Bisphenol A inhibits proliferation and induces apoptosis in micromass cultures of rat embryonic midbrain cells through the JNK, CREB and p53 signaling pathways

Bisphenol A (BPA) has been widely used in the manufacture of polycarbonate plastic, water bottles and food containers. Previous studies have established that BPA could cause developmental toxicity by inhibiting the proliferation and differentiation of rat embryonic midbrain (MB) cells in vitro. However, the underlying mechanisms have not been well studied yet. In the current study, we examined the proliferation and differentiation of MB cells treated with 10−12–10−4 M BPA and found that only 10−4 M BPA inhibited proliferation and differentiation. Then, we investigated the cell cycle progression and apoptosis of MB cells; 10−4 M BPA caused an explicit S phase and G2/M phase arrest in the cell cycle and increased the percentage of apoptotic cells. Moreover, the phosphorylation of mitogen-activated protein kinase (MAPK) and cyclic-AMP response binding protein (CREB) and the expression of some apoptotic regulatory genes were investigated. BPA (10−4 M) reduced the phosphorylation of C-Jun N-terminal kinase (JNK) and CREB, and increased the mRNA expression level of Bax and p53. Our findings demonstrated that BPA could cause developmental toxicity through anti-proliferation and pro-apoptosis in MB cells. Multiple signaling pathways, such as the JNK, CREB and p53-mitochondrial apoptosis pathways, participate in these effects.