Preliminary Exploration Of Cellular Senescence In The Aging Of Ovary

Objective:It has been reported that cellular senescence exists in aging organs and tissues. The aim of our research is to explore the relationship between ovarian aging and cellular senescence. In the first part:We used the method of SA-b-gal(Senescence Associated b-galactosidase) staining to investigate cellular senescence in the ovaries of C57BL/6J female mice of different ages, to clarify the existence and the distribution of cellular senescence in aging ovaries, and to observe and evaluate the changes during ovarian aging. In the second part:to explore whether there is cellular senescence during the development and the growth of the follicle, we detect the staining of cellular senescence in the ovaries of neonatal mice.Methods:All left ovaries were collected from different ages of C57BL/6J mice:6weeks-,12weeks-,32weeks-,40weeks-,48weeks-old for the first part;2days-,5days-,7days-,3weeks-old for the second part. The ovaries were frozen sectioned and stained. SA-b-gal, the marker of cellular senescence, was detected. We evaluated the cellular senescence by using the13point scoring systems which was used in the immunohistochemical staining.Result:The first part:We found that there is an increase of the activity of SA-b-gal in the interstitial cells during the aging in the ovary. While the tendency in the granulosa cells in obscure. The ovaries of12weeks old ones show more positive SA-b-gal, where as in the tissues of elder, cellular senescence is not that magnificent. At the same time, the follicles in the32weeks,40weeks and48weeks is much less than before. We have not seen any positive theca cells all through the research.The second part:There is no positive staining in any age of the ovaries.Conclusion:During the aging of the ovary, the interstitial cells make up the majority part, and the interstitial cellular senescence is increasing with the aging. There exists senescence of the granulosa cells during aging. However, because the magnitude of the granulosa cells is decreased in the aging ovary, the tendency became obscure and it needs to be deeply and comprehensively clarified. The follicular theca cells show no senescence during the aging.During the neonatal follicular development, there is no cellular senescence in the ovary of the infancy. This means that cellular senescence only exists in the aging, not the development of ovary.