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Ethinylestradiol differentially interferes with IGF-I in liver and extrahepatic sites during development of male and female bony fishmore
by Elisabeth Eppler and Natallia Shved
Publication Date: 2007
Publication Name: Journal of Endocrinology
Research Interests: Endocrinology, Aging, Animal Production, In Situ Hybridization, real time PCR, and 20 moreGrowth Hormone, Brain, Liver, Sex ratio, Female, Animals, Male, Early development, Body Size, tESTIS, Clinical Sciences, Pituitary Gland, Tilapia, Gills, Body Weight, Veterinary Sciences, Sexual Development, Ovary, Germ Cell, and Estrogen receptor alpha
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Seawater and freshwater challenges affect the insulin-like growth factors IGF-I and IGF-II in liver and osmoregulatory organs of the tilapiamore
by Elisabeth Eppler and Natallia Shved
Publication Date: 2010
Publication Name: Molecular and Cellular Endocrinology
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IGF-I is distinctly located in the bony fish pituitary as revealed for Oreochromis niloticus, the Nile tilapia, using real-time RT-PCR, in situ hybridisation and immunohistochemistrymore
by Elisabeth Eppler and Natallia Shved
Publication Date: 2007
Publication Name: General and Comparative Endocrinology
Research Interests: Physiology, Zoology, Immunohistochemistry, Gene expression, Real-time RT-PCR, and 15 moreIn Situ Hybridization, Brain Mapping, Animals, Negative Feedback, Nutritional Status, Neurons, Cichlids, Nile Tilapia, Adrenocorticotropic Hormone, Veterinary Sciences, Oreochromis niloticus, Individual Difference, Alpha MSH, In Situ Hybridisation, and Anterior Pituitary
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Growth hormone (GH) treatment acts on the endocrine and autocrine/paracrine GH/IGF-axis and on TNF-α expression in bony fish pituitary and immune organsmore
by Elisabeth Eppler and Natallia Shved
There exist indications that the growth hormone (GH)/insulin-like growth factor (IGF) axis may play a role in fish immune regulation, and that interactions occur via tumour necrosis factor (TNF)-α at least in mammals, but no systematic... more
There exist indications that the growth hormone (GH)/insulin-like growth factor (IGF) axis may play a role in fish immune regulation, and that interactions occur via tumour necrosis factor (TNF)-α at least in mammals, but no systematic data exist on potential changes in GH, IGF-I, IGF-II, GH receptor (GHR) and TNF-α expression after GH treatment. Thus, we investigated in the Nile tilapia the influence of GH injections by real-time qPCR at different levels of the GH/IGF-axis (brain, pituitary, peripheral organs) with special emphasis on the immune organs head kidney and spleen. Endocrine IGF-I served as positive control for GH treatment efficiency. Basal TNF-α gene expression was detected in all organs investigated with the expression being most pronounced in brain. Two consecutive intraperitoneal injections of bream GH elevated liver IGF-I mRNA and plasma IGF-I concentration. Also liver IGF-II mRNA and TNF-α were increased while the GHR was downregulated. In brain, no change occurred in the expression levels of all genes investigated. GH gene expression was exclusively detected in the pituitary where the GH injections elevated both GH and IGF-I gene expression. In the head kidney, GH upregulated IGF-I mRNA to an even higher extent than liver IGF-I while IGF-II and GHR gene expressions were not affected. Also in the spleen, no change occurred in GHR mRNA, however, IGF-I and IGF-II mRNAs were increased. In correlation, in situ hybridisation showed a markedly higher amount of IGF-I mRNA in head kidney and spleen after GH injection. In both immune tissues, TNF-α gene expression showed a trend to decrease after GH treatment. The stimulation of IGF-I and also partially of IGF-II expression in the fish immune organs by GH indicates a local role of the IGFs in immune organ regulation while the differential changes in TNF-α support the in mammals postulated interactions with the GH/IGF-axis which demand for further investigations.
