Effect of leptin on cytotrophoblast proliferation and invasion

The effects of leptin on cytotrophoblast proliferation and invasion activity were investigated. Immunohistochemistry was used to determine the placental expression of leptin in first-trimester pregnancy. By using RT-PCR and quantitative real-time PCR, the expression of leptin in cytotrophoblast and the effect of leptin on cytotrophoblast secretion were detected. The potential of cell proliferation, invasiveness and migration was assessed by MTT, Transwell invasion assay and migration assay respectively when the cytotrophoblast was cultured with different concentrations of leptin. The results showed that: (1) Leptin was distributed diffusely around cell membrane, in cytoplasma, and on nuclear membrane of cytotrophoblast; (2) Leptin mRNA was expressed in cytotrophoblast. Ten ng/mL leptin could promote the secretion of cytotrophoblast significantly (P<0.01); (3) After culture with different concentrations of leptin for 24 h or longer, the proliferation of cytotrophoblast was inhibited, while in 24 h leptin could promote cytotrophoblast invasion and migration. Leptin at a concentration of 500 ng/mL could promote cytotrophoblast invasiveness and migration significantly as compared with controls (P<0.05). It was suggested that leptin could inhibit cytotrophoblast proliferation, and promote cytotrophoblast invasion and migration activity.