RESUMEN
Identifying dietary patterns that contribute to zinc (Zn) and fatty acids intake and their biomarkers that may have an impact on health of males and females. The present study was designed to (a) extract dietary patterns with foods that explain the variation of Zn and PUFAs intake in adult men and women; and (b) evaluate the association between the extracted dietary patterns with circulating levels of serum dihomo-γ-linolenic fatty acid (DGLA) or serum linoleic/dihomo-γ-linolenic (LA/DGLA) ratio in males and females. We used reduced rank regression (RRR) to extract the dietary patterns separated by sex in the NHANES 2011-2012 data. A dietary pattern with foods rich in Zn (1st quintile = 8.67 mg/day; 5th quintile = 11.11 mg/day) and poor in PUFAs (5th quintile = 15.28 g/day; 1st quintile = 18.03 g/day) was found in females (S-FDP2) and the same pattern, with foods poor in PUFAs (5th quintile = 17.6 g/day; 1st quintile = 20.7 g/day) and rich in Zn (1st quintile = 10.4 mg/day; 5th quintile = 12.9 mg/day) (S-MDP2), was found in males. The dietary patterns with foods rich in Zn and poor in PUFAs were negatively associated with serum LA/DGLA ratio. This is the first study to associate the LA/DGLA ratio with Zn and PUFAs related dietary patterns in males and females.
Asunto(s)
Ácido 8,11,14-Eicosatrienoico/sangre , Dieta , Ácidos Grasos Insaturados/administración & dosificación , Ácido Linoleico/sangre , Zinc/administración & dosificación , Estudios Transversales , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Estado Nutricional , Pronóstico , Estudios RetrospectivosRESUMEN
The importance of cytochrome P450 (CYP)-derived arachidonic acid (AA) metabolites, 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) as tumor growth promotors has already been described in several cancer types. The aim of this study was to evaluate the role of these compounds in the biology of pheochromocytoma/paraganglioma. These tumors originate from chromaffin cells derived from adrenal medulla (pheochromocytomas) or extra-adrenal autonomic paraganglia (paragangliomas), and they represent the most common hereditary endocrine neoplasia. According to mutations in the driver genes, these tumors are divided in two clusters: pseudo-hypoxic and kinase-signaling EETs, but not 20-HETE, exhibited a potent ability to sustain growth in a murine pheochromocytoma cell line (MPC) in vitro, EETs promoted an increase in cell proliferation and a decrease in cell apoptosis. In a mouse model of pheochromocytoma, the inhibition of CYP-mediated AA metabolism using 1-aminobenzotriazol resulted in slower tumor growth, a decreased vascularization, and a lower final volume. Also, the expression of AA-metabolizing CYP monooxygenases was detected in tumor samples from human origin, being their apparent abundance and the production of both metabolites higher in tumors from the kinase-signaling cluster. This is the first evidence of the importance of CYP- derived AA metabolites in the biology and development of pheochromocytoma/paraganglioma tumors.
Asunto(s)
Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Neoplasias de las Glándulas Suprarrenales/inducido químicamente , Sistema Enzimático del Citocromo P-450/metabolismo , Ácidos Hidroxieicosatetraenoicos/farmacología , Feocromocitoma/inducido químicamente , Ácido 8,11,14-Eicosatrienoico/farmacología , Adolescente , Neoplasias de las Glándulas Suprarrenales/patología , Adulto , Animales , Línea Celular Tumoral , Niño , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Neovascularización Patológica , Feocromocitoma/patología , Adulto JovenRESUMEN
Thraustochytrids have been isolated from different aquatic systems; however, few studies have reported their occurrence in Antarctica. In this study, 13 strains close to strains belonging to the genera Oblongichytrium, Thraustochytrium, and Aurantiochytrium were isolated from seawater samples collected near the Antarctic Base Professor Julio Escudero (S 62°12'57' E 58°57'35â³). Docosahexaenoic acid (DHA) was found in the total lipids of all the isolates; DHA content of the biomass (dry weight) varied between 3.3 and 33 mg/g under the growth conditions for isolation. Five of the Antarctic thraustochytrids were able to accumulate lipids at levels higher than 20% w/w. Two strains, RT2316-7 and RT2316-13, were selected to test the effect of the incubation temperature (at 5°C for 14 days and at 15°C for 5 days). Incubation temperature had little effect on the lipid content and biomass yield; however, its effect on the fatty acid composition was significant (p < .05). The low incubation temperature favored the accumulation of eicosapentaenoic acid (EPA), palmitic acid and stearic acid in the total lipids of RT2316-7. Percentage of EPA, DHA and the omega-6 fatty acid dihomo-γ-linolenic acid of total fatty acids of RT2316-13 was higher at the low incubation temperature. RT2316-13 accumulated the highest lipid content (30.0 ± 0.5%) with a carbon to nitrogen mass ratio equal to 16.9. On the contrary, lipid accumulation in RT2316-7 occurred at high concentration of the nitrogen sources (monosodium glutamate or yeast extract). The capability to accumulate lipids with a fatty acid profile that can be tuned through cultivation temperature make the Antarctic thraustochytrid RT2316-13 a candidate for the production of lipids with different uses.
