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Scientific Reports Oct 2023To investigate the effects and potential mechanisms of human umbilical cord mesenchymal stem cells, exosomes, and their conditioned media on lipid storage in oleic acid...
To investigate the effects and potential mechanisms of human umbilical cord mesenchymal stem cells, exosomes, and their conditioned media on lipid storage in oleic acid (OA) and palmitic acid (PA) treated hepatocytes and high-fat methionine- choline deficient diet (HFMRCD) induced non-alcoholic steatohepatitis (NASH) mice. AML12 cells were stimulated with OA and PA to establish the lipid storage cell model. HucMSCs, exosomes, and culture medium were then co-cultured. At the same time, C57BL/6 mice were fed an HFMRCD for 6 or 8 weeks to establish a NASH mouse model. The effect of HucMSCs, exosomes, and culture medium on lipid droplet repair of hepatocytes or NASH mice was then assessed. The weight of hepatocytes or liver tissue, Oil Red O, hematoxylin-eosin staining, Masson staining, Western blot, and qPCR were used to detect the related IL-6, TNF-α, TGF-β1 andEI24/AMPK/mTOR pathway expression in hepatocytes and liver tissue. Compared with the model group, the effect of HucMSCs-Ex on inhibiting the accumulation of lipid droplets was more obvious at the cell level. In vivo study showed that HucMSCs-Ex reduces activity scores in NASH mice and improves liver tissue morphology by reducing vacuolar degeneration, fat deposition, and collagen deposition of liver tissue. Western blot and qPCR results showed that inflammatory factors and AMPK/mTOR or EI24-related autophagy pathways were altered before and after treatment. HucMSCs, HucMSC-Ex, and CM can promote autophagy in hepatocytes or NASH mice through the AMPK/mTOR or EI24-related autophagy pathway and alleviate injury associated with lipid deposition, collagen deposition or inflammation, reversing the progression of NASH.
Topics: Mice; Humans; Animals; Non-alcoholic Fatty Liver Disease; Culture Media, Conditioned; Exosomes; AMP-Activated Protein Kinases; Mice, Inbred C57BL; Liver; TOR Serine-Threonine Kinases; Palmitic Acid; Choline; Oleic Acid; Collagen; Mesenchymal Stem Cells
PubMed: 37891247
DOI: 10.1038/s41598-023-45828-3 -
Cell Death & Disease Sep 2023Excessive toxic lipid accumulation in hepatocytes underlies the development of non-alcoholic fatty liver disease (NAFLD), phenotypically characterized by necrosis and...
Excessive toxic lipid accumulation in hepatocytes underlies the development of non-alcoholic fatty liver disease (NAFLD), phenotypically characterized by necrosis and steato-fibrosis, whose molecular mechanism is not yet fully understood. Patients with NAFLD display an imbalanced palmitic (PA) to oleic acid (OA) ratio. Moreover, increasing experimental evidence points out a relevant involvement of the exosomal content in disease progression. Aim of the study was to highlight the PA/OA imbalance within circulating exosomes, the subsequent intracellular alterations, and the impact on NALFD. Liver cells were challenged with exosomes isolated from both healthy subjects and NAFLD patients. The exosomal PA/OA ratio was artificially modified, and biological effects were evaluated. A NAFLD-derived exosomal PA/OA imbalance impacts liver cell cycle and cell viability. OA-modified NAFLD-derived exosomes restored cellular viability and proliferation, whereas the inclusion of PA into healthy subjects-derived exosomes negatively affected cell viability. Moreover, while OA reduced the phosphorylation and activation of the necroptosis marker, Receptor-interacting protein 1 (phospho-RIP-1), PA induced the opposite outcome, alongside increased levels of stress fibers, such as vimentin and fibronectin. Administration of NAFLD-derived exosomes led to increased expression of Elongase 6 (ELOVL6), Stearoyl-CoA desaturase 1 (SCD1), Tumor necrosis factor α (TNF-α), Mixed-lineage-kinase-domain-like-protein (MLKL) and RIP-1 in the hepatocytes, comparable to mRNA levels in the hepatocytes of NAFLD patients reported in the Gene Expression Omnibus (GEO) database. Genetic and pharmacological abrogation of ELOVL6 elicited a reduced expression of downstream molecules TNF-α, phospho-RIP-1, and phospho-MLKL upon administration of NAFLD-derived exosomes. Lastly, mice fed with high-fat diet exhibited higher phospho-RIP-1 than mice fed with control diet. Targeting the Elongase 6-RIP-1 signaling pathway offers a novel therapeutic approach for the treatment of the NALFD-induced exosomal PA/OA imbalance.
