207. The expression of caspase-14 in the human placenta

Abstract

Pro-apoptotic genes have a role in the differentiation process in the placenta leading to the fusion of cytotrophoblast cells to form the protective syncytiotrophoblast layer. The mechanisms of apoptosis in the human placenta are not clearly understood. However, a major placental apoptotic-signalling pathway is known to involve the caspases. Caspase-14 is the most recently discovered member of the caspase family members and has not previously been examined in the human placenta. The aim of the present study was to detect caspase-14 in the human placenta and study its role in apoptosis. Human placentae were collected from first trimester and term gestation. The study consisted of two parts. In the first part, first trimester and term placentae were assessed for caspase-14 by western blotting and mRNA analysis and localised with immunohistochemical studies. In the second part, apoptosis in first trimester placenta was inhibited in an in-vitro model of explant villi culture with superoxide dismutase (SOD) treatment and the genes assessed. The first study demonstrated caspase-14 to be a cytoplasmic protein localised in the cytotrophoblast cells, the mesenchyme and in the syncytiotrophoblast of the first trimester. In the term placenta, caspase-14 was expressed weakly in the syncytiotrophoblast. The immunostaining data suggest a higher expression of caspase-14 in the first trimester compared to the term placenta, and this observation was later confirmed by western blot analysis. Using the SOD in-vitro explant culture model, no significant difference in the caspase-14 protein levels were seen in either the SOD or control group. This novel study demonstrates for the first time that caspase-14 protein and mRNA are present in the human placenta. The function of caspase-14 in the human placenta is unclear.