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1.
Sickle cell disease (SCD) is a group of inherited blood disorders in which clinical illness results from the presence of erythrocytes with sickled haemoglobin (HbS). Blood vessel occlusion is a fundamental pathological process in SCD. Sickle cell haemoglobin C (HbSC) disease and sickle cell anaemia (HbSS) share some pathophysiology and clinical manifestations. However, the former is generally less severe. Erythrocytes of HbSC patients have longer life span, reduced haemolysis, and lower propensity to adhere to vascular endothelium than those of their HbSS counterparts. The structure and function of erythrocytes are strongly modulated by membrane long chain polyunsaturated fatty acids (LCPUFA). We have tested the possibility that HbSC and HbSS patients have different membrane fatty acid composition consistent with the difference in their clinical severity. Steady-state patients, 9 HbSC and 28 HbSS, and 15 HbAA were studied. The HbSC patients had a higher level of linoleic (LA, P<0.05) and docosahexaenoic (DHA, P<0.05) acids, and lower arachidonic acid (AA, P<0.01) and AA/eicosapentaenoic acid (EPA) ratio (P<0.05) in erythrocyte choline phosphoglycerides (CPG) compared with the HbSS group. Similarly, the level of EPA was higher and AA/EPA ratio (P<0.01) lower in serine phosphoglycerides of the HbSC patients. In contrast to the HbSC, the HbSS group had lower levels of EPA (P<0.001), DHA (P<0.05), total n-3 metabolites and total n-3 fatty acids (P<0.001) in erythrocyte CPG compared with the healthy HbAA controls. Moreover, the HbSS patients with disease complications compared with those without complications had reduced DHA and total n-3 fatty acids (P<0.005) in erythrocyte CPG. The abnormalities in erythrocyte in LCPUFA which is manifested by an increase in AA and a decrease in EPA and DHA in HbSS relative to HbSC disease observed in this study are consistent with the contrast in clinical severity between the two entities.  相似文献   

2.
Hypoinsulinemia characteristic to type 1 diabetes may theoretically inhibit the conversion of essential fatty acids to their longer-chain metabolites. Fatty acids were determined in plasma and erythrocyte membrane lipids in young diabetic adults (n=34) and in age-matched healthy controls (n=36). Values of linoleic acid (56.01 [5.02] versus 51.05 [7.32], % by wt, median [range from the first to the third quartile], P<0.00l) and arachidonic acid (AA) (11.17 [2.98] versus 9.69 [1.95] P<0.001) were significantly higher in diabetic subjects than in controls. However, alpha-linolenic acid values did not differ, and docosahexaenoic acid (0.43 [0.12] versus 0.57 [0.29], P<0.01) values were significantly lower in diabetic than in control subjects. Significant inverse correlations were found between AA and hemoglobin A(1c) values in the phospholipid (r=-0.40, P<0.05) and sterol ester (r=-0.40, P<0.05) fractions. The data obtained in the present study suggest that the availability of n-3 long-chain polyunsaturated fatty acid may be reduced in young diabetic adults.  相似文献   

3.
Placental transfer of the long-chain polyunsaturated fatty acids (LCPUFA) arachidonic (AA) and docosahexaenoic (DHA) acids is selectively high to maintain accretion to fetal tissues, especially the brain. The objectives of the present study were to investigate the essential fatty acid (EFA) and LCPUFA status at birth of preterm and term Brazilian infants and their mothers, from a population of characteristically low intake of n-3 LCPUFA, and to evaluate the association between fetal and maternal status, by the determination of the fatty acid composition of the erythrocyte membrane. Blood samples from umbilical cord of preterm (26-36 weeks of gestation; n = 30) and term (37-42 weeks of gestation; n = 30) infants and the corresponding maternal venous blood were collected at delivery. The LCPUFA composition of the erythrocyte membrane and DHA status were similar for mothers of preterm and term infants. Neonatal AA was higher (P < 0.01) whereas its precursor 18:2n-6 was lower (P < 0.01) than maternal levels, as expected. There was no difference in LCPUFA erythrocyte composition between preterm and term infants, except for DHA. Term infants presented a worse DHA status than preterm infants (P < 0.01) and than their mothers (P < 0.01) at delivery. There was a negative correlation of neonatal DHA with maternal AA and a positive correlation between neonatal AA and maternal AA and 18:2n-6 only at term. These results suggest that the persistent low DHA maternal status, together with the comparatively better AA and 18:2n-6 status, might have affected maternal-fetal transfer of DHA when gestation was completed up to term, and possibly contributed to the worse DHA status of term neonates compared with the preterm neonates.  相似文献   

