Parent-of-origin effects on nuclear chromatin organization and behavior in a Drosophila model for Williams-Beuren Syndrome.

Prognosis of neuropsychiatric disorders in progeny requires consideration of individual (1) parent-of-origin effects (POEs) relying on (2) the nerve cell nuclear 3D chromatin architecture and (3) impact of parent-specific miRNAs. Additionally, the shaping of cognitive phenotypes in parents depends on both learning acquisition and forgetting, or memory erasure. These processes are independent and controlled by different signal cascades: the first is cAMPdependent, the second relies on actin remodeling by small GTPase Rac1 - LIMK1 (LIM-kinase 1). Simple experimental model systems such as Drosophila help probe the causes and consequences leading to human neurocognitive pathologies. Recently, we have developed a Drosophila model for Williams-Beuren Syndrome (WBS): a mutant agnts3 of the agnostic locus (X:11AB) harboring the dlimk1 gene. The agnts3 mutation drastically increases the frequency of ectopic contacts (FEC) in specific regions of intercalary heterochromatin, suppresses learning/memory and affects locomotion. As is shown in this study, the polytene X chromosome bands in reciprocal hybrids between agnts3 and the wild type strain Berlin are heterogeneous in modes of FEC regulation depending either on maternal or paternal gene origin. Bioinformatic analysis reveals that FEC between X:11AB and the other X chromosome bands correlates with the occurrence of short (~30 bp) identical DNA fragments partly homologous to Drosophila 372-bp satellite DNA repeat. Although learning acquisition in a conditioned courtship suppression paradigm is similar in hybrids, the middle-term memory formation shows patroclinic inheritance. Seemingly, this depends on changes in miR-974 expression. Several parameters of locomotion demonstrate heterosis. Our data indicate that the agnts3 locus is capable of trans-regulating gene activity via POEs on the chromatin nuclear organization, thereby affecting behavior.

The Effects of Weak Static Magnetic Field on the Development of Organotypic Tissue Culture in Rats.

The effects of weak static magnetic field on the organotypic tissue culture of the rat cerebral cortex, liver, and spleen have been investigated. Exposure to a 200 µT static magnetic field induces tissue development, leading to the intensification of regeneration processes compared to the control explants.

The Drosophila agnostic Locus: Involvement in the Formation of Cognitive Defects in Williams Syndrome.

The molecular basis of the pathological processes that lead to genome disorders is similar both in invertebrates and mammals. Since cognitive impairments in Williams syndrome are caused by LIMK1 hemizygosity, could the spontaneous and mutant variants of the Drosophila limk1 gene serve as a model for studying two diagnostic features from three distinct cognitive defects of the syndrome? These two symptoms are the disturbance of visuospatial orientation and an unusualy strong fixation on the faces of other people during pairwise interaction with a stranger. An experimental approach to the first cognitive manifestation might be an analysis of the locomotor behavior of Drosophila larvae involving visuospatial orientation during the exploration of the surrounding environment. An approach to tackle the second manifestation might be an analysis of the most natural ways of contact between a male and a female during courtship (the first stage of this ritual is the orientation of a male towards a female and following the female with constant fixation on the female's image). The present study of locomotor activity and cognitive repertoire in spontaneous and mutant variants of the Drosophila agnostic locus allows one to bridge alterations in the structure of the limk1 gene and behavior.

Williams syndrome as a model for elucidation of the pathway genes - the brain - cognitive functions: genetics and epigenetics.

