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In moderate-severe CAP, administration of corticosteroids promotes resolution of clinical symptoms and reduces the duration of intravenous antibiotic therapy.

Repeated painting of Dermatophagoides extract produced IgE-associated AEDS-like lesions on the skin of NC mice.

Asthma is a chronic inflammatory disease that is associated with airway remodeling, including hyperplasia of airway epithelial cells and airway smooth muscle cells, and goblet cell differentiation. We wished to address the potential role of histamine, a key biogenic amine involved in allergic reactions, in airway remodeling through the epidermal growth factor receptor (EGFR) pathway. Here, we demonstrate that histamine releases 2 EGFR ligands, amphiregulin and heparin-binding epidermal growth factor-like growth factor (HB-EGF), from airway epithelial cells. Amphiregulin and HB-EGF were expressed in airway epithelium of patients with asthma. Histamine up-regulated their mRNA expression (amphiregulin 3.2-fold, P<0.001; HB-EGF 2.3-fold, P<0.05) and triggered their release (amphiregulin EC(50) 0.50 μM, 31.2 ± 2.7 pg/ml with 10 μM histamine, P<0.01; HB-EGF EC(50) 0.54 μM, 78.5 ± 1.8 pg/ml with 10 μM histamine, P<0.001) compared to vehicle control (amphiregulin 19.3 ± 0.9 pg/ml; HB-EGF 60.2 ± 1.0 pg/ml), in airway epithelial cells. Histamine increased EGFR phosphorylation (2.1-fold by Western blot analysis) and induced goblet cell differentiation (CLCA1 up-regulation by real-time qPCR) in normal human bronchial epithelial (NHBE) cells. Moreover, amphiregulin and HB-EGF caused proliferation and migration of both NHBE cells and human airway smooth muscle cells. These results suggest that histamine may induce airway remodeling via the epithelial-derived EGFR ligands amphiregulin and HB-EGF.

IL-13 is an important mediator of allergen-induced airway hyperresponsiveness. This Th2 cytokine, produced by activated T cells, mast cells, and basophils, has been described to mediate a part of its effects independently of inflammation through a direct modulation of the airway smooth muscle (ASM). Previous studies demonstrated that IL-13 induces hyperresponsiveness in vivo and enhances calcium signaling in response to contractile agonists in vitro. We hypothesized that IL-13 drives human ASM cells (ASMC) to a procontractile phenotype. We evaluated ASM phenotype through the ability of the cell to proliferate, to contract, and to express contractile protein in response to IL-13. We found that IL-13 inhibits human ASMC proliferation (expression of Ki67 and bromodeoxyuridine incorporation) in response to serum, increasing the number of cells in G0/G1 phase and decreasing the number of cells in G2/M phases of the cell cycle. IL-13-induced inhibition of proliferation was not dependent on signal transducer and activator of transcription-6 but was IL-13Rα2 receptor dependent and associated with a decrease of Kruppel-like factor 5 expression. In parallel, IL-13 increased calcium signaling and the stiffening of human ASMC in response to 1 μM histamine, whereas the stiffening response to 30 mM KCl was unchanged. However, Western blot analysis showed unchanged levels of calponin, smooth muscle α-actin, vinculin, and myosin. We conclude that IL-13 inhibits proliferation via the IL-13Rα2 receptor and induces hypercontractility of human ASMC without change of the phenotypic markers of contractility.

Tissue engineering of multilayered constructs that model complex tissues poses a significant challenge for regenerative medicine. In this study, a three-layered scaffold consisting of an electrospun silk fibroin (SF) mat sandwiched between two dense collagen (DC) layers was designed and characterized. It was hypothesized that the SF layer would endow the DC-SF-DC construct with enhanced mechanical properties (e.g., apparent modulus, tensile strength, and toughness), while the surrounding DC layers provide an extracellular matrix-like environment for mesenchymal stem cell (MSC) growth. MSC-seeded DC-SF-DC hybrids were produced using the plastic compression technique and characterized morphologically, chemically, and mechanically. Moreover, MSC viability was assessed for up to 1 wk in culture. Scaffold analyses confirmed compaction and integration of the meso-scaled multilayered DC-SF-DC hybrid, which was reflected in a significantly higher toughness value when compared to DC and SF alone. MSCs directly incorporated into the DC layers remained viable for up to day 7. The ease of multilayered construct fabrication, enhanced biomechanical properties, along with uniformity of cell distribution confirmed the possibility for the incorporation and segregation of different cell types within distinct layers for the regeneration of complex tissues, such as skin, or central nervous system dura mater.

