Effect of nicotine on Oct-4 and Rex-1 expression of mouse embryonic stem cells.

To examine the influence that nicotine exposure has on early embryo development, the present study has applied real-time RT-PCR to investigate changes in Oct-4 and Rex-1 expression in mouse embryonic stem (ES) cells exposed to nicotine alone or in the presence of tubocurarine. Oct-4 is regarded as a candidate master regulator gene for the initiation, maintenance, and differentiation of pluripotent cells. Zfp42/Rex-1, another specific gene of pluripotent cells, also plays a critical role in maintaining stem cell character and pluripotency. Results indicated that nicotine (10-1000 nM) enhanced Oct-4 and Rex-1 expression without altering beta-actin expression. This up-regulation with nicotine (100-1000 nM) was prevented with tubocurarine (10 microM), a nicotinic acetylcholine receptor (nAChRs) antagonist. We conclude that nicotine may influence Oct-4 and Rex-1 expression in ES cells through a mechanism involving the nAChRs.