title: Matrix metalloproteinase and tissue inhibitor of matrix metalloproteinase expression in human preimplantation embryos.
abstract: OBJECTIVE
  To examine human embryos at various stages of preimplantation development for simultaneous expression of matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinases (TIMPs).
  
  
  METHODS
  mRNAs of specific MMPs and TIMPs were examined in single human embryos, at different stages of preimplantation development, by reverse transcription-polymerase chain reaction (RT-PCR). Single embryo immunohistochemistry was applied to examine the protein expression.
  
  
  METHODS
  University-affiliated IVF-ET program.
  
  
  METHODS
  Couples, attending the university-affiliated IVF-ET program, electing to donate poor prognosis embryos with anomalous morphology.
  
  
  METHODS
  None.
  
  
  METHODS
  The expression of MMP-1, MMP-2, MMP-9, TIMP-1, TIMP-2, and TIMP-3 in preimplantation embryos.
  
  
  RESULTS
  The MMP-2 mRNA was expressed consistently during development from one-cell to blastocyst stage. The TIMP-1 and TIMP-3 mRNAs were detected in embryos at all stages; however, in the later preimplantation developmental stages, an increasing proportion of embryos expressing TIMP-1 and TIMP-3 mRNA were noted. The MMP-1, MMP-9, and TIMP-2 mRNAs were detected in only a minority of human embryos studied. Immunohistochemistry showed MMP-1 and TIMP-1 protein expression in preimplantation embryos.
  
  
  CONCLUSIONS
  The existence of MMP and TIMP mRNA expression in human preimplantation embryos argues for a role for these metalloproteinases and their inhibitors during the process of implantation in humans.
mesh_terms: D001755:Blastocyst / Q000201:enzymology* / Q000502:physiology; D004587:Electrophoresis, Agar Gel; D005314:Embryonic and Fetal Development / Q000502:physiology; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D020782:Matrix Metalloproteinases / Q000096:biosynthesis* / Q000235:genetics; D008846:Micromanipulation; D011247:Pregnancy; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019714:Tissue Inhibitor of Metalloproteinases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D019714:Tissue Inhibitor of Metalloproteinases; D020782:Matrix Metalloproteinases