Cardiolipin Fatty Acid Research Articles

A Striking Parallel Between Cardiolipin Fatty Acid Composition and Phylogenetic Belonging in Marine Bivalves: A Possible Adaptative Evolution?

Thirty-five species of marine mollusk bivalves were analyzed for their fatty acid (FA) composition of cardiolipin (Ptd(2)Gro). All species showed a Ptd(2)Gro with strong selectivity for only a few polyunsaturated fatty acids, but three characteristic FA profiles emerged, with clear parallels to bivalve phylogeny. A first group of 12 species belonging to the Eupteriomorphia subgroup (Filibranchia) was characterized by a Ptd(2)Gro almost exclusively composed of 22:6n-3, whereas in the four Filibranchia Pteriomorph species analyzed, this FA was combined with substantial proportions of 18:2n-6 and 18:3n-3. Finally, a third group of 20 species, all belonging to the Heterodonta subclass, possessed Ptd(2)Gro containing predominantly both 22:6n-3 and 20:5n-3. Polyunsaturated FA moieties and arrangements in the Ptd(2)Gro of some marine species investigated in other classes of the mollusk phylum (Gastropoda, Polyplacophora) were found to be different. The present results suggest that the specific Ptd(2)Gro FA compositions in bivalves are likely to be controlled and conserved in species of the same phylogenetic group. Functional significances of the evolution of this mitochondrial lipid structure in bivalves are discussed.

Selective remodeling of cardiolipin fatty acids in the aged rat heart

BackgroundThe heart is rich in cardiolipin, a phospholipid acylated in four sites, predominately with linoleic acid. Whether or not aging alters the composition of cardiolipin acyl chains is controversial. We therefore measured the fatty acid concentration of cardiolipin in hearts of 4, 12 and 24 month old rats that consumed one diet, adequate in fatty acids for the duration of their life.ResultsThe concentration (nmol/g) of linoleic acid was decreased in 24 month old rats (3965 ± 617, mean ± SD) vs 4 month old rats (5525 ± 656), while the concentrations of arachidonic and docosahexaenoic acid were increased in 24 month old rats (79 ± 9 vs 178 ± 27 and 104 ± 16 vs 307 ± 68 for arachidonic and docosahexaenoic acids, 4 months vs 24 months, respectively). Similar changes were not observed in ethanolamine glycerophospholipids or plasma unesterified fatty acids, suggesting specificity of these effects to cardiolipin.ConclusionThese results demonstrate that cardiolipin remodeling occurs with aging, specifically an increase in highly unsaturated fatty acids.

Citrate carrier activity and cardiolipin level in eel ( Anguilla anguilla) liver mitochondria

The activity of the tricarboxylate (citrate) carrier has been assayed in intact liver mitochondria from yellow eel ( Anguilla anguilla) and compared to that from rat. The eel-citrate carrier specific activity was approximately 1.7-fold higher than that assayed in rat-liver mitochondria. The content of the main mitochondrial phospholipids, phosphatidylethanolamine and phosphatidylcholine, did not show a significant difference between the two species, while in eel a higher cardiolipin level was observed. Fatty acid composition of eel-liver mitochondrial phospholipids was characterised by a large amount of unsaturated fatty acids, dominated by octadecaenoic acid (C 18:1 n-9) and docosahexaenoic acid (C 22:6 n-3). The cardiolipin fatty acid pattern of eel-liver mitochondria showed, with respect to the rat, a higher C 20:5 n-3 and C 22:6 n-3 content and a lower amount of C 18:2 n-6 and C 20:4 n-6. A noticeable activity of lipogenic enzymes was also detected in eel liver cytosol. The results of this study suggest that the remarkable activity of the citrate carrier in eel-liver mitochondria can most likely be ascribed to a considerable cardiolipin level. A covariance of citrate carrier and lipogenic enzyme activities was observed.