PubMed: 37752143
DOI: 10.1038/s41419-023-06161-9 -
Molecules (Basel, Switzerland) Sep 2023Non-alcoholic fatty liver disease (NAFLD) is the primary chronic liver disease worldwide, mainly manifested by hepatic steatosis. Hepatic lipids may be derived from...
Non-alcoholic fatty liver disease (NAFLD) is the primary chronic liver disease worldwide, mainly manifested by hepatic steatosis. Hepatic lipids may be derived from dietary intake, plasma free fatty acid (FFA) uptake, or hepatic de novo lipogenesis (DNL). Currently, cellular and animal models of hepatocellular steatosis are widely used to study the pathogenesis of NAFLD and to investigate therapeutic agents. However, whether there are differences between the in vivo and in vitro models of the mechanisms that cause lipid accumulation has not been reported. We used OA/PA-induced NCTC 1469 cells and high-fat-diet-fed C57BL/6J mice to simulate a hepatocyte steatosis model of NAFLD and to detect indicators related to FFA uptake and DNL. In addition, when serological indicators were analysed in the mouse model, it was found that serum FASN levels decreased. The results revealed that, in the cellular model, indicators related to DNL were decreased, FASN enzyme activity was unchanged, and indicators related to FFA uptake were increased, including the high expression of CD36; while, in the animal model, indicators related to both FFA uptake and de novo synthesis were increased, including the high expression of CD36 and the increased protein levels of FASN with enhanced enzyme activity. In addition, after an analysis of the serological indicators in the mouse model, it was found that the serum levels of FASN were reduced. In conclusion, the OA/PA-induced cellular model can be used to study the mechanism of FFA uptake, whereas the high-fat-diet-induced mouse model can be used to study the mechanism of FFA uptake and DNL. Combined treatment with CD36 and FASN may be more effective against NAFLD. FASN in the serum can be used as one of the indicators for the clinical diagnosis of NAFLD.
Topics: Mice; Animals; Mice, Inbred C57BL; Oleic Acid; Palmitic Acid; Non-alcoholic Fatty Liver Disease; Diet, High-Fat; Hepatocytes; Disease Models, Animal; CD36 Antigens; Fatty Acids, Nonesterified
PubMed: 37764494
DOI: 10.3390/molecules28186714 -
Animals : An Open Access Journal From... Nov 2023Skeletal muscle satellite cells have the ability to differentiate into various cells under different conditions. This study aimed to investigate the effects of different...
Skeletal muscle satellite cells have the ability to differentiate into various cells under different conditions. This study aimed to investigate the effects of different concentrations of oleic acid (50, 100, and 200 µmol/L) on the process of lipogenic transdifferentiation in Yanbian bovine satellite cells, as well as its molecular regulatory mechanism. After inducing differentiation with oleic acid for 96 h, it was observed that the addition of oleic acid resulted in the formation of lipid droplets in the bovine satellite cells, and the triglyceride content showed a dose-dependent relationship with the concentration of OA. qPCR results demonstrated a significant downregulation of myogenesis-related factors ( and ) and upregulation of lipogenesis-related factors ( and ) ( < 0.05). Fatty acid metabolism-related factors, SCD and PLIN2, were also significantly upregulated ( < 0.05). These finding were consistent with the results obtained from Western blotting. Transcriptome sequencing analysis identified 278 differentially expressed genes between the control group and the groups treated with OA. KEGG enrichment analysis showed that differentially expressed genes were mainly concentrated in the adenosine monophosphate-activated protein kinase signaling pathway and fatty acid metabolic pathway. Our study presents that the OA induction of Yanbian bovine skeletal muscle satellite cells can promote cellular lipid transdifferentiation and reveals the potential genes and pathways related to OA induction of these satellite cells.
