Valproate Potentiates Androgen Biosynthesis in Human Ovarian Theca Cells

Abstract

In patients with epilepsy, treatment with valproate (VPA) has been reported to be associated with polycystic ovary syndrome-like symptoms including weight gain, hyperandrogenemia, and hyperinsulinemia. We examined the effect of VPA on androgen biosynthesis in ovarian theca cells isolated from follicles of normal cycling women to determine whether the hyperandrogenemia reported with VPA treatment could be a result of direct effects of VPA on the ovary. In long-term cultures of theca cells treated for 72 h with sodium valproate (30-3000 microm), we observed an increase in basal and forskolin-stimulated dehydroepiandrosterone (DHEA), androstenedione, and 17alpha-hydroxyprogesterone production compared with control values. In contrast, low doses of VPA treatment (i.e. 30-300 microm) had no effect on basal and forskolin-stimulated progesterone production, whereas higher doses of VPA (1000-3000 microm) inhibited progesterone production. The most pronounced effect of VPA on androgen biosynthesis was observed in the dose range of 300-3000 microm, which represent therapeutic levels in the treatment of epilepsy and bipolar disorder. Western analyses demonstrated that VPA treatment increased both basal and forskolin-stimulated P450c17 and P450scc protein levels, whereas the amount of steroidogenic acute regulatory protein was unaffected. In transient transfection studies, VPA was found to increase P450 17alpha-hydroxylase and P450 cholesterol side-chain cleavage promoter activity, whereas steroidogenic acute regulatory protein promoter activity was unaffected. Consistent with the ability of VPA to act as a histone deacetylase (HDAC) inhibitor in other cell systems, VPA (500 microm) treatment was observed to increase histone H3 acetylation and P450 17alpha-hydroxylase mRNA accumulation. The HDAC inhibitor butyric acid (500 microm) similarly increased histone H3 acetylation and DHEA biosynthesis, whereas the VPA derivative valpromide (500 microm), which lacks HDAC inhibitory activity, had no effect on histone acetylation or DHEA biosynthesis. These data suggest that VPA-induced ovarian androgen biosynthesis results from changes in chromatin modifications (histone acetylation) that augment transcription of steroidogenic genes. These studies provide the first biochemical evidence to support a role for VPA in the genesis of polycystic ovary syndrome-like symptoms, and establish a direct link between VPA treatment and increased ovarian androgen biosynthesis.

Overexpression of a DENND1A isoform produces a polycystic ovary syndrome theca phenotype

“…Western blot analysis was performed on 35 μg/ln whole-cell lysates harvested from fourth-passage normal and PCOS theca cells were grown until subconfluent and transferred into serum-free medium with and without forskolin for 24 h, as we have previously described (48). Similar results were obtained in Western analyses performed using Abcam antibody specific for the N-terminal and Sigma antibody for intrapeptide sequence of DENND1A, which were visualized using ECL (Pierce).…”

“…The theca cell preparations used in these studies have been described and characterized previously (15-17, 20, 35-38, 47). The steroidogenic phenotypes of the normal and PCOS theca cells have been reported to result from the inherent properties of the cells, rather than the cycle phase at the time that they were isolated (15,17,48). PCOS and normal ovarian tissue came from age-matched women, 38-40 y old.…”

“…The diagnosis of PCOS was made according to National Institutes of Health (NIH) consensus guidelines (10,49), which include hyperandrogenemia, oligoovulation, polycystic ovaries, and the exclusion of 21-hydroxylase deficiency, Cushing's syndrome, and hyperprolactinemia. All of the PCOS theca cell preparations studied came from ovaries of women with fewer than six menses per year and elevated serum total testosterone or bioavailable testosterone levels (15,17,48). Each of the PCOS ovaries contained multiple subcortical follicles of less than 10 mm in diameter.…”

MANAGEMENT OF ENDOCRINE DISEASE: Secondary polycystic ovary syndrome: theoretical and practical aspects

“…By contrast, very interesting data emerged from in vitro studies. In their first study on the topic, Nelson-DeGrave and coworkers (91) demonstrated that in long-term cultures of theca cells isolated from follicles of normal cycling women and of those treated for 72 h with VPA (30-3000 micromoles), an increase in forskolin-stimulated steroidogenesis could be observed. In particular, the most pronounced effect of VPA on androgen biosynthesis was observed in the dose range of 300-3000 microns, which intriguingly represents the therapeutic levels in the treatment of epilepsy and bipolar disorder.…”

Efeitos endócrinos e metabólicos das drogas antiepilépticas

“…Essa hipótese é pouco sustentável, visto que algumas pacientes com SOP e que usam valproato são magras, além do fato de que outras DAE que promovem ganho de peso não mostram relação com a SOP (39). Outra alternativa possível seria que o valproato induziria à biossíntese de androgênios ovarianos, por meio de um aumento da transcrição de genes esteroidogênicos, pelo seu estímulo à acetilação de histonas (40). Entretanto, elevações dos níveis de androgênios e alterações ovulatórias podem ser observadas em até dois terços das usuárias de valproato, mesmo sem aumento na incidência de ovários policís-ticos (41).…”