13 research outputs found

    Glucocorticoids Rapidly Activate cAMP Production via G\u3csub\u3eαs\u3c/sub\u3e to Initiate Non-Genomic Signaling That Contributes to One-Third of Their Canonical Genomic Effects

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    Glucocorticoids are widely used for the suppression of inflammation, but evidence is growing that they can have rapid, non-genomic actions that have been unappreciated. Diverse cell signaling effects have been reported for glucocorticoids, leading us to hypothesize that glucocorticoids alone can swiftly increase the 3′,5′-cyclic adenosine monophosphate (cAMP) production. We found that prednisone, fluticasone, budesonide, and progesterone each increased cAMP levels within 3 minutes without phosphodiesterase inhibitors by measuring real-time cAMP dynamics using the cAMP difference detector in situ assay in a variety of immortalized cell lines and primary human airway smooth muscle (HASM) cells. A membrane- impermeable glucocorticoid showed similarly rapid stimulation of cAMP, implying that responses are initiated at the cell surface. siRNA knockdown of Gαs virtually eliminated glucocorticoidstimulated cAMP responses, suggesting that these drugs activate the cAMP production via a G protein-coupled receptor. Estradiol had small effects on cAMP levels but G protein estrogen receptor antagonists had little effect on responses to any of the glucocorticoids tested. The genomic and non-genomic actions of budesonide were analyzed by RNA-Seq analysis of 24 hours treated HASM, with and without knockdown of Gαs. A 140-gene budesonide signature was identified, of which 48 genes represent a non-genomic signature that requires Gαs signaling. Collectively, this non-genomic cAMP signaling modality contributes to one-third of the gene expression changes induced by glucocorticoid treatment and shifts the view of how this important class of drugs exerts its effect

    Large para-testicular intra-scrotal malignant peripheral nerve sheath tumor managed with radical penectomy: A case report

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    Neurofibromatosis 1 is a relatively rare genetic disease characterized by widespread neurofibromas originating from the peripheral nervous system. Most growths are benign, but some carry a risk of transformation to malignant peripheral nerve sheath tumors. Although these growths can be found anywhere in the body, they are rarely found in the male external genitalia. This report discusses a case of a 25-year-old male patient with neurofibromatosis 1 presenting with a scrotal mass found to have a very large para-testicular intra-scrotal malignant peripheral nerve sheath tumor that required testicle-sparing radical penectomy

    Conditional Survival in de novo Metastatic Urothelial Carcinoma.

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    Second-line therapy is frequently utilized for metastatic urothelial carcinoma, but there are limited data to guide this approach. While an assessment of overall survival based on registry data may not capture the impact of second- and third-line therapies on clinical outcome, this may be reflected in relative conditional survival (RCS).Patients with stage IV urothelial carcinoma diagnosed from 1990-2010 were identified from the Surveillance, Epidemiology and End Results (SEER) dataset. The association of clinicopathologic variables with disease specific survival (DSS) was explored through univariate and multivariate analyses. DSS in subgroups divided by time period (1990-2000 v 2001-2010) was compared using the Kaplan-Meier method and log-rank test. One-year RCS at annual landmarks up to 5 years was compared in subgroups divided by time period.Of 261,987 patients diagnosed with urothelial carcinoma from 1990-2010, 3,110 patients met criteria for the current analysis. Characteristics of patients diagnosed between 1990 and 2000 (n = 810) and 2001 to 2010 (n = 2,300) were similar and there was no significant difference in DSS between the two groups. On multivariate analysis, older age (age ≥ 80) was associated with shorter DSS (HR 1.79, 95%CI 1.48-2.15), but no association was found between time period of diagnosis and outcome. One-year RCS improved substantially through successive annual landmarks up to 5 years, but no differences were seen in subgroups divided by time of diagnosis.No difference in RCS was observed amongst patients with stage IV urothelial carcinoma diagnosed from 1990-2000 and 2001-2010. A lack of difference in RCS (more so than cumulative DSS) may reflect a lack of progress in salvage therapies for the disease

    Crystallisation behaviour of Pebax graphene composite matrix with and without supercritical carbon dioxide assisted polymer processing technique

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    The paper presents an in-depth analysis on the crystallization kinetics of Pebax–graphene composites when processed with and without supercritical fluid carbon dioxide (scCO2) assisted extrusion at various graphene loading concentrations. Crystallization behavior was understood using the Avrami model for isothermal conditions and the Avrami, Ozawa, and combined Avrami-Ozawa model for non-isothermal conditions. The results from crystallization kinetics suggest that the crystal structure transformed from two-dimensional to three-dimensional when processed with scCO2. The overall crystallization rate decreases when the composite matrix was processed with scCO2 under both isothermal and non-isothermal conditions promoting possible exfoliation and crystal rearrangement resulting in homogenization of the composite matrix. The Arrhenius and Kissinger’s activation energy was calculated, which is indicative of restriction opposed by graphene exfoliation to nucleation and crystal growth when processed with scCO2. Crystallite size was calculated from the X-ray diffraction pattern using Scherrer’s equation, where the crystallite size tends to decrease when processed with scCO2 favoring the production of a homogeneous composite matrix due to crystal rearrangement and graphene exfoliation

    PDE8 is Expressed in Human Airway Smooth Muscle and Selectively Regulates cAMP Signaling by β 2 AR-AC6

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    Two cAMP signaling compartments centering around adenylyl cyclase (AC) exist in human airway smooth muscle (HASM) cells, one containing ß2AR-AC6 and another containing E prostanoid receptors (EPR)-AC2. We hypothesized that different phosphodiesterase (PDE) isozymes selectively regulate cAMP signaling in each compartment. According to RNA-seq data, 18 of 24 PDE genes were expressed in primary HASM cells derived from age- and gender-matched donors with and without asthma. PDE8A was the third most abundant of the cAMP-degrading PDE genes, after PDE4A and PDE1A. Knockdown of PDE8A using shRNA evoked 2-fold greater cAMP responses to 1 DM forskolin in the presence of IBMX. Overexpression of AC2 did not alter this response, but overexpression of AC6 increased cAMP responses an additional 80%. We examined cAMP dynamics in live HASM cells using a fluorescent sensor. PF-04957325, a PDE8-selective inhibitor, increased basal cAMP levels by itself, indicating a significant basal level of cAMP synthesis. In the presence of an AC inhibitor to reduce basal signaling, PF-04957325 accelerated cAMP production and increased the inhibition of cell proliferation induced by isoproterenol, but had no effect on cAMP levels or cell proliferation regulated by PGE2. Lipid raft fractionation of HASM cells revealed PDE8A immunoreactivity in buoyant fractions containing caveolin-1 and AC5/6 immunoreactivity. Thus, PDE8 is expressed in lipid rafts of HASM cells where it specifically regulates ß2AR-AC6 signaling without effects on signaling by the EP2/4R-AC2 complex. In airway diseases such as asthma and COPD, PDE8 may represent a novel therapeutic target to modulate HASM responsiveness and airway remodeling
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