◀ Back to IGF1
IGF1 — IGFBP4
Pathways - manually collected, often from reviews:
-
OpenBEL Selventa BEL large corpus:
IGF1
→
IGFBP4
(directlyDecreases)
Evidence: IGFBP-4 is an inhibitor of IGF-I in bone. We show that TGF-beta regulates IGFBP-4 and enhances IGF-I-stimulated growth of cultured human bone cells through increased expression of an IGFBP-4 protease, PAPP-A.
-
Reactome Reaction:
IGF1
→
IGFBP4
(reaction)
Lawrence et al., Proc Natl Acad Sci U S A 1999*, Qin et al., Arch Biochem Biophys 2000*, Byun et al., J Clin Endocrinol Metab 2001*, Laursen et al., Biochem J 2002*, Mohan et al., J Endocrinol 2002, Firth et al., Endocr Rev 2002, Zhou et al., J Endocrinol 2003*, Siwanowicz et al., Structure 2005*, Holly et al., Neuroendocrinology 2006, Gyrup et al., Biochemistry 2007*, Laursen et al., Mol Endocrinol 2007*, Arai et al., J Biol Chem 1994, Bach et al., J Biol Chem 1993, Cianfarani et al., Experientia 1993, Bach et al., Biochim Biophys Acta 1996
-
Reactome Reaction:
IGF1
→
IGFBP4
(direct_complex)
Mohan et al., J Endocrinol 2002, Firth et al., Endocr Rev 2002, Zhou et al., J Endocrinol 2003*, Siwanowicz et al., Structure 2005*, Holly et al., Neuroendocrinology 2006, Arai et al., J Biol Chem 1994, Bach et al., J Biol Chem 1993, Cianfarani et al., Experientia 1993, Bach et al., Biochim Biophys Acta 1996
Protein-Protein interactions - manually collected from original source literature:
Studies that report less than 10 interactions are marked with *
-
IRef Bind Interaction:
IGF1
—
IGFBP4
Siwanowicz et al., Structure 2005*
-
IRef Bind_translation Interaction:
IGF1
—
IGFBP4
(x-ray crystallography)
Siwanowicz et al., Structure 2005*
-
IRef Bind_translation Interaction:
IGF1
—
IGFBP4
(surface plasmon resonance)
Wong et al., Biochim Biophys Acta 1999
-
IRef Biogrid Interaction:
IGFBP4
—
IGF1
(direct interaction, pull down)
Bach et al., J Biol Chem 1993
-
IRef Biogrid Interaction:
IGFBP4
—
IGF1
(direct interaction, pull down)
Qin et al., J Biol Chem 1998*
-
IRef Dip Interaction:
IGFBP4
—
IGF1
(direct interaction, x-ray crystallography)
Siwanowicz et al., Structure 2005*
-
IRef Dip Interaction:
IGFBP4
—
IGF1
(direct interaction, isothermal titration calorimetry)
Siwanowicz et al., Structure 2005*
-
IRef Dip Interaction:
IGFBP4
—
IGF1
(direct interaction, molecular sieving)
Siwanowicz et al., Structure 2005*
-
IRef Hprd Interaction:
IGFBP4
—
IGF1
(in vitro)
Qin et al., J Biol Chem 1998*
-
IRef Ophid Interaction:
IGFBP4
—
IGF1
(aggregation, interologs mapping)
Brown et al., Bioinformatics 2005
-
IRef Ophid Interaction:
IGFBP4
—
IGF1
(aggregation, confirmational text mining)
Qin et al., J Biol Chem 1998*
Text-mined interactions from Literome
Spicer et al., Domest Anim Endocrinol 1999
:
In a third series of experiments,
IGFBP-3 inhibited
125I-IGF-I binding to granulosa cells
Henemyre et al., Mol Reprod Dev 1999
:
These results suggest that uterine
IGFBP-4 expression may not be
dependent on uterine
IGF-I expression
Fottner et al., Horm Metab Res 1999
:
In the present study, we therefore characterized the IGFBPs secreted by bovine adrenocortical cells in primary culture, and investigated the
effect of corticotropin ( ACTH ) and recombinant human
IGF-I and IGF-II on the regulation of
IGFBP synthesis
Gustafsson et al., Am J Physiol 1999
:
IGF-I stimulated gene expression of IGFBP-2 and
IGFBP-4
Wilson et al., Eur J Endocrinol 1999
:
Taken together, these data suggest that, in the monkey,
IGFBP-3 is regulated by factors in addition to GH, and that
