Lipid Exchange Research Articles

Osh Proteins Control Nanoscale Lipid Organization Necessary for PI(4,5)P <sub>2</sub> Synthesis

The plasma membrane (PM) is composed of a complex lipid mixture that forms heterogeneous membrane environments. Yet how small-scale lipid organization controls physiological events at the PM remains largely unknown. Here, we show that ORP/Osh lipid exchange proteins are critical for the synthesis of phosphatidylinositol (4,5)-bisphosphate, PI(4,5)P2, a key regulator of dynamic events at the PM. In real-time assays, we find that unsaturated phosphatidylserine (PS) and sterols, both ORP/Osh protein ligands, synergistically stimulate phosphatidylinositol 4-phosphate 5-kinase (PIP5K) activity. Our biophysical and simulation analyses further reveal an unconventional co-segregation of unsaturated PS and phosphatidylinositol 4-phosphate (PI4P) species in sterol-containing membrane bilayers. Moreover, we show that Osh protein-mediated unsaturated PI4P/PS membrane lipid organization is sensed by the PIP5K specificity loop. Thus, ORP/Osh family members create an unsaturated phospholipid nanoscale environment that drives PIP5K activity and PI(4,5)P2 synthesis that ultimately controls global PM organization and dynamics.

The state of lipid exchange and thrombotic link of hemostasis in patients with chronic non-specific inflammatory diseases of genitals

It has been stated that changes of lipid exchange and increasing of lipid peroxidation are accompanied by the inflammatory process, which show the increase of proatherogenic blood characteristics. In patients with chronic non-specific inflammatory diseases of genitals disorders of phagocytosis mechanisms, increasing of autointoxication and reaction of hypersensitivity of immediate type are revealed after full blood count index. On the basis of analyses results one can conclude that the increase of atherogenic properties of blood plasma in patients with chronic non-specific inflammatory diseases of genitals took place in accordance with vascular endothelium damage. The article is the first to show the effectiveness of complex treatment of different atherosclerotic pathogenesis links by means of correction of proatherogenic lipid fractions and antioxidative complexes.

Diagnostic value and cross-correlation interdependence of indexes of endocrine and lipid exchange at a metabolic syndrome complicated by chronic coronary artery disease and diabetes mellitus type 2

The aim of the research is to set hormonal and lipid indexes as diagnostic markers of metabolic syndrome in intercommunication with its complications, such as coronary artery disease and diabetes mellitus type 2 as the compensated and decompensated stages.Material and methods. Interdependence of endocrine and lipid exchange indexes for patients with a metabolic syndrome assotiated with chronic coronary artery disease and diabetes mellitus type 2 as the compensated and decompensated stage was studied in research. 163 patients with a metabolic syndrome were inspected. Depending on a presence or absence of the assoсiated pathology, three groups formed. The first group was represented by patients with a metabolic syndrome in combination with chronic coronary artery disease, second group — by patients with chronic coronary artery disease and compensated diabetes mellitus type 2, that arose up on a background of a metabolic syndrome. Third group was represented by patients with chronic coronary artery disease and decompensated diabetes mellitus type 2 on a background of a metabolic syndrome. The levels of cortisol, thyroid-stimulating hormone, free thyroxine, prolactin and lipid spectrum indexes were determined. Result. According to results of research, first and second groups were characterized by normal cortisol and prolactin levels and statistically significantly increased thyroid-stimulating hormone level. Statistically significantly increased cortisol and prolactin (in women) levels and the normal thyroid-stimulating hormone level were diagnosed in patients of the third group in comparison with the control and second groups. An amount of free thyroxine in patients of all groups was at the level of control values. Patients with chronic coronary artery disease and decompensated diabetes mellitus type 2 on a background of a metabolic syndrome differed from previous groups by the changes of lipid spectrum: the statistically increase of total cholesterol, triglycerides, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol levels at the reliable decrease of high-density lipoprotein cholesterol level. The cross-correlation analysis confirmed differences between the groups of the compensated and decompensated diabetes mellitus type 2 in association with coronary artery disease on a background of a metabolic syndrome. Correlation connection between the parameters of lipid spectrum, cortisol, prolactin and by a thyroid-stimulating hormone was observed at the patients of the second group. The patients of the third group didn’t have intercommunication between these indicated indexes, correlation was educed only between a cortisol and prolactin (for women). Conclusion. Levels of prolactin, cortisol and thyroid-stimulating hormone at a metabolic syndrome change, depending on the presence of the associated diseases. The normal cortisol and prolactin levels and increase level of thyroid-stimulating hormone was educed in patients with metabolic syndrome with chronic coronary artery disease and also at a metabolic syndrome with chronic coronary artery disease and compensated diabetes mellitus type 2. Increase of cortisol and of prolactin (for women) levels at the normal level of thyroid-stimulating hormone was observed at a metabolic syndrome complicated by chronic coronary artery disease and decompensated diabetes mellitus type 2. Correlation between indexes of lipid exchange and hormonal status was educed at МС complicated by chronic coronary artery disease and compensated stage of diabetes mellitus type 2. This correlation does not appear at a metabolic syndrome with chronic coronary artery disease and decompensated diabetes mellitus type 2. Thus, the changes of the higher indicated hormones play role of diagnostic markers of decompensation of the investigated pathological processes and accompanied by the corresponding changes of lipid spectrum.

