Ommochromes from the Compound Eyes of Insects: Physicochemical Properties and Antioxidant Activity

The objective of this study was screening of ommochromes from the compound eyes of insects and comparison of their antioxidant properties. Ommochromes were isolated in preparative quantities from insects of five different families: Stratiomyidae, Sphingidae, Blaberidae, Acrididae, and Tenebrionidae. The yield of ommochromes (dry pigment weight) was 0.9-5.4% of tissue wet weight depending on the insect species. Isolated pigments were analyzed by high-performance liquid chromatography and represented a mixture of several ommochromes of the ommatin series. The isolated ommochromes displayed a pronounced fluorescence with the emission maxima at 435-450 nm and 520-535 nm; furthermore, the emission intensity increased significantly upon ommochrome oxidation with hydrogen peroxide. The ommochromes produced a stable EPR signal consisting of a singlet line with g = 2.0045-2.0048, width of 1.20-1.27 mT, and high concentration of paramagnetic centers (> 10¹⁷ spin/g dry weight). All the investigated ommochromes demonstrated high antiradical activity measured from the degree of chemiluminescence quenching in a model system containing luminol, hemoglobin, and hydrogen peroxide. The ommochromes strongly inhibited peroxidation of the photoreceptor cell outer segments induced by visible light in the presence of lipofuscin granules from the human retinal pigment epithelium, as well as suppressed iron/ascorbate-mediated lipid peroxidation. The obtained results are important for understanding the biological functions of ommochromes in invertebrates and identifying invertebrate species that could be used as efficient sources of ommochromes for pharmacological preparations to prevent and treat pathologies associated with the oxidative stress development.

Implication of integrin α2β1 in anoikis of SK-Mel-147 human melanoma cells: a non-canonical function of Akt protein kinase

Suppression of anoikis, a kind of apoptosis caused by disruption of contacts between cell and extracellular matrix, is an important prerequisite for cancer cell metastasis. In this communication, we demonstrate that shRNA-mediated depletion of α2 integrin subunit induces anoikis and substantially decreases colony-forming potential in SK-Mel-147 human melanoma cells. Suppression of α2β1 upregulates the levels of pro-apoptotic protein p53 and cyclin-dependent kinase inhibitors p21 and p27. Concomitantly, we detected decrease in the levels of anti-apoptotic protein Bcl-2 and cell cycle regulator c-Myc. Moreover, depletion of α2β1 reduces the activity of protein kinase Erk, while increases activity of Akt kinase. Pharmacological inhibition of P3IK kinase, an upstream activator of Akt, greatly enhanced anoikis in control cells while reduced that in cells with decreased levels of α2β1. Of three isoforms of Akt, down-regulation of Akt1 greatly diminished anoikis of cells depleted of α2β1, while down-regulation of Akt2 and Akt3 sharply increased anoikis in these cells. These findings were supported by the data of pharmacological inhibition of the Akt isoforms. Our results demonstrate for the first time that anoikis induced by α2β1 integrin knockdown can be attenuated by Akt1 inhibition.

Structure and Anti-Inflammatory Activity of a New Unusual Fucosylated Chondroitin Sulfate from Cucumaria djakonovi

Fucosylated chondroitin sulfate CD was isolated from the sea cucumber Cucumaria djakonovi collected from the Avachinsky Gulf of the eastern coast of Kamchatka. Structural characterization of CD was performed using a series of non-destructive NMR spectroscopic procedures. The polysaccharide was shown to contain a chondroitin core [→3)-β-d-GalNAc-(1→4)-β-d-GlcA-(1→]n where about 60% of GlcA residues were 3-O-fucosylated, while another part of GlcA units did not contain any substituents. The presence of unsubstituted both at O-2 and O-3 glucuronic acid residues in a structure of holothurian chondroitin sulfate is unusual and has not been reported previously. Three different fucosyl branches Fucp2S4S, Fucp3S4S and Fucp4S were found in the ratio of 2:1:1. The GalNAc units were mono- or disulfated at positions 4 and 6. Anti-inflammatory activity of CD was assessed on a model of acute peritoneal inflammation in rats. About 45% inhibition was found for CD, while a structurally related linear chondroitin sulfate SS from cartilage of the fish Salmo salar demonstrated only 31% inhibition, indicating that the presence of sulfated fucosyl branches is essential for anti-inflammatory effect of chondroitin sulfates of marine origin.

Implication of Integrin α2β1 in Proliferation and Invasion of Human Breast Carcinoma and Melanoma Cells: Noncanonical Function of Akt Protein Kinase

Blocking the expression of integrin α2β1, which was accomplished by transduction of α2-specific shRNA, resulted in significant inhibition of proliferation and clonal activity in human MCF-7 breast carcinoma and SK-Mel-147 melanoma cells. Along with these changes, deprivation of α2β1 caused a sharp decrease in melanoma cell invasion in vitro. Analysis of integrin-mediating signal pathways that control cell behavior revealed a significant increase in activity of Akt protein kinase in response to depletion of α2β1. The increase in Akt activity that accompanies a suppressive effect on cell invasion contradicts well-known Akt function aimed at stimulation of tumor progression. This contradiction could be explained by the "reversed" (noncanonical) role played by Akt in some cells that consists in suppression rather than promotion of invasive phenotype. To test this suggestion, the effects of Akt inhibitors on invasive activity of SK-Mel-147 cells were investigated. If the above suggestion is true, then inhibition of Akt in cells depleted of α2β1 should result in the restoration of their invasive activity. It appeared that treatment with LY294002, which inhibits all Akt isoforms (Akt1, Akt2, Akt3), not only failed to restore the invasive phenotype of melanoma cells but further attenuated their invasive activity. However, treatment of the cells with an Akt1-specific inhibitor significantly increased their invasion. Thus, the stimulating effect of α2β1 integrin on invasion of melanoma cells is realized through a mechanism based on inhibition of one of the Akt isoforms, which in these cells exhibits a noncanonical function consisting in suppression of invasion.

