Triiodothyronine (T3) stimulates insulin-like growth factor (IGF)-1 and IGF binding protein (IGFBP)-2 production by rat osteoblasts in vitro

1992 ◽  
Vol 126 (5) ◽  
pp. 467-473 ◽  
Author(s):  
Christoph Schmid ◽  
Irene Schläpfer ◽  
Eva Futo ◽  
Margaretha Waldvogel ◽  
Jürg Schwander ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Mrna Expression ◽  
Bone Cells ◽  
Apparent Molecular Weight ◽  
Neonatal Rat ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Serum Free Conditions ◽  
Rat Osteoblasts

Osteoblast-like cells prepared from neonatal rat calvariae and grown under serum-free conditions produce IGF-1 and IGFBPs. In contrast to growth hormone, T3 and PTH increased both IGF-1 mRNA expression and net IGF-1 release in calvaria cells. In addition, they stimulated net production of IGFBP-3 and of an IGFBP with an apparent molecular weight of 32 kDa which was recognized by an antiserum against rat IGFBP-2. Bone cells expressed remarkably high levels of mRNA for IGFBP-2, the predominant IGFBP in serum of newborn rats. T3 at low physiological concentrations but not growth hormone stimulated IGFBP-2 mRNA expression and IGFBP-2 production in bone cells in vitro. Thus, IGFBPs are differentially regulated by these hormones and may play an autocrine/paracrine regulatory role in bone.

scholarly journals Effect of thyroxine administration on the IGF/IGF binding protein system in neonatal and adult thyroidectomized rats

2001 ◽  
Vol 169 (1) ◽  
pp. 111-122 ◽  
Author(s):  
S Ramos ◽  
L Goya ◽  
C Alvarez ◽  
MA Martin ◽  
AM Pascual-Leone
Keyword(s):  
Body Weight ◽  
Mrna Expression ◽  
Plasma Insulin ◽  
Binding Protein ◽  
Adult Rats ◽  
Igf I ◽  
Igf Binding ◽  
Igf Binding Protein

The effects of different doses of thyroxine (T(4)) delivered by injection or s.c. pellet implantation on alterations of the IGF/IGF binding protein (IGFBP) system were studied in neonatal and adult thyroidectomized (Tx) rats. Body weight, blood glucose, plasma insulin, TSH and GH and pituitary GH content, as well as serum IGF-I, IGF-II, IGFBP-1, -2 and -3 and their liver mRNA expression were assayed. Pellet implantation with the smaller dose of T(4) (1.5 microg/100 g body weight (b.w.) per day) in Tx neonatal rats decreased serum IGF-I, -II and the 30 kDa complex of IGFBPs (IGFBP-1 and -2), and increased serum IGFBP-3. Only the larger dose of T(4) (3 microg/100 g b.w. per day) recovered liver mRNA expression of IGF-I and ensured euthyroid status as shown by the normalized levels of plasma TSH. The rapid increase of body weight and serum GH after T(4) administration indicated a high sensitivity to T(4) during the neonatal period. Serum and liver mRNA expression of IGFs and plasma insulin and GH recovered in adult Tx rats after pellet implantation of 1.75 microg/100 g b.w. per day throughout 10 days. The continuous replacement of T(4) by pellet seems to be the most suitable method for thyroid rehabilitation. A very good correlation was found between insulin and IGF-II in Tx neonates treated with T(4) but not between insulin and IGF-I in Tx adults. IGFBP-2 seems to be up-regulated by T(4) deprivation in neonatal and adult rats. Finally, a good correlation as well as a partial correlation were found between IGFs and thyroid hormones in both neonatal and adult Tx populations, suggesting a direct effect in vivo of T(4) on the hepatic secretion of IGFs, as previously suggested in vitro.

scholarly journals Neurite Growth and Polarization on Vitronectin Substrate after in Vitro Trauma is not Enhanced after IGF Treatment

2018 ◽  
Vol 8 (8) ◽  
pp. 151 ◽  
Author(s):  
K. Bergen ◽  
M. Frödin ◽  
C. von Gertten ◽  
A. Sandberg-Nordqvist ◽  
M. Sköld
Keyword(s):  
Hippocampal Neurons ◽  
Molecular Mechanisms ◽  
Brain Injuries ◽  
Neurite Growth ◽  
Cellular Growth ◽  
Neurotrophic Activity ◽  
Igf Binding ◽  
And Migration ◽  
Igf Binding Protein

Following traumatic brain injuries (TBI), insulin-like growth factor (IGF) is cortically widely upregulated. This upregulation has a potential role in the recovery of neuronal tissue, plasticity, and neurotrophic activity, though the molecular mechanisms involved in IGF regulation and the exact role of IGF after TBI remain unclear. Vitronectin (VN), an extracellular matrix (ECM) molecule, has recently been shown to be of importance for IGF-mediated cellular growth and migration. Since VN is downregulated after TBI, we hypothesized that insufficient VN levels after TBI impairs the potential beneficial activity of IGF. To test if vitronectin and IGF-1/IGFBP-2 could contribute to neurite growth, we cultured hippocampal neurons on ± vitronectin-coated coverslips and them treated with ± IGF-1/IGF binding protein 2 (IGFBP-2). Under same conditions, cell cultures were also subjected to in vitro trauma to investigate differences in the posttraumatic regenerative capacity with ± vitronectin-coated coverslips and with ± IGF-1/IGFBP-2 treatment. In both the control and trauma situations, hippocampal neurons showed a stronger growth pattern on vitronectin than on the control substrate. Surprisingly, the addition of IGF-1/IGFBP-2 showed a decrease in neurite growth. Since neurite growth was measured as the number of neurites per area, we hypothesized that IGF-1/IGFBP-2 contributes to the polarization of neurons and thus induced a less dense neurite network after IGF-1/IGFBP-2 treatment. This hypothesis could not be confirmed and we therefore conclude that vitronectin has a positive effect on neurite growth in vitro both under normal conditions and after trauma, but that addition of IGF-1/IGFBP-2 does not have a positive additive effect.

