Membrane Fatty Acid Research Articles

Extended lipid profile in Romanian ischemic stroke patients in relation to stroke severity and outcome: a path analysis model.

IntroductionOur aim was to evaluate the extended lipid profile in ischemic stroke patients and the relationship with stroke type, severity and outcome.Material and methodsWe prospectively enrolled 124 ischemic stroke patients and 40 healthy controls; baseline plasma and erythrocyte membrane fatty acids concentrations and common lipid profile were analysed. Stroke severity was evaluated by NIHSS on admission, while the functional outcome was defined by mRS at discharge and after 3 months.ResultsTotal cholesterol, triglycerides, HDL-cholesterol, DHA, adrenic, stearic and lauric acid were all lower in patients, taking into account that 87.7% of patients did not receive statins before admission. There was a different pattern in plasma and erythrocyte membrane of fatty acids between patients and controls, also omega-3 index was significantly lower in patients. Patients with poor outcome without statins had significantly lower triglyceride (p = 0.028), while the total cholesterol levels were significantly lower in patients with poor outcome (p = 0.03) but with treatment initiated after admission. Bivariate analysis revealed that patients with poor outcome had significantly lower triglyceride levels regardless the statins use, while the total cholesterol and HDL-cholesterol levels were significantly lower in patients with poor outcome under statin treatment. The long-term outcome were positively influenced by age (β̂ = 0.22, p = 0.001), and NIHSS score at admission (β̂ = 0.55, p < 0.001), and negatively by cholesterol levels (β̂ = –0.17, p = 0.031).ConclusionsDHA, adrenic, stearic and lauric acid were lower in stroke patients; plasma adrenic acid was consumed during the acute phase. The most important predictors for long-term outcome was NIHSS at admission followed by age and total cholesterol.

Associations Between Erythrocyte Membrane Fatty Acid Compositions and Biomarkers of Vascular Health in Adults With Type 1 Diabetes With and Without Insulin Resistance: A Cross-Sectional Analysis

ObjectivesThe aim of this study was to assess the relationship between specific erythrocyte fatty acid levels and vascular health in type 1 diabetes (T1D) with and without insulin resistance (IR). MethodsWe analyzed baseline pretreatment data in a subset of 23 patients with T1D from a previously published randomized controlled trial consisting of comprehensive erythrocyte-derived fatty acid profiles and a panel of inflammation-associated endothelial markers. Estimated glucose disposal rate was used to identify and categorize patients with IR. We utilized principal component analysis (PCA) to cluster vascular biomarkers to compute a single “vascular signal” and utilized univariate linear regression models to investigate the association with IR and fatty acid profiles. ResultsSubjects with IR displayed significantly higher levels of linoleic acid (p=0.001), lower levels of eicosapentaenoic acid (EPA) (p<0.001), lower levels of omega-3 polyunsaturated fatty acid (n-3PUFA) (p<0.006) and an increased omega-6 (n-6)PUFA:n-3PUFA ratio (p=0.001). IR was associated with significantly higher linoleic acid levels, total n-6PUFA and an increased ratio of n-6PUFA:n-3PUFA, and negatively associated with arachidonic acid and EPA levels, total saturated fatty acid and total n-3PUFA. The PCA-derived vascular biomarker cluster was positively associated with linoleic acid and n-6PUFA:n-3PUFA ratio, and inversely associated with EPA. ConclusionsSpecific erythrocyte membrane fatty acid compositions are associated with impaired vascular health and IR in adults with T1D. These findings suggest that IR and risk of associated complications may be influenced by specific fatty acid profiles, and thus potentially modified by the selective targeting of dietary fatty acids.

