Reconstruction and analysis of the gene regulatory network for cell wall function in Arabidopsis thaliana L. leaves in response to water deficit.

The plant cell wall represents the outer compartment of the plant cell, which provides a physical barrier and triggers signaling cascades under the influence of biotic and abiotic stressors. Drought is a factor that negatively affects both plant growth and development. Cell wall proteins (CWP) play an important role in the plant response to water deficit. The adaptation mechanisms of the cell wall to water loss are of interest for identifying important genetic factors determining plant drought resistance and provide valuable information on biomarkers for further selection aimed at increasing the yield of crop plants. Using ANDSystem, a gene network describing the regulation of CWPs under water restriction conditions was reconstructed. The analysis of the gene network and the transcriptome data analysis allowed prioritizing transcription factors (TF) based on their enrichment of differentially expressed genes regulated by them. As a result, scores were calculated, acting as indicators of the association of TFs with water deficit. On the basis of the score values, eight most significant TFs were selected. The highest priority was given to the TF GBF3. CWPs were prioritized according to the criterion of summing up the scores of transcription factors regulating these genes. Among the most prioritized CWPs were the AT5G03350 gene encoding a lectin-like protein, AT4G20860 encoding BBE-like 22 required for the oxidation of cellulose degradation products, and AT4G37800 encoding xyloglucan endotransglucosylase/ hydrolase 7. Overall, the implemented algorithm could be used for prediction of regulatory interactions between transcription factors and target genes encoding cell wall proteins in plants.

Prospects for the use of blood elemental status to assess the molecular genetic profile of gliomas.

It has been established that blood element homeostasis is related to gliomagenesis which increases the attractiveness of the analysis of its components as a promising preoperative mediated characteristics of the molecular genetic profile of gliomas. The aim of this work is to analyze the relationship between mineral metabolism parameters and immunohistochemical characteristics of glial tumors and evaluate the clinical significance of blood element homeostasis analysis for preoperative assessment of the molecular profile of gliomas. The levels of cancer specific markers MGMT, Ki-67, p-53, IDH1 were determined immunohistochemically using the corresponding antibody clones. Micronutrient levels were analyzed by inductively coupled plasma atomic emission spectrometry recalculating the results per 1 g of protein which was determined by the Lowry method. The data on cancer-specific marker levels obtained in primary brain tumors (20) and in blood plasma of gliomas patients (20) and practically healthy subjects (5) were compared using a number of statistical programs. We found significant differences in the levels of sodium, potassium, zinc and copper depending on the value of the mitotic index Ki-67 and IDH1 isocitrate dehydrogenase gene mutation. For the first time, a significant correlation showing the consistency between the level of glial tumor cancer-specific markers and blood mineral metabolism was observed. The revealed correlations provide new insights into understanding of gliomagenesis mechanisms and can be used as a predictive preoperative assessment of molecular genetic markers of gliomas.

Review: Tertiary cell wall of plant fibers as a source of inspiration in material design.

The review summarizes the plant lifehacks on material design on the example of the impressive cellulose-enriched cell wall deposited by fibers of many plants. This specific cell wall type is called tertiary since it is deposited after the secondary cell wall and is very distinct in the machinery of formation and function. The basic principles of tertiary cell wall performance include: 1) original composition (two major players - cellulose microfibrils and the version of rhamnogalacturonan I that forms specific supramolecular structures); 2) original cell wall design with axial orientation of all cellulose microfibrils, pronounced lateral interactions between them and the presence of the entrapped rhamnogalacturonan I; 3) dynamic changes in cell wall supramolecular organization due to rhamnogalacturonan I modifications in muro in the course of fiber maturation; 4) the built-in sensors that trace the cell wall state; 5) incorporation of tertiary cell wall into the system with higher level of organization.

Tumor M2-Pyruvate Kinase, Matrix Carbonic Anhydrase IX, and Metalloproteinase 9 - Novel Prognostic Markers of Renal Cell Carcinoma.

