A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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A Low-Testosterone State Associated with Endometrioma Leads to the Apoptosis of Granulosa Cells

<div><p>Although endometriosis is suspected to be a cause of premature ovarian insufficiency (POI), the mechanism(s) underlying this process have not been elucidated. Recently, androgens were shown to promote oocyte maturation and to play a role in folliculogenesis. In addition, several reports have documented low testosterone levels in the follicular fluid obtained from endometriosis patients. We therefore examined whether the low levels of serum testosterone are associated with the apoptosis of granulosa cells in follicles obtained from endometriosis patients. Serum samples were collected from 46 patients with endometriosis and from 62 patients without endometriosis who received assisted reproductive therapy. Specimens of the ovaries obtained from 10 patients with endometrioma were collected using laparoscopy. The mean serum testosterone concentration in the patients with endometriosis was significantly lower than that observed in the patients without endometriosis. Furthermore, high expression of a pro-apoptotic Bcl-2 member, BimEL, in the follicles was found to be associated with a low serum testosterone level. We clarified the underlying mechanisms using a basic approach employing human immortalized granulosa cells derived from a primary human granulosa cell tumor, the COV434 cell line. The <i>in vitro</i> examination demonstrated that testosterone inhibited apoptosis induced by sex steroids depletion via the PI3K/Akt-FoxO3a pathway in the COV434 cells. In conclusion, we elucidated the mechanism underlying the anti-apoptotic effects of testosterone on granulosa cells, and found that a low-testosterone status is a potentially important step in the development of premature ovarian insufficiency in patients with endometriosis.</p></div

Testosterone inhibited the apoptosis via the Akt-FoxO3a pathway in the COV434 granulosa cells.

<p>COV434 cells were incubated in phenol red-free DMEM supplemented with 2% Charcoal Stripped Fetal Bovine Serum (steroid-free conditions; Free) for 12 hours. The COV434 cells were then treated with vehicle or 10 or 100 nM testosterone for 16 hours for the RT-PCR analysis and 24 hours for Western blotting in the presence or absence of flutamide (10 µM) or LY294002 (25 µM) for one hour. A: (a) The mRNA expression of BimEL was determined using RT-PCR, and the beta-actin mRNA expression was used as an internal loading standard. Relative densitometric units of BimEL to beta-actin are shown in panel (d). The cell lysates were analyzed according to Western blotting using antibodies to BimEL (b), PARP (c) or beta-actin. Relative densitometric units of BimEL to beta-actin, and cleaved-PARP to total PARP are shown in panel (e) and (f), respectively. B: The cell lysates were also analyzed according to Western blotting using antibodies to phosphorylated-Akt, Akt (g), phosphorylated-FoxO3a or FoxO3a (h). Relative densitometric units of phosphorylated-Akt to total Akt, and phosphorylated-FoxO3a to total FoxO3a are shown in panel (i) and (j), respectively. Values shown represent the mean ± s.e. from at least three separate experiments. Significant differences are indicated by asterisks. *, p<0.05, **, P<0.01.</p