Effects of motorcycle exhaust on oxidative stress levels in cells of human respiratory tract / 中国职业医学

{L-End}Objective To investigate the effect of motorcycle exhaust (ME) on the level of oxidative stress in different parts of respiratory tract epithelial cells. {L-End}Methods BEAS-2B and A549 cells in logarithmic growth phase were randomly divided into control group, low- and high-dose groups. The two kinds of cells growing on the membrane of Transwell inserts were treated with air-liquid interface (ALI) exposure technique for 60 minutes. The cells in the low- and high- dose groups were treated with diluted gas with the volume ratio of ME to clean air of 1∶20 and 1∶10, respectively, while the cells in the control group were treated with clean air. Cells were collected to detect their relative survival rate using CCK-8 method after exposure. And the levels of malondialdehyde, glutathione and the activity of superoxide dismutase (SOD) of the cells were detected using colorimetry. {L-End}Results The ME exposure dose affected the relative survival rate of cells (P<0.01), which showed a downward trend with the increasing ME exposure doses (all P<0.05). However, there was no significant difference in the main effect of cell types and the interaction effect of ME exposure dose and cell type (all P>0.05). There was a significant interaction between ME exposure dose and cell type in the level of glutathione and the activity of SOD (all P<0.01), and the level of malondialdehyde was a significant main effect of cell type (P<0.01). There was no significant difference in the glutathione level and SOD activity between the low-dose group and the control group (all P>0.05), while the glutathione level and SOD activity in high-dose group were higher than those in the control group and low-dose group in BEAS-2B cells (all P<0.05). The glutathione level decreased with increasing ME exposure dose in A549 cells (all P<0.05). Compared with the control group, the low-dose group had a significantly higher activity of SOD (P<0.05) in A549 cells. The SOD activity of A549 cells in high-dose group was lower than those in control group and low-dose group (all P<0.05). The level of malondialdehyde in A549 cells was higher than those in BEAS-2B cells(P<0.05). {L-End}Conclusion ME exposure can lead to changes in the production of oxidative stress biomarkers in respiratory tract epithelial cells. The oxidative stress response induced by ME exposure varies among respiratory tract epithelial cells from different regions.

Anti-proliferative activities of centella asiatica extracts on human respiratory epithelial cells in vitro / Actividades antiproliferativas del extracto de centella asiatica sobre células epiteliales respiratorias humanas in vitro

Centella asiatica or "pegaga" is well known for its ability in promoting wound healing. This study focused on the effect of Centella asiatica on the proliferation of human respiratory epithelial (RE) cells. RE cells were cultured using co-culture techniques until first passage (P1). Viability cell test by tryphan blue dye exclusion assay showed that there was high percentage of cell viability at both P0 (74 percent) and P1 (91.61 percent). Triplicate MTT assays were carried out with different concentrations of C. asiatica from 15.6 ppm, 31.3 ppm, 62.5 ppm, 125 ppm, 250 ppm, 500 ppm, 1000 ppm, until 2000 ppm. The higher the concentration of C. asiatica, the more inhibitory effect was seen. C. asiatica aqueous extract at concentration 1000 ppm and 2000 ppm demonstrated a significant (p<0.05) inhibitory effect on human RE cells proliferation on day 4 and day 7 after treatment. This provides potential use of C. asiatica extract for the treatment of conditions with respiratory epithelial cells overgrowth.

La Centella asiatica o "pegaga" es conocida por su capacidad para promover la cicatrización de heridas. Este estudio se centró en el efecto de la Centella asiatica sobre la proliferación de las células del epitelio respiratorio (ER) humano. Las células del ER se cultivaron usando técnicas de co-cultivo hasta el primer paso (P1). La prueba la viabilidad celular mediante el ensayo de exclusión del colorante azul de tripano demostró un alto porcentaje de viabilidad celular tanto en P0 (74 por ciento) y P1 (91,61 por ciento). Ensayos de MTT por triplicado se llevaron a cabo con diferentes concentraciones de C. asiatica, desde 15,6 ppm, 31,3 ppm, 62,5 ppm, 125 ppm, 250 ppm, 500 ppm, 1000 ppm, hasta 2000 ppm. Con una mayor concentración de C. asiatica, se observó un mayor efecto inhibitorio. El extracto acuoso de C. asiatica a una concentración de 1000 ppm y 2000 ppm demostró un efecto inhibidor significativo (p<0,05) sobre la proliferación de células del ER humano los días 4 y 7 posterior al tratamiento. Esto proporciona el uso potencial del extracto de C. asiatica para el tratamiento de condiciones con crecimiento excesivo células epiteliales respiratorias.

Respiratory epithelial cell lines exposed to anoxia produced inflammatory mediator / 대한해부학회지

Human epithelial cell lines were utilized to examine the effects of anoxia on cellular growth and metabolism. Three normal human epithelial cells lines (A549, NHBE, and BEAS-2B) as well as a cystic fibrosis cell line (IB3-1) and its mutation corrected cell line (C38) were grown in the presence and absence of oxygen for varying periods of time. Interleukin-8 (IL-8) levels were measured by enzyme-linked immunosorbent assay technique. Cellular metabolism and proliferation were assayed by determining mitochondrial oxidative burst activity by tetrazolium compound reduction. The viability of cells was indirectly measured by lactate dehydrogenase release. A549, NHBE, and BEAS-2B cells cultured in the absence of oxygen showed a progressive decrease in metabolic activity and cell proliferation after one to three days. There was a concomitant increase in IL-8 production. Cell lines from cystic fibrosis (CF) patients did not show a similar detrimental effect of anoxia. However, the IL-8 level was significantly increased only in IB3-1 cells exposed to anoxia after two days. Anoxia appears to affect certain airway epithelial cell lines uniquely with decreased cellular proliferation and a concomitant increased production of a cytokine with neutrophilic chemotactic activity. The increased ability of the CF cell line to respond to anoxia with increased secretion of inflammatory cytokines may contribute to the inflammatory damage seen in CF bronchial airway. This study indicates the need to use different cell lines in in vitro studies investigating the role of epithelial cells in airway inflammation and the effects of environmental influences.

Effect of Mycoplasma pneumoniae on IL-8 Gene Expression in Human Respiratory Epithelial Cells / 소아알레르기및호흡기학회지

PURPOSE: Mycoplasma pneumoniae is a common cause of lower respiratory disease. Several studies have suggested that M. pneumoniae respiratory infection is associated with reactive airway disease and asthma. It has been suggested that Interleukin-8 (IL-8) has a role in the pathogenesis of allergic inflammation of bronchial asthma and is well known to be expressed in bronchial epithelial cells. METHODS: In this study, we examined the effect of M. pneumoniae extract and the role of mitogen-activated protein kinases (MAPKs) on IL-8 expression in human lung epithelial cells. IL-8 levels were determined by an enzyme linked-immunosorbent assay. Extracellular signal-regulated kinase (ERK) phosphorylation was assessed by western blotting. RESULTS: In A549 cells, M. pneumoniae extract induced IL-8 release in a time- or dose- dependent manner. Pretreatment with PD98059, which blocks the activation of MAPK/ERK kinase 1, before M. pneumoniae extract stimulation inhibited the increase in the production of IL-8 by 64.4% at 25 M. Stimulation of A549 cells by extract caused an increase in the activity of ERK, compared with the non-stimulated cells. The extract stimulation had no effect on the activities of p38. CONCLUSION: These observations suggest that activation of ERK by M. pneumoniae extract may be one of the mechanisms that result in the increase of the production of IL-8.