Krüppel-Like Factor 5 Mediates Proinflammatory Cytokine Expression in Lipopolysaccharide-Induced Acute Lung Injury through Upregulation of Nuclear Factor-κB Phosphorylation In Vitro and In Vivo
Figure 3
Effects of lipopolysaccharide (LPS) exposureon intracellular reactive oxygen species (ROS) levels and Krüppel-like factor 5 (KLF5) and p65 expression in human bronchial epithelial cells. Cells from the (a) HBEC and (b) BEAS-2B lines were incubated with medium alone (control), N-acetylcysteine (NAC; 10 mM), or 5 μg/mL LPS for 1 h. Intracellular levels of ROS were measured using 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) assays and flow cytometric analysis. Histograms represent 3 independent experiments. Cells from the (c) HBEC and (d) BEAS-2B lines were incubated with LPS for 1.5 h, and nuclear protein expression was measured using western blotting. DCFH-DA assays indicated that 1 h of LPS treatment increased intracellular ROS levels in the HBEC (a) and BEAS-2B (b) cell lines. LPS also increased KLF5 and nuclear factor-kappaB (NF-κB) translocation in the HBEC and BEAS-2B cell lines. Pretreatment with NAC significantly reduced LPS-induced KLF5 and NF-κB translocation in nuclear extracts of cells from the HBEC (c) and BEAS-2B (d) lines. Each bar graph shows summarized data (mean ± SEM) from 3 separate densitometry experiments after normalization to lamin A/C (an internal control). versus control condition.
