Relationship between Erythrocyte Fatty Acid Composition and Psychopathology in the Vienna Omega-3 Study

This study investigated the relationship between erythrocyte membrane fatty acid (FA) levels and the severity of symptoms of individuals at ultra-high risk (UHR) for psychosis. Subjects of the present study consisted of 80 neuroleptic-naïve UHR patients. Partial correlation coefficients were calculated between baseline erythrocyte membrane FA levels, measured by gas chromatography, and scores on the Positive and Negative Syndrome Scale (PANSS), Global Assessment of Functioning Scale, and Montgomery–Asberg Depression Rating Scale (MADRS) after controlling for age, sex, smoking and cannabis use. Subjects were divided into three groups according to the predominance of positive or negative symptoms based on PANSS subscale scores; membrane FA levels in the three groups were then compared. More severe negative symptoms measured by PANSS were negatively correlated with two saturated FAs (myristic and margaric acids), one ω-9 monounsaturated FA (MUFA; nervonic acid), and one ω-3 polyunsaturated FA (PUFA; docosapentaenoic acid), and were positively correlated with two ω-9 MUFAs (eicosenoic and erucic acids) and two ω-6 PUFAs (γ-linolenic and docosadienoic acids). More severe positive symptoms measured by PANSS were correlated only with nervonic acid. No associations were observed between FAs and MADRS scores. In subjects with predominant negative symptoms, the sum of the ω-9 MUFAs and the ω-6:ω-3 FA ratio were both significantly higher than in those with predominant positive symptoms, whereas the sum of ω-3 PUFAs was significantly lower. In conclusion, abnormalities in FA metabolism may contribute to the neurobiology of psychopathology in UHR individuals. In particular, membrane FA alterations may play a role in negative symptoms, which are primary psychopathological manifestations of schizophrenia-related disability.     

Worst case scenario match analysis and contextual variables in professional soccer players: a longitudinal study

This study aimed to describe the worst-case scenarios (WCS) of professional soccer players by playing position in different durations and analyse WCS considering different contextual variables (match half, match location and match outcome). A longitudinal study was conducted in a professional soccer team. Data were collected from different WCS durations in the total distance (TD), high-speed running distance (HSRD), and sprinting distance (SPD). A mixed analysis of variance was performed to compare different WCS durations between playing positions and contextual variables, making pairwise comparisons by Bonferroni post hoc test. Positional differences were found for TD (p < 0.01, ω_p² = 0.02), HSRD (p < 0.01, ω_p² = 0.01) and SPD (p < 0.01, ω_p² = 0.02). There was a significant interaction when comparing WCS by match half in TD (F = 6.1, p < 0.01, ω_p² = 0.07) but no significant differences in HSRD (p = 0.403, ω_p² = 0) or SPD (p = 0.376, ω_p² = 0). A significant interaction was identified when comparing WCS by match location in TD (F = 51.5, p < 0.01, ω_p² = 0.14), HSRD (F = 19.15, p < 0.01, ω_p² = 0.05) and SPD (F = 8.95, p < 0.01, ω_p² = 0.01) as well as WCS by match outcome in TD (F = 36.4, p < 0.01, ω_p² = 0.08), HSRD (F = 13.6, p < 0.01, ω_p² = 0.04) and SPD (F = 7.4, p < 0.01, ω_p² = 0.02). Positional differences exist in TD, HSRD, and SPD in match-play WCS, and contextual variables such as match half, match location and match outcome have a significant impact on the WCS of professional soccer players.     

