Immunometabolic changes in macrophages in response to house dust mite extract

To date, much remains unclear about the pathogenesis of asthma, one of the most common chronic and highly heterogenic diseases of the respiratory system. The lack of specific and highly effective therapy in case of certain asthma subtypes requires the search for new approaches to treatment. One possible approach would be to influence the metabolism and immune functions of myeloid cells. This approach finds its application in the treatment of cancer and other diseases in the pathogenesis of which macrophages play an important role. It was shown that the pathogenesis of allergic asthma in response to one of the most common allergens, house dust mite, is due to a metabolic TNF-mediated reprogramming of alveolar macrophages. This suggests that influencing the process of TNF production or metabolic adaptations with specific blockers may also lead to a reduction in the symptoms of the course of the disease as a whole. In this work, we experimentally tested whether the previously obtained phenotype that occurs in macrophages in response to HDM cultured in DMEM is preserved if cells are cultured under more physiologically relevant conditions: in a medium closely related in composition to blood plasma. We also analyzed open databases of alveolar macrophages sequencing obtained from patients with asthma or from the lungs of mice in an HDM-induced asthma model in order to correlate specific immunometabolic changes. It was found that macrophages cultured under conditions close to physiological, simultaneously increase the rates of respiration and glycolysis, and also produce TNF in response to HDM. The observed phenotype is consistent with transcriptomic analyzes performed on human and mouse samples, which revealed an increase in the expression of genes related to glycolysis, oxidative phosphorylation, and the TNF signaling pathway. Thus, the data confirm the relevance of the phenotype obtained in vitro to the changes occurring in the in vivo system. However, functional verification at the level of metabolites, proteins and changes in metabolic activity is also required. In addition, it remains to be established how the blocking of individual metabolic pathways affects the features of the functional macrophage phenotype that occurs in response to HDM, and whether this effect can alleviate asthma symptoms

Selective inhibition of HIV-1 reverse transcriptase-associated ribonuclease H activity by hydroxylated tropolones

High-throughput screening of a National Cancer Institute library of pure natural products identified the hydroxylated tropolone derivatives β-thujaplicinol (2,7-dihydroxy-4-1(methylethyl)-2,4,6-cycloheptatrien-1-one) and manicol (1,2,3,4-tetrahydro-5-7-dihydroxy-9-methyl-2-(1-methylethenyl)-6H-benzocyclohepten-6-one) as potent and selective inhibitors of the ribonuclease H (RNase H) activity of human immunodeficiency virus-type 1 reverse transcriptase (HIV-1 RT). β-Thujaplicinol inhibited HIV-1 RNase H in vitro with an IC(50) of 0.2 μM, while the IC(50) for Escherichia coli and human RNases H was 50 μM and 5.7 μM, respectively. In contrast, the related tropolone analog β-thujaplicin (2-hydroxy-4-(methylethyl)-2,4,6-cycloheptatrien-1-one), which lacks the 7-OH group of the heptatriene ring, was inactive, while manicol, which possesses a 7-OH group, inhibited HIV-1 and E.coli RNases H with IC(50) = 1.5 μM and 40 μM, respectively. Such a result highlights the importance of the 2,7-dihydroxy function of these tropolone analogs, possibly through a role in metal chelation at the RNase H active site. Inhibition of HIV-2 RT-associated RNase H indirectly indicates that these compounds do not occupy the nonnucleoside inhibitor-binding pocket in the vicinity of the DNA polymerase domain. Both β-thujaplicinol and manicol failed to inhibit DNA-dependent DNA polymerase activity of HIV-1 RT at a concentration of 50 μM, suggesting that they are specific for the C-terminal RNase H domain, while surface plasmon resonance studies indicated that the inhibition was not due to intercalation of the analog into the nucleic acid substrate. Finally, we have demonstrated synergy between β-thujaplicinol and calanolide A, a nonnucleoside inhibitor of HIV-1 RT, raising the possibility that both enzymatic activities of HIV-1 RT can be simultaneously targeted

Composición en ácidos grasos de los lípidos del polen de palmeras Cycas revoluta

The fatty acid (FA) composition of total extractable and non extractable with chloroform lipids of C. revoluta pollen was determined. Among other minor FAs, unusual Δ5 polymethylene-interrupted FA, Δ5, 11-octadecadienoic acid was found. This FA was found in the seed lipids of C. revoluta earlier, but it was discovered for the first time in pollen lipids.Se determinó la composición en ácidos grasos (AG) de los lípidos totales extraíbles y no extraíbles con cloroformo del polen de la palmera C. revoluta. Entre otros ácidos grasos menores se encontró un AG Δ5 inusual, el ácido octadecadienoico, Δ5,11-polimetilen-interrumpido. Este AG ya fue descrito en los lípidos de semillas de C. revoluta, pero en los lípidos del polen es la primera vez que se describen

Reduced functionality of soil food webs in burnt boreal forests: a case study in Central Russia

