The Roma in Macedonia: Ethnic politics and the marginal condition in a Balkan state

Most of Eastern Europe's five‐to‐seven‐million Roma (Gypsies) welcomed the revolutions of 1989 only to realize that the post‐communist era brought mixed blessing to them. Although since then their political and cultural marginalization had diminished, their social and economic circumstances had clearly deteriorated in East Central Europe and the Balkans alike. The only exception to this rule appears to be the newly independent Republic of Macedonia, where the Roma's conditions in many respects are far superior to those of their counterparts elsewhere in the region. There are several reasons for this phenomenon. In the economic realm the Macedonian Roma's situation has also worsened (although still much better than that of the Roma in other Balkan states) but not as a result of ethnic discrimination but owing to the economic hardships accompanying the post‐communist transitions. In the political sphere, the Roma in Macedonia have benefited from a state whose representatives are willing to rise above sympathetic rhetoric and take concrete steps to alleviate their problems as well as from relatively well organized Romani political parties. Most important, however, are the differences between societal attitudes towards the Roma in Macedonia and elsewhere in Eastern Europe. In Macedonia the Roma's relations with the dominant ethnic group (Macedonians) are primarily characterized by ‘peaceful coexistence’ rather than tension and animosity. Moreover, Romani communities in Macedonia are less isolated from non‐Roma both culturally and socio‐economically. This state of affairs is the result of a number of related factors, most important of which are that the Romani community does not represent a threat to Macedonians given their numerical weakness and lack of political clout in contradistinction to the very real threat posed by the ethnic Albanian community in the country. In turn, the Roma's relations to ethnic Albanians and Turks remain relatively agreeable as well.     

Micrometric segregation of fluorescent membrane lipids: relevance for endogenous lipids and biogenesis in erythrocytes

Micrometric membrane lipid segregation is controversial. We addressed this issue in attached erythrocytes and found that fluorescent boron dipyrromethene (BODIPY) analogs of glycosphingolipids (GSLs) [glucosylceramide (BODIPY-GlcCer) and monosialotetrahexosylganglioside (GM1BODIPY)], sphingomyelin (BODIPY-SM), and phosphatidylcholine (BODIPY-PC inserted into the plasma membrane spontaneously gathered into distinct submicrometric domains. GM1BODIPY domains colocalized with endogenous GM1 labeled by cholera toxin. All BODIPY-lipid domains disappeared upon erythrocyte stretching, indicating control by membrane tension. Minor cholesterol depletion suppressed BODIPY-SM and BODIPY-PC but preserved BODIPY-GlcCer domains. Each type of domain exchanged constituents but assumed fixed positions, suggesting self-clustering and anchorage to spectrin. Domains showed differential association with 4.1R versus ankyrin complexes upon antibody patching. BODIPY-lipid domains also responded differentially to uncoupling at 4.1R complexes [protein kinase C (PKC) activation] and ankyrin complexes (in spherocytosis, a membrane fragility disease). These data point to micrometric compartmentation of polar BODIPY-lipids modulated by membrane tension, cholesterol, and differential association to the two nonredundant membrane:spectrin anchorage complexes. Micrometric compartmentation might play a role in erythrocyte membrane deformability and fragility.     

Acyl Transfer from Membrane Lipids to Peptides Is a Generic Process

The generality of acyl transfer from phospholipids to membrane-active peptides has been probed using liquid chromatography–mass spectrometry analysis of peptide–lipid mixtures. The peptides examined include melittin, magainin II, PGLa, LAK1, LAK3 and penetratin. Peptides were added to liposomes with membrane lipid compositions ranging from pure phosphatidylcholine (PC) to mixtures of PC with phosphatidylethanolamine, phosphatidylserine or phosphatidylglycerol. Experiments were typically conducted at pH 7.4 at modest salt concentrations (90 mM NaCl). In favorable cases, lipidated peptides were further characterized by tandem mass spectrometry methods to determine the sites of acylation. Melittin and magainin II were the most reactive peptides, with significant acyl transfer detected under all conditions and membrane compositions. Both peptides were lipidated at the N-terminus by transfer from PC, phosphatidylethanolamine, phosphatidylserine or phosphatidylglycerol, as well as at internal sites: lysine for melittin; serine and lysine for magainin II. Acyl transfer could be detected within 3 h of melittin addition to negatively charged membranes. The other peptides were less reactive, but for each peptide, acylation was found to occur in at least one of the conditions examined. The data demonstrate that acyl transfer is a generic process for peptides bound to membranes composed of diacylglycerophospholipids. Phospholipid membranes cannot therefore be considered as chemically inert toward peptides and by extension proteins.     