Characterization of Transgenic Tobacco with an Increased α-Linolenic Acid Level

Microsomal ω-3 fatty acid desaturase catalyzes the conversion of 18:2 (linoleic acid) to 18:3 (α-linolenic acid) in phospholipids, which are the main constituents of extrachloroplast membranes. Transgenic tobacco (Nicotiana tabacum) plants with increased 18:3 contents (designated SIIn plants) were produced through the introduction of a construct with the tobacco microsomal ω-3 fatty acid desaturase gene under the control of the highly efficient promoter containing the E12Ω sequence. 18:3 contents in the SIIn plants were increased by about 40% in roots and by about 10% in leaves compared with the control plants. With regard to growth at 15°C and 25°C and the ability to tolerate chilling at 1°C and 5°C, there were no discernible differences between the SIIn and the control plants. Freezing tolerance in leaves and roots, which was assessed by electrolyte leakage, was almost the same between the SIIn and the control plants. The fluidity of plasma membrane from the SIIn plants was almost the same as that of the control plants. These results indicate that an increase in the 18:3 level in phospholipids is not directly involved in compensation for the diminishment in growth or membrane properties observed under low temperatures.     

Oxidative damages in erythrocytes of patients with metabolic syndrome

The aim of the study was to estimate the changes caused by oxidative stress in structure and function of membrane of erythrocytes from patients with metabolic syndrome (MS). The study involved 85 patients with MS before pharmacological treatment and 75 healthy volunteers as a control group. Cholesterol level, lipid peroxidation, glutathione level (GSH), and antioxidant enzyme activities in erythrocytes were investigated. The damage to erythrocyte proteins was also indicated by means of activity of ATPase (total and Na⁺,K⁺ ATPase) and thiol group level. The membrane fluidity of erythrocytes was estimated by the fluorescent method. The cholesterol concentration and the level of lipid peroxidation were significantly higher, whereas the concentration of proteins thiol groups decreased in the patient group. ATPase and GSH peroxidase activities diminished compared to those in the control group. There were no differences in either catalase or superoxide dismutase activities. The membrane fluidity was lower in erythrocytes from patients with MS than in the ones from control group. These results show changes in red blood cells of patients with MS as a consequence of a higher concentration of cholesterol in the membrane and an increased oxidative stress.     

Adaptation of Escherichia coli O157:H7 to pH Alters Membrane Lipid Composition, Verotoxin Secretion, and Resistance to Simulated Gastric Fluid Acid

The influence of adaptation to pH (from pH 5.0 to 9.0) on membrane lipid composition, verotoxin concentration, and resistance to acidic conditions in simulated gastric fluid (SGF) (pH 1.5, 37°C) was determined for Escherichia coli O157:H7 (HEC, ATCC 43895), an rpoS-deficient mutant of ATCC 43895 (HEC-RM, FRIK 816-3), and nonpathogenic E. coli (NPEC, ATCC 25922). Regardless of the strain, D values (in SGF) of acid-adapted cells were higher than those of non-acid-adapted cells, with HEC adapted at pH 5.0 having the greatest D value, i.e., 25.6 min. Acid adaptation increased the amounts of palmitic acid (C16:0) and decreased cis-vaccenic acid (C18:1ω7c) in the membrane lipids of all strains. The ratio of cis-vaccenic acid to palmitic acid increased at acidic pH, causing a decrease in membrane fluidity. HEC adapted to pH 8.3 and HEC-RM adapted to pH 7.3 exhibited the greatest verotoxin concentrations (2,470 and 1,460 ng/ml, respectively) at approximately 10⁸ CFU/ml. In addition, the ratio of extracellular to intracellular verotoxin concentration decreased at acidic pH, possibly due to the decrease of membrane fluidity. These results suggest that while the rpoS gene does not influence acid resistance in acid-adapted cells it does confer decreased membrane fluidity, which may increase acid resistance and decrease verotoxin secretion.     

The effects of verbascoside on plasma lipid peroxidation level and erythrocyte membrane fluidity during immobilization in rabbits: a time course study