IGF-I can
affect its own bioavailability by increasing circulating concentrations of IGFBP-3
Giannini et al., Mol Cell Endocrinol 1999
:
IGF-I increased IGFBP-3, IGFBP-2 and decreased
IGFBP-4 , while TGF-beta1 decreased IGFBP-3 and apparently increased IGFBP-4
Schams et al., Domest Anim Endocrinol 1999
:
Studies indicate that
IGFBP expression and production in the developing follicle is dependent on both cell type and follicle size and is
regulated by
IGF-1 and gonadotropins
Pattison et al., Mol Cell Endocrinol 1999
(Breast Neoplasms) :
By contrast,
IGFBP-3 phosphorylation in T47D ( BP-3 ) cells was not
affected by retinoic acid or
IGF-I , but appeared slightly increased by estradiol
Huynh et al., Growth Horm IGF Res 2000
:
We examined the
effects of
IGF-I on primary uterine myometrial cell proliferation, and on IGFBP-3 and
IGFBP-4 gene expression ... In cell-free conditioned media
IGF-I protected IGFBP-3 and
enhanced IGFBP-4 proteolysis ... Northern blot analysis indicated that
IGF-I increased
IGFBP-4 mRNA accumulation by stabilizing the mRNA while IGFBP-3 gene expression was slightly decreased
Hodgson et al., Regul Pept 2000
:
On the basis of such an experiment, performed at equilibrium,
IGFBP should
reduce the mitogenic activity of
IGF-1
Dahlfors et al., Endocrinology 2000
:
IGF-I , insulin, or angiotensin II did not
affect IGF-I or
IGFBP mRNA expression
Hayford et al., Growth Horm IGF Res 1998
:
These findings suggest that cAMP, dexamethasone and
IGF-I regulate
IGFBP production in human aorta smooth muscle cells via a complex interplay of changes in transcription, protease activation and dissociation of cell surface bound IGFBPs
Fottner et al., J Endocrinol 2001
:
In the present study, we identified and characterized IGFBP synthesis in normal adult human adrenocortical cells in primary culture, and investigated the
effect of ACTH and recombinant human
IGF-I and -II on the regulation of
IGFBP expression and secretion
Hayes et al., J Clin Endocrinol Metab 2001
(Hypogonadism) :
During rhIGF-I treatment, im expression of
IGF-I declined, and
IGF binding protein-4 increased , similar to the changes during GnRHa alone
Zeeh et al., Eur J Gastroenterol Hepatol 2001
(Colitis) :
Therefore, we investigated the expression of IGFBPs, collagen and collagenase activity in rat colitis and the
effects of
IGF-1 on
IGFBP and collagen expression in rat colonic smooth muscle cells
Boldt et al., Biochem J 2001
:
Pregnancy associated plasma protein-A ( PAPP-A ) has recently been found to cleave
IGFBP-4 in an
IGF dependent manner
Laursen et al., FEBS Lett 2001
:
In the
presence of
IGF ,
IGFBP-4 and -5 are cleaved with similar rates by PAPP-A ... In the
presence of
IGF ,
IGFBP-4 and -5 are cleaved with similar rates by PAPP-A
Sprenger et al., J Endocrinol 2001
(Cell Transformation, Viral) :
Thus,
IGFBP-3 acts in an
IGF dependent manner to inhibit cell growth of benign prostate epithelial cells
Kiepe et al., J Am Soc Nephrol 2001
(Kidney Failure, Chronic) :
Studies on the mechanism by which IGFBP-4 and IGFBP-5 exert opposite effects on chondrocyte proliferation demonstrated that intact
IGFBP-4 prevented the binding of ( 125 )
I-IGF-I to chondrocytes, whereas intact IGFBP-5 enhanced ligand binding and was able to bind specifically to the cell membrane
Bostedt et al., Exp Cell Res 2001
(Bone Neoplasms...) :
We compared the growth rates,
IGFBP production, IGF I binding characteristics, IGF 1R protein and mRNA levels, and the acute
