Effect of retinol on interaction of the protein period1, oxytocin, and GABA at the prenatal period of formation of the circadian clock-mechanism in rats

In mammals, clock-gene proteins are expressed in the neurons of hypot halamic suprachiasmatic nucleus and that of other CNS structures, in the muscles, visceral organs and vessels, thus forming circadian rhythms of many functions. Little is known about the factors of formation of the circadian mechanism at the prenatal period. In the rats, E20 stage is characterized by a high level of oxytocin and selective expression of the first protein of clock-genes PER1. The goal of present study was to check the suggestion on the positive feedback between PER1 and oxytocin at the prenatal period, as well as to elucidate a possible role of PER1 in the regulation of oxytocin and GABA interactions at the period of formation of the cerebral circadian mechanism of clockgenes. With aid of western-blotting, we analyzed the nuclear and cytoplasmic fractions of anterior hypothalamus homogenate from the pregnant females and rat embryos (E20). Retinol metabolites through their nuclear receptor RORa are known to be bound to promoters of oxytocin and per 1 genes. Next day after administration of retinol to the females, a rise in PER1 content was noted in their cytoplasm, whereas in their embryos PER1 content was elevated in the nucleus. In the embryo cytoplasm there was a significant rise in production of oxytocin receptors and a decrease in the level of enzymes of GABA synthesis (glutamate decarboxylases 67 and 65). The results indicate the oxytocin- and retinol-dependent increase in the PER1 expression and the subsequent change in the ratio of oxytocin and GABA efficiency at the prenatal stage of formation of the circadian clockmechanism in the rat embryo anterior hypothalamus.     

Antibody neutralization test in brucellosis]

The authors present the results of study of the antibody neutralization test in brucellosis with the use of erythrocytes sensitized with lipopolysaccharide. This test was shown to be highly specific and sensitive in detection of brucellae and brucellosis antigen in pathological material, food and objects of external environment.     

The Biodiversity and Antimicrobial Activity of Bacteria Isolated from the Bottom Sediments of the Chukchi Sea

Russian Journal of Marine Biology - Two hundred and forty eight strains of heterotrophic microorganisms were isolated from bottom sediments of the Chukchi Sea. A 16S rRNA gene sequence analysis was...     

Effect of stimulation of the hypothalamic nuclei on the lipid concentration and ATPase activity of the mitochondrial and microsomal fractions of the rabbit heart]

Stimulation of the ventro-medial nuclei of the hypothalamus led to reduction in the concentration of phospholipids, triglycerides, and cholesterol in the mitochondria of the rabbit heart. Cholesterol load against this background elevated the concentration of cholesterol and reduced the phospholipid concentration even more. The heart mitochondrial and microsomal activity of Ca2+--ATP-ase was reduced. These data differed from the results recieved in the action of cholesterol alone. The research carried out showed that the action of exogenous cholesterol depended on the mechanisms regulating the lipid metabolism.     

RuvbL1 and RuvbL2 enhance aggresome formation and disaggregate amyloid fibrils

The aggresome is an organelle that recruits aggregated proteins for storage and degradation. We performed an siRNA screen for proteins involved in aggresome formation and identified novel mammalian AAA+ protein disaggregases RuvbL1 and RuvbL2. Depletion of RuvbL1 or RuvbL2 suppressed aggresome formation and caused buildup of multiple cytoplasmic aggregates. Similarly, downregulation of RuvbL orthologs in yeast suppressed the formation of an aggresome‐like body and enhanced the aggregate toxicity. In contrast, their overproduction enhanced the resistance to proteotoxic stress independently of chaperone Hsp104. Mammalian RuvbL associated with the aggresome, and the aggresome substrate synphilin‐1 interacted directly with the RuvbL1 barrel‐like structure near the opening of the central channel. Importantly, polypeptides with unfolded structures and amyloid fibrils stimulated the ATPase activity of RuvbL. Finally, disassembly of protein aggregates was promoted by RuvbL. These data indicate that RuvbL complexes serve as chaperones in protein disaggregation.     

Proteasome activity in tumors of female reproductive system

Proteasomes (multiproteinase protein complexes) are known to play an important role in cancer pathogenesis, however, few information about their activity in human tumor tissues is available so far. We studied chymotrypsin-like activity of proteasomes in tissues of breast cancer (BC) and endometrial cancer (EC). The chymotrypsin-like total proteasome activity and the 20S and 26S proteasome activity in malignant tissues were shown to be significantly higher in malignant tumors than in normal tissues. No increase in proteasome activity was registered with larger tumor size in both BC and EC, whereas proteasome activity was changed with respect to the extent of tumor involvement. In breast cancer tissues, significant reductions in the total and the 26S proteaome activities were observed in tumors with regional lymph node metastases as compared to tumors without metastases. In endometrial cancer tissues, the total proteasome activity and the 20S and 26S proteasome activities were increased as the depth of myometrial invasion. The data obtained indicate that the proteasome acyivity is significantly changed in the process of cancerogenesis and further study is needed to develop new additional prognostic criteria and effective anti-tumor agents in molecular-directed therapy.