Fig. 7.

Cnr1^−/− trophoblast cells are less invasive than WT cells. (A) Glycogen trophoblast cell invasion into decidua basalis on day 14 of pregnancy in Cnr1^−/− mice is shallow as shown by CDX2 immunostaining. (Scale bar, 100 μm.) (B) In Cnr1^−/− mice, the number of COX2-positive cells invading the maternal decidua around the ectoplacental cone is low. (Scale bar, 200 μm.) (C) Western blotting of COX2 levels in extracts of isolated EPC from day 10 WT and Cnr1^−/− implantation sites. (D) In vitro invasion assays show that numbers of Cnr1^−/−/Cnr2^−/− TS cells successfully penetrating through the matrigel are much lower than those of Faah^−/− and WT TS cells. Invasion of WT TS cells was attenuated by a CNR1 antagonist SR141716 (SR1, 7 nM), indicating that this receptor is critical for normal TS cell invasion. Results are representative of at least two to three independent samples.