American journal of respiratory cell and molecular biology
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Am. J. Respir. Cell Mol. Biol. · Oct 2004
Comparative StudyChemokines in bronchiolar epithelium in the development of chronic obstructive pulmonary disease.
The inflammatory chemokines interleukin-8, macrophage inflammatory protein-1alpha, and monocyte chemoattractant protein-1, are reportedly involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). Although bronchiolar epithelial cells and macrophages are known to be the cellular sources, the relative contribution of each cell type remains to be elucidated. In the present study, we first quantified cytokine mRNA in human bronchiolar epithelial cells and macrophages obtained using laser-capture microdissection and explored the relationship with early-stage COPD. ⋯ No difference was observed in macrophages. Complementary DNA (cDNA) array further revealed the overexpression of CC chemokine receptor 2 in bronchiolar epithelial cells from smokers with airflow limitation and/or emphysema. This study supports the role of bronchiolar epithelium as the source of increased inflammatory chemokine levels in the early development of COPD and also demonstrates the potential use of laser-capture microdissection, combined with reverse transcriptase-polymerase chain reaction and cDNA microarrays, to investigate functional profiles of individual structural and inflammatory cells in human lungs.
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Am. J. Respir. Cell Mol. Biol. · Oct 2004
Regulation of c-Jun N-terminal kinase and p38 kinase pathways in endothelial cells.
The rapid and transient induction of E-selectin gene expression by inflammatory tumor necrosis factor (TNF)-alpha in endothelial cells is mediated by signaling pathways which involve c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) kinase pathways. To explore this regulation, we first observed that in the continuous presence of cytokine TNF, activation of JNK-1 in both nuclear and cytoplasmic compartments peaked at 15-30 min, with activity returning to uninduced levels by 60 min. Phosphorylation of both the p38 kinase and its molecular target, the nuclear transcription factor, activating transcription factor-2, were transient after TNF-alpha or interleukin (IL)-1beta induction. ⋯ Inhibition of MKP-1 expression through the use of small interfering RNAs prolonged the cytokine-induced p38 and JNK kinase phosphorylation. Our results suggest that endogenous inhibitors of the MAPK cascade, such as the dual-specificity phosphatases like MKP-1 may be important for the postinduction repression of MAPK activity and E-selectin transcription in endothelial cells. Thus, these inhibitors may play an important role in limiting the inflammatory effects of TNF-alpha and IL-1beta.