© 2017, Pleiades Publishing, Ltd. Abstract: Functionality of soil food webs after forest fires remains generally unexplored. We address this question by studying both burnt and unburnt spruce forests in Central European Russia (Tver Region). In August 2014 we sampled two spatially distant blocks consisting of forest areas burnt in 2010 and the respective unburnt controls. We analyzed biomass and structure of soil food webs as well as carbon mobilization with respect to carbon stocks in the dead wood, litter and soil after burning. The biomass of soil fauna was moderately reduced in the burnt plots. For some groups like testate amoebae and enchytraeids, however, this decrease was highly significant and corresponded with the decreased C-stock in litter. For the other taxa changes in biomass were insignificant. At the same time C-flow through the soil food web after fire was strongly reduced mainly due to the reduction of biomass of active fungi and secondary decomposers. The overall consumption rate of detritus by the soil food web strongly decreased in the burnt forests and was maintained predominantly by the decomposition activity of bacteria instead of fungi. This resulted in the reduction of the total soil food web functionality related with C-mobilization in the forests four years after a fire event. Brief Summary: We compared rates of carbon mobilization by soil food webs in burnt and unburnt boreal forests in Central Russia. Despite of only slight decrease in soil animal biomass, consumption rate of carbon in the soil food webs after fire was considerably lower and mainly associated with soil bacteria instead of fungi

Macrophages from naked mole-rat possess distinct immunometabolic signatures upon polarization

The naked mole-rat (NMR) is a unique long-lived rodent which is highly resistant to age-associated disorders and cancer. The immune system of NMR possesses a distinct cellular composition with the prevalence of myeloid cells. Thus, the detailed phenotypical and functional assessment of NMR myeloid cell compartment may uncover novel mechanisms of immunoregulation and healthy aging. In this study gene expression signatures, reactive nitrogen species and cytokine production, as well as metabolic activity of classically (M1) and alternatively (M2) activated NMR bone marrow-derived macrophages (BMDM) were examined. Polarization of NMR macrophages under pro-inflammatory conditions led to expected M1 phenotype characterized by increased pro-inflammatory gene expression, cytokine production and aerobic glycolysis, but paralleled by reduced production of nitric oxide (NO). Under systemic LPS-induced inflammatory conditions NO production also was not detected in NMR blood monocytes. Altogether, our results indicate that NMR macrophages are capable of transcriptional and metabolic reprogramming under polarizing stimuli, however, NMR M1 possesses species-specific signatures as compared to murine M1, implicating distinct adaptations in NMR immune system

Intracellular S1P Generation Is Essential for S1P-Induced Motility of Human Lung Endothelial Cells: Role of Sphingosine Kinase 1 and S1P Lyase

Earlier we have shown that extracellular sphingosine-1-phosphate (S1P) induces migration of human pulmonary artery endothelial cells (HPAECs) through the activation of S1P(1) receptor, PKCε, and PLD2-PKCζ-Rac1 signaling cascade. As endothelial cells generate intracellular S1P, here we have investigated the role of sphingosine kinases (SphKs) and S1P lyase (S1PL), that regulate intracellular S1P accumulation, in HPAEC motility

Tridimensional model structure and patterns of molecular evolution of Pepino mosaic virus TGBp3 protein

<p>Abstract</p> <p>Background</p> <p><it>Pepino mosaic virus </it>(PepMV) is considered one of the most dangerous pathogens infecting tomatoes worldwide. The virus is highly diverse and four distinct genotypes, as well as inter-strain recombinants, have already been described. The isolates display a wide range on symptoms on infected plant species, ranging from mild mosaic to severe necrosis. However, little is known about the mechanisms and pattern of PepMV molecular evolution and about the role of individual proteins in host-pathogen interactions.</p> <p>Methods</p> <p>The nucleotide sequences of the triple gene block 3 (TGB3) from PepMV isolates varying in symptomatology and geographic origin have been analyzed. The modes and patterns of molecular evolution of the TGBp3 protein were investigated by evaluating the selective constraints to which particular amino acid residues have been subjected during the course of diversification. The tridimensional structure of TGBp3 protein has been modeled <it>de novo </it>using the Rosetta algorithm. The correlation between symptoms development and location of specific amino acids residues was analyzed.</p> <p>Results</p> <p>The results have shown that TGBp3 has been evolving mainly under the action of purifying selection operating on several amino acid sites, thus highlighting its functional role during PepMV infection. Interestingly, amino acid 67, which has been previously shown to be a necrosis determinant, was found to be under positive selection.</p> <p>Conclusions</p> <p>Identification of diverse selection events in TGB3p3 will help unraveling its biological functions and is essential to an understanding of the evolutionary constraints exerted on the <it>Potexvirus </it>genome. The estimated tridimensional structure of TGBp3 will serve as a platform for further sequence, structural and function analysis and will stimulate new experimental advances.</p