scholarly journals Structure and lipid distribution of polyenoic very-long-chain fatty acids in the brain of peroxisome-deficient patients (Zellweger syndrome)

1987 ◽  
Vol 248 (1) ◽  
pp. 61-67 ◽  
Author(s):  
P Sharp ◽  
A Poulos ◽  
A Fellenberg ◽  
D Johnson

The polyenoic fatty acids with carbon chain lengths from 26 to 38 (very-long-chain fatty acids, VLCFA) previously detected in abnormal amounts in Zellweger syndrome brain have been shown to be n-6 derivatives and therefore probably derived by chain elongation of shorter-chain n-6 fatty acids such as linoleic acid and arachidonic acid. Polyenoic VLCFA are also present in Zellweger syndrome liver, but this tissue differs significantly from brain in that the saturated and mono-unsaturated derivatives are the major VLCFA. Zellweger syndrome brain polyenoic VLCFA are present in the neutral lipids predominantly in cholesterol esters, with smaller amounts in the non-esterified fatty acid and triacylglycerol fractions. These fatty acids are barely detectable in any of the major phospholipids, but are present in significant amounts in an unidentified minor phospholipid. The polyenoic VLCFA composition of this lipid differs markedly from that observed for all other lipids, as it contains high proportions of pentaenoic and hexaenoic fatty acids with 34, 36 and 38 carbon atoms. A polar lipid with the chromatographic properties in normal brain contains similar fatty acids. It is postulated that the polyenoic VLCFA may play an important role in normal brain and accumulate in Zellweger syndrome brain because of a deficiency in the peroxisomal beta-oxidation pathway, although a possible peroxisomal role in the control of carbon-chain elongation cannot be discounted.

1988 ◽  
Vol 253 (3) ◽  
pp. 645-650 ◽  
Author(s):  
A Poulos ◽  
P Sharp ◽  
D Johnson ◽  
C Easton

The n-6 tetra- and pentaenoic fatty acids with carbon chain lengths greater than 32 found in normal brain are located predominantly in a separable species of phosphatidylcholine. A similar phospholipid is found in increased amounts in the brain of peroxisome-deficient (Zellweger's syndrome) patients, but the fatty acid composition differs in that penta- and hexaenoic derivatives predominate. Our data strongly suggest that the polyenoic very long chain fatty acids are confined to the sn-1 position of the glycerol moiety, while the sn-2 position is enriched in saturated, monounsaturated and polyunsaturated fatty acids with less than 24 carbon atoms. It is postulated that these unusual molecular species of phosphatidylcholine may play some, as yet undefined, role in brain physiology.


1990 ◽  
Vol 269 (3) ◽  
pp. 671-677 ◽  
Author(s):  
J M Street ◽  
H Singh ◽  
A Poulos

The metabolism of [1-14C]lignoceric acid (C24:0) and [1-14C]tetracosatetraenoic acid (C24:4, n-6) was studied in normal skin fibroblast cultures and in cultures from patients with defects in peroxisomal β-oxidation (but normal peroxisomal numbers). Cells from X-linked adrenoleukodystrophy (ALD) patients with a presumed defect in a peroxisomal acyl-CoA synthetase, specific for fatty acids of carbon chain lengths greater than 22 (very-long-chain fatty acids; VLCFA), showed a relatively normal production of radiolabelled CO2 and water-soluble metabolites from [1-14C]C24:0. However, the products of synthesis from acetate de novo (released by β-oxidation), i.e. C16 and C18 fatty acids, were decreased, and carbon chain elongation of the fatty acid was increased. In contrast, cell lines from two patients with an unidentified lesion in peroxisomal β-oxidation (peroxisomal disease, PD) showed a marked deficiency in CO2 and water-soluble metabolite production, a decreased synthesis of C16 and C18 fatty acids and an increase in carbon chain elongation. The relatively normal β-oxidation activity of ALD cells appears to be related to low uptake of substrate, as a defect in β-oxidation is apparent when measurements are performed on cell suspensions under high uptake conditions. Oxidation of [1-14C]C24:4 was relatively normal in ALD cells and in the cells from one PD patient but abnormal in those from the other. Our data suggest that, despite the deficiency in VLCFA CoA synthetase, ALD cells retain a near normal ability to oxidize both saturated and polyunsaturated VLCFA under some culture conditions. However, acetate released by β-oxidation of the saturated VLCFA and, to a much lesser degree, the polyunsaturated VLCFA, appears to be used preferentially for the production of CO2 and water-soluble products, and acetate availability for fatty acid synthesis in other subcellular compartments is markedly decreased. It is likely that the increased carbon chain elongation of the saturated VLCFA which is also observed reflects the increased availability of substrate (C24:0) and/or an increase in microsomal elongation activity in ALD cells.