Asunto(s)
Reactores Biológicos/microbiología , Ácidos Grasos Omega-3/biosíntesis , Estramenopilos/metabolismo , Ácido 8,11,14-Eicosatrienoico/análisis , Regiones Antárticas , Membrana Celular/fisiología , Ácidos Docosahexaenoicos/análisis , Ácido Eicosapentaenoico/análisis , Ácido Palmítico/análisis , Agua de Mar , Ácidos Esteáricos/análisis , Estramenopilos/clasificación , Estramenopilos/crecimiento & desarrollo , Estramenopilos/aislamiento & purificación , TemperaturaRESUMEN
Zika virus (ZIKV) has emerged as one of the most medically relevant viral infections of the past decades; the devastating effects of this virus over the developing brain are a major matter of concern during pregnancy. Although the connection with congenital malformations are well documented, the mechanisms by which ZIKV reach the central nervous system (CNS) and the causes of impaired cortical growth in affected fetuses need to be better addressed. We performed a non-invasive, metabolomics-based screening of saliva from infants with congenital Zika syndrome (CZS), born from mothers that were infected with ZIKV during pregnancy. We were able to identify three biomarkers that suggest that this population suffered from an important inflammatory process; with the detection of mediators associated with glial activation, we propose that microcephaly is a product of immune response to the virus, as well as excitotoxicity mechanisms, which remain ongoing even after birth.
Asunto(s)
Microcefalia/etiología , Saliva/química , Infección por el Virus Zika/diagnóstico , Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Biomarcadores , Femenino , Desarrollo Fetal , Feto , Humanos , Lactante , Recién Nacido , Inflamación/complicaciones , Estudios Longitudinales , Masculino , Metabolómica/métodos , Microcefalia/virología , Madres , Parto , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Virosis , Virus Zika/patogenicidad , Infección por el Virus Zika/virologíaRESUMEN
Cats have limited Δ6 desaturase activity. However, γ-linolenate (GLA) feeding may by-pass the Δ6 desaturase step allowing arachidonate (ARA) accumulation via Δ5-desaturation. Alternatively, high dietary linoleate (LNA) may induce limited Δ6 desaturase also resulting in ARA accumulation. Fatty acid profiles were determined after feeding high LNA, high GLA, or adequate LNA diets. Adult female cats (n = 29) were assigned to one of three groups and fed for 8 weeks. Plasma samples were collected at weeks 0, 2, 4 and 8 for plasma triacylglycerol (TAG), total cholesterol (TC), lipoprotein (LP), and plasma and red blood cell membrane phospholipid fatty acid determinations. Time, but no diet, effects were observed for TAG, TC, and LP fractions at weeks 2 and 4 with significant increases likely due to increased dietary fat. However, all values were within feline normal limits. The GLA diet resulted in increased dihomo-γ-linolenic acid (DGLA) and ARA as early as week 2, supporting a ∆5 desaturase. Further evidence of Δ5 desaturase was found at high dietary LNA with the appearance of a novel fatty acid, 20:3 ∆7, 11, 14, apparently formed via ∆5 desaturation and chain elongation of LNA. However, Δ6 desaturase induction at high dietary LNA concentration was not observed. Cats are able to maintain plasma and red blood cell ARA when fed a practical diet containing GLA using what appears to be an active Δ5 desaturase enzyme.