Genomic diseases or syndromes with multiple manifestations arise spontaneously and unpredictably as a result of contiguous deletions and duplications generated by unequal recombination in chromosomal regions with a specific architecture. The Williams syndrome is believed to be one of the most attractive models for linking genes, the brain, behavior and cognitive functions. It is a neurogenetic disorder resulting from a 1.5 Mb deletion at 7q11.23 which covers more than 20 genes; the hemizigosity of these genes leads to multiple manifestations, with the behavioral ones comprising three distinct domains: 1) visuo-spatial orientation; 2) verbal and linguistic defect; and 3) hypersocialisation. The shortest observed deletion leads to hemizigosity in only two genes: eln and limk1. Therefore, the first gene is supposed to be responsible for cardiovascular pathology; and the second one, for cognitive pathology. Since cognitive pathology diminishes with a patient's age, the original idea of the crucial role of genes straightforwardly determining the brain's morphology and behavior was substituted by ideas of the brain's plasticity and the necessity of finding epigenetic factors that affect brain development and the functions manifested as behavioral changes. Recently, non-coding microRNAs (miRs) began to be considered as the main players in these epigenetic events. This review tackles the following problems: is it possible to develop relatively simple model systems to analyze the contribution of both a single gene and the consequences of its epigenetic regulation in the formation of the Williams syndrome's cognitive phenotype? Is it possible to use Drosophila as a simple model system?

[Expression of the Drosophila melanogaster limk1 gene 3'-UTRs mRNA in Yeast Saccharomyces cerevisiae].

The stability of mRNA and its translation efficacy in higher eukaryotes are influenced by the interaction of 3'-untranscribed regions (3'-UTRs) with microRNAs and RNA-binding proteins. Since Saccharomyces cerevisiae lack microRNAs, it is possible to evaluate the contribution of only 3'-UTRs' and RNA-binding proteins' interaction in post-transcriptional regulation. For this, the post-transcriptional regulation of Drosophila limk1 gene encoding for the key enzyme of actin remodeling was studied in yeast. Analysis of limkl mRNA 3'-UTRs revealed the potential sites of yeast transcriptional termination. Computer remodeling demonstrated the possibility of secondary structure formation in limkl mRNA 3'-UTRs. For an evaluation of the functional activity of Drosophila 3'-UTRs in yeast, the reporter gene PHO5 encoding for yeast acid phosphatase (AP) fused to different variants of Drosophila limk1 mRNA 3'-UTRs (513, 1075, 1554 bp) was used. Assessments of AP activity and RT-PCR demonstrated that Drosophila limkl gene 3'-UTRs were functionally active and recognized in yeast. Therefore, yeast might be used as an appropriate model system for studies of 3'-UTR's role in post-transcriptional regulation.

Initiation of the 3':5'-AMP-induced protein kinase A Iα regulatory subunit conformational transition. Part I. A202 and A326 are critical residues.

Protein-ligand docking and molecular dynamics studies have shown that the key event initiated by 3':5'-AMP binding to the A- and B-domains of protein kinase A Iα regulatory subunit is formation of a hydrogen bond between 3':5'-AMP and A202(A326) (the residue in parentheses being from the B-domain). The A202(A326) amide group movement associated with the bond formation leads to reorganization of the phosphate binding cassette (PBC) (the short 3(10)-helix becomes the long α-helix). This process results in L203(L327) displacement and finally causes hinge (B-helix) rotation. The L203(L327) displacement and packing into the hydrophobic pocket formed by the PBC and ß2ß3-loop also depends on the ß2ß3-loop conformation. The correct conformation is maintained by R, I, E, but not K at position 209(333) of the A- and B-domains. So, the R209K and R333K mutants have problems with reaching B-conformation. The apo-form of the 3':5'-AMP-binding domain also undergoes transition from H- to B-conformation. In this case, the movement of A202(A326) amide group seems to be a result of reorganization of the PBC into a more stable α-helix.

[The role of stacking interactions in the mechanisms of binding of the glycine site of NMDA-receptor with antagonists and 3-hydroxykynurenine].

