EP2A promotes human CD34 +cell homing in vitro but not proliferation / 中国病理生理杂志

ABSTRACT

AIM:To investigate the role of prostaglandin E2receptor 2 agonist (EP2A) in proliferation and homing of human CD34 +cells. METHODS:Bone marrow fluid and peripheral blood containing stem cells were collected from healthy donors mobilized by granulocyte colony-stimulating factor in our department. Human CD34 +cells were isolated by the method of magnetic-activated cell sorting microbeads. Bone marrow mononuclear cells were isolated by Ficoll-Paque centrifugation,and the bone marrow mesenchymal stem cells(BMMSC) were cultured with L-DMEM. Human CD34 +cells and BMMSC were divided into 4 groups,and treated with PGE2(as positive control),DMSO(as negative control),EP2A and EP2A+prostaglandin E2receptor 2 antagonist (EP2AA),respectively. After exposed to the reagents,human CD34 +cell viability was measured by CCK-8 assay,the number of colonies was evaluated by colony-formation assay,the cell cycle distribution was analyzed by flow cytometry,and the protein expression of survivin,β-catenin and CXC chemokine receptor 4 (CXCR4) was detrmined by Western blot. Moreover, the concentration of stromal cell-derived factor-1α (SDF-1α) in the BMMSC was detected by ELISA. RESULTS:The cell viability and the colony number of human CD34 +cells in EP2A group were not higher than those in negative control group. Furthermore,the proportion of human CD34 +cells treated with EP2A in G2/M phase was not elevated compared with negative control group. The protein expression of survivin and β-cate-nin did not up-regulated in human CD34 +cells exposed to EP2A,but the protein expression of CXCR4 in human CD34 +cells and the concentration of SDF-1α in BMMSC were elevated. CONCLUSION:EP2A promotes human CD34 +cell homing in vitro but not proliferation.