IGF I response ( stimulation of glycogen synthesis ) after pretreatment of the cells in serum-free medium with or without added IGF I or medium supplemented with 5 % fetal calf serum ( FCS )
Price et al., Exp Lung Res 2001
:
PDGF-BB regulates
IGF mediated
IGFBP-4 proteolysis in fetal lung fibroblasts ... These studies demonstrate that PDGF-BB increases the accumulation of ICFBP-4 in fetal rat lung fibroblasts CM through increased production and by inhibiting
IGF mediated
IGFBP-4 proteolysis
Søe et al., Eur J Biochem 2002
:
Cleavage of
IGFBP-4 is dramatically
enhanced by the addition of IGF, whereas cleavage of IGFBP-5 is slightly inhibited by
IGF , as previously established with human PAPP-A
Yamane et al., Int J Dev Biol 2002
:
The exogenous
IGF-I stimulated differentiation of tongue myoblasts and
induced the expressions of endogenous
IGFBP4 , 5, and 6, suggesting that these IGFBPs were involved in the regulation of tongue myoblast differentiation by the IGF-I
Green et al., Kidney Int 2003
(Acidosis...) :
Acidosis increased the expression of IGF-I binding protein-4 (
IGFBP-4 , an
inhibitor of
IGF-I activity ), whereas coincubation with PTH during acidic conditions abrogated the up-regulation of IGFBP-4
Hsu et al., J Biol Chem 1992
:
The fasting induced increase in
IGFBP-30K is
inhibited by
IGF-I and by des-IGF-I and, to a lesser extent, by insulin ... Unlike cell associated IGFBP-30K, secretion of
IGFBP was
stimulated ( 6.8 +/- 0.5-fold, n = 2 ) by
IGF-I , whereas IGFBP secretion was inhibited 54 % by insulin ... These results demonstrate coordinate
regulation of
IGFBP by serum starvation and
IGF-I , such that at low concentrations of IGF-I, cell surface binding protein increases whereas binding protein secretion decreases
Mohan et al., Acta Endocrinol (Copenh) 1992
(Bone Neoplasms...) :
In this study, we sought to determine by Western ligand blotting the
effects of growth hormone,
IGF-I and IGF-II on the production of IGFBP-3 and
IGFBP-4 in TE89 human osteosarcoma cells and in untransformed normal human bone cells derived from rib
Sheikh et al., Biochem Biophys Res Commun 1992
(Breast Neoplasms) :
The levels of
IGFBP-4 and IGFBP-5 were
increased in MCF-7 cells by estradiol and
IGF-I , respectively, indicating that these BPs may contribute to the growth stimulatory response to these mitogens
Hassager et al., J Clin Endocrinol Metab 1992
:
In addition,
IGF-I markedly
increased levels of the 29/32/34 kDa
IGFBP triplet in U-2 cells, but had little or no effect in the other human and rat osteosarcoma cell lines ... In addition,
IGF-I markedly
increased levels of the 29/32/34 kDa
IGFBP triplet in U-2 cells, but had little or no effect in the other human and rat osteosarcoma cell lines
Grimes et al., Endocrinology 1992
:
IGF-I , IGF-II, and the IGF-I analogs, but not insulin, also
induced production of an unidentified 30-kDa
IGFBP not normally detectable in these cultures ... IGF-I,
IGF-II , and the IGF-I analogs, but not insulin, also
induced production of an unidentified 30-kDa
IGFBP not normally detectable in these cultures
Martin et al., Endocrinology 1992
:
In this study we report that exogenous and endogenous IGFBP-3 inhibit production of an
IGF inducible
IGFBP
Fowlkes et al., Endocrinology 1992
:
The
IGF dependent decrease in
IGFBP-4 was prevented by coincubation of the media with serine protease inhibitors, EDTA, or 1,10-phenanthrolene, suggesting that IGFs may activate an IGFBP-4 specific metallo-serine protease present in fibroblast conditioned media ... The demonstration that
