These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Insulin-like growth factor-binding proteins (IGF-BPs) produced by human skin fibroblasts: immunological relationship to other human IGF-BPs.
    Author: Martin JL, Baxter RC.
    Journal: Endocrinology; 1988 Oct; 123(4):1907-15. PubMed ID: 2970958.
    Abstract:
    We have characterized the insulin-like growth factor-binding protein (IGF-BP) produced by neonatal human skin fibroblasts in monolayer culture using antibodies specific for the acid-stable subunit of the 150K GH-dependent IGF-BP complex, BP-53, and the amniotic fluid IGF-BP, BP-28. Fibroblasts produced 65.3 +/- 10.4 ng/ml.72 h (SE; n = 6) immunoreactive BP-53 in serum-free medium; this was stimulated by increasing fetal bovine serum in the medium up to 385.3 +/- 49.0 ng/ml.72 h at 10% serum. Epidermal growth factor (EGF) also caused dose-dependent stimulation of BP-53 production, with a maximal effect (3-fold increase) at 30 ng/ml EGF. No immunoreactive BP-28 production was detectable in the presence or absence of serum or EGF. Neutral gel chromatography of serum-free medium revealed a peak of immunoreactive BP-53 at about 50K, with a smaller species at 20-30 K. Serum- and EGF-stimulated cells produced higher levels of about 50K BP-53, and an additional peak of immunoreactivity at 150K was present in serum-stimulated, but not EGF-stimulated, samples. Comparison of IGF-I and IGF-II binding by fibroblast BP-53 revealed slightly higher IGF-II than IGF-I binding, and association constants of 3-4 x 10(10) liter/mol for both IGFs, similar to BP-53 from human plasma. Affinity labeling of acid-stripped medium followed by nonreduced sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed specifically cross-linked IGF-binding species of 60K (identical to labeled plasma BP-53), 42K, and 37K. Only the 60K and 42K complexes were precipitable by antiserum to plasma BP-53, and none was precipitable by anti-BP-28 serum, suggesting that the 37K band might represent a third class of IGF-BP. We conclude that neonatal skin fibroblasts produce no BP-28, but do produce two IGF-BPs immunologically homologous to human plasma BP-53, one of which shows size and IGF-binding characteristics identical to the plasma protein.
    [Abstract] [Full Text] [Related] [New Search]