| 1. |
- Bjarnason, Ragnar, 1959, et al.
(author)
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Cartilage oligomeric matrix protein increases in serum after the start of growth hormone treatment in prepubertal children
- 2004
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In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 89:10, s. 5156-60
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Journal article (peer-reviewed)abstract
- Both GH and IGF-I stimulate bone growth, but the molecular mechanisms mediating their effects on the growth plate are not fully understood. We measured gene expression by microarray analysis in primary cultured human chondrocytes treated with either GH or IGF-I. One of the genes found to be up-regulated by both GH and IGF-I was that encoding cartilage oligomeric matrix protein (COMP). This protein is predominantly found in the extracellular matrix of cartilage. Mutations in the COMP gene have been associated with syndromes of short stature. To verify that COMP is regulated by GH in vivo, we measured COMP levels in serum in short children treated with GH. The study included 113 short prepubertal children (14 girls and 99 boys) with a mean (+/- sd) age of 8.84 +/- 2.76 yr, height sd score of -2.74 +/- 0.67, and IGF-I sd score of -1.21 +/- 1.07 at the start of GH administration. Serum levels of COMP were 1.58 +/- 0.28, 1.83 +/- 0.28 (P < 0.0001), 1.91 +/- 0.28 (P < 0.0001), 1.78 +/- 0.28 (P < 0.001), and 1.70 +/- 0.24 (P < 0.05) microg/ml at baseline and after 1 wk and 1, 3, and 12 months, respectively.In conclusion, we have demonstrated that COMP expression is up-regulated by both GH and IGF-I in primary cultured human chondrocytes. Furthermore, serum levels of COMP increase after the start of GH treatment in short children.
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| 2. |
- Bohlooly-Yeganeh, Mohammad, 1966, et al.
(author)
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Enhanced spontaneous locomotor activity in bovine GH transgenic mice involves peripheral mechanisms
- 2001
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In: Endocrinology. ; 142:10, s. 4560-4567
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Journal article (peer-reviewed)abstract
- Clinical and experimental studies indicate a role for GH in mechanisms related to anhedonia/hedonia, psychic energy, and reward. Recently we showed that transgenic mice with general overexpression of bovine GH display increased spontaneous locomotor activity. In the present study, we investigated whether this behavioral change is owing to a direct action of GH in the central nervous system or to peripheral GH actions. A transgenic construct, containing the glial fibrillary acidic protein promoter directing specific expression of bovine GH to the central nervous system, was designed. The central nervous system-specific expression of bovine GH in the glial fibrillary acidic protein-bovine GH transgenic mice was confirmed, but no effect on spontaneous locomotor activity was observed. Serum bovine GH levels were increased in glial fibrillary acidic protein-bovine GH transgenic mice but clearly lower than in transgenic mice with general overexpression of bovine GH. In contrast to the transgenic mice with general overexpression of bovine GH, glial fibrillary acidic protein-bovine GH mice did not display any difference in serum IGF-I levels. The levels of free T(3) and the conversion of the free T(4) to free T(3) were only increased in transgenic mice with general overexpression of bovine GH, but serum corticosterone levels were similarly increased in both transgenic models. These results suggest that free T(3) and/or IGF-I, affecting dopamine and serotonin systems in the central nervous system, may mediate the enhanced locomotor activity observed in transgenic mice with general overexpression of bovine GH.
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| 3. |
- Olsson, Bob, 1969, et al.
(author)
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T-cell-mediated cytotoxicity toward platelets in chronic idiopathic thrombocytopenic purpura.
- 2003
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In: Nature medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 9:9, s. 1123-4
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Journal article (peer-reviewed)abstract
- Chronic idiopathic thrombocytopenic purpura (ITP) is a bleeding disorder that is characterized by increased platelet destruction and is believed to be autoantibody mediated. In this study, CD3+ T cells from ITP patients had increased expression of genes involved in cell-mediated cytotoxicity. In addition, cytotoxic cell-mediated lysis of autologous platelets was shown in active ITP. Our data suggest that T-cell-mediated cytotoxicity is an alternative mechanism for platelet destruction in ITP.
