The regulation of type-I collagen synthesis by insulin-like growth factor-I in human osteoblast-like SaOS-2 cells

1996 ◽  
Vol 433 (1-2) ◽  
pp. 123-128 ◽  
Author(s):  
Y. Kudo ◽  
Mitsutoshi Iwashita ◽  
Tomiko Iguchi ◽  
Yoshihiko Takeda
Keyword(s):  
Growth Factor ◽  
Collagen Synthesis ◽  
Type I Collagen ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Human Osteoblast ◽  
Factor I ◽  
Growth Factor I

scholarly journals Age-related changes in effects of insulin-like growth factor I on human osteoblast-like cells

1997 ◽  
Vol 324 (3) ◽  
pp. 753-760 ◽  
Author(s):  
Patricia Y. d'AVIS ◽  
Chester R. FRAZIER ◽  
Jay R. SHAPIRO ◽  
Neal S. FEDARKO
Keyword(s):  
Extracellular Matrix ◽  
Steady State ◽  
Growth Factor ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Human Osteoblast ◽  
Factor I ◽  
Igf I ◽  
Age Dependent ◽  
Growth Factor I

The role of insulin-like growth factor I (IGF-I) in extracellular matrix metabolism was studied in both proliferating and confluent human osteoblast-like cultures derived from donors of different ages. In proliferating cultures, recombinant human (rh)IGF-I was found to increase the incorporation of [3H]thymidine in a dose- and age-dependent manner. To study cell proliferation dynamically, continuous growth curves with and without rhIGF-I were modelled by a modified logistic function. Increasing doses of rhIGF-I decreased the lag time and maximal growth rates, whereas plateau values decreased only at the highest dose (100 ng/ml). In post-proliferative cell strains, rhIGF-I (0.1–100 ng/ml) increased levels of type I collagen, biglycan and decorin, and to a smaller extent fibronectin and thrombospondin, whereas it decreased the levels of hyaluronan and a versican-like proteoglycan when protein and proteoglycan metabolism were followed by steady-state radiolabelling with [3H]proline, [3H]glucosamine or [35S]sulphate. These responses to rhIGF-I were found to be age-dependent, with osteoblast-like cells derived from younger patients being more responsive to rhIGF-I. When extracellular matrix turnover was analysed by pulse–chase experiments, rhIGF-I had no effect. The steady-state levels of collagen, decorin, hyaluronan and a versican-like proteoglycan for bone cells treated with rhIGF-I on day 7 in culture were equivalent to levels of these matrix components in untreated osteoblasts grown for 14 days. These results are consistent with rhIGF-I's altering cellular proliferative capacity and matrix synthesis, causing a change in the osteoblast differentiated state.

Insulin-like growth factor-I attenuates the inhibitory effect of type I collagen through β1 integrin receptor

2005 ◽  
Vol 336 (3) ◽  
pp. 836-841 ◽  
Author(s):  
Niraporn Chutivongse ◽  
Piyamas Sumrejkanchanakij ◽  
Tussanee Yongchaitrakul ◽  
Prasit Pavasant
Keyword(s):  
Growth Factor ◽  
Type I Collagen ◽  
Inhibitory Effect ◽  
Type I ◽  
Β1 Integrin ◽  
Insulin Like Growth Factor ◽  
Integrin Receptor ◽  
Factor I ◽  
Growth Factor I

Insulin-like growth factor I enhances the formation of type I collagen in hydrocortisone-treated human osteoblasts

1993 ◽  
Vol 13 (5) ◽  
pp. 297-302 ◽  
Author(s):  
Kenneth B. Jonsson ◽  
Sverker Ljunghall ◽  
Olle Karlström ◽  
Anna G. Johansson ◽  
Hans Mallmin ◽  
...  
Keyword(s):  
Growth Factor ◽  
Type I Collagen ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Human Osteoblasts ◽  
Factor I ◽  
Type I Procollagen ◽  
Igf I ◽  
Growth Factor I ◽  
Selective Effects

