Opposing Effects of Glutathione Depletion and Follicle-Stimulating Hormone on Reactive Oxygen Species and Apoptosis in Cultured Preovulatory Rat Follicles

Abstract

Oxidative stress and depletion of the antioxidant glutathione (GSH) trigger apoptosis in many systems. Previous work showed that antioxidants prevented apoptosis as effectively as FSH in preovulatory follicles. We aimed to test the hypotheses that follicular reactive oxygen species (ROS) initiate apoptosis and that follicular GSH protects against apoptosis. Preovulatory follicles were isolated from ovaries of immature rats primed with pregnant mare serum gonadotropin. Negative control (0-h) follicles were processed immediately. Others were cultured for 2 to 48 h with 1) medium alone, 2) 75 ng/ml ovine FSH, or 3) FSH plus 100 mum buthionine sulfoximine (BSO), a specific inhibitor of GSH synthesis. Total GSH concentrations declined in follicles cultured without FSH for 48 h, whereas FSH increased GSH levels above those observed at 0 h. BSO suppressed GSH to undetectable levels. Treatment with FSH prevented apoptosis in granulosa cells, measured by terminal dUTP transferase-mediated nick-end-labeling and activated caspase 3 immunohistochemistry. Addition of BSO partially and significantly reversed the antiapoptotic effect of FSH on granulosa cells; supplementation of GSH completely prevented BSO-induced granulosa cell apoptosis. Whole-follicle ROS production, measured as dichlorofluorescein and rhodamine fluorescence using confocal microscopy, was significantly increased by 4 h of culture and increased further thereafter. FSH significantly suppressed ROS production, and the addition of BSO partially overcame this effect of FSH. These findings provide evidence that oxidative stress induces apoptosis in preovulatory follicles and that the antiapoptotic effect of FSH is mediated in part by stimulation of follicular GSH synthesis and suppression of ROS production.

Effect of Selenium Nanoparticles on Anti-Oxidative Level, Egg Production and Quality and Blood Parameter of Laying Hens Exposed to Deoxynivalenol

“…In this research, the levels of these enzymes were significantly (P<0.05) inhibited by DON compared with the control, indicating that DON could induce oxidative stress in laying hens. This result is consistent with the previous research described above, and studies have also found that oxidative stress affects the female reproductive system by inhibiting follicle cell growth [26,27] or by even damaging ovarian and uterine cells. This is the probable explanation for why the DON group exhibited a lower egg production rate (71.15%) compared with the other groups.…”

“…The selenium nanoparticle (SeNP), which is one form of elemental selenium (Se0), has lower toxicity and better absorption and it is most effective when provided to broiler chicken under oxidative stress with the same dose but different sources of Se (organic, inorganic and nano-Se) [28]. According to some studies, the size of SeNPs synthesized by microorganisms has mostly been between 20 and 300 nm [20,26,27], and the diameter of the SeNPs in this research was 50 to 110 nm, which is consistent with previous research.…”

Impairment of Na+,K+-ATPase in CD95(APO-1)-induced human T-cell leukemia cell apoptosis mediated by glutathione depletion and generation of hydrogen peroxide

“…Intracellular GSH depletion is capable of sensitizing many types of cells to apoptosis; 19,20 however, little is known concerning the relationship between intracellular GSH loss and Na þ ,K þ -ATPase. In present study, Fas L decreased the intracellular GSH content as early as 30 min (data not shown), consistent with Fas L-induced inhibition of Na þ ,K þ -ATPase transport activity (Figure 1c).…”

Effects of massive ovulation on oxidation state and function of the ovaries in laying hens

“…The present results indicate that massive ovulation may aggravate oxidative stress in laying hens. In vitro studies have shown that excessive ROS generation inhibits follicular development, induces granular cell apoptosis, and causes follicular atresia (26)(27)(28)(29)(30). The decline of ovarian function in modern laying hens may be associated with oxidative stress induced by massive ovulation.…”