Myelin structure and composition of myelinated tissue in the African lungfish

2008 ◽  
Vol 4 (2) ◽  
pp. 59-70 ◽  
Author(s):  
Daniel A. Kirschner ◽  
Jothie Karthigesan ◽  
Oscar A. Bizzozero ◽  
Bela Kosaras ◽  
Hideyo Inouye
Keyword(s):  
Electron Microscopy ◽  
Fatty Acids ◽  
Radial Component ◽  
Membrane Lipid ◽  
Myelin Structure ◽  
Pns Myelin ◽  
Membrane Lipid Bilayer ◽  
African Lungfish ◽  
Protopterus Dolloi ◽  
Typical Range

To analyze myelin structure and the composition of myelinated tissue in the African lungfish (Protopterus dolloi), we used a combination of ultrastructural and biochemical techniques. Electron microscopy showed typical multilamellar myelin: CNS sheaths abutted one another, and PNS sheaths were separated by endoneurial collagen. The radial component, prominent in CNS myelin of higher vertebrates, was suggested by the pattern of staining but was poorly organized. The lipid and myelin protein compositions of lungfish tissues more closely resembled those of teleost than those of higher vertebrates (frog, mouse). Of particular note, for example, lungfish glycolipids lacked hydroxy fatty acids. Native myelin periodicities from unfixed nerves were in the range of those for higher vertebrates rather than for teleost fish. Lungfish PNS myelin had wider inter-membrane spaces compared with other vertebrates, and lungfish CNS myelin had spaces that were closer in value to those in mammalian than to amphibian or teleost myelins. The membrane lipid bilayer was narrower in lungfish PNS myelin compared to other vertebrates, whereas in the CNS myelin the bilayer was in the typical range. Lungfish PNS myelin showed typical compaction and swelling responses to incubation in acidic or alkaline hypotonic saline. The CNS myelin, by contrast, did not compact in acidic saline but did swell in the alkaline solution. This lability was more similar to that for the higher vertebrates than for teleost.

scholarly journals Triple-Knockout, Synuclein-Free Mice Display Compromised Lipid Pattern

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3078
Author(s):  
Irina A. Guschina ◽  
Natalia Ninkina ◽  
Andrei Roman ◽  
Mikhail V. Pokrovskiy ◽  
Vladimir L. Buchman
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Family Members ◽  
Ether Lipid ◽  
Brain Regions ◽  
Membrane Lipid ◽  
Lipid Binding ◽  
Synaptic Functions ◽  
Ethanolamine Plasmalogens ◽  
Lipid Pattern

Recent studies have implicated synucleins in several reactions during the biosynthesis of lipids and fatty acids in addition to their recognised role in membrane lipid binding and synaptic functions. These are among aspects of decreased synuclein functions that are still poorly acknowledged especially in regard to pathogenesis in Parkinson’s disease. Here, we aimed to add to existing knowledge of synuclein deficiency (i.e., the lack of all three family members), with respect to changes in fatty acids and lipids in plasma, liver, and two brain regions in triple synuclein-knockout (TKO) mice. We describe changes of long-chain polyunsaturated fatty acids (LCPUFA) and palmitic acid in liver and plasma, reduced triacylglycerol (TAG) accumulation in liver and non-esterified fatty acids in plasma of synuclein free mice. In midbrain, we observed counterbalanced changes in the relative concentrations of phosphatidylcholine (PC) and cerebrosides (CER). We also recorded a notable reduction in ethanolamine plasmalogens in the midbrain of synuclein free mice, which is an important finding since the abnormal ether lipid metabolism usually associated with neurological disorders. In summary, our data demonstrates that synuclein deficiency results in alterations of the PUFA synthesis, storage lipid accumulation in the liver, and the reduction of plasmalogens and CER, those polar lipids which are principal compounds of lipid rafts in many tissues. An ablation of all three synuclein family members causes more profound changes in lipid metabolism than changes previously shown to be associated with γ-synuclein deficiency alone. Possible mechanisms by which synuclein deficiency may govern the reported modifications of lipid metabolism in TKO mice are proposed and discussed.

Fatty acyl chain structure, orientational order, and the lipid phase transition in Acholeplasma laidlawii B membranes. A review of recent 19F nuclear magnetic resonance studies

1984 ◽  
Vol 62 (11) ◽  
pp. 1134-1150 ◽  
Author(s):  
P. M. Macdonald ◽  
B. D. Sykes ◽  
R. N. McElhaney
Keyword(s):  
Phase Transition ◽  
Fatty Acids ◽  
Nuclear Magnetic Resonance ◽  
Acyl Chain ◽  
Orientational Order ◽  
Membrane Lipid ◽  
Fatty Acyl ◽  
Fatty Acyl Chain ◽  
Lipid Phase ◽  
Lipid Phase Transition

