Fig. 6.

Human CD34⁺-derived primary mast cells express MrgX1 and MrgX2 and respond to PMX-53 for degranulation and Ca²⁺ mobilization. Human CD34⁺-derived primary mast cells were stimulated with C5aP, PMX-53, PMX-53S, and PMX-53C (1 μM), and percentage degranulation (β-hexosaminidase release) was determined (A). MrgX1 and MrgX2 receptor expression was determined in CD34⁺-derived primary mast cells by RT-PCR (A, inset). C5a (B), PMX-53 (C), and PMX-53S but not PMX-53C (D) induced Ca²⁺ mobilization in CD34⁺-derived mast cells. Data shown are representative of three similar experiments. Statistical significance was determined by one-way ANOVA with Dunnett's post test. *, p < 0.05.