Identifying targets for COPD treatment through gene expression analyses

Despite the status of chronic obstructive pulmonary disease (COPD) as a major global health problem, no currently available therapies can limit COPD progression. Therefore, an urgent need exists for the development of new and effective treatments for COPD. An improved understanding in the molecular pathogenesis of COPD can potentially identify molecular targets to facilitate the development of new therapeutic modalities. Among the best approaches for understanding the molecular basis of COPD include gene expression profiling techniques, such as serial analysis of gene expression or microarrays. Using these methods, recent studies have mapped comparative gene expression profiles of lung tissues from patients with different stages of COPD relative to healthy smokers or non-smokers. Such studies have revealed a number of differentially-regulated genes associated with COPD progression, which include genes involved in the regulation of inflammation, extracellular matrix, cytokines, chemokines, apoptosis, and stress responses. These studies have shed new light on the molecular mechanisms of COPD, and suggest novel targets for clinical treatments

Carbon monoxide inhibits Fas activating antibody-induced apoptosis in endothelial cells

<p>Abstract</p> <p>Background</p> <p>The extrinsic apoptotic pathway initiates when a death ligand, such as the Fas ligand, interacts with its cell surface receptor (<it>ie</it>., Fas/CD95), forming a death-inducing signaling complex (DISC). The Fas-dependent apoptotic pathway has been implicated in several models of lung or vascular injury. Carbon monoxide, an enzymatic product of heme oxygenase-1, exerts antiapoptotic effects at low concentration <it>in vitro </it>and <it>in vivo</it>.</p> <p>Methods</p> <p>Using mouse lung endothelial cells (MLEC), we examined the antiapoptotic potential of carbon monoxide against apoptosis induced by the Fas/CD95-activating antibody (Jo2). Carbon monoxide was applied to cell cultures <it>in vitro</it>. The expression and/or activation of apoptosis-related proteins and signaling intermediates were determined using Western Immunoblot and co-immunoprecipitation assays. Cell death was monitored by lactate dehydrogenase (LDH) release assays. Statistical significance was determined by student T-test and a value of <it>P </it>< 0.05 was considered significant.</p> <p>Results</p> <p>Treatment of MLEC with Fas-activating antibody (Jo2) induced cell death associated with the formation of the DISC, and activation of caspases (-8, -9, and -3), as well as the pro-apoptotic Bcl-2 family protein Bax. Exposure of MLEC to carbon monoxide inhibited Jo2-induced cell death, which correlated with the inhibition of DISC formation, cleavage of caspases-8, -9, and -3, and Bax activation. Carbon monoxide inhibited the phosphorylation of the Fas-associated death domain-containing protein, as well as its association with the DISC. Furthermore, carbon monoxide induced the expression of the antiapoptotic protein FLIP and increased its association with the DISC.</p> <p>CO-dependent cytoprotection against Fas mediated apoptosis in MLEC depended in part on activation of ERK1/2-dependent signaling.</p> <p>Conclusions</p> <p>Carbon monoxide has been proposed as a potential therapy for lung and other diseases based in part on its antiapoptotic effects in endothelial cells. In vitro, carbon monoxide may inhibit both Fas/caspase-8 and Bax-dependent apoptotic signaling pathways induced by Fas-activating antibody in endothelial cells. Strategies to block Fas-dependent apoptotic pathways may be useful in development of therapies for lung or vascular disorders.</p

The Stokes Phenomenon and Quantum Tunneling for de Sitter Radiation in Nonstationary Coordinates

We study quantum tunneling for the de Sitter radiation in the planar coordinates and global coordinates, which are nonstationary coordinates and describe the expanding geometry. Using the phase-integral approximation for the Hamilton-Jacobi action in the complex plane of time, we obtain the particle-production rate in both coordinates and derive the additional sinusoidal factor depending on the dimensionality of spacetime and the quantum number for spherical harmonics in the global coordinates. This approach resolves the factor of two problem in the tunneling method.Comment: LaTex 10 pages, no figur