Erythrocyte Membrane Alterations Research Articles

Alectinib-induced Non-immune Hemolytic Anemia due to Erythrocyte Membrane Alterations: A Retrospective Evaluation

Alectinib-induced Non-immune Hemolytic Anemia due to Erythrocyte Membrane Alterations: A Retrospective Evaluation

Coenzyme Q10 supplementation affects cellular ionic balance: relevance to aging.

Aging results into disruptive physiological functioning and cellular processes that affect the composition and structure of the plasma membrane. The plasma membrane is the major regulator of ionic homeostasis thatregulates the functioning of membrane transporters and exchangers. Coenzyme Q10 is a lipid-soluble antioxidant molecule that declines during aging and age-associated diseases. The presentstudy aims to explore the role of Coenzyme Q10 supplementation to rats during aging on membrane transporters and redox biomarkers. The studywas conducted on young and old male Wistar rats supplemented with 20 mg/kg b.w. of Coenzyme Q10 per day. After a period of 28days, rats were sacrificed and erythrocyte membrane was isolated. The result exhibits significant decline in biomarkers of oxidative stress in old control rats when compared with young control. The effect of Coenzyme Q10 supplementation was more pronounced in old rats. Thefunctioning of membrane transporters and Na+/H+ exchanger showed potential return to normal levels in the Coenzyme Q10 treated rats. Overall, the results demonstrate that Coenzyme Q10 plays an important role in maintaining redox balance in cells which interconnects with membrane integrity. Thus, Coenzyme Q10 supplementation may play animportant role in protecting age related alterations inerythrocyte membrane physiology.

Dantu Blood Group Erythrocytes Form Large Plasmodium falciparum Rosettes Less Commonly.

Dantu erythrocytes, which express a hybrid glycophorin B/A protein, are protective against severe malaria. Recent studies have shown that Dantu impairs Plasmodium falciparum invasion by increasing erythrocyte membrane tension, but its effects on pathological host-parasite adhesion interactions such as rosetting, the binding of uninfected erythrocytes to P. falciparum-infected erythrocytes, have not been investigated previously. The expression of several putative host rosetting receptors-including glycophorin A (GYPA), glycophorin C (GYPC), complement receptor 1 (CR1), and band 3, which complexes with GYPA to form the Wrightb blood group antigen-are altered on Dantu erythrocytes. Here, we compare receptor expression, and rosetting at both 1 hour and 48 hours after mixing with mature trophozoite-stage Kenyan laboratory-adapted P. falciparum strain 11019 parasites in Dantu and non-Dantu erythrocytes. Dantu erythrocytes showed lower staining for GYPA and CR1, and greater staining for band 3, as observed previously, whereas Wrightb and GYPC staining did not vary significantly. No significant between-genotype differences in rosetting were seen after 1 hour, but the percentage of large rosettes was significantly less in both Dantu heterozygous (mean, 16.4%; standard error of the mean [SEM], 3.2) and homozygous donors (mean, 15.4%; SEM, 1.4) compared with non-Dantu erythrocytes (mean, 32.9%; SEM, 7.1; one-way analysis of variance, P = 0.025) after 48 hours. We also found positive correlations between erythrocyte mean corpuscular volume (MCV), the percentage of large rosettes (Spearman's rs = 0.5970, P = 0.0043), and mean rosette size (rs = 0.5206, P = 0.0155). Impaired rosetting resulting from altered erythrocyte membrane receptor expression and reduced MCV might add to the protective effect of Dantu against severe malaria.

Oil from Mullet Roe Byproducts: Effect of Oil Extraction Method on Human Erythrocytes and Platelets.

