Human GnRH-secreting cultured neurons express activin betaA subunit mRNA and secrete dimeric activin A.
OBJECTIVE
To evaluate the expression of activin betaA-subunit mRNA and the secretion of activin A in/from cultured GnRH-secreting neuronal cells cloned from human olfactory epithelium (FNC-B4), which showed biochemical and antigenic properties of GnRH-secreting neurons.


METHODS
FNC-B4 cells were cultured in basal and conditioned media.


METHODS
Reverse transcription-polymerase chain reaction (RTR-PCR) evaluated the expression of activin betaA-subunit mRNA. By using a specific ELISA, dimeric activin A concentrations were measured in culture media, in the absence or presence of carvone or forskolin and with different doses of progesterone, GnRH, and estradiol.


RESULTS
RT-PCR experiments performed on total RNA isolated from FNC-B4 cells, using specific primers for the activin betaA gene, showed a 787bp DNA band corresponding to the betaA gene. FNC-B4 cells secreted activin A, and the highest accumulation in conditioned medium was achieved after 3h culture: the addition of forskolin, but not of carvone, was able to stimulate the release of activin A from cultured neuronal cells (P<0.01). When progesterone or GnRH was added, a significant accumulation of activin A was observed (P<0.01), while estradiol administration did not significantly affect activin A secretion.


CONCLUSIONS
To date, this is the only study, in an in vitro human model reporting, that GnRH-secreting neuronal cells expressed activin betaA-subunit mRNA, and released dimeric activin A in culture medium. The expression and secretion of activin suggests that in these cells activin A might exert its action by autocrine/paracrine mechanisms.
Florio
P
P
Department of Reproductive Medicine and Child Development, Division of Obstetrics and Gynecology, University of Pisa, Pisa, Italy.
Vannelli
G B
GB
Luisi
S
S
Barni
T
T
Zonefrati
R
R
Falaschi
C
C
Bifulco
G
G
Genazzani
A R
AR
Petraglia
F
F
D028341:Activins; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000081005:Cyclohexane Monoterpenes; D019281:Dimerization; D004622:Embryo, Mammalian; D004958:Estradiol / Q000494:pharmacology; D015870:Gene Expression; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007265:Inhibins / Q000235:genetics* / Q000378:metabolism*; D039821:Monoterpenes; D009474:Neurons / Q000378:metabolism*; D009831:Olfactory Mucosa; D011374:Progesterone / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013729:Terpenes / Q000494:pharmacology
D000081005:Cyclohexane Monoterpenes; D039821:Monoterpenes; D012333:RNA, Messenger; D013729:Terpenes; D028341:Activins; D005576:Colforsin; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; D007265:Inhibins; C006923:carvone