Salt, glucose, glycine, and sucrose protect Escherichia coli O157:H7 against acid treatment in laboratory media

This study investigated the effects of combinations of acetic or malic acid and various solutes (salt, glucose, glycine, or sucrose) on the survival of Escherichia coli O157:H7 in laboratory broth. Additionally, the effectiveness of combining organic acids and various concentrations of salt (0–18%) or sucrose (0–100%) with different water activity values against E. coli O157:H7 were evaluated. For treatment of 1% malic acid, the addition of 3% salt showed synergistic effect. Whereas, when 3% salt, glucose, glycine, or sucrose was added to 1% acetic acid, the solutes antagonized the action of the acid against E. coli O157:H7. Acetic, lactic, or propionic acid combined with salt at either 7 or 9% or sucrose at 60, 80, or 100% resulted in the highest resistance of E. coli O157:H7. From a result of evaluating the membrane fatty acid (MFA) composition of cells, salt or sucrose significantly increased levels of saturated fatty acids (SFAs) or SFAs and cyclopropane fatty acids, respectively. From the results of this study, the addition of solutes and organic compounds may increase the tolerance of E. coli O157:H7 to acetic, lactic, and propionic acid treatments and that the salt or sucrose significantly affects cell MFA composition.

Omega-3 Fatty Acids in Erythrocyte Membranes as Predictors of Lower Cardiovascular Risk in Adults without Previous Cardiovascular Events.

Background: This study investigated the association of omega-3 polyunsaturated fatty acids (n-3 PUFA) within erythrocyte membranes and cardiovascular risk assessed by three different estimates. Methods: Inclusion criteria were individuals of both sexes, 30 to 74 years, with at least one cardiovascular risk factor, and no previous cardiovascular events (n = 356). Exclusion criteria were individuals with acute or chronic severe diseases, infectious diseases, pregnant, and/or lactating women. Plasma biomarkers (lipids, glucose, and C-reactive protein) were analyzed, and nineteen erythrocyte membrane fatty acids (FA) were identified. The cardiovascular risk was estimated by Framingham (FRS), Reynolds (RRS), and ACC/AHA-2013 Risk Scores. Three patterns of FA were identified (Factor 1, poor in n-3 PUFA), (Factor 2, poor in PUFA), and (Factor 3, rich in n-3 PUFA). Results: Total cholesterol was inversely correlated with erythrocyte membranes C18:3 n-3 (r = −0.155; p = 0.004), C22:6 n-3 (r = −0.112; p = 0.041), and total n-3 (r = −0.211; p < 0.001). Total n-3 PUFA was associated with lower cardiovascular risk by FRS (OR = 0.811; 95% CI= 0.675–0.976). Regarding RRS, Factor 3 was associated with 25.3% lower odds to have moderate and high cardiovascular risk (OR = 0.747; 95% CI = 0.589–0.948). The ACC/AHA-2013 risk score was not associated with isolated and pooled FA. Conclusions: n-3 PUFA in erythrocyte membranes are independent predictors of low-risk classification estimated by FRS and RRS, which could be explained by cholesterol-lowering effects of n-3 PUFA.

Effect of pravastatin on erythrocyte membrane fatty acid contents in patients with chronic kidney disease.

BackgroundStatin treatment has decreased the risk of cardiovascular events in patients with chronic kidney disease (CKD). Erythrocyte membrane oleic acid level is higher in patients with acute coronary syndrome. This study aimed to evaluate the effect of pravastatin on the erythrocyte membrane fatty acid (FA) contents in patients with CKD.MethodsSixty-two patients were enrolled from January 2017 to March 2019 (NCT02992548). Pravastatin was initially administered at a dose of 20 mg for 24 weeks. The pravastatin dose was increased to 40 mg after 12 weeks if it was necessary to control dyslipidemia. The primary outcome was change in erythrocyte membrane FA, including oleic acid, after pravastatin treatment for 24 weeks.ResultsForty-five patients finished this study, and there was no adverse effect related to pravastatin. Compared with baseline, total cholesterol and low-density lipoprotein cholesterol levels were significantly decreased after pravastatin treatment. Compared with baseline, saturated FA, oleic acid, and arachidonic acid levels were significantly increased and polyunsaturated FA and linoleic acid (LA) levels were significantly decreased after pravastatin treatment. There was also a decrease in eicosapentaenoic acid after pravastatin treatment in CKD patients with estimated glomerular filtration rate < 60 mL/min/1.73 m2.ConclusionAdministration of pravastatin in patients with CKD leads to a decrease in FA known to be protective against the risk of CVD. Omega-3 FA or LA supplementation might be necessary to recover changes in erythrocyte membrane FA contents when pravastatin is used for treating dyslipidemia in patients with CKD.