Background: The valorization of byproducts to obtain high nutritional value foods is of utmost importance for our planet where the population is booming. Among these products are oils rich in ω-3 fatty acids produced from fishery byproducts. Recently, mullet roe oil from roe byproducts was produced that was rich in the ω-3 fatty acids eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA). Oils are customarily characterized for their composition and degree of oxidation but little is known of their biological effects, especially the effect of the extraction method. Methods: The purpose of this study was to evaluate the effects of freshly extracted mullet roe oil from mullet roe byproducts and the effect of the extraction method on human red blood cells (hRBCs) and platelets. To this end, the hemocompatibility (cytotoxicity), oxidative effects, and erythrocyte membrane changes were examined after 1 and 24 h of incubation. Antiplatelet effects were also assessed in vitro. Results: The expeller press oil extraction method and alcalase-assisted extraction produced the most biocompatible oils, as shown by hemocompatibility measurements and the absence of erythrocyte membrane alterations. Solvent extracts and protease-assisted extraction oils resulted in the rupture of red blood cells at different examined dilutions, creating hemolysis. Conclusions: It seems that the proper functioning of oil-erythrocyte interactions cannot be explained solely by ROS. Further investigations combining chemical analysis with oil-cell interactions could be used as an input to design high nutritional value oils using green extraction technologies. All samples exhibited promising antiplatelet and antiblood clotting effects in vitro.

Balanites aegyptiaca (Heglig Dates) Reduces Oxidative Stress and Biophysical Alterations of Erythrocyte Membranes in Streptozotocin-Induced Diabetic Rats

Balanites aegyptiaca (Heglig Dates) Reduces Oxidative Stress and Biophysical Alterations of Erythrocyte Membranes in Streptozotocin-Induced Diabetic Rats

Melatonin stabilizes age-dependent alterations in erythrocyte membrane induced by ‘Artificial Light at Night’ in a chronodisrupted model of rat

Growing evidence has shown that Artificial light at night (ALAN) is one of the threatening risk factors which disrupt circadian homeodynamics of cellular processes. The chronobiological role of melatonin seems to represent an important aspect of its contribution to healthy aging. In the present study, we examined the age dependent effect of melatonin on erythrocyte membrane transporters and oxidative stress biomarkers against ALAN to understand the degree of photo-oxidative damage in chronodisrupted rat model. Young (3 months) and old (24 months) male Wistar rats were subdivided in the following four young groups (n = 4) ; (i) control (ii) melatonin (10 mg/kg) (iii) ALAN (500 lx) (iv) ALAN (500 lx) + melatonin (10 mg/kg) and four old groups (n = 4); (v) control (vi) melatonin (10 mg/kg) (vii) ALAN (500 lx) (viii) ALAN (500 lx) + melatonin (10 mg/kg) to the experimental conditions for 10 days. Our findings demonstrated that ALAN significantly enhanced erythrocyte membrane lipid hydroperoxides (LHPs), protein carbonyl (PCO) while reduced total thiol (T-SH), and sialic acid (SA) level with higher amplitude in old ALAN group is restored by exogenous supplementation of melatonin. Activity of membrane transporters, sodium potassium ATPase (NKA) and plasma membrane calcium ion ATPase (PMCA) is significantly reduced meanwhile sodium hydrogen exchanger (NHE) activity is enhanced under the influence of ALAN with higher extent in old groups is effectively ameliorated by melatonin treatment. Further melatonin reduced osmotic fragility of erythrocyte in both young and old rats. It has been concluded from results that ALAN provoked redox insult and disrupt transporters activity more prominently in erythrocyte membrane of aged groups. Exogenous supplementation of melatonin is one of the possible therapeutic approaches to reinforce circadian modulations against ALAN in aged populations.

