Localization of Fibrillin-I in the Human Term Placenta

Objective: We determined the level of message for fibrillin-1, a single-stranded glycoprotein found in the elastic micropfibrils of the extracellular matrix, in human placenta compared with other adult human tissues and localized the protein int he term human placenta. Methods: Northern blot analysis using a cDNA specific for fibrillin-1 was used to compare message levels in several adult human tissues and placenta. Immunohistochemical staining, using a monoclonal antibody to human fibrillin-1, was used to visualize the sitz of fibrillin-1 in term human placenta. Results: Larger amounts of message for fibrillin-1 were present in placenta than in any of the other tissues tested. Staining for fibrillin-1 was present in the villous stroma but not in the basement membranes, trophoblast cells, or in blood vessels of stem, mature intermediate, or terminal villi. Conclusions: Fibrillin-1 is distributed extensively in the villous stroma of the term human placenta and may contribute elastic properties to the placenta and basal plate required for an active uterus.