Feeding frequency affects the growth performance, nutrient digestion and absorption of growing pigs with the same daily feed intake

Feeding-frequency regimen is an important part of animal husbandry and production, which can influence the feeding behavior and regulate the growth of animals. The present study was conducted to investigate the growth, digestion and absorption functions of growing pigs under different feeding frequencies with the same total daily feed intake. Twenty-four Duroc × Landrance × Yorkshire growing pigs were randomly assigned to three groups: feeding one time per day (M1), feeding three times per day (M3) and feeding five times per day (M5); each group consisted of eight replicates (pens), with one pig per pen. During the one-month experimental period, each pig was fed an equal amount of diet daily. The results showed that final body weight (FBW), average daily gain (ADG) in M3 and M5 groups were significantly higher than in the M1 group, but feed: gain (F: G) was significantly lower than in the M1 group (P < 0.05). Apparent total tract digestibility (ATTD) of crude protein (CP) in the M3 and M5 groups was significantly higher than that in the M1 group (P < 0.05). Compared with the M1 group, the activities of trypsin and chymotrypsin in the pancreas of M3 and M5 groups were significantly increased (P < 0.05). The activity of pepsin in M3 and M5 groups tended to increase (P = 0.08), while the activity of duodenum sucrase and ileum lipase in M3 and M5 groups was significantly decreased (P < 0.05). A lower level of maltase activity but a higher level of lipase in duodenum were found in the M5 group as compared with in the M1 group (P < 0.05). The mRNA expression of genes EAAT3, ATB0,+, T1R1 and PepT1 in duodenum of pigs in M3 and M5 groups were significantly higher than those in the M1 group. Moreover, the mRNA expression of fatty acid transport protein 2 (FATP2) and plasma membrane fatty acid binding protein (FABPpm) in duodenum in M3 and M5 groups, and FABPpm in ileum in the M5 group tended to increase as compared with the M1 group. Different feeding frequencies had no effect on the levels of cholecystokinin (CCK), glucose-dependent insulinotropic polypeptide (GIP), peptide tyrosine (PYY) and glucagon-like peptide-1 (GLP-1) in duodenum and ileum. These results indicate that feeding frequency affected the digestion and absorption of protein and fat in growing pigs, and eventually impacted the growth performance of pigs with the same daily feed intake.

The effect of calcium palmitate on bacteria associated with infant gut microbiota.

Gut microbiota development in formula‐fed and breast‐fed infants is known to differ. This could relate to the usage of unmodified vegetable oil instead of mammalian fat in infant formula (IF), causing the enhanced formation of the poorly soluble soap calcium palmitate (CP) in the infant's gut. Here we investigate in vitro the possible influence of CP on the infant gut bacteria. The growth of several bacterial species dominant in the infant's gut was analyzed by culturing in media with CP. Faecalibacterium prausnitzii as a sensitive representative was analyzed in detail by scanning transmission electron microscopy, membrane staining, gas chromatography, and microbial fuel cell experiments. Of all bacteria tested, the growth of several bifidobacteria and F. prausnitzii was reduced at 0.01 mg/ml CP, Bifidobacterium infantis stopped growing completely. CP reduced the cell envelope thickness of F. prausnitzii, disturbed the cell membrane fatty acids and function of membrane proteins involved in electron transport. CP inhibited the growth of bifidobacteria and faecalibacteria. This suggests that modification of fat in IF may benefit the development of the gut microbiota in formula‐fed infants by supporting the colonization of important beneficial bacteria in early life. Future clinical studies are needed to confirm this.

Dietary supplementation of mustard oil reduces blood glucose levels by triggering insulin receptor signaling pathway