Thalassemia Associated Pulmonary Hypertension

Cardiac disease is the main cause of death in both forms of thalassemia; thalassemia major (TM) and thalassemia intermedia (TI). Pulmonary hypertension (PH) is one of the cardiopulmonary morbidities with high mortality that, if not treated, may trigger right-sided heart failure and premature death. PH is defined as a mean pulmonary artery pressure of ≥25 mmHg at rest or ≥30 mmHg during exercise. The prevalence of PH is known to be higher in TI than in TM. Moreover, the pathophysiology of PH in thalassemia appears to be sophisticated and complex. Risk factors for occurrence of PH consists of non-transfusion dependent thalassemia (NTDT), sub-optimally transfused transfusion dependent thalassemia (TDT), splenectomy, thrombocytosis, anemia, NRBC ≥ 300 × 106, iron accumulation, history of thrombosis and older age. Other parameters which aggravate the risk of PH include hemolysis, oxidative stress, hypoxemia, alteration of erythrocyte membrane, decline of nitric oxide biological availability, arginine abnormal regulation and arginase excess. The screening method for PH is Doppler echocardiography but the gold standard for detection of PH is right heart catheterization (RHC). Current medical therapeutic options in PH comprise hydroxyurea, L- Carnitine, sildenafil, calcium channel antagonists, endothelin 1-receptor blockers and prostacyclin agonists. The only curative surgical method for the refractory and severe cases of PH is pulmonary endarterectomy. In this article, the etiology, pathophysiology, diagnostic methods and novel therapies of thalassemia associated PH are discussed.

Erythrocyte membrane fluidity as a marker of diabetic retinopathy in type 1 diabetes mellitus.

A high level of glycosylated haemoglobin (HbA1c), which is a nonenzymatic glycosylation product, is correlated with an increased risk of developing microangiopathic complications in Diabetes Mellitus (DM). Erythrocyte membrane fluidity could provide a complementary index to monitor the development of complications since it is influenced by several hyperglycaemia-induced pathways and other independent risk factors. 15 healthy controls and 33 patients with long-duration (≥20years) type 1 Diabetes Mellitus (T1DM) were recruited. Diabetic subjects were classified into two groups: T1DM, constituted by 14 nonretinopathic patients, and T1DM+RD, constituted by 19 patients in any stage of diabetic retinopathy. Red blood cells (RBC) were incubated with the fluorescent Laurdan probe and median values of Generalized Polarization (GP), representative of membrane fluidity, were compared between the two groups. Baseline characteristics among groups have been compared with Student's t test or ANOVA. Values of P<.05 were considered statistically significant. All the participants were comparable for age, Body Mass Index (BMI), creatinine and lipid profile. The duration of diabetes was similar for T1DM (34.4±7.8years) and T1DM+RD (32.8±7.5years) subjects as well as values of HbA1c: (55.6±8.1) mmol/mol for T1DM and (61.2±11.0) mmol/mol for T1DM+RD, respectively. Erythrocyte plasmatic membranes of RD patients were found to be more fluid (GP: 0.40±0.04) than non-RD patients (GP: 0.43±0.03) with a statistically significant difference (P=.035). Altered erythrocyte membrane fluidity may therefore represent a marker of retinopathy in T1DM patients as a result of post-translational modifications of multifactorial aetiology (nonenzymatic glycosylation of proteins, generation of reactive oxygen species, lipid peroxidation).

Induced alteration of rat erythrocyte membrane with effect of pyrethroid based compounds.

The effects of tetramethrin and prallethrin exposure on plasma total proteins, free amino acids, albumins, urea, urea nitrogen, uric acid, creatinine were tested. Serum SGOT, SGPT and lipid profile, antioxidants super oxide dismutase (SOD), catalase, GSH, G-Px, phospholipids, cholesterol, C/P ratio in membranes of erythrocyte and membrane fluidity were analyzed. The reason of the study were analyzed to examine the possessions of mosquito repellent pyrethroid (MRP) based compounds tetramethrin and prallethrin exposure on plasma profile, antioxidant status of erythrocyte membrane, membrane fluidity in male Wistar rats. We tested chronically for three months exposure every day (continuously for 8–10 h per day by inhalation) of tetramethrin and prallethrin markedly available (MRP) repellents treated on male Wistar rats. Our results confirmed that tetrarmethrin and prallethrin treatment effect of plasma profile alterations, and lipid homeostasis mechanism in Red Blood cells (RBCs). Tetramethrin and prallethrin treatment significantly increased in erythrocyte membrane phospholipids and decreased levels of cholesterol with no change of protein content, increased C/P ration levels. Inhalation of tetramethrin and prallethrin stimulate plasma biophysical and biochemical modify SGOT, SGPT, erythrocyte membrane cholesterol and phospholipid levels, individual phospholipids and membrane fluidity of exposure rats compared to controls.