We studied the changes in the level of plasma lipid peroxidation indicated by malondialdehyde (MDA) level and erythrocyte membrane fluidity expressed by the value of order parameter (S) during single hindlimb immobilization of 21 days using thiobarbituric acid - reactive substances method and spin label electron spin resonance method, respectively. The impacts of verbascoside that has been proved its antioxidative activity on the measured parameters were examined. 11 New Zealand white rabbits were immobilized and divided into two groups. The rabbits in the verbascoside group were administrated with 0.8 mg/kg of verbascoside twice a day orally throughout the immobilization. The rabbits in the placebo group were treated with normal saline. In placebo group, the results showed that the level of MDA significantly increased on day 3, peaked on day 7, and was still significantly higher on day 14 of immobilization, compared with the value measured before immobilization. The value of S reached the highest on day 7 and subsequently lowered but still higher on day 14 than those measured before immobilization. Compared with placebo group, there were lower MDA level (P < 0.05, 0.001, and 0.05 for days 3, 7, and 14, respectively) and higher erythrocyte membrane fluidity (P < 0.05, 0.001, and 0.001 for days 3, 7, and 14, respectively) in verbascoside group. The data indicated that immobilization caused temporal changes of increase in plasma lipid peroxidation and decrease in erythrocyte membrane fluidity. Verbascoside might have the effects to moderate oxidative stress and erythrocyte membrane fluidity during immobilization.     

Geniposide Protects Primary Cortical Neurons against Oligomeric Aβ1-42-Induced Neurotoxicity through a Mitochondrial Pathway

Mitochondrial dysfunction plays a key role in the progression of Alzheimer’s disease (AD). The accumulation of amyloid-beta peptide (Aβ) in the brains of AD patients is thought to be closely related to neuronal mitochondrial dysfunction and oxidative stress. Therefore, protecting mitochondria from Aβ-induced neurotoxicity is an effective strategy for AD therapeutics. In a previous study, we found that geniposide, a pharmacologically active compound purified from gardenia fruit, has protective effects on oxidative stress and mitochondrial dysfunction in AD transgenic mouse models. However, whether geniposide has a protective effect on Aβ-induced neuronal dysfunction remains unknown. In the present study, we demonstrate that geniposide protects cultured primary cortical neurons from Aβ-mediated mitochondrial dysfunction by recovering ATP generation, mitochondrial membrane potential (MMP), and cytochrome c oxidase (CcO) and caspase 3/9 activity; by reducing ROS production and cytochrome c leakage; as well as by inhibiting apoptosis. These findings suggest that geniposide may attenuate Aβ-induced neuronal injury by inhibiting mitochondrial dysfunction and oxidative stress.     

AMPKα1 Deletion Shortens Erythrocyte Life Span in Mice: ROLE OF OXIDATIVE STRESS*

AMP-activated protein kinase (AMPK) is an energy sensor essential for maintaining cellular energy homeostasis. Here, we report that AMPKα1 is the predominant isoform of AMPK in murine erythrocytes and mice globally deficient in AMPKα1 (AMPKα1^−/−), but not in those lacking AMPKα2, and the mice had markedly enlarged spleens with dramatically increased proportions of Ter119-positive erythroid cells. Blood tests revealed significantly decreased erythrocyte and hemoglobin levels with increased reticulocyte counts and elevated plasma erythropoietin concentrations in AMPKα1^−/− mice. The life span of erythrocytes from AMPKα1^−/− mice was less than that in wild-type littermates, and the levels of reactive oxygen species and oxidized proteins were significantly increased in AMPKα1^−/− erythrocytes. In keeping with the elevated oxidative stress, treatment of AMPKα1^−/− mice with the antioxidant, tempol, resulted in decreased reticulocyte counts and improved erythrocyte survival. Furthermore, the expression of Foxo3 and reactive oxygen species scavenging enzymes was significantly decreased in erythroblasts from AMPKα1^−/− mice. Collectively, these results establish an essential role for AMPKα1 in regulating oxidative stress and life span in erythrocytes.     

