金属蛋白酶-2(MMP-2)和金属蛋白酶抑制因子(TIMP-1,-3)mRNA在小鼠胎盘中的表达

本实验利用原位杂交对小鼠妊娠不同时期胎盘中MMP－2，TIMP－2，－3mRNA的表达进行了研究。结果表明；MMP－2主要在具有很强的侵润能力的海绵滋养层细胞中表达，到妊娠13．5天时，MMP－2的表达明显降低，说明此时的滋养层细胞基本上失去侵润能力。TMIP－1和TMIP－3在滋养层细胞和蜕膜细胞中都有表达，这两种抑制因子的协同表达，一方面能够调控滋养层细胞侵入子宫内膜的深度，另一方面，滋养层细胞自身既表达MMP－2又表达TIMPs，可能对其自身有保护作用，使得MMP的水解功能局限于子宫蜕膜的特定区域。在妊娠10．5天，滋养层巨细胞同时表达TIMP－1，－3mRNA，这可能与其功能的转换是一致的；因为此时小鼠滋养层巨细胞体积最大，且不再增殖，同时其功能屯从侵入型向内分泌型转换。所以，MMPs和TIMPs在小鼠滋养层细胞和子宫蜕膜中的协同表达表明其在着床过程中可能发挥重要作用。

EXPRESSION OF MMP-2, TIMP-1,-3 mRNAs IN MOUSE PLACENTA

Expression of MMP 2, TIMP 1, 3 mRNAs in the mouse placenta at various stages of pregnancy was examined using in situ hybridization. The results showed that MMP 2 mRNA mainly localized in the spongiotrophoblast cells on day 10 5 and day 11 5, indicating invasive property of this type of the cells. On day 13 5 of pregnancy, the expression of MMP 2 decreased in the spongiotrophoblast cells, which was consistent with the fact that these cells almost stop to invade into the decidua at this time. TIMP 1 and TIMP 3 mRNA were expressed in both decidual and trophoblast cells. The decidual cells expressed TIMP 1 and TIMP 3 mRNA on day 7 5 and day 8 5. TIMP 1 and TIMP 3 mRNA was mainly detected in the spongiotrophoblast cells after day8 5 to day 12 5. The synergistic expression of these two kinds of inhibitors may regulate the invasion of trophoblast cells. Trophoblast cells expressed both MMP 2 and TIMPs, indicating that these cells may avoid to be destroyed by the proteinase secreted by themselves through this mechanism and limited the proteolytic activity of MMPs toward certain region in the maternal decidua. On day 10 5, trophoblast giant cell expressed both TIMP 1 and TIMP 3 mRNA, which may be consistent with their functional switch. So it is reasonable to suggest that MMP 2, TIMP 1 and TIMP 3 play an important role in the process of mouse placentation.