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1.
Callose balancing at plasmodesmata.
Wu, SW, Kumar, R, Iswanto, ABB, Kim, JY
Journal of experimental botany. 2018;(22):5325-5339
Abstract
In plants, communication and molecular exchanges between different cells and tissues are dependent on the apoplastic and symplastic pathways. Symplastic molecular exchanges take place through the plasmodesmata, which connect the cytoplasm of neighboring cells in a highly controlled manner. Callose, a β-1,3-glucan polysaccharide, is a plasmodesmal marker molecule that is deposited in cell walls near the neck zone of plasmodesmata and controls their permeability. During cell differentiation and plant development, and in response to diverse stresses, the level of callose in plasmodesmata is highly regulated by two antagonistic enzymes, callose synthase or glucan synthase-like and β-1,3-glucanase. The diverse modes of regulation by callose synthase and β-1,3-glucanase have been uncovered in the past decades through biochemical, molecular, genetic, and omics methods. This review highlights recent findings regarding the function of plasmodesmal callose and the molecular players involved in callose metabolism, and provides new insight into the mechanisms maintaining plasmodesmal callose homeostasis.
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2.
Effects of cereal bar containing polydextrose on subjective feelings of appetite and energy intake in overweight adults over 15 d.
Martinelli, M, Hick, E, Walz, F, Drago, SR
International journal of food sciences and nutrition. 2018;(7):892-899
Abstract
The effects of 15 d polydextrose (16.7 g) consumption on energy intake (EI) and appetite feelings were investigated. Overweight adults consumed a polydextrose-bar or a control-bar matched in energy content as a midmorning snack for 15 consecutive days in a single-blind, randomised, crossover design. The two 15-d intervention periods were separated by a 15-d washout period. On the day 1 and the day 15 of each intervention period, energy intake (primary outcome) and appetite feelings (secondary outcome) were assessed. There were not significant main effects of the day, type of bar, or their interaction for EI (at lunchtime test meal, at rest of the day, or at total daily) or subjective feelings (hunger, desire to eat, fullness, and prospective food consumption) during the satiation and satiety periods. The results showed the consumption of polydextrose-bar during 15 d did not significantly affect energy intake and subjective feelings of appetite in overweight adults.
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3.
Pullulan based oral thin film formulation of zolmitriptan: Development and optimization using factorial design.
Prajapati, VD, Chaudhari, AM, Gandhi, AK, Maheriya, P
International journal of biological macromolecules. 2018;(Pt B):2075-2085
Abstract
The goal of study was to formulate and characterize pullulan based oral thin film (OTF) of zolmitriptan by solvent casting method. Based on preliminary trials, glass, PEG 400 and sucralose were selected as casting surface, water-miscible plasticizer and sweetener for OTF, respectively. A 32 factorial design was used to study the effect of amount of PEG 400 (X1) and sucralose (X2) as independent variables on tensile strength (Y1), elasticity (Y2), % in-vitro drug release in phosphate buffer of pH 6.8 at 5min (Q5min, Y3) and overall taste of OTF (Y4) as responses. OTF of batch F4 (PEG 400, 200mg; sucralose, 12mg) was identified as an optimized batch showing in-vitro, in-vivo disintegration time 20.70 and 21.58s, respectively; 95.53% Q5min; satisfactory thickness, strength, % elongation, ease of handling, smooth mouthfeel, excellent overall taste; even distribution of all ingredients in pullulan OTF (SEM study); and stable film at specified conditions concluding that pullulan, PEG 400 and sucralose are used in combination to make palatable, stable OTF of zolmitriptan.
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4.
Starch degradation, abscisic acid and vesicular trafficking are important elements in callose priming by indole-3-carboxylic acid in response to Plectosphaerella cucumerina infection.
Gamir, J, Pastor, V, Sánchez-Bel, P, Agut, B, Mateu, D, García-Andrade, J, Flors, V
The Plant journal : for cell and molecular biology. 2018;(3):518-531
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Abstract
A fast callose accumulation has been shown to mediate defence priming in certain plant-pathogen interactions, but the events upstream of callose assembly following chemical priming are poorly understood, mainly because those steps comprise sugar transfer to the infection site. β-Amino butyric acid (BABA)-induced resistance in Arabidopsis against Plectosphaerella cucumerina is known to be mediated by callose priming. Indole-3-carboxylic acid (ICOOH, also known as I3CA) mediates BABA-induced resistance in Arabidopsis against P. cucumerina. This indolic compound is found in a common fingerprint of primed metabolites following treatments with various priming stimuli. In the present study, we show that I3CA induces resistance in Arabidopsis against P. cucumerina and primes enhancement of callose accumulation. I3CA treatment increased abscisic acid (ABA) levels before infection with P. cucumerina. An intact ABA synthesis pathway is needed to activate a starch amylase (BAM1) to trigger augmented callose deposition against P. cucumerina during I3CA-IR. To verify the relevance of the BAM1 amylase in I3CA-IR, knockdown mutants and overexpressors of the BAM1 gene were tested. The mutant bam1 was impaired to express I3CA-IR, but complemented 35S::BAM1-YFP lines in the background of bam1 restored an intact I3CA-IR and callose priming. Therefore, a more active starch metabolism is a committed step for I3CA-IR, inducing callose priming in adult plants. Additionally, I3CA treatments induced expression of the ubiquitin ligase ATL31 and syntaxin SYP131, suggesting that vesicular trafficking is relevant for callose priming. As a final element in the callose priming, an intact Powdery Mildew resistant4 (PMR4) gene is also essential to fully express I3CA-IR.
