Rattus norvegicus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA141463 | ENA |
REPOSITORIES: ENA
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Project description:This study, using a growth hormone (GH)-deficient dwarf animal model and peripheral GH replacement, investigated the effects of circulating IGF-1 during adolescence on IGF-1 levels in the brain. Our results demonstrated that hippocampal IGF-1 protein concentrations during adolescence are highly regulated by circulating IGF-1, which were reduced by GH deficiency and restored by systematic GH replacement. In contrast, IGF-1 levels in the CSF were decreased by GH deficiency but not restored by GH replacement. Furthermore, analysis of gene expression using microarrays and RT-PCR indicated that circulating IGF-1 levels did not modify the transcription of IGF-1 or its receptor in the hippocampus but did regulate genes that are involved in microvascular structure and function, brain development, and synaptic plasticity, which potentially support brain structures involved in cognitive function during this important developmental period.
2011-07-21 | GSE29512 | GEO
Project description:This study, using a growth hormone (GH)-deficient dwarf animal model and peripheral GH replacement, investigated the effects of circulating IGF-1 during adolescence on IGF-1 levels in the brain. Our results demonstrated that hippocampal IGF-1 protein concentrations during adolescence are highly regulated by circulating IGF-1, which were reduced by GH deficiency and restored by systematic GH replacement. In contrast, IGF-1 levels in the CSF were decreased by GH deficiency but not restored by GH replacement. Furthermore, analysis of gene expression using microarrays and RT-PCR indicated that circulating IGF-1 levels did not modify the transcription of IGF-1 or its receptor in the hippocampus but did regulate genes that are involved in microvascular structure and function, brain development, and synaptic plasticity, which potentially support brain structures involved in cognitive function during this important developmental period. GH-deficient dwarf (dw/dw) and heterozygous (HZ) rats were identified at postnatal day 33-34. Starting from d35, dw/dw rats received subcutaneous injection of either 300µg GH (dw/dw+GH) or saline (dw/dw+sal) for 7d or 30d. HZ animals received saline for the same periods as controls. Animals (n=4/group for each time point) were sacrificed, the hippocampi were dissected, and total RNA were isolated for subsequent transcriptomic profiling.
2011-07-20 | E-GEOD-29512 | biostudies-arrayexpress
Project description:Healthy adults with serum insulin like growth factor -1 (IGF-I) levels at the lowest quartile of normal ranges have increased fat metabolism and reduced glucose utlisation compared with those in the highest quartile during fasting We used gene expression in skeletal muscle to explore metabolism during fasting We selected healthy males from a bioresource based on extremes of circulating IGF-I levels on stored sera and evaluated during a 24 hour fasting
2013-11-15 | E-GEOD-49297 | biostudies-arrayexpress
Project description:In rats, learning and memory performance decline during normal aging, which makes this rodent species a suitable model to evaluate therapeutic strategies. In aging rats, insulin-like growth factor-I (IGF-I), is known to significantly improve spatial memory accuracy as compared to control counterparts. A constellation of gene expression changes underlie the hippocampal phenotype of aging but no studies on the effects of IGF-I on the hippocampal transcriptome of old rodents have been documented. Here, we assessed the effects of IGF-I gene therapy on spatial memory performance in old female rats and compared them with changes in the hippocampal transcriptome.
2017-06-17 | GSE100021 | GEO
Project description:Basic helix loop helix enhancer 40 (Bhlhe40) is a transcription factor expressed in rodent hippocampus, however, its role in neuronal function is not well understood. Here, we used Bhlhe40 null mice on a congenic C57Bl6/J background (Bhlhe40 KO) to investigate the impact of Bhlhe40 on neuronal excitability and synaptic plasticity. A whole genome expression array predicted that Bhlhe40 KO mice have up-regulated insulin-related pathways and down-regulated neuronal signaling-related pathways in the hippocampus. We validated that insulin degrading enzyme mRNA (Ide) and IDE protein are significantly downregulated in Bhlhe40 KO hippocampi. No significant difference was observed in hippocampal insulin levels. In hippocampal slices, we found CA1 neurons have increased miniature excitatory post-synaptic current (mEPSC) amplitude and decreased inhibitory post-synaptic current (IPSC) amplitude, indicating hyper-excitability in CA1 neurons in Bhlhe40 KO mice. At CA1 synapses, we found a reduction in long term potentiation (LTP) and long term depression (LTD), indicating an impairment in hippocampal synaptic plasticity in Bhlhe40 KO hippocampal slices. Bhlhe40 KO mice displayed no difference in seizure response to the convulsant kainic acid (KA) relative to controls. We found that while Bhlhe40 KO mice have decreased exploratory behavior they do not display alterations in spatial learning and memory. Together this suggests that Bhlhe40 plays a role in modulating neuronal excitability and synaptic plasticity ex vivo, however, Bhlhe40 alone does not play a significant role in seizure susceptibility and learning and memory in vivo. In addition, based on the reduction in IDE protein levels in these mice, there may be dysregulation of other known IDE substrates, namely insulin growth factor (Igf)-1, Igf-2, and Amyloid beta (Aβ).
