Insulin-like growth factor (IGF) receptors and mediation of somatic growth

1984 ◽  
Vol 20 (6) ◽  
pp. 1419
Author(s):  
Peter Nissley
Keyword(s):  
Growth Factor ◽  
Somatic Growth ◽  
Insulin Like Growth Factor ◽  
Igf Receptors

Effects of environmental salinity on somatic growth and growth hormone/insulin-like growth factor-I axis in juvenile tilapia Oreochromis mossambicus

2007 ◽  
Vol 73 (5) ◽  
pp. 1025-1034 ◽  
Author(s):  
Sameh MAGDELDIN ◽  
Katsuhisa UCHIDA ◽  
Tetsuya HIRANO ◽  
E Gordon GRAU ◽  
Ahmed ABDELFATTAH ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Somatic Growth ◽  
Oreochromis Mossambicus ◽  
Insulin Like Growth Factor ◽  
Environmental Salinity ◽  
Factor I ◽  
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.

Structural, gene expression, and functional analysis of the fugu (Takifugu rubripes) insulin-like growth factor binding protein-4 gene

2009 ◽  
Vol 296 (3) ◽  
pp. R558-R566 ◽  
Author(s):  
Mingyu Li ◽  
Yun Li ◽  
Ling Lu ◽  
Xianlei Wang ◽  
Qingli Gong ◽  
...  
Keyword(s):  
Growth Factor ◽  
Expression Patterns ◽  
Biological Action ◽  
Takifugu Rubripes ◽  
Insulin Like Growth Factor ◽  
Igf Binding Proteins ◽  
Physiological Regulation ◽  
Functional Conservation ◽  
Igf Receptors ◽  
And Function

The insulin-like growth factor (IGF) signaling pathway is a conserved pathway that regulates animal development, growth, metabolism, reproduction, and aging. The biological actions of IGFs are modulated by IGF-binding proteins (IGFBPs). Although the structure and function of fish IGFBP-1, -2, -3, and -5 have been elucidated, there is currently no report on the full-length structure of a fish IGFBP-4 nor its biological action. In this study, we cloned and characterized the IGFBP-4 gene from fugu. Sequence comparison, phylogenetic, and synteny analyses indicate that its chromosomal location, gene, and protein structure are similar to its mammalian orthologs. Fugu IGFBP-4 mRNA was easily detectable in all adult tissues examined with the exception of spleen. Older animals tended to have higher levels of IGFBP-4 mRNA in the muscle and eyes compared with younger animals. Starvation resulted in significant increases in IGFBP-4 mRNA abundance in the muscle, liver, gallbladder, and brain. Overexpression of fugu and human IGFBP-4 in zebrafish embryos caused a significant decrease in body size and somite number, suggesting that fugu IGFBP-4 inhibits growth and development, possibly by binding to IGFs and inhibiting their binding to the IGF receptors. These results provide new information about the structural and functional conservation, expression patterns, and physiological regulation of the IGFBP-4 gene in a teleost fish.

scholarly journals RAT C6 GLIAL CELLS EXPRESS INSULIN-LIKE GROWTH FACTOR (IGF) RECEPTORS AND SYNTHESIZE AND SECRETE IGF-I

1988 ◽  
Vol 23 (1) ◽  
pp. 107-107
Author(s):  
W Kiess ◽  
L Lee ◽  
D E Graham ◽  
L Greenstein ◽  
M M Reehler
Keyword(s):  
Growth Factor ◽  
Glial Cells ◽  
Insulin Like Growth Factor ◽  
Igf Receptors ◽  
Igf I

scholarly journals Delineation of atypical insulin receptors from classical insulin and type I insulin-like growth factor receptors in human placenta

1989 ◽  
Vol 257 (1) ◽  
pp. 101-107 ◽  
Author(s):  
H A Jonas ◽  
A J Cox ◽  
L C Harrison
Keyword(s):  
Growth Factor ◽  
Insulin Receptor ◽  
Human Placenta ◽  
Insulin Receptors ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Binding Properties ◽  
High Affinity ◽  
Igf Receptors ◽  
Placental Membranes

Insulin-like growth factor (IGF)-binding sites copurifying with human placental insulin receptors during insulin-affinity chromatography consist of two immunologically distinct populations. One reacts with monoclonal antibody alpha IR-3, but not with antibodies to the insulin receptor, and represents Type I IGF receptors; the other reacts only with antibodies to the insulin receptor and is precipitated with a polyclonal receptor antibody (B-10) after labelling with 125I-multiplication-stimulating activity (MSA, rat IGF-II). The latter is a unique sub-population of atypical insulin receptors which differ from classical insulin receptors by their unusually high affinity for MSA (Ka = 2 x 10(9) M-1 compared with 5 x 10(7) M-1) and relative potencies for insulin, MSA and IGF-I (40:5:1 compared with 150:4:1). They represent 10-20% of the total insulin receptor population and account for 25-50% of the 125I-MSA binding activity in Triton-solubilized placental membranes. Although atypical and classical insulin receptors are distinct, their immunological properties are very similar, as are their binding properties in response to dithiothreitol, storage at -20 degrees C and neuraminidase digestion. We conclude that atypical insulin receptors with moderately high affinity for IGFs co-exist with classical insulin receptors and Type I IGF receptors in human placenta. They provide an explanation for the unusual IGF-II binding properties of human placental membranes and may have a specific role in placental growth and/or function.