IGF-I and IGF-II can
promote directly the proteolytic degradation of
IGFBP-4 into fragments that do not bind IGFs provides a novel mechanism by which the IGFs may increase their own availability and/or activity in biological fluids
Kühl et al., Glia 2003
:
When added exogenously,
IGFBP-6 reduced O2A cell survival in the absence of
IGF-1 and inhibited IGF-1 stimulated survival in a partially IGF-1 dependent and partially IGF-1 independent fashion
McCusker et al., J Endocrinol 2004
:
Soluble IGFBP-5 and
IGFBP-4 depressed the binding of ( 125 ) I-IGF-I and ( 125 ) I-IGF-II to the IGF-1R, but did not
affect binding of ( 125 ) I-R ( 3 )
-IGF-I
Tanaka et al., Int J Cancer 2004
(MAP Kinase Signaling System...) :
IGF-I induced
IGFBP-4 proteolysis by PAPP-A may enhance cell growth and invasion through IGF-I dependent Akt and ERK1/2 activation and subsequently upregulation of uPA
Sirotkin et al., J Reprod Dev 2003
:
These observations demonstrate the
involvement of
IGF-I and OT in the control of ovarian follicular size and follicular cell proliferation, progestagen, estrogen,
IGFBP-3 , inhibin A and B secretion and in cAMP/PKA- and MAPK/ERK1 dependent intracellular mechanisms
King et al., Invest Ophthalmol Vis Sci 2004
:
IGFBP production by these cells is further
increased by
IGF-I and -II, growth factors known to be present and active in proliferative vitreoretinal disorders, suggesting that Müller cells represent a potential source of vitreous IGFBPs in disorders involving this cell type
Voge et al., Peptides 2004
:
Ligand blotting revealed that both IGF-1 and -2 increased IGFBP-2 and -5 ( protein ) and had no effect on IGFBP-3 ( protein ), whereas
IGF-1 ( but not IGF-2 )
increased IGFBP-4 ( protein ), suggesting IGFBP-2, -4, and -5 are post-transcriptionally regulated
Kiepe et al., Endocrinology 2005
:
We therefore studied the
effect of
IGF-I on
IGFBP synthesis and the involved intracellular signaling pathways in two cell culture models of rat growth plate chondrocytes
Fleming et al., J Endocrinol 2005
:
In BME cells,
IGFBP-6 protein levels were readily detectable under basal conditions and were
increased by
IGF-I ...
IGF-I increased
IGFBP-4 mRNA levels by 2-fold in both cell types ... In vitro immuno-neutralization experiments showed that blocking PAPP-A prevented the ability of
IGF-I to
stimulate IGFBP-4 proteolysis
Moon et al., Int J Cancer 2006
(Carcinoma, Non-Small-Cell Lung...) :
However, under certain circumstances,
IGFBP-3 can
enhance the activity of
IGF by protecting IGF from degradation
Thraikill et al., J Clin Invest 1990
:
Cultured human decidual cells release three IGF-BPs with 24,000, 30,000, and 34,000 Mr. Using ligand blot analysis and an RIA for the 30,000-Mr form ( IGF-BP-1 ), we examined the
effects of
IGF-I ( 10-1,000 ng/ml ), insulin ( 10-10,000 ng/ml ), and relaxin ( 10-250 ng/ml ) on decidual cell
IGF-BP release after 120 h of hormone exposure
LaTour et al., Mol Endocrinol 1990
(Osteosarcoma) :
Previous work indicated that hIGFBP-4 is the predominant IGFBP expressed by human osteoblast-like cells, and that
IGFBP-4 binds and
inhibits the mitogenic activities of
IGF-I and IGF-II
Cheung et al., Endocrinology 1991
(Neuroblastoma) :
Purified
IGFBP-4 inhibited the binding of [ 125I ]
IGF-I by its receptor and blunted stimulation of [ 3H ] thymidine incorporation by IGF-I ... Purified
IGFBP-4 inhibited the binding of [ 125I
] IGF-I by its receptor and blunted stimulation of [ 3H ] thymidine incorporation by IGF-I
