Overexpression of Insulin-like Growth Factor Binding Protein-3 by Senescent Human Fibroblasts: Attenuation of the Mitogenic Response to IGF-I

1995 ◽  
Vol 219 (2) ◽  
pp. 315-321 ◽  
Author(s):  
Vitalii G. Grigoriev ◽  
Elena J. Moerman ◽  
Samuel Goldstein
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
Human Fibroblasts ◽  
Insulin Like Growth Factor ◽  
Mitogenic Response ◽  
Factor Binding ◽  
Igf I

Influence of insulin-like growth factor-binding protein-2 on plasma clearance and transfer of insulin-like growth factors-I and -II from plasma into mammary-derived lymph and milk of goats

1996 ◽  
Vol 150 (1) ◽  
pp. 121-127 ◽  
Author(s):  
C G Prosser ◽  
J Schwander
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Plasma Clearance ◽  
Binding Protein ◽  
Plasma Concentrations ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Lactating Goats ◽  
Igf I ◽  
Insulin Like Growth Factors

Abstract Plasma clearance of insulin-like growth factors-I and -II (IGF-I and -II) and insulin-like growth factor-binding protein-2 (IGFBP-2) from lactating goats (n=4) was determined following a single intravenous injection of the corresponding 125I-labelled human protein. Transfer of these proteins out of the vascular space was monitored by their subsequent appearance in mammary-derived lymph and milk. Clearance of 125I-IGFBP-2 from circulation was 0·37 ± 0·06 ml/min/kg, which is markedly greater than that of 125I-IGF-I or -II (0·11 ± and 0·12 ± 0·01 ml/min/kg respectively). This was also reflected in longer elimination half-lives for IGF-I (353 ± 6 min) and -II (254 ± 8 min) compared with IGFBP-2 (110 ± 9 min). Three hours after injection of the 125I-labelled protein, the plasma:lymph ratio of trichloroacetic acid-precipitable radioactivity was 1·54 ±0·04, 3·3 ±0·6 and 4·1 ±0·4 for IGFBP-2, IGF-I and -II respectively. The form of 125I-IGFBP-2 in lymph was not different from that of plasma. Elevation of plasma concentrations of IGFBP-2 by its intravenous infusion significantly decreased plasma half-life of both IGF-I and -II (251 ± 8 and 198 ±7 min respectively). Although the amount and rate of transfer of IGF into mammary-derived lymph was decreased slightly by IGFBP-2, concentrations eventually obtained were not different from control. However, secretion of IGFs into milk was significantly reduced by IGFBP-2, particularly in the case of IGF-I. These results are consistent with the ability of all three compounds to cross the vascular endothelium intact and of IGFBP-2 to decrease the uptake of IGF by mammary epithelium and subsequent secretion into milk. IGFBP-2 may well have acted to target plasma IGF towards non-mammary tissues, thus explaining the more rapid plasma clearance of IGFs in the presence of elevated IGFBP-2. Journal of Endocrinology (1996) 150, 121–127

A homologous radioimmunoassay for ovine insulin-like growth factor-binding protein-2: ontogenesis and the response to growth hormone, placental lactogen and insulin-like growth factor-I treatment in sheep

1995 ◽  
Vol 144 (1) ◽  
pp. 75-82 ◽  
Author(s):  
B W Gallaher ◽  
B H Breier ◽  
W F Blum ◽  
S N McCutcheon ◽  
P D Gluckman
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Binding Protein ◽  
Negative Relationship ◽  
Serum Levels ◽  
Treated Group ◽  
Placental Lactogen ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Igf I

Abstract Although insulin-like growth factor-binding protein-2 (IGFBP-2) is an abundant IGFBP in fetal and postnatal plasma, its regulation is not yet clearly understood. To address this question in sheep, we purified ovine IGFBP-2 and developed a homologous radioimmunoassay. We have studied its ontogenesis and measured serum concentrations of ovine IGFBP-2 after bovine growth hormone (bGH), ovine placental lactogen (oPL) and IGF-I treatment. Concentrations of IGFBP-2 were high at 125 days of gestation (550 ± 15 μg/l) but fell after birth P<0·05) and plateaued after 1 year of age (340 ± 20 μg/l). In lactating ewes, bGH treatment for 7 days significantly reduced (21%; P<0·05) IGFBP-2 relative to the saline-treated group. Similarly, in neonatal lambs, bGH treatment from day 3 to day 23 of life reduced (P<0·05) IGFBP-2 by 23% relative to the saline-treated group. oPL had no effect on serum levels of IGFBP-2 in the ewe or the neonatal lamb. In well-fed yearling lambs, treatment with IGF-I reduced IGFBP-2 values by 27% (P<0·05) relative to control animals. In yearling lambs, reduced nutrition increased plasma IGFBP-2 (41%; P<0·05). However this increase was abolished by IGF-I treatment. The changes in plasma levels of IGFBP-2 were positively related to changes in IGF-II while there was a negative relationship between circulating IGF-I and IGFBP-2 such that both IGF-I and IGF-II may play a role in the regulation of IGFBP-2 in serum. Journal of Endocrinology (1995) 144, 75–82

Colocalization of insulin-like growth factor-binding protein with insulin-like growth factor I