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5.
Mutations outside the N-terminal part of RBCK1 may cause polyglucosan body myopathy with immunological dysfunction: expanding the genotype-phenotype spectrum.
Krenn, M, Salzer, E, Simonitsch-Klupp, I, Rath, J, Wagner, M, Haack, TB, Strom, TM, Schänzer, A, Kilimann, MW, Schmidt, RLJ, et al
Journal of neurology. 2018;(2):394-401
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Abstract
A subset of patients with polyglucosan body myopathy was found to have underlying mutations in the RBCK1 gene. Affected patients may display diverse symptoms ranging from skeletal muscular weakness, cardiomyopathy to chronic autoinflammation and immunodeficiency. It was suggested that the exact localization of the mutation within the gene might be responsible for the specific phenotype, with N-terminal mutations causing severe immunological dysfunction and mutations in the middle or C-terminal part leading to a myopathy phenotype. We report the clinical, immunological and genetic findings of two unrelated individuals suffering from a childhood-onset RBCK1-asscociated disease caused by the same homozygous truncating mutation (NM_031229.2:c.896_899del, p.Glu299Valfs*46) in the middle part of the RBCK1 gene. Our patients suffered from a myopathy with cardiac involvement, but in contrast to previous reports on mutations in this part of the gene, also displayed signs of autoinflammation and immunodeficiency. Our report suggests that RBCK1 mutations at locations that were previously thought to lack immunological features may also present with immunological dysfunction later in the disease course. This notably broadens the genotype-phenotype correlation of RBCK1-related polyglucosan body myopathy.
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6.
β-(1→6)-D-glucan secreted during the optimised production of exopolysaccharides by Paecilomyces variotii has immunostimulatory activity.
Osaku, EF, Menolli, RA, de M Costa, CRL, Tessaro, FHG, de Melo, RH, do Amaral, AE, Duarte, PAD, de Santana Filho, AP, Ruthes, AC, da C Silva, JL, et al
Antonie van Leeuwenhoek. 2018;(6):981-994
Abstract
Paecilomyces variotii is a filamentous fungus that occurs worldwide in soil and decaying vegetation. Optimization of the fermentation process for exopolysaccharide (EPS) production from the fungus P. variotii, structure determination and immuno-stimulating activity of EPS were performed. Response surface methodology (RSM) coupled with central composite design (CCD) was used to optimize the physical and chemical factors required to produce EPS in submerged fermentation. Preliminary investigations to choose the three factors for the present work were made using a factorial experimental design. Glucose, ammonium nitrate (NH4NO3) and pH were used as variables for which, with constant temperature of 28 °C and agitation of 90 rpm, the optimal process parameters were determined as glucose values of 0.96%, NH4NO3 0.26% and pH 8.0. The three parameters presented significant effects. In this condition of culture, the main composition of the isolated EPS was a linear β-(1 → 6)-linked-D-glucan, as determined by Nuclear Magnetic Resonance (NMR) and methylation analysis. This polysaccharide is a very unusual as an EPS from fungi, especially a filamentous fungus such as P. variotii. Murine peritoneal macrophages cultivated with β-glucan for 6 and 48 h showed an increase in TNF-α, IL-6 and nitric oxide release with increased polysaccharide concentrations. Therefore, we conclude that the β-(1 → 6)-linked-D-glucan produced in optimised conditions of P. variotii cultivation has an immune-stimulatory activity on murine macrophages.
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A review on versatile applications of blends and composites of pullulan with natural and synthetic polymers.
Tabasum, S, Noreen, A, Maqsood, MF, Umar, H, Akram, N, Nazli, ZI, Chatha, SAS, Zia, KM
International journal of biological macromolecules. 2018;(Pt A):603-632
Abstract
Pullulan is a non-ionic, linear, water-soluble and a neutral polysaccharide. It is composed of α-(1,6) repeated maltotriose units via α-(1,4) glycosidic bond having chemical formula (C6H10O5)n. It shows non-immunogenic, non-toxic, non-carcinogenic and non-mutagenic properties. It is used in food edible coatings, films, as flocculant, foaming agent and adhesive. It may also be used as a carrier for bioactive compounds and a protective packaging for food and pharmaceutical products. Therefore, it is blended with different polymers such as carrageenan, mucilages, chitosan, cellulose, sodium alginate, starch, polyethyleneimine, whey-protein, polyisopropylacrylamide, histone, jeffamine, polyamidoamine, pemulen, hyaluronic acid, polyvinyl alcohol and caboxymethyl cellulose. In this article, a comprehensive overview of combination of pullulan with natural and synthetic polymers and their applications in biomedical field involving drug delivery system, tissue engineering, wound healing and gene therapy, is presented. It also describes the utilization of pullulan based materials in food industry, water treatment and pharmaceutical industry. All the technical scientific issues have been addressed; highlighting the recent advancements.
