A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

AmylPepPred: Amyloidogenic Peptide Prediction tool

We present an efficient computational architecture designed using supervised machine learning model to predict amyloid fibril forming protein segments, named AmylPepPred. The proposed prediction model is based on bio-physio-chemical properties of primary sequences and auto-correlation function of their amino acid indices. AmylPepPred provides a user friendly web interface for the researchers to easily observe the fibril forming and non-fibril forming hexmers in a given protein sequence. We expect that this stratagem will be highly encouraging in discovering fibril forming regions in proteins thereby benefit in finding therapeutic agents that specifically aim these sequences for the inhibition and cure of amyloid illnesses.

Availability

AmylPepPred is available freely for academic use at www.zoommicro.in/amylpeppred     

The cyclooxygenases

Cyclooxygenases (COXs) catalyze the rate-limiting step in the production of prostaglandins, bioactive compounds involved in processes such as fever and sensitivity to pain, and are the target of aspirin-like drugs. COX genes have been cloned from coral, tunicates and vertebrates, and in all the phyla where they are found, there are two genes encoding two COX isoenzymes; it is unclear whether these genes arose from an early single duplication event or from multiple independent duplications in evolution. The intron-exon arrangement of COX genes is completely conserved in vertebrates and mostly conserved in all species. Exon boundaries largely define the four functional domains of the encoded protein: the amino-terminal hydrophobic signal peptide, the dimerization domain, the membrane-binding domain, and the catalytic domain. The catalytic domain of each enzyme contains distinct peroxidase and cyclooxygenase active sites; COXs are classified as members of the myeloperoxidase family. All COXs are homodimers and monotopic membrane proteins (inserted into only one leaflet of the membrane), and they appear to be targeted to the lumenal membrane of the endoplasmic reticulum, where they are N-glycosylated. In mammals, the two COX genes encode a constitutive isoenzyme (COX-1) and an inducible isoenzyme (COX-2); both are of significant pharmacological importance.     

Arachidonic acid metabolism in growth control of A549 human lung adenocarcinoma cells

The role of individual eicosanoids of the arachidonic acid (AA) cascade in the growth control of A549 human lung adenocarcinoma cells has been studied. Cyclooxygenase and lipoxygenase metabolites of [¹⁴C]AA incorporated were actively synthesized in the cultures of tumor cells with full confluence unaccomplished. In such cultures inhibitors of AA metabolism (indomethacin and esculetin) and also a lipoxygenase metabolite of AA, 15-hydroxyeicosatetraenoic acid (15-HETE), significantly suppressed the incorporation of [³H]thymidine and biosynthesis of prostaglandin E₂(PGE₂). Other lipoxygenase metabolites of AA (5-HETE and 12-HETE) had no effect on these parameters. The basic fibroblast growth factor (bFGF) had practically no affect on the growth of A549 cells and the PGE₂ production in cultures with 5% fetal calf serum (FCS); however, in the presence of 0.5% FCS this factor significantly increased the number of tumor cells. The growth-stimulating effect of bFGF was completely abolished by a cyclooxygenase inhibitor indomethacin. The data suggest a key role of PGE₂ in the growth control of A549 cells with an active synthesis of cyclooxygenase and lipoxygenase metabolites of AA, its importance in realization of the mitogenic effect of bFGF, and specific features of 15-HETE as a down-regulator of the PGE₂-dependent proliferation.     

'Navius' kissing stents for coronary bifurcation stenosis,recreating a new metallic carina: an IVUS-assessed case report

We report a case of implantation of a new design of stent which allows creation of a double-hemispheric lumen for the treatment of a bifurcational stenosis. The unfavourable outcome following the implantation of this stent is described.     

Interference by methylcobalamin analogues with synthesis of cobalamin coenzymes in human lymphocytes in vitro.

1. 72 h uptake of cyano[57Co]cobalamin and formation of 57Co-labelled methylcobalamin, adenosylcobalamin and hydroxocobalamin has been estimated with and without the addition of methylcobalamin analogues in phytohaemagglutinin-stimulated lymphocytes from healthy human subjects. 2. Difluorochloromethylcobalamin reduced cell uptake of cyanocobalamin and caused a disproportionate reduction in synthesis of adenosylcobalamin. 3. Methylcobalamin-palladium trichloride reduced cell uptake of cyanobalamin more effectively than did difluorochloromethylcobalamin and reduced the formation of methylcobalamin, adenosylcobalamin and hydroxocobalamin in proportion. 4. The results suggest that in addition to inhibiting uptake of cyanocobalamin, one or both compounds may have interfered directly with the mechanism of synthesis of the cobalamin coenzymes.     

Biosynthesis of chlorophyll P-680 of photosystem II in greening leaves of plants adapted to heat shock

In etiolated pea and maize leaves illuminated after incubation at 38 degreesC, a new dark reaction was shown manifested in the bathochromic shift of spectral bands and accompanied by esterification of the product of protochlorophyllide photochemical reduction--Chld 684/676: Chld 684/676 --> Chl 688/680. After completion of the reaction a rapid (20-30 sec) quenching of the fluorescence of the reaction product (Chl 688/680) was observed. The reaction Chld 684/676 --> Chl 688/680 is inhibited under anaerobic conditions and in the presence of cyanide; the reaction accompanied by Chl 688/680 fluorescence quenching is not observed in pea mutants with impaired function of photosystem II reaction centers. The spectral properties of the formed Chl form with the absorption maximum at 680 nm, fluorescence quenching, and simultaneous synthesis of pheophytin suggest that the reaction is connected with the chlorophyll of photosystem II reaction center--P-680.