a b s t r a c t
Article history:
Received 4 August 2016
Received in revised form 1 September 2016
Accepted 10 September 2016
Available online 11 September 2016
Aims: Ferutinin is a diaucane sesquiterpene with a high estrogenic activity. Since ferutinin is able to enhance osteoblastic
differentiation of human amniotic fluid stem cells (hAFSCs), the aim of this study was to evaluate the
role of the estrogen receptors α (ERα) and G-protein coupled receptor 30 (GPR30) in ferutinin-mediated osteoblastic
differentiation.Moreover, itwas investigated ifMEK/ERK and PI3K/Akt signaling pathways are involved in
ferutinin-induced effects.
Main methods: hAFSCs were cultured in a standard medium or in an osteoblastic medium for 14 or 21 days and
ferutinin was added at 10−8 M. Immunofluorescence techniques and Western-blot 21analysis were used to
study estrogen receptors and signaling pathways.
Key findings: In both undifferentiated and differentiated hAFSCs we identified ERα and GPR30 with a nuclear or
cytoplasmatic localization, respectively. The presence of ferutinin in the osteoblastic mediumleads to an increase
in ERα expression. To dissect the role of estrogen receptors,MPP and G15 were used to selectively block ERα and
GPR30, respectively. Notably, ferutinin enhanced osteoblastic differentiation in cells challenged with G15.
Ferutininwas able to increase ERK and Akt phosphorylationswith a different timing activation. These phosphorylationswere
antagonized by PD0325901, aMEK inhibitor, andwortmannin, a PI3K inhibitor. BothMPP and G15
inhibited the ferutinin-induced MEK/ERK and PI3K/Akt pathway activations. In the osteoblastic condition,
PD0325901, but not wortmannin, reduced the expression of OPN and RUNX-2, whereas ferutinin abrogated
the down-modulation triggered by PD0325901.
Significance: PI3K/Akt pathways seems to mediate the enhancement of hAFSCs osteoblastic differentiation triggered
by ferutinin through ERα.
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