Figure 2.

Increased calcium by histamine stimulation enhanced CBE activity and AE2 expression in HaCaT keratinocytes. Stimulation with 500 nM histamine induced an increase in Ca²⁺ in HaCaT keratinocytes for the control (A) and at 48 h (B). (C) Analysis of the resting Ca²⁺ level. Bars indicate the mean ± SEM of the number of experiments (** p < 0.05, *** p < 0.001, n = 20). (D) CBE activity of HaCaT keratinocytes with (gray open square) and without (control, black open square) 3 mM CaCl₂ and with co-stimulation of 3 mM CaCl₂ and 10 μM BAPTA-AM (orange open square) at 48 h. (E) Analysis of CBE activity. Bars indicate the mean ± SEM of the number of experiments. (** p < 0.01, n = 4). (F) Protein expression of AE2 and β-actin with 3 mM CaCl₂ at 48 h. The β-actin was used as a loading control. (G) Analysis of AE2 expression with or without 3 mM CaCl₂ at 48 h. Bars indicate the means ± SEM (* p < 0.05, n = 4).