“Mouse Pups Born from Eggs Derived from the Granulosa Cells That Surround Oocytes”, 2019-12-24 (; similar):
Ovarian follicles are the basic functional unit of the ovary and consist of an oocyte, the immature egg, which is surrounded by granulosa cells. Besides being crucial to the development of follicles, studies have shown that granulosa cells possess plasticity that shows stem cell-like properties.
“The thing about in vitro fertilization is that they only use the oocyte for the procedure”, says senior author Lin Liu, of the College of Life Sciences at Nankai University. “After the egg retrieval, the granulosa cells in the follicle are discarded. It got us thinking, what if we can use these granulosa cells? Since every egg has thousands of granulosa cells surrounding it, if we can induce them into pluripotent cells and turn those cells into oocytes, aren’t we killing two birds with one stone?”
Granulosa cells tend to undergo cell death and differentiation once removed from the follicles. Liu and his team including Ph.D. students Chenglei Tian and Haifeng Fu developed a chemical “cocktail” with Rock inhibitor and crotonic acid for creating chemically induced pluripotent stem cells (CiPSCs) from granulosa cells. The research team introduced Rock inhibitor to prevent cell death and promote proliferation. In combination with other important small chemicals, crotonic acid facilitates the induction of granulosa cells into germline-competent pluripotent stem cells that exhibit pluripotency similar to embryonic stem cells.