title: [Changes of angiopoietin 1 expression in G-CSF induced hematopoietic stem progenitor cells mobilization].
abstract: OBJECTIVE
  To investigate the changes and mechanism of angiopoietin1 (Ang1) in murine bone marrow during G-CSF induced mobilization of hematopoietic stem/progenitor cell.
  
  
  METHODS
  The proportion of Lin-Sca1⁺cKit⁺ (LSK) cells in peripheral blood of C57BL/6 mice before and after G-CSF mobilization was detected by flow cytometry. Expression changes of Ang1 and osteocalcin (OCN) during HSC mobilization were determined by immunohistochemistry, enzyme linked immunosorbent assay (ELISA) and real-time fluorescence quantitative PCR. The number of osteoblasts in the bone marrow was counted under the microscope.
  
  
  RESULTS
  After treated with G-CSF, the proportion of LSK cells in peripheral blood significantly increased from the controls (0.04 ± 0.01)% to (0.61 ± 0.05)% at day 5 (P<0.05). Before G-CSF mobilization, the endosteum cells expressed higher level of OCN and Ang1 than that of bone marrow nucleated cells. The mRNA expression level of OCN was significantly reduced from 28.64 ± 8.61 in the controls to 12.55 ± 7.06 on day 3 and 4.75 ± 1.62 on day 5, and the expression level of Ang1 also declined from 2.84 ± 0.95 in the controls to 0.93 ± 0.30 on day 3 and to 0.92 ± 0.22 on day 5 after G-CSF mobilization. The number of endosteum osteoblasts was significantly decreased after mobilization (P<0.05). The Ang1 expression was decreased in the BM after mobilization. The serum OCN was significantly reduced from (24.11 ± 3.17) ng/ml in the controls to (9.96 ± 2.16) ng/ml on day 3 and (8.43 ± 2.62) ng/ml on day 5, and the Ang1 also declined from (2.24 ± 0.52) ng/ml in the controls to (1.21±0.38) ng/ml on day 3 and (0.90±0.24) ng/ml on day 5.
  
  
  CONCLUSIONS
  In G-CSFinduced HSPC mobilization, the bone marrow osteoblasts retraction causes reduction of Ang1, and the reduction of Ang1 may contribute to HSPC mobilization.
authors.affiliation: The First Affiliated Hospital of Guangxi Medical University, Guangxi 530021, China.
authors.forename: Tianshou
authors.initials: T
authors.lastname: Li
authors.affiliation: The First Affiliated Hospital of Guangxi Medical University, Guangxi 530021, China.
authors.forename: Qiaochuan
authors.initials: Q
authors.lastname: Li
authors.affiliation: The First Affiliated Hospital of Guangxi Medical University, Guangxi 530021, China.
authors.forename: Sidan
authors.initials: S
authors.lastname: Li
authors.affiliation: The First Affiliated Hospital of Guangxi Medical University, Guangxi 530021, China.
authors.forename: Yinchao
authors.initials: Y
authors.lastname: Nie
authors.affiliation: The First Affiliated Hospital of Guangxi Medical University, Guangxi 530021, China.
authors.forename: Lugui
authors.initials: L
authors.lastname: Qiu
mesh_terms: D000818:Animals; D001853:Bone Marrow; D001854:Bone Marrow Cells; D016179:Granulocyte Colony-Stimulating Factor; D019650:Hematopoietic Stem Cell Mobilization; D006412:Hematopoietic Stem Cells; D051379:Mice; D008810:Mice, Inbred C57BL; D010006:Osteoblasts; D012333:RNA, Messenger
chemical_list: D012333:RNA, Messenger; D016179:Granulocyte Colony-Stimulating Factor