the early stages of wound repair is beneficial.


METHODS
We have constructed a novel chimeric expression plasmid in which the biologically active portion of the human epidermal growth factor (EGF) gene is fused in-frame to the human granulocyte colony-stimulating factor signal sequence.


RESULTS
Clonally selected human fibroblasts transfected with this construct secrete biologically active EGF. After the transplantation of irradiated gene-transfected fibroblasts suspended in fibrin glue to murine full-thickness wounds, EGF can be demonstrated for at least seven days in the wounds, slowly decreasing from initially 470 pg/ml to 140 pg/ml on day 7. No EGF was found in the wound at day 14.


CONCLUSIONS
A single application of irradiated EGF genetransfected fibroblasts to wounds can thus continuously deliver the transgene in vivo and could be used to administer drugs to the wound bed during the crucial first seven days of wound-healing.
Rosenthal
F M
FM
Department of Medicine I Hematology/Oncology, University Medical Center Freiburg, Germany.
Cao
L
L
Tanczos
E
E
Kopp
J
J
Andree
C
C
Stark
G B
GB
Mertelsmann
R
R
Kulmburg
P
P
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004815:Epidermal Growth Factor / Q000235:genetics* / Q000378:metabolism; D005347:Fibroblasts / Q000502:physiology / Q000528:radiation effects / Q000637:transplantation; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects; D051379:Mice; D008819:Mice, Nude; D008969:Molecular Sequence Data; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D014945:Wound Healing / Q000502:physiology*
D011993:Recombinant Fusion Proteins; D004815:Epidermal Growth Factor