Acids In Lipid Classes Research Articles

#3976 THE ROLE OF GENDER DIFFERENCES AND MENOPAUSE IN OBESITY-RELATED RENAL DISEASE, RENAL INFLAMMATION AND LIPOTOXICITY

Abstract Background and Aims The pathogenesis of obesity related-renal disease is unknown. Gender differences may have a role in renal damage in obesity. In particular, menopause can promote renal disease in obese women. In a previous study we observed that obese male and female mice developed albuminuria, hyperfiltration and glomerulomegaly, and these changes were more severe in those obese ovariectomized females. In this study we evaluated renal inflammation and lipotoxicity in that model. Method Twenty-two males and 57 females C57BL6/J mice were randomized to standard diet (SD) or high fat diet (HFD) for six months. A group of female animals on SD o HFD was ovariectomized to induce menopause. In renal tissue we evaluated cytokines: NF-κβ, IL-1β, MCP-1, TNF-α and total lipid content, lipid classes, fatty acid profile and fatty acids in lipid classes. Part of the lipidomic analysis was performed in urine. Results Obese males and females showed higher NF-κβ, TNF-α and MCP-1 in renal tissue (Fig. 1). Obese females ovariectomized had higher IL-1β and TNF-α compared with obese female not-ovariectomized (Fig. 1B). Obese animals showed lower pro-inflammatory fatty acids (16:0, 16:1n-7 and 18:2n-6) and higher anti-inflammatory fatty acid (22:6 n-3) (Fig. 2A). This pattern was also observed in specific lipid classes and urine. Finally, obese females ovariectomized had a more exacerbated pattern, with high 18:0 in phosphatidylcholine, high 18:0 DMA phosphatidylethanolamine and low 16:0 in triglycerides (Fig. 2B-D). Conclusion In conclusion, obesity induces inflammation and an unbalanced (pro-inflammatory) lipidic profile in renal tissue. This pattern seems to be enhanced in obesity after menopause.

Pigs Fed a Diet That Emulates the American Dietary Pattern Have Altered Hepatic Lipid Metabolism and Plasma and Follicular Fluid Lipidomes (P08-036-19)

ObjectivesPreviously we developed the Total Western Diet (TWD), a diet formulated by translating data from NHANES to a rodent diet using the concept of nutrient density. The TWD provides micro and macronutrients at the 50th percentile of daily American intake levels for both macro and micronutrients. To extend the model, the TWD for pigs was formulated and fed to pigs to determine the effects of the TWD on the plasma and follicular fluid (FF) lipidomes and the hepatic lipid profile. MethodsTen female, mature pigs were assigned to either the TWD (n = 5) or a control, low-fat commercial sow diet (n = 5). Pigs were fed for 12 weeks and allowed ad lib access to diets. Weights and food intake were measured weekly. Plasma and FF samples were collected at the end of the study to determine effects of treatment on the plasma and FF lipidomes as analyzed by LC-MS. Liver samples were also taken at the terminus of the study and the hepatic lipid profile was measured by GC-MS. ResultsPigs fed the TWD gained significantly more weight, 92.8 ± 9.5 vs. 54.2 ± 11.2 kg (P < 0.001)and had an increased fasted blood glucose, 123.2 ± 13.7 vs 91.4 ± 7.9 mg/dl (P < 0.01) compared to control pigs. There were 23 plasma lipid metabolites that were significantly affected by dietary treatment (P < 0.05). Interestingly, out of that total, 14 of those were sphingomyelin species, which were all increased in the TWD fed pigs. Similarly, in the FF, eight lipid metabolites were significantly different between treatments, including four sphingomyelin species, which were all higher in the TWD fed pigs. Pigs fed the TWD had significantly more hepatic non-esterified fatty acids (P < 0.05) compared to controls. Moreover, dihomo-gamma-linolenic acid was significantly higher in the triglyceride and free fatty acid lipid classes in pigs fed the TWD relative to pigs fed the control diet (P < 0.05). ConclusionsThese data demonstrate that some features of human metabolic syndrome are recapitulated in pigs fed a diet that emulates the American dietary pattern. Furthermore, these features are accompanied by changes to the plasma and FF lipidome, as well as the hepatic lipid profile in female pigs. These data suggest that sphingomyelin species in plasma and FF may be associated with overfeeding and metabolic syndrome. Funding SourcesUtah State University SPARC Award and Utah Agricultural Experiment Station.