The aim of the study was to assess the possibility of using plasma levels of tumor M2-pyruvate kinase (Tu M2-PK), matrix carbonic anhydrase IX (CA9), and matrix metalloproteinase 9 (MMP9) in patients with renal cell cancer as predictors of the disease course and the response to treatment. MATERIALS AND METHODS: Samples of blood plasma or serum of 46 patients with clear cell renal cancer T1-4N0-1M0-1 obtained before surgery and 8-9 days after surgery were tested. The control group consisted of 20 practically healthy individuals, comparable in age with the examined patients. Quantitative determination of Tu M2-PK in EDTA-added blood plasma was performed by enzyme-linked immunosorbent assay using a ScheBo Tumor M2-PK test (Germany). Determination of CA9 by ELISA was performed using a Human Carbonic Anhydrase IX Quantikine ELISA Kit (USA) and MMP9 - using a Quantikine ELISA Kit (USA). RESULTS: In patients with renal cell carcinoma, a statistically significant increase in the level of Tu M2-PK, CA9 and a statistically significant decrease in MMP9 in comparison with the control group were found. The level of Tu M2-PK in patients with localized kidney cancer was significantly lower than in patients with disseminated cancer. An increase in size of the primary tumor and a decrease in the degree of its differentiation correlated with an increase in Tu M2-PK, and decrease in CA9 and MMP9 in the blood serum. Performing surgery equivalent to nephrectomy did not change the Tu M2-PK levels in the early postoperative period, but caused a decrease in the levels of CA9 and MMP9. CONCLUSION: The results indicate a potential significance of Tu M2-PK, CA9, and MMP9 as biological markers for predicting the disease course in patients with renal cell carcinoma.

Screenplay of flax phloem fiber behavior during gravitropic reaction.

Flax phloem fibers act as constitutively formed "muscles" that support the vertical position of the high but narrow stem. The specific mechanical properties of flax fibers and of similar fibers in other plant species are provided by the development of tertiary cell wall with tensed cellulose microfibrils. The work of phloem fibers becomes especially pronounced during the restoration of stem vertical position if it was disturbed. Gravistimulation of flax plants induces considerable modification of phloem fibers at the pulling stem side - the lumen diameter increases, while the cell wall thickness goes down. Here we show that the action of phloem fibers as motors of stem vertical position restoration is coupled to the cell wall remodelling as well as the increase of osmolytes (mainly potassium and malate) content, and accumulation of the γ-amino-butyric acid that may be involved in signalling events. The molecular players that take part in these processes are suggested.

[Microbiological analysis as effective tool for optimization of empirical antibiotic therapy in the urological clinic].

AIM: to study the features of microbiota in patients of urological departments and to optimize the schemes of antibiotic therapy. MATERIALS AND METHODS: Data of microbiological studies in patients of urological departments in 2017 years were analyzed. Isolation of pathogens was carried out using standard techniques. A disk diffusion test using Mueller-Hinton agar with BioRad disks was used to determine the sensitivity. The statistical analysis was performed using the WHONET 5.4 program. In addition, a comparison with the results of the PCR study was done. RESULTS: A total of 672 etiological pathogens were isolated in whole clinic in 2017 year. From those, 173 pathogens were found in the urological clinic, which accounted for 25.7% of the total number. Gram-negative bacteria predominated and its proportion was 59.23%. Gram-positive bacteria were isolated in 24.4%, and fungi were found in 16.37% of cases. The structure of pathogens isolated from stoma or obtained by catheterization was not significantly different. Most frequently isolated pathogens included @K. pneumonia (22.8%), @E. coli (21.2%), @C. albicans (17%), @P. aeruginosa (11%), @E. aerogenes (6%) and @S. aureus (3 %). @K. pneumonia usually had an unfavorable resistance pattern. E. coli isolated from urine samples had more favorable resistance pattern in comparison to pathogens obtained from stoma. The bacteria which were found in intensive care unit had the increased level of resistance. CONCLUSION: Gram-negative bacteria predominate in the urological clinic with a relatively high proportion of extended-spectrum beta-lactamase-producing organisms. Risk factors for the emergence of multi-resistant pathogens are the treatment in the intensive care unit and the presence of stomas or catheters. The PCR method, carried out in parallel with routine microbiological studies and regular analysis of the overall bacterial spectrum, allows to optimize the starting antibiotic therapy from the first day of the disease. The use of cephalosporins is not justified in the most cases. Aminoglycosides and fluoroquinolones remain effective. The use of either -Lactamase-protected penicillins or fosfomycin is possible only after obtaining the results of bacteriological study. When prescribing carbapenems, the risk of inefficiency is especially high in patients with stomas/catheters and transferred from the intensive care unit.