Effect of thyroid status on lipid composition and peroxidation in the mouse liver

In order to analyze the possible relationship between metabolic rate and oxidative stress, OF1 female mice were rendered hyper- or hypothyroid for 4–5 weeks by administration of 0.0012% l-thyroxine (T 4) or 0.05% 6- n-propyl-2-thiouracil (PTU), respectively, in their drinking water. Treatment with T 4 resulted in increased basal metabolic rate measured by oxygen consumption and liver cytochrome oxidase activity without altering the glutathione redox system. Endogenous lipid peroxidation, sensitivity to lipid peroxidation and fatty acid unsaturation were decreased in the hyperthyroid group. Hypothyroidism also decreased phosphatidylcholine and cardiolipin fatty acid unsaturation but not in total lipids, and thus lipid peroxidation was not altered. Cardiolipin, a mainly mitochondrial lipid, was the most profoundly altered fraction by both hyper- and hypothyroidism. It is suggested that the lipid changes observed in hyperthyroid animals can protect them against an increased oxidative attack to tissue lipids due to their increased mitochondrial activities.

Membrane lipids of red muscle mitochondria from land-locked and sea-run Arctic char, Salvelinus alpinus

Although laboratory studies of the effects of temperature, salinity, and diet on biological membranes of fish indicate substantial alterations in phospholipid and fatty acid composition to maintain functional properties, there are few parallel studies of wild populations. We, therefore, examined the red muscle, mitochondrial phospholipids and phospholipid fatty acids in two fish populations differing in their environmental temperature, salinity, and diet. Sea-run and freshwater (land-locked) Arctic char (Salvelinus alpinus L.) were collected from Igloolik Island, Northwest Territories, Canada, in the summer of 1991. Several differences between the phospholipids of these fish, and those reported for red muscle mitochondria in other fish species, included a higher cardiolipin content and a higher proportion of short-chain monoenes, especially 16:1. In congruence with previous studies of changes in cardiolipin fatty acids in other species of cold-acclimated fish, the fatty acid content of cardiolipin of both Arctic char groups was more saturated and less polyunsaturated than in warm-acclimated fish. Other aspects of the lipid composition of these membranes were not consistent with laboratory studies of cold-acclimated fish. For example, the fatty acids comprising phosphatidylethanolamine and phosphatidylcholine were more saturated than would be predicted based on laboratory studies of cold-acclimated fish. Some of these differences may be attributable to differences in the proportions of dietary n3 and n6 fatty acids in freshwater and marine environments. A strategy common to both groups of Arctic char is the maintenance of a similar relationship between phospholipid fatty acid chain length and degree of unsaturation in both Arctic char populations in spite of differences in diet and thermal regimes. The observed differences in membrane composition between land-locked and sea-run fish presumably act to maintain mitochondrial function in these different environments.

Dietary fatty acid composition induces comparable changes in cardiolipin fatty acid profile of heart and brain mitochondria.

The fatty acid profile of cardiolipin (CL) from brain and cardiac mitochondria was measured to determine whether CL isolated from these two tissue sources responded similarly to alterations in dietary fat composition. Male Wistar rats were fed 20% (w/w) diets containing 2 to 12% (w/w) 18:2n-6 for four weeks. Despite higher baseline levels of CL 18:2n-6 in cardiac (54 +/- 1% of total fatty acids) compared to brain (13 +/- 1%) mitochondria, CL 18:2n-6 levels increased in proportion to dietary 18:2 levels. The degree of change in 18:2n-6 was comparable with both tissues showing an approximate 1.5- to 2-fold increase. The time course of changes in CL fatty acid profile was examined in a subsequent experiment in which animals were fed 20% (w/w) fat diets containing either 3 or 15% alpha-linoleate. Changes in cardiac CL 18:1, 18:2n-6, and 22:6n-3 levels were observed within one week of feeding. While statistically significant differences were not observed in brain CL until the second week of feeding, the time course did not differ substantively from that observed in heart. The results from this study suggest that while baseline fatty acid profile of cardiac and neural CL differ, mitochondria from both tissues show comparable sensitivity to changes in dietary fat composition. Furthermore, it would appear that the turnover rate of fatty acids in CL is similar in both tissues.

Stimulation of brown adipose tissue activity in tumor-bearing rats.