Abstract 2506: Untargeted and targeted multiplatform metabolomic and lipidomic approaches for monitoring biological effects in serum from total body irradiated humans

Abstract Investigation of responses to radiation therapy or exposure to radiation in an intentional or accidental manner have identified significant biomarkers for biodosimetry and monitoring of individuals in urine through metabolomics (1). We extend the investigation in serum by combining targeted and untargeted methodologies with a multiplatform approach. Serum was collected from patients exposed to total body irradiation (TBI) prior to hematopoietic stem cell transplantation at Memorial Sloan Kettering Cancer Center. The underlying diseases (chronic myelogenous leukemia, acute lymphocytic leukemia, acute myeloid leukemia, non-Hodgkin lymphoma, or myelodysplastic syndrome) were in remission and the cohort included both males and females. Serum was collected prior to irradiation, at 3-8 h after a single dose of 1.25 Gy, and at 24h after three fractions of 1.25 Gy each. Untargeted metabolomic and lipidomic approaches with liquid chromatography (LC) mass spectrometry (MS) and gas chromatography (GC) MS demonstrated significant perturbations at the later time point and higher total dose. Alterations in circulating levels were observed in lipids from monoacylglycerol, triacylglycerol, phosphatidylcholine, phosphatidylglycerol, phosphatidylserine, and phosphatidic acid lipid classes. Fatty acids were some of the most dysregulated lipids, with increased levels linked to pro-inflammatory processes. To further investigate the presence of low abundance pro-inflammatory metabolites, we utilized a targeted and highly quantitative approach measuring downstream molecules from fatty acids, such as thromboxanes, prostaglandins, and leukotrienes that can act as signaling molecules and mediators of systemic inflammation. Results identified a rapid response within the first 3-8 hours primarily mediated through the enzymatic action of lipoxygenase (LOX) and cytochrome P450 (CYP450), although some dissipated at the later time point. Less significant alterations were observed in the anti-inflammatory pathway, although the fatty acid precursor α-linolenic acid remained elevated in both time points. Finally, as observed in our previous published study of a similar cohort (1), sex-dependent differences were analyzed and unlike the urinary results, females appeared to be more responsive to radiation effects as measured in serum with lipidomics and metabolomics. No sex differences were observed with the targeted approach. The ability to identify and quantify small molecules in blood following radiation exposure can therefore be utilized to not only monitor systemic effects of radiotherapy but also to generate signatures that can be utilized to identify accidentally exposed individuals that may require medical intervention. 1. Laiakis EC et al. Radiat Res 2014; 181: 350-361. Citation Format: Evagelia C. Laiakis, Evan L. Pannkuk, Siddheshwar Chauthe, Yi-Wen Wang, Ming Lian, Tytus D. Mak, Christopher A. Barker, Giuseppe Astarita, Albert J. Fornace. Untargeted and targeted multiplatform metabolomic and lipidomic approaches for monitoring biological effects in serum from total body irradiated humans [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2506. doi:10.1158/1538-7445.AM2017-2506

Determination of the fatty acid profile of neutral lipids, free fatty acids and phospholipids in human plasma

Knowledge of the fatty acid composition of lipid classes in human plasma is an important factor in the investigation of human metabolism. Therefore, a method for the analysis of neutral lipid (NL), phospholipid (PL) and free fatty acids (FFA) in human plasma has been developed and validated. Separation of lipid classes was carried out by solid phase extraction of the lipid extract. The fractions were transesterified and the resulting fatty acid methyl esters were determined by GC/FID. For the method to be validated, precision, detection and quantification limits, as well as recovery, were determined for combined lipid extraction, solid phase extraction and GC analysis. The lipid extraction was miniaturized and simplified by application of an ultrasound ‘Sonotrode’. The resolution of lipid classes was optimized with appropriate standards added to a representative plasma sample. In addition, a rapid derivatization procedure using trimethylsulfoniumhydroxide was established. Low determination limits (1.5, 0.2 and 1.3 μg/g plasma for NL, PL and FFA, respectively) indicate that the method’s sensitivity is sufficient to quantify even minor components. Furthermore, recovery for NL and PL fatty acids was found to range from 80% to 110%. The results were similar for FFA apart from more polar free fatty acids due to their higher solubility in water. Repetitive measurements showed very good precision apart from the long chain PUFA for which the coefficients of variation were significantly higher. The present method is applicable to the quantitation of fatty acids in lipid classes of human plasma including several minor components.

Composition of plasma fatty acids and non-cholesterol sterols in anorexia nervosa.