Dietary fatty acids can alter membrane fatty acid composition with the consequent change in the action of various receptors. Incorporation of mustard oil was found to increase insulin secretion, reduce blood glucose levels, and increase the expression of glucose transporter gene 4 (Glut4). Three-week-old male Wistar rats were fed with 8% lipid-inclusive isocaloric mash diet. There were non-diabetic control (NDC) and diabetic control (DC) groups fed with ghee, and similarly non-diabetic (NDT) and diabetic treatment (DT) groups fed with mustard oil. Streptozotocin (STZ) was administered intraperitoneally once at a dose rate of 40 mg/kg bodyweight for the induction of diabetes. Blood glucose was estimated using glucometer periodically. Lipids were extracted from mustard oil and in tissue samples, and fatty acid estimation was done using gas chromatography (GC). Gene expression of 84 genes related to diabetes was measured in muscle tissue using Qiagen™ RT2 polymerase chain reaction (PCR) profiler array. The real-time PCR data obtained as threshold cycle (Ct) values were analyzed using Ingenuity Pathway Analysis® (IPA®) software. After induction of diabetes by day 30, the average glucose levels were above 500 mg/dL in diabetic groups, but for the mustard oil treatment group, they were reduced to 337 mg/dL by the 60 days of treatment. Significantly higher levels of unsaturated fatty acids particularly linoleic acid and linolenic acid were found in mustard oil treatment groups. Insulin receptor signaling was prominent in both ghee-fed normal and mustard oil–fed diabetic treatment groups. Glucose was found to be the major upstream regulator in all the groups except for ghee-fed diabetic control group. Mustard oil inclusion in the diet reduces blood glucose levels by increased insulin receptor signaling, thereby partially reversing diabetic state in experimentally induced diabetic rats.

Inactivation of Staphylococcus aureus using ultrasound in combination with thyme essential oil nanoemulsions and its synergistic mechanism

The present study investigated the antimicrobial effect and mechanism of ultrasound (US) with thyme essential oil nanoemulsions (TEON) on the inactivation of Staphylococcus aureus (S. aureus) cells. A remarkable increase in reducing the population of S. aureus was observed when cells were subjected to combined US (3.33 W/mL, 3 min) and TEON (0.375 mg/mL) treatment, which exhibited synergistic inactivation efficiency and caused a 3.21-log reduction in viability. The most severe damage to cell morphology was visualized in US + TEON group using scanning electron microscopy. Other proposed mechanisms involved that ultrasound reduced the membrane hydrophobicity, which increased the exposure of cell membrane to TEON. Moreover, the greatest degree of membrane permeabilization was evaluated, along with the massive leakage of intracellular contents. Depolarization in membrane potential was also observed and confirmed by the excessive outflow of K+ and influx of Ca2+. On the other hand, a significant decrease in membrane fluidity was monitored and further verified by the modifications in bacterial membrane fatty acid profile. This study also highlighted the impact of US + TEON treatment on bacterial membrane compositions involving proteins, nucleic acids, and phospholipids by infrared spectroscopy. Current study provides a proof-of-concept into the synergistic mechanisms of the integrated technology for enhancing S. aureus inactivation.

DeltaF508 CFTR Hetero- and Homozygous Paediatric Patients with Cystic Fibrosis Do Not Differ with Regard to Nutritional Status.

The purpose of this study was to compare the nutritional status between deltaF508 CFTR hetero- and homozygous paediatric patients with cystic fibrosis. We assessed the percentage profiles of fatty acids measured in erythrocyte membranes and the serum levels of vitamins A, D3, E and K1 in the studied groups. We also measured the weights and heights and calculated the body mass indexes (BMIs). The studied groups consisted of 34 heterozygous and 30 homozygous patients. No statistically significant differences were found in the serum vitamins or erythrocyte membrane fatty acid profiles between the hetero- and homozygous patient groups, except for heptadecanoic acid (p = 0.038). The mean percentiles of height, weight and BMI did not differ significantly between the two groups. The homozygous and heterozygous paediatric patients with cystic fibrosis were similar in terms of their nutritional statuses.

Mammals to membranes: A reductionist story.

This is the story of a series of reductionist studies that started with an attempt to explain what underpins the high-level of aerobic metabolism in mammals (i.e. associated with the evolution of endothermy) and almost forty years later had led to investigations into the role of membrane lipids in determining metabolism. Initial studies showed that the increase in aerobic metabolism in mammals was driven by a combination of increases in mitochondrial volume and membrane densities, organ size and changes in the molecular activity of enzymes. The increase in the capacity to produce energy was matched by an increase in energy use, notably driven by increases in H+, Na+ and K+ fluxes. In the case of increased Na+ flux, it was found this was matched by increases in Na+-dependent metabolism at the tissue level and increases in enzyme activity at a cellular level but not by an increase in the number of sodium pumps. To maintain Na+ gradient across cell membranes, increased Na+ flux is not controlled by an increase in sodium pump number but rather by an increase in sodium pump molecular activity (i.e. an increase the substrate turnover rate of each sodium pump) in tissues of endotherms. This increase in molecular activity is coupled to an increase in the level of highly unsaturated polyunsaturated fatty acids (PUFA) in membranes, a mechanism similar to that used by ectotherms to ameliorate decreasing activities of metabolic processes in the cold. Determination of how changes in membrane fatty acid composition can change the activities of proteins in membranes will be the next step in this story.