Conover et al., J Clin Invest 1991
(Cell Transformation, Viral) :
The
IGF-I induced change in
IGFBP levels was not a type I IGF receptor mediated effect on IGFBP synthesis because ( a ) high concentrations of insulin did not mimic IGF-I 's effect ; ( b ) IGF-II and IGF-I analogues having reduced affinity for the IGF-I receptor were equipotent with IGF-I in increasing medium IGFBPs ; ( c ) [ QAYL ] IGF-I, and IGF-I analogue having normal receptor affinity and decreased affinity for IGFBPs, had no effect ; and ( d ) alpha IR-3, a monoclonal antibody specific for the type I IGF receptor, did not block IGF-I stimulated increases in IGFBPs ... The IGF-I induced change in IGFBP levels was not a type I
IGF receptor mediated
effect on
IGFBP synthesis because ( a ) high concentrations of insulin did not mimic IGF-I 's effect ; ( b ) IGF-II and IGF-I analogues having reduced affinity for the IGF-I receptor were equipotent with IGF-I in increasing medium IGFBPs ; ( c ) [ QAYL ] IGF-I, and IGF-I analogue having normal receptor affinity and decreased affinity for IGFBPs, had no effect ; and ( d ) alpha IR-3, a monoclonal antibody specific for the type I IGF receptor, did not block IGF-I stimulated increases in IGFBPs
Gourmelen et al., Acta Paediatr Scand Suppl 1991
(Dwarfism) :
Subcutaneous injection of IGF-I, 40 micrograms/kg, provoked an increase in serum IGF-I levels to close to the lower limits of the normal range and a small increase in IGFBP-3, suggesting that IGF-I has a direct effect on the synthesis of this
GH/IGF-I dependent
IGFBP
Laursen et al., Mol Endocrinol 2007
:
Furthermore, we find that PAPP-A mediated IGF dependent cleavage of IGFBP-4 is inhibited by IGFBP-5, which sequesters IGF from IGFBP-4, and that cleavage of both
IGFBP-4 and -5 is
required for the release of bioactive
IGF
Chesik et al., Cytokine Growth Factor Rev 2007
(Central Nervous System Neoplasms...) :
In particular,
IGFBP-2 plays a dominant role in
IGF regulation in the CNS and is upregulated in several pathological conditions, including MS
Durai et al., Colorectal Dis 2007
(Colorectal Neoplasms) :
Its binding proteins (
IGFBP ) are
involved in local regulation of
IGF
Ryan et al., Br J Cancer 2009
(Adenocarcinoma...) :
IGFBP4 inhibits
IGF1 activity but cleavage by pregnancy associated plasma protein-A ( PAPP-A ) protease releases active IGF1
Martin et al., Endocrinology 1990
(Cell Transformation, Neoplastic) :
These results indicate that
IGF-I and IGF-II
induce an
IGFBP that is different from previously characterized human IGFBPs
Ekström et al., Hormone research in pædiatrics 2011
(Insulin Resistance...) :
After 8 months without treatment, we examined the short- and long-term
effects of
IGF-I/BP-3-Tx and, subsequently, IGF-I-Tx on 12-hour overnight levels of
IGF-I , GH, insulin, IGFBP-1, insulin sensitivity by hyperinsulinemic euglycemic clamp, body composition by dual-energy X-ray absorptiometry and linear growth
Ritvos et al., Endocrinology 1988
(Choriocarcinoma...) :
34 K
IGF-BP inhibited the binding of [ 125I ] iodo- ( Thr59 )
IGF-I to JEG-3 monolayers in a concentration dependent manner by forming with the tracer a soluble complex that could not bind to the cell surface as demonstrated by competitive binding and cross linking experiments
McCusker et al., J Cell Physiol 1988
:
IGF-I , although it interferes with the assay and thereby lowers the amount of detectable IGF-BP,
stimulated the secretion of
IGF-BP from all three cell types
