Lipids of stages in the life-cycle of the cestode Spirometra mansonoides

The kinds and amounts of the lipids of each stage (egg, coracidium, procercoid, plerocercoid, adult) in the life-cycle of the cestode Spirometra mansonoides, and of environmental lipids, have been examined by combinations of TEAE-cellulose and silicic acid column, silica gel thin-layer and SCOT column gas-liquid chromatography. Major lipids of all stages were triacylglycerols, cholesterol, diphosphatidylglycerol, phosphatidlethanolamine, phosphatidylserine, phosphatidylinositol, and phosphatidylcholine. Minor lipids were sterol esters, fatty acids, benzoquinones, partial glycerides, phosphatidic acid, sphingolipids and lysolipids. Triacylglycerols decreased and cholesterol and phospholipids, particularly diphosphatidylglycerol and phosphatidylcholine, increased during embryo-genesis (egg to coracidium). Neutral and phosphoglycerides had characteristic fatty acyl group patterns irrespective of life-cycle stage, except for procercoid lipids, which were unique in their content of branched and odd-numbered forms. The patterns seen in the total lipids of the various life-cycle stages were qualitatively similar to those of the environments of those stages, but were often quantitatively dissimilar.     

The incorporation and utilization of radiolabelled lipids by adult Schistosoma mansoni in vitro

Live adult Schistosoma mansoni, maintained in vitro were able to absorb and utilize radiolabelled arachidonic acid, linolenic acid, 3-sn-phosphatidylcholine, tripalmitylgylcerol and cholesterol in the culture medium. Differential centrifugation demonstrated that all these lipids were incorporated into the parasite's various membrane structures. Analysis by thin-layer chromatography of the labelled compounds which resulted from incubation with the labelled lipids revealed that arachidonic acid, linolenic acid and fatty acids of tripalmitylglyceron and 3-sn-phosphatidylcholine was present largely as triacylglycerol with smaller amounts of labelled diacylglycerol, phospholipids and fatty acids. The labelled polar head group of 3-sn-phosphatidylcholine was cleaved from the molecule during incorporation, which suggested that hydrolysis of complex lipids is an integral part of the absorption mechanism. Cholesterol was not apparently altered during incorporation or further metabolized. It was also observed that arachidonic acid was incorporated more readily than the other lipids, however, no prostaglandin biosynthesis was detected.     

Structure and synthesis of a lipid-containing bacteriophage. XVIII. Modification of the lipid composition in bacteriophage PM2.

An unsaturated fatty acid auxotroph was isolated from Pseudomonas BAL-31. The fatty acid compositions of the auxotroph, wild-type cells, and virions grown on the auxotroph were determined in media supplemented with unsaturated fatty acids. The fatty acid composition in virions, in general, reflected that in host cells, although some differences were observed. The phospholipid composition in virions was very different from that in host cells and varied depending on the fatty acid used in the medium. Virions with altered lipid composition showed almost the same heat stability and stability with respect to pH.     

Characterization of Lipids Associated with Macromolecules of the Intercellular Matrix of Human Aorta

Macroscopically lesion-free parts of human aortas with no or light lesions (group I) and with advanced atherosclerotic lesions (group II) were submitted to a series of successive extractions in order to “solubilize” all the macromolecular components of the arterial wall (“chemical dissection”). Lipids were extracted with methanol-chloroform from all these macromolecular fractions and analyzed for cholesterol, triglycerides, phospholipids. The fatty acid composition of the separated fractions was determined by GLC. The lipid composition and fatty acid spectrum of the macromolecular fractions of group I and group II aortas was compared.

Total lipids increased in the freely extractable (“non associated lipids, ～ 78 % of total) fraction as well as in the fraction “associated” with collagen and elastin. Free and esterified cholesterol increased also both in the “freely extractable” and in the collagen-elastin-associated lipids”, ～ 78 % of total) fraction as well was higher (+ 100 %) than that of free cholesterol (+ 60%).

Triglycerides increase also by 15 to 70 % in all fractions except in the elastin-associated fraction.