Ab initio quantum chemical calculations of benzene dimer, benzene dimer with 5,7 clorination of one aromatic ring, 3-hydroxykynurenine, and kunurenic acid molecules situated above Phe484 aromatic ring of receptor binding site fragment were carried out in order to investigate the role of stacking interaction in the binding of agonists and antagonists with the glycine site of the NMDA receptor NR1 subunit. All calculations were done with the help of GAMESS 6.4 software with 6-31G** atomic gaussian basal functions with complete optimization of geometry and taking into account the electron correlation up to the second-order Moller-Plesset perturbation theory. It was shown that the parallel dislodged conformations of the benzene dimer is energetically most advantageous. Successive substitution of chlorine atoms for the protons of one aromatic ring in 7 and 5 positions leads to an increase in stacking-interaction energy and a mutual displacement of aromatic rings. In the case of kunurenic acid and its derivatives, which are NMDA receptor antagonists, the increase in the energy of stacking interactions leads to the strengthening of inhibition of the ion channel, whereas the 3-hydroxykynurenine molecule is neither agonist, nor antagonist for the glycine site of the NMDA receptor due to the sterical constraints.

[Effect of adaptation to high altitude on the state of electric cardiac stability and lipid peroxidation during catecholamine cardionecrosis in rats]. / Vliianie adaptatsii k vysokogor'iu na sostoianie élektricheskoi stabil'nosti serdtsa i perekisnogo okisleniia lipidov pri katekholaminovom kardionekroze u krys.

The change of electric cardiac stability parameters and LP in catecholamine cardio necrosis in rats simulated by prolonged injection of increasing doses of noradrenaline was studied in this work. It was established that noradrenaline injection in low-altitude (760 m) and high-altitude (3200 m) is accompanied by hypertrophy, microcirculation disturbances, ischemia and cardiomyocytes necrosis, ECS decrease, LP activation and decrease of enzymatic activity of antioxidant defense. ECS of animals adapted to high-altitude decreased less and their LP processes were more active with preservation of enzymatic activity of antioxidant defense.

[Changes in hemocoagulation in altitude-sensitive animals with catecholamine cardiac necrosis]. / Izmenenie gemokoaguliatsii pri katekholaminovom kardionekroze u ne adaptirovannykh k vysokogor'iu zhivotnykh.

Norepinephrine injected to adult Wistar rats at low altitude (760 m) and high altitude (3200 m) induced hypertrophy and focal myocardial necrosis ascribed to, specifically, changes in blood hypercoagulation. More pronounced changes developed in altitude-sensitive animals in the mountains.

[Changes in hypoxic resistance and conditional avoidance reflex during hypobaric adaptation on the "flatland" and in mountains]. / Izmenenie gipoksicheskoi ustoichivosti i uslovnykh refleksov izbeganiia u krys pri gipoadaptatsii na "ravnine" i v usloviiakh gor.

White rats--males with mass 200-250 g were exposed ipobaroadaptation (rise on 12,000 m with an exposition 5 minutes) with periodic testing them on gipocsition stability. After shaping in the result of gipobaroadaptation stressostability, that it was judged in 2-3 times enlarging of reserve time, rats produced conditional reflexes at active avoid (CRAA) as on plain area (760 m) so in high-mountainous (2500 m). It is observed that gipobaroadaptation increases gipocsition stability and accelerates the CRAA shaping on plain area and in mountains. The maximum effect of gipocsition stahility increasing, CRAA consolidation and perfecting of efferention synthesis at high-mountainous gipobaroadaptation rats is more significant, thah at "flat." gipobaroadaptation has important protective significance for function of a brain, decreasing its sensibility to lock of oxygen and fixing maximum adaptive responses.

[Effects of high altitude on changes in blood coagulation in rats during prolonged administration of noradrenaline]. / Vliianie vysokogor'ia na izmenenie gemokoaguliatsii u krys pri dlitel'nom vvedenii noradrenalina.

Alterations of the plasma factors of hemocoagulation produced by injection of norepinephrine (NE) at progressively increasing doses over 14 days (the total dose ran 35 mg/kg of body mass) were studied in three groups of rats, i.e., animals bred at the low altitude of 760 m in Bishkek (group I), animals in-adapted (group II) and adapted to high altitude of the Tuya-Ashu pass (3200 m, Group III). By the 7th day of NE injection group-I developed a moderate hypercoagulation which persisted till the end of experiment. In adapted animals the high altitude exposure initiated hypocoagulation shifts which then gave place to hypercoagulation ones due to elevated activity of the procoagulant component of homeostasis. Maximally pronounced hypercoagulation charges were recorded in in-adapted rats (group II) and interpreted as a stress-reaction to natural hypoxia augmented by the stress-agent (NE). High altitude revealed greater defense-adaptive potential of the homeostatic system manifested as enhancement of the anticoagulation blood activity, e.g., increased ability to inactivate thromboplastin and thrombin, and fibrinolysis.