Influence of Modified Fucoidan and Related Sulfated Oligosaccharides on Hematopoiesis in Cyclophosphamide-Induced Mice

Immunosuppression derived after cytostatics application in cancer chemotherapy is considered as an adverse side effect that leads to deterioration of quality of life and risk of infectious diseases. A linear sulfated (1→3)-α-l-fucan M-Fuc prepared by chemical modification of a fucoidan isolated from the brown seaweed Chordaria flagelliformis, along with two structurally related synthetic sulfated oligosaccharides, were studied as stimulators of hematopoiesis on a model of cyclophosphamide immunosuppression in mice. Recombinant granulocyte colony-stimulating factor (r G-CSF), which is currently applied in medicine to treat low blood neutrophils, was used as a reference. Polysaccharide M-Fuc and sulfated difucoside DS did not demonstrate significant effect, while sulfated octasaccharide OS showed higher activity than r G-CSF, causing pronounced neutropoiesis stimulation. In addition, production of erythrocytes and platelets was enhanced after the octasaccharide administration. The assessment of populations of cells in blood and bone marrow of mice revealed the difference in mechanisms of action of OS and r G-CSF.

Features of the Effect of a Complex Probiotic with Bacillus Bacteria and the Larvae of Hermetia illucens Biomass on Mozambique Tilapia (Oreochromis mossambicus O. niloticus) and Russian Sturgeon (Acipenser gueldenstaedti) Fry

A study of the effect of a complex probiotic preparation with bacteria of the genus Bacillus and a microdose of larvae of the fly Hermetia illucens on the physiological. parameters of fish has been carried out. It was established that introduction of the complex into artificial feeds for tilapia and Russian sturgeon juveniles during their incubation in recirculating aquaculture systems improves the digestion efficiency and increases the rate of fish growth and body mass accumulation. In tilapia, a decrease in the cholesterol level was revealed, while in sturgeon, an increase in the hemoglobin content was found. It was noted that a probiotic with biologically active agents H. illucens had a stimulating effect on the development of sexual gonads in female sturgeon fry, promoted an increase in the ovary mass, and provided for the development of eggs without morphological disturbances.

[BLOCKING SENSORIMOTOR DISORDERS IN STRIATIC DOPAMINERGIC DEFICIENT MICE BY THE EXTRACTS OF "REMEDY BEETLE" ALPHITOBIUS DIAPERINUS]

Five groups of C57Bl/6JSto mice (groups 1-5) were tested on a vertical pole 2 weeks since subcutaneous administration of proneurotoxin MPTP (40 mg per kg b. w.) to groups 2-5. Group 1 served as control. It is known that this MPTP dosage forms within 2 weeks sensorimotor disturbances similar to the initial stage of Parkinson's disease. One week before MPTP injection and during all the period after it (2 weeks) animals of groups 3-5 got one of the three extracts of biomass homogenate of the «remedy beetle» Alphitobius diaperinus as an additive to their food (8 g per 1 kg of food). The extracts were as follows: water (N 1), water-methanol (N 2) and water-methanol one after solid-phase extraction (N 3). All extracts were immobilized on a phytocarrier. Animals of groups 1 & 2 used ordinary food. Sensorimotor disturbances which could be clearly seen in the 2nd group of mice (MPTP) were absent in group 1 (control) as well as groups 3-5 which received an «antidote» with their food as one of the extracts of homogenate of the beetle biomass. The extract N 3 demonstrated maximal efficiency of all.

Anticoagulant and antithrombotic activities of modified xylofucan sulfate from the brown alga Punctaria plantaginea

Selectively and totally sulfated (1 → 3)-linked linear homofucans bearing ∼ 20 monosaccharide residues on average have been prepared from the branched xylofucan sulfate isolated from the brown alga Punctaria plantaginea. Anticoagulant and antithrombotic properties of the parent biopolymer and its derivatives were assessed in vitro. Highly sulfated linear fucan derivatives were shown to inhibit clot formation in APTT assay and ristocetin induced platelets aggregation, while the partially sulfated analogs were inactive. In the experiments with purified proteins, fucan derivatives with degree of sulfation of ∼ 2.0 were found to enhance thrombin and factor Xa inhibition by antithrombin III. The effect of sulfated fucans on thrombin inhibition, which was similar to those of heparinoid Clexane(®) (enoxaparin) and of a fucoidan from the brown alga Saccharina latissima studied previously, can be explained by the multicenter interaction and formation of a ternary complex thrombin-antithrombin III-polysaccharide. The possibility of such complexation was confirmed by computer docking study.

Fucoidans as a platform for new anticoagulant drugs discovery

Anionic fucose-containing polysaccharides (fucoidans of brown seaweeds, sulfated fucans and fucosylated chondroitin sulfates of invertebrates) are attracting a rapidly growing research interest due to different types of their biological activity discovered in recent years. In particular, algal fucoidans are characterized by large structural variations depending on the species used for their isolation and by the lack of structural regularity due to random distribution of both carbohydrate and non-carbohydrate substituents along the polymer chains. These features make it difficult to find distinct correlations between structural elements and biological properties of polysaccharides. Nevertheless, there is expectation that systematic structural and biochemical studies of fucoidans will form a basis for the development of new drugs. Herewith we summarize our recent results on the influence of fucoidan structure on blood coagulation.

