scholarly journals Palmitic acid promotes resistin-induced insulin resistance and inflammation in SH-SY5Y human neuroblastoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hamza Amine ◽  
Yacir Benomar ◽  
Mohammed Taouis

AbstractSaturated fatty acids such as palmitic acid promote inflammation and insulin resistance in peripheral tissues, contrasting with the protective action of polyunsaturated fatty acids such docosahexaenoic acid. Palmitic acid effects have been in part attributed to its potential action through Toll-like receptor 4. Beside, resistin, an adipokine, also promotes inflammation and insulin resistance via TLR4. In the brain, palmitic acid and resistin trigger neuroinflammation and insulin resistance, but their link at the neuronal level is unknown. Using human SH-SY5Yneuroblastoma cell line we show that palmitic acid treatment impaired insulin-dependent Akt and Erk phosphorylation whereas DHA preserved insulin action. Palmitic acid up-regulated TLR4 as well as pro-inflammatory cytokines IL6 and TNFα contrasting with DHA effect. Similarly to palmitic acid, resistin treatment induced the up-regulation of IL6 and TNFα as well as NFκB activation. Importantly, palmitic acid potentiated the resistin-dependent NFkB activation whereas DHA abolished it. The recruitment of TLR4 to membrane lipid rafts was increased by palmitic acid treatment; this is concomitant with the augmentation of resistin-induced TLR4/MYD88/TIRAP complex formation mandatory for TLR4 signaling. In conclusion, palmitic acid increased TLR4 expression promoting resistin signaling through TLR4 up-regulation and its recruitment to membrane lipid rafts.

2020 ◽  
Vol 75 (6) ◽  
pp. 585-593
Author(s):  
O. Yu. Kytikovа ◽  
T. P. Novgorodtseva ◽  
Yu. K. Denisenko ◽  
M. V. Antonyuk ◽  
T. A. Gvozdenko

Toll-like receptors (TLRs) are important players in innate and adaptive immune responses involved in the initiation of the inflammatory process in response to the stimulating influence of endogenous (аllarmine) and exogenous ligands (pathogens viruses, bacteria, fungi). It has now become apparent that not only viral and bacterial infections but non-infectious inflammatory diseases are accompanied by the activation of inflammatory response systems and the development of chronic inflammation associated with disorders in the regulation of the TLRs system. In this regard, the ligand-independent activation of TLRs, which occurs with the participation of lipids, is actively studied. Their signalling functions of TLRs implemented in unique microdomains does membrane lipid rafts that coordinate many cellular processes. The ability to activate TLRs has been found for saturated fatty acids (SFAs), both exogenous and endogenous. On the other hand, TLRs can be inhibited by omega-3 polyunsaturated fatty acids (PUFAs), which can block the inflammatory process. The activation of TLRs triggers a signal cascade that induces the production of reactive oxygen and nitrogen species. The development of oxidative stress is accompanied by the formation of oxidized forms of phospholipids (Ox-PLs), which also induce the development of chronic inflammation. At the same time, Ox-PLs is characterized not only by pro-inflammatory but also anti-inflammatory activity, which necessitates in-depth studies of their role in the implementation of these processes. This review article discusses the mechanisms by which SFAs, PUFAs, and Ox-PLs modulate TLRs activation in lipid rafts. Research into the details of these mechanisms will contribute to the development of a strategy to reduce the risk of chronic diseases caused by inflammatory reactions mediated by TLRs.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ban-Hock Khor ◽  
◽  
Sharmela Sahathevan ◽  
Ayesha Sualeheen ◽  
Mohammad Syafiq Md Ali ◽  
...  