SATURATED FATTY ACIDS IN ERYTHROCYTE MEMBRANES IN ADOLESCENTS WITH TYPE 1 DIABETES MELLITUS

Objective: Type 1 diabetes mellitus (T1DM) is associated with early development of atherosclerosis. The aim of this study was to assess the association between saturated fatty acids (SFAs) contained in erythrocyte membranes and some indices of vascular damage in a sample of adolescents with T1DM. Design and method: Participants in regular follow-up at the Paediatric Diabetology Unit of Verona were sent for evaluation at the Vascular Laboratory of the General Medicine &amp; Hypertension Unit Central blood pressure (BP), Pulse Wave Velocity (PWV) and Pulse Wave Analysis (PWA) were measured by the SphygmoCor Xcel, carotid Intima Media Thickness (cIMT) and carotid distensibility (DC) by ultrasound and elaborated with a dedicated hardware. Blood samples were evaluated for erythrocyte membrane SFA, expressed as a percentage of total Fatty Acids (FAs). Results: Hundred and forty-seven adolescents (78 males and 69 females, mean age 17,25 ± 1,93 years) were studied. Fifteen patients were classified as hypertensive (10,2%) according to current European Guidelines. Thirteen patients had central systolic BP (cSBP) (8,8%), 60 cIMT (40,8%), 49 (33,3%) DC and 1 PWV (0,7%) above the 95th percentile for sex and age/height. We observed a correlation between total SFAs and cSB and z-cSBP (r = 0,260 and 0,269 respectively, p &lt; 0,05), not confirmed when each SFA was analysed separately. Furthermore, a positive correlation between total SFAs and either PWV or z-PWV was detectable (r = 0,241 and 0,251 respectively, p &lt; 0,05). The latter association remained significant even after adjustment for age, sex, Body Mass Index (BMI), duration of diabetes, HbA1c, total cholesterol, triglycerides-HDL ratio. Total SFAs were also associated with BMI (r = 0,191, p &lt; 0,05). Conclusions: Erythrocyte membrane FAs are associated with vascular (cSBP and PWV) and anthropometric parameters in patients with T1DM. The amount of SFAs in membranes does not depend only on diet, as they are also neo-synthetized from glucidic precursors. Thus, it can be speculated that a bad glycemic control could translate into a higher substrate amount to produce the different SFAs. Further studies are needed to better understand the mechanisms and the regulations of these pathways

Role of Omega 3 Fatty acids, Vitamin D, Vitamin B12, Vitamin B6 and Folate in Mental wellbeing- A Short review of Literature

Neuropsychiatric conditions have been linked to around 14 percent of the global disease burden, mainlydue to the chronically debilitating nature of depression and other widespread mental disorders, alcohol anddrug use disorders, and psychosis. The science and lay press have confirmed that vitamin D is an importantfactor that can have major health benefits in the prevention and treatment of many chronic diseases. Mostpeople have inadequate vitamin D levels in this country. This is also relevant for people with depression andother mental illnesses as well. Inadequate food consumption, lifestyle or other factors are a major causes ofVitamin D deficiency. Successful diagnosis and treatment of insufficient levels of vitamin D in people withdepression and other mental illnesses could be a simple and cost-effective therapy that could enhance thelong-term health outcomes and quality of life of patients. It is now well known that omega-3 fatty acids areimportant for physical health, and there is growing evidence that omega-3 fatty acids may also be importantfor mental health. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the two major omega-3fatty acids in fish oil, have essential biological roles within the CNS. DHA is a major structural componentof neuronal membranes, and modifying the neuronal membrane fatty acid composition contributes tofunctional changes in the behaviour of phospholipid membrane-embedded receptors and other proteins.EPA has major physiological roles that can influence the behaviour of neurons. For innumerable aspectsof brain functioning, adequate nutrition is needed. A modifiable risk factor for depression may be the poorquality of diet. The goal was to evaluate and synthesize the existing understanding of the role of nutritionin mental well-being. The risk of depression is increased by low omega-3 fatty acid status. Both fish oil andfolic acid supplements have been successfully used to treat depression. The response to antidepressants isdecreased by folate deficiency. Deficiencies in folate, vitamin B12, Vitamin D, Omega 3 fatty acids, VitaminB6 tend to be more prevalent in depressed individuals than in nondepressed individuals. In this short reviewof Literature we have focused on role of Omega 3 Fatty acids, Vitamin D, Vitamin B12, Vitamin B6 andFolate in Mental wellbeing.

