It is commonly accepted that airway hyperresponsiveness (AHR) is a chronic airway inflammation although the exact mechanism of its pathogenesis is still unclear. In the past ten years, an epithelial defect hypothesis has gradually gained supports from the main stream. Airway epithelium is no longer considered only as a simple mechanic barrier but an active interface between the inner and outer environment. Bronchial epithelial cells play a critical role in maintenance of homeostasis in the airway local microenvironment through a wide range of physiologic functions including anti-oxidation, exocrine/endocrine secretions, mucus production and antigen presentation under health and stressed/inflamed/injured conditions. It is reasonably hypothesized that disruption of these functional processes or defects in airway epithelium integrity may be the initial steps leading to airway hyperresponsiveness such as in asthma and chronic obstructive pulmonary disease.
Animals ; Bronchi ; cytology ; Bronchial Hyperreactivity ; physiopathology ; Epithelial Cells ; pathology ; Humans

Bronchi ; cytology ; Cell Culture Techniques ; Cells, Cultured ; Humans ; Myocytes, Smooth Muscle ; cytology

OBJECTIVETo investigate the effect of thymic stromal lymphopoietin (TSLP) on the permeablily of monolayer bronchial epithelial cells in vitro.

METHODSCultured human bronchial epithelial cell line 16HBE was exposed to 0.1 or 1 ng/ml TSLP for 0, 0.5, 6, 12, or 24 h, and the epithelial monolayer permeability was assessed by measuring transepithelial electrical resistance (TER), permeability to FITC-labeled dextran (FITC-DX) and expression of E-cadherin.

RESULTSCompared with the control cells group, 16HBE cell monolayer showed significantly increased TER (P<0.001) and decreased FITC-DX fluorescence in the lower chamber (P<0.05) following exposure to 0.1 and 1 ng/ml TSLP, but these changes were not dose-dependent. Exposure to 0.1 ng/ml TSLP resulted in significantly increased expression of E-cadherin. The 16HBE monolayer exposed to 0.1 ng/ml TSLP for 24 h showed the most obvious increase of TER and E-cadherin expression (P<0.05); FITC-DX fluorescence level was markedly decreased after TSLP exposure for 12 h and 24 h (P<0.05), and the effect was more obvious in 12 h group.

CONCLUSIONTSLP can protect the barrier function of normal bronchial epithelial cells in vitro.

Bronchi ; cytology ; Cadherins ; metabolism ; Cell Line ; Cytokines ; pharmacology ; Epithelial Cells ; drug effects ; Humans ; Permeability

OBJECTIVETo investigate the effect of 1,25-dihydroxyvitamin D3 (1,25VD3) on house dust mites (HDM)-induced expression of thymic stromal lymphopoietin (TSLP) in human airway epithelial cells in vitro.

METHODSHuman airway epithelial 16HBE cells were incubated with 200, 400, and 800 U/L in the absence or presence of 1,25VD3 (10(-8) mol/L) for 6 h and 24 h, and TSLP mRNA and protein expressions in the cells were assessed using quantitative PCR and ELISA.

RESULTS16HBE cells incubated with HDM at 200, 400, and 800 U/L showed significantly increased TSLP mRNA and protein expressions (P<0.05). Pretreatment of the cells with 1,25VD3 obviously lowered 400 U/L HDM-induced TSLP expressions (P<0.05), but 1,25VD3 added along with HDM in the cells did not produce significant effects on TSLP expressions (P=0.58).

CONCLUSIONBoth 1,25VD3 and HDM can induce TSLP expression and release in 16HBE cells, but pretreatment with 1,25VD3 can decrease HDM-augmented TSLP expression in the cells.

Animals ; Bronchi ; cytology ; Calcitriol ; pharmacology ; Cell Line ; Cytokines ; metabolism ; Epithelial Cells ; drug effects ; metabolism ; Humans ; Pyroglyphidae