Influence of fucoidans on hemostatic system

Three structurally different fucoidans from the brown seaweeds Saccharina latissima (SL), Fucus vesiculosus (FV), and Cladosiphon okamuranus (CO), two chemically modified fucoidans with a higher degree of sulfation (SL-S, CO-S), and a synthetic totally sulfated octasaccharide (OS), related to fucoidans, were assessed on anticoagulant and antithrombotic activities in different in vitro experiments. The effects were shown to depend on the structural features of the compounds tested. Native fucoidan SL with a degree of sulfation (DS) of 1.3 was found to be the most active sample, fucoidan FV (DS 0.9) demonstrated moderate activity, while the polysaccharide CO (DS 0.4) was inactive in all performed experiments, even at high concentrations. Additional introduction of sulfate groups into fucoidan SL slightly decreased the anticoagulant effect of SL-S, while sulfation of CO, giving rise to the preparation CO-S, increased the activity dramatically. The high level of anticoagulant activity of polysaccharides SL, SL-S, and CO-S was explained by their ability to form ternary complexes with ATIII-Xa and ATIII-IIa, as well as to bind directly to thrombin. Synthetic per-O-sulfated octasaccharide OS showed moderate anticoagulant effect, determined mainly by the interaction of OS with the factor Xa in the presence of ATIII. Comparable tendencies were observed in the antithrombotic properties of the compounds tested.

[Special effects of a complex probiotic containing cellulolytic bacteria Cellulomonas on actively growing rabbits]

It was shown that the association of probiotic bacteria of the genuses Bacillus and Cellulomonas form biolayers on the surface of beet marc particles. The positive effect of a fodder additive that contained the biolayer on the basis of a phytomatrix on the growth and development of young rabbits was shown. Feeding of animals with a mixed fodder that contained 0.1% preparation resulted in stimulation of digestion of all components of the food. Among other components of the mixed fodder, cellulose was digested most effectively. An increase in the biomass of symbiotic bacteria and enzymatic activity in the blindgut chymus was also observed. The positive nitrogen balance demonstrated an increase in the nitrogen content in animals and a decrease of its losses with excretion. The mechanism of response of the rabbit's organism to introduction of the complex probiotic preparation into the digestive tract is discussed.

Integrin α5β1 simultaneously controls EGFR-dependent proliferation and Akt-dependent pro-survival signaling in epidermoid carcinoma cells

To delineate distinctive role of the components of α5β1 integrin-EGFR axis in control of epidermoid carcinoma cell proliferation, we performed individual inhibition of α5β1 and EGFR via genetic and phamacological methods, respectively. We demonstrated that pharmacological inhibition of epidermal growth factor receptor (EGFR) significantly affected proliferation of A431 human cells by inducing the G0/G1 cell cycle arrest, whereas shRNA-mediated depletion of α5 subunit of α5β1 integrin led to a similar type of cell cycle arrest followed by significant apoptosis. Both treatments resulted in suppression of activated (phosphorylated) forms of focal adhesion kinase (FAK) and Erk. However, unlike EGFR inhibition, depletion of α5 led to substantial suppression of AKT activity. Accordingly, pharmacological inhibition of EGFR and AKT recapitulated detrimental effects caused by shRNA-mediated depletion of α5. Moreover, depletion of α5 led to a severe drop in the amounts of active EGFR. Thus, for the first time, we demonstrated that α5β1 integrin simultaneously maintains pro-survival signaling via continuous activation of AKT and up-regulates proliferation via activation of EGFR.

[Implication of integrin alpha5beta1 in human breast carcinoma apoptosis and drug resistance]

Doxorubicin-resistant MCF-7Dox line, which is a derivative of the drug-sensitive MCF-7 human breast carcinoma line, differs from the latter by a strongly reduced expression of the alpha2beta1 integrin and a highly increased expression of the alpha5beta1 receptor. Silencing of this integrin in the MCF-7Dox cells by transfection with alpha5-specific siRNA markedly stimulated anoikis and increased sensitivity of the cells to doxorubicin. Alpha5beta1 silencing also leads to significant inhibition of the activity of kinases Akt and Erk2 in MCF-7Dox cells. Our results suggest that integrins alpha5beta1-induced signals, controlling distinct aspects of cell behavior, are conducted through the common signal pathways.

Fucans, but not fucomannoglucuronans, determine the biological activities of sulfated polysaccharides from Laminaria saccharina brown seaweed

Sulfated polysaccharides from Laminaria saccharina (new name: Saccharina latissima) brown seaweed show promising activity for the treatment of inflammation, thrombosis, and cancer; yet the molecular mechanisms underlying these properties remain poorly understood. The aim of this work was to characterize, using in vitro and in vivo strategies, the anti-inflammatory, anti-coagulant, anti-angiogenic, and anti-tumor activities of two main sulfated polysaccharide fractions obtained from L. saccharina: a) L.s.-1.0 fraction mainly consisting of O-sulfated mannoglucuronofucans and b) L.s.-1.25 fraction mainly composed of sulfated fucans. Both fractions inhibited leukocyte recruitment in a model of inflammation in rats, although L.s.-1.25 appeared to be more active than L.s.-1.0. Also, these fractions inhibited neutrophil adhesion to platelets under flow. Only fraction L.s.-1.25, but not L.s.-1.0, displayed anticoagulant activity as measured by the activated partial thromboplastin time. Investigation of these fractions in angiogenesis settings revealed that only L.s.-1.25 strongly inhibited fetal bovine serum (FBS) induced in vitro tubulogenesis. This effect correlated with a reduction in plasminogen activator inhibitor-1 (PAI-1) levels in L.s.-1.25-treated endothelial cells. Furthermore, only parent sulfated polysaccharides from L. saccharina (L.s.-P) and its fraction L.s.-1.25 were powerful inhibitors of basic fibroblast growth factor (bFGF) induced pathways. Consistently, the L.s.-1.25 fraction as well as L.s.-P successfully interfered with fibroblast binding to human bFGF. The incorporation of L.s.-P or L.s.-1.25, but not L.s.-1.0 into Matrigel plugs containing melanoma cells induced a significant reduction in hemoglobin content as well in the frequency of tumor-associated blood vessels. Moreover, i.p. administrations of L.s.-1.25, as well as L.s.-P, but not L.s.-1.0, resulted in a significant reduction of tumor growth when inoculated into syngeneic mice. Finally, L.s.-1.25 markedly inhibited breast cancer cell adhesion to human platelet-coated surfaces. Thus, sulfated fucans are mainly responsible for the anti-inflammatory, anticoagulant, antiangiogenic, and antitumor activities of sulfated polysaccharides from L. saccharina brown seaweed.