Decreased erythrocyte binding of Siglec-9 increases neutrophil activation in sickle cell disease

Oxidative stress and inflammation promote vaso-occlusion in sickle cell disease (SCD). CD33-related Sialic acid-binding immunoglobulin-type lectins (CD33rSiglecs) are cell surface proteins that recognize sialic acids inhibit innate immune cell functions. We have shown that Siglec-9 on human neutrophils interact with erythrocyte sialic acids (prominently glycophorin-A (GYPA) to suppress neutrophil reactive oxygen species (ROS). We hypothesized that altered sickle erythrocyte membrane sialic acid leads to decreased Siglec-9 binding capability, and thus a decreased neutrophil oxidative burst. SS erythrocytes express significantly more sialic acid than AA erythrocytes (p = 0.02). SS erythrocytes displayed significantly less Siglec-9-Fc binding 39% ± 11 (mean ± SEM) compared to AA erythrocytes 78% ± 5 (p = 0.009). Treatment of AA erythrocytes with sialidase to remove sialic acid decreased binding to 3% ± 7.9 (p ≤ 0.001). When freshly isolated neutrophils were incubated with AA erythrocytes, neutrophils achieved 16% ± 6 of the oxidative burst exhibited by a stimulated neutrophil without erythrocytes. In contrast, neutrophils incubated with SS erythrocytes achieved 47% ± 6 of the oxidative burst (AA versus SS, p = 0.03). Stimulated neutrophils incubated with AA erythrocytes showed minimal NET formation while with SS erythrocytes NETs increased. SS erythrocytes are deficient in binding to neutrophil Siglec-9 which may contribute to the increased oxidative stress in SCD.

Alterations of the erythrocyte membrane by in vitro action of Trichinella spiralis muscle larvae.

The complex life cycle of Trichinella spiralis includes the migration of newborn larvae through the bloodstream to their encystment in muscle. The parasite establishes an intimate contact with the erythrocytes of the host both during the migration of the newborn larvae and when encysting, as this parasite causes intense vascularization in the muscle cell. The goal of this work was to study the effects of various concentrations of T. spiralis muscle larvae (ML) on erythrocyte membranes. The treatment was performed by incubating human erythrocytes with equal volume of different concentrations of ML for 30 minutes, with controlled agitation (37°C). The control erythrocytes (with no contact with the larvae) were incubated in the same way with an equal volume of physiological solution. To evaluate the alterations to the erythrocytes by the action of the larvae and in the respective controls, an Erythrocyte Rheometer and a Digital Image Analysis technique were used. The results indicated that when the larval concentration was higher, the aggregation and erythrocyte membrane alterations were also higher. Also, the erythrocyte deformability index and the erythrocyte elasticity increased. The values of isolated cell coefficient varied from 0.51 in the treatment with 100 larvae/ml to 0.91 in the incubation with 1000 larvae/ml. This experiment shows that T. spiralis muscle larvae affect significantly the red blood cell aggregation and the erythrocyte viscoelastic properties.