Objective: Although benzene is a confirmed environmental carcinogen, the mechanism of its carcinogenicity remains largely unclear. The suggested oncogene, miR-221, is elevated and plays important roles in various tumors, but its role in benzene-induced carcinogenesis remains unknown. Methods: In the present study, we constructed hydroquinone (HQ, a representative metabolite of benzene with biological activity)-transformed malignant cell line (16HBE-t) and analyzed the level of miR-221 in it with qRT-PCR. Exosomes from 16HBE-t cells incubated with or without an miR-221 inhibitor were isolated by ultracentrifugation, characterized by transmission electron microscopy and laser scanning confocal microscope, and then transfected into 16HBE cells. The effects of exosomal miR-221 on apoptosis induced by HQ in recipient cells were determined using flow cytometry. Results: The amount of miR-221 in 16HBE-t was significantly increased compared with controls. When recipient cells ingested exosomes derived from 16HBE-t, miR-221 was increased, and apoptosis induced by HQ was inhibited. Blocking miR-221 in 16HBE-t using an inhibitor did not significantly alter miR-221 or apoptosis in recipient cells. Conclusion Exosomal miR-221 secreted by 16HBE-t inhibits apoptosis induced by HQ in normal recipient cells.
Apoptosis ; Bronchi/cytology* ; Cell Line, Transformed ; Epithelial Cells ; Exosomes ; Humans ; Hydroquinones ; MicroRNAs

OBJECTIVETo evaluate the effect of 25-hydroxyvitamin D(3) on the expression and distribution of vitamin D receptor in normal human bronchial epithelial cells.

METHODSMTT assay was used to assess the viability of human airway epithelial cell line 16HBE following a 24-h exposure to different concentrations of 25-hydroxyvitamin D(3). Real-time quantitative PCR, Western blotting, and immunofluorescence assay were used to observe the expression and distribution of vitamin D receptor in the cells following the exposure.

RESULTSCompared with the control cells, 16HBE cells exposed to different concentrations of 25-hydroxyvitamin D(3) exhibited no significantly increase in the expression or distribution of vitamin D receptor.

CONCLUSIONThe influence of 25-hydroxyvitamin D(3) on bronchial epithelial cells might be independent of the expression and translocation of vitamin D receptor.

Bronchi ; cytology ; Calcifediol ; pharmacology ; Cell Line ; Epithelial Cells ; cytology ; metabolism ; Humans ; RNA, Messenger ; genetics ; metabolism ; Receptors, Calcitriol ; genetics ; metabolism

OBJECTIVETo investigate the changes in human airway smooth muscle cell (HASMC) migration and related signaling pathway after interference with PTEN gene expression.

METHODHASMCs were infected with an adenovirus vector and RNA interference vector of human PTEN gene to establish the cell model with PTEN gene over-expression (Ad-GFP-PTEN-HASMC) and one with PTEN gene silencing (Ad-shPTEN-HASMC), using Ad-GFP-infected and a blank cells as the negative controls and LY294002 as the positive control. Fluorescence microscopy and flow cytometric analysis were used to evaluate the transfection efficiency, and Western blotting was performed to examine the expression of PTEN and the activation of AKT and ERK1/2 signal pathway. Transwell assay and wound healing assay were used to assess the migration of HASMCs.

RESULTSThe adenovirus over-expression vector and RNA interference vector significantly affected the expression of human PTEN gene. Up-regulation of PTEN gene resulted in a slow-down of the HASMC migration, an inhibition of PI3K/AKT signal pathway at the protein level but no changes in Ras-Raf-MEK1/2-ERK1/2 signal pathway. Down-regulated PTEN gene expression, however, was not associated with an enhancement of HASMC migration, but activated PI3K/AKT signal pathway and inhibited Ras-Raf-MEK1/2-ERK1/2 signal pathway.

CONCLUSIONUpregulation of PTEN gene can effectively inhibit airway smooth muscle cell migration, the effect of which is probably mediated by the PI3K/AKT pathway.

Adenoviridae ; genetics ; Bronchi ; cytology ; Cell Movement ; Cells, Cultured ; Gene Expression ; Genetic Vectors ; Humans ; Lung ; cytology ; Myocytes, Smooth Muscle ; cytology ; metabolism ; pathology ; PTEN Phosphohydrolase ; metabolism ; RNA Interference ; Transfection

OBJECTIVETo investigate SiO2-induced EMT in human bronchial epithelial cells HBE in vitro.

METHODSHBE cells were cultured and then stimulated with indicated doses of SiO2 (0, 50, 100, 200, 300 µg/ml). The morphological changes were observed by microscope. In addition, Western blot was per-formed to detect the expression of E-cad, α-SMA and Vim. The changes of migration ability were examined by wound-healing assay in vitro.

