Evidence that formation of vimentin mitogen-activated protein kinase (MAPK) complex mediates mast cell activation following FcεRI/CC chemokine receptor 1 cross-talk

Accumulating evidence points to cross-talk between FcεRI and CC chemokine receptor (CCR)-mediated signaling pathways in mast cells. Here, we propose that vimentin, a protein comprising type III intermediate filament, participates in such cross-talk for CCL2/monocyte chemotactic protein 1 (MCP-1) production in mast cells, which is a mechanism for allergic inflammation. Co-stimulation via FcεRI, using IgE/antigen, and CCR1, using recombinant CCL3/macrophage inflammatory protein-1α (MIP-1α), increased expression of phosphorylated, disassembled, and soluble vimentin in rat basophilic leukemia (RBL)-2H3 cells expressing human CCR1 (RBL-CCR1 cells) and bone marrow-derived murine mast cells, both models of mucosal type mast cells. Furthermore, co-stimulation enhanced production of CCL2 as well as phosphorylation of MAPK. Treating the cells with p38 MAPK inhibitor SB203580, but not with MEK inhibitor PD98058, reduced CCL2 production, suggesting that p38 MAPK, but not ERK1/2, plays a critical role in the chemokine production. Immunoprecipitation analysis showed that vimentin interacts with phosphorylated ERK1/2 and p38 MAPKs in the co-simulated cells. Preventing disassembly of the vimentin by aggregating vimentin filaments using β,β'-iminodipropionitrile reduced the interaction of vimentin with phosphorylated MAPKs as well as CCL2 production in the cells. Taken together, disassembled vimentin interacting with phosphorylated p38 MAPK could mediate CCL2 production in mast cells upon FcεRI and CCR1 activation.     

Diversity of Streptomyces spp. in Eastern Himalayan region - computational RNomics approach to phylogeny

Isolation and characterization of actinomycetes from soil samples from altitudinal gradient of North-East India were investigated for computational RNomics based phylogeny. A total of 52 diverse isolates of Streptomyces from the soil samples were isolated on four different media and from these 6 isolates were selected on the basis of cultural characteristics, microscopic and biochemical studies. Sequencing of 16S rDNA of the selected isolates identified them to belong to six different species of Streptomyces. The molecular morphometric and physico-kinetic analysis of 16S rRNA sequences were performed to predict the diversity of the genus. The computational RNomics study revealed the significance of the structural RNA based phylogenetic analysis in a relatively diverse group of Streptomyces.     

Theoretical calculations of a model of NOS indazole inhibitors: Interaction of aromatic compounds with Zn-porphyrins

We report a theoretical approach, at the M05-2x/6-311+G(d) level, to explain the affinity of indazoles for nitric oxide synthases using a simplified model of porphyrin. The theoretical E_rel = E_i stacking–E_i apical values correlate with the experimental inhibition percents allowing to predict that 3,7-dinitro-1H-indazole should be a good NOS inhibitor.     

A tracheomycosis as a tool for studying the impact of stem xylem dysfunction on leaf water status and gas exchange in Citrus aurantium L.

Permanent xylem blockage is a common result of attacks by herbivores and fungi. The mitosporic fungus Phoma tracheiphila (Petri) Kantschaveli et Gikachvili, is the agent of a Citrus tracheomycosis (“malsecco disease”) causing xylem impairment and leading to leaf shedding and plant dieback. In the present study, this pathogen was used for monitoring the effects of increasing levels of stem hydraulic resistance (R _stem) on leaf water status and gas exchange. In this view, measurements are reported of changes in the hydraulic resistance of infected stems (R _stem) of C. aurantium (sour orange) during progressive and irreversible xylem blockage with parallel measurements of leaf water potential and conductance to water vapour. Leaves were highly responsive to increasing R _stem as due to fungal infection, with substantial stomatal closure and drop in water potential.     

Purification and characterization of the second Streptomyces phospholipase A2 refolded from an inclusion body

A secreted phospholipase A(2) (PLA(2)) from Streptomyces violaceoruber A-2688, previously identified by us, is the first PLA(2) identified in prokaryotes. Genome sequence data of Streptomyces coelicolor A3(2) indicates that the bacterium carries two genes encoding hypothetical PLA(2)s, which exhibit 100 and 78% identity, respectively, to the S. violaceoruber PLA(2). In this study, we named the former and latter proteins as the first and second PLA(2)s, respectively. When the second PLA(2) was expressed in Escherichia coli cells, it formed an inclusion body. The present study demonstrates a method to purify it to homogeneity without the disappearance of the enzymatic activity: the inclusion body was washed with sodium deoxycholate and dissolved in the presence of 2 M urea at pH 12, then refolded by the dilution method. The refolding of enzyme was confirmed by the circular dichroism spectrum. The second PLA(2) purified to homogeneity had the same specific activity as that of the S. violaceoruber PLA(2) and the yield was approximately 6.8 mg/L culture. The second PLA(2) exhibits similar enzymatic properties to the S. violaceoruber PLA(2), except that the former enzyme does not utilize phophatidic acid as a substrate. The surface electrostatic potential of the S. coelicolor PLA(2) model, which is created by the computer-homology modeling, suggests that the positively charged surface of the enzyme does not affect the substrate specificity.     

