Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-3 are key regulators of extracellular matrix degradation by mouse embryos.
Embryo implantation in humans and rodents is a highly invasive yet tightly controlled process involving extracellular matrix (ECM) degradation. Matrix metalloproteinase 9 (MMP-9) has been implicated as the major facilitator of this ECM degradation. MMP-9 is expressed by the embryo's trophoblast cells, whereas tissue inhibitor of metalloproteinases 3 (TIMP-3) is expressed by the maternal uterine cells immediately adjacent to the trophoblast. We examined the functional roles of MMP-9 and TIMP-3 during in vitro ECM degradation by mouse embryos. Blastocysts were treated with either MMP-9 antisense or sense oligonucleotides and incubated on an ECM gel. The extent of ECM degradation exhibited by the blastocysts due to proteinase secretion was quantified. Embryos exposed to MMP-9 antisense oligonucleotides exhibited reduced ECM-degrading activity as compared with controls, and this reduced activity was correlated with the level of MMP-9 secreted by the embryos. The functional role of TIMP-3 was then examined by incubating blastocysts on an ECM gel that had been impregnated with various amounts of TIMP-3. In a dose-dependent manner, increases in TIMP-3 resulted in a reduction in ECM degradation and were correlated with diminished MMP-9 activity. These results provide important functional evidence that in vitro ECM degradation is regulated by embryo-derived MMP-9 and ECM-derived TIMP-3.
Whiteside
E J
EJ
Centre for Molecular Biotechnology, School of Life Sciences, Queensland University of Technology, Brisbane, Queensland 4001, Australia. e.whiteside@qut.edu.au
Jackson
M M
MM
Herington
A C
AC
Edwards
D R
DR
Harvey
M B
MB
D000818:Animals; D001755:Blastocyst / Q000502:physiology / Q000648:ultrastructure; D002460:Cell Line; D006224:Cricetinae; D017077:Culture Media, Conditioned; D046508:Culture Techniques; D010064:Embryo Implantation; D004622:Embryo, Mammalian / Q000502:physiology / Q000648:ultrastructure*; D004791:Enzyme Inhibitors; D005109:Extracellular Matrix / Q000378:metabolism*; D007668:Kidney; D020780:Matrix Metalloproteinase 9 / Q000502:physiology*; D061965:Matrix Metalloproteinase Inhibitors; D051379:Mice; D009841:Oligonucleotides / Q000494:pharmacology; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000502:physiology*
D017077:Culture Media, Conditioned; D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; D009841:Oligonucleotides; D016376:Oligonucleotides, Antisense; D019717:Tissue Inhibitor of Metalloproteinase-3; D020780:Matrix Metalloproteinase 9