RESULTS(1) After exposure to SiO2, HBE cells lost contact with their neighbor and displayed a spindle-shape, fibroblast-like morphology. (2) Compared with the control, the E-cad (300 µg/ml group) expression downregulated 2.98 fold (P < 0.05), and the Vim (300 µg/ml group) and α-SMA (200 µg/ml group) expression upregulated 4.46 fold and 3.55 fold (P < 0.05). There were significant differences between 100, 200, 300 µg/ml groups and the control group (P < 0.05). (3) In the test group, the percentage of wound-healing areas/wound areas were larger than those in control group (P < 0.05).

CONCLUSIONSSiO2 could induce EMT in human bronchial epithelial cells.

Bronchi ; cytology ; Cells, Cultured ; Epithelial Cells ; cytology ; drug effects ; Epithelial-Mesenchymal Transition ; drug effects ; Humans ; Silicon Dioxide ; adverse effects ; Stromal Cells ; cytology ; drug effects

AIMTo investigate the expression of androgen receptors in the extragenital tissues of developing human embryo.

METHODSUsing immunohistochemistry, we investigated the distribution of androgen receptor (AR) in the extragenital tissues of paraffin-embedded tissue sections of first trimester (8-12 weeks gestation) human embryos. Gender was determined by polymerized chain reaction.

RESULTSThere were no differences in the expression and distribution of AR in male and female embryos at any stage of gestation. AR expression was seen in the thymus gland. The bronchial epithelium of the lungs showed intense positive staining with surrounding stroma negative. Furthermore, positive staining for androgen receptor was exhibited in the spinal cord with a few positive cells in the surrounding tissues. Cardiac valves also showed strong positive staining but with faint reactivity of the surrounding cardiac muscle. There was no staining in kidney, adrenal, liver or bowel.

CONCLUSIONThis study demonstrates that immunoreactive AR protein is present in a wide variety of human first trimester fetal tissues and shows the potential for androgen affecting tissues, which are mostly not considered to be androgen dependent. Moreover, it implies that androgen might act as a trophic factor and affect the early development of these organs rather than simply sexual differentiation.

Bronchi ; cytology ; embryology ; metabolism ; Female ; Fetus ; cytology ; metabolism ; Heart ; embryology ; Humans ; Immunohistochemistry ; methods ; Male ; Myocardium ; cytology ; metabolism ; Pregnancy ; Pregnancy Trimester, First ; Receptors, Androgen ; genetics ; metabolism ; Spinal Cord ; cytology ; embryology ; metabolism ; Thymus Gland ; cytology ; embryology ; metabolism

OBJECTIVETo investigate the effect of hydrogen dioxide (H(2)O(2)) on the release and translocation of high mobility group box 1 release (HMGB1) from normal human bronchiolar epithelial cells (HBE).

METHODSMTT assay was used to assess the viability of HBE135-E6E7 cells exposed to different concentrations of H(2)O(2). The expression and location of HMGB1 in the cytoplasm, nuclei and culture medium of the exposed cells were determined using Western blotting and immunofluorescence assay.

RESULTSExposure to 125 µmmol/L H(2)O(2) did not obviously affect the cell viability. At the concentration of 250 µmmol/L, H(2)O(2) significantly decreased the cell viability (P<0.05), but significant cell death occurred only after exposure to 400 µmmol/L H(2)O(2) (P=0.000). Compared with the control cells, the cells exposed to 12.5, 125 and 250 µmmol/L H(2)O(2) for 24 h showed significantly increased levels of HMGB1 in the culture medium (P<0.05), and exposure to 125 µmmol/L H(2)O(2) for 12 and 24 h also caused significantly increased HMGB1 level (P<0.05). Exposure to 125 µmmol/L H(2)O(2) for 24 h significantly increased HMGB1 expression in the cytoplasm but decreased its expression in the nucleus. HMGB1 translocation from the nuclei to the cytoplasm and to the plasmalemma occurred after 125 µmmol/L H(2)O(2) exposure for 12 h and 24 h, respectively.

CONCLUSIONH(2)O(2) can induce HMGB1 translocation and release in human bronchial epithelial cells, suggesting the involvement of HMGB1 in airway oxidative stress in chronic inflammatory diseases such as asthma and COPD.

Bronchi ; cytology ; Cell Line ; Epithelial Cells ; drug effects ; metabolism ; HMGB1 Protein ; drug effects ; metabolism ; Humans ; Hydrogen Peroxide ; pharmacology ; Protein Transport