Role of ςB in Heat, Ethanol, Acid, and Oxidative Stress Resistance and during Carbon Starvation in Listeria monocytogenes

To determine the contribution of sigma B (ς^B) to survival of stationary-phase Listeria monocytogenes cells following exposure to environmental stresses, we compared the viability of strain 10403S with that of an isogenic nonpolar sigB null mutant strain after exposure to heat (50°C), ethanol (16.5%), or acid (pH 2.5). Strain viabilities were also determined under the same conditions in cultures that had been previously exposed to sublethal levels of the same stresses (45°C, 5% ethanol, or pH 4.5). The ΔsigB and wild-type strains had similar viabilities following exposure to ethanol and heat, but the ΔsigB strain was almost 10,000-fold more susceptible to lethal acid stress than its parent strain. However, a 1-h preexposure to pH 4.5 yielded a 1,000-fold improvement in viability for the ΔsigB strain. These results suggest the existence in L. monocytogenes of both a ς^B-dependent mechanism and a pH-dependent mechanism for acid resistance in the stationary phase. ς^B contributed to resistance to both oxidative stress and carbon starvation in L. monocytogenes. The ΔsigB strain was 100-fold more sensitive to 13.8 mM cumene hydroperoxide than the wild-type strain. Following glucose depletion, the ΔsigB strain lost viability more rapidly than the parent strain. ς^B contributions to viability during carbon starvation and to acid resistance and oxidative stress resistance support the hypothesis that ς^B plays a role in protecting L. monocytogenes against environmental adversities.     

Purification and Biochemical Analysis of the Cytoplasmic Membrane from the Desiccation-Tolerant Cyanobacterium Nostoc commune UTEX 584

The cytoplasmic membrane of the heterocystous cyanobacterium Nostoc commune UTEX 584 was isolated free of thylakoids and phycobiliprotein-membrane complexes by flotation centrifugation. Purified membranes had a buoyant density of 1.07 g cm⁻³ and were bright orange. Twelve major proteins were detected in the membrane, and of these, the most abundant had molecular masses of 83, 71, 68, 51, and 46 kilodaltons. The ester-linked fatty acids of the methanol fraction contained 16:0, 18:0, 18:1ω9c, 20:0, and 20:3ω3 with no traces of hydroxy fatty acids. Compound 20:3ω3 represented 56.8% of the total fatty acid methyl esters, a feature which distinguishes the cell membrane of N. commune UTEX 584 from those of all other cyanobacteria which have been characterized to date. Fatty acid 18:3 was not detected. Carotenoids were analyzed by highperformance liquid chromatography. The cytoplasmic membrane contained β-carotene and echinenone as the dominant carotenoids and lacked chlorophyll a and pheophytin a. Whole cells contained β-carotene and echinenone, and lesser amounts of zeaxanthin and (3R)-cryptoxanthin.     

Effects of weight loss on erythrocyte membrane composition and fluidity in overweight and moderately obese women

A previous study showed chemical and physical impairment of the erythrocyte membrane of overweight and moderately obese women. The present study investigated the effects of a low-calorie diet (800 kcal/day deficit for 8 weeks) on erythrocyte membrane properties in 70 overweight and moderately obese (body mass index, 25-33 kg/m²) normotensive, nondiabetic women. At the end of dietary intervention, 24.3% of women dropped out, 45.7% lost less than 5% of their initial weight (Group I) and only 30% of patients lost at least 5% of their initial body weight (Group II). Group I showed no significant changes in erythrocyte membrane composition and function. The erythrocyte membranes of Group II showed significant reductions in malondialdehyde, lipofuscin, cholesterol, sphingomyelin, palmitic acid and nervonic acid and an increase in di-homo-γ-linolenic acid, arachidonic acid and membrane fluidity. Moreover, Group II showed an improvement in total cholesterol, low-density lipoprotein cholesterol, glycemia and insulin resistance. These changes in erythrocyte membrane composition could reflect a virtuous cycle resulting from the reduction in insulin resistance associated with increased membrane fluidity that, in turn, results in a sequence of metabolic events that concur to further improve membrane fluidity.     

