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Zhong Nan Da Xue Xue Bao. Yi Xue Ban =... Nov 2021High fat-induced podocyte injury is one of the important factors leading to obesity related nephropathy (ORG), but the mechanism is not clear. This study aims to explore...
OBJECTIVES
High fat-induced podocyte injury is one of the important factors leading to obesity related nephropathy (ORG), but the mechanism is not clear. This study aims to explore the mechanism of period circadian clock 3 (PER3) in the oxidative stress and inflammation induced by palmitic acid (PA) in podocytes.
METHODS
The C57BL/6J mice were fed with chow and high-fat diet for 16 weeks. The PER3 expression in kidney tissues were detected in the normal body weight group and the obesity group. The PER3 mRNA and protein expression were detected after the podocytes were induced with different concentrations (0, 50, 150 and 300 μmol/L) of PA for 48 h. The PER3 mRNA and protein expression were detected after the podocytes were induced with 150 μmol/L PA for 0, 24, 36, and 48 h. Triglyceride (TG) levels were examined in the PA group, the adenovirus (ad)-PER3+PA group, and the siRNA-PER+PA group after the podocytes were transfected by Ad-PER3 or small interfering RNA (siRNA)-PER3 for 48 h and subsequently were induced with 150 μmol/L PA for 48 h. The differential gene expression was detected using RNA sequencing (RNA-seq) after podocytes were transfected by siRNA-PER3 (siRNA-PER3 group) and siRNA-control (siRNA-control group), respectively. The mRNA levels of nephrin, podocin, podocalyxin, podoplanin, superoxide dismutase 1 (SOD1), glutathione peroxidase 1 (GPX1), catalase (CAT), and the levels of malondialdehyde (MDA), glutathione (GSH), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) and interleukin-2 (IL-2) were detected after podocytes were transfected with Ad-PER3 or Ad-control for 48 h and then they were induced by 150 μmol/L PA for 48 h.
RESULTS
The PER3 was down-regulated in the obesity group compared with the normal body weight group (<0.05), and the PER3 was significantly down-regulated after the podocytes were treated with 150 μmol/L for 48 h compared with 0, 24, and 36 h (all <0.01). The TG contents were significantly decreased in the Ad-PER3+PA group compared with the PA group (<0.05). On the contrary, TG contents were increased in the siRNA-PER3+PA group compared with the PA group (<0.05). The RNA-seq results showed that: compared with the siRNA-control group, the differential genes in the siRNA-PER3 group were enriched in different pathways including oxidative phosphorylation, TNF signaling pathway, extracellular matrix receptor interaction, fatty acid metabolism, and fatty acid degradation (all <0.05). The podocyte marker genes (nephrin, podocin, podocalyxin and podoplanin), oxidative stress (SOD1, GPX1, CAT and GSH), and inflammation factors (TNF-α, IL-6, IL-1β and IL-2) were significantly down-regulated in the Ad-PER3+PA group compared with the PA group (all <0.05).
CONCLUSIONS
PER3 can decrease the PA-induced oxidative stress and inflammatory factor secretion via inhibiting the lipogenesis in podocytes.
Topics: Animals; Circadian Clocks; Mice; Mice, Inbred C57BL; Oxidative Stress; Palmitic Acid; Podocytes
PubMed: 34911851
DOI: 10.11817/j.issn.1672-7347.2021.210019 -
The Science of the Total Environment May 2021The toxicity of arsenic (As) can be influenced by many nutrients in food. However, the combined effects and underlying mechanisms of As and palmitic acid (PA) are still...