Nutrigenetic characteristics of patients with nonalcoholic liver disease combined with metabolic syndrome

Objective — to detect possible association of polymorphisms of the Pro12Ala of PPARG2 gene (rs1801282) and ADRB3 gene (rs4994) with a degree of fatty liver and metabolic disorders in patients with NAFLD.Materials and methods. The study involved 78 patients (43 men and 35 women with a mean age 42.0 ± 5.2 years with NAFLD and 30 subjects of control group without signs of damaged liver (13 men and 27 women, the mean age 38.0 ± 7.1 years. The determination of polymorphisms in the PPARG2 and ADRB3 genes was carried out by a real-time polymerase chain reaction (PCR) method.Results. the results of the study demonstrated the predominance of CC homozygotes of the Pro12Ala polymorphism of the PPARG2 gene and the heterozygote on the polymorphism of Trp64Arg of the ADRB3 gene compared to the control group. The significant association between the activity of visceral adipose tissue in patients with homo- and heterozygous genotypes in the minor 64Arg allele of the ADRB3 gene was determined. However in the carriers of Pro12Ala genotype of PPARG2 gene (heterozygote), the significantly higher insulin levels were reveled in comparison with the patients with homozygote 12 Pro allele. No association between Pro12Ala polymorphism of PPARG2 gene and indices of lipid exchange was reveled. The significantly higher levels of the low density lipoproteins in comparison with Trp64Trp carriers was established during the investigation of their association with polymorphism Trp64Arg of ADRB3 gene. The maximal degree of fatty infiltration of liver tissue was revealed in the carriers of the Pro12Ala heterozygous genotype PPARG2 gene and the genotype Trp64Trp of the ADRB3 gene.Conclusions. In patients with NAFLD and concomitant MS, there was a predominance of carriers of the homozygous CC polymorphism of the Pro12Ala PPARG2 gene and heterozygotes for the Trp64Arg polymorphism of the ADRB3 gene compared with the control group. An association of visceral adipose tissue activity was found in patients with homozygous and heterozygous genotypes in the minor 64Arg ADRB3 gene. Among patients with NAFLD with the Pro12Ala genotype of the PPARG2 gene and the Trp64Trp genotype of the ADRB3 gene, steatosis of 3 degrees was predominant.