Tsuchiya K, Siddiqui S, Risse P-A, Hirota N, Martin JG. The presence of LPS in OVA inhalations affects airway inflammation and AHR but not remodeling in a rodent model of asthma. Am J Physiol Lung Cell Mol Physiol 303: L54 -L63, 2012. First published April 20, 2012 doi:10.1152/ajplung.00208.2011 is the most frequently used allergen in animal models of asthma. Lipopolysaccharide (LPS) contaminating commercial OVA may modulate the evoked airway inflammatory response to OVA. However, the effect of LPS in OVA on airway remodeling, especially airway smooth muscle (ASM) has not been evaluated. We hypothesized that LPS in commercial OVA may enhance allergen-induced airway inflammation and remodeling. Brown Norway rats were sensitized with OVA on day 0. PBS, OVA, or endotoxin-free OVA (Ef-OVA) was instilled intratracheally on days 14,19,24. Bronchoalveolar lavage (BAL) fluid, lung, and intrathoracic lymph node tissues were collected 48 h after the last challenge. Immunohistochemistry for ␣-smooth muscle actin, Periodic-Acid-Schiff staining, and real-time qPCR were performed. Airway hyperresponsiveness (AHR) was also measured. BAL fluid macrophages, eosinophils, neutrophils, and lymphocytes were increased in OVA-challenged animals, and macrophages and neutrophils were significantly lower in Ef-OVA-challenged animals. The ASM area in larger airways was significantly increased in both OVA and Ef-OVA compared with PBS-challenged animals. The mRNA expression of IFN-␥ and IL-13 in lung tissues and IL-4 in lymph nodes was significantly increased by both OVA and Ef-OVA compared with PBS and were not significantly different between OVA and Ef-OVA. Monocyte chemoattractant protein (MCP)-1 in BAL fluid and AHR were significantly increased in OVA but not in Ef-OVA. LPS contamination in OVA contributes to the influx of macrophages and MCP-1 increase in the airways and to AHR after OVA challenges but does not affect OVA-induced Th1 and Th2 cytokine expression, goblet cell hyperplasia, and ASM remodeling. animal model; airway hyperresponsiveness; Brown Norway rat; endotoxin; ovalbumin LIPOPOLYSACCHARIDE (LPS) is a cell wall component of Gramnegative bacteria and ubiquitous in the environment and is often present in polluted air as well as in household dust. There has been substantial interest in LPS for its effects on respiratory immunity since the development of the hygiene hypothesis (32, 38). Toll-like receptor 4 (TLR4) is a receptor for LPS, and activation of TLR4 is required to prime dendritic cells and epithelial cells for optimal responses to antigen exposure (12). Stimulation of TLR4 is essential for downstream cellular events that are mediated by mitogen-activated protein kinase p38 and c-Jun NH2-terminal kinase, leading to nuclear translocation of NF-B, resulting in cytokine mRNA transcription and release of proinflammatory cytokines (37).Ovalbumin (OVA) is widely used in animal models of asthma to study mechanisms of airway inflammation, airway hyperresponsiveness (AHR), and airway remodeling. However, commercial OVA has ...

Many G protein-coupled receptors (GPCRs) possess a putative cytoplasmic helical domain, termed helix 8 (H8), at the proximal region of the C-terminal tail. However, the significance of this domain is not fully understood. Here, we demonstrate the requirement of H8 for the proper folding of GPCRs for passage through the quality control in the endoplasmic reticulum (ER). In the human leukotriene B(4) type-2 receptor (hBLT2), lack of H8 led to an accumulation of the receptor (hBLT2/DeltaH8) in the ER. Similar results were obtained in two representative human GPCRs, dopamine type-1 and lysophosphatidic acid type-2 receptors, which were engineered to lack H8. Treatment with the several ligands, which act as pharmacological chaperones, facilitated the surface expression of hBLT2/DeltaH8. The surface-trafficked hBLT2/DeltaH8 exhibited an agonist-evoked increase in Ca(2+), demonstrating that H8 is not critical for ligand binding and activation of coupled G proteins. Thus, these results suggest that the H8 region of hBLT2 plays an important role in transport-competent receptor folding.