The response of the hepatic insulin-like growth factor system to growth hormone and dexamethasone in calves

Hammon, H.M.; Zbinden, Y.; Sauerwein, H.; Breier, Bernhard H.; Blum, J.W.; Donkin, Shawn S.

doi:10.1677/joe.0.1790427

Cited by 21 publications

(18 citation statements)

References 41 publications

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“…The decreased expression of IGFBP-5 following Dex treatment is similar to previous reports that glucocorticoids, such as Dex, have growth suppressing effects, inhibit the somatotropic axis, and long-term treatment leads to bone loss and osteoporosis [31][32][33][34]. Our data are similar to previous observations that Dex treatment decreased expression of IGF-I, IGFBP-3, and IGFBP-5, stimulatory factors, and increased expression of IGFBP-4, an inhibitory factor, in human osteoblast-like cells and decreased IGFBP-5 expression in preosteoblastic human bone marrow stromal cells [35,36].…”

Section: Coordinated Expression Of Igfbp-5 Fhl-2 and Adam-9 In Respsupporting

confidence: 88%

Regulation of insulin-like growth factor binding protein-5, four and a half lim-2, and a disintegrin and metalloprotease-9 expression in osteoblasts

Govoni

Amaar

Kramer

et al. 2006

Growth Hormone & IGF Research

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The roles of insulin-like growth factors (IGFs) in regulating growth and their modulation by six IGF binding proteins (IGFBP) are well established. IGFBP-5, the most abundant IGFBP stored in bone, is an important regulator of bone formation via IGF-dependent and -independent mechanisms. Two new proteins, four and a half lim (FHL)-2, a transcription modulator that interacts with IGFBP-5, and a disintegrin and metalloprotease (ADAM)-9, an IGFBP-5 protease, have been identified as potential regulators of IGFBP-5 action in bone. We tested the hypothesis that agents which modulate bone formation by regulating IGFBP-5 expression would also regulate FHL-2 and ADAM-9 expression in a coordinated manner. We evaluated the expression of IGFBP-5, FHL-2, and ADAM-9 by real-time reverse transcriptase (RT)-PCR during differentiation of mouse bone marrow stromal cells into osteoblasts and in response to treatment with bone formation modulators in the LSaOS human osteosarcoma cell line. IGFBP-5 and FHL-2 increased 4.3-and 3.0-fold (P ≤ 0.01), respectively, during osteoblast differentiation. Dexamethasone (Dex), an inhibitor of bone formation, decreased IGFBP-5 and FHL-2 and increased ADAM-9 in LSaOS cells (P ≤ 0.05). Bone morphogenic protein (BMP)-7, a stimulator of bone formation, increased IGFBP-5 and decreased ADAM-9 (P < 0.01). To determine if BMP-7 would eliminate Dex inhibition of IGFBP-5, cells were treated with Dex + BMP-7. The BMP-7-induced increase in IGFBP-5 was reduced, but not eliminated, in the presence of Dex (P ≤ 0.01), indicating that BMP-7 and Dex may regulate IGFBP-5 via different mechanisms. Transforming growth factor (TGF)-β, a stimulator of bone formation, increased IGFBP-5 and FHL-2 expression (P ≤ 0.01). IGF-I and TNF-α decreased expression of ADAM-9 (P < 0.05). In conclusion, our findings are consistent with the hypothesis that FHL-2 and ADAM-9 are important modulators of IGFBP-5 actions and are, in part, regulated in a coordinated manner in bone.

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Section: Coordinated Expression Of Igfbp-5 Fhl-2 and Adam-9 In Respsupporting

confidence: 88%

Regulation of insulin-like growth factor binding protein-5, four and a half lim-2, and a disintegrin and metalloprotease-9 expression in osteoblasts

Govoni

Amaar

Kramer

et al. 2006

Growth Hormone & IGF Research

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“…Consistent with this, this study showed that GH injection increased mRNA expression of IGF1 and ALS in both the cows fed concentrates and the cows fed hay. GH has been shown to stimulate liver expression of IGFBP3 mRNA in rats (Albiston & Herington 1992, Domene et al 1993, Scharf et al 1996, sheep (Bassett et al 1998), and pigs (Dunaiski et al 1999), but not in cattle (Hammon et al 2003, Radcliff et al 2004. This study showed that GH injection increased IGFBP3 mRNA expression in the liver of cows fed hay, but not in those fed concentrates.…”