scholarly journals Endometrial Inhibin/Activin β-B Subunit Expression Is Related to Decidualization and Is Reduced in Tubal Ectopic Pregnancy

2008 ◽  
Vol 93 (6) ◽  
pp. 2375-2382 ◽  
Author(s):  
A. W. Horne ◽  
S. van den Driesche ◽  
A. E. King ◽  
S. Burgess ◽  
M. Myers ◽  
...  
Keyword(s):  
Ectopic Pregnancy ◽  
Stromal Fibroblasts ◽  
Tubal Ectopic Pregnancy ◽  
B Subunit ◽  
Subunit Expression ◽  
Igf Binding ◽  
Differential Gene ◽  
Ectopic Pregnancies ◽  
Igf Binding Protein

Abstract Context: Ectopic pregnancy is common but remains difficult to diagnose accurately. There is no serum test to differentiate ectopic from intrauterine gestation. Objective: Our objective was to investigate differential gene expression in decidualized endometrium of ectopic pregnancy. Design: Tissue and serum analysis informed by microarray study was performed. Setting: The study was performed at a large United Kingdom teaching hospital. Patients or Other Participants: Women undergoing surgical termination of pregnancy (n = 8), evacuation of uterus for miscarriage (n = 6), and surgery for tubal ectopic pregnancy (n = 11) were included in the study. Endometrium was collected from normally cycling women undergoing hysterectomy. Interventions: Decidualized endometrium was subjected to microarray analysis, morphological assessment, and immunohistochemistry. Endometrial stromal fibroblasts were cultured in the presence of decidualizing stimuli. Main Outcome Measures: Differential expression of potentially secreted molecules was calculated. Results: Inhibin/activin β-B expression was lower in decidualized endometrium from ectopic pregnancies when compared with that of ongoing pregnancies (P < 0.01) or miscarriages (P < 0.01). The localization of the β-B subunit was more marked in decidualized than nondecidualized stroma. Decidualization of stromal fibroblasts in vitro was associated with increased β-B expression (P < 0.05). Endometrial stroma of ectopic pregnancies was less decidualized morphologically (P < 0.05), with lower prolactin (P < 0.01) and IGF binding protein-1 (P < 0.005) expression. Serum activin B was lower in ectopic pregnancies (P < 0.005) than in intrauterine pregnancies, whereas there was no difference in progesterone concentrations. Conclusions: Despite similar concentrations of progesterone, the endometrium of ectopic pregnancies is less decidualized than intrauterine pregnancies. Expression of the β-B subunit is related to decidualization and can be detected in the circulation as activin B. Serum activin B concentrations are lower in ectopic pregnancy.

A Bayesian Approach to Diagnose Growth Hormone Deficiency in Children: Insulin-Like Growth Factor Type 1 Is Valuable for Screening and IGF-Binding Protein Type 3 for Confirmation

2020 ◽  
Vol 93 (3) ◽  
pp. 197-205
Author(s):  
Thais H. Inoue-Lima ◽  
Gabriela A. Vasques ◽  
Marilena Nakaguma ◽  
Luciana Pinto Brito ◽  
Berenice B. Mendonça ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Growth Hormone Deficiency ◽  
Bayesian Approach ◽  
Hormone Deficiency ◽  
Igf Binding ◽  
Factor Type ◽  
Igf Binding Protein ◽  
Type 3

Growth hormone and parathyroid hormone stimulate IGFBP-3 in rat osteoblasts

1994 ◽  
Vol 267 (2) ◽  
pp. E226-E233 ◽  
Author(s):  
C. Schmid ◽  
I. Schlapfer ◽  
M. Peter ◽  
M. Boni-Schnetzler ◽  
J. Schwander ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Parathyroid Hormone ◽  
Growth Factor ◽  
Culture Media ◽  
Insulin Like Growth Factor ◽  
Igf I ◽  
Conditioned Cell Culture Medium ◽  
Rat Osteoblasts ◽  
Igfbp 3

Osteoblast-like cells prepared from calvaria of newborn rats produce insulin-like growth factor (IGF) I and several insulin-like growth factor binding proteins (IGFBPs) in vitro. Among the IGFBPs found in conditioned cell culture medium, IGFBP-3 is the most abundant. Intact IGFBP-3, as assessed by 125I-labeled IGF-II ligand blot analysis, is more abundant in culture media of cells exposed to growth hormone (GH) or to parathyroid hormone (PTH), both at 5 x 10(-9) mol/l, for 24 h. At the same time, concentrations of IGF-I are increased in media of cells exposed to PTH but not to GH, compared with hormone-free control cultures. IGFBP-3 mRNA is increased in osteoblasts exposed to PTH or to GH but not in response to 5 x 10(-9) mol/l IGF-I. PTH exerts a rapid (within 2 h) stimulatory effect on IGF-I and IGFBP-3 production, both at the message and peptide levels, whereas GH increases only IGFBP-3, both at the message and peptide levels (after 24 h). We conclude that IGF-I does not mediate increased IGFBP-3 production by rat osteoblasts in response to GH and PTH.

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