No abstract

Side population (SP) cells were isolated by FACS from a human amnion mesenchymal cell (AMC) layer soon after enzyme treatment. The yield of SP cells from AMC layer (AMC-SP cells) was about 0.1-0.2%. AMC-SP cells grew well with cell doublings of 40-80 days of culture. FACS profiles and immunocytostaining showed that AMC-SP cells were composed of two different cells immunologically: HLA I − /II − and HLA I + /II − . Oct-3/4 was detected in the nucleus of AMC-SP cells, when the culture was examined at the third, sixth, and 10th passages. RT-PCR showed that AMC-SP cells expressed the Oct-4, Sox-2, and Rex-1 genes. Immunocytochemistry revealed that all AMC-SP cells were vimentin + , CK19+ , and nestin + . In addition, flow cytometry analysis showed that SP cells had high expression of CD13, CD29, CD44, CD46, CD49b, CD49c, CD49e, CD59, CD140a, and CD166 but low expression of CD 49d, and CD51. No evidence of expression was obtained for CD34, CD45, CD49a, CD56, CD90, CD105, CD106, CD117, CD133, CD271, or Flk-1. Upon appropriate differentiation protocols, AMC-SP cells differentiated to several cell lineages such as neuroectodermal, osteogenic, chondrogenic, and adipogenic cells. These results indicate that AMC-SP cells have multilineage potential to several cell lineages with unique immunological characteristics such as HLA I − /II − or HLA I + /II − . AMC-SP cells should be of considerable value for regenerative medicine because they do not induce acute rejection after allotransplantation, they do not cause ethical issues, and there is no limit of supply.

In a previous report, we showed that follicles isolated from frozen/thawed mouse ovarian tissues reached the mature follicle stage on the 12th day of culture. However, the developmental ability was lower than that of fresh ovarian tissue. The purpose of this study was to define a culture system with some technical modification for preantral follicles isolated from frozen/thawed ovarian tissue and to confirm cell injury. Ovaries obtained from three-week-old female mice were cryopreserved by the rapid freezing method. Preantral follicles isolated from frozen/thawed ovarian tissues were cultured for 12 -16 days. The follicles were then stimulated with human chorionic gonadotropin. In vitro fertilization was performed on the released cumulus-oocyte complexes (COCs). Preantral follicle viability was assessed by supravital staining using Hoechst 33258. Using this stain cell death was found in part of the granulosa cells of a follicle obtained from frozen/thawed ovarian tissue. On the 14th and 16th days of culture, the diameters of follicles isolated from frozen/thawed ovaries were larger than on the 12th day of culture. The released COCs were fertilized and developed to the blastocyst stage in 15.8% (12/76) of the oocytes taken from the fresh group, and in 0% (0/73), 2.9% (2/69) and 19.1% (22/115) of the oocytes taken from the frozen/thawed group that had been cultured for 12, 14 and 16 days respectively. The preantral follicles isolated from frozen/thawed mouse ovarian tissues developed slowly compared with the freshly prepared preantral follicles. During prolonged culture from 12 to 16 days, these follicles obtained the potential to fertilize and develop to the blastocyst stage.

Our findings suggest that the ovarian toxicity of PTX is mild and transient. Use of PTX may help to maintain the fertility of younger women because the fertility of rats was not influenced at 24 days after exposure to this drug.

Cryopreservation of ovarian tissues containing many immature oocytes occurs in both gamete/embryo research and clinical medicine. Using vitrification, we studied factors related to meiosis after cryopreservation using the COCs (cumulus oocyte complexes) and preantral follicles obtained from cryopreserved ovarian tissues. COCs were isolated and cultured for 17 approximately 19 hr. Thereafter, Metaphase II stage (MII stage) oocytes and fertilized oocytes after IVF were observed at a rate of 76.5% and 60.0%, respectively. Preantral follicles (100 approximately 130 microm in diameter) were isolated and cultured in alpha MEM containing hFSH, ITS, and FBS. HCG and EGF were added to the media to stimulate ovulation on the 12th day of culture. The survival rates of the follicles obtained from the frozen/thawed ovaries were 66.4%. After 12 days of culture, the diameter of the follicles isolated from fresh (620.2 +/- 11.3 microm) and frozen/thawed ovaries (518.7 +/- 15.1 microm) differed as did the estradiol concentrations (3474.2 +/- 159 pg/ml vs. 1508.2 +/- 134 pg/ml). After in vitro ovulation, MII stage oocytes were observed in 84.5% of the fresh group and 60.5% of the frozen/thawed group while the fertilization rate was 74.2% and 53.5%, respectively. These studies demonstrate that cryopreservation of mouse ovarian tissues by vitrification did not affect the oocyte's ability to undergo meiosis. Thus, this technique may become a powerful tool for the preservation of the female gamete.