Lipid exchange between lipoproteins of low and high density taking into account the oxidation of low-density lipoproteins

У роботі запропонована модифікована модель перенесення ліпідів між ліпопротеїнами низької і високої щільності (ЛПНЩ і ЛПВЩ). Модифікація стосується введення в модель обміну ліпідами в стінці судини ЛПНЩ, модифікуються під дією потоку радикалів, з ЛПВЩ. Вивчено вплив потоку радикалів, ліпідного стану організму і концентрації СЕТР на обмін ліпідами. Аналіз модельних розрахунків показує, що в умовах дії потоків радикалів зі швидкістю перенесення ефірів холестерину (СЕ) і тригліцеридів (Tg) між ЛПНЩ і ЛПВЩ змінює свій характер: СЕ переносяться до ЛПВЩ, а Tg - до ЛПНЩ. Така зміна характеру перенесення може вплинути на зворотний транспорт холестерину (ЗТХ).

Biophysical Parameters of the Sec14 Phospholipid Exchange Cycle

Sec14, the major yeast phosphatidylcholine (PC)/phosphatidylinositol (PI) transfer protein (PITP), coordinates PC and PI metabolism to facilitate an appropriate and essential lipid signaling environment for membrane trafficking from trans-Golgi membranes. The Sec14 PI/PC exchange cycle is essential for its essential biological activity, but fundamental aspects of how this PITP executes its lipid transfer cycle remain unknown. To address some of these outstanding issues, we applied time-resolved small-angle neutron scattering for the determination of protein-mediated intervesicular movement of deuterated and hydrogenated phospholipids in vitro. Quantitative analysis by small-angle neutron scattering revealed that Sec14 PI- and PC-exchange activities were sensitive to both the lipid composition and curvature of membranes. Moreover, we report that these two parameters regulate lipid exchange activity via distinct mechanisms. Increased membrane curvature promoted both membrane binding and lipid exchange properties of Sec14, indicating that this PITP preferentially acts on the membrane site with a convexly curved face. This biophysical property likely constitutes part of a mechanism by which spatial specificity of Sec14 function is determined in cells. Finally, wild-type Sec14, but not a mixture of Sec14 proteins specifically deficient in either PC- or PI-binding activity, was able to effect a net transfer of PI or PC down opposing concentration gradients in vitro.

Inhibition of Cannabinoid Receptor 1 Can Influence the Lipid Metabolism in Mice with Diet-Induced Obesity.

A growing number of evidences accumulated about critical metabolic role of cannabinoid type 1 receptor (CB1), carnitine palmitoyltransferase-1 (CPT1) and peroxisome proliferator-activated receptors (PPARs) in some peripheral tissues, including adipose tissue, liver, skeletal muscle and heart. To better understand the interactions of CB1, CPT1 and PPARs in these tissues, 30 diet-induced obese (DIO) C57BL/6J male mice were obtained, weight-matched and divided into two groups (15 in each group): (i) DIO/vehicle mice (D-Veh) and (ii) DIO/SR141716 mice (D-SR) treated with SR141716 (or rimonabant, a selective CB1 receptor blocker) administered orally (10mg/kg daily). Another 15 mice fed standard diet (STD) formed the STD/vehicle group (S-Veh). At the end of 3-week treatment, mean body weight was 28.4 ± 0.5,36.5 ± 0.8, and30.3 ± 1.2g for the S-Veh, D-Veh, and D-SR group, respectively (p < 0.05; D-Veh vs. D-SR). Liver weight in the D-SR group was also decreased significantly compared to the D-Veh group (p < 0.05). Serum levels of total cholesterol, high-density lipoprotein cholesterol, leptin and adiponectin in the D-SR group were ameliorated compared to the D-Veh group (p < 0.05). Both qRT-PCR and Western blot assay revealed that CB1 expression levels were efficiently blocked by SR141716 in subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), skeletal muscles and liver (D-SR vs. D-Veh; p < 0.05), whereas there was no significant difference between S-Veh and D-Veh mice (p > 0.05). Simultaneously with the reduction of CB1 expression in the D-SR group, the expression levels of CPT1A isoform (protein) in the liver and heart and CPT1B isoform (protein) in the SAT, VAT, liver and skeletal muscles were significantly increased (p < 0.05; D-SR vs. D-Veh). Interestingly, the CPT1A and CPT1B expression levels in heart were detected slightly. The expression levels of PPARα in the SAT, VAT, liver and skeletal muscles and PPARγ in the SAT and skeletal muscles in the D-SR group were significantly increased compared to the D-Veh mice (p < 0.05). However, the PPARβ expression level differed from that of PPARα and PPARγ. Taken together, these data indicate that the inhibition of CB1 could ameliorate lipid metabolism via the stimulation of the CPT1A and CPT1B expression in vivo. Simultaneously, the PPARα and PPARγ expression levels significantly differed compared to that of PPARβ in obesity and lipid metabolism-related disorders under blockade of CB1. Both the mechanism of the influence of CB1 inhibition on lipid metabolism in the examined tissues and the specific mechanism of PPARα, PPARγ and PPARβ involvement in lipid exchange under these conditions remain to be further elucidated.