[Anaerobic solid-phase fermentation of plant substrates by Bacillus subtilis]

Solid-phase growth of Bacillus subtilis 8130 on cellulose-rich plant substrates (presscakes or pulp) under hypoxic conditions was accompanied by cellulose depolymerization, protein hydrolysis, and degradation of other plant components, including some processes of mixed-type carbohydrate fermentation. The bacterial fermentation yielded propionic, butyric, and hexanoic acids and butyric acid derivatives. The bacterial metabolism and fermentation degree can be characterized by the proportions of fatty acids in the reaction mixture. The product of sea buckthorn cake fermentation has a good sorption quality.

A comparative study of the anti-inflammatory, anticoagulant, antiangiogenic, and antiadhesive activities of nine different fucoidans from brown seaweeds

The anti-inflammatory, antiangiogenic, anticoagulant, and antiadhesive properties of fucoidans obtained from nine species of brown algae were studied in order to examine the influence of fucoidan origin and composition on their biological activities. All fucoidans inhibited leucocyte recruitment in an inflammation model in rats, and neither the content of fucose and sulfate nor other structural features of their polysaccharide backbones significantly affected the efficacy of fucoidans in this model. In vitro evaluation of P-selectin-mediated neutrophil adhesion to platelets under flow conditions revealed that only polysaccharides from Laminaria saccharina, L. digitata, Fucus evanescens, F. serratus, F. distichus, F. spiralis, and Ascophyllum nodosum could serve as P-selectin inhibitors. All fucoidans, except that from Cladosiphon okamuranus carrying substantial levels of 2-O-alpha-D-glucuronopyranosyl branches in the linear (1-->3)-linked poly-alpha-fucopyranoside chain, exhibited anticoagulant activity as measured by activated partial thromboplastin time whereas only fucoidans from L. saccharina, L. digitata, F. serratus, F. distichus, and F. evanescens displayed strong antithrombin activity in a platelet aggregation test. The last fucoidans potently inhibited human umbilical vein endothelial cell (HUVEC) tubulogenesis in vitro and this property correlated with decreased levels of plasminogen-activator inhibitor-1 in HUVEC supernatants, suggesting a possible mechanism of fucoidan-induced inhibition of tubulogenesis. Finally, fucoidans from L. saccharina, L. digitata, F. serratus, F. distichus, and F. vesiculosus strongly blocked MDA-MB-231 breast carcinoma cell adhesion to platelets, an effect which might have critical implications in tumor metastasis. The data presented herein provide a new rationale for the development of potential drugs for thrombosis, inflammation, and tumor progression.

The role of beta1 integrin subfamily in anchorage-dependent apoptosis of breast carcinoma cells differing in multidrug resistance

Integrin expression was investigated in MCF-7 human breast adenocarcinoma line and in the MCF-7Dox line, which was selected from MCF-7 by a resistance to multiple antitumor drugs (MDR). We have shown that acquisition of MDR was accompanied by a drastically reduced expression of some integrins of the beta1-subfamily (alpha2beta1, alpha3beta1, alpha6beta1) and of alpha vbeta5 intergin in the adenocarcinoma cells. In contrast, expression of alpha5beta1 integrin was markedly increased in the MDR cells. Along with multiple antitumor drug resistance, MCF-7Dox cells demonstrate elevated resistance to anchorage-dependent apoptosis (anoikis) and enhanced in vitro invasive activity. To elucidate the implication of beta1-integrins in the above phenotypic modifications, the effect of beta1-integrin signaling was assayed. Stimulation of beta1-mediated signaling was accomplished by treating of the cells with antibodies to the beta1-subunit common for members of the beta1-subfamily. These data show that activation of beta1-integrin signaling markedly upregulated anoikis of the adenocarcinoma cells.

[A study of the mechanisms of probiotic effect of Bacillus subtilis 8130 strain]

The wild-type Bacillus subtilis strain 8130 secreted metabolites that stimulated two to three times the growth of the test cultures of lactic acid bacteria. It exhibited endoglucanase activity that depended on the composition of nutrient medium. The addition of the product of two-stage culturing of B. subtilis 8130 to the diet of pigs (0.2% of fodder weight) made it possible to increase the daily weight gain by 19% and decrease the consumption of mixed fodder by 10%. Digestion of protein, fat, and other organic compounds increased by 3-4% and cellulose by 12%. It was shown that B. subtilis 8130 is a probiotic with targeted action stimulating digestion (primarily the digestion of cellulose). The enrichment of a dry-beer pellet with the product of solid-phase fermentation by bacillus (1 x 10(8) cells per gram dry pellet) allowed the pellet to entered into the diet of a calf (6% of the weight of fodder with probiotic), causing additional weight gain by 12% and a 10% economy of fodder consumption.