PubMed: 38066969
DOI: 10.3390/ani13233618 -
Frontiers in Nutrition 2023To realize the potential of sainfoins to contribute to sustainable agriculture and expand on demonstrated uses and benefits, domestication is occurring to develop...
To realize the potential of sainfoins to contribute to sustainable agriculture and expand on demonstrated uses and benefits, domestication is occurring to develop perennial Baki™ bean, the trade name used by The Land Institute for pulses (i.e., grain legumes) derived from sainfoins. The objective of this study was to characterize amino acid and fatty acid profiles of depodded seeds from commercial sainfoin () seed lots, and compare these results with data published in the Global Food Composition Database for Pulses. The fatty acid profile consisted primarily of polyunsaturated fatty acids (56.8%), compared to monounsaturated (29.0%) and saturated fatty acids (14.2%), and -3 fatty acids (39.5%), compared to -9 (28.4%) and -6 (17.6%) fatty acids. The essential fatty acid linolenic acid (18,3 -3) was the most abundant fatty acid (39.2%), followed by oleic acid (18,1 cis-9) (27.8%), and the essential fatty acid linoleic acid (18,2 -6) (17.3%). The amino acid profile consisted primarily of the nonessential amino acids glutamic acid (18.3%), arginine (11.6%), and aspartic acid (10.8%), followed by the essential amino acids leucine (6.8%), and lysine (5.8%). Essential amino acid content met adult daily requirements for each amino acid. This indicates that sainfoin seeds may be a complete plant protein source. However, further research is necessary to better understand protein quality, defined by protein digestibility in addition to the amino acid profile. By demonstrating favorable fatty acid and amino acid profiles to human health, these results contribute to a growing body of evidence supporting the potential benefits of perennial Baki™ bean, a novel, perennial pulse derived from sainfoins.
PubMed: 38283912
DOI: 10.3389/fnut.2023.1292628 -
Metabolites Dec 2023A key response to glucose stress is an increased production of unsaturated fatty acids to balance the increase in saturated fatty acids in the membrane. The homolog of...
A key response to glucose stress is an increased production of unsaturated fatty acids to balance the increase in saturated fatty acids in the membrane. The homolog of stearoyl-CoA desaturase, FAT-7, introduces the first double bond into saturated C18 fatty acids yielding oleic acid, and is a critical regulatory point for surviving cold and glucose stress. Here, we incorporated C stable isotopes into the diet of nematodes and quantified the C-labelled fatty acid using GC-MS and HPLC/MS-MS to track its metabolic response to various concentrations of glucose. Previous work has analyzed the membrane composition of when responding to mild glucose stress and showed few alterations in the overall fatty acid composition in the membrane. Here, in nematodes exposed to higher concentrations of glucose, a specific reduction in oleic acid and linoleic acid was observed. Using time courses and stable isotope tracing, the response of fatty acid metabolism to increasing levels of glucose stress is characterized, revealing the funneling of monounsaturated fatty acids to preserve the abundance of polyunsaturated fatty acids. Taken together, higher levels of glucose unveil a specific reduction in oleic and linolenic acid in the metabolic rewiring required to survive glucose stress.
PubMed: 38132867
DOI: 10.3390/metabo13121185 -
BioRxiv : the Preprint Server For... Oct 2023Lipogenesis is a vital but often dysregulated metabolic pathway. We report super-resolution multiplexed vibrational imaging of lipogenesis rates and pathways using...