1985 ◽  
Vol 71 (2-3) ◽  
pp. 301-306 ◽  
Author(s):  
Tetsuo Sakai ◽  
Yasunobu Antoku ◽  
Ikuo Goto ◽  
Jun Ochiai ◽  
Hiroshi Iwashita ◽  
...  

1995 ◽  
Vol 311 (2) ◽  
pp. 689-697 ◽  
Author(s):  
S J Hardy ◽  
B S Robinson ◽  
A Ferrante ◽  
C S T Hii ◽  
D W Johnson ◽  
...  

Fatty acids with more than 22 carbon atoms (very-long-chain fatty acids; VLCFAs) are normal cellular components that have been implicated in the pathophysiology of a number of peroxisomal disorders. To date, however, essentially nothing is known regarding their biological activities. Ca2+ mobilization is an important intracellular signalling system for a variety of agonists and cell types. Given that several polyunsaturated long-chain fatty acids mobilize intracellular Ca2+ and that we have postulated that the VLCFAs may be involved in signal transduction, we examined whether the tetraenoic VLCFA induced Ca2+ mobilization in human neutrophils. We report that fatty acid-induced intracellular Ca2+ mobilization declined for fatty acid species of more than 20 carbon atoms, but increased again as the carbon chain length approached 30. This Ca2+ mobilization occurred independently of inositol 1,4,5-triphosphate production and protein kinase C translocation and involved both the release of Ca2+ from the intracellular stores and changes to the influx or efflux of the ion. We further observed that triacontatetraenoic acid [30:4(n-6)] mobilized Ca2+ from a thapsigargin-insensitive intracellular pool distinct from the thapsigargin-sensitive pools affected by arachidonic acid [20:4(n - 6)] or N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP). 20:4 (n - 6) induced strong superoxide production (chemiluminescence) which was inhibited by thapsigargin pretreatment. In contrast, fatty acid-induced superoxide production progressively declined as the carbon chain length increased beyond 20-22 carbon atoms. Further studies suggested that the thapsigargin-insensitive Ca2+ mobilization elicited by 30:4 (n - 6) was not related to oxyradical formation, while the thapsigargin-sensitive Ca2+ mobilization induced by 20:4 (n - 6) may be involved in the initiation but not necessarily the maintenance of superoxide production. In conclusion, this is the first report to demonstrate a biological activity for the VLCFA and indicates that 30:4 (n - 6) influences second messenger systems in intact cells that differ from those affected by long-chain fatty acids such as 20:4 (n - 6).


1988 ◽  
Vol 34 (6) ◽  
pp. 1041-1045 ◽  
Author(s):  
N A Hall ◽  
G W Lynes ◽  
N M Hjelm

Abstract We describe an HPLC method for measurement of ratios of concentrations of very-long-chain fatty acids (VLCFA) in plasma. The method, which involves ultraviolet detection of p-bromophenacyl derivatives of fatty acids, is validated by comparison with a gas chromatographic-mass spectrometric (GC-MS) method. The correlation between the ratios of 24-carbon fatty acids to 22-carbon fatty acids (C24/C22) estimated by the two methods was close (r = 0.976) as was the correlation for the C26/C22 ratios (r = 0.947). Increased VLCFA ratios could be demonstrated by either technique in patients with adrenoleukodystrophy, Zellweger syndrome, and infantile Refsum's disease. The HPLC method also measures phytanate concentrations in plasma. Control VLCFA ratios (for subjects without peroxisomal disorders) obtained by the two methods agree well with those reported by Moser et al. (Ann Neurol 1984; 16:628-41). For subjects younger than one year, ratios for C24/C22 and C26/C22 fatty acids were significantly greater than in older subjects.


1978 ◽  
Vol 174 (2) ◽  
pp. 379-386 ◽  
Author(s):  
H Osmundsen ◽  
J Bremer

Rates of acylcarnitine oxidation by isolated heart mitochondria from various animal species were measured polarographically, and by using a spectrophotometric assay [see Osmundsen & Bremer (1977) Biochem. J. 164, 621-633]. Polarographic measurements do not give a correct guide to abilities to beta-oxidize very-long-chain acylcarnitines, in particular C22:1 fatty acylcarnitines. 2. No significant species differences were detected in the abilities to beta-oxidize various C22:1 fatty acylcarnitines. Significant species differences were, however, detected when rates of beta-oxidation were correlated with rates of respiration brought about by very-long-chain acylcarnitines. We concluded that some aspects of oxidative metabolism (possibly the oxidation of tricarboxylic acid-cycle intermediates) are inhibited by very-long-chain fatty acids in some species (e.g. the rat and the cat but not in others (e.g. the pig and the rabbit). 3. It is proposed that the pattern of variation of rates of oxidation of various acylcarnitines (as measured spectrophotometrically) of various chain lengths can be used as a guide to the chain-length specificities of the acyl-CoA dehydrogenases of beta-oxidation (EC 1.3.99.3).


Sign in / Sign up

Export Citation Format

Share Document