The orientational order parameters of monofluoropalmitic acids biosynthetically incorporated into membranes of Acholeplasma laidlawii B in the presence of a large excess of a variety of structurally diverse fatty acids have been determined via 19F nuclear magnetic resonance (19F NMR) spectroscopy. It is demonstrated that these monofluoropalmitic acids are relatively nonperturbing membrane probes based upon physical (differential scanning calorimetry), biochemical (membrane lipid analysis), and biological (growth studies) criteria. 19F NMR is shown to convey the same qualitative and quantitative picture of membrane lipid order provided by 2H-NMR techniques and to be sensitive to the structural characteristics of the membrane fatty acyl chains, as well as to the lipid phase transition. Representatives of each naturally occurring class of fatty acyl chain structures, including straight-chain saturated, methyl-branched, monounsaturated, and alicyclic-ring-substituted fatty acids, were studied and the 19F-NMR order parameters were correlated with the lipid phase transitions (determined calorimetrically). The lipid phase transition was the prime determinant of overall orientational order regardless of fatty acid structure. Effects upon orientational order attributable to specific structural substituents were discernible, but were secondary to the effects of the lipid phase transition. In the gel state, relative overall order was directly proportional to the temperature of the particular lipid phase transition. Not only the overall order, but also the order profile across the membrane was sensitive to the presence of particular structural substituents. In particular, in the gel state specific fatty acyl structures demonstrated a characteristic disordering effect in the membrane order profile. These various observations can be merged to provide a unified picture of the manner in which fatty acyl chain chemistry modulates the physical state of membrane lipids.

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
Keyword(s):  
Insulin Resistance ◽  
Fatty Acids ◽  
Palmitic Acid ◽  
Lipid Rafts ◽  
Acid Treatment ◽  
Protective Action ◽  
Saturated Fatty Acids ◽  
Membrane Lipid ◽  
Human Neuroblastoma ◽  
Peripheral Tissues

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.

scholarly journals PHLIP ARG-Mutant Interactions with the Membrane Lipid Bilayer

2021 ◽  
Vol 120 (3) ◽  
pp. 232a
Author(s):  
Hannah M. Visca ◽  
Oleg A. Andreev ◽  
Yana K. Reshetnyak
Keyword(s):  
Lipid Bilayer ◽  
Membrane Lipid ◽  
Membrane Lipid Bilayer

scholarly journals STRUCTURE-FUNCTION RELATIONSHIPS IN THE ADIPOSE CELL

1970 ◽  
Vol 46 (2) ◽  
pp. 342-353 ◽  
Author(s):  
Samuel W. Cushman
Keyword(s):  
Electron Microscopy ◽  
Fatty Acids ◽  
Colloidal Gold ◽  
Intracellular Transport ◽  
Nonesterified Fatty Acid ◽  
Experimental Conditions ◽  
Nonesterified Fatty Acids ◽  
Adipose Cell ◽  
Cell Functions ◽  
The Relationship

Pinocytic activity in the adipose cell has been examined by measuring the uptake of colloidal gold. Pinocytic activity occurs in the isolated adipose cell under all experimental conditions; a portion of the vesicular elements of the cell can be identified by electron microscopy as pinocytic in origin. The isolated adipose cell appears to take up serum albumin by pinocytosis. Pinocytic activity in the isolated adipose cell is enhanced by epinephrine, but not by insulin. The relationship between pinocytosis and the metabolic activity of the adipose cell has been studied by measuring simultaneously the uptake of radioactive colloidal gold, the incorporation of 14C-counts from U-glucose-14C into CO2, total lipid, triglyceride glycerol and triglyceride fatty acids, and the release of nonesterified fatty acids in the absence of hormones and in the presence of insulin or epinephrine. Correlations between hormone-produced alterations in lipid metabolism and in pinocytic activity suggest that intracellular nonesterified fatty acid levels are a factor in the regulation of both the cell's pinocytic activity and its metabolism and that pinocytosis in the adipose cell functions in the extracellular-intracellular transport of nonesterified fatty acids.

Time-Course of Changes in the Plasma–Membrane Lipid Bilayer and Cellular Ultrastructure Induced by Tumour Necrosis Factor-α in K 562 and Daudi Cells

1995 ◽  
Vol 23 (4) ◽  
pp. 254-263 ◽  
Author(s):  
M Marutaka ◽  
H Iwagaki ◽  
K Mizukawa ◽  
N Tanaka ◽  
K Orita
Keyword(s):  
Plasma Membrane ◽  
Cell Membrane ◽  
Membrane Fluidity ◽  
Time Course ◽  
Membrane Lipid ◽  
Plasma Membrane Lipid ◽  
Membrane Lipid Bilayer ◽  
Cell Membrane Fluidity ◽  
K 562 Cells ◽  
Factor Α

The time-course of changes in the plasma-membrane lipid bilayer induced by tumour necrosis factor-α (TNF) were investigated in cultured cells using spin-label electron-spin-resonance techniques. Treatment of K 562 cells, a human chronic myelocytic leukaemia cell line, in suspension culture with TNF for up to 6 h caused an initial increase in cell-membrane fluidity, which returned to the control level after 12 h of treatment. After 24 h of treatment, the cell-membrane fluidity had decreased and this decrease was maintained after 48 h of treatment. In Daudi cells, a human malignant lymphoma cell line, TNF, did not induce any changes in cell-membrane fluidity, indicating that the effect of TNF on membrane structure is cell-specific. The early and transient change in membrane fluidity in K 562 cells is probably related to signal generation, while the later, persistent change may reflect the phenotype of TNF-treated cells, in particular, changes in the plasma membrane-cytoplasmic complex. Histochemical electron microscopic studies indicated that the membrane fluidity changes induced by TNF have an ultrastructural correlate.

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