Pathogen-induced conditioning of the primary xylem vessels - a prerequisite for the formation of bacterial emboli by Pectobacterium atrosepticum.

Representatives of Pectobacterium genus are some of the most harmful phytopathogens in the world. In the present study, we have elucidated novel aspects of plant-Pectobacterium atrosepticum interactions. This bacterium was recently demonstrated to form specific 'multicellular' structures - bacterial emboli in the xylem vessels of infected plants. In our work, we showed that the process of formation of these structures includes the pathogen-induced reactions of the plant. The colonisation of the plant by P. atrosepticum is coupled with the release of a pectic polysaccharide, rhamnogalacturonan I, into the vessel lumen from the plant cell wall. This polysaccharide gives rise to a gel that serves as a matrix for bacterial emboli. P. atrosepticum-caused infection involves an increase of reactive oxygen species (ROS) levels in the vessels, creating the conditions for the scission of polysaccharides and modification of plant cell wall composition. Both the release of rhamnogalacturonan I and the increase in ROS precede colonisation of the vessels by bacteria and occur only in the primary xylem vessels, the same as the subsequent formation of bacterial emboli. Since the appearance of rhamnogalacturonan I and increase in ROS levels do not hamper the bacterial cells and form a basis for the assembly of bacterial emboli, these reactions may be regarded as part of the susceptible response of the plant. Bacterial emboli thus represent the products of host-pathogen integration, since the formation of these structures requires the action of both partners.

Pretreatment of Sugar Beet Pulp with Dilute Sulfurous Acid is Effective for Multipurpose Usage of Carbohydrates.

Sulfurous acid was used for pretreatment of sugar beet pulp (SBP) in order to achieve high efficiency of both extraction of carbohydrates and subsequent enzymatic hydrolysis of the remaining solids. The main advantage of sulfurous acid usage as pretreatment agent is the possibility of its regeneration. Application of sulfurous acid as hydrolyzing agent in relatively low concentrations (0.6-1.0 %) during a short period of time (10-20 min) and low solid to liquid ratio (1:3, 1:6) allowed effective extraction of carbohydrates from SBP and provided positive effect on subsequent enzymatic hydrolysis. The highest obtained concentration of reducing substances (RS) in hydrolysates was 8.5 %; up to 33.6 % of all carbohydrates present in SBP could be extracted. The major obtained monosaccharides were arabinose and glucose (9.4 and 7.3 g/l, respectively). Pretreatment of SBP with sulfurous acid increased 4.6 times the yield of glucose during subsequent enzymatic hydrolysis of remaining solids with cellulase cocktail, as compared to the untreated SBP. Total yield of glucose during SBP pretreatment and subsequent enzymatic hydrolysis amounted to 89.4 % of the theoretical yield. The approach can be applied directly to the wet SBP. Hydrolysis of sugar beet pulp with sulfurous acid is recommended for obtaining of individual monosaccharides, as well as nutritional media.

Plant oligosaccharides - outsiders among elicitors?

This review substantiates the need to study the plant oligoglycome. The available information on oligosaccharins - physiologically active fragments of plant cell wall polysaccharides - is summarized. The diversity of such compounds in chemical composition, origin, and proved biological activity is highlighted. At the same time, plant oligosaccharides can be considered as outsiders among elicitors of various natures in research intensity of recent decades. This review discusses the reasons for such attitude towards these regulators, which are largely connected with difficulties in isolation and identification. Together with that, approaches are suggested whose potentials can be used to study oligosaccharins. The topics of oligosaccharide metabolism in plants, including the ways of formation, transport, and inactivation are presented, together with data on biological activity and interaction with plant hormones. The current viewpoints on the mode of oligosaccharin action - perception, signal transduction, and possible "targets" - are considered. The potential uses of such compounds in medicine, food industry, agriculture, and biotechnology are discussed.

Tissue-specific rhamnogalacturonan I forms the gel with hyperelastic properties.