4.
Neuroinflammation is present in the majority of acute and chronic neurological disorders. Excess or prolonged inflammation in the brain is thought to exacerbate neuronal damage and loss. Identifying modulators of neuroinflammation is an active area of study since it may lead to novel therapies. Omega-3 polyunsaturated fatty acids (n-3 PUFA) are anti-inflammatory in many non-neural tissues; their role in neuroinflammation is less studied. This review summarizes the relationship between n-3 PUFA and brain inflammation in animal models of brain injury and aging. Evidence by and large shows protective effects of n-3 PUFA in models of sickness behavior, stroke, aging, depression, Parkinson's disease, diabetes, and cytokine- and irradiation-induced cognitive impairments. However, rigorous studies that test the direct effects of n-3 PUFA in neuroinflammation in vivo are lacking. Future research in this area is necessary to determine if, and if so which, n-3 PUFA directly target brain inflammatory pathways. n-3 PUFA bioactive metabolites may provide novel therapeutic targets for neurological disorders with a neuroinflammatory component.  相似文献   

5.
The objective of these studies with rat hepatocytes in primary culture was to establish that: (a) membrane phospholipids would become enriched with the specific fatty acid supplemented to the media and (b) hepatocyte monolayer triacylglycerol synthetic rates were dependent on the type of fatty acid enrichment of the membrane phospholipids. Hepatocytes cultured in the absence of media lipid developed a phospholipid fatty acid composition which is indicative of an essential fatty acid deficiency. The extensive rise in 18:1(n - 9) content indicated that delta 9-desaturase was active. The fatty acid composition of phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol in the microsomal- and mitochondrial-enriched fractions was highly dependent upon the type of fatty acid supplemented to the medium. Incorporation of fatty acids into phospholipids was rapid, and a new steady-state in fatty acid composition was achieved within approx. 36 h. Changes in the fatty acid composition of these hepatocyte phospholipid subclasses resulting from media supplementation with 18:2/20:4(n-6) or 20:5(n-3) were similar, but not identical, to changes which occurred in vivo as a result of consuming diets rich in 18:2(n-6) or 20:5(n-3). Hepatocyte lipogenesis was highly dependent upon the type of fatty acid supplemented to the medium. Prior conditioning with 16:0 increased triacylglycerol synthesis and secretion. Secretion of triacylglycerol was reduced by polyenoic fatty acid enrichment with 20:5(n-3) greater than 20:4/18:2(n-6). The suppression of triacylglycerol synthesis by 20:5(n-3) was due to an increased (P less than 0.05) diacylglycerol specific activity, which indicates that 20:5(n-3) suppression of hepatic triacylglycerol production may be caused in part by the inhibition of diacylglycerol acyltransferase.  相似文献   

6.
7.

Background

Numerous signaling pathways function in the brain ventricular system, including the most important - GABAergic, glutaminergic and dopaminergic signaling. Purinergic signalization system - comprising nucleotide receptors, nucleotidases, ATP and adenosine and their degradation products - are also present in the brain. However, the precise role of nucleotide signalling pathway in the ventricular system has been not elucidated so far. The aim of our research was the identification of all three elements of purinergic signaling pathway in the porcine brain ventricular system.

Results

Besides nucleotide receptors on the ependymocytes surface, we studied purines and pyrimidines in the CSF, including mechanisms of nucleotide signaling in the swine model (Sus scrofa domestica). The results indicate presence of G proteins coupled P2Y receptors on ependymocytes and also P2X receptors engaged in fast signal transmission. Additionally we found in CSF nucleotides and adenosine in the concentration sufficient to P receptors activation. These extracellular nucleotides are metabolised by adenylate kinase and nucleotidases from at least two families: NTPDases and NPPases. A low activity of these nucleotide metabolising enzymes maintains nucleotides concentration in ventricular system in micromolar range. ATP is degraded into adenosine and inosine.

