Role of mechanical stretching and lipopolysaccharide in early apoptosis and IL-8 of alveolar epithelial type II cells A549

OBJECTIVE@#To investigate the effects of mechanical stretching and lipopolysaccharide (LPS) on the early apoptosis and IL-8 production of alveolar epithelial type II cells A549.@*METHODS@#The experimental matrix consisted of three integrated studies. In the first study, A549 cells were subjected to different stretching strain frequency and duration time to see the effects on the early apoptosis. In the second study, A549 cells were subjected to mechanical stretch (15% 4 h, 0.5 Hz) and LPS (1 or 100 ng/mL) to see whether mechanical strain and LPS also have an addictive effect on the early apoptosis. In the third study to investigate whether this addictive effect could be induced by LPS and mechanical stretch on IL-8 production, A549 cells were subjected to LPS (100 ng/mL) and mechanical strain (15%, 0.5 Hz, 4 h). Real time PCR and enzyme linked immunosorbent assay were used to measure mRNA and protein level of IL-8. The early apoptosis was detected by flow cytometry.@*RESULTS@#Mechanical stretch induced the early apoptosis in a force and frequency and time-dependent manner. In the presence of LPS, mechanical stretch enhanced LPS-induced early apoptosis, especially in 100 ng/mL LPS group compared with 1 ng/mL LPS and the control group. Mechanical stretch increased IL-8 production and enhanced LPS-induced IL-8 screation both in mRNA and protein levels.@*CONCLUSIONS@#Mechanical stretch can induce the early apoptosis and IL-8 secretion. Mechanical stretch and LPS have an addictive effect on the early apoptosis and IL-8 production in alveolar type 2 cells, which is one of the mechanisms of ventilator-induced lung injury.

Identification of genes regulated by HBV preS1-transactivated protein 2 binding protein 1 / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To identify genes regulated by HBV preS1-transactivated protein 2 binding protein 1 (PS1TP2BP1).</p><p><b>METHODS</b>PS1TP2BP1 gene was amplified by polymerase chain reaction (PCR) technique and cloned into the eukaryotic expression vector pcDNA 3.1/my-c-His A. The mRNAs isolated from HepG2 cells transfected recombinant eukaryotic expression vector pcDNA 3.1/myc-HisA-PS1TP2BP1 and pcDNA 3.1/myc-HisA empty vector were used to construct subtractive library. The differentially expressed genes were identified and analyzed.</p><p><b>RESULTS</b>35 differentially expressed clones were obtained. Colony PCR identified 15 clones with 200-1000 bp inserts. Sequence analysis identified 15 differentially expressed genes.</p><p><b>CONCLUSION</b>This study provides data for further characterize the function of PS1TP2BP1.</p>