DNA-Hydrolyzing Antibodies from Sera of Autoimmune-Prone MRL/MpJ-lpr Mice

Catalytically active antibodies (abzymes) hydrolyzing proteins, polysaccharides, ATP, DNA, and RNA have been detected in the sera of patients with various autoimmune and some viral diseases, but abzymes from the sera of animals are practically unstudied. The development of lupus-like autoimmune disease of MRL/MpJ-lpr mice is an experimental model for study of autoimmune pathologies and immunopathogenesis. In this work, homogeneous IgG preparations were isolated from the sera of MRL/MpJ-lpr mice. These antibodies (Abs), their Fab-fragments, and isolated light chains were shown to possess catalytic activity in DNA hydrolysis, whereas Abs from the sera of control healthy mice did not hydrolyze DNA. The data demonstrate that DNA hydrolyzing activity is an intrinsic property of Abs from MRL/MpJ-lpr mice. It was shown that various markers of autoimmune pathologies (level of total protein concentration in urea (proteinuria), Abs titers to native and denatured DNA, and DNA-hydrolyzing activity of IgG) increased in animals with aging, but they noticeably increased (2-22 times) only after appearance of obvious indicators of pathology independently of age. The highest increase in proteinuria (25-fold), anti-DNA Abs titers (12-19-fold), and abzyme activity (120-fold) was found in mice after their immunization with DNA–protein complex.     

Bioremediation Potential of Biochar-Immobilized Cells of Azospirillum brasilense

Microbiology - A biopreparation consisting of the cells of Azospirillum brasilense strain SR80 immobilized on wood biochar was characterized. Sorption of oil by biochar and its colonization by...     

Delayed effect of prenatal exposure to hypoxia on the susceptibility of rats to electric seizures

We studied the delayed effects of prenatal exposure to hypoxia on the susceptibility of rats to seizures. The later was estimated using graded electroshock. The experiments were performed in two groups of 1.5-year-old male Wistar rats. The experimental group consisted of the animals that were exposed to hypoxia on day 14 of prenatal development, and the control group consisted of the animals that developed under the normal conditions. In the rats subjected to prenatal hypoxia, seizure episodes induced by weak currents in the range of 10–40 mA and their average duration were more pronounced as compared to the control animals.     

Inhibition of micro-RNA-induced RNA silencing by 2′-O-methyl oligonucleotides in Drosophila S2 cells

Summary More than 90 different micro-ribonucleic acid (miRNA) encoding genes have been identified in Drosophila, yet the function of only two of these, bantam and DmiR-14, has been elucidated. In an effort to develop a general strategy for the analysis of miRNA function in Drosophila, two procedures were developed, in a Schneider line 2 cell culture system, which may be adapted to that end. First, we show that endogenous miRNAs can partially inhibit the expression of a transiently transfected reporter gene that has been modified to contain sequences complementary to that miRNA in the 3′ UTR of a target messenger RNA (mRNA). Inhibition occurs by RNA interference (RNAi), which involves mRNA degradation. Second, we demonstrate that this miRNA-induced RNAi can be partially rescued with 2′-O-methyl oligonucleotides that contain sequences complementary to the cognate miRNA. We discuss how these techniques may be used, in vivo, both for localizing the tissue distribution of endogenous miRNAs during Drosophila development and identifying phenotypes associated with a loss of miRNA function.     

The degradation of three-ringed polycyclic aromatic hydrocarbons by wood-inhabiting fungus Pleurotus ostreatus and soil-inhabiting fungus Agaricus bisporus

The degradation of two isomeric three-ringed polycyclic aromatic hydrocarbons by the white rot fungus Pleurotus ostreatus D1 and the litter-decomposing fungus Agaricus bisporus F-8 was studied. Despite some differences, the degradation of phenanthrene and anthracene followed the same scheme, forming quinone metabolites at the first stage. The further fate of these metabolites was determined by the composition of the ligninolytic enzyme complexes of the fungi. The quinone metabolites of phenanthrene and anthracene produced in the presence of only laccase were observed to accumulate, whereas those formed in presence of laccase and versatile peroxidase were metabolized further to form products that were further included in basal metabolism (e.g. phthalic acid). Laccase can catalyze the initial attack on the PAH molecule, which leads to the formation of quinones, and that peroxidase ensures their further oxidation, which eventually leads to PAH mineralization.A. bisporus, which produced only laccase, metabolized phenanthrene and anthracene to give the corresponding quinones as the dominant metabolites. No products of further utilization of these compounds were detected. Thus, the fungi's affiliation with different ecophysiological groups and their cultivation conditions affect the composition and dynamics of production of the ligninolytic enzyme complex and the completeness of PAH utilization.     

Peroxidases from alfalfa roots: Catalytic properties and participation in degradation of polycyclic aromatic hydrocarbons

From the roots and root exudates of 3-week-old plants of alfalfa (Medicago sativa L.), anionic and cationic peroxidases differing in principal physicochemical and catalytic properties were isolated and purified. Main features of anionic peroxidases detected in the roots and root exudates were identical. Phenanthrene present in the soil used for alfalfa growing influenced the number of forms and activity of peroxidases in crude enzyme preparations but did not affect the properties of pure enzymes. In the presence of a synthetic mediator, purified peroxidases can oxidize phenanthrene and its derivatives, including potential microbial metabolites of polycyclic aromatic hydrocarbons (PAH). The fact that the enzymes excreted in root exudates in a purified form can oxidase PAH proves their participation in degradation of PAH and their microbial metabolites in alfalfa rhizosphere. These new data indicate that the processes of plant and microbial degradation of pollutants in the rhizosphere are coupled; they are relevant to understanding the molecular mechanisms of degradation of persistent pollutants by plant-microbial complexes.