We have studied the effect of insulin-like growth factor I (IGF-I) on the formation of osteocalcin and type I collagen in isolated human osteoblasts. IGF-I at and above 0.1 nM stimulated the formation of type I collagen as measured by the type I procollagen carboxyterminal peptide (PICP), in human osteoblasts, incubated for 72 hrs in serumfree conditions. The secretion of osteocalcin was not affected by IGF-I while 1,25(OH)2 vitamin D3 significantly enhanced the formation of osteocalcin. When human osteoblast-like cells were incubated with hydrocortisone (1 μM), a significant decrease in the release of both PICP and osteocalcin was seen. Addition of IGF-I to human osteoblasts also treated with hydrocortisone normalized the PICP-formation but did not affect the suppressed osteocalcin-formation. These data indicate that IGF-I reverses selective effects of hydrocortisone on bone.

scholarly journals A Polymorphism in Type I Deiodinase Is Associated with Circulating Free Insulin-Like Growth Factor I Levels and Body Composition in Humans

2005 ◽  
Vol 90 (1) ◽  
pp. 256-263 ◽  
Author(s):  
Robin P. Peeters ◽  
Annewieke W. van den Beld ◽  
Hans van Toor ◽  
Andre G. Uitterlinden ◽  
Joop A. M. J. L. Janssen ◽  
...  
Keyword(s):  
Body Composition ◽  
Growth Factor ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Free Insulin ◽  
Growth Factor I

scholarly journals Purified hybrid insulin/insulin-like growth factor-I receptors bind insulin-like growth factor-I, but not insulin, with high affinity

1993 ◽  
Vol 290 (2) ◽  
pp. 419-426 ◽  
Author(s):  
M A Soos ◽  
C E Field ◽  
K Siddle
Keyword(s):  
Monoclonal Antibody ◽  
Growth Factor ◽  
Insulin Receptors ◽  
Beta Subunit ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf Receptors ◽  
Igf I ◽  
Growth Factor I

Hybrid insulin/insulin-like growth factor-I (IGF-I) receptors have previously been described in human placenta, but it has not been possible to study their properties in the presence of classical insulin receptors and type I IGF receptors. To facilitate the purification of hybrids, we produced an anti-peptide monoclonal antibody IGFR 1-2, directed against the C-terminal peptide of the type I IGF receptor beta-subunit. The antibody bound native human and rat type I IGF receptors, and reacted specifically with the beta-subunit on immunoblots. Solubilized placental microsomal membranes were depleted of classical type I IGF receptors by incubation with an immobilized monoclonal antibody IGFR 24-55, which reacts well with type I receptors but very poorly with hybrid receptors. Residual hybrid receptors were then isolated by incubation with immobilized antibody IGFR 1-2, and recovered by elution with excess of synthetic peptide antigen. Binding properties of hybrids were compared with those of immuno-affinity-purified insulin receptors and type I IGF receptors, by using the radioligands 125I-IGF-I and 125I-insulin. Hybrids bound approx. 20 times as much 125I-IGF-I as 125I-insulin at tracer concentrations (approx. 0.1 nM). The binding of 125I-insulin, but not 125I-IGF-I, to hybrids increased after treatment with dithiothreitol to reduce disulphide bonds between the alpha-subunits. Hybrids behaved very similarly to type I receptors with respect to the inhibition of 125I-IGF-I binding by unlabelled IGF-I and insulin. By contrast, the affinity of hybrids for insulin was approx. 10-fold lower than that of classical insulin receptors, as assessed by inhibition of 125I-insulin binding by unlabelled hormone. It is concluded that the properties of insulin receptors, but not IGF receptors, are markedly affected by assembly as hybrid compared with classical structures, and that hybrids are more likely to be responsive to IGF-I than insulin under physiological conditions.

Sign in / Sign up

Export Citation Format

Share Document