The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Joakim Franz - One of the best experts on this subject based on the ideXlab platform.
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trans fats inhibit autophagy induced by Saturated Fatty Acids
EBioMedicine, 2018Co-Authors: Allan Sauvat, Guo Chen, Kevin Muller, Mingming Tong, Fanny Aprahamian, Sylvere Durand, Giulia Cerrato, Lucillia Bezu, Marion Leduc, Joakim FranzAbstract:Depending on the length of their carbon backbone and their saturation status, natural Fatty Acids have rather distinct biological effects. Thus, longevity of model organisms is increased by extra supply of the most abundant natural cis-unSaturated Fatty acid, oleic acid, but not by that of the most abundant Saturated Fatty acid, palmitic acid. Here, we systematically compared the capacity of different Saturated, cis-unSaturated and alien (industrial or ruminant) trans-unSaturated Fatty Acids to provoke cellular stress in vitro, on cultured human cells expressing a battery of distinct biosensors that detect signs of autophagy, Golgi stress and the unfolded protein response. In contrast to cis-unSaturated Fatty Acids, trans-unSaturated Fatty Acids failed to stimulate signs of autophagy including the formation of GFP-LC3B-positive puncta, production of phosphatidylinositol-3-phosphate, and activation of the transcription factor TFEB. When combined effects were assessed, several trans-unSaturated Fatty Acids including elaidic acid (the trans-isomer of oleate), linoelaidic acid, trans-vaccenic acid and palmitelaidic acid, were highly efficient in suppressing autophagy and endoplasmic reticulum stress induced by palmitic, but not by oleic acid. Elaidic acid also inhibited autophagy induction by palmitic acid in vivo, in mouse livers and hearts. We conclude that the well-established, though mechanistically enigmatic toxicity of trans-unSaturated Fatty Acids may reside in their capacity to abolish cytoprotective stress responses induced by Saturated Fatty Acids.
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Trans-Fats Inhibit Autophagy Induced by Saturated Fatty Acids
Elsevier, 2018Co-Authors: Allan Sauvat, Guo Chen, Kevin Muller, Mingming Tong, Fanny Aprahamian, Sylvere Durand, Giulia Cerrato, Lucillia Bezu, Marion Leduc, Joakim FranzAbstract:Depending on the length of their carbon backbone and their saturation status, natural Fatty Acids have rather distinct biological effects. Thus, longevity of model organisms is increased by extra supply of the most abundant natural cis-unSaturated Fatty acid, oleic acid, but not by that of the most abundant Saturated Fatty acid, palmitic acid. Here, we systematically compared the capacity of different Saturated, cis-unSaturated and alien (industrial or ruminant) trans-unSaturated Fatty Acids to provoke cellular stress in vitro, on cultured human cells expressing a battery of distinct biosensors that detect signs of autophagy, Golgi stress and the unfolded protein response. In contrast to cis-unSaturated Fatty Acids, trans-unSaturated Fatty Acids failed to stimulate signs of autophagy including the formation of GFP-LC3B-positive puncta, production of phosphatidylinositol-3-phosphate, and activation of the transcription factor TFEB. When combined effects were assessed, several trans-unSaturated Fatty Acids including elaidic acid (the trans-isomer of oleate), linoelaidic acid, trans-vaccenic acid and palmitelaidic acid, were highly efficient in suppressing autophagy and endoplasmic reticulum stress induced by palmitic, but not by oleic acid. Elaidic acid also inhibited autophagy induction by palmitic acid in vivo, in mouse livers and hearts. We conclude that the well-established, though mechanistically enigmatic toxicity of trans-unSaturated Fatty Acids may reside in their capacity to abolish cytoprotective stress responses induced by Saturated Fatty Acids. Keywords: Fasting, Ketogenic diet, Immune response, Immunosurveillance, Obesity, Aging, Cytoprotection, Systems biolog
Daniel H Hwang - One of the best experts on this subject based on the ideXlab platform.
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mechanisms for the activation of toll like receptor 2 4 by Saturated Fatty Acids and inhibition by docosahexaenoic acid
European Journal of Pharmacology, 2016Co-Authors: Daniel H Hwang, Jeonga Kim, Joo Young LeeAbstract:Saturated Fatty Acids can activate Toll-like receptor 2 (TLR2) and TLR4 but polyunSaturated Fatty Acids, particularly docosahexaenoic acid (DHA) inhibit the activation. Lipopolysaccharides (LPS) and lipopetides, ligands for TLR4 and TLR2, respectively, are acylated by Saturated Fatty Acids. Removal of these Fatty Acids results in loss of their ligand activity suggesting that the Saturated Fatty acyl moieties are required for the receptor activation. X-ray crystallographic studies revealed that these Saturated Fatty acyl groups of the ligands directly occupy hydrophobic lipid binding domains of the receptors (or co-receptor) and induce the dimerization which is prerequisite for the receptor activation. Saturated Fatty Acids also induce the dimerization and translocation of TLR4 and TLR2 into lipid rafts in plasma membrane and this process is inhibited by DHA. Whether Saturated Fatty Acids induce the dimerization of the receptors by interacting with these lipid binding domains is not known. Many experimental results suggest that Saturated Fatty Acids promote the formation of lipid rafts and recruitment of TLRs into lipid rafts leading to ligand independent dimerization of the receptors. Such a mode of ligand independent receptor activation defies the conventional concept of ligand induced receptor activation; however, this may enable diverse non-microbial molecules with endogenous and dietary origins to modulate TLR-mediated immune responses. Emerging experimental evidence reveals that TLRs play a key role in bridging diet-induced endocrine and metabolic changes to immune responses.