The toxicity of arsenic (As) can be influenced by many nutrients in food. However, the combined effects and underlying mechanisms of As and palmitic acid (PA) are still unclear. Here, cell viability, oxidative stress, lipids accumulation, gene expression profiles, and metabolome profiles of human hepatoma HepG2 cells exposed to As, PA, and As + PA were analyzed and compared. Results showed that co-exposure of 100 μM PA and 2 μM As induced lower cell viability, higher intracellular reactive oxygen species level, more lipid droplet accumulation, and more intracellular triglyceride contents than As alone or PA alone exposure. High-throughput quantitative PCR and H NMR-based metabolomics analysis showed that co-exposure of As and PA caused all toxic effects on gene expression and metabolome profiles induced by As alone or PA alone exposure, and showed higher toxicities. Gene expression profiles in the As + PA group had higher similarity with those in the As group than the PA group. However, PA played a more important role in metabolism disorder than As in their interactive effects. Oxidative stress and lipid metabolism disorder were found to be the main toxic effects in the As + PA group. Several differentially expressed genes (such as OXR1, OXSR1, INSR, and PPARA) and changed metabolites (such as pyruvate, acetate, and L-phenylalanine) were involved in the combined toxicity of As and PA. This study provides basic information on the interactive effects of As and PA, which is useful for the health risk assessment of As and FFA.
Topics: Arsenic; Carcinoma, Hepatocellular; Hep G2 Cells; Humans; Lipid Metabolism; Lipid Metabolism Disorders; Oxidative Stress; Palmitic Acid
PubMed: 33736254
DOI: 10.1016/j.scitotenv.2020.144849 -
Journal of Molecular Neuroscience : MN Mar 2022Neuroinflammation is a mechanism by which obesity or a high-fat diet leads to cognitive impairment. MiR-124, a highly expressed microRNA in the brain, can alleviate...
Neuroinflammation is a mechanism by which obesity or a high-fat diet leads to cognitive impairment. MiR-124, a highly expressed microRNA in the brain, can alleviate neuroinflammation by regulating microglial activation, but its mechanism is unclear. The aim of the study was to explore whether miR-124 exerted this effect through TLR4/MyD88/NF-κB p65/NLRP3 signaling in palmitic acid-treated BV2 cells. Prepared BV2 cells were treated with palmitic acid to establish an in vitro model of a high-fat diet. An miR-124 mimic and inhibitor were adopted to upregulate and downregulate the expression of miR-124, respectively. TAK-242 and NLRP3 siRNA were used to downregulate the expression of TLR4 and NLRP3. The expression levels of miR-124, signaling proteins (TLR4, MyD88, and NF-κB p65), inflammasome markers (NLRP3 and IL-1β), and microglial activated markers (CD206, Arg-1, CD86, and iNOS) were measured by qPCR and western blotting. The pyroptosis rate was assessed using flow cytometry. First, palmitic acid upregulated TLR4/MyD88/NF-κB p65 signaling, increased NLRP3 expression, elevated the pyroptosis rate, and promoted the microglial proinflammatory response in BV2 cells. Second, the miR-124 mimic and inhibitor separately alleviated and aggravated the effect of palmitic acid on microglial activation and NLRP3 expression. The miR-124 mimic also downregulated TLR4/MyD88/NF-κB p65 signaling. Third, TAK-242 did not affect the expression of miR-124 but simulated the protective effect of the miR-124 mimic on microglial activation and NLRP3 expression. Fourth, NLRP3 siRNA also inhibited the microglial proinflammatory response in BV2 cells. MiR-124 prevented the microglial proinflammatory response through TLR4/MyD88/NF-κB p65/NLRP3 signaling in palmitic acid-treated BV2 cells.
Topics: Cell Line; MicroRNAs; Microglia; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Palmitic Acid; Toll-Like Receptor 4
PubMed: 34652636
DOI: 10.1007/s12031-021-01921-8 -
Early Human Development Nov 2001The distribution of long-chain saturated fatty acids in triglycerides is different in infant formulas to that in human milk. In human milk, palmitic acid is...
