Expression of vegi, vascular endothelial growth inhibitor, and its impact on cellular functions of keratinocytes [Abstract]

Vascular endothelial growth inhibitor (VEGI), via its potential receptor, DR-3,is a key regulator of cell growth and apoptosis in endothelial cells and epithelial cells. It isaberrantly expression in malignant conditions. We have previously reported that VEGI was expressed at a higher level in chronic wound tissues than in acute wounds. In the present study, we investigate if VEGI plays role in keratinocytes. Human keratinocyte cell line, HaCaT, was used in the study. The VEGI-expression construct was used to transfect HaCaT cells, which expressed little VEGI, HaCaTVEGIexp. We constructed an anti-DR3 transgene in order to generate a DR3 knockdown subline. Expression of VEGI and DR-3 was determined using PCR as well as immunocytochemical method. The effect of VEGI expression on cell growth, adhesion and migration were determined using an in vitro colorimetric and electric cell-substrate sensing (ECIS) methods. We successfully established a new subline, HaCaTVEGIexp, which expressed human VEGI. HaCaTVEGIexp had a slow rate of cell growth in comparison with control cells. Using ECIS assay, We have shown that over-expression of VEGI in the cells (HaCaTVEGIexp) had a significant effect on reducing the migration of HaCaT cells (po0.01). Likewise, knocking down DR3 from HaCaT cells had a significant effect on the spead of cell migration. The present study shows that VEGI is an important cytokine in the regulation of migration in keratinocytes. Together with the early observation in wound tissue, it is an pivotal factor in the process of wound healing