Monomeric and Multimeric Blockers of Selectins: Comparison of in vitro and in vivo Activity

The potency of the oligosaccharides SiaLe(x), SiaLe(a), HSO(3)Le(x), and HSO(3)Le(a), their conjugates with polyacrylamide (PAA, 40 kD), and other monomeric and polymeric selectin inhibitors has been compared with that of the polysaccharide fucoidan. The following assay systems were used: 1) a 96-well assay based either on the use of recombinant E-, P-, and L-selectins or an analogous assay with natural P-selectin isolated from human platelets; 2) a platelet-based P-selectin cell assay; and 3) a rat model of peritoneal inflammation. IC(50) values for the neoglycoconjugate SiaLe(a)-PAA were 6, 40, and 85 microM for recombinant E-, P-, and L-selectins, respectively; all monomeric inhibitors were about two orders of magnitude weaker. PAA-conjugates, containing as a ligand tyrosine-O-sulfate (sTyr) in addition to one of the sialylated oligosaccharides, were the most potent synthetic blockers in vitro. Compared with fucoidan, the most potent known P- and L-selectin blocker, the bi-ligand glycoconjugate HSO(3)Le(a)-PAA-sTyr displayed similar inhibitory activity in vitro towards L-selectin and about ten times lower activity towards P-selectin. All of the tested synthetic polymers displayed a similar ability to inhibit neutrophil extravasation in the peritonitis model (in vivo) at 10 mg/kg. The data provide evidence that monomeric SiaLe(x) is considerably more effective as a selectin blocker in vivo than in vitro, whereas the opposite is true for fucoidan and the bi-ligand neoglycoconjugate HSO(3)Le(a)-PAA-sTyr.

[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 Synthesis and NMR and Conformational Studies of Fucoidan Fragments: VI.1Fragments with an -(1 2)-Linked Fucobioside Unit

A series of selectively sulfated di- and trisaccharide derivatives corresponding to the potential fragments of fucoidans with a (1-->2)-alpha-bound fucobioside unit were synthesized and studied by 1H and 13C NMR spectroscopy. NOE experiments and molecular modeling were used for a conformational analysis of the compounds synthesized. In the case of disaccharides, the experimental NOE values were found to agree with those obtained using modeling with the use of density functional theory (DFT) and differ from those resulting from modeling by the molecular mechanics MM3 force field. Trisaccharide fragments partially or completely sulfated in position 4 turned out to be correctly described by both MM3 force field and DFT computation. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 2; see also http://www.maik.ru.

P-selectin blocking potency of multimeric tyrosine sulfates in vitro and in vivo

P-selectin blocking potency was investigated using synthetic monomeric and polymeric anionic compounds containing sulfate groups such as O-sulfotyrosine (sTyr) and/or sulfated Lewis structures. A non-carbohydrate-containing polyacrylamide conjugate sTyr-PAA (80% mol of sTyr) was a remarkably potent inhibitor of P-selectin binding in vitro, having an IC(50) value of 6 ng/mL (equivalent to 10 nM calculated on the basis of sTyr residues or 0.1 nM calculated by the mass of the macromolecule). The inhibitory effect of sTyr-PAA (80%) towards P-selectin is significantly greater than that of fucoidan (IC(50), 100 ng/mL). However, sTyr-PAA (80%) was less effective than fucoidan at reducing neutrophil extravasation in an in vivo rat model of peritonitis.

[Cellulose decomposition under nitrogen deficiency by bacteria isolated from the intestines of phytophagous vertebrates]

A nitrogen-fixing strain identified as Klebsiella pneumonia 402-2 and two endoglucanase-synthesizing Bacillus strains were isolated from the intestines of phytophagous animals. One of the Bacillus strains was identified as Bacillus subtilis GL. Klebsiella pneumoniae 402-2 increased the endoglucanase activity of both Bacillus strains in mixed cultures. The data on the taxonomic position of strains 402-2 and GL and on the nitrogen-fixing capacity of strain 402-2 were confirmed by sequencing and analyzing their 16S rRNA genes and by amplifying the nitrogenase gene nifH.

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.

[Effects of mannose derivatives on development of selectin-dependent peritoneal inflammation in rats and mice]

The inhibitory effect of mannose-containing oligosaccharides on model carbohydrate ligand interaction with E-, P- and L-selectins in vitro, as well as on the ability of these compounds to block the leukocyte extravasation in rat and mouse peritonitis in vivo was studied. The monomeric and polymeric compounds, 4-nitrophenylthiomannoside, phenylmannoside, conjugated with polyacrylic acid, and alpha-mannose, conjugated with polyacrylamide, inhibited the binding of the model ligand to P- and L-selectins (but not to E-selectin). Intravenous injection of these compounds was found to cause a dose-dependent reduction of neutrophil accumulation in rat peritoneum. The polysaccharide mannan was inactive in both types of experiments. The conjugate of phenylmannoside with polyacrylic acid was the most effective blocker as in vitro experiments, as well as in vivo. The inhibitory effect of subcutaneous injection of 4-nitrophenylthiomannoside on mouse peritonitis was demonstrated.

[Nitrogen requirements of Microtus rossiaemeridionalis]

Total nitrogen requirements in the small herbivorous rodent Microtus rossiaemeridionalis were studied. When provided with two kinds of standard laboratory food (about 20 and 0% digestible protein, respectively) ad libitum (cafeteria diet), the voles chose a diet of 14% protein. The total daily (with urine and faeces) nitrogen losses were, in this case, determined as 3.65 +/- 0. 60 mg N/g of body mass. When provided with a protein-free diet alone, the animals lost 0.90 +/- 0.05 mg N/g body mass per day, comprising about 3% of their body mass daily. It was proposed that the consumption of a low-fiber diet (about 4% in both kinds of food) could affect the gastrointestinal bacterial flora and, thus, lead to changes in the primarily herbivorous nitrogen metabolism.