Rhamnogalacturonans I are complex pectin polysaccharides extremely variable in structure and properties and widely represented in various sources. The complexity and diversity of the structure of rhamnogalacturonans I are the reasons for the limited information about the properties and supramolecular organization of these polysaccharides, including the relationship between these parameters and the functions of rhamnogalacturonans I in plant cells. In the present work, on the example of rhamnogalacturonan I from flax gelatinous fibers, the ability of this type of pectic polysaccharides to form at physiological concentrations hydrogels with hyperelastic properties was revealed for the first time. According to IR spectroscopy, water molecules are more tightly retained in the gelling rhamnogalacturonan I from flax fiber cell wall in comparison with the non-gelling rhamnogalacturonan I from primary cell wall of potato. With increase in strength of water binding by rhamnogalacturonan I, there is an increase in elastic modulus and decrease in Poisson's ratio of gel formed by this polysaccharide. The model of hyperelastic rhamnogalacturonan I capture by laterally interacting cellulose microfibrils, constructed using the finite element method, confirmed the suitability of rhamnogalacturonan I gel with the established properties for the function in the gelatinous cell wall, allowing consideration of this tissue- and stage-specific pectic polysaccharide as an important factor in creation of gelatinous fiber contractility.

Arrangement of mixed-linkage glucan and glucuronoarabinoxylan in the cell walls of growing maize roots.

BACKGROUND AND AIMS: Plant cell enlargement is unambiguously coupled to changes in cell wall architecture, and as such various studies have examined the modification of the proportions and structures of glucuronoarabinoxylan and mixed-linkage glucan in the course of cell elongation in grasses. However, there is still no clear understanding of the mutual arrangement of these matrix polymers with cellulose microfibrils and of the modification of this architecture during cell growth. This study aimed to determine the correspondence between the fine structure of grass cell walls and the course of the elongation process in roots of maize (Zea mays). METHODS: Enzymatic hydrolysis followed by biochemical analysis of derivatives was coupled with immunohistochemical detection of cell wall epitopes at different stages of cell development in a series of maize root zones. KEY RESULTS: Two xylan-directed antibodies (LM11 and ABX) have distinct patterns of primary cell wall labelling in cross-sections of growing maize roots. The LM11 epitopes were masked by mixed-linkage glucan and were revealed only after lichenase treatment. They could be removed from the section by xylanase treatment. Accessibility of ABX epitopes was not affected by the lichenase treatment. Xylanase treatment released only part of the cell wall glucuronoarabinoxylan and produced two types of products: high-substituted (released in polymeric form) and low-substituted (released as low-molecular-mass fragments). The amount of the latter was highly correlated with the amount of mixed-linkage glucan. CONCLUSIONS: Three domains of glucuronoarabinoxylan were determined: one separating cellulose microfibrils, one interacting with them and a middle domain between the two, which links them. The middle domain is masked by the mixed-linkage glucan. A model is proposed in which the mixed-linkage glucan serves as a gel-like filler of the space between the separating domain of the glucuronoarabinoxylan and the cellulose microfibrils. Space for glucan is provided along the middle domain, the proportion of which increases during cell elongation.

Spatial structure of plant cell wall polysaccharides and its functional significance.

Plant polysaccharides comprise the major portion of organic matter in the biosphere. The cell wall built on the basis of polysaccharides is the key feature of a plant organism largely determining its biology. All together, around 10 types of polysaccharide backbones, which can be decorated by different substituents giving rise to endless diversity of carbohydrate structures, are present in cell walls of higher plants. Each of the numerous cell types present in plants has cell wall with specific parameters, the features of which mostly arise from the structure of polymeric components. The structure of polysaccharides is not directly encoded by the genome and has variability in many parameters (molecular weight, length, and location of side chains, presence of modifying groups, etc.). The extent of such variability is limited by the "functional fitting" of the polymer, which is largely based on spatial organization of the polysaccharide and its ability to form supramolecular complexes of an appropriate type. Consequently, the carrier of the functional specificity is not the certain molecular structure but the certain type of the molecules having a certain degree of heterogeneity. This review summarizes the data on structural features of plant cell wall polysaccharides, considers formation of supramolecular complexes, gives examples of tissue- and stage-specific polysaccharides and functionally significant carbohydrate-carbohydrate interactions in plant cell wall, and presents approaches to analyze the spatial structure of polysaccharides and their complexes.

[Impact of a learning program on the psychological aspects of quality of life in patients with prosthetic heart valves].