AbstractThe metabolic impact of circulating fatty acids (FAs) in patients requiring hemodialysis (HD) is unknown. We investigated the associations between plasma triglyceride (TG) FAs and markers of inflammation, insulin resistance, nutritional status and body composition. Plasma TG-FAs were measured using gas chromatography in 341 patients on HD (age = 55.2 ± 14.0 years and 54.3% males). Cross-sectional associations of TG-FAs with 13 markers were examined using multivariate linear regression adjusted for potential confounders. Higher levels of TG saturated fatty acids were associated with greater body mass index (BMI, r = 0.230), waist circumference (r = 0.203), triceps skinfold (r = 0.197), fat tissue index (r = 0.150), serum insulin (r = 0.280), and homeostatic model assessment of insulin resistance (r = 0.276), but lower malnutrition inflammation score (MIS, r =  − 0.160). Greater TG monounsaturated fatty acid levels were associated with lower lean tissue index (r =  − 0.197) and serum albumin (r =  − 0.188), but higher MIS (r = 0.176). Higher levels of TG n-3 polyunsaturated fatty acids (PUFAs) were associated with lower MIS (r =  − 0.168) and interleukin-6 concentrations (r =  − 0.115). Higher levels of TG n-6 PUFAs were associated with lower BMI (r =  − 0.149) but greater serum albumin (r = 0.112). In conclusion, TG monounsaturated fatty acids were associated with poor nutritional status, while TG n-3 PUFAs were associated with good nutritional status. On the other hand, TG saturated fatty acids and TG n-6 PUFAs had both favorable and unfavorable associations with nutritional parameters.


Metabolism ◽  
2000 ◽  
Vol 49 (2) ◽  
pp. 220-224 ◽  
Author(s):  
M. Manco ◽  
A.V. Greco ◽  
E. Capristo ◽  
D. Gniuli ◽  
A. De Gaetano ◽  
...  

Circulation ◽  
2017 ◽  
Vol 135 (suppl_1) ◽  
Author(s):  
Amanda Fretts ◽  
Fumiaki Imamura ◽  
Chaoyu Yu ◽  
Alexis C Frazier-Wood ◽  
Maria Lankinen ◽  
...  

Background: Circulating saturated fatty acids are biomarkers of diet and metabolism that may influence the pathogenesis of diabetes. Unlike palmitic acid (16:0), which has been extensively studied, little is known of the relationship of very long-chain saturated fatty acids (VLSFAs), with 20 carbons or more, to diabetes risk. Objective: To investigate the associations of circulating levels of VLSFA with incident diabetes. Methods: A meta-analysis was conducted within a consortium of prospective (cohort or nested case-control) studies having circulating measures of one or more VLSFAs, including arachidic acid (20:0), behenic acid (22:0) and lignoceric acid (24:0). Standardized analysis was conducted in each study using pre-specified models, exposures, outcomes, and covariates. Study-specific estimates were pooled using fixed effects meta-analysis. Results: Current findings were based on 9 participating studies, including 46,549 total participants and 13,750 incident diabetes. In multivariable-adjusted analyses, higher levels of all 3 VLSFAs were associated with lower risk of incident diabetes. Pooled RRs (95% CI) per interquintile range were 0.80 (0.71-0.90) for 20:0; 0.83 (0.76-0.91) for 22:0; and 0.70 (0.63-0.79) for 24:0, after adjustment for demographics, lifestyle factors and clinical conditions. Additional adjustments for circulating palmitic acid and triglyceride levels moved the RRs toward the null (illustrated for 24:0, in model 3 of the Figure ). Conclusions: Based on meta-analysis of results from several studies around the world, biomarker levels of VLSFA are associated with lower risk of incident diabetes, potentially mediated by effects on circulating triglycerides and 16:0.


2012 ◽  
Vol 56 (8) ◽  
pp. 1212-1222 ◽  
Author(s):  
Clare M. Reynolds ◽  
Fiona C. McGillicuddy ◽  
Karen A. Harford ◽  
Orla M. Finucane ◽  
Kingston H. G. Mills ◽  
...  

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3771
Author(s):  
Laurent L’homme ◽  
Benan Pelin Sermikli ◽  
Bart Staels ◽  
Jacques Piette ◽  
Sylvie Legrand-Poels ◽  
...  

Growth differentiation factor-15 (GDF-15) and its receptor GFRAL are both involved in the development of obesity and insulin resistance. Plasmatic GDF-15 level increases with obesity and is positively associated with disease progression. Despite macrophages have been recently suggested as a key source of GDF-15 in obesity, little is known about the regulation of GDF-15 in these cells. In the present work, we sought for potential pathophysiological activators of GDF15 expression in human macrophages and identified saturated fatty acids (SFAs) as strong inducers of GDF15 expression and secretion. SFAs increase GDF15 expression through the induction of an ER stress and the activation of the PERK/eIF2/CHOP signaling pathway in both PMA-differentiated THP-1 cells and in primary monocyte-derived macrophages. The transcription factor CHOP directly binds to the GDF15 promoter region and regulates GDF15 expression. Unlike SFAs, unsaturated fatty acids do not promote GDF15 expression and rather inhibit both SFA-induced GDF15 expression and ER stress. These results suggest that free fatty acids may be involved in the control of GDF-15 and provide new molecular insights about how diet and lipid metabolism may regulate the development of obesity and T2D.


