Figure 1.

Decidual spiral artery remodeling in the placental-decidual co-culture model. A: Representative photomicrograph of a PDC. B: An EVT column (cytokeratin) attaching to the decidual epithelial surface (bracket). A few interstitial EVTs (arrowheads) are observed in the superficial decidual stroma arising from a well-attached EVT cell column. C: Isotype control. D–F: Representative serial sections from a day 6 PDC shown with scale of decidual depth. Progressive remodeling occurs along an artery in the direction of trophoblast (F: cytokeratin) invasion (left to right). The segment of the artery at the superficial epithelial decidual surface (Su) contains EVTs in the lumen (arrowhead, F) and is more fully remodeled. Early vascular remodeling is observed in the mid-segment of the arteriole (Mi) by endothelial cell (D: CD31, asterisk) swelling and disruption, and VSMC loss (E: α-SMA, open arrowheads) in the absence of trophoblast. Deep vessels (De) demonstrate no evidence of remodeling. G and H: Intact arterioles from the superficial portion of decidua-only cultures have no trophoblast present (G: cytokeratin) and possess multiple layers of vascular smooth muscle (H: α-SMA). I and J: Veins were excluded from analysis by morphology. Serial sections demonstrate a thin endothelial layer (I: CD31) and sporadic VSMC (J: α-SMA, arrows). Scale bars = 100 μm.