Decreased Erythrocyte Binding Capability for Neutrophil Siglec-9 Is a Source of Oxidative Stress in Sickle Cell Disease

IntroductionOxidative stress and inflammation promote hemolysis and vaso-occlusion in sickle cell disease (SCD). Erythrocytes can play a pro-oxidative and anti-oxidative role in disease-associated inflammation through iron-driven free radical production and endogenous anti-oxidants. In SCD, HbS accelerated auto-oxidation, iron de-compartmentalization, and inflammatory cell-derived oxidants drive this oxidative stress. CD33-related Sialic acid-binding immunoglobulin-type lectins (CD33rSiglecs) are cell surface proteins that recognize sialic acids in “Self-Associated Molecular Patterns” (SAMPs) and typically inhibit innate immune cell functions via cytosolic signaling. Recent studies have shown that Siglec-9 on human neutrophils in circulating blood interact with erythrocyte sialic acids (prominently glycophorin-A (GYPA) to suppress neutrophil reactivity, including reactive oxygen species (ROS) production. Modification of erythrocyte membrane sialic acids interferes with their ability to inhibit neutrophil activation and oxidative burst. As erythrocytes age and undergo cellular damage there is a loss of membrane bound sialoglycoproteins. Several studies have indicated that this reduction in the sialome is accelerated on the sickle erythrocyte. We hypothesize that altered sickle erythrocyte membrane sialic acid leads to decreased Siglec-9 binding capability, and that decreased binding of neutrophil Siglec-9 to sickle erythrocyte sialic acid enhances neutrophil activation and oxidative burst.Methods & ResultsBinding of recombinant Siglec-9-Fc protein to AA (n=9) and SS erythrocytes (n=7) was measured using flow cytometry. SS erythrocytes displayed significantly less Siglec-9-Fc binding 45% ± 11.9 (mean ± SEM) compared to AA erythrocytes 82% ± 5.4 (p=.03). Treatment of AA erythrocytes with neuraminidase to remove sialic acid decreased binding to 4% ± 7.9.Neutrophil ROS production was measured by flow cytometry using dihydrorhodamine 123 (DHR123). Neutrophils were purified from AA donors (n=5) and SS (n=11) or AA erythrocytes (n=5) were added to the neutrophils at a ratio of 50 erythrocytes to 1 neutrophil. Oxidative burst was stimulated using phorbol 12-myristate 13-acetate (PMA). AA erythrocytes decreased PMA-stimulated neutrophil ROS production by 84% ± 6.7. In contrast, SS erythrocytes decreased PMA-stimulated neutrophil ROS production by 53% ± 6.8 (p=0.03,).Recent studies have shown that neutrophil extracellular trap (NET) formation is pathogenic in SCD. We added AA and SS erythrocytes (50:1) to neutrophils stimulated with PMA and NET formation was assessed using Syto Orange, Syto Green and confocal microscopy. PMA-stimulated neutrophils incubated with AA erythrocytes showed minimal NET formation. In contrast, AA erythrocytes treated with neuraminidase to remove sialic acid had increased NET formation. PMA-stimulated neutrophils incubated with SS erythrocytes showed increased NET formation.ConclusionsA constant disease state of oxidative stress and inflammation underlies SCD pathophysiology. These data demonstrate that SS erythrocytes with decreased membrane sialic acid are deficient in binding to neutrophil Siglec-9. The decreased binding of SS erythrocytes to neutrophil Siglec-9 diminishes the ability of SS erythrocytes to properly modulate neutrophil activation, which may contribute to the oxidative stress and increased state of basal inflammation inherent to SCD. The overall reduction in number of RBCs in SS may also be a factor? [Display omitted] DisclosuresBelcher:CSL Behring: Research Funding. Vercellotti:CSL Behring: Research Funding.