Free fatty acids increased by 40 to 400 % in all extracts associated with macromolecular fractions but not in the “freely extractable” fraction where they decreased. Phospholipids show less marked variations (～ 10 %) and decrease in the elastin associated lipids of group II aortas.

The fatty acid spectrum of group II lipids associated with macromolecules differs from that of group I. There is a relative increase of longer chains (C > 18, especially 20: 1 and 20: 2 acids). No such increase in the “long” fatty acids was seen in the “freely extractable” lipid fraction.

Elastin isolated from group II aortas is significantly enriched in total lipids, cholesterol (free and esterified) and free fatty acids and contains the widest spectrum of fatty acids (from 11:2 to 22: 1) with a significant fraction of total fatty acids as “odd” carbon chains.

There appears to be a correlation between the decrease of triglyceride-bound fatty acids and the increase of free fatty acids. The free fatty acid concentration exceeds both in group I and II aortas the concentration of fatty acid esters. This increase in free fatty acids “associated” with intercellular matrix macromolecules and especially with elastin may be the result of an increased hydrolysis of esters and/or a decreased esteri-fication in advanced atherosclerotic aortas. The accumulation of long chain and “odd” fatty acids in elastin may be an important factor in its accelerated degradation during the atherosclerotic process.     

Observations on the lipids ofOochoristica agamae (Cestoda)

An investigation of the lipids ofOochoristica agamae, an anoplocephalid cestode of theAgama lizard, was undertaken. Total lipids of the parasite accounted for 8.4% of the fresh weight; neutral lipids comprised 82.98% of the total, glycolipids, 5.01%, and phospholipids, 12.03%. The major lipid classes inO. agamae include triglycerides, cholesterol, phosphatidyl choline, and phosphatidyl ethanolamine. The 16-and 18-carbon fatty acids were predominant in the parasite. Hexadecenoic acid, usually found at low concentrations in the lipids of helminth parasites, was the most abundant of the 16-carbon fatty acids ofO. agamae (notably in the neutral lipid fraction). Although octadecatrienoic acid occurred only in trace amounts in the intestinal contents of the host, significant amounts of this fatty acid were detected in the parasite. A lack of 20-carbon fatty acids was determined in the lipids of the host's intestinal contents and the neutral lipid fraction of the parasite.O. agamae is suspected to be capable of modifying fatty acids obtained from dietary sources by chain elongation.     

Lipids of parasitic and saprophytic leptospires

The lipid composition of five parasitic and six saprophytic leptospires was compared. Lipids comprise 18 to 26% of the dry weight of the cells after chloroform-methanol extraction. No residual (bound) lipid was found after acid or alkaline hydrolysis of the extracted residue. The total lipid was composed of 60 to 70% phospholipid, and the remaining lipid was free fatty acids. The phospholipid fraction contained phosphatidylethanolamine as the major component, and phosphatidylglycerol and diphosphatidylglycerol were minor components with traces of lysophatidylethanolamine sometimes found. The major fatty acids of leptospires were hexadecanoic, hexadecenoic, and octadecenoic acids. Both the unusual cis-11-hexadecenoic acid and the more common cis-9-hexadecenoic acid were synthesized by the leptospires. Neither the parasitic nor the saprophytic leptospires can chain elongate fatty acids. However, they were capable of β-oxidation of fatty acids. Both groups of leptospires desaturate fatty acids by an aerobic pathway. When the parasite canicola was cultivated on octadecanoic acid, 87% of the hexadecenoic acid was the 11 isomer, whereas the saprophyte semeranga consisted of 10% of this isomer. In addition, the saprophytic leptospires contained more tetradecanoic acid than the parasites. No differences were observed in the lipid composition of virulent and avirulent strains of canicola.     

Serum Paraoxonase 1 Activity Is Associated with Fatty Acid Composition of High Density Lipoprotein

Introduction. Cardioprotective effect of high density lipoprotein (HDL) is, in part, dependent on its related enzyme, paraoxonase 1 (PON1). Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. Methods. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Results. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA). PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω6 fatty acids of HDL. Conclusion. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health.     

