Effects On The Growth Of ECV304 And Expression Of ESM-1 And Tight Junction Of THCE Cells By Lipopolysaccharide

Objective To investigate the effects of lipopolysaccharide (LPS) on the growth of human umbilical vein endothelial cells and expression of endothelial cell-specific molecule-1 (ESM-1) and the tight junction (TJ) in simian virus (SV)40-immortalized human corneal epithelia (THCE) cells. Methods The endothelial cells were cultured by LPS at different time intervals. The morphology of endothelial cells was observed and the cell proliferation was measured by MTT method. The expressions of ESM-1 and ERK (external-signal regulated kinase), and the phosphorylation of ERK were detected by immuocytochemistry. Immunofluorescence was used to determine the distributions of occludin, ZO-1, ZO-2 and claudin-1 in LPS-treated THCE cells. The expressions of occluding, ZO-1 and ZO-2 were detected by Western blot in LPS-treated THCE cells. Transepithelial electrical resistance (TER) was measured using a voltohmmeter. Results The morphology of endothelial cells was altered to become long cord-like in shape and array in disorder by LPS after 24h and significantly after 48h. The cell proliferation was stimulated by LPS during 1h, which was significant at 0.5h by both lul/ml and 5ul/ml LPS (P<0.05) while was significant at 1h by lul/ml LPS (P<0.05). The expression of ESM-1 was quickly enhanced at 0.5h and significantly at lh, additionally the effect of 5μl/ml was more than that of 1μl/ml at lh. There was no change of expression of ERK, but ERK phosphorylation was remarkable increased at 0.5h to 4h. The immunostaining of ZO-2 disappeared from cell borders with 3μl/ml LPS treatment for 6h, whereas occludin, ZO-1 and claudin-1 staining apparently did not change. Treatment of the cells with LPS (1μl/ml. 6h incubation) reduced ZO-1 and ZO-2 content to 40% and 35% of control levels, respectively. Specifically, a dose-dependent decline in ZO-2 content was apparent, correlating with the disappearance of ZO-2 from cell borders. Treatment of cultured THCE cells with LPS caused a dose- and time-dependent increase in monolayer permeability as...