Pekonen et al., J Clin Endocrinol Metab 1988
:
Purified 34K
IGF-BP as well as decidual cytosols
inhibited [ 125I
] IGF-I binding to placental receptors ... Purified 34K
IGF-BP as well as decidual cytosols
inhibited [ 125I ]
IGF-I binding to placental receptors
Carlsson-Skwirut et al., Biochim Biophys Acta 1989
:
This biological activity of recombinant truncated
IGF-1 was not
affected by the
IGF-BP at concentrations which abolished the biological activity of recombinant IGF-1
Pekonen et al., Fertil Steril 1989
(Obesity...) :
The 34K IGF binding protein ( 34K
IGF-BP ) has been shown to
inhibit the binding of
IGF-I to its receptor
Lee et al., Pediatr Res 1989
(Growth Disorders...) :
IGF-BP25 has been shown to
inhibit IGF mitogenic action in vitro
Chen et al., J Cell Physiol 1994
(Breast Neoplasms...) :
Therefore,
IGFBP-3 secreted by MCF-7 cells can
enhance IGF-I stimulation of DNA synthesis, increase IGF-I binding to these cells, and prevent IGF-I induced desensitization of its own receptor, suggesting that IGFBP-3 plays a significant role in IGF-I mediated breast carcinoma proliferation
Irwin et al., Regul Pept 1993
:
We have investigated the
regulation by insulin,
IGF-I , and IGF-II, of
IGFBP secretion in human endometrial stromal cells decidualized in vitro, and examined the interrelationship between the induced changes in IGFBP levels and the biological responses of stromal cells to IGFs
Caroni et al., J Cell Biol 1994
(Paralysis) :
In tissue culture experiments with sensory- and motoneurons we demonstrate that the neurite promoting activity of
IGF1 is
blocked by
IGF-BP4 , and that a similar IGF-BP-sensitive activity is detected in muscle extracts from paralyzed, but not from control muscle
McCarthy et al., J Cell Physiol 1994
:
By Western ligand blot analysis, 24 h treatment with PGE2 elevated the 24 and 38-47 kDa IGFBPs and to a lesser extent the 30/32 kDa complex, hGH elevated the 38-47 kDa IGFBPs, and
IGF-I and IGF-II each
increased the 30/32 kDa
IGFBP complex
Iwashita et al., Horm Res 1994
:
Similarly,
IGFBP-1 inhibited
125I-IGF-I binding to granulosa cells
Boney et al., Endocrinology 1994
:
The presence of a larger isoform of IGFBP-2 in a differentiation dependent manner and a potentially novel
IGFBP in
response to
IGF-I suggests that these IGFBPs may be important in modulating IGF-I action in adipogenesis
Oguchi et al., Am J Physiol 1994
:
IGF-I stimulated mainly IGF-BP-3 production, but epidermal growth factor (EGF) and transforming growth factor-alpha ( TGF-alpha )
stimulated predominantly
IGF-BP-4 secretion
Durham et al., J Clin Endocrinol Metab 1995
:
Our data indicate that elevated endogenous levels of
IGF can
activate IGFBP-4 proteolysis, because in hOB cultures lacking detectable IGFBP-4 protein 1 ) basal IGF messenger ribonucleic acid expression was increased ; 2 ) IGF-II peptide levels were elevated ; 3 ) IGF neutralizing antibodies added to hOB-CM attenuated the proteolysis of exogenous IGFBP-4 ; and 4 ) recombinant human IGFBP-4 was proteolyzed into 2 immunoreactive fragments of approximately 18 and 14 kilodaltons during cell-free incubations in these hOB-CM without the addition of exogenous IGF
Durham et al., Endocrinology 1995
(Osteosarcoma) :
Transient cell transformation induced by incubating human osteoblasts transfected with a temperature-sensitive mutant of simian virus-40 T-antigen at the permissive temperature or by treating hOB cells with phorbol ester tumor promoters also resulted in inhibition of
IGF dependent