Relationship between Hydroxy Fatty Acids and Prostaglandin E2 in Gingival Tissue

Bacterial hydroxy fatty acids and alpha-hydroxy fatty acids have been demonstrated in complex lipid extracts of subgingival plaque and gingival tissue. However, little is known about the relationship between these hydroxy fatty acids in plaque and gingival tissues or the significance of these complex lipids in promoting inflammatory periodontal disease. The present study determined the percentages of ester-linked and amide-linked hydroxy fatty acids in complex lipids recovered from plaque and gingival tissue samples and the relationship between bacterial hydroxy fatty acids and alpha-hydroxy fatty acids in the lipid extracts. To evaluate a potential role for these hydroxy fatty acids in inflammatory periodontal disease, gingival tissue samples were examined for a relationship between prostaglandin E₂ (PGE₂) and hydroxy fatty acids recovered in gingival lipid. This investigation demonstrated that alpha-hydroxy fatty acids are only ester linked in plaque lipids but are largely amide linked in gingival tissue lipids. Furthermore, the level of alpha-hydroxy fatty acid in gingival lipid is directly related to the level of the bacterial hydroxy fatty acid 3-OH iso-branched C_17:0 (3-OH iC_17:0) in the same lipid extract. However, the relationship between hydroxy fatty acids in gingival lipids does not parallel the fatty acid relationship observed in plaque lipids. Finally, alpha-hydroxy fatty acid levels in gingival tissue lipids correlate directly with the recovery of PGE₂ in the same tissue samples. These results demonstrate that alpha-hydroxy fatty acid levels in gingival lipids are directly related to both 3-OH iC_17:0 bacterial lipid levels and PGE₂ levels. These results indicate that in periodontal tissues there are unusual host-parasite interactions involving penetration of bacterial lipid in association with an altered gingival lipid metabolism and prostaglandin synthesis.     

Cellular fatty acids during fowlpox virus infection of three different host systems.

Fatty acid compositions of host cells during fowlpox virus infection have been studied by complementary thin-layer and gas-liquid chromatographic techniques. Three different host systems have been studied: the in vivo infection of the chick scalp, the in ovo infection of the chick embryo chorioallantoic membrane, and the in vitro infection of chick embryo fibroblast cell cultures. Extensive alterations in fatty acid composition of the host cell accompany the fowlpox infection of the chick scalp. The noticeable trends are toward greater unsaturation and a depletion of odd numbered fatty acids. In contrast, the fatty acid compositions of the chorioallantoic membrane and chick embryo cell cultures are not altered significantly following fowlpox virus infection. A slight increase in pentaenoic fatty acids was the only consistent effect of infection in these systems. To the extent that the fatty acid composition of a cell reflects its fatty acid metabolism, it can be concluded that the alterations in fatty acid metabolism observed in the chick scalp are not a constant feature of fowlpox virus infection, and therefore probably represent a host-determined response to infection.     

Lipid composition of metacestodes of Taenia taeniaeformis and lipid changes during growth

A lipid analysis was performed on developing metacestodes of Taenia taeniaeformis removed from the livers of rats at times varying from 3 to 35 weeks post infection. Lipid accounted for 7–21% of the dry weight of the parasites. The highest proportions were found at the earlier stages. The distribution was as follows; neutral lipid 27–45%; glycolipid 5–11%; and phospholipid 50–61%. The major neutral lipid was cholesterol, and minor neutral lipids were sterol esters, triglycerides, diglycerides and monoglycerides. Hydrocarbons were present throughout development, but in the highest amounts at the earlier stages. Five different glycolipids were found, all of which were identified as glycosphingolipids. An increase in the proportion of more complex glycolipids was noted as parasites grew older. Ten different phospholipids were identified, with the major components being phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine. Other phospholipids were: lysophosphatides, phosphatidylinositol, phosphatidic acid, diphosphatidylglycerol, sphingomyelin, and an unknown phospholipid component. Changes in the relative amounts of the two major phospholipids were found when the early and late stages were compared. Two lipids found throughout development were identified as glycosylated dolichol phosphates, and they comprised between 1 and 3% of the total phospholipid fraction. Nineteen fatty acids were detected, and the fatty acid distribution for each lipid class at each stage was determined. Seven major fatty acids were common to each. These were: hexadecanoic, octadecanoic, oleic, linoleic, arachidonic, docosanoic, and docosahexaenoic.     