Despite anorexia, cancer development is frequently accompanied by an increase of energy expenditure. Considering the pivotal role played by brown adipose tissue (BAT) in the energy metabolism of small mammals, we investigated the functional and compositional modification in BAT of anorexic tumor-bearing (Yoshida sarcoma) and pair-fed control rats. BAT thermogenic activity (assessed by maximal mitochondrial GDP binding) was 1.8-fold greater in tumor-bearing rats than in controls, while the thermogenic capacity (assessed by measurement of uncoupling protein) was unchanged. This suggests that tumor bearing had induced an unmasking of uncoupling protein sites. BAT hypertrophy and hyperplasia, characteristic of full-fledged BAT activation, did not occur. The mitochondrial oxidative capacity of BAT (assessed by cytochrome c oxidase activity) was 1.6-fold lower in tumor-bearing than in control rats. The main compositional modification observed in BAT of tumor-bearing rats was an increase in the saturation of cardiolipin fatty acids. These results suggest that the BAT stimulation induced by tumor bearing after 10 days is almost exclusively functional and that the tissue development is limited, probably by anorexia. However, a suppressive effect of anorexia inhibition by tumor bearing cannot be excluded.

Decreased Cytochrome Oxidase Activity and Changes in Phospholipids in Heart Mitochondria from Hypothyroid Rats

The effect of hypothyroidism on kinetic characteristics of cytochrome oxidase in rat heart mitochondria was studied. Mitochondrial preparations from control and hypothyroid rats had equivalent K m values for cytochrome c, while the maximal activity of the oxidase was significantly decreased (more than 30%) in mitochondrial preparations from hypothyroid rats. This decrease is associated to a parallel decrease in state 3 respiration. The cytochrome aa 3 content was slightly decreased (by around 15%) in mitochondria from hypothyroid rats. The Arrhenius plot characteristics differ for cytochrome oxidase activity in mitochondria from hypothyroid rats as compared with control rats in that the breakpoint of the biphasic plot is shifted to a higher temperature. Cardiolipin content was markedly decreased in the mitochondrial membrane from hypothyroid rats. No alterations were found in the pattern of cardiolipin fatty acid distribution of mitochondrial membrane from control and hypothyroid rats. The effects of the hypothyroid state on the activity of cytochrome oxidase, on cytochrome aa 3 levels, and on cardiolipin contents were completely reversed by following the treatment of hypothyroid rats with thyroid hormone. The results support the conclusion that the depressed mitochondrial cytochrome oxidase activity in the hypothyroid state is due, at least in part, to a decrease in the cardiolipin content of the mitochondrial inner membrane.

Properties of the mitochondrial membrane and carnitine palmitoyltransferase I in the periportal and the perivenous zone of the liver: Effects of chronic ethanol feeding

Rats were fed for 35 days a high-fat diet containing either 36% of total calories as ethanol (ethanol group) or an isocaloric amount of carbohydrate (control group). Then, mitochondria were isolated from the periportal and the perivenous zone of the liver in order to study the acinar heterogeneity of the effects of prolonged ethanol administration upon the properties of carnitine palmitoyltransferase I (CPT-I) and its membrane environment. Chronic ethanol ingestion selectively decreased CPT-I activity in periportal hepatocytes but equally increased enzyme sensitivity to malonyl-CoA and enzyme energy of activation in the two zones of the liver. In control animals, mitochondrial membrane showed higher fluidity and lower degree of saturation of phospholipid fatty acyl moieties in periportal than in perivenous hepatocytes. Prolonged ethanol feeding (i) decreased mitochondrial membrane fluidity; (ii) increased the proportion of palmitic acid and decreased that of arachidonic acid in mitochondrial phosphatidylcholine and phosphatidylethanolamine, whereas it drastically reduced the content of linoleic acid and concomitantly increased that of saturated and monoenoic fatty acids in cardiolipin; (iii) suppressed the disordering effects of the addition of ethanol to mitochondrial suspensions. All these ethanol-induced alterations of membrane fluidity and fatty acyl composition were not significantly different between periportal and perivenous mitochondria. In conclusion, chronic ethanol feeding changes the activity of CPT-I in a zone-selective manner but modifies both the regulatory properties of the enzyme and the properties of its lipid environment in a non-zone-selective manner. Hence factors in addition to the properties of the mitochondrial membrane seem to be involved in the ethanol-induced alterations of the CPT-I enzyme.

