Prostaglandin E2 promotes human CD34+ cells homing through EP2 and EP4 in vitro

Recently, certain studies have demonstrated in vitro that prostaglandin E2 (PGE2) promotes human cluster of differentiation (CD)34(+) cell homing. However, the sub-type receptors activated by PGE2 are unknown, as the PGE2 receptor EP1-4 subtypes (EP1-4) are expressed on the membrane of human CD34(+) cells. Based on the above, the present study aimed to screen the receptor subtype activity by PGE2 to promote human CD34(+) cell homing. It was observed that human CD34(+) cells expressed the four PGE2 sub-receptors, particularly EP2 and 4. PGE2 increased EP2 and 4 mRNA expression significantly, while EP1 and 3 mRNA exhibited no significant alteration. PGE2, EP2 agonist (EP2A), and EP4A upregulated C-X-C chemokine receptor 4 mRNA and protein expression in human CD34(+) cells, and promoted stromal cell-derived factor 1 alpha (SDF-1 alpha) expression in bone marrow mesenchymal stem cells (BMMSCs). These phenomena were inhibited by the associated receptor antagonists. PGE2, EP2A, and EP4A facilitated human CD34(+) cell migration towards SDF-1 alpha and BMMSCs. The results of the present study suggested that PGE2 promoted human CD34(+) cell homing through EP2 and 4 receptors in vitro.