AIM: To evaluate the impact of a learning program on quality of life indicators in patients with prosthetic heart valves (PHV). SUBJECTS AND METHODS: One hundred and twenty-two patients with PHV were examined. A study group consisted of 72 patients who were trained at PHV school; a control group comprised 50 untrained patients. The comparison groups were matched for age, gender, education level, the underlying disease that had been a cause of heart disease, and the type of PHV. The SF-36 questionnaire assessing quality of life was used to evaluate the effectiveness of the learning program. RESULTS: At baseline, before cardiac surgery, the patients with PHV showed low physical and mental health indicators in both groups. At 6-month follow-up, the physical health component was increased by 23.8% in the control group and by 27.4% in the study group trained by the learning program (p < 0.05). Analysis of the scores of each scale of the questionnaire yielded significant results in both groups after 6 months of cardiac surgery (p < 0.05), which showed better quality of life. The comparison groups had significant differences only in the scores of the mental health component. Thus, following 6 months the mental health component was 24.1% higher in the learning program group than in the control one (p < 0.05). CONCLUSION: The learning program for patients with PHV, which is based on the principle of continuity of the in- and outpatient management, contributes to better quality of life mainly due to an improvement in the mental health component.

Glucuronoarabinoxylan extracted by treatment with endoxylanase from different zones of growing maize root.

Glucuronoarabinoxylan is a key tethering glucan in the primary cell wall of cereals. Glucuronoarabinoxylan was extracted from different zones of maize (Zea mays L.) roots using endoxylanase that specifically cleaves ß-(1,4)-glycoside bond between two consequent unsubstituted xylose residues. Changes in polysaccharide structure during elongation growth were characterized. Glucuronoarabinoxylan extractable after the endoxylanase treatment consisted of high molecular weight (30-400 kDa) and low molecular weight (<10 kDa) fractions. The presence of high molecular weight derivatives indicated that part of the natural glucuronoarabinoxylan is not digestible by the endoxylanase. This could be due to the revealed peculiar structural features, such as high level of substitution of xylose, absence of unsubstituted xylose residues existing in sequence, and significant degree of acetylation. In maize root meristem the indigestible fraction was 98% of the total extracted glucuronoarabinoxylan. This portion decreases to 47% during elongation. Also, the average molecular weight of indigestible glucuronoarabinoxylan reduced twofold. These changes in the ratio of glucuronoarabinoxylan fragments with different structure during root cell growth could reflect a transition of polysaccharide from its separating (highly substituted indigestible glucuronoarabinoxylan) form to that binding to cellulose microfibrils or other glucuronoarabinoxylan molecules and, hence, retarding growth.

[Cell wall proteins of plant fibers].

The cell wall of the same type - phloem fibers (Linum usitatissimum L.), active forming the thick secondary cell wall, - was obtained. Weakly bound cell wall proteins of phloem fibers were extracted and it subsequent separation and obtaining mass spectra was carried out. For identification and attachment of identified proteins to a specific cell compartments a variety ofbioinformatics methods was used. Were identified 93 proteins, many of which were defined as predicted, putative or hypothetical. At the same 21 proteins were identified as cell-wall protein. The absence of such marker proteins of the primary cell wall as xyloglucan-endotransglycosilase, expansins indirectly confirms that in the sample for extraction of proteins dominated the secondary cell wall.

[Senescence and apoptosis of protoplasts from flax fibers: an ultrastructural analysis].

Plant fibers represent specialized cells that perform a mechanical function. Their development includes the following phases, typical for the most plant cells: anlage, extension growth, specialization, senescence, and apoptosis. Ultrastructural analysis of these cells has been carried out at the late phases of their development (senescence and apoptosis) using flax phloem fibers, a classical object for the analysis of sclerenchyma fiber formation. The results of the performed analysis show that flax fiber protoplasts remain viable until the end ofa vegetation season. The ultrastructural analysis of flax phloem fibers has not revealed any typical apoptosis manifestations. Gradual degradation of the cytoplasm starts during the active thickening of a secondary cell wall and manifests via the intensification of autolytic processes, causing a partial loss of cell content. The final stage represents the breaking of tonoplast integrity. The obtained data allow us to suppose that the apoptosis of flax fibers occurs during their senescence, and its program is similar to the cell death program realized in the xylem fibers of woody plants.

