Figure 6.

Generation of a differentiation model of epidermal cells in vitro. Human epidermal keratinocytes (HEKs) and human immortalized keratinocyte (HaCaT) cells were switched to the medium containing 1.5 mM Ca²⁺ for the indicated time periods to generate differentiating epidermal cells. Morphological changes in (A) HEKs and (B) HaCaT cells after Ca²⁺ treatment for 0, 12, and 24 h. After switching the cells to the medium containing 1.5 mM Ca²⁺, both (A) HEKs and (B) HaCaT cells became enlarged and flattened. All scale bars represent 100 μm. (C and D) RT-qPCR was performed to detect the expression of CK10, CK14 and CK19 in (C) HEK and (D) HaCaT cells after Ca²⁺ treatment for the indicated time periods. Our data showed that Ca²⁺ treatment upregulated CK10 and CK14 mRNA levels in a time-dependent manner in epidermal keratinocytes, whereas the mRNA levels of CK19 decreased significantly in response to Ca²⁺ stimulation. ^**P<0.01.