The distribution of long-chain saturated fatty acids in triglycerides is different in infant formulas to that in human milk. In human milk, palmitic acid is predominantly esterified in the sn-2 position (beta-position) of the triglycerides, whereas in infant formulas, it is esterified mainly in the sn-1,3 positions (alpha,alpha'-positions). The specific distribution of the fatty acids in the triglyceride plays a key role in lipid digestion and absorption. We studied fatty-acid, calcium and magnesium composition in the faeces of three groups of at term newborn infants fed different diets: Group A (n=12) was fed from birth to 2 months with human milk (66% palmitic acid in beta-position), Group B (n=12) was fed with formula alpha (19% palmitic acid esterified in beta-position) for 2 months, and Group C (n=12) was fed with formula alpha during the first month and with formula beta (44.5% palmitic acid in beta-position) during the second month. Samples were taken at the end of the first month (t0) and at the end of the second month (t1). Groups A and C presented significantly lower contents of palmitic acid in faeces at t1 than at t0, whereas in Group B, amounts remained similar. Faecal calcium in Groups A and C decreased in the second month (t1), although the fall was no statistically significant. In Group B, calcium amounts showed no change. We found that infant formula beta when compared with infant formula alpha reduced significantly the contents of total fatty acids and palmitic acid in faeces. We conclude that palmitic acid in beta-position is, therefore, beneficial for term infants.
Topics: Calcium; Chromatography, Gas; Dietary Fats; Fatty Acids; Feces; Humans; Infant Food; Infant, Newborn; Magnesium; Milk, Human; Palmitic Acid; Triglycerides
PubMed: 11755039
DOI: 10.1016/s0378-3782(01)00210-9 -
Biochemical Pharmacology Nov 2023Melatonin (MLT) is ahormonal substance reported with various pharmacological activities.Based on its effects of neuroprotection and metabolic regulation, the aim of the...
Melatonin protects HT-22 cells against palmitic acid-induced glucolipid metabolic dysfunction and cell injuries: Involved in the regulation of synaptic plasticity and circadian rhythms.
Melatonin (MLT) is ahormonal substance reported with various pharmacological activities.Based on its effects of neuroprotection and metabolic regulation, the aim of the present study is to investigate its potential effect on palmitic acid (PA)-induced cell injuries and glucolipid metabolic dysfunction and explore the possible mechanism. Briefly, HT-22 cells were challenged with PA (0.1 mM, 24 h) and treated with MLT (10-10 mol/L). Cell proliferation, lipid accumulation and glucose consumption were detected. The protein expression of key molecular involved with the function of synaptic plasticity and circadian rhythms were measured via western blotting, and the expression of Map-2, MT1A, MT1B and Bmal1 were measured via immunofluorescence staining. The results showed that MLT could alleviate the neurotoxicity induced by PA, as indicated by the increased cell proliferation, enhanced fluorescence intensity of Map-2, and decreased lipid deposition and insulin resistance. Moreover, treatment of MLT could reverse the imbalanced expression of p-Akt, p-ERK, Synapsin I, Synaptotagmin I, BDNF, MT1B, Bmal1, and Clock in PA-induced HT-22 cells. These results suggested a remarkably neuroprotective effect of MLT against PA-induced cell injury and glucolipid metabolic dysfunction, the mechanism of which might be involved in the regulation of synaptic plasticity and circadian rhythms.
Topics: Melatonin; Palmitic Acid; ARNTL Transcription Factors; Circadian Rhythm; Neuronal Plasticity
PubMed: 37804870
DOI: 10.1016/j.bcp.2023.115846 -
Colloids and Surfaces. B, Biointerfaces Sep 2020Understanding the interaction of ions with fatty acids is important to identify their roles in various bioprocesses and to build novel biomimetic systems. In this study,...
Understanding the interaction of ions with fatty acids is important to identify their roles in various bioprocesses and to build novel biomimetic systems. In this study, the molecular organization of palmitic acid (PA) films on alkaline buffer solutions (pH 7.4) with and without divalent Ca was measured at a constant surface area using Langmuir troughs coupled with microscopy and X-ray interfacial techniques. Without Ca, PA molecules remained a monolayer organization; however, with Ca, formation of the inverted bilayers of PA-Ca superstructures caused a spontaneous 2D to 3D transformation under no compression due to the strong interaction between PA and the divalent cation. Self-assembly of this highly-organized inverted bilayer superstructure involved a two-step process of nucleation and nuclei growth. During nucleation, densely packed PA and Ca monolayer firstly corrugated and some of PA and Ca molecules ejected out from the monolayer; the ejected molecules then reorganized and formed the inverted bilayer nuclei. Nucleation was followed by nuclei growth, during which PA and Ca in the monolayer kept integrating into the inverted bilayer structure through molecule migration and PA rotation around Ca.