Changes in Phospholipid Fatty Acid Composition of Mouse Cardiac Organelles after Feeding Graded Amounts of Docosahexaenoate in Presence of High Levels of Linoleate

Mice were fed diets containing a constant supply of linoleic acid (18:2n-6, LA) as ethyl ester representing 5% by weight of the total fat (5 wt%), in combination with graded amounts of purified docosahexaenoate (22:6n-3, DHA). Cardiac sarcoplasmic reticulum (SR) and mitochondrial phospholipids (PL) from mice fed the diet without DHA contained higher levels of n-6 long chain polyunsaturated fatty acids (PUFA) (22:4n-6 and 22:5n-6) compared to total PL of liver. In the cardiac mitochondrial PL, the level of LA, DHA, the total content of PUFA and the P/S ratio were significantly higher than in SR. A small increase in dietary DHA from 0 to 0.43 wt% induced a 3.6-fold increase in PL DHA content from both cardiac organelles, with a concurrent reduction of n-6 PUFA. The changes in fatty acid PL composition were much more moderate when dietary DHA level was increased to 0.85 and 3.74 wt%. Feeding the lowest amount of DHA resulted in a 6-fold decrease in the value of n-6/n-3 PUFA ratio and a 3.5-fold decrease in the value of 20 carbon chain/22 carbon chain PUFA ratio. DHA was readily depleted from cardiac PL, and only arachidonic acid was retained in the PL from both organelles, after feeding a fat-deficient diet. Despite these drastic modifications in PL fatty acid composition, the maximum velocity (Vm) of SR Ca2+, Mg2+-ATPase was not affected, which indicates that SR cardiac membrane adapts to changes in fatty acid composition to prevent important modifications of its functional properties. However, the Vm of mitochondrial oligomycin-sensitive ATPase was slightly increased in mice fed the lowest amount of DHA. This might be due to an increase in P/S ratio and/or to a modification of cardiolipin fatty acid composition, since this PL is required for optimum function of this enzyme. It is concluded that DHA is strongly taken up by mouse cardiac PL, even in the presence of high dietary LA levels, but its acylation into PL has only little effect on the cardiac ATPase activities.

Positional distribution of fatty acids in cardiolipin of mitochondria from 21-day-old rats.

Pure cardiolipins (1,3-diphosphatidylglycerol) were prepared from mitochondria of heart, liver and kidney from 21-day-old male Wistar rats and submitted to Naja naja venom phospholipase A2 (EC 3.1.1.4) action. Incubation conditions were controlled carefully, and a complete hydrolysis of cardiolipin to lysocardiolipin (di [1 (1'') acyl sn-glycero-3-phosphoryl] 1',3'-sn-glycerol) and fatty acids from positions 2(2'') was obtained in less than two hr practically without side reactions. Cardiolipins from the three organs contained low levels of saturated fatty acids; stearic acid accounted for 0.4-0.7% and palmitic acid for 1.4-3.5% of total fatty acids. These percentages apparently depended on the organ. In all three cases, linoleic acid was the major component, but its percentage varied from 62-78% of total fatty acids. Acyl chains linked to positions 1 (1'') of all three cardiolipin preparations exhibited a similar pattern: they were composed of linoleic acid for 85-89%. This fatty acid also was the main component esterified at position 2 (2''), but its percentage was much more variable: from 39.8% in heart to 51.2% in kidney and 67.8% in liver mitochondria. The remaining acids comprised octadecenoic and polyunsaturated fatty acids with more than 18 carbon atoms in different proportions. As opposed to other phospholipids, cis-vaccenic acid, and not oleic acid, was the main octadecenoic acid present in cardiolipins. Octadecenoic acids were nine- to 10-fold more concentrated at positions 2 (2'') than at positions 1 (1''). The percentage of cis-vaccenic acid was four- to five-fold higher than that of oleic acid at positions 2 (2''), whereas oleic acid dominated at positions 1 (1'').(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiolipin vesicles can accommodate cholesterol up to 0.80 mole fraction, i.e. one molecule per cardiolipin fatty acid chain

Cardiolipin-cholesterol interactions were studied by time-resolved fluorescence spectroscopy with 1,6-diphenyl-1, 3,5-hexatriene as probe. The residual anisotropy parameter, r ∞ (reflecting the fatty acid chain packing), was measured in the liquid crystalline phase as a function of cholesterol addition. Two main results are reported: (i) a slight increase of the order parameter, S, computed from the r ∞ value as S = ( r ∞/ r 0) 1 2 , in the physiological concentration range of cholesterol; (ii) a sharp enhancement of S from a cholesterol mole fraction ( X̄ chl) of 0.20 and up to X̄ chl of 0.80. This is in contrast to unsaturated kcithin systems for which a continuous increase of the order parameter was monitored, culminating at X̄ chl = 0.50, the wellknown maximum level of incorporation of cholesterol into lecithin model membranes.