Section: Discussionmentioning

confidence: 65%

Effect of feeding level on serum IGF1 response to GH injection

Hall²,

Akers³

et al. 2010

Journal of Endocrinology

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This study was conducted to further understand the mechanism by which nutrition modulates GH-induced changes in serum IGF1 concentration in cattle. Cows were fed hay only or corn-based concentrates in addition to hay for 8 weeks. At week 8, serum concentrations of IGF1, IGF-binding protein 3 (IGFBP3), and acid-labile subunit (ALS) as well as their mRNA levels in liver were determined immediately before and 7 days after an injection of GH formulated for sustained release. GH injection caused greater increases in both serum IGF1 concentration and liver IGF1 mRNA expression in the cows fed concentrates than in those fed hay. In the cows fed concentrates, the magnitude of the GH-induced increase in serum IGF1 concentration was, however, much greater than that in liver IGF1 mRNA expression. This difference was not due to GH-induced IGF1 mRNA being translated more efficiently. GH injection also induced greater increases in serum IGFBP3 and ALS concentrations in the cows fed concentrates than fed hay. The injection, however, did not induce a greater increase in IGFBP3 or ALS mRNA in the cows fed concentrates than fed hay. These data and the fact that the ternary complex of IGF1/IGFBP3/ALS stabilizes each of the components in the blood suggest that in cows, increased nutrition enhances serum IGF1 response to GH not only by increasing IGF1 mRNA response to GH in the liver, but also by elevating IGFBP3 and ALS concentrations in the blood.

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“…Time changes in the plasma IGFBP-3 concentration were small, and surprisingly, no feeding effect was observed during the intensive MR-feeding period. Previous studies have shown an increase in plasma IGFBP-3 in calves with age [79,80] and MR-feeding intensity [32], and plasma IGFBP-3 normally follows plasma IGF-I, because IGFBP-3, together with an acid-labile subunit, binds most of the IGF-I in circulation and therefore correlates well with IGF-I [28,37,38]. In addition, the plasma IGFBP-3 inversely correlates with IGFBP-2 during growth [29,37], which was also not observed in the present study.…”

Section: Discussionmentioning

confidence: 99%

Effects of Feeding Milk Replacer Ad Libitum or in Restricted Amounts for the First Five Weeks of Life on the Growth, Metabolic Adaptation, and Immune Status of Newborn Calves

et al. 2016

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The pre-weaning period is critical for calf health and growth, and intensive milk feeding programs may assist postnatal development by improving body growth and organ maturation. The aim of the present work was to study the effects of ad libitum milk replacer (MR) feeding on the growth, metabolic adaptation, health, and immune status of newborn calves. Twenty-eight newborn Holstein and Holstein x Charolais crossbred calves were fed ad libitum (ADLIB) or in restricted amounts (6 liters per day; RES) during the first five weeks of life. The MR intake in the ADLIB treatment was gradually reduced at weeks 6 and 7, and all calves then received 6 liters of MR per day until day 60. Blood samples were collected to measure the plasma concentrations of metabolites, insulin, insulin-like growth factor (IGF)-I and IGF binding proteins (IGFBP), immunoglobulins, and acute phase proteins. The expression of mRNA associated with both the somatotropic axis and gluconeogenic enzymes was measured in the liver on day 60. Intensive feeding improved MR intake and growth in ADLIB without influencing concentrate intake. Carcass weight, perirenal fat, and muscle mass were greater in ADLIB. Plasma concentrations of glucose, triglycerides, insulin, and IGF-I were greater, whereas plasma concentrations of β-hydroxybutyrate, total protein, albumin, urea, IGFBP-2 and -4, and fibrinogen were lower at distinct time points in ADLIB. The hepatic mRNA expression of cytosolic phosphoenolpyruvate carboxykinase was greater in ADLIB. Most metabolic and endocrine differences occurred during the MR feeding period, but a slightly greater concentrate intake was associated with increased plasma IGF-I and insulin at the end of the study. The immune and health status of the calves were not affected by MR feeding. However, increased plasma fibrinogen in the RES group suggested differences in the acute phase response.

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The response of the hepatic insulin-like growth factor system to growth hormone and dexamethasone in calves

Cited by 21 publications

References 41 publications

Regulation of insulin-like growth factor binding protein-5, four and a half lim-2, and a disintegrin and metalloprotease-9 expression in osteoblasts

Regulation of insulin-like growth factor binding protein-5, four and a half lim-2, and a disintegrin and metalloprotease-9 expression in osteoblasts

Effect of feeding level on serum IGF1 response to GH injection

Effects of Feeding Milk Replacer Ad Libitum or in Restricted Amounts for the First Five Weeks of Life on the Growth, Metabolic Adaptation, and Immune Status of Newborn Calves

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