Asunto(s)
Ácido Araquidónico/sangre , Grasas Insaturadas en la Dieta/metabolismo , Ácido Graso Desaturasas/metabolismo , Ácido Linoleico/sangre , Ácido gammalinolénico/sangre , Ácido 8,11,14-Eicosatrienoico/sangre , Animales , Peso Corporal , Gatos , Femenino , Cromatografía de Gases y Espectrometría de Masas , Metabolismo de los Lípidos , Hígado/metabolismoRESUMEN
Ethnicity-related differences in maternal n-3 and n-6 fatty acid status may be relevant to ethnic disparities in birth outcomes observed worldwide. The present study explored differences in early pregnancy n-3 and n-6 fatty acid composition of maternal plasma phospholipids between Dutch and ethnic minority pregnant women in Amsterdam, the Netherlands, with a focus on the major functional fatty acids EPA (20 : 5n-3), DHA (22 : 6n-3), dihomo-gamma-linolenic acid (DGLA; 20 : 3n-6) and arachidonic acid (AA; 20 : 4n-6). Data were derived from the Amsterdam Born Children and their Development (ABCD) cohort (inclusion January 2003 to March 2004). Compared with Dutch women (n 2443), Surinamese (n 286), Antillean (n 63), Turkish (n 167) and Moroccan (n 241) women had generally lower proportions of n-3 fatty acids (expressed as percentage of total fatty acids) but higher proportions of n-6 fatty acids (general linear model; P < 0.001). Ghanaian women (n 54) had higher proportions of EPA and DHA, but generally lower proportions of n-6 fatty acids (P < 0.001). Differences were most pronounced in Turkish and Ghanaian women, who, by means of a simple questionnaire, reported the lowest and highest fish consumption respectively. Adjustment for fish intake, however, hardly attenuated the differences in relative EPA, DHA, DGLA and AA concentrations between the various ethnic groups. Given the limitations of this observational study, further research into the ethnicity-related differences in maternal n-3 and n-6 fatty acid patterns is warranted, particularly to elucidate the explanatory role of fatty acid intake v. metabolic differences.
Asunto(s)
Dieta/etnología , Ácidos Grasos Omega-3/sangre , Ácidos Grasos Omega-6/sangre , Peces , Fenómenos Fisiologicos Nutricionales Maternos/etnología , Ácido 8,11,14-Eicosatrienoico/sangre , Adulto , Análisis de Varianza , Animales , Ácido Araquidónico/sangre , Distribución de Chi-Cuadrado , Ácidos Docosahexaenoicos/sangre , Femenino , Ghana/etnología , Humanos , Marruecos/etnología , Países Bajos , Estado Nutricional , Embarazo , Primer Trimestre del Embarazo , Suriname/etnología , Turquía/etnología , Adulto JovenRESUMEN
Sertoli cells play a central role in spermatogenesis, its development and regulation. They are target cells for androgen action in the seminiferous tubules. The Sertoli cell is considered to be the most important cell type in the testis with regard to essential fatty acid metabolism. We studied the response to testosterone of cultured Sertoli cells from immature rats by determining the fatty acid composition of total cellular lipids as well as by the biosynthesis of polyunsaturated fatty acids. Fatty acid methyl esters were analysed by gas liquid chromatography and radiochromatography. Two doses of testosterone were tested (150 and 300 ng ml(-1)). Significant differences were found in fatty acids derived from total cellular lipids after 8 days in culture in the presence of testosterone (300 ng ml(-1), for 48 h). Compared to controls, the hormone produced a significant increase of 16:1 and 18:1 n-9, and of 18:2 n-6, and a decrease of 20:4 and 22:5 n-6 in total cellular lipids. The decrease in the n-6 fatty acid ratios 20:4/20:3, 20:4/18:2 and 24:5/24:4, and the increase in 18:1n-9/18:0 and 16:1n-9/16:0 ratios were taken as an indirect signal of testosterone effects on Delta5, Delta6 and Delta9 desaturase activities. The drop in Delta5 and Delta6 desaturase activities was corroborated by analysing the transformation of [1-14C]20:3 n-6 into its higher homologues. We concluded that testosterone modifies the fatty acid pattern of cultured Sertoli cells, and this hormone is involved in polyunsaturated fatty acid biosynthesis, modulating Delta5 and Delta6 desaturases activity.
Asunto(s)
Andrógenos/farmacología , Ácidos Grasos Insaturados/metabolismo , Células de Sertoli/metabolismo , Testosterona/farmacología , Ácido 8,11,14-Eicosatrienoico/farmacocinética , Animales , Radioisótopos de Carbono , Células Cultivadas , Ácidos Grasos Insaturados/biosíntesis , Masculino , Ratas , Ratas Wistar , Células de Sertoli/citología , Células de Sertoli/efectos de los fármacosRESUMEN
The essential fatty acid deficiency (EFAD) is a metabolic condition related to cancer development. We studied the effect of eicosapentaenoic acid (EPA, 20:5 n-3) and eicosatrienoic acid (ETA, 20:3 n-9), an essential fatty acid (EFA) and non-EFA respectively, on tumour cells parameters linked to tumour progression and metastases. Human tumour cell lines (T-24 from urothelium, MCF-7 from breast and HRT-18 from colon) were used. EPA showed an anti-proliferative effect on the three lines. ETA showed the following effects: in T-24, the lipid peroxidation was decreased and E-cadherin was undetectable; in MCF-7, increased E-cadherin expression enhanced the lipid peroxidation and decreased cell proliferation; on HRT-18, the E-cadherin expression and lipid peroxidation diminished, whereas cell proliferation was increased. In conclusion, EFA (20:5 n-3) exhibited beneficial effects, whereas unusual ETA showed an opposite effect on some tumour parameters. The possible riskiness of EFA-deprivation, along with the potential of EFA as natural nutrapeutic products for human tumour prevention and treatment, makes EFA worthy of further consideration.
