scholarly journals Inflammation is a modulator of the insulin-like growth factor (IGF)/IGF-binding protein system inducing reduced bioactivity of IGFs in cystic fibrosis

2006 ◽  
Vol 154 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Maria E Street ◽  
Maria A Ziveri ◽  
Cinzia Spaggiari ◽  
Isabella Viani ◽  
Cecilia Volta ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Growth Factor ◽  
Binding Protein ◽  
Serum Insulin ◽  
Molecular Forms ◽  
Insulin Like Growth Factor ◽  
Serum Concentrations ◽  
C Peptide ◽  
Igf I ◽  
Igfbp 3

Objective: In inflammatory bowel diseases, increased serum interleukin (IL)-6 levels are associated with high serum insulin-like growth factor-binding protein 2 (IGFBP-2) levels, and cytokines modify the insulin-like growth factor (IGF)/IGFBP system in models in vitro. In cystic fibrosis (CF) the IGF/IGFBP system has not been extensively studied, and relationships with proinflammatory cytokines have not been explored. The aim of this study was to investigate the IGF/IGFBP system and verify changes dependent on IL-1β, IL-6, tumour necrosis factor α (TNFα), and insulin. Methods: Eighteen subjects with CF (mean age 26.6 ± 1.1 years) and 18 controls, comparable for age, sex, and body mass index, were enrolled. Serum IGF-I, IGF-II, IGFBP-2, IGFBP-3, IL-1β, IL-6, TNFα, insulin and C-peptide were measured. Different molecular forms of IGFBP-2 and IGFBP-3 were investigated by Western immunoblotting. The patients were analysed as a whole and as two subgroups depending on established clinical criteria (Swachman–Kulczycki score). Results: Patients had higher serum concentrations of IL-1β, IL-6, TNFα and IGFBP-2 than controls. Serum concentrations of IGF-I and IGF-II were significantly lower and insulin and C-peptide levels significantly increased in CF compared with healthy controls whereas IGFBP-3 serum concentrations were similar, with comparable IGF-I/IGFBP-3 and decreased IGF-I/IGFBP-2 and IGF-II/IGFBP-2 molar ratios. From correlation analysis we detected a significant positive correlation between IGFBP-2 and IL-6 and a negative correlation between IGFBP-2 and IGFBP-3. Conclusions: Our findings suggest that inflammation is an important modulator of the IGF/IGFBP system with an overall reduction in IGF bioactivity in CF.

Long-term treatment of Laron type dwarfs with insulin-like growth factor-1 increases serum insulin-like growth factor-binding protein-3 in the absence of growth hormone activity

1993 ◽  
Vol 128 (2) ◽  
pp. 144-149 ◽  
Author(s):  
Hannah Kanety ◽  
Avraham Karasik ◽  
Beatrice Klinger ◽  
Aviva Silbergeld ◽  
Zvi Laron
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Binding Protein ◽  
Serum Insulin ◽  
Continuous Treatment ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Long Term Treatment ◽  
Igf I ◽  
Igfbp 3

Insulin-like growth factor binding protein-3 (IGFBP-3) is the major carrier of insulin-like growth factor I (IGF-1) in serum, and its production is growth hormone (GH) dependent. It is unclear whether in humans IGFBP-3 production is directly regulated by GH or mediated via IGF-I. We addressed this question in six patients with Laron-type dwarfism, a syndrome characterized by the absence of GH receptor activity (LTD), who were chronically treated with recombinant IGF-I. Analysis of the electrophoretic profiles of serum IGFBPs in these patients by Western ligand blotting revealed an extremely low IGFBP-3 level. A striking progressive increase in serum IGFBP-3 was observed with continuous treatment, despite the absence of GH action. In LTD children, serum IGFBP-3 increased up to 19-fold after six months of therapy and equalled levels observed in controls, whereas in adult LTD patients the increase was smaller. A rise in serum levels of 34, 30 and 24 kDa BPs (presumably IGFBP-2, -1 and -4, respectively was also noted with chronic IGF-I therapy. This proof of GH-independent induction of IGFBP-3 by IGF-1 may be a major advantage in the therapeutic use of biosynthetic IGF-I in several types of short stature children.

Specimen processing time and measurement of total insulin-like growth factor-I (IGF-I), free IGF-I, and IGF binding protein-3 (IGFBP-3)

2006 ◽  
Vol 16 (2) ◽  
pp. 86-92 ◽  
Author(s):  
Tiffany G. Harris ◽  
Howard D. Strickler ◽  
Herbert Yu ◽  
Michael N. Pollak ◽  
E. Scott Monrad ◽  
...  
Keyword(s):  
Growth Factor ◽  
Processing Time ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Specimen Processing ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Igfbp 3

scholarly journals Genetic Determinants of Circulating Insulin-Like Growth Factor (IGF)-I, IGF Binding Protein (BP)-1, and IGFBP-3 Levels in a Multiethnic Population

2007 ◽  
Vol 92 (9) ◽  
pp. 3660-3666 ◽  
Author(s):  
Iona Cheng ◽  
Katherine DeLellis Henderson ◽  
Christopher A. Haiman ◽  
Laurence N. Kolonel ◽  
Brian E. Henderson ◽  
...  
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Genetic Determinants ◽  
Igf I ◽  
Igf Binding ◽  
Multiethnic Population ◽  
Igf Binding Protein ◽  
Igfbp 3

Measurement of Human Igf-II Using Sephacryl Extraction: A Rapid and Reliable Assay Method

1996 ◽  
Vol 33 (3) ◽  
pp. 201-208 ◽  
Author(s):  
Barbara H Mason ◽  
Michele A Tatnell ◽  
Ian M Holdaway
Keyword(s):  
Growth Factor ◽  
Binding Proteins ◽  
Complete Removal ◽  
Assay Method ◽  
Insulin Like Growth Factor ◽  
Serum Concentrations ◽  
Igf Binding Proteins ◽  
Factor Ii ◽  
Igf I ◽  
Igfbp 3

Measurement of insulin-like growth factor II (IGF-II) in human serum is complicated by the presence of IGF binding proteins and usually involves cumbersome extraction procedures followed by radioimmunoassay. We have utilized an extraction process developed for measuring insulin-like growth factor II in ovine serum using Sephacryl HR100, and have applied this to the extraction of human samples followed by radioimmunoassay for human IGF-II. The assay yielded 98% recovery of unlabelled IGF-II, parallelism between dilutions of eluate and the standard curve, complete removal of binding proteins and near-complete removal of IGF-I, and intra- and interassay coefficients of variation of 5% and 9%, respectively. The normal range for serum IGF-II in women was 490–1056 μg/L, and IGF-II levels were positively correlated with serum concentrations of insulin-like growth factor binding protein-3 (IGFBP-3) but not with IGF-I levels. Mean serum concentrations of IGF-II were reduced below normal in a number of hypopituitary patients and children with short stature and IGF-II concentrations in these subjects correlated positively with IGF-I and IGFBP-3. In acromegalic patients IGF-II levels were usually normal and were negatively correlated with IGF-I concentrations. From our experience with the above results the present assay appears particularly suitable for clinical measurements and research projects where high sample throughput is required.

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