Anorexia nervosa is a model of simple starvation accompanied by secondary hyperlipoproteinemia. The pattern of plasma fatty acids influences the levels of plasma lipids and lipoproteins. The concentration of plasma lathosterol is a surrogate marker of cholesterol synthesis de novo, concentrations of campesterol and beta-sitosterol reflect resorption of exogenous cholesterol. The aim of the study was to evaluate fatty acids in plasma lipid classes and their relationship to plasma lipids, lipoproteins, cholesterol precursors and plant sterols. We examined 16 women with anorexia nervosa and 25 healthy ones. Patients with anorexia nervosa revealed increased concentrations of total cholesterol, triglycerides, HDL-cholesterol, campesterol and beta-sitosterol. Moreover, a decreased content of n-6 polyunsaturated fatty acids was found in all lipid classes. These changes were compensated by an increased content of monounsaturated fatty acids in cholesteryl esters, saturated fatty acids in triglycerides and both monounsaturated and saturated fatty acids in phosphatidylcholine. The most consistent finding in the fatty acid pattern concerned a decreased content of linoleic acid and a raised content of palmitoleic acid in all lipid classes. The changes of plasma lipids and lipoproteins in anorexia nervosa are the result of complex mechanisms including decreased catabolism of triglyceride-rich lipoproteins, normal rate of cholesterol synthesis and increased resorption of exogenous cholesterol.

A Mechanism for Rancidity Retardation by Partial Oil Extraction of Pecans

Shelf life is a major problem in the marketing of pecans, particularly at the retail level. A procedure to extend the shelf life of pecans was described. The full-oil and supercritical carbon dioxide extracted (22% and 27% reduced-oil) native pecan kernels packaged in standard air mixture (21% O2, 79% N2), stored for up to 37 weeks at 25 °C and 55% RH, were subjected to hexanal analysis, sensory analysis, and determination of lipid class changes, that occur as the pecans age. Hexanal concentration of reduced-oil pecans was negligible throughout the storage, while full-oil pecans reached excessive levels by 22 weeks. Hexanal analysis was in agreement with the sensory scores. Free fatty acid lipid class was selectively extracted during the partial oil extraction process. Reduction in free fatty acids, and an overall reduction in lipid content on a per kernel basis, decreased the sites for oxidative deterioration and contributed to enhanced shelf-life of pecans. Work was supported by OCAST grant AR4-044 and the Oklahoma Agricultural Experiment Station.

Effect of growth temperature on the biosynthesis of eukaryotic lipid molecular species by the cyanobacterium Spirulina platensis

The incorporation of linoleic acid added at mmolar concentrations to the culture medium of the photosynthetic prokaryote Spirulina platensis results in the synthesis of membrane glycerolipids with a eukaryotic distribution of fatty acid chain length on the glycerol backbone (Pham Quoc et al., Biochim. Biophys. Acta [1993] 1168, 94–99). This distribution contrasts with the usual prokaryotic one found in lipids of cyanobacteria. A subsequent desaturation of the exogenously supplied fatty acid resulted in a large increase of γ-linolenic acid. In order to estimate the capacities of S. platensis for bioconversion of fatty acids in lipid classes, the effects of different temperatures of growth were studied in linoleic acid-supplemented cultures. The lipid composition was affected by growth temperature, the synthesis of SQDG was stimulated at low temperature. The molecular species of each lipid were isolated and analyzed. Whatever the temperature of growth, the biosynthesis of eukaryotic C18/C18 lipid molecular species was observed in all lipid classes. Furthermore, the proportion of eukaryotic lipids increased at low temperature (24°C). The desaturation of C18 fatty acids at C1 and C2 positions of the glycerol moiety occurred and was further stimulated when the growth temperature was lowered. The resulting proportion of γ-linolenic acid increased significantly in cultures supplemented with linoleate at low temperatures. Finally a pathway for the synthesis of eukaryotic lipids and the desaturation of fatty acids esterified to the acyl lipids of linoleate-supplemented S. platensis can be suggested.

Influence of growth rate on pigment and lipid composition of the microalgaIsochrysis aff.galbana clone T.iso

A continuous culture ofIsochrysis aff.galbana clone T.iso, used to feedPecten maximus larvae at IFREMER (Brest, France), was carried out in a chemostat at its optimum temperature for growth (26 °C). Changes in pigments, lipid class (neutral, glyco- and phospholipids) and degree of fatty acid unsaturation were studied at three different growth rates (0.33, 0.5, 1 d−1). As predicted by chemostat theory, a slow growth rate produced higher cell numbers and higher biomass per unit volume. These cells were low in chlorophylla and carotenoids, but rich in neutral lipids. In contrast, cultures with a fast growth rate yielded lower cell concentrations, buth higher chlorophylla, carotenoid and membrane lipid contents per cell. Changes in polyunsaturated fatty acid distribution were related to differences in algal growth rates. Neutral lipids contained mainly saturated and monounsaturated fatty acids (C18:1ω9) at low growth rates whereas they were enriched in polyunsaturated fatty acids, especially C22:6ω3, at high growth rates. Therefore, it is suggested that the growth rate in continuous cultures be controlled so as to adjust the relative proportions of polyunsaturated fatty acids in lipid classes of the diet meant for larval nutrition.