2012 ◽  
Vol 11 (1) ◽  
pp. 36 ◽  
Author(s):  
Keisuke Sawada ◽  
Kyuichi Kawabata ◽  
Takatoshi Yamashita ◽  
Kengo Kawasaki ◽  
Norio Yamamoto ◽  
...  

2015 ◽  
Vol 36 (3) ◽  
pp. 852-865 ◽  
Author(s):  
Wiebke Gehrmann ◽  
Wiebke Würdemann ◽  
Thomas Plötz ◽  
Anne Jörns ◽  
Sigurd Lenzen ◽  
...  

Background/Aims: Elevated levels of non-esterified fatty acids (NEFAs) are under suspicion to mediate β-cell dysfunction and β-cell loss in type 2 diabetes, a phenomenon known as lipotoxicity. Whereas saturated fatty acids show a strong cytotoxic effect upon insulin-producing cells, unsaturated fatty acids are not toxic and can even prevent toxicity. Experimental evidence suggests that oxidative stress mediates lipotoxicity and there is evidence that the subcellular site of ROS formation is the peroxisome. However, the interaction between unsaturated and saturated NEFAs in this process is unclear. Methods: Toxicity of rat insulin-producing cells after NEFA incubation was measured by MTT and caspase assays. NEFA induced H2O2 formation was quantified by organelle specific expression of the H2O2 specific fluorescence sensor protein HyPer. Results: The saturated NEFA palmitic acid had a significant toxic effect on the viability of rat insulin-producing cells. Unsaturated NEFAs with carbon chain lengths >14 showed, irrespective of the number of double bonds, a pronounced protection against palmitic acid induced toxicity. Palmitic acid induced H2O2 formation in the peroxisomes of insulin-producing cells. Oleic acid incubation led to lipid droplet formation, but in contrast to palmitic acid induced neither an ER stress response nor peroxisomal H2O2 generation. Furthermore, oleic acid prevented palmitic acid induced H2O2 production in the peroxisomes. Conclusion: Thus unsaturated NEFAs prevent deleterious hydrogen peroxide generation during peroxisomal β-oxidation of long-chain saturated NEFAs in rat insulin-producing cells.


2010 ◽  
Vol 298 (6) ◽  
pp. E1122-E1130 ◽  
Author(s):  
Sun Ju Choi ◽  
Francis Kim ◽  
Michael W. Schwartz ◽  
Brent E. Wisse

Hypothalamic inflammation induced by high-fat feeding causes insulin and leptin resistance and contributes to the pathogenesis of obesity. Since in vitro exposure to saturated fatty acids causes inflammation and insulin resistance in many cultured cell types, we determined how cultured hypothalamic neurons respond to this stimulus. Two murine hypothalamic neuronal cell cultures, N43/5 and GT1–7, were exposed to escalating concentrations of saturated fatty acids for up to 24 h. Harvested cells were evaluated for activation of inflammation by gene expression and protein content. Insulin-treated cells were evaluated for induction of markers of insulin receptor signaling (p-IRS, p-Akt). In both hypothalamic cell lines, inflammation was induced by prototypical inflammatory mediators LPS and TNFα, as judged by induction of IκBα (3- to 5-fold) and IL-6 (3- to 7-fold) mRNA and p-IκBα protein, and TNFα pretreatment reduced insulin-mediated p-Akt activation by 30% ( P < 0.05). By comparison, neither mixed saturated fatty acid (100, 250, or 500 μM for ≤6 h) nor palmitate exposure alone (200 μM for ≤24 h) caused inflammatory activation or insulin resistance in cultured hypothalamic neurons, whereas they did in control muscle and endothelial cell lines. Despite the lack of evidence of inflammatory signaling, saturated fatty acid exposure in cultured hypothalamic neurons causes endoplasmic reticulum stress, induces mitogen-activated protein kinase, and causes apoptotic cell death with prolonged exposure. We conclude that saturated fatty acid exposure does not induce inflammatory signaling or insulin resistance in cultured hypothalamic neurons. Therefore, hypothalamic neuronal inflammation in the setting of DIO may involve an indirect mechanism mediated by saturated fatty acids on nonneuronal cells.


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