Growth Hormone Cannot Enhance the Recovery of Dexamethasone-Induced Osteopenia after Withdrawal in Young Female Wistar Rats

Huang, Tien-Shang; Yang, Rong‐Sen; Tsai, Tsang-Wu; Liu, Shing‐Hwa

doi:10.1620/tjem.204.257

Cited by 7 publications

(9 citation statements)

References 50 publications

(58 reference statements)

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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: 87%

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: 87%

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 proposed explanation of this effect is the fact that DEX could impair the synthesis of collagen fibres that build each trabecula. The inhibitory role of GCs in the cross‐linking of collagen and their influence on lysyl oxidase were demonstrated (Huang et al., 2004; McIwraith, 2004). The mechanical and supportive role of the bone as a connective tissue in the body depends on the orientation of the collagen fibres (Freemont, 1998).…”

Section: Discussionmentioning

confidence: 99%

“…Disproportions in the growth and the development of DEX‐treated infants were observed at 1 year of age with an increased risk of osteopenia (Weiler et al., 1997; Smink et al., 2003; Levy‐Marchal et al., 2004). The use of GCs during childhood – a time of high bone turnover – may delay the effect of catch‐up growth (Ward et al., 1999; Smith et al., 2000; Huang et al., 2004; Desai et al., 2005; Sayer and Cooper, 2005).…”

Section: Introductionmentioning

confidence: 99%

Bone development of suckling piglets after prenatal, neonatal or perinatal treatment with dexamethasone

Sliwa

Dobrowolski

Piersiak

2010

Animal Physiology Nutrition

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In mammals, the release from growth-inhibiting conditions results in catch-up growth. To investigate animal evidence for whether prenatal dexamethasone (DEX) treatment leads to the development of growth restriction especially reduced mineralization of skeleton, and release from it leads to the phenomenon of catch-up, piglets were prenatally exposed to DEX (3.0 mg/sow per day(-2)) during the last 24 days of prenatal life and tested further in two different ways: discontinued at birth and continued administration of DEX (0.5 mg/kg day(-2)) to piglets through 30 days of neonatal life. Using dual energy X-ray absorptiometry methods, bone mineral density (BMD) and bone mineral content (BMC) were measured. The three-point bending test was applied to determine the mechanical properties of the bones. Furthermore, geometric properties of the bones were assessed. Serum concentration of osteocalcin (OC) was determined. Histomorphological analysis of the ribs was also performed. The consequences of neonate DEX treatment and in utero DEX exposure were reflected in a dramatic decrease of BMD, BMC and blood serum OC concentration and geometric parameters of piglets' bones. Prenatal action of DEX during the last 24 days of pregnancy resulted in continued neonatal modification of bone tissues, thus diminishing bone quality, and negatively influenced structural development and mechanical properties, finally increasing the risk of fractures of ribs and limb bones. Prenatal DEX treatment limited to the last 24 days of foetal life did not reduce the term birth weight and the growth of suckling piglets followed up to 30 days of neonatal life, and catch-up in bone mineralization did not occur.

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“…A histomorfometria ou histologia quantitativa consiste na contagem ou medida dos componentes celulares e avaliação de alteração na microarquitetura óssea. É um método que permite a medida da mineralização e o estudo da formação óssea, especialmente na osteoporose induzida por glicocorticóides, caracterizada por adelgaçamento das trabéculas sem perfuração, que leva a uma redução no volume do osso (HUANG et al, 2004;ZECCHIN et al, 2004;CARBONARE et al, 2005;PIAI et al, 2005).…”

Section: Revisão Da Literaturaunclassified

Avaliação radiográfica e histomorfométrica da mandíbula de ratas medicadas com corticóide e bifosfonato

Mahl

Fontoura

Borelli

et al. 2009

R. Fac. Odontol. Porto Alegre

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Glucocorticoids and biphosphonates are drugs that interfere in bone structure. In order to assess if these changes are evident at radiographies and histological slides, 36 wistar female rats were allocated to 3 groups of 12 animals. Group 1 received saline solution (subcutaneous injections -2 ml/kg), groups 2 and 3 received metilprednisolone acetate (1 mg/kg). Group 3 received also risedronate (3mg/kg). The animals were killed, the left hemimandíble was dissected, radiographed and histologically prepared. One observer blind to the group composition measured the optical density and trabecular proportion means. The ANOVA, complemented by Tukey´s test (=5%) showed significantly smaller mean in the group 2 (glucocorticoid, 165.54±8.95) than in groups 1 (control, 182.96±4.53) and 3 (180.99±6.21). The groups 1 and 3 do not differ between themselves. The same statistical tests showed significant histological differences among groups. Group 2 (glucocorticoid, 53.94±12.53) had the smallest mean proportion of bone trabeculae per field, and group 3 (risedronate, 81.14±7.20) the largest. Both differ significantly from group 1 (control, 72.00±5.95) (F=37.56;p<0.01). In conclusion, glucocorticoid and biphosphonate administration interferes with rats mandibular trabecular proportion and these changes are radiographically detectable..

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Growth Hormone Cannot Enhance the Recovery of Dexamethasone-Induced Osteopenia after Withdrawal in Young Female Wistar Rats

Cited by 7 publications

References 50 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

Bone development of suckling piglets after prenatal, neonatal or perinatal treatment with dexamethasone

Avaliação radiográfica e histomorfométrica da mandíbula de ratas medicadas com corticóide e bifosfonato

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