Collisional lipid exchange among DIBMA-encapsulated nanodiscs (DIBMALPs)

Copolymers of diisobutylene/maleic acid (DIBMA), styrene/maleic acid (SMA), and styrene/maleimide (SMI) solubilise membrane proteins and surrounding lipids directly from artificial and biological membranes to form polymer-bounded nanodiscs. Although they preserve a lipid-bilayer core, these nanodiscs are much more dynamic than other membrane mimics, as we have recently demonstrated for two SMA variants. Here, we used time-resolved Förster resonance energy transfer spectroscopy to quantify the kinetics and unravel the mechanisms of lipid transfer among DIBMA-encapsulated nanodiscs (DIBMALPs), with particular emphasis on the role of Coulombic repulsion, which is modulated by ionic strength and nanodisc size. Our results show that DIBMALPs exchange lipids through both binary and ternary collisions on the timescale of seconds to minutes under typical experimental conditions. By contrast, nanodiscs bounded by SMA polymers exchange lipids considerably faster through binary collisions, whereas vesicles and nanodiscs based on membrane scaffold proteins exchange lipids much more slowly through lipid monomer diffusion. As DIBMALPs are polyanionic, collisional lipid transfer is substantially accelerated by screening of Coulombic repulsion caused by increasing ionic strength or nanodisc size. Analysis of the ionic-strength dependence in terms of an extended version of the Debye–Hückel equation suggests an effective DIBMALP charge number of z = −47, which is considerably larger than that previously determined for nanodiscs bounded by more hydrophobic SMA polymers.

Development of biotechnology of fermented milk product with Lactobacillus reuteri LR1 and the evaluation of its functional property in experiment in vitro and in vivo

In this article the biotechnology of the dairy product based on the probiotic strain of Lactobacillus reuteri LR1 is presented. The following conditions of milk fermentation were screened: fermentation by monoculture of Lactobacillus reuteri LR1, fermentation by monoculture of Lactobacillus reuteri LR1 with addition of yeast extract as growth-promoting factor, and combined fermentation by Lactobacillus reuteri LR1, Lactobacillus helveticus NK1 and Streptococcus thermophilus (HTC). It had been demonstrated that after 8 hours of cultivation the number of Lactobacillus reuteri LR1 cells in the monoculture with introduced yeast extract was up to 5,9×108 CFU/cm3 whereas cell count for the monoculture without yeast extract introduction was 1,6×107 CFU/cm3. The optimized biotechnological parameters of the dairy product fermentation, which provided the required Lactobacillus reuteri LR1 cell count, were as follows: Lactobacillus reuteri LR1 starter dosage of 6%, HTC starter dosage of 3-4%, fermentation temperature of 37±1 °C, and fermentation duration of 6 hours. The developed product possessed an apparent antagonistic activity against test-cultures of such pathogenic and opportunistic microorganisms as E. coli ATCC 25922, Salmonella typhimurium, Staphylococcus aureus ATCC 6538 and Klebsiella pneumoniae. The survival of the test-cultures cultivated with the obtained dairy product on the first cultivation day was from 36 to 46% and on the second - from 8 to 20%, in comparison with the pure test-cultures. The investigation of the functional properties of the obtained dairy product was carried out by the single-factor experiment with the albino Wistar rat-stock (initial body weight 160±10 g, n=10 in each group). Its positive effect on the rats' microbiome composition and lipid exchange indices has been demonstrated. It had been shown that the administration of the obtained dairy product in the rats' diet (5 ml per day per os) during 30 days didn't cause any abnormalities in the health status and behavior of the laboratory animals of spf-category. The number and distribution of leucocytes and lymphocytes, and granulocytes in all rats' populations (intact, control and treatment) were within the normal range. Upon the introduction of the developed dairy product into the rats' diet, the increased levels of bifidobacteria, lactic acid bacteria and typical for normal rats' microflora enterobacteria were observed in the rats' microbiome. As for the biochemical indices that characterize rats' lipid metabolism, the rats consuming fermented dairy products (control and treatment) demonstrated statistically significant reduction of blood serum cholesterol level compared to the intact rat group; additionally the rats consuming the developed in this study dairy product (treatment) demonstrated statistically significant reduction of blood serum triglyceride level compared to the intact rats. Utilized in this study Lactobacillus reuteri LR1 is the first strain that was purified in Russia and characterized as useful for manufacturing of the probiotic food products, since currently only Lactobacillus reuteri strains of foreign origin can be seen on the market.

