Histamine N-methyltransferase Modulates Human Bronchial Smooth Muscle Contraction

To elucidate the modulatory role of histamine-degrading enzymes in airway constrictor responses, human bronchial strips were studied under isometric conditions in vitro. Pretreatment of tissues with the histamine N-methyltransferase (HMT) inhibitor SKF 91488 specifically potentiated the contractile responses to histamine, causing a leftward displacement of the concentration response curves, whereas the diamine oxidase inhibitor aminoguanidine had no effect. This potentiation was attenuated by mechanical removal of the epithelium. The HMT activity was detected in the human bronchi, which was less in the epithelium-denuded tissues than the epithelium-intact tissues. These results suggest that HMT localized to the airway epithelium may play a protective role against histamine-mediated bronchoconstriction in humans

Isoproterenol Increases CI Diffusion Potential Difference of Rabbit Trachea through Nitric Oxide Generation1

ABSTRAC

Electrospun amplified fiber optics

A lot of research is focused on all-optical signal processing, aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for an efficient signal transmission. However, the complex fabrication methods, involving high-temperature processes performed in highly pure environment, slow down the fabrication and make amplified components expensive with respect to an ideal, high-throughput and room temperature production. Here, we report on near infrared polymer fiber amplifiers, working over a band of about 20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and show amplified spontaneous emission with good gain coefficients as well as low optical losses (a few cm^-1). The amplification process is favoured by the high fiber quality and low self-absorption. The found performance metrics promise to be suitable for short-distance operation, and the large variety of commercially-available doping dyes might allow for effective multi-wavelength operation by electrospun amplified fiber optics.Comment: 27 pages, 8 figure

TorsinA participates in endoplasmic reticulum-associated degradation

TorsinA is an $AAA^+$ ATPase located within the lumen of the endoplasmic reticulum and nuclear envelope, with a mutant form causing early onset torsion dystonia (DYT1). Here we report a new function for torsinA in endoplasmic reticulum-associated degradation (ERAD). Retro-translocation and proteosomal degradation of a mutant cystic fibrosis transmembrane conductance regulator $(CFTR\Delta F508)$ was inhibited by downregulation of torsinA or overexpression of mutant torsinA, and facilitated by increased torsinA. Retro-translocation of cholera toxin was also decreased by downregulation of torsinA. TorsinA associates with proteins implicated in ERAD, including Derlin-1, VIMP, and p97. Further, torsinA reduces endoplasmic reticulum stress in nematodes overexpressing $CFTR\Delta F508$, and fibroblasts from DYT1 dystonia patients are more sensitive than controls to endoplasmic reticulum stress and less able to degrade mutant CFTR. Therefore, compromised ERAD function in the cells of DYT1 patients may increase sensitivity to endoplasmic reticulum stress with consequent alterations in neuronal function contributing to the disease state

Nitrosothiols in the immune system: Signaling and protection

Antioxidants and Redox Signaling 18.3 (2013): 288-308Significance: In the immune system, nitric oxide (NO) has been mainly associated with antibacterial defenses exerted through oxidative, nitrosative, and nitrative stress and signal transduction through cyclic GMP-dependent mechanisms. However, S-nitrosylation is emerging as a post-translational modification (PTM) involved in NO-mediated cell signaling. Recent Advances: Precise roles for S-nitrosylation in signaling pathways have been described both for innate and adaptive immunity. Denitrosylation may protect macrophages from their own S-nitrosylation, while maintaining nitrosative stress compartmentalized in the phagosomes. Nitrosothiols have also been shown to be beneficial in experimental models of autoimmune diseases, mainly through their role in modulating T-cell differentiation and function. Critical Issues: Relationship between S-nitrosylation, other thiol redox PTMs, and other NO-signaling pathways has not been always taken into account, particularly in the context of immune responses. Methods for assaying S-nitrosylation in individual proteins and proteomic approaches to study the S-nitrosoproteome are constantly being improved, which helps to move this field forward. Future Directions: Integrated studies of signaling pathways in the immune system should consider whether S-nitrosylation/denitrosylation processes are among the PTMs influencing the activity of key signaling and adaptor proteins. Studies in pathophysiological scenarios will also be of interest to put these mechanisms into broader contexts. Interventions modulating nitrosothiol levels in autoimmune disease could be investigated with a view to developing new therapiesFinanced by the Spanish Government grants CSD2007-00020 (RosasNet, Consolider-Ingenio 2010 programme), CP07/00143 (Miguel Servet programme), and PS09/00101; and PI10/0213

