R. Djafarzadeh, A. Mojaat, A. Belen Vicente, I. von Lüttichau, P.J. Nelson
Exogenously added GPI-anchored tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) displays enhanced and novel biological activities
The family of tissue inhibitors of metalloproteinases
(TIMPs) exhibits diverse physiological/biological functions
including the inhibition of active matrix metalloproteinases,
regulation of proMMP activation, cell growth,
and the modulation of angiogenesis. TIMP-1 is a secreted
protein that can be detected on the cell surface
through its interaction with surface proteins. The diverse
biological functions of TIMP-1 are thought to lie, in part,
in the kinetics of TIMP-1/MMP/surface protein interactions.
Proteins anchored by glycoinositol phospholipids
(GPIs), when purified and added to cells in vitro, are
incorporated into their surface membranes. A GPI anchor
was fused to TIMP-1 to generate a reagent that could be
added directly to cell membranes and thus focus defined
concentrations of TIMP-1 protein on any cell surface
independent of protein-protein interaction. Unlike native
TIMP-1, exogenously added GPI anchored TIMP-1 protein
effectively blocked release of MMP-2 and MMP-9
from osteosarcoma cells. TIMP-1-GPI was a more effective
modulator of migration and proliferation than TIMP
1. While control hTIMP-1 protein did not significantly
affect migration of primary microvascular endothelial
cells at the concentrations tested, the GPI-anchored
TIMP-1 protein showed a pronounced suppression of
endothelial cell migration in response to bFGF. In addition,
TIMP-1-GPI was more effective at inducing microvascular
endothelial proliferation. In contrast, fibroblast
proliferation was suppressed by the agent. Reagents
based on this method should assist in the dissection of
the protease cascades and activities involved in TIMP
biology. Membranefixed TIMP-1 may represent a more
effective version of the protein for use in therapeutic
expression.
Biological Chemistry, Walter de Gruyter
Print ISSN: 1431-6730
Volume: 385, 07/2004
Pages: 655 - 663
Show full article (external site)
Show all available items of this journal
Search
