|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|5523023||1546064||2018||8 صفحه PDF||سفارش دهید||دانلود کنید|
- Granulosa cells cultured under 5% than 20% O2 better retain primary phenotype.
- Culturing granulosa cells under 5% than 20% O2 lessens impact of heat stress.
- Melatonin interacts with temperature to affect cell number and progesterone at 5% O2.
Our understanding of the effects of temperature on granulosa cell (GC) physiology is primarily limited to inÂ vitro studies conducted under atmospheric (â¼20% O2) conditions. In the current series of factorial experiments we identify important effects of O2 level (i.e. 5% vs 20% O2) on GC viability and steroidogenesis, and go onto report effects of standard (37.5Â Â°C) vs high (40.0Â Â°C) temperatures under more physiologically representative (i.e. 5%) O2 levels in the presence of different levels of melatonin (0, 20, 200 and 2000Â pg/ml); a potent free-radical scavenger and abundant molecule within the ovarian follicle. Cells aspirated from antral (4-6Â mm) follicles were cultured in fibronectin-coated wells using serum-free M199 for up to 144Â h. At 37.5Â Â°C viable cell number was enhanced and luteinization reduced under 5 vs 20% O2. Oxygen level interacted (PÂ <Â 0.001) with time in culture to affect aromatase activity and cell estradiol (E2) production (pg/mL/105Â cells). These decreased between 48 and 96Â h for both O2 levels but increased again by 144Â h for cells cultured under 5% but not 20% O2. Progesterone (P4) concentration (ng/mL/105Â cells) was greater (PÂ <Â 0.001) under 20 vs 5% O2 at 96 and 144Â h. Cell number increased (PÂ <Â 0.01) with time in culture under 5% O2 irrespective of temperature. However, higher doses of melatonin increased viable cell number at 40.0Â Â°C but reduced viable cell number at 37.5Â Â°C (PÂ =Â 0.004). Melatonin also reduced (PÂ <Â 0.001) ROS generation at both O2 levels across all concentrations. E2 increased with time in culture at both temperatures under 5% O2, however P4 declined between 96 and 144Â hÂ at 40.0 but not 37.5Â Â°C. Furthermore, melatonin interacted (PÂ <Â 0.001) with temperature in a dose dependent manner to increase P4 at 37.5Â Â°C but to reduce P4 at 40.0Â Â°C. Transcript expression for HSD3B1 paralleled temporal changes in P4 production, and those for HBA were greater at 5% than 20% O2, suggesting that hemoglobin synthesis is responsive to changes in O2 level. In conclusion, 5% O2 enhances GC proliferation and reduces luteinization. Elevated temperatures under 5% O2 reduce GC proliferation and P4 production. Melatonin reduces ROS generation irrespective of O2 level and temperature, but interacts with temperature in a dose dependent manner to influence GC proliferation and luteinization.
Journal: Theriogenology - Volume 105, 1 January 2018, Pages 107-114