Redox proteomics of the inflammatory secretome identifies a common set of redoxins and other glutathionylated proteins released in inflammation, influenza virus infection and oxidative stress

Protein cysteines can form transient disulfides with glutathione (GSH), resulting in the production of glutathionylated proteins, and this process is regarded as a mechanism by which the redox state of the cell can regulate protein function. Most studies on redox regulation of immunity have focused on intracellular proteins. In this study we have used redox proteomics to identify those proteins released in glutathionylated form by macrophages stimulated with lipopolysaccharide (LPS) after pre-loading the cells with biotinylated GSH. Of the several proteins identified in the redox secretome, we have selected a number for validation. Proteomic analysis indicated that LPS stimulated the release of peroxiredoxin (PRDX) 1, PRDX2, vimentin (VIM), profilin1 (PFN1) and thioredoxin 1 (TXN1). For PRDX1 and TXN1, we were able to confirm that the released protein is glutathionylated. PRDX1, PRDX2 and TXN1 were also released by the human pulmonary epithelial cell line, A549, infected with influenza virus. The release of the proteins identified was inhibited by the anti-inflammatory glucocorticoid, dexamethasone (DEX), which also inhibited tumor necrosis factor (TNF)-α release, and by thiol antioxidants (N-butanoyl GSH derivative, GSH-C4, and N-acetylcysteine (NAC), which did not affect TNF-α production. The proteins identified could be useful as biomarkers of oxidative stress associated with inflammation, and further studies will be required to investigate if the extracellular forms of these proteins has immunoregulatory functions

Clarithromycin is an effective immunomodulator when administered late in experimental pyelonephritis by multidrug-resistant Pseudomonas aeruginosa

BACKGROUND: To apply clarithromycin as an immunomodulatory treatment in experimental urosepsis by multidrug-resistant Pseudomonas aeruginosa. METHODS: Acute pyelonephritis was induced in 40 rabbits after inoculation of the test isolate in the renal pelvis. Therapy was administered upon signs of sepsis in four groups: A, controls; B, intravenous clarithromycin; C, amikacin; and D, both agents. Survival and vital signs were recorded; blood was sampled for culture and estimation of pro-inflammatory mediators; monocytes were isolated for determination of apoptotic rate and ex vivo TNFα secretion. Quantitative cultures and biopsies of organs were performed after death. RESULTS: Increased rectal temperature and oxygen saturation were found in groups B and D compared to A and C. Mean survival of groups A, B, C and D was 2.65, 7.15, 4.25 and 8.70 days respectively. No differences were noted between groups concerning bacterial load in blood and tissues and serum endotoxins. Serum MDA and total caspase-3 activity of monocytes of group D decreased following treatment compared to other groups. Negative correlation was detected between cytoplasmic caspase-3 and ex vivo secretion of TNFα of blood monocytes of group A; similar correlation was not found for any other group. Pathology scores of liver and lung of group B were lower than group A. CONCLUSION: Clarithromycin administered late in experimental urosepsis by multidrug-resistant P. aeruginosa prolonged survival and ameliorated clinical findings. Its effect is probably attributed to immunomodulatory intervention on blood monocytes

Single-Dose Intravenous Toxicity Study of IRDye 800CW in Sprague-Dawley Rats

Objective: Fluorophore-labeled contrast imaging agents are moving toward clinical use for a number of applications. The near-infrared dye IRDye 800CW is frequently used in its N-hydroxysuccinamide (NHS) ester form for labeling these agents. Following conjugation or breakdown of a labeled ligand, excess NHS ester is converted to the carboxylate form. To prepare for clinical use as a near-infrared fluorophore, a toxicity study was conducted on IRDye 800CW carboxylate. Methods: Male and female Sprague–Dawley rats were given a single intravenous or intradermal administration of IRDye 800CW carboxylate; Indocyanine Green was used as a comparative control. Animals were injected with varying doses of the test and control articles and observed for up to 14 days. Clinical chemistry, hematological, and pharmacokinetic analyses were performed on subgroups of animals. Organs were analyzed for content of the test article. Tissues were analyzed microscopically for pathological changes. Results: Based on hematologic, clinical chemistry, and histopathologic evaluation, single administration of IRDye 800CW carboxylate intravenously at dose levels of 1, 5, and 20 mg/kg or 20 mg/kg intradermally produced no pathological evidence of toxicity. Conclusion: A dose of 20 mg/kg was identified as the no observed adverse effect level following IV or ID routes of administration of IRDye 800CW