1991 ◽  
Vol 261 (1) ◽  
pp. F22-F28 ◽  
Author(s):  
S. Kobayashi ◽  
D. R. Clemmons ◽  
M. A. Venkatachalam
Keyword(s):  
Growth Factor ◽  
Cultured Cells ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Intense Staining ◽  
Factor Binding ◽  
Factor I ◽  
Collecting Ducts ◽  
Igf I ◽  
Growth Factor I

We report the localization of insulin-like growth factor I (IGF-I) and a 25-kDa form of insulin-like growth factor-binding protein (IGF-BP-1) in adult rat kidney. The antigens were localized using a rabbit anti-human IGF-I antibody, and a rabbit anti-human IGF-BP-1 antibody raised against human 25-kDa IGF-BP-1 purified from amniotic fluid. Immunohistochemistry by the avidin-biotin peroxidase conjugate technique showed that both peptides are located in the same nephron segments, in the same cell types. The most intense staining was in papillary collecting ducts. There was moderate staining also in cortical collecting ducts and medullary thick ascending limbs of Henle's loop. In collecting ducts the antigens were shown to be present in principal cells but not in intercalated cells. In distal convoluted tubules, cortical thick ascending limbs, and in structures presumptively identified as thin limbs of Henle's loops there was only modest staining. The macula densa, however, lacked immunoreactivity. Colocalization of IGF-I and IGF-BP-1 in the same cells supports the notion, derived from studies on cultured cells, that the actions of IGF-I may be modified by IGF-BPs that are present in the same location.

scholarly journals Insulin-like growth factor binding protein-3 induces angiogenesis through IGF-I- and SphK1-dependent mechanisms

2007 ◽  
Vol 5 (4) ◽  
pp. 835-845 ◽  
Author(s):  
R. GRANATA ◽  
L. TROVATO ◽  
E. LUPIA ◽  
G. SALA ◽  
F. SETTANNI ◽  
...  
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Igf I

The concentration of insulin-like growth factor-I and insulin-like growth factor-binding protein-1 in human umbilical cord serum at delivery: relation to fetal weight

1991 ◽  
Vol 129 (3) ◽  
pp. 459-464 ◽  
Author(s):  
H. S. Wang ◽  
J. Lim ◽  
J. English ◽  
L. Irvine ◽  
T. Chard
Keyword(s):  
Growth Factor ◽  
Umbilical Cord ◽  
Fetal Growth ◽  
Gestational Age ◽  
Umbilical Artery ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Factor I ◽  
Igf I

ABSTRACT Serum levels of insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-1 (IGFBP-1) have been determined by radioimmunoassay in the maternal circulation (n = 91) and in the umbilical artery (n = 56) and vein (n = 90) of man. In both the umbilical artery and vein, the concentration of serum IGF-I showed an inverse correlation with birthweight (P < 0·005 and P < 0·001 respectively); the mean serum IGF-I levels in the small-for-gestational-age (SGA) group were significantly higher than those in average-for-gestational-age (AGA) neonates (P <0·01 and P < 0·001 respectively). However, maternal serum IGF-I showed no association with birthweight and there was no significant difference between the SGA and AGA groups. These observations imply that the production of IGF-I in the maternal and fetal compartments is independent and that there is unlikely to be transfer of IGF-I across the placenta. Serum IGFBP-1 levels in both maternal and umbilical cord blood (artery and vein) showed an inverse relation to birthweight (P <0·001, P<0·005 and P<0·001 respectively). Increased IGFBP-1 levels in the umbilical artery and vein were observed in the SGA group. These findings suggest that IGFBP-1 might inhibit the action of IGF-I in both the maternal and the fetal compartments and that the rise in IGFBP-1 could be a primary factor in retardation of fetal growth. Alternatively, circulating IGF-I and IGFBP-1 levels may only be a secondary reflection of local tissue events involved in fetal growth. Journal of Endocrinology (1991) 129, 459–464

Radioimmunoassay of insulin-like growth factor-binding protein-6 in human serum and other body fluids

1992 ◽  
Vol 134 (1) ◽  
pp. 133-139 ◽  
Author(s):  
R. C. Baxter ◽  
H. Saunders
Keyword(s):  
Cerebrospinal Fluid ◽  
Growth Factor ◽  
Human Serum ◽  
Follicular Fluid ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Igf I ◽  
The Mean ◽  
Igfbp 3

ABSTRACT A radioimmunoassay has been established for the insulin-like growth factor-binding protein, IGFBP-6, isolated from a human transformed fibroblast cell-line. The binding proteins IGFBP-I and IGFBP-3 did not cross-react, but both IGF-I and IGF-II markedly inhibited IGFBP-6 tracer binding to antiserum. This inhibition, greater for IGF-II than for IGF-I, was fully reversed by the addition of IGFBP-3 to sequester the IGFs. After fractionation of human serum and follicular fluid samples by gel chromatography, interference in the radioimmunoassay by fractions corresponding to the 150 kDa IGF-IGFBP complex could be eliminated by IGFBP-3. The equivalent fractions from cerebrospinal fluid and amniotic fluid fractionation did not interfere in the assay. The mean IGFBP-6 level in adult human serum was 0·221 ±0·110 mg/l, with values significantly higher in men than women, and slightly decreased in pregnancy. Similar values were seen in umbilical cord serum and in amniotic and follicular fluid samples, while the mean level in cerebrospinal fluid was slightly lower, 0·152±0·049 mg/l. This assay will facilitate studies on the regulation of IGFBP-6 production, and its role as an IGF carrier. Journal of Endocrinology (1992) 134, 133–139

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