Asunto(s)
Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Ácido 8,11,14-Eicosatrienoico/farmacología , Línea Celular Tumoral/efectos de los fármacos , Alcadienos/análisis , Western Blotting , Cadherinas/análisis , Cadherinas/metabolismo , División Celular/efectos de los fármacos , Línea Celular Tumoral/metabolismo , Cromatografía de Gases , Ácido Eicosapentaenoico/farmacología , Electroforesis en Gel de Poliacrilamida , Ácidos Grasos/análisis , Ácidos Grasos Esenciales/deficiencia , Ácidos Grasos Esenciales/farmacología , Humanos , Inmunohistoquímica , Peroxidación de Lípido/efectos de los fármacosRESUMEN
BACKGROUND: Early suspicion of essential fatty acid deficiency (EFAD) or omega3-deficiency may rather focus on polyunsaturated fatty acid (PUFA) or long-chain PUFA (LCP) analyses than clinical symptoms. We determined cut-off values for biochemical EFAD, omega3-and omega3/22:6omega3 [docosahexaenoic acid (DHA)]-deficiency by measurement of erythrocyte 20:3omega9 (Mead acid), 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3, respectively. METHODS: Cut-off values, based on 97.5 percentiles, derived from an apparently healthy omnivorous group (six Dominica breast-fed newborns, 32 breast-fed and 27 formula+LCP-fed Dutch low-birth-weight infants, 31 Jerusalem infants, 33 Dutch 3.5-year-old infants, 69 omnivorous Dutch adults and seven Dominica mothers) and an apparently healthy group with low dietary LCP intake (81 formula-fed Dutch low-birth-weight infants, 12 Dutch vegans). Cut-off values were evaluated by their application in an EFAD suspected group of 108, mostly malnourished, Pakistani children, three pediatric patients with chronic fat-malabsorption (abetal-ipoproteinemia, congenital jejunal and biliary atresia) and one patient with a peroxisomal beta-oxidation disorder. RESULTS: Erythrocyte 20:3omega9, 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3 proved age-dependent up to 0.2 years. Cut-off values for ages above 0.2 years were: 0.46mol% 20:3omega9 for EFAD, 0.068mol/mol 22:5omega6/20:4omega6 for omega3-deficiency, 0.22mol/mol 22:5omega6/22:6omega3 for omega3/DHA-marginality and 0.48mol/mol 22:5omega6/22:6omega3 for omega3/DHA-deficiency. Use of RBC 20:3omega9 and 22:5omega6/20:4omega6 cut-off values identified 20.4% of the Pakistani subjects as EFAD+omega3-deficient, 12.9% as EFAD+omega3-sufficient, 38.9% as EFA-sufficient+omega3-deficient and 27.8% as EFA-sufficient+omega3-sufficient. The patient with the peroxisomal disorder was classified as EFA-sufficient, omega3-sufficient (based on RBC 22:5omega6/20:4omega6) and omega3/DHA-deficient (based on RBC 22:5omega6/22:6omega3). The three other pediatric patients were classified as EFAD, omega3-deficient and omega3/DHA-deficient. CONCLUSION: Use of the combination of the present cut-off values for EFA, omega3 and omega3/DHA status assessment, as based on 97.5 percentiles, may serve for PUFA supplement intervention until better concepts have emerged.
