Defining the molecular role of gp91phox in the immune manifestation of acute allergic asthma using a preclinical murine model

<p>Abstract</p> <p>Objective</p> <p>The phenomena manifested during inflammation require interplay between circulating effector cells, local resident cells, soluble mediators and genetic host factors to establish, develop and maintain itself. Of the molecues involed in the initiation and perpetuation of acute allergic inflammation in asthma, the involvement of effector cells in redox reactions for producing O₂^-(superoxide anion) through the mediation of NADPH oxidase is a critical step. Prior data suggest that reactive oxygen species (ROS) produced by NADPH oxidase homologues in non-phagocytic cells play an important role in the regulation of signal transduction, while macrophages use a membrane-associated NADPH oxidase to generate an array of oxidizing intermediates which inactivate MMPs on or near them.</p> <p>Materials and Methods and Treatment</p> <p>To clarify the role of gp91phox subunit of NADPH oxidase in the development and progression of an acute allergic asthma phenotype, we induced allergen dependent inflammation in a gp91<it>^phox</it>-/- single knockout and a gp91phox-/-MMP-12-/- double knockout mouse models.</p> <p>Results</p> <p>In the knockout mice, both inflammation and airway hyperreactivity were more extensive than in wildtype mice post-OVA. Although OVA-specific IgE in plasma were comparable in wildtype and knockout mice, enhanced inflammatory cell recruitment from circulation and cytokine release in lung and BALf, accompanied by higher airway resistance as well as Penh in response to methacholine, indicate a regulatory role for NADPH oxidase in development of allergic asthma. While T cell mediated functions like Th2 cytokine secretion, and proliferation to OVA were upregulated synchronous with the overall robustness of the asthma phenotype, macrophage upregulation in functions such as proliferation, and mixed lymphocyte reaction indicate a regulatory role for gp91phox and an overall non-involvement or synergistic involvement of MMP12 in the response pathway (comparing data from gp91phox-/- and gp91phox-/-MMP-12-/- mice).</p

Mannose-rich guar gum nanoparticles as a novel therapeutic drug against inflammatory diseases

The potential to deliver nanoparticles, like polymer-based nanoparticles that can be enriched with functional groups to ensure entry into cells, directly into targeted cells is important for the therapy of inflammatory diseases. Plant-derived nanoparticles, with inherent anti-inflammatory activity and modified to allow receptor-mediated uptake, can be used as effective therapy with minimal side effects. The particle used in this study is an edible polysaccharide, derived from Cyamopsis tetragonoloba, with a galactomannan component. The particle was made mannose-rich to increase specificity towards cells expressing mannose receptors, and initially tagged with rhodamine isothiocyanate to trace its path. This study aimed to determine the therapeutic effect of the guar gum nanoparticle (GN) in vitro and in vivo in inflammatory diseases. In vitro studies on RAW 264.7 cells showed successful uptake of the nanoparticle, in a short duration of time, via their mannose receptors. Nitric oxide and MTS assays showed anti-inflammatory effects of GN. In vivo mouse model of thioglycollate-induced peritonitis showed significant decrease in inflammation, indicating its anti-inflammatory effect, and increase in clonogenic potential, indicating its regenerative potential, on intraperitoneal administration of GN. The results reflect the potential of the nanoparticle in cellular trafficking, site- specific drug delivery and bioimaging applications