Haemato-protective influence of dietary fenugreek (Trigonella foenum-graecum L.) seeds is potentiated by onion (Allium cepa L.) in streptozotocin-induced diabetic rats

We have recently reported the beneficial modulation of metabolic abnormalities and oxidative stress in diabetic rats by dietary fenugreek seeds and onion. This investigation evaluated the protective influence of dietary fenugreek seeds (100 g kg−1) and onion (30 g kg−1) on erythrocytes of streptozotocin-induced diabetic rats, through modulation of reduced haematological indices and antisickling potency. This study also evaluated the altered erythrocyte membrane lipid profile and beneficial countering of increased lipid peroxidation, osmotic fragility, along with reduced membrane fluidity and deformability, nitric oxide production and echinocyte formation. Dietary fenugreek seeds and onion appeared to counter the deformity and fragility of erythrocytes partially in diabetic rats by their antioxidant potential and hypocholesterolemic property. The antisickling potency of these spices was accomplished by a substantial decrease in echinocyte population and AGEs in diabetic rats. Further insight into the factors that might have reduced the fluidity of erythrocytes in diabetic rats revealed changes in the cholesterol: phospholipid ratio, fatty acid profile, and activities of membrane-bound enzymes. Dietary fenugreek seeds and onion offered a beneficial protective effect to the red blood cells, the effect being higher with fenugreek + onion. This is the first report on the hemato-protective influence of a nutraceutical food component in diabetic situation.

Cigarette smokers develop altered erythrocyte membrane composition: an investigation unmasking the role of membrane bound integral protein GLUT 1

Erythrocytes in cigarette smokers are prone to oxidative damage. Here, we sought to elucidate the facts behind modifications and possible defense system developed in erythrocyte of cigarette smokers. We observed significant increase in stomatocytes and spherocytes, and osmotic fragility of erythrocyte, along with reduced level of protein thiol and increased fluorescence anisotropy in isolated membrane. Denaturing gel electrophoresis indicated alterations in band 3, band 4.2 and band 4.5. Among those, Glut 1 (i.e. band 4.5), which transports glucose (insulin independent) and dehydroascorbate (DHA), was selectively chosen for its long history in reducing reactive oxygen species (ROS). The increased Glut 1 level in smokers was confirmed by immunoblotting and immunocytochemistry. Furthermore, smokers showed significantly higher glucose uptake in whole blood. The intracellular (Ic) ROS (as indicated by 2′,7′-dichlorofluorescin) was significantly higher in smokers as evidenced by flow cytometric assay. Glucose and DHA alone or together significantly reduced IcROS at higher rate in smokers. However, in presence of Glut 1 specific blocker, phloretin, neither glucose nor DHA could reduce IcROS in both non-smokers and smokers. This confirms that Glut 1 by transporting glucose or DHA attenuates IcROS. Therefore, we conclude that erythrocytes, although altered morphologically, also develop a defense system by upregulating Glut 1 to combat with enhanced Ic oxidative insult in cigarette smokers.

Erythrocyte Membrane Fluidity Alterations in Sudden Sensorineural Hearing Loss Patients: The Role of Oxidative Stress.

Introduction Sudden sensorineural hearing loss (SSNHL) involves an acute unexplained hearing loss, nearly always unilateral, that occurs over less than a 72-hour period. SSNHL pathogenesis is not yet fully understood. Cochlear vascular occlusion has been proposed as a potential mechanism of hearing damage and cochlear ischaemia has been related to alterations of cochlear microvessels. In addition, some researchers have focused their attention on the rheological alterations and blood hyperviscosity. Erythrocyte deformability plays a key role in determining blood viscosity, and it is critical to cochlear perfusion. It has been shown that oxidative stress-induced erythrocyte membrane fluidity alterations are linked to the progression of cardiovascular diseases. Methods To determine whether erythrocytes from SSNHL patients show signs of oxidative stress, and whether this condition can modify the haemorheologic profile in these patients, we analysed haemorheologic profile and erythrocyte oxidative stress in 35 SSNHL patients and 35 healthy subjects, matched for age and sex. Fluorescence anisotropy was used to evaluate the fluidity of erythrocyte membranes. Results Our results show a significant structural and functional involvement of erythrocyte membrane alterations in SSNHL, as well as elevated levels of membrane lipid peroxidation and intracellular reactive oxygen species (ROS) production. In addition, erythrocyte-derived ROS and erythrocyte lipid peroxidation positively correlated with whole blood viscosity and erythrocyte deformability. Moreover, in vitro experiments demonstrated that ROS display a key role in erythrocyte membrane fluidity. Conclusion These findings indicate that erythrocyte oxidative stress plays a key role in the pathogenesis of SSNHL and pave the way to new therapeutic interventions.