Rational Design Principles for the Transport and Subcellular Distribution of Nanomaterials into Plant Protoplasts.

The ability to control the subcellular localization of nanoparticles within living plants offers unique advantages for targeted biomolecule delivery and enables important applications in plant bioengineering. However, the mechanism of nanoparticle transport past plant biological membranes is poorly understood. Here, a mechanistic study of nanoparticle cellular uptake into plant protoplasts is presented. An experimentally validated mathematical model of lipid exchange envelope penetration mechanism for protoplasts, which predicts that the subcellular distribution of nanoparticles in plant cells is dictated by the particle size and the magnitude of the zeta potential, is advanced. The mechanism is completely generic, describing nanoparticles ranging from quantum dots, gold and silica nanoparticles, nanoceria, and single-walled carbon nanotubes (SWNTs). In addition, the use of imaging flow cytometry to investigate the influence of protoplasts' morphological characteristics on nanoparticle uptake efficiency is demonstrated. Using DNA-wrapped SWNTs as model nanoparticles, it is found that glycerolipids, the predominant lipids in chloroplast membranes, exhibit stronger lipid-nanoparticle interaction than phospholipids, the major constituent in protoplast membrane. This work can guide the rational design of nanoparticles for targeted delivery into specific compartments within plant cells without the use of chemical or mechanical aid, potentially enabling various plant engineering applications.

Preparation of asymmetric phospholipid vesicles for use as cell membrane models.

Freely suspended liposomes are widely used as model membranes for studying lipid-lipid and protein-lipid interactions. Liposomes prepared by conventional methods have chemically identical bilayer leaflets. By contrast, living cells actively maintain different lipid compositions in the two leaflets of the plasma membrane, resulting in asymmetric membrane properties that are critical for normal cell function. Here, we present a protocol for the preparation of unilamellar asymmetric phospholipid vesicles that better mimic biological membranes. Asymmetry is generated by methyl-β-cyclodextrin-catalyzed exchange of the outer leaflet lipids between vesicle pools of differing lipid composition. Lipid destined for the outer leaflet of the asymmetric vesicles is provided by heavy-donor multilamellar vesicles containing a dense sucrose core. Donor lipid is exchanged into extruded unilamellar acceptor vesicles that lack the sucrose core, facilitating the post-exchange separation of the donor and acceptor pools by centrifugation because of differences in vesicle size and density. We present two complementary assays allowing quantification of each leaflet's lipid composition: the overall lipid composition is determined by gas chromatography-mass spectrometry, whereas the lipid distribution between the two leaflets is determined by NMR, using the lanthanide shift reagent Pr3+. The preparation protocol and the chromatographic assay can be applied to any type of phospholipid bilayer, whereas the NMR assay is specific to lipids with choline-containing headgroups, such as phosphatidylcholine and sphingomyelin. In ~12 h, the protocol can produce a large yield of asymmetric vesicles (up to 20 mg) suitable for a wide range of biophysical studies.

