REQUIREMENT FOR TRANSGLUTAMINASE IN PROGESTERONE-INDUCED DECIDUALIZATION OF HUMAN ENDOMETRIAL STROMAL CELLS

Differentiation of endometrial stromal cells (decidualization) is esse ntial for embryo implantation and maintenance of pregnancy. By sequent ial complementary DNA subtractive hybridization, one of the messenger RNAs (mRNA) induced by progesterone in human endometrial stromal cells decidualized in vitro was identified as that of a tissue transglutami nase type II (TGase). TGase mRNA was induced within 6 h after the addi tion of progesterone to the culture, and the effect was dose dependent . Both the TGase inhibitor monodansylcadaverine and oligodeoxynucleoti de complementary to the TGase mRNA inhibited the decidualization, as a ssessed by PRL production and morphological transformation. Expression of TGase mRNA in human decidua and endometria exposed to high levels of progesterone in vivo was demonstrated by Northern blotting and in s itu hybridization. These data suggest that TGase is necessary for the decidualization of human endometrial stromal cells and that clarificat ion of the mechanism of action of TGase will facilitate further insigh t into the diagnosis and treatment of infertility.