Membrane lipid regulation in Acholeplasma laidlawii grown with saturated fatty acids. Biosynthesis of a triacylglucolipid forming reversed micelles

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.

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Revealing Further Insights on Chilling Injury of Postharvest Bananas by Untargeted Lipidomics

Foods ◽

10.3390/foods9070894 ◽

2020 ◽

Vol 9 (7) ◽

pp. 894 ◽

Cited By ~ 1

Author(s):

Juan Liu ◽

Qingxin Li ◽

Junjia Chen ◽

Yueming Jiang

Keyword(s):

Fatty Acids ◽

Low Temperature ◽

Unsaturated Fatty Acids ◽

Membrane Lipids ◽

Saturated Fatty Acids ◽

Chilling Injury ◽

Membrane Damage ◽

Membrane Lipid ◽

Banana Fruit ◽

Control Fruit

Chilling injury is especially prominent in postharvest bananas stored at low temperature below 13 °C. To elucidate better the relationship between cell membrane lipids and chilling injury, an untargeted lipidomics approach using ultra-performance liquid chromatography–mass spectrometry was conducted. Banana fruit were stored at 6 °C for 0 (control) and 4 days and then sampled for lipid analysis. After 4 days of storage, banana peel exhibited a marked chilling injury symptom. Furthermore, 45 lipid compounds, including glycerophospholipids, saccharolipids, and glycerolipids, were identified with significant changes in peel tissues of bananas stored for 4 days compared with the control fruit. In addition, higher ratio of digalactosyldiacylglycerol (DGDG) to monogalactosyldiacylglycerol (MGDG) and higher levels of phosphatidic acid (PA) and saturated fatty acids but lower levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and unsaturated fatty acids were observed in banana fruit with chilling injury in contrast to the control fruit. Meanwhile, higher activities of phospholipase D (PLD) and lipoxygenase (LOX) were associated with significantly upregulated gene expressions of MaPLD1 and MaLOX2 and higher malondialdehyde (MDA) content in chilling injury-related bananas. In conclusion, our study indicated that membrane lipid degradation resulted from reduced PC and PE, but accumulated PA, while membrane lipid peroxidation resulted from the elevated saturation of fatty acids, resulting in membrane damage which subsequently accelerated the chilling injury occurrence of banana fruit during storage at low temperature.

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Excretion of triacylglycerol as a matrix lipid facilitating apoplastic accumulation of a lipophilic metabolite shikonin.

10.1101/2021.08.04.455005 ◽

2021 ◽

Author(s):

Kanade Tatsumi ◽

Takukji Ichino ◽

Natsumi Isaka ◽

Akifumi Sugiyama ◽

Yozo Okazaki ◽

...

Keyword(s):

Fatty Acids ◽

Cell Death ◽

Membrane Lipids ◽

Saturated Fatty Acids ◽

Membrane Lipid ◽

Lithospermum Erythrorhizon ◽

Cell Secretion ◽

Oil Droplets

Plants produce a large variety of lipophilic metabolites, many of which are secreted by cells and accumulated in apoplasts. The mechanism of secretion remains largely unknown, because hydrophobic metabolites, which may form oil droplets or crystals in cytosol, inducing cell death, cannot be directly secreted by transporters. Moreover, some secondary metabolic lipids react with cytosolic components leading to their decomposition. Lipophilic metabolites should thus be solubilized by matrix lipids and compartmentalized by membrane lipids. The mechanism of lipophilic metabolite secretion was assessed using shikonin, a red naphthoquinone lipid, in Lithospermum erythrorhizon. Cell secretion of shikonin also involved the secretion of about 30% of triacylglycerol (TAG), composed predominantly of saturated fatty acids. Shikonin production was associated with the induction of large amounts of the membrane lipid phosphatidylcholine. Together with in vitro reconstitution, these findings suggest a novel role for TAG as a matrix lipid for the secretion of lipophilic metabolites.

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AdipoR2 is Essential for Membrane Lipid Homeostasis in Response to Dietary Saturated Fats

10.1101/2020.06.11.144329 ◽

2020 ◽

Author(s):

Ranjan Devkota ◽

Mario Ruiz ◽

Henrik Palmgren ◽

Marcus Ståhlman ◽

Himjyot Jaiswal ◽

...

Keyword(s):

Fatty Acids ◽

Saturated Fatty Acids ◽

Saturated Fat ◽

Membrane Lipid ◽

Hek293 Cells ◽

Lipid Homeostasis ◽

Human Endothelial Cells ◽

Adiponectin Receptor 2 ◽

Varied Diet ◽

Essential Function

ABSTRACTMembrane lipid composition influences vital processes in all types of cells. The mechanisms by which cells maintain membrane lipid homeostasis while obtaining most of their constituent fatty acids from a varied diet remain largely unknown. In an attempt to discover such mechanisms, we performed an unbiased forward genetic screen in Caenorhabditis elegans and conclude that the adiponectin receptor 2 (AdipoR2) pathway is essential to prevent saturated fat-mediated cellular toxicity. Transcriptomics, lipidomics and membrane property analyses in human HEK293 cells and primary human endothelial cells further support our conclusion that the essential function of AdipoR2 is to respond to membrane rigidification by promoting fatty acid desaturation. Our results demonstrate that AdipoR2-dependent regulation of membrane homeostasis is a fundamental mechanism conserved from nematodes to mammals that prevents saturated fat-mediated lipotoxicity.ONE SENTENCE SUMMARYThe AdipoR2 protein insures membrane homeostasis in response to dietary saturated fatty acids that promote membrane rigidification.