Lipid distribution,composition and uptake in bovine articular cartilage studied using Raman micro‐spectrometry and confocal microscopy

The distribution and composition of endogenous lipids in articular cartilage and transport of exogenous fatty acids have been investigated on a microscopic scale in fresh bovine articular cartilage. To investigate the distribution and composition of the endogenous lipids, hyperspectral Raman maps were taken of chondrocytes and their surrounding matrix in both the deep and superficial zones. These revealed differences in both lipid distribution and composition between the two zones. Extracellular lipid was observed surrounding the cells in the superficial zone but not in the deep zone. Additionally, intracellular lipid droplets were observed that were larger and more numerous in the deep zone (P = 0.01). The extracellular lipid was primarily free saturated fatty acid, whereas the cellular lipid droplets contained triglycerides with unsaturated fatty acid chains. Fatty acid uptake and transport were investigated by incubating cartilage samples in Dulbecco's modified Eagle's medium containing fluorescently labelled palmitate for a range of times and temperatures. After incubation, the palmitate distribution was imaged using confocal microscopy. Palmitate accumulated preferentially in the territorial matrix only in the superficial zone where the concentration was up to 100‐fold greater than that in the bulk matrix (P = 0.001). Palmitate uptake by the chondrocytes in both zones showed differential temperature sensitivity (P = 0.05), which would support the idea that cells take up palmitate by both active and passive mechanisms. The study reveals large differences between chondrocytes in the superficial and deep zones in their lipid content, in their extracellular lipid environment and in their access to exogenous fatty acids.     

High-performance liquid chromatographic analysis of bacterial fatty acid composition for chemotaxonomic characterization of oral streptococci.

A high-performance liquid chromatographic method was developed to analyze the fatty acid composition of bacterial lipids. After saponification of lipids extracted from bacteria, the liberated fatty acids were labeled with a fluorescence reagent, 4-bromomethyl-7-acetoxycoumarin, followed by reversed-phase high-performance liquid chromatographic separation and fluorescence detection. All bacterial fatty acids were simultaneously separated within 30 min and sensitively determined. This method was applied to the chemotaxonomic characterization of oral streptococci. The fatty acid composition of phospholipids and total lipids distinguished Streptococcus mutans from any other species examined and showed that Streptococcus sanguis had a close taxonomic relationship with Streptococcus salivarius.     

Lipids of Treponema pallidum Kazan 5

The lipid composition of Treponema pallidum Kazan 5 cultivated in a lipid-defined medium was investigated. Lipids comprised 18 to 20% of the dry weight of the treponeme. Glycolipid and phospholipids accounted for 90 to 95% of the total lipids and free fatty acids made up the remaining 5 to 10%. The major polar lipids were the glycolipid, 1-(O-alpha-d-galactopyranosyl)-2,3-diglyceride (45 to 55%), and phosphatidylcholine (30 to 40%). Phosphatidylethanolamine (5 to 10%), an unidentified compound (1 to 2%), and occasional trace amounts of diphosphatidylglycerol (cardiolipin) were also found. The monogalactosyldiglyceride was also a major component (50%) of the lipids of the Reiter, Noguchi, and Nichols strains of T. pallidum. The fatty acid composition of Kazan 5 usually consisted of saturated and unsaturated fatty acids ranging from 14 to 18 carbons depending upon the fatty acids added to the culture medium. When the cells were cultivated on elaidic acid (trans-9-octadecenoic acid), their lipids contained only elaidic acid.     

Cellular Fatty Acid Composition of Legionella longbeachae sp. nov.

The cellular fatty acid composition of Legionella longbeachae was determined by gas-liquid chromatography. As in other Legionella species, the fatty acids of this new species are characterized by relatively large amounts of branched-chain acids.     

