OBJECTIVETo study the alternative expression and sequence of human elongation factor-1 delta (human EF-1 delta p31) during malignant transformation of human bronchial epithelial cells induced by cadmium chloride (CdC12) and its possible mechanism.

METHODSTotal RNA was isolated at different stages of transformed human bronchial epithelial cells (16HBE) induced by CdCl2 at a concentration of 5.0 microM. Special primers and probe for human EF-1 delta p31 were designed and expression of human EF-1 delta mRNA from different cell lines was detected with fluorescent quantitative PCR technique. EF-18 cDNA from different cell lines was purified and cloned into pMD 18-T vector followed by confirming and sequencing analysis.

RESULTSThe expressions of human EF-1 beta p31 at different stages of 16HBE cells transformed by CdCl2 was elevated (P < 0.01 or P < 0.05). Compared with their corresponding non-transformed cells, the overexpression level of EF-1 delta p31 was averagely increased 2.9 folds in Cd-pretransformed cells, 4.3 folds in Cd-transformed cells and 7.2 folds in Cd-tumorigenic cells. No change was found n the sequence of overexpressed EF-1beta p31 at different stages of 16HBE cells transformed by CdCl2.

CONCLUSIONOverexpression of human EF-1beta p31 is positively correlated with malignant transformation of 16HBE cells induced by CdC12, but is not correlated with DNA mutations.

Cadmium Chloride ; Cell Line ; Cell Transformation, Neoplastic ; chemically induced ; metabolism ; Epithelial Cells ; drug effects ; metabolism ; pathology ; Gene Expression Regulation, Neoplastic ; Humans ; Peptide Elongation Factor 1 ; genetics ; metabolism ; Respiratory Mucosa ; drug effects ; metabolism ; pathology ; Sequence Analysis, DNA

No abstract available.
Air Pollutants/*toxicity ; Animals ; Biological Markers/metabolism ; Cell Proliferation/*drug effects ; Female ; Immunohistochemistry ; Inhalation Exposure ; Mice ; Mice, Inbred BALB C ; Nasal Mucosa/drug effects/pathology ; Ozone/*toxicity ; Proliferating Cell Nuclear Antigen/metabolism ; Respiratory Mucosa/*drug effects/metabolism/pathology ; Skin/*drug effects/metabolism/pathology

The EGFR plays an essential role in goblet cell hyperplasia and mucus hypersecretion. EGFR has an intrinsic tyrosine kinase activity that, when activated, induces the production of MUC5AC through the signaling kinase cascade in the airway epithelium. We have investigated the effects of an EGFR tyrosine kinase inhibitor, gefitinib, on ovalbumin (OVA)-induced, allergic inflammation in airway epithelia of mice. OVA-sensitized mice were pretreated with gefitinib at two different doses (12.5 and 50 mg/kg) and then challenged with OVA. The OVA challenge increased the total cell count and eosinophil count in bronchoalveolar lavage fluid (BALF), as well as the concentrations of T-helper2 (Th2) cytokines, such as IL-4 and IL-13, overall eosinophil recruitment in the lung tissue and airway hyperresponsiveness (AHR). Pretreatment with gefitinib reduced the inflammatory cell counts and released cytokine concentrations (IL-4 and IL-13) in BALF, as well as eosinophil recruitment in the lungs and AHR, in a dose-dependent manner. This was associated with decreased EGFR and Akt phosphorylation. We showed that gefitnib inhibits EGFR and phosphoinositol 3'-kinase (PI3K)/Akt activation which were activated in OVA sensitized mice. These findings suggest that inhibitors of the EGFR cascade may have a role in the treatment of asthma.
Animals ; Antineoplastic Agents/*therapeutic use ; Bronchoalveolar Lavage Fluid/cytology ; Cytokines/biosynthesis ; Enzyme Activation ; Eosinophils/cytology ; Goblet Cells/pathology ; Inflammation/drug therapy/metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; Phosphorylation ; Proto-Oncogene Proteins c-akt/metabolism ; Quinazolines/*therapeutic use ; Receptor, Epidermal Growth Factor/*antagonists & inhibitors/metabolism ; Respiratory Hypersensitivity/*drug therapy/etiology/metabolism ; Respiratory Mucosa/drug effects/pathology

OBJECTIVETo investigate the role of matrix metalloproteinase-9 (MMP-9) and its tissue inhibitor (TIMP-1) in the pathogenesis of bronchial asthma and assess the effect of steroid treatment on MMP-9 and TIMP-1 levels. Matrix metalloproteinases are a family of zinc and calcium-dependent endopeptidases. Many MMPs such as MMP-1, MMP-2, MMP-3 are associated with asthma, in which MMP-9 is the key factor in asthma. Tissue inhibitor-1 of metalloproteinases is a specific inhibitor of MMP-9; the MMP-9 and TIMP-1 imbalance could lead to airway inflammation and remodeling in lung disease such as asthma.

METHODSForty Wistar rats were divided into 4 groups randomly: control, asthma model 7 days (7-day group), asthma model 21 days (21-day group) and steroid treatment groups. Asthma model of rats were established by ovalbumin (OVA) sensitization and challenge with mist inhalation. The expression of MMP-9 and TIMP-1 in lung tissues was detected by immunocytochemistry, RT-PCR and Western blotting.

RESULTS(1) By observing the changes of action, tracing respiratory curves, detecting level of serum IgE level and observing the lung tissues sections, the authors demonstrated that the rat asthmatic models were successfully established. (2) The lung tissue sections of the asthma groups stained with hematoxiline and eosin (HE) showed many inflammatory cell infiltrations around the bronchioli and accompanying arterioles, hyperplasia of caliciform cells, broken bronchial mucous membrane and thickening of submucosal layer. The hyperplasia of airway smooth muscle and basement membrane were more significant in asthma model 21-day group than that in 7-day group. These changes were improved after treatment. (3) The expression of MMP-9 in rat's lung tissues: the expression was 2.71 +/- 0.37 in 7-day group, 1.76 +/- 0.27 in 21-day group, 0.88 +/- 0.18 in the treatment group and 0.52 +/- 0.10 in the control group (F = 151.52, P < 0.01). The expression of TIMP-1 in rat's lung tissues was 1.13 +/- 0.19 in the 7-day group, 1.55 +/- 0.24 in 21-day group, 0.77 +/- 0.15 in the treatment group and 0.47 +/- 0.08 in the control group (F = 69.46, P < 0.01). (4) The results of immunocytochemistry and protein expression were consistent with those of RT-PCR.

CONCLUSIONThe protein and mRNA expression level of MMP-9 and TIMP-1 was high in asthmatic rat's lung tissues. Down-regulation of the expression of MMP-9 and TIMP-1 by steroids may be one of the mechanisms by which airway inflammation and remodeling are inhibited in asthma.

Administration, Inhalation ; Animals ; Asthma ; drug therapy ; metabolism ; Blotting, Western ; Bronchi ; metabolism ; pathology ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Gene Expression Regulation, Enzymologic ; Glucocorticoids ; administration & dosage ; therapeutic use ; Immunohistochemistry ; Inflammation ; drug therapy ; metabolism ; pathology ; Lung ; drug effects ; metabolism ; pathology ; Male ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Rats ; Rats, Wistar ; Respiratory Mucosa ; drug effects ; metabolism ; pathology ; Reverse Transcriptase Polymerase Chain Reaction ; Tissue Inhibitor of Metalloproteinase-1 ; genetics ; metabolism