[Nitrogen fixation--new fenomenon in rodent feeding]

We have conducted a series of experiments in order to test hypothesis about the possible use of nitrogen fixation by small phytophagous mammals as a way to supplement their nitrogen balance. Two groups of red voles Clethrionomys rutilis were kept on rations with different protein nitrogen content. Three days later, the rate of nitrogen fixation was determined in different regions of the digestive tract. Nitrogen-fixing activity has been detected in the GI tract of all studied voles, specifically in those regions, where symbiocenoses were present; it was particularly high in animals of the experimental group under the conditions of dietary nitrogen limitation. A mixed culture of bacteria capable of nitrogen fixation has been isolated from the digestive tract of red voles.

[Analysis of various taxon specific parameters of the guard hair cuticles for development of the mammalian identification system by morphometric characteristics of their hair]

Mathematical indices of the structure of the external surface of guard hairs have been developed on the basis of a KS300 system of automatic image analysis (Kontrom Elektronik, Germany), which are capable of serving, in some cases, as diagnostic parameters of large taxa (order, family). The guard hair morphology is affected by various factors, such as body region where a given hair is located, season, diet, sex of individual, and state of its health, which is expressed in changes of some morphometric data. For a more complete analysis of the characteristics of the guard hair structure, it is necessary to use indices that describe the macro- and microstructure of the external surface of the stem and its internal structure.

Adaptation to salt stress in a salt-tolerant strain of the yeast Yarrowia lipolytica

We have studied the cellular mechanisms underlying adaptation to salt stress in a newly isolated osmo- and salt-tolerant strain of the yeast Yarrowia lipolytica. When cells are incubated in the presence of 9% NaCl, a rapid change in their size and shape is observed. Salt stress is accompanied by an increase in the intracellular level of glycerol, free amino acids (notably proline and aliphatic amino acids), and Na+, as well as by changes in lipid and fatty acid composition.

[Inhibitory activity of monomeric and polymeric selectin ligands]

The ability of tetrasaccharides (SiaLex, SiaLea, HSO3Lex), their conjugates with polyacrylamide (40 kDa), and several other monomeric and polymeric substances to block selectins has been compared with that of polysaccaride fucoidan. Two assay systems were used: one was constructed on the base of recombinant E-, P-, and L-selectins; the other was a rat model of peritoneal inflammation. IC50 values for the neoglycoconjugate SiaLea-PAA were 6, 40, and 85 microM with the recombinant E-, P-, and L-selectins, respectively; all monomeric inhibitors were about two orders of magnitude weaker. PAA-conjugates, containing as a ligand tyrosine-o-sulfate in addition to one of the above mentioned oligosaccharides, were the most potent synthetic blockers. Compared with the most potent of the known inhibitors, fucoidan, bi-ligand glycoconjugate HSO3Lea-PAA-sTyr, displayed in vitro similar activity in blocking L-selectin, while its activity towards P-selectin was ten times lower. All the synthetic polymers tested were able to inhibit neutrophil extravasation to inflammation site, acting in concentration about 10 mg/kg. Thus, the effect of SiaLex is considerably more effective in vivo than in vitro, whereas heavily charged fucoidan and bi-ligand neoglycoconjugate acted in converse manner.

[Development of microbiological technology of air deodoration in laboratory-industrial conditions using a pilot plant]

Laboratory tests were performed to select a complex of bacterial strains capable of effective deodoration of waste air produced by an animal formulated feed works under elevated temperature with the presence of numerous organic pollutants. The complex included species from the general Nocardia, Rhodococcus, and Comamonas. The biocatalyst was tested in a real industrial process with the use of a pilot plant for microbiological deodoration of waste air. The test lasted for over six months and confirmed the efficiency of the development method of deodoration.

[Sulfated polysaccharides as inhibitors of receptor activity of P-selectin and P-selectin-dependent inflammation]

The inhibitory effects of sulfated polysaccharides-fucoidan and heparin on P-selectin-ligand interaction in vitro and on the ability of fucoidan to inhibit the leukocyte extravasation in rat peritonitis were studied. The lectin activity of P-selectin in vitro was based on its ability to bind lectin-labeled synthetic ligand, Sialyl-Lea/x, conjugated with polyacrylamide (PAA). Fucoidan and heparin inhibited binding of labeled ligand to both purified P-selectin and the activated platelets expressing P-selectin on their surface. The inhibitory effect of fucoidan 100-fold higher than that of heparin. As P-selectin plays an important role at an earlier stage of the inflammation process, the antiinflammatory action of fucoidan on P-selectin-dependent peritonitis in rats was studied. Peritonitis was induced by intraperitoneal injection of the peptone solution and was characterized by an increase in total cell number and neutrophil percentage in rat peritone exudate. Intravenous injection of fucoidan was found to cause a dose- and time-dependent reduction of neutrophil extravasation into inflamed peritoneum. The minimal dose of fucoidan, that was able to produce 96.8 +/- 2.9% inhibition of neutrophil extravasation--if administered within the first 15 min after peptone-B was 0.8 mg per rat. Significant effect of fucoidan injection (about 80% inhibition) was also obtained 1.5 h after the induction of inflammation. Fucoidan administered 2.5 h after peptone had virtually no effect on neutrophil extravasation. The data obtained show that fucoidan blocks the inflammation process at its earlier stages--most probably at the expense of its interaction with P-selectin.