[Effects of high altitude on the morphofunctional state of mast cells of the subcutaneous connective tissue during physical exercise]. / Vliianie vysokogor'ia na morfofunktsional'noe sostoianie tuchnykh kletok podkozhnoi soedinitel'noi tkani pri fizicheskikh nagruzkakh.

The Wistar male rats were exposed to submaximum exercise (by swimming for 5 hours) at a high altitude (HA) environment (the Tuya-Ashu Pass, 3200 m above sea level). Sampling was done on Days 1, 15, 30 and 45 of animal living in the mountains. The control group of animals was examined in the lowlands regions (Bishkek, 760 m above sea level). It is indicated that during exercises performed in the mountain environments the mast cell reaction judging from the morphologic manifestations is similar to that observed during adaptation without exercises but in this case the cell restoration occurs more rapidly. The study of the time-course of changes in the morphofunctional state of mast cells in both groups of animals allows one to conclude that such an early significant degranulation and mass degradation at early times are conditioned not only by stressful reaction of the body but also by the effects of HA hypoxia and exercise stimulating their subsequent accelerated proliferation due to migration of juvenile forms from the region of cambial reserve to the skin surface compartments.

[Clinico-immunological characteristics of people who worked within the 30-kilometer zone of the accident at the Chernobyl Atomic Power Plant 4 years after the accident]. / Kliniko-immunologicheskaia kharakteristika kontingenta lits, rabotavshikh v 30-kilometrovoi zone avarii na Chernobyl'skoi AES cherez 4 goda posle radiatsionnoi avarii.

Clinical examination with immune status assessment of more than 300 healthy persons, who worked in 30-km Chernobyl NPP zone four years after the accident was carried out. The clinical characters of immune deficiency were detected in 6.67% of examined persons and appeared as repeated respiratory diseases. Significant increase in mean level of leukocytes and lymphocytes was revealed. Activation of T-helper link of cell immunity was determined by increase of CD4+ cells in 35.2% of examined persons, that were lower than in people who took part in Chernobyl accident amelioration in 1986. Decrease in content of T-cells and B-cells was observed in 1/4 and 3/4 of persons correspondingly by rosette assays. No changes in serum immunoglobulins level was observed.

[Features of mast cell status and blood coagulation during long-term administration of noradrenaline in mountain dogs]. / Osobennosti sostoianiia tuchnykh kletok i gemokoaguliatsii pri dlitel'nom vvedenii noradrenalina u gornykh sobak.

The total number of mast cells and their forms is increased, degranulation is weakly marked in dogs permanent of medium altitude (1650 m) in comparison with low altitude dogs (760 m) after the long-term NA injections addition with reaction similarities some differences were observed. The total number of mast cells is decreased less considerably, the number of average forms of maturity and to some extent the number of the third power degranulation are increased in altitude dogs. The decrease of the high altitude adaptive heparin level is observed, the activity of fibrinolytic system is marked facilitating the prevention of microcirculatory disturbances. Thus, mast cells and hemocoagulation systems of altitude are more resistant to the long-term noradrenaline loadings.

[Mast cell and blood coagulation functions during prolonged noradrenaline administration]. / Sostoianie tuchnykh kletok i gemokoaguliatsii pri dlitel'nom vvedenii noradrenalina.

During the long term noradrenaline injection (0.56 microgram/kg/min-2 hours during six days) the number of connective tissue mast cells decreases in dogs. Mature cells disappears and the percentage of young forms increases. Marked degranulation develops. 5-10 cell groups and chains are formed. The increase of free heparin level and the activation of anticoagulant unit hemostasis correspond to these changes. It is due to mast cells discharge of biologically active heparin which is an unspecific adaptogen.