Fatty acid composition of cardiolipin from guinea pig Harderian gland.

The fatty acid composition of cardiolipin from the Harderian gland of guinea pig was examined by gas chromatography and gas chromatography-mass spectrometry. At least 33 kinds of fatty acids were detected. Oleic acid was the most prominent component, accounting for 18.2 mol% of the total fatty acids. About 70.2 mol% of fatty acids had methyl branches. Ethyl branches were also detected (1.3 mol%). Straight chain saturated acids comprised only 10.3 mol%. On the other hand, linoleic, linolenic, and arachidonic acids were not found in this lipid. The 2-(2'-) acyl moieties contained larger amounts of oleic acid and smaller amounts of branched chain acids than the 1-(1'-)acyl moieties, but the saturated straight chain acids showed even distribution between the 1-(1'-) and 2-(2'-)positions. The fatty acids of cardiolipin from the liver of the same animal were also examined. Linoleic acid was the most abundant component (66.9 mol%), and saturated straight chain acids occupied 21.9 mol%. Branched chain acids were detected but comprised only 11.2 mol%.

Phospholipids and glycerides composition during spheroplasts formation of Mycobacterium smegmatis ATCC 14468.

The phospholipids and glycerides composition of spheroplasts of Mycobacterium smegmatis ATCC 14468 was examined. The percent total phospholipids in total lipids as well as cardiolipin were found to be higher in spheroplasts as compared to their parent forms. Increase in cardiolipin and free fatty acids content and decrease in triglycerides levels were observed during spheroplasts formation. The results suggest that increase in cardiolipin content in spheroplasts is an adaptational change concomitant with the loss of cell walls.

Lipid changes with aging in cardiac mitochondrial membranes

Mitochondrial membranes were isolated from the myocardium of young (4-month-old) and aged (33-month-old) male Long-Evans rats and compared in terms of cholesterol content and phospholipid and fatty acid composition. In aged rats, as compared to young, the major observations include: markedly higher cholesterol content; increased percentage of sphingomyelin and diphosphatidylglycerol (cardiolipin); in fatty acids, variable changes, with a predominant increase in the 16:0 in most phospholipids except cardiolipin, and sporadic increase in the longer chain (20:0, 24:0) fatty acids in cardiolipin; decreased unsaturation index for most phospholipids but increased for cardiolipin. These results are tentatively interpreted as indicative of an aging-related decrease in fluidity and energy transduction of mitochondrial membrane in the heart of aged rats and may be responsible, in part, for the decrements in cardiac function with aging.

Cardiolipin of Chlamydomonas reinhardtii 137

The fatty acids of cardiolipin from the phototrophic green alga Chlamydomonas reinhardtii 137 + have been quantitatively analysed. Comparison is made at the molecular level between the cardiolipin of Chlamydomonas and that of higher plant tissue.

Isolation and characterization of cytidine diphosphate diglyceride from beef liver.

Cytidine diphosphate diglyceride was isolated from beef liver by a combination of silicic acid column, DEAE-cellulose column, and this layer chromatography. The product (5.8 to 17.4 mumol/kg of liver) contained cytidine/phosphate/fatty acids in the molar proportions 1.05/2.0/2.05 (theoretical, 1.0/2.0/2.0) (average for three preparations). The liponucleotide was split quantitatively by a partially purified hydrolase from Escherichia coli, specific for CDP-diglyceride, (Raetz, C. R. H., Hirschberg, C. B., Dowhan, W., Wickner, W. T., and Kennedy, E. P. (1972) J. Biol. Chem. 247, 2245-2247) into phosphatidic acid and a water-soluble nucleotide that was chromatographically identical with CMP. No dCMP was located in these hydrolysates. The liver liponucleotide was more effective than a synthetic preparation of CDP-diglyceride in promoting the formation of phosphatidylinositol with guinea pig brain microsomes. The fatty acid composition of CDP-diglyceride was compared with metabolically related phospholipids from beef liver. The liponucleotide had a similar composition to phosphatidylinositol, characterized by a high level of stearate and with arachidonate as the major unsaturated fatty acid. The content of arachidonate in both lipids was significantly higher than that in phosphatidic acid. The profile of fatty acids of cardiolipin was quite unlike that of CDP-diglyceride. These findings suggest several alternatives for the metabolic origins of beef liver CDP-diglyceride: (a) CDP-diglyceride is formed from an atypical pool of phosphatidic acid, (b) the enzyme is selective for arachidonoyl-containing species of phosphatidic acid, (c) the liponucleotide may also be derived from phosphatidylinositol by the back-reaction of CDP-diglyceride: inositol phosphatidyltransferase.

