HYALURONAN SYNTHASE 2 (HAS2) REGULATES MIGRATION OF EPIDERMAL KERATINOCYTES

Hyaluronan (HA) is a linear polysaccharide abundant in the extracellular space between epidermal keratinocytes. It is synthesized at the inner face of the plasma membrane by hyaluronan synthases (Has). We probed the importance of hyaluronan in keratinocytes by establishing cell lines carrying exogenous hyaluronan synthase 2 (Has2) gene(s) in sense and antisense orientations in order to increase and decrease their hyaluronan synthesis, respectively. The cell lines with the sense Has2 cDNA showed increased HA synthesis, while most cell lines with Has2 antisense cDNA contained less HA. Has2 antisense cells differed from control cell lines; they spread at a slower rate and retained a rounded morphology for a longer time. Further, during the first 24 hours after plating, proliferation was delayed in the antisense cell lines. In an in vitro wounding assay the antisense cells showed a significantly decreased migration rate as compared to controls. Cell lines with the Has2 sense cDNA were similar to the control cell lines in spreading and proliferation rates. However, they migrated faster than control cell lines.