Effects Of Abca1 On The Regulatory Pathway Between LXR And ApoM

[Objective]: To investigate potential role of ABCA1 on LXR mediated regulation of apoM in HepG2 cells.[Methods]: HepG2 cells were incubated with LXR agonist TO901317 with or without ABCA1 antagonist DIDS at different concentrations, and apoM mRNA levels were determined by the real-time RT-PCR.[Results]: TO901317 at 25μmol/L could significantly inhibit apoM expression in HepG2 cells (q=5.340, P<0.05), which was not blocked by addition of ABCA1 antogonist. Whereas ABCA1 antagonist itself could also inhibit apoM expression in HepG2 cells. TO901317 and DIDS have additive effects on the inhibition of apoM mRNA expression in HepG2 cells (q=8.821, P<0.001).[Conclusion]: The present study suggested that hepatic apoM expression is also regulated by ABCA1 and LXR mediated inhibition of apoM expression is not via ABCA1 pathway. The detailed mechanism needs further investigation.