Fucoidan inhibits leukocyte recruitment in a model peritoneal inflammation in rat and blocks interaction of P-selectin with its carbohydrate ligand

Neutrophil recruitment into systemic inflammatory sites in vivo is thought to be initiated by selectin-mediated endothelial adherence. The effect of fucoidan (natural sulfated polymer of L-fucose) on the selectin dependent PMN migration into rat peritoneum following the induction of inflammation by peptone injection was studied. Peritonitis was characterized by an increase in the total cell number (from 45.3 x 10(6) to 91.6 x 10(6)/rat), and by highly elevated PMN content (from 0.2% to 58%) in the rat peritoneal cavity 3 h after peptone injection. Intravenous administration of fucoidan was found to reduce, in a dose-dependent manner, neutrophil migration into peritoneum. Fucoidan in a dose as low as 0.8 mg per rat caused 96.8% reduction of neutrophil extravasation. The inhibitory effect of fucoidan was also dependent on the time intervals between the peptone and fucoidan injections. The maximal inhibitory effect of fucoidan was observed within the first 15 min after the induction of peritonitis and it was maintained at a level of 80% during 1.5 h. Administration of fucoidan 2.5 h after peptone injection had practically no effect on PMN extravasation. Since P-selectin is known to play a key role at the earlier stages of PMN extravasation, it was suggested that the inhibitory effect of fucoidan was mostly due to its interaction with P-selectin. The in vitro experiments demonstrated the high affinity of fucoidan for both isolated P-selectin and P-selectin in plasma membranes of activated platelets.

[Change of isoforms' spectrum of alpha-L-fucoside secreted by affected cells in some hereditary lysosomal diseases]

In vitro it was studied the isoform spectra of the intracellular and secreted alpha-L-fucosidase from skin fibroblasts of patients with Fabry disease (glycolipidosis), Hurler and Sanfilippo D diseases (mucopolysaccharodosis, types I and III) and in the normal state was studied. It was shown that the multiple form profile of secreted alpha-L-fucosidase in patients fibroblasts was changed as compared to that in control: the pathological cells were characterized by expression of more basic isoforms of alpha-L-fucosidase. The changes were similar to those in sucrose-loaded normal cells, modelling storage disease. The data obtained allow the suggestion that the intracellular accumulation of compounds whose hydrolysis was disturbed on a hereditary deficiency of enumerated glycosidases can influence the posttranslational processing of alpha-L-fucosidase, the enzyme which is not primary affected in these disorders. These data allow the conclusion that the high phenotypic heterogenity of lysosomic storage diseases is possibly due to the influence of so-called epigenetic factors involving the changes in properties of such glycosidases as are not associated with a primary hereditary defect.

[The structure of the skin of the external auditory canal and the antiviral activity of the cerumen in carnivorous mammals]

The structure of the meatus acusticus externus skin was studied in the sable, mink, and European polecat with a parallel estimation of antiherpetic activity of the cerumen. Morphologically, these species differ in the degree of fat cellulose development, vascularization, and association with the lymphoid tissue. Lymphocytes are present both in the tissue and along the skin gland ducts and hair follicles up to the external surface only in the sable. The cerumen samples have antiviral activity also in the sable alone. The relationship between physiological properties of the mammalian cerumen and morphogenetic features is discussed.

[The anti-infective properties of mammalian earwax]

The cerumen (earwax) of some mammals possesses antistaphylococcal, antimicrococcal and antiherpes activities. The cerumen of two thirds of individuals, irrespective of their species identity and sex, has antiviral properties. The mean chemotherapeutical index in the studied groups follows a significantly decreasing sequence: dogs, humans without signs of herpes infections, rabbits, and humans with clinically expressed herpes infection. Cerumen of almost 25% of humans of the compared groups displays the immunostimulating activity. The cerumen of all studied individuals contains yeast-like fungi. A suggestion is put forward that the products of their metabolism stimulate local release of interferon-like substances by the lymphoid tissue in the cerumen.

Lysosomal glycosidases in different populations of human thymocytes

Lysosomal glycosidase activities were studied in human thymocyte fractions obtained by two methods: (A) fractionation in Percoll density gradient and (B) separation from the cells forming rosettes with sheep erythrocytes (E-RFC). (A) affords fraction L, enriched with immature and endogenously activated thymocytes, and fraction H containing mature thymocytes. By use of (B), fraction E-RFC--enriched with non-activated immature thymocytes--was obtained. Comparative study of E-RFC and H revealed diverse alterations in activities of glycosidases during thymocytes maturation, specifically decreases in alpha-L-fucosidase and alpha-D-mannosidase and an increase in beta-D-galactosidase. Comparing E-RFC and L demonstrates increases in activities of studied glycosidases following endogenous activation of thymocytes.

[Bacteria in the secretion of auxiliary sacs in the opening of the cheek pouches in Campbell hamsters]

A specific and balanced bacterial community exists in the secrete of auxiliary sacs (AS) in the opening of buccal pockets of Campbell hamsters. Parents pass these bacteria to the progeny through certain forms of their social behavior. The bacterial community forms in babies by the 20th day, i.e. when they are abandoned by parents and start independent existence. A composition of the bacterial community in the AS secrete is independent of the host sex; however, it depends on the physiological state of the host organism, e.g. it changes during lactation. A removal of the AS secrete, containing bacteria, has adverse effects on the hamster physiology: it causes intestine dysbacteriosis, active propagation of Protozoa and parasitic worms. The lack of a normal microbial community in the AS of babies, who did not get the AS secrete from their parents, has analogous consequences.

[The participation of vaginal bacteria in Phodopus campbelli in the chemical communication between male and female]

Phodopus campbelli commonly occurs in dry steppe and semidesert zone of south Siberia, Mongolia and China. Using radiotelemetry we found that a male has to cover about 2 km from his burrow to encounter a receptive female. Female in estrus marks a small area around its burrow by vaginal smear. Experiments were carried out in laboratory to discover the nature of this strong signal. In a "open field" area four boxes within stimuli we recorded the time complemented spent by males near boxes to study the attractive effect of intact receptive female, germ culture of vaginal smear and artificial mixed culture of bacteria which were found in the vaginal smear of Ph. campbelli receptive female. Males (n = 15) spent significantly more time near the boxes with female in estrus or day before estrus as compared with two other days of cycle. Germ culture from vaginal smear sampled on the estrus day was more attractive to males on 6th day than on the 2, -3, -5, -7, -8--or 9th days of cultivation, pure culture or germ culture sampled on anestrus. Mixed culture, which simulated the proportion of predominant bacteria in the estrus vaginal smear, was significantly more attractive for males on the 3rd day of cultivation. Thus sexual attractant of Ph. campbelli could be produced by some bacteria located in the vagina in estrus and it takes a couple of days of cultivation for maximum attractive effect.