IGFBP-4 proteolysis
Conover et al., Endocrinology 1995
:
These data demonstrate that IGF peptide and glucocorticoid individually modulate IGFBP expression and indicate that glucocorticoid has distinct effects on
IGF regulation of
IGFBP depending upon the particular IGFBP and the underlying mechanism of IGF regulation
Duclos et al., Growth Regul 1994
(Liver Neoplasms, Experimental) :
This suggested that
IGF binding to LMH was
due mainly to membrane bound
IGFBP rather than to type 1 IGF receptors
Grellier et al., Br J Haematol 1995
:
Characterization of
insulin-like growth factor binding proteins ( IGFBP ) and
regulation of
IGFBP-4 in bone marrow stromal cells
Näntö-Salonen et al., Endocrinology 1993
(Hypothyroidism...) :
The effects on IGFBP-2 ontogeny, and
IGFBP-4 expression in the mature animal, however, are either direct thyroid hormone effects, or mediated by some other route,
independent of GH, IGFs, or
IGF receptors
McFarland et al., Gen Comp Endocrinol 1993
:
Equimolar levels of
IGF-I or insulin
stimulated IGFBP release, however, at levels lower than that induced by IGF-II
Conover et al., Endocrinology 1993
:
In HFCM from cells treated with vehicle, GH, insulin, epidermal growth factor, steroid hormones, or forskolin,
IGF-II induced the select loss of detectable
IGFBP-4 during the assay ... Treatment of cells with actinomycin-D or cycloheximide could prevent a phorbol ester induced block of
IGF dependent
IGFBP-4 proteolysis
Myers et al., Endocrinology 1993
:
In the present study, we observed that the
IGF-I mediated decrease in
IGFBP-4 accumulation could be explained by increased IGFBP-4 proteolysis
Benedict et al., J Gerontol 1994
:
In control animals, a striking
increase ( 143 % ) in the predominant 39-45 kDa serum
IGFBP ( BP-3 ), with little change in serum
IGF-I , accompanied the marked deceleration of growth which occurred between 2 and 8 months ; the levels of IGF-I and its BPs declined by 15 % and 34 %, respectively, later in life
Lee et al., J Clin Endocrinol Metab 1996
(Nephrotic Syndrome) :
We speculate that low serum
IGF-I and IGFBP-3 levels would be partially
due to the increased urinary losses of serum
IGF-IGFBP complexes, especially that of 150 kDa, and these changes may contribute to growth failure in persistent nephrotic syndrome
Chevalley et al., Eur J Endocrinol 1996
:
In the present study of normal human osteoblast-like ( HOB ) cells, we tested the hypothesis that dexamethasone ( Dex )
inhibits IGF anabolic activity in bone by altering expression of IGF binding proteins ( IGFBPs ), particularly by decreasing expression of IGFBP-5 and IGFBP-3 ( which enhance IGF activity ) and increasing expression of
IGFBP-4 ( which inhibits IGF actions )
Grellier et al., J Endocrinol 1996
:
Since
IGF-I may
regulate IGFBP production, the effect of IGF-I on IGFBPs expressed by TC-1 cells was determined
Kummer et al., Endocrinology 1996
:
The stimulatory
effect of bFGF and
IGF-I on
IGFBP production was apparent after a 2- to 3-day exposure of the mesencephalic cultures to the peptides ... We propose that the
up-regulation of
IGFBP-4 by
IGF-I and bFGF may serve to localize IGF-I to sites of action in the nervous system and thereby potentiate the neurotrophic actions of IGF-I
Hembree et al., J Anim Sci 1996
:
Insulin-like growth factor binding proteins (
IGFBP ) may act locally as autocrine or paracrine
regulators of
insulin-like growth factor activity in specific tissues such as muscle
Arai et al., Endocrinology 1996
:
In summary,
IGFBP-2 binding to glycosaminoglycans is
dependent upon binding of
IGF-I and IGF-II to IGFBP-2
Chen et al., J Anim Sci 1996
:
We examined the time course of insulin-like growth factor binding protein (
IGFBP ) secretion and hormonal
regulation of IGFBP and
IGF-I secretion in porcine stromal vascular ( S-V ) cultures
Glander et al., Hum Reprod 1996
:
IGF-I is mainly controlled by concentrations of human growth hormone ( HGH ), influences cell proliferation and differentiation and its action is
mediated by insulin-like growth factor binding proteins (
IGFBP ), placental protein 14 (PP14) and prostate-specific antigen (PSA)
Monaco et al., J Endocrinol 1997
(Body Weight) :
The decrease in IGFBP-3 and increase in lower molecular weight
IGFBP may have
contributed to the reduction in serum
IGF-I by increasing IGF-I clearance from the circulation
Morales et al., Arch Biochem Biophys 1997
:
By contrast,
IGF-1 ( 10 ng/ml )
increased IGF-BP by < 2-fold ( n = 4 ), and retinoic acid, at 1 x 10 ( -8 ) M was not effective ( n = 3 )
Oguchi et al., Zhonghua Min Guo Xiao Er Ke Yi Xue Hui Za Zhi 1997
:
The
effects of
IGF-I and EGF on
IGFBP secretion diminished with increasing cell differentiation
Gentilini et al., J Cell Physiol 1998
(Hepatitis, Viral, Human) :
IGFBP-4 protein levels decreased in
response to
IGF-I ...
IGF-I and TGF-beta differentially
regulate IGFBP-3,
IGFBP-4 , and IGFBP-5 expression, which, in turn, may modulate the in vitro and in vivo action of IGF-I
Giannini et al., Metabolism 1997
:
In fact, ( 1 ) IGFBP mRNA levels were not modified after stimulation with 100 nmol/L IGF-I, ( 2 ) 100 nmol/L
IGF plus an equimolar concentration of alpha IR3 did not
affect IGFBP production, ( 3 ) Des ( 1-3 ) IGF-I had no effect on IGFBP modulation, whereas at 10 nmol/L it enhanced BREC thymidine cell incorporation, and ( 4 ) 100 nmol/L insulin, which at this concentration can cross-react with the IGF-I receptor, did not modify the IGFBP pattern
McCusker et al., J Cell Physiol 1998
:
IGFBP secretion by L6 cells is
stimulated by both
insulin/IGF-I and cAMP dependent pathways, whereas IGFBP-5 secretion by BC3H-1 cells is stimulated only by the insulin/IGF pathway
Elmlinger et al., Eur J Endocrinol 1998
:
Elevated insulin-like growth factor (IGF) binding protein ( IGFBP)-2 and
IGFBP-4 expression of leukemic T-cells is
affected by autocrine/paracrine IGF-II action but not by
IGF type I receptor expression ... Through inhibition using JB1, a peptide inhibiting the IGF signal transduction by blocking the IGF-I-R, we demonstrated the
involvement of the
IGF-I-R in
IGFBP-2 and -4 expression and leukemic cell growth ... Thus, although IGF-I-R mediates the autocrine/paracrine effects of the IGFs,
IGF-I-R mRNA expression is most probably not
involved in the differential
IGFBP-2/IGFBP-4 expression in leukemic cells
Sunic et al., Endocrinology 1998
:
The aim of this study was to investigate the
effects of
IGF-I and IL-1 on
IGFBP production by ovine articular chondrocytes ( OAC ) and the roles of these IGFBPs in the regulation of proteoglycan synthesis
Duan et al., J Biol Chem 1998
:
In this study, we examined the
role of autocrine/paracrine secreted
IGF-I in controlling the expression of
IGFBP-4 and IGFBP-5 as well as the effects of these IGFBPs in modulating the cellular replication response to IGF-I
Cabrol et al., Arch Pediatr 1998
(Growth Disorders...) :
Elevated
IGFBP levels may
contribute to a reduced
IGF activity, especially in dialysed patients