DO TRANS FATTY ACIDS (TFA) IMPAIR BIOSYNTHESIS OF LONG-CHAIN POLYUNSATURATES (LCP) IN MAN?

Humans consume large amounts of TFA due to the extensive use of hydrogenated fats in food production. TFA consumption is considered safe for man, but side effects including impaired synthesis of LCP (20 & 22 carbons) have been observed in animal studies. We have previously documented materno-fetal transfer of TFA in humans. Therefore, we looked for possible effects of TFA on LCP status during early life, when LCP modulate tissue growth and development. Methods: Blood plasma samples were obtained in 29 clinically well-premature infants (gest. age 34.0±1.8 wks., birthwt. 1694±173 g, M±SD) prior to feeding in the morning of day 3 post partum, when milk intake was still very low. No infant had received fat infusions. Fatty acids in lipid classes were determined by high-resolution gas-liquid-chromatography. Results: Both total TFA and elaidic acid (18:1t), the main dietary TFA, were inversely correlated to LCP in plasma lipids. In triglycerides, linear correlation coefficients (r) for 18:1t were significant (P<0.05* & 0.01**) for LCP (n-6-LCP: -0.41*, n-3-LCP: -0.50**, total LCP: -0.55**) and for product substrate ratios of LCP biosynthesis (20:4/18:2n-6: -0.47**, 22:6/18:3n-3: -0.50**). Similar results were found in other lipid classes for 18:1t and total TFA. Conclusions: 1. TFA exposure may impair biosynthesis of n-6- and n-3-LCP in man. 2. Since the capacity for LCP biosynthesis is limited during early life and LCP accretion is essential for normal functional development of membrane rich tissues (e.g. brain), a high intrauterine TFA exposure may have serious risks for fetus and neonate. 3. This observation is the first indication of possible untoward effects of TFA in man.

Effect of cyproterone acetate-ethinyl estradiol treatment on the proportions of linoleic and sebaleic acids in various skin surface lipid classes.

The effect of high-dose cyproterone acetate-ethinyl estradiol treatment on rates of sebum secretion and on the proportions of linoleic acid (18:2 delta 9,12) and sebaleic acid (18:2 delta 5,8) in the skin surface lipids of three female acne patients was examined. Changes in rates of sebum secretion were evaluated indirectly by measuring the ratio of wax esters/(cholesterol + cholesterol esters) in the subjects' skin surface lipid. In two of the subjects, this ratio indicated a reduction of sebum secretion rates to the childhood range. Concomitantly, there was an increase in linoleic acid and a decrease in sebaleic acid in all lipid classes. In the third subject, in whom there was only a small reduction in sebum secretion rate, the proportion of linoleic acid in the cholesterol esters more than doubled, but the changes in the other lipid classes were small or nonexistent. The results indicate that the proportions of linoleic acid and sebaleic acid in sebum are influenced by sebum secretion rates.

Multiple Discriminant Analysis of Fatty Acids from Male Scalp Hair Lipids

AbstractLipids extracted from the scalp hair of Caucasian boys, teenagers and adults and Black Teenagers of a boarding school, were saponified and the groups compared with respect to the total fatty acids by multiple discriminant analysis. The lipid yields from Black ranged higher than those from Caucasians. Among the Caucasians, differences based on age were not significant. The total acids of hair lipids from Blacks differed significantly as compared to those of the White groups, a trend also supported by analyses of acids in lipid classes of men 24–70 years of age. Hair from the latter was pooled according to race and scalp condition (balding and non‐balding). With the latter 4 adult categories, acids of the mono‐, di‐ and tri‐acylglycerols and the free fatty acids were ascertained and compared, both on the basis of the over‐all acids as well as in terms of the prominent saturated and unsaturated homologs. Racial differences were encountered in the fatty acids, the saturated acids distinguishing the free fatty acids and triacylglycerols and the unsaturated, the mono‐ and di‐acylglycerols. For each category, the ratios of free fatty acids to triacylglycerols were not significant in contrast to the component acids as such. As based on the acids, significant differences also occurred with scalp condition in the respective racial groupings.