Lipogenesis is a vital but often dysregulated metabolic pathway. We report super-resolution multiplexed vibrational imaging of lipogenesis rates and pathways using isotopically labelled oleic acid and glucose as probes in live adipocytes and hepatocytes. These findings suggest oleic acid inhibits lipogenesis (DNL), but not total lipogenesis, in hepatocytes. No significant effect is seen in adipocytes. These differential effects may be due to alternate regulation of DNL between cell types and could help explain the complicated role oleic acid plays in metabolism.
PubMed: 37873279
DOI: 10.1101/2023.10.04.560581 -
Biomolecules Dec 2023(1) Background: Cadmium (Cd) is a potentially toxic element with a long half-life in the human body (20-40 years). Cytotoxicity mechanisms of Cd include increased levels...
(1) Background: Cadmium (Cd) is a potentially toxic element with a long half-life in the human body (20-40 years). Cytotoxicity mechanisms of Cd include increased levels of oxidative stress and apoptotic signaling, and recent studies have suggested that these aspects of Cd toxicity contribute a role in the pathobiology of non-alcoholic fatty liver disease (NAFLD), a highly prevalent ailment associated with hepatic lipotoxicity and an increased generation of reactive oxygen species (ROS). In this study, Cd toxicity and its interplay with fatty acid (FA)-induced lipotoxicity have been studied in intestinal epithelium and liver cells; the cytoprotective function of melatonin (MLT) has been also evaluated. (2) Methods: human liver cells (HepaRG), primary murine hepatocytes and Caco-2 intestinal epithelial cells were exposed to CdCl before and after induction of lipotoxicity with oleic acid (OA) and/or palmitic acid (PA), and in some experiments, FA was combined with MLT (50 nM) treatment. (3) Results: CdCl toxicity was associated with ROS induction and reduced cell viability in both the hepatic and intestinal cells. Cd and FA synergized to induce lipid droplet formation and ROS production; the latter was higher for PA compared to OA in liver cells, resulting in a higher reduction in cell viability, especially in HepaRG and primary hepatocytes, whereas CACO-2 cells showed higher resistance to Cd/PA-induced lipotoxicity compared to liver cells. MLT showed significant protection against Cd toxicity either considered alone or combined with FFA-induced lipotoxicity in primary liver cells. (4) Conclusions: Cd and PA combine their pro-oxidant activity to induce lipotoxicity in cellular populations of the gut-liver axis. MLT can be used to lessen the synergistic effect of Cd-PA on cellular ROS formation.
Topics: Mice; Humans; Animals; Fatty Acids, Nonesterified; Cadmium; Melatonin; Reactive Oxygen Species; Caco-2 Cells; Hepatocytes; Non-alcoholic Fatty Liver Disease; Fatty Acids; Palmitic Acid; Oleic Acid
PubMed: 38136629
DOI: 10.3390/biom13121758 -
Journal of Oleo Science 2024Unsaturated fatty acids, such as oleic and linoleic acids, are easily oxidized by exposure to temperature and light in the presence of air to form unsaturated fatty acid... (Comparative Study)
Comparative Study
Unsaturated fatty acids, such as oleic and linoleic acids, are easily oxidized by exposure to temperature and light in the presence of air to form unsaturated fatty acid hydroperoxides as primary oxidation products. However, the catabolic rates of unsaturated fatty acid hydroperoxides in the human body remain unknown. In this study, ethyl esters of C-labeled linoleic acid (*C18:2-EE) and oleic acid (*C18:1-EE) and their hydroperoxides (*C18:2-EE-OOH and *C18:1-EE-OOH, respectively) prepared by the photo-oxidation of *C18:2-EE and *C18:1-EE, respectively, were administered to mice and their catabolic rates were determined by measuring the expired CO levels. *C18:2-EE-OOH and *C18:1-EE-OOH were β-oxidized faster than *C18:2-EE and *C18:1-EE, respectively. Notably, rapid β-oxidation of *C18:2-EE-OOH and *C18:1-EE-OOH was similar to that of medium-chain fatty acids, such as octanoic acid. Then, degradation products of C18:2-EE-OOH and C18:1-EE-OOH were analyzed under gastric conditions by gas chromatography/mass spectrometry. Major decomposition products of C18:2-EE-OOH and C18:1-EE-OOH were medium-chain compounds, such as octanoic acid ethyl ester, 9-oxo-nonanoic acid ethyl ester, and 10-oxo-8-decenoic acid ethyl esters, indicating that C18:2-EE-OOH and C18:1-EE-OOH isomers formed during photo-oxidation were decomposed under acidic conditions. These findings support previous reports that dietary lipid hydroperoxides are not absorbed into the intestine as lipid hydroperoxides but as degradation products. This is the first study to suggest that dietary lipid hydroperoxides decompose during gastric digestion to form medium-chain compounds that are directly absorbed into the liver via the portal vein and rapidly catabolized via β-oxidation.