VPS13A and VPS13C are lipid transport proteins differentially localized at ER contact sites.

Mutations in the human VPS13 genes are responsible for neurodevelopmental and neurodegenerative disorders including chorea acanthocytosis (VPS13A) and Parkinson's disease (VPS13C). The mechanisms of these diseases are unknown. Genetic studies in yeast hinted that Vps13 may have a role in lipid exchange between organelles. In this study, we show that the N-terminal portion of VPS13 is tubular, with a hydrophobic cavity that can solubilize and transport glycerolipids between membranes. We also show that human VPS13A and VPS13C bind to the ER, tethering it to mitochondria (VPS13A), to late endosome/lysosomes (VPS13C), and to lipid droplets (both VPS13A and VPS13C). These findings identify VPS13 as a lipid transporter between the ER and other organelles, implicating defects in membrane lipid homeostasis in neurological disorders resulting from their mutations. Sequence and secondary structure similarity between the N-terminal portions of Vps13 and other proteins such as the autophagy protein ATG2 suggest lipid transport roles for these proteins as well.

Fabrication of Multicomponent, Spatially Segregated DNA and Protein-Functionalized Supported Membrane Microarray.

Deoxyribonucleic acid (DNA) has been used as a material for a variety of applications, including surface functionalization for cell biological or in vitro reconstitution studies. Use of DNA-based surface functionalization eliminates limitations of multiplexing posed by traditionally used methods in applications requiring spatially segregated surface functionalization. Recently, we have reported a stochastic, membrane fusion-based strategy to fabricate multicomponent membrane array substrates displaying spatially segregated protein ligands using biotin-streptavidin and Ni-NTA-polyhistidine interactions. Here, we report the delivery of DNA oligonucleotide-conjugated lipid molecules to membrane corrals, allowing spatially segregated membrane corral functionalization in a membrane microarray. Incubation of microbeads coated with the supported membrane resulted in an exchange of lipid contents with planar membrane corrals present on a micropatterned substrate. Increases in the system temperature and membrane corral size resulted in alterations in the rate constant of lipid exchange, which are in agreement with our previously developed analytical model and further confirm that lipid exchange is a diffusion-based process that takes place after the formation of a long "fusion-stalk" between the two membranes. We take advantage of the physical dimensions of the fusion-stalk with a large aspect ratio to deliver DNA oligonucleotide-conjugated lipid molecules to membrane corrals. We believe that the ability to functionalize membrane corrals with DNA oligonucleotides significantly increases the utility of the stochastic fusion-mediated lipid delivery strategy in the functionalization of biomolecules such as DNA or DNA-conjugated protein ligands.

Competitive organelle-specific adaptors recruit Vps13 to membrane contact sites

The regulated expansion of membrane contact sites, which mediate the nonvesicular exchange of lipids between organelles, requires the recruitment of additional contact site proteins. Yeast Vps13 dynamically localizes to membrane contacts that connect the ER, mitochondria, endosomes, and vacuoles and is recruited to the prospore membrane in meiosis, but its targeting mechanism is unclear. In this study, we identify the sorting nexin Ypt35 as a novel adaptor that recruits Vps13 to endosomal and vacuolar membranes. We characterize an interaction motif in the Ypt35 N terminus and identify related motifs in the prospore membrane adaptor Spo71 and the mitochondrial membrane protein Mcp1. We find that Mcp1 is a mitochondrial adaptor for Vps13, and the Vps13-Mcp1 interaction, but not Ypt35, is required when ER-mitochondria contacts are lost. All three adaptors compete for binding to a conserved six-repeat region of Vps13 implicated in human disease. Our results support a competition-based model for regulating Vps13 localization at cellular membranes.