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Saturated Fatty Acids activate tlr mediated proinflammatory signaling pathways
Journal of Lipid Research, 2012Co-Authors: Shurong Huang, Jennifer M Rutkowsky, Ryan G Snodgrass, Kikumi D Onomoore, Dina A Schneider, John W Newman, Sean H Adams, Daniel H HwangAbstract:Toll-like receptor 4 (TLR4) and TLR2 were shown to be activated by Saturated Fatty Acids (SFAs) but inhibited by docosahexaenoic acid (DHA). However, one report suggested that SFA-induced TLR activation in cell culture systems is due to contaminants in BSA used for solubilizing Fatty Acids. This report raised doubt about proinflammatory effects of SFAs. Our studies herein demonstrate that sodium palmitate (C16:0) or laurate (C12:0) without BSA solubilization induced phosphorylation of inhibitor of nuclear factor-κB α, c-Jun N-terminal kinase (JNK), p44/42 mitogen-activated-kinase (ERK), and nuclear factor-κB subunit p65, and TLR target gene expression in THP1 monocytes or RAW264.7 macrophages, respectively, when cultured in low FBS (0.25%) medium. C12:0 induced NFκB activation through TLR2 dimerized with TLR1 or TLR6, and through TLR4. Because BSA was not used in these experiments, contaminants in BSA have no relevance. Unlike in suspension cells (THP-1), BSA-solubilized C16:0 instead of sodium C16:0 is required to induce TLR target gene expression in adherent cells (RAW264.7). C16:0-BSA transactivated TLR2 dimerized with TLR1 or TLR6 and through TLR4 as seen with C12:0. These results and additional studies with the LPS sequester polymixin B and in MyD88−/− macrophages indicated that SFA-induced activation of TLR2 or TLR4 is a Fatty acid-specific effect, but not due to contaminants in BSA or Fatty acid preparations.
Michael J Pagliassotti - One of the best experts on this subject based on the ideXlab platform.
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Saturated Fatty Acids promote endoplasmic reticulum stress and liver injury in rats with hepatic steatosis
Endocrinology, 2006Co-Authors: Dong Wang, Yure Wei, Michael J PagliassottiAbstract:Nonalcoholic Fatty liver disease is a relatively new hepatic sequela of obesity and type 2 diabetes. The pathogenesis of liver injury and disease progression in nonalcoholic Fatty liver disease, however, is poorly understood. The present study examined the hypothesis that the composition of Fatty Acids in the steatotic liver promotes liver injury. Using dietary models of hepatic steatosis characterized by similar accumulation of total triglyceride but different composition of Fatty Acids, we show that hepatic steatosis characterized by increased Saturated Fatty Acids is associated with increased liver injury and markers of endoplasmic reticulum stress (e.g. X-box binding protein-1 mRNA splicing and glucose-regulated protein 78 expression). These changes preceded and/or occurred independently of obesity and differences in leptin, TNFα, insulin action, and mitochondrial function. In addition, hepatic steatosis characterized by increased Saturated Fatty Acids reduced proliferative capacity in response to par...
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Saturated Fatty Acids promote endoplasmic reticulum stress and liver injury in rats with hepatic steatosis
Endocrinology, 2006Co-Authors: Dong Wang, Yuren Wei, Michael J PagliassottiAbstract:Nonalcoholic Fatty liver disease is a relatively new hepatic sequela of obesity and type 2 diabetes. The pathogenesis of liver injury and disease progression in nonalcoholic Fatty liver disease, however, is poorly understood. The present study examined the hypothesis that the composition of Fatty Acids in the steatotic liver promotes liver injury. Using dietary models of hepatic steatosis characterized by similar accumulation of total triglyceride but different composition of Fatty Acids, we show that hepatic steatosis characterized by increased Saturated Fatty Acids is associated with increased liver injury and markers of endoplasmic reticulum stress (e.g. X-box binding protein-1 mRNA splicing and glucose-regulated protein 78 expression). These changes preceded and/or occurred independently of obesity and differences in leptin, TNFalpha, insulin action, and mitochondrial function. In addition, hepatic steatosis characterized by increased Saturated Fatty Acids reduced proliferative capacity in response to partial hepatectomy and increased liver injury in response to lipopolysaccharide. These data suggest that the composition of Fatty Acids in the steatotic liver is an important determinant of susceptibility to liver injury.
Allan Sauvat - One of the best experts on this subject based on the ideXlab platform.