Association between alcohol-induced erythrocyte membrane alterations and hemolysis in chronic alcoholics.

The present study aimed to understand the association between erythrocyte membrane alterations and hemolysis in chronic alcoholics. Study was conducted on human male volunteers aged between 35–45 years with a drinking history of 8–10 years. Results showed that plasma marker enzymes AST, ALT, ALP and γGT were increased in alcoholic subjects. Plasma and erythrocyte membrane lipid peroxidation, erythrocyte lysate nitric oxide (NOx) levels were also increased significantly in alcoholics. Furthermore, erythrocyte membrane protein carbonyls, total cholesterol, phospholipid and cholesterol/phospholipid (C/P) ratio were increased in alcoholics. SDS-PAGE analysis of erythrocyte membrane proteins revealed that increased density of band 3, protein 4.2, 4.9, actin and glycophorins, whereas glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and glycophorin A showed slight increase, however, decreased ankyrin with no change in spectrins (α and β) and protein 4.1 densities were observed in alcoholics. Moreover, alcoholics red blood cells showed altered morphology with decreased resistance to osmotic hemolysis. Increased hemolysis showed strong positive association with lipid peroxidation (r = 0.703, p<0.05), protein carbonyls (r = 0.754, p<0.05), lysate NOx (r = 0.654, p<0.05) and weak association with C/P ratio (r = 0.240, p<0.05). Bottom line, increased lipid and protein oxidation, altered membrane C/P ratio and membrane cytoskeletal protein profile might be responsible for the increased hemolysis in alcoholics.

Altered erythrocyte membrane protein composition mirrors pleiotropic effects of hypertension susceptibility genes and disease pathogenesis.

The study was designed to assess the effects of polymorphisms in genes associated with essential hypertension on the variation of erythrocyte membrane proteins (EMPs) in hypertensive patients. Major EMPs content was analyzed in blood from 1162 unrelated Russians (235 hypertensive patients, 176 healthy controls, and 751 random individuals from the Central Russia population). Essential hypertension patients were genotyped for 11 polymorphisms of essential hypertension susceptibility genes including ADD1 (rs4961), GNB3 (rs5443, rs16932941), NOS3 (rs1799983, rs2070744), ACE (rs5186), AGTR1 (rs5186), AGT (rs699, rs4762), MR (rs5534), and TGFB1 (rs1800471). EMP contents and their relationship with the genetic loci were analyzed using various statistical tests. Sex-specific differences in EMP contents between the cases and controls were observed. Regardless of sex, hypertensives exhibited mainly decreased levels of alpha (SPTA1) and beta-spectrin (SPTB) and increased levels of glucose transporter (GLUT1) as compared with healthy subjects (P ≤ 0.001). EMP correlated differently in essential hypertension patients and controls. Almost 70% of the joint variation in the EMP levels is explained by five gender-specific principal components. The essential hypertension susceptibility genes showed considerable effects on the levels of spectrins and glucose transporter. A joint variation of the genes explained about half the total polygenic variance in the GLUT1, SPTA1, and SPTB levels in hypertensives. The study showed that essential hypertension susceptibility genes are the important factors of the inherited EMP variation, and their pleitropic effects may be mirrored in the altered expression of genes encoding cytoskeletal proteins and those related to intracellular glucose metabolism.

Flavonoids in Microheterogeneous Media, Relationship between Their Relative Location and Their Reactivity towards Singlet Oxygen.

