ANGPTL4 regulates plasma triglyceride levels by inhibiting lipoprotein lipase. Inactivation of ANGPTL4 decreases plasma triglycerides and reduces risk of coronary artery disease. Unfortunately, targeting ANGPTL4 for the therapeutic management of dyslipidemia and atherosclerosis is hampered by the observation that mice and monkeys in which ANGPTL4 is inactivated exhibit lipid accumulation in mesenteric lymph nodes. In mice these pathological events exclusively unfold upon feeding a high saturated fatty acid diet and are followed by an ultimately lethal pro-inflammatory response and chylous ascites. Here we show that Angptl4-/- mice fed a diet rich in trans fatty acids develop numerous lipid-filled giant cells in their mesenteric lymph nodes, yet do not have elevated serum amyloid and haptoglobin, do not exhibit ascites, and survive, unlike Angptl4-/- mice fed a saturated fatty acid-rich diet. In RAW264.7 macrophages the saturated fatty acid palmitate markedly increases markers of inflammation and the unfolded protein response, whereas the trans-unsaturated elaidate and the cis-unsaturated oleate have the opposite effect. In conclusion, trans and saturated fatty acids have very distinct biological effects. Furthermore, lipid accumulation in mesenteric lymph nodes is uncoupled from activation of an acute-phase response and chylous ascites, suggesting that ANGPTL4 should not be fully dismissed as target for dyslipidemia.
Feeding <i>Angptl4</i><sup>-/-</sup> mice <i>trans</i> fat promotes foam cell formation in mesenteric lymph nodes without leading to ascites.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Industrial Trans Fatty Acids Stimulate SREBP2-Mediated Cholesterogenesis and Promote Non-Alcoholic Fatty Liver Disease.
Treatment
View SamplesScope: Consumption of industrial trans fatty acids unfavourably alters plasma cholesterol and has been linked to NAFLD. However, the mechanisms underlying these deleterious effects of trans fatty acids are unclear. Here, we aim to investigate the molecular mechanisms of action of industrial trans fatty acids. Methods & Results: Hepa1-6 hepatoma cells were incubated with elaidate, oleate, or palmitate. C57Bl/6 mice were fed diets rich in trans-unsaturated, cis-unsaturated or saturated fatty acids. Transcriptomics analysis of Hepa1-6 cells showed that elaidate but not oleate or palmitate induced expression of genes involved in cholesterol biosynthesis. Induction of cholesterogenesis by elaidate was mediated by increased SREBP2 and dependent on SCAP, yet independent of LXR and UBXD8. Elaidate decreased intracellular free cholesterol levels and repressed the anti-cholesterogenic effect of exogenous cholesterol. In mice, the trans-unsaturated diet increased the ratio of liver to gonadal fat mass, steatosis, hepatic cholesterol levels, ALT activity, and fibrosis markers, suggesting enhanced NAFLD, compared to the cis-unsaturated and saturated diets. Conclusion: Elaidate induces cholesterogenesis in vitro via activation of the SCAP-SREBP axis, likely by lowering intracellular free cholesterol and attenuating cholesterol-dependent repression of SCAP. This pathway potentially underlies the increase in liver cholesterol and NAFLD by industrial trans fatty acids.
Industrial Trans Fatty Acids Stimulate SREBP2-Mediated Cholesterogenesis and Promote Non-Alcoholic Fatty Liver Disease.
No sample metadata fields
View SamplesScope: Consumption of industrial trans fatty acids unfavourably alters plasma cholesterol and has been linked to NAFLD. However, the mechanisms underlying these deleterious effects of trans fatty acids are unclear. Here, we aim to investigate the molecular mechanisms of action of industrial trans fatty acids. Methods & Results: Hepa1-6 hepatoma cells were incubated with elaidate, oleate, or palmitate. C57Bl/6 mice were fed diets rich in trans-unsaturated, cis-unsaturated or saturated fatty acids. Transcriptomics analysis of Hepa1-6 cells showed that elaidate but not oleate or palmitate induced expression of genes involved in cholesterol biosynthesis. Induction of cholesterogenesis by elaidate was mediated by increased SREBP2 and dependent on SCAP, yet independent of LXR and UBXD8. Elaidate decreased intracellular free cholesterol levels and repressed the anti-cholesterogenic effect of exogenous cholesterol. In mice, the trans-unsaturated diet increased the ratio of liver to gonadal fat mass, steatosis, hepatic cholesterol levels, ALT activity, and fibrosis markers, suggesting enhanced NAFLD, compared to the cis-unsaturated and saturated diets. Conclusion: Elaidate induces cholesterogenesis in vitro via activation of the SCAP-SREBP axis, likely by lowering intracellular free cholesterol and attenuating cholesterol-dependent repression of SCAP. This pathway potentially underlies the increase in liver cholesterol and NAFLD by industrial trans fatty acids.
Industrial Trans Fatty Acids Stimulate SREBP2-Mediated Cholesterogenesis and Promote Non-Alcoholic Fatty Liver Disease.