Effect of amphotericin B-deoxycholate (Fungizone) on the mitochondria of Wistar rats' renal proximal tubules cells.

Amphotericin B-deoxycholate (Fungizone [FZ]) is a widely used potent antimycotic drug in spite of its nephrotoxic effect via different mechanisms. The effect of FZ on renal cell bioenergetics is not clear. The current study evaluated the effect of FZ on the bioenergetics of albino rats' isolated renal proximal tubule cells (PTCs). The cytotoxic effect of FZ on the isolated renal cells was assessed by MTT and lactate dehydrogenase (LDH) assays. The effect of FZ on the PTCs uptake (OAT1 and OCT2) and efflux (P-gp and MRP2) transporters was evaluated. Then, the effect of FZ on mitochondria was assessed by studying complexes I-IV activities, lactate assay, oxygen consumption rates (OCR), and western blotting for all mitochondrial complexes. Moreover, the effect of FZ on mitochondrial membrane fluidity (MMF) and fatty acids composition was evaluated. Additionally, the protective effect of coenzyme q10 was studied. Outcomes showed that FZ was cytotoxic to the PTCs in a concentration and time-dependent patterns. FZ significantly inhibited the studied uptake and efflux tubular transporters with inhibition of the mitochondrial complexes activities and parallel increase in lactate production and decrease in OCRs. Finally, FZ significantly reduced the expression of all mitochondrial complexes in addition to significant increase in MMF and MMFA concentration. Coenzyme Q10 was found to significantly decrease FZ-induced cytotoxicity and transporters impairment in the PTC. FZ significantly inhibits bioenergetics of PTC, which may stimulate the cascade of cell death and clinical nephrotoxicity.

Type 2 diabetes preventive effects with a 12-months sardine-enriched diet in elderly population with prediabetes: An interventional, randomized and controlled trial

Fish could play a role in preventing type 2 diabetes (T2D) but there has been little specification about the type of fish and the preventive mechanism involved in its health claim. The sardine is a source of omega-3 and taurine that, in isolation or in synergy, would produce T2D-delaying through different molecular mechanism. The consumption of twice a week of sardine, during one year would reduce T2D-developing risk in a population with prediabetes (preDM) and old age. 152 subjects with fasting glucose between 100-124 mg/dL aged ≥65 yo were recruited from three primary care centers in Barcelona and were randomly distributed among two interventional groups: control group (CG) and sardine group (SG). Both groups received same T2D-prevention nutritional during a year but only SG had to add 200 g of sardine per week. All variables were collected before to start and at the end of the diet. (ClinicalTrials.gov: NCT03557541). 152 people were randomized into CG (n=77) and SG (n=75) with 18 and 12 drop outs respectively. Subjects in SG, significantly compared to CG, decreased percentage classified-individuals in a very high risk group to develop T2D according to FINDRISC (p=0.035). In addition to increasing HDL-cholesterol and adiponectin and decreasing triglycerides (p<0.05) and blood pressure (<0.05), SG showed a lower HOMA-IR (p=0.032). The consumption of sardine characteristics nutrients as omega-3, EPA and DHA, vitamin D, fluorine and taurine were higher for SG (p<0.05). These results agreed with the increased of taurine, fatty acid (FA) omega-3 and bile acids circulating metabolites (p<0.05). Changes erythrocyte membrane FA were detected only in SG with a decrease of 5 omega-6 FA (p<0.001) and an increase of 3 omega-3 FA types (p<0.001). We conclude that a year T2D-prevention diet with sardine supplementation has a greater protective effect against developing T2D and CV events.

