Heparin-Binding Proteins in the Rat Brain

Using a histochemical technique, we found that in rat embryos heparin-binding sites are localized within ventricular regions of the neural tube. The highest intensity of the heparin-binding activity was observed in the membranes of migrating nerve cells. Heparin-binding membrane-associated proteins were isolated and purified from the brains of newborn rats; molecular masses of two such proteins were measured (19 and 28 kdalton). The level of affinity for binding of heparan sulfate to the purified proteins was characterized by equilibrium constants of 1.7 · 10^-3 and 6.7 · 10^-3. Binding of heparan sulfate to the above proteins was more intensive at low ion force and pH values within the 3.0 to 4.0 range and about 6.0.     

Proteasome Expression in Ovarian Heterotopic Allografts of Wistar and August Rats under Induction of Donor-Specific Tolerance

Russian Journal of Developmental Biology - The aim of this work is to investigate the dynamics for the ovarian tissue engraftment of inbred August rats transplanted to outbred Wistar rats and vice...     

Uncharged P-selectin blockers

The blocking potency of P- and L-selectin was studied for certain small molecule mannosides and their polyacrylamide (PAA, 30 kDa) conjugates in comparison to SiaLe(x) and fucoidan. Two experimental systems were used: (1) solid phase static assay based on recombinant selectins, and (2) P-selectin dependent rat peritoneal inflammation. betaMan-SC6H4NO2- p was four times more potent P-selectin inhibitor as compared to SiaLe(x). Docking of this molecule onto the P-selectin carbohydrate-binding site demonstrated that a nitro group enabled an electrostatic interaction with residue Lys 84, while the phenyl ring and the CH2 at C-6 contacted the CH2 groups of the same Lys residue. In vivo, betaMan-SC6H4NO2- p blocked experimental inflammation better than SiaLe(x), but significantly lower than fucoidan. In vitro Man-polyacrylic acid conjugates appeared to be very potent inhibitors comparable to fucoidan, uncharged Man-PAA proved rather active, comparable to SiaLe(x)-PAA both in vitro, and in vivo, whereas mannan did not display any P-selectin blocking effect.     

The effect of long-term lactobacilli (lactic acid bacteria) enteral treatment on the central nervous system of growing rats

The aim of this study was to explore the relationship between consumption of large doses of lactic acid bacteria (LAB) and the behaviour and brain morphobiochemistry of normal growing rats. Four groups of rats were treated with LAB cultures twice daily for 6 months. The control group received 1 ml of saline per treatment, while two experimental groups received 1 ml of living bacteria (Lactobacillus plantarum and Lactobacillus fermentum, respectively) and the remaining group received a heat-treated (inactivated) L. fermentum culture. After 2 and 6 months of treatment, respectively, eight animals from each group were sacrificed, and specimens were taken for further analyses. The behaviour of the rats was evaluated five times in an open-field test at monthly intervals throughout the study. Lactobacilli treatment for 2 months induced changes in the motoric behaviour of the rats. The concentration of the astrocytesoluble and filament glial fibrillary acidic protein (GFAP) decreased in the posterior part of the hemispheres, including the thalamus, hippocampus and cortex of the rats treated with L. fermentum. A greater decrease in filament GFAP (up to 50%) was shown in the group receiving the live form of L. fermentum. In contrast, the GFAP in the live L. plantarum-treated group increased, showing elevated levels of the soluble and filament forms of GFAP in the posterior part of the hemispheres.A 60–66% decrease in the amount of the astrocyte-specific Ca-binding protein S-100b was shown in the posterior parts of the hemispheres and in the hindbrain of rats given LAB for 2 months.Prolonged feeding with LAB for 4 months up to full adulthood led to a further decrease in astrocyte reaction, reflected as an additional decrease in the amount of soluble GFAP and locomotor activity in all experimental groups. The changes in filament GFAP and S-100b appeared to disappear after prolonged feeding (total of 6 months) with LAB.In summary, LAB dietary treatment affected the ontogenetic development of the astrocytes, with the highest intensity observed in the early stages of rat development. It can be postulated that LAB treatment may play a preventive role in neurological diseases by decreasing astrocyte reaction and, consequently, lowering locomotor activity.     

Microbacterium oxydans, a symbiont of Djungarian hamster, displaying probiotic properties

A resident microorganism (strain Kho-17) was isolated from secretions of the specific glandular structures at the angles of mouth of Djungarian hamster (Phodopus campbelli). According to cultural, morphological, and physiological properties as well as to the phylogenetic analysis basing on the sequences of 16S rRNA gene and analysis of the cell wall the strain was assigned to the species Microbacterium oxydans. The bacterium isolated displayed probiotic properties when administered orally as a suspension of live cells for 20 days to Syrian hamster (Mesocricetus auratus), which manifested themselves in increased body weight and weights of several organs and stimulation of both cell-mediated and humoral immunities.     

The role of hyaluronate in morphogenesis of the neurons

The data about organization of the extracellular matrix (ECM) components and their interplay in the mammalian brain are rather limited. Hyaluronate (HA) is one of the main ECM glycosaminoglycans. Its location and function in the brain are believed to be mediated through its interaction with HA-binding proteins and proteoglycans. In this report, we describe distribution of the total HA-binding activity in the cells in the course of postnatal development of the rat brain and the effect of HA on cultured neurons. A high level of the HA-binding activity was found in the newborn cerebellum, but it quickly decreased after postnatal day 1. On postnatal day 5, strong HA-binding activity was demonstrated only in apical parts of growth cones of Purkinje cells. The data showed rapid down-regulation of HA-binding activity at the first stage of cerebellum maturation (migration of granule cells and beginning of differentiation of neurons). To obtain more information concerning a key role of HA in morphogenesis of neurons, low density cell cultures of the hippocampal neurons were used. The presence of HA in the substrate led to an increase in the cell adherence. However, a part of the cells got differentiated later. These data allow us to suggest that interactions between extracellular HA and cell-surface receptors can regulate motility and differentiation of the neurons.