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8.
A randomized controlled trial comparing a xyloglucan-based nasal spray with saline in adults with symptoms of rhinosinusitis.
Allegrini, A, Pavone, D, Carluccio, F
Current medical research and opinion. 2018;(3):377-385
Abstract
BACKGROUND This study assessed the efficacy, safety and tolerability of a xyloglucan-based nasal spray in the treatment of symptoms of rhinosinusitis. METHODOLOGY In this randomized, double-blind study, 40 patients with itching, nasal congestion or continuous sneezing and a Total Nasal Symptom Score (TNSS) of ≥8 were randomized to 2 weeks' treatment with a xyloglucan-based nasal spray ("xyloglucan") or a physiological saline nasal spray ("saline"). Assessments included the TNSS, rhinosinusitis severity index, nocturnal awakenings, use of rescue medication, safety and tolerability. RESULTS Baseline symptom scores were similar between groups. At treatment end, improvements from baseline were observed in both groups for TNSS (xyloglucan 58%; saline 35%, both p < .05) and number of nocturnal awakenings (p < .05). A significant improvement in the rhinosinusitis severity index was observed only with xyloglucan (p < .05). At treatment end, mean [SD] scores were significantly lower in the xyloglucan group versus the saline group for TNSS (3.60 [2.16] vs. 5.40 [2.64], p < .05), rhinosinusitis severity index (7.55 [1.19] vs. 6.45 [1.40], p < .05), and rhinorrhea and itching (both p < .05). No rescue medication was used. Both treatments were well tolerated. CONCLUSIONS A xyloglucan-based nasal spray provided greater relief of rhinosinusitis symptoms than a physiological saline spray and was well tolerated. Trial registration number (EUDRACT): 2014-000143-32.
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9.
Emerging models on the regulation of intercellular transport by plasmodesmata-associated callose.
Amsbury, S, Kirk, P, Benitez-Alfonso, Y
Journal of experimental botany. 2017;(1):105-115
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Abstract
The intercellular transport of molecules through membranous channels that traverse the cell walls-so-called plasmodesmata-is of fundamental importance for plant development. Regulation of plasmodesmata aperture (and transport capacity) is mediated by changes in the flanking cell walls, mainly via the synthesis/degradation (turnover) of the (1,3)-β-glucan polymer callose. The role of callose in organ development and in plant environmental responses is well recognized, but detailed understanding of the mechanisms regulating its accumulation and its effects on the structure and permeability of the channels is still missing. We compiled information on the molecular components and signalling pathways involved in callose turnover at plasmodesmata and, more generally, on the structural and mechanical properties of (1,3)-β-glucan polymers in cell walls. Based on this revision, we propose models integrating callose, cell walls, and the regulation of plasmodesmata structure and intercellular communication. We also highlight new tools and interdisciplinary approaches that can be applied to gain further insight into the effects of modifying callose in cell walls and its consequences for intercellular signalling.
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10.
Pollen tube access to the ovule is mediated by glycoprotein secretion on the obturator of apple (Malus × domestica, Borkh).
Losada, JM, Herrero, M
Annals of botany. 2017;(6):989-1000
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Abstract
BACKGROUND AND AIMS Within the ovary, the obturator bridges the pathway of the pollen tube from the style to the ovule. Despite its widespread presence among flowering plants, its function has only been studied in a handful of species, and the molecules involved in pollen tube-obturator cross-talk have not been explored hitherto. This work evaluates the involvement of glucans and glycoproteins on pollen tube growth in the obturator of apple flowers ( Malus × domestica) . METHODS Pollen tube kinetics were sequentially examined in the pistil and related to changes occurring on the obturator using histochemistry and inmunocytochemistry. To discriminate between changes in the obturator induced by pollen tubes from those developmentally regulated, both pollinated and unpollinated pistils were examined. KEY RESULTS Pollen tube growth rates were slow in the stigma, faster in the style and slow again in the ovary. The arrival of pollen tubes at the obturator was concomitant with the secretion of proteins, saccharides and glycoprotein epitopes belonging to extensins and arabinogalactan proteins (AGPs). While some of these secretions - extensins and AGPs labelled by JIM13 - were developmentally regulated, others - AGPs labelled by JIM8 - were elicited by the presence of pollen tubes. Following pollen tube passage, all these glycoproteins were depleted. CONCLUSIONS The results show a timely secretion of glycoproteins on the obturator surface concomitant with pollen tube arrival at this structure. The fact that their secretion is depleted following pollen tube passage strongly suggests their role in regulating pollen tube access to the ovule. Remarkably, both the regulation of the secretion of the different glycoproteins, as well as their association with the performance of pollen tubes exhibit similarities with those observed in the stigma, in line with their common developmental origin.