NADPH Oxidase has a Regulatory Role in Acute Allergic Asthma

Objective: For the establishment of inflammation, a constant interplay between different effector cells from circulation, local resident cells, soluble mediators and genetic host factors is required. Molecular mechanisms, initiating and perpetuating inflammation, in particular, the involvement of effector cells in redox reactions for producing O2- (superoxide anion) through the mediation of NADPH oxidase is a critical step. Prior data suggest that reactive oxygen species (ROS) produced by NADPH oxidase homologues in non-phagocytic cells play an important role in the regulation of signal transduction, while macrophages use a membrane-associated NADPH oxidase to generate an array of oxidizing intermediates which inactivate MMPs on or near them. Materials, Methods and Treatment: To clarify the role of NADPH oxidase in T cell-initiated, macrophage-associated allergic asthma, we induced allergen dependent inflammation in a gp91phox-/- mouse. Results: Both inflammation and airway hyperreactivity were more extensive than in wildtype mice post-OVA. Although OVA-specific IgE in plasma were comparable in wildtype and knockout mice, enhanced inflammatory cell recruitment from circulation and cytokine release in lung and BALf, accompanied by higher airway resistance as well as Penh in response to methacholine, indicates a regulatory role for NADPH oxidase in development of allergic asthma. While T cell-mediated functions like Th2 cytokine secretion, and proliferation to OVA were up-regulated synchronous with the overall robustness of the asthma phenotype, macrophage up-regulation in functions such as proliferation, mixed lymphocyte reaction, and MCP-1 directed chemotaxis, but downregulation of respiratory burst response indicates a forking in their signaling pathways. gp91phox-/- MMP12 double knockout (DKO) mice show a similar phenotype as the gp91phox-/- showing the non-involvement or synergistic involvement of MMP12 in the response pathway. In mixed lymphocyte reaction using the Increased B7.1 but reduced B7.2 and MHC class II expression indicating alteration of co-stimulatory molecule expression critical for T cell activation on both gp91phox-/- and DKO mice may explain the mechanism by which gp91phox may regulate Th2 pathway in allergic asthma

Human Embryonic Stem Cells Differentiated to Lung Lineage-Specific Cells Ameliorate Pulmonary Fibrosis in a Xenograft Transplant Mouse Model

Our aim was to differentiate human (h) embryonic stem (ES) cells into lung epithelial lineage-specific cells [i.e., alveolar epithelial type I (AEI) and type II (AEII) cells and Clara cells] as the first step in the development of cell-based strategies to repair lung injury in the bleomycin mouse model of idiopathic pulmonary fibrosis (IPF). A heterogeneous population of non-ciliated lung lineage-specific cells was derived by a novel method of embryoid body (EB) differentiation. This differentiated human cell population was used to modulate the profibrotic phenotype in transplanted animals.Omission or inclusion of one or more components in the differentiation medium skewed differentiation of H7 hES cells into varying proportions of AEI, AEII, and Clara cells. ICG-001, a small molecule inhibitor of Wnt/β-catenin/Creb-binding protein (CBP) transcription, changed marker expression of the differentiated ES cells from an AEII-like phenotype to a predominantly AEI-like phenotype. The differentiated cells were used in xenograft transplantation studies in bleomycin-treated Rag2γC(-/-) mice. Human cells were detected in lungs of the transplanted groups receiving differentiated ES cells treated with or without ICG-001. The increased lung collagen content found in bleomycin-treated mice receiving saline was significantly reduced by transplantation with the lung-lineage specific epithelial cells differentiated from ES cells. A significant increase in progenitor number was observed in the airways of bleomycin-treated mice after transplantation of differentiated hES cells.This study indicates that ES cell-based therapy may be a powerful novel approach to ameliorate lung fibrosis

Role of free radicals in human inflammatory diseases

The role of free radicals can be found in the inflammatory process which is a complex process resulting many human diseases. Inflammations are mainly divided into acute and chronic inflammation depending on various inflammatory processes and cellular mechanisms. In recent years, there has been a great deal of attention to the field of free radical chemistry. Free radicals such as reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated by our body by various endogenous systems, exposure to different physiochemical conditions or pathological states. The purpose of the present review is to mention the role of free radical formation in the most common inflammatory processes in animals. Continued oxidative stress can lead to chronic inflammation, which in turn could mediate the most chronic diseases including cancer, diabetes, cardiovascular, neurological, and pulmonary diseases. ROS and RNS are well recognized for playing role as deleterious species. ROS and RNS are normally generated by tightly regulated enzymes, such as NO synthase (NOS) and NAD(P)H oxidase isoforms, respectively. The detrimental effect of free radicals causing health damages is termed oxidative stress and nitrosative stress. Overproduction of ROS results in oxidative stress, a deleterious process that can damage cell structures, including lipids, proteins, and DNA