MT1-MMP and RECK are involved in human CD34+ progenitor cell retention, egress, and mobilization
Yaron Vagima, … , Arnon Nagler, Tsvee Lapidot
Yaron Vagima, … , Arnon Nagler, Tsvee Lapidot
Published February 9, 2009
Citation Information: J Clin Invest. 2009;119(3):492-503. https://doi.org/10.1172/JCI36541.
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Research Article Hematology

MT1-MMP and RECK are involved in human CD34+ progenitor cell retention, egress, and mobilization

Abstract

The mechanisms governing hematopoietic progenitor cell mobilization are not fully understood. We report higher membrane type 1–MMP (MT1-MMP) and lower expression of the MT1-MMP inhibitor, reversion-inducing cysteine-rich protein with Kazal motifs (RECK), on isolated circulating human CD34+ progenitor cells compared with immature BM cells. The expression of MT1-MMP correlated with clinical mobilization of CD34+ cells in healthy donors and patients with lymphoid malignancies. Treatment with G-CSF further increased MT1-MMP and decreased RECK expression in human and murine hematopoietic cells in a PI3K/Akt-dependent manner, resulting in elevated MT1-MMP activity. Blocking MT1-MMP function by Abs or siRNAs impaired chemotaxis and homing of G-CSF–mobilized human CD34+ progenitors. The mobilization of immature and maturing human progenitors in chimeric NOD/SCID mice by G-CSF was inhibited by anti–MT1-MMP treatment, while RECK neutralization promoted motility and egress of BM CD34+ cells. BM c-kit+ cells from MT1-MMP–deficient mice also exhibited inferior chemotaxis, reduced homing and engraftment capacities, and impaired G-CSF–induced mobilization in murine chimeras. Membranal CD44 cleavage by MT1-MMP was enhanced following G-CSF treatment, reducing CD34+ cell adhesion. Accordingly, CD44-deficient mice had a higher frequency of circulating progenitors. Our results reveal that the motility, adhesion, homing, and mobilization of human hematopoietic progenitor cells are regulated in a cell-autonomous manner by dynamic and opposite changes in MT1-MMP and RECK expression.

Authors

Yaron Vagima, Abraham Avigdor, Polina Goichberg, Shoham Shivtiel, Melania Tesio, Alexander Kalinkovich, Karin Golan, Ayelet Dar, Orit Kollet, Isabelle Petit, Orly Perl, Ester Rosenthal, Igor Resnick, Izhar Hardan, Yechiel N. Gellman, David Naor, Arnon Nagler, Tsvee Lapidot

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Figure 3

G-CSF–induced changes in MT1-MMP and RECK expression are dependent on PI3K/Akt signaling.

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G-CSF–induced changes in MT1-MMP and RECK expression are dependent on PI...
(A) MT1-MMP and RECK membranal levels on CD34+ progenitors detected in BM cells obtained from untreated chimeric mice following 48-hour treatment in vitro with G-CSF in the presence of the PI3K inhibitor LY294002 (PI3Ki) or DMSO vehicle (–). MFI was determined by flow cytometry and expressed as fold change compared with samples treated only with DMSO (mean ± SD of 3 independent experiments). *P < 0.05. (B) Representative immunohistochemical analysis of phospho-Akt levels (brown staining) in the BM sections of chimeric NOD/SCID mice treated (+) with G-CSF or untreated (–). Scale bar: 50 μm. (C) Relative changes in percentage of phospho-Akt–positive human hematopoietic cells repopulating the BM of chimeric mice treated with G-CSF or untreated, as determined by flow cytometry. Data are shown as fold change relative to PBS-treated (–) counterparts (mean ± SD of at least 3 independent experiments in duplicates). **P < 0.01. (D) Real-time PCR analysis of Mt1-mmp and Reck expression in the BM of Balb/c mice treated with G-CSF and with or without rapamycin (RAPA) or left untreated. Data are represented as fold change (mean ± SD for 10 and 5 independent experiments for G-CSF and G-CSF + RAPA, respectively, normalized to HPRT control). *P < 0.05, **P < 0.01. (E) Number of CFU cells (CFU-Cs; indicated as black circles) detected in 1 ml PB of Balb/c mice treated with G-CSF with or without RAPA or left untreated, as described in D. n = 6 mice for each treatment from 3 independent experiments. *P < 0.05 (left asterisk compares left and middle columns; right asterisk compares middle and right columns). Mean values for each group are indicated by horizontal lines.