2018-05-03 | GSE85959 | GEO
Project description:Analysis of newborn mouse epidermis lacking the expression of Insulin receptor (IR) and Insulin like growth factor 1 receptor (IGF-1R). Results show that IR/IGF-1R signalling control epidermal morphogenesis.
2013-05-18 | GSE47065 | GEO
Project description:Although Insulin-like Growth Factor (IGF-1) signaling promotes tumor growth and cancer progression, IGF-1 Receptor-targeted therapies have shown poor clinical efficacy. The mechanistic basis for this is unclear as is our understanding of what distinguishes IGF-1R signaling from the closely related Insulin receptor (IR) signaling. This study illuminates both issues. A site in the IGF-1R C-terminal tail incorporating two tyrosines that are not present in the Insulin receptor (IR) was previously shown to be essential for IGF-1-mediated cancer cell survival, migration and tumorigenic growth. Here, we establish that the Y1250/Y1251 site is autophosphorylated in a cell adhesion-dependent manner.
2020-05-15 | PXD017644 | Pride
Project description:Neurotrophic factors (NTFs) are a relevant group of secreted proteins that modulate growth, differentiation, repair, and survival of neurons; playing a role in the maintenance of the synaptic unions, dendrites and axons; also, being crucial for peripheral nervous system development and regulating plasticity in the adult central nervous system. On the other hand, insulin-like growth factor 1 (IGF-1) has been ascertained multiple beneficial actions in the brain: neuro-development, -protection, -genesis and plasticity. To further investigate the possible mechanisms underlying IGF-1 deficiency in the establishment of neurological disease, microarray and RT-qPCR gene expression analyses coupled with in silico processing were performed in an experimental model of partial IGF-1 deficiency. Results show that the mere IGF-1 deficiency seems to be responsible for an altered expression of genes coding for neurotrophic factors (particularly ciliary neurotrophic factor and mesencephalic astrocyte-derived neurotrophic factor), their receptors and signaling pathways (specially RET). The presented findings support that IGF-1 deficiency might be involved in the establishment and progression of neurodegenerative disorders.
2018-12-29 | E-MTAB-7508 | biostudies-arrayexpress
Project description:Protein malnutrition promotes hepatic steatosis, decreases insulin-like growth factor (IGF)-I production, and retards growth. In order to identify new molecules involved in such changes, we conducted DNA microarray analysis for liver samples of rats fed isoenergetic low protein diet for 8 hours, and identified fibroblast growth factor 21 (Fgf21) as one of the most strongly up-regulated genes under conditions of acute protein malnutrition (P<0.05, FDR<0.001). In addition, amino acid deprivation from the culture media increased Fgf21 mRNA levels in rat liver-derived RL-34 cells (P<0.01). Thus, it was suggested that amino acid limitation directly increases Fgf21 expression. FGF21 is a polypeptide hormone that regulates glucose and lipid metabolism. Using transgenic mice, FGF21 has also been shown to promote a growth hormone-resistant state and suppress IGF-I. Therefore, to further determine whether the up-regulation of Fgf21 under protein malnutrition causes hepatic steatosis and growth retardation following decrease in IGF-I, we fed isoenergetic low protein diet to Fgf21-knockout (KO) mice. Fgf21-KO did not rescue growth retardation and reduced plasma IGF-I concentration of mice fed the low-protein diet. Meanwhile, Fgf21-KO mice showed greater epididymal white adipose tissue weight as well as hepatic triglyceride and cholesterol levels under protein malnutrition (P<0.05). Taken together, we showed that protein deprivation directly increases Fgf21 expression. However, growth retardation and decreased IGF-I were not mediated by increased FGF21 expression under protein malnutrition. Furthermore, up-regulated FGF21 rather appears to have a protective effect against obesity and hepatic steatosis in protein malnourished animals. Livers of rats from 2 groups (control (15P) or low-protain (5P) diet fed groups), total of 6 samples (3 replicates for each group) were analyzed.
2015-01-15 | E-GEOD-64970 | biostudies-arrayexpress
Project description:Non–islet-cell tumor hypoglycemia (NICTH) is a rare paraneoplastic phenomenon seen in both dogs and humans. NICTH syndrome is derived from incompletely processed forms of insulin-like growth factor–II (IGF–II) by tumors, commonly named as big IGF–II. In the present study, a previously developed targeted PRM MS-based method for cats have been optimized and applied to simultaneously quantify the levels of IGF–I, IGF–II, and IGFBP–3, and for the first time, the levels of big IGF–II in dogs. This method allows the absolute quantification of these proteins using a mixture of QPrEST™ proteins previously designed for humans, reducing the variations due to the methodology, and the amount of serum needed for the analysis.
2018-11-04 | PXD009277 | Pride