Role of ERα in the immunomodulatory effects of 4HT
To study the molecular mechanism of high-dose 4HT responses, we analyzed
the involvement of ERα in 4HT transcriptional activity using macrophages
isolated from ERαKO animals. 10 µM 4HT induced a 6-fold increase inVegfα mRNA in ERα-KO macrophages (Figure 2), similarly with
wild-type cells, while smaller concentrations of 4HT did not induce any
effect (data not shown). As expected, E2 did not trigger transcriptional
responses in the absence of ERα and, as consequence, also 4HT
interference and synergistic effects with E2 were not detected. These
data strongly indicated that the transcriptional activity of high 4HT
levels is ERα-independent.