Antioxidative responses in Vitis vinifera infected by grapevine fanleaf virus

The antioxidative response of grapevine leaves (Vitis vinifera cv. Trebbiano) affected by the presence of grapevine fanleaf virus was studied during the summer of 2010 at three different harvest times (July 1st and 26th, and August 30th). At the first and second harvest, infected leaves showed increases in the concentration of superoxide radical and hydrogen peroxide, the latter increasing for enhanced activity of superoxide dismutase. In contrast, at the last harvest time, increases in the ascorbate pool and ascorbate peroxidase activity maintained hydrogen peroxide to control levels. The glutathione pool was negatively affected as summer progressed, showing a decrease in its total and reduced form amounts. At the same time, increases in the ascorbate pool were observed, making antioxidant defenses of grapevine effective also at the last harvest time. Increases in phenolic acids, and in particular in p-hydroxybenzoic acid, at the first and second harvest might have enhanced the efficiency of the antioxidant system through an interrelation between a peroxidase/phenol/ascorbate system and the NADPH/glutathione/ascorbate cycle. The lack of increase in p-hydroxybenzoic acid at the third harvest could be due instead to the enhanced utilization of this acid for hydrogen peroxide detoxification. With time, grapevine plants lost their capacity to contrast the spread of grapevine fanleaf virus, but acquired a greater ability to counteract pathogen-induced oxidative stress, being endowed with more reduced antioxidant pools.     

Modeling the estrogen receptor to growth factor receptor signaling switch in human breast cancer cells

Breast cancer cells develop resistance to endocrine therapies by shifting between estrogen receptor (ER)-regulated and growth factor receptor (GFR)-regulated survival signaling pathways. To study this switch, we propose a mathematical model of crosstalk between these pathways. The model explains why MCF7 sub-clones transfected with HER2 or EGFR show three GFR-distribution patterns, and why the bimodal distribution pattern can be reversibly modulated by estrogen. The model illustrates how transient overexpression of ER activates GFR signaling and promotes estrogen-independent growth. Understanding this survival-signaling switch can help in the design of future therapies to overcome resistance in breast cancer.     

Field trapping of male Phyllonorycter ringoniella using variable ratios of pheromone components

The sex pheromone of Phyllonorycter ringoniella (Matsumura) (Lepidoptera: Gracillariidae) has been identified to be a blend of (Z)‐10‐tetradecenyl acetate (Z10‐14:OAc) and E4,Z10‐tetradecadienyl acetate (E4,Z10‐14:OAc) in Japan, Korea, and China. However, the commercial product based on previous results is not attractive enough to be used for monitoring and controlling apple leafminer populations in the field. We re‐investigated the attractiveness of the two pheromone components, singly and in blends, in apple orchards in Shangdong and Shaanxi, the main apple‐growing provinces in China. Our results revealed that Z10‐14:OAc alone was not attractive to P. ringoniella male moths in the field, but E4,Z10‐14:OAc alone not only was strongly attractive but caught more males than any of the blends of Z10‐14:OAc and E4,Z10‐14:OAc tested. The most attractive blend ratios differed slightly for the two locations. No clear dose–response relationship was obtained for the 2:8 blend of Z10‐14:OAc and E4,Z10‐14:OAc. However, the dose–response field study of E4,Z10‐14:OAc alone showed that 1 mg per lure achieved the highest moth catch. These findings differ from the previous report of the best pheromone blend in China. Our data showed that E4,Z10‐14:OAc is the major component of the pheromone of P. ringoniella.     

