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 1α (SDF‑1α) 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‑1α and BMMSCs. The results of the present study suggested that PGE2 promoted human CD34+ cell homing through EP2 and 4 receptors in vitro.