Topics: Calcium; Hydrogen-Ion Concentration; Ions; Kinetics; Molecular Dynamics Simulation; Palmitic Acid; Particle Size; Surface Properties
PubMed: 32408262
DOI: 10.1016/j.colsurfb.2020.111100 -
Journal of the American Chemical Society Apr 2017Lipids have fundamental roles in the structure, energetics, and signaling of cells and organisms. The recent discovery of fatty acid esters of hydroxy fatty acids...
Lipids have fundamental roles in the structure, energetics, and signaling of cells and organisms. The recent discovery of fatty acid esters of hydroxy fatty acids (FAHFAs), lipids with potent antidiabetic and anti-inflammatory activities, indicates that our understanding of the composition of lipidome and the function of lipids is incomplete. The ability to synthesize and test FAHFAs was critical in elucidating the roles of these lipids, but these studies were performed with racemic mixtures, and the role of stereochemistry remains unexplored. Here, we synthesized the R- and S- palmitic acid ester of 9-hydroxystearic acid (R-9-PAHSA, S-9-PAHSA). Access to highly enantioenriched PAHSAs enabled the development of a liquid chromatography-mass spectrometry (LC-MS) method to separate and quantify R- and S-9-PAHSA, and this approach identified R-9-PAHSA as the predominant stereoisomer that accumulates in adipose tissues from transgenic mice where FAHFAs were first discovered. Furthermore, biochemical analysis of 9-PAHSA biosynthesis and degradation indicate that the enzymes and pathways for PAHSA production are stereospecific, with cell lines favoring the production of R-9-PAHSA and carboxyl ester lipase (CEL), a PAHSA degradative enzyme, selectively hydrolyzing S-9-PAHSA. These studies highlight the role of stereochemistry in the production and degradation of PAHSAs and define the endogenous stereochemistry of 9-PAHSA in adipose tissue. This information will be useful in the identification and characterization of the pathway responsible for PAHSA biosynthesis, and access to enantiopure PAHSAs will elucidate the role of stereochemistry in PAHSA activity and metabolism in vivo.
Topics: Adipose Tissue; Animals; Esters; HEK293 Cells; Humans; Lipase; Lipids; Mice; Mice, Transgenic; Molecular Structure; Palmitic Acid; Stearic Acids; Stereoisomerism
PubMed: 28350171
DOI: 10.1021/jacs.7b01269 -
Effects of palmitic acid on lipid metabolism homeostasis and apoptosis in goose primary hepatocytes.Molecular and Cellular Biochemistry Apr 2011Studies have shown that not only does palmitic acid promote triglyceride (TG) accumulation, but it also affects cell viability in in vitro steatosis models. However, to...
Studies have shown that not only does palmitic acid promote triglyceride (TG) accumulation, but it also affects cell viability in in vitro steatosis models. However, to what degree these effects are mediated by steatosis in goose primary hepatocytes is unknown. In this study, the effects of palmitic acid on the lipid metabolism homeostasis pathway and on apoptosis were determined. The authors measured the mRNA levels of genes involved in TG synthesis, lipid deposition, fatty acid oxidation and the assembly and secretion of VLDL-TG in goose primary hepatocytes. The results indicated that palmitic acid can significantly reduce the activity of goose hepatocytes, and that palmitic acid had a significant effect on TG accumulation; however, with increasing palmitic acid concentrations, the extracellular TG and extracellular VLDL concentration gradually decreased. With increasing palmitic acid concentrations, the gene expression levels of DGAT1, DGAT2, PPARα, CPT-1, FoxO1 and MTTP (which regulate hepatic TG synthesis, fatty acid oxidation and the assembly and secretion of VLDL-TGs) first increased and then decreased; the change in PLIN gene expression was palmitic acid dose-dependent, similar to the regulatory mode of intracellular TG accumulation. In conclusion, this study clearly shows that palmitic acid can promote TG accumulation and induce apoptosis in goose primary hepatocytes, and this effect may be related to the lipid metabolism pathway.
