Effect of recombinant IGF binding protein-1 on primary cultures of human keratinocytes and fibroblasts: selective enhancement of IGF-1 but not IGF-2-induced cell proliferation.
The present report describes the mitogenic effect of recombinant IGF-2 on cultured human keratinocytes and fibroblasts compared to that of IGF-1. Furthermore, the modulating effect of a recently expressed recombinant form of placental-derived IGF-binding protein 1 (IGFBP-1) on IGF-induced proliferation was examined. A dose-dependent increase, up to 100%, in cell proliferation was seen in cultured human keratinocytes with IGF-2 and -1 and the proliferative response was comparable to the effect of epidermal growth factor (EGF). In human fibroblasts, IGF-1 stimulated DNA synthesis up to 300% for IGF-1 and up to 200% for IGF-2. The mitogenic effect of IGF-1 was enhanced by IGFBP-1 in both cell types. In contrast, the IGF-2-induced mitogenic effect was unperturbed. These findings indicate that the interaction between IGFs and their binding proteins may induce different responses depending upon the ligand and the target cell.
Kratz
G
G
Department of Anatomy, Karolinska Institute, Stockholm, Sweden.
Lake
M
M
Ljungström
K
K
Forsberg
G
G
Haegerstrand
A
A
Gidlund
M
M
D015153:Blotting, Western; D002352:Carrier Proteins / Q000502:physiology*; D002455:Cell Division / Q000502:physiology*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D007335:Insulin-Like Growth Factor II / Q000502:physiology*; D015603:Keratinocytes / Q000166:cytology; D011994:Recombinant Proteins / Q000494:pharmacology
D002352:Carrier Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II