Biosíntesis de novo de glicerofosfolípidos y longevidad

BackgroundThe glycerophospholipids, synthesised from diacylglycerol (DAG), are one of the main lipid components of cell membranes. The lipid profile is an optimised feature associated with animal longevity. In this context, the hypothesis is presented that the DAG biosynthesis rate, and thus, the glycerophospholipids content, is related to animal longevity. Material and methodsA plasma lipidomic analysis was performed based on the mass spectrometry of 11 mammalian species with a maximum longevity ranging from 3.5 to 120 years. Lipid identification was based on exact mass, retention time, and isotopic distribution. ANOVA test was applied to differentiate the lipids between animal species. The relationship between these lipids and longevity was carried out with a Spearman correlation. Data was analysed using SPSS and MetaboAnalyst. ResultsAmong the 1,061 different lipid molecular species found between species, 47 were defined as DAG. Interestingly, 14 of them showed a negative correlation with mammalian maximum longevity. Multivariate statistics revealed that 14 DAGs were enough to define mammalian species and their maximum longevity. ConclusionsData suggest that long-lived mammalian species have a lower rate of glycerophospholipids synthesis through the de novo pathway, possibly associated with a lower rate of membrane lipid exchange, which in turn is related to lower energy expenditure.

THICKNESS OF subcutaneous AND preperitoneal fat: ASSESSMENT AND IMPORTANCE OF THE PARAMETER IN PREGNANT WOMEN WITH COMPONENTS OF METABOLIC SYNDROME

Objective: to assess results of ultrasonography of the thickness of subcutaneous and preperitoneal fat in women with components of metabolic syndrome in the first trimester of pregnancy (n = 143). Material and methods. Anthropometrical parameters, indicators of carbohydrate and lipid exchange have been investigated. The thickness of subcutaneous and preperitoneal fat has been studied. Results. It has been found that increased thickness of subcutaneous and preperitoneal fat is observed in pregnant women with both metabolic syndrome and risk factors for development of metabolic syndrome. Women of reproductive age with obesity make a risk group of development of metabolic disorders in the gestational period. Conclusion. To prevent metabolic disorders and reproductive losses, it is necessary to take measures to reduce overweight in women before pregnancy. Prevalence and importance of obesity and metabolic syndrome in female patients of reproductive age necessitate further comprehensive and thorough investigation of pathogenetic mechanisms of its development aimed at decrease of cardiovascular risks in future.

Lipoprotein Particle Formation by Proapoptotic tBid

The interactions of Bcl-2 family proteins with intracellular lipids are essential for the regulation of apoptosis, a mechanism of programmed cell death that is central to the health and development of multicellular organisms. Bid and its caspase-8 cleavage product, tBid, promote the permeabilization of the mitochondrial outer membrane and sequester antiapoptotic Bcl-2 proteins to counter their cytoprotective activity. Bid and tBid also promote lipid exchange, a characteristic trait of apoptosis. Here, we show that tBid is capable of associating with phospholipids to form soluble, nanometer-sized lipoprotein particles that retain binding affinity for the antiapoptotic protein Bcl-xL. The tBid lipoprotein particles form with a lipid/protein stoichiometry in the range of 20/1 and have a diameter of ∼11.5 nm. Lipoparticle-bound tBid retains an α-helical structure and binds Bcl-xL through its third Bcl-2 homology motif, forming a soluble, lipid-associated heteroprotein complex. The results shed light on the role of lipids in mediating Bcl-2 protein mobility and interactions.

The Inner Nuclear Membrane Is a Metabolically Active Territory that Generates Nuclear Lipid Droplets

SummaryThe inner nuclear membrane (INM) encases the genome and is fused with the outer nuclear membrane (ONM) to form the nuclear envelope. The ONM is contiguous with the endoplasmic reticulum (ER), the main site of phospholipid synthesis. In contrast to the ER and ONM, evidence for a metabolic activity of the INM has been lacking. Here, we show that the INM is an adaptable membrane territory capable of lipid metabolism. S. cerevisiae cells target enzymes to the INM that can promote lipid storage. Lipid storage involves the synthesis of nuclear lipid droplets from the INM and is characterized by lipid exchange through Seipin-dependent membrane bridges. We identify the genetic circuit for nuclear lipid droplet synthesis and a role of these organelles in regulating this circuit by sequestration of a transcription factor. Our findings suggest a link between INM metabolism and genome regulation and have potential relevance for human lipodystrophy.