Publication Date: 2011
Publication Name: Fish & Shellfish Immunology
Research Interests: Zoology, Gene expression, In Situ Hybridization, Spleen, Growth Hormone, and 14 moreLiver, Animals, Immune regulation, Fisheries Sciences, Cichlids, Nile Tilapia, Real Time, Tumor necrosis factor-alpha, Head Kidney, Veterinary Sciences, Cell communication, Growth Factor, In Situ Hybridisation, and Gene Expression Regulation
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A Survey on the Expression of IGF-I in the Early Developing Bony Fish with Special Emphasis on the Tilapia, Oreochromis niloticusmore
by Elisabeth Eppler and Natallia Shved
Publication Date: 2005
Publication Name: Annals of the New York Academy of Sciences
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Further Insights into the Insulin-like Growth Factor-I System of Bony Fish Pituitary with Special Emphasis on Reproductive Phases and Social Statusmore
by Elisabeth Eppler and Natallia Shved
Publication Date: 2009
Publication Name: Annals of the New York Academy of Sciences
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Organ-specific expression of IGF-I during early development of bony fish as revealed in the tilapia, Oreochromis niloticus, by in situ hybridization and immunohistochemistry: indication for the particular importance of local IGF-Imore
by Elisabeth Eppler and Natallia Shved
Publication Date: 2006
Publication Name: Cell and Tissue Research
Research Interests: Immunohistochemistry, In Situ Hybridization, Brain, Kidney, Muscle, and 17 moreCartilage, Pancreas, Animals, Heart, Muscles, Early development, Skin, Medical Physiology, Epidermis, Tilapia, Skeletal Muscle, Myocardium, Larva, Gills, Gastrointestinal Tract, Oreochromis niloticus, and Epidermal Stem Cells
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Challenge with 17α-ethinylestradiol (EE2) during early development persistently impairs growth, differentiation, and local expression of IGF-I and IGF-II in immune organs of tilapiamore
by Elisabeth Eppler and Natallia Shved
The enormous expansion of world-wide aquaculture has led to increasing interest in the regulation of fish immune system. Estrogen has recently been shown to inhibit the endocrine (liver-derived) and autocrine/paracrine local insulin-like... more
The enormous expansion of world-wide aquaculture has led to increasing interest in the regulation of fish immune system. Estrogen has recently been shown to inhibit the endocrine (liver-derived) and autocrine/paracrine local insulin-like growth factor-I system in fish. In order to address the potential actions of estrogen on the IGF system in immune organs, tilapia were fed with 17alpha-ethinylestradiol (EE2)-enriched food from 10 to 40 days post fertilization (DPF) to induce functional feminization, an approach commonly used in aquaculture. EE2-treated and control fish were sampled at 75 and 165 DPF. The expression levels of ER-alpha, IGF-I, IGF-II and growth hormone receptor (GH-R) mRNA in spleen and head kidney were determined by real-time PCR and the expressing sites of IGF-I mRNA identified by in situ hybridisation. Ratios of spleen length and weight to body length and weight were determined. At 165 DPF, the length (4.9% vs. 7.6%) and weight (0.084% vs. 0.132%) ratios were significantly lowered in EE2-treated fish and number and size of the melanomacrophage centres were considerably reduced. At 75 DPF, both in spleen and head kidney of EE2-treated fish the expression levels of IGF-I and IGF-II mRNA were markedly diminished. The suppression was more pronounced for IGF-I (spleen: -12.071-fold; head kidney: -8.413-fold) than for IGF-II (spleen: -4.102-fold; head kidney: -1.342-fold). In agreement, clearly fewer leucocytes and macrophages in head kidney and spleen of EE2-treated fish contained IGF-I mRNA as shown by in situ hybridisation. ER-alpha mRNA expression in spleen was increased at 75 DPF but unchanged in head kidney. GH-R gene expression showed a mild upregulation at 165 DPF in both tissues. Thus, exposure to EE2 during early development affected distinctly the IGF system in tilapia immune organs. It led to lasting impairment of spleen growth and differentiation that can be attributed to an interaction of EE2 with IGF-I and, less pronouncedly, IGF-II. Especially, the impairment of spleen and melanomacrophage centres might interfere with the antigen presentation capacity of the immune system and, thus, alter susceptibility to infection.
Publication Date: 2009
Publication Name: Fish & Shellfish Immunology
Research Interests: Zoology, Gene expression, In Situ Hybridization, Protein Stability, Estrogen Receptor, and 16 moreSpleen, real time PCR, Cell Differentiation, Animals, Antigen Presentation, Early development, Fisheries Sciences, mRna expression levels, Immune system, Tilapia, Estrogens, Growth Hormone Receptor, Veterinary Sciences, Fish and Shellfish Diseases, In Situ Hybridisation, and Gene Expression Regulation
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A systematic immunohistochemical survey of the distribution patterns of GH, prolactin, somatolactin, β–TSH, β–FSH, β–LH, ACTH, and α–MSH in the adenohypophysis of Oreochromis niloticus, the Nile tilapiamore
by Elisabeth Eppler and Natallia Shved
Publication Date: 2006
Publication Name: Cell and Tissue Research
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Insulin-like growth factor I (IGF-I) in a growth-enhanced transgenic (GH-overexpressing) bony fish, the tilapia (Oreochromis niloticus): indication for a higher impact of autocrine/paracrine than of endocrine IGF-Imore
by Elisabeth Eppler and Natallia Shved
Publication Date: 2007
Publication Name: Transgenic Research
Research Interests: Technology, Skeletal muscle biology, Immunohistochemistry, Real-time RT-PCR, In Situ Hybridization, and 11 moreBiological Sciences, Growth Hormone, Liver, Animals, mRna expression levels, Tilapia, Skeletal Muscle, The Endocrine System Function, Oreochromis niloticus, Transgenic, and Radioimmunoassay
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