Simulated Microgravity Induces the Proliferative Inhibition and Morphological Changes in Porcine Granulosa Cells.

Astronauts are always faced with serious health problems during prolonged spaceflights. Previous studies have shown that weightlessness significantly affects the physiological function of female astronauts, including a change in reproductive hormones and ovarian cells, such as granulosa and theca cells. However, the effects of microgravity on these cells have not been well characterized, especially in granulosa cells. This study aimed to investigate the effects of simulated microgravity (SMG) on the proliferation and morphology of porcine granulosa cells (pGCs). pGC proliferation from the SMG group was inhibited, demonstrated by the reduced O.D. value and cell density in the WST-1 assay and cell number counting. SMG-induced pGCs exhibited an increased ratio of cells in the G0/G1 phase and a decreased ratio of cells in the S and G2/M phase. Western blot analysis indicated a down-regulation of cyclin D1, cyclin-dependent kinase 4 (cdk4), and cyclin-dependent kinase 6 (cdk6), leading to the prevention of the G1-S transition and inducing the arrest phase. pGCs under the SMG condition showed an increase in nuclear area. This caused a reduction in nuclear shape value in pGCs under the SMG condition. SMG-induced pGCs exhibited different morphologies, including fibroblast-like shape, rhomboid shape, and pebble-like shape. These results revealed that SMG inhibited proliferation and induced morphological changes in pGCs.

Radiation Degradation of ß-Glucan with a Potential for Reduction of Lipids and Glucose in the Blood of Mice.

: Water-soluble and low molecular weight (Mw) ß-glucans were successfully prepared by γ-irradiation of water-insoluble yeast ß-glucans. The radiation dose used for the degradation of yeast ß-glucan was remarkably reduced by increasing the pH of the sample or combining with hydrogen peroxide treatment. Radiation-degraded ß-glucans with molecular weights in the range of 11-48 kDa reduced the total cholesterol, triglyceride, low density lipoprotein (LDL) cholesterol, and glucose levels in the blood of administered mice. The decreasing levels of both lipid and glucose indexes in the blood of tested mice strongly depended on the molecular weight of the ß-glucan, and the radiation-degraded ß-glucan with a molecular weight of about 25 kDa was found to be the most effective for the reduction of blood lipid and glucose levels. Particularly, the oral administration of 25 kDa ß-glucan, with a daily dose of about 2 mg per head, reduced the total cholesterol, triglyceride, LDL-cholesterol, and glucose levels in the blood of tested mice to about 47.4%, 48.5%, 45.7%, and 47.2%, respectively. The effects on the reduction of blood lipid and glucose levels were also found to be stable after 20 days of stopping administration. These results indicate that the degraded ß-glucan with a molecular weight of about 25 kDa prepared by γ-ray irradiation is a very promising ingredient that can be used in nutraceutical food for therapeutics of diabetic and dyslipidemia.

Morphological changes during replicative senescence in bovine ovarian granulosa cells.

The objective of this study was to evaluate replicative senescence of bovine granulosa cells (bGCs) during in vitro long-term culture. WST-1 assay analysis showed that bGCs proliferation was reduced from primary culture to 14th passage. The several bGCs from the 3rd passage and 7th passage exposed the weak activity of beta-galactosidase, while a strongly positive staining of beta-galactosidase was observed in bGCs from 14th passage. Flow cytometry analysis showed that bGCs were induced to cell cycle arrest at G0/G1 phase through in vitro expansion. TERT transcript expression of bGCs was downregulated from primary culture to 14th passage. The cell and nuclear area of bGCs were dramatically increased from 14th passage to 25th passage. The nucleocytoplasmic ratio of bGCs was dramatically reduced in 22th passage (4.32%) and 25th passage (2.45%), comparing to previous passages: primary culture (10.67%), 7th passage (9.21%), or 14th passage (10.33%). The number of microfilament bundle of bGCs was increased in 22nd passage (67.42 ± 17.76) and 25th passage (56.31 ± 22.45). The diameter of microfilament bundle of bGCs in 25th passage was dramatically increased to 1.88 ± 0.32 µm comparing to the primary culture (1.15 ± 0.03 µm). In this study, we also assessed the nuclear form factor which illustrates the level of nuclear circular form. A reduction of nuclear form factor was observed in bGCs during long-term in vitro expansion. The changes of nuclear form factor were correlated to other senescent characteristics, especially the nucleocytoplasmic ratio.