scholarly journals Overlap of Peak Growth Activity and Peak IGF-1 to IGFBP Ratio: Delayed Increase of IGFBPs Versus IGF-1 in Serum as a Mechanism to Speed up and down Postnatal Weight Gain in Mice

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1516 ◽  
Author(s):  
Michael Walz ◽  
Luong Chau ◽  
Christina Walz ◽  
Mandy Sawitzky ◽  
Daniela Ohde ◽  
...  
Keyword(s):  
Weight Gain ◽  
Growth Factor ◽  
Somatic Growth ◽  
Daily Weight Gain ◽  
Molar Ratio ◽  
Strong Increase ◽  
Insulin Like Growth Factor ◽  
Weight Gains ◽  
Growth Activity ◽  
Males And Females

Forced expression of insulin-like growth factor binding proteins (IGFBPs) in transgenic mice has clearly revealed inhibitory effects on somatic growth. However, by this approach, it cannot be solved if or how IGFBPs rule insulin-like growth factor (IGF)-dependent growth under normal conditions. In order to address this question, we have used growth-selected mouse models (obese and lean) and studied IGF-1 and IGFBPs in serum with respect to longitudinal growth activity in males and females compared with unselected controls. In mice of both genders, body weights were recorded and daily weight gains were calculated. Between 2 and 54 weeks of age, serum IGF-1 was determined by ELISA and intact IGFBP-2, -3 and -4 were quantified by Western ligand blotting. The molar ratio of IGF-1 to the sum of IGFBP-2 to -4 was calculated for all groups and plotted against the daily weight gain curve. Growth-selected mice are characterized by higher daily weight gains and extended periods of elevated growth activity if compared to matched unselected controls. Therefore, adult mice from the obese and lean groups can achieve more than twofold increased body weight in both genders (p < 0.001). Between 2 and 11 weeks of age, in obese and lean mice of both genders, serum IGF-1 concentrations are increased more prominently if compared to unselected controls (p < 0.001). Instead, substantial decreases of IGFBPs, particularly of IGFBP-2, are observed in males and females of all groups at the age of 2 to 4 weeks (p < 0.001). Due to the strong increase of IGF-1 but not of IGFBPs between two and four weeks of age, the ratio of IGF-1 to IGFBP-2 to -4 in serum significantly increased in all groups and genders (p < 0.05). Notably, the IGF-1 to IGFBP ratio was higher in male and female obese mice if compared to unselected controls (p < 0.05).

An acid-stable insulin-like growth factor (IGF)-binding protein from pig serum inhibits binding of IGF-I and IGF-II to vascular endothelial cells

1989 ◽  
Vol 120 (2) ◽  
pp. 231-236 ◽  
Author(s):  
R. Gopinath ◽  
P. E. Walton ◽  
T. D. Etherton
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Binding Protein ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Igf Receptors ◽  
Igf I ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Acid Stable

ABSTRACT The effects of a porcine insulin-like growth factor (IGF)-binding protein on binding of IGF-I and IGF-II to porcine aortic endothelial cells (PAEC) were determined. Binding of 125I-labelled IGF-I and -II to IGF receptors was inhibited by IGF-binding protein. IGF-binding protein inhibited binding of IGF-I and -II in a dose-dependent manner with half-maximal inhibition occurring at 5·43 and 108 μg/l respectively. A125I-labelled IGF-I–IGF-binding protein complex, formed by incubating 125I-labelled IGF-I with IGF-binding protein overnight at 4 °C, did not effectively bind to endothelial IGF receptors. Addition of IGF-binding protein to PAEC previously incubated with IGF-I caused a marked dissociation of bound IGF-I (47% dissociation within 12 h). These results indicate that the acid-stable IGF-binding protein which appears to be a part of the 150 kDa GH-dependent binding protein, blocks binding of IGF-I and -II by the IGF receptors and appears to exhibit a higher affinity for IGF-I than the endothelial type-I IGF receptor. The ramifications of this latter point with respect to transfer of circulating IGFs (bound to their IGF-binding proteins) across the vascular endothelium are not clear. Journal of Endocrinology (1989) 120, 231–236

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