[Efficacy of the education program in the improvement of treatment compliance in patients with artificial heart valves].

The study included 94 patients with artificial heart valves aged 55.5 +/- 68 years including 47 (50%) with rheumatic heart diseases, 26 (27.7%) with infectious endocarditis, 21 (22.3%) with connective tissue dysplasia. Compliance with the treatment was estimated by the method of S.V. Davydov before and after education. The leading causes of poor compliance was insufficient socio-medical knowledge and dissatisfaction with the prescribed therapeutic regimen. The education program permitted to achieve a 3-fold decrease in the incidence of negative factors affecting compliance and 1.5-fold increase in the frequency of positive factors; socio-medical awareness and satisfaction with the prescribed treatment increased by 45.8% and 37.1% respectively (p < 0.05). The integral index of compliance before education +4.39 +/- 0.09 characterized it as a moderately positive one. It increased to +8.11 +/- 1.23 after education (p < 0.01). It is concluded that the education program based on the principle of continuity of in- and out-patient treatment improved compliance and socio-medical awareness of the patients, promoted their medico-social adaptation, increased satisfaction with the prescribed treatment and its outcome.

Formation of plant cell wall supramolecular structure.

Plant cell wall is an example of a widespread natural supramolecular structure: its components are considered to be the most abundant organic compounds renewable by living organisms. Plant cell wall includes numerous components, mainly polysaccharidic; its formation is largely based on carbohydrate-carbohydrate interactions. In contrast to the extracellular matrix of most other organisms, the plant cell compartment located outside the plasma membrane is so structured that has been named "wall". The present review summarizes data on the mechanisms of formation of this supramolecular structure and considers major difficulties and results of research. Existing approaches to the study of interactions between polysaccharides during plant cell wall formation have been analyzed, including: (i) characterization of the structure of natural polysaccharide complexes obtained during cell wall fractionation; (ii) analysis of the interactions between polysaccharides "at mixing in a tube"; (iii) study of the interactions between isolated individual plant cell wall matrix polysaccharides and microfibrils formed by cellulose-synthesizing microorganisms; and (iv) investigation of cell wall formation and modification directly in plant objects. The key stages in formation of plant cell wall supramolecular structure are defined and characterized as follows: (i) formation of cellulose microfibrils; (ii) interactions between matrix polysaccharides within Golgi apparatus substructures; (iii) interaction between matrix polysaccharides, newly secreted outside the plasma membrane, and cellulose microfibrils during formation of the latter; (iv) packaging of the formed complexes and individual polysaccharides in cell wall layers; and (v) modification of deposited cell wall layers.

[Biogenesis of plant fibers].

The fiber (in terms of plant biology) is an individual cells characterized by spindle shape, length of up to several centimeters, well developed cell wall, and mechanical function. The review summarizes different, sometimes contradictory view points about duration, segregation and mechanisms of realization of individual stages of fiber biogenesis. Initiation and coordinated and intrusive growth are considered, as well as formation of secondary cell wall, including its gelatinous layers, and senescence. Biogenesis of fibers ontogenetically related to various tissues has been analyzed and the data about marker stage-specific characters of these cells. The data summarized in this review willow not only deeper understanding the development of cells with such unique characters, but also interpret the growth mechanisms for much more cell types, in which it is more difficult to identify individual stages of biogenesis than in the sclerenchyme fibers.

[Structural characterization of tissue-specific galactan from flax fibers by 1H NMR and MALDI TOF mass spectrometry].

A high-molecular-mass polysaccharide galactan (M 2000 kDa) was isolated from flax at the stage of cell wall thickening of the bast fiber development. The polymer structure was studied by 1H NMR spectroscopy and MALDI TOF mass spectrometry. It is built up of Gal (59%), Rha (15%), GalA (23%), and Ara (3%) residues. The galactan backbone consists of successively alternating monomer disaccharide units (--> 4GalA1 --> 2Rha1 -->)n and is similar in its structure to the backbone of rhamnogalacturonan-1 (RG-I). Rhamnose residues bear in position 4 beta-(1 --> 4)-galactose side chains of various lengths with a polymerization degree of up to 28 or higher. A part of the side chains have branchings.