PROBLEM: The purpose of this study was to define the temporal expression and to quantitate the mRNA levels of collagenase, 72 kDa, 92 kDa, and membrane-type matrix metallo-proteinases during the peri-implantation period of pregnancy in the mouse uterus. Embryonic expression of 72 kDa and 92 kDa matrix metalloproteinases, as well as interleukin 1α, was also investigated.
METHODS: Uterine matrix metalloproteinases were detected using gelatin substrate gel electrophoresis (zymography) and reverse-transcription polymerase chain reaction methodology was used to detect and quantitate different mRNA species in the mouse uterus and blastocyst.
RESULTS: Collagenase, 72 kDa, and 92 kDa matrix metalloproteinases are developmentally regulated during the peri-implantation period of pregnancy, but membrane-type matrix metalloproteinase appears to be expressed constitutively. Matrix metalloproteinase mRNA levels have been quantitated and confirm the observed developmental expression patterns. Prominent expression of both 92 kDa matrix metalloproteinase and interleukin 1α was observed in blastocysts during outgrowth while weak expression of the 72 kDa matrix metalloproteinase was detected.
CONCLUSIONS: The data provide evidence of matrix metalloproteinase expression in vivo and substantiate their potential role in tissue remodeling prior to and during blastocyst implantation. Expression of interleukin 1α, 92 kDa, and 72 kDa matrix metalloproteinases suggests that these proteins are important for trophoblast invasion associated with implantation of the early embryo.