Treatment
View SamplesScope: Consumption of industrial trans fatty acids unfavourably alters plasma cholesterol and has been linked to NAFLD. However, the mechanisms underlying these deleterious effects of trans fatty acids are unclear. Here, we aim to investigate the molecular mechanisms of action of industrial trans fatty acids. Methods & Results: Hepa1-6 hepatoma cells were incubated with elaidate, oleate, or palmitate. C57Bl/6 mice were fed diets rich in trans-unsaturated, cis-unsaturated or saturated fatty acids. Transcriptomics analysis of Hepa1-6 cells showed that elaidate but not oleate or palmitate induced expression of genes involved in cholesterol biosynthesis. Induction of cholesterogenesis by elaidate was mediated by increased SREBP2 and dependent on SCAP, yet independent of LXR and UBXD8. Elaidate decreased intracellular free cholesterol levels and repressed the anti-cholesterogenic effect of exogenous cholesterol. In mice, the trans-unsaturated diet increased the ratio of liver to gonadal fat mass, steatosis, hepatic cholesterol levels, ALT activity, and fibrosis markers, suggesting enhanced NAFLD, compared to the cis-unsaturated and saturated diets. Conclusion: Elaidate induces cholesterogenesis in vitro via activation of the SCAP-SREBP axis, likely by lowering intracellular free cholesterol and attenuating cholesterol-dependent repression of SCAP. This pathway potentially underlies the increase in liver cholesterol and NAFLD by industrial trans fatty acids.
Industrial Trans Fatty Acids Stimulate SREBP2-Mediated Cholesterogenesis and Promote Non-Alcoholic Fatty Liver Disease.
Treatment
View SamplesANGPTL4 regulates plasma lipids, making it an attractive target for correcting dyslipidemia. However, ANGPTL4 inactivation in mice fed a high fat diet causes chylous ascites, an acute-phase response, and mesenteric lymphadenopathy. Here, we studied the role of ANGPTL4 in lipid uptake in macrophages and in the above-mentioned pathologies using Angptl4-hypomorphic and Angptl4-/- mice. Angptl4 expression in peritoneal and bone marrow-derived macrophages was highly induced by lipids. Recombinant ANGPTL4 decreased lipid uptake in macrophages, whereas deficiency of ANGPTL4 increased lipid uptake, upregulated lipid-induced genes, and increased respiration. ANGPTL4 deficiency did not alter LPL protein levels in macrophages. Angptl4-hypomorphic mice with partial expression of a truncated N-terminal ANGPTL4 exhibited reduced fasting plasma triglyceride, cholesterol, and non-esterified fatty acid levels, strongly resembling Angptl4-/- mice. However, during high fat feeding, Angptl4-hypomorphic mice showed markedly delayed and attenuated elevation in plasma serum amyloid A and much milder chylous ascites than Angptl4-/- mice, despite similar abundance of lipid-laden giant cells in mesenteric lymph nodes. In conclusion, ANGPTL4 deficiency increases lipid uptake and respiration in macrophages without affecting LPL protein levels. Compared with the absence of ANGPTL4, low levels of N-terminal ANGPTL4 mitigate the development of chylous ascites and an acute-phase response in mice.
Characterization of ANGPTL4 function in macrophages and adipocytes using <i>Angptl4</i>-knockout and <i>Angptl4</i>-hypomorphic mice.
No sample metadata fields
View SamplesThe liver is one of the most sexually dimorphic organs as measured by gene expression differences. About 80% of the sexually dimorphic genes are known to be regulated by growth hormone (GH). Somatostatin (SST) inhibits the release of GH.
Somatostatin is essential for the sexual dimorphism of GH secretion, corticosteroid-binding globulin production, and corticosterone levels in mice.
Sex, Specimen part
View SamplesPancreatic islet transplantation was performed in the subcutaneous space of diabetic nude mice. In order to promote long survival and function of transplanted islets a plasma-based scaffold was developed in combination with fibroblasts as graft-supporting accesory cells. Gene expression analysis was carried out to evaluate expression differences due to the presence of fibroblast which could explain the long-term glycemic control observed under these circumstances.
Fibroblasts accelerate islet revascularization and improve long-term graft survival in a mouse model of subcutaneous islet transplantation.
Disease, Time
View SamplesNeuroblastoma (NBL) is an embryonal cancer of the sympathetic nervous system (SNS) that causes 15% of pediatric cancer deaths. High-risk neuroblastoma is characterized by N-Myc amplification and segmental chromosomal gains and losses. Due to limited disease models, the etiology of neuroblastoma is largely unknown, including both the cell of origin and the majority of oncogenic drivers. We have established a novel system for studying neuroblastoma based on the transformation of neural crest cells (NCCs), the progenitor cells of the SNS, isolated from mouse embryonic day 9.5 trunk neural tube explants. Based on pathology and gene expression analysis, we report the first successful transformation of wild-type NCCs into NBL by enforced expression of N-Myc to generate phenotypically and molecularly accurate tumors that closely model human MYCN-amplified NBL. Using comparative genomic hybridization, we found that NCC-derived neuroblastoma tumors acquired copy number gains and losses that are syntenic to those observed in human MYCN-amplified neuroblastoma including 17q gain, 2p gain and loss of 1p36. When p53-compromised NCCs were transformed with N-Myc we generated primitive neuroectodermal tumors with divergent differentiation including osteosarcoma. These subcutaneous tumors were metastatic to regional lymph nodes, liver and lung. Our novel experimental approach accurately models human neuroblastoma and establishes a new system with potential to study early stages of neuroblastoma oncogenesis, to functionally assess neuroblastoma oncogenic drivers, and to characterize neuroblastoma metastasis.
MYCN induces neuroblastoma in primary neural crest cells.
Specimen part
View SamplesIdentify genes which are induced in wild type, crel ko, and relbcrle dbko B cells under BAFF stimulation, and find the differential expressed genes which are distinct from wildtype controls. Overall design: RNA-seq analysis of wild type, crelko, relbcrel dbko follicular B cells stimulated with BAFF ligand for 6 hours and wildtype only for 27 hours
B-cell survival and development controlled by the coordination of NF-κB family members RelB and cRel.
No sample metadata fields
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