Asunto(s)
Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Eritrocitos/química , Ácidos Grasos Esenciales/sangre , Ácidos Grasos Omega-3/sangre , Ácido 8,11,14-Eicosatrienoico/sangre , Alimentación con Biberón , Lactancia Materna , Niño , Preescolar , Dieta Vegetariana , Dominica , Humanos , Lactante , Recién Nacido de Bajo Peso/sangre , Recién Nacido , Israel , Países Bajos , Pakistán , Valores de Referencia , Reproducibilidad de los ResultadosRESUMEN
Primary culture is a suitable system to study lipid metabolism and polyunsaturated fatty acid biosynthesis. Sertoli cell-enriched preparations were used to determine the fatty acid composition after 5 and 7 days in culture (serum free) as well as the uptake and metabolism of [1-14C]eicosa-8,11,14-trienoic acid. The addition of unlabeled linoleic acid (0.2 and 2.0 microg/ml) was also evaluated. Fatty acid methyl esters derived from cellular lipids were analyzed by gas liquid chromatography and radiochromatography. After 5 days in culture, cells had significantly less 18:2, 20:4, 22:5 and 24:5 and more 18:3, 20:3, 22:4 and 24:4 n-6 fatty acids than non-cultured cells. On day 7, an additional increment in 22:4 n-6 and a decrease in linoleic, gamma-linoleic and 24:4 n-6 fatty acids were observed. The presence of linoleic acid (low dose) produced a significant decrease in saturated and monounsaturated acids and an increase in 18:2, 20:4 and 22:5 n-6 fatty acids. At a high concentration almost all fatty acids belonging to 18:2 n-6 increased significantly. The drop in 20:4 n-6/20:3 n-6 ratio was considered as an indirect evidence of a Delta 5 desaturase activity depression. This assumption was corroborated by studying the transformation of [1-14C]eicosa-8,11,14-trienoic acid into 20:4, 22:4, 22:5, 24:4 and 24:5 n-6 fatty acids. We conclude that Sertoli cells after 7 days in culture evidenced changes in the fatty acid profile similar to those described under fat deprivation. The addition of linoleic acid reverted this pattern and indicated that the Delta 5 desaturase activity is a limiting step in the polyunsaturated fatty acid biosynthesis.
Asunto(s)
Ácidos Grasos Insaturados/biosíntesis , Ácidos Grasos Insaturados/metabolismo , Ácido Linoleico/metabolismo , Células de Sertoli/metabolismo , Ácido 8,11,14-Eicosatrienoico/metabolismo , Animales , Células Cultivadas , Medio de Cultivo Libre de Suero , Ácidos Grasos Omega-6 , Ácido Linoleico/administración & dosificación , Masculino , Ratas , Ratas Wistar , Células de Sertoli/citologíaRESUMEN
Thiols represent preferential targets of peroxynitrite in biological systems. In this work, we investigated the mechanisms and kinetics of the reaction of peroxynitrite with the dithiol dihydrolipoic acid (DHLA) and its oxidized form, lipoic acid (LA). Peroxynitrite reacted with DHLA being oxidation yields higher at alkaline pH. The stoichiometry for the reaction was two thiols oxidized per peroxynitrite. LA formation accounted for approximately 50% DHLA consumption at pH 7.4, probably reflecting secondary reactions between LA and peroxynitrite. Indeed, peroxynitrous acid reacted with LA with an apparent second-order rate constant (k(2app)) of 1400 M(-1) s(-1) at pH 7.4 and 37 degrees C. Nitrite and LA-thiosufinate were formed as reaction products. Surprisingly, the k(2app) for peroxynitrite-dependent DHLA oxidation was only 250 M(-1) s(-1) per thiol, at pH 7.4 and 37 degrees C. Testing various low-molecular-weight thiols, we found that an increase in the thiol pK (pK(SH)) value correlated with a decrease of k(2app) for the reaction with peroxynitrite at pH 7.4. The pK(SH) for DHLA is 10.7, in agreement with its modest reactivity with peroxynitrite.
Asunto(s)
Oxígeno/metabolismo , Ácido Peroxinitroso/metabolismo , Compuestos de Sulfhidrilo/metabolismo , Ácido Tióctico/metabolismo , Ácido 8,11,14-Eicosatrienoico/metabolismo , Antioxidantes/farmacología , Relación Dosis-Respuesta a Droga , Concentración de Iones de Hidrógeno , Cinética , Espectrometría de Masas , Modelos Químicos , Ácido Peroxinitroso/química , Unión Proteica , Ácidos Sulfónicos/química , Ácido Tióctico/química , Factores de TiempoRESUMEN
Walker 256 tumour-bearing rats were fed pelleted chow containing low-gamma-linolenic acid (GLA) (2.98%) or high-GLA (5.55%) during the twelve-day period after subcutaneous implantation of the tumour. The presence of n-6, polyunsaturated GLA in the diet caused a concentration-dependent decrease in tumour growth, reaching an almost 50% reduction in final tumour weight in the high-GLA group. The eicosatrienoic acid content of the whole tumour homogenate and of the Percoll-purified mitochondrial fraction was increased by the GLA-rich diets. Changes in the fatty acid composition of the cytoplasmic acyl CoA pool were also found, with increases in GLA content in both the low- and high-GLA groups. Additionally, increases in eicosatrienoic acid and arachidonic acid were found in the high-GLA group. Both the cytoplasmic acyl CoA content and the mitochondrial acyl CoA synthetase activity were increased by GLA in the diet and lipid peroxidation was also increased as determined by an increase in TBARS content. Changes in mitochondrial fatty acid composition were accompanied by a decrease in the mitochondrial membrane potential in the high-GLA group. Tumours from the control and GLA groups were examined by transmission electron microscopy. This revealed an increase in mitochondrial area and volume in the high-GLA group, in comparison with the control group, as well as a change in general cell ultrastructure, with many cells found in an apoptotic state or in a necrotic state, possibly secondary to apoptosis. The data presented show that the addition of GLA to the diet of Walker 256 tumour-bearing rats can greatly decrease the rate of development of the tumour burden. This may be, in part, due to the accumulation of poorly metabolised acyl CoA's within the tumour cell cytoplasm which, when coupled with altered mitochondrial composition, membrane potential and ultrastructure, may be a signal for cell death.