Membrane-bound Δ12 fatty acid desaturase (FAD12); From Brassica napus to E. coli expression system

Fatty acid desaturase catalyzes the desaturation reactions by insertion of double bonds into the fatty acyl chain, producing unsaturated fatty acids. Though soluble fatty acid desaturases have been studied widely in advanced organisms, there are very limited studies of membrane fatty acid desaturases due to the difficulty of generating recombinant desaturase. Brassica napus is a rapeseed, which possesses a range of different membrane-bound desaturases capable of producing fatty acids including Δ3, Δ4, Δ8, Δ9, Δ12, and Δ15 fatty acids. The 1155 bp open reading frame of Δ12 fatty acid desaturase (FAD12) from Brassica napus codes for 383 amino acid residues with a molecular weight of 44 kDa. It was expressed in Escherichia coli at 37 °C in soluble and insoluble forms when induced with 0.5 mM IPTG. Soluble FAD12 has been purified using Ni2+-Sepharose affinity chromatography with a total protein yield of 0.728 mg/mL. Gas chromatography–mass spectrometry (GC–MS) analysis revealed that desaturase activity of FAD12 could produce linoleic acid from oleic acid at a retention time of 17.6 with a conversion rate of 47%. Characterization of purified FAD12 revealed the optimal temperature of FAD12 was 50 °C with 2 mM preferred substrate concentration of oleic acid. Analysis of circular dichroism (CD) showed FAD12 was made up of 47.3% and 0.9% of alpha-helix and β-sheet secondary structures. The predicted Tm value was 50.2 °C.

The Absence of Hydrodynamic Stress Promotes Acquisition of Freezing Tolerance and Freeze-Dependent Asexual Reproduction in the Red Alga 'Bangia' sp. ESS1.

The ebb tide causes calm stress to intertidal seaweeds in tide pools; however, little is known about their physiological responses to loss of water movement. This study investigated the effects of static culture of ‘Bangia’ sp. ESS1 at 15 °C on tolerance to temperature fluctuation. The freezing of aer-obically cultured thalli at −80 °C for 10 min resulted in the death of most cells. By contrast, statically cultured thalli acquired freezing tolerance that increased cell viability after freeze–thaw cycles, although they did not achieve thermotolerance that would enable survival at the lethal temperature of 32 °C. Consistently, the unsaturation of membrane fatty acids occurred in static culture. Notably, static culture of thalli enhanced the release of asexual spores after freeze-and-thaw treatment. We conclude that calm stress triggers both the acquisition of freezing tolerance and the promotion of freezing-dependent asexual reproduction. These findings provide novel insights into stress toler-ance and the regulation of asexual reproduction in Bangiales.

Impaired Cytoskeletal and Membrane Biophysical Properties of Acanthocytes in Hypobetalipoproteinemia - A Case Study.

Familial hypobetalipoproteinemia is a metabolic disorder mainly caused by mutations in the apolipoprotein B gene. In its homozygous form it can lead without treatment to severe ophthalmological and neurological manifestations. In contrast, the heterozygous form is generally asymptomatic but associated with a low risk of cardiovascular disease. Acanthocytes or thorny red blood cells (RBCs) are described for both forms of the disease. However, those morphological changes are poorly characterized and their potential consequences for RBC functionality are not understood. Thus, in the present study, we asked whether, to what extent and how acanthocytes from a patient with heterozygous familial hypobetalipoproteinemia could exhibit altered RBC functionality. Acanthocytes represented 50% of the total RBC population and contained mitoTracker-positive surface patches, indicating the presence of mitochondrial fragments. While RBC osmotic fragility, calcium content and ATP homeostasis were preserved, a slight decrease of RBC deformability combined with an increase of intracellular free reactive oxygen species were observed. The spectrin cytoskeleton was altered, showing a lower density and an enrichment in patches. At the membrane level, no obvious modification of the RBC membrane fatty acids nor of the cholesterol content were detected but the ceramide species were all increased. Membrane stiffness and curvature were also increased whereas transversal asymmetry was preserved. In contrast, lateral asymmetry was highly impaired showing: (i) increased abundance and decreased functionality of sphingomyelin-enriched domains; (ii) cholesterol enrichment in spicules; and (iii) ceramide enrichment in patches. We propose that oxidative stress induces cytoskeletal alterations, leading to increased membrane stiffness and curvature and impaired lipid lateral distribution in domains and spicules. In addition, ceramide- and spectrin-enriched patches could result from a RBC maturation defect. Altogether, the data indicate that acanthocytes are associated with cytoskeletal and membrane lipid lateral asymmetry alterations, while deformability is only mildly impaired. In addition, familial hypobetalipoproteinemia might also affect RBC precursors leading to disturbed RBC maturation. This study paves the way for the potential use of membrane biophysics and lipid vital imaging as new methods for diagnosis of RBC disorders.

