[The effect of matrix metalloproteinase-9 in granulocyte colony stimulation factor-induced stem cell mobilization].
OBJECTIVE
To investigate the effects of matrix metalloproteinase-9 (MMP-9) on granulocyte colony stimulation factor (G-CSF)-induced hematopoietic stem/progenitor cell (HSPC) mobilization in healthy donors of hematopoietic stem cells.


METHODS
Peripheral blood (PB) samples and bone marrow (BM) blood samples were collected from 12 healthy donors of hematopoietic stem cell before and 5 days after G-CSF-induced mobilization. CD34(+) cells were isolated and purified. ELISA was used to detect the protein expression of MMP-9 in the peripheral blood and BM blood of the healthy donors. The protein expression of MMP-9 in the BM blood was detected by ELISA and immunohistochemistry, and the stromal cell-derived factor-1 (SDF-1) level in the BM blood was detected by ELISA. The mRNA expression of MMP-9 in the BM blood samples was detected by RT-PCR. HT1080 cells rich in MMP-9 were cultured. CD34(+) cells were co-cultured with the supernatant of HT1080 cell culture fluid. CD34(+) cells cultured in Iscove's modified Dulbecco's medium were used as control group. Fluorescence-activated cell sorter was used to detect the CXCR4 expression on the surface of the CD34(+) cells. In the transwell experiment CD34(+) cells were divided into 4 groups: control group, o-phenanthroline (MMP-9 chemical inhibitor, MPI) group, HT1080 sup group, and HT1080 + MPI group to be co-cultured with buffer, o-phenanthroline, supernatant of culture fluid of HT1080 cells, or supernatant of culture fluid of HT1080 cells Flow cytometry was used to calculate the cell migration capacity.


RESULTS
The MMP-9 level of BM and PB of the healthy donors 5 days after G-CSF mobilization were 278 ng/ml +/- 34 ng/ml and 392 ng/ml +/- 284 ng/ml respectively, both significantly higher than those before G-CSF mobilization (42 ng/ml +/- 17 ng/ml and 27 ng/ml +/- 12 ng/ml respectively (P < 0.01 and P < 0.05). Western blotting showed that the SDF-1 level in the supernatant 5 days after G-CSF mobilization was 5.9 ng/ml +/- 1.0 ng/ml, significantly lower than that before G-CSF mobilization (7.2 ng/ml +/- 0.7 ng/ml, P < 0.05). The CXCR4 levels of the CD34(+) cell from both PB and BM blood were up-regulated after co-culture with the supernatant of HT1080 cells (both P < 0.05). The migration capacity of CD34(+) cells cultured in the supernatant of HT1080 cells was increased significantly (P < 0.05), however, this effect could be inhibited by MIP (P < 0.05). The PB WBC numbers of the G-CSF group and G-CSF + MPI group were 14.9 x 10(6)/L +/- 4.3 x 10(6)/L and 12.3 x 10(6)/L +/- 1.2 x 10(6)/L respectively, the PB WBC numbers of the G-CSF + MPI group was significantly lower than that of the G-CSF group (P < 0.05), however, significantly higher than that of the negative control group (6.8 x 10(6)/L +/- 2.5 x 10(6)/L, P < 0.05). The CFU of the G-CSF group was (84 +/- 10) U/2 x 10(5) MNC, significantly higher than that of the G-CSF + MPI group, (69 +/- 3) U/2 x 10(5) MNC (P < 0.05). The BM MNC number of the G-CSF group was 12.7 x 10(6)/L +/- 0.7 x 10(6)/L, not significantly different from that of the G-CSF + MPI groups (13.1 x 10(6)/L +/- 1.3 x 10(6)/L; P > 0.05).


CONCLUSIONS
MMP-9 probably facilitates HSPC mobilization by degrading SDF-1, up-regulating CXCR4 expression on the CD34(+) cells, and increasing the migration ability of CD34(+) cells.
Jin
Feng-yan
FY
State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, China Academy Medical Sciences & Peking Union Medical College, Tianjin 300020, China.
Qiu
Lu-gui
LG
Li
Qiao-chuan
QC
Meng
Heng-xing
HX
Wang
Ya-fei
YF
Yu
Zhen
Z
Li
Qian
Q
Han
Jun-ling
JL
D018952:Antigens, CD34 / Q000097:blood; D001854:Bone Marrow Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression / Q000187:drug effects; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods*; D006801:Humans; D007150:Immunohistochemistry; D020780:Matrix Metalloproteinase 9 / Q000097:blood* / Q000235:genetics; D010618:Phenanthrolines / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction
D018952:Antigens, CD34; C527276:CXCR4 protein, human; D010618:Phenanthrolines; D012333:RNA, Messenger; D019718:Receptors, CXCR4; D016179:Granulocyte Colony-Stimulating Factor; D020780:Matrix Metalloproteinase 9; C025205:1,10-phenanthroline