Upregulated expression of human beta defensin-1 and -3 mRNA during differentiation of keratinocyte immortalized cell lines, HaCaT and PHK16-0b

Human beta-defensins (hBDs) belong to a group of antimicrobial peptide that are expressed in the epithelial cells. The present study investigated mRNA expression levels of the beta-defensins, hBD-1, -2 and -3, in human keratinocytes during differentiation in vitro. Immortalized keratinocyte cell lines, HaCaT and PHK16-0b, were used in this study; in order to stimulate differentiation, the Ca(2+) concentration in the growth media was increased from 0.3 to 1.8 mM. Four days after the increase, the expression levels of hBD-1 and -3 were increased in both cell lines, followed by an increase in the mRNA levels of the differentiation markers, involucrin and keratin 10. No increased expression of hBD-2 was observed. The results indicate that keratinocyte differentiation may stimulate hBD-1 and -3 expression in stratified squamous epithelia.