Skeletal muscle lipids. III. Changes in fatty acid composition of individual phosphoglycerides in man from fetal to middle age

The fatty acids in cardiolipin, choline phosphoglyc- MATERIALS AND METHODS eride, ethanolamine phosphoglyceride, inositol phosphoglycer- ide, and serine phosphoglyceride in the human gastrocnemius Material muscle were studied for changes between early fetal age to mid- The of the material and the procedure used for dle age. In cardiolipin, choline phosphoglyceride, and ethanol- amine phosphoglyceride, the relative total amount of the linoleic collection have been described earlier (1). The material in acid series increased considerably during the prenatal period and this study consisted of muscle samples from 10 fetuses, 10 reached maximum values during the first year of life. In inositol aged to lo yr, aged lo to 20~ phosphoglyceride and serine phosphoglyceride, only slight adults between 2O and 3o Yr Of age, and adults be- changes in the sum of fatty acids of the linoleic acid series were tween 50 and 60 yr of age. Most of the samples were ob- found. An increase in the concentration of fatty acids of the lino- lenic acid series was found in ethanolamine phosphoglyceride and serine phosphoglyceride, while only minor amounts of these fatty acids were present in choline phosphoglyceride and inositol phosphoglyceride and not at all in cardiolipin. During the peri- od studied, the amount of plasmalogen in ethanolamine phos- phoglyceride decreased slightly during the first year of life and then remained at 40%. The amount of plasmalogen increased in choline phosphoglyceride from 8% at the middle of the gesta- tional period to 15% 1 yr after birth. The individual phospho- lipids were found to have characteristic fatty acid patterns.

Alteration of the phospholipid composition of Staphylo-coccus aureus cultured in medium containing NaCl

1. 1. Cardiolipin of Staphylococcus aureus 209 P markedly increases and phosphatidylglycerol and lysylphosphatidylglycerol diminish as the NaCl concentration of the culture medium increases. 2. 2. The major change in fatty acid composition lies in the proportion of branched acids, resulting in an increase of the branched fatty acids in cardiolipin when cultured in high NaCl medium.

Negligible release of cardiolipin during milk secretion by the ruminant

The presence of cardiolipin (diphosphatidyl glycerol) in lactating mammary tissue (cow and goat) was investigated. The tissue was separated into subcellular fractions by sedimentation; the identities of the fractions were confirmed by electron microscopy. Polar lipids recovered from the fractions, the whole tissues, and milks were analyzed by two-dimensional thin-layer chromatography and the percentages of cardiolipin were determined. The phospholipids of whole mammary tissue from the cow and goat contain 3-5% cardiolipin which is concentrated largely, if not exclusively, in the mitochondria. Although milk may on occasion have up to 1% cardiolipin in its phospholipids, some normal milks contain less than 0.15%. Since tissue contains 20-30 times the amount (mg/g) of phospholipids in milk, the quantitative ratio of tissue to milk cardiolipin is several hundred to one. We interpret this to mean that the mechanism of milk secretion is highly selective and insures retention of mitochondria within the cell even though they are decidedly smaller than milk fat globules which are continuously secreted. Our findings substantiate the conception that there is very little disintegration of the cell or disruption of the plasma membrane during milk secretion. The fatty acids of cardiolipin from lactating mammary tissue of cow, goat, and pig are highly unsaturated; they contain 50% or more octadecadienoic acid.