Membrane fluidity of platelets and erythrocytes in patients with Alzheimer's disease and the effect of small amounts of aluminium on platelet and erythrocyte membranes

The membrane fluidity of platelet and erythrocyte membranes in 10 Alzheimer's disease patients and 9 age-matched controls was studied. The platelet membranes of patients with Alzheimer's disease were found to be significantly more fluid than those of controls (p<0.02). However, erythrocyte membranes of Alzheimer patients were less fluid (more viscous) than those of controls (p<0.05). On further investigation of platelet and erythrocyte membranes obtained from healthy volunteers, the fluidity was found to change with increasing aluminium concentrations. When aluminium ammonium sulphate (0.01–10 M) was added to membrane suspensions, the fluidity of platelet membranes was increased, whereas the fluidity of erythrocyte membranes was decreased (i.e. the microviscosity was increased).     

Dietary Repletion with ω3 Fatty Acid or with COX Inhibition Reverses Cognitive Effects in F3 ω3 Fatty-Acid–Deficient Mice

Dietary deficiency of ω3 fatty acid during development leads to impaired cognitive function. However, the effects of multiple generations of ω3 fatty-acid deficiency on cognitive impairment remain unclear. In addition, we sought to test the hypothesis that the cognitive impairments of ω3 fatty-acid–deficient mice are mediated through the arachidonic acid–cyclooxygenase (COX) pathway. To address these issues, C57BL/6J mice were bred for 3 generations and fed diets either deficient (DEF) or sufficient (SUF) in ω3 fatty acids. At postnatal day 21, the F3 offspring remained on the dam''s diet or were switched to the opposite diet, creating 4 groups. In addition, 2 groups that remained on the dam''s diet were treated with a COX inhibitor. At 19 wk of age, spatial-recognition memory was tested on a Y-maze. Results showed that 16 wk of SUF diet reversed the cognitive impairment of F3 DEF mice. However, 16 wk of ω3 fatty-acid–deficient diet impaired the cognitive performance of the F3 SUF mice, which did not differ from that of the F3 DEF mice. These findings suggest that the cognitive deficits after multigenerational maintenance on ω3 fatty-acid–deficient diet are not any greater than are those after deficiency during a single generation. In addition, treatment with a COX inhibitor prevented spatial-recognition deficits in F3 DEF mice. Therefore, cognitive impairment due to dietary ω3 fatty-acid deficiency appears to be mediated by the arachidonic acid–COX pathway and can be prevented by 16 wk of dietary repletion with ω3 fatty acids or COX inhibition.Abbreviations: AA, arachidonic acid; COX, cyclooxygenase; DEF, ω3 fatty-acid–deficient; DHA, docosahexaenoic acid; MWM, Morris water maze; SUF, ω3 fatty-acid–sufficientDietary deficiency of ω3 fatty acid is associated with impaired cognitive function. For example, rats on ω3 fatty-acid–deficient diet took significantly longer to locate the platform during the swimming test in the Morris water-maze (MWM) test.⁶ Previous studies report that dietary ω3 fatty-acid deficiency led to significantly shorter latencies in the passive-avoidance test in rats³ and increased time in the Barnes circular test in mice.⁷ However, ω3 fatty-acid–deficient diet increased the time and number of entries in the maze-learning task in a single generation of mice.²² These findings may suggest that ω3 fatty-acid–deficient diet influences cognitive function in animals by impairing their performance in spatial-recognition memory tasks.Previous studies have shown that rodents raised on an ω3 fatty-acid–deficient diet over 2 or 3 generations have impaired learning performance in the MWM task.^17,25 Dietary ω3 fatty-acid deficiency in the F2 and F3 rats prolonged the escape latency and delayed acquisition of the MWM task compared with those of rats fed an ω3 fatty-acid–sufficient diet for both generations.¹⁷ In a subsequent study, F3 rats fed on ω3 fatty-acid–deficient diet since birth or at weaning had a lower mean swimming speed to locate the platform during the MWM task.¹⁸ Previous studies show that feeding mice an ω3 fatty-acid–deficient diet for 3 generations reduced swimming performance in the MWM test.²⁵ Interestingly, feeding rats suboptimal levels of docosahexaenoic acid (DHA) for four generations significantly prolonged latencies in the MWM task compared those of rats fed higher levels of DHA.