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Influence of thermal acclimation on membrane lipid composition of rainbow trout liver

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1979.236.1.r91 ◽

1979 ◽

Vol 236 (1) ◽

pp. R91-R101 ◽

Cited By ~ 8

Author(s):

J. R. Hazel

Keyword(s):

Fatty Acids ◽

Rainbow Trout ◽

Polyunsaturated Fatty Acids ◽

Cold Acclimation ◽

Saturated Fatty Acids ◽

Total Content ◽

Membrane Lipid ◽

Salmo Gairdneri ◽

Acclimation Temperature ◽

Induced Changes

Rainbow trout (Salmo gairdneri) acclimated to 5 degrees C possessed larger livers and less neutral lipid per gram of liver than 20 degrees C-acclimated animals; quantities of liver glycolipid, phospholipid, and cholesterol did not vary significantly with acclimation temperature. The relative proportions of phosphatidylethanolamine increased significantly following cold exposure, whereas the quantities of sphingomyelin and cardiolipin declined. For all phosphatides examined (phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, lysolecithin, cardiolipin, sphingomyelin) cold acclimation resulted in 1) an increase in the quantity of polyunsaturated fatty acids, 2) a reduction in the level of saturated fatty acids, and 3) little change in the total content of monoenes and dienes. The increased content of polyunsaturated fatty acids in choline and ethanolamine phosphatides following cold acclimation was confined to the 2-position and occurred at the expense of monoenes and dienes. The relative proportions of n - 3 fatty acids, and less frequently n - 6 fatty acids, increased in phosphatides of cold-acclimated trout, whereas the relative proportions of n - 9 fatty acids declined. These data suggest a preferential incorporation of fatty acids belonging to the linolenic acid family at reduced temperatures. Temperature-induced changes in the chemical composition of trout liver phospholipids counteracted the effects of acute temperature change on nonelectrolyte permeability of isolated liposomes.

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Membrane Lipid Metabolism in Acholeplasma laidlawii A EF 22. Influence of Cholesterol and Temperature Shift-Down on Incorporation of Fatty Acids and Synthesis of Membrane Lipid Specie.

European Journal of Biochemistry ◽

10.1111/j.1432-1033.1978.tb12212.x ◽

1978 ◽

Vol 85 (1) ◽

pp. 65-76 ◽

Cited By ~ 48

Author(s):

Anders CHRISTIANSSON ◽

Ake WIESLANDER

Keyword(s):

Fatty Acids ◽

Lipid Metabolism ◽

Temperature Shift ◽

Membrane Lipid ◽

Acholeplasma Laidlawii

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Modification of sperm fatty acid composition during epididymal maturation in bats

Reproduction ◽

10.1530/rep-18-0463 ◽

2019 ◽

pp. 77-85 ◽

Cited By ~ 2

Author(s):

Nicolas J Fasel ◽

Kevin McMillian ◽

Ulrike Jakop ◽

Laurent Méné-Saffrané ◽

Kathrin M Engel ◽

...

Keyword(s):

Fatty Acids ◽

Fatty Acid Composition ◽

Fatty Acid ◽

Acid Composition ◽

Saturated Fatty Acids ◽

Biochemical Properties ◽

Membrane Lipid ◽

Sperm Velocity ◽

Epididymal Maturation ◽

Cauda Epididymidis

Biochemical properties of polyunsaturated fatty acids (PUFAs) are fundamental to sperm movements. Amongst all adjustments operated during epididymal maturation, sperm membrane lipid composition is remodelled. Specifically, the proportion of PUFAs usually increases from the caput towards the cauda epididymidis. In mammals, PUFAs are predominantly acquired through the diet, which can consequently impact male fertility. We aimed at analysing to what extent n-6 and n-3 PUFAs are incorporated into sperm in the Seba’s short-tailed bat (Carollia perspicillata), and at demonstrating the effect of the sperm fatty acid composition on sperm mobility. We therefore provided food varying in fatty acid composition to males of C. perspicillata and measured the fatty acid composition and mobility traits in spermatozoa collected from the caput and cauda epididymides. We found that n-6 and n-3 PUFAs and saturated fatty acids were significantly related to sperm velocity but not to the proportion of progressive sperm (i.e. motility). Concomitant to an increase in sperm velocity, the level of fatty acid saturation increased from the caput to the cauda epididymidis, while the proportion of PUFAs remained similar along the epididymis. A reduction in n-6 PUFAs counterbalanced an increase in n-3 PUFAs. The food treatments did not affect the sperm fatty acid composition. Our results suggest that a precise endogenous control rather than dietary effects determines sperm fatty acid composition in C. perspicillata.

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The role of lipids in the signaling mechanisms of toll-like receptors

Annals of the Russian academy of medical sciences ◽

10.15690/vramn1179 ◽

2020 ◽

Vol 75 (6) ◽

pp. 585-593

Author(s):

O. Yu. Kytikovа ◽

T. P. Novgorodtseva ◽

Yu. K. Denisenko ◽

M. V. Antonyuk ◽

T. A. Gvozdenko

Keyword(s):

Fatty Acids ◽

Chronic Inflammation ◽

Lipid Rafts ◽

Bacterial Infections ◽

Inflammatory Process ◽

Saturated Fatty Acids ◽

Membrane Lipid ◽

Omega 3 ◽

Toll Like Receptors ◽

Inflammatory Reactions

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.

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