Conclusions

Our results confirm the thesis about cross-talking between brain and ventricular system functioning in physiological as well as pathological conditions. The close interaction of brain and ventricular system may elicit changes in qualitative and quantitative composition of purines and pyrimidines in CSF. These changes can be dependent on the physiological state of brain, including pathological processes in CNS.  相似文献   

8.
Free fatty acids protect erythrocytes against hypotonic haemolysis in a certain low concentration range and become haemolytic at higher concentrations. The chain length dependence of this biphasic behaviour was investigated using human erythrocytes. The results can be summarized as follows: (i) A critical minimum chain length is required for both effects. Octanoic acid (C8) and fatty acids with a shorter chain length do not have any effect on the osmotic resistance of erythrocytes. (ii) Decanoic acid (C10) decreases the extent of hypo-osmotic haemolysis and does not become haemolytic at higher concentrations. (iii) Dodecanoic acid (C12) represents the minimum chain length for the typical concentration-dependent biphasic behaviour with protection against hypo-osmotic haemolysis at a certain low concentration range and subsequent haemolysis at higher concentrations. (iv) Tetradecanoic acid (C14) exhibits two concentration ranges of protection against hypo-osmotic haemolysis, each followed by haemolytic concentrations. (v) The observed effects are not correlated with the critical micellar concentrations of the investigated fatty acids.  相似文献   

9.
10.
In order to evaluate the effects of fatty acids on immune cell membrane structure and function, it is often necessary to maintain cells in culture. However, cell culture conditions typically reverse alterations in polyunsaturated fatty acid (PUFA) composition achieved by dietary lipid manipulation. Therefore, we hypothesized that T-cells from transgenic mice expressing the Caenorhabditis elegans n-3 desaturase (fat-1) gene would be resistant to the culture-induced loss of n-3 PUFA and, therefore, obviate the need to incorporate fatty acids or homologous serum into the medium. CD4+ T-cells were isolated from (i) control wild type (WT) mice fed a safflower oil-n-6 PUFA enriched diet (SAF) devoid of n-3 PUFA, (ii) fat-1 transgenic mice (enriched with endogenous n-3 PUFA) fed a SAF diet, or (iii) WT mice fed a fish oil (FO) based diet enriched in n-3 PUFA. T-cell phospholipids isolated from WT mice fed FO diet (enriched in n-3 PUFA) and fat-1 transgenic mice fed a SAF diet (enriched in n-6 PUFA) were both enriched in n-3 PUFA. As expected, the mol% levels of both n-3 and n-6 PUFA were decreased in cultures of CD4+ T-cells from FO-fed WT mice after 3 d in culture. In contrast, the expression of n-3 desaturase prevented the culture-induced decrease of n-3 PUFA in CD4+ T-cells from the transgenic mice. Carboxyfluorescein succinidyl ester (CFSE) -labeled CD4+ T-cells from fat-1/SAF vs. WT/SAF mice stimulated with anti-CD3 and anti-CD28 for 3 d, exhibited a reduced (P<0.05) number of cell divisions. We conclude that fat-1-containing CD4+ T-cells express a physiologically relevant, n-3 PUFA enriched, membrane fatty acid composition which is resistant to conventional cell culture-induced depletion.  相似文献   

11.
Erythrocyte membrane proteins obtained from individuals with sickle cell anemia show an SDS polyacrylamide gel pattern that differs in five regions from the normal pattern. These membranes when compared with membranes from normal individuals also show a marked decrease in sialic acid content which correlates with a marked reduction of the periodic acid-Schiff staining of the three major glycoprotein components. The observed membrane protein and glycoprotein changes are a characteristic of all the red cells in sickle cell anemia and do not correlate with the proportion of irreversibly sickled cells.  相似文献   