Isoform patterns of lysosomal glycosidases in phenotypically different leukemic lymphoid cells

Isoform patterns of six lysosomal glycosidases were studied in leukemic lymphoid cells phenotypically related to B and T cells at distinct stages of differentiation. In all types of cells, the activity of glycosidases under study was expressed in two major isoforms. No correlation was observed between isoform patterns and cell phenotypes. The beta-hexosaminidase isoform ratios for phenotypically related leukemic lymphoid cells but isolated from different sources (blood and spleen) differed. It was suggested that cell localization affects isoform expression. An anomalous alpha-mannosidase was detected in lymphoid cells from lymph nodes, while it was lacking in the phenotypically related blood lymphoid cells from the same patients. Isoform I of beta-hexosaminidase was recorded in lymphoid cells of patients with anemias.

[The interaction between bacteria and the surface of the skin and hair in mammals]

There is a certain equilibrium between the organism and the bacteria on the surface of the animal's skin, which depends on the structure and physicochemical properties of the external cover. The structure of cuticular scale of the rabbit hair and the number of bacteria on it are related to the physiological condition of the animal. In diseased rabbits the relief of the hair surface becomes more complicated, the number of bacteria uniformly distributing along the hair stem increases and the capacity of the hair for adhesion of new bacteria is enhanced. Stimulation of non-specific immunity of animals leads to smoothing of the scale surface, uniform disappearance of bacteria and decreased adhesion of new microorganisms. The cuticle structure and adhesive properties of the hair can be used as criteria for assessing certain influences on the organism.

Acidic alpha-D-mannosidase in phenotypically different leukemic lymphoid cells

The activity of acid alpha-mannosidase in phenotypically characterized lymphoid cells, isolated from peripheral blood, spleen and lymph nodes of patients with various lymphoproliferative disorders has been studied. Cells with different immunophenotypes were shown to have different alpha-mannosidase activity levels. The lowest alpha-mannosidase activity was observed in cells phenotypically corresponding to early B cells obtained from B-CLL patients. The highest activity was determined in cells with phenotypes of activated, CD11c-expressing B cells from B-NHL and HCL patients. There were considerable differences in alpha-mannosidase activity between peripheral blood and spleen lymphoid cells of B-NHL patients with spleen damage. The data obtained may be used in classification, primary diagnosis and staging of hematopoietic malignancies.

[Lymphoid cell glycosidases in various forms of lymphoproliferative disorders]

Activity of 8 glycosidases (6 acid lysosomal and 2 neutral cytosolic enzymes) was estimated in lymphoid cells of 28 patients with different forms of lymphoproliferative disorders: B- and T-chronic lymphocytic leukemia (CLL), non-Hodgkins lymphoma (NHL), Sezary syndrome, hairy cell leukemia (HCL) and B- and T-acute lymphoblastic leukemia (ALL). Activity of these glycosidases was also studied in mononuclear cells and granulocytes of healthy volunteers and in immature myeloid cells of 16 patients with chronic myeloid leukemia (CML). In lymphoid cells of all the patients studied (except of ALL) the glycosidases activity was decreased as compared with that of normal mononuclear cells and immature myeloid cells. Activity of the majority enzymes studied was higher in T-lymphoid cells of patients with lymphoproliferative disorders as compared with B-cells. The highest glycosidases activity was found in ALL cells and the lowest--in CLL cells of the patients with B-lymphoid cells forms of the disease. Activities of N-acetyl-beta-D-hexosaminidase, alpha-D-mannosidase and beta-D-glucuronidase were distinctly dissimilar in cells of the patients with B-CLL, B-NHL and HCL. Estimation of these glycosidases activity in lymphoid cells may be of importance in differential diagnosis of lymphoproliferative disorders.

[The dynamics of the bacterial associations in the vaginal mucus of female Syrian hamsters during the sexual cycle]

Autofluctuations in the numbers of bacteria, leukocytes and epithelial cells were observed in the vaginal secretion of Syrian female hamsters. The amplitude of fluctuations depended both on individual features of females and on environmental factors like light conditions. It was suggested that vaginal bacteria perform functions of a stimulator for local immunity to protect against infections and play a sanitary role to eliminate epithelial cells and remains of spermatozoids. A case is possible that products of the bacterium vital activity contribute also to the formation of female sex pheromone.

[Neutral alpha-mannosidase in human B- and T-lymphoid cells]

The presence of neutral alpha-mannosidase activity in normal and pathological lymphoid cells has been demonstrated. The specific activities of the enzyme in different cell types were similar with the exception of B-cells from B-CLL patients when it was a little higher. The activity of acid alpha-mannosidase was also determined in these lymphoid cells. The neutral to acid alpha-mannosidase activity ratio was different in B- and T-cells: in the former neutral alpha-mannosidase activity prevailed, whereas in the latter the predominance of acid alpha-mannosidase activity was apparent. Neutral alpha-mannosidases from pathological B- and T-cells were partially purified and their properties were investigated. In both cell types the enzyme was localized in the cytosol, was very labile and could be stabilized with Mn2+ and dithiothreitol. The enzyme was activated by Co2+ and inhibited by Zn2+ and EDTA. Swainsonine inhibited the B-cell neutral alpha-mannosidase somewhat more strongly in comparison with the T-cell enzyme.