Nicotinamide Phosphoribosyltransferase Attenuates Methotrexate Response in Juvenile Idiopathic Arthritis and In Vitro

Variability in response to methotrexate (MTX) in the treatment of juvenile idiopathic arthritis (JIA) remains unpredictable and poorly understood. Based on previous studies implicating an interaction between nicotinamide phosphoribosyltransferase (NAMPT) expression and MTX therapy in inflammatory arthritis, we hypothesized that increased NAMPT expression would be associated with reduced therapeutic response to MTX in patients with JIA. A significant association was found between increased plasma concentrations of NAMPT and reduced therapeutic response in patients with JIA treated with MTX. Inhibition of NAMPT in cell culture by either siRNA-based gene silencing or pharmacological inhibition with FK-866 was found to result in a fourfold increase in the pharmacological activity of MTX. Collectively, these findings provide evidence that NAMPT inhibits the pharmacological activity of MTX and may represent a predictive biomarker of response, as well as a therapeutic target, in the treatment of JIA with MTX

Systematic documentation and analysis of human genetic variation in hemoglobinopathies using the microattribution approach

We developed a series of interrelated locus-specific databases to store all published and unpublished genetic variation related to hemoglobinopathies and thalassemia and implemented microattribution to encourage submission of unpublished observations of genetic variation to these public repositories. A total of 1,941 unique genetic variants in 37 genes, encoding globins and other erythroid proteins, are currently documented in these databases, with reciprocal attribution of microcitations to data contributors. Our project provides the first example of implementing microattribution to incentivise submission of all known genetic variation in a defined system. It has demonstrably increased the reporting of human variants, leading to a comprehensive online resource for systematically describing human genetic variation in the globin genes and other genes contributing to hemoglobinopathies and thalassemias. The principles established here will serve as a model for other systems and for the analysis of other common and/or complex human genetic diseases

The Effect of Iron Limitation on the Transcriptome and Proteome of Pseudomonas fluorescens Pf-5

One of the most important micronutrients for bacterial growth is iron, whose bioavailability in soil is limited. Consequently, rhizospheric bacteria such as Pseudomonas fluorescens employ a range of mechanisms to acquire or compete for iron. We investigated the transcriptomic and proteomic effects of iron limitation on P. fluorescens Pf-5 by employing microarray and iTRAQ techniques, respectively. Analysis of this data revealed that genes encoding functions related to iron homeostasis, including pyoverdine and enantio-pyochelin biosynthesis, a number of TonB-dependent receptor systems, as well as some inner-membrane transporters, were significantly up-regulated in response to iron limitation. Transcription of a ribosomal protein L36-encoding gene was also highly up-regulated during iron limitation. Certain genes or proteins involved in biosynthesis of secondary metabolites such as 2,4-diacetylphloroglucinol (DAPG), orfamide A and pyrrolnitrin, as well as a chitinase, were over-expressed under iron-limited conditions. In contrast, we observed that expression of genes involved in hydrogen cyanide production and flagellar biosynthesis were down-regulated in an iron-depleted culture medium. Phenotypic tests revealed that Pf-5 had reduced swarming motility on semi-solid agar in response to iron limitation. Comparison of the transcriptomic data with the proteomic data suggested that iron acquisition is regulated at both the transcriptional and post-transcriptional levels

MC-PPEA as a new and more potent inhibitor of CLP-induced sepsis and pulmonary inflammation than FK866

Peixin Huang,1 Mark W Lee Jr,2 Keivan Sadrerafi,2 Daniel P Heruth,1 Li Q Zhang,1 Dev Maulik,3,4 Shui Qing Ye1,4 1Division of Experimental and Translational Genetics, Department of Pediatrics, The Children’s Mercy Hospital, University of Missouri Kansas City School of Medicine Kansas City, 2Department of Chemistry, University of Missouri, Columbia, MO, 3Department of Biomedical and Health Informatics, University of Missouri Kansas City School of Medicine, 4Department of Obstetrics and Gynecology, Truman Medical Center, Kansas City, MO, USA Abstract: Our previous study indicated that overexpression of nicotinamide phosphoribosyltransferase (NAMPT) aggravated acute lung injury, while knockdown of NAMPT expression attenuated ventilator-induced lung injury. Recently, we found that meta-carborane-butyl-3-(3-pyridinyl)-2E-propenamide (MC-PPEA, MC4), in which the benzoylpiperidine moiety of FK866 has been replaced by a carborane, displayed a 100-fold increase in NAMPT inhibition over FK866. Here, we determined the effects of MC4 and FK866 on cecal ligation and puncture (CLP) surgery-induced sepsis in C57BL/6J mice. MC4 showed stronger inhibitory effects than FK866 on CLP-induced mortality, serum tumor necrosis factor α (TNFα) levels, pulmonary myeloperoxidase activity, alveolar injury, and interleukin 6 and interleukin1β messenger RNA levels. In vitro cell permeability and electric cell–substrate impedance sensing assays demonstrated that MC4 inhibited TNFα- and thrombin-mediated pulmonary endothelial cell permeability better than FK866. MC4 also exerted more potent effects than FK866, at concentrations as low as 0.3 nM, to attenuate TNFα-mediated intracellular cytokine expression, nicotinamide adenine dinucleotide (NAD+) and its reduced form NADH levels, and nuclear factor kappa B p65 phosphorylation and nuclear translocation in A549 cells. Our results strongly suggest that the newly developed MC4 is a more potent suppressor of CLP-induced pulmonary inflammation and sepsis than FK866, with potential clinical application as a new treatment agent for sepsis and inflammation. Keywords: NAMPT, pulmonary inflammation, sepsi