Influence of maternal smoking on trophoblast apoptosis throughout development: Possible involvement of Xiap regulation

Maternal smoking is associated with severe perinatal complications and sign ificant placental pathologies with underlying ultrastructural changes. in t his study, we examined the influence of maternal smoking on trophoblast apo ptosis throughout development and correlated those findings with changes in expression of X-linked inhibitor of apoptosis protein (Xiap) as well as Fa s and Fas ligand (FasL). Trophoblast apoptosis was determined by DNA fragme ntation and TUNEL. Protein expression was assessed by Western blotting and immunohistochemistry. Maternal smoking was associated with increased tropho blast apoptosis in the first trimester but decreased trophoblast apoptosis near term. Placental Xiap levels decreased significantly throughout develop ment in nonsmokers (P < 0.05) but remained elevated in smokers. Fas and Fas L levels did not vary significantly throughout development nor between grou ps. However, procaspase-3 levels were significantly increased in smokers at term. Our results suggest that maternal smoking has different effects at d ifferent stages of trophoblast differentiation and that this is regulated i n part through modulations in placental Xiap expression.