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trans fats inhibit autophagy induced by Saturated Fatty Acids
EBioMedicine, 2018Co-Authors: Allan Sauvat, Guo Chen, Kevin Muller, Mingming Tong, Fanny Aprahamian, Sylvere Durand, Giulia Cerrato, Lucillia Bezu, Marion Leduc, Joakim FranzAbstract:Depending on the length of their carbon backbone and their saturation status, natural Fatty Acids have rather distinct biological effects. Thus, longevity of model organisms is increased by extra supply of the most abundant natural cis-unSaturated Fatty acid, oleic acid, but not by that of the most abundant Saturated Fatty acid, palmitic acid. Here, we systematically compared the capacity of different Saturated, cis-unSaturated and alien (industrial or ruminant) trans-unSaturated Fatty Acids to provoke cellular stress in vitro, on cultured human cells expressing a battery of distinct biosensors that detect signs of autophagy, Golgi stress and the unfolded protein response. In contrast to cis-unSaturated Fatty Acids, trans-unSaturated Fatty Acids failed to stimulate signs of autophagy including the formation of GFP-LC3B-positive puncta, production of phosphatidylinositol-3-phosphate, and activation of the transcription factor TFEB. When combined effects were assessed, several trans-unSaturated Fatty Acids including elaidic acid (the trans-isomer of oleate), linoelaidic acid, trans-vaccenic acid and palmitelaidic acid, were highly efficient in suppressing autophagy and endoplasmic reticulum stress induced by palmitic, but not by oleic acid. Elaidic acid also inhibited autophagy induction by palmitic acid in vivo, in mouse livers and hearts. We conclude that the well-established, though mechanistically enigmatic toxicity of trans-unSaturated Fatty Acids may reside in their capacity to abolish cytoprotective stress responses induced by Saturated Fatty Acids.
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Trans-Fats Inhibit Autophagy Induced by Saturated Fatty Acids
Elsevier, 2018Co-Authors: Allan Sauvat, Guo Chen, Kevin Muller, Mingming Tong, Fanny Aprahamian, Sylvere Durand, Giulia Cerrato, Lucillia Bezu, Marion Leduc, Joakim FranzAbstract:Depending on the length of their carbon backbone and their saturation status, natural Fatty Acids have rather distinct biological effects. Thus, longevity of model organisms is increased by extra supply of the most abundant natural cis-unSaturated Fatty acid, oleic acid, but not by that of the most abundant Saturated Fatty acid, palmitic acid. Here, we systematically compared the capacity of different Saturated, cis-unSaturated and alien (industrial or ruminant) trans-unSaturated Fatty Acids to provoke cellular stress in vitro, on cultured human cells expressing a battery of distinct biosensors that detect signs of autophagy, Golgi stress and the unfolded protein response. In contrast to cis-unSaturated Fatty Acids, trans-unSaturated Fatty Acids failed to stimulate signs of autophagy including the formation of GFP-LC3B-positive puncta, production of phosphatidylinositol-3-phosphate, and activation of the transcription factor TFEB. When combined effects were assessed, several trans-unSaturated Fatty Acids including elaidic acid (the trans-isomer of oleate), linoelaidic acid, trans-vaccenic acid and palmitelaidic acid, were highly efficient in suppressing autophagy and endoplasmic reticulum stress induced by palmitic, but not by oleic acid. Elaidic acid also inhibited autophagy induction by palmitic acid in vivo, in mouse livers and hearts. We conclude that the well-established, though mechanistically enigmatic toxicity of trans-unSaturated Fatty Acids may reside in their capacity to abolish cytoprotective stress responses induced by Saturated Fatty Acids. Keywords: Fasting, Ketogenic diet, Immune response, Immunosurveillance, Obesity, Aging, Cytoprotection, Systems biolog
Yvon Mbesse G Kongbonga - One of the best experts on this subject based on the ideXlab platform.
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classification of vegetable oils based on their concentration of Saturated Fatty Acids using laser induced breakdown spectroscopy libs
Food Chemistry, 2014Co-Authors: Yvon Mbesse G Kongbonga, Hassen Ghalila, Marthe Boyomo Onana, Zohra Ben LakhdarAbstract:Spectrochemical analyses of organic liquid media such as vegetable oils and sweetened water were performed with the use of LIBS. The aim of this work is to study, on the basis of spectral analyses by LIBS technique of "Swan band" of C2 emitted by different vegetable oils in liquid phase, the characteristics of each organic media. Furthermore this paper proposes, as a classification, a single parameter that could be used to determine the concentration of Saturated Fatty Acids of vegetable oils. A Nd:YAG operating at λ=532 nm and an energies per pulse of 30 mJ was focused onto the surface of the liquid in ambient air. Following ablation of vegetable oils and sweetened water, we find that vibrational bonds of C2 were released from the molecule containing carbon-carbon bonds linear. In the case of vegetable oils, we find a clear relationship between C2 emission from the plasma and the concentration of Saturated Fatty Acids in the oil.