Asunto(s)
Apoptosis/efectos de los fármacos , Carcinoma 256 de Walker/metabolismo , Mitocondrias/metabolismo , Mitocondrias/ultraestructura , Ácido gammalinolénico/farmacología , Ácido 8,11,14-Eicosatrienoico/metabolismo , Animales , Ácido Araquidónico/metabolismo , Carcinoma 256 de Walker/enzimología , Carcinoma 256 de Walker/ultraestructura , Coenzima A Ligasas/metabolismo , Grasas de la Dieta/farmacología , Relación Dosis-Respuesta a Droga , Peroxidación de Lípido/efectos de los fármacos , Masculino , Microscopía Electrónica , Ratas , Ratas Wistar , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismoRESUMEN
The incorporation of [1-(14)C]20:3 n-6 and its desaturation product, [1-(14)C]20:4 n-6 into nuclear lipids from rat liver cells were investigated during in vitro delta5 desaturation. [1-(14)C]20:3 n-6 activated as 20:3 n-6-CoA by nuclear long chain acyl-CoA synthetase was: (1) incorporated into nuclear lipids mainly esterified to phospholipids and in a lesser proportion, to triglycerides and diglycerides; and (2) desaturated to 20:4 n-6-CoA by the nuclear delta5 desaturase. The amount of [1-(14)C]20:4 n-6 acid synthesized in cell nuclei increased along with time and was stimulated by the cytosol fraction. The major proportion of 20:4 n-6 was found in phospholipids and in a lesser proportion it remained as free fatty acids and was esterified to triglycerides and diglycerides. 20:4 n-6-CoA was incorporated into nuclear lipids and hydrolyzed to free fatty acid. These results indicate that liver cell nuclei possess the necessary enzymes to incorporate the delta5 desaturase substrate (20:3 n-6) as well as the product of desaturation (20:4 n-6) into nuclear TG, DG and PL following an acyl-CoA dependent pathway.
Asunto(s)
Ácido 8,11,14-Eicosatrienoico/metabolismo , Acil-CoA Deshidrogenasa de Cadena Larga/metabolismo , Ácido Araquidónico/metabolismo , Núcleo Celular/metabolismo , Ácido Graso Desaturasas , Animales , Radioisótopos de Carbono/metabolismo , Fraccionamiento Celular , Citosol/metabolismo , delta-5 Desaturasa de Ácido Graso , Metabolismo de los Lípidos , Hígado/citología , Masculino , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
This work evaluates how the abnormalities in fatty acid biosynthesis, already described in diabetic rats, were extended to Sertoli and Leydig cells isolated from testes of streptozotocin-treated rats. Both kinds of cells were incubated in the presence of labeled eicosa-8,11,14-trienoic acid. The uptake of the substrate and its conversion to arachidonic acid were significantly depressed in both cell types compared to the non-diabetic controls. The indirect evidence of this inhibition was observed in the total fatty acid pattern of the cells where the 20:4 n-6/18:2 n-6 ratio was significantly decreased. The addition of insulin to the incubation medium produced no changes in the uptake of the substrate by the cells. Under similar experimental conditions the synthesis of arachidonic acid was partially recovered, however, the values obtained were still below those ones of cells isolated from control animals. These results were correlated with the fatty acid profile of different lipid fractions of plasma and with the activity of enzymes involved in polyunsaturated fatty acids biosynthesis measured in the testicular microsomes of diabetic rats. We conclude that Sertoli and Leydig cells evidenced similar lipid disorders than those observed in the whole testis or in other tissues of diabetic rats, and that the biosynthesis of arachidonic acid is under insulin regulation.
Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Células Intersticiales del Testículo/metabolismo , Metabolismo de los Lípidos , Células de Sertoli/metabolismo , Ácido 8,11,14-Eicosatrienoico/metabolismo , Ácido 8,11,14-Eicosatrienoico/farmacocinética , Animales , Ácido Araquidónico/biosíntesis , Transporte Biológico Activo , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/tratamiento farmacológico , Ácido Graso Desaturasas/metabolismo , Ácido Graso Sintasas/metabolismo , Ácidos Grasos/química , Ácidos Grasos/metabolismo , Ácidos Grasos Insaturados/metabolismo , Técnicas In Vitro , Insulina/farmacología , Células Intersticiales del Testículo/efectos de los fármacos , Lípidos/sangre , Lípidos/química , Masculino , Microsomas/metabolismo , Ratas , Ratas Wistar , Células de Sertoli/efectos de los fármacos , Testículo/metabolismoRESUMEN
Eicosatrienoic acid (ETA 5,8,11, n-9) is abnormally increased by essential fatty acid deficiency (EFAD), a condition associated with alterations of cell proliferation and differentiation. In comparison to certain EFAs, addition of ETA at a low concentration resulted in a reduction in the expression of the cell-cell adhesion molecule, E-cadherin, and to a lesser degree, of desmoglein, along with increased invasion of Matrigel by human squamous cell carcinoma (SCC) cells in vitro. At higher concentrations, ETA stimulated the growth of SCC cells. As previously shown, n-6 EFAs (mainly 18:3 n-6, GLA), up-regulated the expression of E-cadherin and desmoglein. This is the first report showing that the abnormal 20:3 n-9 (Mead's acid) is a down regulator of antimetastatic E-cadherin and desmoglein expression.
Asunto(s)
Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Cadherinas/metabolismo , Carcinoma de Células Escamosas/metabolismo , Proteínas del Citoesqueleto/metabolismo , Ácido 8,11,14-Eicosatrienoico/farmacología , Bisbenzimidazol/metabolismo , Western Blotting , Cadherinas/inmunología , Moléculas de Adhesión Celular , División Celular , Desmogleínas , Desmoplaquinas , Relación Dosis-Respuesta a Droga , Humanos , Inmunohistoquímica , Células Tumorales Cultivadas , Ácido gammalinolénico/metabolismoRESUMEN
In spite of the large quantities of epoxyeicosatrienoic acids (EEts) released by reproductive tissues, their function has not yet been determined. In order to analyze the influence of epoxygenase products on isolated uterine function, Clotrimazole, a cytochrome P450 inhibitor was used. The drug decreased isolated rat uterine isometric developed tension (IDT) and frequency (FC). 14,15 EEt induced a contractile response when added at 10(11) M, 8,9 EEt and 11,12 EEt produced an increment of IDT when added to 10(-7) M and 5,6 EEt did not modify IDT values. A contractile stimulatory effect was observed when 14,15 EEt (10(-7) M) was added to a tissue bath preparation containing Clotrimazole (20 microM). On the other hand, uterine contractile response to 14,15 EEt addition was partially abolished by indomethacin (10(-6) M), a well known cyclooxygenase inhibitor. Uterine response to 5,6; 8,9 and 11,12 EEts was not modified by indomethacin. This is the first evidence of 14-15 EEt uterotonic properties, possibly exerted in part through the cyclooxygenase pathway.
Asunto(s)
Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Ácido 8,11,14-Eicosatrienoico/farmacología , Contracción Uterina/efectos de los fármacos , Animales , Clotrimazol/farmacología , Inhibidores de la Ciclooxigenasa/farmacología , Inhibidores Enzimáticos del Citocromo P-450 , Relación Dosis-Respuesta a Droga , Estradiol/farmacología , Femenino , Técnicas In Vitro , Indometacina/farmacología , Contracción Isométrica/efectos de los fármacos , Ovariectomía , Prostaglandina-Endoperóxido Sintasas/metabolismo , Ratas , Ratas WistarRESUMEN
Delta 9, delta 6 and delta 5 desaturation activity and the thioesterification of eicosa-8,11,14-trienoic acid (DGLA) were measured in spontaneously hypertensive rats (SHR) compared to normotensive controls (WKY). SHR exhibited lower levels in the long-chain fatty acyl-CoA (LCFA) synthetase and in delta 6 and delta 5 desaturase activities in liver. The enzymatic activity changes were reflected on the fatty acid composition of liver microsomes. In testis, the thioesterification of DGLA and its conversion to arachidonic acid, (AA), at the delta 5 desaturation step were also depressed in SHR. We conclude that, in SHR, the alteration in polyunsaturated fatty acid (PUFA) metabolism may influence the synthesis of AA-derived eicosanoids involved in the control of blood pressure regulation.