ИЗМЕНЕНИЕ ПОКАЗАТЕЛЕЙ СВОБОДНО-РАДИКАЛЬНОГО СТАТУСА, АНТИОКСИДАНТНОЙ ЗАЩИТЫ И МОРФОЛОГИЧЕСКИЕ ИЗМЕНЕНИЯ ЭРИТРОЦИТОВ ПЕРИФЕРИЧЕСКОЙ КРОВИ БЕРЕМЕННЫХ ПЕРВОГО ТРИМЕСТРА С ЦИТОМЕГАЛОВИРУСНОЙ ИНФЕКЦИЕЙ

The aim is to study the features of changes of free-radical status, antioxidant protection and morphologic changes of erythrocytes of the peripheral blood of pregnant women of the first trimester with exacerbation of cytomegalovirus infection (CMVI). 35 pregnant women with exacerbation of CMVI in the first trimester of gestation (the main group) and 35 pregnant women without this pathology of the same age and term as the patients of the main group were examined. Erythrocytes of the venous blood stabilized by heparine as well as blood plasma became the material of the study. There has been studied the condition of lipid peroxidation (LP) by the contents of diene conjugates and active products reacting with thiobarbituric acid; the state of nonenzymatic antioxidant protection by the contents of α-tocopherol as well as of the enzyme of erythrocytes (superoxide dismutase); morphologic changes of erythrocytes. It was found out that the exacerbation of CMVI in the first trimester of pregnancy is associated with activation of LP processes which include modification of not only primary, reverse stages of this process – the increase of the concentration of diene conjugates (p&lt;0.001), but they lead to an increased formation of secondary active products reacting with thiobarbituric acid (p&lt;0.001), intensifying the destructive action on the membrane of erythrocytes. Primary and secondary products of LP against the decrease of concentration of erythrocyte superoxide dismutase (p&lt;0.001) and α-tocopherol (p&lt;0.001) are accumulated in increasing concentrations and become potential factors of erythrocytes damage causing their functional and metabolic inferiority. Metabolic disturbances and damages of cellular membranes lead to the increase of population of echinocytes, target-like and degenerative forms of erythrocytes, which can be accompanied by a high probability of intravascular hemolysis and contribute to the development of hemic hypoxia complicating the infectious process and the course of pregnancy. Within the present hyperoxidation and suppression of antioxidant protection that lead to the worsening of the rheology of blood, women with exacerbation of CMVI in the first trimester of pregnancy should be prescribed the medicine stabilizing the lipid exchange.

Role of glycans in cholesteryl ester transfer protein revealed by molecular dynamics simulation.

Current cholesteryl ester transfer protein (CETP) inhibitors are designed based on the unglycosylated crystal structure, and most of them have failed to cure cardiovascular disease (CVD). It is particularly important for us to investigate the glycosylation structure of CETP (CETP-G) and effect of glycans on the structure and function of CETP. Here, we used a total of 3.0-μs molecular dynamics (MD) trajectories of nascent structure of CETP (CETP-N) and CETP-G to study their structural differentiations, to shed new light on the CETP-mediated lipid exchange. In accordance with our simulations and previous mutation studies, relative to CETP-N, CETP-G adopts a more stretched shape with higher hydrophobic and hydrophilic solvent-accessible surface area (SASA) of N-terminal oscillating with larger amplitude, in which Glycan88 provides partial assistance for CEs through the N-terminal. Glycan341 reduces the flexibility of neck flap, with the interference of CEs through the neck region. Besides, Glycan240 reduces the flexibility of Helix-X to interfere the CEs transfer. Glycan396 decreases the flexibility and increases the hydrophobic SASA of C-terminal. Overall, these glycans affect the dynamics and structure of CETP through forming H-bonds with surrounding residues, and the sampled conformations of glycan is also affected by its surrounding residues. Thus, glycans are an integral part of CETP, further studies on the CETP inhibition and treatment of CVD should fully consider the effect of glycans.