Insulin-like growth factor-binding protein (IGFBP)-3 contains a highly basic COOH-terminal heparin-binding region, the P3 region, which is thought to be important in the binding of IGFBP-3 to endothelial cells. IGFBP-3 and IGFBP-4, and their chimeras IGFBP-3(4) and IGFBP-4(3), were treated with plasmin and with thrombin, proteases known to cleave IGFBP-3. IGFBP-3 was highly susceptible to plasm...

Human intestinal smooth muscle in culture produces insulin-like growth factor (IGF)-I and IGF binding protein (IGFBP)-3, IGFBP-4, and IGFBP-5, which modulate the effects of IGF-I. This study examined the regulation of IGFBP production by endogenous IGF-I. R3-IGF-I, an agonist unaffected by IGFBPs, elicited concentration-dependent increase in growth, measured by [(3)H]thymidine incorporation, an...

Adjuvant arthritis is an animal model of rheumatoid arthritis that decreases liver and circulating IGF-I as well as skeletal muscle mass. The aim of this work was to elucidate whether IGF-I administration was able to prevent the effect of arthritis on body weight and on two skeletal muscles, gastrocnemius and soleus. On day 4 after adjuvant injection, control and arthritic rats were treated wit...

CONTEXT Acid-labile subunit (ALS) deficiency due to homozygous inactivation of the ALS gene (IGFALS) is associated with moderate short stature, and in few cases pubertal delay. The clinical expression of heterozygosity is unknown. OBJECTIVE To investigate the clinical, laboratory, and radiological features of homozygous and heterozygous carriers of a novel mutation in the ALS gene in comparis...

Background Epidemiologic evidence shows that obesity is associated with a greater risk of aggressive prostate cancer (PCa) and PCa-specific mortality and this is observed mainly in men with the TMPRSS2-ERG gene fusion. Obesity is often associated with comorbid conditions such as type 2 diabetes and hyperglycemia: we investigated whether some of the exposures associated with disturbed metabolism...

Insulin-like growth factor I (IGF-I) is a potent mitogen for both normal and transformed mammary epithelial cells (MEC), and IGF-binding protein-3 (IGFBP-3) potentiates IGF-I action in these cells. The synthesis of IGFBP-3 is stimulated by both IGF-I and agents that increase intracellular cAMP (e.g. forskolin) in the bovine MEC line MAC-T. In addition, the combination of IGF-I and cAMP increase...

The insulin-like growth factors (IGFs) stimulate mitogenesis in a variety of cell types both in vitro and in vivo. These effects are mediated by both IGF receptors and a family of IGF binding proteins (IGFBPs), which are found complexed with the IGFs in serum and tissue fluids. Here we compare the sites of expression during early rat embryogenesis of the genes encoding the RGD-containing IGF bi...

Kuemmerle, John F. Endogenous IGF-I regulates IGF binding protein production in human intestinal smooth muscle cells. Am J Physiol Gastrointest Liver Physiol 278: G710– G717, 2000.—Human intestinal smooth muscle in culture produces insulin-like growth factor (IGF)-I and IGF binding protein (IGFBP)-3, IGFBP-4, and IGFBP-5, which modulate the effects of IGF-I. This study examined the regulation o...

Insulin-like growth factor-I (IGF-I)-mediated growth of cells can be modulated by specific IGF binding proteins (IGFBPs) that inhibit or augment IGF-I ligand-receptor interaction. IGFBP expression and production by human intestinal muscle cells in culture was characterized in rapidly growing cells ( day 3 of culture), in confluent cells ( day 7), and in postconfluent cells ( day 14). RT-PCR ana...

The hypoglycemic potential of circulating IGFs is thought to be regulated through the formation of ternary complexes consisting of an IGF, either IGF binding protein-3 (IGFBP-3) or IGFBP-5, and the acid-labile subunit. These high molecular weight complexes are confined to the circulation and represent a reservoir of IGF with a prolonged half-life. In this study, we show that hypoglycemia, induc...