12.
In summary, we have shown that the conventional explanation for the site of action of a ligand which alters the conductance of a membrane ion channel is that the ligand interacts or binds with the ion channel protein, changing its conductance, is inadequate to explain the primary site of action of the antiarrhythmic n-3 PUFAs. We have shown that when a neutral asparagine is replaced by a positively charged lysine in the N406 amino acid site in the alpha-subunit of the human cardiac sodium channel, the n-3 fatty acids lose their inhibitory action on the sodium current. The inadequacy of this finding to explain the primary site of action of the n-3 PUFAs is demonstrated by the inhibitory effect on all other cardiac ion channels, so far tested. We show that ion channels, which share no amino acid homology with the PUFAs, have their conductance also reduced in the presence of the PUFAs, Thus a more general conceptual framework or paradigm is needed to account for the broad action of the PUFAs on diverse different ion channels lacking amino acid homology. We have been testing the membrane tension hypothesis of Andersen and associates. According to this hypothesis, the fatty acids are not acting directly on the ion channel protein but accumulating in the phospholipid membrane in immediate juxtaposition to the site in the membrane where the ion channel protein penetrates the membrane phospholipid bilayer. This alters membrane tensions exerted by the phospholipid membrane on the ion channel, which in turn causes conformational changes in the ion channel, altering the conductance of the ion channel. Our preliminary data seem to support this membrane tension hypothesis.  相似文献   

13.

Background

Little is known about the interplay between n-3 fatty acids and genetic variants for diabetes-related traits at the genome-wide level. The present study aimed to examine variance contributions of genotype by environment (GxE) interactions for different erythrocyte n-3 fatty acids and genetic variants for diabetes-related traits at the genome-wide level in a non-Hispanic white population living in the U.S.A. (n = 820). A tool for Genome-wide Complex Trait Analysis (GCTA) was used to estimate the genome-wide GxE variance contribution of four diabetes-related traits: HOMA-Insulin Resistance (HOMA-IR), fasting plasma insulin, glucose and adiponectin. A GxE genome-wide association study (GWAS) was conducted to further elucidate the GCTA results. Replication was conducted in the participants of the Boston Puerto Rican Health Study (BPRHS) without diabetes (n = 716).

Results

In GOLDN, docosapentaenoic acid (DPA) contributed the most significant GxE variance to the total phenotypic variance of both HOMA-IR (26.5%, P-nominal = 0.034) and fasting insulin (24.3%, P-nominal = 0.042). The ratio of arachidonic acid to eicosapentaenoic acid + docosahexaenoic acid contributed the most significant GxE variance to the total variance of fasting glucose (27.0%, P-nominal = 0.023). GxE variance of the arachidonic acid/eicosapentaenoic acid ratio showed a marginally significant contribution to the adiponectin variance (16.0%, P-nominal = 0.058). None of the GCTA results were significant after Bonferroni correction (P < 0.001). For each trait, the GxE GWAS identified a far larger number of significant single-nucleotide polymorphisms (P-interaction ≤ 10E-5) for the significant E factor (significant GxE variance contributor) than a control E factor (non-significant GxE variance contributor). In the BPRHS, DPA contributed a marginally significant GxE variance to the phenotypic variance of HOMA-IR (12.9%, P-nominal = 0.068) and fasting insulin (18.0%, P-nominal = 0.033).

Conclusion

Erythrocyte n-3 fatty acids contributed a significant GxE variance to diabetes-related traits at the genome-wide level.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-781) contains supplementary material, which is available to authorized users.  相似文献   