A spectrophotometric coupled enzyme assay to measure the activity of succinate dehydrogenase

Respiratory complex II (succinate:ubiquinone oxidoreductase) connects the tricarboxylic acid cycle to the electron transport chain in mitochondria and many prokaryotes. Complex II mutations have been linked to neurodegenerative diseases and metabolic defects in cancer. However, there is no convenient stoichiometric assay for the catalytic activity of complex II. Here, we present a simple, quantitative, real-time method to detect the production of fumarate from succinate by complex II that is easy to implement and applicable to the isolated enzyme, membrane preparations, and tissue homogenates. Our assay uses fumarate hydratase to convert fumarate to malate and uses oxaloacetate decarboxylating malic dehydrogenase to convert malate to pyruvate and to convert NADP⁺ to NADPH; the NADPH is detected spectrometrically. Simple protocols for the high-yield production of the two enzymes required are described; oxaloacetate decarboxylating malic dehydrogenase is also suitable for accurate determination of the activity of fumarate hydratase. Unlike existing spectrometric assay methods for complex II that rely on artificial electron acceptors (e.g., 2,6-dichlorophenolindophenol), our coupled assay is specific and stoichiometric (1:1 for succinate oxidation to NADPH formation), so it is suitable for comprehensive analyses of the catalysis and inhibition of succinate dehydrogenase activities in samples with both simple and complex compositions.     

FERM domain promotes resveratrol-induced apoptosis in endothelial cells via inhibition of NO production

Focal adhesion kinase (FAK) consists of an N-terminal band 4.1; ezrin, radixin, moesin (FERM) domain; tyrosine kinase domain; and C-terminal FA targeting domain. Here we show that ectopically expressed FERM is largely located in the cytosolic fraction under quiescent conditions. We further found that this ectopically expressed FERM domain aggravates endothelial cell apoptosis triggered by 100 μM resveratrol, whereas FERM had no effect on apoptosis induced by TNF-α. We determined that resveratrol at low doses (<20 μM) promotes phosphorylation (S1177) of eNOS via an AMPK-dependent pathway. The presence of the FERM domain blocked this resveratrol-stimulated eNOS phosphorylation and NO production. Thus, the pro-apoptotic activity of cytosolic FERM domain is at least partially mediated by down-regulation of NO, a critical cell survival factor. Consistently, we found that the apoptosis induced by cytosolic FERM in the presence of resveratrol was reversed by an NO donor, SNAP. In conclusion, FERM located in the cytosolic fraction plays a pivotal role in aggravating cell apoptosis through diminishing NO production.     

Hormonal changes and energy substrate availability during the hibernation cycle of Syrian hamsters

Animals have to adapt to seasonal variations in food resources and temperature. Hibernation is one of the most efficient means used by animals to cope with harsh winter conditions, wherein survival is achieved through a significant decrease in energy expenditure. The hibernation period is constituted by a succession of torpor bouts (hypometabolism and decrease in body temperature) and periodic arousals (eumetabolism and euthermia). Some species feed during these periodic arousals, and thus show different metabolic adaptations to fat-storing species that fast throughout the hibernation period. Our study aims to define these metabolic adaptations, including hormone (insulin, glucagon, leptin, adiponectin, GLP-1, GiP) and metabolite (glucose, free fatty acids, triglycerides, urea) profiles together with body composition adjustments. Syrian hamsters were exposed to varied photoperiod and temperature conditions mimicking different phases of the hibernation cycle: a long photoperiod at 20 °C (LP20 group), a short photoperiod at 20 °C (SP20 group), and a short photoperiod at 8 °C (SP8). SP8 animals were sampled either at the beginning of a torpor bout (Torpor group) or at the beginning of a periodic arousal (Arousal group). We show that fat store mobilization in hamsters during torpor bouts is associated with decreased circulating levels of glucagon, insulin, leptin, and an increase in adiponectin. Refeeding during periodic arousals results in a decreased free fatty acid plasma concentration and an increase in glycemia and plasma incretin concentrations. Reduced incretin and increased adiponectin levels are therefore in accordance with the changes in nutrient availability and feeding behavior observed during the hibernation cycle of Syrian hamsters.