In this work, the relationship between the molecular structure of three flavonoids (kaempferol, quercetin and morin), their relative location in microheterogeneous media (liposomes and erythrocyte membranes) and their reactivity against singlet oxygen was studied. The changes observed in membrane fluidity induced by the presence of these flavonoids and the influence of their lipophilicity/hydrophilicity on the antioxidant activity in lipid membranes were evaluated by means of fluorescent probes such as Laurdan and diphenylhexatriene (DPH). The small differences observed for the value of generalized polarization of Laurdan (GP) curves in function of the concentration of flavonoids, indicate that these three compounds promote similar alterations in liposomes and erythrocyte membranes. In addition, these compounds do not produce changes in fluorescence anisotropy of DPH, discarding their location in deeper regions of the lipid bilayer. The determined chemical reactivity sequence is similar in all the studied media (kaempferol < quercetin < morin). Morin is approximately 10 times more reactive than quercetin and 20 to 30 times greater than kaempferol, depending on the medium.

Erythrocyte phospholipid molecular species and fatty acids of Down syndrome children compared with non-affected siblings

The majority of children with Down syndrome (DS) develop Alzheimer's disease (AD) at an early age. Although long-chain n-3 fatty acids (FA) are protective of neurodegeneration, little is known about the FA status in DS. In the present study, we aimed to investigate whether children with DS presented altered plasma and erythrocyte membrane phospholipids (PL) FA composition, when compared with their non-affected siblings. Venous blood samples were analysed for plasma and erythrocyte membrane FA composition by TLC followed by GC techniques. Lipid molecular species were determined by electrospray ionisation/tandem MS (ESI-MS/MS). FA analysis measured by standard GC showed an increased concentration of MUFA and a decreased concentration of plasmalogens in major PL fractions, but there were no differences in the concentrations of arachidonic acid or DHA. However, as identified by ESI-MS/MS, children with DS had increased levels of the following erythrocyte PL molecular species: 16 : 0-16 : 0, 16 : 0-18 : 1 and 16 : 0-18 : 2n-6, with reduced levels of 16 : 0-20 : 4n-6 species. Children with DS presented significantly higher levels of MUFA in both plasma and erythrocyte membrane, as well as higher levels of saturated and monounsaturated molecular species. Of interest was the almost double proportion of 16 : 0-18 : 2n-6 and nearly half the proportion of 16 : 0-20 : 4n-6 of choline phosphoacylglycerol species in children with DS compared with their non-affected siblings. These significant differences were only revealed by ESI-MS/MS and were not observed in the GC analysis. Further investigations are needed to explore molecular mechanisms and to test the association between the pathophysiology of DS and the risk of AD.

Altered erythrocyte membrane fatty acid profile in typical Rett syndrome: Effects of omega-3 polyunsaturated fatty acid supplementation

This study mainly aims at examining the erythrocyte membrane fatty acid (FAs) profile in Rett syndrome (RTT), a genetically determined neurodevelopmental disease. Early reports suggest a beneficial effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) on disease severity in RTT. A total of 24 RTT patients were assigned to ω-3 PUFAs-containing fish oil for 12 months in a randomized controlled study (average DHA and EPA doses of 72.9, and 117.1mg/kgb.w./day, respectively). A distinctly altered FAs profile was detectable in RTT, with deficient ω-6 PUFAs, increased saturated FAs and reduced trans 20:4 FAs. FAs changes were found to be related to redox imbalance, subclinical inflammation, and decreased bone density. Supplementation with ω-3 PUFAs led to improved ω-6/ω-3 ratio and serum plasma lipid profile, decreased PUFAs peroxidation end-products, normalization of biochemical markers of inflammation, and reduction of bone hypodensity as compared to the untreated RTT group. Our data indicate that a significant FAs abnormality is detectable in the RTT erythrocyte membranes and is partially rescued by ω-3 PUFAs.