Topics: Animals; Apoptosis; Cell Culture Techniques; Cell Death; Cells, Cultured; Drug Evaluation, Preclinical; Geese; Gene Expression Regulation; Hepatocytes; Intracellular Space; Lipid Metabolism; Lipoproteins, VLDL; Osmolar Concentration; Palmitic Acid; Triglycerides
PubMed: 21152956
DOI: 10.1007/s11010-010-0680-6 -
Archives of Toxicology Jun 2023Intestinal cells are continuously exposed to food constituents while adapting to peristaltic movement and fluid shear stress. Oleic acid (OA) and palmitic acid (PA) are...
Intestinal cells are continuously exposed to food constituents while adapting to peristaltic movement and fluid shear stress. Oleic acid (OA) and palmitic acid (PA) are among the most prevalent fatty acids with respect to dietary lipids. Despite the central importance of dietary lipids for a balanced diet, awareness about potential detrimental effects related to excessive consumption is increasing; this includes toxicity, metabolic deregulation, and, particularly for cancer cells, a benefit from the uptake of fatty acids related to promotion of metastasis. Expanding on this, we started elucidating the effects of OA and PA (25-500 µM) on non-transformed human intestinal epithelial cells (HCEC-1CT) in comparison to colon carcinoma cells (HCT116), with regard to the mechanosensory apparatus. Hence, intestinal cells' motility is on the one side essential to ensure adaption to peristaltic movement and barrier function, but also to enable metastatic progression. Incubation with both OA and PA (≥ 25 µM) significantly decreased membrane fluidity of HCT116 cells, whereas the effect on HCEC-1CT was more limited. Application of rhodamine-labelled PA demonstrated that the fatty acid is incorporated into the plasma membrane of HCT116, which could not be observed in the non-tumorigenic cell line. Down-streaming into the intracellular compartment, a pronounced rearrangement of actin cytoskeleton was evident in both cell lines (OA and PA; 25 and 100 µM). This was accompanied by a variation of translocation efficiency of the mechanosensitive co-transcription factor YAP1, albeit with a stronger effect seen for PA and the cancer cells. Untargeted proteomic analysis confirmed that exposure to OA and PA could alter the response capacity of HCT116 cells to fluid shear stress. Taken together, OA and PA were able to functionally modulate the mechanosensory apparatus of intestinal cells, implying a novel role for dietary fatty acids in the regulation of intestinal pathophysiology.
Topics: Humans; Palmitic Acid; Mechanotransduction, Cellular; Proteomics; Fatty Acids; Oleic Acid
PubMed: 37117602
DOI: 10.1007/s00204-023-03495-3 -
Biochemical Society Transactions Feb 2013The covalent attachment of palmitic acid to one or more cysteine residues (S-palmitoylation) is a widespread modification of signalling proteins. With the finding that... (Review)
Review
The covalent attachment of palmitic acid to one or more cysteine residues (S-palmitoylation) is a widespread modification of signalling proteins. With the finding that palmitoylation is a dynamic process, it is now widely accepted that repeated cycles of palmitoylation/depalmitoylation could be involved in the regulation of multiple signalling processes. Palmitoylation also represents a common post-translational modification of the GPCRs (G-protein-coupled receptors). Functionally, palmitoylation of GPCRs has been shown to play a central role in the regulation of multiple receptor functions, including determining the efficiency and selectivity of G-protein coupling, receptor phosphorylation and desensitization, endocytosis and transport to the plasma membrane. The present review summarizes our current knowledge of the palmitoylation of serotonin (5-hydroxytryptamine) receptors and its role in the regulation of receptor functions.
Topics: Endocytosis; Lipoylation; Models, Molecular; Palmitic Acid; Protein Processing, Post-Translational; Protein Transport; Receptors, Serotonin
PubMed: 23356264
DOI: 10.1042/BST20120235