Asunto(s)
Ácido 8,11,14-Eicosatrienoico/metabolismo , Ácido Araquidónico/biosíntesis , Hipertensión/metabolismo , Animales , Ácidos Grasos Monoinsaturados/metabolismo , Masculino , Microsomas Hepáticos/metabolismo , Ácido Palmítico/metabolismo , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKYRESUMEN
A long-chain fatty acyl-CoA synthetase that catalyzes the activation of long-chain fatty acids as thioesters of CoA, was described in rat liver nuclei. This is the first step for further metabolization of fatty acids in the cell. Up to now, it has been shown that long-chain fatty acyl-CoA synthetase is located in the endoplasmic reticulum, in plasma membrane, in mitochondria and in peroxisomes. The nuclear long-chain fatty acyl-CoA synthetase was assayed using palmitic (16:0), linoleic (18:2n-6) and 8,11,14-eicosatrienoic (20:3n-6) acids as substrates and was stimulated linearly with nuclear protein concentration and with incubation time The higher enzymatic activity was observed with 18:2n-6 and 20:3n-6 acids as substrates. The synthesis of palmitoyl-CoA, linoleyl-CoA and 8,11,14-eicosatrienoyl-CoA followed normal Michaelis-Menten kinetics with respect to the corresponding substrate concentrations. The acyl-CoA synthetase seems to be saturated at a substrate concentration of 12.8 microM for all the acids tested. The apparent Km values decreased in the following order 20:3n-6 > 18:2n-6 > 16:0. The lowest apparent Km for palmitic acid indicates a preference for acylation of this acid in the cell nucleus.
Asunto(s)
Núcleo Celular/enzimología , Coenzima A Ligasas/metabolismo , Hígado/enzimología , Proteínas Represoras , Proteínas de Saccharomyces cerevisiae , Ácido 8,11,14-Eicosatrienoico/metabolismo , Animales , Cinética , Ácido Linoleico , Ácidos Linoleicos/metabolismo , Hígado/citología , Masculino , Ácido Palmítico/metabolismo , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
It is well-known that ethanol alters fatty acid and glycerolipid metabolism in liver, but most of the studies have been deleloped on rats, so little known about the corresponding effects on human liver. We have chosen the Hep G2 human hepatoma cell line, which appears be an excellent in vitro model system. Cells were incubated in ethanol containing medium (0-400 mM) for 48 h. Incorporation and metabolism of radioactive substrates (14C(U) glycerol, [1-(14)C] palmitic acid and [1-(14)C] eicosatrienoic acid (n-6) were analyzed in cellular and conditioned medium lipids. Cellular growth rate and lipid composition of control and ethanol-treated cells were also studied. The results showed that ethanol inhibited logarithmic cellular growth rate in a concentration dependent manner, without affecting viability. Ethanol (400 mM) did not modify cellular major lipid composition except for an increase of cholesteryl esters, but produced a decrease in the proportions of myristic, palmitic and palmitoleic acids. Ethanol enchanced the incorporation of radioactive fatty acids into cellular glycerolipids but did not alter the rate of incorporation of 14C(U) glycerol. This was attributed to an isotopic solution of the radioactive glycerol as a result of increasde alfa-glycerophosphate biosynthesis. Incorporation of radioactive fatty acids and glycerol into conditioned medium glycerolipids were increased in cells incubated in presence of ethanol. The increased incorporation of 14C glycerol into conditioned medium together with a simultaneous diminuition in labeling cellular glycerides suggest that there would be a simulation of the export of these lipid classes to conditioned medium. Conversion of [1-(14)C] palmitic to oleic acid and eicosatrienoic to arachidonic acid were inhibited in 400 mM ethanol treated cells suggesting an inhibition of delta 9 and delta 5 desaturase activity. (AU)
Asunto(s)
Humanos , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Glucolípidos/metabolismo , Ácidos Grasos/metabolismo , Etanol/farmacología , Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Glucolípidos/antagonistas & inhibidores , Glicerol/metabolismo , Ácidos Palmíticos/metabolismo , Ácido 8,11,14-Eicosatrienoico/metabolismo , Células Tumorales CultivadasRESUMEN
Se señalan los posibles efectos de una dieta deficiente en grasa sobre la salud. Una dieta con poca cantidad de grasa hace díficil cubrir las necesidades de energía del cuerpo humano y ocasiona una disminución de la actividad física espontánea, pérdida progresiva de peso, cambios metabólicos adaptativos adicionales y alteraciones en la función reproductiva de lamujer y el crecimiento de los niños. El ácido linoleico y el ácido Ó-linolénico, que deben ser suministrados imprescindiblemente por la dieta, tienen funciones energéticas y estructurales, y a partir de ellos se producen derivados que tienen sus mismas funciones; además, ellos son precursores de eicosanoides. La grasa de la dieta puede modificar la composición de lípidos de las membranas celulares y esto, a su vez, alterar su fluidez y afectar sus funciones. La absorción y utilización de antioxidantes liposolubles disminuyen con una ingestión baja de ggrasa. Por tanto, un acantidad insuficiente o una calidad inapropiada de grasa en la dieta puede afectar diversos procesos vitales y ser perjudicial para la salud (AU)