The structurally similar,penta-acylated lipopolysaccharides of Porphyromonas gingivalis and Bacteroides elicit strikingly different innate immune responses

Lipid A structural modifications can substantially impact the host's inflammatory response to bacterial LPS. Bacteroides fragilis, an opportunistic pathogen associated with life-threatening sepsis and intra-abdominal abscess formation, and Bacteroides thetaiotaomicron, a symbiont pivotal for proper host intestinal tissue development, both produce an immunostimulatory LPS comprised of penta-acylated lipid A. Under defined conditions, Porphyromonas gingivalis, an oral pathogen associated with periodontitis, also produces an LPS bearing a penta-acylated lipid A. However, this LPS preparation is 100–1000 times less potent than Bacteroides LPS in stimulating endothelial cells. We analyzed Bacteroides and P. gingivalis lipid A structures using MALDI-TOF MS and gas chromatography to determine the structural basis for this phenomenon. Even though both Bacteroides and P. gingivalis lipid A molecules are penta-acylated and mono-phosphorylated, subtle differences in mass and fatty acid content could account for the observed difference in LPS potency. This fatty acid heterogeneity is also responsible for the peak “clusters” observed in the mass spectra and obfuscates the correlation between LPS structure and immunostimulatory ability. Further, we show the difference in potency between Bacteroides and P. gingivalis LPS is TLR4-dependent. Altogether, the data suggest subtle changes in lipid A structure may profoundly impact the host's innate immune response.     

Fatty acid composition of gliding bacteria: oral isolates of Capnocytophaga compared with Sporocytophaga.

The extractable and bound lipids and cellular fatty acids of the gram-negative gliding bacteria, Capnocytophaga sputigena, C. gingivalis, and C. ochracea were compared to the non-host-related gliding bacterium Sporocytophaga myxococcoides. The extractable lipids represented between 17 and 28% of the cell dry weight, whereas only 2 to 4% of the lipids were in the bound fraction. The methyl esters of the cellular fatty acids were mainly aC15:0, which accounted for 69 to 73% of the total extractable fatty acids; S. myxococcoides had a similar distribution of branched-chain fatty acids; however, aC17:0 was the predominant fatty acid in this free-living gliding organism.     

Altered lipid metabolism in livers of rainbow trout fed cyclopropenoid fatty acids.

The incorporation of ¹⁴C-labeled fatty acids isotopic phosphorus into liver lipids of rainbow trout (Salmo gairdneri) that had received either 200 or 300 ppm of cyclopropenoid fatty acids (CPFA) in the diet for 14 days was studied. The amount of [³²P]O4 incorporated into liver phospholipids was lower in fish fed CPFA than in controls, with the greatest difference being in an unknown phospholipid. High levels of free [¹⁴C]oleic acid were found in livers from CPFA-fed fish after perfusion with this fatty acid, while none was detected in the controls. CPFA feeding lowered the incorporation of oleic acid into lipids of microsomal and mitochondrial fractions, but increased it in the 105,000g supernatant phospholipids. The type of dietary protein fed was shown to influence CPFA effects.     

The fatty acid composition of Northern-Canadian marine and terrestrial mammals

The low mortality from cardiovascular disease in Greenland Eskimos has been attributed to their consumption of diets rich in omega-3 fatty acids. These fatty acids are found in fish and marine mammal lipids. Whereas the fatty acid composition of several fish species has been documented, information is more limited on the mammals which feature significantly in the diets of many Arctic populations. This study investigated the fatty acid composition of commonly eaten marine mammals, as well as the polar bear and caribou. The tissue fatty acid composition was species-dependent, probably reflecting to some degree differences in feeding habits. The marine mammals and the amphibious polar bear, but not the caribou, contained substantial quantities of long chain omega-3 fatty acids. These studies further document the transfer of omega-3 fatty acids through the food chain to man and suggest that marine mammal and polar bear lipids are significant sources of omega-3 fatty acids.     

Lipid alterations induced by nifurtimox in Trypanosoma cruzi

The influence of growth in the presence of nifurtimox on total lipids of Trypanosoma cruzi epimastigotes was determined. Nifurtimox-treated organisms showed greater amounts of unsaturated fatty acids as compared with control cells. 18:2 was the major component in the total esterified lipid fraction. Similar results were observed on the free fatty acid composition as detected by trimethylsilyl derivatization of the total lipids.