14.
Epidermal fatty acid-binding protein (E-FABP), a member of the family of FABPs, exhibits a robust expression in neurons during axonal growth in development and in nerve regeneration following nerve injury. This study examines the impact of E-FABP expression in normal neurite extension in differentiating pheochromocytoma cell (PC12) cultures supplemented with selected long chain free fatty acids (LCFFA). We found that E-FABP binds to a broad range of saturated and unsaturated LCFFAs, including those with potential interest for neuronal differentiation and axonal growth such as C22:6n-3 docosahexaenoic acid (DHA), C20:5n-3 eicosapentaenoic acid (EPA), and C20:4n-6 arachidonic acid (ARA). PC12 cells exposed to nerve growth factor (NGFDPC12) exhibit high E-FABP expression that is blocked by mitogen-activated protein kinase kinase (MEK) inhibitor U0126. Nerve growth factor-differentiated pheochromocytoma cells (NGFDPC12) antisense clones (NGFDPC12-AS) which exhibit low E-FABP expression have fewer/shorter neurites than cells transfected with vector only or NGFDPC12 sense cells (NGFDPC12-S). Replenishing NGFDPC12-AS cells with biotinylated recombinant E-FABP (biotin-E-FABP) protein restores normal neurite outgrowth. Cellular localization of biotin-E-FABP in NGFDPC12 was detected mostly in the cytoplasm and in the nuclear region. Treatment of NGFDPC12 with DHA, EPA, or ARA further enhances neurite length but it does not trigger further induction of TrkA or MEK phosphorylation or E-FABP mRNA observed in differentiating PC12 cells without LCFFA supplementation. Significantly, DHA and EPA neurite stimulating effects are higher in NGFDPC12-S than in NGFDPC12-AS cells. These findings are consistent with the scenario that neurite extension of differentiating PC12 cells, including further stimulation by DHA and EPA, requires sufficient cellular levels of E-FABP.  相似文献   

15.
Atlantic salmon (Salmo salar) preadipocytes, isolated from visceral adipose tissue, differentiate from an unspecialized fibroblast like cell type to mature adipocytes filled with lipid droplets in culture. The expression of the adipogenic gene markers peroxisome proliferated activated receptor (PPAR) alpha, lipoprotein lipase (LPL), microsomal triglyceride transfer protein (MTP), fatty acid transport protein (FATP) 1 and fatty acid binding protein (FABP) 3 increased during differentiation. In addition, we describe a novel alternatively spliced form of PPARgamma (PPARgamma short), the expression of which increased during differentiation. Eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA) lowered the triacylglycerol (TAG) accumulation in mature salmon adipocytes compared to oleic acid (18:1n-9, OA). This finding indicates that a reduced level of highly unsaturated n-3 fatty acids (HUFAs) in fish diets, when the traditional marine oil is exchanged for n-9 fatty acids (FAs) rich vegetable oils (VOs), may influence visceral fat deposition in salmonids. Moreover, major differences in the metabolism of EPA, DHA and OA at different stages during differentiation of adipocytes occur. Most of the EPA and DHA were oxidized in preadipocytes, while they were mainly stored in TAGs in mature adipocytes in contrast to OA which was primarily stored in TAGs at all stages of differentiation.  相似文献   

16.
Rats fed a semipurified diet supplemented with 3% (w/w) safflower oil [Saf, n-3 fatty acid deficient, high linoleic acid (18:2n-6)] through two generations exhibit decreased correct response ratios in a brightness-discrimination learning test compared with rats fed 3% perilla oil [Per, high alpha-linolenic acid (18:3n-3)]. This is associated with a decreased DHA (22:6n-3)-to-arachidonic acid (20:4n-6) ratio in brain lipids. In the first set of experiments, dietary oil was shifted from Saf to a mixture of 2.4% safflower oil plus 0.6% DHA after weaning (Saf-DHA), but all parameters measured in the learning test were essentially unchanged. Brain 22:6n-3 content of the Saf-DHA group reached that of the Per group but the levels of 20:4n-6 and docosatetraenoic acid (22:4n-6) did not decrease to those of the Per group at the start of the test. In the second set of experiments, dietary oil was shifted to a mixture of 0.6% safflower oil plus 1.2% oleic acid (OA) plus 1.2% DHA (Saf-OA-DHA group) with 18:2n-6 content comparable to that of the Per group. The Saf-OA-DHA group exhibited a learning performance similar to that of the Per group; brain 22:6n-3, 20:4n-6, and 22:4n-6 contents were also comparable to those of the Per group. These results indicate that the altered learning behavior associated with a long-term n-3 fatty acid deficiency is reversed by supplementing 22:6n-3 after weaning, when the levels of competing n-6 fatty acids in the diet and brain lipids are limited.  相似文献   