Topics: Animals; Oxidation-Reduction; Oleic Acid; Linoleic Acid; Carbon Dioxide; Carbon Isotopes; Mice; Male; Hydrogen Peroxide
PubMed: 38825538
DOI: 10.5650/jos.ess23236 -
Parasites & Vectors Nov 2023The protozoan parasite Toxoplasma gondii encodes a dozen Rab proteins, which are parts of the small GTPase superfamily and regulate intracellular membrane trafficking....
BACKGROUND
The protozoan parasite Toxoplasma gondii encodes a dozen Rab proteins, which are parts of the small GTPase superfamily and regulate intracellular membrane trafficking. Our previous study showed that depletion of Rab1B caused severe defects regarding parasite growth and morphological structure, yet early defects of endocytic trafficking and vesicle sorting to the rhoptry in T. gondii are not expected to have a strong effect. To understand this discrepancy, we performed an integrated analysis at the level of transcriptomics and metabolomics.
METHODS
In the study, tetracycline-inducible TATi/Ty-Rab1B parasite line treated with ATc at three different time points (0, 18 and 24 h) was used. We first observed the morphological changes caused by Rab1B depletion via transmission electron technology. Then, high-throughput transcriptome along with non-targeted metabolomics were performed to analyze the RNA expression and metabolite changes in the Rab1B-depleted parasite. The essential nature of Rab1B in the parasite was revealed by the integrated omics approach.
RESULTS
Transmission electron micrographs showed a strong disorganization of endo-membranes in the Rab1B-depleted parasites. Our deep analysis of transcriptome and metabolome identified 2181 and 2374 differentially expressed genes (DEGs) and 30 and 83 differentially expressed metabolites (DEMs) at 18 and 24 h of induction in the tetracycline-inducible parasite line, respectively. These DEGs included key genes associated with crucial organelles that contain the rhoptry, microneme, endoplasmic reticulum and Golgi apparatus. The analysis of qRT-PCR verified some of the key DEGs identified by RNA-Seq, supporting that the key vesicular regulator Rab1B was involved in biogenesis of multiple parasite organelles. Functional enrichment analyses revealed pathways related to central carbon metabolisms and lipid metabolisms, such as the TCA cycle, glycerophospholipid metabolism and fatty acid biosynthesis and elongation. Further correlation analysis of the major DEMs and DEGs supported the role of Rab1B in biogenesis of fatty acids (e.g. myrisoleic acid and oleic acid) (R > 0.95 and P < 0.05), which was consistent with the scavenging role in biotin via the endocytic process.
CONCLUSIONS
Rab1B played an important role in parasite growth and morphology, which was supported by the replication assay and transmission electron microscopy observation. Our multi-omics analyses provided detailed insights into the overall impact on the parasite upon depletion of the protein. These analyses reinforced the role of Rab1B in the endocytic process, which has an impact on fatty acid biogenesis and the TCA cycle. Taken together, these findings contribute to our understanding of a key vesicular regulator, Rab1B, on parasite metabolism and morphological formation in T. gondii.
Topics: Animals; Toxoplasma; Transcriptome; Gene Expression Profiling; Parasites; Fatty Acids; Tetracyclines; Protozoan Proteins
PubMed: 37941035
DOI: 10.1186/s13071-023-06030-6