Red Blood Cell Fatty Acids and Risk of Colorectal Cancer in The European Prospective Investigation into Cancer and Nutrition (EPIC).

A growing body of evidence suggests that alterations of dietary fatty acid (FA) profiles are associated with colorectal cancer risk. However, data from large-scale epidemiologic studies using circulating FA measurements to objectively assess individual FA and FA categories are scarce. We investigate the association between red blood cell (RBC) membrane FAs and risk of colorectal cancer in a case-control study nested within a large prospective cohort. After a median follow-up of 6.4 years, 1,069 incident colorectal cancer cases were identified and matched to 1,069 controls among participants of the European Prospective Investigation into Cancer and Nutrition (EPIC). The FA composition of RBC phospholipids (in mol%) was analyzed by gas chromatography, and their association with risk of colorectal cancer was estimated by multivariable adjusted conditional logistic regression models. After correction for multiple testing, subjects with higher concentrations of RBC stearic acid were at higher risk for colorectal cancer (OR = 1.23; 95% CI = 1.07-1.42, per 1 mol%). Conversely, colorectal cancer incidence decreased with increasing proportions of RBC n-3 PUFA, particularly eicosapentaenoic acid (0.75; 0.62-0.92, per 1 mol%). The findings for the n-6 PUFA arachidonic acid were inconsistent. The positive association between prediagnostic RBC stearic acid and colorectal cancer reflects putative differences in FA intake and metabolism between cancer cases and matched controls, which deserve further investigation. The inverse relationship between EPA and colorectal cancer is in line with the repeatedly reported protective effect of fish consumption on colorectal cancer risk. These findings add to the evidence on colorectal cancer prevention.

Relationship Between Composition of Fatty Acid in Platelet Phospholipid Membrane and Markers of Oxidative Stress in Healthy Men and Men After a Myocardial Infarction.

BackgroundOxidative stress (OS) is known to be extremely damaging for phospholipids in cell membranes, especially their polyunsaturated fatty acids (PUFAs). OS is known to be associated with increased platelet activation and thrombosis, which lead to cardiovascular lesions. The aim of this study was to investigate how changes in the composition of fatty acids (FAs) in the platelet phospholipid membrane correlate with OS in healthy men and in men who have experienced a myocardial infarction (post-MI men).Material/MethodsFA methyl esters from the platelet phospholipid membrane of 79 apparently healthy and 20 post-MI men were identified using gas chromatography/mass spectrometry. Malondialdehyde (MDA) was measured in the blood serum using high-performance liquid chromatography, and platelet-white blood cell aggregates (PWAs) were analysed based on whole-blood flow cytometry. The composition of platelet membrane FAs was compared to MDA concentration (μg/l) and the percentage of PWA formation between healthy men and individuals who had suffered a myocardial infarction (MI).ResultsStatistically, post-MI patients had a significantly higher concentration of blood serum MDA than those in the control group (p=0.000). The level of PUFAs was also higher in the platelet phospholipid membrane of post-MI patients than in healthy individuals (p=0.016). However, the percentage of PWA formation was lower in patients compared with the control group (p<0.05).ConclusionsA higher level of blood serum MDA concentration due to OS stimulates platelets to incorporate more PUFAs into the phospholipid membrane, thereby affecting platelet activation. This may lead the individual to develop cardiovascular diseases in the future.