17.
Statins are highly effective cholesterol-lowering drugs but may have broader effects on metabolism. This investigation examined effects of simvastatin on serum levels of n-6 and n-3 polyunsaturated fatty acids (PUFAs). Subjects were 106 healthy adults with hypercholesterolemia randomly assigned to receive placebo or 40 mg simvastatin daily for 24 weeks. Serum fatty acids were analyzed by gas chromatography. Total fatty acid concentration fell 22% in subjects receiving simvastatin (P<.001), with similar declines across most fatty acids. However, concentrations of arachidonic acid (AA, 20:4n-6), eicosapentanoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) were unchanged. Relative percentages of linoleic acid (LA, 18:2n-6) and alpha-linolenic acid (LNA, 18:3n-3), decreased while AA and DHA increased (P's < or = .007). In addition, simvastatin increased the AA:EPA ratio from 15.5 to 18.8 (P<.01), and tended to increase the AA:DHA ratio (P=.053). Thus, simvastatin lowered serum fatty acid concentrations while also altering the relative percentages of important PUFAs.  相似文献   

18.
We investigated whether maternal fat intake alters amniotic fluid and fetal intestine phospholipid n-6 and n-3 fatty acids. Female rats were fed a 20% by weight diet from fat with 20% linoleic acid (LA; 18:2n-6) and 8% alpha-linolenic acid (ALA; 18:3n-3) (control diet, n = 8) or 72% LA and 0.2% ALA (n-3 deficient diet, n = 7) from 2 wk before and then throughout gestation. Amniotic fluid and fetal intestine phospholipid fatty acids were analyzed at day 19 gestation using HPLC and gas-liquid chromotography. Amniotic fluid had significantly lower docosahexaenoic acid (DHA; 22:6n-3) and higher docosapentaenoic acid (DPA; 22:5n-6) levels in the n-3-deficient group than in the control group (DHA: 1.29 +/- 0.10 and 6.29 +/- 0.33 g/100 g fatty acid; DPA: 4.01 +/- 0.35 and 0.73 +/- 0.15 g/100 g fatty acid, respectively); these differences in DHA and DPA were present in amniotic fluid cholesterol esters and phosphatidylcholine (PC). Fetal intestines in the n-3-deficient group had significantly higher LA, arachidonic acid (20:4n-6), and DPA levels; lower eicosapentaenoic acid (EPA; 20:5n-3) and DHA levels in PC; and significantly higher DPA and lower EPA and DHA levels in phosphatidylethanolamine (PE) than in the control group; the n-6-to-n-3 fatty acid ratio was 4.9 +/- 0.2 and 32.2 +/- 2.1 in PC and 2.4 +/- 0.03 and 17.1 +/- 0.21 in PE in n-3-deficient and control group intestines, respectively. We demonstrate that maternal dietary fat influences amniotic fluid and fetal intestinal membrane structural lipid essential fatty acids. Maternal dietary fat can influence tissue composition by manipulation of amniotic fluid that is swallowed by the fetus or by transport across the placenta.  相似文献   

19.
20.
The effect of feeding different amounts of n-6 and n-3 fatty acids (FA) to hens on immune tissue FA composition and leukotriene production of hatched chicks was investigated. Hens were fed diets supplemented with either 3.0% sunflower oil (Diet I), 1.5% sunflower+1.5% fish oil (Diet II), or 3.0% fish oil (Diet III) for 46 days. The hatched chicks were fed a diet containing C18:3n-3, but devoid of longer chain n-6 and n-3 FA, for 21 days. Spleen docosahexaenoic acid (DHA) content was higher in chicks from hens fed Diet III (P<0.05). The bursa content of arachidonic acid was lower in chicks hatched from hens fed Diet III (P<0.05), and the ratio of n-6 to n-3 FA was significantly higher in bursa of chicks hatched to hens fed Diet I (P<0.05). Eicosapentaenoic acid (EPA) and DHA contents were higher in bursa of chicks hatched from hens fed Diet III (P<0.05). Thrombocytes from chicks hatched to hens fed Diet III produced the most leukotriene B(5) (LTB(5)). The ratio of LTB(5) to LTB(4) concentrations was also highest (P<0.05) in chicks hatched to hens fed Diet III. These results indicate that modulating maternal dietary n-6 and n-3 FA may alter leukotriene production in chicks, which could lead to less inflammatory-related disorders in poultry.  相似文献   

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