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| 4. |
- Olsson, Bob, 1969
(author)
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The role of GH in the regulation of energy homeostasis, lipid metabolism and cardiovascular function in transgenic mice
- 2001
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Doctoral thesis (other academic/artistic)abstract
- The aim of this thesis was, using two transgenic models, to investigate some metabolic diseases associated with acromegaly e.g. hypertension and alterations in lipid and lipoprotein metabolism. We also studied the positive effect of Growth Hormone (GH), and possible molecular causes, on body composition and energy homeostasis using these GH transgenic models.We have used two different GH transgenic mouse models, one model overexpressing GH generally, controlled by the metallothionine promoter (Mt-bGH), and one model where the GH overexpression is restricted to the CNS, using the glial fibrillary acidic protein promoter (GFAP-bGH).Using telemetric technique, we have found that Mt-bGH transgenic mice have a salt-insensitive hypertension. Furthermore, the Mt-bGH transgenic mice have altered lipoprotein profiles and serum lipids, hyperinsulinemia and hyperglycaemia. Moreover, the hepatic gene expression profiles analysed by micro-array, revealed decreased gene expression of PPARa and SREBP-1 together with decreased expression of genes involved in fatty acid activation, b-oxidation, ketone body formation, lipogenesis, cholesterol metabolism, gluconeogenesis and amino acid catabolism. When analysed by indirect calorimetry, the Mt-bGH transgenic mice also had an increased resting metabolic rate on a normal diet that was enhanced by a Western diet, increased body temperature and increased hepatic gene expression of UCP2. Furthermore, the Mt-bGH transgenic mice had an increased respiratory exchange rate and food intake on both diets but still a lean body composition.The GFAP-bGH mice had an increased food intake resulting in massive obesity along with an increased expression of AGRP and NPY. These mice also had alterations in lipid and lipoprotein metabolism, hyperinsulinemia and pancreatic islet hypertrophy but normal blood glucose levels.GH stimulates food intake by increasing the hypothalamic gene expression of AGRP and NPY. This results in obesity in the GFAP-bGH transgenic mice but the high circulating levels of GH in the Mt-bGH mice, resulting in elevated RMR, body temperature, and T3 levels prevent obesity and result in a lean body composition. We have also found several risk factors for cardiovascular disease in these two GH transgenic models, such as high LDL cholesterol, insulin resistance, hypertension and indications of a decreased reverse cholesterol transport. These models may be useful tools in understanding the underlying mechanisms for cardiovascular disease in patients with acromegaly.
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| 5. |
- Sjögren, Klara, 1970, et al.
(author)
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Disproportional skeletal growth and markedly decreased bone mineral content in growth hormone receptor -/- mice.
- 2000
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In: Biochemical and biophysical research communications. - : Elsevier BV. - 0006-291X. ; 267:2, s. 603-8
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Journal article (peer-reviewed)abstract
- Growth hormone (GH) is important for skeletal growth as well as for a normal bone metabolism in adults. The skeletal growth and adult bone metabolism was studied in mice with an inactivated growth hormone receptor (GHR) gene. The lengths of femur, tibia, and crown-rump were, as expected, decreased in GHR-/- mice. Unexpectedly, GHR-/- mice displayed disproportional skeletal growth reflected by decreased femur/crown-rump and femur/tibia ratios. GHR-/- mice demonstrated decreased width of the growth plates in the long bones and disturbed ossification of the proximal tibial epiphysis. Furthermore, the area bone mineral density (BMD) as well as the bone mineral content (BMC)/body weight were markedly decreased in GHR-/- mice. The decrease in BMC in GHR-/- mice was not due to decreased trabecular volumetric BMD but to a decreased cross-sectional cortical bone area In conclusion, GHR-/- mice demonstrate disproportional skeletal growth and markedly decreased bone mineral content.
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