¹² These results suggest that multigenerational feeding of an ω3 fatty-acid–deficient diet impairs performance in tests of spatial-recognition memory.Importantly, after several generations of ω3 fatty-acid deficiency, switching rats to a sufficient diet at birth restored their performance on the spatial-recognition task to normal.¹⁸ Similarly, cognitive impairment in the brightness-discrimination test in mice after 2 generations of dietary ω3 fatty-acid deficiency was reversed by providing ω3 fatty-acid–sufficient diet after weaning.⁹ Cognitive performance in the MWM test did not differ in mice provided an ω3 fatty-acid–sufficient diet only and those switched at 7 wk of age from an ω3 fatty-acid–deficient diet to a sufficient diet.⁴ Overall, these findings indicate that the cognitive impairments due to ω3 fatty-acid deficiency are reversed by providing a diet containing sufficient amounts of ω3 fatty acids.Previous studies have been shown that the cognitive and memory deficits of a transgenic mouse model are due to increased prostaglandin activity from formation of cyclooxygenase (COX).¹³ Dietary ω3 fatty acid deficiency has been suggested to increase prostaglandin activity in animals.¹⁶ Therefore, the administration of a COX inhibitor may protect against cognitive impairment in the elevated plus-maze task by inhibiting the synthesis of prostaglandin.¹¹ Treatment with a COX inhibitor improved open-field exploration in mice by inhibiting the synthesis of prostaglandin.²³ Similarly, COX inhibitors such as celecoxib inhibit prostaglandin E2 levels and consequently improve cognitive performance in rats as assessed by the elevated plus-maze test.⁵ In addition, the administration of naproxen, another COX inhibitor, was protective against motor and cognitive impairment in rats by decreasing oxidative stress.¹⁴ Moreover, naproxen reduced oxidative stress levels and prevented neurologic disorders, especially memory deficits, in an animal model of excitotoxic neuronal injury.²⁰ Clearly, these findings suggest that COX inhibitors may protect against cognitive and memory deficits in animals by inhibiting prostaglandin activity.Clarifying the differences in cognitive function between the first and third generations of mice likely would improve our understanding of the factors contributing to differences in cognitive deficits due to dietary ω3 fatty-acid deficiency. To this end, we raised and maintained third-generation mice on a diet either sufficient or deficient in ω3 fatty acids or on a cross-over diet. Spatial-recognition memory in the F3 mice was tested by using the Y-maze. The aim of our transgenerational studies was to determine whether dietary ω3 fatty-acid deficiency causes severe cognitive impairment in F3 mice. In addition, these studies examined the hypothesis that the cognitive impairment of F3 mice on an ω3 fatty-acid deficient diet results from increased prostaglandin activity due to eicosanoid production from the arachidonic acid (AA)–COX pathway. Furthermore, we hypothesized that treatment with naproxen, a COX inhibitor, would improve cognitive function as a result of inhibiting prostaglandin activity.     

Decreased membrane fluidity and altered susceptibility to peroxidation and lipid composition in overweight and obese female erythrocytes

The increased generation of reactive oxygen species that occurs in the condition of obesity may be responsible for oxidative injury to erythrocyte membranes, which could lead to a decrease in tissue oxygenation. Therefore, we have looked into the effects of obesity on both indexes of oxidative damage and physical-chemical properties of erythrocyte membranes in 50 overweight or obese [25 < body mass index (BMI) < 33], normotensive, nondiabetic women and 50 age-matched lean healthy women (BMI < 25). In the obese group compared with the lean group, we found that a) the onset of free radical-induced erythrocyte hemolysis and the ratio between reduced and oxidized glutathione were reduced, whereas the rate of free radical-induced damage increased; b) the n-3 fatty acid and the phospholipid contents decreased; c) the ratio between cholesterol and phospholipids increased; and d) the membrane fluidity decreased. These findings suggest an impairment of erythrocyte membrane physical-chemical properties in overweight and obese people as a consequence of oxidative injury that might be part of a pathogenetic mechanism responsible for obesity-related pathologies such as atherosclerosis and hypertension.