An X-linked haplotype of Neandertal origin is present among all non-African populations

Recent work on the Neandertal genome has raised the possibility of admixture between Neandertals and the expanding population of Homo sapiens who left Africa between 80 and 50 Kya (thousand years ago) to colonize the rest of the world. Here, we provide evidence of a notable presence (9% overall) of a Neandertal-derived X chromosome segment among all contemporary human populations outside Africa. Our analysis of 6,092 X-chromosomes from all inhabited continents supports earlier contentions that a mosaic of lineages of different time depths and different geographic provenance could have contributed to the genetic constitution of modern humans. It indicates a very early admixture between expanding African migrants and Neandertals prior to or very early on the route of the out-of-Africa expansion that led to the successful colonization of the planet.     

Repetitive Somatic Embryogenesis of Ocotea catharinensis Mez. (Lauraceae): Effect of Somatic Embryo Developmental Stage and Dehydration

Repetitive embryogenesis of Ocotea catharinensis from globular/early cotyledonary somatic embryos was successfully supported by WPM supplemented with 22.7 g l⁻¹ sorbitol, 20 g l⁻¹ sucrose, 400 mg l⁻¹ glutamine and 2 g l⁻¹ Phytagel. The best medium to induce repetitive embryogenesis in cotyledonary somatic embryos was half strength WPM supplemented with 20 g l⁻¹ sucrose, 400 mg l⁻¹ glutamine, 1.5 g l⁻¹ activated charcoal and 2 g l⁻¹ Phytagel. The mature somatic embryos gradually air dehydrated showed repetitive embryogenesis after subculture on half strength B5 medium supplemented with 20 g l⁻ sucrose, 20 g l⁻¹ Phytagel, 1.5 g l⁻¹ activated charcoal, 115.6 μM gibberellic acid and 214.8 μM naphthaleneacetic acid. The early cotyledonary, cotyledonary and mature somatic embryos tolerated respectively 95, 86 and 54% fresh weight losses without losing their repetitive embryogenesis potential. Cotyledonary and mature somatic embryos gradually air dehydrated in sealed Petri dishes showed 40–41% repetitive embryogenesis respectively after 20 days and 12 weeks desiccation storage. Repetitive embryogenesis in cotyledonary somatic embryos was significantly stimulated by chemical dehydration with 0.5 M sorbitol and 56% repetitive embryogenesis was achieved even after exposure to 2 M sorbitol for 24 h. The cotyledonary somatic embryos when alginate-encapsulated showed 47% repetitive embryogenesis even after chemical dehydration in 1.5 M sorbitol for 4 days followed by 1 h air dehydration, but failed to survive to the same dehydration conditions without encapsulation. The optimized repetitive embryogenesis and desiccation protocols offer the possibility to use in vitro techniques for continuous reliable somatic embryo production and short term germplasm storage.     

Involvement of differentially accumulated proteins and endogenous auxin in adventitious root formation in micropropagated shoot cuttings of Cedrela fissilis Vellozo (Meliaceae)

Plant Cell, Tissue and Organ Culture (PCTOC) - Investigation of the biochemical and molecular changes during rooting in woody species can reveal how specific molecules are involved in adventitious...     

Phytochemical and pharmacological investigation of <Emphasis Type="Italic">Spiraea chamaedryfolia</Emphasis>: a contribution to the chemotaxonomy of <Emphasis Type="Italic">Spiraea</Emphasis> genus

Objective

Diterpene alkaloids are secondary plant metabolites and chemotaxonomical markers with a strong biological activity. These compounds are characteristic for the Ranunculaceae family, while their occurrence in other taxa is rare. Several species of the Spiraea genus (Rosaceae) are examples of this rarity. Screening Spiraea species for alkaloid content is a chemotaxonomical approach to clarify the classification and phylogeny of the genus. Novel pharmacological findings make further investigations of Spiraea diterpene alkaloids promising.

Results

Seven Spiraea species were screened for diterpene alkaloids. Phytochemical and pharmacological investigations were performed on Spiraea chamaedryfolia, the species found to contain diterpene alkaloids. Its alkaloid-rich fractions were found to exert a remarkable xanthine-oxidase inhibitory activity and a moderate antibacterial activity. The alkaloid distribution within the root was clarified by microscopic techniques.